Transition from direct to indirect band structure induced by the AlSb layer inserted in the GaSb/AlSb quantum well

Abstract
A 6.5-nm coupled double GaSb/AlSb quantum well separated by 1, 2, 3 or 4 monolayers AlSb has been investigated by photoluminescence spectroscopy at a temperature of 2 K. When the AlSb layer thickness is more than 1 monolayer (ML), this system changes from direct to indirect energy-band structure, which is well described by a model based on a finite potential well and transmission probability.