Abstract

The aim of this research was to undertake a study to improve the optoelectronic properties of the CdS/Si Junctions. There are CdS thin films were deposited using a spray pyrolysis technique, this was followed by annealing at various temperatures (400-600) oC, in order to optimize the film properties. X-ray diffraction tests have been demonstrated that the structure of all CdS films are polycrystalline with cubic and hexagonal wurtizte structure together, with preferential orientation in the H(002) and C(111) direction around the c-axis. In addition to new peaks have been appearing with an increase in the intensity of H (002) in x-ray diffraction pattern with increasing annealing temperature to 600 oC.The value of capacitance as a function of reverse bias voltage at 40 KHz frequency has indicated to that these hetero-junctions are abrupt. Moreever, the thermal treatment has been led to increases the built in potential from 0.15 V to 0.62 V, and also expand the width of the depletion layer from 66.6nm to 143.81nm.The increasing of annealing temperature to 500C was led to increase the forward current, and when annealing temperature exceeds 500 the value of the current start falling. In general I-V Measurements for CdS/Si heterojunctions showed typical rectifying characteristic, and the ideality factor varies within the range of (1.31 -1.89).