Observation of deep levels in undoped GaSb grown by molecular beam epitaxy

Abstract

Deep levels in undoped GaSb grown by molecular beam epitaxy are investigated with the deep level transient spectroscopy method. The measurements are performed on diodes consisting of undoped and Te-doped GaSb layers. Three hole traps are detected in the undoped GaSb, the activation energies of shallowest and deepest traps being 0.25 and 0.63 eV, respectively. The depth profile of trap concentration suggests that the origin of these two traps is related to native defects or interdiffusion of Te from n+ layer. The capture cross sections of these traps are also measured by using the filling pulse technique.