Photoconductive properties of GaAs{sub 1{minus}x}N{sub x} double heterostructures as a function of excitation wavelength
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. (NREL), Golden, CO (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC36-99GO10337
- OSTI ID:
- 756333
- Report Number(s):
- NREL/CP-520-27634; TRN: AH200017%%241
- Resource Relation:
- Conference: Materials Research Society's 1999 Fall Meeting, Boston. MA (US), 11/29/1999--12/03/1999; Other Information: PBD: 22 May 2000
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
14 SOLAR ENERGY
SEMICONDUCTOR MATERIALS
GALLIUM NITRIDES
GALLIUM ARSENIDES
ENERGY GAP
HETEROJUNCTIONS
PHOTOVOLTAIC CONVERSION
RECOMBINATION
PHOTOVOLTAICS
DOUBLE HETEROSTRUCTURES
RECOMBINATION LIFETIMES
ULTRA-HIGH FREQUENCY PHOTOCONDUCTIVE DECAYSPECTRAL RESPONSE
PHOTOCONDUCTIVITY