Studies on electrodeposited As2S3 thin films by double exposure holographic interferometry technique

Arsenic trisulphide (As2S3) thin films have been deposited onto stainless steel and fluorine doped tin oxide (FTO) coated glass substrates by electrodeposition technique using arsenic trioxide (As2O3) and sodium thiosulphate (Na2S2O3) as precursors and ethylene diamine tetracetic acid (EDTA) as a complexing agent. Double exposure holographic interferometry (DEHI) technique was used to determine the thickness and stress of As2S3 thin films. It was observed that the thickness of the thin film increases whereas film stress to the substrate decreases with an increase in the deposition time. X-ray diffraction and water contact angle measurements showed polycrystalline and hydrophilic surface respectively. The bandgap energy increases from 1.82 to 2.45 eV with decrease in the film thickness from 2.2148 to 0.9492 μm.