Abstract

We report charge trapping effects in a ferromagnetic (Ga,Mn)As thin film observed during measurements of the photovoltage under inhomogeneous illumination conditions. Using a laser diode as the excitation source, the temperature-dependent response has been observed, with open-circuit voltages as high as -1.4V. The unexpectedly large and sharp temperature-de pendent responses are explained in terms of the excitation of photo-generated charges and their trapping in localised states, or separation of the charges across the film/substrate interface. The sharp features found in the signals suggest their possible use for studying localised trapping states in semiconductors using inhomogeneous illumination. (C) 2008 Elsevier B.V. All rights reserved.

Details

Actions