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Title: Composition Dependence of Schottky Barrier Heights and Bandgap Energies of GaNxAs1-x Synthesized by Ion Implantation and Pulsed-Laser Melting

Abstract

We present a systematic investigation on the band structure of the GaN{sub x}As{sub 1-x} alloys synthesized using nitrogen ion implantation followed by pulsed-laser melting and rapid thermal annealing. The evolution of the nitrogen-concentration depth profile is consistent with liquid-phase diffusion, solute trapping at the rapidly moving solidification front, and surface evaporation. The reduction of the Schottky barrier height of the {Gamma}-like threshold at nitrogen composition up to x = 0.016 is studied by ballistic electron emission microscopy (BEEM) and determined quantitatively using the second voltage derivative BEEM spectra to be -191 {+-} 63 meV per x = 0.01, which is close to the corresponding slope for samples grown by low-temperature molecular beam epitaxy. This slope is also consistent with the bandgap narrowing measured on the same samples by photomodulated reflectance and is consistent with the band anticrossing model for the splitting of the conduction band in the GaN{sub x}As{sub 1-x} alloys. Lithographically patterned GaN{sub x}As{sub 1-x} dots are imaged by BEEM. Analysis of BEEM spectra of the locally confined dots indicates an alloying-induced decrease in the Schottky barrier height of four times the thermal energy at room temperature.

Authors:
; ; ; ;
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Solar Energy Technologies Program
OSTI Identifier:
1022355
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 104; Journal Issue: 11, December 2008; Related Information: Article No. 113722; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALLOYS; ANNEALING; DIFFUSION; ELECTRON EMISSION; EVAPORATION; ION IMPLANTATION; MELTING; MICROSCOPY; MOLECULAR BEAM EPITAXY; NITROGEN; NITROGEN IONS; SOLIDIFICATION; SOLUTES; SPECTRA; TRAPPING; Solar Energy - Photovoltaics

Citation Formats

Kim, T, Alberi, K, Dubon, O D, Aziz, M J, and Narayanamurti, V. Composition Dependence of Schottky Barrier Heights and Bandgap Energies of GaNxAs1-x Synthesized by Ion Implantation and Pulsed-Laser Melting. United States: N. p., 2008. Web. doi:10.1063/1.3041154.
Kim, T, Alberi, K, Dubon, O D, Aziz, M J, & Narayanamurti, V. Composition Dependence of Schottky Barrier Heights and Bandgap Energies of GaNxAs1-x Synthesized by Ion Implantation and Pulsed-Laser Melting. United States. doi:10.1063/1.3041154.
Kim, T, Alberi, K, Dubon, O D, Aziz, M J, and Narayanamurti, V. Mon . "Composition Dependence of Schottky Barrier Heights and Bandgap Energies of GaNxAs1-x Synthesized by Ion Implantation and Pulsed-Laser Melting". United States. doi:10.1063/1.3041154.
@article{osti_1022355,
title = {Composition Dependence of Schottky Barrier Heights and Bandgap Energies of GaNxAs1-x Synthesized by Ion Implantation and Pulsed-Laser Melting},
author = {Kim, T and Alberi, K and Dubon, O D and Aziz, M J and Narayanamurti, V},
abstractNote = {We present a systematic investigation on the band structure of the GaN{sub x}As{sub 1-x} alloys synthesized using nitrogen ion implantation followed by pulsed-laser melting and rapid thermal annealing. The evolution of the nitrogen-concentration depth profile is consistent with liquid-phase diffusion, solute trapping at the rapidly moving solidification front, and surface evaporation. The reduction of the Schottky barrier height of the {Gamma}-like threshold at nitrogen composition up to x = 0.016 is studied by ballistic electron emission microscopy (BEEM) and determined quantitatively using the second voltage derivative BEEM spectra to be -191 {+-} 63 meV per x = 0.01, which is close to the corresponding slope for samples grown by low-temperature molecular beam epitaxy. This slope is also consistent with the bandgap narrowing measured on the same samples by photomodulated reflectance and is consistent with the band anticrossing model for the splitting of the conduction band in the GaN{sub x}As{sub 1-x} alloys. Lithographically patterned GaN{sub x}As{sub 1-x} dots are imaged by BEEM. Analysis of BEEM spectra of the locally confined dots indicates an alloying-induced decrease in the Schottky barrier height of four times the thermal energy at room temperature.},
doi = {10.1063/1.3041154},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 11, December 2008,
volume = 104,
place = {United States},
year = {2008},
month = {12}
}