HZB, Humboldt University achieved 24.6% efficiency in CIGS-perovskite cell

Researchers from Helmholtz-Zentrum Berlin (HZB) and Humboldt University Berlin developed a CIGS-perovskite tandem solar cell with a certified 24.6% efficiency, verified by the Fraunhofer Institute for Solar Energy Systems. These tandem solar cells, made of two semiconductor thin films, achieved high efficiency with minimal material use. CIGS thin films, known for their flexibility, allowed for diverse applications. The team improved the contact layers between the top perovskite and bottom CIGS cells, leading to this efficiency milestone. The top cell was developed at TU Berlin, while the perovskite absorber layer was produced in an HZB-Humboldt joint lab. HZB researchers fabricated the CIGS sub-cell and used the KOALA system for vacuum deposition. HZB had previously set records for tandem solar cells, including silicon-perovskite combinations. Researchers expect further efficiency improvements, potentially exceeding 30%. Recently, Westlake University from China developed a flexible tandem solar cell with 23.4% efficiency