Electronic structure of InAs/GaSb superlattice for the modelling of MWIR pin photodiode

•We present a 18-bands k.p method to simulate energies and wavefunctions.•We study three different type of InAs/GaSb superlattices structures.•Calculated bandgaps are in good agreement with results for symmetrical superlattice.•We explain from model the difference of behaviour between the structures.•We calculate intrinsic carrier concentration and effective mass.

An 18-band k.p formalism has been developed to determine the band structure and wavefunctions of InAs/GaSb type II superlattices (T2SL). Bandgap results are in good agreement with measurements for symetrical superlattices. Thus, we are able to calculate intrinsic properties of InAs/GaSb SL as the effective mass, the density of state and the free carrier concentration. Then we compare the modelled and measured electro-optical properties of three different SL structures with a different InAs to GaSb thickness ratio R per SL period, but having the same cut-off wavelength of 5 μm at 77 K.