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

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 Ga(0.33)Ino(0.67)Sb 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 degrees C for a 1 gm 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 8-12 gm was obtained, and estimated detectivity peak at room temperature was approximately 7x10(7) cm Hz112 W-1, which is 1.3 times higher than without a Ga0.33In0.67Sb electron barrier. These results demonstrate that our InAs Sbi, PVS is a promising device for the 8-12 mu m wavelength range at room temperature.