Cyclic voltammetry study of electrodeposition of Cu(In,Ga)Se2 thin films

The electrodeposition of Cu(In,Ga)Se2 has been investigated by cyclic voltammetry (CV) in a DMF-aqueous solution that contained citrate as a complexing agent. The effects of the citrate ion on the reduction potentials of Cu2+, In3+, Ga3+ and H2SeO3 were examined for a unitary system. Furthermore, a cyclic voltammetry study was performed in a ternary Cu–In–Se system, a quaternary Cu–In–Ga–Se system, and binary Cu–Se, In–Se and Ga–Se systems. The insertion of In and Ga into the solid phase may proceed by an underpotential deposition mechanism, which involves two different routes: In3+ and Ga3+ reduction by a surface-induced effect from Cu3Se2 and/or reaction with H2Se.