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Photoconductivity as a Function of Temperature in MOCVD Grown Gallium Nitride Films

Published online by Cambridge University Press:  26 February 2011

C. H. Qiu
Affiliation:
Astralux Inc., 2386 Vassar Drive, Boulder, CO 80303–5763
W. Melton
Affiliation:
University of Colorado, Dept. of Electrical Engineering, Boulder, CO 80309-0425
J. I. Pankove
Affiliation:
Astralux Inc., 2386 Vassar Drive, Boulder, CO 80303–5763 University of Colorado, Dept. of Electrical Engineering, Boulder, CO 80309-0425
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Abstract

The optical absorption in gallium nitride (GaN) films was studied by photoconductivity (PC) spectroscopy at various temperatures. At all the measured temperatures, the photoconductivity per incident photon increases with photon energy hv from 1.8 eV to 3.0 eV approximately as exp(hv/E0). Surprisingly, the measured photoconductivity tail to the infrared becomes more pronounced in magnitude at lower temperatures. We suggest from the data that the photoconductivity is dominated by majority carriers, and that the quantum efficiency η for conducting electron and hole generation by across-gap excitation increases with increasing temperature.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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