High-efficiency Cu(In,Ga)Se/sub 2/-based thin-film solar cells: 16.8% total-area 1-sun and 17.2% total-area 22-sun device performance

We report here on a confirmed world-record MgF/sub 2//ZnO/Cu(In,Ga)Se/sub 2//Mo/soda-lime solar cell with a total-area (active-area) efficiency of 16.8% (17.5%) under air mass (AM)1.5 test conditions. Improvements relative to previous record devices are in the short-circuit current (J/sub SC/). We additionally report on a 15.3% efficient, 4.85-cm/sup 2/ cell that confirms good area uniformity. This structure was also utilized in a device fabricated for operation under concentration. The 1-sun, direct spectrum measurement yielded a 15.1% efficient cell. Under 5- and 22-sun concentration, the cell improved to 16.5% and 17.2%, respectively. This achievement is significant in that it proves a compatibility of polycrystalline thin-film and concentrator technologies. Further optimization could yield 1-sun performance in excess of 17% and concentrator performance in excess of 20%. A path to this goal is outlined.