Measurement of bulk lifetime and surface recombination velocity by infrared absorption due to pulsed optical excitation

Knowledge of both carrier bulk lifetime τb and surface recombination velocity S are necessary to analyze and model electron devices. In this paper, the analytical results of Luke and Cheng [J. Appl. Phys. 61, 2282 (1987)] are applied to examine excess carrier decay due to pulsed Gaussian optical excitation to extract values of τb and S under low level injection. The nondestructive, contactless measurement technique utilizes a visible pulsed laser pump beam and a CW infrared laser probe beam. Values for τb and S are obtained for a number of different Si samples. The effect of varying the pump beam frequency is examined. The technique is simple to use in the laboratory and the parameter extraction from the measured data is straightforward.