Complex dielectric, complex electric modulus, and electrical conductivity in Al/(Graphene-PVA)/p-Si (metal-polymer-semiconductor) structures

Abstract

In this study, the real and imaginary components of the complex dielectric (ε* = ε′ - jε'′), complex electric modulus (M* = M′ + jM'′), and electrical conductivity (σac) were investigated for fabricated Al/(5% graphene (Gr)-PVA)/p-Si (metal-polymer-semiconductor (MPS)) type structures in wide frequency (5 kHz–5 MHz) and voltage (±4 V) ranges by using impedance (Y = 1/Z = G + jωC) measurements. To determine more charges/energy in a capacitor, a high dielectric (5% Gr-PVA) organic interface layer was used for growth by using the electrospinning method. We observed that the capacitance of the MPS was increased considerably by using this interlayer. As the frequency increased from 5 kHz to 5 MHz, the ε′ values changed from 32.586 to 1.132 due to the presence of surface/dipole polarization and the number of surface states (Nss). The lower M′ values observed at low frequencies were related to the long-range mobility of charge carriers. The magnitudes and positions of the peaks observed in the tanδ-V and M″-V plots varied with the frequency. Furthermore, the observed magnitudes and positions of the peaks in the tanδ-V and M″-V plots changed with the frequency. Thus, we showed that a (5% Gr-PVA) organic interlayer should be preferred to an insulator obtained with the traditional method because of its flexibility, low energy consumption, and simple grown process.