The effect of manganese impurity on the interlayer Al/PVP:CdS/P-Si Schottky structure and its dielectric properties

Abstract

Introduction:In this research, cadmium sulfide (CdS) and cadmium sulfide doped with 3 cc manganese (3cc Mn-CdS) nanostructures have been prepared by ultrasound-assisted method and obtained products have been used for preparation of PVC: CdS and PVP: 3 cc Mn-CdS nanocomposites as an interfacial layer of the metal-polymer-semiconductor (MPS) Schottky structures. The structural, morphological, purity and optical properties of prepared nanostructures have been investigated by XRD, SEM, EDX and UV-Vis analyzes. The XRD of CdS sample confirmed the formation of the cadmium sulfide with cubic phase and its average nanocrystallite size obtained 6 nm. EDX analysis of both samples confirmed the pure phase of the prepared nanostructures. The energy gap of the CdS and 3 cc Mn-CdS nanostructures was calculated through the energy gap diagram 4.2 eV and 3.6 eV, respectively, that these values are bigger than from its bulk value (2.5 eV) due to the quantum confinement effect.Methods:Dielectric parameters such as ɛ′, ɛ″ and tan δ, of Al /PVP: CdS/ p-Si (MPS1) and Al /PVP: 3 cc Mn-CdS / p-Si (MPS2) Schottky structures are calculated and compared using C/G-f measurements in the frequency range of 100 Hz –1 MHz.Findings:The results showed that the dielectric parameters are strong function frequency. Also, doping of cadmium sulfide nanostructures with a very small amount of manganese source leads to a decrease in the dielectric constant, conductivity, and increase in the series resistance and loss tangent of the MPS2 compared to MPS1 Schottky structure.

Keywords

• dielectric parameters
• c/g-f measurements
• dielectric constant
• loss tangent
• electrical conductivity