Effect of defect layer on the creation of electronic states in GaAs/GaAlAs multi-quantum wells

The current paper presents a theoretical study of the transmission and the electronic band structure for multi-quantum wells, consisting of two periodic semiconductor materials, containing a defect layer. The dynamic tuning of this defect layer (material defect), inserted into the structure in question, is carefully investigated, using the Green’s function for the theoretical calculations. Results show that both the position and the thickness of the defect layer can play an essential role in the creation of localized states, which favors the transfer of electrons,without using a higher energy. Moreover, the number of periods, the thickness of the well layer and the Al concentration in the defect layer barrier have also shown that the width band changes, when the structure contained a defect. Furthermore, we found the increase of Al concentration in defect layer gives possibilities to create states into the gap bands. These defect states show important variations inside the gap bands versus the physical parameters characterizing the defect layer.