Novel IR Photodetectors Based on GaN/AlGaN HEMT with QWs or QDs in the Barrier

Abstract

We present results of computation of electron energy levels in GaN/AlGaN QWs and QDs embedded in the barrier of HEMT structures. Wurtzite materials and, in addition 3-d confinement for QDs, cancel polarization limitations regarding the light absorption. Computations are performed with the help of envelope functions for the QWs and of a pseudopotential method for the QDs. Very small dots are considered (with a height of 5 Ga layers) that can be achieved using Volmer-Weber formation mechanism. Electron intersubband optical transitions reach middle- and near-infra-red regions.