硒化前后电沉积贫铜和富铜的Cu(In1-xGax)Se2薄膜成分及结构的比较

采用电沉积法获得了接近化学计量比的贫铜和富铜的Cu（In_1-xGa_x）Se₂（CIGS）预置层，研究比较了两种预置层及其硒化处理后的成分和结构特性.得到了明确的实验证据证明，硒化后富铜薄膜中的Cu_xSe相会聚集凝结成结晶颗粒分散在表面.研究表明：在固态源硒化处理后，薄膜成分基本不变；当预置层中原子比Cu/（In+Ga）<11时，硒化后薄膜表面存在大量的裂纹；而当Cu/（In+Ga） >12时，可以消除裂纹的产生，形成等轴状小晶粒；富铜预置层硒化时蒸发沉积少量In，Ga和Se后，电池效率已达到68%；而贫铜预置层硒化后直接制备的电池效率大于2%，值得进一步深入研究. 关键词： 1-xGa_x）Se₂薄膜')" href="#">Cu（In_1-xGa_x）Se₂薄膜 电沉积 硒化处理 贫铜或富铜薄膜

Comparison of the compositions and structures of electrodeposited Cu-poor and Cu-rich Cu(In1-xGax)Se2 films before and after selenization

Cu-poor and Cu-rich near stoichiometric Cu (In_1-x Ga_x)Se₂(CIGS) precursor films were obtained by one-step electrodeposition from acid aqueous baths, and the compositions and structures of the as-deposited films before and after selenization were investigated. The straightforward experimental evidence was first obtained, which showed that Cu_x Se compound was conglomerated as rather large crystal grains which was distributed on the surface of the film for the Cu-rich films after seleniztion. The results indicated that the film composition was changed barely after selenization. When the ratio Cu/(In+Ga)＜1.1, there were many cracks on the surface of CIGS after selenization. When Cu/(In+Ga)＞1.2, no cracks were formed on the surface of the thin films. The efficiency of solar cells bnilt directly from Cu-poor films after selenization achieved above 2%, which is pending further investigation. Furthermore, the efficiency of solar cells bult from Cu-rich CIGS films after selenization and deposition of a few In, Ga and Se by PVD has achieved 6.8%.