Patent ID: 7179677

Claim:
A process for making a thin film ZnO/Cu(InGa)Se 2 solar cell without depositing a buffer layer and by Zn doping from a vapor phase, comprising: a) depositing Cu(InGa)Se 2 layer on a metal back contact deposited on a glass substrate; b) heating the Cu(InGa)Se 2 layer on said metal back contact on said glass substrate to a temperature range between about 100° C. to about 250° C.; c) subjecting the heated layer of Cu(InGa)Se 2 to an evaporant species from Zn acetate dihydrate to dope the Cu(InGa)Se 2 with Zn and form a ZnO deposit and etching with acetic acid in an amount of 50% by volume in water to remove the ZnO deposit; and d) sputter depositing ZnO on the Zn acetate dihydrate evaporant species treated layer of Cu(InGa)Se 2 .