Effect of series resistance and interface states on the I– V, C– V and G/ ω– V characteristics in Au/Bi-doped polyvinyl alcohol (PVA)/n-Si Schottky barrier diodes at room temperature

Abstract

The forward and reverse bias current–voltage ( I– V), capacitance–voltage ( C– V) and conductance–voltage ( G/ ω– V) characteristics of the Au/PVA (Bi-doped)/n-Si Schottky barrier diodes (SBDs) have been investigated at room temperature by taking the interface states ( N ss) and series resistance ( R s) effects into account. The voltage dependent profiles of resistance ( R i ) were obtained from both the I– V and C/ G– V measurements by using Ohm’s Law and Nicollian methods. The obtained values of R i with agreement each other especially at sufficiently high bias voltages which correspond the value of R s of the diode. Therefore, the energy density distribution profile of N ss was obtained from the forward bias I– V data taking the bias dependence of the effective barrier height (BH) Φ e and R s into account. The high value of ideality factor ( n) was attributed to high density of N ss and interfacial polymer layer at metal/semiconductor ( M/ S) interface. In order to examine the frequency dependence of some of the electrical parameters such as doping donor concentration ( N D), Φ e, R s and N ss values, C– V and G/ ω– V measurements of the diode were performed at room temperature in the frequency range of 50 kHz–5 MHz. Experimental results confirmed that the N ss, R s and interfacial layer are important parameters that influence electrical characteristics of SBD.