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The capacitance-voltage ( C – V ) and conductance-voltage ( G/\omega – V ) data for Al/(0.07Zn-doped polyvinyl alcohol)/p-Si structure have been performed (at ±6-V biases) in a frequency interval of 1–400 kHz at room temperature. Utilizing form conductance method, N\textsf {ss} values were specified from admittance measurements. The reason of higher C and G values obtained at lower frequencies was ascribed to the surface states located at MS interface and insulator layer. The increment at capacitance and conductance was occurred in consequence of the ac signal that followed easily by the surface states at these lower frequencies. The surface states existence also generates peaks at conductance versus logarithm of frequency ( Gp/\omega -log (f) ) plots under distinct voltage values. The acquired values of N\text {ss} and relaxation time (\tau ) are in the interval of \textsf {1.94} \times \textsf {10}^{\textsf {14}} – \textsf {1.67}\times \textsf {10}^{\textsf {14}} eV ^-\textsf 1\cdot \textsf cm^-\textsf 2 and \textsf 2.81 \times \textsf 10^-\textsf 3 – \textsf 1.30 \times \textsf 10^-\textsf 5 s, respectively. [ABSTRACT FROM PUBLISHER] more...

A metal-polymer-semiconductor (MPS) structure based on 5 wt% graphene (Gr) doped polyvinyl alcohol (PVA) thin film was fabricated by using the electrospinning method. Admittance (Y = G + iωC) based measurements of Al/Gr-PVA/p-Si (MPS) structure were performed in the frequency range from 5 kHz to 5 MHz at room temperature. Significant shifts in capacitance (C) and conductance (G) characteristics were observed for the MPS structure. The C and G value decrease with increase in frequency. The variation of C and G with frequency comes from the existence of interface states. the interface state density (N ss) was estimated by various methods such as low-high frequency capacitance (C LF -C HF), Hill-Coleman and conductance. The N ss value obtained from all methods decreased as the frequency increased. Because as the frequency increases, the interface states cannot follow alternating current (ac) signal. Meanwhile, the measured capacitance and conductance were corrected taking into account the effect of series resistance (R s). • The fabricated of Al/Gr-PVA/p-Si (MPS) structures. • The characterization electrical parameters by using admittance spectroscopy method. • Frequency and voltage dependent profiles of interface state and series resistance. • The effect of interfacial organic layer (Gr doped PVA) on the impedance measurements. • The N ss vs V profiles extracted from three different methods (low-high frequency capacitance, conductance and Hill-Coleman). [ABSTRACT FROM AUTHOR] more...

The frequency dependence of admittance measurements (capacitance--voltage (C--V) and conductance--voltage (G/ω--V)) of Au/SnO2/n-Si (MOS) capacitors was investigated by taking into account the effects of the interface states (Nss) and series resistance (Rs) at room temperature. Admittance measurements were carried out in frequency and bias voltage ranges of 1 kHz-1 MHz and (-5 V)-(+9 V) respectively. The values of Nss and Rs were determined by using a conductance method and estimating from the admittance measurements of the MOS capacitors. At low frequencies, the interface states can follow the AC signal and yield excess capacitance and conductance. In addition, the parallel conductance (Gp/ω) versus log(f) curves at various voltages include a peak due to the presence of interface states. It is observed that the Nss and their time constant (τ) range from 1.23x1012 eV-1 ⋅ cm-2 and from 7.29x10-5 to 1.81x10-5s, respectively [ABSTRACT FROM AUTHOR] more...