Abstract
It is very important to study the crystallization of hybrid organic–inorganic perovskites because their thin films are usually prepared from solution. The investigation on the growth of perovskite films is however limited by their polycrystallinity. In this work, methylammonium lead triiodide single crystals grown from solutions with different methylammonium iodide (MAI):lead iodide (PbI2) ratios were investigated. We observed a V-shaped dependence of the crystallization onset temperature on the MAI:PbI2 ratio. This is attributed to the MAI effects on the supersaturation of precursors and the interfacial energy of the crystal growth. At low MAI:PbI2 ratio (<1.7), more MAI leads to the supersaturation of the precursors at lower temperature. At high MAI:PbI2 ratio, the crystal growing plans change from (100)-plane dominated to (001)-plane dominated. The latter have higher interfacial energy than the former, leading to a higher crystallization onset temperature.
Original language | English (US) |
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Pages (from-to) | 16073-16076 |
Number of pages | 4 |
Journal | Angewandte Chemie - International Edition |
Volume | 56 |
Issue number | 50 |
DOIs | |
State | Published - Dec 11 2017 |
Bibliographical note
Funding Information:talline materials, which is supported by the SEM images (Supporting Information, Figure S4). Apart from the surface, the crystals were cleaved, and no boundary was observed on the cleaved faces. The crystals can be categorized into three types in terms of their shapes. Crystals grown from the precursor solutions with the ratios of 1, 1.2, and 1.5 have the same shape, and they are annotated as type I. The crystal shape becomes very different for the ratios of 1.7 and 2. They are annotated as type II and type III, respectively. The face indexes of the crystal surfaces were determined by the powder XRD (Supporting Information, Figure S5 and Table S1).
Publisher Copyright:
© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Keywords
- crystallization
- growing planes
- interfacial energy
- methylammonium iodide
- perovskites
ASJC Scopus subject areas
- Catalysis
- General Chemistry