Photoconductive properties of GaAs{sub 1{minus}x}N{sub x} double heterostructures as a function of excitation wavelength

Conference · Mon May 22 04:00:00 EDT 2000

OSTI ID:756333

Ahrenkiel, R K; Mascarenhas, A; Johnston, S W; Zhang, Y; Friedman, D J; Vernon, S M

The ternary semiconductor GaAs{sub 1{minus}x}N{sub x} with 0 < x < 0.3 can be grown epitaxially on GaAs and has a very large bowing coefficient. The alloy bandgap can be reduced to about 1.0 eV with about a 3% nitrogen addition. In this work, the authors measured the internal spectral response and recombination lifetime of a number of alloys using the ultra-high frequency photoconductive decay (UHFPCD) method. The data shows that the photoconductive excitation spectra of the GaAs{sub 0.97}N{sub 0.03} alloy shows a gradual increase in response through the absorption edge near E{sub g}. This contrasts with most direct bandgap semiconductors that show a steep onset of photoresponse at E{sub g}. The recombination lifetimes frequently are much longer than expected from radiative recombination and often exceeded 1.0{mu}s. The data were analyzed in terms of a band model that includes large potential fluctuations in the conduction band due to the random distribution of nitrogen atoms in the alloy.

• Research Organization: National Renewable Energy Lab., Golden, CO (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC36-99GO10337
• OSTI ID: 756333
• Report Number(s): NREL/CP-520-27634
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
DOUBLE HETEROSTRUCTURES
ENERGY GAP
GALLIUM ARSENIDES
GALLIUM NITRIDES
HETEROJUNCTIONS
PHOTOCONDUCTIVITY
PHOTOVOLTAIC CONVERSION
PHOTOVOLTAICS
RECOMBINATION
RECOMBINATION LIFETIMES
SEMICONDUCTOR MATERIALS
ULTRA-HIGH FREQUENCY PHOTOCONDUCTIVE DECAYSPECTRAL RESPONSE