The effect of caesium alloying on the ultrafast structural dynamics of hybrid organic–inorganic halide perovskites

Journal article

. We find that caesium incorporation primarily inhibits the slower 'reorientational jump' modes of the organic cation, whilst a smaller effect on the fast 'wobbling time' may be due to distortions and rigidisation of the inorganic cuboctahedral cage. 2DIR centre-line-slope analysis further reveals that while static disorder increases with caesium substitution, the dynamic disorder (reflected in the phase memory of the N-H stretching mode of methylammonium) is largely independent of caesium addition. Our results contribute to the development of a unified model of cation dynamics within organohalide perovskites.

Authors: Gallop, NP; Ye, J; Greetham, GM; Jansen, TLC; Dai, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Journal of Materials Chemistry A: materials for energy and sustainability
• Volume: 10
• Issue: 42
• Pages: 22408-22418
• Publication date: 2022-11-01
• DOI: 10.1039/d2ta05207e
• EISSN: 2050-7496
• ISSN: 2050-7488
• Language: English
• Keywords: Perovskite (structure); Inorganic chemistry; Organic chemistry; Halide; Caesium; Computational chemistry; Crystallography; Chemical physics; Chemistry; Materials science; Molecular dynamics; Phase (matter)