Temperature and voltage dependences of dielectric properties and ac electrical conductivity in Au/PVC+TCNQ/p-Si structures

Abstract

Dielectric properties and ac conductivity (σac) of Au/PVC+TCNQ/p-Si structures have been investigated in the wide temperature range of 80–420K using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements at 1MHz. It has been found that the forward bias C–V plots exhibit a distinct peak especially at a high temperature. Effects of the series resistance (Rs), interfacial PVC+TCNQ layer and the density distribution of interfaces׳ traps (Dit) on the electrical peak and the dielectric properties were investigated in detail. All of the dielectric properties such as the real and imaginary parts of dielectric constants (ε′,ε″), electric moduli (M′ and M″), loss tangent (tanδ), and σac values were found to be strong functions of temperature and applied bias voltage. These changes become considerably high especially in the depletion region. In addition, the voltage dependent Rs values were obtained and they increased with decreasing temperature C–V–T and G/ω–V–T measurements confirmed that Rs, Dit, and PVC+TCNQ layers are very important parameters that strongly influence both dielectric properties and σac of structures.