Influence of the p-type doping on the radiometric performances of MWIR InAs/GaSb superlattice photodiodes

In this paper, quantum efficiency (QE) measurements performed on type-II InAs/GaSb superlattice (T2SL) photodiodes operating in the mid-wavelength infrared domain, are reported. Several comparisons were made in order to determine the SL structure showing optimum radiometric performances: same InAsrich SL structure with different active zone thicknesses (from 0.5 mu m to 4 mu m) and different active zone doping (n-type versus p-type), same 1 mu m thick p-type active zone doping with different SL designs (InAs-rich versus GaSb-rich and symmetric SL structures). Best result was obtained for the p-type doped InAs-rich SL photodiode, with a 4 mu m active zone thickness, showing a QE that reaches 61% at lambda = 2 mu m and 0 V bias voltage. (C) 2014 Elsevier B.V. All rights reserved.