Dark Current Simulation in Interband Cascade Photodetectors Operating in Room Temperature

Interband cascade type-II mid-wavelength infrared (MWIR) InAs/GaSb superlattice (T2SL) detector in room temperature (300 K) is investigated. A single stage in the cascade is a double heterostructure with the absorber sandwiched between electron and hole barriers. The absorber region is non-intentionally doped and is made of MWIR 9ML InAs/9ML GaSb T2SL. At low temperatures structure has a residual doping of p-type, but at room temperature the SL is n-type with n(300K) = 10(16) cm(-3). In this article we calculate dark current being treated as a sum of two currents: average bulk current and average leakage current, flowing through the device. Average bulk current is theoretically calculated, while the average leakage current results from a comparison of theoretically estimated bulk current and measured one. We show that it is possible to fit theoretical model to experimental data, assuming that transport in absorber region is determined by the dynamics of the intrinsic carriers. Based on the fit we estimated carrier lifetime equal about 100 ns at temperature 300 K.