Dielectric properties of $\hbox {Ag/Ru}_{0.03}$–PVA/n-Si structures

Abstract

$\hbox {Ag/Ru}_{0.03}{-}\hbox {PVA}$/n-Si structures were successfully prepared and their morphological and electrical properties were investigated. The obtained electrical results suggested that the complex dielectric constant ($\varepsilon ^{*}=\varepsilon ^{\prime }-{j\varepsilon ^{\prime \prime }}$), complex electric modulus $M^{*}=M^{\prime } + { jM}^{\prime \prime }$, loss tangent (tan $\delta$) and alternating current (ac) electrical conductivity ($\sigma _{\mathrm{ac}})$ are all a strong function of the frequency (f) and applied voltage. The changes in these parameters are the results of the existence of the surface states ($N_{\mathrm{ss}})$ or interface traps ($D_{\mathrm{it}} = N_{\mathrm{ss}})$, interfacial polymer layer, surface and dipole polarizations and hopping mechanisms. The values of $\varepsilon ^{\prime }$ and $\varepsilon ^{\prime \prime }$ show a steep decline with increasing frequency and then reach a constant value at high frequency, whereas the increments of $M^{\prime }$ and $M^{\prime \prime }$ with frequency are exponential. The tan $\delta \, vs$. log f plot has a strong peak behaviour, especially in the accumulation region. These experimental results suggested that the $\hbox {Ru}_{0.03}{-}\hbox {PVA}$ interfacial layer could be used as a high dielectric material instead of conventional materials.