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

Journal Article · Mon Dec 01 04:00:00 EST 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3041154· OSTI ID:1022355

Kim, T; Alberi, K; Dubon, O D; Aziz, M J; Narayanamurti, V

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.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO.
• Sponsoring Organization: USDOE Office of Solar Energy Technologies Program
• DOE Contract Number: AC36-08GO28308
• OSTI ID: 1022355
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11, December 2008 Vol. 104; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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
Solar Energy - Photovoltaics
TRAPPING