Yang, F.; Tockhorn, P.; Musiienko, A.; Lang, F.; Menzel, D.; Macqueen, R.; Köhnen, E.; Xu, K.; Mariotti, S.; Mantione, D.; Merten, L.; Hinderhofer, A.; Li, B.; Wargulski, D.R.; Harvey, S.P.; Zhang, J.; Scheler, F.; Berwig, S.; Roß, M.; Thiesbrummel, J.; Al-Ashouri, A.; Brinkmann, K.O.; Riedl, T.; Schreiber, F.; Abou-Ras, D.; Snaith, H.; Neher, D.; Korte, L.; Stolterfoht, M.; Albrecht, S.: Minimizing Interfacial Recombination in 1.8 eV Triple-Halide Perovskites for 27.5% Efficient All-Perovskite Tandems. Advanced Materials 36 (2024), p. 2307743/1-13
10.1002/adma.202307743
Open Access Version
Abstract:
All-perovskite tandem solar cells show great potential to enable the highest performance at reasonable costs for a viable market entry in the near future. In particular, wide-bandgap (WBG) perovskites with higher open-circuit voltage (VOC) are essential to further improve the tandem solar cells’ performance. Here, a new 1.8 eV bandgap triple-halide perovskite composition in conjunction with a piperazinium iodide (PI) surface treatment is developed. With structural analysis, it is found that the PI modifies the surface through a reduction of excess lead iodide in the perovskite and additionally penetrates the bulk. Constant light-induced magneto-transport measurements are applied to separately resolve charge carrier properties of electrons and holes. These measurements reveal a reduced deep trap state density, and improved steady-state carrier lifetime (factor 2.6) and diffusion lengths (factor 1.6). As a result, WBG PSCs achieve 1.36 V VOC, reaching 90% of the radiative limit. Combined with a 1.26 eV narrow bandgap (NBG) perovskite with a rubidium iodide additive, this enables a tandem cell with a certified scan efficiency of 27.5%.