Theoretical Simulation of a Room Temperature HgCdTe Long-Wave Detector for Fast Response − Operating Under Zero Bias Conditions

Abstract

The paper reports on a long-wave infrared (cut-off wavelength ~ 9 µm) HgCdTe detector operating under unbiased condition and room temperature (300 K) for both short response time and high detectivity operation. The optimal structure in terms of the response time and detectivity versus device architecture was shown. The response time of the long-wave (active layer Cd composition, xCd = 0.19) HgCdTe detector for 300 K was calculated at a level of τs ~ 1 ns for zero bias condition, while the detectivity − at a level of D * ~ 10 9 cmHz 1/2 /W assuming immersion. It was presented that parameters of the active layer and P + barrier layer play a critical role in order to reach τs ≤ 1 ns. An extra series resistance related to the processing (RS+ in a range 5−10 Ω) increased the response time more than two times (τs ~ 2.3 ns).