Frequency and voltage dependent electrical and dielectric properties of Ag/nGO doped PVA/p-Si sandwich structure at room temperature

In present study, we investigated frequency and voltage dependence of electrical and dielectric properties of Ag/nGO doped poly(vinyl alcohol) (PVA)/ p-Si structures. The nGO-PVA films were prepared by using improved Hummers method and this thin film layers were analyzed with SEM and EDX. The main parameters as ideality factor (n), barrier height (Φ _bo ) and saturation current (I ₀ ) were obtained from current–voltage (I-V) measurements. The frequency dependent electrical characteristics of structure investigated using capacitance–voltage (C–V) and conductance–voltage (G/ω–V) measurements in the frequency range of 10 kHz to 1000 kHz in 300 K absolute temperature. The capacitance, conductance and series resistance (R _S ) values decreased with increasing frequency. These decreases at higher frequencies are attributed to existence of interface state densities. The presence of the interface state densities (N _SS ) are also evidenced as a peak in the capacitance, conductance and series resistance–frequency characteristics. After, the dielectric properties of Ag/GO-PVA/ p-Si structures were obtained using C–V and G/ω–V measurements in the same frequency ranges. The values of dielectric constant (ε′), dielectric loss (ε″), and loss tangent (tanδ) decreases with increasing frequency while ac electrical conductivity (σ _ac ) increase with increasing frequency. Our results showed that frequency dependent electrical and dielectric properties were strongly frequency and voltage dependent.