Probing the Electron Beam-Induced Structural Evolution of Halide Perovskite Thin Films by Scanning Transmission Electron Microscopy
| Autor: | Zhi-Yi Hu, Xiaoxing Ke, Li Wang, Yi-Bing Cheng, Yu Li, Xiahan Sang, Jing-Ru Han, Gustaaf Van Tendeloo, Chenquan Yang, Xian-Gang Zhou, Zhi-Wen Yin, Wei Li |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Halide 02 engineering and technology 010402 general chemistry 01 natural sciences Atomic units Condensed Matter::Materials Science Scanning transmission electron microscopy Physics::Atomic and Molecular Clusters Physics::Atomic Physics Physical and Theoretical Chemistry Thin film Perovskite (structure) business.industry Physics 021001 nanoscience & nanotechnology Structural evolution 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Chemistry General Energy Cathode ray Optoelectronics 0210 nano-technology business Engineering sciences. Technology |
| Zdroj: | The journal of physical chemistry: C : nanomaterials and interfaces |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.1c02156 |
| Popis: | A deep understanding of the fine structure at the atomic scale of halide perovskite materials has been limited by their sensitivity to the electron beam that is widely used for structural characterization. The sensitivity of a gamma-CsPbIBr2 perovskite thin film under electron beam irradiation is revealed by scanning transmission electron microscopy (STEM) through a universal large-range electron dose measurement, which is based on discrete single-electron events in the STEM mode. Our research indicates that the gamma-CsPbIBr2 thin film undergoes structural changes with increasing electron overall dose (e(-).A(-2)) rather than dose rate (e(-).A(-2).s(-1)), which suggests that overall dose is the key operative parameter. The electron beam-induced structural evolution of gamma-CsPbIBr2 is monitored by fine control of the electron beam dose, together with the analysis of high-resolution (S)TEM, diffraction, and energy-dispersive X-ray spectroscopy. Our results show that the gamma-CsPbIBr2 phase first forms an intermediate phase [e.g., CsPb(1-x)(IBr)((3-y))] with a superstructure of ordered vacancies in the pristine unit cell, while a fraction of Pb2+ is reduced to Pb-0. As the electron dose increases, Pb nanoparticles precipitate, while the remaining framework forms the Cs2IBr phase, accompanied by some amorphization. This work provides guidelines to minimize electron beam irradiation artifacts for atomic-resolution imaging on CsPbIBr2 thin films. |
| Databáze: | OpenAIRE |
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