Dielectric properties of Al/PVA/p-Si (MPS) Structure as a function of frequency and voltage

Metal-Polymer-Semiconductor (MPS) structure Al/PVA/p-Si was fabricated using polyvinyl alcohol (PVA) as an organic interfacial layer on a p-type silicon wafer by spin coating method. Frequency dependent dielectric properties like real and imaginary part of dielectric permittivity (dielectric constant epsilon' and dielectric loss epsilon ''), dissipation factor or loss tangent (tan delta), real and imaginary parts of the electric modulus (M', M '') of the fabricated MPS structure were investigated for various frequencies from 50 KHz to 1 MHz. Frequency dispersion has been found for all dielectric parameters. Simultaneously these were found to be a function of voltage. It was found that epsilon' and epsilon. decrease with the increase in frequency. M' increases with frequency while M '' shows a peak behaviour that shifts towards lower frequency with increasing applied voltage. All these changes in dielectric parameters may be attributed to surface states distribution at PVA/p-Si interface and interfacial polarization. (C) 2019 Published by Elsevier Ltd.