Solliance and U.S-based MiaSolé announced a new record - power conversion efficiency of 23% on a flexible tandem solar cell: a top flexible semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

This achievement comes only 9 months after the January 2019 announcement by Solliance and MiaSolé regarding a flexible solar cell with an impressive power conversion efficiency of 21.5%. The solar cell, similarly to this newly announced one, combined two thin-film solar cell technologies into a 4 terminal tandem solar cell stack: a top flexible semi-transparent perovskite solar cell with a bottom flexible copper indium gallium selenide (CIGS) cell.

A team led by Prof. Steve Albrecht from the HZB has announced a new world-record: a tandem solar cell with certified efficiency of 23.26% that combines the semiconducting materials perovskite and CIGS. One reason for this success lies in the cell’s intermediate layer of organic molecules: they self-organize to cover even rough semiconductor surfaces. Two patents have been filed for these layers.

Perovskite-based solar cells have experienced an incredibly rapid increase in efficiency over the last ten years. The combination of perovskites with classical semiconductor materials such as silicon and copper-indium-gallium-selenide (CIGS) compounds in tandem solar cells promises low-cost, high-performance solar modules for the future. However, losses at the electrodes between the two semiconductors considerably reduce the efficiency.