This paper presents a thorough analysis of the current-voltage characteristics of uncooled HgCdTe detectors optimized for different spectral ranges. HgCdTe heterostructures were grown by means of metal-organic chemical vapor deposition (MOCVD) on GaAs substrates. The obtained detector structures were measured using a Keysight B1500A semiconductor device analyser controlled via LabVIEW for automation. The experimental characteristics were compared with numerical calculations performed using the commercial platform SimuAPSYS (Crosslight). SimuAPSYS supports detector design and allows one to understand different mechanisms occurring in the analysed structures. The dark current density experimental data were compared with theoretical results at a temperature of 300 K for short, medium, and long wavelength infrared ranges. The dark current density of detectors optimized for different wavelengths was determined using various generation-recombination mechanisms. Proper matching between experimental and theoretical data was obtained by shifting the Shockley-Read-Hall carrier lifetime and the Auger-1 and Auger-7 recombination rates. Exemplary spectral responses were also discussed, giving a better insight into detector performance. The matching level was proven with a theoretical evaluation of the zero-bias dynamic resistance-area product (R0A) and the current responsivity of the designed detectors.
Keywords: HOT; HgCdTe heterostructure; current–voltage characteristics; infrared detectors.