Influence of temperature, thickness and intensity of illumination on the capacitance-voltage and current voltage characteristics of coplanar ZnTe thin films.

Abstract

This paper examines the influence of temperature, thickness and illumination of different intensities on the capacitance-voltage (C-V) and current-voltage (I-V) characteristics of coplanar ZnTe thin films of thickness range (300-700 nm). Capacitance–voltage (C-V) measurements of ZnTe thin films were performed by a sweep of voltages from -10 to +10 V at different elevated temperatures in the range 298-398 K. The temperature dependence of the measured capacitance for the different applied voltage was studied. The dependence of capacitance on the reciprocal of film thickness, yields a permittivity value of ZnTe, assuming that the capacitance follows a simple parallel plate relationship. The current-voltage (I-V) characteristics of ZnTe films at room temperature (RT) for different thicknesses showed the Ohmic conduction mechanism at low voltages, while at higher voltages, the trap-charge-limited conduction (TCLC) was dominant. The temperature dependence of current allows the determination of some essential parameters of ZnTe. Discussion of the obtained results and their comparison with the previously published data are also given.