Abstract
The mechanical properties of formamidinium lead halide perovskites (FAPbX3, X=Br or I) grown by inverse-temperature crystallization have been studied by nanoindentation. The measured Young's moduli (9.7–12.3 GPa) and hardnesses (0.36–0.45 GPa) indicate good mechanical flexibility and ductility. The effects of hydrogen bonding were evaluated by performing ab initio molecular dynamics on both formamidinium and methylammonium perovskites and calculating radial distribution functions. The structural and chemical factors influencing these properties are discussed by comparison with corresponding values in the literature for other hybrid perovskites, including double perovskites. Our results reveal that bonding in the inorganic framework and hydrogen bonding play important roles in determining elastic stiffness. The influence of the organic cation becomes more important for structures at the limit of their perovskite stability, indicated by high tolerance factors.
Original language | English (US) |
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Pages (from-to) | 3740-3745 |
Number of pages | 6 |
Journal | CHEMSUSCHEM |
Volume | 10 |
Issue number | 19 |
DOIs | |
State | Published - Oct 9 2017 |
Bibliographical note
Funding Information:S.S. and A.K.C. thank the Ras Al Khaimah Center for Advanced Materials for financial support. J.O. and F.H.I. acknowledge the support of the Ministry of Education (R-284-000-147-112) and National University of Singapore. S.S. and Z.D. thank the Cambridge Overseas Trust and the China Scholarship Council. F.W. is a holder of an A*STAR international fellowship granted by the Agency for Science, Technology and Research, Singapore. The calculations were performed at the Cambridge HPCS and the U.K. National Supercomputing Service, ARCHER. Access to the latter was obtained through the UKCP consortium and funded by EPSRC under Grant No. EP/K014560/1 (DOI: 10.17863/CAM.10947 to the open access computational data).
Publisher Copyright:
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- hybrid perovskites
- lead halides
- mechanical properties
- nanoindentation
- photovoltaics
ASJC Scopus subject areas
- Environmental Chemistry
- General Chemical Engineering
- General Materials Science
- General Energy