Electrodeposition of copper-indium-diselenide (CuInSe₂) thin films

The electrodeposited CuInSe₂ films were investigated in this paper. The deposition parameters of various solution concentrations, applied potential, pH value and complexing agent were examined to characterize film quality. The electrolyte solution was formed by mixing an appropriate proportion of copper sulfate, indium sulfate and selenium dioxide. Sodium citrate was used as complexing agent. Citric and sulfuric acids were used for adjusting electrolyte pH value. The experimental results revealed that the deposited and annealed CIS films have an atomic ratio of [Cu]:[In]:[Se] = 26.94:26.74:46.31. It is near to the stoichiometry of an atomic ratio ([Cu]:[In]:[Se] = 1:1:2). Unfortunately, this film has a poor adhesion problem. In order to overcome the adhesion problem, the triethanolamine and sodium dodecyl sulfate are used as complexing agents and wetting agents, respectively. A good adhesion was obtained. However, these additives result in a shortcoming of insufficient indium content in the formation film.