Electrochemical Synthesis of In2Se3 Thin Films from Citrate Bath. Structural, Optical and Morphological Investigations

Abstract In this work, indium selenide In2Se3 thin films were synthesized by electrodeposition in potentiostatic mode from aqueous solution containing InCl3 and SeO2 in acid medium (pH 4.2) with sodium citrate as complexing agent at ambient temperature with heat treatment of electrodeposited films at different temperatures. Voltammetry method was used to investigate the electrochemical behavior of the electrodeposition bath. The structural characterization of elaborate films was performed by X-rays diffraction (XRD) and Raman spectroscopy, the morphological one was carried out by scanning electron microscopy (SEM) and atomic force microscopy (AFM), the UV–Visible spectrophotometry was used to investigate their optical proprieties, whereas the Mott–Schottky measurement was used also to study their semiconducting properties. The results showed that the annealed deposit at 350, 450°C and the as-deposited films take the rhombohedral β-crystalline phase hR5 of In2Se3, as-deposited and annealed In2Se3 are photoactive thin films with band-gap energies 1.33, 1.55 eV respectively and belong to n-type semiconductors with number of charge carriers in order of 1021/cm3. The obtained deposits have nanometric grain size and less roughness surface.