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Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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1

Narrow band gap amorphous silicon semiconductors  

DOE Patents [OSTI]

Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

Madan, A.; Mahan, A.H.

1985-01-10T23:59:59.000Z

2

Wide band gap semiconductor templates  

DOE Patents [OSTI]

The present invention relates to a thin film structure based on an epitaxial (111)-oriented rare earth-Group IVB oxide on the cubic (001) MgO terminated surface and the ion-beam-assisted deposition ("IBAD") techniques that are amendable to be over coated by semiconductors with hexagonal crystal structures. The IBAD magnesium oxide ("MgO") technology, in conjunction with certain template materials, is used to fabricate the desired thin film array. Similarly, IBAD MgO with appropriate template layers can be used for semiconductors with cubic type crystal structures.

Arendt, Paul N. (Los Alamos, NM); Stan, Liliana (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); DePaula, Raymond F. (Santa Fe, NM); Usov, Igor O. (Los Alamos, NM)

2010-12-14T23:59:59.000Z

3

Toward Photochemical Water Splitting Using Band-Gap-Narrowed Semiconductors and Transition-Metal Based Molecular Catalysts  

SciTech Connect (OSTI)

We are carrying out coordinated theoretical and experimental studies of toward photochemical water splitting using band-gap-narrowed semiconductors (BGNSCs) with attached multi-electron molecular water oxidation and hydrogen production catalysts. We focus on the coupling between the materials properties and the H{sub 2}O redox chemistry, with an emphasis on attaining a fundamental understanding of the individual elementary steps in the following four processes: (1) Light-harvesting and charge-separation of stable oxide or oxide-derived semiconductors for solar-driven water splitting, including the discovery and characterization of the behavior of such materials at the aqueous interface; (2) The catalysis of the four-electron water oxidation by dinuclear hydroxo transition-metal complexes with quinonoid ligands, and the rational search for improved catalysts; (3) Transfer of the design principles learned from the elucidation of the DuBois-type hydrogenase model catalysts in acetonitrile to the rational design of two-electron hydrogen production catalysts for aqueous solution; (4) Combining these three elements to examine the function of oxidation catalysts on BGNSC photoanode surfaces and hydrogen production catalysts on cathode surfaces at the aqueous interface to understand the challenges to the efficient coupling of the materials functions.

Muckerman,J.T.; Rodriguez, J.A.; Fujita, E.

2009-06-07T23:59:59.000Z

4

Method of manufacturing flexible metallic photonic band gap structures, and structures resulting therefrom  

DOE Patents [OSTI]

A method of manufacturing a flexible metallic photonic band gap structure operable in the infrared region, comprises the steps of spinning on a first layer of dielectric on a GaAs substrate, imidizing this first layer of dielectric, forming a first metal pattern on this first layer of dielectric, spinning on and imidizing a second layer of dielectric, and then removing the GaAs substrate. This method results in a flexible metallic photonic band gap structure operable with various filter characteristics in the infrared region. This method may be used to construct multi-layer flexible metallic photonic band gap structures. Metal grid defects and dielectric separation layer thicknesses are adjusted to control filter parameters.

Gupta, Sandhya (Bloomington, MN); Tuttle, Gary L. (Ames, IA); Sigalas, Mihail (Ames, IA); McCalmont, Jonathan S. (Ames, IA); Ho, Kai-Ming (Ames, IA)

2001-08-14T23:59:59.000Z

5

Metallic photonic-band-gap filament architectures for optimized incandescent lighting Sajeev John and Rongzhou Wang  

E-Print Network [OSTI]

Metallic photonic-band-gap filament architectures for optimized incandescent lighting Sajeev John occur 3,4 . Tra- ditionally incandescent lighting filaments, despite being driven from equilibrium the blackbody spectrum. This suggests the pos- sibility of higher efficiency incandescent lighting, through

John, Sajeev

6

Band gap tuning in transition metal oxides by site-specific substitution  

DOE Patents [OSTI]

A transition metal oxide insulator composition having a tuned band gap includes a transition metal oxide having a perovskite or a perovskite-like crystalline structure. The transition metal oxide includes at least one first element selected form the group of Bi, Ca, Ba, Sr, Li, Na, Mg, K, Pb, and Pr; and at least one second element selected from the group of Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Hf, Ta, W, Re, Os, Ir, and Pt. At least one correlated insulator is integrated into the crystalline structure, including REMO.sub.3, wherein RE is at least one Rare Earth element, and wherein M is at least one element selected from the group of Co, V, Cr, Ni, Mn, and Fe. The composition is characterized by a band gap of less of 4.5 eV.

Lee, Ho Nyung; Chisholm, Jr., Matthew F; Jellison, Jr., Gerald Earle; Singh, David J; Choi, Woo Seok

2013-12-24T23:59:59.000Z

7

Waveguides in three-dimensional metallic photonic band-gap materials  

SciTech Connect (OSTI)

We theoretically investigate waveguide structures in three-dimensional metallic photonic band-gap (MPBG) materials. The MPBG materials used in this study consist of a three-dimensional mesh of metallic wires embedded in a dielectric. An {ital L}-shaped waveguide is created by removing part of the metallic wires. Using finite difference time domain simulations, we found that an 85{percent} transmission efficiency can be achieved through the 90{degree} bend with just three unit cell thickness MPBG structures. thinsp {copyright} {ital 1999} {ital The American Physical Society}

Sigalas, M.M.; Biswas, R.; Ho, K.M.; Soukoulis, C.M. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)] [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Crouch, D.D. [Advanced Electromagnetic Technologies Center, Raytheon Corporation, Rancho Cucamonga, California 91729 (United States)] [Advanced Electromagnetic Technologies Center, Raytheon Corporation, Rancho Cucamonga, California 91729 (United States)

1999-08-01T23:59:59.000Z

8

Wide-band-gap, alkaline-earth-oxide semiconductor and devices utilizing same  

DOE Patents [OSTI]

This invention relates to novel and comparatively inexpensive semiconductor devices utilizing semiconducting alkaline-earth-oxide crystals doped with alkali metal. The semiconducting crystals are produced by a simple and relatively inexpensive process. As a specific example, a high-purity lithium-doped MgO crystal is grown by conventional techniques. The crystal then is heated in an oxygen-containing atmosphere to form many [Li].degree. defects therein, and the resulting defect-rich hot crystal is promptly quenched to render the defects stable at room temperature and temperatures well above the same. Quenching can be effected conveniently by contacting the hot crystal with room-temperature air.

Abraham, Marvin M. (Oak Ridge, TN); Chen, Yok (Oak Ridge, TN); Kernohan, Robert H. (Oak Ridge, TN)

1981-01-01T23:59:59.000Z

9

Blueshift of optical band gap in ZnO thin films grown by metal-organic chemical-vapor deposition  

E-Print Network [OSTI]

. INTRODUCTION Zinc oxide ZnO is a wide direct band-gap 3.37 eV semiconductor with a broad range of applications. Dimethylzinc DMZn , N2 gas, and high-purity O2 were used as the zinc source, carrier gas, and oxidizing agent including light-emitting devices,1 varistors,2 solar cells,3 and gas sensors.4 Moreover, ZnO is a promising

10

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

11

Lattice matched semiconductor growth on crystalline metallic substrates  

DOE Patents [OSTI]

Methods of fabricating a semiconductor layer or device and said devices are disclosed. The methods include but are not limited to providing a metal or metal alloy substrate having a crystalline surface with a known lattice parameter (a). The methods further include growing a crystalline semiconductor alloy layer on the crystalline substrate surface by coincident site lattice matched epitaxy. The semiconductor layer may be grown without any buffer layer between the alloy and the crystalline surface of the substrate. The semiconductor alloy may be prepared to have a lattice parameter (a') that is related to the lattice parameter (a). The semiconductor alloy may further be prepared to have a selected band gap.

Norman, Andrew G; Ptak, Aaron J; McMahon, William E

2013-11-05T23:59:59.000Z

12

Fabrication of photonic band gap materials  

DOE Patents [OSTI]

A method for forming a periodic dielectric structure exhibiting photonic band gap effects includes forming a slurry of a nano-crystalline ceramic dielectric or semiconductor material and monodisperse polymer microspheres, depositing a film of the slurry on a substrate, drying the film, and calcining the film to remove the polymer microspheres therefrom. The film may be cold-pressed after drying and prior to calcining. The ceramic dielectric or semiconductor material may be titania, and the polymer microspheres may be polystyrene microspheres.

Constant, Kristen (Ames, IA); Subramania, Ganapathi S. (Ames, IA); Biswas, Rana (Ames, IA); Ho, Kai-Ming (Ames, IA)

2002-01-15T23:59:59.000Z

13

Adaptive algorithms for QCSE optical modulators Excitonic optical absorption at near band gap photon energies in III-V compound semiconductor  

E-Print Network [OSTI]

. Typically, such designs make use of simple rectangular potential wells in the AlGaAs/GaAs or InP/InGaAsP1 Adaptive algorithms for QCSE optical modulators Excitonic optical absorption at near band gap of the quantum well, the excitonic optical absorption strength and energy can be manipulated. This quantum

Levi, Anthony F. J.

14

Effects of anneals in ammonia on the interface trap density near the band edges in 4Hsilicon carbide metal-oxide-semiconductor capacitors  

E-Print Network [OSTI]

­silicon carbide metal-oxide-semiconductor capacitors Gilyong Chung, Chin Che Tin, and John R. Williamsa) Physics. Silicon carbide is the only wide band gap semiconductor that has a native oxide, and metal temperature capacitance­voltage measurements are reported for SiO2/4H­SiC n and p type metal

Pantelides, Sokrates T.

15

Narrow energy band gap gallium arsenide nitride semi-conductors and an ion-cut-synthesis method for producing the same  

DOE Patents [OSTI]

A method for forming a semi-conductor material is provided that comprises forming a donor substrate constructed of GaAs, providing a receiver substrate, implanting nitrogen into the donor substrate to form an implanted layer comprising GaAs and nitrogen. The implanted layer is bonded to the receiver substrate and annealed to form GaAsN and nitrogen micro-blisters in the implanted layer. The micro-blisters allow the implanted layer to be cleaved from the donor substrate.

Weng, Xiaojun; Goldman, Rachel S.

2006-06-06T23:59:59.000Z

16

Low band gap polymers Organic Photovoltaics  

E-Print Network [OSTI]

Low band gap polymers for Organic Photovoltaics Eva Bundgaard Ph.D. Dissertation Ris National Bundgaard Title: Low band gap polymers for Organic photovoltaics Department: The polymer department Report the area of organic photovoltaics are focusing on low band gap polymers, a type of polymer which absorbs

17

Voltage-matched, monolithic, multi-band-gap devices  

SciTech Connect (OSTI)

Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a sting of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

Wanlass, Mark W.; Mascarenhas, Angelo

2006-08-22T23:59:59.000Z

18

Voltage-Matched, Monolithic, Multi-Band-Gap Devices  

DOE Patents [OSTI]

Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a string of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

Wanlass, M. W.; Mascarenhas, A.

2006-08-22T23:59:59.000Z

19

Optical properties of two-dimensional transition metal dichalcogenides  

E-Print Network [OSTI]

The re-discovery of the atomically thin transition metal dichalcogenides (TMDs), which are mostly semiconductors with a wide range of band gaps, has diversified the family of two-dimensional materials and boosted the ...

Lin, Yuxuan, S.M. Massachusetts Institute of Technology

2014-01-01T23:59:59.000Z

20

Silicon metal-semiconductor-metal photodetector  

DOE Patents [OSTI]

Silicon MSM photodiodes sensitive to radiation in the visible to near infrared spectral range are produced by altering the absorption characteristics of crystalline Si by ion implantation. The implantation produces a defected region below the surface of the silicon with the highest concentration of defects at its base which acts to reduce the contribution of charge carriers formed below the defected layer. The charge carriers generated by the radiation in the upper regions of the defected layer are very quickly collected between biased Schottky barrier electrodes which form a metal-semiconductor-metal structure for the photodiode.

Brueck, Steven R. J. (Albuquerque, NM); Myers, David R. (Albuquerque, NM); Sharma, Ashwani K. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Silicon metal-semiconductor-metal photodetector  

DOE Patents [OSTI]

Silicon MSM photodiodes sensitive to radiation in the visible to near infrared spectral range are produced by altering the absorption characteristics of crystalline Si by ion implantation. The implantation produces a defected region below the surface of the silicon with the highest concentration of defects at its base which acts to reduce the contribution of charge carriers formed below the defected layer. The charge carriers generated by the radiation in the upper regions of the defected layer are very quickly collected between biased Schottky barrier electrodes which form a metal-semiconductor-metal structure for the photodiode.

Brueck, Steven R. J. (Albuquerque, NM); Myers, David R. (Albuquerque, NM); Sharma, Ashwani K. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

22

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to...

23

Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition and Remarkable Large Magnetism. Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition...

24

Method for Creating Photonic Band Gap Materials - Energy Innovation...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a photonic band gap. These microstructures have the potential to change the way optoelectronic devices, such as photodiodes, LEDs, and integrated optical circuit elements, are...

25

acoustic band gaps: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

type of phononic crystals manufactured Institute of Physics. DOI: 10.10631.2167794 The propagation of acoustic waves in periodic composite Deymier, Pierre 2 Acoustic band gap...

26

Energy Band-Gap Engineering of Graphene Nanoribbons Melinda Y. Han,1  

E-Print Network [OSTI]

, New York, New York 10027, USA 2 Department of Physics, Columbia University, New York, New York 10027Energy Band-Gap Engineering of Graphene Nanoribbons Melinda Y. Han,1 Barbaros O¨ zyilmaz,2 Yuanbo an energy gap near the charge neutrality point. Individual graphene layers are contacted with metal

Kim, Philip

27

Fabrication of Ceramic Layer-by-Layer Infrared Wavelength Photonic Band Gap Crystals  

SciTech Connect (OSTI)

Photonic band gap (PBG) crystals, also known as photonic crystals, are periodic dielectric structures which form a photonic band gap that prohibit the propagation of electromagnetic (EM) waves of certain frequencies at any incident angles. Photonic crystals have several potential applications including zero-threshold semiconductor lasers, the inhibition of spontaneous emission, dielectric mirrors, and wavelength filters. If defect states are introduced in the crystals, light can be guided from one location to another or even a sharp bending of light in micron scale can be achieved. This generates the potential for optical waveguide and optical circuits, which will contribute to the improvement in the fiber-optic communications and the development of high-speed computers.

Henry Hao-Chuan Kang

2004-12-19T23:59:59.000Z

28

Characterization of Novel Semiconductor Alloys for Band Gap Engineering  

E-Print Network [OSTI]

including high efficiency photovoltaics and light emittingEngineering 1.2.1 High Efficiency Photovoltaics 1.2.2 High1.2.1 High Efficiency Photovoltaics There has been

Broesler, Robert Joseph

2010-01-01T23:59:59.000Z

29

Recent emission channeling studies in wide band gap semiconductors  

E-Print Network [OSTI]

We present results of recent emission channeling experiments on the lattice location of implanted Fe and rare earths in wurtzite GaN and ZnO. In both cases the majority of implanted atoms are found on substitutional cation sites. The root mean square displacements from the ideal substitutional Ga and Zn sites are given and the stability of the Fe and rare earth lattice location against thermal annealing is discussed.

Wahl, Ulrich; Rita, E; Alves, E; Carvalho-Soares, Joo; De Vries, Bart; Matias, V; Vantomme, A

2005-01-01T23:59:59.000Z

30

Substrate-induced band gap opening in epitaxial graphene  

E-Print Network [OSTI]

H.A. Electronic states of graphene nanoribbons studied withS.G. Louie. Energy gaps in graphene nanoribbons. Phys. Rev.band-gap engineering of graphene nanoribbons. Phys. Rev.

2008-01-01T23:59:59.000Z

31

First principles study of Fe in diamond: A diamond-based half metallic dilute magnetic semiconductor  

SciTech Connect (OSTI)

Half-metallic ferromagnetic ordering in semiconductors, essential in the emerging field of spintronics for injection and transport of highly spin polarised currents, has up to now been considered mainly in IIIV and IIVI materials. However, low Curie temperatures have limited implementation in room temperature device applications. We report ab initio Density Functional Theory calculations on the properties of Fe in diamond, considering the effects of lattice site, charge state, and Fermi level position. We show that the lattice sites and induced magnetic moments of Fe in diamond depend strongly on the Fermi level position and type of diamond co-doping, with Fe being energetically most favorable at the substitutional site in p-type and intrinsic diamond, while it is most stable at a divacancy site in n-type diamond. Fe induces spin polarized bands in the band gap, with strong hybridization between Fe-3d and C-2s,2p bands. We further consider Fe-Fe spin interactions in diamond and show that substitutional Fe{sup +1} in p-type diamond exhibits a half-metallic character, with a magnetic moment of 1.0??{sub B} per Fe atom and a large ferromagnetic stabilization energy of 33?meV, an order of magnitude larger than in other semiconductors, with correspondingly high Curie temperatures. These results, combined with diamond's unique properties, demonstrate that Fe doped p-type diamond is likely to be a highly suitable candidate material for spintronics applications.

Benecha, E. M. [Department of Physics, University of South Africa, P.O. Box 392, UNISA 0003 Pretoria (South Africa); Lombardi, E. B., E-mail: lombaeb@unisa.ac.za [College of Graduate Studies, University of South Africa, P.O. Box 392, UNISA 0003 Pretoria (South Africa)

2013-12-14T23:59:59.000Z

32

Modeling of Photonic Band Gap Crystals and Applications  

SciTech Connect (OSTI)

In this work, the authors have undertaken a theoretical approach to the complex problem of modeling the flow of electromagnetic waves in photonic crystals. The focus is to address the feasibility of using the exciting phenomena of photonic gaps (PBG) in actual applications. The authors start by providing analytical derivations of the computational electromagnetic methods used in their work. They also present a detailed explanation of the physics underlying each approach, as well as a comparative study of the strengths and weaknesses of each method. The Plane Wave expansion, Transfer Matrix, and Finite Difference time Domain Methods are addressed. They also introduce a new theoretical approach, the Modal Expansion Method. They then shift the attention to actual applications. They begin with a discussion of 2D photonic crystal wave guides. The structure addressed consists of a 2D hexagonal structure of air cylinders in a layered dielectric background. Comparison with the performance of a conventional guide is made, as well as suggestions for enhancing it. The studies provide an upper theoretical limit on the performance of such guides, as they assumed no crystal imperfections and non-absorbing media. Next, they study 3D metallic PBG materials at near infrared and optical wavelengths. The main objective is to study the importance of absorption in the metal and the suitability of observing photonic band gaps in such structures. They study simple cubic structures where the metallic scatters are either cubes or interconnected metallic rods. Several metals are studied (aluminum, gold, copper, and silver). The effect of topology is addressed and isolated metallic cubes are found to be less lossy than the connected rod structures. The results reveal that the best performance is obtained by choosing metals with a large negative real part of the dielectric function, together with a relatively small imaginary part. Finally, they point out a new direction in photonic crystal research that involves the interplay of metallic-PBG rejection and photonic band edge absorption. They propose that an absolute metallic-PBG may be used to suppress the infrared part of the blackbody emission and, emit its energy only through a sharp absorption band. Potential applications of this new PBG mechanism include highly efficient incandescent lamps and enhanced thermophotovoltaic energy conversion. The suggested lamp would be able to recycle the energy that would otherwise go into the unwanted heat associated with usual lamps, into light emitted in the visible spectrum. It is estimated this would increase the efficiency over conventional lamps by about 40%.

Ihab Fathy El-Kady

2002-08-27T23:59:59.000Z

33

Transformation Optics with Photonic Band Gap Media  

E-Print Network [OSTI]

We introduce a class of optical media based on adiabatically modulated, dielectric-only, and potentially extremely low-loss, photonic crystals. The media we describe represent a generalization of the eikonal limit of transformation optics (TO). The foundation of the concept is the possibility to fit frequency isosurfaces in the k-space of photonic crystals with elliptic surfaces, allowing them to mimic the dispersion relation of light in anisotropic effective media. Photonic crystal cloaks and other TO devices operating at visible wavelengths can be constructed from optically transparent substances like glasses, whose attenuation coefficient can be as small as 10 dB/km, suggesting the TO design methodology can be applied to the development of optical devices not limited by the losses inherent to metal-based, passive metamaterials.

Urzhumov, Yaroslav A

2010-01-01T23:59:59.000Z

34

Method of physical vapor deposition of metal oxides on semiconductors  

DOE Patents [OSTI]

A process for growing a metal oxide thin film upon a semiconductor surface with a physical vapor deposition technique in a high-vacuum environment and a structure formed with the process involves the steps of heating the semiconductor surface and introducing hydrogen gas into the high-vacuum environment to develop conditions at the semiconductor surface which are favorable for growing the desired metal oxide upon the semiconductor surface yet is unfavorable for the formation of any native oxides upon the semiconductor. More specifically, the temperature of the semiconductor surface and the ratio of hydrogen partial pressure to water pressure within the vacuum environment are high enough to render the formation of native oxides on the semiconductor surface thermodynamically unstable yet are not so high that the formation of the desired metal oxide on the semiconductor surface is thermodynamically unstable. Having established these conditions, constituent atoms of the metal oxide to be deposited upon the semiconductor surface are directed toward the surface of the semiconductor by a physical vapor deposition technique so that the atoms come to rest upon the semiconductor surface as a thin film of metal oxide with no native oxide at the semiconductor surface/thin film interface. An example of a structure formed by this method includes an epitaxial thin film of (001)-oriented CeO.sub.2 overlying a substrate of (001) Ge.

Norton, David P. (Knoxville, TN)

2001-01-01T23:59:59.000Z

35

Photonic-band-gap properties for two-component slow light  

SciTech Connect (OSTI)

We consider two-component ''spinor'' slow light in an ensemble of atoms coherently driven by two pairs of counterpropagating control laser fields in a double tripod-type linkage scheme. We derive an equation of motion for the spinor slow light (SSL) representing an effective Dirac equation for a massive particle with the mass determined by the two-photon detuning. By changing the detuning the atomic medium acts as a photonic crystal with a controllable band gap. If the frequency of the incident probe light lies within the band gap, the light experiences reflection from the sample and can tunnel through it. For frequencies outside the band gap, the transmission and reflection probabilities oscillate with the increasing length of the sample. In both cases the reflection takes place into the complementary mode of the probe field. We investigate the influence of the finite excited state lifetime on the transmission and reflection coefficients of the probe light. We discuss possible experimental implementations of the SSL using alkali-metal atoms such as rubidium or sodium.

Ruseckas, J.; Kudriasov, V.; Juzeliunas, G.; Unanyan, R. G.; Otterbach, J.; Fleischhauer, M. [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, Vilnius 01108 (Lithuania); Fachbereich Physik and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, Kaiserslautern D-67663 (Germany)

2011-06-15T23:59:59.000Z

36

Multi-junction, monolithic solar cell using low-band-gap materials lattice matched to GaAs or Ge  

DOE Patents [OSTI]

A multi-junction, monolithic, photovoltaic solar cell device is provided for converting solar radiation to photocurrent and photovoltage with improved efficiency. The solar cell device comprises a plurality of semiconductor cells, i.e., active p/n junctions, connected in tandem and deposited on a substrate fabricated from GaAs or Ge. To increase efficiency, each semiconductor cell is fabricated from a crystalline material with a lattice constant substantially equivalent to the lattice constant of the substrate material. Additionally, the semiconductor cells are selected with appropriate band gaps to efficiently create photovoltage from a larger portion of the solar spectrum. In this regard, one semiconductor cell in each embodiment of the solar cell device has a band gap between that of Ge and GaAs. To achieve desired band gaps and lattice constants, the semiconductor cells may be fabricated from a number of materials including Ge, GaInP, GaAs, GaInAsP, GaInAsN, GaAsGe, BGaInAs, (GaAs)Ge, CuInSSe, CuAsSSe, and GaInAsNP. To further increase efficiency, the thickness of each semiconductor cell is controlled to match the photocurrent generated in each cell. To facilitate photocurrent flow, a plurality of tunnel junctions of low-resistivity material are included between each adjacent semiconductor cell. The conductivity or direction of photocurrent in the solar cell device may be selected by controlling the specific p-type or n-type characteristics for each active junction.

Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO); Friedman, Daniel J. (Lakewood, CO)

2001-01-01T23:59:59.000Z

37

Optical absorption and band gap reduction in (Fe1-xCrx)2O3 solid...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Optical absorption and band gap reduction in (Fe1-xCrx)2O3 solid solutions: A first-principles study. Optical absorption and band gap reduction in (Fe1-xCrx)2O3 solid solutions: A...

38

Electronic structure of Pt based topological Heusler compounds with C1{sub b} structure and 'zero band gap'  

SciTech Connect (OSTI)

Besides of their well-known wide range of properties it was recently shown that many of the heavy Heusler semiconductors with 1:1:1 composition and C1{sub b} structure exhibit a zero band gap behavior and are topological insulators induced by their inverted band structure. In the present study, the electronic structure of the Heusler compounds PtYSb and PtLaBi was investigated by bulk sensitive hard x-ray photoelectron spectroscopy. The measured valence band spectra are clearly resolved and in well agreement to the first-principles calculations of the electronic structure of the compounds. The experimental results give clear evidence for the zero band gap state.

Ouardi, Siham; Shekhar, Chandra; Fecher, Gerhard H.; Kozina, Xeniya; Stryganyuk, Gregory; Felser, Claudia [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Ueda, Shigenori; Kobayashi, Keisuke [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan)

2011-05-23T23:59:59.000Z

39

Electrical characteristics and thermal stability of HfO{sub 2} metal-oxide-semiconductor capacitors fabricated on clean reconstructed GaSb surfaces  

SciTech Connect (OSTI)

HfO{sub 2}/GaSb interfaces fabricated by high-vacuum HfO{sub 2} deposition on clean reconstructed GaSb surfaces were examined to explore a thermally stable GaSb metal-oxide-semiconductor structure with low interface-state density (D{sub it}). Interface Sb-O bonds were electrically and thermally unstable, and post-metallization annealing at temperatures higher than 200?C was required to stabilize the HfO{sub 2}/GaSb interfaces. However, the annealing led to large D{sub it} in the upper-half band gap. We propose that the decomposition products that are associated with elemental Sb atoms act as interface states, since a clear correlation between the D{sub it} and the Sb coverage on the initial GaSb surfaces was observed.

Miyata, Noriyuki, E-mail: nori.miyata@aist.go.jp; Mori, Takahiro; Yasuda, Tetsuji [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568 (Japan); Ohtake, Akihiro [National Institute for Materials Science (NIMS), Tsukuba, Ibaraki 305-0044 (Japan); Ichikawa, Masakazu [The University of Tokyo, Tokyo 113-8656 (Japan)

2014-06-09T23:59:59.000Z

40

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide ThinIon CoolingSubstrateSubstrate-Induced Band-Gap

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide ThinIonSubstrate-Induced Band-Gap Opening in

42

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications  

DOE Patents [OSTI]

A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

Wanlass, Mark W. (Golden, CO)

1994-01-01T23:59:59.000Z

43

Thermal ionization induced metal-semiconductor transition and room temperature ferromagnetism in trivalent doped ZnO codoped with lithium  

SciTech Connect (OSTI)

Thermal ionization induced metallic to semiconductor (MST) transition occurring at 460?K for Zn{sub 0.97}Al{sub 0.03}O, 463?K for Zn{sub 0.94}Al{sub 0.03}Li{sub 0.03}O, and 503?K for Zn{sub 0.91}Al{sub 0.03}Li{sub 0.03}Mn{sub 0.03}O has been found in the sol-gel synthesized (using hexamethylenetetramine), trivalent doped (Al, Mn) ZnO codoped with lithium. Increase in the thermally ionized carrier concentration due to Al doping is responsible for near band edge (NBE) peak shift causing Fermi level to move into conduction band making it metallic consistent with resistivity results. Free carrier (thermally activated) neutralization with ionized donor is responsible for semiconducting nature, which is supported from the free carrier screening produced energy shift in the NBE of photoluminescence peak. Furthermore, independently band gap shrinkage is also obtained from UV-Visible studies confirming localization induced MST. An anti-correlation is found between defect density (DLE) and room temperature ferromagnetism (RTFM) indicating intrinsic defects are not directly responsible for RTFM.

Sivagamasundari, A.; Chandrasekar, S.; Pugaze, R.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry 605 014 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry 605 014 (India)

2014-03-07T23:59:59.000Z

44

Light trapping design for low band-gap polymer solar cells  

E-Print Network [OSTI]

Light trapping design for low band-gap polymer solar cells Stephen Foster1,* and Sajeev John1,2 1 demonstrate numerically a 2-D nanostructured design for light trapping in a low band-gap polymer solar cell, "Light harvesting improvement of organic solar cells with self- enhanced active layer designs," Opt

John, Sajeev

45

Significant Reduction in NiO Band Gap upon Formation of LixNi1?xO Alloys: Applications to Solar Energy Conversion  

SciTech Connect (OSTI)

Long-term sustainable solar energy conversion relies on identifying economical and versatile semiconductor materials with appropriate band structures for photovoltaic and photocatalytic applications (e.g., band gaps of ?1.52.0 eV). Nickel oxide (NiO) is an inexpensive yet highly promising candidate. Its charge-transfer character may lead to longer carrier lifetimes needed for higher efficiencies, and its conduction band edge is suitable for driving hydrogen evolution via water-splitting. However, NiOs large band gap (?4 eV) severely limits its use in practical applications. Our first-principles quantum mechanics calculations show band gaps dramatically decrease to ?2.0 eV when NiO is alloyed with Li2O. We show that LixNi1?xO alloys (with x=0.125 and 0.25) are p-type semiconductors, contain states with no impurity levels in the gap and maintain NiOs desirable charge-transfer character. Lastly, we show that the alloys have potential for photoelectrochemical applications, with band edges well-placed for photocatalytic hydrogen production and CO2 reduction, as well as in tandem dye-sensitized solar cells as a photocathode.

Alidoust, Nima; Toroker, Maytal; Keith, John A.; Carter, Emily A.

2014-01-01T23:59:59.000Z

46

Single-junction solar cells with the optimum band gap for terrestrial concentrator applications  

DOE Patents [OSTI]

A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

Wanlass, M.W.

1994-12-27T23:59:59.000Z

47

OPTIMIZATION OF GRADED BAND GAP CdHgTe SOLAR CELLS A. BOUAZZI (*), Y. MARFAING and J. MIMILA-ARROYO  

E-Print Network [OSTI]

145 OPTIMIZATION OF GRADED BAND GAP CdHgTe SOLAR CELLS A. BOUAZZI (*), Y. MARFAING and J. MIMILA and an n-type CdHgTe alloy of uniform band gap as the base region. The optimization of solar energy conversion is conducted with respect to two constitutive para- meters : the gradient of the band gap

Boyer, Edmond

48

Tunable frequency band-gap and pulse propagation in a strongly nonlinear diatomic chain  

E-Print Network [OSTI]

One-dimensional nonlinear phononic crystals have been assembled from periodic diatomic chains of stainless steel cylinders alternated with Polytetrafluoroethylene (PTFE) spheres. We report the presence of acoustic band gaps in the dispersion relation of the linearized systems and study the transformation of single and multiple pulses in linear, nonlinear and strongly nonlinear regimes with numerical calculations and experiments. The limiting frequencies of the band gap are within the audible frequency range (20-20,000 Hz) and can be tuned by varying the particle's material properties, mass and initial compression. Pulses rapidly transform within very short distances from the impacted end due to the influence of the band gap in the linear and in nonlinear elastic chains. The effects of an in situ band gap created by a mean dynamic compression are observed in the strongly nonlinear wave regime.

E. B. Herbold; J. Kim; V. F. Nesterenko; S. Wang; C. Daraio

2008-06-26T23:59:59.000Z

49

Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure  

E-Print Network [OSTI]

We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG) structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental ...

Hu, Min

50

Thermophotovoltaic conversion using selective infrared line emitters and large band gap photovoltaic devices  

DOE Patents [OSTI]

Efficient thermophotovoltaic conversion can be performed using photovoltaic devices with a band gap in the 0.75-1.4 electron volt range, and selective infrared emitters chosen from among the rare earth oxides which are thermally stimulated to emit infrared radiation whose energy very largely corresponds to the aforementioned band gap. It is possible to use thermovoltaic devices operating at relatively high temperatures, up to about 300.degree. C., without seriously impairing the efficiency of energy conversion.

Brandhorst, Jr., Henry W. (Auburn, AL); Chen, Zheng (Auburn, AL)

2000-01-01T23:59:59.000Z

51

A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang, and Thomas Y. Hsiang  

E-Print Network [OSTI]

A 75 GHz silicon metal-semiconductor-metal Schottky photodiode Sotiris Alexandrou, Chia-Chi Wang-semiconductor-metal (MSM) photodiodes with 300 nm finger width and spacing were measured with a subpicosecond electro of silicon MSM photodiodes. A configuration is suggested to improve the speed of these detectors at long

52

Strain and electric field induced electronic properties of two-dimensional hybrid bilayers of transition-metal dichalcogenides  

SciTech Connect (OSTI)

Tunability of the electronic properties of two-dimensional bilayer hetero structures of transition-metal dichalcogenides (i.e., MX{sub 2}-M?X?{sub 2} with (M, M??=?Mo, W; X, X??=?S, Se) is investigated. Application of both strain and electric field is found to modify the band gap and carrier effective mass in the hybrid bilayers considered. The calculated results based on density functional theory suggest that the tensile strain considerably changes the band gap of semiconducting bilayers; it makes the band gap to be indirect, and later initiates the semiconductor-to-metal transition. Application of the external electric fields, on the other hand, shows asymmetric variation in the band gap leading to the closure of the gap at about 0.51.0?V/. Tuning of the band gap and carrier effective mass in such a controlled manner makes the hybrid bilayers of transition metal dichalcogenides to be promising candidates for application in electronic devices at nanoscale.

Sharma, Munish, E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com; Kumar, Ashok; Ahluwalia, P. K., E-mail: munishsharmahpu@live.com, E-mail: pk-ahluwalia7@yahoo.com [Department of Physics, Himachal Pradesh University, Shimla 171005 (India); Pandey, Ravindra [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States)

2014-08-14T23:59:59.000Z

53

Science and applications of infrared semiconductor nanocrystals  

E-Print Network [OSTI]

In this work we study several applications of semiconductor nanocrystals (NCs) with infrared band gaps. In the first half, we explore the physics of two systems with applications in NC based photovoltaics. The physics of ...

Geyer, Scott Mitchell

2010-01-01T23:59:59.000Z

54

E-Print Network 3.0 - active complementary metal-oxide-semiconductor...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

ion-implanted p and n dopants in germanium Summary: wavelength spectrum allowing optoelectronic integra- tion to enhance complementary-metal-oxide- semiconductor... lim- its in...

55

E-Print Network 3.0 - area metal-oxide-semiconductor electron...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

inversion layer mobility Joo-Hiuk Son,a) Seongtae... measured absorption of terahertz radiation pulses by metal-oxide-semiconductor MOS inversion layers... of the...

56

Band gap engineering for graphene by using Na{sup +} ions  

SciTech Connect (OSTI)

Despite the noble electronic properties of graphene, its industrial application has been hindered mainly by the absence of a stable means of producing a band gap at the Dirac point (DP). We report a new route to open a band gap (E{sub g}) at DP in a controlled way by depositing positively charged Na{sup +} ions on single layer graphene formed on 6H-SiC(0001) surface. The doping of low energy Na{sup +} ions is found to deplete the ?* band of graphene above the DP, and simultaneously shift the DP downward away from Fermi energy indicating the opening of E{sub g}. The band gap increases with increasing Na{sup +} coverage with a maximum E{sub g}?0.70?eV. Our core-level data, C 1s, Na 2p, and Si 2p, consistently suggest that Na{sup +} ions do not intercalate through graphene, but produce a significant charge asymmetry among the carbon atoms of graphene to cause the opening of a band gap. We thus provide a reliable way of producing and tuning the band gap of graphene by using Na{sup +} ions, which may play a vital role in utilizing graphene in future nano-electronic devices.

Sung, S. J.; Lee, P. R.; Kim, J. G.; Ryu, M. T.; Park, H. M.; Chung, J. W., E-mail: jwc@postech.ac.kr [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2014-08-25T23:59:59.000Z

57

Band gap and electronic structure of MgSiN{sub 2}  

SciTech Connect (OSTI)

Density functional theory calculations and electron energy loss spectroscopy indicate that the electronic structure of ordered orthorhombic MgSiN{sub 2} is similar to that of wurtzite AlN. A band gap of 5.7?eV was calculated for both MgSiN{sub 2} (indirect) and AlN (direct) using the Heyd-Scuseria-Ernzerhof approximation. Correction with respect to the experimental room-temperature band gap of AlN indicates that the true band gap of MgSiN{sub 2} is 6.2?eV. MgSiN{sub 2} has an additional direct gap of 6.3?eV at the ? point.

Quirk, J. B., E-mail: james.quirk09@imperial.ac.uk; Rsander, M.; McGilvery, C. M.; Moram, M. A. [Department of Materials, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Palgrave, R. [Department of Chemistry, University College London, Gordon Street WC1H 0AJ (United Kingdom)

2014-09-15T23:59:59.000Z

58

One-dimensional electromagnetic band gap structures formed by discharge plasmas in a waveguide  

SciTech Connect (OSTI)

We demonstrate the ability to develop one-dimensional electromagnetic band gap structure in X-band waveguide solely by using the positive columns of glow discharges in neon at the middle pressure. Plasma inhomogeneities are distributed uniformly along a typical X-band waveguide with cross section of 23??10?mm{sup 2}. It is shown that electron densities larger than 10{sup 14?}cm{sup ?3} are needed in order to create an effective one-dimensional electromagnetic band gap structure. Some applications for using the one-dimensional electromagnetic band gap structure in waveguide as a control of microwave (broadband filter and device for variation of pulse duration) are demonstrated.

Arkhipenko, V. I.; Simonchik, L. V., E-mail: l.simonchik@dragon.bas-net.by; Usachonak, M. S. [B.I. Stepanov Institute of Physics of the NAS of Belarus, Ave. Nezavisimostsi 68, 220072 Minsk (Belarus); Callegari, Th.; Sokoloff, J. [Universit de Toulouse, UPS, INPT, LAPLACE, Laboratoire Plasma et Conversion d'Energie, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France)

2014-09-28T23:59:59.000Z

59

Polarization dependence of the temporal response of metal-semiconductor-metal photodetectors  

E-Print Network [OSTI]

of MSM-PD effi- ciency when the electrode period ( ) is comparable to the wavelength of the incident-semiconductor-metal photodetector temporal response is shown to be significant, and largest for devices with electrode periods less insensitive devices require special electrode patterning7 or . When used as a polarization analyzer/ detector

Van Driel, Henry M.

60

Direct measurements of band gap grading in polycrystalline CIGS solar cells  

E-Print Network [OSTI]

We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

M. P. Heinrich; Z-H. Zhang; Y. Zhang; O. Kiowski; M. Powalla; U. Lemmer; A. Slobodskyy

2010-09-20T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Direct measurements of band gap grading in polycrystalline CIGS solar cells  

E-Print Network [OSTI]

We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

Heinrich, M P; Zhang, Y; Kiowski, O; Powalla, M; Lemmer, U; Slobodskyy, A

2010-01-01T23:59:59.000Z

62

SPECTROSCOPIE DE DEFAUTS -LUMINESCENCE I. THE ANALYSIS OF WIDE BAND GAP SEMICONDUCTORS  

E-Print Network [OSTI]

'impuretes donneurs, accepteurs et pieges isoelectroniques,et de leur extension a I'identification d'espkces chimiques of impurity, donors, acceptors and isoelectronic traps, and their extension to the identification of chemical junctions with quite heavy doping to provide the desired high bulk conduc- tivity, certainly in the 10'' cm

Boyer, Edmond

63

Band gap structure modification of amorphous anodic Al oxide film by Ti-alloying  

SciTech Connect (OSTI)

The band structure of pure and Ti-alloyed anodic aluminum oxide has been examined as a function of Ti concentration varying from 2 to 20 at.?%. The band gap energy of Ti-alloyed anodic Al oxide decreases with increasing Ti concentration. X-ray absorption spectroscopy reveals that Ti atoms are not located in a TiO{sub 2} unit in the oxide layer, but rather in a mixed Ti-Al oxide layer. The optical band gap energy of the anodic oxide layers was determined by vacuum ultraviolet spectroscopy in the energy range from 4.1 to 9.2?eV (300135?nm). The results indicate that amorphous anodic Al{sub 2}O{sub 3} has a direct band gap of 7.3?eV, which is about ?1.4?eV lower than its crystalline counterpart (single-crystal Al{sub 2}O{sub 3}). Upon Ti-alloying, extra bands appear within the band gap of amorphous Al{sub 2}O{sub 3}, mainly caused by Ti 3d orbitals localized at the Ti site.

Canulescu, S., E-mail: stec@fotonik.dtu.dk; Schou, J. [Department of Photonics Engineering, Technical University of Denmark, 4000 Roskilde (Denmark); Rechendorff, K.; Pleth Nielsen, L. [Danish Technological Institute, Kongsvang Alle 29, 8000 Aarhus (Denmark); Borca, C. N. [Paul Scherrer Institute, 5232 Villigen (Switzerland); Jones, N. C.; Hoffmann, S. V. [ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus (Denmark); Bordo, K.; Ambat, R. [Department of Mechanical Engineering, Technical University of Denmark, 2800 Kongens Lyngby (Denmark)

2014-03-24T23:59:59.000Z

64

The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films  

E-Print Network [OSTI]

MRSEC The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films D Science & Engineering Center For zinc-indium-tin oxide (ZITO) films, grown by pulsed-laser deposition was replaced by substitution with zinc and tin in equal molar proportions (co-substitution). All ZITO films

Shahriar, Selim

65

Current transport, gate dielectrics and band gap engineering in graphene devices  

E-Print Network [OSTI]

Current transport, gate dielectrics and band gap engineering in graphene devices Wenjuan Zhu In this work, we studied current transport in mono-, bi- and tri-layer graphene. We find that both of the electrical field of the substrate surface polar phonons in bi-layer/tri-layer graphenes. We also find

Perebeinos, Vasili

66

Size effect on the electronic and optical band gap of CdSe QD  

SciTech Connect (OSTI)

Present paper deals with a critical and comprehensive analysis of the dependence of photo emission (PE) electronic band gap and optical absorption (OA) excitonic band gap on the size of CdSe QD, via connecting it with excitonic absorbance wavelength. Excitonic absorbance wavelength is determined through an empirical fit of established experimental evidences. Effective excitonic charge and Bohr radius is determined as a function of size. Increase in size of the CdSe QD results in greater Bohr radius and smaller effective excitonic charge. Excitonic binding energy as a degree of size of QD is also calculated which further relates with the difference in PE electronic and OA optical band gaps. It is also shown that with increase in size of CdSe QD, the excitonic binding energy decreases which consequently increases differences in two band gaps. Our results are very well comparable with the established results. Explanation for the origin of the unusual optical properties of CdSe QD has been also discussed.

Sisodia, Namita, E-mail: namitasisodiya@gmail.com [Department of Physics, Holkar Science College, Indore-45200 (India)

2014-04-24T23:59:59.000Z

67

Exploiting pattern transformation to tune phononic band gaps in a two-dimensional granular crystal  

E-Print Network [OSTI]

) cylinders is investigated numerically. This system was previously shown to undergo a pattern transformation with uniaxial compression by Go¨ncu¨ et al. [Soft Matter 7, 2321 (2011)]. The dispersion relations, or elastic waves in certain frequency ranges known as band gaps is an important feature of these materials

68

Reflection technique for thermal mapping of semiconductors  

DOE Patents [OSTI]

Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

Walter, Martin J. (Lee, NY)

1989-06-20T23:59:59.000Z

69

Ultrathin metal-semiconductor-metal resonator for angle invariant visible band transmission filters  

SciTech Connect (OSTI)

We present transmission visible wavelength filters based on strong interference behaviors in an ultrathin semiconductor material between two metal layers. The proposed devices were fabricated on 2?cm??2?cm glass substrate, and the transmission characteristics show good agreement with the design. Due to a significantly reduced light propagation phase change associated with the ultrathin semiconductor layer and the compensation in phase shift of light reflecting from the metal surface, the filters show an angle insensitive performance up to 70, thus, addressing one of the key challenges facing the previously reported photonic and plasmonic color filters. This principle, described in this paper, can have potential for diverse applications ranging from color display devices to the image sensors.

Lee, Kyu-Tae; Seo, Sungyong; Yong Lee, Jae; Jay Guo, L., E-mail: guo@umich.edu [Department of Electrical Engineering and Computer Science, The University of Michigan, Ann Arbor, Michigan 48109 (United States)

2014-06-09T23:59:59.000Z

70

Multiple percolation tunneling staircase in metal-semiconductor nanoparticle composites  

SciTech Connect (OSTI)

Multiple percolation transitions are observed in a binary system of RuO{sub 2}-CaCu{sub 3}Ti{sub 4}O{sub 12} metal-semiconductor nanoparticle composites near percolation thresholds. Apart from a classical percolation transition, associated with the appearance of a continuous conductance path through RuO{sub 2} metal oxide nanoparticles, at least two additional tunneling percolation transitions are detected in this composite system. Such behavior is consistent with the recently emerged picture of a quantum conductivity staircase, which predicts several percolation tunneling thresholds in a system with a hierarchy of local tunneling conductance, due to various degrees of proximity of adjacent conducting particles distributed in an insulating matrix. Here, we investigate a different type of percolation tunneling staircase, associated with a more complex conductive and insulating particle microstructure of two types of non-spherical constituents. As tunneling is strongly temperature dependent, we use variable temperature measurements to emphasize the hierarchical nature of consecutive tunneling transitions. The critical exponents corresponding to specific tunneling percolation thresholds are found to be nonuniversal and temperature dependent.

Mukherjee, Rupam; Huang, Zhi-Feng; Nadgorny, Boris [Department of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201 (United States)

2014-10-27T23:59:59.000Z

71

Pre-Stressed Viscoelastic Composites: Effective Incremental Moduli and Band-Gap Tuning  

SciTech Connect (OSTI)

We study viscoelastic wave propagation along pre-stressed nonlinear elastic composite bars. In the pre-stressed state we derive explicit forms for the effective incremental storage and loss moduli with dependence on the pre-stress. We also derive a dispersion relation for the effective wavenumber in the case of arbitrary frequency, hence permitting a study of viscoelastic band-gap tuning via pre-stress.

Parnell, William J. [School of Mathematics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)

2010-09-30T23:59:59.000Z

72

Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device  

E-Print Network [OSTI]

565 Self-Assembled Metal/Molecule/Semiconductor Nanostructures for Electronic Device and Contact attracted interest for electronic device and ma- terials applications. The first class involves the for-assembled semiconductor structures, the electronic device functionality has been limited by the difficulty in achieving

Woodall, Jerry M.

73

Transition-metal silicides as materials for magnet-semiconductor heterostructures*  

E-Print Network [OSTI]

Transition-metal silicides as materials for magnet-semiconductor heterostructures* Peter Kratzer as of binary late transition metal monosilicides, in contact with the Si surface. For the Heusler alloy Co2MnSi, we could show that the 001 surface retains the half-metallic character of the bulk if a fully Mn

74

Effect of silver incorporation in phase formation and band gap tuning of tungsten oxide thin films  

SciTech Connect (OSTI)

Silver incorporated tungsten oxide thin films are prepared by RF magnetron sputtering technique. The effect of silver incorporation in micro structure evolution, phase enhancement, band gap tuning and other optical properties are investigated using techniques such as x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and UV-Visible spectroscopy. Effect of silver addition in phase formation and band gap tuning of tungsten oxide thin films are investigated. It is found that the texturing and phase formation improves with enhancement in silver content. It is also found that as the silver incorporation enhances the thickness of the films increases at the same time the strain in the film decreases. Even without annealing the desired phase can be achieved by doping with silver. A broad band centered at the wavelength 437 nm is observed in the absorption spectra of tungsten oxide films of higher silver incorporation and this can be attributed to surface plasmon resonance of silver atoms present in the tungsten oxide matrix. The transmittance of the films is decreased with increase in silver content which can be due to increase in film thickness, enhancement of scattering, and absorption of light caused by the increase of grain size, surface roughness and porosity of films and enhanced absorption due to surface plasmon resonance of silver. It is found that silver can act as the seed for the growth of tungsten oxide grains and found that the grain size increases with silver content which in turn decreases the band gap of tungsten oxide from 3.14 eV to 2.70 eV.

Jolly Bose, R.; Kumar, R. Vinod; Sudheer, S. K.; Mahadevan Pillai, V. P. [Department of Optoelectronics, University of Kerala, Kariyavattom, Thiruvananthapuram, Kerala 695581 (India); Reddy, V. R.; Ganesan, V. [UGC - DAE Consortium for Scientific Research, Khandwa Road, Indore 452017, Madhyapradesh (India)

2012-12-01T23:59:59.000Z

75

Analysis of plasma-magnetic photonic crystal with a tunable band gap  

SciTech Connect (OSTI)

In this paper, electromagnetic wave propagation through the one-dimensional plasma-magnetic photonic crystal in the presence of external magnetic field has been analyzed. The dispersion relation, transmission and reflection coefficients have been obtained by using the transfer matrix method. It is investigated how photonic band gap of photonic crystals will be tuned when both dielectric function {epsilon} and magnetic permeability {mu} of the constitutive materials, depend on applied magnetic field. This is shown by one dimensional photonic crystals consisting of plasma and ferrite material layers stacked alternately.

Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A. [Department of Physics and Plasma Research Institute of Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

2013-04-15T23:59:59.000Z

76

Direct space-time observation of pulse tunneling in an electromagnetic band gap  

SciTech Connect (OSTI)

We present space-time-resolved measurements of electromagnetic pulses tunneling through a coaxial electromagnetic band gap structure. The results show that during the tunneling process the field distribution inside the barrier is an exponentially decaying standing wave whose amplitude increases and decreases as it slowly follows the temporal evolution of the input pulse. At no time is a pulse maximum found inside the barrier, and hence the transmitted peak is not the incident peak that has propagated to the exit. The results support the quasistatic interpretation of tunneling dynamics and confirm that the group delay is not the traversal time of the input pulse peak.

Doiron, Serge; Hache, Alain [Department de physique et d'astronomie, Universite de Moncton, Moncton, New Brunswick, E1A 3E9 (Canada); Winful, Herbert G. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Avenue, Ann Arbor, Michigan 48109-2122 (United States)

2007-08-15T23:59:59.000Z

77

Metal-insulator-semiconductor structures on p-type GaAs with low interface state density  

E-Print Network [OSTI]

Metal-insulator-semiconductor structures on p-type GaAs with low interface state density Zhi Chen properties of in situ deposited Si3N4 /Si/p-GaAs metal-insulator-semiconductor structures have been offered by a low gate leakage technology in GaAs, such as metal insulator structures, func- tional Ga

Chen, Zhi

78

Periodic dielectric structure for production of photonic band gap and devices incorporating the same  

DOE Patents [OSTI]

A periodic dielectric structure which is capable of producing a photonic band gap and which is capable of practical construction. The periodic structure is formed of a plurality of layers, each layer being formed of a plurality of rods separated by a given spacing. The material of the rods contrasts with the material between the rods to have a refractive index contrast of at least two. The rods in each layer are arranged with their axes parallel and at a given spacing. Adjacent layers are rotated by 90.degree., such that the axes of the rods in any given layer are perpendicular to the axes in its neighbor. Alternating layers (that is, successive layers of rods having their axes parallel such as the first and third layers) are offset such that the rods of one are about at the midpoint between the rods of the other. A four-layer periocity is thus produced, and successive layers are stacked to form a three-dimensional structure which exhibits a photonic band gap. By virtue of forming the device in layers of elongate members, it is found that the device is susceptible of practical construction.

Ho, Kai-Ming (Ames, IA); Chan, Che-Ting (Ames, IA); Soukoulis, Costas (Ames, IA)

1994-08-02T23:59:59.000Z

79

Metal-semiconductor hybrid thin films in field-effect transistors  

SciTech Connect (OSTI)

Metal-semiconductor hybrid thin films consisting of an amorphous oxide semiconductor and a number of aluminum dots in different diameters and arrangements are formed by electron beam lithography and employed for thin-film transistors (TFTs). Experimental and computational demonstrations systematically reveal that the field-effect mobility of the TFTs enhances but levels off as the dot density increases, which originates from variations of the effective channel length that strongly depends on the electric field distribution in a transistor channel.

Okamura, Koshi, E-mail: koshi.okamura@kit.edu; Dehm, Simone [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)] [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); Hahn, Horst [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany) [Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany); KIT-TUD Joint Research Laboratory Nanomaterials, Technische Universitt Darmstadt, Petersenstr. 32, 64287 Darmstadt (Germany)

2013-12-16T23:59:59.000Z

80

Ultraviolet GaN photodetectors on Si via oxide buffer heterostructures with integrated short period oxide-based distributed Bragg reflectors and leakage suppressing metal-oxide-semiconductor contacts  

SciTech Connect (OSTI)

Based on a novel double step oxide buffer heterostructure approach for GaN integration on Si, we present an optimized Metal-Semiconductor-Metal (MSM)-based Ultraviolet (UV) GaN photodetector system with integrated short-period (oxide/Si) Distributed Bragg Reflector (DBR) and leakage suppressing Metal-Oxide-Semiconductor (MOS) electrode contacts. In terms of structural properties, it is demonstrated by in-situ reflection high energy electron diffraction and transmission electron microscopy-energy dispersive x-ray studies that the DBR heterostructure layers grow with high thickness homogeneity and sharp interface structures sufficient for UV applications; only minor Si diffusion into the Y{sub 2}O{sub 3} films is detected under the applied thermal growth budget. As revealed by comparative high resolution x-ray diffraction studies on GaN/oxide buffer/Si systems with and without DBR systems, the final GaN layer structure quality is not significantly influenced by the growth of the integrated DBR heterostructure. In terms of optoelectronic properties, it is demonstrated thatwith respect to the basic GaN/oxide/Si system without DBRthe insertion of (a) the DBR heterostructures and (b) dark current suppressing MOS contacts enhances the photoresponsivity below the GaN band-gap related UV cut-off energy by almost up to two orders of magnitude. Given the in-situ oxide passivation capability of grown GaN surfaces and the one order of magnitude lower number of superlattice layers in case of higher refractive index contrast (oxide/Si) systems with respect to classical III-N DBR superlattices, virtual GaN substrates on Si via functional oxide buffer systems are thus a promising robust approach for future GaN-based UV detector technologies.

Szyszka, A., E-mail: szyszka@ihp-microelectronics.com, E-mail: adam.szyszka@pwr.wroc.pl [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Faculty of Microsystem Electronics and Photonics, Wroclaw University of Technology, Janiszewskiego 11/17, 50-372 Wroclaw (Poland); Lupina, L.; Lupina, G.; Schubert, M. A.; Zaumseil, P. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Haeberlen, M.; Storck, P.; Thapa, S. B. [Siltronic, Hanns-Seidel-Platz 4, 81737 Mnchen (Germany); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); BTU Cottbus-Senftenberg, Konrad-Zuse-Strasse 1, 03046 Cottbus (Germany)

2014-08-28T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Transition metal oxides on organic semiconductors Yongbiao Zhao a  

E-Print Network [OSTI]

semiconductors (OSs) structure has been widely used in inverted organic optoelectronic devices, including toward in simplifying the fabrication process of the organic optoelectronic devices. ? 2014 Elsevier B], have gained great attention because of their wide applications in optoelectronic devices composed

Demir, Hilmi Volkan

82

Band gap corrections for molecules and solids using Koopmans theorem and Wannier functions  

E-Print Network [OSTI]

We have proposed a method for correcting the Kohn-Sham eigen energies in the density functional theory (DFT) based on the Koopmans theorem using Wannier functions. The method provides a general approach applicable for molecules and solids for electronic structure calculations. It does not have any adjustable parameters and the computational cost is at the DFT level. For solids, the calculated eigen energies agree well with the experiments for not only the band gaps, but also the energies of other valence and conduction bands. For molecules, the calculated eigen energies agree well with the experimental ionization potentials and electron affinities, and show better trends than the traditional Delta-self-consistent-field (?SCF) results.

Ma, Jie

2015-01-01T23:59:59.000Z

83

Microwave band gap and cavity mode in spoof-insulator-spoof waveguide with multiscale structured surface  

E-Print Network [OSTI]

We propose a multiscale spoof-insulator-spoof (SIS) waveguide by introducing periodic geometry modulation in the wavelength scale to a SIS waveguide made of perfect electric conductor. The MSIS consists of multiple SIS subcells. The dispersion relationship of the fundamental guided mode of the spoof surface plasmon polaritons (SSPPs) is studied analytically within the small gap approximation. It is shown that the multiscale SIS possesses microwave band gap (MBG) due to the Bragg scattering. The "gap maps" in the design parameter space are provided. We demonstrate that the geometry of the subcells can efficiently adjust the effective refraction index of the elementary SIS and therefore further control the width and the position of the MBG. The results are in good agreement with numerical calculations by the finite element method (FEM). For finite-sized MSIS of given geometry in the millimeter scale, FEM calculations show that the first-order symmetric SSPP mode has zero transmission in the MBG within frequency...

Zhang, Qiang; Han, Dezhuan; Qin, Fei Fei; Zhang, Xiao Ming; Yao, Yong

2015-01-01T23:59:59.000Z

84

L{sub g}?=?100?nm In{sub 0.7}Ga{sub 0.3}As quantum well metal-oxide semiconductor field-effect transistors with atomic layer deposited beryllium oxide as interfacial layer  

SciTech Connect (OSTI)

In this study, we have fabricated nanometer-scale channel length quantum-well (QW) metal-oxide-semiconductor field effect transistors (MOSFETs) incorporating beryllium oxide (BeO) as an interfacial layer. BeO has high thermal stability, excellent electrical insulating characteristics, and a large band-gap, which make it an attractive candidate for use as a gate dielectric in making MOSFETs. BeO can also act as a good diffusion barrier to oxygen owing to its small atomic bonding length. In this work, we have fabricated In{sub 0.53}Ga{sub 0.47}As MOS capacitors with BeO and Al{sub 2}O{sub 3} and compared their electrical characteristics. As interface passivation layer, BeO/HfO{sub 2} bilayer gate stack presented effective oxide thickness less 1 nm. Furthermore, we have demonstrated In{sub 0.7}Ga{sub 0.3}As QW MOSFETs with a BeO/HfO{sub 2} dielectric, showing a sub-threshold slope of 100?mV/dec, and a transconductance (g{sub m,max}) of 1.1 mS/?m, while displaying low values of gate leakage current. These results highlight the potential of atomic layer deposited BeO for use as a gate dielectric or interface passivation layer for IIIV MOSFETs at the 7?nm technology node and/or beyond.

Koh, D., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); SEMATECH, Inc., Albany, New York 12203 (United States); Kwon, H. M. [Department of Electronics Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, T.-W., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org; Veksler, D.; Gilmer, D.; Kirsch, P. D. [SEMATECH, Inc., Albany, New York 12203 (United States); Kim, D.-H. [SEMATECH, Inc., Albany, New York 12203 (United States); GLOBALFOUNDRIES, Malta, New York 12020 (United States); Hudnall, Todd W. [Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, 78666 (United States); Bielawski, Christopher W. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Maszara, W. [GLOBALFOUNDRIES, Santa Clara, California 95054 (United States); Banerjee, S. K. [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

2014-04-21T23:59:59.000Z

85

Low resistance barrier layer for isolating, adhering, and passivating copper metal in semiconductor fabrication  

SciTech Connect (OSTI)

Cubic or metastable cubic refractory metal carbides act as barrier layers to isolate, adhere, and passivate copper in semiconductor fabrication. One or more barrier layers of the metal carbide are deposited in conjunction with copper metallizations to form a multilayer characterized by a cubic crystal structure with a strong (100) texture. Suitable barrier layer materials include refractory transition metal carbides such as vanadium carbide (VC), niobium carbide (NbC), tantalum carbide (TaC), chromium carbide (Cr.sub.3 C.sub.2), tungsten carbide (WC), and molybdenum carbide (MoC).

Weihs, Timothy P. (Baltimore, MD); Barbee, Jr., Troy W. (Palto Alto, CA)

2002-01-01T23:59:59.000Z

86

Optical properties of metallic (III, Mn)V ferromagnetic semiconductors in the infrared to visible range  

E-Print Network [OSTI]

We report on a study of the ac conductivity and magneto-optical properties of metallic ferromagnetic (III, Mn)V semiconductors in the infrared to visible spectrum at zero temperature. Our analysis is based on the successful kinetic exchange model...

Hankiewicz, EM; Jungwirth, T.; Dietl, T.; Timm, C.; Sinova, Jairo.

2004-01-01T23:59:59.000Z

87

Effects of surface termination on the band gap of ultrabright Si29 nanoparticles: Experiments and computational models  

E-Print Network [OSTI]

Effects of surface termination on the band gap of ultrabright Si29 nanoparticles: Experiments constituting a H-terminated reconstructed Si surface was recently proposed as a structural prototype termination with a N linkage in butylamine and O linkage in pentane . The emission band for N-termination

Braun, Paul

88

Here, we present the fabrication and use of plastic Photonic Band Gap Bragg fibres in photonic textiles for applications in  

E-Print Network [OSTI]

Here, we present the fabrication and use of plastic Photonic Band Gap Bragg fibres in photonicsection, Bragg fibres feature periodic sequence of layers of two distinct plastics. Under ambient illumination SCHICKER2 , NING GUO1 , CHARLES DUBOIS3 , RACHEL WINGFIELD2 & MAKSIM SKOROBOGATIY1 COLOUR-ON-DEMAND

Skorobogatiy, Maksim

89

Photovoltaic devices with low band gap polymers Eva Bundgaarda, Sean Shaheenb, David S. Ginleyb, Frederik C. Krebsa  

E-Print Network [OSTI]

Photovoltaic devices with low band gap polymers Eva Bundgaarda, Sean Shaheenb, David S. Ginleyb, Colorado, USA Abstract Progress in organic photovoltaic devices has recently resulted in reported temperature, active area of the device and molecular weight of the polymer, on the photovoltaic response

90

Band gap tuning in GaN through equibiaxial in-plane strains S. K. Yadav,2  

E-Print Network [OSTI]

in photovoltaics and light emission diodes LEDs . The InGaN system has been intensively studied during the past to the large atomic size mismatch between Ga and In.3 Thus, other methods to tune the band gap are needed for potential appli- cations of GaN and related materials systems. It is well-known that the structure

Alpay, S. Pamir

91

Predicting New TiO2 Phases with Low Band Gaps by a Multiobjective Global Optimization Approach  

E-Print Network [OSTI]

stable. This is equivalent to a global optimization problem of a biobjective function, i.e., total energyPredicting New TiO2 Phases with Low Band Gaps by a Multiobjective Global Optimization Approach Hou as a novel global optimization algorithm to predict new polymorphs of bulk TiO2 with better optical

Gong, Xingao

92

Wide-band-gap InAlAs solar cell for an alternative multijunction approach Marina S. Leite,1,a  

E-Print Network [OSTI]

Wide-band-gap InAlAs solar cell for an alternative multijunction approach Marina S. Leite,1,a Robyn L. Woo,2 William D. Hong,2 Daniel C. Law,2 and Harry A. Atwater1 1 California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, USA 2 Boeing-Spectrolab Inc., 12500

Atwater, Harry

93

Photonic band gap airbridge microcavity resonances in GaAs/AlxOy waveguides  

E-Print Network [OSTI]

-dielectric-contrast GaAs/AlxOy IIIV compound semiconductor structure. The photonic crystal is defined by a regularly of optical states will be modified and quantized by such a cavity. Typical semiconductor optical cavities measurements of a one- dimensional PBG air-bridge optical microcavity are pre- sented here. A schematic

Fan, Shanhui

94

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research  

SciTech Connect (OSTI)

Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. (Spire Corp., Bedford, MA (United States))

1993-02-01T23:59:59.000Z

95

IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 16, NO. 6, JUNE 2001 623 MetalSemiconductorMetal Traveling-Wave  

E-Print Network [OSTI]

in high-power distributed PD array or terahertz signal generation. Index Terms--Low-temperature-grown Ga­Semiconductor­Metal Traveling-Wave Photodetectors Jin-Wei Shi, Kian-Giap Gan, Yi-Jen Chiu, Yen-Hung Chen, Chi-Kuang Sun, Member-TWPD). Demonstrated devices were fabricated using low-temperature grown GaAs (LTG-GaAs). In order to achieve high

Bowers, John

96

PHYSICAL REVIEW B 90, 115209 (2014) Computational search for direct band gap silicon crystals  

E-Print Network [OSTI]

abundance, silicon is the preferred solar-cell material despite the fact that current silicon materials have semiconductor. For this reason, the most widely used solar-cell materials are all silicon based [1]. Current

Lee, Jooyoung

97

X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment  

SciTech Connect (OSTI)

In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

Marsh, Roark A.; /MIT /MIT /NIFS, Gifu /JAERI, Kyoto /LLNL, Livermore; Shapiro, Michael A.; Temkin, Richard J.; /MIT; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC

2012-06-11T23:59:59.000Z

98

Superatoms and Metal-Semiconductor Motifs for Cluster Materials  

SciTech Connect (OSTI)

A molecular understanding of catalysis and catalytically active materials is of fundamental importance in designing new substances for applications in energy and fuels. We have performed reactivity studies and ultrafast ionization and coulomb explosion studies on a variety of catalytically-relevant materials, including transition metal oxides of Fe, Co, Ni, Cu, Ti, V, Nb, and Ta. We demonstrate that differences in charge state, geometry, and elemental composition of clusters of such materials determine chemical reactivity and ionization behavior, crucial steps in improving performance of catalysts.

Castleman, A. W.

2013-10-11T23:59:59.000Z

99

Thermovoltaic semiconductor device including a plasma filter  

DOE Patents [OSTI]

A thermovoltaic energy conversion device and related method for converting thermal energy into an electrical potential. An interference filter is provided on a semiconductor thermovoltaic cell to pre-filter black body radiation. The semiconductor thermovoltaic cell includes a P/N junction supported on a substrate which converts incident thermal energy below the semiconductor junction band gap into electrical potential. The semiconductor substrate is doped to provide a plasma filter which reflects back energy having a wavelength which is above the band gap and which is ineffectively filtered by the interference filter, through the P/N junction to the source of radiation thereby avoiding parasitic absorption of the unusable portion of the thermal radiation energy.

Baldasaro, Paul F. (Clifton Park, NY)

1999-01-01T23:59:59.000Z

100

(Data in thousand metric tons of silicon content unless otherwise noted) Domestic Production and Use: Estimated value of silicon alloys and metal (excluding semiconductor-and solar-  

E-Print Network [OSTI]

Production and Use: Estimated value of silicon alloys and metal (excluding semiconductor- and solar- grade and aluminum alloys and the chemical industry. The semiconductor and solar industries, which manufacture chips China, 49%; Russia, 20

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

1/f noise in semiconductor and metal nanocrystal solids  

SciTech Connect (OSTI)

Electrical 1/f noise is measured in thin films of CdSe, CdSe/CdS, ZnO, HgTe quantum dots and Au nanocrystals. The 1/f noise, normalized per nanoparticle, shows no systematic dependence on the nanoparticle material and the coupling material. However, over 10 orders of magnitude, it correlates well with the nearest neighbor conductance suggesting some universal magnitude of the 1/f noise in these granular conductors. In the hopping regime, the main mechanism of 1/f noise is determined to be mobility fluctuated. In the metallic regime obtained with gold nanoparticle films, the noise drops to a similar level as bulk gold films and with a similar temperature dependence.

Liu, Heng, E-mail: leophy@gmail.com; Lhuillier, Emmanuel, E-mail: emmanuel.lhuillier@espci.fr; Guyot-Sionnest, Philippe [James Franck Institute, The University of Chicago, 929 E 57th Street, Chicago, Illinois 60637 (United States)

2014-04-21T23:59:59.000Z

102

Optical limiting of layered transition metal dichalcogenide semiconductors  

E-Print Network [OSTI]

Nonlinear optical property of transition metal dichalcogenide (TMDC) nanosheet dispersions, including MoS2, MoSe2, WS2, and WSe2, was performed by using Z-scan technique with ns pulsed laser at 1064 nm and 532 nm. The results demonstrate that the TMDC dispersions exhibit significant optical limiting response at 1064 nm due to nonlinear scattering, in contrast to the combined effect of both saturable absorption and nonlinear scattering at 532 nm. Selenium compounds show better optical limiting performance than that of the sulfides in the near infrared. A liquid dispersion system based theoretical modelling is proposed to estimate the number density of the nanosheet dispersions, the relationship between incident laser fluence and the size of the laser generated micro-bubbles, and hence the Mie scattering-induced broadband optical limiting behavior in the TMDC dispersions.

Dong, Ningning; Feng, Yanyan; Zhang, Saifeng; Zhang, Xiaoyan; Chang, Chunxia; Fan, Jintai; Zhang, Long; Wang, Jun

2015-01-01T23:59:59.000Z

103

Metal-insulator-semiconductor structure on low-temperature grown GaAs M. Young, W. Li, and T. P. Ma  

E-Print Network [OSTI]

Metal-insulator-semiconductor structure on low-temperature grown GaAs A. Chen,a M. Young, W. Li Received 28 July 2006; accepted 30 October 2006; published online 7 December 2006 The metal-insulator dielectrics and metal-insulator-semiconductor MIS structures; for ex- ample, in situ deposited Ga2O3 Gd2O3

Woodall, Jerry M.

104

Fast 8 kV metal-oxide semiconductor field-effect transistor switch R. E. Continetti, D. R. Cyr,al and D. M. Neumarkb)  

E-Print Network [OSTI]

V. A key to this approach is the use of a metal-oxide varistor (MOV) to clamp the voltage acrossa givenFast 8 kV metal-oxide semiconductor field-effect transistor switch R. E. Continetti, D. R. Cyr transformer-isolatedpower metal-oxide semiconductor field-effect transistors in seriesis described

Neumark, Daniel M.

105

Prospects and merits of metal-clad semiconductor lasers from nearly UV to far IR  

E-Print Network [OSTI]

Using metal-clad (or plasmonic) waveguide structures in semiconductor lasers carries a promise of reduced size, threshold, and power consumption. This promise is put to a rigorous theoretical test, that takes into account increased waveguide loss, Auger recombination, and Purcell enhancement of spontaneous recombination. The conclusion is that purported benefits of metal waveguides are small to nonexistent for all the band-to-band and intersubband lasers operating from UV to Mid-IR range, with a prominent exception of far-IR and THz quantum cascade lasers. For these devices, however, metal waveguides already represent the state of the art, and the guiding mechanism in them has far more in common with a ubiquitous transmission line than with plasmonics.

Khurgin, Jacob B

2015-01-01T23:59:59.000Z

106

Amorphous silicon enhanced metal-insulator-semiconductor contacts for silicon solar cells  

SciTech Connect (OSTI)

Carrier recombination at the metal-semiconductor contacts has become a significant obstacle to the further advancement of high-efficiency diffused-junction silicon solar cells. This paper provides the proof-of-concept of a procedure to reduce contact recombination by means of enhanced metal-insulator-semiconductor (MIS) structures. Lightly diffused n{sup +} and p{sup +} surfaces are passivated with SiO{sub 2}/a-Si:H and Al{sub 2}O{sub 3}/a-Si:H stacks, respectively, before the MIS contacts are formed by a thermally activated alloying process between the a-Si:H layer and an overlying aluminum film. Transmission/scanning transmission electron microscopy (TEM/STEM) and energy dispersive x-ray spectroscopy are used to ascertain the nature of the alloy. Idealized solar cell simulations reveal that MIS(n{sup +}) contacts, with SiO{sub 2} thicknesses of ?1.55?nm, achieve the best carrier-selectivity producing a contact resistivity ?{sub c} of ?3 m? cm{sup 2} and a recombination current density J{sub 0c} of ?40 fA/cm{sup 2}. These characteristics are shown to be stable at temperatures up to 350?C. The MIS(p{sup +}) contacts fail to achieve equivalent results both in terms of thermal stability and contact characteristics but may still offer advantages over directly metallized contacts in terms of manufacturing simplicity.

Bullock, J., E-mail: james.bullock@anu.edu.au; Cuevas, A.; Yan, D. [Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia); Demaurex, B.; Hessler-Wyser, A.; De Wolf, S. [Ecole Polytechnique Fdrale de Lausanne (EPFL), Institute of Micro Engineering (IMT), Photovoltaics and Thin Film Electronic Laboratory PVLab, Maladire 71b, CH-200 Neuchtel (Switzerland)

2014-10-28T23:59:59.000Z

107

Production of pulsed, mass-selected beams of metal and semiconductor clusters  

SciTech Connect (OSTI)

We report on the development of a beam line for mass-selected metal and semiconductor clusters. The cluster source combines the principles of plasma sputtering and gas condensation. Both techniques together allow to produce clusters in a wide size range. With the aid of a time-of-flight system, small clusters (i.e., Cu{sub n}{sup +}, n<100) are selected and pure beams containing only one cluster size are provided. For large clusters (containing several thousands of atoms), a beam with a narrow size distribution is obtained. A 90 deg. quadrupole deviator is used to separate charged clusters from neutral ones.

Kamalou, Omar; Rangama, Jimmy; Ramillon, Jean-Marc; Guinement, Patrick; Huber, Bernd A. [CIMAP, CEA-CNRS-ENSICaen-UCBN, Bv. Henry Becquerel (B.P. 5133), F-14070 Caen Cedex 05 (France)

2008-06-15T23:59:59.000Z

108

A 10-kW SiC Inverter with A Novel Printed Metal Power Module With Integrated Cooling Using Additive Manufacturing  

SciTech Connect (OSTI)

With efforts to reduce the cost, size, and thermal management systems for the power electronics drivetrain in hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), wide band gap semiconductors including silicon carbide (SiC) have been identified as possibly being a partial solution. This paper focuses on the development of a 10-kW all SiC inverter using a high power density, integrated printed metal power module with integrated cooling using additive manufacturing techniques. This is the first ever heat sink printed for a power electronics application. About 50% of the inverter was built using additive manufacturing techniques.

Chinthavali, Madhu Sudhan [ORNL; Ayers, Curtis William [ORNL; Campbell, Steven L [ORNL; Wiles, Randy H [ORNL; Ozpineci, Burak [ORNL

2014-01-01T23:59:59.000Z

109

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium titanate  

E-Print Network [OSTI]

AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors using barium strontium-effect transistors have been formed by incorporating barium strontium titanate (BST) deposited by rf magnetron in increased leakage. Due to its large dielectric constant, barium strontium ti- tanate [Ba1-xSrxTiO3, (BST

York, Robert A.

110

Transient radiation hardened CMOS (complementary metal oxide semiconductor) operational amplifiers. Master's thesis  

SciTech Connect (OSTI)

General strategies are developed for designing radiation hardened bulk and silicon on insulator (SOI) complementary metal oxide semiconductor (CMOS) operational amplifiers. Comparisons are made between each technology concerning photocurrent mechanisms and the inherent advantages of SOI CMOS. Methods are presented for analysing circuit designs and minimizing the net photocurrent responses. Analysis is performed on standard operational amplifier circuits and subcircuits to demonstrate the usefulness of these methods. Radiation hardening topics discussed include superior radiation hardened topologies, photocurrent compensation and its limitations, and methods to ensure a preferred direction of photocurrent response. Several operational amplifier subcircuits are compared for their hardness characteristics. Folded cascode and three-stage operational amplifiers were fabricated on an SOI CMOS test chip supported by Texas Instruments, Incorporated. At the time of publication, the circuit operation was verified but radiation data were not yet available.

Trombley, G.J.

1989-01-01T23:59:59.000Z

111

Physics of band-gap formation and its evolution in the pillar-based phononic crystal structures  

SciTech Connect (OSTI)

In this paper, the interplay of Bragg scattering and local resonance is theoretically studied in a phononic crystal (PnC) structure composed of a silicon membrane with periodic tungsten pillars. The comparison of phononic band gaps (PnBGs) in three different lattice types (i.e., square, triangular, and honeycomb) with different pillar geometries shows that different PnBGs have varying degrees of dependency on the lattice symmetry based on the interplay of the local resonances and the Bragg effect. The details of this interplay is discussed. The significance of locally resonating pillars, specially in the case of tall pillars, on PnBGs is discussed and verified by examining the PnBG position and width in perturbed lattices via Monte Carlo simulations. It is shown that the PnBGs caused by the local resonance of the pillars are more resilient to the lattice perturbations than those caused by Bragg scattering.

Pourabolghasem, Reza; Mohammadi, Saeed; Eftekhar, Ali Asghar; Adibi, Ali [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Khelif, Abdelkrim [Institut FEMTO-ST, Universit de Franche-Comt, CNRS, 32 Avenue de l'Observatoire, 25044 Besanon Cedex (France)

2014-07-07T23:59:59.000Z

112

Conductivity and optical band gaps of polyethylene oxide doped with Li{sub 2}SO{sub 4} salt  

SciTech Connect (OSTI)

The conductivity and optical properties of Li{sub 2}SO{sub 4} doped polyethylene oxide (PEO) films were studied. The polymer electrolyte films are prepared using solution casting technique. The material phase change was confirmed by X-ray diffraction (XRD) technique. Optical absorption study was conducted using UV- Vis. Spectroscopy in the wavelength range 1901100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.814.51eV and 4.843.43eV respectively with increasing the Li{sub 2}SO{sub 4}. The conductivity found to increases with increasing the dopant concentration due to strong hopping mechanism at room temperature.

Chapi, Sharanappa, E-mail: dehu2010@gmail.com; Raghu, S., E-mail: dehu2010@gmail.com; Subramanya, K., E-mail: dehu2010@gmail.com; Archana, K., E-mail: dehu2010@gmail.com; Mini, V., E-mail: dehu2010@gmail.com; Devendrappa, H., E-mail: dehu2010@gmail.com [Dept. of Physics, Mangalore University, Mangalagangothri-574199 (India)

2014-04-24T23:59:59.000Z

113

Investigation of anisotropic photonic band gaps in three-dimensional magnetized plasma photonic crystals containing the uniaxial material  

SciTech Connect (OSTI)

In this paper, the dispersive properties of three-dimensional (3D) magnetized plasma photonic crystals (MPPCs) composed of anisotropic dielectric (the uniaxial material) spheres immersed in homogeneous magnetized plasma background with face-centered-cubic (fcc) lattices are theoretically investigated by the plane wave expansion method, as the Voigt effects of magnetized plasma are considered. The equations for calculating the anisotropic photonic band gaps (PBGs) in the first irreducible Brillouin zone are theoretically deduced. The anisotropic PBGs and two flatbands regions can be obtained. The effects of the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency, and external magnetic field on the dispersive properties of the 3D MPPCs are investigated in detail, respectively, and some corresponding physical explanations are also given. The numerical results show that the anisotropy can open partial band gaps in 3D MPPCs with fcc lattices and the complete PBGs can be found compared to the conventional 3D MPPCs doped by the isotropic material. The bandwidths of PBGs can be tuned by introducing the magnetized plasma into 3D PCs containing the uniaxial material. It is also shown that the anisotropic PBGs can be manipulated by the ordinary-refractive index, extraordinary-refractive index, filling factor, plasma frequency, and external magnetic field, respectively. The locations of flatbands regions cannot be manipulated by any parameters except for the plasma frequency and external magnetic field. Introducing the uniaxial material can obtain the complete PBGs as the 3D MPPCs with high symmetry and also provides a way to design the tunable devices.

Zhang, Hai-Feng [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China) [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China)] [China; Liu, Shao-Bin; Kong, Xiang-Kun [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)] [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

2013-09-15T23:59:59.000Z

114

Band-gap nonlinear optical generation: The structure of internal optical field and the structural light focusing  

SciTech Connect (OSTI)

A novel approach for the enhancement of nonlinear optical effects inside globular photonic crystals (PCs) is proposed and systematically studied via numerical simulations. The enhanced optical harmonic generation is associated with two- and three-dimensional PC pumping with the wavelength corresponding to different PC band-gaps. The interactions between light and the PC are numerically simulated using the finite-difference time-domain technique for solving the Maxwell's equations. Both empty and infiltrated two-dimensional PC structures are considered. A significant enhancement of harmonic generation is predicted owing to the highly efficient PC pumping based on the structural light focusing effect inside the PC structure. It is shown that a highly efficient harmonic generation could be attained for both the empty and infiltrated two- and three-dimensional PCs. We are demonstrating the ability for two times enhancement of the parametric decay efficiency, one order enhancement of the second harmonic generation, and two order enhancement of the third harmonic generation in PC structures in comparison to the nonlinear generations in appropriate homogenous media. Obviously, the nonlinear processes should be allowed by the molecular symmetry. The criteria of the nonlinear process efficiency are specified and calculated as a function of pumping wavelength position towards the PC globule diameter. Obtained criterion curves exhibit oscillating characteristics, which indicates that the highly efficient generation corresponds to the various PC band-gap pumping. The highest efficiency of nonlinear conversions could be reached for PC pumping with femtosecond optical pulses; thus, the local peak intensity would be maximized. Possible applications of the observed phenomenon are also discussed.

Zaytsev, Kirill I., E-mail: kirzay@gmail.com; Katyba, Gleb M.; Yakovlev, Egor V.; Yurchenko, Stanislav O., E-mail: st.yurchenko@mail.ru [Bauman Moscow State Technical University, 2nd Baumanskaya str. 5, Moscow 105005 (Russian Federation); Gorelik, Vladimir S. [P. N. Lebedev Physics Institute of the Russian Academy of Sciences, Leninskiy Prospekt 53, Moscow 119991 (Russian Federation)

2014-06-07T23:59:59.000Z

115

Proton-induced transient effects in a metal-semiconductor-metal (MSM) photodetector for optical-based data transfer  

SciTech Connect (OSTI)

The authors present a study of proton transient effects in metal-semiconductor-metal (MSM) photodetectors, which demonstrates their inherent advantage for minimizing Single Event Effects (SEEs) in proton environments. Upset mechanisms are characterized for 830 nm GaAs and 1300 nm InGaAs detectors. Only protons incident at grazing angles are likely to cause a bit errors by direct ionization. The MSM technology appears to be a more robust to single bit errors than thicker 1300 nm p-i-n diode structures which the authors have previously shown to be susceptible to errors from direct ionization events at all angles, and also are relatively high optical powders. For a given receiver, the relative contributions of direct ionization and nuclear reaction upset mechanisms at a specific data rate and optical power are determined by the geometry of the charge collection volume of the detector. The authors show that state-of-the-art p-i-n detectors can also display a reduced sensitivity to direct ionization by incident protons except at grazing angles.

Marshall, C.J. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States); [NRL, Washington, DC (United States); Marshall, P.W.; Carts, M.A. [NRL, Washington, DC (United States)] [NRL, Washington, DC (United States); [SFA, Largo, MD (United States); Reed, R.A.; LaBel, K.A. [NASA/GSFC, Greenbelt, MD (United States)] [NASA/GSFC, Greenbelt, MD (United States)

1998-12-01T23:59:59.000Z

116

Electron-Phonon Coupling and Thermal Conductance at a Metal-Semiconductor Interface: First-principles Analysis  

E-Print Network [OSTI]

The mechanism of heat transfer and the contribution of electron-phonon coupling to thermal conductance of a metal-semiconductor interface remains unclear in the present literature. We report ab initio simulations of a technologically important titanium silicide (metal) - silicon (semiconductor) interface to estimate the Schottky barrier height (SBH), and the strength of electron-phonon and phonon-phonon heat transfer across the interface. The electron and phonon dispersion relations of TiSi$_2$ with C49 structure and the TiSi$_2$-Si interface are obtained using first-principles calculations within the density functional theory (DFT) framework. These are used to estimate electron-phonon linewidths and the associated Eliashberg function that quantifies coupling. We show that the coupling strength of electrons with interfacial phonon modes is of the same order of magnitude as coupling of electrons to phonon modes in the bulk metal, and its contribution to electron-phonon interfacial conductance is comparable to ...

Sadasivam, Sridhar; Fisher, Timothy S

2015-01-01T23:59:59.000Z

117

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Final subcontract report, 1 April 1988--31 March 1990  

SciTech Connect (OSTI)

This report describes work to achieve a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed throughout this work is metal-organic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or it may contain a p-n junction of its own and form the bottom cell of a two-junction tandem solar cell structure. The III-V material for the single-junction case is GaAs, and for the two-junction case it is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include (1) a 17.6%-efficient GaAs-on-Si solar cell; (2) an 18.5%-efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8%-efficient GaAs-on-GaAs solar cell; (4) a 28.7%-efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) the measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. [Spire Corp., Bedford, MA (United States)

1993-07-01T23:59:59.000Z

118

On the sub-band gap optical absorption in heat treated cadmium sulphide thin film deposited on glass by chemical bath deposition technique  

SciTech Connect (OSTI)

The sub-band gap optical absorption in chemical bath deposited cadmium sulphide thin films annealed at different temperatures has been critically analyzed with special reference to Urbach relation. It has been found that the absorption co-efficient of the material in the sub-band gap region is nearly constant up to a certain critical value of the photon energy. However, as the photon energy exceeds the critical value, the absorption coefficient increases exponentially indicating the dominance of Urbach rule. The absorption coefficients in the constant absorption region and the Urbach region have been found to be sensitive to annealing temperature. A critical examination of the temperature dependence of the absorption coefficient indicates two different kinds of optical transitions to be operative in the sub-band gap region. After a careful analyses of SEM images, energy dispersive x-ray spectra, and the dc current-voltage characteristics, we conclude that the absorption spectra in the sub-band gap domain is possibly associated with optical transition processes involving deep levels and the grain boundary states of the material.

Chattopadhyay, P.; Karim, B.; Guha Roy, S. [Department of Electronic Science, University of Calcutta, 92, A.P.C. Road, Kolkata 700009 (India)

2013-12-28T23:59:59.000Z

119

Method to determine the position-dependant metal correction factor for dose-rate equivalent laser testing of semiconductor devices  

DOE Patents [OSTI]

A method reconstructs the charge collection from regions beneath opaque metallization of a semiconductor device, as determined from focused laser charge collection response images, and thereby derives a dose-rate dependent correction factor for subsequent broad-area, dose-rate equivalent, laser measurements. The position- and dose-rate dependencies of the charge-collection magnitude of the device are determined empirically and can be combined with a digital reconstruction methodology to derive an accurate metal-correction factor that permits subsequent absolute dose-rate response measurements to be derived from laser measurements alone. Broad-area laser dose-rate testing can thereby be used to accurately determine the peak transient current, dose-rate response of semiconductor devices to penetrating electron, gamma- and x-ray irradiation.

Horn, Kevin M.

2013-07-09T23:59:59.000Z

120

Size-dependent shifts of the Nel temperature and optical band-gap in NiO nanoparticles  

SciTech Connect (OSTI)

Bulk NiO is a well-known antiferromagnet with Neel temperature T{sub N}(?)?=?524?K and an optical band-gap E{sub g}?=?4.3?eV. With decrease in particle size D from 40?nm to 4?nm of NiO, systematic changes of T{sub N} and E{sub g} are observed and discussed here. From magnetic measurements, the changes in T{sub N} with D are found to fit finite-size scaling equation T{sub N}(D)?=?T{sub N}(?) [1 ? (?{sub o}/D){sup ?}] with ??=?3.2??0.5 and ?{sub o}?=?3.2??0.2?nm, in good agreement with the predictions for a Heisenberg system. The observed blue shifts of E{sub g} with decrease in D reaching E{sub g}?=?5.12?eV for D???4?nm are likely due to quantum confinement and non-stoichiometry.

Thota, Subhash, E-mail: mseehra@wvu.edu, E-mail: subhasht@iitg.ac.in [Department of Physics, Indian Institute of Technology, Guwahati, Assam 781039 (India); Shim, J. H.; Seehra, M. S., E-mail: mseehra@wvu.edu, E-mail: subhasht@iitg.ac.in [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26506 (United States)

2013-12-07T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
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121

Exploring Visible-Light-Responsive Photocatalysts for Water Splitting Based on Novel Band-gap Engineering Strategies  

E-Print Network [OSTI]

Chapter 4 Boron Carbides as Efficient, Metal-Free, Visible-and transition metals, the boron carbide products werex Chapter Boron Carbides as Efficient, Metal-free, Visible-

Liu, Jikai

2013-01-01T23:59:59.000Z

122

Diamond logic inverter with enhancement-mode metal-insulator-semiconductor field effect transistor  

SciTech Connect (OSTI)

A diamond logic inverter is demonstrated using an enhancement-mode hydrogenated-diamond metal-insulator-semiconductor field effect transistor (MISFET) coupled with a load resistor. The gate insulator has a bilayer structure of a sputtering-deposited LaAlO{sub 3} layer and a thin atomic-layer-deposited Al{sub 2}O{sub 3} buffer layer. The source-drain current maximum, extrinsic transconductance, and threshold voltage of the MISFET are measured to be ?40.7?mAmm{sup ?1}, 13.2??0.1?mSmm{sup ?1}, and ?3.1??0.1?V, respectively. The logic inverters show distinct inversion (NOT-gate) characteristics for input voltages ranging from 4.0 to ?10.0?V. With increasing the load resistance, the gain of the logic inverter increases from 5.6 to as large as 19.4. The pulse response against the high and low input voltages shows the inversion response with the low and high output voltages.

Liu, J. W., E-mail: liu.jiangwei@nims.go.jp [International Center for Young Scientists (ICYS), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Liao, M. Y.; Imura, M. [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Watanabe, E.; Oosato, H. [Nanofabrication Platform, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Koide, Y., E-mail: koide.yasuo@nims.go.jp [Optical and Electronic Materials Unit, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Nanofabrication Platform, NIMS, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Center of Materials Research for Low Carbon Emission, NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

2014-08-25T23:59:59.000Z

123

Visible-light absorption and large band-gap bowing of GaN1-xSbx from first principles  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

Applicability of the Ga(Sbx)N1-x alloys for practical realization of photoelectrochemical water splitting is investigated using first-principles density functional theory incorporating the local density approximation and generalized gradient approximation plus the Hubbard U parameter formalism. Our calculations reveal that a relatively small concentration of Sb impurities is sufficient to achieve a significant narrowing of the band gap, enabling absorption of visible light. Theoretical results predict that Ga(Sbx)N1-x alloys with 2-eV band gaps straddle the potential window at moderate to low pH values, thus indicating that dilute Ga(Sbx)N1-x alloys could be potential candidates for splitting water under visible light irradiation.

Sheetz, R. Michael; Richter, Ernst; Andriotis, Antonis N.; Lisenkov, Sergey; Pendyala, Chandrashekhar; Sunkara, Mahendra K.; Menon, Madhu

2011-08-01T23:59:59.000Z

124

Structure and red shift of optical band gap in CdOZnO nanocomposite synthesized by the sol gel method  

SciTech Connect (OSTI)

The structure and the optical band gap of CdOZnO nanocomposites were studied. Characterization using X-ray diffraction (XRD), transmission electron microscopy (TEM) and diffuse reflectance spectroscopy (DRS) analysis confirms that CdO phase is present in the nanocomposites. TEM analysis confirms the formation of spheroidal nanoparticles and nanorods. The particle size was calculated from DebeySherrer?s formula and corroborated by TEM images. FTIR spectroscopy shows residual organic materials (aromatic/Olefinic carbon) from nanocomposites surface. CdO content was modified in the nanocomposites in function of polyvinylalcohol (PVA) added. The optical band gap is found to be red shift from 3.21 eV to 3.11 eV with the increase of CdO content. Photoluminescence (PL) measurements reveal the existence of defects in the synthesized CdOZnO nanocomposites. - Graphical abstract: Optical properties of ZnO, CdO and ZnO/CdO nanoparticles. Display Omitted - Highlights: TEM analysis confirms the presence of spherical nanoparticles and nanorods. The CdO phase is present in the nanocomposites. The band gap of the CdOZnO nanocomposites is slightly red shift with CdO content. PL emission of CdOZnO nanocomposite are associated to structural defects.

Mosquera, Edgar, E-mail: edemova@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Fsicas y Matemticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile); Pozo, Ignacio del, E-mail: ignacio.dpf@gmail.com [Facultad de Ciencias Naturales, Matemticas y del Medio Ambiente, Universidad Tecnolgica Metropolitana, Av. Jos Pedro Alessandri 1242, Santiago (Chile); Morel, Mauricio, E-mail: mmorel@ing.uchile.cl [Laboratorio de Materiales a Nanoescala, Departamento de Ciencia de los Materiales, Facultad de Ciencias Fsicas y Matemticas, Universidad de Chile, Av. Tupper 2069, Santiago (Chile)

2013-10-15T23:59:59.000Z

125

Mechanistic Studies of Charge Injection from Metallic Electrodes into Organic Semiconductors Mediated by Ionic Functionalities: Final Report  

SciTech Connect (OSTI)

Metal-organic semiconductor interfaces are important because of their ubiquitous role in determining the performance of modern electronics such as organic light emitting diodes (OLEDs), fuel cells, batteries, field effect transistors (FETs), and organic solar cells. Interfaces between metal electrodes required for external wiring to the device and underlying organic structures directly affect the charge carrier injection/collection efficiency in organic-based electronic devices primarily due to the mismatch between energy levels in the metal and organic semiconductor. Environmentally stable and cost-effective electrode materials, such as aluminum and gold typically exhibit high potential barriers for charge carriers injection into organic devices leading to increased operational voltages in OLEDs and FETs and reduced charge extraction in photovoltaic devices. This leads to increased power consumption by the device, reduced overall efficiency, and decreased operational lifetime. These factors represent a significant obstacle for development of next generation of cheap and energy-efficient components based on organic semiconductors. It has been noticed that introduction of organic materials with conjugated backbone and ionic pendant groups known as conjugated poly- and oligoelectrolytes (CPEs and COEs), enables one to reduce the potential barriers at the metal-organic interface and achieve more efficient operation of a device, however exact mechanisms of the phenomenon have not been understood. The goal of this project was to delineate the function of organic semiconductors with ionic groups as electron injection layers. The research incorporated a multidisciplinary approach that encompassed the creation of new materials, novel processing techniques, examination of fundamental electronic properties and the incorporation of the resulting knowledgebase into development of novel organic electronic devices with increased efficiency, environmental stability, and reduced cost. During the execution of the project, main efforts were focused on the synthesis of new charge-bearing organic materials, such as CPEs and COEs, and block copolymers with neutral and ionic segments, studies of mechanisms responsible for the charge injection modulation in devices with ionic interlayers, and use of naturally occurring charged molecules for creation of enhanced devices. The studies allowed PIs to demonstrate the usefulness of the proposed approach for the improvement of operational parameters in model OLED and FET systems resulting in increased efficiency, decreased contact resistance, and possibility to use stable metals for fabrication of device electrodes. The successful proof-of-the-principle results potentially promise development of light-weight, low fabrication cost devices which can be used in consumer applications such as displays, solar cells, and printed electronic devices. Fundamental mechanisms responsible for the phenomena observed have been identified thus advancing the fundamental knowledgebase.

Nguyen, Thuc-Quyen [UCSB; Bazan, Guillermo [UCSB; Mikhailovsky, Alexander [UCSB

2014-04-15T23:59:59.000Z

126

Dilute magnetic semiconductor and half-metal behaviour mediated by 3d transition-metal doped in black/blue phosphorene  

E-Print Network [OSTI]

Using first-principles calculations, we present a theoretical study of the structural, electronic and magnetic properties of 3d transition metal (TM) atoms interacting with phosphorus monovacancies in two-dimensional black/blue phosphorene. We pay special attention to the magnetic properties of these substitutional impurities and find that they can be fully understood by a simple model based on the Hund's rule. For TM-doped black phosphorene, the calculated band structures of substitutional Ti, Cr, Mn, Fe and Ni impurities show dilute magnetic semiconductor (DMS) properties while those of substitutional Sc, V and Co impurities show nonmagnetic property. For TM-doped blue phosphorene, the calculated band structures of substitutional V, Cr, Mn and Fe impurities show DMS properties, and those of substitutional Ti and Ni impurities show half-metal properties, while Sc and V impurities show nonmagnetic property. We identify three different regimes associated with the occupation of different phosphorus-metal hybrid...

Yu, Weiyang; Niu, Chun-Yao; Li, Chong; Cho, Jun-Hyung; Jia, Yu

2015-01-01T23:59:59.000Z

127

Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector  

SciTech Connect (OSTI)

This paper presents a multichannel, time-resolved picosecond laser ultrasound system that uses a custom complementary metal-oxide-semiconductor linear array detector. This novel sensor allows parallel phase-sensitive detection of very low contrast modulated signals with performance in each channel comparable to that of a discrete photodiode and a lock-in amplifier. Application of the instrument is demonstrated by parallelizing spatial measurements to produce two-dimensional thickness maps on a layered sample, and spectroscopic parallelization is demonstrated by presenting the measured Brillouin oscillations from a gallium arsenide wafer. This paper demonstrates the significant advantages of our approach to pump probe systems, especially picosecond ultrasonics.

Smith, Richard J.; Light, Roger A.; Johnston, Nicholas S.; Pitter, Mark C.; Somekh, Mike G. [Institute of Biophysics, Imaging and Optical Science, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom); Sharples, Steve D. [Applied Optics Group, Electrical Systems and Optics Research Division, University of Nottingham, Nottinghamshire NG7 2RD (United Kingdom)

2010-02-15T23:59:59.000Z

128

Ballistic performance comparison of monolayer transition metal dichalcogenide MX{sub 2} (M = Mo, W; X = S, Se, Te) metal-oxide-semiconductor field effect transistors  

SciTech Connect (OSTI)

We study the transport properties of monolayer MX{sub 2} (M?=?Mo, W; X?=?S, Se, Te) n- and p-channel metal-oxide-semiconductor field effect transistors (MOSFETs) using full-band ballistic non-equilibrium Green's function simulations with an atomistic tight-binding Hamiltonian with hopping potentials obtained from density functional theory. We discuss the subthreshold slope, drain-induced barrier lowering (DIBL), as well as gate-induced drain leakage (GIDL) for different monolayer MX{sub 2} MOSFETs. We also report the possibility of negative differential resistance behavior in the output characteristics of nanoscale monolayer MX{sub 2} MOSFETs.

Chang, Jiwon; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

2014-02-28T23:59:59.000Z

129

Diverse and tunable electronic structures of single-layer metal phosphorus trichalcogenides for photocatalytic water splitting  

SciTech Connect (OSTI)

The family of bulk metal phosphorus trichalcogenides (APX{sub 3}, A = M{sup II}, M{sub 0.5}{sup I}M{sub 0.5}{sup III}; X = S, Se; M{sup I}, M{sup II}, and M{sup III} represent Group-I, Group-II, and Group-III metals, respectively) has attracted great attentions because such materials not only own magnetic and ferroelectric properties, but also exhibit excellent properties in hydrogen storage and lithium battery because of the layered structures. Many layered materials have been exfoliated into two-dimensional (2D) materials, and they show distinct electronic properties compared with their bulks. Here we present a systematical study of single-layer metal phosphorus trichalcogenides by density functional theory calculations. The results show that the single layer metal phosphorus trichalcogenides have very low formation energies, which indicates that the exfoliation of single layer APX{sub 3} should not be difficult. The family of single layer metal phosphorus trichalcogenides exhibits a large range of band gaps from 1.77 to 3.94 eV, and the electronic structures are greatly affected by the metal or the chalcogenide atoms. The calculated band edges of metal phosphorus trichalcogenides further reveal that single-layer ZnPSe{sub 3}, CdPSe{sub 3}, Ag{sub 0.5}Sc{sub 0.5}PSe{sub 3}, and Ag{sub 0.5}In{sub 0.5}PX{sub 3} (X = S and Se) have both suitable band gaps for visible-light driving and sufficient over-potentials for water splitting. More fascinatingly, single-layer Ag{sub 0.5}Sc{sub 0.5}PSe{sub 3} is a direct band gap semiconductor, and the calculated optical absorption further convinces that such materials own outstanding properties for light absorption. Such results demonstrate that the single layer metal phosphorus trichalcogenides own high stability, versatile electronic properties, and high optical absorption, thus such materials have great chances to be high efficient photocatalysts for water-splitting.

Liu, Jian [School of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan (China) [School of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan (China); Beijing Computational Science Research Center, Beijing 100084 (China); College of Electrical and Information Engineering, Hunan Institute of Engineering, Xiangtan 411105, Hunan (China); Li, Xi-Bo; Wang, Da; Liu, Li-Min, E-mail: ppeng@hnu.edu.cn, E-mail: limin.liu@csrc.ac.cn [Beijing Computational Science Research Center, Beijing 100084 (China)] [Beijing Computational Science Research Center, Beijing 100084 (China); Lau, Woon-Ming [Beijing Computational Science Research Center, Beijing 100084 (China) [Beijing Computational Science Research Center, Beijing 100084 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan 610207 (China); Peng, Ping, E-mail: ppeng@hnu.edu.cn, E-mail: limin.liu@csrc.ac.cn [School of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan (China)] [School of Materials Science and Engineering, Hunan University, Changsha 410082, Hunan (China)

2014-02-07T23:59:59.000Z

130

Theory of non-Markovian decay of a cascade atom in high-Q cavities and photonic band-gap materials  

E-Print Network [OSTI]

The dynamics of a three-level atom in a cascade configuration with both transitions coupled to a single structured reservoir of quantized field modes is treated using Laplace transform methods applied to the coupled amplitude equations. Results are also obtained from master equations by two different approaches, that is, involving either pseudomodes or quasimodes. Two different types of reservoir are considered, namely a high-Q cavity and a photonic band-gap system, in which the respective reservoir structure functions involve Lorentzians. Non-resonant transitions are included in the model. In all cases non-Markovian behaviour for the atomic system can be found, such as oscillatory decay for the high-Q cavity case and population trapping for the photonic band-gap case. In the master equation approaches, the atomic system is augmented by a small number of pseudomodes or quasimodes, which in the quasimode approach themselves undergo Markovian relaxation into a flat reservoir of continuum quasimodes. Results from these methods are found to be identical to those from the Laplace transform method including two-photon excitation of the reservoir with both emitting sequences. This shows that complicated non-Markovian decays of an atomic system into structured EM field reservoirs can be described by Markovian models for the atomic system coupled to a small number of pseudomodes or quasimodes.

B. M. Garraway; B. J. Dalton

2006-02-13T23:59:59.000Z

131

Experimental study on vertical scaling of InAs-on-insulator metal-oxide-semiconductor field-effect transistors  

SciTech Connect (OSTI)

We have investigated effects of the vertical scaling on electrical properties in extremely thin-body InAs-on-insulator (-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs). It is found that the body thickness (T{sub body}) scaling provides better short channel effect (SCE) control, whereas the T{sub body} scaling also causes the reduction of the mobility limited by channel thickness fluctuation (?T{sub body}) scattering (?{sub fluctuation}). Also, in order to achieve better SCEs control, the thickness of InAs channel layer (T{sub channel}) scaling is more favorable than the thickness of MOS interface buffer layer (T{sub buffer}) scaling from a viewpoint of a balance between SCEs control and ?{sub fluctuation} reduction. These results indicate necessity of quantum well channel structure in InAs-OI MOSFETs and these should be considered in future transistor design.

Kim, SangHyeon, E-mail: dadembyora@mosfet.t.u-tokyo.ac.jp, E-mail: sh-kim@kist.re.kr; Yokoyama, Masafumi; Nakane, Ryosho; Takenaka, Mitsuru; Takagi, Shinichi [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ichikawa, Osamu; Osada, Takenori; Hata, Masahiko [Sumitomo Chemical Co., Ltd., 6 Kitahara, Tsukuba, Ibaraki 300-3294 (Japan)

2014-06-30T23:59:59.000Z

132

Photo-response of a P3HT:PCBM blend in metal-insulator-semiconductor capacitors  

SciTech Connect (OSTI)

Metal-insulator-semiconductor capacitors are investigated, in which the insulator is cross-linked polyvinylphenol and the active layer a blend of poly(3-hexylthiophene), P3HT, and the electron acceptor [6,6]-phenyl-C{sub 61}-butyric acid methyl ester (PCBM). Admittance spectra and capacitance-voltage measurements obtained in the dark both display similar behaviour to those previously observed in P3HT-only devices. However, the photo-capacitance response is significantly enhanced in the P3HT:PCBM case, where exciton dissociation leads to electron transfer into the PCBM component. The results are consistent with a network of PCBM aggregates that is continuous through the film but with no lateral interconnection between the aggregates at or near the blend/insulator interface.

Devynck, M.; Rostirolla, B.; Watson, C. P.; Taylor, D. M., E-mail: d.m.taylor@bangor.ac.uk [School of Electronic Engineering, Bangor University, Dean Street, Bangor, Gwynedd LL57 1UT (United Kingdom)

2014-11-03T23:59:59.000Z

133

Electron Transport Behavior on Gate Length Scaling in Sub-50 nm GaAs Metal Semiconductor Field Effect Transistors  

SciTech Connect (OSTI)

Short channel GaAs Metal Semiconductor Field Effect Transistors (MESFETs) have been fabricated with gate length to 20 nm, in order to examine the characteristics of sub-50 nm MESFET scaling. Here the rise in the measured transconductance is mainly attributed to electron velocity overshoot. For gate lengths below 40 nm, however, the transconductance drops suddenly. The behavior of velocity overshoot and its degradation is investigated and simulated by using a transport model based on the retarded Langevin equation (RLE). This indicates the existence of a minimum acceleration length needed for the carriers to reach the overshoot velocity. The argument shows that the source resistance must be included as an internal element, or appropriate boundary condition, of relative importance in any model where the gate length is comparable to the inelastic mean free path of the carriers.

Han, Jaeheon [Department of Electronic Engineering, Kangnam University, 111 Gugal-dong, Giheung-gu, Yongin-city, Gyeonggi-do, Korea 446-702 (Korea, Republic of)

2011-12-23T23:59:59.000Z

134

Selective CO{sub 2} reduction conjugated with H{sub 2}O oxidation utilizing semiconductor/metal-complex hybrid photocatalysts  

SciTech Connect (OSTI)

We developed a new hybrid photocatalyst for CO{sub 2} reduction, which is composed of a semiconductor and a metal complex. In the hybrid photocatalyst, ?G between the position of conduction band minimum (E{sub CBM}) of the semiconductor and the CO{sub 2} reduction potential of the complex is an essential factor for realizing fast electron transfer from the conduction band of semiconductor to metal complex leading to high photocatalytic activity. On the basis of this concept, the hybrid photocatalyst InP/Ru-complex, which functions in aqueous media, was developed. The photoreduction of CO{sub 2} to formate using water as an electron donor and a proton source was successfully achieved as a Z-scheme system by functionally conjugating the InP/Ru-complex photocatalyst for CO{sub 2} reduction with a TiO{sub 2} photocatalyst for water oxidation. The conversion efficiency from solar energy to chemical energy was ca. 0.04%, which approaches that for photosynthesis in a plant. Because this system can be applied to many other inorganic semiconductors and metal-complex catalysts, the efficiency and reaction selectivity can be enhanced by optimization of the electron transfer process including the energy-band configurations, conjugation conformations, and catalyst structures. This electrical-bias-free reaction is a huge leap forward for future practical applications of artificial photosynthesis under solar irradiation to produce organic species.

Morikawa, T., E-mail: morikawa@mosk.tytlabs.co.jp; Sato, S., E-mail: morikawa@mosk.tytlabs.co.jp; Arai, T., E-mail: morikawa@mosk.tytlabs.co.jp; Uemura, K., E-mail: morikawa@mosk.tytlabs.co.jp; Yamanaka, K. I., E-mail: morikawa@mosk.tytlabs.co.jp; Suzuki, T. M., E-mail: morikawa@mosk.tytlabs.co.jp; Kajino, T., E-mail: morikawa@mosk.tytlabs.co.jp; Motohiro, T., E-mail: morikawa@mosk.tytlabs.co.jp [Toyota Central R and D Labs, Inc., Nagakute, Aichi 480-1192 (Japan)

2013-12-10T23:59:59.000Z

135

Direct observation of both contact and remote oxygen scavenging of GeO{sub 2} in a metal-oxide-semiconductor stack  

SciTech Connect (OSTI)

In the path to incorporating Ge based metal-oxide-semiconductor into modern nano-electronics, one of the main issues is the oxide-semiconductor interface quality. Here, the reactivity of Ti on Ge stacks and the scavenging effect of Ti were studied using synchrotron X-ray photoelectron spectroscopy measurements, with an in-situ metal deposition and high resolution transmission electron microscopy imaging. Oxygen removal from the Ge surface was observed both in direct contact as well as remotely through an Al{sub 2}O{sub 3} layer. The scavenging effect was studied in situ at room temperature and after annealing. We find that the reactivity of Ti can be utilized for improved scaling of Ge based devices.

Fadida, S., E-mail: sivanfa@tx.technion.ac.il; Shekhter, P.; Eizenberg, M. [Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa (Israel); Cvetko, D. [Laboratorio TASC/IOM-CNR, Area di ricerca, Trieste (Italy); Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia); Floreano, L.; Verdini, A. [Laboratorio TASC/IOM-CNR, Area di ricerca, Trieste (Italy); Nyns, L.; Van Elshocht, S. [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Kymissis, I. [Department of Electrical Engineering, Columbia University, New York, New York 10027 (United States)

2014-10-28T23:59:59.000Z

136

Interfacial oxide re-growth in thin film metal oxide III-V semiconductor systems  

SciTech Connect (OSTI)

The Al{sub 2}O{sub 3}/GaAs and HfO{sub 2}/GaAs interfaces after atomic layer deposition are studied using in situ monochromatic x-ray photoelectron spectroscopy. Samples are deliberately exposed to atmospheric conditions and interfacial oxide re-growth is observed. The extent of this re-growth is found to depend on the dielectric material and the exposure temperature. Comparisons with previous studies show that ex situ characterization can result in misleading conclusions about the interface reactions occurring during the metal oxide deposition process.

McDonnell, S.; Dong, H.; Hawkins, J. M.; Brennan, B.; Milojevic, M.; Aguirre-Tostado, F. S.; Zhernokletov, D. M.; Hinkle, C. L.; Kim, J.; Wallace, R. M.

2012-04-02T23:59:59.000Z

137

Electronic properties of III-nitride semiconductors: A first-principles investigation using the Tran-Blaha modified Becke-Johnson potential  

SciTech Connect (OSTI)

In this work, we use density functional theory to investigate the influence of semilocal exchange and correlation effects on the electronic properties of III-nitride semiconductors considering zinc-blende and wurtzite crystal structures. We find that the inclusion of such effects through the use of the Tran-Blaha modified Becke-Johnson potential yields an excellent description of the electronic structures of these materials giving energy band gaps which are systematically larger than the ones obtained with standard functionals such as the generalized gradient approximation. The discrepancy between the experimental and theoretical band gaps is then significantly reduced with semilocal exchange and correlation effects. However, the effective masses are overestimated in the zinc-blende nitrides, but no systematic trend is found in the wurtzite compounds. New results for energy band gaps and effective masses of zinc-blende and wurtzite indium nitrides are presented.

Araujo, Rafael B., E-mail: rafaelbna@gmail.com; Almeida, J. S. de, E-mail: jailton-almeida@hotmail.com; Ferreira da Silva, A. [Instituto de Fsica, Universidade Federal da Bahia, Campus Universitrio de Ondina, 40210-340 Salvador, Bahia (Brazil)

2013-11-14T23:59:59.000Z

138

VOLUME 84, NUMBER 19 P H Y S I C A L R E V I E W L E T T E R S 8 MAY 2000 Theory and Experiments on Elastic Band Gaps  

E-Print Network [OSTI]

Investigaciones Científicas (CSIC), Serrano 144, 28006 Madrid, Spain 2 Ames Laboratory, Iowa State University, Ames, Iowa 50011 3 Instituto de Acústica, CSIC, Serrano 144, 28006 Madrid, Spain 4 Instituto de Física Aplicada, CSIC, Serrano 144, 28006 Madrid, Spain (Received 26 February 1999) We study elastic band gaps

139

Hybrid density functional calculations of the band gap of GaxIn1-xN Xifan Wu,1 Eric J. Walter,2 Andrew M. Rappe,3 Roberto Car,1 and Annabella Selloni1  

E-Print Network [OSTI]

Hybrid density functional calculations of the band gap of GaxIn1-xN Xifan Wu,1 Eric J. Walter,2 Andrew M. Rappe,3 Roberto Car,1 and Annabella Selloni1 1Chemistry Department, Princeton University Recent theoretical work has provided evidence that hybrid functionals, which include a fraction of exact

Rappe, Andrew M.

140

Performance analysis of boron nitride embedded armchair graphene nanoribbon metaloxidesemiconductor field effect transistor with Stone Wales defects  

SciTech Connect (OSTI)

We study the performance of a hybrid Graphene-Boron Nitride armchair nanoribbon (a-GNR-BN) n-MOSFET at its ballistic transport limit. We consider three geometric configurations 3p, 3p + 1, and 3p + 2 of a-GNR-BN with BN atoms embedded on either side (2, 4, and 6 BN) on the GNR. Material properties like band gap, effective mass, and density of states of these H-passivated structures are evaluated using the Density Functional Theory. Using these material parameters, self-consistent Poisson-Schrodinger simulations are carried out under the Non Equilibrium Green's Function formalism to calculate the ballistic n-MOSFET device characteristics. For a hybrid nanoribbon of width ?5?nm, the simulated ON current is found to be in the range of 265??A280??A with an ON/OFF ratio 7.1 10{sup 6}7.4 10{sup 6} for a V{sub DD}?=?0.68?V corresponding to 10?nm technology node. We further study the impact of randomly distributed Stone Wales (SW) defects in these hybrid structures and only 2.5% degradation of ON current is observed for SW defect density of 3.18%.

Chanana, Anuja; Sengupta, Amretashis; Mahapatra, Santanu [Nano Scale Device Research Laboratory, Department of Electronic Systems Engineering, Indian Institute of Science, Bangalore 560 012 (India)

2014-01-21T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Band gap of CdTe and Cd{sub 0.9}Zn{sub 0.1}Te crystals  

SciTech Connect (OSTI)

The band gap E{sub g} of the CdTe and Cd{sub 0.9}Zn{sub 0.1}Te crystals and its temperature dependence are determined by optical methods. This is motivated by considerable contradictoriness of the published data, which hampers the interpretation and calculation of characteristics of detectors of X-ray and {gamma} radiation based on these materials (E{sub g} = 1.39-1.54 and 1.51-1.6 eV for CdTe and Cd{sub 0.9}Zn{sub 0.1}Te, respectively). The used procedure of determination of E{sub g} is analyzed from the viewpoint of the influence of the factors leading to inaccuracies in determination of its value. The measurements are performed for well-purified high-quality samples. The acquired data for CdTe (E{sub g} = 1.47-1.48 eV) and Cd{sub 0.9}Zn{sub 0.1}Te (E{sub g} = 1.52-1.53 eV) at room temperature substantially narrow the range of accurate determination of E{sub g}.

Kosyachenko, L. A., E-mail: lakos@chv.ukrpact.net; Sklyarchuk, V. M.; Sklyarchuk, O. V.; Maslyanchuk, O. L. [Chernovtsy National University (Ukraine)

2011-10-15T23:59:59.000Z

142

Band-Gap Reduction and Dopant Interaction in Epitaxial La,Cr Co-doped SrTiO3 Thin Films  

SciTech Connect (OSTI)

We show that by co-doping SrTiO3 (STO) epitaxial thin films with equal amounts of La and Cr it is possible to produce films with an optical band gap ~0.9 eV lower than that of undoped STO. Sr1-xLaxTi1-xCrxO3 thin films were deposited by molecular beam epitaxy and characterized using x-ray photoelectron spectroscopy and x-ray absorption near-edge spectroscopy to show that the Cr dopants are almost exclusively in the Cr3+ oxidation state. Extended x-ray absorption fine structure measurements and theoretical modeling suggest that it is thermodynamically preferred for La and Cr dopants to occupy nearest neighbor A- and B-sites in the lattice. Transport measurements show that the material exhibits variable-range hopping conductivity with high resistivity. These results create new opportunities for the use of doped STO films in photovoltaic and photocatalytic applications.

Comes, Ryan B.; Sushko, Petr; Heald, Steve M.; Colby, Robert J.; Bowden, Mark E.; Chambers, Scott A.

2014-12-03T23:59:59.000Z

143

Gallium arsenide-based ternary compounds and multi-band-gap solar cell research. Annual subcontract report, 15 April 1988--14 June 1990  

SciTech Connect (OSTI)

Aim of this contract is the achievement of a high-efficiency, low-cost solar cell. The basic approach to the problem is centered upon the heteroepitaxial growth of a III-V compound material onto a single-crystal silicon wafer. The growth technique employed is metalorganic chemical vapor deposition. The silicon wafer may serve as a mechanical substrate and ohmic contact for a single-junction device, or may contain a p-n junction of its own and form the bottom cell of a two junction tandem solar cell structure. The III-V material for the single-junction case is GaAs and for the two-junction case is either GaAlAs or GaAsP, either material having the proper composition to yield a band gap of approximately 1.7 eV. Results achieved in this contract include the following: (1) a 17.6% efficient GaAs-on-Si solar cell; (2) an 18.5% efficient GaAs-on-Si concentrator solar cell at 400 suns; (3) a 24.8% efficient GaAs-on-GaAs solar cell; (4) a 28.7% efficient GaAs-on-GaAs concentrator solar cell at 200 suns; (5) measurement of the effects of dislocation density and emitter doping on GaAs cells; and (6) improvements in the growth process to achieve reproducible thin AlGaAs window layers with low recombination velocities and environmental stability.

Vernon, S. [Spire Corp., Bedford, MA (United States)

1993-02-01T23:59:59.000Z

144

Semiconductor nanowires DOI: 10.1002/smll.200500094  

E-Print Network [OSTI]

of a semiconductor Si nanowire, synthesized via the VLS pro- cess, into metallic nickel silicide through parameters. Anisotropic growth of a metal onto a semiconductor nanowire (or a semicon- ductor on a metal approach to prepare metal/semiconductor nano- wire heterostructures by transforming specific sections

Rogers, John A.

145

Photoinduced energy transfer in transition metal complex oligomers  

SciTech Connect (OSTI)

The work done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. The authors have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed them to prepare a variety of other ligands which may have unique applications (vide infra). They have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived (> 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, the authors have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

NONE

1997-06-01T23:59:59.000Z

146

Photoinduced energy transfer in transition metal complex oligomers  

SciTech Connect (OSTI)

The work we have done over the past three years has been directed toward the preparation, characterization and photophysical examination of mono- and bimetallic diimine complexes. The work is part of a broader project directed toward the development of stable, efficient, light harvesting arrays of transition metal complex chromophores. One focus has been the synthesis of rigid bis-bidentate and bis-tridentate bridging ligands. We have managed to make the ligand bphb in multigram quantities from inexpensive starting materials. The synthetic approach used has allowed us prepare a variety of other ligands which may have unique applications (vide infra). We have prepared, characterized and examined the photophysical behavior of Ru(II) and Re(I) complexes of the ligands. Energy donor/acceptor complexes of bphb have been prepared which exhibit nearly activationless energy transfer. Complexes of Ru(II) and Re(I) have also been prepared with other polyunsaturated ligands in which two different long lived ( > 50 ns) excited states exist; results of luminescence and transient absorbance measurements suggest the two states are metal-to-ligand charge transfer and ligand localized {pi}{r_arrow}{pi}* triplets. Finally, we have developed methods to prepare polymetallic complexes which are covalently bound to various surfaces. The long term objective of this work is to make light harvesting arrays for the sensitization of large band gap semiconductors. Details of this work are provided in the body of the report.

NONE

1997-04-01T23:59:59.000Z

147

Process for producing chalcogenide semiconductors  

DOE Patents [OSTI]

A process for producing chalcogenide semiconductor material is disclosed. The process includes forming a base metal layer and then contacting this layer with a solution having a low pH and containing ions from at least one chalcogen to chalcogenize the layer and form the chalcogenide semiconductor material.

Noufi, R.; Chen, Y.W.

1985-04-30T23:59:59.000Z

148

Investigation on edge fringing effect and oxide thickness dependence of inversion current in metal-oxide-semiconductor tunneling diodes with comb-shaped electrodes  

SciTech Connect (OSTI)

A particular edge-dependent inversion current behavior of metal-oxide-semiconductor (MOS) tunneling diodes was investigated utilizing square and comb-shaped electrodes. The inversion tunneling current exhibits the strong dependence on the tooth size of comb-shaped electrodes and oxide thickness. Detailed illustrations of current conduction mechanism are developed by simulation and experimental measurement results. It is found that the electron diffusion current and Schottky barrier height lowering for hole tunneling current both contribute on inversion current conduction. In MOS tunneling photodiode applications, the photoresponse can be improved by decreasing SiO{sub 2} thickness and using comb-shaped electrodes with smaller tooth spacing. Meantime, the high and steady photosensitivity can also be approached by introducing HfO{sub 2} into dielectric stacks.

Lin, Chien-Chih; Hsu, Pei-Lun; Lin, Li; Hwu, Jenn-Gwo, E-mail: jghwu@ntu.edu.tw [Graduate Institute of Electronics Engineering, Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China)

2014-03-28T23:59:59.000Z

149

Theoretical study of influencing factors on the dispersion of bulk band-gap edges and the surface states in topological insulators Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3}  

SciTech Connect (OSTI)

The dispersion of the band-gap edge states in bulk topological insulators Bi{sub 2}Te{sub 3} and Bi{sub 2}Se{sub 3} is considered within density functional theory. The dependences of this dispersion both on the approximation used for an exchange-correlation functional at fixed unit cell parameters and atomic positions and on these parameters and positions that are obtained upon structural relaxation performed using a certain approximated functional are analyzed. The relative position of the Dirac point of topologically protected surface states and the valence band maximum in the surface electronic structure of the topological insulators is discussed.

Rusinov, I. P., E-mail: rusinovip@gmail.com; Nechaev, I. A. [Tomsk State University (Russian Federation); Chulkov, E. V. [Donostia International Physics Center (DIPC) (Spain)

2013-06-15T23:59:59.000Z

150

IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide Semiconductor Field  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON NANOTECHNOLOGY, VOL. 10, NO. 3, MAY 2011 499 TiSi2 Nanocrystal Metal Oxide memory window, faster writing and erasing, and longer retention lifetime as a result of the metallic property of the silicide NCs. Due to thermally stable, CMOS compatible properties, TiSi2 NCs are highly

Yang, Zheng

151

Linker-Induced Anomalous Emission of Organic-Molecule Conjugated Metal-Oxide Nanoparticles  

SciTech Connect (OSTI)

Semiconductor nanoparticles conjugated with organic- and dye-molecules to yield high efficiency visible photoluminescence (PL) hold great potential for many future technological applications. We show that folic acid (FA)-conjugated to nanosize TiO2 and CeO2 particles demonstrates a dramatic increase of photoemission intensity at wavelengths between 500 and 700 nm when derivatized using aminopropyl trimethoxysilane (APTMS) as spacer-linker molecules between the metal oxide and FA. Using density-functional theory (DFT) and time-dependent DFT calculations we demonstrate that the strong increase of the PL can be explained by electronic transitions between the titania surface oxygen vacancy (OV) states and the low-energy excited states of the FA/APTMS molecule anchored onto the surface oxygen bridge sites in close proximity to the OVs. We suggest this scenario to be a universal feature for a wide class of metal oxide nanoparticles, including nanoceria, possessing a similar band gap (3 eV) and with a large surface-vacancy-related density of electronic states. We demonstrate that the molecule-nanoparticle linker can play a crucial role in tuning the electronic and optical properties of nanosystems by bringing optically active parts of the molecule and of the surface close to each other.

Turkowski, Volodymyr; Babu, Suresh; Le, Duy; Kumar, Amit; Haldar, Manas K.; Wagh, Anil V.; Hu, Zhongjian; Karakoti, Ajay S.; Gesquiere, Andre J.; Law, Benedict; Mallik, Sanku; Rahman, Talat S.; Leuenberger, Michael N.; Seal, Sudipta

2012-06-26T23:59:59.000Z

152

Predicted band structures of III-V semiconductors in the wurtzite phase  

SciTech Connect (OSTI)

While non-nitride III-V semiconductors typically have a zinc-blende structure, they may also form wurtzite crystals under pressure or when grown as nanowhiskers. This makes electronic structure calculation difficult since the band structures of wurtzite III-V semiconductors are poorly characterized. We have calculated the electronic band structure for nine III-V semiconductors in the wurtzite phase using transferable empirical pseudopotentials including spin-orbit coupling. We find that all the materials have direct gaps. Our results differ significantly from earlier ab initio calculations, and where experimental results are available (InP, InAs, and GaAs) our calculated band gaps are in good agreement. We tabulate energies, effective masses, and linear and cubic Dresselhaus zero-field spin-splitting coefficients for the zone-center states. The large zero-field spin-splitting coefficients we find may facilitate the development of spin-based devices.

De, A.; Pryor, Craig E. [Department of Physics and Astronomy and Optical Science and Technology Center, University of Iowa, Iowa City, Iowa 52242 (United States)

2010-04-15T23:59:59.000Z

153

Study of microstructure and semiconductor to metallic conductivity transition in solid state sintered Li{sub 0.5}Mn{sub 0.5}Fe{sub 2}O{sub 4??} spinel ferrite  

SciTech Connect (OSTI)

Li{sub 0.5}Mn{sub 0.5}Fe{sub 2}O{sub 4} ferrite has been prepared by solid state sintering route. XRD pattern showed single phased cubic spinel structure. The samples exhibited typical character of plastoferrite with ring shaped surface microstructure. New feature observed in the present ferrite is the frequency activated conductivity transition from semiconductor to metallic state above 800?K. The increase of conductivity with frequency in the semiconducting regime follows Jonscher power law, while decrease of conductivity in metallic regime obeys Drude equation. The conductivity in semiconductor regime has been understood by hopping mechanism of localized charge carriers among the cations in B sites of cubic spinel structure. At higher temperatures, overlapping of electronic orbitals from neighbouring ions and free particle like motion of lighter Li{sup +} ions among interstitial lattices contributed metallic conductivity. The samples provided evidence of localized nature of the charge carriers at lower temperatures and increasing delocalized character with the increase of measurement temperature. From application point of view, such ferrites behave as semiconductor at low temperature and allow electromagnetic wave to pass through, but transform into a metallic reflector with negative dielectric constant at high temperature.

Bhowmik, R. N., E-mail: rnbhowmik.phy@pondiuni.edu.in; Vijayasri, G. [Department of Physics, Pondicherry University, R. Venkataraman Nagar, Kalapet, Puducherry-605 014 (India)

2013-12-14T23:59:59.000Z

154

Lattice mismatched compound semiconductors and devices on silicon  

E-Print Network [OSTI]

III-V compound semiconductors, due to their superior electron mobility, are promising candidates for n-type metal-oxide-semiconductor field effect transistors (MOSFETs). However, the limited size of III-V substrates and ...

Yang, Li, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

155

Features of conduction mechanisms in Si/oligo-{beta}-naphthol/metal heterostructures  

SciTech Connect (OSTI)

Conduction mechanisms in Si-polymer-metal heterostructures with oligo-{beta}-naphthol as a wide band-gap polymer have been studied. The results obtained are explained within the models of hopping transport via trap levels, Schottky emission, and field tunneling emission. Different charge transport mechanisms operate in different temperature ranges and under different electric fields.

Hasannli, Sh. M., E-mail: Hasanli_sh@rambler.ru; Mursakulov, N. N.; Samedova, U. F.; Abdulzade, N. N.; Mamedov, B. A. [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan); Guseynov, R. K. [Ganja State University (Azerbaijan)

2010-07-15T23:59:59.000Z

156

Thin film three-dimensional topological insulator metal-oxide-semiconductor field-effect-transistors: A candidate for sub-10?nm devices  

SciTech Connect (OSTI)

Three-dimensional (3D) topological insulators (TI) are a new state of quantum matter in which surface states reside in the bulk insulating energy bandgap and are protected by time-reversal symmetry. It is possible to create an energy bandgap as a consequence of the interaction between the conduction band and valence band surface states from the opposite surfaces of a TI thin film, and the width of the bandgap can be controlled by the thin film thickness. The formation of an energy bandgap raises the possibility of thin-film TI-based metal-oxide-semiconductor field-effect-transistors (MOSFETs). In this paper, we explore the performance of MOSFETs based on thin film 3D-TI structures by employing quantum ballistic transport simulations using the effective continuous Hamiltonian with fitting parameters extracted from ab-initio calculations. We demonstrate that thin film transistors based on a 3D-TI structure provide similar electrical characteristics compared to a Si-MOSFET for gate lengths down to 10?nm. Thus, such a device can be a potential candidate to replace Si-based MOSFETs in the sub-10?nm regime.

Akhavan, N. D., E-mail: nima.dehdashti@uwa.edu.au; Jolley, G.; Umana-Membreno, G. A.; Antoszewski, J.; Faraone, L. [Department of Electrical, Electronic and Computer Engineering, University of Western Australia, Crawley, WA 6009 (Australia)

2014-08-28T23:59:59.000Z

157

Characterization of device parameters in high-temperature metal-oxide-semiconductor field-effect transistors in. beta. -SiC thin films  

SciTech Connect (OSTI)

Both inversion- and depletion-mode n-channel metal-oxide-semiconductor field-effect transistors (MOSFETs) have been fabricated on ..beta..-SiC thin films grown by chemical-vapor deposition. The inversion-mode devices were made on in situ doped (Al) p-type ..beta..-SiC(100) thin films grown on Si(100) substrates. The depletion-mode MOSFETs were made on n-type ..beta..-SiC(111) thin films grown on the Si(0001) face of a 6H ..cap alpha..-SiC substrates. Stable saturation and low subthreshold currents were achieved at drain-source voltages exceeding 5 and 25 V for the inversion-mode and depletion-mode devices, respectively. The transconductance increased with temperature up to 673 K for the short-gate-length devices, of either mode, and then decreased with further increases in temperature. It is proposed that the transconductances and threshold voltages for the inversion-mode devices are greatly affected by minority-carrier injection from the source. Stable transistor action was observed for both types of devices at temperatures up to 823 K, with the depletion-mode devices operating very well up to 923 K.

Palmour, J.W.; Kong, H.S.; Davis, R.F.

1988-08-15T23:59:59.000Z

158

Positive bias temperature instability in p-type metal-oxide-semiconductor devices with HfSiON/SiO{sub 2} gate dielectrics  

SciTech Connect (OSTI)

We present a detailed investigation on positive-bias temperature stress (PBTS) induced degradation of nitrided hafnium silicate (HfSiON)/SiO{sub 2} gate stack in n{sup +}-poly crystalline silicon (polySi) gate p-type metal-oxide-semiconductor (pMOS) devices. The measurement results indicate that gate dielectric degradation is a composite effect of electron trapping in as-fabricated as well as newly generated neutral traps, resulting a significant amount of stress-induced leakage current and generation of surface states at the Si/SiO{sub 2} interface. Although, a significant amount of interface states are created during PBTS, the threshold voltage (V{sub T}) instability of the HfSiON based pMOS devices is primarily caused by electron trapping and detrapping. It is also shown that PBTS creates both acceptor- and donor-like interface traps via different depassivation mechanisms of the Si{sub 3}???SiH bonds at the Si/SiO{sub 2} interface in pMOS devices. However, the number of donor-like interface traps ?N{sub it}{sup D} is significantly greater than that of acceptor-like interface traps ?N{sup A}{sub it}, resulting the PBTS induced net interface traps as donor-like.

Samanta, Piyas, E-mail: piyas@vcfw.org [Department of Physics, Vidyasagar College for Women, 39 Sankar Ghosh Lane, Kolkata 700 006 (India); Huang, Heng-Sheng; Chen, Shuang-Yuan [Institute of Mechatronic Engineering, National Taipei University of Technology, No. 1, Sec. 3, Chung-Hsiao E. Rd., Taipei 106, Taiwan (China); Liu, Chuan-Hsi [Department of Mechatronic Technology, National Taiwan Normal University, No. 162, Sec. 1, He-Ping E. Rd., Taipei 106, Taiwan (China); Cheng, Li-Wei [Central R and D Division, United Microelectronics Corporation, No. 3, Li-Hsin Rd. II, Hsinchu 300, Taiwan (China)

2014-02-21T23:59:59.000Z

159

Onset of Metallic Behavior in Magnesium Clusters Owen C. Thomas, Weijun Zheng, Shoujun Xu, and Kit H. Bowen, Jr.  

E-Print Network [OSTI]

Onset of Metallic Behavior in Magnesium Clusters Owen C. Thomas, Weijun Zheng, Shoujun Xu, and Kit-selected magnesium cluster anions, Mgn ÿ , over the size range, n 3­35. Their s-p band gaps were observed to close in the finite size re- gime for the case of magnesium. Magnesium is a particu- larly instructive case because

Simons, Jack

160

Sample size requirements for estimating effective dose from computed tomography using solid-state metal-oxide-semiconductor field-effect transistor dosimetry  

SciTech Connect (OSTI)

Purpose: Effective dose (ED) is a widely used metric for comparing ionizing radiation burden between different imaging modalities, scanners, and scan protocols. In computed tomography (CT), ED can be estimated by performing scans on an anthropomorphic phantom in which metal-oxide-semiconductor field-effect transistor (MOSFET) solid-state dosimeters have been placed to enable organ dose measurements. Here a statistical framework is established to determine the sample size (number of scans) needed for estimating ED to a desired precision and confidence, for a particular scanner and scan protocol, subject to practical limitations. Methods: The statistical scheme involves solving equations which minimize the sample size required for estimating ED to desired precision and confidence. It is subject to a constrained variation of the estimated ED and solved using the Lagrange multiplier method. The scheme incorporates measurement variation introduced both by MOSFET calibration, and by variation in MOSFET readings between repeated CT scans. Sample size requirements are illustrated on cardiac, chest, and abdomenpelvis CT scans performed on a 320-row scanner and chest CT performed on a 16-row scanner. Results: Sample sizes for estimating ED vary considerably between scanners and protocols. Sample size increases as the required precision or confidence is higher and also as the anticipated ED is lower. For example, for a helical chest protocol, for 95% confidence and 5% precision for the ED, 30 measurements are required on the 320-row scanner and 11 on the 16-row scanner when the anticipated ED is 4 mSv; these sample sizes are 5 and 2, respectively, when the anticipated ED is 10 mSv. Conclusions: Applying the suggested scheme, it was found that even at modest sample sizes, it is feasible to estimate ED with high precision and a high degree of confidence. As CT technology develops enabling ED to be lowered, more MOSFET measurements are needed to estimate ED with the same precision and confidence.

Trattner, Sigal [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Cheng, Bin [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States)] [Department of Biostatistics, Columbia University Mailman School of Public Health, New York, New York 10032 (United States); Pieniazek, Radoslaw L. [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States)] [Center for Radiological Research, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York 10032 (United States); Hoffmann, Udo [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)] [Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States); Douglas, Pamela S. [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States)] [Department of Medicine, Division of Cardiology, Duke University, Durham, North Carolina 27715 (United States); Einstein, Andrew J., E-mail: andrew.einstein@columbia.edu [Department of Medicine, Division of Cardiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York and Department of Radiology, Columbia University Medical Center and New York-Presbyterian Hospital, New York, New York (United States)

2014-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

A methodology to identify and quantify mobility-reducing defects in 4H-silicon carbide power metal-oxide-semiconductor field-effect transistors  

SciTech Connect (OSTI)

In this paper, we present a methodology for the identification and quantification of defects responsible for low channel mobility in 4H-Silicon Carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs). To achieve this, we use an algorithm based on 2D-device simulations of a power MOSFET, density functional simulations, and measurement data. Using physical modeling of carrier mobility and interface traps, we reproduce the experimental I-V characteristics of a 4H-SiC doubly implanted MOSFET through drift-diffusion simulation. We extract the position of Fermi level and the occupied trap density as a function of applied bias and temperature. Using these inputs, our algorithm estimates the number of possible trap types, their energy levels, and concentrations at 4H-SiC/SiO{sub 2} interface. Subsequently, we use density functional theory (DFT)-based ab initio simulations to identify the atomic make-up of defects causing these trap levels. We study silicon vacancy and carbon di-interstitial defects in the SiC side of the interface. Our algorithm indicates that the D{sub it} spectrum near the conduction band edge (3.25?eV) is composed of three trap types located at 2.82.85?eV, 3.05?eV, and 3.13.2?eV, and also calculates their densities. Based on DFT simulations, this work attributes the trap levels very close to the conduction band edge to the C di-interstitial defect.

Ettisserry, D. P., E-mail: deva@umd.edu; Goldsman, N. [Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742 (United States); Lelis, A. [U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783 (United States)

2014-03-14T23:59:59.000Z

162

Calculation of the electron structure of vacancies and their compensated states in III-VI semiconductors  

SciTech Connect (OSTI)

The Green's functions theory and the bond-orbital model are used as a basis for calculations of the electron structure of local defects-specifically, vacancies and their compensated states in III-VI semiconductors. The energy levels in the band gap are established, and the changes induced in the electron densities in the GaS, GaSe, and InSe semiconductors by anion and cation vacancies and their compensated states are calculated. It is established that, if a vacancy is compensated by an atom of an element from the same subgroup with the same tetrahedral coordination and if the ionic radius of the compensating atom is smaller than that of the substituted atom, the local levels formed by the vacancy completely disappear. It is shown that this mechanism of compensation of vacancies provides a means not only for recovering the parameters of the crystal, but for improving the characteristics of the crystal as well.

Mehrabova, M. A., E-mail: Mehrabova@mail.ru; Madatov, R. S. [Azerbaijan National Academy of Sciences, Institute of Radiation Problems (Azerbaijan)

2011-08-15T23:59:59.000Z

163

Enhanced visible-light absorption of mesoporous TiO2 by co-doping with transition-metal/nitrogen ions  

SciTech Connect (OSTI)

Titanium (IV) oxide, TiO2, has been the object of intense scrutiny for energy applications. TiO2 is inexpensive, non-toxic, and has excellent corrosion resistance when exposed to electrolytes. A major drawback preventing the widespread use TiO2 for photolysis is its relatively large band gap of ~3eV. Only light with wavelengths shorter than 400 nm, which is in the ultraviolet portion of the spectrum, has sufficient energy to be absorbed. Less than 14 percent of the solar irradiation reaching the earth s surface has energy exceeding this band gap. Adding dopants such as transition metals has long been used to reduce the gap and increase photocatalytic activity by accessing the visible part of the solar spectrum. The degree to which the band gap is reduced using transition metals depends in part on the overlap of the d-orbitals of the transition metals with the oxygen p-orbitals. Therefore, doping with anions such as nitrogen to modify the cation-anion orbital overlap is another approach to reduce the gap. Recent studies suggest that using a combination of transition metals and nitrogen as dopants is more effective at introducing intermediate states within the band gap, effectively narrowing it. Here we report the synthesis of mesoporous TiO2 spheres, co-doped with transition metals and nitrogen that exhibit a nearly flat absorbance response across the visible spectrum extending into the near infrared.

Mathis, John [Embry-Riddle Aeronautical University; Bi, Zhonghe [ORNL; Bridges, Craig A [ORNL; Kidder, Michelle [ORNL; Paranthaman, Mariappan Parans [ORNL

2013-01-01T23:59:59.000Z

164

Semiconductor heterojunction band offsets and charge neutrality  

E-Print Network [OSTI]

involving lasers, light emitting diodes, and metal-semiconductor field effect transistors, the models of Schottky and Bardeen correspond only to limiting cases, in which the energy barriers for electrons at the interface respectively vary linearly... of metal-lead sulfide contacts on the polarity of the applied voltage. In the 1930's, Tamm, Mott, Schottky and others developed the basic theory related to surface and interface semiconductor properties. Schottky introduced the first modern model Journal...

Lee, Chomsik

2012-06-07T23:59:59.000Z

165

HAPPY NEW YEAR! Semiconductor Spintronics  

E-Print Network [OSTI]

Semiconductors MnGa S=5/2 moment Mn++ plus hole 200 unit cells Yakunin et al. PRL 96 216806 (2004) #12;Atomic Insulating Metallic Carrier-mediated Long-range Order Ohno, Munekata et al. PRL '89 PRL '92 APL `96 Mechanism;Theory of Spin Hamiltonian Konig et al. PRL (2000), PRB (2002) #12;Envelope Function Theory Light Holes

Nikolic, Branislav K.

166

Wafer-fused semiconductor radiation detector  

DOE Patents [OSTI]

Wafer-fused semiconductor radiation detector useful for gamma-ray and x-ray spectrometers and imaging systems. The detector is fabricated using wafer fusion to insert an electrically conductive grid, typically comprising a metal, between two solid semiconductor pieces, one having a cathode (negative electrode) and the other having an anode (positive electrode). The wafer fused semiconductor radiation detector functions like the commonly used Frisch grid radiation detector, in which an electrically conductive grid is inserted in high vacuum between the cathode and the anode. The wafer-fused semiconductor radiation detector can be fabricated using the same or two different semiconductor materials of different sizes and of the same or different thicknesses; and it may utilize a wide range of metals, or other electrically conducting materials, to form the grid, to optimize the detector performance, without being constrained by structural dissimilarity of the individual parts. The wafer-fused detector is basically formed, for example, by etching spaced grooves across one end of one of two pieces of semiconductor materials, partially filling the grooves with a selected electrical conductor which forms a grid electrode, and then fusing the grooved end of the one semiconductor piece to an end of the other semiconductor piece with a cathode and an anode being formed on opposite ends of the semiconductor pieces.

Lee, Edwin Y. (Livermore, CA); James, Ralph B. (Livermore, CA)

2002-01-01T23:59:59.000Z

167

Semiconductor switch geometry with electric field shaping  

DOE Patents [OSTI]

An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium.

Booth, Rex (Livermore, CA); Pocha, Michael D. (Livermore, CA)

1994-01-01T23:59:59.000Z

168

Semiconductor switch geometry with electric field shaping  

DOE Patents [OSTI]

An optoelectric switch is disclosed that utilizes a cylindrically shaped and contoured GaAs medium or other optically active semiconductor medium to couple two cylindrically shaped metal conductors with flat and flared termination points each having an ovoid prominence centrally extending there from. Coupling the truncated ovoid prominence of each conductor with the cylindrically shaped optically active semiconductor causes the semiconductor to cylindrically taper to a triple junction circular line at the base of each prominence where the metal conductor conjoins with the semiconductor and a third medium such as epoxy or air. Tapering the semiconductor at the triple junction inhibits carrier formation and injection at the triple junction and thereby enables greater current carrying capacity through and greater sensitivity of the bulk area of the optically active medium. 10 figs.

Booth, R.; Pocha, M.D.

1994-08-23T23:59:59.000Z

169

L-asparagine crystals with wide gap semiconductor features: Optical absorption measurements and density functional theory computations  

SciTech Connect (OSTI)

Results of optical absorption measurements are presented together with calculated structural, electronic, and optical properties for the anhydrous monoclinic L-asparagine crystal. Density functional theory (DFT) within the generalized gradient approximation (GGA) including dispersion effects (TS, Grimme) was employed to perform the calculations. The optical absorption measurements revealed that the anhydrous monoclinic L-asparagine crystal is a wide band gap material with 4.95 eV main gap energy. DFT-GGA+TS simulations, on the other hand, produced structural parameters in very good agreement with X-ray data. The lattice parameter differences ?a, ?b, ?c between theory and experiment were as small as 0.020, 0.051, and 0.022, respectively. The calculated band gap energy is smaller than the experimental data by about 15%, with a 4.23 eV indirect band gap corresponding to Z???? and Z???? transitions. Three other indirect band gaps of 4.30 eV, 4.32 eV, and 4.36 eV are assigned to ?3 ???, ?1 ???, and ?2 ??? transitions, respectively. ?-sol computations, on the other hand, predict a main band gap of 5.00 eV, just 50 meV above the experimental value. Electronic wavefunctions mainly originating from O 2pcarboxyl, C 2pside chain, and C 2pcarboxyl orbitals contribute most significantly to the highest valence and lowest conduction energy bands, respectively. By varying the lattice parameters from their converged equilibrium values, we show that the unit cell is less stiff along the b direction than for the a and c directions. Effective mass calculations suggest that hole transport behavior is more anisotropic than electron transport, but the mass values allow for some charge mobility except along a direction perpendicular to the molecular layers of L-asparagine which form the crystal, so anhydrous monoclinic L-asparagine crystals could behave as wide gap semiconductors. Finally, the calculations point to a high degree of optical anisotropy for the absorption and complex dielectric function, with more structured curves for incident light polarized along the 100 and 101 directions.

Zanatta, G.; Gottfried, C. [Departamento de Bioqumica, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre-RS (Brazil)] [Departamento de Bioqumica, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre-RS (Brazil); Silva, A. M. [Universidade Estadual do Piau, 64260-000 Piripiri-Pi (Brazil)] [Universidade Estadual do Piau, 64260-000 Piripiri-Pi (Brazil); Caetano, E. W. S., E-mail: ewcaetano@gmail.com [Instituto de Educao, Cincia e Tecnologia do Cear, 60040-531 Fortaleza-CE (Brazil)] [Instituto de Educao, Cincia e Tecnologia do Cear, 60040-531 Fortaleza-CE (Brazil); Sales, F. A. M.; Freire, V. N. [Departamento de Fsica, Universidade Federal do Cear, Caixa Postal 6030, 60455-760 Fortaleza-CE (Brazil)] [Departamento de Fsica, Universidade Federal do Cear, Caixa Postal 6030, 60455-760 Fortaleza-CE (Brazil)

2014-03-28T23:59:59.000Z

170

On the origin of the two-dimensional electron gas at AlGaN/GaN heterojunctions and its influence on recessed-gate metal-insulator-semiconductor high electron mobility transistors  

SciTech Connect (OSTI)

It is commonly accepted that interface states at the passivation surface of AlGaN/GaN heterostructures play an important role in the formation of the 2DEG density. Several interface state models are cited throughout literature, some with discrete levels, others with different kinds of distributions, or a combination of both. The purpose of this article is to compare the existing interface state models with both direct and indirect measurements of these interface states from literature (e.g., through the hysteresis of transfer characteristics of Metal-Insulator-Semiconductor High Electron Mobility Transistors (MISHEMTs) employing such an interface in the gate region) and Technology Computer Aided Design (TCAD) simulations of 2DEG densities as a function of the AlGaN thickness. The discrepancies between those measurements and TCAD simulations (also those commonly found in literature) are discussed. Then, an alternative model inspired by the Disorder Induced Gap State model for compound semiconductors is proposed. It is shown that defining a deep border trap inside the insulator can solve these discrepancies and that this alternative model can explain the origin of the two dimensional electron gas in combination with a high-quality interface that, by definition, has a low interface state density.

Bakeroot, B., E-mail: Benoit.Bakeroot@elis.ugent.be [Centre for Microsystems Technology (CMST), imec and Ghent University, Technologiepark 914a, 9052 Gent (Belgium); You, S.; Van Hove, M.; De Jaeger, B.; Geens, K.; Stoffels, S.; Decoutere, S. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Wu, T.-L.; Hu, J. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, 3001 Leuven (Belgium)

2014-10-07T23:59:59.000Z

171

Impact of SF{sub 6} plasma treatment on performance of TaN-HfO{sub 2}-InP metal-oxide-semiconductor field-effect transistor  

SciTech Connect (OSTI)

In this work, the experimental impact of SF{sub 6} plasma treatment on the performance of InP metal-oxide-semiconductor field-effect transistors is presented. S and F are incorporated into atomic layer deposited HfO{sub 2} via postgate SF{sub 6} plasma treatment. The decreased subthreshold swing, gate leakage (I{sub g}), and increased effective channel mobility ({mu}{sub eff}) indicate that better interface and bulk oxide quality have been achieved with SF{sub 6} plasma treatment due to the formation of stronger Hf-F bonds. Drive current (I{sub d}), transconductance (G{sub m}), and effective channel mobility ({mu}{sub eff}) are improved by 22.3%, 35%, and 35%, respectively, compared with those of control devices.

Wang Yanzhen; Chen Yenting; Zhao Han; Xue Fei; Zhou Fei; Lee, Jack C. [Department of Electrical and Computer Engineering, Microelectronics Research Center, University of Texas at Austin, Austin, Texas 78758 (United States)

2011-01-24T23:59:59.000Z

172

Method for forming metal contacts  

DOE Patents [OSTI]

Methods of forming metal contacts with metal inks in the manufacture of photovoltaic devices are disclosed. The metal inks are selectively deposited on semiconductor coatings by inkjet and aerosol apparatus. The composite is heated to selective temperatures where the metal inks burn through the coating to form an electrical contact with the semiconductor. Metal layers are then deposited on the electrical contacts by light induced or light assisted plating.

Reddington, Erik; Sutter, Thomas C; Bu, Lujia; Cannon, Alexandra; Habas, Susan E; Curtis, Calvin J; Miedaner, Alexander; Ginley, David S; Van Hest, Marinus Franciscus Antonius Maria

2013-09-17T23:59:59.000Z

173

(Data in thousand metric tons of silicon content unless otherwise noted) Domestic Production and Use: Estimated value of silicon metal and alloys (excluding semiconductor-grade silicon)  

E-Print Network [OSTI]

%; China, 16%; South Africa, 13%; Canada, 12%; and other, 39%. Tariff: Item Number Normal Trade Relations metal: Brazil, 37%; South Africa, 25%; Canada, 14%; Norway, 6%; and other, 18%. Total: Brazil, 20 energy costs. Demand for silicon metal comes primarily from the aluminum and chemical industries

174

Graded core/shell semiconductor nanorods and nanorod barcodes  

DOE Patents [OSTI]

Graded core/shell semiconductor nanorods and shapped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

Alivisatos, A. Paul; Scher, Erik C.; Manna, Liberato

2013-03-26T23:59:59.000Z

175

Graded core/shell semiconductor nanorods and nanorod barcodes  

DOE Patents [OSTI]

Graded core/shell semiconductor nanorods and shaped nanorods are disclosed comprising Group II-VI, Group III-V and Group IV semiconductors and methods of making the same. Also disclosed are nanorod barcodes using core/shell nanorods where the core is a semiconductor or metal material, and with or without a shell. Methods of labeling analytes using the nanorod barcodes are also disclosed.

Alivisatos, A. Paul (Oakland, CA); Scher, Erik C. (San Francisco, CA); Manna, Liberato (Lecce, IT)

2010-12-14T23:59:59.000Z

176

Surface Science Letters Bulk-defect dependent adsorption on a metal oxide surface  

E-Print Network [OSTI]

-6028(01)01067-6 #12;Titanium dioxide is a wide-band gap semicon- ductor (Egap 3 eV) that can easily be reducedSurface Science Letters Bulk-defect dependent adsorption on a metal oxide surface: S/TiO2(1 1 0) E Abstract The adsorption of molecular sulfur on TiO2(1 1 0)(1 ? 1) has been studied with scanning tunneling

Diebold, Ulrike

177

Optical nano-woodpiles: large-area metallic photonic crystals and metamaterials  

E-Print Network [OSTI]

to be flexible and stretch-tuneable without issues of bowing or collapse4,17. They also benefit from a high refractive index contrast due to the metal wires which exhibit negative permittivity below the metals plasma frequency, widening the band gap20,21. Gold... .-H., Kim, Y.-S., Constant, K. & Ho, K.-M. Woodpile metallic photonic crystals fabricated by using soft lithography for tailored thermal emission. Adv. Mater. 19, 791794 (2007). 8. Rinne, S. A., Garcia-Santamaria, F. & Braun, P. V. Embedded cavities...

Ibbotson, Lindsey A.; Demetriadou, Angela; Stephen, Croxall; Hess, Ortwin; Baumberg, Jeremy J.

2015-02-09T23:59:59.000Z

178

High-field electroluminescence in semiconductor tunnel junctions with a Mn-doped GaAs layer  

SciTech Connect (OSTI)

We investigated high-field electroluminescence (EL) in semiconductor tunnel junctions with a Mn-doped GaAs layer (here, referred to as GaAs:Mn). Besides the band-gap emission of GaAs, the EL spectra show visible light emissions with two peaks at 1.94?eV and 2.19?eV, which are caused by d-d transitions of the Mn atoms excited by hot electrons. The threshold voltages for band-gap and visible light EL in the tunnel junctions with a GaAs:Mn electrode are 1.3?V higher than those of GaAs:Mn excited by hot holes in reserve biased p{sup +}-n junctions, which is consistent with the hot carrier transport in the band profiles of these structures. Our EL results at room temperature show that the electron temperature in GaAs:Mn can be as high as ?700?K for a low input electrical power density of 0.4?W/cm{sup 2}, while the lattice temperature of the GaAs:Mn layer can be kept at 340?K.

Hai, Pham Nam [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-0033 (Japan); Yatsui, Takashi; Ohtsu, Motoichi; Tanaka, Masaaki [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Nanophotonics Research Center, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2014-09-21T23:59:59.000Z

179

Mixed semiconductor nanocrystal compositions  

DOE Patents [OSTI]

Composition comprising one or more energy donors and one or more energy acceptors, wherein energy is transferred from the energy donor to the energy acceptor and wherein: the energy acceptor is a colloidal nanocrystal having a lower band gap energy than the energy donor; the energy donor and the energy acceptor are separated by a distance of 40 nm or less; wherein the average peak absorption energy of the acceptor is at least 20 meV greater than the average peak emission energy of the energy donor; and wherein the ratio of the number of energy donors to the number of energy acceptors is from about 2:1 to about 1000:1.

Maskaly, Garry R. (Los Alamos, NM); Schaller, Richard D. (Santa Fe, NM); Klimov, Victor I. (Los Alamos, NM)

2011-02-15T23:59:59.000Z

180

Unitary lens semiconductor device  

DOE Patents [OSTI]

A unitary lens semiconductor device and method. The unitary lens semiconductor device is provided with at least one semiconductor layer having a composition varying in the growth direction for unitarily forming one or more lenses in the semiconductor layer. Unitary lens semiconductor devices may be formed as light-processing devices such as microlenses, and as light-active devices such as light-emitting diodes, photodetectors, resonant-cavity light-emitting diodes, vertical-cavity surface-emitting lasers, and resonant cavity photodetectors.

Lear, Kevin L. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Rare-earth transition-metal intermetallics: Structure-bonding-property relationships  

SciTech Connect (OSTI)

The explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding property relationships. The work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides Re{sub 2-x}Fe{sub 4}Si{sub 14-y} and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi{sub 2}: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb{sub 3}Zn{sub 3.6}Al{sub 7.4}: Partially ordered structure of Tb{sub 3}Zn{sub 3.6}Al{sub 7.4} compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn{sub 39}(Cr{sub x}Al{sub 1-x}){sub 81}: These layered structures are similar to icosahedral Mn-Al quasicrystalline compounds. Therefore, this compound may provide new insights into the formation, composition and structure of quasicrystalline materials.

Han, M.K.

2006-05-06T23:59:59.000Z

182

Rare-Earth Transition-Metal Intermetallics: Structure-bonding-Property Relationships  

SciTech Connect (OSTI)

Our explorations of rare-earth, transition metal intermetallics have resulted in the synthesis and characterization, and electronic structure investigation, as well as understanding the structure-bonding-property relationships. Our work has presented the following results: (1) Understanding the relationship between compositions and properties in LaFe{sub 13-x}Si{sub x} system: A detailed structural and theoretical investigation provided the understanding of the role of a third element on stabilizing the structure and controlling the transformation of cubic NaZn{sub 13}-type structures to the tetragonal derivative, as well as the relationship between the structures and properties. (2) Synthesis of new ternary rare-earth iron silicides RE{sub 2-x}Fe{sub 4}Si{sub 14-y} and proposed superstructure: This compound offers complex structural challenges such as fractional occupancies and their ordering in superstructure. (3) Electronic structure calculation of FeSi{sub 2}: This shows that the metal-semiconductor phase transition depends on the structure. The mechanism of band gap opening is described in terms of bonding and structural distortion. This result shows that the electronic structure calculations are an essential tool for understanding the relationship between structure and chemical bonding in these compounds. (4) Synthesis of new ternary rare-earth Zinc aluminides Tb{sub 3}Zn{sub 3.6}Al{sub 7.4}: Partially ordered structure of Tb{sub 3}Zn{sub 3.6}Al{sub 7.4} compound provides new insights into the formation, composition and structure of rare-earth transition-metal intermetallics. Electronic structure calculations attribute the observed composition to optimizing metal-metal bonding in the electronegative (Zn, Al) framework, while the specific ordering is strongly influenced by specific orbital interactions. (5) Synthesis of new structure type of Zn{sub 39}(Cr{sub x}Al{sub 1-x}){sub 81}: These layered structures are similar to icosahedral Mn-Al quasicrystalline compounds. Therefore, this compound may provide new insights into the formation, composition and structure of quasicrystalline materials.

Mi-Kyung Han

2006-05-01T23:59:59.000Z

183

Role of the dielectric for the charging dynamics of the dielectric/barrier interface in AlGaN/GaN based metal-insulator-semiconductor structures under forward gate bias stress  

SciTech Connect (OSTI)

The high density of defect states at the dielectric/III-N interface in GaN based metal-insulator-semiconductor structures causes tremendous threshold voltage drifts, ?V{sub th}, under forward gate bias conditions. A comprehensive study on different dielectric materials, as well as varying dielectric thickness t{sub D} and barrier thickness t{sub B}, is performed using capacitance-voltage analysis. It is revealed that the density of trapped electrons, ?N{sub it}, scales with the dielectric capacitance under spill-over conditions, i.e., the accumulation of a second electron channel at the dielectric/AlGaN barrier interface. Hence, the density of trapped electrons is defined by the charging of the dielectric capacitance. The scaling behavior of ?N{sub it} is explained universally by the density of accumulated electrons at the dielectric/III-N interface under spill-over conditions. We conclude that the overall density of interface defects is higher than what can be electrically measured, due to limits set by dielectric breakdown. These findings have a significant impact on the correct interpretation of threshold voltage drift data and are of relevance for the development of normally off and normally on III-N/GaN high electron mobility transistors with gate insulation.

Lagger, P., E-mail: peter.lagger@infineon.com [Infineon Technologies Austria AG, Siemensstrae 2, 9500 Villach (Austria); Institute of Solid State Electronics, Vienna University of Technology, Floragasse 7, 1040 Wien (Austria); Steinschifter, P.; Reiner, M.; Stadtmller, M.; Denifl, G.; Ostermaier, C. [Infineon Technologies Austria AG, Siemensstrae 2, 9500 Villach (Austria); Naumann, A.; Mller, J.; Wilde, L.; Sundqvist, J. [Fraunhofer IPMS-CNT, Knigsbrcker Strae 178, 01099 Dresden (Germany); Pogany, D. [Institute of Solid State Electronics, Vienna University of Technology, Floragasse 7, 1040 Wien (Austria)

2014-07-21T23:59:59.000Z

184

Electrical and structural characterization of metal germanides.  

E-Print Network [OSTI]

??Metal-semiconductor contacts have been widely studied in the past 60 years. These structures are of importance in the microelectronics industry. As the scaling down of (more)

Chawanda, Albert

2011-01-01T23:59:59.000Z

185

Semiconductor bridge (SCB) detonator  

DOE Patents [OSTI]

The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length.

Bickes, Jr., Robert W. (Albuquerque, NM); Grubelich, Mark C. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

186

Semiconductor bridge (SCB) detonator  

DOE Patents [OSTI]

The present invention is a low-energy detonator for high-density secondary-explosive materials initiated by a semiconductor bridge (SCB) igniter that comprises a pair of electrically conductive lands connected by a semiconductor bridge. The semiconductor bridge is in operational or direct contact with the explosive material, whereby current flowing through the semiconductor bridge causes initiation of the explosive material. Header wires connected to the electrically-conductive lands and electrical feed-throughs of the header posts of explosive devices, are substantially coaxial to the direction of current flow through the SCB, i.e., substantially coaxial to the SCB length. 3 figs.

Bickes, R.W. Jr.; Grubelich, M.C.

1999-01-19T23:59:59.000Z

187

Thin Film Reliability SEMICONDUCTORS  

E-Print Network [OSTI]

Thin Film Reliability SEMICONDUCTORS Our goal is to develop new ways to evaluate the reliability $250 billion per year. As semiconductor devices become ultra miniaturized, reliability testing becomes-world conditions as possible will enable product designers to better balance performance and reliability

188

REVIEW ARTICLE Semiconductor quantum dot-sensitized  

E-Print Network [OSTI]

of low-cost and high-performance solar cells for sustainable energy sources to re- place fossil fuels has) fabrication methods of QDs, and 4) nanocrystalline photoelectrodes for solar cells. We also make suggestions band gap depending on the QD size, 2) a larger extinction coefficient, 3) higher stability toward water

Cao, Guozhong

189

Features of the band structure and conduction mechanisms in the n-HfNiSn semiconductor heavily doped with Ru  

SciTech Connect (OSTI)

The crystal and electronic structure and energy and kinetic properties of the n-HfNiSn semiconductor heavily doped with a Ru acceptor impurity are investigated in the temperature and Ru concentration ranges T = 80400 K and N{sub A}{sup Ru} ? 9.5 10{sup 19}?5.7 10{sup 20} cm{sup ?3} (x = 00.03), respectively. The mechanism of structural-defect generation is established, which changes the band gap and degree of compensation of the semiconductor and consists in the simultaneous concentration reduction and elimination of donor structural defects by means of the displacement of ?1% of Ni atoms from the Hf (4a) positions, the generation of acceptor structural defects upon the substitution of Ru atoms for Ni atoms in the 4c positions, and the generation of donor defects in the form of vacancies in the Sn (4b) positions. The calculated electronic structure of HfNi{sub 1?x}Ru{sub x}Sn is consistent with the experiment. The results obtained are discussed within the Shklovsky-Efros model for a heavily doped and compensated semiconductor.

Romaka, V. A., E-mail: vromaka@polynet.lviv.ua [National Academy of Sciences of Ukraine, Pidstrygach Institute for Applied Problems in Mechanics and Mathematics (Ukraine); Rogl, P. [Universitt Wien, Institut fr Physikalische Chemie (Austria); Romaka, V. V. [National University Lvivska Politekhnika (Ukraine); Stadnyk, Yu. V. [Ivan Franko National University of Lviv (Ukraine); Korzh, R. O.; Krayovskyy, V. Ya. [National University Lvivska Politekhnika (Ukraine); Horyn, A. M. [Ivan Franko National University of Lviv (Ukraine)

2014-12-15T23:59:59.000Z

190

Conductive layer for biaxially oriented semiconductor film growth  

DOE Patents [OSTI]

A conductive layer for biaxially oriented semiconductor film growth and a thin film semiconductor structure such as, for example, a photodetector, a photovoltaic cell, or a light emitting diode (LED) that includes a crystallographically oriented semiconducting film disposed on the conductive layer. The thin film semiconductor structure includes: a substrate; a first electrode deposited on the substrate; and a semiconducting layer epitaxially deposited on the first electrode. The first electrode includes a template layer deposited on the substrate and a buffer layer epitaxially deposited on the template layer. The template layer includes a first metal nitride that is electrically conductive and has a rock salt crystal structure, and the buffer layer includes a second metal nitride that is electrically conductive. The semiconducting layer is epitaxially deposited on the buffer layer. A method of making such a thin film semiconductor structure is also described.

Findikoglu, Alp T. (Los Alamos, NM); Matias, Vladimir (Santa Fe, NM)

2007-10-30T23:59:59.000Z

191

Invited paper History of Semiconductors  

E-Print Network [OSTI]

AbstractThe history of semiconductors is presented beginning with the first documented observation of a semiconductor effect (Faraday), through the development of the first devices (point-contact rectifiers and transistors, early field-effect transistors) and the theory of semiconductors up to the contemporary devices (SOI and multigate devices). Keywordsband theory, laser, Moores law, semiconductor, transistor.

Lidia ?ukasiak; Andrzej Jakubowski

192

Ferromagnetism in Oxide Semiconductors  

SciTech Connect (OSTI)

In order to become a practical technology, semiconductor spintronics requires the discovery and utilization of ferromagnetic semiconductors which exhibit spin polarization in the majority carrier band at and above room temperature. Intrinsic remanent magnetization would allow spin polarized currents to be propagated in such materials without the need for a continuous magnetic field. However, the discovery and understanding of such materials is proving to be a grand challenge in solid-state science. Indeed, one of the 125 critical unanswered scientific questions recently posed in Science magazine asks, Is it possible to create magnetic semiconductors that work at room temperature?

Chambers, Scott A.; Droubay, Timothy C.; Wang, Chong M.; Rosso, Kevin M.; Heald, Steve M.; Schwartz, S. A.; Kittilstved, Kevin R.; Gamelin, Daniel R.

2006-11-01T23:59:59.000Z

193

Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt  

SciTech Connect (OSTI)

The objective of this research was to investigate the viability of oxide magnetic semiconductors as potential materials for spintronics. We identified some members of the solid solution series of ilmenite (FeTiO3) and hematite (Fe2O3), abbreviated as (IH) for simplicity, for our investigations based on their ferromagnetic and semiconducting properties. With this objective in focus we limited our investigations to the following members of the modified Fe-titanates: IH33 (ilmenitehematite with 33 atomic percent hematite), IH45 (ilmenite-hematite with 45 atomic percent hematite), Mn-substituted ilmenite (Mn-FeTiO3), and Mn-substituted pseudobrookite (Mn- Fe2TiO5). All of them are: 1. wide bandgap semiconductors with band gaps ranging in values between 2.5 to 3.5 eV; 2. n-type semiconductors; 3.they exhibit well defined magnetic hysteresis loops and 4. their magnetic Curie points are greater than 400K. Ceramic, film and single crystal samples were studied and based on their properties we produced varistors (also known as voltage dependent resistors) for microelectronic circuit protection from power surges, three-terminal microelectronic devices capable of generating bipolar currents, and an integrated structured device with controlled magnetic switching of spins. Eleven refereed journal papers, three refereed conference papers and three invention disclosures resulted from our investigations. We also presented invited papers in three international conferences and one national conference. Furthermore two students graduated with Ph.D. degrees, three with M.S. degrees and one with B.S. degree. Also two post-doctoral fellows were actively involved in this research. We established the radiation hardness of our devices in collaboration with a colleague in an HBCU institution, at the Cyclotron Center at Texas A&M University, and at DOE National Labs (Los Alamos and Brookhaven). It is to be appreciated that we met most of our goals and expanded vastly the scope of research by including investigations of Mn-FeTiO3, Mn-Fe2TiO5 and by producing a novel three terminal device capable of generating bipolar currents besides producing radiation resistant varistors and a magnetically switchable device. Furthermore we conclusively established the radiation hardness of the four modified iron titanates we studied. In all our publications, conference and seminar presentations, dissertations and theses sponsorship of DOE has been acknowledged

Dr. R. K. Pandey, Cudworth Endowed Professor (Professor Emeritus of The Unviersity of Alabama)

2008-11-24T23:59:59.000Z

194

Phosphorous doping a semiconductor particle  

DOE Patents [OSTI]

A method (10) of phosphorus doping a semiconductor particle using ammonium phosphate. A p-doped silicon sphere is mixed with a diluted solution of ammonium phosphate having a predetermined concentration. These spheres are dried (16, 18), with the phosphorus then being diffused (20) into the sphere to create either a shallow or deep p-n junction. A good PSG glass layer is formed on the surface of the sphere during the diffusion process. A subsequent segregation anneal process is utilized to strip metal impurities from near the p-n junction into the glass layer. A subsequent HF strip procedure is then utilized to removed the PSG layer. Ammonium phosphate is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirement.

Stevens, Gary Don (18912 Ravenglen Ct, Dallas, TX 75287); Reynolds, Jeffrey Scott (703 Horizon, Murphy, TX 75094)

1999-07-20T23:59:59.000Z

195

Thermal Conductivity of Polycrystalline Semiconductors and Ceramics  

E-Print Network [OSTI]

semiconductors and ceramics with desired thermalthermal conductivity of several polycrystalline semiconductors and ceramics,Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

Wang, Zhaojie

2012-01-01T23:59:59.000Z

196

Picosecond soft X-ray absorption measurement of the photo-inducedinsulator-to-metal transition in VO2.  

SciTech Connect (OSTI)

We directly measure the photoinduced insulator-to-metal transition in VO2 using time-resolved near-edge x-ray absorption. Picosecond pulses of synchrotron radiation are used to detect the redshift in the vanadium L3edge at 516 eV, which is associated with the transient collapse of the low-temperature band gap. We identify a two-component temporal response, corresponding to an ultrafast transformation over a 50 nm surface layer, followed by 40 m/s thermal growth of the metallic phase into the bulk.

Cavalleri, Andrea; Chong, Henry H.W.; Fourmaux, Sylvain; Glover,Thornton E.; Heimann, Phil A.; Kieffer, Jean Claude; Mun, B. Simon; Padmore, Howard A.; Schoenlein, Robert W.

2004-02-01T23:59:59.000Z

197

Metal Oxide Semiconductors for Solar Energy Harvesting.  

E-Print Network [OSTI]

??The correlation between energy consumption and human development illustrates the importance of this societal resource. We will consume more energy in the future. In light (more)

Thimsen, Elijah

2009-01-01T23:59:59.000Z

198

High temperature thermoelectric characterization of III-V semiconductor thin films by oxide bonding  

E-Print Network [OSTI]

-W-N diffusion barrier. A thermoelectric material, thin film ErAs:InGaAlAs metal/semiconductor nanocomposite temperature to 840 K for this material and the results show the thermoelectric power factor multiplied material characterization of semiconductor thin films for thermoelectric power generation, photovoltaic

Bowers, John

199

High-Temperature Thermoelectric Characterization of IIIV Semiconductor Thin Films by Oxide Bonding  

E-Print Network [OSTI]

-temperature thermoelectric charac- terization of thin-film III­V semiconductor materials that suffer from the side- effect-temperature surface passivation, and metallization with a Ti-W-N diffusion barrier. A thermoelectric material, thin-temperature material characterization of semiconductor thin films for thermoelectric power generation, photovoltaic

200

Investigation of abnormal negative threshold voltage shift under positive bias stress in input/output n-channel metal-oxide-semiconductor field-effect transistors with TiN/HfO{sub 2} structure using fast I-V measurement  

SciTech Connect (OSTI)

This letter investigates abnormal negative threshold voltage shifts under positive bias stress in input/output (I/O) TiN/HfO{sub 2} n-channel metal-oxide-semiconductor field-effect transistors using fast I-V measurement. This phenomenon is attributed to a reversible charge/discharge effect in pre-existing bulk traps. Moreover, in standard performance devices, threshold-voltage (V{sub t}) shifts positively during fast I-V double sweep measurement. However, in I/O devices, V{sub t} shifts negatively since electrons escape from bulk traps to metal gate rather than channel electrons injecting to bulk traps. Consequently, decreasing pre-existing bulk traps in I/O devices, which can be achieved by adopting Hf{sub x}Zr{sub 1?x}O{sub 2} as gate oxide, can reduce the charge/discharge effect.

Ho, Szu-Han; Chen, Ching-En; Tseng, Tseung-Yuen [Department of Electronics Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China); Chang, Ting-Chang, E-mail: tcchang@mail.phys.nsysu.edu.tw; Lu, Ying-Hsin; Tsai, Jyun-Yu; Liu, Kuan-Ju [Department of Physics, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Cheng, Osbert; Huang, Cheng-Tung; Lu, Ching-Sen [Device Department, United Microelectronics Corporation, Tainan Science Park, Taiwan (China)

2014-03-17T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Multiband semiconductor compositions for photovoltaic devices  

DOE Patents [OSTI]

The highly mismatched alloy Zn1-yMnyOxTe1-x, 0.ltoreq.y<1 and 0band gap of the Zn1-yMnyTe host. With multiple band gaps that fall within the solar energy spectrum, Zn1-yMnyOxTe1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.

Walukiewicz, Wladyslaw; Yu, Kin Man; Wu, Junqiao

2010-05-04T23:59:59.000Z

202

Multiband semiconductor compositions for photovoltaic devices  

DOE Patents [OSTI]

The highly mismatched alloy Zn.sub.1-yMn.sub.yO.sub.xTe.sub.1-x, 0.ltoreq.y<1 and 0band gap of the Zn.sub.1-yMn.sub.yTe host. With multiple band gaps that fall within the solar energy spectrum, Zn.sub.1-yMn.sub.yO.sub.xTe.sub.1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.

Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA); Wu, Junqiao (Belmont, MA)

2012-03-06T23:59:59.000Z

203

2012 DEFECTS IN SEMICONDUCTORS GORDON RESEARCH CONFERENCE, AUGUST 12-17, 2012  

SciTech Connect (OSTI)

The meeting shall strive to develop and further the fundamental understanding of defects and their roles in the structural, electronic, optical, and magnetic properties of bulk, thin film, and nanoscale semiconductors and device structures. Point and extended defects will be addressed in a broad range of electronic materials of particular current interest, including wide bandgap semiconductors, metal-oxides, carbon-based semiconductors (e.g., diamond, graphene, etc.), organic semiconductors, photovoltaic/solar cell materials, and others of similar interest. This interest includes novel defect detection/imaging techniques and advanced defect computational methods.

GLASER, EVAN

2012-08-17T23:59:59.000Z

204

Kansas Advanced Semiconductor Project  

SciTech Connect (OSTI)

KASP (Kansas Advanced Semiconductor Project) completed the new Layer 0 upgrade for D0, assumed key electronics projects for the US CMS project, finished important new physics measurements with the D0 experiment at Fermilab, made substantial contributions to detector studies for the proposed e+e- international linear collider (ILC), and advanced key initiatives in non-accelerator-based neutrino physics.

Baringer, P.; Bean, A.; Bolton, T.; Horton-Smith, G.; Maravin, Y.; Ratra, B.; Stanton, N.; von Toerne, E.; Wilson, G.

2007-09-21T23:59:59.000Z

205

Structure and electronic properties features of amorphous chalhogenide semiconductor films prepared by ion-plasma spraying  

SciTech Connect (OSTI)

Structure of amorphous chalcogenide semiconductor glassy As-S-Se films, obtained by high-frequency (HF) ion-plasma sputtering has been investigated. It was shown that the length of the atomic structure medium order and local structure were different from the films obtained by thermal vacuum evaporation. Temperature dependence of dark conductivity, as well as the dependence of the spectral transmittance has been studied. Conductivity value was determined at room temperature. Energy activation conductivity and films optical band gap have been calculated. Temperature and field dependence of the drift mobility of charge carriers in the HF As-S-Se films have been shown. Bipolarity of charge carriers drift mobility has been confirmed. Absence of deep traps for electrons in the As{sub 40}Se{sub 30}S{sub 30} spectrum of localized states for films obtained by HF plasma ion sputtering was determined. Bipolar drift of charge carriers was found in amorphous As{sub 40}Se{sub 30}S{sub 30} films obtained by ion-plasma sputtering of high-frequency, unlike the films of these materials obtained by thermal evaporation.

Korobova, N., E-mail: korobova3@mail.ru; Timoshenkov, S. [Department of Microelectronics, National Research University of Electronic Technology (MIET), Zelenograd (Russian Federation); Almasov, N.; Prikhodko, O. [al-Farabi Kazakh National University, Almaty (Kazakhstan); Tsendin, K. [Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation)

2014-10-21T23:59:59.000Z

206

Dielectric function of diluted magnetic semiconductors in the infrared regime  

E-Print Network [OSTI]

We present a study of the dielectric function of metallic (III,Mn)V diluted magnetic semiconductors in the infrared regime. Our theoretical approach is based on the kinetic exchange model for carrier induced (III,Mn)V ferromagnetism. The dielectric...

Aguado, R.; Lopez-Sancho, MP; Sinova, Jairo; Brey, L.

2004-01-01T23:59:59.000Z

207

Correlation between surface chemistry, density and band gap in...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of WO3 films. The XPS analyses indicate the formation of stoichiometric WO3 with tungsten existing in fully oxidized valence state (W6+). However, WO3 films grown at high...

208

Band Gap Optimization of Two-Dimensional Photonic Crystals Using ...  

E-Print Network [OSTI]

Jul 10, 2009 ... proven very important as device components for integrated optics ...... Inhibited spontaneous emission in solid-state physics and electronics.

2009-07-10T23:59:59.000Z

209

Experimental study of photonic band gap accelerator structures  

E-Print Network [OSTI]

This thesis reports theoretical and experimental research on a novel accelerator concept using a photonic bandgap (PBG) structure. Major advances in higher order mode (HOM) damping are required for the next generation of ...

Marsh, Roark A

2009-01-01T23:59:59.000Z

210

Method for Creating Photonic Band Gap Materials - Energy Innovation Portal  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvancedMetamaterialsInnovationEnergy

211

Correlation between surface chemistry, density and band gap in  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed Newcatalyst phases on &gamma;-Al2O3. | EMSLHydrogenin

212

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide ThinIon CoolingSubstrate

213

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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214

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystalline Gallium Oxide ThinIon

215

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAbout »Lab (Newport NewsStyle Substrate-Induced

216

Charge transport mechanisms of graphene/semiconductor Schottky barriers: A theoretical and experimental study  

SciTech Connect (OSTI)

Graphene has been proposed as a material for semiconductor electronic and optoelectronic devices. Understanding the charge transport mechanisms of graphene/semiconductor Schottky barriers will be crucial for future applications. Here, we report a theoretical model to describe the transport mechanisms at the interface of graphene and semiconductors based on conventional semiconductor Schottky theory and a floating Fermi level of graphene. The contact barrier heights can be estimated through this model and be close to the values obtained from the experiments, which are lower than those of the metal/semiconductor contacts. A detailed analysis reveals that the barrier heights are as the function of the interface separations and dielectric constants, and are influenced by the interfacial states of semiconductors. Our calculations show how this behavior of lowering barrier heights arises from the Fermi level shift of graphene induced by the charge transfer owing to the unique linear electronic structure.

Zhong, Haijian; Liu, Zhenghui; Xu, Gengzhao; Shi, Lin; Fan, Yingmin; Yang, Hui [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Xu, Ke, E-mail: kxu2006@sinano.ac.cn; Wang, Jianfeng; Ren, Guoqiang [Suzhou Institute of Nano-Tech and Nano-Bionics, CAS, Suzhou 215123 (China); Suzhou Nanowin Science and Technology Co., Ltd., Suzhou 215123 (China)

2014-01-07T23:59:59.000Z

217

Coated semiconductor devices for neutron detection  

DOE Patents [OSTI]

A device for detecting neutrons includes a semi-insulated bulk semiconductor substrate having opposed polished surfaces. A blocking Schottky contact comprised of a series of metals such as Ti, Pt, Au, Ge, Pd, and Ni is formed on a first polished surface of the semiconductor substrate, while a low resistivity ("ohmic") contact comprised of metals such as Au, Ge, and Ni is formed on a second, opposed polished surface of the substrate. In one embodiment, n-type low resistivity pinout contacts comprised of an Au/Ge based eutectic alloy or multi-layered Pd/Ge/Ti/Au are also formed on the opposed polished surfaces and in contact with the Schottky and ohmic contacts. Disposed on the Schottky contact is a neutron reactive film, or coating, for detecting neutrons. The coating is comprised of a hydrogen rich polymer, such as a polyolefin or paraffin; lithium or lithium fluoride; or a heavy metal fissionable material. By varying the coating thickness and electrical settings, neutrons at specific energies can be detected. The coated neutron detector is capable of performing real-time neutron radiography in high gamma fields, digital fast neutron radiography, fissile material identification, and basic neutron detection particularly in high radiation fields.

Klann, Raymond T. (Bolingbrook, IL); McGregor, Douglas S. (Whitmore Lake, MI)

2002-01-01T23:59:59.000Z

218

Semiconductor radiation detector  

DOE Patents [OSTI]

A semiconductor radiation detector is provided to detect x-ray and light photons. The entrance electrode is segmented by using variable doping concentrations. Further, the entrance electrode is physically segmented by inserting n+ regions between p+ regions. The p+ regions and the n+ regions are individually biased. The detector elements can be used in an array, and the p+ regions and the n+ regions can be biased by applying potential at a single point. The back side of the semiconductor radiation detector has an n+ anode for collecting created charges and a number of p+ cathodes. Biased n+ inserts can be placed between the p+ cathodes, and an internal resistor divider can be used to bias the n+ inserts as well as the p+ cathodes. A polysilicon spiral guard can be implemented surrounding the active area of the entrance electrode or surrounding an array of entrance electrodes.

Patt, Bradley E. (Sherman Oaks, CA); Iwanczyk, Jan S. (Los Angeles, CA); Tull, Carolyn R. (Orinda, CA); Vilkelis, Gintas (Westlake Village, CA)

2002-01-01T23:59:59.000Z

219

Effect of annealing on the kinetic properties and band parameters of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals  

SciTech Connect (OSTI)

The results of studies of the kinetic properties of Hg{sub 1?x?y}Cd{sub x}Eu{sub y}Se semiconductor crystals in the ranges of temperatures T = 77300 K and magnetic fields H = 0.55 kOe before and after heat treatment of the samples in Se vapors are reported. It is established that annealing of the samples in Se vapors induces a decrease in the electron concentration. From the concentration dependence of the electron effective mass at the Fermi level, the band gap, the matrix element of interband interaction, and the electron effective mass at the bottom of the conduction band are determined.

Kovalyuk, T. T., E-mail: tarik-1006@mail.ru; Maistruk, E. V.; Maryanchuk, P. D. [Chernivtsy National University (Ukraine)

2014-12-15T23:59:59.000Z

220

Semiconductor Ion Implanters  

SciTech Connect (OSTI)

In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion. Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

MacKinnon, Barry A. [Isys, 2727 Walsh Ave., Suite 103, Santa Clara, CA 95051 (United States); Ruffell, John P. [Group 3, LLC, Sunnyvale, CA 94086 (United States)

2011-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Anodic Aluminum Oxide Templated Channel Electrodes via Atomic Layer A. B. F. Martinsona,b  

E-Print Network [OSTI]

60439, USA Dye-sensitized solar cells (DSSCs) utilize high surface area metal oxide sintered particle aluminum oxide membranes via atomic layer deposition. Introduction Dye sensitized solar cells (DSSCs) These photoelectrochemical cells use molecular dyes to sensitize high area, wide band gap semiconductor oxide photoanodes

222

Low temperature production of large-grain polycrystalline semiconductors  

DOE Patents [OSTI]

An oxide or nitride layer is provided on an amorphous semiconductor layer prior to performing metal-induced crystallization of the semiconductor layer. The oxide or nitride layer facilitates conversion of the amorphous material into large grain polycrystalline material. Hence, a native silicon dioxide layer provided on hydrogenated amorphous silicon (a-Si:H), followed by deposited Al permits induced crystallization at temperatures far below the solid phase crystallization temperature of a-Si. Solar cells and thin film transistors can be prepared using this method.

Naseem, Hameed A. (Fayetteville, AR); Albarghouti, Marwan (Loudonville, NY)

2007-04-10T23:59:59.000Z

223

Method of passivating semiconductor surfaces  

DOE Patents [OSTI]

A method of passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

Wanlass, Mark W. (Golden, CO)

1990-01-01T23:59:59.000Z

224

Method of passivating semiconductor surfaces  

SciTech Connect (OSTI)

A method is described for passivating Group III-V or II-VI semiconductor compound surfaces. The method includes selecting a passivating material having a lattice constant substantially mismatched to the lattice constant of the semiconductor compound. The passivating material is then grown as an ultrathin layer of passivating material on the surface of the Group III-V or II-VI semiconductor compound. The passivating material is grown to a thickness sufficient to maintain a coherent interface between the ultrathin passivating material and the semiconductor compound. In addition, a device formed from such method is also disclosed.

Wanlass, M.W.

1990-06-19T23:59:59.000Z

225

Noise and synamics in semiconductor lasers  

E-Print Network [OSTI]

In this thesis, theoretical and experimental work on the noise and dynamics in continuous wave and mode-locked semiconductor lasers is presented. The main focus is on semiconductor cascade lasers and semiconductor mode-locked ...

Rana, Farhan, 1971-

2003-01-01T23:59:59.000Z

226

Layered semiconductor neutron detectors  

DOE Patents [OSTI]

Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

Mao, Samuel S; Perry, Dale L

2013-12-10T23:59:59.000Z

227

Avalanche semiconductor radiation detectors  

SciTech Connect (OSTI)

Operation of novel avalanche semiconductor detector, produced on the basis of heterojunctions Si-SiC and Si-Si{sub x}O{sub y} is described. A uniform avalanche process with gain from 10{sup 3} to 10{sup 5} can be reached depending on the conductivity of SiC and Si{sub x}O{sub y} layers. Two types of avalanche photodetectors designed for applications in wavelength range 500--10,00 nm with quantum efficiency 60 {+-} 10% (650 nm) and 200--700 nm with quantum efficiency 60 {+-} 15% (450 nm) are presented.

Sadygov, Z.Y. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation); [Azerbaijan Academy of Sciences, Baku (Azerbaijan). Physics Inst.; Zheleznykh, I.M.; Kirillova, T.A. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research] [Russian Academy of Sciences, Moscow (Russian Federation). Inst. for Nuclear Research; Malakhov, N.A.; Jejer, V.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation)] [Joint Inst. for Nuclear Research, Dubna (Russian Federation)

1996-06-01T23:59:59.000Z

228

Optoelectronic cooling of mechanical modes in a semiconductor nanomembrane  

E-Print Network [OSTI]

Optical cavity cooling of mechanical resonators has recently become a research frontier. The cooling has been realized with a metal-coated silicon microlever via photo-thermal force and subsequently with dielectric objects via radiation pressure. Here we report cavity cooling with a crystalline semiconductor membrane via a new mechanism, in which the cooling force arises from the interaction between the photo-induced electron-hole pairs and the mechanical modes through the deformation potential coupling. The optoelectronic mechanism is so efficient as to cool a mode down to 4 K from room temperature with just 50 uW of light and a cavity with a finesse of 10 consisting of a standard mirror and the sub-wavelength-thick semiconductor membrane itself. The laser-cooled narrow-band phonon bath realized with semiconductor mechanical resonators may open up a new avenue for photonics and spintronics devices.

K. Usami; A. Naesby; T. Bagci; B. Melholt Nielsen; J. Liu; S. Stobbe; P. Lodahl; E. S. Polzik

2010-11-22T23:59:59.000Z

229

Reactive codoping of GaAlInP compound semiconductors  

DOE Patents [OSTI]

A GaAlInP compound semiconductor and a method of producing a GaAlInP compound semiconductor are provided. The apparatus and method comprises a GaAs crystal substrate in a metal organic vapor deposition reactor. Al, Ga, In vapors are prepared by thermally decomposing organometallic compounds. P vapors are prepared by thermally decomposing phospine gas, group II vapors are prepared by thermally decomposing an organometallic group IIA or IIB compound. Group VIB vapors are prepared by thermally decomposing a gaseous compound of group VIB. The Al, Ga, In, P, group II, and group VIB vapors grow a GaAlInP crystal doped with group IIA or IIB and group VIB elements on the substrate wherein the group IIA or IIB and a group VIB vapors produced a codoped GaAlInP compound semiconductor with a group IIA or IIB element serving as a p-type dopant having low group II atomic diffusion.

Hanna, Mark Cooper (Boulder, CO); Reedy, Robert (Golden, CO)

2008-02-12T23:59:59.000Z

230

Chemical nanofabrication: a general route to surface-patterned and free-standing transition metal chalcogenide nanostructures{  

E-Print Network [OSTI]

; such properties are important for battery storage capacity.4 WS2 nanotubes exhibit a red shift in their band gap

Odom, Teri W.

231

Characterization of Amorphous Zinc Tin Oxide Semiconductors....  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Amorphous Zinc Tin Oxide Semiconductors. Characterization of Amorphous Zinc Tin Oxide Semiconductors. Abstract: Amorphous zinc tin oxide (ZTO) was investigated to determine the...

232

Opportunities for Wide Bandgap Semiconductor Power Electronics...  

Energy Savers [EERE]

Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen...

233

Variable temperature semiconductor film deposition  

DOE Patents [OSTI]

A method of depositing a semiconductor material on a substrate is disclosed. The method sequentially comprises (a) providing the semiconductor material in a depositable state such as a vapor for deposition on the substrate; (b) depositing the semiconductor material on the substrate while heating the substrate to a first temperature sufficient to cause the semiconductor material to form a first film layer having a first grain size; (c) continually depositing the semiconductor material on the substrate while cooling the substrate to a second temperature sufficient to cause the semiconductor material to form a second film layer deposited on the first film layer and having a second grain size smaller than the first grain size; and (d) raising the substrate temperature, while either continuing or not continuing to deposit semiconductor material to form a third film layer, to thereby anneal the film layers into a single layer having favorable efficiency characteristics in photovoltaic applications. A preferred semiconductor material is cadmium telluride deposited on a glass/tin oxide substrate already having thereon a film layer of cadmium sulfide.

Li, X.; Sheldon, P.

1998-01-27T23:59:59.000Z

234

Band structure engineering of anatase TiO{sub 2} by metal-assisted P-O coupling  

SciTech Connect (OSTI)

In this work, we demonstrate that the metal-assisted P-O coupling is an effective approach to improve the photoelectrochemical properties of TiO{sub 2}. The (Sc + P) and (In + P) codoping effects on electronic structures and photocatalytic activities of anatase TiO{sub 2} are examined by performing hybrid density functional theory calculations. It is found that the coupling of P dopant with the second-nearest neighboring O atom assisted by acceptor metals (Sc/In) leads to the fully occupied and delocalized intermediate bands within the band gap of anatase TiO{sub 2}, which is driven by the P-O antibonding states (?*). This metal-assisted P-O coupling can prevent the recombination of photogenerated electron-hole pairs and effectively reduce the band gap of TiO{sub 2}. Moreover, the band edge alignments in (Sc + P) and (In + P) codoped anatase TiO{sub 2} are desirable for water-splitting. The calculated optical absorption curves indicate that (Sc + P) and (In + P) codoping in anatase TiO{sub 2} can also effectively enhance the visible light absorption.

Wang, Jiajun; Meng, Qiangqiang [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)] [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Huang, Jing [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); School of Materials and Chemical Engineering, Anhui Jianzhu University, Hefei, Anhui 230601 (China); Li, Qunxiang, E-mail: liqun@ustc.edu.cn; Yang, Jinlong [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China) [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-05-07T23:59:59.000Z

235

Physics with isotopically controlled semiconductors  

SciTech Connect (OSTI)

This paper is based on a tutorial presentation at the International Conference on Defects in Semiconductors (ICDS-25) held in Saint Petersburg, Russia in July 2009. The tutorial focused on a review of recent research involving isotopically controlled semiconductors. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, is the most prominent effect for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples.

Haller, E. E., E-mail: eehaller@lbl.gov [University of California at Berkeley, Department of Materials Science and Engineering (United States)

2010-07-15T23:59:59.000Z

236

LCD, low-temperature soldering and compound semiconductor : the sources, market, applications and future prospects of indium in Malaysia  

E-Print Network [OSTI]

Indium is a minor but very valuable metal. Decreasing supplies of indium from refining and increasing demands from LCD, low-temperature soldering and compound semiconductors have stimulated the indium price increase ...

Yong, Foo Nun

2006-01-01T23:59:59.000Z

237

Photoelectrochemistry in particulate systems. 7. Electron-transfer reactions of indium sulfide semiconductor colloids  

SciTech Connect (OSTI)

Small semiconductor colloids of In/sub 2/S/sub 3/ have been prepared in aqueous and nonaqueous media and their absorption properties characterized. A transient photobleaching and formation of S/sup .-/ and S/sub 2/H/sub 2//sup .-/ radicals have been observed upon laser pulse (355 nm) excitation of these colloids. With the aid of transient absorption spectra, the anodic corrosion process in these semiconductor colloids has been elucidated by using laser flash photolysis and pulse radiolysis techniques. With the use of a zwitterionic viologen compound, the interfacial charge-transfer process at the semiconductor surface has been studied. The quantum yield for the reduction of zwitterionic viologen was 0.07, which is similar to the value obtained with other metal chalcogenide semiconductor colloids. The microenvironment of the stabilizer (Nafion) influenced the charge-transfer process between the semiconductor and the redox decay.

Kamat, P.V.; Dimitrijevic, N.M.; Fessenden, R.W.

1988-04-21T23:59:59.000Z

238

Electrodeposited doped II-VI semiconductor films and devices incorporating such films  

SciTech Connect (OSTI)

This patent describes a photovoltaic device. It comprises: a first thin film of a compound semiconductor of a first conductivity type including tellurium and a metal selected from Group IIB of the Periodic Table of Elements and containing as a dopant impurity in a concentration not exceeding 10{sup 20} atoms per cubic centimeter a metal selected from Group IB, a second semiconductor thin film in contact with the first semiconductor thin film and having a second conductivity type opposite that of the first conductivity type and electrical contacts to each of the first and second semiconductor thin films. Also described is the device wherein the first thin film is p-type cadmium telluride.

Ondris, M.; Picher, M.A.; Brownfield, R.E.

1990-03-20T23:59:59.000Z

239

Semiconductor radiation detector  

DOE Patents [OSTI]

A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

Bell, Zane W. (Oak Ridge, TN); Burger, Arnold (Knoxville, TN)

2010-03-30T23:59:59.000Z

240

Semiconductor Bridge Cable Test  

SciTech Connect (OSTI)

The semiconductor bridge (SCB) is an electroexplosive device used to initiate detonators. A C cable is commonly used to connect the SCB to a firing set. A series of tests were performed to identify smaller, lighter cables for firing single and multiple SCBs. This report provides a description of these tests and their results. It was demonstrated that lower threshold voltages and faster firing times can be achieved by increasing the wire size, which reduces ohmic losses. The RF 100 appears to be a reasonable substitute for C cable when firing single SCBs. This would reduce the cable volume by 68% and the weight by 67% while increasing the threshold voltage by only 22%. In general, RG 58 outperforms twisted pair when firing multiple SCBs in parallel. The RG 58's superior performance is attributed to its larger conductor size.

KING, TONY L.

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Semiconductor device PN junction fabrication using optical processing of amorphous semiconductor material  

DOE Patents [OSTI]

Systems and methods for semiconductor device PN junction fabrication are provided. In one embodiment, a method for fabricating an electrical device having a P-N junction comprises: depositing a layer of amorphous semiconductor material onto a crystalline semiconductor base, wherein the crystalline semiconductor base comprises a crystalline phase of a same semiconductor as the amorphous layer; and growing the layer of amorphous semiconductor material into a layer of crystalline semiconductor material that is epitaxially matched to the lattice structure of the crystalline semiconductor base by applying an optical energy that penetrates at least the amorphous semiconductor material.

Sopori, Bhushan; Rangappan, Anikara

2014-11-25T23:59:59.000Z

242

Metallization and insulization during impact  

SciTech Connect (OSTI)

It is pointed out that the large strains produced by hypervelocity impacts can be expected to produce dramatic changes in the chemical bonding (electronic structures) of materials. This will change the mechanical behavior towards increased ductility when a semiconductor is compressed until it becomes metallic; and towards increased brittleness when a transition metal is expanded so as to localize its d-band electrons. Both isotropic compression (expansion) and shear strains can cause these transformations. Critical deformation criteria are given based on the observed cubic to tetragonal transformations in compressed semiconductors.

Gilman, J.J.

1992-10-01T23:59:59.000Z

243

Mathematical Modeling of Semiconductor Devices  

E-Print Network [OSTI]

fibers. Optoelectronic emitters convert an electronic signal into light. Examples are light-emitting diodes (LED) used in displays and indication lambs and semiconductor lasers used in compact disk systems

Jngel, Ansgar

244

Seebeck coefficient in organic semiconductors  

E-Print Network [OSTI]

Seebeck coefficient in organic semiconductors A dissertation submitted for the degree of Doctor of Philosophy Deepak Venkateshvaran Fitzwilliam College & Optoelectronics Group, Cavendish Laboratory University of Cambridge February 2014 The end...

Venkateshvaran, Deepak

2014-07-01T23:59:59.000Z

245

Modeling the semiconductor industry dynamics  

E-Print Network [OSTI]

The semiconductor industry is an exciting and challenging industry. Strong demand at the application end, plus the high capital intensity and rapid technological innovation in manufacturing, makes it difficult to manage ...

Wu, Kailiang

2008-01-01T23:59:59.000Z

246

Microbially-mediated method for synthesis of non-oxide semiconductor nanoparticles  

DOE Patents [OSTI]

The invention is directed to a method for producing non-oxide semiconductor nanoparticles, the method comprising: (a) subjecting a combination of reaction components to conditions conducive to microbially-mediated formation of non-oxide semiconductor nanoparticles, wherein said combination of reaction components comprises i) anaerobic microbes, ii) a culture medium suitable for sustaining said anaerobic microbes, iii) a metal component comprising at least one type of metal ion, iv) a non-metal component containing at least one non-metal selected from the group consisting of S, Se, Te, and As, and v) one or more electron donors that provide donatable electrons to said anaerobic microbes during consumption of the electron donor by said anaerobic microbes; and (b) isolating said non-oxide semiconductor nanoparticles, which contain at least one of said metal ions and at least one of said non-metals. The invention is also directed to non-oxide semiconductor nanoparticle compositions produced as above and having distinctive properties.

Phelps, Tommy J.; Lauf, Robert J.; Moon, Ji Won; Rondinone, Adam J.; Love, Lonnie J.; Duty, Chad Edward; Madden, Andrew Stephen; Li, Yiliang; Ivanov, Ilia N.; Rawn, Claudia Jeanette

2014-06-24T23:59:59.000Z

247

A new family of metal chalogenide thin film electrodes for photoelectrochemical applications  

SciTech Connect (OSTI)

A new family of metal/semiconductor electrocomposite photoelectrodes is described for photoelectrochemical (PEC) applications. These electrocomposites are prepared from an aqueous dispersion containing the targeted metal (in ionic form) and the semiconductor particles. Electrodeposition of the metal affords a matrix in which the semiconductor particles are occluded. This approach is illustrated for nickel/TiO{sub 2} and nickel/CdS model candidates. The influence of preparation variables (deposition potential, temperature, pH, semiconductor content) on the PEC behavior is described.

Rajeshwar, K.; Tacconi, N.R. de [Univ. of Texas, Arlington, TX (United States)

1996-10-01T23:59:59.000Z

248

Electrochemical lithiation and delithiation for control of magnetic properties of nanoscale transition metal oxides  

E-Print Network [OSTI]

Transition metal oxides comprise a fascinating class of materials displaying a variety of magnetic and electronic properties, ranging from half-metallic ferromagnets like CrO2, ferrimagnetic semiconductors like Fey's, and ...

Sivakumar, Vikram

2008-01-01T23:59:59.000Z

249

Wide-Bandgap Semiconductors  

SciTech Connect (OSTI)

With the increase in demand for more efficient, higher-power, and higher-temperature operation of power converters, design engineers face the challenge of increasing the efficiency and power density of converters [1, 2]. Development in power semiconductors is vital for achieving the design goals set by the industry. Silicon (Si) power devices have reached their theoretical limits in terms of higher-temperature and higher-power operation by virtue of the physical properties of the material. To overcome these limitations, research has focused on wide-bandgap materials such as silicon carbide (SiC), gallium nitride (GaN), and diamond because of their superior material advantages such as large bandgap, high thermal conductivity, and high critical breakdown field strength. Diamond is the ultimate material for power devices because of its greater than tenfold improvement in electrical properties compared with silicon; however, it is more suited for higher-voltage (grid level) higher-power applications based on the intrinsic properties of the material [3]. GaN and SiC power devices have similar performance improvements over Si power devices. GaN performs only slightly better than SiC. Both SiC and GaN have processing issues that need to be resolved before they can seriously challenge Si power devices; however, SiC is at a more technically advanced stage than GaN. SiC is considered to be the best transition material for future power devices before high-power diamond device technology matures. Since SiC power devices have lower losses than Si devices, SiC-based power converters are more efficient. With the high-temperature operation capability of SiC, thermal management requirements are reduced; therefore, a smaller heat sink would be sufficient. In addition, since SiC power devices can be switched at higher frequencies, smaller passive components are required in power converters. Smaller heat sinks and passive components result in higher-power-density power converters. With the advent of the use of SiC devices it is imperative that models of these be made available in commercial simulators. This enables power electronic designers to simulate their designs for various test conditions prior to fabrication. To build an accurate transistor-level model of a power electronic system such as an inverter, the first step is to characterize the semiconductor devices that are present in the system. Suitable test beds need to be built for each device to precisely test the devices and obtain relevant data that can be used for modeling. This includes careful characterization of the parasitic elements so as to emulate the test setup as closely as possible in simulations. This report is arranged as follows: Chapter 2--The testing and characterization of several diodes and power switches is presented. Chapter 3--A 55-kW hybrid inverter (Si insulated gate bipolar transistor--SiC Schottky diodes) device models and test results are presented. A detailed description of the various test setups followed by the parameter extraction, modeling, and simulation study of the inverter performance is presented. Chapter 4--A 7.5-kW all-SiC inverter (SiC junction field effect transistors (JFET)--SiC Schottky diodes) was built and tested. The models built in Saber were validated using the test data and the models were used in system applications in the Saber simulator. The simulation results and a comparison of the data from the prototype tests are discussed in this chapter. Chapter 5--The duration test results of devices utilized in buck converters undergoing reliability testing are presented.

Chinthavali, M.S.

2005-11-22T23:59:59.000Z

250

Electromagnetic compatibility in semiconductor manufacturing  

SciTech Connect (OSTI)

Electromagnetic Interference (EMI) causes problems in semiconductor manufacturing facilities that range from nuisances to major disruptions of production. In many instances, these issues are addressed in a reactionary rather than proactive manner by individuals who do not have the experience or the equipment necessary to combat EMI problems in a timely, cost effective manner. This approach leads to expensive retrofits, reduced equipment availability, long recovery times, and in some cases, line yield impacts. The goal of electromagnetic compatibility (EMC) in semiconductor manufacturing is to ensure that semiconductor process, metrology, and support equipment operate as intended without being affected by electromagnetic disturbances either transmitted through air (radiated interference), or transferred into the equipment via a conductive media (conducted interference). Rather than being neglected until serious issues arise, EMC should be considered in the early stages of facility design, in order to gain the most benefit at the lowest cost.

Montoya, J.A. [Intel Corp., Hillsboro, OR (United States)

1995-12-31T23:59:59.000Z

251

Waste minimization in semiconductor processing  

SciTech Connect (OSTI)

The US semiconductor industry uses 5--7 thousand pounds of arsine annually. Fifty to eighty percent of the arsine used becomes a waste product, which requires abatement. Traditional methods of abatement are reviewed with an emphasis on dry chemical scrubbing. A variety of dry chemical scrubbing materials were evaluated for arsine capacity, using activated carbon as the baseline for comparison. Of the available technologies, dry chemical scrubbing is the most effective means of minimizing arsenic containing waste generated from semiconductor effluents. A copper oxide based media has been identified which has high capacity, high efficiency and treats the spectrum of gases used in MOCVD processes. Reclaim and recovery of spent scrubber media has the potential to drastically reduce arsenic waste from semiconductor manufacturing.

Hardwick, S.J.; Mailloux, J.C. [Novapure Corp., Danbury, CT (United States)

1994-12-31T23:59:59.000Z

252

Optical Properties and Potential Applications of Doped Semiconductor...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Optical Properties and Potential Applications of Doped Semiconductor Nanoparticles. Abstract:...

253

Correlated exciton dynamics in semiconductor nanostructures  

E-Print Network [OSTI]

The absorption and dissipation of energy in semiconductor nanostructures are often determined by excited electron dynamics. In semiconductors, one fundamentally important electronic state is an exciton, an excited electron ...

Wen, Patrick, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

254

Method of preparing nitrogen containing semiconductor material  

DOE Patents [OSTI]

A method of combining group III elements with group V elements that incorporates at least nitrogen from a nitrogen halide for use in semiconductors and in particular semiconductors in photovoltaic cells.

Barber, Greg D.; Kurtz, Sarah R.

2004-09-07T23:59:59.000Z

255

Thin-film solar cell fabricated on a flexible metallic substrate  

DOE Patents [OSTI]

A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

Tuttle, John R.; Noufi, Rommel; Hasoon, Falah S.

2006-05-30T23:59:59.000Z

256

Thin-Film Solar Cell Fabricated on a Flexible Metallic Substrate  

DOE Patents [OSTI]

A thin-film solar cell (10) is provided. The thin-film solar cell (10) comprises a flexible metallic substrate (12) having a first surface and a second surface. A back metal contact layer (16) is deposited on the first surface of the flexible metallic substrate (12). A semiconductor absorber layer (14) is deposited on the back metal contact. A photoactive film deposited on the semiconductor absorber layer (14) forms a heterojunction structure and a grid contact (24) deposited on the heterjunction structure. The flexible metal substrate (12) can be constructed of either aluminium or stainless steel. Furthermore, a method of constructing a solar cell is provided. The method comprises providing an aluminum substrate (12), depositing a semiconductor absorber layer (14) on the aluminum substrate (12), and insulating the aluminum substrate (12) from the semiconductor absorber layer (14) to inhibit reaction between the aluminum substrate (12) and the semiconductor absorber layer (14).

Tuttle, J. R.; Noufi, R.; Hasoon, F. S.

2006-05-30T23:59:59.000Z

257

Searching Room Temperature Ferromagnetism in Wide Gap Semiconductors Fe-doped Strontium Titanate and Zinc Oxide  

E-Print Network [OSTI]

Scientic findings in the very beginning of the millennium are taking us a step further in the new paradigm of technology: spintronics. Upgrading charge-based electronics with the additional degree of freedom of the carriers spin-state, spintronics opens a path to the birth of a new generation of devices with the potential advantages of non-volatility and higher processing speed, integration densities and power efficiency. A decisive step towards this new age lies on the attribution of magnetic properties to semiconductors, the building block of today's electronics, that is, the realization of ferromagnetic semiconductors (FS) with critical temperatures above room temperature. Unfruitful search for intrinsic RT FS lead to the concept of Dilute(d) Magnetic Semiconductors (DMS): ordinary semiconductor materials where 3 d transition metals randomly substitute a few percent of the matrix cations and, by some long-range mechanism, order ferromagnetically. The times are of intense research activity and the last few ...

Pereira, LMC; Wahl, U

258

Sandia National Laboratories: Semiconductor Revolution  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErikGroundbreaking Work onClimateSemiconductor Revolution Semiconductor

259

Semiconductor electrode with improved photostability characteristics  

DOE Patents [OSTI]

An electrode is described for use in photoelectrochemical cells having an electrolyte which includes an aqueous constituent. The electrode consists of a semiconductor and a hydrophobic film disposed between the semiconductor and the aqueous constituent. The hydrophobic film is adapted to permit charges to pass therethrough while substantially decreasing the activity of the aqueous constituent at the semiconductor surface thereby decreasing the photodegradation of the semiconductor electrode.

Frank, A.J.

1985-02-19T23:59:59.000Z

260

Semiconductor nanocrystal-based phagokinetic tracking  

DOE Patents [OSTI]

Methods for determining metabolic properties of living cells through the uptake of semiconductor nanocrystals by cells. Generally the methods require a layer of neutral or hydrophilic semiconductor nanocrystals and a layer of cells seeded onto a culture surface and changes in the layer of semiconductor nanocrystals are detected. The observed changes made to the layer of semiconductor nanocrystals can be correlated to such metabolic properties as metastatic potential, cell motility or migration.

Alivisatos, A Paul; Larabell, Carolyn A; Parak, Wolfgang J; Le Gros, Mark; Boudreau, Rosanne

2014-11-18T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Metal silicide nanoelectromechanical relays for low power applications.  

E-Print Network [OSTI]

??ABSTRACT Scaling down the metal-oxide-semiconductor field effect transistor (MOSFET) has continuously brought lower cost, higher density and increased performance since the 1960s. However, as MOS (more)

Stanford University, Dept. of Electrical; Engineering

2014-01-01T23:59:59.000Z

262

First-principles study of thin magnetic transition-metal silicide films on Si(001) Hua Wu, Peter Kratzer, and Matthias Scheffler  

E-Print Network [OSTI]

First-principles study of thin magnetic transition-metal silicide films on Si(001) Hua Wu, Peter of ferromag- netic FM materials have been suggested for the fabrication of metal/semiconductor heterojunctions s : 75.70. i, 73.20.At, 68.35.Md I. INTRODUCTION Metal-semiconductor heterojunctions have received much

263

Neutron detection using boron gallium nitride semiconductor material  

SciTech Connect (OSTI)

In this study, we developed a new neutron-detection device using a boron gallium nitride (BGaN) semiconductor in which the B atom acts as a neutron converter. BGaN and gallium nitride (GaN) samples were grown by metal organic vapor phase epitaxy, and their radiation detection properties were evaluated. GaN exhibited good sensitivity to ?-rays but poor sensitivity to ?-rays. Moreover, we confirmed that electrons were generated in the depletion layer under neutron irradiation. This resulted in a neutron-detection signal after ?-rays were generated by the capture of neutrons by the B atoms. These results prove that BGaN is useful as a neutron-detecting semiconductor material.

Atsumi, Katsuhiro [Department of Electrical and Electronic Engineering, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Inoue, Yoku; Nakano, Takayuki, E-mail: ttnakan@ipc.shizuoka.ac.jp [Department of Electrical and Materials Science, Graduate School of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8561 (Japan); Mimura, Hidenori; Aoki, Toru [Research Institute of Electronics, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu 432-8011 (Japan)

2014-03-01T23:59:59.000Z

264

Semiconductor bridge (SCB) igniter  

DOE Patents [OSTI]

In an explosive device comprising an explosive material which can be made to explode upon activation by activation means in contact therewith; electrical activation means adaptable for activating said explosive material such that it explodes; and electrical circuitry in operation association with said activation means; there is an improvement wherein said activation means is an electrical material which, at an elevated temperature, has a negative temperature coefficient of electrical resistivity and which has a shape and size and an area of contact with said explosive material sufficient that it has an electrical resistance which will match the resistance requirements of said associated electrical circuitry when said electrical material is operationally associated with said circuitry, and wherein said electrical material is polycrystalline; or said electrical material is crystalline and (a) is mounted on a lattice matched substrate or (b) is partially covered with an intimately contacting metallization area which defines its area of contact with said explosive material.

Bickes, Jr., Robert W. (Albuquerque, NM); Schwarz, Alfred C. (Albuquerque, NM)

1987-01-01T23:59:59.000Z

265

Role of strain on electronic and mechanical response of semiconducting transition-metal dichalcogenide monolayers: An ab-initio study  

SciTech Connect (OSTI)

We characterize the electronic structure and elasticity of monolayer transition-metal dichalcogenides MX{sub 2} (M ?= ?Mo, W, Sn, Hf and X ?= ?S, Se, Te) based on 2H and 1T structures using fully relativistic first principles calculations based on density functional theory. We focus on the role of strain on the band structure and band alignment across the series of materials. We find that strain has a significant effect on the band gap; a biaxial strain of 1% decreases the band gap in the 2H structures, by as a much as 0.2 ?eV in MoS{sub 2} and WS{sub 2}, while increasing it for the 1T cases. These results indicate that strain is a powerful avenue to modulate their properties; for example, strain enables the formation of, otherwise impossible, broken gap heterostructures within the 2H class. These calculations provide insight and quantitative information for the rational development of heterostructures based on this class of materials accounting for the effect of strain.

Guzman, David M.; Strachan, Alejandro, E-mail: strachan@purdue.edu [School of Materials Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907-2044 (United States)

2014-06-28T23:59:59.000Z

266

Mechanical scriber for semiconductor devices  

DOE Patents [OSTI]

A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer.

Lin, Peter T. (East Brunswick, NJ)

1985-01-01T23:59:59.000Z

267

Mechanical scriber for semiconductor devices  

DOE Patents [OSTI]

A mechanical scriber using a scribing tip, such as a diamond, provides controlled scriber forces with a spring-loaded compound lever arrangement. The scribing force and range of scribing depth are adjusted by a pair of adjustable micrometer heads. A semiconductor device, such as a multilayer solar cell, can be formed into scribed strips at each layer. 5 figs.

Lin, P.T.

1985-03-05T23:59:59.000Z

268

Back-side readout semiconductor photomultiplier  

DOE Patents [OSTI]

This disclosure provides systems, methods, and apparatus related to semiconductor photomultipliers. In one aspect, a device includes a p-type semiconductor substrate, the p-type semiconductor substrate having a first side and a second side, the first side of the p-type semiconductor substrate defining a recess, and the second side of the p-type semiconductor substrate being doped with n-type ions. A conductive material is disposed in the recess. A p-type epitaxial layer is disposed on the second side of the p-type semiconductor substrate. The p-type epitaxial layer includes a first region proximate the p-type semiconductor substrate, the first region being implanted with p-type ions at a higher doping level than the p-type epitaxial layer, and a second region disposed on the first region, the second region being doped with p-type ions at a higher doping level than the first region.

Choong, Woon-Seng; Holland, Stephen E

2014-05-20T23:59:59.000Z

269

High-performance self-aligned inversion-channel In{sub 0.53}Ga{sub 0.47}As metal-oxide-semiconductor field-effect-transistors by in-situ atomic-layer-deposited HfO{sub 2}  

SciTech Connect (OSTI)

Self-aligned inversion-channel In{sub 0.53}Ga{sub 0.47}As metal-oxide-semiconductor field-effect-transistors (MOSFETs) have been fabricated using the gate dielectrics of in-situ directly atomic-layer-deposited (ALD) HfO{sub 2} followed by ALD-Al{sub 2}O{sub 3}. There were no surface pretreatments and no interfacial passivation/barrier layers prior to the ALD. TiN/Al{sub 2}O{sub 3} (4?nm)/HfO{sub 2} (1?nm)/In{sub 0.53}Ga{sub 0.47}As/InP MOS capacitors exhibited well-behaved capacitance-voltage characteristics with true inversion behavior, low leakage current densities of ?10{sup ?8}?A/cm{sup 2} at 1?MV/cm, and thermodynamic stability at high temperatures. Al{sub 2}O{sub 3} (3?nm)/HfO{sub 2} (1?nm)/In{sub 0.53}Ga{sub 0.47}As MOSFETs of 1 ?m gate length, with 700?C800?C rapid thermal annealing in source/drain activation, have exhibited high extrinsic drain current (I{sub D}) of 1.5?mA/?m, transconductance (G{sub m}) of 0.84 mS/?m, I{sub ON}/I{sub OFF} of ?10{sup 4}, low sub-threshold swing of 103?mV/decade, and field-effect electron mobility of 1100 cm{sup 2}/V??s. The devices have also achieved very high intrinsic I{sub D} and G{sub m} of 2?mA/?m and 1.2?mS/?m, respectively.

Lin, T. D.; Chang, W. H.; Chang, Y. C.; Hong, M., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Chu, R. L.; Chang, Y. H. [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)] [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Lee, M. Y.; Hong, P. F.; Chen, Min-Cheng [National Nano Device Laboratories, Hsinchu 30076, Taiwan (China)] [National Nano Device Laboratories, Hsinchu 30076, Taiwan (China); Kwo, J., E-mail: raynien@phys.nthu.edu.tw, E-mail: mhong@phys.ntu.edu.tw [Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

2013-12-16T23:59:59.000Z

270

Heterojunction thin films based on multifunctional metal oxides for photovoltaic application  

SciTech Connect (OSTI)

Metal oxides based multifunctional heterojunction thin films of ZnO/SnO{sub 2} and ZnO/SnO{sub 2}/CuO QDs were prepared by spin-coating technique. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The optical absorption studies revealed that the film thickness has considerable effect on the band gap values and is found to be in the range of 3.733.48 eV. The photoluminescence spectra showed several weak visible emission peaks related to the deep level defects (450-575 nm). Finally, the current density-voltage (J-V) characteristic of ZnO/SnO{sub 2}/CuO QDs (ZSCI) based heterojunction thin film coated on ITO is also reported.

Prabhu, M.; Soundararajan, N.; Ramachandran, K. [School of Physics, Madurai Kamaraj University, Madurai - 625021 (India); Marikkannan, M.; Mayandi, J. [School of Chemistry, Madurai Kamaraj University, Madurai - 625021 (India)

2014-04-24T23:59:59.000Z

271

Investigation of redox processes at semiconductor electrode liquid junctions  

SciTech Connect (OSTI)

Research in fundamental aspects of photoelectrochemical cells has been in the following areas: chemical probes for hot carrier processes, electrostatic theory for describing electrical interactions at interfaces, and kinetics of electron transfer at ideal semiconductor solution interfaces. Our goal is to achieve a better understanding of dark and photo-induced current flow at the semiconductor electrode/redox electrolyte interface (SEI) so that devices and processes utilizing this interface for solar energy conversion can be developed or improved. Our most important accomplishment has been the development of a redox system capable of detecting hot electrons at the p-InP/acetonitrile interface. Also, we have examined electrostatic theory for the image potential of an ion as a function of distance from the SEI. Finally, our group was one of the first to realize that the 2-dimensional metal chalcogenides (MC) are excellent materials for fundamental studies of electron transfer at the SEI. One of the chief potential advantages for use of MC's is the formation of semiconductor/liquid junctions with nearly ideal electrochemical properties. 27 refs., 1 fig.

Koval, C.A.

1990-08-01T23:59:59.000Z

272

Spectroscopy of Charge Carriers and Traps in Field-Doped Single Crystal Organic Semiconductors  

SciTech Connect (OSTI)

The proposed research aims to achieve quantitative, molecular level understanding of charge carriers and traps in field-doped crystalline organic semiconductors via in situ linear and nonlinear optical spectroscopy, in conjunction with transport measurements and molecular/crystal engineering. Organic semiconductors are emerging as viable materials for low-cost electronics and optoelectronics, such as organic photovoltaics (OPV), organic field effect transistors (OFETs), and organic light emitting diodes (OLEDs). Despite extensive studies spanning many decades, a clear understanding of the nature of charge carriers in organic semiconductors is still lacking. It is generally appreciated that polaron formation and charge carrier trapping are two hallmarks associated with electrical transport in organic semiconductors; the former results from the low dielectric constants and weak intermolecular electronic overlap while the latter can be attributed to the prevalence of structural disorder. These properties have lead to the common observation of low charge carrier mobilities, e.g., in the range of 10-5 - 10-3 cm2/Vs, particularly at low carrier concentrations. However, there is also growing evidence that charge carrier mobility approaching those of inorganic semiconductors and metals can exist in some crystalline organic semiconductors, such as pentacene, tetracene and rubrene. A particularly striking example is single crystal rubrene (Figure 1), in which hole mobilities well above 10 cm2/Vs have been observed in OFETs operating at room temperature. Temperature dependent transport and spectroscopic measurements both revealed evidence of free carriers in rubrene. Outstanding questions are: what are the structural features and physical properties that make rubrene so unique? How do we establish fundamental design principles for the development of other organic semiconductors of high mobility? These questions are critically important but not comprehensive, as the nature of charge carriers is known to evolve as the carrier concentration increases, due to the presence of intrinsic disorder in organic semiconductors. Thus, a complementary question is: how does the nature of charge transport change as a function of carrier concentration?

Zhu, Xiaoyang

2014-12-10T23:59:59.000Z

273

Characterization and electrical modeling of semiconductors bridges  

SciTech Connect (OSTI)

Semiconductor bridges (SCBs) are finding increased use as initiators for explosive and pyrotechnic devices. They offer advantages in reduced voltage and energy requirements, coupled with excellent safety features. The design of explosive systems which implement either SCBs or metal bridgewires can be facilitated through the use of electrical simulation software such as the PSpice{reg_sign} computer code. A key component in the electrical simulation of such systems is an electrical model of the bridge. This report has two objectives: (1) to present and characterize electrical data taken in tests of detonators which employ SCBs with BNCP as the explosive powder; and (2) to derive appropriate electrical models for such detonators. The basis of such models is a description of the resistance as a function of energy deposited in the SCB. However, two important features which must be added to this are (1) the inclusion of energy loss through such mechanisms as ohmic heating of the aluminum lands and heat transfer from the bridge to the surrounding media; and (2) accounting for energy deposited in the SCB through heat transfer to the bridge from the explosive powder after the powder ignites. The modeling procedure is entirely empirical; i.e., models for the SCB resistance and the energy gain and loss have been estimated from experimental data taken over a range of firing conditions. We present results obtained by applying the model to the simulation of SCB operation in representative tests.

Marx, K.D. [Sandia National Labs., Livermore, CA (United States); Bickes, R.W. Jr.; Wackerbarth, D.E. [Sandia National Labs., Albuquerque, NM (United States)

1997-03-01T23:59:59.000Z

274

Enhanced von Weizscker Wang-Govind-Carter kinetic energy density functional for semiconductors  

SciTech Connect (OSTI)

We propose a new form of orbital-free (OF) kinetic energy density functional (KEDF) for semiconductors that is based on the Wang-Govind-Carter (WGC99) nonlocal KEDF. We enhance within the latter the semi-local von Weizscker KEDF term, which is exact for a single orbital. The enhancement factor we introduce is related to the extent to which the electron density is localized. The accuracy of the new KEDF is benchmarked against Kohn-Sham density functional theory (KSDFT) by comparing predicted energy differences between phases, equilibrium volumes, and bulk moduli for various semiconductors, along with metal-insulator phase transition pressures. We also compare point defect and (100) surface energies in silicon for a broad test of its applicability. This new KEDF accurately reproduces the exact non-interacting kinetic energy of KSDFT with only one additional adjustable parameter beyond the three parameters in the WGC99 KEDF; it exhibits good transferability between semiconducting to metallic silicon phases and between various III-V semiconductors without parameter adjustment. Overall, this KEDF is more accurate than previously proposed OF KEDFs (e.g., the Huang-Carter (HC) KEDF) for semiconductors, while the computational efficiency remains at the level of the WGC99 KEDF (several hundred times faster than the HC KEDF). This accurate, fast, and transferable new KEDF holds considerable promise for large-scale OFDFT simulations of metallic through semiconducting materials.

Shin, Ilgyou [Department of Chemistry, Princeton University, Princeton, New Jersey 08544-1009 (United States)] [Department of Chemistry, Princeton University, Princeton, New Jersey 08544-1009 (United States); Carter, Emily A., E-mail: eac@princeton.edu [Department of Mechanical and Aerospace Engineering, Program in Applied and Computational Mathematics, and Andlinger Center for Energy and the Environment, Princeton University, Princeton, New Jersey 08544-5263 (United States)

2014-05-14T23:59:59.000Z

275

Ferromagnetism in Doped Thin-Film Oxide and Nitride Semiconductors and Dielectrics  

SciTech Connect (OSTI)

The principal goal in the field of high-Tc ferromagnetic semiconductors is the synthesis, characterization and utilization of semiconductors which exhibit substantial carrier spin polarization at and above room temperature. Such materials are of critical importance in the emerging field of semiconductor spintronics. The interaction leading to carrier spin polarization, exchange coupling between the dopant spins and the valence or conduction band, is known to be sufficiently weak in conventional semiconductors, such as GaAs and Si, that magnetic ordering above cryogenic temperatures is essentially impossible. Since the provocative theoretical predictions of Tc above ambient in p-Mn:ZnO and p-Mn:GaN (T. Dietl et al., Science 287 1019 (2000)), and the observation of room-temperature ferromagnetism in Co:TiO2 anatase (Y. Matsumoto et al., Science 291 854 (2001)), there has been a flurry of work in oxides and nitrides doped with transition metals with unpaired d electrons. It has even been claimed that room-temperature ferromagnetism can be obtained in certain d0 transition metals oxides without a dopant. In this Report, the field of transition metal doped oxides and nitrides is critically reviewed and assessed from a materials science perspective. Since much of the field centers around thin film growth, this Report focuses on films prepared not only by conventional vacuum deposition methods, but also by spin coating colloidal nanoparticles.

Chambers, Scott A.

2006-10-01T23:59:59.000Z

276

Stretchable semiconductor elements and stretchable electrical circuits  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Rogers, John A. (Champaign, IL); Khang, Dahl-Young (Seoul, KR); Menard, Etienne (Durham, NC)

2009-07-07T23:59:59.000Z

277

Optical devices featuring textured semiconductor layers  

DOE Patents [OSTI]

A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

Moustakas, Theodore D. (Dover, MA); Cabalu, Jasper S. (Cary, NC)

2012-08-07T23:59:59.000Z

278

Optical devices featuring textured semiconductor layers  

DOE Patents [OSTI]

A semiconductor sensor, solar cell or emitter, or a precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate. The textured layers enhance light extraction or absorption. Texturing in the region of multiple quantum wells greatly enhances internal quantum efficiency if the semiconductor is polar and the quantum wells are grown along the polar direction. Electroluminescence of LEDs of the invention is dichromatic, and results in variable color LEDs, including white LEDs, without the use of phosphor.

Moustakas, Theodore D. (Dover, MA); Cabalu, Jasper S. (Cary, NC)

2011-10-11T23:59:59.000Z

279

Probing Excitonic Dark States in Single-layer Tungsten Disulfide  

E-Print Network [OSTI]

Transition metal dichalcogenide (TMDC) monolayer has recently emerged as an important two-dimensional semiconductor with promising potentials for electronic and optoelectronic devices. Unlike semi-metallic graphene, layered TMDC has a sizable band gap. More interestingly, when thinned down to a monolayer, TMDC transforms from an indirect bandgap to a direct bandgap semiconductor, exhibiting a number of intriguing optical phenomena such as valley selective circular dichroism, doping dependent charged excitons, and strong photocurrent responses. However, the fundamental mechanism underlying such a strong light-matter interaction is still under intensive investigation. The observed optical resonance was initially considered to be band-to-band transitions. In contrast, first-principle calculations predicted a much larger quasiparticle band gap size and an optical response that is dominated by excitonic effects. Here, we report experimental evidence of the exciton dominance mechanism by discovering a series of exc...

Ye, Ziliang; O'Brien, Kevin; Zhu, Hanyu; Yin, Xiaobo; Wang, Yuan; Louie, Steven G; Zhang, Xiang

2014-01-01T23:59:59.000Z

280

Low Energy Ion Implantationin Semiconductor Manufacturing | U...  

Office of Science (SC) Website

Low Energy Ion Implantation in Semiconductor Manufacturing Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science...

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Photon Statistics of Semiconductor Light Sources.  

E-Print Network [OSTI]

??In recent years, semiconductor light sources have become more and more interesting in terms of applications due to their high efficiency and low cost. Advanced (more)

Amann, Marc

2010-01-01T23:59:59.000Z

282

CCEC Seminar Wireless Sensors for SemiconductorWireless Sensors for Semiconductor  

E-Print Network [OSTI]

CCEC Seminar Wireless Sensors for SemiconductorWireless Sensors for Semiconductor Manufacturing perhaps. In this talk, we describe our efforts in developing a new class of wireless sensors for use in semiconductor manufacturing. These sensors are fully self-contained with on board power, communications

Akhmedov, Azer

283

Photovoltaic property of bismuth ferrite thin films and its application in non-volatile memory.  

E-Print Network [OSTI]

??In conventional junction-based photovoltaic cells, the photovoltage is usually smaller than the semiconductor band gap, due to the limitation of the energy barrier at the (more)

Guo, Rui.

2013-01-01T23:59:59.000Z

284

Low Frequency Noise in Nano-Devices  

E-Print Network [OSTI]

device quality, reliability and the degradation processes. The generation- recombination noise which. His current research interests include low frequency noise, wide-band-gap semiconductors, UV light

285

Electronic properties and reliability of the silicon dioxide / silicon carbide interface.  

E-Print Network [OSTI]

??Silicon carbide has been preferred over other wide band-gap semiconductors for high power applications because of its unique ability to grow a thermal oxide, challenges (more)

Rozen, John

2008-01-01T23:59:59.000Z

286

Minding the Gap Makes for More Efficient Solar Cells  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

properties of these materials go through a dramatic change that makes them ideal for solar energy applications. These materials can go from indirect band gap semiconductors to...

287

Measuring Speedy Electrons in Silicon  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

scientists have taken snapshots of this very brief band-gap jump and timed it at 450 attoseconds. Image: Stephen Leone The entire semiconductor industry, not to mention...

288

Optic probe for semiconductor characterization  

DOE Patents [OSTI]

Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

Sopori, Bhushan L. (Denver, CO); Hambarian, Artak (Yerevan, AM)

2008-09-02T23:59:59.000Z

289

Spectroscopy of Charge Carriers and Traps in Field-Doped Organic Semiconductors  

SciTech Connect (OSTI)

This research project aims to achieve quantitative and molecular level understanding of charge carriers and traps in field-doped organic semiconductors via in situ optical absorption spectroscopy, in conjunction with time-resolved electrical measurements. During the funding period, we have made major progress in three general areas: (1) probed charge injection at the interface between a polymeric semiconductor and a polymer electrolyte dielectric and developed a thermodynamic model to quantitatively describe the transition from electrostatic to electrochemical doping; (2) developed vibrational Stark effect to probe electric field at buried organic semiconductor interfaces; (3) used displacement current measurement (DCM) to study charge transport at organic/dielectric interfaces and charge injection at metal/organic interfaces.

Zhu, Xiaoyang; Frisbie, C Daniel

2012-08-13T23:59:59.000Z

290

Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronic...  

Broader source: Energy.gov (indexed) [DOE]

Opportunities for Wide Bandgap Semiconductor Power Electronics for Hydrogen and Fuel Cell Applications Webinar: Opportunities for Wide Bandgap Semiconductor Power Electronics...

291

New ALS Technique Guides IBM in Next-Generation Semiconductor...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

New ALS Technique Guides IBM in Next-Generation Semiconductor Development New ALS Technique Guides IBM in Next-Generation Semiconductor Development Print Wednesday, 21 January 2015...

292

Engineering Density of States of Earth Abundant Semiconductors...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

of States of Earth Abundant Semiconductors for Enhanced Thermoelectric Power Factor Engineering Density of States of Earth Abundant Semiconductors for Enhanced Thermoelectric...

293

Preparation of a semiconductor thin film  

DOE Patents [OSTI]

A process for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

Pehnt, Martin (TuBingen, DE); Schulz, Douglas L. (Denver, CO); Curtis, Calvin J. (Lakewood, CO); Ginley, David S. (Evergreen, CO)

1998-01-01T23:59:59.000Z

294

Hybrid anode for semiconductor radiation detectors  

DOE Patents [OSTI]

The present invention relates to a novel hybrid anode configuration for a radiation detector that effectively reduces the edge effect of surface defects on the internal electric field in compound semiconductor detectors by focusing the internal electric field of the detector and redirecting drifting carriers away from the side surfaces of the semiconductor toward the collection electrode(s).

Yang, Ge; Bolotnikov, Aleksey E; Camarda, Guiseppe; Cui, Yonggang; Hossain, Anwar; Kim, Ki Hyun; James, Ralph B

2013-11-19T23:59:59.000Z

295

Preparation of a semiconductor thin film  

DOE Patents [OSTI]

A process is disclosed for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

Pehnt, M.; Schulz, D.L.; Curtis, C.J.; Ginley, D.S.

1998-01-27T23:59:59.000Z

296

e! Science News Semiconductor manufacturing technique holds  

E-Print Network [OSTI]

arsenide chips manufactured in multilayer stacks: light sensors, high-speed transistors and solar cellse! Science News Semiconductor manufacturing technique holds promise for solar energy Published semiconductor manufacturing method pioneered at the University of Illinois, the future of solar energy just got

Rogers, John A.

297

Nonlinear Peltier effect in semiconductors Mona Zebarjadia  

E-Print Network [OSTI]

Nonlinear Peltier effect in semiconductors Mona Zebarjadia Department of Electrical Engineering; published online 18 September 2007 Nonlinear Peltier coefficient of a doped InGaAs semiconductor is calculated numerically using the Monte Carlo technique. The Peltier coefficient is also obtained analytically

298

Nano- sized strontium titanate metal oxide semiconductor oxygen gas sensors.  

E-Print Network [OSTI]

??The project focuses on strontium titanate (SrTiO3> material, a very important material for oxygen sensors. The advantages of the material are low cost and stability (more)

Hu, Ying.

2008-01-01T23:59:59.000Z

299

Spin injection and transport in semiconductor and metal nanostructures  

E-Print Network [OSTI]

coefficient and can be determined for our devices from two-terminal spin valvecoefficient of the spin-selective contacts, ? n and ? sf are total transport time through the spin valve andcoefficient of the spin-selective contacts, ? n and ? sf are total transport time through the spin valve and

Zhu, Lei

2009-01-01T23:59:59.000Z

300

Hydrogenated Graphene Nanoflakes: Semiconductor to Half-Metal Transition  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching. | EMSL Bubbles andof theCoal toAnand Remarkable

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Metal Oxide Semiconductor Nanoparticles Open the Door to New Medical  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvanced Materials AdvancedInnovations | Argonne

302

Metal Oxide Semiconductor Nanoparticles Pave the Way for Medical Innovation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergy StorageAdvanced Materials AdvancedInnovations |

303

Calculation of metallic and insulating phases of V{sub 2}O{sub 3} by hybrid density functionals  

SciTech Connect (OSTI)

The electronic structure of vanadium sesquioxide V{sub 2}O{sub 3} in its different phases has been calculated using the screened exchange hybrid density functional. The hybrid functional accurately reproduces the experimental electronic properties of all three phases, the paramagnetic metal (PM) phase, the anti-ferromagnetic insulating phase, and the Cr-doped paramagnetic insulating (PI) phase. We find that a fully relaxed supercell model of the Cr-doped PI phase based on the corundum structure has a monoclinic-like local strain around the substitutional Cr atoms. This is found to drive the PI-PM transition, consistent with a Peierls-Mott transition. The PI phase has a calculated band gap of 0.15 eV, in good agreement with experiment.

Guo, Yuzheng; Robertson, John, E-mail: jr@eng.cam.ac.uk [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom)] [Department of Engineering, University of Cambridge, Cambridge CB3 0FA (United Kingdom); Clark, Stewart J. [Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom)] [Department of Physics, University of Durham, Durham DH1 3LE (United Kingdom)

2014-02-07T23:59:59.000Z

304

Novel room temperature ferromagnetic semiconductors  

SciTech Connect (OSTI)

Today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one 'spintronic' device that exploits both charge and 'spin' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 mu-m thick transparent pulsed laser deposited films of the Mn (<4 at. percent) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm areas showed homogeneous distribution of Mn substituting for Zn a 2+ state in the ZnO lattice. Ferromagnetic Resonance (FMR) technique is used to confirm the existence of ferromagnetic ordering at temperatures as high as 425K. The ab initio calculations were found to be consistent with the observation of ferromagnetism arising from fully polarized Mn 2+ state. The key to observed room temperature ferromagnetism in this system is the low temperature processing, which prevents formation of clusters, secondary phases and the host ZnO from becoming n-type. The electronic structure of the same Mn doped ZnO thin films studied using XAS, XES and RIXS, revealed a strong hybridization between Mn 3d and O 2p states, which is an important characteristic of a Dilute magnetic Semiconductor (DMS). It is shown that the various processing conditions like sintering temperature, dopant concentration and the properties of precursors used for making of DMS have a great influence on the final properties. Use of various experimental techniques to verify the physical properties, and to understand the mechanism involved to give rise to ferromagnetism is presented. Methods to improve the magnetic moment in Mn doped ZnO are also described. New promising DMS materials (such as Cu doped ZnO are explored). The demonstrated new capability to fabricate powder, pellets, and thin films of room temperature ferromagnetic semiconductors thus makes possible the realization of a wide range of complex elements for a variety of new multifunctional phenomena related to Spintronic devices as well as magneto-optic components.

Gupta, Amita

2004-11-01T23:59:59.000Z

305

Novel spin-electronic properties of BC{sub 7} sheets induced by strain  

SciTech Connect (OSTI)

Based on first-principles calculations, the authors have investigated the electronic and magnetic properties of BC{sub 7} sheets with different planar strains. It is found that metalsemiconductor transition appears at the biaxial strain of 15.5%, and the sheets are characteristic of spin-polarized semiconductor with a zero band-gap. The band-gap rapidly increases with strain, and reaches a maximum value of 0.60 eV at the strain of 20%. Subsequently, the band-gap decreases until the strain reaches up to 22% and shows a semiconductor-half metal transformation. It will further present metal properties until the strain is up to the maximum value of 35%. The magnetic moments also have some changes induced by biaxial strain. The numerical analysis shows that the two-dimensional distortions have great influences on the magnetic moments. The novel spin-electronic properties make BC{sub 7} sheets have potential applications in future spintronic nanodevices.

Xu, Lei; Dai, ZhenHong, E-mail: zhdai@ytu.edu.cn; Sui, PengFei; Sun, YuMing; Wang, WeiTian [Computational Physics Laboratory, Institute of Opto-Electronic Information Science and Technology, Yantai University, Yantai 264005 (China)

2014-11-01T23:59:59.000Z

306

Crossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts  

E-Print Network [OSTI]

-dominated transport at the superconductor-semiconductor contacts as Schottky barrier thickness decreases of such a crossover in a thin-film structure, and are of interest for investigations of hybrid superconductor-semiconductorCrossover from tunneling to meta.llic behavior in superconductofgsemiconductor contacts A. W

Woodall, Jerry M.

307

Boron doping a semiconductor particle  

DOE Patents [OSTI]

A method (10,30) of boron doping a semiconductor particle using boric acid to obtain a p-type doped particle. Either silicon spheres or silicon powder is mixed with a diluted solution of boric acid having a predetermined concentration. The spheres are dried (16), with the boron film then being driven (18) into the sphere. A melt procedure mixes the driven boron uniformly throughout the sphere. In the case of silicon powder, the powder is metered out (38) into piles and melted/fused (40) with an optical furnace. Both processes obtain a p-type doped silicon sphere with desired resistivity. Boric acid is not a restricted chemical, is inexpensive, and does not pose any special shipping, handling, or disposal requirements.

Stevens, Gary Don (18912 Ravenglen Ct., Dallas, TX 75287); Reynolds, Jeffrey Scott (703 Horizon, Murphy, TX 75094); Brown, Louanne Kay (2530 Poplar Tr., Garland, TX 75042)

1998-06-09T23:59:59.000Z

308

Heating device for semiconductor wafers  

DOE Patents [OSTI]

An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly of light energy sources for emitting light energy onto a wafer. In particular, the light energy sources are positioned such that many different radial heating zones are created on a wafer being heated. For instance, in one embodiment, the light energy sources form a spiral configuration. In an alternative embodiment, the light energy sources appear to be randomly dispersed with respect to each other so that no discernable pattern is present. In a third alternative embodiment of the present invention, the light energy sources form concentric rings. Tuning light sources are then placed in between the concentric rings of light.

Vosen, Steven R. (Berkeley, CA)

1999-01-01T23:59:59.000Z

309

Heating device for semiconductor wafers  

DOE Patents [OSTI]

An apparatus for heat treating semiconductor wafers is disclosed. The apparatus includes a heating device which contains an assembly of light energy sources for emitting light energy onto a wafer. In particular, the light energy sources are positioned such that many different radial heating zones are created on a wafer being heated. For instance, in one embodiment, the light energy sources form a spiral configuration. In an alternative embodiment, the light energy sources appear to be randomly dispersed with respect to each other so that no discernible pattern is present. In a third alternative embodiment of the present invention, the light energy sources form concentric rings. Tuning light sources are then placed in between the concentric rings of light. 4 figs.

Vosen, S.R.

1999-07-27T23:59:59.000Z

310

Stabilization of Electrocatalytic Metal Nanoparticles at Metal...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene Triple Junction Points. Stabilization of Electrocatalytic Metal Nanoparticles at Metal-Metal Oxide-Graphene...

311

Low temperature lithographically patterned metal oxide transistors for large area electronics  

E-Print Network [OSTI]

Optically transparent, wide bandgap metal oxide semiconductors are a promising candidate for large-area electronics technologies that require lightweight, temperature-sensitive flexible substrates. Because these thin films ...

Wang, Annie I. (Annie I-Jen), 1981-

2011-01-01T23:59:59.000Z

312

Electronic structure and conductivity of nanocomposite metal (Au,Ag,Cu,Mo)-containing amorphous carbon films  

SciTech Connect (OSTI)

In this work, we study the influence of the incorporation of different metals (Me = Au, Ag, Cu, Mo) on the electronic structure of amorphous carbon (a-C:Me) films. The films were produced at room temperature using a novel pulsed dual-cathode arc deposition technique. Compositional analysis was performed with secondary neutral mass spectroscopy whereas X-ray diffraction was used to identify the formation of metal nanoclusters in the carbon matrix. The metal content incorporated in the nanocomposite films induces a drastic increase in the conductivity, in parallel with a decrease in the band gap corrected from Urbach energy. The electronic structure as a function of the Me content has been monitored by x-ray absorption near edge structure (XANES) at the C K-edge. XANES showed that the C host matrix has a dominant graphitic character and that it is not affected significantly by the incorporation of metal impurities, except for the case of Mo, where the modifications in the lineshape spectra indicated the formation of a carbide phase. Subtle modifications of the spectral lineshape are discussed in terms of nanocomposite formation.

Endrino, Jose L.; Horwat, David; Gago, Raul; Andersson, Joakim; Liu, Y.S.; Guo, Jinghua; Anders, Andre

2008-05-14T23:59:59.000Z

313

370 IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING, VOL. 23, NO. 3, AUGUST 2010 Statistical Detection of Defect Patterns  

E-Print Network [OSTI]

and cause higher scrap rate, and therefore should be controlled tightly. In semiconductor industry- faces. Typical examples include hot-rolling processes produc- ing sheet metal, and fabrication processes of Industrial and Systems Engineer- ing, University of Wisconsin-Madison, Madison, WI 53706 USA (e-mail: qzhou3

Zhou, Shiyu

314

Influences of semiconductor morphology on the mechanical fatigue behavior of flexible organic electronics  

SciTech Connect (OSTI)

The influence of crystalline morphology on the mechanical fatigue of organic semiconductors (OSCs) was investigated using 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as a crystalline OSC and poly(triarylamine) (PTAA) as an amorphous OSC. During cyclic bending, resistances of the OSCs were monitored using the transmission-line method on a metal-semiconductor-metal structure. The resistance of the TIPS-pentacene increased under fatigue damage in tensile-stress mode, but no such degradation was observed in the PTAA. Both OSCs were stable under compressive bending fatigue. The formation of intergranular cracks at the domain boundaries of the TIPS-pentacene was responsible for the degradation of its electrical properties under tensile bending fatigue.

Lee, Young-Joo; Yeon, Han-Wool; Shin, Hae-A-Seul; Joo, Young-Chang, E-mail: ycjoo@snu.ac.kr [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of)] [Department of Materials Science and Engineering, Seoul National University, 151-744 Seoul (Korea, Republic of); Uk Lee, Yong; Evans, Louise A. [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)] [Center for Process Innovation Limited, Thomas Wright Way, NETPark, Sedgefield, TS21 3FG County Durham (United Kingdom)

2013-12-09T23:59:59.000Z

315

Transport Equations for Semiconductors Prof. Dr. Ansgar Jungel  

E-Print Network [OSTI]

- cations have been invented; for instance, semiconductor lasers, solar cells, light-emitting diodes (LED

Jngel, Ansgar

316

ECE 344--Semiconductor Devices & Materials ECE Department, UMass Amherst  

E-Print Network [OSTI]

Topics: Fundamentals of Semiconductors; Theory of Electrical Conduction; Device Operations (See "Class

Massachusetts at Amherst, University of

317

Diluted magnetic semiconductor nanowires exhibiting magnetoresistance  

DOE Patents [OSTI]

A method for is disclosed for fabricating diluted magnetic semiconductor (DMS) nanowires by providing a catalyst-coated substrate and subjecting at least a portion of the substrate to a semiconductor, and dopant via chloride-based vapor transport to synthesize the nanowires. Using this novel chloride-based chemical vapor transport process, single crystalline diluted magnetic semiconductor nanowires Ga.sub.1-xMn.sub.xN (x=0.07) were synthesized. The nanowires, which have diameters of .about.10 nm to 100 nm and lengths of up to tens of micrometers, show ferromagnetism with Curie temperature above room temperature, and magnetoresistance up to 250 Kelvin.

Yang, Peidong (El Cerrito, CA); Choi, Heonjin (Seoul, KR); Lee, Sangkwon (Daejeon, KR); He, Rongrui (Albany, CA); Zhang, Yanfeng (El Cerrito, CA); Kuykendal, Tevye (Berkeley, CA); Pauzauskie, Peter (Berkeley, CA)

2011-08-23T23:59:59.000Z

318

Investigation of the basic physics of high efficiency semiconductor hot carrier solar cell. Annual status report, 31 May 1994-30 May 1995  

SciTech Connect (OSTI)

The main purpose of this research program is to investigate potential semiconductor materials and their multi-band-gap MQW (multiple quantum wells) structures for high efficiency solar cells for aerospace and commercial applications. The absorption and PL (photoluminescence) spectra, the carrier dynamics, and band structures have been investigated for semiconductors of InP, GaP, GaInP, and InGaAsP/InP MQW structures, and for semiconductors of GaAs and AlGaAs by previous measurements. The barrier potential design criteria for achieving maximum energy conversion efficiency, and the resonant tunneling time as a function of barrier width in high efficiency MQW solar cell structures have also been investigated in the first two years. Based on previous carrier dynamics measurements and the time-dependent short circuit current density calculations, an InAs/InGaAs - InGaAs/GaAs - GaAs/AlGaAs MQW solar cell structure with 15 bandgaps has been designed. The absorption and PL spectra in InGaAsP/InP bulk and MQW structures were measured at room temperature and 77 K with different pump wavelength and intensity, to search for resonant states that may affect the solar cell activities. Time-resolved IR absorption for InGaAsP/InP bulk and MQW structures has been measured by femtosecond visible-pump and IR-probe absorption spectroscopy. This, with the absorption and PL measurements, will be helpful to understand the basic physics and device performance in multi-bandgap InAs/InGaAs - InGaAs/InP - InP/InGaP MQW solar cells. In particular, the lifetime of the photoexcited hot electrons is an important parameter for the device operation of InGaAsP/InP MQW solar cells working in the resonant tunneling conditions. Lastly, time evolution of the hot electron relaxation in GaAs has been measured in the temperature range of 4 K through 288 K using femtosecond pump-IR-probe absorption technique.

Alfano, R.R.; Wang, W.B.; Mohaidat, J.M.; Cavicchia, M.A.; Raisky, O.Y.

1995-05-01T23:59:59.000Z

319

Eyesafe pulsed microchip laser using semiconductor saturable absorber R. Fluck,a)  

E-Print Network [OSTI]

a metal-organic chemical vapor deposition MOCVD grown InGaAsP/InP semiconductor saturable absorber mirror an InGaAsP/InP SESAM to obtain a higher modulation depth than for an InGaAs/GaAs SESAM.15 The InGaAsP coupler and the SESAM. The ytterbium codoping of the glass makes possible the efficient absorption

Keller, Ursula

320

Chalcogels : porous metal-chalcogenide networks from main-group metal ions. Effect of surface polarizability on selectivity in gas separation.  

SciTech Connect (OSTI)

We report the synthesis of metal-chalcogenide gels and aerogels from anionic chalcogenide clusters and linking metal ions. Metal ions such as Sb{sup 3+} and Sn{sup 2+}, respectively chelated with tartrate and acetate ligands, react in solution with the chalcogenide clusters to form extended polymeric networks that exhibit gelation phenomena. Chalcogenide cluster anions with different charge densities, such as [Sn{sub 2}S{sub 6}]{sup 4-} and [SnS{sub 4}]{sup 4-}, were employed. In situ rheological measurements during gelation showed that a higher charge density on the chalcogenide cluster favors formation of a rigid gel network. Aerogels obtained from the gels after supercritical drying have BET surface areas from 114 to 368 m{sup 2}/g. Electron microscopy images coupled with nitrogen adsorption measurements showed the pores are micro (below 2 nm), meso (2-50 nm), and macro (above 50 nm) regions. These chalcogels possess band gaps in the range of 1.00-2.00 eV and selectively adsorb polarizable gases. A 2-fold increase in selectivity toward CO{sub 2}/C{sub 2}H{sub 6} over H{sub 2} was observed for the Pt/Sb/Ge{sub 4}Se{sub 10}-containing aerogel compared to aerogel containing Pt{sub 2}Ge{sub 4}S{sub 10}. The experimental results suggest that high selectivity in gas adsorption is achievable with high-surface-area chalcogenide materials containing heavy polarizable elements.

Bag, S.; Kanatzidis, M. G.; Materials Science Division; Northwestern Univ.

2010-10-06T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

EXCITONIC EIGENSTATES OF DISORDERED SEMICONDUCTOR QUANTUM WIRES  

E-Print Network [OSTI]

of semiconductors are exploited in solar cells, light emitting diodes, and lasers, and, furthermore, future UNIVERSITY OF MINNESOTA 400 Lind Hall 207 Church Street S.E. Minneapolis, Minnesota 554550436 Phone: 612

322

Semiconductor-nanocrystal/conjugated polymer thin films  

DOE Patents [OSTI]

The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.

Alivisatos, A. Paul (Oakland, CA); Dittmer, Janke J. (Munich, DE); Huynh, Wendy U. (Munich, DE); Milliron, Delia (Berkeley, CA)

2010-08-17T23:59:59.000Z

323

Electrical Usage Characterization of Semiconductor Processing Tools  

E-Print Network [OSTI]

This paper presents the basic concepts in performing an energy and power audit of a semiconductor process tool. A protocol exists that fully describes these measurements and their use and applicability and it will be described. This protocol...

Hinson, S. R.

324

Surface phonons of III-V semiconductors  

E-Print Network [OSTI]

are the simplest of all semiconductor surfaces. Their atomic relaxations and electronic surface states are rather well understood. There have, however, been surprisingly few experimental studies of their vibrational properties, and ours in the first detailed...

Das, Pradip Kumar

1994-01-01T23:59:59.000Z

325

Helicon wave excitation to produce energetic electrons for manufacturing semiconductors  

DOE Patents [OSTI]

A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18-0.35 mm or less.

Molvik, Arthur W. (Livermore, CA); Ellingboe, Albert R. (Fremont, CA)

1998-01-01T23:59:59.000Z

326

Helicon wave excitation to produce energetic electrons for manufacturing semiconductors  

DOE Patents [OSTI]

A helicon plasma source is controlled by varying the axial magnetic field or rf power controlling the formation of the helicon wave. An energetic electron current is carried on the wave when the magnetic field is 90 G; but there is minimal energetic electron current when the magnetic field is 100 G in one particular plasma source. Similar performance can be expected from other helicon sources by properly adjusting the magnetic field and power to the particular geometry. This control for adjusting the production of energetic electrons can be used in the semiconductor and thin-film manufacture process. By applying energetic electrons to the insulator layer, such as silicon oxide, etching ions are attracted to the insulator layer and bombard the insulator layer at higher energy than areas that have not accumulated the energetic electrons. Thus, silicon and metal layers, which can neutralize the energetic electron currents will etch at a slower or non-existent rate. This procedure is especially advantageous in the multilayer semiconductor manufacturing because trenches can be formed that are in the range of 0.18--0.35 mm or less. 16 figs.

Molvik, A.W.; Ellingboe, A.R.

1998-10-20T23:59:59.000Z

327

High-efficiency photovoltaics based on semiconductor nanostructures  

SciTech Connect (OSTI)

The objective of this project was to exploit a variety of semiconductor nanostructures, specifically semiconductor quantum wells, quantum dots, and nanowires, to achieve high power conversion efficiency in photovoltaic devices. In a thin-film device geometry, the objectives were to design, fabricate, and characterize quantum-well and quantum-dot solar cells in which scattering from metallic and/or dielectric nanostructures was employed to direct incident photons into lateral, optically confined paths within a thin (~1-3um or less) device structure. Fundamental issues concerning nonequilibrium carrier escape from quantum-confined structures, removal of thin-film devices from an epitaxial growth substrate, and coherent light trapping in thin-film photovoltaic devices were investigated. In a nanowire device geometry, the initial objectives were to engineer vertical nanowire arrays to optimize optical confinement within the nanowires, and to extend this approach to core-shell heterostructures to achieve broadspectrum absorption while maintaining high opencircuit voltages. Subsequent work extended this approach to include fabrication of nanowire photovoltaic structures on low-cost substrates.

Yu, Paul K.L. [University of California, San Diego; Yu, Edward T. [University of Texas at Austin; Wang, Deli [University of California, San Diego

2011-10-31T23:59:59.000Z

328

Optical temperature indicator using thermochromic semiconductors  

DOE Patents [OSTI]

A reversible optical temperature indicator utilizes thermochromic semiconductors which vary in color in response to various temperature levels. The thermochromic material is enclosed in an enamel which provides protection and prevents breakdown at higher temperatures. Cadmium sulfide is the preferred semiconductor material. The indicator may be utilized as a sign or in a striped arrangement to clearly provide a warning to a user. The various color responses provide multiple levels of alarm.

Kronberg, J.W.

1995-01-01T23:59:59.000Z

329

Optical devices featuring nonpolar textured semiconductor layers  

DOE Patents [OSTI]

A semiconductor emitter, or precursor therefor, has a substrate and one or more textured semiconductor layers deposited onto the substrate in a nonpolar orientation. The textured layers enhance light extraction, and the use of nonpolar orientation greatly enhances internal quantum efficiency compared to conventional devices. Both the internal and external quantum efficiencies of emitters of the invention can be 70-80% or higher. The invention provides highly efficient light emitting diodes suitable for solid state lighting.

Moustakas, Theodore D; Moldawer, Adam; Bhattacharyya, Anirban; Abell, Joshua

2013-11-26T23:59:59.000Z

330

Fabrication of Semiconductors by Wet Chemical Etch  

E-Print Network [OSTI]

- ern devices. Beginning with Bardeen, Brittain and Shockleys invention of the transistor in Bell Labs in 1947 and Kilby and Noyces introduction of the integrated circuit about a decade later, semiconductor devices have dramat- ically advanced... ad- dition of impurities, their conductivity can be altered. With the need to manu- facture devices at the micro- and nano- scale, the semiconductor industry has followed Moores Law, the trend that the number of transistors placed...

Francoviglia, Laura

2008-07-01T23:59:59.000Z

331

A Semiconductor Microlaser for Intracavity Flow Cytometry  

SciTech Connect (OSTI)

Semiconductor microlasers are attractive components for micro-analysis systems because of their ability to emit coherent intense light from a small aperture. By using a surface-emitting semiconductor geometry, we were able to incorporate fluid flow inside a laser microcavity for the first time. This confers significant advantages for high throughput screening of cells, particulates and fluid analytes in a sensitive microdevice. In this paper we discuss the intracavity microfluidics and present preliminary results with flowing blood and brain cells.

Akhil, O.; Copeland, G.C.; Dunne, J.L.; Gourley, P.L.; Hendricks, J.K.; McDonald, A.E.

1999-01-20T23:59:59.000Z

332

Electron gas grid semiconductor radiation detectors  

DOE Patents [OSTI]

An electron gas grid semiconductor radiation detector (EGGSRAD) useful for gamma-ray and x-ray spectrometers and imaging systems is described. The radiation detector employs doping of the semiconductor and variation of the semiconductor detector material to form a two-dimensional electron gas, and to allow transistor action within the detector. This radiation detector provides superior energy resolution and radiation detection sensitivity over the conventional semiconductor radiation detector and the "electron-only" semiconductor radiation detectors which utilize a grid electrode near the anode. In a first embodiment, the EGGSRAD incorporates delta-doped layers adjacent the anode which produce an internal free electron grid well to which an external grid electrode can be attached. In a second embodiment, a quantum well is formed between two of the delta-doped layers, and the quantum well forms the internal free electron gas grid to which an external grid electrode can be attached. Two other embodiments which are similar to the first and second embodiment involve a graded bandgap formed by changing the composition of the semiconductor material near the first and last of the delta-doped layers to increase or decrease the conduction band energy adjacent to the delta-doped layers.

Lee, Edwin Y. (Livermore, CA); James, Ralph B. (Livermore, CA)

2002-01-01T23:59:59.000Z

333

E-Print Network 3.0 - amorphous semiconductor state Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

semiconductors have been proposed... sensitivity) and use the power of organic chemistry to rationally design new synthetic semiconductors without... semiconductors?" one is...

334

E-Print Network 3.0 - area semiconductor laser Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

areas of semiconductor... for conducting research on wide bandgap semiconductor optoelectronics in my research group, within the Center... bandgap III-Nitride semiconductor...

335

Near-Infrared Photoluminescence Enhancement in Ge/CdS and Ge/ZnS Core/Shell Nanocrystals: Utilizing IV/II-VI Semiconductor Epitaxy  

SciTech Connect (OSTI)

Ge nanocrystals have a large Bohr radius and a small, size-tunable band gap that may engender direct character via strain or doping. Colloidal Ge nanocrystals are particularly interesting in the development of near-infrared materials for applications in bioimaging, telecommunications and energy conversion. Epitaxial growth of a passivating shell is a common strategy employed in the synthesis of highly luminescent IIVI, IIIV and IVVI semiconductor quantum dots. Here, we use relatively unexplored IV/IIVI epitaxy as a way to enhance the photoluminescence and improve the optical stability of colloidal Ge nanocrystals. Selected on the basis of their relatively small lattice mismatch compared with crystalline Ge, we explore the growth of epitaxial CdS and ZnS shells using the successive ion layer adsorption and reaction method. Powder X-ray diffraction and electron microscopy techniques, including energy dispersive X-ray spectroscopy and selected area electron diffraction, clearly show the controllable growth of as many as 20 epitaxial monolayers of CdS atop Ge cores. In contrast, Ge etching and/or replacement by ZnS result in relatively small Ge/ZnS nanocrystals. The presence of an epitaxial IIVI shell greatly enhances the near-infrared photoluminescence and improves the photoluminescence stability of Ge. Ge/IIVI nanocrystals are reproducibly 13 orders of magnitude brighter than the brightest Ge cores. Ge/4.9CdS core/shells show the highest photoluminescence quantum yield and longest radiative recombination lifetime. Thiol ligand exchange easily results in near-infrared active, water-soluble Ge/IIVI nanocrystals. We expect this synthetic IV/IIVI epitaxial approach will lead to further studies into the optoelectronic behavior and practical applications of Si and Ge-based nanomaterials.

Guo, Yijun [Ames Laboratory; Rowland, Clare E [Argonne National Laboratory; Schaller, Richard D [Argonne National Laboratory; Vela, Javier [Ames Laboratory

2014-08-26T23:59:59.000Z

336

Thin film solar cell including a spatially modulated intrinsic layer  

DOE Patents [OSTI]

One or more thin film solar cells in which the intrinsic layer of substantially amorphous semiconductor alloy material thereof includes at least a first band gap portion and a narrower band gap portion. The band gap of the intrinsic layer is spatially graded through a portion of the bulk thickness, said graded portion including a region removed from the intrinsic layer-dopant layer interfaces. The band gap of the intrinsic layer is always less than the band gap of the doped layers. The gradation of the intrinsic layer is effected such that the open circuit voltage and/or the fill factor of the one or plural solar cell structure is enhanced.

Guha, Subhendu (Troy, MI); Yang, Chi-Chung (Troy, MI); Ovshinsky, Stanford R. (Bloomfield Hills, MI)

1989-03-28T23:59:59.000Z

337

Photoelectrochemistry of Semiconductor Nanowire Arrays  

SciTech Connect (OSTI)

This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

Mallouk, Thomas E; Redwing, Joan M

2009-11-10T23:59:59.000Z

338

Dissipative chaos in semiconductor superlattices  

SciTech Connect (OSTI)

We consider the motion of ballistic electrons in a miniband of a semiconductor superlattice (SSL) under the influence of an external, time-periodic electric field. We use a semiclassical, balance-equation approach, which incorporates elastic and inelastic scattering (as dissipation) and the self-consistent field generated by the electron motion. The coupling of electrons in the miniband to the self-consistent field produces a cooperative nonlinear oscillatory mode which, when interacting with the oscillatory external field and the intrinsic Bloch-type oscillatory mode, can lead to complicated dynamics, including dissipative chaos. For a range of values of the dissipation parameters we determine the regions in the amplitude-frequency plane of the external field in which chaos can occur. Our results suggest that for terahertz external fields of the amplitudes achieved by present-day free-electron lasers, chaos may be observable in SSL{close_quote}s. We clarify the nature of this interesting nonlinear dynamics in the superlattice{endash}external-field system by exploring analogies to the Dicke model of an ensemble of two-level atoms coupled with a resonant cavity field, and to Josephson junctions. {copyright} {ital 1996 The American Physical Society.}

Alekseev, K.N.; Berman, G.P. [Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Center for Nonlinear Studies and Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); [Kirensky Institute of Physics, 660036, Krasnoyarsk (Russia); [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 (United States); Campbell, D.K.; Cannon, E.H.; Cargo, M.C. [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 (United States)] [Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois 61801-3080 (United States)

1996-10-01T23:59:59.000Z

339

Spin Transport in Semiconductor heterostructures  

SciTech Connect (OSTI)

The focus of the research performed under this grant has been the investigation of spin transport in magnetic semiconductor heterostructures. The interest in these systems is motivated both by their intriguing physical properties, as the physical embodiment of a spin-polarized Fermi liquid, as well as by their potential applications as spintronics devices. In our work we have analyzed several different problems that affect the spin dynamics in single and bi-layer spin-polarized two-dimensional (2D) systems. The topics of interests ranged from the fundamental aspects of the electron-electron interactions, to collective spin and charge density excitations and spin transport in the presence of the spin-orbit coupling. The common denominator of these subjects is the impact at the macroscopic scale of the spin-dependent electron-electron interaction, which plays a much more subtle role than in unpolarized electron systems. Our calculations of several measurable parameters, such as the excitation frequencies of magneto-plasma modes, the spin mass, and the spin transresistivity, propose realistic theoretical estimates of the opposite-spin many-body effects, in particular opposite-spin correlations, that can be directly connected with experimental measurements.

Domnita Catalina Marinescu

2011-02-22T23:59:59.000Z

340

Transmissive metallic contact for amorphous silicon solar cells  

DOE Patents [OSTI]

A transmissive metallic contact for amorphous silicon semiconductors includes a thin layer of metal, such as aluminum or other low work function metal, coated on the amorphous silicon with an antireflective layer coated on the metal. A transparent substrate, such as glass, is positioned on the light reflective layer. The metallic layer is preferably thin enough to transmit at least 50% of light incident thereon, yet thick enough to conduct electricity. The antireflection layer is preferably a transparent material that has a refractive index in the range of 1.8 to 2.2 and is approximately 550A to 600A thick.

Madan, A.

1984-11-29T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Metal aminoboranes  

DOE Patents [OSTI]

Metal aminoboranes of the formula M(NH2BH3)n have been synthesized. Metal aminoboranes are hydrogen storage materials. Metal aminoboranes are also precursors for synthesizing other metal aminoboranes. Metal aminoboranes can be dehydrogenated to form hydrogen and a reaction product. The reaction product can react with hydrogen to form a hydrogen storage material. Metal aminoboranes can be included in a kit.

Burrell, Anthony K.; Davis, Benjamin J.; Thorn, David L.; Gordon, John C.; Baker, R. Thomas; Semelsberger, Troy Allen; Tumas, William; Diyabalanage, Himashinie Vichalya; Shrestha, Roshan P.

2010-05-11T23:59:59.000Z

342

Thin film reactions on alloy semiconductor substrates  

SciTech Connect (OSTI)

The interactions between Pt and In{sub .53}Ga{sub .47}As have been studied. In{sub .53}Ga{sub .47}As substrates with 70nm Pt films were encapsulated in SiO{sub 2}, and annealed up to 600{degree}C in flowing forming gas. The composition and morphology of the reaction product phases were studied using x-ray diffraction, Auger depth profiling, and transmission electron microscopy. The reaction kinetics were examined with Rutherford Backscattering. Results show that Pt/In{sub .53}Ga{sub .47}As reacts to form many of the reaction products encountered in the Pt/GaAs and Pt/InP reactions: PtGa, Pt{sub 3}Ga, and PtAs{sub 2}. In addition, a ternary phase, Pt(In:Ga){sub 2}, develops, which is a solid solution between PtIn{sub 2} and PtGa{sub 2}. The amount of Ga in the ternary phase increases with annealing temperature, which causes a decrease in the lattice parameter of the phase. The reaction products show a tendency to form layered structures, especially for higher temperatures and longer annealing times. Unlike the binary case, the PtAs{sub 2}, phase is randomly oriented on the substrate, and is intermingle with a significant amount of Pt(In:Ga){sub 2}. Following Pt/In{sub .53}Ga{sub .47}As reactions, two orientation relationships between the Pt(In:Ga){sub 2} product phase and the substrate were observed, despite the large mismatch with the substrate ({approximately}8%). For many metal/compound semiconductor interactions, the reaction rate is diffusion limited, i.e. exhibits a parabolic dependence on time. An additional result of this study was the development of an In-rich layer beneath the reacted layer. The Auger depth profile showed a substantial increase in the sample at this layer. This is a significant result for the production of ohmic contacts, as the Schottky barrier height in this system lower for higher In concentrations. 216 refs.

Olson, D.A.

1990-11-01T23:59:59.000Z

343

Pulsed laser ablation growth and doping of epitaxial compound semiconductor films  

SciTech Connect (OSTI)

Pulsed laser ablation (PLA) has several characteristics that are potentially attractive for the growth and doping of chemically complex compound semiconductors including (1) stoichiometric (congruent) transfer of composition from target to film, (2) the use of reactive gases to control film composition and/or doping via energetic-beam-induced reactions, and (3) low-temperature nonequilibrium phase formation in the laser-generated plasma ``plume.`` However, the electrical properties of compound semiconductors are far more sensitive to low concentrations of defects than are the oxide metals/ceramics for which PLA has been so successful. Only recently have doped epitaxial compound semiconductor films been grown by PLA. Fundamental studies are being carried out to relate film electrical and microstructural properties to the energy distribution of ablated species, to the temporal evolution of the ablation pulse in ambient gases, and to beam assisted surface and/or gas-phase reactions. In this paper the authors describe results of ex situ Hall effect, high-resolution x-ray diffraction, transmission electron microscopy, and Rutherford backscattering measurements that are being used in combination with in situ RHEED and time-resolved ion probe measurements to evaluate PLA for growth of doped epitaxial compound semiconductor films and heterostructures. Examples are presented and results analyzed for doped II-VI, I-III-VI, and column-III nitride materials grown recently in this and other laboratories.

Lowndes, D.H.; Rouleau, C.M.; Geohegan, D.B.; Budai, J.D.; Poker, D.B. [Oak Ridge National Lab., TN (United States). Solid State Div.; Puretzky, A.A. [Inst. of Spectroscopy, Troitsk (Russian Federation); Strauss, M.A.; Pedraza, A.J.; Park, J.W. [Univ. of Tennessee, Knoxville, TN (United States)

1995-12-01T23:59:59.000Z

344

Light sources based on semiconductor current filaments  

DOE Patents [OSTI]

The present invention provides a new type of semiconductor light source that can produce a high peak power output and is not injection, e-beam, or optically pumped. The present invention is capable of producing high quality coherent or incoherent optical emission. The present invention is based on current filaments, unlike conventional semiconductor lasers that are based on p-n junctions. The present invention provides a light source formed by an electron-hole plasma inside a current filament. The electron-hole plasma can be several hundred microns in diameter and several centimeters long. A current filament can be initiated optically or with an e-beam, but can be pumped electrically across a large insulating region. A current filament can be produced in high gain photoconductive semiconductor switches. The light source provided by the present invention has a potentially large volume and therefore a potentially large energy per pulse or peak power available from a single (coherent) semiconductor laser. Like other semiconductor lasers, these light sources will emit radiation at the wavelength near the bandgap energy (for GaAs 875 nm or near infra red). Immediate potential applications of the present invention include high energy, short pulse, compact, low cost lasers and other incoherent light sources.

Zutavern, Fred J. (Albuquerque, NM); Loubriel, Guillermo M. (Albuquerque, NM); Buttram, Malcolm T. (Sandia Park, NM); Mar, Alan (Albuquerque, NM); Helgeson, Wesley D. (Albuquerque, NM); O'Malley, Martin W. (Edgewood, NM); Hjalmarson, Harold P. (Albuquerque, NM); Baca, Albert G. (Albuquerque, NM); Chow, Weng W. (Cedar Crest, NM); Vawter, G. Allen (Albuquerque, NM)

2003-01-01T23:59:59.000Z

345

Extracting hot carriers from photoexcited semiconductor nanocrystals  

SciTech Connect (OSTI)

This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called Shockley-Queisser limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates hot charge carriers that quickly cool to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a phonon bottleneck wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

Zhu, Xiaoyang

2014-12-10T23:59:59.000Z

346

Two-Photon Emission from Semiconductors  

E-Print Network [OSTI]

We report the first experimental observations of two-photon emission from semiconductors, to the best of our knowledge, and develop a corresponding theory for the room-temperature process. Spontaneous two-photon emission is demonstrated in optically-pumped bulk GaAs and in electrically-driven GaInP/AlGaInP quantum wells. Singly-stimulated two-photon emission measurements demonstrate the theoretically predicted two-photon optical gain in semiconductors - a necessary ingredient for any realizations of future two-photon semiconductor lasers. Photon-coincidence experiment validates the simultaneity of the electrically-driven GaInP/AlGaInP two-photon emission, limited only by detector's temporal resolution.

Alex Hayat; Pavel Ginzburg; Meir Orenstein

2007-10-25T23:59:59.000Z

347

Substrate solder barriers for semiconductor epilayer growth  

DOE Patents [OSTI]

During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In modular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substrate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating.

Drummond, Timothy J. (Tijeras, NM); Ginley, David S. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

348

Substrate solder barriers for semiconductor epilayer growth  

DOE Patents [OSTI]

During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In modular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substrate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating.

Drummond, T.J.; Ginley, D.S.; Zipperian, T.E.

1989-05-09T23:59:59.000Z

349

Substrate solder barriers for semiconductor epilayer growth  

DOE Patents [OSTI]

During the growth of compound semiconductors by epitaxial processes, substrates are typically mounted to a support. In molecular beam epitaxy, mounting is done using indium as a solder. This method has two drawbacks: the indium reacts with the substrate, and it is difficult to uniformly wet the back of a large diameter substrate. Both of these problems have been successfully overcome by sputter coating the back of the substrate with a thin layer of tungsten carbide or tungsten carbide and gold. In addition to being compatible with the growth of high quality semiconductor epilayers this coating is also inert in all standard substate cleaning etchants used for compound semiconductors, and provides uniform distribution of energy in radiant heating. 1 tab.

Drummond, T.J.; Ginley, D.S.; Zipperian, T.E.

1987-10-23T23:59:59.000Z

350

Study of optical parameters of the Se-As chalcogenide semiconductor system containing EuF{sub 3} impurities  

SciTech Connect (OSTI)

Optical properties of chalcogenide vitreous semiconductors of composition Se{sub 95}As{sub 5} containing different amounts of rare-earth metal fluorides (EuF{sub 3}) are studied, and, on this basis, the fundamental parameters, such as the refractive index and extinction coefficient, are determined. The dependences of these parameters on the content of EuF{sub 3} molecules are nonmonotonic: the low content (below 0.25 at %) aids in decreasing the parameters, whereas the high content tends to increase them. From the analysis of the results with consideration for the structural features of chalcogenide vitreous semiconductors of the Se{sub 95}As{sub 5} system (the presence of ordered high-coordinated microregions separated from each other by regions with a lower atomic density), it is concluded that the optical properties of the chalcogenide vitreous semiconductor system under study can be described in the context of Penn's model.

Isayev, A. I.; Mekhtiyeva, S. I.; Garibova, S. N., E-mail: sgaribova@rambler.ru; Alekperov, R. I.; Zeynalov, V. Z. [Azerbaijan National Academy of Sciences, Abdullaev Institute of Physics (Azerbaijan)

2011-08-15T23:59:59.000Z

351

Blasting detonators incorporating semiconductor bridge technology  

SciTech Connect (OSTI)

The enormity of the coal mine and extraction industries in Russia and the obvious need in both Russia and the US for cost savings and enhanced safety in those industries suggests that joint studies and research would be of mutual benefit. The author suggests that mine sites and well platforms in Russia offer an excellent opportunity for the testing of Sandia`s precise time-delay semiconductor bridge detonators, with the potential for commercialization of the detonators for Russian and other world markets by both US and Russian companies. Sandia`s semiconductor bridge is generating interest among the blasting, mining and perforation industries. The semiconductor bridge is approximately 100 microns long, 380 microns wide and 2 microns thick. The input energy required for semiconductor bridge ignition is one-tenth the energy required for conventional bridgewire devices. Because semiconductor bridge processing is compatible with other microcircuit processing, timing and logic circuits can be incorporated onto the chip with the bridge. These circuits can provide for the precise timing demanded for cast effecting blasting. Indeed tests by Martin Marietta and computer studies by Sandia have shown that such precise timing provides for more uniform rock fragmentation, less fly rock, reduce4d ground shock, fewer ground contaminants and less dust. Cost studies have revealed that the use of precisely timed semiconductor bridges can provide a savings of $200,000 per site per year. In addition to Russia`s vast mineral resources, the Russian Mining Institute outside Moscow has had significant programs in rock fragmentation for many years. He anticipated that collaborative studies by the Institute and Sandia`s modellers would be a valuable resource for field studies.

Bickes, R.W. Jr.

1994-05-01T23:59:59.000Z

352

DECENTRALIZING SEMICONDUCTOR CAPACITY PLANNING VIA INTERNAL MARKET COORDINATION  

E-Print Network [OSTI]

1 DECENTRALIZING SEMICONDUCTOR CAPACITY PLANNING VIA INTERNAL MARKET COORDINATION SULEYMAN KARABUK semiconductor manufacturer: marketing managers reserve capacity from manufacturing based on product demands, while attempting to maximize profit; manufacturing managers allocate capacity to competing marketing

Wu, David

353

APPLIED PHYSICS REVIEWS Semi-insulating semiconductor heterostructures: Optoelectronic  

E-Print Network [OSTI]

APPLIED PHYSICS REVIEWS Semi-insulating semiconductor heterostructures: Optoelectronic properties of optoelectronic properties of and uses for semi-insulating semiconductor heterostructures and thin films. The principal optical and optoelectronic properties of semi-insulating epilayers and heterostructures

Nolte, David D.

354

A New Cleanroom for a Next-Generation Semiconductor Research...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

A New Cleanroom for a Next-Generation Semiconductor Research Tool A New Cleanroom for a Next-Generation Semiconductor Research Tool Print The new Sector 12 cleanroom under...

355

Electroluminescence in ion gel gated organic polymer semiconductor transistors  

E-Print Network [OSTI]

This thesis reports the light emission in ion gel gated, thin film organic semiconductor transistors and investigates the light emission mechanism behind these devices. We report that ion gel gated organic polymer semiconductor transistors emit...

Bhat, Shrivalli

2011-07-12T23:59:59.000Z

356

Acoustoelectric Harmonic Generation in a Photoconductive Piezoelectric Semiconductor  

E-Print Network [OSTI]

Acoustoelectric Harmonic Generation in a Photoconductive Piezoelectric Semiconductor W. Arthur, R harmonics in the low frequency regime (. Piezoelectric semiconductors can exhibit harmonic generation because of interactions between the acoustic

357

Dry etching method for compound semiconductors  

DOE Patents [OSTI]

A dry etching method. According to the present invention, a gaseous plasma comprising, at least in part, boron trichloride, methane, and hydrogen may be used for dry etching of a compound semiconductor material containing layers including aluminum, or indium, or both. Material layers of a compound semiconductor alloy such as AlGaInP or the like may be anisotropically etched for forming electronic devices including field-effect transistors and heterojunction bipolar transistors and for forming photonic devices including vertical-cavity surface-emitting lasers, edge-emitting lasers, and reflectance modulators.

Shul, Randy J. (Albuquerque, NM); Constantine, Christopher (Safety Harbor, FL)

1997-01-01T23:59:59.000Z

358

Surface plasmon polariton assisted red shift in excitonic emission of semiconductor microflowers  

SciTech Connect (OSTI)

We report on the study of metal nanoparticle-semiconductor hybrid system composed of ?-indium sulfide (?-In{sub 2}S{sub 3}) and gold (Au) nanoparticles. ?-In{sub 2}S{sub 3} micron sized flower like structures (?1 ?m) and Au nanoparticles (?10 nm) were synthesized by chemical route. These Au nanoparticles have surface plasmon resonance at ? 520 nm. We study the influence of Au surface plasmon polaritons on the radiative properties of the ?-In{sub 2}S{sub 3} microflowers. As a result of the coupling between the surface plasmon polaritons and the excitons there is a red shift ? 50 nm in emission spectrum of hybrid ?-In{sub 2}S{sub 3}-Au system. Such hybrid systems provide scope for a control on the optical properties of semiconductor microstructures, thus rendering them suitable for specific device applications in optoelectronics and photovoltaics.

Parameswaran, Chithra [Centre for Nanotechnology Research, VIT University, Vellore 632014 (India); Warrier, Anita R., E-mail: cvijayan@iitm.ac.in; Bingi, Jayachandra, E-mail: cvijayan@iitm.ac.in; Vijayan, C., E-mail: cvijayan@iitm.ac.in [Indian Institute of Technology Madras, Chennai 600036 (India)

2014-10-15T23:59:59.000Z

359

Control of ionization processes in high band gap materials via tailored  

E-Print Network [OSTI]

on Ultrafast Electron Dynamics in Femtosecond Optical Breakdown of Dielectrics," Phys. Rev. Lett. 83, 5182­5182

Kassel, Universität

360

Strain-tunable Photonic Band Gap Microcavity Waveguides in Silicon at 1.55 m  

E-Print Network [OSTI]

+ , Sang-Gook Kim+ * Columbia University, New York, NY 10027 + Massachusetts Institute of Technology for reconfiguration of the optical characteristics based on user-demand, but also for compensation against external the Optical Response of Photonic Bandgap Structures, edited by Philippe M. Fauchet, Paul V. Braun, Proceedings

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Tunable band gap in graphene with a noncentrosymmetric superlattice potential Rakesh P. Tiwari and D. Stroud  

E-Print Network [OSTI]

and a hexagonal Brillouin zone BZ . The Fermi-energy EF of homogeneous, neutral graphene lies at the so A number of workers have investigated the possibility of building graphene electronic circuits without of the low-energy charge carriers is anisotropically renormalized,11 while a corrugated graphene sheet

Stroud, David

362

E-Print Network 3.0 - accurate band gaps Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Technological University Collection: Physics 7 Improving the efficiency of bulk heterojunction solar cells Summary: the amount of photons absorbed by the film by decreasing the...

363

Partial frequency band gap in one-dimensional magnonic crystals M. Kostylev,1,a  

E-Print Network [OSTI]

approach. It is shown that, due to the one-dimensional artificial periodicity of the medium, the gaps with the artificial spatial periodicity of the structure. In this work, by measuring the frequencies of collective on a silicon substrate using deep ultraviolet lithography with 248 nm exposure wavelength followed by a lift

Adeyeye, Adekunle

364

Novel wide band gap materials for highly efficient thin film tandem solar cells  

SciTech Connect (OSTI)

Tandem solar cells (TSCs), which use two or more materials to absorb sunlight, have achieved power conversion efficiencies of >25% versus 11-20% for commercialized single junction solar cell modules. The key to widespread commercialization of TSCs is to develop the wide-band, top solar cell that is both cheap to fabricate and has a high open-circuit voltage (i.e. >1V). Previous work in TSCs has generally focused on using expensive processing techniques with slow growth rates resulting in costs that are two orders of magnitude too expensive to be used in conventional solar cell modules. The objective of the PLANT PV proposal was to investigate the feasibility of using Ag(In,Ga)Se2 (AIGS) as the wide-bandgap absorber in the top cell of a thin film tandem solar cell (TSC). Despite being studied by very few in the solar community, AIGS solar cells have achieved one of the highest open-circuit voltages within the chalcogenide material family with a Voc of 949mV when grown with an expensive processing technique (i.e. Molecular Beam Epitaxy). PLANT PVâ??s goal in Phase I of the DOE SBIR was to 1) develop the chemistry to grow AIGS thin films via solution processing techniques to reduce costs and 2) fabricate new device architectures with high open-circuit voltage to produce full tandem solar cells in Phase II. PLANT PV attempted to translate solution processing chemistries that were successful in producing >12% efficient Cu(In,Ga)Se2 solar cells by replacing copper compounds with silver. The main thrust of the research was to determine if it was possible to make high quality AIGS thin films using solution processing and to fully characterize the materials properties. PLANT PV developed several different types of silver compounds in an attempt to fabricate high quality thin films from solution. We found that silver compounds that were similar to the copper based system did not result in high quality thin films. PLANT PV was able to deposit AIGS thin films using a mixture of solution and physical vapor deposition processing, but these films lacked the p-type doping levels that are required to make decent solar cells. Over the course of the project PLANT PV was able to fabricate efficient CIGS solar cells (8.7%) but could not achieve equivalent performance using AIGS. During the nine-month grant PLANT PV set up a variety of thin film characterization tools (e.g. drive-level capacitance profiling) at the Molecular Foundry, a Department of Energy User Facility, that are now available to both industrial and academic researchers via the grant process. PLANT PV was also able to develop the back end processing of thin film solar cells at Lawrence Berkeley National Labs to achieve 8.7% efficient CIGS solar cells. This processing development will be applied to other types of thin film PV cells at the Lawrence Berkeley National Labs. While PLANT PV was able to study AIGS film growth and optoelectronic properties we concluded that AIGS produced using these methods would have a limited efficiency and would not be commercially feasible. PLANT PV did not apply for the Phase II of this grant.

Brian E. Hardin, Stephen T. Connor, Craig H. Peters

2012-06-11T23:59:59.000Z

365

Bispyridinium-phenylene-based copolymers: low band gap n-type alternating copolymers  

E-Print Network [OSTI]

Bispyridinium-phenylene-based conjugated donoracceptor copolymers were synthesized by a Stille cross-coupling and cyclization sequence. These polyelectrolytes are freely soluble in organic solvents and display broad optical ...

Swager, Timothy Manning

366

Final Report: Laser-Material Interactions Relevant to Analytic Spectroscopy of Wide Band Gap Materials  

SciTech Connect (OSTI)

We summarize our studies aimed at developing an understanding of the underlying physics and chemistry in terms of laser materials interactions relevant to laser-based sampling and chemical analysis of wide bandgap materials. This work focused on the determination of mechanisms for the emission of electrons, ions, atoms, and molecules from laser irradiation of surfaces. We determined the important role of defects on these emissions, the thermal, chemical, and physical interactions responsible for matrix effects and mass-dependent transport/detection. This work supported development of new techniques and technology for the determination of trace elements contained such as nuclear waste materials.

Dickinson, J. T. [Washington State University] [Washington State University

2014-04-05T23:59:59.000Z

367

Detection of DNA Hybridization Using the Near-Infrared Band-Gap  

E-Print Network [OSTI]

shift of 2 meV, with a detection sensitivity of 6 nM. The energy shift is modeled by correlating in the solution- based systems, is advantageous due to the sensitivity and selectivity of the technique.14 absorption of blood and tissue17-19 and the low auto- fluorescence of cells20 in the nIR. Furthermore, SWNTs

Allen, Jont

368

Photonic band gap of a graphene-embedded quarter-wave stack  

SciTech Connect (OSTI)

Here, we present a mechanism for tailoring the photonic band structure of a quarter-wave stack without changing its physical periods by embedding conductive sheets. Graphene is utilized and studied as a realistic, two-dimensional conductive sheet. In a graphene-embedded quarter-wave stack, the synergic actions of Bragg scattering and graphene conductance contributions open photonic gaps at the center of the reduced Brillouin zone that are nonexistent in conventional quarter-wave stacks. Such photonic gaps show giant, loss-independent density of optical states at the fixed lower-gap edges, of even-multiple characteristic frequency of the quarter-wave stack. The conductive sheet-induced photonic gaps provide a platform for the enhancement of light-matter interactions.

Fan, Yuancheng [Ames Laboratory; Wei, Zeyong [Tongji University; Li, Hongqiang [Tongji University; Chen, Hong [Tongji University; Soukoulis, Costas M [Ames Laboratory

2013-12-10T23:59:59.000Z

369

Engineering the electromagnetic vacuum for controlling light with light in a photonic-band-gap microchip  

E-Print Network [OSTI]

laser beams ( 1 W steady-state holding power and 5 nW switching power) through mutual coherent resonant broadened collection of "atoms" situated adjacent to the waveguide channel. The "inverted" atomic system can the PBG, light cannot propagate, leading to some fundamentally new opti- cal phenomena

John, Sajeev

370

Alternative Wide-Band-Gap Materials for Gamma-Ray Spectroscopy  

E-Print Network [OSTI]

Engineering and Radiological Sciences) in The University of Michigan 2013 Doctoral Committee: Professor Zhong emotionally, physically, spiritually, and intellectually through every moment of my graduate school career, the Orion group would not be successful without the great work of his graduate students. It has been a truly

He, Zhong

371

Second harmonic generation from direct band gap quantum dots pumped by femtosecond laser pulses  

SciTech Connect (OSTI)

We report on nonlinear optical experiments performed on Cu{sub 2}S quantum dots (QDs) pumped by femtosecond laser pulses. We conduct a theoretical simulation and experiments to determine their second harmonic generation characteristics. Furthermore, we demonstrate that the QDs have a second harmonic generation conversion efficiency of up to 76%. Our studies suggest that these Cu{sub 2}S QDs can be used for solar cells, bioimaging, biosensing, and electric detection.

Liu, Liwei, E-mail: liulw@cust.edu.cn; Wang, Yue; Hu, Siyi; Ren, Yu; Huang, Chen [School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022, People's Republic of China and International Joint Research Center for Nanophotonics and Biophotonics, Changchun University of Science and Technology, Changchun, Jilin 130022 (China)

2014-02-21T23:59:59.000Z

372

Tuning laser-induced band gaps in graphene Hernn L. Calvo,1,2  

E-Print Network [OSTI]

Statistischen Physik, RWTH Aachen University, D-52056 Aachen, Germany 3 CIN2 (ICN­CSIC), Catalan Institute-infrared laser technology in a transport setup, thereby opening prom- ising prospects for graphene to the Dirac points K and K . Since we consider a clean sample and given that the ac field does not introduce

373

Broadband optical coupling between microstructured fibers and photonic band gap circuits: Two-dimensional paradigms  

E-Print Network [OSTI]

simple two-dimensional design models. We demonstrate an effective large- bandwidth small-footprint beam platform for integrated optics. Unlike conventional paradigms such as silicon on insulator SOI waveguides that guide light on a chip by total internal reflection index guiding , PBG-based microcircuits can guide

John, Sajeev

374

Tunable micro-cavities in photonic band-gap yarns and optical fibers  

E-Print Network [OSTI]

The vision behind this work is the fabrication of high performance innovative fiber-based optical components over kilometer length-scales. The optical properties of these fibers derive from their multilayer dielectric ...

Benoit, Gilles, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

375

Excitation, Ionization, and Desorption: How Sub-band gap Photons Modify the  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsing ZirconiaPolicy and Assistance100 tonusingdeposition. | EMSLStructure of

376

Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I. Ben-Zvi, P. Study ofJ U LYOffsets at

377

Band-Gap Reduction and Dopant Interaction in Epitaxial La,Cr Co-doped  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone6 M. Babzien, I. Ben-Zvi, P. Study ofJ U LYOffsets atSrTiO3 Thin

378

Optimal Preventive Maintenance Scheduling in Semiconductor Manufacturing  

E-Print Network [OSTI]

1 Optimal Preventive Maintenance Scheduling in Semiconductor Manufacturing Xiaodong Yao, Emmanuel on Control Applications in 2001. #12;2 Abstract Preventive Maintenance (PM) scheduling is a very challenging schedule with that of a baseline reference schedule are also presented. Index Terms preventive maintenance

Marcus, Steven I.

379

Semiconductor detectors with proximity signal readout  

SciTech Connect (OSTI)

Semiconductor-based radiation detectors are routinely used for the detection, imaging, and spectroscopy of x-rays, gamma rays, and charged particles for applications in the areas of nuclear and medical physics, astrophysics, environmental remediation, nuclear nonproliferation, and homeland security. Detectors used for imaging and particle tracking are more complex in that they typically must also measure the location of the radiation interaction in addition to the deposited energy. In such detectors, the position measurement is often achieved by dividing or segmenting the electrodes into many strips or pixels and then reading out the signals from all of the electrode segments. Fine electrode segmentation is problematic for many of the standard semiconductor detector technologies. Clearly there is a need for a semiconductor-based radiation detector technology that can achieve fine position resolution while maintaining the excellent energy resolution intrinsic to semiconductor detectors, can be fabricated through simple processes, does not require complex electrical interconnections to the detector, and can reduce the number of required channels of readout electronics. Proximity electrode signal readout (PESR), in which the electrodes are not in physical contact with the detector surface, satisfies this need.

Asztalos, Stephen J. [XIA, LLC, Hayward, CA (United States)

2014-01-30T23:59:59.000Z

380

Organic conductive films for semiconductor electrodes  

DOE Patents [OSTI]

According to the present invention, improved electrodes overcoated with conductive polymer films and preselected catalysts are provided. The electrodes typically comprise an inorganic semiconductor over-coated with a charge conductive polymer film comprising a charge conductive polymer in or on which is a catalyst or charge-relaying agent.

Frank, A.J.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Optical temperature sensor using thermochromic semiconductors  

DOE Patents [OSTI]

Optical thermometry is a growing technological field which exploits the ability of certain materials to change their optical properties with temperature. A subclass of such materials are those which change their color as a reversible and reproducible function of temperature. These materials are thermochromic. This invention is a composition to measure temperature utilizing thermochromic semiconductors.

Kronberg, J.W.

1994-01-01T23:59:59.000Z

382

Solid State Lighting Semiconductor Spectroscopy & Devices  

E-Print Network [OSTI]

and fluorescent lamps, are very inefficient in transforming energy into light. Due to upcoming problems in energy % of Earth's total power consumption is used for lighting! Figure 3: Earth at night from space. Evolution inside a semiconductor for light emission. Over 150 years ago... How to achieve white LEDs? Figure 5

Strathclyde, University of

383

Mathematical Tools in Optimal Semiconductor Design  

E-Print Network [OSTI]

year to year. The original aim was to produce more devices per unit area, e.g. the Semiconductor discuss the construction of descent algorithms employing the ad- joint state and investigate the electronic behavior of the device appropriately. This reveals several challenging problems for electrical

Hinze, Michael

384

HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS  

E-Print Network [OSTI]

HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS M.D. MCCLUSKEY* University) spectroscopy of hydrogen and deuterium in GaP, AlSb, ZnSe, and GaN has provided important information about the structures of dopant- hydrogen complexes and their interaction with the host lattice. In GaN:Mg, for example

McCluskey, Matthew

385

High resolution scintillation detector with semiconductor readout  

DOE Patents [OSTI]

A novel high resolution scintillation detector array for use in radiation imaging such as high resolution Positron Emission Tomography (PET) which comprises one or more parallelepiped crystals with at least one long surface of each crystal being in intimate contact with a semiconductor photodetector such that photons generated within each crystal by gamma radiation passing therethrough is detected by the photodetector paired therewith.

Levin, Craig S. (Santa Monica, CA); Hoffman, Edward J. (Los Angeles, CA)

2000-01-01T23:59:59.000Z

386

Effect of contact metals on the piezoelectric properties of aluminum nitride thin films  

SciTech Connect (OSTI)

The converse piezoelectric response of aluminum nitride evaluated using standard metal insulator semiconductor structures has been found to exhibit a linear dependence on the work function of the metal used as the top electrode. The apparent d33 of the 1501100 nm films also depends on the dc bias applied to the samples.

Harman, J.P.; Kabulski, A. (West Virginia U., Morgantown, WV); Pagan, V.R. (West Virginia U., Morgantown, WV); Famouri, K. (West Virginia U., Morgantown, WV); Kasarla, K.R.; Rodak, L.E. (West Virginia U., Morgantown, WV); Hensel, J.P.; Korakakis, D.

2008-07-01T23:59:59.000Z

387

Metal inks  

DOE Patents [OSTI]

Self-reducing metal inks and systems and methods for producing and using the same are disclosed. In an exemplary embodiment, a method may comprise selecting metal-organic (MO) precursor, selecting a reducing agent, and dissolving the MO precursor and the reducing agent in an organic solvent to produce a metal ink that remains in a liquid phase at room temperature. Metal inks, including self-reducing and fire-through metal inks, are also disclosed, as are various applications of the metal inks.

Ginley, David S; Curtis, Calvin J; Miedaner, Alex; van Hest, Marinus Franciscus Antonius Maria; Kaydanova, Tatiana

2014-02-04T23:59:59.000Z

388

Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials  

E-Print Network [OSTI]

electron storage, electrochromic, and photoelectrochromicV. Thin Solid Films Electrochromic and photoelectrochemical

Wheeler, Damon Andreas

2013-01-01T23:59:59.000Z

389

Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials  

E-Print Network [OSTI]

purity hydrogen gas (Praxair). 5.3.3 Electron Microscopy (purity hydrogen gas (Praxair). 6.3.3 UV-Vis, Electron

Wheeler, Damon Andreas

2013-01-01T23:59:59.000Z

390

Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials  

E-Print Network [OSTI]

cancer treatment, sensors, lasers, and solar cells. Onedetectors, solar energy conversion, sensors, and manydetectors, solar energy conversion, lasers, and sensors. A

Wheeler, Damon Andreas

2013-01-01T23:59:59.000Z

391

Synthesis, Characterization, and Ultrafast Dynamics of Metal, Metal Oxide, and Semiconductor Nanomaterials  

E-Print Network [OSTI]

S. R. ; Cowan, A. J. ; Barroso, M. ; Sivula, K. ; Ye, J. ;3861. (167) Pendlebury, S. R. ; Barroso, M. ; Cowan, A. J. ;+. (199) Pendlebury, S. ; Barroso, M. ; Cowan, A. ; Sivula,

Wheeler, Damon Andreas

2013-01-01T23:59:59.000Z

392

Bi-Se doped with Cu, p-type semiconductor  

DOE Patents [OSTI]

A Bi--Se doped with Cu, p-type semiconductor, preferably used as an absorber material in a photovoltaic device. Preferably the semiconductor has at least 20 molar percent Cu. In a preferred embodiment, the semiconductor comprises at least 28 molar percent of Cu. In one embodiment, the semiconductor comprises a molar percentage of Cu and Bi whereby the molar percentage of Cu divided by the molar percentage of Bi is greater than 1.2. In a preferred embodiment, the semiconductor is manufactured as a thin film having a thickness less than 600 nm.

Bhattacharya, Raghu Nath; Phok, Sovannary; Parilla, Philip Anthony

2013-08-20T23:59:59.000Z

393

Ge-related faceting and segregation during the growth of metastable (GaAs){sub 1{minus}x}(Ge{sub 2}){sub x} alloy layers by metal{endash}organic vapor-phase epitaxy  

SciTech Connect (OSTI)

(GaAs){sub 1{minus}x}(Ge{sub 2}){sub x} alloy layers, 0{lt}x{lt}0.22, have been grown by metal{endash}organic vapor-phase epitaxy on vicinal (001) GaAs substrates. Transmission electron microscopy revealed pronounced phase separation in these layers, resulting in regions of GaAs-rich zinc-blende and Ge-rich diamond cubic material that appears to lead to substantial band-gap narrowing. For x=0.1 layers, the phase-separated microstructure consisted of intersecting sheets of Ge-rich material on {l_brace}115{r_brace}B planes surrounding cells of GaAs-rich material, with little evidence of antiphase boundaries. Atomic force microscopy revealed {l_brace}115{r_brace}B surface faceting associated with the phase separation. {copyright} {ital 1999 American Institute of Physics.}

Norman, A.G.; Olson, J.M.; Geisz, J.F.; Moutinho, H.R.; Mason, A.; Al-Jassim, M.M. [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States)] [National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401 (United States); Vernon, S.M. [Spire Corporation, One Patriots Park, Bedford, Massachusetts 01730 (United States)] [Spire Corporation, One Patriots Park, Bedford, Massachusetts 01730 (United States)

1999-03-01T23:59:59.000Z

394

Lithium Doping of Single-Walled Carbon Nanotubes for Battery and Semiconductor Applications Kevin Donaher, Columbia University, Georgia Institute of Technology SURF 2010 Fellow  

E-Print Network [OSTI]

Lithium Doping of Single-Walled Carbon Nanotubes for Battery and Semiconductor Applications Kevin Jang, Mentor: Wonsang Koh Abstract The properties of lithium doped (5,5) metallic and (8 lithium binds to carbon nanotubes and how this affects the band structure of the semiconducting carbon

Li, Mo

395

Silicone metalization  

DOE Patents [OSTI]

A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

2008-12-09T23:59:59.000Z

396

Silicone metalization  

DOE Patents [OSTI]

A system for providing metal features on silicone comprising providing a silicone layer on a matrix and providing a metal layer on the silicone layer. An electronic apparatus can be produced by the system. The electronic apparatus comprises a silicone body and metal features on the silicone body that provide an electronic device.

Maghribi, Mariam N. (Livermore, CA); Krulevitch, Peter (Pleasanton, CA); Hamilton, Julie (Tracy, CA)

2006-12-05T23:59:59.000Z

397

X-ray induced optical reflectivity  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity.Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4), a semiconductor(gallium arsenide,GaAs), and a metal (gold,Au), obtained with ?100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

Durbin, Stephen M.

2012-01-01T23:59:59.000Z

398

Monolithic integration of rare-earth oxides and semiconductors for on-silicon technology  

SciTech Connect (OSTI)

Several concepts of integration of the epitaxial rare-earth oxides into the emerging advanced semiconductor on silicon technology are presented. Germanium grows epitaxially on gadolinium oxide despite lattice mismatch of more than 4%. Additionally, polymorphism of some of the rare-earth oxides allows engineering of their crystal structure from hexagonal to cubic and formation of buffer layers that can be used for growth of germanium on a lattice matched oxide layer. Molecular beam epitaxy and metal organic chemical vapor deposition of gallium nitride on the rare-earth oxide buffer layers on silicon is discussed.

Dargis, Rytis, E-mail: dargis@translucentinc.com; Clark, Andrew; Erdem Arkun, Fevzi [Translucent, Inc., 952 Commercial St., Palo Alto, California 94303 (United States); Grinys, Tomas; Tomasiunas, Rolandas [Institute of Applied Research, Vilnius University, Sauletekio al. 10, LT-10223 Vilnius (Lithuania); O'Hara, Andy; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, 2515 Speedway, C1600, Austin, Texas 78712 (United States)

2014-07-01T23:59:59.000Z

399

Semiconductor P-I-N detector  

DOE Patents [OSTI]

A semiconductor P-I-N detector including an intrinsic wafer, a P-doped layer, an N-doped layer, and a boundary layer for reducing the diffusion of dopants into the intrinsic wafer. The boundary layer is positioned between one of the doped regions and the intrinsic wafer. The intrinsic wafer can be composed of CdZnTe or CdTe, the P-doped layer can be composed of ZnTe doped with copper, and the N-doped layer can be composed of CdS doped with indium. The boundary layers is formed of an undoped semiconductor material. The boundary layer can be deposited onto the underlying intrinsic wafer. The doped regions are then typically formed by a deposition process or by doping a section of the deposited boundary layer.

Sudharsanan, Rengarajan (53 Timber Line Dr., Nashua, NH 03062); Karam, Nasser H. (577 Lowell St., Lexington, MA 02173)

2001-01-01T23:59:59.000Z

400

Optical cavity furnace for semiconductor wafer processing  

DOE Patents [OSTI]

An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

Sopori, Bhushan L.

2014-08-05T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Proximity charge sensing for semiconductor detectors  

DOE Patents [OSTI]

A non-contact charge sensor includes a semiconductor detector having a first surface and an opposing second surface. The detector includes a high resistivity electrode layer on the first surface and a low resistivity electrode on the high resistivity electrode layer. A portion of the low resistivity first surface electrode is deleted to expose the high resistivity electrode layer in a portion of the area. A low resistivity electrode layer is disposed on the second surface of the semiconductor detector. A voltage applied between the first surface low resistivity electrode and the second surface low resistivity electrode causes a free charge to drift toward the first or second surface according to a polarity of the free charge and the voltage. A charge sensitive preamplifier coupled to a non-contact electrode disposed at a distance from the exposed high resistivity electrode layer outputs a signal in response to movement of free charge within the detector.

Luke, Paul N; Tindall, Craig S; Amman, Mark

2013-10-08T23:59:59.000Z

402

Method of transferring strained semiconductor structure  

DOE Patents [OSTI]

The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the deposited multilayer structure is bonded to a second substrate and is separated away at the interface, which results in transferring a multilayer structure from one substrate to the other substrate. The multilayer structure includes at least one strained semiconductor layer and at least one strain-induced seed layer. The strain-induced seed layer can be optionally etched away after the layer transfer.

Nastasi, Michael A. (Santa Fe, NM); Shao, Lin (College Station, TX)

2009-12-29T23:59:59.000Z

403

GaTe semiconductor for radiation detection  

DOE Patents [OSTI]

GaTe semiconductor is used as a room-temperature radiation detector. GaTe has useful properties for radiation detectors: ideal bandgap, favorable mobilities, low melting point (no evaporation), non-hygroscopic nature, and availability of high-purity starting materials. The detector can be used, e.g., for detection of illicit nuclear weapons and radiological dispersed devices at ports of entry, in cities, and off shore and for determination of medical isotopes present in a patient.

Payne, Stephen A. (Castro Valley, CA); Burger, Arnold (Nashville, TN); Mandal, Krishna C. (Ashland, MA)

2009-06-23T23:59:59.000Z

404

A Markovian analysis of semiconductor manufacturing processes  

E-Print Network [OSTI]

) Karan L. Watson (Member) Martin A. Wortman (Member) ep Sastri (Member) o W. Howze (Head of Department) December 1991 ABSTRACT A Markovian Analysis of Semiconductor Manufacturing Processes. (December 1991) Kent Eugene Schultz, B. S. , Iowa... grateful to Dr. Martin Wortman, for his pa- tience and endless stream of examples to help me understand stochastic processes. I would also like to thank Dr. Tep Sastri for his patience and for always having a refer- ence available when I needed it...

Schultz, Kent Eugene

2012-06-07T23:59:59.000Z

405

Photovoltaic healing of non-uniformities in semiconductor devices  

DOE Patents [OSTI]

A method of making a photovoltaic device using light energy and a solution to normalize electric potential variations in the device. A semiconductor layer having nonuniformities comprising areas of aberrant electric potential deviating from the electric potential of the top surface of the semiconductor is deposited onto a substrate layer. A solution containing an electrolyte, at least one bonding material, and positive and negative ions is applied over the top surface of the semiconductor. Light energy is applied to generate photovoltage in the semiconductor, causing a redistribution of the ions and the bonding material to the areas of aberrant electric potential. The bonding material selectively bonds to the nonuniformities in a manner such that the electric potential of the nonuniformities is normalized relative to the electric potential of the top surface of the semiconductor layer. A conductive electrode layer is then deposited over the top surface of the semiconductor layer.

Karpov, Victor G.; Roussillon, Yann; Shvydka, Diana; Compaan, Alvin D.; Giolando, Dean M.

2006-08-29T23:59:59.000Z

406

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Urbana, IL); Lee, Keon Jae (Savoy, IL); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Champaign, IL); Zhu, Zhengtao (Urbana, IL)

2009-11-24T23:59:59.000Z

407

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2013-05-14T23:59:59.000Z

408

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2014-03-04T23:59:59.000Z

409

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Durham, NC); Lee, Keon Jae (Daejeon, KR); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Raleigh, NC); Zhu, Zhengtao (Urbana, IL)

2011-07-19T23:59:59.000Z

410

Deposition method for producing silicon carbide high-temperature semiconductors  

DOE Patents [OSTI]

An improved deposition method for producing silicon carbide high-temperature semiconductor material comprising placing a semiconductor substrate composed of silicon carbide in a fluidized bed silicon carbide deposition reactor, fluidizing the bed particles by hydrogen gas in a mildly bubbling mode through a gas distributor and heating the substrate at temperatures around 1200.degree.-1500.degree. C. thereby depositing a layer of silicon carbide on the semiconductor substrate.

Hsu, George C. (La Crescenta, CA); Rohatgi, Naresh K. (W. Corine, CA)

1987-01-01T23:59:59.000Z

411

Method and system for powering and cooling semiconductor lasers  

DOE Patents [OSTI]

A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.

Telford, Steven J; Ladran, Anthony S

2014-02-25T23:59:59.000Z

412

Method of transferring a thin crystalline semiconductor layer  

DOE Patents [OSTI]

A method for transferring a thin semiconductor layer from one substrate to another substrate involves depositing a thin epitaxial monocrystalline semiconductor layer on a substrate having surface contaminants. An interface that includes the contaminants is formed in between the deposited layer and the substrate. Hydrogen atoms are introduced into the structure and allowed to diffuse to the interface. Afterward, the thin semiconductor layer is bonded to a second substrate and the thin layer is separated away at the interface, which results in transferring the thin epitaxial semiconductor layer from one substrate to the other substrate.

Nastasi, Michael A. (Sante Fe, NM); Shao, Lin (Los Alamos, NM); Theodore, N. David (Mesa, AZ)

2006-12-26T23:59:59.000Z

413

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print The possibility of using electrons' spins in addition to their charge in information technology has...

414

Statistical Methods for Enhanced Metrology in Semiconductor/Photovoltaic Manufacturing  

E-Print Network [OSTI]

process control charts (SPC) for product quality and processstatistical process control (SPC) charts. The concept is toMethods Univariate SPC for semiconductor manufacturing

Zeng, Dekong

2012-01-01T23:59:59.000Z

415

Multiplex Chaos Synchronization in Semiconductor Lasers with Multiple Optoelectronic Feedbacks  

E-Print Network [OSTI]

Secure chaos based multiplex communication system scheme is proposed utilizing globally coupled semiconductor lasers with multiple variable time delay optoelectronic feedbacks.

E. M. Shahverdiev; K. A. Shore

2011-11-06T23:59:59.000Z

416

Beam excited acoustic instability in semiconductor quantum plasmas  

SciTech Connect (OSTI)

The instability of hole-Acoustic waves due to electron beam in semiconductor quantum plasmas is examined using the quantum hydrodynamic model. The quantum effects are considered including Bohm potential, Fermi degenerate pressure, and exchange potential of the semiconductor quantum plasma species. Our model is applied to nano-sized GaAs semiconductor plasmas. The variation of the growth rate of the unstable mode is obtained over a wide range of system parameters. It is found that the thermal effects of semiconductor species have significance over the hole-Acoustic waves.

Rasheed, A.; Siddique, M.; Huda, F. [Department of Physics, Government College University, Faisalabad 38000 (Pakistan); Jamil, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Jung, Y.-D. [Department of Applied Physics and Department of Bionanotechnology, Hanyang University, Ansan, Kyunggi-Do 426-791 (Korea, Republic of)

2014-06-15T23:59:59.000Z

417

Method for depositing high-quality microcrystalline semiconductor materials  

DOE Patents [OSTI]

A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.

Guha, Subhendu (Bloomfield Hills, MI); Yang, Chi C. (Troy, MI); Yan, Baojie (Rochester Hills, MI)

2011-03-08T23:59:59.000Z

418

Exchange interaction studies in magnetic semiconductors by neutron scattering.  

E-Print Network [OSTI]

??Theories predict that making a dilute magnetic semiconductor strongly p -type would allow it to remain ferromagnetic at room temperature. This is of intrest as (more)

Wiren, Zachary Quincy

2008-01-01T23:59:59.000Z

419

Electrical Characterization of Individual Semiconductor Nanocrystals  

E-Print Network [OSTI]

device contacted by Pd electrodes, with TEM of singlereactions induced by the Pd electrode metal. High-resolutioncontacted via evaporated Pd electrodes. Device charging

Sheldon, Matthew Thomas

2010-01-01T23:59:59.000Z

420

The Technical and Economic Potential for Electricity Energy Efficiency in a Semiconductor Manufacturing Plant  

E-Print Network [OSTI]

In recent years, there has been renewed interest in energy efficiency in the semiconductor industry. The declining prices for semiconductor products has prompted semiconductor manufacturing plants to control costs so as to maintain profitability...

Lee, A. H. W.; Golden, J. W.; Zarnikau, J. W.

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy  

SciTech Connect (OSTI)

We report on a cost-effective optical setup for characterizing light-emitting semiconductor devices with optical-feedback confocal infrared microscopy and optical beam-induced resistance change.We utilize the focused beam from an infrared laser diode to induce local thermal resistance changes across the surface of a biased integrated circuit (IC) sample. Variations in the multiple current paths are mapped by scanning the IC across the focused beam. The high-contrast current maps allow accurate differentiation of the functional and defective sites, or the isolation of the surface-emittingp-i-n devices in the IC. Optical beam-induced current (OBIC) is not generated since the incident beam energy is lower than the bandgap energy of the p-i-n device. Inhomogeneous current distributions in the IC become apparent without the strong OBIC background. They are located at a diffraction-limited resolution by referencing the current maps against the confocal reflectance image that is simultaneously acquired via optical-feedback detection. Our technique permits the accurate identification of metal and semiconductor sites as well as the classification of different metallic structures according to thickness, composition, or spatial inhomogeneity.

Sarmiento, Raymund; Cemine, Vernon Julius; Tagaca, Imee Rose; Salvador, Arnel; Mar Blanca, Carlo; Saloma, Caesar

2007-11-01T23:59:59.000Z

422

Semiconductor bridge, SCB, ignition of energetic materials  

SciTech Connect (OSTI)

Sandia National Laboratories` semiconductor bridge, SCB, is now being used for the ignition or initiation of a wide variety of exeoergic materials. Applications of this new technology arose because of a need at the system level to provide light weight, small volume and low energy explosive assemblies. Conventional bridgewire devices could not meet the stringent size, weight and energy requirements of our customers. We present an overview of SCB technology and the ignition characteristics for a number of energetic materials including primary and secondary explosives, pyrotechnics, thermites and intermetallics. We provide examples of systems designed to meet the modern requirements that sophisticated systems must satisfy in today`s market environments.

Bickes, R.W.; Grubelich, M.D.; Harris, S.M.; Merson, J.A.; Tarbell, W.W.

1997-04-01T23:59:59.000Z

423

Transient Rayleigh scattering from single semiconductor nanowires  

SciTech Connect (OSTI)

Transient Rayleigh scattering spectroscopy is a new pump-probe technique to study the dynamics and cooling of photo-excited carriers in single semiconductor nanowires. By studying the evolution of the transient Rayleigh spectrum in time after excitation, one can measure the time evolution of the density and temperature of photo-excited electron-hole plasma (EHP) as they equilibrate with lattice. This provides detailed information of dynamics and cooling of carriers including linear and bimolecular recombination properties, carrier transport characteristics, and the energy-loss rate of hot electron-hole plasma through the emission of LO and acoustic phonons.

Montazeri, Mohammad; Jackson, Howard E.; Smith, Leigh M. [Department of Physics, University of Cincinnati, Cincinnati, OH 45221-0011 (United States); Yarrison-Rice, Jan M. [Department of Physics, Miami University, Oxford, OH 45056 (United States); Kang, Jung-Hyun; Gao, Qiang; Tan, Hark Hoe; Jagadish, Chennupati [Department of Electronic Materials Engineering, Research School of Physics and Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

2013-12-04T23:59:59.000Z

424

Area 1: Semiconductor Physics Sorin P. Voinigescu  

E-Print Network [OSTI]

: dual polysilicon gates, selfaligned silicides 2003: strain engineering: SiGe source/drain regions 2007: HfO2 gate stack and metal gates 2011: Multiple gate (MGFET) or FinFET 22nm Node Highk/Metal Tri+ STI n+ Deep nwell p substrate STI p+ silicide contact STI STI nwell gate n+ n+ halo implants p+ p+ STI

Prodiæ, Aleksandar

425

Iron oxidation state of FeTiO3 under high pressure X. Wu,1,* G. Steinle-Neumann,1 O. Narygina,1 I. Kantor,1,2 C. McCammon,1 S. Pascarelli,3 G. Aquilanti,3 V. Prakapenka,2  

E-Print Network [OSTI]

the oxygen bridge in the adjacent octahedral, then decreases at higher pressure due to the ilmenite in the materials and earth sci- ences. Ilmenite is a wide-band-gap semiconductor with a 2.5 eV band gap,1 which

Steinle-Neumann, Gerd

426

Metal oxide films on metal  

DOE Patents [OSTI]

A structure including a thin film of a conductive alkaline earth metal oxide selected from the group consisting of strontium ruthenium trioxide, calcium ruthenium trioxide, barium ruthenium trioxide, lanthanum-strontium cobalt oxide or mixed alkaline earth ruthenium trioxides thereof upon a thin film of a noble metal such as platinum is provided.

Wu, Xin D. (Los Alamos, NM); Tiwari, Prabhat (Los Alamos, NM)

1995-01-01T23:59:59.000Z

427

Magnetically and electrically tunable semiconductor quantum waveguide inverter  

E-Print Network [OSTI]

Magnetically and electrically tunable semiconductor quantum waveguide inverter M. J. Gilbert,a) R implementations. We present an electrically tunable semiconductor quantum waveguide implementation of an inverter. On the other hand, if a ``0'' is present in the control bit, then the qubit is inverted. In a recent study

Gilbert, Matthew

428

ECE 451 -Fall 2011 Physics of Semiconductor Devices (3)  

E-Print Network [OSTI]

ECE 451 - Fall 2011 Physics of Semiconductor Devices (3) Electronics and Optoelectronics-Photon Scattering Processes (Optional) 18. Novel Optoelectronics and Electronics Devices (Optional) Structure on Semiconductor Physics and Device Physics, Draft Version (2010). Other Additional References or Readings: 1. J

Gilchrist, James F.

429

Communication using Synchronization of Chaos in Semiconductor Lasers with optoelectronic  

E-Print Network [OSTI]

Communication using Synchronization of Chaos in Semiconductor Lasers with optoelectronic feedback S. The Chaos in the single-mode semiconductor lasers is generated by means of an optoelectronic feedback with optoelectronic feedback has been demonstrated for quite slow data rates by using chaotic wavelength fluctuations

Illing, Lucas

430

Multistability in a semiconductor laser with optoelectronic feedback  

E-Print Network [OSTI]

Multistability in a semiconductor laser with optoelectronic feedback Guang-Qiong Xia1,2 , Sze with delayed optoelectronic feedback is observed experimentally. For a given delay time, the observed dynamical-oscillating semiconductor lasers subject to delayed optoelectronic mutual coupling," Phys. Rev. E 73, 047201-1-4 (2006) 8. G

Chan, Sze-Chun

431

On a mathematical model for hot carrier injection in semiconductors  

E-Print Network [OSTI]

On a mathematical model for hot carrier injection in semiconductors Naoufel Ben Abdallah (1) Pierre of a semiconductor device heavily depends on the injection mechanism of carriers into the active regions through by the relation V bi = U th log N + N \\Gamma ; where U th = kBT=q is the thermal voltage and N + ; N \\Gamma

Schmeiser, Christian

432

hal00267005, Modeling semiconductor thermal properties. The dispersion role.  

E-Print Network [OSTI]

, or in solar panels 3 , and are even used in medicine 4 . The increasing use of semiconductor micro in transistors 6 and semiconductor nano#12;lms in solar cells. At these low scale, Fourier's law may give , similar to photon intensity used in radiative transfer 24 . Thus, the energy ux per apparent surface unit

Paris-Sud XI, Université de

433

Modular Algorithms for Transient Semiconductor Device Simulation, Part I  

E-Print Network [OSTI]

Modular Algorithms for Transient Semiconductor Device Simulation, Part I: Analysis of the Outer, is introduced at dis- crete time steps for the one-dimensional semiconductor device model. The it- eration as approximate Newton iterations. Continuation is employed as the time-stepping bridge. 1 Introduction In Part I

Jerome, Joseph W.

434

Photonic switching devices based on semiconductor nanostructures  

E-Print Network [OSTI]

Focusing and guiding light into semiconductor nanostructures can deliver revolutionary concepts for photonic devices, which offer a practical pathway towards next-generation power-efficient optical networks. In this review, we consider the prospects for photonic switches using semiconductor quantum dots (QDs) and photonic cavities which possess unique properties based on their low dimensionality. The optical nonlinearity of such photonic switches is theoretically analyzed by introducing the concept of a field enhancement factor. This approach reveals drastic improvement in both power-density and speed, which is able to overcome the limitations that have beset conventional photonic switches for decades. In addition, the overall power consumption is reduced due to the atom-like nature of QDs as well as the nano-scale footprint of photonic cavities. Based on this theoretical perspective, the current state-of-the-art of QD/cavity switches is reviewed in terms of various optical nonlinearity phenomena which have been utilized to demonstrate photonic switching. Emerging techniques, enabled by cavity nonlinear effects such as wavelength tuning, Purcell-factor tuning and plasmonic effects are also discussed.

Chao-Yuan Jin; Osamu Wada

2014-02-26T23:59:59.000Z

435

Apparatus for the etching for semiconductor devices  

SciTech Connect (OSTI)

Apparatus for the etching of semiconductor devices which includes, in combination, an etching chamber containing the semiconductor device to be etched, an electrodeless etching plasma forming chamber having an inlet connected to a source of continuously flowing etching gas and having an outlet connected to said etching chamber in fluid flow communication; a helical inductive resonator coupler for coupling a source of R.F. electrical power into the electrodeless plasma forming chamber for continuously forming etching plasma from the etching gas flowing therethrough; this inductive resonator coupler including a grounded hollow cylinder of electrically conductive material, with a grounded base member at one end; a helically coiled wire conductor concentrically mounted within the cylinder and spaced from the inner walls thereof; the plasma forming chamber being mounted substantially concentrically within the coil, the end of the coil toward the base member being grounded; and an electrical coupling for applying into the coil an R.F. source of electrical power at a position near, but spaced from, the grounded end thereof.

Reinberg, A.R.; Steinberg, G.N.

1983-01-11T23:59:59.000Z

436

Distributed Quantum Computation Architecture Using Semiconductor Nanophotonics  

E-Print Network [OSTI]

In a large-scale quantum computer, the cost of communications will dominate the performance and resource requirements, place many severe demands on the technology, and constrain the architecture. Unfortunately, fault-tolerant computers based entirely on photons with probabilistic gates, though equipped with "built-in" communication, have very large resource overheads; likewise, computers with reliable probabilistic gates between photons or quantum memories may lack sufficient communication resources in the presence of realistic optical losses. Here, we consider a compromise architecture, in which semiconductor spin qubits are coupled by bright laser pulses through nanophotonic waveguides and cavities using a combination of frequent probabilistic and sparse determinstic entanglement mechanisms. The large photonic resource requirements incurred by the use of probabilistic gates for quantum communication are mitigated in part by the potential high-speed operation of the semiconductor nanophotonic hardware. The system employs topological cluster-state quantum error correction for achieving fault-tolerance. Our results suggest that such an architecture/technology combination has the potential to scale to a system capable of attacking classically intractable computational problems.

Rodney Van Meter; Thaddeus D. Ladd; Austin G. Fowler; Yoshihisa Yamamoto

2009-09-17T23:59:59.000Z

437

Metals 2000  

SciTech Connect (OSTI)

This strategic planning exercise identified and characterized new and emerging advanced metallic technologies in the context of the drastic changes in global politics and decreasing fiscal resources. In consideration of a hierarchy of technology thrusts stated by various Department of Defense (DOD) spokesmen, and the need to find new and creative ways to acquire and organize programs within an evolving Wright Laboratory, five major candidate programs identified are: C-17 Flap, Transport Fuselage, Mach 5 Aircraft, 4.Fighter Structures, and 5. Missile Structures. These results were formed by extensive discussion with selected major contractors and other experts, and a survey of advanced metallic structure materials. Candidate structural applications with detailed metal structure descriptions bracket a wide variety of uses which warrant consideration for the suggested programs. An analysis on implementing smart skins and structures concepts is given from a metal structures perspective.

Allison, S.W.; Rogers, L.C.; Slaughter, G. [Oak Ridge National Lab., TN (United States); Boensch, F.D. [6025 Oak Hill Lane, Centerville, OH (United States); Claus, R.O.; de Vries, M. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)

1993-05-01T23:59:59.000Z

438

Dendritic metal nanostructures  

DOE Patents [OSTI]

Dendritic metal nanostructures made using a surfactant structure template, a metal salt, and electron donor species.

Shelnutt, John A. (Tijeras, NM); Song, Yujiang (Albuquerque, NM); Pereira, Eulalia F. (Vila Nova de Gaia, PT); Medforth, Craig J. (Winters, CA)

2010-08-31T23:59:59.000Z

439

PRECISION CLEANING OF SEMICONDUCTOR SURFACES USING CARBON DIOXIDE-BASED FLUIDS  

SciTech Connect (OSTI)

The Los Alamos National Laboratory, on behalf of the Hewlett-Packard Company, is conducting tests of a closed-loop CO{sub 2}-based supercritical fluid process, known as Supercritical CO{sub 2} Resist Remover (SCORR). We have shown that this treatment process is effective in removing hard-baked, ion-implanted photoresists, and appears to be fully compatible with metallization systems. We are now performing experiments on production wafers to assess not only photoresist removal, but also residual surface contamination due to particulate and trace metals. Dense-phase (liquid or supercritical) CO{sub 2}, since it is non-polar, acts like an organic solvent and therefore has an inherently high volubility for organic compounds such as oils and greases. Also, dense CO{sub 2} has a low-viscosity and a low dielectric constant. Finally, CO{sub 2} in the liquid and supercritical fluid states can solubilize metal completing agents and surfactants. This combination of properties has interesting implications for the removal not only of organic films, but also trace metals and inorganic particulate. In this paper we discuss the possibility of using CO{sub 2} as a precision-cleaning solvent, with particular emphasis on semiconductor surfaces.

J. RUBIN; L. SIVILS; A. BUSNAINA

1999-07-01T23:59:59.000Z

440

Investigation of the impact of insulator material on the performance of dissimilar electrode metal-insulator-metal diodes  

SciTech Connect (OSTI)

The performance of thin film metal-insulator-metal (MIM) diodes is investigated for a variety of large and small electron affinity insulators using ultrasmooth amorphous metal as the bottom electrode. Nb{sub 2}O{sub 5}, Ta{sub 2}O{sub 5}, ZrO{sub 2}, HfO{sub 2}, Al{sub 2}O{sub 3}, and SiO{sub 2} amorphous insulators are deposited via atomic layer deposition (ALD). Reflection electron energy loss spectroscopy (REELS) is utilized to measure the band-gap energy (E{sub G}) and energy position of intrinsic sub-gap defect states for each insulator. E{sub G} of as-deposited ALD insulators are found to be Nb{sub 2}O{sub 5}?=?3.8?eV, Ta{sub 2}O{sub 5}?=?4.4?eV, ZrO{sub 2}?=?5.4?eV, HfO{sub 2}?=?5.6?eV, Al{sub 2}O{sub 3}?=?6.4?eV, and SiO{sub 2}?=?8.8?eV with uncertainty of 0.2?eV. Current vs. voltage asymmetry, non-linearity, turn-on voltage, and dominant conduction mechanisms are compared. Al{sub 2}O{sub 3} and SiO{sub 2} are found to operate based on Fowler-Nordheim tunneling. Al{sub 2}O{sub 3} shows the highest asymmetry. ZrO{sub 2}, Nb{sub 2}O{sub 5}, and Ta{sub 2}O{sub 5} based diodes are found to be dominated by Frenkel-Poole emission at large biases and exhibit lower asymmetry. The electrically estimated trap energy levels for defects that dominate Frenkel-Poole conduction are found to be consistent with the energy levels of surface oxygen vacancy defects observed in REELS measurements. For HfO{sub 2}, conduction is found to be a mix of trap assisted tunneling and Frenkel-Poole emission. Insulator selection criteria in regards to MIM diodes applications are discussed.

Alimardani, Nasir; Tan, Cheng; Lampert, Benjamin P.; Conley, John F., E-mail: jconley@eecs.oregonstate.edu [School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331 (United States); King, Sean W. [Logic Technology Development, Intel Corporation, Hillsboro, Oregon 97124 (United States); French, Benjamin L. [Ocotillo Materials Laboratory, Intel Corporation, Chandler, Arizona 85248 (United States)

2014-07-14T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Mechano-Activated Electronic and Molecular Structures  

E-Print Network [OSTI]

and conductive. In the bulk, graphite is an anisotropic metal. For a single graphite plane (graphene), it is a zero band gap semiconductor. Diamond contains only sp 3 hybridization which results in the strong, directional ? bond. It has a hardness of 100 GPa... between atoms and molecules via heat. A study on tailoring the electronic structure of a bilayer graphene via potassium doping was reported by T. Ohta et al. 13 In the study, they synthesized the bilayer graphene thin film on insulating carbide...

Wang, Ke

2011-02-22T23:59:59.000Z

442

Development of fluorocarbon evaporative cooling recirculators and controls for the ATLAS pixel and semiconductor tracking detectors  

E-Print Network [OSTI]

Development of fluorocarbon evaporative cooling recirculators and controls for the ATLAS pixel and semiconductor tracking detectors

Bayer, C; Bonneau, P; Bosteels, Michel; Burckhart, H J; Cragg, D; English, R; Hallewell, G D; Hallgren, Bjrn I; Kersten, S; Kind, P; Langedrag, K; Lindsay, S; Merkel, M; Stapnes, Steinar; Thadome, J; Vacek, V

2000-01-01T23:59:59.000Z

443

Simulation of neutron radiation damage in silicon semiconductor devices.  

SciTech Connect (OSTI)

A code, Charon, is described which simulates the effects that neutron damage has on silicon semiconductor devices. The code uses a stabilized, finite-element discretization of the semiconductor drift-diffusion equations. The mathematical model used to simulate semiconductor devices in both normal and radiation environments will be described. Modeling of defect complexes is accomplished by adding an additional drift-diffusion equation for each of the defect species. Additionally, details are given describing how Charon can efficiently solve very large problems using modern parallel computers. Comparison between Charon and experiment will be given, as well as comparison with results from commercially-available TCAD codes.

Shadid, John Nicolas; Hoekstra, Robert John; Hennigan, Gary Lee; Castro, Joseph Pete Jr.; Fixel, Deborah A.

2007-10-01T23:59:59.000Z

444

Photonic crystal membrane reflectors by magnetic field-guided metal-assisted chemical etching  

SciTech Connect (OSTI)

Metal-assisted chemical etching (MacEtch) is a simple etching method that uses metal as the catalyst for anisotropic etching of semiconductors. However, producing nano-structures using MacEtch from discrete metal patterns, in contrast to interconnected ones, has been challenging because of the difficulties in keeping the discrete metal features in close contact with the semiconductor. We report the use of magnetic field-guided MacEtch (h-MacEtch) to fabricate periodic nanohole arrays in silicon-on-insulator (SOI) wafers for high reflectance photonic crystal membrane reflectors. This study demonstrates that h-MacEtch can be used in place of conventional dry etching to produce ordered nanohole arrays for photonic devices.

Balasundaram, Karthik; Mohseni, Parsian K.; Li, Xiuling, E-mail: wzhou@uta.edu, E-mail: xiuling@illinois.edu [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)] [Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Shuai, Yi-Chen; Zhao, Deyin; Zhou, Weidong, E-mail: wzhou@uta.edu, E-mail: xiuling@illinois.edu [Department of Electrical Engineering, NanoFAB Center, University of Texas at Arlington, Arlington, Texas 76019 (United States)] [Department of Electrical Engineering, NanoFAB Center, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2013-11-18T23:59:59.000Z

445

Evaluation of Novel Semiconductor Materials Potentially Useful in Solar Cells: Cooperative Research and Development Final Report, CRADA number CRD-06-00172  

SciTech Connect (OSTI)

Evaluation of novel semiconductor materials potentially useful in solar cells. NREL will fabricate, test and analyze solar cells from EpiWorks' wafers produced in 2-3 separate growth campaigns. NREL will also characterize material from 2-3 separate EpiWorks material development campaigns. Finally, NREL will visit EpiWorks and help establish any necessary process, such as spectral CV measurements and III-V on Si metalization processes and help validate solar cell designs and performance.

Geisz, J.

2010-07-01T23:59:59.000Z

446

Energy Conservation Through Water Usage Reduction in the Semiconductor Industry  

E-Print Network [OSTI]

The semiconductor industry uses large amounts of Ultrapure Water (UPW) in the wafer fabrication process. Producing UPW involves energy-intensive operations, such as membrane separations, ultraviolet lamps, and continuous pumping and recirculation...

Mendicino, L.; McCormack, K.; Gibson, S.; Patton, B.; Lyon, D.; Covington, J.

447

Data sheet acquired from Harris Semiconductor Buffered Inputs  

E-Print Network [OSTI]

1 Data sheet acquired from Harris Semiconductor SCHS121D Features · Buffered Inputs · Typical. The suffixes 96 and R denote tape and reel. The suffix T denotes a small-quantity reel of 250. CAUTION

Kretchmar, R. Matthew

448

Data sheet acquired from Harris Semiconductor Four Operating Modes  

E-Print Network [OSTI]

1 Data sheet acquired from Harris Semiconductor SCHS164F Features · Four Operating Modes - Shift Ld PDIP NOTE: When ordering, use the entire part number. The suffixes 96 and R denote tape and reel

Kretchmar, R. Matthew

449

AlGaN/GaN-based power semiconductor switches  

E-Print Network [OSTI]

AlGaN/GaN-based high-electron-mobility transistors (HEMTs) have great potential for their use as high efficiency and high speed power semiconductor switches, thanks to their high breakdown electric field, mobility and ...

Lu, Bin, Ph. D. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

450

Thermo-electrically pumped semiconductor light emitting diodes  

E-Print Network [OSTI]

Thermo-electric heat exchange in semiconductor light emitting diodes (LEDs) allows these devices to emit optical power in excess of the electrical power used to drive them, with the remaining power drawn from ambient heat. ...

Santhanam, Parthiban

2014-01-01T23:59:59.000Z

451

Improving reuse of semiconductor equipment through benchmarking, standardization, and automation  

E-Print Network [OSTI]

The 6D program at Intel Corporation was set up to improve operations around capital equipment reuse, primarily in their semiconductor manufacturing facilities. The company was faced with a number of challenges, including ...

Silber, Jacob B. (Jacob Bradley)

2006-01-01T23:59:59.000Z

452

Semiconductor nanowire array: potential substrates for photocatalysis and photovoltaics  

E-Print Network [OSTI]

Semiconductor nanowire array: potential substrates for photocatalysis and photovoltaics Yiying Wu, these nanowire arrays could find unique applications in photocatalysis and photovoltaics. KEY WORDS luminescence efficiency [5,6], enhancement of thermoelectric figure of merit [7] and lowered lasing threshold

Yang, Peidong

453

Translating semiconductor device physics into nanoparticle films for electronic applications  

E-Print Network [OSTI]

This thesis explores and quantifies some of the important device physics, parameters, and mechanisms of semiconductor nanocrystal quantum dot (QD) electronic devices, and photovoltaic devices in particular. This involves ...

Wanger, Darcy Deborah

2014-01-01T23:59:59.000Z

454

Semiconductor nanocrystals : synthesis, mechanisms of formation, and applications in biology  

E-Print Network [OSTI]

The primary focus of this thesis is the synthesis and applications of semiconductor nanocrystals, or quantum dots (QDs). Novel synthetic routes to ternary 1-III-VI QDs are presented, and we report the first highly luminescent ...

Allen, Peter M. (Peter Matthew)

2010-01-01T23:59:59.000Z

455

Exploring and enhancing conductivity in semiconductor nanoparticle films  

E-Print Network [OSTI]

Semiconductor nanocrystals (NCs) are a promising material for use in opto-electronic devices as their optical properties tune with particle size. NCs formed via colloidal synthesis are suspended in solution by the organic ...

Porter, Venda Jane

2007-01-01T23:59:59.000Z

456

Phenomenological band structure model of magnetic coupling in semiconductors  

E-Print Network [OSTI]

Phenomenological band structure model of magnetic coupling in semiconductors Gustavo M. Dalpian a,1­18]. Several models have been proposed to explain the phenomena, including the phenomenological Zener

Gong, Xingao

457

FRONTIERS ARTICLE Theory of multiexciton generation in semiconductor nanocrystals  

E-Print Network [OSTI]

FRONTIERS ARTICLE Theory of multiexciton generation in semiconductor nanocrystals Eran Rabani a's function formalism to calculate the efficiency of multiexciton generation in nanocrystal quantum dots multiexciton generation in nanocrystals, are reviewed and rederived from the unified theory as certain

Baer, Roi

458

Printable semiconductor structures and related methods of making and assembling  

DOE Patents [OSTI]

The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Urbana, IL); Lee, Keon Jae (Tokyo, JP); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Westmont, IL); Meitl, Matthew (Champaign, IL); Zhu, Zhengtao (Rapid City, SD); Ko, Heung Cho (Urbana, IL); Mack, Shawn (Goleta, CA)

2010-09-21T23:59:59.000Z

459

Printable semiconductor structures and related methods of making and assembling  

DOE Patents [OSTI]

The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

Nuzzo, Ralph G.; Rogers, John A.; Menard, Etienne; Lee, Keon Jae; Khang; , Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao; Ko, Heung Cho; Mack, Shawn

2013-03-12T23:59:59.000Z

460

Printable semiconductor structures and related methods of making and assembling  

DOE Patents [OSTI]

The present invention provides a high yield pathway for the fabrication, transfer and assembly of high quality printable semiconductor elements having selected physical dimensions, shapes, compositions and spatial orientations. The compositions and methods of the present invention provide high precision registered transfer and integration of arrays of microsized and/or nanosized semiconductor structures onto substrates, including large area substrates and/or flexible substrates. In addition, the present invention provides methods of making printable semiconductor elements from low cost bulk materials, such as bulk silicon wafers, and smart-materials processing strategies that enable a versatile and commercially attractive printing-based fabrication platform for making a broad range of functional semiconductor devices.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Durham, NC); Lee, Keon Jae (Tokyo, JP); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Westmont, IL); Meitl, Matthew (Raleigh, NC); Zhu, Zhengtao (Rapid City, SD); Ko, Heung Cho (Urbana, IL); Mack, Shawn (Goleta, CA)

2011-10-18T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Spectral properties of semiconductor nanocrystals and their applications  

E-Print Network [OSTI]

The ability to engineer the optical properties of the semiconductor nanocrystals by controlling their growth - size, shape, materials, coatings, etc - makes them appealing for many optical applications. Despite the impressive ...

Liptay, Thomas J. (Thomas John)

2007-01-01T23:59:59.000Z

462

DOI: 10.1002/adma.200601787 Microsolidics: Fabrication of Three-Dimensional Metallic  

E-Print Network [OSTI]

.[18] The technique has also been used to form 3D connec- tions (e.g., bridging opposite sides approaches to bridge electrical "islands" of metal by heating solid rods of solder "on chip"--the solder oxide semiconductor field-effect transistors,[26] and flexible goldpolymer nano- composites as passive

Prentiss, Mara

463

Gain assisted propagation of surface plasmon polaritons on planar metallic waveguides  

E-Print Network [OSTI]

and optical gain in InGaAsP quantum well lasers," Semiconductors 36, 344-353 (2002). 17. S. Y. Hu, D. B. Young compensate for the absorption losses in the metal. The conditions for existence of a surface plasmon

Fainman, Yeshaiahu

464

Trending: Metal Oxo Bonds  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

including materials science, chemistry, and biology. Highly covalent metal-oxygen multiple bonds (metal oxos) are the building blocks of metal oxides and have a bearing...

465

Composite metal membrane  

DOE Patents [OSTI]

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, Nathaniel M. (Espanola, NM); Dye, Robert C. (Los Alamos, NM); Snow, Ronny C. (Los Alamos, NM); Birdsell, Stephan A. (Los Alamos, NM)

1998-01-01T23:59:59.000Z

466

Composite metal membrane  

DOE Patents [OSTI]

A composite metal membrane including a first metal layer of Group IVB met or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof is provided together with a process for the recovery of hydrogen from a gaseous mixture including contacting a hydrogen-containing gaseous mixture with a first side of a nonporous composite metal membrane including a first metal of Group IVB metals or Group VB metals, the first metal layer sandwiched between two layers of an oriented metal of palladium, platinum or alloys thereof, and, separating hydrogen from a second side of the nonporous composite metal membrane.

Peachey, N.M.; Dye, R.C.; Snow, R.C.; Birdsell, S.A.

1998-04-14T23:59:59.000Z

467

Thermally robust semiconductor optical amplifiers and laser diodes  

DOE Patents [OSTI]

A highly heat conductive layer is combined with or placed in the vicinity of the optical waveguide region of active semiconductor components. The thermally conductive layer enhances the conduction of heat away from the active region, which is where the heat is generated in active semiconductor components. This layer is placed so close to the optical region that it must also function as a waveguide and causes the active region to be nearly the same temperature as the ambient or heat sink. However, the semiconductor material itself should be as temperature insensitive as possible and therefore the invention combines a highly thermally conductive dielectric layer with improved semiconductor materials to achieve an overall package that offers improved thermal performance. The highly thermally conductive layer serves two basic functions. First, it provides a lower index material than the semiconductor device so that certain kinds of optical waveguides may be formed, e.g., a ridge waveguide. The second and most important function, as it relates to this invention, is that it provides a significantly higher thermal conductivity than the semiconductor material, which is the principal material in the fabrication of various optoelectronic devices.

Dijaili, Sol P. (Moraga, CA); Patterson, Frank G. (Danville, CA); Walker, Jeffrey D. (El Cerrito, CA); Deri, Robert J. (Pleasanton, CA); Petersen, Holly (Manteca, CA); Goward, William (Antioch, CA)

2002-01-01T23:59:59.000Z

468

Celebrating Faculty Excellence acclaiming the awards, honors,  

E-Print Network [OSTI]

of the world's foremost experts on doping wide band-gap semiconductors, creating blue and ultraviolet light-emitting diodes (leds) and lasers that have led to improved consumer products, including sharper laser printers

469

Photoluminescence and Extended X-ray Absorption Fine Structure Studies on CdTe Material.  

E-Print Network [OSTI]

??The direct-band-gap semiconductor CdTe is an important material for fabricating high efficiency, polycrystalline thin-film solar cells in a heterojunction configuration. The outstanding physical properties of (more)

Liu, Xiangxin

2006-01-01T23:59:59.000Z

470

Visible and Infra-red Light Emission in Boron-Doped Wurtzite Silicon Nanowires  

E-Print Network [OSTI]

Silicon, the mainstay semiconductor in microelectronic circuitry, is considered unsuitable for optoelectronic applications owing to its indirect electronic band gap, which limits its efficiency as a light emitter. Here we ...

Fabbri, Filippo

471

Thin Film Solid-State Reactions Forming Carbides as Contact Materials for Carbon-Containing Semiconductors  

SciTech Connect (OSTI)

Metal carbides are good candidates to contact carbon-based semiconductors (SiC, diamond, and carbon nanotubes). Here, we report on an in situ study of carbide formation during the solid-state reaction between thin films. The solid-state reaction was examined between 11 transition metals (W, Mo, Fe, Cr, V, Nb, Mn, Ti, Ta, Zr, and Hf) and an amorphous carbon layer. Capping layers (C or TiN) of different thicknesses were applied to prevent oxidation. Carbide formation is evidenced for nine metals and the phases formed have been identified (for a temperature ranging from 100 to 1100 C). W first forms W{sub 2}C and then WC; Mo forms Mo{sub 2}C; Fe forms Fe{sub 3}C; Cr first forms metastable phases Cr{sub 2}C and Cr{sub 3}C{sub 2-x}, and finally forms Cr{sub 3}C{sub 2}; V forms VC{sub x}; Nb transforms into Nb{sub 2}C followed by NbC; Ti forms TiC; Ta first forms Ta{sub 2}C and then TaC; and Hf transforms into HfC. The activation energy for the formation of the various carbide phases has been obtained by in situ x-ray diffraction.

Leroy,W.; Detavernier, C.; Van Meirhaeghe, R.; Lavoie, C.

2007-01-01T23:59:59.000Z

472

Three-Dimensional Topological Insulators in I-III-VI2 and II-IV-V2 Chalcopyrite Semiconductors  

SciTech Connect (OSTI)

The recent discovery of topological insulators with exotic metallic surface states has garnered great interest in the fields of condensed matter physics and materials science.1 A number of spectacular quantum phenomena have been predicted when the surface states are under the influence of magnetism and superconductivity,2 5 which could open up new opportunities for technological applications in spintronics and quantum computing. To achieve this goal, material realization of topological insulators with desired physical properties is of crucial importance. Based on first-principles calculations, here we show that a large number of ternary chalcopyrite compounds of composition I-III-VI2 and II-IV-V2 can realize the topological insulating phase in their native states. The crystal structure of chalcopyrites is derived from the frequently used zinc-blende structure, and many of them possess a close lattice match to important mainstream semiconductors, which is essential for a smooth integration into current semiconductor technology. The diverse optical, electrical and structural properties of chalcopyrite semiconductors,6 and particularly their ability to host room-temperature ferromagnetism,7 9 make them appealing candidates for novel spintronic devices.

Feng, wanxiang [Chinese Academy of Sciences; Ding, Jun [Beijing National Laboratory for Condensed Matter Physics/Chinese Academy of Scie; Xiao, Di [ORNL; Yao, yugui [Chinese Academy of Sciences

2011-01-01T23:59:59.000Z

473

Three-Dimensional Topological Insulators in I-III-VI$_2$ and II-IV-V$_2$ Chalcopyrite Semiconductors  

E-Print Network [OSTI]

The recent discovery of topological insulators with exotic metallic surface states has garnered great interest in the fields of condensed matter physics and materials science. A number of spectacular quantum phenomena have been predicted when the surface states are under the influence of magnetism and superconductivity, which could open up new opportunities for technological applications in spintronics and quantum computing. To achieve this goal, material realization of topological insulators with desired physical properties is of crucial importance. Based on first-principles calculations, here we show that a large number of ternary chalcopyrite compounds of composition I-III-VI$_2$ and II-IV-V$_2$ can realize the topological insulating phase in their native states. The crystal structure of chalcopyrites is derived from the frequently used zinc-blende structure, and many of them possess a close lattice match to important mainstream semiconductors, which is essential for a smooth integration into current semiconductor technology. The diverse optical, electrical and structural properties of chalcopyrite semiconductors, and particularly their ability to host room-temperature ferromagnetism, make them appealing candidates for novel spintronic devices.

Wanxiang Feng; Jun Ding; Di Xiao; Yugui Yao

2010-07-31T23:59:59.000Z

474

Realizing high-quality, ultra-large momentum states using semiconductor hyperbolic metamaterials  

E-Print Network [OSTI]

We employ both the effective medium approximation (EMA) and Bloch theory to compare the dispersion properties of semiconductor hyperbolic metamaterials (SHMs) at mid-infrared frequencies and metallic hyperbolic metamaterials (MHMs) at visible frequencies. This analysis reveals the conditions under which the EMA can be safely applied for both MHMs and SHMs. We find that the combination of precise nanoscale layering and the longer infrared operating wavelengths puts the SHMs well within the effective medium limit and, in contrast to MHMs, allows the attainment of very high photon momentum states. In addition, SHMs allow for new phenomena such as ultrafast creation of the hyperbolic manifold through optical pumping. In particular, we examine the possibility of achieving ultrafast topological transitions through optical pumping which can photo-dope appropriately designed quantum wells on the femtosecond time scale.

Campione, Salvatore; Luk, Ting S; Sinclair, Michael B

2015-01-01T23:59:59.000Z

475

Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys  

SciTech Connect (OSTI)

The layer structured hexagonal boron nitride carbon semiconductor alloys, h-(BN)C, offer the unique abilities of bandgap engineering (from 0 for graphite to ?6.4 eV for h-BN) and electrical conductivity control (from semi-metal for graphite to insulator for undoped h-BN) through alloying and have the potential to complement III-nitride wide bandgap semiconductors and carbon based nanostructured materials. Epilayers of (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys were synthesized by metal-organic chemical vapor deposition (MOCVD) on (0001) sapphire substrates. Hall-effect measurements revealed that homogeneous (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys are naturally n-type. For alloys with x = 0.032, an electron mobility of about 20 cm{sup 2}/Vs at 650?K was measured. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition and analyze chemical bonding states. Both composition and chemical bonding analysis confirm the formation of alloys. XPS results indicate that the carbon concentration in the alloys increases almost linearly with the flow rate of the carbon precursor (propane (C{sub 3}H{sub 8})) employed during the epilayer growth. XPS chemical bonding analysis showed that these MOCVD grown alloys possess more C-N bonds than C-B bonds, which possibly renders the undoped h-(BN){sub 1-x}(C{sub 2}){sub x} alloys n-type and corroborates the Hall-effect measurement results.

Uddin, M. R.; Doan, T. C.; Li, J.; Lin, J. Y.; Jiang, H. X., E-mail: hx.jiang@ttu.edu [Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX 79409 (United States); Ziemer, K. S. [Department of Chemical Engineering, Northeastern University, Boston, MA 02115 (United States)

2014-08-15T23:59:59.000Z

476

Metal Hydrides  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department of EnergyDevelopmentTechnologies |Charles Page -toMetabolic PathwaysMetal

477

Mechanochemical processing for metals and metal alloys  

DOE Patents [OSTI]

A set of processes for preparing metal powders, including metal alloy powders, by ambient temperature reduction of a reducible metal compound by a reactive metal or metal hydride through mechanochemical processing. The reduction process includes milling reactants to induce and complete the reduction reaction. The preferred reducing agents include magnesium and calcium hydride powders. A process of pre-milling magnesium as a reducing agent to increase the activity of the magnesium has been established as one part of the invention.

Froes, Francis H. (Moscow, ID); Eranezhuth, Baburaj G. (Moscow, ID); Prisbrey, Keith (Moscow, ID)

2001-01-01T23:59:59.000Z

478

Spin-polarized lasing in a highly photoexcited semiconductor microcavity  

E-Print Network [OSTI]

Lasing in semiconductors is generally independent of the spins of electrons and holes, which constitute the gain medium. However, in a few spin-controlled lasers, spin-polarized carriers with long spin relaxation times ($\\sim$1 ns) result in continuous or sub-nanosecond pulsed circularly polarized stimulated emission. In these spin-controlled semiconductor lasers, a spin-imbalanced population inversion has been considered necessary. Here, we demonstrate room-temperature spin-polarized ultrafast ($\\sim$10 ps) lasing in a highly optically excited GaAs microcavity embedded with InGaAs multiple quantum wells within which the spin relaxation time is less than 10 ps. The laser radiation remains highly circularly polarized even when excited by \\emph{nonresonant} \\emph{elliptically} polarized light. In contrast to conventional semiconductor lasers, it exhibits a nonlinear input-output relation, energy shifts, and spectral broadening as a function of the photoexcited density. Such spin-polarized lasing is attributed t...

Hsu, Feng-kuo; Lee, Yi-Shan; Lin, Sheng-Di; Lai, Chih-Wei

2015-01-01T23:59:59.000Z

479

Efficient semiconductor light-emitting device and method  

DOE Patents [OSTI]

A semiconductor light-emitting device and method. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL).

Choquette, Kent D. (Albuquerque, NM); Lear, Kevin L. (Albuquerque, NM); Schneider, Jr., Richard P. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

480

Efficient semiconductor light-emitting device and method  

DOE Patents [OSTI]

A semiconductor light-emitting device and method are disclosed. The semiconductor light-emitting device is provided with at least one control layer or control region which includes an annular oxidized portion thereof to channel an injection current into the active region, and to provide a lateral refractive index profile for index guiding the light generated within the device. A periodic composition grading of at least one of the mirror stacks in the device provides a reduced operating voltage of the device. The semiconductor light-emitting device has a high efficiency for light generation, and may be formed either as a resonant-cavity light-emitting diode (RCLED) or as a vertical-cavity surface-emitting laser (VCSEL). 12 figs.

Choquette, K.D.; Lear, K.L.; Schneider, R.P. Jr.

1996-02-20T23:59:59.000Z

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Wafer Fusion for Integration of Semiconductor Materials and Devices  

SciTech Connect (OSTI)

We have developed a wafer fusion technology to achieve integration of semiconductor materials and heterostructures with widely disparate lattice parameters, electronic properties, and/or optical properties for novel devices not now possible on any one substrate. Using our simple fusion process which uses low temperature (400-600 C) anneals in inert N{sub 2} gas, we have extended the scope of this technology to examine hybrid integration of dissimilar device technologies. As a specific example, we demonstrate wafer bonding vertical cavity surface emitting lasers (VCSELs) to transparent AlGaAs and GaP substrates to fabricate bottom-emitting short wavelength VCSELs. As a baseline fabrication technology applicable to many semiconductor systems, wafer fusion will revolutionize the way we think about possible semiconductor devices, and enable novel device configurations not possible by epitaxial growth.

Choquette, K.D.; Geib, K.M.; Hou, H.Q.; Allerman, A.A.; Kravitz, S.; Follstaedt, D.M.; Hindi, J.J.

1999-05-01T23:59:59.000Z

482

OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES  

SciTech Connect (OSTI)

This chapter provides an overview of some recent research activities on the study of optical and dynamic properties of semiconductor nanomaterials. The emphasis is on unique aspects of these properties in nanostructures as compared to bulk materials. Linear, including absorption and luminescence, and nonlinear optical as well as dynamic properties of semiconductor nanoparticles are discussed with focus on their dependence on particle size, shape, and surface characteristics. Both doped and undoped semiconductor nanomaterials are highlighted and contrasted to illustrate the use of doping to effectively alter and probe nanomaterial properties. Some emerging applications of optical nanomaterials are discussed towards the end of the chapter, including solar energy conversion, optical sensing of chemicals and biochemicals, solid state lighting, photocatalysis, and photoelectrochemistry.

Grant, C D; Zhang, J Z

2007-09-28T23:59:59.000Z

483

Wavelength-resonant surface-emitting semiconductor laser  

DOE Patents [OSTI]

A wavelength resonant semiconductor gain medium is disclosed. The essential feature of this medium is a multiplicity of quantum-well gain regions separated by semiconductor spacer regions of higher bandgap. Each period of this medium consisting of one quantum-well region and the adjacent spacer region is chosen such that the total width is equal to an integral multiple of 1/2 the wavelength in the medium of the radiation with which the medium is interacting. Optical, electron-beam and electrical injection pumping of the medium is disclosed. This medium may be used as a laser medium for single devices or arrays either with or without reflectors, which may be either semiconductor or external.

Brueck, Steven R. J. (Albuquerque, NM); Schaus, Christian F. (Albuquerque, NM); Osinski, Marek A. (Albuquerque, NM); McInerney, John G. (Cedar Crest, NM); Raja, M. Yasin A. (Albuquerque, NM); Brennan, Thomas M. (Albuquerque, NM); Hammons, Burrell E. (Tijeras, NM)

1989-01-01T23:59:59.000Z

484

Solar Energy Materials & Solar Cells 91 (2007) 15991610 Improving solar cell efficiency using photonic band-gap materials  

E-Print Network [OSTI]

Solar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using) solar energy conversion systems (or solar cells) are the most widely used power systems. However and reliable solar-cell devices is presented. We show that due their ability to modify the spectral and angular

Dowling, Jonathan P.

485

PHYSICAL REVIEW B 84, 035315 (2011) Theoretical analysis of the crystal structure, band-gap energy, polarization, and piezoelectric  

E-Print Network [OSTI]

have already been incorporated in flat panel displays and solar cells as transparent electrodesO can be tailored by alloying ZnO with BeO for applications such as electrodes in flat panel displays and solar cells, blue and ultraviolet (UV) light emitting devices, and highly sensitive UV detectors. We

Alpay, S. Pamir

2011-01-01T23:59:59.000Z

486

One-photon band gap engineering of borate glass doped with ZnO for photonics applications  

SciTech Connect (OSTI)

Lithium tungsten borate glass of the composition (0.56-x)B{sub 2}O{sub 3}-0.4Li{sub 2}O-xZnO-0.04WO{sub 3} (0 {<=}x{<=} 0.1 mol. %) is prepared for photonics applications. The glass is doped with ZnO to tune the glass absorption characteristics in a wide spectrum range (200-2500 nm). Chemical bond approach, including chemical structure, electronegativity, bond ionicity, nearest-neighbor coordination, and other chemical bonding aspect, is used to analyze and to explain the obtained glass properties such as: transmittance, absorption, electronic structure parameters (bandgap, Fermi level, and Urbach exciton-phonon coupling), Wannier free excitons excitation (applying Elliott's model), and two-photon absorption coefficient as a result of replacement of B{sub 2}O{sub 3} by ZnO.

Abdel-Baki, Manal [Glass Department, National Research Centre, Dokki 12311 Giza (Egypt); Abdel-Wahab, Fathy A.; El-Diasty, Fouad [Physics Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo (Egypt)

2012-04-01T23:59:59.000Z

487

PHYSICAL REVIEW B 84, 245206 (2011) First-principles study of band gap engineering via oxygen vacancy doping  

E-Print Network [OSTI]

formulate guidelines that can be used to predict the location of oxygen vacancies in perovskite solid transport of O2- ions through the oxide electrolyte membrane over a range of temperatures. In solar energy several chemical compositions and different cation arrangements for the two Zr-modified solid solutions

Rappe, Andrew M.

488

Quasiparticle band structure and density-functional theory: Single-particle excitations and band gaps in lattice models  

E-Print Network [OSTI]

ARTICLES Quasiparticle band structure and density-functional theory: Single-particle excitations-particle eigenvalues. Without rigorous basis even for the exact density-functional theory , these are often taken, eigenvalues obtained from density-functional theory DFT , and those from a corresponding LDA. Notable among

Hess, Daryl W.

489

Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon band gap  

E-Print Network [OSTI]

Propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates: A split of phonon the propagation of Lamb waves in one-dimensional quasiperiodic composite thin plates made of tungsten B spectra, Raman scattering spectra, and propagating modes of acoustic waves on corrugated surfaces.14

Li, Baowen