Determining electrical and dielectric parameters of Al/ZnS-PVA/p-Si (MPS) structures in wide range of temperature and voltage

摘要

In this study zinc sulphide (ZnS) nanostructures have been prepared by microwave-assisted method in presence of polyvinyl alcohol (PVA) as a capping agent. The structural and morphological properties of prepared sample have been investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). These analyses confirm that the sample has nano structure. They have been used this sample to fabrication of Al/ZnS-PVA/p-Si structure. The effect of temperature and voltage on the electrical and dielectric parameters of the Al/ZnS-PVA/p-Si (MPS) structures has been investigated in the wide range of temperature (140–340 K) and voltage (− 2 V to + 4 V) using capacitance/conductance-voltage ( C / G–V) measurements at 500 kHz. Experimental measurements revealed that the values of C / G–V increase with increasing temperature but the values of series resistance ( R ~( s )) increase with decreasing temperature. As well as the dielectric parameters such as the values of real and imaginary parts of the dielectric constants ( ε′ and ε″ ) and electric modules ( M′ and M″ ), loss tangent ( tanδ ), and ac electrical conductivity ( σ ~( ac )) were obtained using C and G / ω data. These parameters are found out as strong functions of temperature and voltage. While the values of ε′ , ε″ and tanδ increase with increasing temperature, the values of σ ~( ac ), M′ and M″ decrease. The Arrhenius plot (ln(σ~(ac)) vs q/kT) shows two distinct linear ranges with different slopes or activation energies ( E ~( a )) at low (140–230 K) and high (260–340 K) temperatures. Both values of R ~( s )and (ZnS-PVA) interfacial layers are also very effective parameters on the electric and dielectric properties.