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

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/omega-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 (D-it) and series resistance (R-s) at room temperature. The voltage and frequency dependent profile of D-it were evaluated from the low-high frequency capacitance (C-LF-C-HF) and Hill-Coleman methods. The R-s profiles for various frequencies and voltages were evaluated using Nicollian-Brews admittance method. D-it and R-s both decrease almost exponentially with increasing frequency. It has been found that R-s is more effective at high frequencies in the accumulation region, while D-it influences the characteristics in the depletion region at low frequencies. Measured capacitance (C-m) and measured conductance (G(m)) were improved to corrected capacitance (C-c) and corrected conductance (G(c)) to eliminate the effect of R-s 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.