TRANSIENT PHOTOCURRENTS IN CDTE AND CDTE-O SPUTTERED FILMS

Transient photocurrents between coplanar electrodes have been measured in CdTe polycrystalline films and CdTe:O amorphous films, using the t ime of flight technique. Both kinds of film were grown by the R.F. spu ttering technique. The transient photocurrents in the CdTe films have a power law behavior and show a great influence of trapping and recomb ination of charge A shoulder in the photocurrents measured at high tem peratures is observed in the CdTe:O films. The time position of this s houlder is independent of the bias voltage and thermally activated, wi th an activation energy of 0.69 eV. The photocurrent shape is explaine d by a suitable multiple trapping model.