Growth of InAsSb alloys on GaAs and Si substrates for uncooled infrared photodetector applications

Abstract

In this paper, we report on the growth and characterization of InAsSb alloys on GaAs and Si substrates for uncooled infrared photodetector applications. The fabrication and characterization of photodetectors from the grown layers are also reported. The photovoltaic and photoconductive devices were grown on (100) GaAs and Si substrates, respectively, using molecular beam epitaxy (MBE). The composition of InAs1-xSbx layers was 0.95 in both cases and cut-off wavelength of 7 - 8 micrometer has been obtained. At 300 K, the photovoltaic detectors on GaAs substrates resulted in a sharp cut-off wavelength of 7.5 micrometer with a peak responsivity as high as 0.32 V/W at 6.5 micrometer. For the photoconductive detectors on Si substrates, cut-off wavelength of 8 micrometer has been observed with a responsivity of 6.3 X 10-2 V/W at 7 micrometer under an electric field of 420 V/m.