Room-temperature operation of InAsSb/InAsPSb photodetectors with a cut-off wavelength of 4.3μm

Room-temperature operation of InAsSb/InAsPSb photodetectors with a cut-off wavelength of 4.3 mu m has been realized. Surface-illuminated heterostructure photodiodes were fabricated using epilayers crown by liquid-phase epitaxy at temperatures between 550 and 500 degrees C. A peak responsivity of 0.7 A/W and a detectivity of 1.1 x 10(9) cm.Hz(1/2)/W were obtained at 4 mu m. Temperature dependence of the photoresponsivity and the detectivity of the detectors was also investigated between 200 and 297 K. The results showed that these heterostructure photodetectors have potential applications in CO2 gas sensors.