Dark Current Simulation and Analysis for InAs/GaSb Long wavelength Infrared Barrier Detectors

The authors reported a heterojunction dark current simulation method for InAs/GaSb long wavelength infrared barrier detectors. Calculations using the dark current model with energy band offset have shown that the theoretical and experimental data of the model are highly consistent. The energy band offsets of absorption and barrier region in the detectors were calculated by the 8-band k·p method. Then, the dark current model of heterojunction was established and compared with the homojunction model previously adopted. The agreement between the theoretical predictions and the experimental measurement led us to propose a barrier device structure with low dark current in long wavelength infrared domain. The results show that under a small reverse bias (V < -100 mV), the G-R and surface leakage current dominate, while the tunneling dark current occupies a leading position with a large bias (V > -320 mV) at 77 K. The dark current density under −10 mV bias voltage is 1.16 × 10-4A/cm2.