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

We use the 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 mum. We use a theoretical model that includes an extended generation source and depletion region to simulate the EBIC current on both sides of the p-n junction. The electron minority diffusion length in the p-superlattice, L-e, is extracted from the simulation, from which the electron lifetime tau(e) is obtained. L-e increases from 0.275 mum at 5.3 K to 0.355 mum at 100 K. tau(e) drops from 1.5 ns at 5.3 K to 0.13 ns at 100 K. (C) 2004 American Institute of Physics.