Wang, Ya-Ru Kim, Gee Yeong Kotomin, Eugene Moia, Davide Maier, Joachim 2024-01-19T12:31:54Z 2024-01-19T12:31:54Z 2022-04-05 2022-03 2515-7655 https://pubs.kist.re.kr/handle/201004/115554 Mixed halide perovskites have attracted great interest for applications in solar cells, light emitting diodes and other optoelectronic devices due to their tunability of optical properties. However, these mixtures tend to undergo de-mixing into separate phases when exposed to light (photo de-mixing), which compromises their operational reliability in devices. Several models have been proposed to elucidate the origin of the photo de-mixing process, including the contribution of strain, electronic carrier stabilization due to composition dependent electronic energies, and light induced ionic defect formation. In this perspective we discuss these hypotheses and focus on the importance of investigating defect chemical and ion transport aspects in these systems. We discuss possible optoionic effects that can contribute to the driving force of de-mixing and should therefore be considered in the overall energy balance of the process. These effects include the selective self-trapping of photo-generated holes as well as scenarios involving multiple defects. This perspective provides new insights into the origin of photo de-mixing from a defect chemistry point of view, raising open questions and opportunities related to the phase behavior of mixed halide perovskites. English IOP Publishing Photo de-mixing in mixed halide perovskites: the roles of ions and electrons Article 10.1088/2515-7655/ac47f3 1 JPhys Energy, v.4, no.1 JPhys Energy 4 1 Y scie scopus 000766358900001 Energy & Fuels Materials Science, Multidisciplinary Energy & Fuels Materials Science Article PHASE SEGREGATION LEAD IODIDE LIGHT PERFORMANCE CONDUCTION CH3NH3PBI3 TRANSPORT EFFICIENT CHEMISTRY LIFETIME mixed halide perovskites photo de-mixing ion transport defect chemistry optoionics