Revisiting the nanocrystal formation process of zero-dimensional perovskite
| Autor: | Ruijia Sun, Xiaojia Wang, Hong Liu, Wei Zheng, Yeqi Liu, Yuhai Zhang, Nianqiao Liu |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Ostwald ripening
Photoluminescence Materials science Renewable Energy Sustainability and the Environment Nucleation 02 engineering and technology General Chemistry Activation energy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Amorphous solid symbols.namesake Nanocrystal Chemical physics symbols General Materials Science 0210 nano-technology Black spot Perovskite (structure) |
| Zdroj: | Journal of Materials Chemistry A. 9:4658-4663 |
| ISSN: | 2050-7496 2050-7488 |
| Popis: | The nanocrystal (NC) form of zero-dimensional perovskite (Cs4PbBr6) has attracted a great deal of attention due to both its elusive green emission and phase-pure nature, which has posed a major challenge to the impurity theory used to explain CsPbBr3 being an emitter. In this work, we revisit the NC formation process in real time by using an in situ photoluminescence (PL) monitoring system. Through analyzing the evolution of the PL spectra, the formation process was divided into two stages, namely the nucleation stage and growing stage, which were well explained by the LaMer mechanism and the Ostwald ripening model. In addition, the Johnson–Mehl–Avrami (JMA) model was used to simulate the transformation from non-emissive Cs4PbBr6 to green-emitting Cs4PbBr6, and the ensuing activation energy (Ea = 39.0 ± 5.0 kJ mol−1) was extracted. Importantly, an accompanied transformation from “white spots” to “black spots” was observed, which suggested that the black spots were responsible for PL emission despite their amorphous nature. Our work represents a step forward in unraveling the PL origin of the Cs4PbBr6 phase, although the nature of the white and black spots remained elusive. |
| Databáze: | OpenAIRE |
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