BLEACHING AND SPECTRAL SHAPE MODIFICATION OF CDS PHOTOCURRENT DUE TO HE-NE-LASER PUMPING

The influence of He-Ne laser pumping on the photocurrent of a CdS sing le crystal was studied in the range 450-700 nm at. room temperature. I t nas observed that the photocurrent iras extremely dependent on laser irradiation. A low pump intensity of 64 mW.cm(-2) quenches the photoc urrent by more than three orders of magnitude. The pumping also induce s a spectral shape modification, i,e,, a reduction oi the gap photocon ductivity at 500 nm below the photocurrent due to trap levels at 540 n m, The phenomena are explained in terms oi. two-photon absorption.