Revealing the Origin of Luminescence Center in 0D Cs4PbBr6 Perovskite
| Autor: | Guoying Feng, Lixin Xie, Chong Wang, Shenyu Dai, Viktor G. Hadjiev, Guang Yang, Liangzi Deng, Qingkai Yu, Zhaojun Qin, Chunzheng Wu, Jiming Bao, Yizhou Ni, Zhiming Wang, Shuo Chen |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Condensed Matter - Materials Science
Photoluminescence Materials science business.industry General Chemical Engineering Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Materials Chemistry Optoelectronics Center (algebra and category theory) 0210 nano-technology business Luminescence Perovskite (structure) |
| Popis: | Zero dimensional perovskite Cs4PbBr6 has attracted considerable attention recently not only because of its highly efficient green photoluminescence (PL), but also its two highly debated opposing mechanisms of the luminescence: embedded CsPbBr3 nanocrystals versus intrinsic Br vacancy states. After a brief discussion on the root cause of the controversy, we provide sensitive but non-invasive methods that can not only directly correlate luminescence with the underlying structure, but also distinguish point defects from embedded nanostructures. We first synthesized both emissive and non-emissive Cs4PbBr6 crystals, obtained the complete Raman spectrum of Cs4PbBr6 and assigned all Raman bands based on density functional theory simulations. We then used correlated Raman-PL as a passive structure-property method to identify the difference between emissive and non-emissive Cs4PbBr6 crystals and revealed the existence of CsPbBr3 nanocrystals in emissive Cs4PbBr6. We finally employed a diamond anvil cell to probe the response of luminescence centers to hydrostatic pressure. The observations of fast red-shifting, diminishing and eventual disappearance of both green emission and Raman below Cs4PbBr6 phase transition pressure of ~3 GPa is compatible with CsPbBr3 nanocrystal inclusions as green PL emitters and cannot be explained by Br vacancies. The resolution of this long-lasting controversy paves the way for further device applications of low dimensional perovskites, and our comprehensive optical technique integrating structure-property with dynamic pressure response is generic and can be applied to other emerging optical materials to understand the nature of their luminescent centers. |
| Databáze: | OpenAIRE |
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