Phase Segregation in Cs-, Rb- and K-Doped Mixed-Cation (MA)x(FA)1–xPbI3 Hybrid Perovskites from Solid-State NMR

• DOI: 10.1021/jacs.7b07223
• Publication Date: 2017-09-11T20:19:05Z
• Authors: Dominik J. Kubicki; Daniel Prochowicz; Albert Hofstetter; Shaik M. Zakeeruddin; Michael Grätzel; Lyndon Emsley
• Keywords: Formamidinium; Rubidium; Caesium; Chalcogen; Lattice (music)

Hybrid (organic–inorganic) multication lead halide perovskites hold promise for a new generation of easily processable solar cells. Best performing compositions to date are multiple-cation solid alloys formamidinium (FA), methylammonium (MA), cesium, and rubidium halides which provide power conversion efficiencies up around 22%. Here, we elucidate the atomic-level nature Cs Rb incorporation into perovskite lattice FA-based materials. We use 133Cs, 87Rb, 39K, 13C, 14N solid-state MAS NMR probe microscopic composition Cs-, Rb-, K-, MA-, FA-containing phases in double-, triple-, quadruple-cation bulk thin film. Contrary previous reports, have found no proof or K 3D these systems. also show that structure mechanochemical bears close resemblance films, making them good benchmark structural studies. These findings fundamental understanding previously reported excellent photovoltaic parameters systems their superior stability.