Hydrothermal–electrochemical deposition of semiconductor thin films: the case of CuIn(Al)Se2 compound

Electrochemical deposition of CuIn(Al)Se2 thin film from quaternary aqueous solution of Cu, In, Al and Se salts has been carried out at different temperatures (25, 55 and 80 °C) and it was found that optical properties, crystallinity and phase purity of the as-deposited CuIn(Al)Se2 films are enhanced at higher temperature. Consequently, electrodeposition of CuIn(Al)Se2 under hydrothermal condition at high temperature (120 °C) and at different potentials is performed. The characterization of the obtained layers indicates that single phase chalcopyrite film could be deposited by synergism of the electrodeposition and hydrothermal methods at optimized deposition potential (−600 mV). Superior photoconductivity has also been observed in case of electrodeposited layer at 120 °C (hydrothermal condition). More interestingly, post annealing of CIAS thin film prepared by developed procedure at 200 °C (ambient atmosphere) results in dense microcrystalline layer with a photoconductivity 300 times higher than the sample deposited at room temperature.