Room temperature operating InAsSb-based photovoltaic infrared sensors grown by metalorganic vapor phase epitaxy

Abstract

We have developed InAsxSb1−x-based photovoltaic infrared sensors (PVS) for room temperature operation by metalorganic vapor phase epitaxy (MOVPE). To obtain high performance, we improved the crystallinity of the InAs0.12Sb0.88 absorber layer and utilized a Ga0.33In0.67Sb electron barrier layer. An investigation of InAs0.12Sb0.88 growth conditions using a high-quality InSb buffer layer showed that we were able to obtain the smallest full-width at half-maximum (FWHM) of the X-ray diffraction omega rocking curve, 560 arcsec, for a growth temperature of 520°C for a 1µm thick layer. Moreover, we successfully grew a Ga0.33In0.67Sb barrier layer coherently on an InAs0.12Sb0.88 absorber layer, which is the first report of GayIn1−ySb growth on Sb-rich InAsxSb1−x. An InAsxSb1−x PVS with a responsivity at wavelengths of 8–12µm was obtained, and estimated detectivity peak at room temperature was approximately 7×107cmHz1/2W−1, which is 1.3 times higher than without a Ga0.33In0.67Sb electron barrier. These results demonstrate that our InAsxSb1−x PVS is a promising device for the 8–12µm wavelength range at room temperature.