Electrochemical deposition of zinc oxide films from non-aqueous solution: a new buffer/window process for thin film solar cells

Zinc oxide is a wide band gap semiconductor with wide application in thin f ilm devices such as n-type window layers for thin film solar cells, piezoel ectric and luminescent devices, and for catalytic applications. We have cat hodically electrodeposited films of ZnO by reduction of dissolved oxygen in a non-aqueous solution (dimethylsulfoxide) containing a Zn salt. This meth od allows a large deposition potential window and gives films with high tra nsparency, good crystallinity and adherence. The ZnO was electrodeposited o n Cu(In,Ga)Se-2 as a buffer layer. The resulting solar cells gave higher li ght-to-electricity conversion efficiencies (> 11%) than those made with con ventional r.f. sputtered insulating ZnO. (C) 2000 Elsevier Science S.A. All rights reserved.