Sensitive parameters affecting dark current characteristics of SCD

The sensitive parameters affecting the dark current characteristics are further studied by using InAs/GaSb type II superlattice (T2SL) pBpp structure long wavelength Infrared photodetectors. Generation of recombination (G-R), surface leakage current and tunneling current are the main components of dark current. Using pBpp structure can suppress them effectively, thereby decreasing dark current. Based on the k \ub7 p method, the band structure of InAs/GaSb T2SL and InAs/AlSb T2SL can be obtained by solving the 8-band k \ub7 p model. We have calculated different doping levels of pBpp detector and different layer thicknesses of pBpp detector. For pBpp device, we consider the dark current for different contact layer doping and different absorber layer doping. We also study the influence of different contact layer thicknesses and different absorber layer thicknesses on dark current. The dark current of pBpp detector is dominant by tunneling current at low temperature, and diffusion is the main limiting mechanism in dark current at high temperature, for barrier layer inhibits generation-recombination contribution. Eventually, the dark current of a pBpp structure has been calculated for versus voltage at 77 K