A Study of Photo-response and Photoelectrical properties of Cadmium Telluride Thin Film

The detailed analysis of photo-response and photoelectrical properties of thermally deposited Cadmium Telluride (CdTe) thin film has been reported in this paper. The photocurrent of the CdTe thin film was measured as a function of applied bias voltage within the range of 10–20 V with the interval of 2 V for the intensity of illumination of 30 mW/cm2 and 100 mW/cm2. The photocurrent at the termination of illumination (Io), probability of escape of an electron from the trap per second (p) and trap depth (Et) have been calculated. Considerable increases in photocurrent were observed in CdTe thin film at high applied bias voltage. Also, the space charge limited conduction (SCLC) parameters of the film were carried out under the dark and illumination environment. For increasing intensity of illumination, the effect of defects in CdTe thin film is minimized. Uniform distribution of localized states density showed from the straight line of plot ln (I/V) versus V.