Quantitative Analysis of the Persistent Photoconductivity Effect in GaAlAs as a Function of Pressure and Modelisation of its non Exponential Time Decay Kinetics

We present a quantitative analysis of the persistent photoconductivity (PPC) observed in AlGaAs sample as a function of pressure and Aluminum composition at various fixed temperatures. The results give experimental evidence of the band structure dependence of the PPC in AlGaAs since equivalent changes in PPC amplitude were induced either by change of Al composition or by equivalent change of pressure. The fitting of the decay kinetics by our model enables us to work out the capture coefficient and consequently the capture barrier for several pressures or equivalent Al compositions.