Publication Date:
2019
Description:
〈p〉Lead-based organic-inorganic hybrid perovskite (OIHP) solar cells can attain efficiencies over 20%. However, the impact of ion mobility and/or organic depletion, structural changes, and segregation under operating conditions urge for decisive and more accurate investigations. Hence, the development of analytical tools for accessing the grain-to-grain OIHP chemistry is of great relevance. Here, we used synchrotron infrared nanospectroscopy (nano-FTIR) to map individual nanograins in OIHP films. Our results reveal a spatial heterogeneity of the vibrational activity associated to the nanoscale chemical diversity of isolated grains. It was possible to map the chemistry of individual grains in CsFAMA [Cs〈sub〉0.05〈/sub〉FA〈sub〉0.79〈/sub〉MA〈sub〉0.16〈/sub〉Pb(I〈sub〉0.83〈/sub〉Br〈sub〉0.17〈/sub〉)〈sub〉3〈/sub〉] and FAMA [FA〈sub〉0.83〈/sub〉MA〈sub〉0.17〈/sub〉Pb(I〈sub〉0.83〈/sub〉Br〈sub〉0.17〈/sub〉)〈sub〉3〈/sub〉] films, with information on their local composition. Nanograins with stronger nano-FTIR activity in CsFAMA and FAMA films can be assigned to PbI〈sub〉2〈/sub〉 and hexagonal polytype phases, respectively. The analysis herein can be extended to any OIHP films where organic cation depletion/accumulation can be used as a chemical label to study composition.〈/p〉
Electronic ISSN:
2375-2548
Topics:
Natural Sciences in General
Permalink
