The effect of gamma irradiation on electrical characteristics of Au/polyvinyl alcohol (Co, Zn-doped)/n-Si Schottky barrier diodes

To show the effect of gamma radiation, Au/Polyvinyl Alcohol (Co, Zn‐doped)/n‐Si Schottky barrier diodes (SBDs) were exposed to 60Co γ‐ray source at room temperature. These structures were investigated by using current‐voltage (I‐V), capacitance‐voltage (C‐V), and conductance‐voltage (G/ω‐V) measurement methods before and after irradiation. The C‐V and G/ω‐V measurements were carried out at 1 MHz. The density of interface states (Nss) as a function of Ec‐Ess was obtained from the forward bias I‐V data by taking into account the bias dependence effective barrier height (ϕe) and series resistance (Rs) of device at room temperature. Experimental results show that the values of ideality factor (n), Rs, and Nss increased after gamma irradiation. It was found to degrade the reverse leakage current with radiation whereas its effect on the forward I‐V characteristics was negligible. The results show that main effect of the radiation is the generation of Nss with energy level within the forbidden band gap of Si between polymer and semiconductor. In addition, the values of Rs were determined from Cheung's method, and it was seen that these values increased with radiation effect. As seen I‐V and C‐V characteristics, the main electrical parameters such as ideality factor (n), Rs, Nss were strongly influenced with the presence of radiation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010