Triethanolamine-facilitated one-step electrodeposition of CuAlSe2 thin films and the mechanistic studies utilizing cyclic voltammetry

• Single-step electrodeposition of CuAlSe2 was achieved in acidic aqueous solutions by introducing TEA into deposition bath.
• The possible mechanism of the formation of CuAlSe2 thin films was investigated by cyclic voltammetry.
• The introduction of TEA creates an appropriate environment for co-deposition reaction and improves adhesion of deposits on substrate.

The electrochemical behavior of the compositional ingredients CuCl2, AlCl3 and SeO2 individually or collectively in acidic aqueous solution was investigated on a glassy carbon electrode using the technique of cyclic voltammetry. Co-electrodeposition mechanism of CuAlSe2 was attempted to be unraveled through cyclic voltammetric study of the electroactive species. The formation of CuAlSe2 was found to be achieved by the generation of the compounds Al2Se3 and Cu2Se via reductions and/or chemical reactions of the precursors. Triethanolamine as the complexing agent was introduced in the electrodeposition of CuAlSe2 on indium doped tin oxide glass substrates in order to assist the deposition and the stoichiometric composition of CuAlSe2 thin films was fabricated. The deposited thin films were characterized by X-ray diffraction, scanning electron microscopy, UV–Vis spectrometry, Auger electron spectroscopy and energy dispersive X-ray spectrometry analysis.