Patent ID: 8124870

Claim:
A tandem thin-film photovoltaic device, comprising: a substrate; a back contact layer disposed on the substrate; a bottom solar absorber layer disposed on the back contact layer; a bottom heterojunction partner layer disposed on the bottom solar absorber layer; a semi-transparent interconnect layer, including: a semi-transparent contact layer disposed on the bottom heterojunction partner layer, and a semi-transparent contact interface layer including a Cu(X)Te 2 material disposed on the semi-transparent contact layer, wherein X is at least one of In, Ga, and Al; a top solar absorber layer disposed on the semi-transparent interconnect layer, the top solar absorber layer including one of a Group I-III-VI.sub.2 material and a Group II-VI material; a top heterojunction partner layer disposed on the top solar absorber layer; and a semi-transparent top contact layer disposed on the top heterojunction partner layer.