Dielectric, modulus and conductivity studies of Au/PVP/n-Si (MPS) structure in the wide range of frequency and voltage at room temperature

Abstract

Both the real-imaginary components of complex dielectric permittivity and electric modulus, and ac conductivity of Au/PVP/n-Si (MPS) structures were analyzed by admittance spectroscopy technique between 1 and 500 kHz, − 3 and 5 V. The polyvinylpyrrolidone (PVP) polymer layer was deposited on n-Si wafer by spin-coating technique. The e′, e″, M′, M″ and σac values were calculated from the admittance measurements and they are quite function of frequency and voltage due to a special distribution of surface states at PVP/n-Si interface, interfacial/dipole polarizations at low frequencies. While the e′ and e″ values decrease as frequency increases, the σac, M′ and M″ increase. The ln(σac) vs ln(ω) plot for 3V has two linear region between 1 and 20 kHz, 30 and 500 kHz frequencies, respectively. The obtained 0.033 slope value for low-frequencies which corresponding to dc conductivity and it is almost independent of frequency, but it obtained 0.46 for high-frequencies which corresponding ac conductivity and is strong function of frequency due to the increase eddy current. As a result, the prepared MPS structure can be used as charges/energy storage device due to the dielectric property of the PVP polymer layer.