3AO.7.1 Introductory Oral: Perovskite/Silicon Tandem Cells: Self-Assembled Monolayer as HTL for 29.2% Efficiency and Progress in Upscaling to Large Areas
Monday, 7th September 2020
13:30 - 15:00
E. Köhnen, A. Al-Ashouri, A. Magomedov, M. Roß, E. Kasparavicius, J.A. Marquez-Prieto, P. Caprioglio, M. Stolterfoht, A.B. Morales-Vilches, B. Li, B. Rech, R. Schlatmann, L. Korte, D. Neher, T. Unold, T. Malinauskas, V. Getautis, B. Stannowski, S. Albrecht
Perovskite solar cells attracted great attention due to the unprecedented increase in power conversion efficiency (PCE) over the last decade. The perovskite’s tunable bandgap opens up the possibility to combine these perovskite solar cells with various types of photovoltaic technologies into multijunction cells. It has been demonstrated that tandem cells combining market-leading and well-established silicon solar cells with perovskite solar cells can surpass the efficiency limit of the individual cells. With 28% for monolithic perovskite/silicon tandem solar cells, presented by Oxford PV, the tandem efficiency already surpassed the record values for both silicon and perovskite single junction cells. Although further details of this cell are unknown, the cell size has been reported to 1 cm². Indeed, most of the reported high efficiency tandem solar cells are fabricated with similar sizes, demonstrating that upscaling of this technology is still a major challenge. Here we emphasize the crucial role of substrate-controlled perovskite growth, introducing a new self-assembled monolayer (SAM) for perovskite solar cells which not only increases the efficiency but can also be deposited conformally on large areas and even on rough or textured surfaces. The superior properties of the SAM enables a world record efficiency of 29.15% for tandem solar cells on 1 cm² and upscaling to highly efficient tandem solar cells on 61 cm2.