Minority carrier diffusion length and lifetime for electrons in a type-II InAs/GaSb superlattice photodiode

The use of electron-beam-induced current (EBIC) technique to investigate carrier transport characteristics in a type-II InAs/GaSb superlattice photodiode with cutoff wavelength at 7.7 μm was discussed. It was observed that, to simulate the EBIC current on both sides of the p-n junctions, a theoretical model that includes an extended generation source and depletion region was used. It was also observed that the electron minority diffusion length in the p-superlattice, L _e, was extracted from the simulation, from which the electron lifetime τ _e was obtained. The results show that the EBIC measurement was a useful method to extract fundamental parameters in T2-SL photodiode devices.