Preparation of zinc sulfide polymer nanocomposites and investigated of their dielectric properties

Akbari, Bashir and Azizian-Kalandaragh, Yashar (2016) Preparation of zinc sulfide polymer nanocomposites and investigated of their dielectric properties. Masters thesis, University of Mohaghegh Ardabili.

Text (تهیه نانوکامپوزیت¬های پلیمری سولفید روی و بررسی خواص دی¬الکتریک آن¬ها) Bashir Akbari.pdf Download (409kB)

Abstract

In this research a simple microwave-assisted method have been used for preparation of ZnS nanostructures in presence of PVA as a capping agent. The prepared sample has been investigated by UV-Vis spectroscopy, X-Ray diffraction (XRD). The objective of this research is determine some main electrical and dielectric parameters of the Au/ZnS-PVA/n-Si structures using admittance measurements. For this aim, capacitance/conductance-voltage-frequency (C/G-V-f) measurements were performed at various frequencies (10 kHz-200 kHz) and voltages (±3 V) by 50 mV steps at 300 K. Some main electrical parameters such as the concentration of donor atoms (ND), diffusion potential (VR), Fermi energy level (EF) and barrier height (ΦB(C-V)) values were obtained from the reverse bias C-2-V plots for each frequency. The voltage dependent profile of series resistance (Rs) and surface states (Nss) profiles of the structure was also obtained using Admittance and low–high frequency methods. Both the Rs-V and Nss-V plots have a distinctive peaks in the depletion region due to the spatial distribution. The effect of Rs and interfacial layer on the C-Vend G/ω -V characteristics are found remarkable at high frequencies. Therefore, the high frequency C-V and G/ω -V plots were corrected to eliminate the effect of Rs. In addition, some main dielectric parameters such as the real and imaginary parts of dielectric constants (ε' and ε'') and electric modules (M’ and M”), loss tangent (tanδ), and ac electrical conductivity (δac) values were obtained using C and G/ω data and they are found to a strong functions of frequency and applied bias voltage. Experimental results confirmed that the Nss, Rs and interfacial layer of the MPS structure are more important parameters that strongly influence both the electric and dielectric properties.

Actions (login required)

View Item