One-Step Electrodeposited Cu-In-Ga Thin Films and Cu(In,Ga)Se2 Absorber Synthesis for Solar Cells

作者：Lydie Ribeaucourt, Elisabeth Chassaing, Grégory Savidand, Daniel Lincot · 发表于：ECS Transactions · 年份：2010 · DOI：10.1149/1.3318499 · 被引用次数：4 · 研究领域：Chalcogenide Semiconductor Thin Films、Semiconductor materials and interfaces、Silicon and Solar Cell Technologies

Cu-In-Ga electrodeposition on Mo substrate is carried out in acidic aqueous media. Subsequent selenization leads to Cu(In,Ga)Se2 absorber for thin film solar cells. First, conditions to achieve one-step Cu-In-Ga electrodeposition are analysed. Then, Cu-In and Cu-Ga systems are studied. Cu-In electrodeposition is realized under diffusion-control conditions. For Cu-Ga system, first Cu(II) diffusion-controlled reduction occurs, followed by kinetic under-potential deposition (UPD) of Ga, leading to the formation of CuGa2 compound. Finally Cu-In-Ga electrodeposition is investigated. For Cu-In-Ga system, CuGa2 compound is not noticed, Ga-O codeposition is favored. In presence of citrate, Ga metal is deposited without oxide. Cu(II) and In(III) reductions are both diffusion-controlled, and Ga(III) kinetically controlled, allowing composition control at fixed pH and potential, but with dendritic growth. After selenization, complete Ga insertion is noticed in the formed chalcopyrite absorber. Solar cells with 4% efficiency were achieved despite porous morphology of the absorber.