Modelling of MWIR HgCdTe complementary barrier HOT detector

Abstract The paper reports on the photoelectrical performance of medium wavelength infrared (MWIR) HgCdTe complementary barrier infrared detector (CBIRD) with n -type barriers. CBIRD nB 1 nB 2 HgCdTe/B 1,2 - n type detector is modelled with commercially available software APSYS by Crosslight Software Inc. The detailed analysis of the detector’s performance such as dark current, photocurrent, responsivity, detectivity versus applied bias, operating temperature, and structural parameters (cap, barriers and absorber doping; and absorber and barriers compositions) are performed pointing out optimal working conditions. Both conduction and valence bands’ alignment of the HgCdTe CBIRD structure are calculated stressing their importance on detectors performance. It is shown that higher operation temperature (HOT) conditions achieved by commonly used thermoelectric (TE) coolers allows to obtain detectivities D ∗  ≈ 2 × 10 10  cm Hz 1/2 /W at T  = 200 K and reverse polarisation V  = 400 mV, and differential resistance area product RA  = 0.9 Ωcm 2 at T  = 230 K for V  = 50 mV, respectively. Finally, CBIRD nB 1 nB 2 HgCdTe/B 1,2 - n type state of the art is compared to unipolar barrier HgCdTe nBn/B- n type detector, InAs/GaSb/B-Al 0.2 Ga 0.8 Sb type-II superlattice (T2SL) nBn detectors, InAs/GaSb T2SLs PIN and the HOT HgCdTe bulk photodiodes’ performance operated at near-room temperature ( T  = 230 K). It was shown that the RA product of the MWIR CBIRD HgCdTe detector is either comparable or higher (depending on structural parameters) to the state of the art of HgCdTe HOT bulk photodiodes and both A III B V 6.1 A family T2SLs nBn and PIN detectors.