Structural Morphology and Electrical Properties of Vacuum Evaporated SnS Thin Films

Abstract

Using thermal evaporation technique tin Sulphide (SnS) thin films have been deposited on glass slides have been deposited at room temperature using SnS powder. The deposited films have been investigated through X- ray diffraction measurements to determine structural properties. The deposited SnS films found polycrystalline with an orthorhombic structure. The grain size found to increase with thickness. The surface morphology of the films has been examined using atomic force microscopy AFM. The chemical compositions of the films have been determined using energy dispersive analysis of x-rays (EDAX). The dielectric properties of SnS thin films deposited with different thickness (100,200,and 300nm) are presented in this work. The dielectric permittivity ε and ac conductivity σac were measured at temperatures in the range of 293–493 K and frequencies in the range of 10 kHz–100MHz. It is found that there are two conductivity mechanisms and hence two activation energies converts to one mechanism with the increase of thickness. The ac activation energy EAC decreases with increase of thickness and frequency. The exponent s shows a progressive decrease with thickness. The results are explained in terms of structural difference by the effect of thickness and thermal treatment. Few anomalies in dielectric studies were observed near 340 and440K, respectively. These points were related to crystalline phase transitions. Dark-conductivity and photo-conductivity increases with increase of thickness.