Electrodeposition of Semiconductors Thin Films with Different Composition and Band Gap Underpotential Deposition

Cu2SnZnS4-type compounds have attracted interest as low cost and high conversion efficiency solar cell devices, because of their appropriate band gap energies and absorption coefficients values. In the last years our group has developed an ongoing research aimed at the electrodeposition from aqueous solution of thin films of technological semiconductors. In this work, we exploited alternated electrodeposition of Cu, Sn, Zn and S by ECALD to obtain sulfide thin films, controlling the growth of the structures at the nanometric level. The study included the analysis of the electrochemical behavior of the solution containing the single elements, to assess the most efficient deposition of controlled amounts of material. By alternating deposition of the elements, growth of thin films has been obtained. Band gaps of the deposited materials exhibit modulation with sample composition and thickness.