Photoconductivity study of semiconductors using the surface acoustic wave convolver

Photoconductivity study of a semiconductor using the SAW convolver is presented. The semiconductor is placed either on or a small distance above the SAW delay line. A fast rise time pulse of light is applied to the semiconductor surface through the piezoelectric substrate, and the resulting change in the semiconductor conductance is observed by the relaxation of the SAW propagation loss. This technique has the important advantage that no ohmic contact to the semiconductor is needed.