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

The forward and reverse bias currentevoltage (I-V), capacitance-voltage (C-V) and conductance-voltage (G/omega-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) Phi(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), Phi(e), R-s and N-ss values, C-V and G/omega-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. (C) 2011 Elsevier B. V. All rights reserved.