Abstract
In this paper, we make a study on the effect of films thickness on the electrical properties of the dielectric Dy2O3 deposited on p-Si substrate. The electrical characteristics of Al/Dy2O3/p-Si hetero-structure were investigated in the temperature range of 270–420K. The conductance and capacitance-frequency measurements were performed as a function of temperature. The results indicate that the electrical properties are strongly dependent on both temperature and frequency. It was found that both C and G are quite sensitive to frequency at relatively low frequencies. The AC conductance characteristic was found to obey Jonscher universal power law. Also, the Dy2O3 films exhibited a thermally activated conductance, i.e., G(T)=G0 exp(−Ea/kBT), over a considerable temperature range. Activation energy is deduced from the variation of conductance with temperature as it decreases from 172 to 82meV whenever the thickness of Dy2O3 film increases. Besides, the dielectric properties of Al/Dy2O3/p-Si hetero-structure are studied by means of complex impedance spectroscopy. The frequency-dependence of the dielectric constant ε׳ and dielectric loss ε″ of the elaborated samples is subsequently investigated at different temperatures. Experimental results reveal that the aforementioned parameters have strong frequency dependence. The obtained values of ε׳ and ε″ show increments with decreasing frequency. However, increasing frequency levels cause an increase in the AC electrical conductivity. In order to gain an insight into the electric nature of the samples, the Cole–Cole diagrams are also investigated at different temperatures.