Critical Intermediate Structure That Directs the Crystalline Texture and Surface Morphology of Organo-Lead Trihalide Perovskite
| Autor: | Hwo-Shuenn Sheu, Je-Wei Chang, Yu-Yun Hsiao, Shao Sian Li, U-Ser Jeng, Yen-Chien Kuo, Chia-Hao Chen, Chung-Yao Lin, Chun-Wei Chen, Hao-Chung Chia, Chun-Jen Su, Yi-Kang Lan, Shih-Chang Weng, An-Chung Su |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Materials science Annealing (metallurgy) Photoemission spectroscopy Iodide Trihalide Ab initio 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Epitaxy 01 natural sciences 0104 chemical sciences Crystallography Octahedron chemistry General Materials Science Sublimation (phase transition) 0210 nano-technology |
| Zdroj: | ACS applied materialsinterfaces. 9(42) |
| ISSN: | 1944-8252 |
| Popis: | We have identified an often observed yet unresolved intermediate structure in a popular processing with dimethylformamide solutions of lead chloride and methylammonium iodide for perovskite solar cells. With subsecond time-resolved grazing-incidence X-ray scattering and X-ray photoemission spectroscopy, supplemental with ab initio calculation, the resolved intermediate structure (CH3NH3)2PbI2Cl2·CH3NH3I features two-dimensional (2D) perovskite bilayers of zigzagged lead-halide octahedra and sandwiched CH3NH3I layers. Such intermediate structure reveals a hidden correlation between the intermediate phase and the composition of the processing solution. Most importantly, the 2D perovskite lattice of the intermediate phase is largely crystallographically aligned with the [110] planes of the three-dimensional perovskite cubic phase; consequently, with sublimation of Cl ions from the organo-lead octahedral terminal corners in prolonged annealing, the zigzagged octahedral layers of the intermediate phase can merge with the intercalated methylammonium iodide layers for templated growth of perovskite crystals. Regulated by annealing temperature and the activation energies of the intermediate and perovskite, deduced from analysis of temperature-dependent structural kinetics, the intermediate phase is found to selectively mature first and then melt along the layering direction for epitaxial conversion into perovskite crystals. The unveiled epitaxial conversion under growth kinetics controls might be general for solution-processed and intermediate-templated perovskite formation. |
| Databáze: | OpenAIRE |
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