Investigation of frequency and voltage dependence surface states and series resistance profiles using admittance measurements in Al/p-Si with Co3O4-PVA interlayer structures

Al/ CO3O4-PVA/ p-Si structures were fabricated, and their surface states (N-ss) and series resistance (R-s) profiles were obtained using admittance technique in the frequency range of 5 kHz-1 MHz at room temperature. The values of both capacitance (C) and conductance (G/omega) decrease with increasing frequency due to the existence of N-ss, interfacial layer and surface polarization. The G/omega-V profile has two distinctive peaks for each frequency at about 0.9 V and 1.5 V due to the particular density distribution of N-ss at p-Si/Co3O4 interface, interfacial layer and R-s of the structure. The magnitude of two peaks increases with decreasing frequency and shift towards negative voltages. N-ss-ln(f) profile that obtained from Hill Coleman technique decreases exponentially with increasing frequency. Voltage dependent profile of R-s was obtained from C and G/omega data using Nicollian and Brews technique. It has two peaks and peak values decreases with increasing frequency. In addition, the concentration of acceptor atoms (N-A), Fermi energy level (E-F) and barrier height (BH) values were obtained from reverse bias C-2-V plots for each frequency at room temperature.