Temperature dependent noise performance of Hg/sub 1-x/Cd/sub x/Te photoconductive detectors

Abstract

Background limited infrared photodetector (BLIP) performance, attained at cryogenic temperatures, is the maximum performance achievable by a photoconductive detector. By increasing the operating temperature, low cost detectors can be realised using thermoelectric cooling (>200 K). Investigation of temperature dependent performance of Hg/sub 1-x/Cd/sub x/Te infrared detectors is essential for developing device structures and fabrication technologies capable of producing BLIP performance. In this paper the performance of n-type x=0.31 Hg/sub 1-x/Cd/sub x/Te photoconductors under reduced cooling is examined experimentally and theoretically. Measurements gave a background limited D/sub /spl lambda//* of 1.9/spl times/10/sup 11/ cm Hz/sup 1/2/W/sup -1/ up to 170 K and D/sub /spl lambda//* values of 7.3/spl times/10/sup 10/ and 6.4/spl times/10/sup 9/ cm Hz/sup 1/2/W/sup -1/ were measured at 200 K and 300 K, respectively.