Theoretical utmost performance of the (1Â 0Â 0) long-wave HgCdTe Auger suppressed photodetectors grown on GaAs

The vast majority of HgCdTe detectors designed to detect long wavelength (8-14 μm) infrared radiation must be cooled to achieve the required performance. It must be stressed that cooling requirement is both expensive and bulky and the main objective is to reach higher operating temperature condition preserving near background limited performance and high speed response. In order to reach that goal the thermal generation rate needs to be reduced below the photon generation rate. Except Auger 7, p-type HgCdTe active layers are mostly limited by technology dependent Shockley-Read-Hall generation-recombination processes. One of the ways to reduce of the trap density is a growth of the (1 0 0) HgCdTe epilayers on GaAs substrates. In addition, that orientation allows reaching lower carrier concentration in comparison to the commonly used (1 1 1) orientation (5 × 1015-1016 cm−3). In this paper we report on theoretical utmost performance of (1 0 0) HgCdTe Auger suppressed photodetectors grown on GaAs substrates. (1 0 0) HgCdTe orientation allows to reduce p-type doping to the level of ∼5 × 1014 cm−3 in analyzed long wavelength range. In addition Shockley-Read-Hall traps could be reduced to the level of ∼4.4 × 108 cm−3 resulting in suppression of the dark current by nearly two orders of magnitude within the range ∼20 ÷ 0.31 A/cm2 and detectivity, ∼1010−1011 cmHz1/2/W at temperature 230 K, voltage 200 mV.