2021 Fiscal Year Annual Research Report
Development of halide perovskite composite with thermal-conductive microstructure for high power LED
| Project/Area Number |
20F40051
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| Research Institution | Kyoto University |
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Principal Investigator |
田部 勢津久 京都大学, 人間・環境学研究科, 教授 (20222119)
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| Co-Investigator(Kenkyū-buntansha) |
ZHENG RUILIN 京都大学, 人間・環境学研究科(研究院), 外国人特別研究員
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| Project Period (FY) |
2020-11-13 – 2023-03-31
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| Keywords | ペロブスカイト / 結晶化ガラス / 量子ドット / 波長シフト / 相転移 |
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| Outline of Annual Research Achievements |
The in situ growth mechanism of halide QDs in amorphous oxide matrix was elucidated by electron microscope, high-energy X-ray scattering, and spectroscopic technique. Complex multi-phase transitions were proved to exist in the oxide matrix, and the obtained QDs glass shows multi-phases coexisting microstructure. The crystallization process from nanoglass to QDs can be induced, including mechanical force, hydration, and heat treatment. Chem. Mater. 34, (2022).
Structural evolution of CsPbBr3 QDs in different glass matrices was analyzed by temperature-dependent PL spectra, absorption spectra, high-energy X-ray structure factor, and pair distribution function. The results show that the lattice parameters and atomic spacing of QDs are affected by the glass composition. The most possibility can be attributed to the thermal expansion mismatch between CsPbBr3 QDs and the glass matrix. Materials 15, (2022).
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
The improvement of performance of CsPbX3 NCs in glass matrices requires understanding of in situ growth process and the relationship between the properties of NCs and glass matrix where they are embedded. We have demonstrated the in situ growth mechanism of CsPbX3 NCs in a glass matrix is totally different from the explanation based on the traditional formation process of glass ceramics, which gives us a better insight into the property modulation of CsPbX3 NCs with heterogeneous structure. In addition, our research paves a new way toward the development of a facile in situ method to reveal the multi-physics co-induced phase transitions and property change of CsPbX3 NCs.
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| Strategy for Future Research Activity |
Based on the in situ growth mechanism proposed by us, the core-shell CsPbBr3 NCs would be possible to synthesize in an amorphous matrix by controlling the preparation condition. By adjusting "nanoglass" composition and controlling the cooling rate, we can prepare multilayer core-shell CsPbBr3-ZnS QDs in an amorphous matrix. The all-in-one method, including core-shell heterojunction structure, ion doping, and embedding in glass matrix, would suppress the spontaneous expansion of CsPbBr3 NCs. The "self-straining effect" based on multilayer core-shell heterogeneous structure will be observed and clarified. Engineering will be used to design and regulate the novel core-shell perovskite NCs, which may pave a new way toward development of a facile in situ method for the dry chemistry synthesis of core-shell nanomaterials.
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