Charge trapping effects in photovoltage measurements of (Ga,Mn)As
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.
WOS:000261910300026
2008
403
4288
4291
REVIEWED
EPFL