Theoretical electronic band structures and transport in InAs/GaSb type II nanostructure superlattice for medium infrared detection

Abstract

[eng] We report here the electronic band structure of nanostructure type II superlattice (SL) InAs(d1 = 21 Å)/GaSb(d2 = 24 Å) performed in the envelope function formalism. We calculated the energy E(d1), E(kz), E(kp) and the effective mass in the direction of growth kz and in plane kp of the SL. When the temperature increases, the band gap Eg decreases and the corresponding cutoff wavelength λc increases. We interpreted photoluminescence and transport measurements of Haugan et al. with an agreement in the calculated gaps. The computed density of states and Fermi energy position indicated that the sample is a p type semiconductor with a transition from bi-dimensional to tri-dimensional conductivity near 20 K. This sample is medium infrared detector (3.92 μm < λc < 5.92 μm) and a stable alternative for application in infrared optoelectronic devices. The electronic transport parameters calculated here are necessary for the design of infrared photo-detectors.