Analysis of admittance measurements of Al/Gr-PVA/p-Si (MPS) structure

A metal-polymer-semiconductor (MPS) structure based on 5 wt% graphene (Gr) doped polyvinyl alcohol (PVA) thin film was fabricated by using the electrospinning method. Admittance (Y = G + i omega C) based measurements of Al/Gr-PVA/p-Si (MPS) structure were performed in the frequency range from 5 kHz to 5 MHz at room tem-perature. Significant shifts in capacitance (C) and conductance (G) characteristics were observed for the MPS structure. The C and G value decrease with increase in frequency. The variation of C and G with frequency comes from the existence of interface states. the interface state density (Nss) was estimated by various methods such as low-high frequency capacitance (CLF-CHF), Hill-Coleman and conductance. The Nss value obtained from all methods decreased as the frequency increased. Because as the frequency increases, the interface states cannot follow alternating current (ac) signal. Meanwhile, the measured capacitance and conductance were corrected taking into account the effect of series resistance (Rs).

Automated summary

A metal-polymer-semiconductor (MPS) structure based on 5 wt% graphene doped polyvinyl alcohol thin film was fabricated, and its frequency characteristics were measured. The capacitance and conductance of the structure were found to decrease with increasing frequency, and the interface state density was estimated using various methods.