On the Use of the Photoacoustic Technique for Monitoring the Doping Concentration Dependence of the Surface Recombination Velocity

In this paper we study the surface recombination velocity of GaAs by means of the photoacoustic technique (PA). By fitting the experimental frequency dependence of the PA signal phase we were able to evaluate this parameter. The experiment was carried out in GaAs samples prepared by liquid phase epitaxy and doped with different concentrations of Ge. It is shown that the PA technique is sensitive to changes of the surface states originated by the doping concentration levels and it is demonstrated that this technique gives a promised non-invasive and non-destructive method to measure and evaluate the surface recombination velocity.