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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

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

SciTech Connect

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

3

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

4

Forward Raman compression via photonic band gap in metals or warm dense matter  

SciTech Connect

The group velocity of a light pulse in photonic band gap material could considerably deviate from the speed of light in vacuum. A forward stoke and a pump pulse of different speeds would enable the Raman compression in metals or the warm dense matter. A small window of the parameter regime, where the compression is feasible via the forward Raman scattering, is identified.

Son, S. [18 Caleb Lane, Princeton, New Jersey 08540 (United States); Moon, Sung Joon [Program in Applied and Computational Mathematics, Princeton University, Princeton, New Jersey 08544 (United States)

2011-08-15T23:59:59.000Z

5

Analytical descriptions of the band structure of direct-band-gap zinc-blende-structure semiconductors in the k?p Kane model  

Science Journals Connector (OSTI)

In the framework of the well-known k?p Kane band theory, accurate analytical approximations of conduction- and valence-band dispersion of direct-band-gap zinc-blende-structure semiconductors are derived when the spin-orbit-splitting energy does not exceed the band-gap energy. These approximations include the interactions with the remote bands. The expressions of the eigenfunctions are also obtained. The present analysis elucidates and unifies previous analytical band descriptions.

H.-J. Drouhin and J. Peretti

1991-10-15T23:59:59.000Z

6

Optimizing the Q value in three-dimensional metallic photonic band gap crystals  

E-Print Network (OSTI)

, and for improving solar energy collection.12 The complementary inductive metallic patches are also FSS with a low in the transmission are created by removing portions of the metallic rods in a single defect layer. A high quality composed of material with a high dielectric constant in a lower dielec- tric background such as air

Soukoulis, Costas

7

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

NLE Websites -- All DOE Office Websites (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...

8

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

9

Electronic materials with a wide band gap: recent developments  

Science Journals Connector (OSTI)

Usually, semiconductors with a band gap Eg 3 eV or larger are called wide band gap materials. Their optical emission can span the whole of the visible spectrum, enabling the development of devices for solid-state lighting. In addition, a large Eg results in a high electrical breakthrough field, which is interesting for high-power electronics.

Klimm, D.

2014-08-29T23:59:59.000Z

10

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.

11

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print 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 devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key characteristic of all semiconductors, an energy gap (band gap) in its electronic band structure. A multi-institutional collaboration under the leadership of researchers with Berkeley Lab and the University of California, Berkeley, have now demonstrated that growing an epitaxial film of graphene on a silicon carbide substrate results in a significant band gap, 0.26 electron volts (eV), an important step toward making graphene useful as a semiconductor.

12

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

NLE Websites -- All DOE Office Websites (Extended Search)

Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print 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 devices, have to overcome silicon's superb collection of materials properties as well as sophisticated fabrication technologies refined by six decades of effort by materials scientists and engineers. Graphene, one of the latest contenders, has a rather impressive list of features of its own but has lacked a key characteristic of all semiconductors, an energy gap (band gap) in its electronic band structure. A multi-institutional collaboration under the leadership of researchers with Berkeley Lab and the University of California, Berkeley, have now demonstrated that growing an epitaxial film of graphene on a silicon carbide substrate results in a significant band gap, 0.26 electron volts (eV), an important step toward making graphene useful as a semiconductor.

13

Low band gap polymers Organic Photovoltaics  

E-Print Network (OSTI)

Low band gap polymers for Organic Photovoltaics Eva Bundgaard Ph.D. Dissertation Risø 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

14

Efficient Band Gap Prediction for Solids  

E-Print Network (OSTI)

An efficient method for the prediction of fundamental band gaps in solids using density functional theory (DFT) is proposed. Generalizing the Delta self-consistent-field (?SCF [delta SCF]) method to infinite solids, the ...

Chan, Maria K.

15

Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries...  

NLE Websites -- All DOE Office Websites (Extended Search)

Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Abstract: Structure and electronic properties of...

16

Semiconductor assisted metal deposition for nanolithography applications  

DOE Patents (OSTI)

An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

Rajh, Tijana (Naperville, IL); Meshkov, Natalia (Downers Grove, IL); Nedelijkovic, Jovan M. (Belgrade, YU); Skubal, Laura R. (West Brooklyn, IL); Tiede, David M. (Elmhurst, IL); Thurnauer, Marion (Downers Grove, IL)

2001-01-01T23:59:59.000Z

17

Semiconductor assisted metal deposition for nanolithography applications  

DOE Patents (OSTI)

An article of manufacture and method of forming nanoparticle sized material components. A semiconductor oxide substrate includes nanoparticles of semiconductor oxide. A modifier is deposited onto the nanoparticles, and a source of metal ions are deposited in association with the semiconductor and the modifier, the modifier enabling electronic hole scavenging and chelation of the metal ions. The metal ions and modifier are illuminated to cause reduction of the metal ions to metal onto the semiconductor nanoparticles.

Rajh, Tijana (Naperville, IL); Meshkov, Natalia (Downers Grove, IL); Nedelijkovic, Jovan M. (Belgrade, YU); Skubal, Laura R. (West Brooklyn, IL); Tiede, David M. (Elmhurst, IL); Thurnauer, Marion (Downers Grove, IL)

2002-01-01T23:59:59.000Z

18

Anomalous Doppler effects in phononic band gaps  

Science Journals Connector (OSTI)

Doppler effects in periodic acoustic media were studied theoretically and experimentally. Analytical formulas are derived using the Green’s function formalism. We found that a far field observer cannot hear the sound inside a band gap from a stationary source, but a moving source can be heard even if the frequency is inside the gap, and the Doppler shifts can be inverted or anomalously large.

Xinhua Hu; Zhihong Hang; Jensen Li; Jian Zi; C. T. Chan

2006-01-30T23:59:59.000Z

19

Substrate-Induced Band-Gap Opening in Epitaxial Graphene  

NLE Websites -- All DOE Office Websites (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...

20

Ideal Soliton Environment Using Parametric Band Gaps  

Science Journals Connector (OSTI)

Simultaneous solitary wave solutions for laser propagation in nonlinear parametric media with up to ( 3+1) dimensions are proved to exist. The combination of the large dispersion of a Bragg grating and the strong nonlinearity of ?(2) optical material results in stable behavior with short interaction distances and low power requirements. The solutions are obtained by using the effective mass approximation to reduce the coupled propagation equations to those describing a dispersive parametric nonlinear waveguide, and are verified by solving the complete set of coupled band-gap equations numerically.

H. He and P. D. Drummond

1997-06-09T23:59:59.000Z

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)

1997-01-01T23:59:59.000Z

22

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

23

Strain-induced band-gap engineering of graphene monoxide and its effect on graphene  

Science Journals Connector (OSTI)

Using first-principles calculations we demonstrate the feasibility of band-gap engineering in two-dimensional crystalline graphene monoxide (GMO), a recently reported graphene-based material with a 1:1 carbon/oxygen ratio. The band gap of GMO, which can be switched between direct and indirect, is tunable over a large range (0–1.35 eV) for accessible strains. Electron and hole transport occurs predominantly along the zigzag and armchair directions (armchair for both) when GMO is a direct- (indirect-) gap semiconductor. A band gap of ?0.5 eV is also induced in graphene at the K? points for GMO/graphene hybrid systems.

H. H. Pu; S. H. Rhim; C. J. Hirschmugl; M. Gajdardziska-Josifovska; M. Weinert; J. H. Chen

2013-02-13T23:59:59.000Z

24

Measurements of CsI band-gap closure to 93 GPa  

Science Journals Connector (OSTI)

Infrared-absorption measurements to a peak pressure of 93 GPa document the pressure-induced closure of the band gap of CsI to about 4450 cm-1 (0.55 eV). In accord with previous spectroscopic measurements to 60 GPa, our data show that the band gap of CsI decreases continuously with pressure, and metallization (complete closure of the gap) is expected to occur above 100 GPa. A recent claim that CsI becomes metallic at 65±5 GPa is therefore spurious.

Quentin Williams and Raymond Jeanloz

1986-01-13T23:59:59.000Z

25

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

26

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

NLE Websites -- All DOE Office Websites (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...

27

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

28

Inorganic Graphenylene: A Porous Two-Dimensional Material With Tunable Band Gap  

E-Print Network (OSTI)

By means of ab initio calculations we investigate the possibility of existence of a boron nitride (BN) porous two-dimensional nanosheet which is geometrically similar to the carbon allotrope known as biphenylene carbon. The proposed structure, which we called Inorganic Graphenylene (IGP), is formed spontaneously after selective dehydrogenation of the porous Boron Nitride (BN) structure proposed by Ding et al. We study the structural and electronic properties of both porous BN and IGP and it is shown that, by selective substitution of B and N atoms with carbon atoms in these structures, the band gap can be significantly reduced, changing their behavior from insulators to semiconductors, thus opening the possibility of band gap engineering for this class of two-dimensional materials.

Perim, Eric; Atreto, Pedro Alves da Silva; Galvão, Douglas

2014-01-01T23:59:59.000Z

29

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

30

Synthesis of electromagnetic modes in photonic band gap fibers  

E-Print Network (OSTI)

In this paper, we report on the successful synthesis of three individual modes, HE11, TEo0, and TE02 for transmission in photonic band gap fibers at near infrared wavelengths. We measure the propagation losses of the HE11 ...

Hu, Qichao

2007-01-01T23:59:59.000Z

31

Fabry-Perot tuning of the band-gap polarity in plasmonic crystals Jin E. Kihm,1 Y. C. Yoon,1 D. J. Park,1 Y. H. Ahn,1 C. Ropers,2 C. Lienau,2,3 J. Kim,4 Q. H. Park,5 and D. S. Kim1,  

E-Print Network (OSTI)

-resolved transmission spectra of nanoslit arrays in metal films demonstrate band-gap formation resulting from surface-gap flipping. Our results indicate an interesting route towards band-gap engineering in plasmonic crystals. DOI of electronic and photonic band gaps--i.e., energy regions with a vanishing density of states in crystal- line

Peinke, Joachim

32

Contacts Between Metals and Between a Metal and a Semiconductor  

Science Journals Connector (OSTI)

The problem of contacts between metals and between a metal and a semiconductor is treated classically with the help of the results of wave mechanical theory of electron energy states in solids. The potential and electron density distributions in the two bodies near the contact are discussed. The bodies are assumed to be in immediate contact. The problem of a body in vacuum and the problem of two bodies separated by a gap are discussed qualitatively.

H. Y. Fan

1942-10-01T23:59:59.000Z

33

Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries  

SciTech Connect

Structure and electronic properties of carbon nanotubes (CNTs) with grain boundaries (GBs) are investigated using density-functional calculations, where the GBs parallel and perpendicular to the tube axis are considered. Simulation results show that the GBs have a great effect on the electronic properties of the CNTs. For the GBs along the tube axis, the CNTs are narrow or zero band gap (<0.16 eV) materials, independent of the misorientation angle and diameter. For the GBs perpendicular to the tube axis, localized electronic states appear within the GBs regions, leading to a larger band gap of up to 0.6 eV. It is convenient to transport and localize the electrons and holes by engineering the GBs. These findings are of great significance for developing carbon-based nanomaterials and electronic devices.

Wang, Zhiguo; Zhou, Yungang; Zhang, Yanwen; Gao, Fei

2012-01-26T23:59:59.000Z

34

Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries  

SciTech Connect

Structure and electronic properties of carbon nanotubes (CNTs) with grain boundaries (GBs) are investigated using density-functional calculations, where the GBs parallel and perpendicular to the tube axis are considered. Simulation results show that the GBs have a great effect on the electronic properties of the CNTs. For the GBs along the tube axis, the CNTs are narrow or zero band gap (<0.16 eV) materials, independent of the misoritentaion angle and diameter. For the GBs perpendicular to the tube axis, localized electronic states appear within the GBs regions, leading to a larger band gap of up to 0.6 eV. It is convenient to transport and localize the electrons and holes by engineering the GBs. These findings are of great significance for developing carbon-based nanomaterials and electronic devices.

Wang, Zhiguo [Department of Applied Physics, University of Electronic Science and Technology of China; Zhou, Yungang [Department of Applied Physics, University of Electronic Science and Technology of China; Zhang, Yanwen [ORNL; Gao, Fei [ORNL

2011-01-01T23:59:59.000Z

35

Realization of Spin Gapless Semiconductors: The Heusler Compound Mn2CoAl  

Science Journals Connector (OSTI)

Recent studies have reported an interesting class of semiconductor materials that bridge the gap between semiconductors and half-metallic ferromagnets. These materials, called spin gapless semiconductors, exhibit a band gap in one of the spin channels and a zero band gap in the other and thus allow for tunable spin transport. Here, we report the first experimental verification of the spin gapless magnetic semiconductor Mn2CoAl, an inverse Heusler compound with a Curie temperature of 720 K and a magnetic moment of 2?B. Below 300 K, the compound exhibits nearly temperature-independent conductivity, very low, temperature-independent carrier concentration, and a vanishing Seebeck coefficient. The anomalous Hall effect is comparatively low, which is explained by the symmetry properties of the Berry curvature. Mn2CoAl is not only suitable material for room temperature semiconductor spintronics, the robust spin polarization of the spin gapless semiconductors makes it very promising material for spintronics in general.

Siham Ouardi; Gerhard H. Fecher; Claudia Felser; Jürgen Kübler

2013-03-05T23:59:59.000Z

36

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

37

Composition and temperature-induced effects on the phonon spectra of narrow-band-gap Hg1-xCdxTe  

Science Journals Connector (OSTI)

Compositional and temperature-dependent Raman and infrared spectroscopies on the narrow-band-gap II-VI alloy, Hg1-xCdxTe (0?x?0.29), are reported in this paper. Raman measurements over this composition range confirm the two-mode behavior of the optical phonons in the alloy, with the frequency positions exhibiting a monotonic change with the alloy composition x. A resonant enhancement of the HgTe-like forbidden longitudinal-optic mode is observed near the E1 band gap of the alloy. Alloy induced perturbations on the electronic states lead to a smearing and a weakening of the resonance with increasing alloy composition. The optical phonons in this small band-gap alloy exhibit anomalous frequency shifts as a function of temperature vis-à-vis normal wide-band-gap semiconductors. This anomaly is attributed to the strong electron-phonon interaction in narrow-band-gap systems, which overshadows the dominant anharmonic (phonon-phonon) interaction in usual semiconductors. A detailed compositional dependent second-order Raman spectra is also reported.

Shyama Rath, K. P. Jain, S. C. Abbi, C. Julien, and M. Balkanski

1995-12-15T23:59:59.000Z

38

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

NLE Websites -- All DOE Office Websites (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...

39

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

SciTech Connect

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

40

Semiconductor-To-Metal Transitions in Transition-Metal Compounds  

Science Journals Connector (OSTI)

The theory presented in a previous paper is applied to the transition-metal compounds which are known to exhibit semiconductor-to-metal transitions. In particular, the predictions of the theory are compared with the experimental results of Feinleib and Paul on V2O3. Very good agreement is obtained for the magnitude of the energy gap and for its pressure and stress coefficients. The theory appears to be consistent with the available data on the other oxides of vanadium and titanium as well. Band models for all of these compounds are suggested. The effects of spin-disorder scattering and broadening, polaron formation, and non-stoichiometry are considered quantitatively.

David Adler; Julius Feinleib; Harvey Brooks; William Paul

1967-03-15T23:59:59.000Z

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.


41

Lattice Boltzmann model for photonic band gap materials  

Science Journals Connector (OSTI)

An efficient technique for computing photonic band structure and defect modes is proposed based on the lattice Boltzmann model. Physically, it is a scheme based on the kinetics of the virtual microscopic process, rather than a solution of the macroscopic Maxwell equations. The method has significant advantages of being naturally suited for massively parallel machine, as well as speed and convenience, providing another methodology for photonic band gap materials and, also, for general electromagnetic scattering problems in open region when incorporated with the perfectly matched layer technique.

Zhifang Lin; Haiping Fang; Jianjun Xu; Jian Zi; Xiangdong Zhang

2003-02-07T23:59:59.000Z

42

Pseudomorphic GeSn/Ge(001) quantum wells: Examining indirect band gap bowing  

SciTech Connect

A study of the bandgap character of compressively strained GeSn{sub 0.060-0.091}/Ge(001) quantum wells grown by molecular beam epitaxy is reported. The built-in strain in GeSn wells leads to an increased separation between L and {Gamma} conduction band minima. The prevalent indirect interband transitions in GeSn were probed by photoluminescence spectroscopy. As a result we could simulate the L-valley bowing parameter in GeSn alloys, b{sub L} = 0.80 {+-} 0.06 eV at 10 K. From this we conclude that even compressively strained GeSn/Ge(001) alloys could become direct band gap semiconductors at the Sn-fraction higher than 17.0 at. %.

Tonkikh, Alexander A. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Institute for Physics of Microstructures RAS, GSP-105, Nizhniy Novgorod (Russian Federation); Eisenschmidt, Christian; Schmidt, Georg [Institute of Physics, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 3 D-01620, Halle (Saale) (Germany); Talalaev, Vadim G. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); ZIK SiLi-Nano, Martin Luther University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3 D-06120, Halle (Saale) (Germany); Zakharov, Nikolay D.; Werner, Peter [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Schilling, Joerg [ZIK SiLi-Nano, Martin Luther University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3 D-06120, Halle (Saale) (Germany)

2013-07-15T23:59:59.000Z

43

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

SciTech Connect

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

44

Comparative study of polyoxometalates and semiconductor metal oxides as catalyst. Photochemical oxidative degradation of thioethers  

SciTech Connect

The photochemical degradation of thioether substrates catalyzed by representative semiconductor metal oxides and sulfides (anatase TiO{sub 2}, SnO{sub 2}, cubic WO{sub 3}, and CdS) and photoredox-active early-transition-metal polyometalates (W{sub 10}O{sub 32}{sup 4{minus}}, PMo{sub 12}O{sub 40}{sup 3{minus}}, PW{sub 12}O{sub 40}{sup 3{minus}}, SiMo{sub 12}O{sub 40}{sup 4{minus}}, PV{sub 2}Mo{sub 10}O{sub 10}{sup 5{minus}}, and P{sub 2}W{sub 18}O{sub 62}{sup 6{minus}}) have been examined under both anaerobic and aerobic conditions. Under anaerobic conditions, all the semiconductors are completely ineffective at photochemically oxidizing or degrading the exemplary thioether substrate tetrahydrothiophene (THT) in the oxidatively resistant solvent acetonitrile. In contrast, all the homogeneous polyoxometalate systems under the same reaction condition, except the neutral tetra-n-butylammonium (Q) salt of PW{sub 12}O{sub 40}{sup 3{minus}}, are quite effective. The latter systems generate products derived from the carbon-based radical {alpha} to the sulfur atom and not sulfoxide or sulfone, the usual products of thioether oxidation by oxometal species. The rate for the most active anaerobic system, that involving the photochemical degradation of THT by Q{sub 4}W{sub 10}O{sub 32}, under optically dilute conditions, is first order in W{sub 10}O{sub 32} {sup 4{minus}} and light intensity and variable order in THT substrate. A rate law consistent with these data is given. Upon addition of O{sub 2}, TiO{sub 2} (with or without Pt(O)) becomes highly active, SnO{sub 2} becomes active, but WO{sub 3} and CdS remain inactive. Reactivity in thioether oxidation is dominated by the interactions of the semiconductors with O{sub 2} and O{sub 2}-derived intermediates; there is no correlation between reactivity and semiconductor band gap. Upon addition of O{sub 2}, all the polyoxometalate systems become more active. 29 refs., 4 figs., 3 tabs.

Chambers, R.C.; Hill, C.L. (Emory Univ., Atlanta, GA (United States))

1991-06-26T23:59:59.000Z

45

Onset of current selfquenching in a metalCdSLaS cold cathode in the presence of inelastic scattering in the CdS layer  

E-Print Network (OSTI)

# a wide band gap semiconductor #un­ doped CdS# sandwiched between a metallic contact that sup­ plies scattering in the CdS layer Yamini Modukuru and Marc Cahay a) Department of Electrical Engineering­charge effects in the cathode to anode gap region of a recently proposed metal/CdS/LaS cold cathode and its

Cahay, Marc

46

Evidence of the semiconductor-metal transition in V{sub 2}O{sub 5} thin films by the pulsed laser photoacoustic method  

SciTech Connect

In this work, the pulsed photoacoustic technique was used to investigate the semiconductor-metal transition of thin vanadium pentoxide films (V{sub 2}O{sub 5}) under increasing temperature. The V{sub 2}O{sub 5} thin films were simultaneously deposited by RF magnetron sputtering at room temperature, on corning glass and SnO{sub 2}:F/glass substrates, in order to compare the photoacoustic response. The elemental and structural analysis of the V{sub 2}O{sub 5} films was performed by Rutherford backscattering spectroscopy and X-ray diffraction. The optical transmission and band gap were determined using UV-Vis spectroscopy. The electrical properties were measured using four-point probe measurements with the Van der Pauw geometry.

Perez-Pacheco, A.; Acosta-Najarro, D. R.; Cruz-Manjarrez, H.; Rodriguez-Fernandez, L.; Pineda-Santamaria, J. C; Aguilar-Franco, M. [Instituto de Fisica-Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico)] [Instituto de Fisica-Universidad Nacional Autonoma de Mexico, Mexico DF (Mexico); Castaneda-Guzman, R. [Laboratorio de Fotofisica y Peliculas Delgadas, CCADET-UNAM, Mexico DF (Mexico)] [Laboratorio de Fotofisica y Peliculas Delgadas, CCADET-UNAM, Mexico DF (Mexico)

2013-05-14T23:59:59.000Z

47

InAlAs EPITAXIAL GROWTH FOR WIDE BAND GAP SOLAR CELLS Marina S. Leite  

E-Print Network (OSTI)

InAlAs EPITAXIAL GROWTH FOR WIDE BAND GAP SOLAR CELLS Marina S. Leite 1 , Robyn L. Woo 2 , William vapor phase epitaxy and wide band gap solar cell fabrication. X-ray diffraction and transmissionAlAs solar cells lattice-matched to InP were grown and electrically characterized under AM 1.5 global 1-sun

Atwater, Harry

48

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

49

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

SciTech Connect

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

50

Metal contacts on ZnSe and GaN  

SciTech Connect

Recently, considerable interest has been focused on the development of blue light emitting materials and devices. The focus has been on GaN and ZnSe, direct band gap semiconductors with bands gaps of 3.4 and 2.6 eV, respectively. To have efficient, reliable devices it is necessary to have thermally and electrically stable Ohmic contacts. This requires knowledge of the metal-semiconductor reaction behavior. To date few studies have investigated this behavior. Much information has accumulated over the years on the behavior of metals on Si and GaAs. This thesis provides new knowledge for the more ionic wide band gap semiconductors. The initial reaction temperatures, first phases formed, and phase stability of Pt, Pd, and Ni on both semiconductors were investigated. The reactions of these metals on ZnSe and GaN are discussed in detail and correlated with predicted behavior. In addition, comparisons are made between these highly ionic semiconductors and Si and GaAs. The trends observed here should also be applicable to other II-VI and III-Nitride semiconductor systems, while the information on phase formation and stability should be useful in the development of contacts for ZnSe and GaN devices.

Duxstad, K.J. [Univ. of California, Berkeley, CA (United States). Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

1997-05-01T23:59:59.000Z

51

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

SciTech Connect

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 ?1.5–2.0 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, NiO’s 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 NiO’s 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

52

Ternary silicon germanium nitrides: A class of tunable band gap materials  

Science Journals Connector (OSTI)

Ternary silicon germanium nitrides with compositions of both Si1?xGexN and (Si1?xGex)3N4 are predicted to have a band gap that decreases as the germanium:silicon ratio increases. The band gap is indirect for the silicon-rich compounds but becomes direct as the germanium content increases, due to greater mixing of s and p states in the conduction band. This effect of band gap tunability has recently been reported for (Si1?xGex)3N4 in the spinel structure [Boyko et al., Phys. Rev. B 81, 155207 (2010)]. Our results suggest that this is a more general effect and that ternary group-14 nitrides should form a class of semiconducting materials for which the band gap can be tuned by controlling the composition.

Judy N. Hart; Neil L. Allan; Frederik Claeyssens

2011-12-27T23:59:59.000Z

53

Triple photonic band-gap structure dynamically induced in the presence of spontaneously generated coherence  

SciTech Connect

We study a cold atomic sample coherently driven into the five-level triple-{Lambda} configuration for attaining a dynamically controlled triple photonic band-gap structure. Our numerical calculations show that three photonic band gaps with homogeneous reflectivities up to 92% can be induced on demand around the probe resonance by a standing-wave driving field in the presence of spontaneously generated coherence. All these photonic band gaps are severely malformed with probe reflectivities declining rapidly to very low values when spontaneously generated coherence is gradually weakened. The triple photonic band-gap structure can also be attained in a five-level chain-{Lambda} system of cold atoms in the absence of spontaneously generated coherence, which however requires two additional traveling-wave fields to couple relevant levels.

Gao Jinwei; Bao Qianqian; Wan Rengang; Cui Cuili; Wu Jinhui [College of Physics, Jilin University, Changchun 130012 (China)

2011-05-15T23:59:59.000Z

54

Systematic Study of Electronic Phases, Band Gaps and Band Overlaps of Bismuth Antimony Nanowires  

E-Print Network (OSTI)

We have developed an iterative one dimensional model to study the narrow band-gap and the associated non-parabolic dispersion relations for bismuth antimony nanowires. An analytical approximation has also been developed. Based on the general model, we have developed, we have calculated and analyzed the electronic phase diagrams and the band-gap/band-overlap map for bismuth antimony nanowires, as a function of stoichiometry, growth orientation, and wire width.

Shuang Tang; Mildred Dresselhaus

2013-12-03T23:59:59.000Z

55

Chemical Tuning of Metal-Semiconductor Interfaces  

Science Journals Connector (OSTI)

We report a study of the Schottky barrier for Pb films grown on Si surfaces terminated by various metals (Ag, In, Au, and Pb) to explore the atomic-scale physics of the interface barrier and a means to control the barrier height. Electronic confinement by the Schottky barrier results in quantum well states in the Pb films, which are measured by angle-resolved photoemission. The barrier height is determined from the atomic-layer-resolved energy levels and the line widths. A calculation based on the known interface chemistry and the electronegativity yields predicted barrier heights in good agreement with the experiment.

D. A. Ricci; T. Miller; T.-C. Chiang

2004-09-20T23:59:59.000Z

56

Band gap and electronic structure of MgSiN{sub 2}  

SciTech Connect

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; Råsander, 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

57

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

58

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

59

Band gaps in InN/GaN superlattices: Nonpolar and polar growth directions  

SciTech Connect

The electronic structures of nonpolar short-period InN/GaN superlattices (SLs) grown in the wurtzite a- and m-directions have been calculated and compared to previous calculations for polar superlattices (grown in the c-direction). The variation of the band gaps with the composition (m, n) of the mInN/nGaN unit cells of the superlattices was examined. The band structures were obtained by self-consistent calculations based on the local density approximation to the density functional theory using the Linear-Muffin-Tin-Orbital method with a semi-empirical correction for the band gaps. The calculated band gaps and their pressure coefficients for nonpolar superlattices are similar to those calculated for bulk InGaN alloys with an equivalent In/Ga concentration ratio. This is very different from what has been found in polar superlattices where the band gaps are much smaller and vanish when the number m of InN layers in the unit cell exceeds three. A strong internal electric field is responsible for this behavior of polar structures. Experimental photoluminescence data for polar SLs agree very well with gaps calculated for the nonpolar structures. It is suggested that this is caused by screening of the electric field in the polar structures by carriers originating from unintentional defects.

Gorczyca, I., E-mail: iza@unipress.waw.pl; Skrobas, K.; Suski, T. [Institute of High Pressure Physics, UNIPRESS, 01-142 Warsaw (Poland); Christensen, N. E.; Svane, A. [Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C (Denmark)

2013-12-14T23:59:59.000Z

60

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

SciTech Connect

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

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

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

NLE Websites -- All DOE Office Websites (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...

62

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

NLE Websites -- All DOE Office Websites (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...

63

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

64

Defects in wide band gap semiconductors: magneto-optical double resonance studies  

Science Journals Connector (OSTI)

Recent results obtained in the investigation of shallow donors in GaN with optical detection of electron paramagnetic resonance via the so-called yellow luminescence are reviewed as well as recent results on the silicon vacancy in SiC using optical detection of electron paramagnetic resonance via the magnetic circular dichroism of the absorption. The power of these double resonance methods is illustrated. The possibility of electrical detection of electron paramagnetic resonance in the electrical conductivity is also briefly discussed as future development.

Johann-Martin Spaeth

2004-01-01T23:59:59.000Z

65

Planar graphene-narrow-gap semiconductor-graphene heterostructure  

Science Journals Connector (OSTI)

A planar heterostructure composed of two graphene films between which a narrow-gap semiconductor ... paradox is absent when conical points of the graphene Brillouin zone are in the band gap...

P. V. Ratnikov; A. P. Silin

2008-11-01T23:59:59.000Z

66

Picosecond response of gallium-nitride metal–semiconductor–metal photodetectors  

Science Journals Connector (OSTI)

Metal–semiconductor–metal ultraviolet photodiodes fabricated on GaN were tested in the picosecond regime with an electro-optic sampling system. A device with a feature size of 1 ?m showed a response with 1.4 ps rise time and 3.5 ps full width at half maximum. The derived electron velocity 1.43×10 7 ? cm/s is in good agreement with independent photoexcitation measurements. A slower impulse response was observed in a device with smaller feature size of 0.5?? m .

Jianliang Li; Ying Xu; T. Y. Hsiang; W. R. Donaldson

2004-01-01T23:59:59.000Z

67

Electron Beam Source Molecular Beam Epitaxy of AlxGal?xAs Graded Band Gap Device Structures  

Science Journals Connector (OSTI)

A new method has been developed for the growth of graded band-gap AlxGal?xAs alloys by molecular beam epitaxy which is based upon electron. beam evaporation of the Group III elements ... . The large dynamic respo...

R. J. Malik; A. F. J. Levi; B. F. Levine…

1989-01-01T23:59:59.000Z

68

Multi junction solar cells using band-gap induced cascaded light absorption  

Science Journals Connector (OSTI)

We propose multi junction solar cells using an optical reflection system formed by arranging plural solar cells in decreasing order of their band gaps for achieving cascaded light absorption by their own band gaps: the first solar cell absorbs some light with a photon energy higher than the highest band gap and reflects the residual light with a lower photon energy to the second solar cell. We further propose to use plural batteries for charging electrical power generated by the individual solar cells to overcome the current matching problem in the multi-junction solar cells. We experimentally demonstrated reflection-type multi junction solar cells using commercially available hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si) solar cells using air mass 1.5 light illumination. A high open circuit voltage of 24.3 V was achieved, which was a sum of 19.3 and 5.0 V for the individual a-Si:H and c-Si solar cells. However, since there was no current matching between the a-Si:H and c-Si solar cells, the a-Si:H?c-Si serially connected solar cell gave a maximum power of 0.057 W, which was lower than 0.063 W, the sum of those for the individual a-Si:H and c-Si solar cells. The method of charging electrical power from individual solar cells is useful to efficiently achieve electrical power from individual a-Si:H and c-Si solar cells in the absence of current matching in multi junction solar cells.

Toshiyuki Sameshima; Hitomi Nomura; Shinya Yoshidomi; Masahiko Hasumi

2014-01-01T23:59:59.000Z

69

Photonic band gaps in three-dimensional network structures with short-range order  

SciTech Connect

We present a systematic study of photonic band gaps (PBGs) in three-dimensional (3D) photonic amorphous structures (PASs) with short-range order. From calculations of the density of optical states (DOS) for PASs with different topologies, we find that tetrahedrally connected dielectric networks produce the largest isotropic PBGs. Local uniformity and tetrahedral order are essential to the formation of PBGs in PASs, in addition to short-range geometric order. This work demonstrates that it is possible to create broad, isotropic PBGs for vector light fields in 3D PASs without long-range order.

Liew, Seng Fatt; Noh, Heeso [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States); Yang, Jin-Kyu [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States); Department of Optical Engineering, Kongju National University, Kongju 314-701 (Korea, Republic of); Schreck, Carl F. [Department of Physics, Yale University, New Haven, Connecticut 06511 (United States); Dufresne, Eric R. [Department of Physics, Yale University, New Haven, Connecticut 06511 (United States); Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511 (United States); Department of Chemical and Environmental Engineering, Yale University, New Haven, Connecticut 06511 (United States); Department of Cell Biology, Yale University, New Haven, Connecticut 06511 (United States); O'Hern, Corey S. [Department of Physics, Yale University, New Haven, Connecticut 06511 (United States); Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511 (United States); Cao, Hui [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States); Department of Physics, Yale University, New Haven, Connecticut 06511 (United States)

2011-12-15T23:59:59.000Z

70

Photovoltages Larger than the Band Gap in Thin Films of Germanium  

Science Journals Connector (OSTI)

Photovoltages much larger than the band gap were investigated in thin films of germanium deposited obliquely onto Pyrex substrates. The voltages were studied as functions of angle of deposit film thickness intensity of illumination temperature and ambient atmosphere. A model is presented which explains the following observations. Positive and negative photovoltages exist simultaneously in a single sample; which of these predominates changes with time. Dark resistance and photovoltage exhibit the same temperature dependence with identical activation energies indicating that both dark resistance and photovoltage arise from the same elementary processes.

H. Kallmann; G. Marmor Spruch; S. Trester

1972-01-01T23:59:59.000Z

71

Is it effective to harvest visible light by decreasing the band gap of photocatalytic materials?  

SciTech Connect

In situ variations in the electron work function and photo-current of TiO{sub 2} nanotubes demonstrate that long-wavelength illumination only has a minor effect on the excitation of electrons in the nanotubes after being exposed to short-wavelength light or when the short-wavelength light coexisted, indicating that the solar spectrum may not be utilized as efficiently as expected by extending the absorption spectrum of the photocatalytic material to visible light range with decreased band gaps.

Fu Ning; Tang Xinhu; Li Dongyang [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2G6 (Canada)

2012-02-27T23:59:59.000Z

72

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

SciTech Connect

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

73

Importance of carrier dynamics and conservation of momentum in atom-selective STM imaging and band gap determination of GaAs(110)  

Science Journals Connector (OSTI)

Scanning tunneling microscopy and spectroscopy measurements on the GaAs(110) surface with complementary theoretical calculations are performed to clarify the effects involved in the tunneling of unpinned semiconductor surfaces. We show that the flatband and tip-induced band bending as well as equilibrium conditions are insufficient to describe the effects involved. Instead, carrier dynamics and conservation of momentum of the tunneling electrons need to be taken into account for a complete description of the contributions of the valence or conduction band states. The results allow us to understand the unique properties needed to achieve the atom-selective imaging observed on these surfaces as well as the determination of the band gap energy.

N. D. Jäger, E. R. Weber, K. Urban, and Ph. Ebert

2003-04-29T23:59:59.000Z

74

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

75

Metal-to-Semiconductor Transition in Hexagonal NiS  

Science Journals Connector (OSTI)

Recent electrical resistivity measurements have shown that the hexagonal form of stoichiometric NiS exhibits an abrupt metal-to-semiconductor transition at 264°K. Neutron diffraction studies have shown that a first-order paramagnetic-to-antiferromagnetic transition also occurs at 264°K. No crystal lattice distortion is observed at the transition nor detected at 4.2°K, suggesting that this may be a transition of the kind considered by Adler and Brooks. The measured magnetic moment at 4.2°K is 1.66±0.08 ?? and at 260°K it is 150.±0.10 ?? indicating that the sublattice magnetization is within 10% of saturation immediately upon ordering. The neutron data also shown that no more than about 1% of the Ni atoms migrate to tetragonal interstitial sites on warming from 4.2°K to room temperature. Thus, Ni atom migration apparently plays no part in this transition. The powder magnetic susceptibility is 2.24×10-6 emu/g at 300°K and is virtually temperature-independent above the transition. ? increases abruptly at 264°K by about 15% and exhibits some field-cooling effects. Studies on the compounds NiXS, for X=1.01, 0.99, 0.97, and 0.94 show that excess sulfur lowers the transition temperature.

JOSEPH T. SPARKS and TED KOMOTO

1968-10-01T23:59:59.000Z

76

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

77

Photonic-band-gap effects in two-dimensional polycrystalline and amorphous structures  

SciTech Connect

We study numerically the density of optical states (DOS) in two-dimensional photonic structures with short-range positional order and observe a transition from polycrystalline to amorphous photonic systems. In polycrystals, photonic band gaps (PBGs) are formed within individual domains, which leads to a depletion of the DOS similar to that in periodic structures. In amorphous photonic media, the domain sizes are too small to form PBGs, thus the depletion of the DOS is weakened significantly. The critical domain size that separates the polycrystalline and amorphous regimes is determined by the attenuation length of Bragg scattering, which depends not only on the degree of positional order but also the refractive-index contrast of the photonic material. Even with relatively low-refractive-index contrast, we find that modest short-range positional order in photonic structures enhances light confinement via collective scattering and interference.

Yang, Jin-Kyu; Noh, Heeso; Liew, Seng-Fatt [Department of Applied Physics, Yale University, New Haven, Connecticut 06520-8482 (United States); Schreck, Carl [Department of Physics, Yale University, New Haven, Connecticut 06520-8120 (United States); Guy, Mikhael I. [Science and Research Software Core, Yale University, New Haven, Connecticut 06520-8286 (United States); O'Hern, Corey S. [Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520-8286 (United States); Department of Physics, Yale University, New Haven, Connecticut 06520-8120 (United States); Cao, Hui [Department of Applied Physics, Yale University, New Haven, Connecticut 06520-8482 (United States); Department of Physics, Yale University, New Haven, Connecticut 06520-8120 (United States)

2010-11-15T23:59:59.000Z

78

Stabilization of temperature dependence of band Gap by introducing nitrogen ion into GaInNP alloy  

SciTech Connect

The photoluminescence (PL) spectra of GaInNP are observed to survey the origin of the unique behavior of the band gap caused by incorporating nitrogen ions. The temperature dependence of the PL peak position is carefully analyzed. It is found that the reduction of the temperature alteration owing to the nitrogen incorporation arises from the hybridization between the nitrogen local 3s and 3p orbitals and the conduction band. In the GaInNP and host GaInP with the indium content around 50%, which has a direct band gap slightly lower than an X-valley, the band gap shrinkage with temperature is mediated by an LA phonon at X point.

Emura, Shuichi; Nonoguchi, Shogo; Kim, Kang Min [The Institute of Scientific and Industrial Research, Osaka Univ., Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan)

2013-12-04T23:59:59.000Z

79

More insights into band gap graded a-SiGe:H solar cells by experimental and simulated data  

SciTech Connect

An experimental and numerical study of a-SiGe:H based solar cells with band gap graded i-layer in the shape of a V is presented. The variation of the location of the band gap minimum has strong influence on the solar cell performance. Comparisons of experimental and simulated data of the dark IV-behavior, IV-curves under illumination and the quantum efficiency allow insights into the transport and recombination behavior within the solar cell. The simulations reveal that the position as well as the charge state of the defects determine the device characteristics.

Zimmer, J.; Stiebig, H.; Foelsch, J.; Finger, F.; Eickhoff, T.; Wagner, H.

1997-07-01T23:59:59.000Z

80

Metal-semiconductor hybrid thin films in field-effect transistors  

SciTech Connect

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 Universität Darmstadt, Petersenstr. 32, 64287 Darmstadt (Germany)

2013-12-16T23:59:59.000Z

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

Block Copolymer Templated Chemistry for the Formation of Metallic Nanoparticle Arrays on Semiconductor Surfaces  

Science Journals Connector (OSTI)

One of key ingredients for many future applications is the ability to precisely pattern nanoscale features on technologically relevant semiconductor surfaces such as silicon and germanium, as well as compound semiconductors such as gallium arsenide and indium phosphide. ... Deposition of these metals is possible presumably due to the water solubility of their oxides:? Ge oxide,14c As oxide,24 and P oxide25 are soluble in water. ...

Masato Aizawa; Jillian M. Buriak

2007-09-25T23:59:59.000Z

82

Unveiling and controlling the electronic structure of oxidized semiconductor surfaces: Crystalline oxidized InSb(100)(1 × 2)-O  

Science Journals Connector (OSTI)

The exothermic nature of oxidation causes nearly all semiconductor applications in various fields like electronics, medicine, photonics, and sensor technology to acquire an oxidized semiconductor surface part during the application manufacturing. The significance of understanding and controlling the atomic scale properties of oxidized semiconductor surfaces is expected to increase even further with the development of nanoscale semiconductor crystals. The nature of oxidized semiconductor layers is, however, hard to predict and characterize as they are usually buried and amorphous. To shed light on these issues, we pursue a different approach based on oxidized III-V semiconductor layers that are crystalline. We present a comprehensive characterization of oxidized crystalline InSb(100)(1×2)-O layers by ab initio calculations, photoelectron spectroscopy, scanning tunneling microscopy, and spectroscopy, and demonstrate the electronic band structures of different oxidized phases of the semiconductor, which elucidate the previous contradictory semiconductor-oxidation effects. At 0.5 monolayer (ML) oxidation, oxygen atoms tend to occupy subsurface Sb sites, leading to metallic states in the semiconductor band gap, which arise from top dimers. When the oxidation is increased to the 1.0–2.0 ML concentration, oxygen occupies also interstitial sites, and the insulating band structure without gap states is stabilized with unusual occupied In dangling bonds. In contrast, the 2.5–3.0 ML oxide phases undergo significant changes toward a less ordered structure. The findings suggest a methodology for manipulating the electronic structure of oxidized semiconductor layers.

J. J. K. Lång; M. P. J. Punkkinen; M. Tuominen; H.-P. Hedman; M. Vähä-Heikkilä; V. Polojärvi; J. Salmi; V.-M. Korpijärvi; K. Schulte; M. Kuzmin; R. Punkkinen; P. Laukkanen; M. Guina; K. Kokko

2014-07-29T23:59:59.000Z

83

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

84

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

85

Single-photon imaging in complementary metal oxide semiconductor processes  

Science Journals Connector (OSTI)

...integrated in new materials, e.g. germanium-on-silicon...implemented as an active or as passive...bias of the cathode or the anode...A review of active and passive...voltage at the cathode to follow an...semiconductor material with decreasing...region. The cathode (in this case...whereas active quenching is...

2014-01-01T23:59:59.000Z

86

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. Ã? 2014 Elsevier B], have gained great attention because of their wide applications in optoelectronic devices composed

Demir, Hilmi Volkan

87

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

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 III–V 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

88

Long-term research in Japan: amorphous metals, metal oxide varistors, high-power semiconductors and superconducting generators  

SciTech Connect

The review revealed that significant activity is under way in the research of amorphous metals, but that little fundamental work is being pursued on metal oxide varistors and high-power semiconductors. Also, the investigation of long-term research program plans for superconducting generators reveals that activity is at a low level, pending the recommendations of a study currently being conducted through Japan's Central Electric Power Council.

Hane, G.J.; Yorozu, M.; Sogabe, T.; Suzuki, S.

1985-04-01T23:59:59.000Z

89

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

SciTech Connect

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

90

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 27, 1999) Special Issue Paper 565 INTRODUCTION Self-assembly techniques provide a means to real- ize itself to the assembly of specific device structures or intercon- nected devices. For self-assembled

Woodall, Jerry M.

91

Designing Semiconductor Metal Oxides for Photoelectrochemical Energy Conversion  

Science Journals Connector (OSTI)

Innovative materials hold the key for renewable energy conversion. In this talk, we will introduce our recent progress in semiconducting metal oxides, which underpin a number of...

Wang, Lianzhou

92

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

93

X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment  

SciTech Connect

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

94

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

95

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

96

Mixed Semiconductor Nanocrystal Compositions  

NLE Websites -- All DOE Office Websites (Extended Search)

Mixed Semiconductor Nanocrystal Compositions Mixed Semiconductor Nanocrystal Compositions Mixed Semiconductor Nanocrystal Compositions Composition comprising one or more energy donors and one or more energy acceptors. Available for thumbnail of Feynman Center (505) 665-9090 Email Mixed Semiconductor Nanocrystal Compositions 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

97

Superatoms and Metal-Semiconductor Motifs for Cluster Materials  

SciTech Connect

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

98

Selective Alcohol Dehydrogenation and Hydrogenolysis with Semiconductor-Metal Photocatalysts: Toward Solar-to-Chemical Energy Conversion of Biomass-Relevant Substrates  

Science Journals Connector (OSTI)

Selective Alcohol Dehydrogenation and Hydrogenolysis with Semiconductor-Metal Photocatalysts: Toward Solar-to-Chemical Energy Conversion of Biomass-Relevant Substrates ... Coupled semiconductors of well-matched band energies are convenient to improve charge sepn. ...

T. Purnima A. Ruberu; Nicholas C. Nelson; Igor I. Slowing; Javier Vela

2012-09-13T23:59:59.000Z

99

Emission of Band-Gap-Energy Positrons from Surfaces of LiF, NaF, and Other Ionic Crystals  

Science Journals Connector (OSTI)

Energetic positrons implanted into various ionic crystal surfaces are reemitted with a maximum kinetic energy (14.7 ± 0.7 eV for LiF) near the band-gap energy. The evidence suggests that, at least for LiF and NaF, the emission originates from bulk-formed positronium (Ps) breaking up after diffusing to the surface. In our model, the positrons are Auger emitted when the Ps electrons recombine with holes at the surface, and the spectrum of positron energies thus reflects the density of empty surface states.

A. P. Mills; Jr. and William S. Crane

1984-11-26T23:59:59.000Z

100

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

SciTech Connect

The electronic and magnetic properties of graphene nanoflakes (GNFs) can be tuned by patterned adsorption of hydrogen. Controlling the H coverage from bare GNFs to half hydrogenated and then to fully hydrogenated GNFs, the transformation of small-gap semiconductor {yields} half-metal {yields} wide-gap semiconductor occurs, accompanied by a magnetic {yields} magnetic {yields} nonmagnetic transfer and a nonmagnetic {yields} magnetic {yields} nonmagnetic transfer for triangular and hexagonal nanoflakes, respectively. The half hydrogenated GNFs, associated with strong spin polarization around the Fermi level, exhibit the unexpected large spin moment that is scaled squarely with the size of flakes. The induced spin magnetizations of these nanoflakes align parallel and lead to a substantial collective character, enabling the half hydrogenated GNFs to be spin-filtering flakes. These hydrogenation-dependent behaviors are then used to realize an attractive approach to engineer the transport properties, which provides a new route to facilitate the design of tunable spin devices.

Zhou, Yungang; Wang, Zhiguo; Yang, Ping; Sun, Xin; Zu, Xiaotao; Gao, Fei

2012-03-08T23:59:59.000Z

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.


101

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.

102

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

103

DOE/BES/NSET annual report on growth of metal and semiconductor nanostructures using localized photocatalysts.  

SciTech Connect

Our overall goal is to understand and develop a novel light-driven approach to the controlled growth of unique metal and semiconductor nanostructures and nanomaterials. In this photochemical process, bio-inspired porphyrin-based photocatalysts reduce metal salts in aqueous solutions at ambient temperatures to provide metal nucleation and growth centers. Photocatalyst molecules are pre-positioned at the nanoscale to control the location and morphology of the metal nanostructures grown. Self-assembly, chemical confinement, and molecular templating are some of the methods used for nanoscale positioning of the photocatalyst molecules. When exposed to light, the photocatalyst molecule repeatedly reduces metal ions from solution, leading to deposition and the synthesis of the new nanostructures and nanostructured materials. Studies of the photocatalytic growth process and the resulting nanostructures address a number of fundamental biological, chemical, and environmental issues and draw on the combined nanoscience characterization and multi-scale simulation capabilities of the new DOE Center for Integrated Nanotechnologies, the University of New Mexico, and Sandia National Laboratories. Our main goals are to elucidate the processes involved in the photocatalytic growth of metal nanomaterials and provide the scientific basis for controlled synthesis. The nanomaterials resulting from these studies have applications in nanoelectronics, photonics, sensors, catalysis, and micromechanical systems. The proposed nanoscience concentrates on three thematic research areas: (1) the creation of nanoscale structures for realizing novel phenomena and quantum control, (2) understanding nanoscale processes in the environment, and (3) the development and use of multi-scale, multi-phenomena theory and simulation. Our goals for FY03 have been to understand the role of photocatalysis in the synthesis of dendritic platinum nanostructures grown from aqueous surfactant solutions under ambient conditions. The research is expected to lead to highly nanoengineered materials for catalysis mediated by platinum, palladium, and potentially other catalytically important metals. The nanostructures made also have potential applications in nanoelectronics, nanophotonics, and nanomagnetic systems. We also expect to develop a fundamental understanding of the uses and limitations of biomimetic photocatalysis as a means of producing metal and semiconductor nanostructures and nanomaterials. The work has already led to a relationship with InfraSUR LLC, a small business that is developing our photocatalytic metal reduction processes for environmental remediation. This work also contributes to science education at a predominantly Hispanic and Native American university.

Haddad, Raid Edward; Brinker, C. Jeffrey; Shelnutt, John Allen; Yang, Yi; Nuttall, H. Eric; Watt, Richard K.; Singl, Anup K.; Challa, Sivakumar R.; Wang, Zhongchun; van Swol, Frank B.; Pereira, Eulalia; Qiu, Yan; Jiang, Ying-Bing; Xu, Huifang; Medforth, Craig J.; Song, Yujiang

2003-10-01T23:59:59.000Z

104

Anomalous temperature-dependent band gaps in CuInS2 studied by surface-barrier electroreflectance  

Science Journals Connector (OSTI)

The lowest-energy gaps of CuInS2 have been studied by low-field surface-barrier electroreflectance in the temperature range from 10 to 300 K. Anomalous temperature dependence of E0 and E0+?0 have been found. Below 120 K the temperature coefficient of the band gap is 4.3×10-5 eV/K for E0 and 5.8×10-5 eV/K for E0+?0. Above 120 K the coefficients become -8.7×10-5 eV/K and -4.4×10-5 eV/K for E0 and E0+?0. These temperature-dependent energy gaps are explained by the reduction of d levels in the upper valence band due to thermal expansion and the competition with the electron-phonon interaction. The temperature dependence of spin-orbit splitting in our experiment confirms this explanation.

T. M. Hsu and J. H. Lin

1988-03-15T23:59:59.000Z

105

Photonic band gap in an imperfect atomic diamond lattice: Penetration depth and effects of finite size and vacancies  

Science Journals Connector (OSTI)

We study the effects of finite size and of vacancies on the photonic band gap recently predicted for an atomic diamond lattice. Close to a Jg=0?Je=1 atomic transition, and for atomic lattices containing up to N?3×104 atoms, we show how the density of states can be affected by both the shape of the system and the possible presence of a fraction of unoccupied lattice sites. We numerically predict and theoretically explain the presence of shape-induced border states and of vacancy-induced localized states appearing in the gap. We also investigate the penetration depth of the electromagnetic field which we compare to the case of an infinite system.

Mauro Antezza and Yvan Castin

2013-09-25T23:59:59.000Z

106

Nature of the Band Gap and Origin of the Electro-/Photo-Activity of Co3O4  

SciTech Connect

Co3O4 exhibits intriguing physical, chemical and catalytic properties and has demonstrated great potential for next-generation renewable energy applications. These interesting properties and promising applications are underpinned by its electronic structure and optical properties, which are unfortunately poorly understood and the subject of considerable debate over many years. Here, we unveil a consistent electronic structural description of Co3O4 by synergetic infrared optical and in situ photoemission spectroscopy as well as standard density functional theory calculations. In contrast to previous assumptions, we demonstrate a much smaller fundamental band gap, which is directly related to its efficient electro-/photoactivity. The present results may help to advance the fundamental understanding and provide guidance for the use of oxidematerials in photocatalysis and solar applications.

Qiao, L.; Xiao, Haiyan Y.; Meyer, H. M.; Sun, J. N.; Rouleau, C. M.; Puretzky, A. A.; Geohegan, D. B.; Ivanov, Ilia N.; Yoon, M.; Weber, William J.; Biegalski, Michael D.

2013-08-21T23:59:59.000Z

107

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

SciTech Connect

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 190–1100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.81–4.51eV and 4.84–3.43eV 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

108

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

SciTech Connect

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

109

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

SciTech Connect

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

110

Wide band-gap, fairly conductive p-type hydrogenated amorphous silicon carbide films prepared by direct photolysis; solar cell application  

SciTech Connect

Wide optical band-gap (2.0--2.3 eV) undoped and boron-doped hydrogenated amorphous silicon carbide (a-SiC:H) films have been prepared by both direct photo and rf glow discharge (GD plasma) decomposition of pure methylsilanes or acetylene and disilane gas mixtures. The photochemically prepared p-type films showed higher dark conductivities and lower activation energies. For an optical band gap of 2.0 eV a high conductivity of 7.0 x 10/sup -5/ (S cm/sup -1/) and a low activation energy of 0.33 eV have been measured. The first trial of these wide band-gap, fairly conductive films as a window layer in a p-i-n solar cell showed the high conversion efficiency of 9.46% under AM1 insolation.

Yamada, A.; Kenne, J.; Konagai, M.; Takahashi, K.

1985-02-01T23:59:59.000Z

111

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

SciTech Connect

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

112

(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%; Venezuela, 15%; Canada, 8%; and other, 8%. Silicon metal: Brazil, 38%; South Africa, 24%; Canada, 16

113

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.

114

Simple Way to Engineer Metal–Semiconductor Interface for Enhanced Performance of Perovskite Organic Lead Iodide Solar Cells  

Science Journals Connector (OSTI)

Simple Way to Engineer Metal–Semiconductor Interface for Enhanced Performance of Perovskite Organic Lead Iodide Solar Cells ... ‡ School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China ... However, ALD technique has the problems of strict working environment like vacuum and high cost precursors. ...

Yuzhuan Xu; Jiangjian Shi; Songtao Lv; Lifeng Zhu; Juan Dong; Huijue Wu; Yin Xiao; Yanhong Luo; Shirong Wang; Dongmei Li; Xianggao Li; Qingbo Meng

2014-04-01T23:59:59.000Z

115

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

SciTech Connect

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

116

Sharp semiconductor-to-metal transition of VO{sub 2} thin films on glass substrates  

SciTech Connect

Outstanding phase transition properties of vanadium dioxide (VO{sub 2}) thin films on amorphous glass were achieved and compared with the ones grown on c-cut sapphire and Si (111) substrates, all by pulsed laser deposition. The films on glass substrate exhibit a sharp semiconductor-to-metal transition (?4.3?°C) at a near bulk transition temperature of ?68.4?°C with an electrical resistance change as high as 3.2?×?10{sup 3} times. The excellent phase transition properties of the films on glass substrate are correlated with the large grain size and low defects density achieved. The phase transition properties of VO{sub 2} films on c-cut sapphire and Si (111) substrates were found to be limited by the high defect density.

Jian, Jie; Chen, Aiping [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843-3128 (United States); Zhang, Wenrui [Material Science and Engineering Program, Texas A and M University, College Station, Texas 77843-3128 (United States); Wang, Haiyan, E-mail: wangh@ece.tamu.edu [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843-3128 (United States); Material Science and Engineering Program, Texas A and M University, College Station, Texas 77843-3128 (United States)

2013-12-28T23:59:59.000Z

117

Analysis of photonic band gap in dispersive properties of tunable three-dimensional photonic crystals doped by magnetized plasma  

SciTech Connect

In this paper, the magnetooptical effects in dispersive properties for two types of three-dimensional magnetized plasma photonic crystals (MPPCs) containing homogeneous dielectric and magnetized plasma with diamond lattices are theoretically investigated for electromagnetic (EM) wave based on plane wave expansion (PWE) method, as incidence EM wave vector is parallel to the external magnetic field. The equations for two types of MPPCs with diamond lattices (dielectric spheres immersed in magnetized plasma background or vice versa) are theoretically deduced. The influences of dielectric constant, plasma collision frequency, filling factor, the external magnetic field, and plasma frequency on the dispersive properties for both types of structures are studied in detail, respectively, and some corresponding physical explanations are also given. From the numerical results, it has been shown that the photonic band gaps (PBGs) for both types of MPPCs can be manipulated by plasma frequency, filling factor, the external magnetic field, and the relative dielectric constant of dielectric, respectively. Especially, the external magnetic field can enlarge the PBG for type-2 structure (plasma spheres immersed in dielectric background). However, the plasma collision frequency has no effect on the dispersive properties of two types of three-dimensional MPPCs. The locations of flatbands regions for both types of structures cannot be tuned by any parameters except for plasma frequency and the external magnetic field. The analytical results may be informative and of technical use to design the MPPCs devices.

Zhang HaiFeng [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China); Liu Shaobin; Yang Huan [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Kong Xiangkun [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing University of Information Science and Technology, Nanjing 210044 (China)

2013-03-15T23:59:59.000Z

118

The properties of photonic band gaps for three-dimensional plasma photonic crystals in a diamond structure  

SciTech Connect

In this paper, the properties of photonic band gaps (PBGs) for two types of three-dimensional plasma photonic crystals (PPCs) composed of isotropic dielectric and unmagnetized plasma with diamond lattices are theoretically investigated for electromagnetic waves based on a modified plane wave expansion method. The equations for type-1 structure are theoretically deduced, which depend on the diamond lattices realization (dielectric spheres immersed in plasma background). The influences of dielectric constant of dielectric, plasma collision frequency, filling factor, and plasma frequency on PBGs are investigated, respectively, and some corresponding physical explanations and the possible methods to realize the three-dimensional PPCs in experiments are also given. From the numerical results, it has been shown that not only the locations but also the gap/midgap ratios of the PBGs for two types of PPCs can be tuned by plasma frequency, filling factor, and the relative dielectric constant, respectively. However, the plasma collision frequency has no effect on the frequency ranges and gap/midgap ratios of the PBGs for two types of PPCs.

Zhang Haifeng [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Nanjing Artillery Academy, Nanjing 211132 (China); Liu Shaobin [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); State Key Laboratory of Millimeter Waves of Southeast University, Nanjing Jiangsu 210096 (China); Kong Xiangkun, Chenchen; Bian Borui [College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

2013-04-15T23:59:59.000Z

119

Wide-band-gap solar cells with high stabilized performance. Annual subcontract report, July 15, 1994--July 14, 1995  

SciTech Connect

This report describes work performed by Pennsylvania State University in collaboration with the NREL Wide-Band-Gap Team. The goal of this team is to develop a single-junction, wide-gap solar cell with good stabilized parameters. The objectives of the subcontract are to (1) develop a cost-effective amorphous silicon PV technology to foster a viable amorphous silicon PV industry in the US, ensuring that this industry remains a world leader in the a-Si technology; (2) help the US a-Si PV industry achieve the US DOE PV Program FY 1995 milestone of 10% stable efficiency commercial thin-film modules; (3) help the US a-Si PV industry achieve 12% stable efficiency multi-junction a-Si:H modules for large-scale utility use by the year 2005. Issues covered in this report include (1) improved understanding of stability in materials and solar cells, (2) intrinsic materials optimization, (3) solar cells optimized for intrinsic layer performance, (4) p-type layer optimization, (5) top cell interfaces, and (6) solar cell grading.

Wronski, C.R.; Collins, R.W.; Fonash, S.J. [Pennsylvania State Univ., University Park, PA (United States)

1995-11-01T23:59:59.000Z

120

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

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


121

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

122

Catalytic photooxidation of pentachlorophenol using semiconductor nanoclusters  

SciTech Connect

Pentachlorophenol (PCP) is a toxic chlorinated aromatic molecule widely used as fungicide, a bactericide and a wood preservation, and thus ubiquitous in the environment. The authors report photo-oxidation of PCP using a variety of nanosize semiconductor metal oxides and sulfides in both aqueous and polar organic solvents and compare the photo-oxidation kinetics of these nanoclusters to widely studied bulk powders like Degussa P-25 TiO{sub 2} and CdS. They study both the light intensity dependence of PCP photooxidation for nanosize SnO{sub 2} and the size dependence of PCP photooxidation for both nanosize SnO{sub 2} and MoS{sub 2}. They find an extremely strong size dependence for the latter which they attribute to its size-dependent band gap and the associated change in redox potentials due to quantum confinement of the hole-electron pair. The authors show that nanosize MoS{sub 2} with a diameter of d=3.0 nm and an absorbance edge of {approximately}450 nm is a very effective photooxidation catalyst for complete PCP mineralization, even when using only visible light irradiation.

WILCOXON,JESS P.

2000-04-17T23:59:59.000Z

123

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

124

3D Assembly of Semiconductor and Metal Nanocrystals: Hybrid CdTe/Au Structures with Controlled Content  

Science Journals Connector (OSTI)

(3) Recently, attention was attracted by the possibility to create functional gels and aerogels via self-assembly of colloidal NCs(4) or clusters of metal chalcogenides,(5) which may open enormous opportunities for semiconductor technology, catalysis and photocatalysis, optoelectronics and photonics, sorbents and filters. ... A critical point drier (13200J-AB from Spi Supplies) was used for supercritical CO2 drying to prevent the fine nanostructures from collapsing and to obtain self-supporting aerogel monoliths. ...

Vladimir Lesnyak; André Wolf; Aliaksei Dubavik; Lars Borchardt; Sergei V. Voitekhovich; Nikolai Gaponik; Stefan Kaskel; Alexander Eychmüller

2011-07-21T23:59:59.000Z

125

Ultra-high vacuum fabrication and electrical characterization of environmentally sensitive metal oxide semiconductor capacitors  

SciTech Connect

We describe an integrated, ultra-high vacuum system for metal oxide semiconductor (MOS) device fabrication and characterization. Such a system is advantageous for electrical property measurements of electronic devices consisting of environmentally sensitive materials especially as device dimensions approach the nanoscale. Without exposure to atomosphere, MOS capacitors were fabricated by evaporating gate metal on molecular-beam-epitaxy (MBE) grown dielectrics on 3 inch-diameter substrates through a shadow mask in a UHV electrode-patterning chamber. The finished device is transferred in vacuum to an in-situ, UHV electrical characterization probe station that was designed with standard UHV coaxial feedthroughs and UHV-compatible, Kapton-insulated coaxial cable. The probe station also includes a heated sample stage that allows for annealing and measurements in a controlled ambient. We obtained excellent agreement between air-ambient ex-situ and in-situ probe station measurements utilizing a capacitor standard compatible with UHV based on single crystal sapphire as the dielectric. The measurements show less than 0.3 % dispersion for frequencies from 20 Hz to 1 MHz. We have successfully measured MOS capacitors and are sensitive to a density of interface states of 1x1010 states cm-2 eV-1. These measurements also show 0.5 % dispersion for measurement frequencies from 20 Hz to 1 kHz and less than 0.1 % from 1 kHz to 1 MHz. The integrated system presented here is one where complex, MBE-grown MOS heterostructures can be synthesized and tested rapidly to elucidate new field-effect-device physics and functionality.

Billman, Curt [Oak Ridge National Laboratory (ORNL); Walker, Frederick Joseph [ORNL

2007-01-01T23:59:59.000Z

126

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

SciTech Connect

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

127

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

SciTech Connect

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

Low-band-gap, amorphous-silicon-based alloys by photochemical vapor deposition: Final report, 1 October 1985--30 November 1986  

SciTech Connect

Thin films of hydrogenated amorphous silicon-germanium alloys were deposited by mercury-sensitized photochemical vapor deposition using a novel photo-CVD reactor. Thin films of a-Si/sub 1-x/Ge/sub x/:H with 0 less than or equal to x less than or equal to 1 and 1.0 less than E/sub g/ less than 1.8 eV were deposited from mixtures of silane and disilane with germane and inert gas diluents at substrate temperatures from 160/degree/ to 200/degree/C. Alloy films were characterized by measurements of photo- and dark conductivity, electron mobility-lifetime product, sub-band-gap absorption, and density of states. Dilution with hydrogen increased the photoconductivity to 10/sup /minus/5/ Scm and mobility-lifetime product to 6 /times/ 10/sup /minus/8/ cm/sup 2/V for alloys having a band gap of 1.4 eV.

Baron, B.N.; Hegedus, S.S.; Jackson, S.C.

1988-02-01T23:59:59.000Z

129

Low-band-gap, amorphous-silicon-based alloys by chemical vapor deposition: Annual subcontract report, 1 October 1985-31 January 1986  

SciTech Connect

This research was conducted to determine the potential of photochemical vapor deposition (photo-CVD) for producing high-quality, low-band-gap amorphous silicon germanium alloys for use in high-efficiency, multijunction, thin-film photovoltaic solar cells. A photo-CVD reactor for mercury-sensitized photolysis of silane-germane and disilane-germane mixtures was developed. Alloy thin films of undoped a-Si/sub 1-x/Ge/sub x/:H were deposited using mercury vapor mixed with SiH/sub 4/ or Si/sub 2/H/sub 6/, GeH/sub 4/, and diluent gas of Ar, He, or H/sub 2/. Materials properties were characterized by measurements of Ge content, optical transmission and reflection, and dark and photo-conductivity. Opto-electronic properties of photo-CVD a-Si/sub 1-x/Ge/sub x/:H were found to be comparable to glow discharge and sputtered materials. Moreover, p-i-n solar cells with low-band-gap i-layers were able to be fabricated by photo-CVD.

Baron, B.N.; Jackson, S.C.

1986-12-01T23:59:59.000Z

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

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

SciTech Connect

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

132

Band gap tuning and optical absorption in type-II InAs/GaSb mid infrared short period superlattices: 14 bands K Dot-Operator p study  

SciTech Connect

The MBE growth of short-period InAs/GaSb type-II superlattice structures, varied around 20.5 A InAs/24 A GaSb were [J. Applied physics, 96, 2580 (2004)] carried out by Haugan et al. These SLs were designed to produce devices with an optimum mid-infrared photoresponse and a sharpest photoresponse cutoff. We have used a realistic and reliable 14-band k.p formalism description of the superlattice electronic band structure to calculate the absorption coefficient in such short-period InAs/GaSb type-II superlattices. The parameters for this formalism are known from fitting to independent experiments for the bulk materials. The band-gap energies are obtained without any fitting parameters, and are in good agreement with experimental data.

AbuEl-Rub, Khaled M. [Department of Applied Physical Sciences, Jordan University of Science and Technology Irbid, 21141 (Jordan)

2012-09-06T23:59:59.000Z

133

Band gap engineering of In{sub 2}O{sub 3} by alloying with Tl{sub 2}O{sub 3}  

SciTech Connect

Efficient modulation of the bandgap of In{sub 2}O{sub 3} will open up a route to improved electronic properties. We demonstrate using ab initio calculations that Tl incorporation into In{sub 2}O{sub 3} reduces the band gap and confirm that narrowing of the gap is observed by X-ray photoemission spectroscopy on ceramic surfaces. Incorporation of Tl does not break the symmetry of the allowed optical transitions, meaning that the doped thin films should retain optical transparency in the visible region, in combination with a lowering of the conduction band effective mass. We propose that Tl-doping may be an efficient way to increase the dopability and carrier mobility of In{sub 2}O{sub 3}.

Scanlon, David O., E-mail: d.scanlon@ucl.ac.uk [Kathleen Lonsdale Materials Chemistry, Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ (United Kingdom); Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Regoutz, Anna; Egdell, Russell G. [Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom)] [Department of Chemistry, Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Morgan, David J. [Cardiff Catalysis Institute (CCI), School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT (United Kingdom)] [Cardiff Catalysis Institute (CCI), School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT (United Kingdom); Watson, Graeme W. [School of Chemistry and CRANN, Trinity College Dublin, Dublin 2 (Ireland)] [School of Chemistry and CRANN, Trinity College Dublin, Dublin 2 (Ireland)

2013-12-23T23:59:59.000Z

134

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

SciTech Connect

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

135

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

E-Print Network (OSTI)

, Texas 77843-4242, USA 2Institute of Physics, ASCR, Cukrovarnick? 10, 162 53 Praha 6, Czech Republic 3Department of Physics, University of Texas, Austin, Texas 78712-0264, USA 4Institute of Physics, Polish Academy of Sciences, al. Lotnik?w 32/46, PL-02... of ferromagnetic semiconductors based on (III, Mn)V materials.1?4 These materials have been the focus of intensive research over the recent years after nonequilibrium growth procedures5,6 have demonstrated the ability to achieve a ferromagnetic phase...

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

2004-01-01T23:59:59.000Z

136

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

SciTech Connect

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

137

Band structure properties of (BGa)P semiconductors for lattice matched integration on (001) silicon  

SciTech Connect

We report the band structure properties of (BGa)P layers grown on silicon substrate using metal-organic vapour-phase epitaxy. Using surface photo-voltage spectroscopy we find that both the direct and indirect band gaps of (BGa)P alloys (strained and unstrained) decrease with Boron content. Our experimental results suggest that the band gap of (BGa)P layers up to 6% Boron is large and suitable to be used as cladding and contact layers in GaP-based quantum well heterostructures on silicon substrates.

Hossain, Nadir; Sweeney, Stephen [Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); Hosea, Jeff [Advanced Technology Institute and Department of Physics, University of Surrey, Guildford, Surrey GU2 7XH, UK and Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Johor Bahru 81310 (Malaysia); Liebich, Sven; Zimprich, Martin; Volz, Kerstin; Stolz, Wolfgang [Material Sciences Center and Faculty of Physics, Philipps-University, 35032 Marburg (Germany); Kunert, Bernerdette [NAsP III/V GmbH, Am Knechtacker 19, 35041 Marburg (Germany)

2013-12-04T23:59:59.000Z

138

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

SciTech Connect

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

139

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

SciTech Connect

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

140

Performance characterization of microtomography with complementary metal-oxide-semiconductor detectors for computer-aided defect inspection  

SciTech Connect

We developed a computer-aided defect inspection system based on computed tomography (CT). The system consists of a homemade small cone-beam CT (CBCT) system and a graphical toolbox, which is used to extract a computer-aided design (CAD) model from the CT data. In the small CBCT system, the x-ray imaging detector is based on a complementary metal-oxide-semiconductor photodiode array in conjunction with a scintillator. Imaging performance of the detector was evaluated in terms of modulation-transfer function, noise-power spectrum, and detective quantum efficiency. The tomographic imaging performance of the small CBCT system was evaluated in terms of signal-to-noise ratio and contrast-to-noise ratio. The graphical toolbox to support defect inspection incorporates various functional tools such as volume rendering, segmentation, triangular-mesh data generation, and data reduction. All the tools have been integrated in a graphical-user interface form. The developed system can provide rapid visual inspection as well as quantitative evaluation of defects by comparing the extracted CAD file with the original file, if available, of an object. The performance of the developed system is demonstrated with experimental CT volume data.

Kim, Ho Kyung; Yun, Seungman; Han, Jong Chul; Youn, Hanbean; Cho, Min Kook; Lim, Chang Hwy [School of Mechanical Engineering, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Heo, Sung Kyn; Shon, Cheol-Soon [Sensor Business Division, E-WOO Technology Co., Ltd., Bora-dong, Giheung, Gyeonggi-do 449-904 (Korea, Republic of); Kim, Seong-Sik; Cho, Bong Hae [School of Dentistry, Pusan National University, Ami-dong, Seo-gu, Busan 602-739 (Korea, Republic of); Achterkirchen, Thorsten Graeve [Rad-icon Imaging Corp., Belick Street, Santa Clara, CA 95054-2404 (United States)

2009-05-01T23:59:59.000Z

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.


141

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

SciTech Connect

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

142

Performance analysis of boron nitride embedded armchair graphene nanoribbon metal–oxide–semiconductor field effect transistor with Stone Wales defects  

SciTech Connect

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??A–280??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

143

Novel, band-controlled metal oxide compositions for semiconductor-mediated photocatalytic splitting of water to produce H{sub 2}  

SciTech Connect

Semiconductor-mediated photo-catalytic dissociation of water offers a unique opportunity for the production of H{sub 2}, a sustainable source of energy. More efficient and chemically stable photo-catalysts, however, remain a vital requirement for commercial viability of this process. The recent research in my group has focused on the synthesis of several new metal oxide (MO) photo-catalysts, such as: LaInO{sub 3}, GaFeO{sub 3}, InVO{sub 4}, In{sub 2}TiO{sub 5} and nanotubular TiO{sub 2}. These samples of controlled grain morphology have been synthesized by using different synthesis protocols and with and without coating of a noble metal co-catalyst. The doping of an impurity, either at cationic or at anionic lattice site, has helped in the tailoring of band structure and making these oxides visible-light-sensitive. Our study has revealed that the surface characteristics, grain morphology, band structure, and doping-induced lattice imperfections control the photo-physical properties and overall photo-catalytic water splitting activity of these metal/MO composites [1-6]. We have demonstrated that, besides promoting certain charge-transfer steps, metal-semiconductor interfaces influence the adsorption of water molecules and their subsequent interaction with photo-generated electron-hole pair at the catalyst surface. The role played by the above-mentioned micro-structural properties in photo-catalytic water splitting process will be discussed.

Gupta, Narendra M. [Catalysis Division, National Chemical Laboratory, Dr. Homi Bhabha Road, Pune - 411008 (India)

2013-02-05T23:59:59.000Z

144

Magnetism, half-metallicity and electrical transport properties of V- and Cr-doped semiconductor SnTe: A theoretical study  

SciTech Connect

This work presents results for the electronic structure, magnetic properties, and electrical resistivity of the semiconductor SnTe doped with 3d transition metals V and Cr. From the standpoint of potential application in spintronics, we look for half-metallic states and analyze their properties in both rock salt and zinc blende structures using ab initio electronic structure methods. In both cases, it is the Sn-sublattice that is doped with the transition metals, as has been the case with experiments performed so far. We find four half-metallic compounds at their optimized cell volumes. Results of exchange interactions and the Curie temperature are presented and analyzed for all the relevant cases. Resistivity calculation based on Kubo-Greenwood formalism shows that the resistivities of these alloys due to transition metal doping of the Sn-sublattice may vary, in most cases, from typical liquid metal or metallic glass value to 2–3 times higher. 25% V-doping of the Sn-sublattice in the rock salt structure gives a very high resistivity, which can be traced to high values of the lattice parameter resulting in drastically reduced hopping or diffusivity of the states at the Fermi level.

Liu, Y. [State Key laboratory of Metastable Materials Science and Technology and College of Science, Yanshan University, Qinhuangdao, Hebei 066004 (China); Bose, S. K. [Physics Department, Brock University, St. Catharines, Ontario L2S 3A1 (Canada); Kudrnovský, J. [Institute of Physics, Academy of the Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

2013-12-07T23:59:59.000Z

145

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.

146

Temperature dependent junction capacitance-voltage characteristics of Ni embedded TiN/SiO{sub 2}/p-Si metal–insulator–semiconductor structure  

SciTech Connect

This work presents the junction capacitance–voltage characteristics of highly textured/epitaxial Ni nanoparticle embedded in TiN matrix (TiN(Ni)) metal-insulator-semiconductor TiN(Ni)/SiO{sub 2}/p-Si (100) heterojunction in the temperature range of 10–300?K. This heterojunction behaves as metal-semiconductor junction with unavoidable leakage through native oxide SiO{sub 2} layer. The clockwise hysteresis loop has been observed in the capacitance-voltage characteristics measured at various frequencies mainly due to presence of trap centers at the TiN(Ni)/SiO{sub 2} interface and these are temperature dependent. The spin-dependent trap charge effect at the interface influences the quadratic nature of the capacitance with magnetic field. The junction magnetocapacitance (JMC) is observed to be dependent on both temperature and frequency. The highest JMC of this heterojunction has been observed at 200?K at higher frequencies (100?kHz–1?MHz). It is found that there is not much effect of band structure modification under magnetic field causing the JMC.

Panda, J.; Nath, T. K., E-mail: tnath@phy.iitkgp.ernet.in [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Chattopadhyay, S. [Department of Physics and Meteorology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 (India); Amity Institute of Nano Technology, Amity University, Sector-125, Noida, Uttar Pradesh 201313 (India)

2013-12-14T23:59:59.000Z

147

Definition: Semiconductor | Open Energy Information  

Open Energy Info (EERE)

Semiconductor Semiconductor Jump to: navigation, search Dictionary.png Semiconductor Any material that has a limited capacity for conducting an electric current. Certain semiconductors, including silicon, gallium arsenide, copper indium diselenide, and cadmium telluride, are uniquely suited to the photovoltaic conversion process.[1] View on Wikipedia Wikipedia Definition A semiconductor is a material which has electrical conductivity to a degree between that of a metal (such as copper) and that of an insulator (such as glass). Semiconductors are the foundation of modern solid state electronics, including transistors, solar cells, light-emitting diodes (LEDs), quantum dots and digital and analog integrated circuits. A semiconductor may have a number of unique properties, one of which is the

148

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

149

Independent and correlated composition behavior of material properties:?Application to energy band gaps for the Ga?In1-?P?As1-? and Ga?In1-?P?Sb?As1-?-? alloys  

Science Journals Connector (OSTI)

A correlated function expansion (CFE) is introduced (a) to identify the role of independent and correlated composition variations upon a desired material property, and (b) to provide an efficient means to compute the property throughout the composition space. As an example the contributions of independent and correlated composition behavior upon the principal energy band gaps for the alloys Ga?In1-?P?As1-? and Ga?In1-?P?Sb?As1-?-? are calculated and analyzed by applying the CFE to the universal tight-binding (UTB) Hamiltonian model of the alloys. The convergence properties of the CFE over the entire composition variable space (?,?,?) are examined upon including independent, pair-, and triple-correlated terms. By retaining only independent component contributions in the CFE it was possible to represent the UTB results to better than 90% accuracy for both the alloys Ga?In1-?P?As1-? and Ga?In1-?P?Sb?As1-?-?. Pair composition correlations contributed approximately 5–10 % to the band gaps in both alloys and for Ga?In1-?P?Sb?As1-?-? the triple correlations were at the level of ?3%. The CFE is a generic tool capable of simplifying efforts at finding desired alloy compositions for material properties.

Kyurhee Shim and Herschel Rabitz

1998-07-15T23:59:59.000Z

150

Evaluation by room?temperature electroreflectance of the 77 K dark?storage time of bulk mercury cadmium telluride measured on metal?insulator semiconductor devices  

Science Journals Connector (OSTI)

We have studied a set of 14 very carefully characterized samples by spectroscopicellipsometry electrolyte electroreflectance (EER) and other measurements and have measured the 77 K storage time ? of metal?insulator semiconductor (MIS)devices built on these samples. The measured storage times ranged from 6.8 to 130.8 ?s. Only the results of the EER measurements showed a correlation with the measured values of ?. We interpret our EER results in terms of a two?phase model consisting of bulk plus very thin highly defectuous regions possibly associated with subgrain boundaries. The observed correlation between the values of the incremental linewidth ?? of the thin defectuous regions and the values of the charge?storage lifetimes ? of the MISdevices is excellent and capable of predicting the values of ?. Furthermore the exact form of the observed correlation is shown to follow immediately from a simple physical model.Correlations between the values of ? and those of other parameters measured by EER were also observed. They suggest a possible simple physical picture for the primary origin of dark current in these devices. This is the first predictive quantitative correlation ever observed between the results of room?temperature optical characterizations of semiconductor materials and the low?temperature electrical performance of devices built on those materials.

Paul M. Raccah; James W. Garland; De Yang; Hisham Abad; Roger L. Strong; Matthew C. McNeill

1989-01-01T23:59:59.000Z

151

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

SciTech Connect

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

152

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

153

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

SciTech Connect

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

154

Effect of the metal-semiconductor phase transition on the rate of hydrogen penetration into vanadium dioxide thin films  

Science Journals Connector (OSTI)

The rates of hydrogen penetration from an aqueous solution of glycerin into ... compared. It has been found that the rate of hydrogen penetration into the metal phase of vanadium dioxide ... order of magnitude hi...

V. N. Andreev; V. A. Klimov

2010-03-01T23:59:59.000Z

155

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

SciTech Connect

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

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

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

157

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

158

Trend of tunnel magnetoresistance and variation in threshold voltage for keeping data load robustness of metal–oxide–semiconductor/magnetic tunnel junction hybrid latches  

Science Journals Connector (OSTI)

The robustness of data load of metal–oxide–semiconductor/magnetic tunnel junction (MOS/MTJ) hybrid latches at power-on is examined by using Monte Carlo simulation with the variations in magnetoresistances for MTJs and in threshold voltages for MOSFETs involved in 90?nm technology node. Three differential pair type spin-transfer-torque-magnetic random access memory cells (4T2MTJ 6T2MTJ and 8T2MTJ) are compared for their successful data load at power-on. It is found that the 4T2MTJ cell has the largest pass area in the shmoo plot in TMR ratio (tunnel magnetoresistance ratio) and Vdd in which a whole 256?kb cell array can be powered-on successfully. The minimum TMR ratio for the 4T2MTJ in 0.9?V?

S. Ikeda; T. Hanyu; H. Ohno

2014-01-01T23:59:59.000Z

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

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

SciTech Connect

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

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
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161

Quantitative determination of local potential values in inhomogeneously doped semiconductors by scanning tunneling microscopy  

Science Journals Connector (OSTI)

Local potential changes arising from nanoscale three-dimensional spatial fluctuations in the dopant distribution in Zn-doped GaAs were investigated quantitatively by scanning tunneling microscopy and spectroscopy at (110) cleavage surfaces. Tunneling spectra measured in areas with different local doping concentration show apparent shifts of the valence band edge and apparent changes of the band gap. A quantitative analysis, combined with band bending and tunnel current simulations, demonstrates that these effects arise from tip-induced band bending that modulates the real potential changes. It is illustrated how exact potential changes between locally high and low doped areas can be determined. It is found that the local potential fluctuations in three-dimensionally doped semiconductors are approximately one order of magnitude smaller that those observed in two-dimensionally doped semiconductors.

P. H. Weidlich, R. E. Dunin-Borkowski, and Ph. Ebert

2011-08-29T23:59:59.000Z

162

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

SciTech Connect

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 2.8–2.85?eV, 3.05?eV, and 3.1–3.2?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

163

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

SciTech Connect

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 abdomen–pelvis 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

164

Entanglement Sudden Death in Band Gaps  

E-Print Network (OSTI)

Using the pseudomode method, we evaluate exactly time-dependent entanglement for two independent qubits, each coupled to a non-Markovian structured environment. Our results suggest a possible way to control entanglement sudden death by modifying the qubit-pseudomode detuning and the spectrum of the reservoirs. Particularly, in environments structured by a model of a density-of-states gap which has two poles, entanglement trapping and prevention of entanglement sudden death occur in the weak-coupling regime.

Ying-Jie Zhang

2009-11-10T23:59:59.000Z

165

ADVERTISEMENT SEMICONDUCTORS  

E-Print Network (OSTI)

ADVERTISEMENT SEMICONDUCTORS: 07.14.2010 Nano-enabled Coating Makes Aircraft Invisible Humble paint... The oil-separating centrifuges will work, but they... MORE FROM IEEE SPECTRUM ROBOTICS: 06.16.2010 Robo.01.2006 Look Out, Beckham: Here Come the Robots At the "World Cup" for robots, the talk is that one day

Stryk, Oskar von

166

Sandia National Labs: PCNSC: Departments: Semiconductor and Optical  

NLE Websites -- All DOE Office Websites (Extended Search)

Semiconductor & Optical Sciences Semiconductor & Optical Sciences > Semiconductor Material & Device Sciences > Advanced Materials Sciences > Lasers, Optics & Remote Sensing Energy Sciences Small Science Cluster Business Office News Partnering Research Jeff Nelson Jerry A. Simmons Sr. Manager Idabelle Idabelle Courtney Admin. Asst. Departments Semiconductor and Optical Sciences The Semiconductor and Optical Sciences Department oversees the operations of the following departments providing new scientific knowledge that can lead to technology solutions in the areas of: Compound semiconductor optoelectronic materials and devices Chemical science to materials technologies, emphasizing the science and engineering of Metal Organic Chemical Vapor Deposition (MOCVD) Remote sensing and detection of WMD proliferation activities

167

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

SciTech Connect

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 Å, 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 2p–carboxyl, C 2p–side chain, and C 2p–carboxyl 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 Bioquímica, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre-RS (Brazil)] [Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, 90035-003 Porto Alegre-RS (Brazil); Silva, A. M. [Universidade Estadual do Piauí, 64260-000 Piripiri-Pi (Brazil)] [Universidade Estadual do Piauí, 64260-000 Piripiri-Pi (Brazil); Caetano, E. W. S., E-mail: ewcaetano@gmail.com [Instituto de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza-CE (Brazil)] [Instituto de Educação, Ciência e Tecnologia do Ceará, 60040-531 Fortaleza-CE (Brazil); Sales, F. A. M.; Freire, V. N. [Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, 60455-760 Fortaleza-CE (Brazil)] [Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, 60455-760 Fortaleza-CE (Brazil)

2014-03-28T23:59:59.000Z

168

Chemical spray pyrolysis deposition and characterization of p-type CuCr1?xMgxO2 transparent oxide semiconductor thin films  

Science Journals Connector (OSTI)

A chemical spray pyrolysis technique for deposition of p-type Mg-doped CuCrO2 transparent oxide semiconductor thin films using metaloorganic precursors is described. As-deposited films contain mixed spinel CuCr2O4 and delafossite CuCrO2 structural phases. Reduction in spinel CuCr2O4 fraction and formation of highly crystalline films with single phase delafossite CuCrO2 structure is realized by annealing at temperatures ?700 °C in argon. A mechanism of synthesis of CuCrO2 films involving precursor decomposition, oxidation and reaction between constituent oxides in the spray deposition process is presented. Post-annealed CuCr0.93Mg0.07O2 thin films show high (?80%) visible transmittance and sharp absorption at band gap energy with direct and indirect optical band gaps 3.11 and 2.58 eV, respectively. Lower (?450 °C) substrate temperature formed films are amorphous and yield lower direct (2.96 eV) and indirect (2.23 eV) band gaps after crystallization. Electrical conductivity of CuCr0.93 Mg0.07O2 thin films ranged 0.6–1 S cm?1 and hole concentration ?2×1019 cm?3 determined from Seebeck analysis. Temperature dependence of conductivity exhibit activation energies ?0.11 eV in 300–470 K and ?0.23 eV in ?470 K region ascribed to activated conduction and grain boundary trap assisted conduction, respectively. Heterojunction diodes of the structure Au/n-(ZnO)/p-(CuCr0.93Mg0.07O2)/SnO2 (TCO) were fabricated which show potential for transparent wide band gap junction device.

S.H. Lim; Suma Desu; A.C. Rastogi

2008-01-01T23:59:59.000Z

169

Details in Semiconductors Gordon Conference, New London, NH, August 3-8, 2008  

SciTech Connect

Continuing its tradition of excellence, this Gordon Conference will focus on research at the forefront of the field of defects in homogeneous and structured semiconductors. The conference will have a strong emphasis on the control of defects during growth and processing, with an increases emphasis on nanostructures as compared to previous conferences. Electronic, magnetic, and optical properties of bulk, thin film, and nanoscale semiconductors will be discussed in detail. In contrast to many conferences, which tend to focus on specific semiconductors, this conference deals with defects in a broad range of bulk and nanoscale electronic materials. This approach has proved to be extremely fruitful for advancing fundamental understanding in emerging materials such as wide-band-gap semiconductors, doped nanoparticles, and organic semiconductors. Presentations of state-of-the-art theoretical methods will contribute to a fundamental understanding of atomic-scale phenomena. The program consists of about twenty invited talks, with plenty of discussion time, and a number of contributed poster sessions. Because of the large amount of discussion time, the conference provides an ideal forum for dealing with topics that are new and/or controversial.

Shengbai Zhang and Nancy Ryan Gray

2009-09-16T23:59:59.000Z

170

Electronic structure of diluted magnetic semiconductor superlattices: In-plane magnetic field effect  

Science Journals Connector (OSTI)

The electronic structure of diluted magnetic semiconductor (DMS) superlattices under an in-plane magnetic field is studied within the framework of the effective-mass theory; the strain effect is also included in the calculation. The numerical results show that an increase of the in-plane magnetic field renders the DMS superlattice from the direct band-gap system to the indirect band-gap system, and spatially separates the electron and the hole by changing the type-I band alignment to a type-II band alignment. The optical transition probability changes from type I to type II and back to type I like at large magnetic field. This phenomenon arises from the interplay among the superlattice potential profile, the external magnetic field, and the sp-d exchange interaction between the carriers and the magnetic ions. The shear strain induces a strong coupling of the light- and heavy-hole states and a transition of the hole ground states from “light”-hole to “heavy”-hole-like states.

Hai-Bin Wu, Kai Chang, and Jian-Bai Xia

2002-04-22T23:59:59.000Z

171

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 Ã? 1) has been studied with scanning tunneling

Diebold, Ulrike

172

Electronic structure of wurtzite II-VI compound semiconductor cleavage surfaces studied by scanning tunneling microscopy  

Science Journals Connector (OSTI)

We report atomically resolved scanning tunneling microscopy (STM) images of cleavage surfaces of wurtzite II-VI compound semiconductors. CdSe(112¯0), CdSe(101¯0), and CdS(101¯0) were investigated. The STM images confirm a 1×1 reconstruction for all surfaces. At negative and positive sample voltages the occupied and empty dangling-bond states above anions and cations, respectively, dominate the contrast of the STM images. No states in the band gap were found. The electronic structure of the surface permits the observation of dopant atoms in subsurface layers and thus also cross-sectional scanning tunneling microscopy studies of point defects and heterostructures.

B. Siemens, C. Domke, Ph. Ebert, and K. Urban

1997-11-15T23:59:59.000Z

173

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

SciTech Connect

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

174

(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

175

Electrostatic screening by semiconductors  

E-Print Network (OSTI)

Electrostatic screening by semiconductors is studied, hics. applying the Thomas-Fermi theory. The semiconductor is treated as a medium with dielectric constant e due to vocalizable atoms, with force charge due to electrons. Two models...

Krcmar, Maja

2012-06-07T23:59:59.000Z

176

Spire Semiconductor formerly Bandwidth Semiconductor LLC | Open Energy  

Open Energy Info (EERE)

Semiconductor formerly Bandwidth Semiconductor LLC Semiconductor formerly Bandwidth Semiconductor LLC Jump to: navigation, search Name Spire Semiconductor (formerly Bandwidth Semiconductor LLC) Place Hudson, New Hampshire Zip 3051 Product Spire-owned US-based manufacturer of gallium-arsenide (GaAs) cells; offers design and manufacturing capabilities of concentrator cells. References Spire Semiconductor (formerly Bandwidth Semiconductor LLC)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Spire Semiconductor (formerly Bandwidth Semiconductor LLC) is a company located in Hudson, New Hampshire . References ↑ "Spire Semiconductor (formerly Bandwidth Semiconductor LLC)" Retrieved from "http://en.openei.org/w/index.php?title=Spire_Semiconductor_formerly_Bandwidth_Semiconductor_LLC&oldid=351621"

177

Life-cycle Assessment of Semiconductors  

E-Print Network (OSTI)

The international technology roadmap for semiconductors,The international technology roadmap for semiconductors:The international technology roadmap for semiconductors,

Boyd, Sarah B.

2009-01-01T23:59:59.000Z

178

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

179

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

180

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

SciTech Connect

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 = 80–400 K and N{sub A}{sup Ru} ? 9.5 × 10{sup 19}?5.7 × 10{sup 20} cm{sup ?3} (x = 0–0.03), 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. [Universität Wien, Institut für 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

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

Oxide Ferromagnetic Semiconductors for Spin-Electronic Transprt  

SciTech Connect

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

182

Picosecond soft x-ray absorption measurement of the photoinduced insulator-to-metal transition in VO2  

Science Journals Connector (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 L3 edge 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.

A. Cavalleri, H. H. W. Chong, S. Fourmaux, T. E. Glover, P. A. Heimann, J. C. Kieffer, B. S. Mun, H. A. Padmore, and R. W. Schoenlein

2004-04-28T23:59:59.000Z

183

Invited paper History of Semiconductors  

E-Print Network (OSTI)

Abstract—The 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). Keywords—band theory, laser, Moore’s law, semiconductor, transistor.

Lidia ?ukasiak; Andrzej Jakubowski

184

Ferromagnetism in Oxide Semiconductors  

SciTech Connect

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

185

INFOGRAPHIC: Wide Bandgap Semiconductors  

Office of Energy Efficiency and Renewable Energy (EERE)

Breakthrough material technology called wide bandgap (WBG) semiconductors can help reduce the amount of wasted heat, boost energy efficiency, improve reliability, reduce cost, and decrease system size in existing and future power electronics.

186

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

187

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

188

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

E-Print Network (OSTI)

Jul 10, 2009 ... the dielectric material and the wave vector. .... which SDP can be well applied, thanks to its efficiency and robustness of handling this type of ...... Band diagrams plotted in the figures below show the eigenvalues moving along ...

2009-07-10T23:59:59.000Z

189

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

190

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

191

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

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

192

Semiconductor Nanoclusters as Potential Photocatalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

0001 0001 Transport and Kinetic Processes in GaN Epitaxial Lateral Overgrowth M. E. Coltrin and C. C. Mitchell Motivation-GaN is a wide band gap semi- conductor with a broad range of potential appli- cations, e.g., high-temperature electronics, op- telectronics, chemical or biological sensors. GaN thin films usually have a high defect den- sity, leading to poor performance. Epitaxial Lat- eral Overgrowth (ELO) has been shown to greatly reduce defect densities, often by factors of 100 or more. We are conducting fundamental studies of GaN growth kinetics during ELO. Accomplishment-In ELO, a mask pattern of dielectric material is deposited on top of a GaN buffer layer. Further growth of GaN occurs se- lectively on exposed areas of the underlying buffer layer, and not on the dielectric material.

193

The roadmap for downscaling and introducing new technologies in the semiconductor industry is well laid out for the next ten years2.  

E-Print Network (OSTI)

The roadmap for downscaling and introducing new technologies in the semiconductor industry is well in the International Technology Roadmap for Semiconductors, one- dimensional structures, such as carbon nanotubes an impact on future post-complementary metal- oxide-semiconductor (CMOS) technology depends on more factors

194

A New Gap-Opening Mechanism in a Triple-Band Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

A New Gap-Opening Mechanism in a A New Gap-Opening Mechanism in a Triple-Band Metal A New Gap-Opening Mechanism in a Triple-Band Metal Print Wednesday, 23 February 2005 00:00 A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface involves not only the expected shift in the electronic structure (band-gap opening) but also a band restructuring that gives rise to an energy gap in a second band. Three's a Crowd

195

Kansas Advanced Semiconductor Project  

SciTech Connect

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

196

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

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 = 77–300 K and magnetic fields H = 0.5–5 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

197

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

SciTech Connect

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

198

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

199

A comparative study of optical absorption and photocatalytic properties of nanocrystalline single-phase anatase and rutile TiO{sub 2} doped with transition metal cations  

SciTech Connect

The effect of nanocrystalline TiO{sub 2} doping with transition metal cations (Cu{sup 2+}, Fe{sup 3+}, Co{sup 2+}, Cr{sup 3+}) on their optical absorption and photocatalytic properties was investigated. The obtained metal-doped TiO{sub 2} samples were characterized by X-ray diffraction, scanning electron microscopy, and UV-vis absorption spectroscopy. It is shown that doping effect on anatase (A) and rutile (R) properties is quite different, being much stronger and complicated on A than on R. Contrary to doped R, doped A revealed a significant red shift of the absorption edge along with the band gap narrowing. Photocatalytic activity of anatase increases upon doping in the order: AR/Co>R/Cu>R/Fe>R/Cr, indicating the inhibitory effect of impurity cations. This fact correlates with the decrease in the UV absorption of the doped rutile in the region of the Hg-lamp irradiation at 4.88 eV. - Graphical abstract: A red shift of the absorption edge of nanocrystalline single-phase anatase after doping with transition metal cations. Highlights: Black-Right-Pointing-Pointer Single-phase anatase and rutile powders surface-doped with transition metal cations. Black-Right-Pointing-Pointer Absorption edge and band gap of rutile do not change with surface doping. Black-Right-Pointing-Pointer Band gap of surface-doped anatase reduces being the lowest for A/Fe. Black-Right-Pointing-Pointer The surface-doping improves photocatalytic activity of anatase. Black-Right-Pointing-Pointer The surface-doping inhibits photocatalytic activity of rutile.

Kernazhitsky, L., E-mail: kern@iop.kiev.ua [Department of Photoactivity, Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, Kiev 03650 (Ukraine); Shymanovska, V.; Gavrilko, T.; Naumov, V. [Department of Photoactivity, Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, Kiev 03650 (Ukraine)] [Department of Photoactivity, Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauki 46, Kiev 03650 (Ukraine); Kshnyakin, V. [Department of Physics, Sumy State University, Rymsky-Korsakov Str. 2, Sumy 40007 (Ukraine)] [Department of Physics, Sumy State University, Rymsky-Korsakov Str. 2, Sumy 40007 (Ukraine); Khalyavka, T. [Laboratory of Photochemistry of Disperse Materials, Institute for Sorption and Problems of Endoecology, National Academy of Sciences of Ukraine, Gen. Naumov Str. 13, Kiev 03164 (Ukraine)] [Laboratory of Photochemistry of Disperse Materials, Institute for Sorption and Problems of Endoecology, National Academy of Sciences of Ukraine, Gen. Naumov Str. 13, Kiev 03164 (Ukraine)

2013-02-15T23:59:59.000Z

200

Chemical vapor deposition of amorphous semiconductor films. Final subcontract report  

SciTech Connect

Chemical vapor deposition (CVD) from higher order silanes has been studied for fabricating amorphous hydrogenated silicon thin-film solar cells. Intrinsic and doped a-Si:H films were deposited in a reduced-pressure, tubular-flow reactor, using disilane feed-gas. Conditions for depositing intrinsic films at growth rates up to 10 A/s were identified. Electrical and optical properties, including dark conductivity, photoconductivity, activation energy, optical absorption, band-gap and sub-band-gap absorption properties of CVD intrinsic material were characterized. Parameter space for depositing intrinsic and doped films, suitable for device analysis, was identified.

Rocheleau, R.E.

1984-12-01T23:59:59.000Z

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.


201

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

202

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

SciTech Connect

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

203

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

204

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

205

Semiconductor devices incorporating multilayer interference regions  

DOE Patents (OSTI)

A semiconductor high reflector comprising a number of thin alternating layers of semiconductor materials is electrically tunable and may be used as a temperature insensitive semiconductor laser in a Fabry-Perot configuration. 8 figs.

Biefeld, R.M.; Drummond, T.J.; Gourley, P.L.; Zipperian, T.E.

1987-08-31T23:59:59.000Z

206

Avalanche semiconductor radiation detectors  

SciTech Connect

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

207

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

208

Method Of Transferring Strained Semiconductor Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

Of Transferring Strained Semiconductor Structures Of Transferring Strained Semiconductor Structures Method Of Transferring Strained Semiconductor Structures The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. June 25, 2013 Method Of Transferring Strained Semiconductor Structures The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having surface contaminants. Available for thumbnail of Feynman Center (505) 665-9090 Email Method Of Transferring Strained Semiconductor Structures The transfer of strained semiconductor layers from one substrate to another substrate involves depositing a multilayer structure on a substrate having

209

Semiconductor Physics at the Optical Sciences Center  

Science Journals Connector (OSTI)

This talk reviews semiconductor physics experiments and theory at the Optical Sciences Center including optical bistability, femtosecond dynamics, as well as semiconductor laser...

Koch, Stephan W

210

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...

211

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

212

Photocatalysis Using Semiconductor Nanoclusters  

SciTech Connect

We report on experiments using nanosize MoS{sub 2} to photo-oxidize organic pollutants in water using visible light as the energy source. We have demonstrated that we can vary the redox potentials and absorbance characteristics of these small semiconductors by adjusting their size, and our studies of the photooxidation of organic molecules have revealed that the rate of oxidation increases with increasing bandgap (i.e. more positive valence band and more negative conduction band potentials). Because these photocatalysis reactions can be performed with the nanoclusters fully dispersed and stable in solution, liquid chromatography can be used to determine both the intermediate reaction products and the state of the nanoclusters during the reaction. We have demonstrated that the MoS{sub 2} nanoclusters remain unchanged during the photooxidation process by this technique. We also report on studies of MoS{sub 2} nanoclusters deposited on TiO{sub 2} powder.

Thurston, T.R.; Wilcoxon,J.P.

1999-01-21T23:59:59.000Z

213

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

214

Web Growth of Semiconductors  

Science Journals Connector (OSTI)

A novel process for growth of diamond?lattice semiconductors is described and a model is proposed for the growth mechanism. For germanium the process yields extended thin flat sheets typically 1 cm wide and 0.1 mm thick of good crystalline quality and relatively flat {111} surfaces. The sheet or web freezes from a liquid film drawn up by surface tension between two coplanar dendrites which originate from a single seed and are grown from the melt simultaneously with the sheet. Resistivity throughout the sheet is quite uniform. Etching of germanium webs shows them to be essentially dislocation?free and does not reveal any microsegregation of impurities. Silicon and indium antimonide have also been grown in this manner.

S. O'Hara; A. I. Bennett

1964-01-01T23:59:59.000Z

215

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

216

Large half-metallic gap in ferromagnetic semi-Heusler alloys CoCrP and CoCrAs  

SciTech Connect

We investigate the electronic structure and magnetism of semi-Heusler alloys CoCrP and CoCrAs using the full-potential linearized augmented plane wave method. The calculations reveal that CoCrP and CoCrAs are half-metallic (HM) ferromagnets with the same magnetic moment of 2.00 {mu}{sub B} per formula unit. Both alloys have large half-metallic gaps (up to 0.50 eV) and wide band gaps (above 1 eV). The half-metallicity of CoCrP and CoCrAs can be retained even when their lattice constants are changed by -4.8% to 6.6% and -7.7% to 4.5%, respectively. The two alloys show great promise in the applications of spin valve and magnetic tunnel junction.

Yao Zhongyu [School of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158 (China); Zhang, Y. S. [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Yao, K. L. [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); International Center of Materials Physics, Chinese Academy of Science, Shenyang 110015 (China)

2012-08-06T23:59:59.000Z

217

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

Jüngel, Ansgar

218

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

219

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

220

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

SciTech Connect

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

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

Wide-Bandgap Semiconductors  

SciTech Connect

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

222

Optical Properties and Potential Applications of Doped Semiconductor...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

223

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

224

Waste minimization in semiconductor processing  

SciTech Connect

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

225

Electromagnetic compatibility in semiconductor manufacturing  

SciTech Connect

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

226

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

227

Ultrafast carrier dynamics in semiconductor quantum dots  

Science Journals Connector (OSTI)

The dynamics of band-edge photoluminescence (PL) in CdS nanocrystals (NC’s) dispersed in a glass matrix are studied with the femtosecond up-conversion technique. The time-resolved PL spectra exhibit several discrete features (three of them are in the NC energy band gap) which are not pronounced in a cw PL spectrum. The initial stage of a PL decay is governed by a depopulation of the lowest extended states due to carrier trapping (localization) on the time scale of 1 ps. The low-energy bands originating from the extended-to-localized state transitions exhibit extremely fast buildup dynamics (rise time is 400–700 fs) which is explained by the preexisting occupation of the localized states. © 1996 The American Physical Society.

V. Klimov; P. Haring Bolivar; H. Kurz

1996-01-15T23:59:59.000Z

228

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

229

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

230

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

231

Spin Hall effect in spin-valley coupled monolayers of transition metal dichalcogenides  

SciTech Connect

We study both the intrinsic and extrinsic spin Hall effect in spin-valley coupled monolayers of transition metal dichalcogenides. We find that whereas the skew-scattering contribution is suppressed by the large band gap, the side-jump contribution is comparable to the intrinsic one with opposite sign in the presence of scalar andmagnetic scattering. Intervalley scattering tends to suppress the side-jump contribution due to the loss of coherence. By tuning the ratio of intra- to intervalley scattering, the spin Hall conductivity shows a sign change in hole-doped samples. The multiband effect in other doping regimes is considered, and it is found that the sign change exists in the heavily hole-doped regime, but not in the electron-doped regime.

Shan, Wen-Yu [Carnegie Mellon University (CMU); Lu, Hai-Zhou [University of Hong Kong, The; Xiao, Di [Carnegie Mellon University (CMU)

2013-01-01T23:59:59.000Z

232

Neutron detection using boron gallium nitride semiconductor material  

SciTech Connect

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

233

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

234

Semiconductor-based optical refrigerator  

DOE Patents (OSTI)

Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

Epstein, Richard I. (Santa Fe, NM); Edwards, Bradley C. (Nekoosa, WI); Sheik-Bahae, Mansoor (Albuquerque, NM)

2002-01-01T23:59:59.000Z

235

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

236

A New Gap-Opening Mechanism in a Triple-Band Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

A New Gap-Opening Mechanism in a Triple-Band Metal Print A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface involves not only the expected shift in the electronic structure (band-gap opening) but also a band restructuring that gives rise to an energy gap in a second band. Three's a Crowd For the condensed-matter physicist, the words "electronic structure" are what it's all about. Short-hand for a description of the way electrons behave in solids, liquids, molecules, and even atoms, electronic structure underlies almost all of the everyday properties of matter from structural strength to electrical conductivity. For example, metals conduct electricity because some of their electrons have access to a continuous band of energies, whereas a break or gap in the band turns the metal into an insulator.

237

A New Gap-Opening Mechanism in a Triple-Band Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

A New Gap-Opening Mechanism in a Triple-Band Metal Print A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface involves not only the expected shift in the electronic structure (band-gap opening) but also a band restructuring that gives rise to an energy gap in a second band. Three's a Crowd For the condensed-matter physicist, the words "electronic structure" are what it's all about. Short-hand for a description of the way electrons behave in solids, liquids, molecules, and even atoms, electronic structure underlies almost all of the everyday properties of matter from structural strength to electrical conductivity. For example, metals conduct electricity because some of their electrons have access to a continuous band of energies, whereas a break or gap in the band turns the metal into an insulator.

238

A New Gap-Opening Mechanism in a Triple-Band Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

A New Gap-Opening Mechanism in a Triple-Band Metal Print A New Gap-Opening Mechanism in a Triple-Band Metal Print A "wire" of indium only one or a few atoms wide grown on a silicon surface comprises an ideal test laboratory for studying one-dimensional (1D) metals. A new example comes from a collaboration between researchers from Yonsei University in Korea, the ALS, and the University of Oregon, who have discovered that the phase transition from metal to insulator that occurs at low temperature in indium wires on the silicon (111) surface involves not only the expected shift in the electronic structure (band-gap opening) but also a band restructuring that gives rise to an energy gap in a second band. Three's a Crowd For the condensed-matter physicist, the words "electronic structure" are what it's all about. Short-hand for a description of the way electrons behave in solids, liquids, molecules, and even atoms, electronic structure underlies almost all of the everyday properties of matter from structural strength to electrical conductivity. For example, metals conduct electricity because some of their electrons have access to a continuous band of energies, whereas a break or gap in the band turns the metal into an insulator.

239

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

240

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

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

Minding the Gap Makes for More Efficient Solar Cells  

NLE Websites -- All DOE Office Websites (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...

242

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

SciTech Connect

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

243

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

SciTech Connect

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 Weizsäcker 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

244

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

SciTech Connect

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

245

Tuning the crystal structure and electronic states of Ag2Se: Structural transitions and metallization under pressure  

Science Journals Connector (OSTI)

We performed synchrotron x-ray diffraction and infrared (IR) experiments combined with evolutionary structure predictions and band structure calculations on Ag2Se to ?20 GPa. We present evidence for phase I (?-Ag2Se) as a potential three-dimensional topological insulator by its increase in optical band gap and the topologically nontrivial nature of its band structure. Higher pressures induce a triple-layer stacking pattern and significantly increase the crystallographic inequivalence of the two Ag sites, where P212121 phase I first reconstructs into a Pnma phase II, and then transforms into a topologically different Cmcm phase III. The radical changes in IR spectra and electronic band structures indicate the metallic nature of the high-pressure phases. Our results highlight the effects of pressure in tuning the crystal structure and electronic states of Ag2Se.

Zhao Zhao; Shibing Wang; Artem R. Oganov; Pengcheng Chen; Zhenxian Liu; Wendy L. Mao

2014-05-22T23:59:59.000Z

246

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

SciTech Connect

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

247

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

248

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

249

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

250

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)

Aßmann, Marc

2010-01-01T23:59:59.000Z

251

Earth-abundant semiconductors for photovoltaic applications ...  

NLE Websites -- All DOE Office Websites (Extended Search)

Earth-abundant semiconductors for photovoltaic applications Thin film photovoltaics (solar cells) has the potential to revolutionize our energy landscape by producing clean,...

252

Sandia National Labs: PCNSC: Research: Compound Semiconductor...  

NLE Websites -- All DOE Office Websites (Extended Search)

and chemistry foundations to advance the state-of-the-art compound semiconductor optoelectronic materials and devices. Our approach is based on a focused effort including...

253

Wide Bandgap Semiconductors for Clean Energy Workshop  

Energy.gov (U.S. Department of Energy (DOE))

A workshop on Wide Bandgap (WBG) Semiconductors for Clean Energy (held July 25, 2012, in Chicago, Illinois) brought together stakeholders from industry and academia to discuss the technical status of WBG semiconductors. The workshop also explored emerging WBG market applications in clean energy and barriers to the development and widespread commercial use of WBG semiconductors. Improving the quality and reliability of WBG semiconductors—and reducing their manufacturing costs—could accelerate their use in automotive, power electronics, solid-state lighting, and other clean energy applications.

254

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...

255

Climate VISION: Private Sector Initiatives: Semiconductors: Work...  

Office of Scientific and Technical Information (OSTI)

Plans The Semiconductor Industry Association has finalized its work plan with the collaboration of EPA. The plan describes actions the industry intends to take to achieve its...

256

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

257

Consistent LDA' + DMFT approach to the electronic structure of transition metal oxides: Charge transfer insulators and correlated metals  

SciTech Connect

We discuss the recently proposed LDA' + DMFT approach providing a consistent parameter-free treatment of the so-called double counting problem arising within the LDA + DMFT hybrid computational method for realistic strongly correlated materials. In this approach, the local exchange-correlation portion of the electron-electron interaction is excluded from self-consistent LDA calculations for strongly correlated electronic shells, e.g., d-states of transition metal compounds. Then, the corresponding double-counting term in the LDA' + DMFT Hamiltonian is consistently set in the local Hartree (fully localized limit, FLL) form of the Hubbard model interaction term. We present the results of extensive LDA' + DMFT calculations of densities of states, spectral densities, and optical conductivity for most typical representatives of two wide classes of strongly correlated systems in the paramagnetic phase: charge transfer insulators (MnO, CoO, and NiO) and strongly correlated metals (SrVO{sub 3} and Sr{sub 2}RuO{sub 4}). It is shown that for NiO and CoO systems, the LDA' + DMFT approach qualitatively improves the conventional LDA + DMFT results with the FLL type of double counting, where CoO and NiO were obtained to be metals. Our calculations also include transition-metal 4s-states located near the Fermi level, missed in previous LDA + DMFT studies of these monoxides. General agreement with optical and the X-ray experiments is obtained. For strongly correlated metals, the LDA' + DMFT results agree well with the earlier LDA + DMFT calculations and existing experiments. However, in general, LDA' + DMFT results give better quantitative agreement with experimental data for band gap sizes and oxygen-state positions compared to the conventional LDA + DMFT method.

Nekrasov, I. A., E-mail: nekrasov@iep.uran.ru; Pavlov, N. S.; Sadovskii, M. V. [Russian Academy of Sciences, Institute for Electrophysics, Ural Branch (Russian Federation)

2013-04-15T23:59:59.000Z

258

Acoustoelectric Interactions in Piezoelectric Semiconductors  

Science Journals Connector (OSTI)

Piezoelectric semiconductors such as cadmium sulfide exhibit a strong coupling between conduction electrons that are present in the substance and acoustic waves that are propagated along certain directions in the material. This energy exchange mechanism is highly nonlinear, and thus the simultaneous introduction of several collinear acoustic waves into the substance generates new signals at the conbination (sum and difference) frequencies. A theoretical explanation of this interaction mechanism, based on consideration of the nonlinear cross term present in the current-density equation, has been developed, and the validity of this method of analysis has been tested and qualitatively confirmed through experimentation.

R. Mauro and W. C. Wang

1970-01-15T23:59:59.000Z

259

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

260

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

SciTech Connect

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

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

Charge-carrier transport in amorphous organic semiconductors  

E-Print Network (OSTI)

Since the first reports of efficient luminescence and absorption in organic semiconductors, organic light-emitting devices (OLEDs) and photovoltaics (OPVs) have attracted increasing interest. Organic semiconductors have ...

Limketkai, Benjie, 1982-

2008-01-01T23:59:59.000Z

262

Comments on the National Technology Roadmap for Semiconductors  

Science Journals Connector (OSTI)

The SIA National Technology Roadmap for Semiconductors (NTRS) [1] represents ... in defining a unified description of the semiconductor technology requirements for ensuring advancements in the performance ... an ...

James F. Freedman

1996-01-01T23:59:59.000Z

263

Engineering Density of States of Earth Abundant Semiconductors...  

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

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

264

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Electronic Structure and Magnetism in Diluted Magnetic Semiconductors Print Wednesday, 29 November 2006 00:00...

265

Wide Bandgap Semiconductors for Clean Energy Workshop Agenda  

Energy Savers (EERE)

Wide Bandgap Semiconductors for Clean Energy Workshop Wednesday, July 25, 2012 Hilton Rosemont O'Hare, Chicago, IL Introduction Wide bandgap (WBG) semiconductors operate at...

266

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

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

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

267

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

268

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

SciTech Connect

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

269

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

270

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

271

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

272

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

273

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.

274

Semiconductor heterojunction band offsets and charge neutrality  

E-Print Network (OSTI)

on semi- conductors A and B like Figure 3. 1, and commutativity of semiconductors A and B, i. e. , DEs(A ? B) = DE?(B ? A). (3. 33) We predict the charge neutrality levels &b, 4is and 4i, might align in semiconductors A, B and C as shown in Figure 3...

Lee, Chomsik

2012-06-07T23:59:59.000Z

275

Novel room temperature ferromagnetic semiconductors  

SciTech Connect

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

276

Stabilization of Electrocatalytic Metal Nanoparticles at Metal...  

NLE Websites -- All DOE Office Websites (Extended Search)

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

277

A Low Temperature Fully Lithographic Process For Metal–Oxide Field-Effect Transistors  

E-Print Network (OSTI)

We report a low temperature ( ~ 100à °C) lithographic method for fabricating hybrid metal oxide/organic field-effect transistors (FETs) that combine a zinc-indium-oxide (ZIO) semiconductor channel and organic, parylene, ...

Sodini, Charles G.

278

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

279

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

SciTech Connect

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

280

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

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

Semiconductor Nanoclusters as Potential Photocatalysts  

NLE Websites -- All DOE Office Websites (Extended Search)

High Power Electronics Based on the 2-Dimensional Electron Gas in GaN High Power Electronics Based on the 2-Dimensional Electron Gas in GaN Heterostructures by S. R. Kurtz, A. A. Allerman, and D. Koleski Motivation-GaN-based electronics offer miniaturization potential of radical proportions for microwave power amplifiers. GaN's large bandgap, high breakdown field, high electron velocity, and excellent thermal properties have led to high electron mobility transistors (HEMT) with up to 10x the power density of GaAs and other traditional semiconductors at frequencies up to 20 GHz. Further contributing to the outstanding performance of GaN-based amplifiers is the highly conducting, 2-dimensional electron gas (2DEG) used for the HEMT channel. Intrinsic polarization and piezoelectric properties of GaN materials can produce a 2DEG at an

282

Energy Management in Semiconductor Cleanrooms  

NLE Websites -- All DOE Office Websites (Extended Search)

6 6 Energy Management in Semiconductor Cleanrooms Cleanrooms are used extensively in the manufacturing of integrated circuits and in the biological and pharmaceutical industries. For particle concentrations to remain low, for example, less than 100 particles/ft3 at >0.5 micrometers (Class 100), the air in the cleanroom must be filtered. Typically, the air is circulated through high-efficiency particulate air (HEPA) filters at a very high rate, such as 400 to 600 room air volumes per hour, to maintain low particle concentrations. The combined effect of high recirculation and a high pressure drop through HEPA filters is higher power costs per unit floor area to operate the cleanroom than to ventilate a commercial building. Cleanrooms are usually ventilated constantly and

283

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

284

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

285

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

286

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

SciTech Connect

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

287

AgBiS2 Semiconductor-Sensitized Solar Cells  

Science Journals Connector (OSTI)

AgBiS2 Semiconductor-Sensitized Solar Cells ... We present a new ternary semiconductor sensitizer-AgBiS2 for solar cells. ... Liquid-junction semiconductor-sensitized solar cells were fabricated from the synthesized AgBiS2 semiconductor. ...

Pen-Chi Huang; Wei-Chih Yang; Ming-Way Lee

2013-08-16T23:59:59.000Z

288

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

Jüngel, Ansgar

289

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

290

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

291

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

292

Metal Aminoboranes  

NLE Websites -- All DOE Office Websites (Extended Search)

Metal Aminoboranes Metal Aminoboranes Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. June 25, 2013 Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.n have been synthesized. Available for thumbnail of Feynman Center (505) 665-9090 Email Metal Aminoboranes Metal aminoboranes of the formula M(NH.sub.2BH.sub.3).sub.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. U.S. Patent No.: 7,713,506 (DOE S-112,798)

293

Mospec Semiconductor Corp | Open Energy Information  

Open Energy Info (EERE)

Mospec Semiconductor Corp Mospec Semiconductor Corp Jump to: navigation, search Name Mospec Semiconductor Corp Place Tainan, Taiwan Sector Solar Product Taiwanese semiconductor products producer; offers monocrystalline silicon wafers and as of April 2008, ingots for the solar industry. Coordinates 22.99721°, 120.180862° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":22.99721,"lon":120.180862,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

294

Hemlock Semiconductor Corp HSC | Open Energy Information  

Open Energy Info (EERE)

Hemlock Semiconductor Corp HSC Hemlock Semiconductor Corp HSC Jump to: navigation, search Name Hemlock Semiconductor Corp (HSC) Place Hemlock, Michigan Zip 48626 Sector Solar Product US-based manufacturer polycrystalline silicon for semiconductor and solar industries. Coordinates 39.589497°, -82.153275° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":39.589497,"lon":-82.153275,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

295

Climate VISION: Private Sector Initiatives: Semiconductors  

Office of Scientific and Technical Information (OSTI)

Letters of Intent/Agreements Letters of Intent/Agreements The U.S. semiconductor industry, represented by the members of the Environmental Protection Agency's PFC Reduction/Climate Partnership for the Semiconductor Industry, has committed to reduce absolute perfluorocompound (PFC) emissions by 10% below the 1995 baseline level by the year 2010. Perfluorocompounds include the most potent and long-lived greenhouse gases such as perfluorocarbons (e.g., CF4, C2F6, C3F8), trifluoromethane (CHF3), nitrogen trifluoride (NF3), and sulfur hexafluoride (SF6). The Environmental Protection Agency's (EPA) voluntary semiconductor industry partnership was developed collaboratively with the Semiconductor Industry Association (SIA). EPA, SIA, and the Partner companies (listed below) are working to reduce industry greenhouse gas (GHG) emissions. EPA's

296

Sandia National Laboratories: wide-bandgap semiconductor  

NLE Websites -- All DOE Office Websites (Extended Search)

electroluminescence was first reported by H.J. Round in 1907, and the first light-emitting diode (LED) was reported by O.V. Losev in 1927. Not until the birth of semiconductor...

297

ITRS: The International Technology Roadmap for Semiconductors  

Science Journals Connector (OSTI)

In a move singular for the world’s industry, the semiconductor industry established a quantitative strategy for its progress with the establishment of the ITRS. In its 17th year, it has been extended in 2009 t...

Bernd Hoefflinger

2012-01-01T23:59:59.000Z

298

Wide Bandgap Semiconductors: Pursuing the Promise  

Energy.gov (U.S. Department of Energy (DOE))

Wide bandgap semiconductor materials are more efficient than their silicon-based counterparts; making it possible to reduce weight, volume, and life-cycle costs in a wide range of power applications.

299

Gaining creative control over semiconductor nanowires  

NLE Websites -- All DOE Office Websites (Extended Search)

Gaining creative control over semiconductor nanowires Gaining creative control over semiconductor nanowires Gaining creative control over semiconductor nanowires Using a microfluidic reactor, Los Alamos researchers transformed the SLS process into a flow-based technique. September 26, 2013 Growth of nanowire precursors in a flowing carrier solvent Growth of nanowire precursors in a flowing carrier solvent The new "flow" solution-liquid-solid method allows scientists to slow down growth and thereby capture mechanistic details as the nanowires grow in solution. A Los Alamos research team has transformed the synthesis process of semiconductor nanowires for use in solar cells, batteries, electronics, sensors and photonics using a solution-liquid-solid (SLS) batch approach to achieve unprecedented control over growth rates, nanowire size and internal

300

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

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

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

302

High-efficiency photovoltaics based on semiconductor nanostructures  

SciTech Connect

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

303

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

304

Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing  

SciTech Connect

Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The microstructural properties such as crystallite size and the microstrain for (-111) and (111) planes are calculated and discussed. Incorporation of Ag led to the lowering of band gap in CuO. Consequently, it is determined that Ag addition has a strong effect on the structural, morphological, surface, and optical properties of CuO grown on flexible substrates by microwave annealing. Tauc's plot is used to determine the optical band gap of CuO and Ag doped CuO films. The values of the indirect and direct band gap for CuO are found to be 2.02 eV and 3.19 eV, respectively.

Das, Sayantan; Alford, T. L. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA and School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)] [Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA and School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)

2013-06-28T23:59:59.000Z

305

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

306

All-optical logic gates based on vertical cavity semiconductor optical amplifiers  

E-Print Network (OSTI)

in International Technology Roadmap for Semiconductors 2007in International Technology Roadmap for Semiconductors 2007The 2007 International Technology Roadmap for Semiconductors

Gauss, Veronica Andrea

2009-01-01T23:59:59.000Z

307

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

NLE Websites -- All DOE Office Websites (Extended Search)

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

308

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

309

3+1 dimensional integrated optics with localized light in a photonic band gap  

E-Print Network (OSTI)

," Phys. Rev. Lett. 58, 2486­ 2489 (1987). 3. D. Wiersma, P. Bartolini, A. Lagendijk, and R. Righini

John, Sajeev

310

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

311

Fano-Hopfield model and photonic band gaps for an arbitrary atomic lattice  

SciTech Connect

We study the light dispersion relation in a periodic ensemble of atoms at fixed positions in the Fano-Hopfield model (the atomic dipole being modeled with harmonic oscillators). Compared to earlier works, we do not restrict to cubic lattices, and we do not regularize the theory by hand but we renormalize it in a systematic way using a Gaussian cutoff in momentum space. Whereas no omnidirectional spectral gap is known for light in a Bravais atomic lattice, we find that, for a wide range of parameters, an omnidirectional gap occurs in a diamond atomic lattice, which may be realized in an experiment with ultracold atoms. The long-wavelength limit of the theory also provides a Lorentz-Lorenz (or Clausius-Mossotti) relation for an arbitrary lattice.

Antezza, Mauro; Castin, Yvan [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS and UPMC, 24 rue Lhomond, 75231 Paris (France)

2009-07-15T23:59:59.000Z

312

Fano-Hopfield model and photonic band gaps for an arbitrary atomic lattice  

Science Journals Connector (OSTI)

We study the light dispersion relation in a periodic ensemble of atoms at fixed positions in the Fano-Hopfield model (the atomic dipole being modeled with harmonic oscillators). Compared to earlier works, we do not restrict to cubic lattices, and we do not regularize the theory by hand but we renormalize it in a systematic way using a Gaussian cutoff in momentum space. Whereas no omnidirectional spectral gap is known for light in a Bravais atomic lattice, we find that, for a wide range of parameters, an omnidirectional gap occurs in a diamond atomic lattice, which may be realized in an experiment with ultracold atoms. The long-wavelength limit of the theory also provides a Lorentz-Lorenz (or Clausius-Mossotti) relation for an arbitrary lattice.

Mauro Antezza and Yvan Castin

2009-07-21T23:59:59.000Z

313

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

SciTech Connect

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

314

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

SciTech Connect

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

315

Low Band Gap Poly(thienylene vinylene)/Fullerene Bulk Heterojunction Photovoltaic Cells  

Science Journals Connector (OSTI)

This work was funded by the Initiative for Renewable Energy and the Environment (IREE) at the University of Minnesota (UMN) and the Xcel Energy Renewable Development Fund. ...

Jung Yong Kim; Yang Qin; Derek M. Stevens; Ozan Ugurlu; Vivek Kalihari; Marc A. Hillmyer; C. Daniel Frisbie

2009-05-21T23:59:59.000Z

316

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

317

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

318

Development of Low Band Gap Polymers for Roll-to-Roll Coated Polymer Solar Cell Modules  

Science Journals Connector (OSTI)

Organic photovoltaics (OPV) have the potential for low production cost. Additionally, there has been an increase in both efficiency and stability of small-area OPV devices prepared in research laboratories wor...

Eva Bundgaard; Frederik Krebs

2011-01-01T23:59:59.000Z

319

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

NLE Websites -- All DOE Office Websites (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...

320

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

SciTech Connect

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 PV�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

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

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

322

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

SciTech Connect

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

323

Thin film reactions on alloy semiconductor substrates  

SciTech Connect

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

324

Extracting hot carriers from photoexcited semiconductor nanocrystals  

SciTech Connect

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

325

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

326

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

SciTech Connect

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

327

Zecon Solar Semiconductor Inc | Open Energy Information  

Open Energy Info (EERE)

Zecon Solar Semiconductor Inc Zecon Solar Semiconductor Inc Jump to: navigation, search Name Zecon Solar & Semiconductor Inc Place Cupertino, California Zip 95014 Sector Solar Product Focused on large-scale solar building integrated PV systems. Coordinates 37.31884°, -122.029244° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.31884,"lon":-122.029244,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

328

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

329

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

330

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

331

Emissivity Correcting Pyrometry of Semiconductor Growth  

NLE Websites -- All DOE Office Websites (Extended Search)

Emissivity Correcting Pyrometry of Semiconductor Growth Emissivity Correcting Pyrometry of Semiconductor Growth by W. G. Breiland, L. A. Bruskas, A. A. Allerman, and T. W. Hargett Motivation-Temperature is a critical factor in the growth of thin films by either chemical vapor deposition (CVD) or molecular beam epitaxy (MBE). It is particularly important in compound semiconductor growth because one is often challenged to grow materials with specific chemical compositions in order to maintain stringent lattice-matching conditions or to achieve specified bandgap values. Optical pyrometry can be used to measure surface temperatures, but the thin film growth causes significant changes in the emissivity of the surface, leading to severe errors in the pyrometer measurement. To avoid these errors, emissivity changes must be measured and

332

Charged steps on III-V compound semiconductor surfaces  

Science Journals Connector (OSTI)

The electrical charge of steps on (110) surfaces of InP, GaP, and GaAs is probed by scanning tunneling microscopy. It is demonstrated that step edges, with and without kinks, are charged and have localized defect states in the band gap. The charge of indium-terminated step edges on p-type doped InP(110) after annealing is found to be independent of the step orientation, while a strong orientation dependence is observed for phosphorus-terminated steps. This is explained by a partial compensation of the charge due to rebonding after phosphorus desorption. The magnitude of charge is estimated to be in the range of +1e to +3e per lattice spacing. © 1996 The American Physical Society.

M. Heinrich, C. Domke, Ph. Ebert, and K. Urban

1996-04-15T23:59:59.000Z

333

Semiconductor Equipment and Materials International SEMI | Open Energy  

Open Energy Info (EERE)

Semiconductor Equipment and Materials International SEMI Semiconductor Equipment and Materials International SEMI Jump to: navigation, search Name Semiconductor Equipment and Materials International (SEMI) Place San Jose, California Zip 95134 2127 Product Global trade association, publisher and conference organiser representing the semiconductor and flat panel display equipment manufacturers. References Semiconductor Equipment and Materials International (SEMI)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Semiconductor Equipment and Materials International (SEMI) is a company located in San Jose, California . References ↑ "Semiconductor Equipment and Materials International (SEMI)" Retrieved from "http://en.openei.org/w/index.php?title=Semiconductor_Equipment_and_Materials_International_SEMI&oldid=350739

334

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

NLE Websites -- All DOE Office Websites (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...

335

Silicon Carbide Power Semiconductor Devices in the Cleanroom...  

NLE Websites -- All DOE Office Websites (Extended Search)

Silicon Carbide Power Semiconductor Devices in the Cleanroom Silicon Carbide Power Semiconductor Devices in the Cleanroom Ron Olson 2012.10.04 I would like to introduce Zach Stum,...

336

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

337

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.

338

Taiwan Semiconductor Manufacturing Co Ltd TSMC | Open Energy Information  

Open Energy Info (EERE)

Semiconductor Manufacturing Co Ltd TSMC Semiconductor Manufacturing Co Ltd TSMC Jump to: navigation, search Name Taiwan Semiconductor Manufacturing Co Ltd (TSMC) Place Hsinchu, Taiwan Zip 300 Sector Solar Product Taiwan-based semiconductor company. The firm is also venturing into solar and LED production. References Taiwan Semiconductor Manufacturing Co Ltd (TSMC)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Taiwan Semiconductor Manufacturing Co Ltd (TSMC) is a company located in Hsinchu, Taiwan . References ↑ "Taiwan Semiconductor Manufacturing Co Ltd (TSMC)" Retrieved from "http://en.openei.org/w/index.php?title=Taiwan_Semiconductor_Manufacturing_Co_Ltd_TSMC&oldid=352012"

339

Method Of Transferring A Thin Crystalline Semiconductor Layer  

NLE Websites -- All DOE Office Websites (Extended Search)

Method Of Transferring A Thin Crystalline Semiconductor Layer Method Of Transferring A Thin Crystalline Semiconductor Layer Method Of Transferring A Thin Crystalline Semiconductor Layer 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. Available for thumbnail of Feynman Center (505) 665-9090 Email Method Of Transferring A Thin Crystalline Semiconductor Layer 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

340

Semiconductor bridge: A plasma generator for the ignition of explosives  

SciTech Connect

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics, propellants, and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ..mu..s), low-energy pulse (less than 3.5 mJ), the SCB produces a hot plasma that ignites explosives. The SCB, a heavily n-doped silicon film, typically 100 ..mu..m long by 380 ..mu..m wide by 2 ..mu..m thick, is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one-tenth the input energy of metal bridgewires. In spite of the low energies for ignition, SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process, plasma formation, optical spectra from the discharge, heat transfer mechanisms from the SCB to the explosive powders, and SCB device applications.

Benson, D.A.; Larsen, M.E.; Renlund, A.M.; Trott, W.M.; Bickes R.W. Jr.

1987-09-01T23:59:59.000Z

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.


341

Semiconductor bridge: A plasma generator for the ignition of explosives  

Science Journals Connector (OSTI)

Small metal bridgewires are commonly used to ignite energetic powders such as pyrotechnics propellants and primary or secondary explosives. In this paper we describe a new means for igniting explosive materials using a semiconductor bridge (SCB). When driven with a short (20 ?s) low?energy pulse (less than 3.5 mJ) the SCB produces a hot plasma that ignites explosives. The SCB a heavily n?doped silicon film typically 100 ?m long by 380 ?m wide by 2 ?m thick is 30 times smaller in volume than a conventional bridgewire. SCB devices produce a usable explosive output in a few tens of microseconds and operate at one?tenth the input energy of metal bridgewires. In spite of the low energies for ignition SCB devices are explosively safe. We describe SCB processing and experiments evaluating SCB operation. Also discussed are the SCB vaporization process plasma formation optical spectra from the discharge heat transfer mechanisms from the SCB to the explosive powders and SCB device applications.

D. A. Benson; M. E. Larsen; A. M. Renlund; W. M. Trott; R. W. Bickes Jr.

1987-01-01T23:59:59.000Z

342

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

343

X-ray induced optical reflectivity  

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

344

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

345

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

346

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

347

Metal Oxides  

Science Journals Connector (OSTI)

Metal oxides are the class of materials having the widest application in gas sensors. This chapter presents information related to the application of various metal oxides in gas sensors designed on different p...

Ghenadii Korotcenkov

2013-01-01T23:59:59.000Z

348

High-Frequency Conductivity of Degenerate Semiconductors  

Science Journals Connector (OSTI)

The problem of high-frequency conductivity of a degenerate semiconductor is investigated by a kinetic description. The finite duration of encounters is taken into account in a self-consistent fashion which properly includes collective effects. This treatment is an extension for quantum plasmas of the Dawson-Oberman method given for classical plasmas.

Amiram Ron and Narkis Tzoar

1963-09-01T23:59:59.000Z

349

Semiconductor Nanowire Optical Antenna Solar Absorbers  

E-Print Network (OSTI)

technology. KEYWORDS Solar cell, semiconductor nanowires, optical antennas, photon management, light trapping a clear, intuitive guidance for the design of efficient NW solar cells. The presented approach to exhibit a strongly angle-dependent optical response and the resulting solar cells require bulky solar

Fan, Shanhui

350

Semiconductor detectors with proximity signal readout  

SciTech Connect

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

351

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

352

Defect Tolerant Semiconductors for Solar Energy Conversion  

Science Journals Connector (OSTI)

Defect Tolerant Semiconductors for Solar Energy Conversion ... He obtained his Ph.D. in Physics at Paris-Sud University where he modeled Hot Carrier Solar Cells by means of Ensemble Monte Carlo methods. ... These surface energies are significantly lower compared to 96 and 102 meV/Å2 for (1010) and (1120) low energy nonpolar GaN surfaces respectively. ...

Andriy Zakutayev; Christopher M. Caskey; Angela N. Fioretti; David S. Ginley; Julien Vidal; Vladan Stevanovic; Eric Tea; Stephan Lany

2014-03-13T23:59:59.000Z

353

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

354

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

355

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

356

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

357

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

358

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

359

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

360

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

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

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

362

A Spintronic Semiconductor with Selectable Charge Carriers  

NLE Websites -- All DOE Office Websites (Extended Search)

A Spintronic Semiconductor with Selectable Charge Carriers Print A Spintronic Semiconductor with Selectable Charge Carriers Print Accentuating the Positive (or the Negative) Spintronics-a type of electronics that makes use of electron spin as well as charge-is already here to a certain extent. The discovery of giant magnetoresistance, a spin-based effect, has revolutionized the information storage industry. Beyond this, however, scientists envision the possibility of combining storage and processing functions in one integrated system. In electronics, processing is done using semiconductor materials like silicon and germanium that have the requisite properties to perform logical operations with both electrons (negative n-type charge carriers) and holes (positive p-type charge carriers). Thus, a spintronically desirable semiconductor would simultaneously have discrete spin-up and spin-down states as well as both positive and negative charge carriers. Strategies for developing spintronic semiconductors have been based on surface doping or on alloying, both of which have drawbacks such as chemical instability or reduced mobility. In BiTeI, however, electron and hole conduction is achieved without modifying the ideal crystal structure. One of the things discovered by Crepaldi et al. was that the electronic band structure of BiTeI bends in different ways near the surface depending on which layer is on top. That, in turn, means that the Fermi level (which determines a material's conductivity) can be located in either the valence band (for positive charge carriers) or the conduction band (for negative charge carriers). With techniques such as molecular-beam epitaxy and chemical vapor deposition, it is realistic to consider that regions with opposite band bending could be patterned on a substrate, opening new possibilities for the manipulation of spin-polarized states.

363

Effects of deformation on the electronic properties of B-C-N nanotubes  

SciTech Connect

We apply first-principles methods, using density functional theory, to investigate the effects of flattening deformation on the electronic properties of BC{sub 2}N and C-doped BNNTs. Four different types of BC{sub 2}N structures are considered. Two of them are semiconductors, and the radial compression produces a significant reduction of the energy band gap. The other two types of structures are metallic, and the effect of radial compression is quite distinct. For one of them it is found the opening of a small band gap, and for the other one no changes are observed. For C-doped tubes, it is also found that the electronic properties undergo significant modifications when subjected to radial compression. - Graphical Abstract: We apply first-principles methods, using density functional theory, to investigate the effects of flattening deformation on the electronic properties of BC{sub 2}N and C-doped BNNTs. Four different types of BC{sub 2}N structures are considered. Two of them are semiconductors, and the radial compression produces a significant reduction of the energy band gap. The other two types of structures are metallic, and the effect of radial compression is quite distinct. For one of them it is found the opening of a small band gap, and for the other one no changes are observed. For C-doped tubes, it is also found that the electronic properties undergo significant modifications when subjected to radial compression. Highlights: Black-Right-Pointing-Pointer We investigated electronic properties of flattened BC{sub 2}N nanotubes. Black-Right-Pointing-Pointer The electronic states depend strongly on compression. Black-Right-Pointing-Pointer It is studied flattened BN nanotubes doped with a carbon atom. Black-Right-Pointing-Pointer The flattened C-doped structures, presents a significant reduction of the gap.

Azevedo, S., E-mail: sazevedo@fisica.ufpb.br [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58059-900 Joao Pessoa-PB (Brazil); Rosas, A. [Departamento de Fisica, Universidade Federal da Paraiba, Caixa Postal 5008, 58059-900 Joao Pessoa-PB (Brazil); Machado, M. [Departamento de Fisica, Universidade Federal de Pelotas, Caixa Postal 354, 96010-900 Pelotas-RS (Brazil); Kaschny, J.R. [Instituto Federal da Bahia-Campus Vitoria da Conquista, Av. Amazonas 3150, 45030-220 Vitoria da Conquista-BA (Brazil); Chacham, H. [Departamento de Fisica, ICEX, Universidade Federal de Minas Gerais, Caixa Postal 702, 30123-970 Belo Horizonte-MG (Brazil)

2013-01-15T23:59:59.000Z

364

Argonne CNM Highlight: Coupling of Single Quantum Dots to Smooth Metal  

NLE Websites -- All DOE Office Websites (Extended Search)

Coupling of Single Quantum Dots to Smooth Metal Films Single Quantum Dots Coupledl to Smooth Metal Films Artist¹s rendition of semiconductor nanocrystals near a gold film. The metal increases nanocrystal emission rates depending on their orientation. [selected as cover image for Phys. Chem. Chem. Phys., 11, 5853 (2009)] Staff in the CNM Nanophotonics Group have measured how light emission from individual colloidal semiconductor nanocrystals, or quantum dots, is modified when in proximity to smooth metal films. Metal nanostructures can strongly modify how quantum dots emit light because of their coupling to electron oscillations in the metal, known as surface plasmons. Emission modification is important for the improvement of light-emitting devices,

365

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

366

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

367

"Magnetically dead" surface layers on ferromagnetic semiconductors  

Science Journals Connector (OSTI)

We perform an exact model calculation for the conduction-band spin structure of ferromagnetic semiconductors. The purpose of this illustrative quasiatomic theory (which is an abstraction of our earlier general theory) is to demonstrate that the case T=0 (i.e., ferromagnetic saturation) exhibits vanishingly small spectral weights of certain quasiparticle or scattering states which, however, become manifest for T>0, and determine the electron-spin polarization. Hence T=0 results cannot be generalized to nonzero temperatures and should not be used to prove or disprove the existence of "magnetically dead" surface layers on ferromagnetic semiconductors. The existence of such dead layers has frequently been postulated to explain the electron-spin polarization in photoemission and field-emission experiments.

W. Nolting and B. Reihl

1983-10-01T23:59:59.000Z

368

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

369

Semiconductor Manufacturing International Corp SMIC | Open Energy  

Open Energy Info (EERE)

Manufacturing International Corp SMIC Manufacturing International Corp SMIC Jump to: navigation, search Name Semiconductor Manufacturing International Corp (SMIC) Place Shanghai, Shanghai Municipality, China Zip 201203 Sector Solar Product Semiconductor group launching solar cell production from its recycled silicon wafers. Coordinates 31.247709°, 121.472618° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":31.247709,"lon":121.472618,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

370

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

371

Electrical Usage Characterization of Semiconductor Processing Tools  

E-Print Network (OSTI)

ELECTRICAL USAGE CHARACTERIZATION OF SEMICONDUCTOR PROCESSING TOOLS Scott R. Hinson Associate Engineer Radian Electronic Systems 15705 Long Vista Drive Austin, TX 78751 Abstract This paper presents the basic concepts in performing... be completed using as much detail as possible. The most often cited reason for aUditing process tools is the large discrepancy between the facilities requirements listed on the tool nameplate and the actual measured usage. I have measured systems...

Hinson, S. R.

372

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

373

Joint CQSE and CASTS Seminar Weekly Seminar  

E-Print Network (OSTI)

principles calculations, we have explored the effects of mechanical strains on the electronic band gap, VBM/CBM positions, and the effective masses of holes and electrons in anatase TiO2. Our calculations showed of the electronic band gaps of the semiconductor-based photocatalysts such as TiO2 is of great importance

Wu, Yih-Min

374

Wide Bandgap Semiconductors: Essential to Our Technology Future |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Wide Bandgap Semiconductors: Essential to Our Technology Future Wide Bandgap Semiconductors: Essential to Our Technology Future Wide Bandgap Semiconductors: Essential to Our Technology Future January 15, 2014 - 8:00am Addthis Learn how wide bandgap semiconductors could impact clean energy technology and our daily lives. | Video by Sarah Gerrity and Matty Greene, Energy Department. Dr. Ernest Moniz Dr. Ernest Moniz Secretary of Energy What are the key facts? North Carolina State University will lead the Energy Department's new manufacturing innovation institute for the next generation of power electronics, focusing on wide bandgap (WBG) semiconductors. Building America's leadership in WBG semiconductor manufacturing while driving down the cost of the technology could lead to more affordable products for businesses and consumers, billions of dollars in energy

375

Climate VISION: Private Sector Initiatives: Semiconductors: Resources and  

Office of Scientific and Technical Information (OSTI)

Semiconductor Industry Association (SIA) The Semiconductor Industry Association (SIA) is the premier trade association representing the U.S. semiconductor industry. Founded in 1977 by five microelectronics innovators, the SIA has grown to include over 100 companies that account for more than 83% of U.S.-based semiconductor production. The SIA provides a forum for domestic semiconductor companies to work collectively to advance the competitiveness of the $70 billion U.S. chip industry. Through its national and international network of chief executive officers and working committees, the SIA shapes public policy on issues important to the industry and provides a spectrum of services to help its members grow their businesses. World Semiconductor Council (WSC)

376

Semiconductor and Materials Company Inc SAMCO | Open Energy Information  

Open Energy Info (EERE)

and Materials Company Inc SAMCO and Materials Company Inc SAMCO Jump to: navigation, search Name Semiconductor and Materials Company Inc (SAMCO) Place Kyoto, Kyoto, Japan Zip 612-8443 Sector Solar Product Japanese manufactruer of semiconductor and solar manufacturing equipment such as etching, deposition and cleaning systems. References Semiconductor and Materials Company Inc (SAMCO)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Semiconductor and Materials Company Inc (SAMCO) is a company located in Kyoto, Kyoto, Japan . References ↑ "Semiconductor and Materials Company Inc (SAMCO)" Retrieved from "http://en.openei.org/w/index.php?title=Semiconductor_and_Materials_Company_Inc_SAMCO&oldid=350738

377

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

378

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

379

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

380

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

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

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

382

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

383

Climate VISION: Private Sector Initiatives: Semiconductors: Resources and  

Office of Scientific and Technical Information (OSTI)

Technical Information Technical Information Download Acrobat Reader Modeling China's Semiconductor Industry Fluorinated Compound Emissions and Drafting a Roadmap for Climate Protection. (PDF 101 KB) 14th Annual International Semiconductor Environment Safety & Health (ISESH) Conference in Jeju, Korea (June 2007) presentation by Scott Bartos, U.S. EPA. Estimating the Impact of Migration to Asian Foundry Production on Attaining the WSC 2010 PFC Reduction Goal. (PDF 458 KB) 11th Annual ISESH Conference in Makuhari, Japan (July 2004) presentation by Scott Bartos, U.S. EPA. Guidelines for Environmental Characterization of Semiconductor Equipment (PDF 361 KB) This document provides guidelines for suppliers of semiconductor processing and abatement equipment to characterize their equipment to meet

384

July 28, 2010, Guiding semiconductor research through collaborative engagement  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

The SRC ... The SRC ... Guiding semiconductor research through collaborative engagement Elizabeth J. Weitzman Exec. VP, SRC Exec. Director, Focus Center Research Program Semiconductor Research Corporation 2 ... Awarded Nat'l Medal of Technology Presidential Citation: "For building the world's largest and most successful university research force to support the ... semiconductor industry; For proving the concept of collaborative research as the first high-tech research consortium; and For creating the concept and methodology that evolved into the International Technology Roadmap for Semiconductors." 3 Key Attributes of SRC Research Entities 1. Accepted IP model. SRC's model has been

385

Semiconductor research capabilities at the Lawrence Berkeley Laboratory  

SciTech Connect

This document discusses semiconductor research capabilities (advanced materials, processing, packaging) and national user facilities (electron microscopy, heavy-ion accelerators, advanced light source). (DLC)

Not Available

1987-02-01T23:59:59.000Z

386

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

387

Semiconductor nanowires for photovoltaic and photoelectrochemical energy conversion  

Science Journals Connector (OSTI)

Semiconductor nanowires (NW) possess several beneficial properties for efficient conversion of solar energy into electricity and chemical energy. Due to their efficient absorption of light, short distances for...

Neil P. Dasgupta; Peidong Yang

2014-06-01T23:59:59.000Z

388

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

389

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

390

Peltier cooling stage utilizing a superconductor-semiconductor junction  

SciTech Connect

This paper describes a Peltier cooling stack. It comprises: a first electrode; a superconducting layer electrically coupled to the first electrode; a semiconducting layer electrically coupled to the superconducting layer; and a second superconducting layer electrically coupled to the semiconductor layer; and a second electrode electrically coupled to the second superconducting layer, electrons flowing under an applied voltage from the first electrode through the first superconducting layer, semiconductor layer, second superconducting layer and second electrode, the electrical junction between the first superconducting layer and semiconductor providing Peltier cooling while the electrical junction between the semiconductor layer and the second superconducting layer providing Peltier heating, whereby a cryogenic Peltier cooling stack is provided.

Skertic, M.M.

1991-04-09T23:59:59.000Z

391

Holey Germanium - New Routes to Ordered Nanoporous Semiconductors  

NLE Websites -- All DOE Office Websites (Extended Search)

currently exploring a variety of applications for these materials, including nanoscale solar cells and adsorption based chemical sensors. Because the semiconductor surface is...

392

Coherence length tunable semiconductor laser with optical feedback  

Science Journals Connector (OSTI)

We report the experimental results to continuously tune the coherence length of a semiconductor laser using an optical feedback scheme. The coherence length can be controlled by...

Wang, Yuncai; Kong, Lingqin; Wang, Anbang; Fan, Linlin

2009-01-01T23:59:59.000Z

393

Organic Semiconductor Chemistry | MIT-Harvard Center for Excitonics  

NLE Websites -- All DOE Office Websites (Extended Search)

Organic Semiconductor Chemistry December 13, 2012 at 3pm36-428 Seth Marder Department of ChemistryBiochemistry, Director, Center for Organic Photonics and Electronics, Georgia...

394

Exchange Coupling in the Ferromagnetic Semiconductor GaMnAs.  

E-Print Network (OSTI)

?? The study of ferromagnetic semiconductors (FMS) continues to be of great interest because of their potential for spintronic devices. While there has been much… (more)

Leiner, Jonathan Carl

2012-01-01T23:59:59.000Z

395

Photons, Electrons and Holes: Fundamentals of Photocatalysis with Semiconductors  

Science Journals Connector (OSTI)

Although not all the heterogeneous photocatalysts are semiconductors, this type of solids represents, by far, the most representative and widely investigated photoactive materials. For that reason, the fundamentals

Juan Manuel Coronado

2013-01-01T23:59:59.000Z

396

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

397

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

398

Fault localization and analysis in semiconductor devices with optical-feedback infrared confocal microscopy  

SciTech Connect

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

399

Pb-free semiconductor ferroelectrics: A theoretical study of Pd-substituted Ba(Ti1-xCex)O3 solid solutions  

E-Print Network (OSTI)

candidates for use as semiconducting ferro- electrics in solar-energy conversion devices. DOI: 10.1103/Phys, though candidate materials are few and far between.1,2 For optimal utilization of the energy in the solar spectrum, a material with a band gap in the range of 1.6­2.0 eV and good charge carrier separation

Rappe, Andrew M.

400

High power semiconductor laser diode arrays  

Science Journals Connector (OSTI)

The cw optical power obtainable from semiconductor laser diodes has been extended to unprecedented levels in recent years through the use of multistripe arrays. By spreading out the optical power with more than 100 stripes single?facet cw output in exces of 5 Watts has been demonstrated and 500 mW cw is now commercially available. Recent improvements to array performance include: arrays up to 1 cm wide that generates quasi?cw (150 usec pulse) output in excesss of 11 Watts and a novel device structure which produces up to 215 mW cw in a single diffraction limited lobe.

Peter S. Cross

1986-01-01T23:59:59.000Z

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.


401

High power semiconductor laser diode arrays  

SciTech Connect

The cw optical power obtainable from semiconductor laser diodes has been extended to unprecedented levels in recent years through the use of multistripe arrays. By spreading out the optical power with more than 100 stripes, single-facet, cw output in exces of 5 Watts has been demonstrated, and 500 mW cw is now commercially available. Recent improvements to array performance include: arrays up to 1 cm wide that generates quasi-cw (150 usec pulse) output in excesss of 11 Watts, and a novel device structure which produces up to 215 mW cw in a single diffraction limited lobe.

Cross, P.S.

1986-08-15T23:59:59.000Z

402

Reusing rinse wastewater at a semiconductor plant  

SciTech Connect

Two pilot rinse wastewater reuse projects were developed as part of a long-term water conservation program for a Motorola semiconductor manufacturing site in Phoenix, Ariz. The conceptual designs for the projects grew out of a detailed wastewater reuse study that characterized wastewater streams at their generation points. Both treatment techniques were specifically researched, bench-tested, and adapted to further water conservation efforts while ensuring 100 percent compliance with appropriate effluent regulations and industrial discharge permit conditions. Together, the pilot projects save the city of Phoenix approximately 45 mil gal (17 {times} 10{sup 4} m{sup 3}) of water annually.

Shah, A.R. [Motorola SCG, McDowell, MD (United States). Environmental, Safety, and Industrial Hygiene Dept.; Ploeser, J.H. [Phoenix Water Services Dept., AZ (United States). Water Conservation Office

1999-08-01T23:59:59.000Z

403

Transient Rayleigh scattering from single semiconductor nanowires  

SciTech Connect

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

404

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

405

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

406

Installation of semiconductor crystal growth and processing facilities in the Building 166 addition at Lawrence Livermore National Laboratory  

SciTech Connect

A new addition has been constructed to Building 166 at Lawrence Livermore National Laboratory (LLNL). This addition is intended to contain facilities as described below. The Metalorganic Chemical Vapor Deposition (MOCVD) facility is a proposed facility for the growth of semiconductor crystals composed of various combinations of gallium, aluminum, indium, arsenic, phosphorous, antimony, silicon, and zinc. This facility will utilize hazardous metal hydride gases (arsine, silane, and disilane) and pyrophoric materials (metal alkyls). The MOCVD process has been intensively developed over the past 10 years and is being safetly utilized in over 75 locations worldwide in both research and manufacturing applications. All equipment in the LLNL MOCVD facility is commercially available and is typical of that used in similar facilities in both industry and academia. The Semiconductor Device Fabrication (SDF) facility is a proposed facility for the fabrication of semiconductor devices from crystals grown in the MOCVD facility. General laboratory chemicals and silane gas will be utilized in this facility. The remaining space in the building addition will consist of an optics laboratory and general purpose work area. The only hazardous materials to be used in these areas are small quantities of common laboratory solvents. For the purposes of this Environmental Assessment, these areas will be considered to be part of the SDF. 27 refs., 4 figs., 6 tabs.

Not Available

1990-08-01T23:59:59.000Z

407

Design Enablement and Design-Centric Assessment of Future Semiconductor Technologies  

E-Print Network (OSTI)

ITRa] International Technology Roadmap for Semiconductors,ITRb] International Technology Roadmap for Semiconductors,val- ues from ITRS technology roadmap [ITRb] and typical

Abou Ghaida, Rani

2012-01-01T23:59:59.000Z

408

Metal Toxicity  

Science Journals Connector (OSTI)

Problems posed to plants by metal toxicity in the soils of the world are basically of two kinds. The first kind are of natural origin. These arise either as a consequence of the nature of the parent material f...

T. McNeilly

1994-01-01T23:59:59.000Z

409

Half-metallicity and stability of the rock salt BaC and SrC (111) surfaces: A density functional study  

SciTech Connect

The electronic structure and magnetic properties of relaxed (111) surfaces of the alkaline-earth monocarbides BaC and SrC in the stable rock salt structure, are calculated on the basis of first principle density functional theory within the framework of self-consistent field plane wave pseudo-potential method, using the generalized gradient approximation for the exchange-correlation functional. The results of this study reveal that the C-terminated (111) surfaces retain the bulk half-metallic property in both BaC and SrC. The half-metallicity of the C-terminated BaC surface is found to be more robust compared to the bulk BaC due to the larger half-metallic energy gap. In contrast, the half-metallic energy gap of the C-terminated SrC surface is found to be smaller than that of the bulk. The Ba-terminated surface of BaC and the Sr-terminated surface of SrC, however, lose their bulk half-metallicity due to the formation of surface states in the majority spin band gap. The calculations also show that the atomic magnetic moments at the half-metallic C-terminated surfaces in both BaC and SrC increase considerably with respect to the corresponding bulk values, which is explained in terms of an increase in the number of unpaired 2p electrons of the carbon atom at the surface. We also discuss the stability of the surfaces via the calculated bulk formation energies. The bulk formation energies for both BaC and SrC in the rock salt structure are found to be positive, which indicate that the surfaces are not stable at normal pressure and temperature conditions, and non-equilibrium growth techniques may be required for the realization of BaC and SrC thin films.

Tabatabaeifar, A. H.; Davatolhagh, S., E-mail: davatolhagh@susc.ac.ir; Foroughpour, M. [Department of Physics, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

2013-12-07T23:59:59.000Z

410

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

411

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

412

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

413

Semiconductors 4-bit I2C LED dimmer  

E-Print Network (OSTI)

Philips Semiconductors PCA9533 4-bit I2C LED dimmer Product data sheet Supersedes data of 2003 Sep 19 2004 Oct 01 INTEGRATED CIRCUITS #12;Philips Semiconductors Product data sheet PCA95334-bit I2C LED dimmer 22004 Oct 01 FEATURES · 4 LED drivers (on, off, flashing at a programmable rate) · 2 selectable

Berns, Hans-Gerd

414

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

415

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

416

Semiconductor Nanowires for Energy Conversion Allon I. Hochbaum*,  

E-Print Network (OSTI)

Semiconductor Nanowires for Energy Conversion Allon I. Hochbaum*, and Peidong Yang* Department. Introduction: Role of Materials in Energy Conversion 527 2. Why Are Semiconductor Nanowires Special? 527 3 of Materials in Energy Conversion Between 2004 and 2030 the annual global consumption of energy is estimated

Wu, Zhigang

417

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

418

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

419

Strain controlled systematic variation of metal-insulator transition in epitaxial NdNiO{sub 3} thin films  

SciTech Connect

We report here the strain dependent structural and electrical transport properties of epitaxial NdNiO{sub 3} thin films. Pulsed laser deposition technique was used to grow the NdNiO{sub 3} thin films on c-axis oriented SrTiO{sub 3} single crystals. Deposited films were irradiated using 200 MeV Ag{sup 15+} ion beam at the varying fluence (1 Multiplication-Sign 10{sup 11}, 5 Multiplication-Sign 10{sup 11}, and 1 Multiplication-Sign 10{sup 12} ions/cm{sup 2}). X-ray diffraction studies confirm the epitaxial growth of the deposited films, which is maintained even up to the highest fluence. Rise in the in-plane compressive strain has been observed after the irradiation. All the films exhibit metal-insulator transition, however, a systematic decrease in the transition temperature (T{sub MI}) has been observed after irradiation, which may be attributed to the increase in the in-plane compression. Raman spectroscopy data reveal that this reduction in T{sub MI}, with the irradiation, is related to the decrease in band gap due to the stress generated by the in-plane compressive strain.

Kumar, Yogesh [Materials Science Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Choudhary, R. J. [UGC-DAE Consortium for Scientific Research, Indore 452 001 (India); Kumar, Ravi [Materials Science Division, Inter University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi 110 067 (India); Centre for Material Science and Engineering, National Institute of Technology, Hamirpur 177 005 (India)

2012-10-01T23:59:59.000Z

420

PRECISION CLEANING OF SEMICONDUCTOR SURFACES USING CARBON DIOXIDE-BASED FLUIDS  

SciTech Connect

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

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

Holographic Thin Film System for Multijunction Solar Cells  

Science Journals Connector (OSTI)

The efficiency of photovoltaic generators based on different semiconductor materials with optimized band gaps can achieve considerably higher values than those obtained with single junction solar cells. For th...

W. H. Bloss; M. Griesinger; E. R. Reinhardt

1983-01-01T23:59:59.000Z

422

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

423

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

424

Temperature dependence of electrical characteristics of Pt/GaN Schottky diode fabricated by UHV e-beam evaporation  

Science Journals Connector (OSTI)

GaN has been the subject of strategic research among all compound semiconductors and has been explored widely and rightly for its various characteristics, like direct wide band gap, high breakdown field, high ...

Ashish Kumar; Shamsul Arafin; Markus Christian Amann…

2013-11-01T23:59:59.000Z

425

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

426

Design of Shallow P-Type Dopants in ZnO: Preprint  

SciTech Connect

This paper describes approaches to lower the acceptor ionization energy in ZnO by codoping acceptors with donor or isovalent atoms and proposes a universal approach to overcome the doping polarity problem for wide-band-gap semiconductors.

Wei, S.-H.; Li, J.; Yan, Y.

2008-05-01T23:59:59.000Z

427

Energy conversion catalysis using semiconducting transition metal cluster compounds  

Science Journals Connector (OSTI)

... semiconducting materials that provide a high density of transition metal d-states bordering the forbidden energy region (d-band semiconductors). During a detailed study of RuS2, the best material ... for photo-induced evolution of oxygen3, it became apparent that ~0.5 eV of energy per transferred electron is lost in the course of trapping positive charge carriers in the ...

N. Alonso Vante; H. Tributsch

1986-10-02T23:59:59.000Z

428

Control of coherence resonance in semiconductor superlattices  

E-Print Network (OSTI)

We study the effect of time-delayed feedback control and Gaussian white noise on the spatio-temporal charge dynamics in a semiconductor superlattice. The system is prepared in a regime where the deterministic dynamics is close to a global bifurcation, namely a saddle-node bifurcation on a limit cycle ({\\it SNIPER}). In the absence of control, noise can induce electron charge front motion through the entire device, and coherence resonance is observed. We show that with appropriate selection of the time-delayed feedback parameters the effect of coherence resonance can either be enhanced or destroyed, and the coherence of stochastic domain motion at low noise intensity is dramatically increased. Additionally, the purely delay-induced dynamics in the system is investigated, and a homoclinic bifurcation of a limit cycle is found.

Johanne Hizanidis; Eckehard Schoell

2008-09-01T23:59:59.000Z

429

Hybrid Semiconductors for Hardier Electronics and Optoelectronics? |  

NLE Websites -- All DOE Office Websites (Extended Search)

Unveiling the Molecular Structure of the Target of Many Drugs Unveiling the Molecular Structure of the Target of Many Drugs A New Scenario for First Life on Earth Surface Orbital 'Roughness' in Colossal Magnetoresistive Oxide Different Roads Toward Quantum Criticality Orbital Reconstruction at a Complex Oxide Interface Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed Hybrid Semiconductors for Hardier Electronics and Optoelectronics? DECEMBER 21, 2007 Bookmark and Share The crystal structure of β-ZnTe(en)0:5, determined by single-crystal x-ray diffraction. Two-monolayerthick ZnTe slabs are interconnected by ethylenediamine (C2N2H8) molecules bonded to zinc atoms. Zn-Green, Te-Red, N-Blue,and C-Gray. Hydrogen atoms are omitted for clarity.

430

Photonic crystal membrane reflectors by magnetic field-guided metal-assisted chemical etching  

SciTech Connect

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

431

Large-area semiconductor detectors of beta radiation  

SciTech Connect

This paper describes silicon semiconductor detectors with a diameter of 90 mm with hole-type conduction. The detectors had been grown with the Czochralski technique and had a specific resistivity lambda - 12 omega /SUP ./ cm and a carrier lifetime tau = 50 usec. In the case of semiconductor detectors for counting, silicon grown from a melt has its advantages because the distribution of the specific resistivity in low-resistivity semiconductor crystals is more homogeneous than in high-resistivity crystals in both longitudinal and transverse direactions relative to the axis of crystal growth.

Azimov, S.A.; Baizakov, B.B.; Karpov, V.S.; Muminov, R.A.

1986-08-01T23:59:59.000Z

432

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

433

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

434

Synthesis of single-walled carbon nanotube (SWNTs) from size-selected catalytic metal particles.  

E-Print Network (OSTI)

Synthesis of single-walled carbon nanotube (SWNTs) from size-selected catalytic metal particles-quality synthesis of single-walled carbon nanotubes (SWNTs) has demonstrated new possibilities of applications and for the controlled synthesis directly on semiconductor materials. In this technique, it is known that material, size

Maruyama, Shigeo

435

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

436

Varian Semiconductor Equipment Associates Inc VSEA | Open Energy  

Open Energy Info (EERE)

Varian Semiconductor Equipment Associates Inc VSEA Varian Semiconductor Equipment Associates Inc VSEA Jump to: navigation, search Name Varian Semiconductor Equipment Associates Inc (VSEA) Place Gloucester, Massachusetts Zip 1930 Sector Services Product Massachusetts-based, designs, manufactures, and services semiconductor processing equipment used in the fabrication of integrated circuits. Coordinates 37.413962°, -76.526305° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":37.413962,"lon":-76.526305,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

437

Ramgraber Semiconductor Equipment GmbH | Open Energy Information  

Open Energy Info (EERE)

Ramgraber Semiconductor Equipment GmbH Ramgraber Semiconductor Equipment GmbH Jump to: navigation, search Name Ramgraber Semiconductor Equipment GmbH Place Brunnthal, Germany Zip 85649 Sector Solar Product Makes semiconductor processing equipment, including solar cell manufacturing lines. Coordinates 48.006898°, 11.684687° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":48.006898,"lon":11.684687,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

438

Argonne licenses diamond semiconductor discoveries to AKHAN Technologies |  

NLE Websites -- All DOE Office Websites (Extended Search)

licenses diamond semiconductor discoveries to AKHAN Technologies licenses diamond semiconductor discoveries to AKHAN Technologies By Joseph Bernstein * By Jared Sagoff * March 4, 2013 Tweet EmailPrint LEMONT, Ill. - The U.S. Department of Energy's Argonne National Laboratory announced today that the laboratory has granted AKHAN Technologies exclusive diamond semiconductor application licensing rights to breakthrough low-temperature diamond deposition technology developed by Argonne's Center for Nanoscale Materials (CNM). The Argonne-developed technology allows for the deposition of nanocrystalline diamond on a variety of wafer substrate materials at temperatures as low as 400 degrees Celsius. The combination of the Argonne's low-temperature diamond technology with AKHAN's Miraj Diamond(tm) process represents the state of the art in diamond semiconductor

439

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

440

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

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

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

442

Generating dispatching rules for semiconductor manufacturing to minimize weighted tardiness  

Science Journals Connector (OSTI)

Dispatching rules play an important role especially in semiconductor manufacturing scheduling, because these fabrication facilities are characterized by high complexity and dynamics. The process of developing and adapting dispatching rules is currently ...

Christoph Pickardt; Jürgen Branke; Torsten Hildebrandt; Jens Heger; Bernd Scholz-Reiter

2010-12-01T23:59:59.000Z

443

Semiconductor Laser Lidar Wind Velocity Sensor for Turbine Control  

Science Journals Connector (OSTI)

A dual line-of-sight CW lidar that measures both wind speed and direction is presented. The wind lidar employs a semiconductor laser, which allows for inexpensive remote sensors geared...

Rodrigo, Peter John; Hu, Qi; Pedersen, Christian

444

Review of the Semiconductor Industry and Technology Roadmap  

Science Journals Connector (OSTI)

The semiconductor industry operates in a constant state of deflation. It is vital to our survival and progress in this knowledge era. The industry is extremely competitive and requires ongoing technological advan...

Sameer Kumar; Nicole Krenner

2002-09-01T23:59:59.000Z

445

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

446

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

447

Energy Conservation Through Water Usage Reduction in the Semiconductor Industry  

E-Print Network (OSTI)

ENERGY CONSERVATION THROUGH WATER USAGE REDUCTION IN THE SEMICONDUCTOR INDUSTRY Laura Mendicino Kathy McCormack Sarah Gibson Bob Patton Dana Lyon Jeff Covington Engineer Engineer ESrn Manager Engineer Engineer Engineer Motorola Austin, TX...

Mendicino, L.; McCormack, K.; Gibson, S.; Patton, B.; Lyon, D.; Covington, J.

448

Facts and Artifacts in the Blinking Statistics of Semiconductor Nanocrystals  

Science Journals Connector (OSTI)

Since its initial discovery just over a decade ago, blinking of semiconductor nanocrystals has typically been described in terms of probability distributions for durations of bright, or “on,” states and dark, or “off,” states. These distributions are ...

Catherine H. Crouch; Orion Sauter; Xiaohua Wu; Robert Purcell; Claudia Querner; Marija Drndic; Matthew Pelton

2010-04-05T23:59:59.000Z

449

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

450

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

451

Semiconductor Aspects of Organic Bulk Heterojunction Solar Cells  

Science Journals Connector (OSTI)

During the last few years organic solar cells have been discussed as a promising alternative to inorganic semiconductors for renewable energy production. These organic photovoltaic devices offer the possibility o...

Christoph J. Brabec

2003-01-01T23:59:59.000Z

452

Ultrafast nonlinear optical properties of passive and active semiconductor devices  

E-Print Network (OSTI)

Nonlinear optical properties and ultrafast carrier dynamics of slab-coupled optical waveguide amplifiers, silicon nanowaveguides, and III-V semiconductor saturable Bragg reflectors are studied. The limits imposed by two ...

Motamedi, Ali Reza

2011-01-01T23:59:59.000Z

453

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

454

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

455

Thin Film Solid-State Reactions Forming Carbides as Contact Materials for Carbon-Containing Semiconductors  

SciTech Connect

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

456

Internal Image Potential in Semiconductors - Effect on Scanning-Tunneling-Microscopy  

E-Print Network (OSTI)

10 10 m ~ o 0 ~ 410 g (25) j(s)=, f dE,D(E?s ) [No(E, ) No(E, qV)?], ? @ mp where mo is the free-electron mass, No(E, ) and No(E, ?qV) are one-dimensional finite-temperature sup- ply functions for electrons in the semiconductor and metal... correct only for a square barrier. If we define the cumulative current density as a function of energy according to Ej (E?s) =e J dE,'D(E,', s )[Xo(E,') Ko(E,' q?V)], ?0 (27) 0.2- ?0.2 ?0.6 5x10 cm (s=5k) the diff'erential current density per...

HUANG, ZH; WEIMER, M.; Allen, Roland E.

1993-01-01T23:59:59.000Z

457

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.

458

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.

459

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

E-Print Network (OSTI)

limited to 6 % in Cu2Te/CdTe junctions [4, 5], 7.9 % in CdS/CdTe heterojunctions and 6 % in homojunc with uniform doping followed by a base region with uni- form gap and doping. Our goal is to find the optimum

Boyer, Edmond

460

Preparation of narrow band gap V2O5/TiO2 composite films by micro-arc oxidation  

Science Journals Connector (OSTI)

V2O5/TiO2...composite films were prepared on pure titanium substrates via micro-arc oxidation (MAO) in electrolytes consisting of NaVO3. Their morphology and elements were characterized by scanning electron micro...

Qiang Luo; Xin-wei Li; Qi-zhou Cai…

2012-11-01T23:59:59.000Z

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.


461

PHYSICAL REVIEW B 85, 155101 (2012) Electronic properties of layered multicomponent wide-band-gap oxides: A combinatorial approach  

E-Print Network (OSTI)

PHYSICAL REVIEW B 85, 155101 (2012) Electronic properties of layered multicomponent wide 2012) The structural, electronic, and optical properties of 12 multicomponent oxides with layered self-consistent screened-exchange local density approximation calculations. Strikingly, despite

Medvedeva, Julia E.

462

One-photon band gap engineering of borate glass doped with ZnO for photonics applications  

SciTech Connect

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

463

Variation of the metal-insulator transition and formation of bipolarons by Cd doping in the thiospinel system Cu1-xCdxIr2S4  

Science Journals Connector (OSTI)

The pseudobinary thiospinel system Cu1-xCdxIr2S4 was investigated by the x-ray-diffraction, electrical resistivity, magnetic-susceptibility, and specific-heat measurements. It was shown that the system exhibits a miscibility-gap behavior for the Cd substitution, however, nearly monophasic samples were obtained by quenching at 1373 K, except for 0.4Cd concentration, the room-temperature electrical conductivity and Pauli susceptibility decrease monotonically, consistent with the hole-filling picture. The first-order metal-insulator transition at about 230 K in the parent compound CuIr2S4 is changed into a second-order transition around 185 K when x?0.25, whereafter the second-order transition disappears at x?0.8. No superconductivity was observed down to 1.8 K. The end-member compound CdIr2S4 is shown as an insulator with a band gap of 0.3 eV. Analysis for the data of magnetic susceptibility and electrical resistivity suggests the formation of bipolarons below 185 K for 0.25

Guanghan Cao; Hideaki Kitazawa; Takehiko Matsumoto; Chunmu Feng

2004-01-15T23:59:59.000Z

464

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

465

Molecular level control of nanoscale composition and morphology: Toward photocatalytic nanocomposites for solar-to-chemical energy conversion of biomass  

SciTech Connect

Understanding the factors influencing nanocrystal formation is a challenge yet to be realized. In comparison to the large number of studies on nanocrystal synthesis and their applications, the number of studies on the effect of the precursor chemistry on nanocrystal composition and shape remains low. Although photochemical fabrication of metalsemiconductor nano-heterostructures is reported in literature, control over the free particle formation and the site of metal deposition have not been achieved. Moreover, utilization of metal- semiconductor nano-heterostructures in photocatalytic reactions other than water splitting is hardly explored. In this thesis, we studied the effect of chalcogenide precursor reactivity on the composition, morphology and the axial anisotropy of cadmiumchalcogenide nanocrystals. We also investigated the influence of the irradiation wavelength in synthesizing metal-semiconductor nano-heterostructures. Finally, we showed that metal semiconductor nano-heterostructures can be used as a photocatalyst for alcohol dehydrogenation reactions. We explored the pathways for the formation of Pt and Pd nanoparticles on CdS and CdS{sub 0.4}Se{sub 0.6} nanorods. This study revealed that the wavelength of irradiation is critical to control free-standing vs. bound metal (Pt and Pd) nanoparticles to semiconductor. Additionally, we observed that metal photodeposition occurs on specific segments of axially anisotropic, compositionally graded CdS0.4Se0.6 nanorods due to the band-gap differential between their nano-domains. We used semiconductor-metal heterostructures for sunlightdriven dehydrogenation and hydrogenolysis of benzyl alcohol. Heterostructure composition dictates activity (turnovers) and product distribution. A few metal (Pt, Pd) islands on the semiconductor surface significantly enhance activity and selectivity and also greatly stabilize the semiconductor against photoinduced etching and degradation.

Ruberu, Thanthrige P. [Ames Laboratory] [Ames Laboratory

2013-05-15T23:59:59.000Z

466

Metal-Centered 17-Electron Radicals CpM(CO)3• (M = Cr, Mo, W): A Combined Negative Ion Photoelectron Spectroscopic and Theoretical Study  

SciTech Connect

Despite the importance of group VI metal-centered 17-electron radicals CpM(CO)3 (Cp = 5-C5H5, M = Cr, Mo, W) in establishing many of the fundamental reactions now known for metal-centered radicals, spectroscopic characterization of their electronic properties and structures has been very challenging due to their high reactivity. Here we report a gas-phase study of these species by means of photodetachment photoelectron spectroscopy (PES) of their corresponding 18-electron anions and theoretical electronic structure calculations. Three well-separated spectral features are observed by PES for each anionic species. Electron affinities (EAs) of CpM(CO)3 were experimentally measured from the threshold of each spectrum to be 2.38 ± 0.02 (M = Cr), 2.63 ± 0.02 (Mo), and 2.63 ± 0.01 eV for (W), well correlated with the reported redox potentials measured in solution. Theoretical calculations for all anionic and neutral (radical) species gave calculated EAs and band gaps that are in good agreement with the experimental data. Molecular orbital (MO) analyses for each anion indicate that the top three occupied MOs are mainly metal-based and contribute to the first spectral feature, whereas the next two MOs are largely from C5H5 moiety and contribute to the second spectral feature. The calculations further exhibit appreciable anion-to-neutral structural changes for all three species but with the change for the W species being the smallest, consistent with the W spectra being better resolved than the other two.

van der Eide, Edwin F.; Hou, Gao-Lei; Deng, Shihu; Wen, Hui; Yang, Ping; Bullock, R. Morris; Wang, Xue B.

2013-04-08T23:59:59.000Z

467

OPTICAL AND DYNAMIC PROPERTIES OF UNDOPED AND DOPED SEMICONDUCTOR NANOSTRUCTURES  

SciTech Connect

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

468

Modeling of electroabsorption in semiconductor quantum structures within the eight-band k?p theory  

Science Journals Connector (OSTI)

We have incorporated electric fields into the eight-band k?p theory, which we have applied to heterostructures, in conjunction with the envelope-function approximation. We use the method of Baraff and Gershoni to implement the electric-field effects in a computer program that calculates the optical properties of direct-band-gap heterostructures in one, two, and three dimensions. Using this method, we calculate the interband and intersubband electroabsorption of multiple quantum wells as well as the interband electroabsorption in superlattices. We illustrate the evolution of the Stark localization of the electron wave function under the application of an external electric field in superlattices. Comparison with experimental data, available in the literature, exhibits very good agreement between theory and experiment, with respect to the spectral shape, the absolute magnitude, and the electric-field dependence of the absorption.

Mats-Erik Pistol and David Gershoni

1994-10-15T23:59:59.000Z

469

Electrocoagulation: A Technology for Water Recycle and Wastewater Treatment in Semiconductor Manufacturing  

E-Print Network (OSTI)

Electrocoagulation: A Technology for Water Recycle and Wastewater Treatment in Semiconductor of treating wastewater streams in the semiconductor manufacturing industry. Electrocoagulation involves wastewater is increasing greatly. The objective is that by using EC to treat wastewater streams, this water

Fay, Noah

470

Unusual Bi-Containing Surface Layers of III–V Compound Semiconductors  

Science Journals Connector (OSTI)

In this chapter, it is first described how the surface science and engineering of the III–V compound semiconductors are relevant to developing the semiconductor-based materials, including bismuth (Bi) containi...

Pekka Laukkanen; Marko Punkkinen

2013-01-01T23:59:59.000Z

471

Semiconductor wire array structures, and solar cells and photodetectors based on such structures  

DOE Patents (OSTI)

A structure comprising an array of semiconductor structures, an infill material between the semiconductor materials, and one or more light-trapping elements is described. Photoconverters and photoelectrochemical devices based on such structure also described.

Kelzenberg, Michael D.; Atwater, Harry A.; Briggs, Ryan M.; Boettcher, Shannon W.; Lewis, Nathan S.; Petykiewicz, Jan A.

2014-08-19T23:59:59.000Z

472

E-Print Network 3.0 - active fabry-perot semiconductor Sample...  

NLE Websites -- All DOE Office Websites (Extended Search)

Physics 45 The Laser DiodeThe Laser Diode Jason HillJason Hill Summary: to a Light Emitting Diode Active medium is a semiconductor pActive medium is a semiconductor p--n...

473

Magnetic study of the electronic states in B-DNA and M-DNA doped with metal ions Kenji Mizoguchi,  

E-Print Network (OSTI)

- tivity of synthetic DNA (poly(G)-poly(C)) with a length of 10 nm to find a semiconducting behaviorMagnetic study of the electronic states in B-DNA and M-DNA doped with metal ions Kenji Mizoguchi. Purified salmon DNA gives intrinsically no EPR signal, which is consistent with DNA being a semiconductor

Mizoguchi, Kenji

474

Metal-phosphate binders  

DOE Patents (OSTI)

A metal-phosphate binder is provided. The binder may include an aqueous phosphoric acid solution, a metal-cation donor including a metal other than aluminum, an aluminum-cation donor, and a non-carbohydrate electron donor.

Howe, Beth Ann [Lewistown, IL; Chaps-Cabrera, Jesus Guadalupe [Coahuila, MX

2009-05-12T23:59:59.000Z

475

Toward a Unified Treatment of Electronic Processes in Organic Semiconductors  

SciTech Connect

A quantitative study of n-type doping in highly crystalline organic semiconductor films establishes the predominant influence of electrostatic forces in these low-dielectric materials. Based on these findings, a self-consistent model of doped (purposely or not) organic semiconductors is proposed in which: (1) the equilibrium free carrier density, nf, is a small fraction of the total charge density; (2) a superlinear increase in conductivity with doping density is universal; (3) nf increases with applied electric field; and (4) the carrier mobility is field-dependent regardless of crystallinity.

Gregg. B.A.

2005-01-01T23:59:59.000Z

476

Theory and Design of Smith-Purcell Semiconductor Terahertz Sources  

E-Print Network (OSTI)

-power semiconductor devices, but have also been demonstrated to be highly useful in the development of state of the art light emitting diode (LED) technology. One of the more promising LED materials, gallium nitride (GaN) comes from the “three-nitride” (III-N) family...-power semiconductor devices, but have also been demonstrated to be highly useful in the development of state of the art light emitting diode (LED) technology. One of the more promising LED materials, gallium nitride (GaN) comes from the “three-nitride” (III-N) family...

Smith, Don DeeWayne

2013-12-06T23:59:59.000Z

477

POWER SEMICONDUCTORS—STATE OF ART AND FUTURE TRENDS  

Science Journals Connector (OSTI)

The importance of effective energy conversion control including power generation from renewable and environmentally clean energy sources increases due to rising energy demand. Power electronic systems for controlling and converting electrical energy have become the workhorse of modern society in many applications both in industry and at home. Power electronics plays a very important role in traction and can be considered as brawns of robotics and automated manufacturing systems. Power semiconductor devices are the key electronic components used in power electronic systems. Advances in power semiconductor technology have improved the efficiency size weight and cost of power electronic systems.

Vitezslav Benda

2011-01-01T23:59:59.000Z

478

Quantum spin Hall effect in two-dimensional transition metal dichalcogenides  

Science Journals Connector (OSTI)

...calculating the one-particle Green’s function with application...Band gaps and quasiparticle energies . Phys. Rev. B 34 , 5390...calculation of bulk and surface Green functions . J. Phys. F 15...Wannier functions for composite energy bands . Phys. Rev. B 56...

Xiaofeng Qian; Junwei Liu; Liang Fu; Ju Li

479

Synthetic Metals 161 (2011) 16181622 Contents lists available at ScienceDirect  

E-Print Network (OSTI)

wavelength (to 1000 nm) and the estimated optical and electrochemical band-gaps of PDTTP are quite small is required to reduce the Rayleigh scattering from the detected object and the background noise. We have, to avoid the indoor lighting noise. Such high sensitivity proximity detection is especially important

480

E-Print Network 3.0 - advanced semiconductor devices Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Northern Illinois University Collection: Engineering 39 Kompetenzzentrum fr Automobil-und Industrieelektronik Summary: of materials for these advanced semiconductor...

Note: This page contains sample records for the topic "band-gap semiconductor metal" from the National Library of EnergyBeta (NLEBeta).
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481

Contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication  

DOE Patents (OSTI)

Methods for contact formation and gettering of precipitated impurities by multiple firing during semiconductor device fabrication are provided. In one embodiment, a method for fabricating an electrical semiconductor device comprises: a first step that includes gettering of impurities from a semiconductor wafer and forming a backsurface field; and a second step that includes forming a front contact for the semiconductor wafer, wherein the second step is performed after completion of the first step.

Sopori, Bhushan

2014-05-27T23:59:59.000Z

482

Electronic structure and ferromagnetism of Mn-doped group-IV semiconductors  

Science Journals Connector (OSTI)

Accurate ab initio full-potential augmented plane wave (FLAPW) electronic calculations within density functional theory in both local density and generalized gradient approximations have been performed for MnxGe1-x and MnxSi1-x ordered alloys, focusing on their electronic and magnetic properties as a function of the host semiconducting matrix (i.e., Si vs Ge), the Mn concentration, and the spin magnetic alignment (i.e., ferromagnetic vs antiferromagnetic). As expected, Mn is found to be a source of holes and localized magnetic moments of about 3?B/Mn. The results show that irrespective of the Mn content, the Ge-based systems are very close to half-metallicity, whereas the Si-based structures just miss the half-metallic behavior due to the crossing of the Fermi level by the lowest conduction bands. Moreover, the ferromagnetic alignment is favored compared to the antiferromagnetic one, with its stabilization generally increasing with Mn content; this is in agreement with recent experimental findings for MnGe systems and supports the view that this class of ferromagnetic semiconductors constitute basic spintronic materials.

A. Stroppa; S. Picozzi; A. Continenza; A. J. Freeman

2003-10-08T23:59:59.000Z

483

A Metal That Becomes Transparent under Pressure | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Under Pressure, Atoms Make Unlikely Alloys Under Pressure, Atoms Make Unlikely Alloys Slowing Down Near the Glass Transition New Light on Improving Engine Efficiencies The Crystal Structure of a Meta-stable Intermediate Particle in Virus Assembly Increasing Magnetic Response of Ferromagnetic Semiconductors under High Pressure Science Highlights Archives: 2013 | 2012 | 2011 | 2010 2009 | 2008 | 2007 | 2006 2005 | 2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed A Metal That Becomes Transparent under Pressure APRIL 20, 2009 Bookmark and Share Sodium clamped in a metallic rhenium gasket between diamond anvils. The photographs were taken through a diamond anvil under combined transmitted and reflected illumination. Sodium, a white metal at pressures below 1.1 Mbar (1 Mbar = 1 million atm), turns black at 1.3 Mbar and becomes

484

Metal Hydrides - Science Needs  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Storage Grand Challenge Pre-Solicitation Meeting, June 19, 2003 1 Metal Hydrides - Science Needs TRADITIONAL METALLIC HYDRIDES: 1.5 to 2 wt.% H. Well studied. COMPLEX...

485

Probing metal solidification nondestructively  

NLE Websites -- All DOE Office Websites (Extended Search)

Probing metal solidification nondestructively This is the first time that high-energy protons have been used to nondestructively image a large metal sample during melting and...

486

Probing metal solidification nondestructively  

NLE Websites -- All DOE Office Websites (Extended Search)

Probing metal solidification nondestructively This is the first time that high-energy protons have been used to nondestructively image a large metal sample during melting...