A facile synthesis of a copper(I) thiourea sulphate complex and its application for highly efficient chalcopyrite solar cells.

The precursor compound plays a crucial role in the development of low-cost chalcogenide thin-film solar cells via a solution approach. In this work, we report on the synthesis of a new complex [Cu((NH 2 ) 2 CS) 3 ] 2 SO 4 ·H 2 O through a simple redox reaction between inexpensive Cu(CH 3 COO) 2 ·H 2 O and thiourea (TU) in water. Using this complex as a copper source, a stable dimethylformamide solution was made and copper indium sulfoselenide CuIn(S,Se) 2 thin film solar cells with a high efficiency of 12.2% have been demonstrated.