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 (Nss) and series resistance (Rs) 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/ω) decrease with increasing frequency due to the existence of Nss, interfacial layer and surface polarization. The G/ω-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 Nss at p-Si/Co3O4 interface, interfacial layer and Rs of the structure. The magnitude of two peaks increases with decreasing frequency and shift towards negative voltages. Nss-ln(f) profile that obtained from Hill Coleman technique decreases exponentially with increasing frequency. Voltage dependent profile of Rs was obtained from C and G/ω data using Nicollian and Brews technique. It has two peaks and peak values decreases with increasing frequency. In addition, the concentration of acceptor atoms (NA), Fermi energy level (EF) and barrier height (BH) values were obtained from reverse bias C−2-V plots for each frequency at room temperature.