Impedance and Interface States Depending on Frequency Analysis of Al/(ZnFe2O4-PVA)/p-Si Structures

Abstract

This study investigates the properties of a film made of zinc ferrite (ZnFe2O4) doped polyvinyl alcohol (PVA). The film is sandwiched between an aluminum (Al) and p-Si semiconductor layers, and electrical measurements are conducted on the structure in a wide scope of frequency besides voltage. The study evaluates the impacts of the ZnFe2O4-PVA interlayer on surface-states (NSS), and complex-impedance (Z* = Z' - jZ''). A remarkable impact of the values of series resistance (RS) and the interlayer on the capacitance-voltage (C-V) and conductance-voltage (G/ω-V) data has been observed at moderate and high frequencies. Hence, the C and G/ω versus V qualities were modified at high frequency to eliminate the outcome of RS. The Hill-Coleman approach was utilized to estimate the values for NSS. Experimental results confirm that both the NSS , RS and the interlayer in the metal-polymer-semiconductor (MPS) structures are critical factors that significantly alter the electrical and dielectric properties. The analysis of the results obtained from the impedance study showed divergent behavior. It was observed that the impedance values increase in the low frequency, while they diminish in the higher frequencies, as a result of the mutual effect between the interface and the dipole polarization. The study suggests that due to its high dielectric value, the ZnFe2O4-PVA interlayer may be a better alternative to conventional insulators for charge/energy storage.