A study of photoconductivity characterization of cadmium telluride thin film

A study has been made on the photoconductivity characterization: (i) growth and decay characteristic and (ii) trap depth analysis of Cadmium Telluride (CdTe) thin film prepared by thermal evaporation technique. With the help of the growth and decay of photo-current versus time at illumination intensity = 100 mW/cm2, the photoconductivity parameters: decay time (τd), dispersion parameter (α), characteristic energy (E0) and characteristic temperature (T0) were obtained as a function of cycle numbers and applied voltage. Also, the trap depth parameters: photocurrent at the termination of illumination (I0), the probability of escape of an electron from the trap per second (p) and trap depth (Et) were determined. All the parameters of the film may be explained on the basis of generation of excess carrier due to photon absorption. The obtained parameters of the film are dependent on cycle numbers as well as applied voltage. These results indicated that the prepared film is applicable for optical switching device.