Zhang, K.; Liu, C.; Peng, Z.; Li, C.; Tian, J.; Li, C.; Cerrillo, J.G.; Dong, L.; Streller, F.; Späth, A.; Musiienko, A.; Englhard, J.; Li, N.; Zhang, J.; Du, T.; Sathasivam, S.; Macdonald, T.J.; These, A.; Le Corre, V.M.; Forberich, K.; Meng, W.; Fink, R.H.; Osvet, A.; Lüer, L.; Bachmann, J.; Tong, J.; Brabec, C.J.: Binary cations minimize energy loss in the wide-band-gap perovskite toward efficient all-perovskite tandem solar cells. Joule 8 (2024), p. 2863-2882
10.1016/j.joule.2024.07.003
Open Access Version (externer Anbieter)
Abstract:
Context & scale Enhancing the performance of perovskite solar cells relies crucially on the surface post-treatment of the perovskite film using large spacer cations. These cations play multifunctional roles, encompassing bulk/surface defect passivation, interfacial energy-level alignment, and the creation of protective low-dimensional phases. Particularly in perovskite-based tandem solar cells that extend beyond the detailed balance (DB) limit, wide-band-gap perovskite front cells encounter significant open-circuit voltage (VOC) and fill factor (FF) losses, constraining overall device performance. In this study, we present a novel approach involving a mixed spacer cation system (i.e., GABr and F-PEAI) applied to the perovskite surface. This innovative treatment leads to a substantial increase in both VOC and FF. A comprehensive experimental-theoretical synergy elucidates that the primary mechanisms behind the enhanced performance are surface defect passivation and interfacial energetic alignment induced by the mixed cations, with a noteworthy exclusion of contributions from low-dimensional phases. These findings deepen our comprehension of the surface passivation mechanism employing large spacer cations on the perovskite surface, offering a pioneering and dependable strategy to mitigate energy losses, thereby advancing the path toward the commercialization of perovskite photovoltaic technologies.