Impedance spectroscopy study of electrical properties of polymer blend interlayered Al/PEG-PVA/p-Si (MPS) structure

Abstract

PEG-PVA polymer blend has been prepared by solution processing and a thin film of the blend has been spin coated as an interfacial layer on a p-Si wafer. Capacitance-voltage (C–V) and conductance-voltage (G/ω-V) characteristics of Al/PEG-PVA/p-Si (metal-polymer-semiconductor) structure were studied in a frequency range of 5 KHz to 1 MHz with voltage bias swept from −4 V to +5 V, by considering interface states density (Dit) and series resistance (Rs) at room temperature. The voltage and frequency dependent profile of Dit were evaluated from the low-high frequency capacitance (CLF-CHF) and Hill-Coleman methods. The Rs profiles for various frequencies and voltages were evaluated using Nicollian-Brews admittance method. Dit and Rs both decrease almost exponentially with increasing frequency. It has been found that Rs is more effective at high frequencies in the accumulation region, while Dit influences the characteristics in the depletion region at low frequencies. Measured capacitance (Cm) and measured conductance (Gm) were improved to corrected capacitance (Cc) and corrected conductance (Gc) to eliminate the effect of Rs at high frequency (1 MHz). Electrical parameters of the fabricated MPS structure and band gap analysis of prepared blend confirms that PEG-PVA blend is a better alternative dielectric material for electronic devices.