Preparation, Characterization and Holographic Interferometric Study of Electrodeposited CuS, CuSe and CuTe Thin Films

Abstract

Holography is an advanced optical technique that enables three-dimensional recording and reconstruction of information using coherent electromagnetic waves. Among its applications, holographic interferometry is a useful non-destructive method for evaluating surface deformation, residual stress and the mechanical behaviour of thin films through the analysis of interference fringe patterns. In the present study, double-exposure holographic interferometry, coupled with mathematical modelling, was used to determine the stress, mass, fringe width and thickness of electrodeposited thin films. Copper chalcogenide thin films were synthesised by electrodeposition under varying deposition times and electrolyte normalities to investigate their influence on film growth, material deposition and substrate deformation. The study was carried out systematically to understand the relationship between deposition parameters and the resulting physical properties of the films. The experimental results showed that, with increasing deposition time, the number of fringes increased from 3 to 8, 4 to 10 and 3 to 10; film thickness increased from 0.949 to 2.531, 1.265 to 3.164 and 0.942 to 3.164 μm; deposited mass increased from 1.865 to 4.975, 3.184 to 7.959 and 2.830 to 9.435 mg; substrate stress decreased from 0.101 to 0.037, 0.075 to 0.030 and 0.101 to 0.030 dyne/cm2; and fringe width decreased from 0.105 to 0.040, 0.314 to 0.051 and 0.127 to 0.045 cm for copper sulphide, copper selenide and copper telluride thin films, respectively. These results indicate enhanced film growth and reduced deformation effects at longer deposition durations. The structural, optical and surface characteristics of the deposited thin films were analysed using X-ray diffraction (XRD), ultraviolet-visible optical absorption spectroscopy and contact angle measurements. These characterisation techniques provided information on the crystallinity, optical behaviour and wettability of the synthesised films.