CIGS film from selenized of the electrodeposited CuIn alloy and CuGa oxide/hydroxide precursor

The difficultness of Ga inclusion in conventional CuInGa plating can be solved by metal-oxide/hydroxide deposition. However, the selenization process with the oxide precursor is very difficult, because of the strong electronegativity of oxygen. In this work, we proposed a strategy of Cu(InGa)Se 2 thin films manufacture with selenization employing mixed precursor. The precursor consists of CuIn alloy and CuGa oxide/hydroxide, and deposited by electrodeposition as the sources of Cu, In and Ga. Then, the selenization process is performed in the mixed atmosphere of selenium vapor, hydrogen and argon. Meanwhile, we investigated the structural, optical and electrical properties of the prepared Cu(InGa)Se 2 thin films, and it implied both the deposition potential and the subsequent selenization time impact the structure and morphology of the thin films. The co-deposition of CuGa oxide/hydroxide improved the Ga deposition ratio, and it exhibited dendrite growth with large deposition potential. The subsequent selenization results in the transformation from the precursor to CuInSe 2 and Cu(InGa)Se 2 , as well as, the long selenization time lead to the oxygen concentration decreasing and high Ga concentration in CuInSe 2 films. In the end, with a potential of −0.5 V versus Ag/AgCl electrode, the film had a photo-generated current density of 0.05 mA/cm 2 , and the CIGS solar cell achieved a conversion efficiency of 1.85%.