Having recognized the potential of hybrid organic-inorganic perovskites solar cells, in recent years the photovoltaic community has shifted its focus away from efficiency improvements to simplifying the processing and improving the stability of devices. In this work, we utilize in situ and time-resolved X-ray scattering to track various phase evolutions during the perovskite film solidification to link the microstructure to the composition. In particular, we unravel the crucial roles of Cs+ and Rb+ in promoting the in situ formation of the perovskite phase prior to thermal annealing, thus preventing segregation of halides and cations. Our study points to a significant new guideline for designing mixed-halide mixed-cation perovskites: the sol-gel formulation must possess the ability to convert directly into the targeted perovskite phase without transitioning through compositionally distinct intermediate phases in order to minimize halide segregation and yield-homogenized films.
Multi-cation Synergy Suppresses Phase Segregation in Mixed-Halide Perovskites
De Bastiani M.;
2019-01-01
Abstract
Having recognized the potential of hybrid organic-inorganic perovskites solar cells, in recent years the photovoltaic community has shifted its focus away from efficiency improvements to simplifying the processing and improving the stability of devices. In this work, we utilize in situ and time-resolved X-ray scattering to track various phase evolutions during the perovskite film solidification to link the microstructure to the composition. In particular, we unravel the crucial roles of Cs+ and Rb+ in promoting the in situ formation of the perovskite phase prior to thermal annealing, thus preventing segregation of halides and cations. Our study points to a significant new guideline for designing mixed-halide mixed-cation perovskites: the sol-gel formulation must possess the ability to convert directly into the targeted perovskite phase without transitioning through compositionally distinct intermediate phases in order to minimize halide segregation and yield-homogenized films.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
