Theoretical Study of Midwave Infrared HgCdTe nBn Detectors Operating at Elevated Temperatures

摘要

We report a theoretical study of mercury cadmium telluride (HgCdTe) unipolar n-type/barrier-type (nBn) detectors for midwave infrared (MWIR) applications at elevated temperatures. The results obtained indicate that the composition, doping, and thickness of the barrier layer in MWIR HgCdTe nBn detectors can be optimized to yield performance levels comparable with those of ideal HgCdTe p-n photodiodes. It is also shown that introduction of an additional barrier at the back contact layer of the detector structure (nBnn(+)) leads to substantial suppression of the Auger generation-recombination (GR) mechanism; this results in an order-of-magnitude reduction in the dark current level compared with conventional nBn or p-n junction-based detectors, thus enabling background-limited detector operation above 200 K.