Anomalous Peak in the Forward-Bias C-V Plot and Temperature-Dependent Behavior of Au/PVA (Ni,Zn-doped)/n-Si(111) Structures

In this study, the temperature-dependent mean density of interface states (N-SS) and series resistance (R-S) profiles of Au/PVA (Ni,Zn-doped)/n-Si(111) structures are determined using current-voltage (I-V) and admittance spectroscopy [capacitance-voltage (C-V) and conductance-voltage G/omega-V] methods. The other main electronic parameters such as zero-bias barrier height (Phi(B0)), ideality factor (n), and doping concentration (N-D) are also obtained as a function of temperature. Experimental results show that the values of Phi(B0), n, R-S, and N-SS are strongly temperature dependent. The values of Phi(B0) and R-S increase with increasing temperature, while those of n and N-SS decrease. The C-V plots of Au/PVA (Ni,Zn-doped)/n-Si(111) structures exhibit anomalous peaks in forward bias (depletion region) at each temperature, and peak positions shift towards negative bias with increasing temperature. The peak value of C has been found to be strongly dependent on N-SS, R-S, and temperature. The experimental data confirm that the values of N-SS, R-S, temperature, and the thickness and composition of the interfacial polymer layer are important factors that influence the main electrical parameters of the device.