A comparison electric-dielectric features of Al/p-Si (MS) and Al/ (Al2O3:PVP)/p-Si (MPS) structures using voltage-current (V-I) and frequency-impedance (f-Z) measurements

In this work, both the Al-(p-Si) (MS) and Al-(Al2O3:PVP)-(p-Si) (MPS) structures were grown onto the same p-type Si wafer in the same conditions to determine the (Al2O3:PVP) organic-interlayer whether the MPS build improves performance or not. For this aim, first, X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM) was used to investigate the structure of the (Al2O3-PVP) inter-layer. Secondly, both the current-voltage (I-V) and capacitance/conductance-frequency (C/G)-f measurements of them were performed at ambient temperature to the comparison of their electric and dielectric properties. Energy-dependence profile of surface states (N-ss) was extracted from the positive bias I-V data by considering the voltage-dependence of BH and n. We found that the (Al2O3: PVP) inter-layer leads to a decrease in surface-states (N-ss), ideality-factor (n), leakage-current, series-resistance (R-s), and increase in barrier (BH), shunt resistance (R-sh), rectification-ratio (RR = I-for./I-rev. at +/- 6 V). Dielectric permittivity and loss (epsilon ', epsilon ''), loss-tangent (tan delta), real & imaginary components of electric modulus (M ', M ''), and ac-conductivity (sigma(ac)) were extracted from the C-f and G-f measurements in the wide frequency range of 200 Hz-1 MHz at 1.5 V. The observed higher values in the epsilon ' and epsilon '' at lower frequencies for MS and MPS structures were attributed to the N-ss and easy polarization of interlayer under electric field.