Lateral diffusion of minority carriers in nBn based type-II InAs/GaSb strained layer superlattice detectors

We report on the investigation of lateral diffusion of minority carriers in nBn based InAs/GaSb strained layer superlattice photodetectors. Values of diffusion length of minority carriers were extracted from temperature dependent I-V measurements. The behavior of diffusion length as a function of applied bias, temperature, and composition of the barrier layer and the values ranging by two orders of magnitude from 77 to 250 K at the same value of applied bias were investigated. The obtained results suggest that at this point the lateral diffusion current could be the limiting factor of the MWIR nBn detector performance at low (<150 K) temperatures.