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Title: Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys

Abstract

The layer structured hexagonal boron nitride carbon semiconductor alloys, h-(BN)C, offer the unique abilities of bandgap engineering (from 0 for graphite to ∼6.4 eV for h-BN) and electrical conductivity control (from semi-metal for graphite to insulator for undoped h-BN) through alloying and have the potential to complement III-nitride wide bandgap semiconductors and carbon based nanostructured materials. Epilayers of (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys were synthesized by metal-organic chemical vapor deposition (MOCVD) on (0001) sapphire substrates. Hall-effect measurements revealed that homogeneous (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys are naturally n-type. For alloys with x = 0.032, an electron mobility of about 20 cm{sup 2}/Vs at 650 °K was measured. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition and analyze chemical bonding states. Both composition and chemical bonding analysis confirm the formation of alloys. XPS results indicate that the carbon concentration in the alloys increases almost linearly with the flow rate of the carbon precursor (propane (C{sub 3}H{sub 8})) employed during the epilayer growth. XPS chemical bonding analysis showed that these MOCVD grown alloys possess more C-N bonds than C-B bonds, which possibly renders the undoped h-(BN){sub 1-x}(C{sub 2}){sub x} alloys n-type and corroborates the Hall-effect measurement results.

Authors:
; ; ; ;  [1];  [2]
  1. Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX 79409 (United States)
  2. Department of Chemical Engineering, Northeastern University, Boston, MA 02115 (United States)
Publication Date:
OSTI Identifier:
22299762
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 4; Journal Issue: 8; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ALLOYS; BORON NITRIDES; CHEMICAL BONDS; CHEMICAL VAPOR DEPOSITION; ELECTRIC CONDUCTIVITY; GRAPHITE; HALL EFFECT; NANOSTRUCTURES; PROPANE; SAPPHIRE; SEMICONDUCTOR MATERIALS; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Uddin, M. R., Doan, T. C., Li, J., Lin, J. Y., Jiang, H. X., E-mail: hx.jiang@ttu.edu, and Ziemer, K. S.. Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys. United States: N. p., 2014. Web. doi:10.1063/1.4894451.
Uddin, M. R., Doan, T. C., Li, J., Lin, J. Y., Jiang, H. X., E-mail: hx.jiang@ttu.edu, & Ziemer, K. S.. Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys. United States. doi:10.1063/1.4894451.
Uddin, M. R., Doan, T. C., Li, J., Lin, J. Y., Jiang, H. X., E-mail: hx.jiang@ttu.edu, and Ziemer, K. S.. Fri . "Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys". United States. doi:10.1063/1.4894451.
@article{osti_22299762,
title = {Electrical transport properties of (BN)-rich hexagonal (BN)C semiconductor alloys},
author = {Uddin, M. R. and Doan, T. C. and Li, J. and Lin, J. Y. and Jiang, H. X., E-mail: hx.jiang@ttu.edu and Ziemer, K. S.},
abstractNote = {The layer structured hexagonal boron nitride carbon semiconductor alloys, h-(BN)C, offer the unique abilities of bandgap engineering (from 0 for graphite to ∼6.4 eV for h-BN) and electrical conductivity control (from semi-metal for graphite to insulator for undoped h-BN) through alloying and have the potential to complement III-nitride wide bandgap semiconductors and carbon based nanostructured materials. Epilayers of (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys were synthesized by metal-organic chemical vapor deposition (MOCVD) on (0001) sapphire substrates. Hall-effect measurements revealed that homogeneous (BN)-rich h-(BN){sub 1-x}(C{sub 2}){sub x} alloys are naturally n-type. For alloys with x = 0.032, an electron mobility of about 20 cm{sup 2}/Vs at 650 °K was measured. X-ray photoelectron spectroscopy (XPS) was used to determine the chemical composition and analyze chemical bonding states. Both composition and chemical bonding analysis confirm the formation of alloys. XPS results indicate that the carbon concentration in the alloys increases almost linearly with the flow rate of the carbon precursor (propane (C{sub 3}H{sub 8})) employed during the epilayer growth. XPS chemical bonding analysis showed that these MOCVD grown alloys possess more C-N bonds than C-B bonds, which possibly renders the undoped h-(BN){sub 1-x}(C{sub 2}){sub x} alloys n-type and corroborates the Hall-effect measurement results.},
doi = {10.1063/1.4894451},
journal = {AIP Advances},
number = 8,
volume = 4,
place = {United States},
year = {Fri Aug 15 00:00:00 EDT 2014},
month = {Fri Aug 15 00:00:00 EDT 2014}
}
  • Hexagonal boron nitride carbon, h(BN){sub 1-x}(C{sub 2}){sub x}, semiconductor alloys have been grown on sapphire substrates by metal-organic chemical vapor deposition. Bandgap tuning through compositional variation has been demonstrated via optical absorption measurements. Furthermore, an enhancement of approximately 10 orders of magnitude in the electrical conductivity has been attained by increasing the carbon concentration (x) from 0 to 0.21. Experimental results revealed evidences that the critical carbon concentration x{sub c} to form the homogenous h(BN){sub 1-x}(C{sub 2}){sub x} alloys, or the carbon solubility in hBN is about 3.2% at a growth temperature of 1300 °C before carbon clusters form. Based onmore » the predicted phase diagram of cubic (BN){sub 1-x}(C{sub 2}){sub x} and the excellent matches in the structural and thermal properties of hBN and graphite, it is expected that homogenous h(BN){sub 1-x}(C{sub 2}){sub x} alloys with higher x can be achieved and the alloy miscibility gap can be reduced or completely removed by increasing the growth temperature. This is a huge advantage over the InGaN alloy system in which InN decomposes at high temperatures and high growth temperature cannot be utilized to close the miscibility gap. The results indicate that the h(BN){sub 1-x}(C{sub 2}){sub x} alloy system has the potential to tackle the challenging issues facing the emerging two-dimension materials beyond graphene, which include realizing the bandgap engineering, conductivity control, and large wafers of homogeneous films.« less
  • Thin films of hexagonal boron nitride carbon, h-(BN){sub 1−x}(C{sub 2}){sub x}, alloys in the C-rich side have been synthesized by metal-organic chemical vapor deposition (MOCVD) on c-plane sapphire substrates. X-ray diffraction measurements confirmed single hexagonal phase of h-(BN){sub 1−x}(C{sub 2}){sub x} epilayers. Electrical transport and Raman spectroscopy measurements results revealed evidences that homogenous h-(BN){sub 1−x}(C{sub 2}){sub x} alloys with x ≥ 95% can be synthesized by MOCVD at a growth temperature of 1300 °C. The variable temperature Hall-effect measurements suggested that a bandgap opening of about 93 meV with respect to graphite has been obtained for h-(BN){sub 1−x}(C{sub 2}){sub x} with x = 0.95, which ismore » consistent with the expected value deduced from the alloy dependence of the energy gap of homogenous h-(BN){sub 1−x}(C{sub 2}){sub x} alloys. Atomic composition results obtained from x-ray photoelectron spectroscopy measurements revealed that the carrier type in C-rich h-(BN){sub 1−x}(C{sub 2}){sub x} alloys is controlled by the stoichiometry ratio between the B and N via changing the V/III ratio during the growth. The demonstration of bandgap opening and conductivity control in C-rich h-(BN){sub 1−x}(C{sub 2}){sub x} alloys provide feasibilities for realizing technologically significant devices including infrared (IR) emitters and detectors active from near to far IR and multi-spectral IR emitters and detectors.« less
  • Within the Kubo-Greenwood formalism we use the fully relativistic, spin-polarized, screened Korringa-Kohn-Rostoker method together with the coherent-potential approximation for layered systems to calculate the resistivity for the permalloy series Ni{sub c}Fe{sub 1{minus}c}. We are able to reproduce the variation of the resistivity across the entire series; notably the discontinuous behavior in the vicinity of the structural phase transition from bcc to fcc. The absolute values for the resistivity are within a factor of 2 of the experimental data. Also the giant magnetoresistance of a series of permalloy-based spin-valve structures is estimated; we are able to reproduce the trends observed onmore » prototypical spin-valve structures.« less
  • Using the first-principle calculations, the stability and electronic properties of two novel types of four-segment armchair (10, 10) BN/C hybrid nanotubes ((BN){sub 5}C{sub 5}(BN){sub 5}C{sub 5}NT and (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT) as well as two-segment armchair (10, 10) BN/C hybrid nanotubes ((BN{sub 20−n}C{sub n}NTs) are systematically investigated. When n increases from 1 to 4, the band gap of (BN){sub 20−n}C{sub n}NTs gradually decreases to a narrow one. When 4≤n≤17, the electronic structure of carbon segment in (BN){sub 20−n}C{sub n}NTs behaves as zigzag graphene nanoribbons whose band gap is modulated by an inherent electric field of the BN segment. ZGNR-likemore » segments in (BN){sub 5}C{sub 5}(BN){sub 5}C{sub 5}NT and (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT behave as narrow gap semiconductor and metal, respectively, due to their different chemical environment. Moreover, the (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT can separate electron and hole carriers, indicating its potential application in solar cell materials. Obvious transport enhancement around the Fermi level is found in the four-segment nanotubes, especially a 6G{sub 0} transmission peak in the metallic (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT. - Graphical abstract: Structural diagram of four-segment (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT and its typical two-probe system. The band structures and transport spectra of (BN){sub 5}C{sub 5}(NB){sub 5}C{sub 5}NT are shown in upper and lower panels. Highlights: ► Transport properties of two types of four-segment BNC hybrid nanotubes are studied. ► Transport enhancements are realized in the four-segment BNC hybrid nanotubes. ► Electron and hole separation is found in four-segment BNC hybrid nanotubes.« less
  • The suitability of Si as an n-type dopant in hexagonal boron nitride (hBN) wide bandgap semiconductor has been investigated. Si doped hBN epilayers were grown via in-situ Si doping by metal organic chemical vapor deposition technique. Hall effect measurements revealed that Si doped hBN epilayers exhibit n-type conduction at high temperatures (T > 800 K) with an in-plane resistivity of ∼12 Ω·cm, electron mobility of μ ∼ 48 cm{sup 2}/V·s and concentration of n ∼ 1 × 10{sup 16} cm{sup −3}. Temperature dependent resistivity results yielded a Si energy level in hBN of about 1.2 eV, which is consistent withmore » a previously calculated value for Si substitutionally incorporated into the B sites in hBN. The results therefore indicate that Si is not a suitable dopant for hBN for room temperature device applications.« less