Mapping Trap Dynamics in a CsPbBr3 Single-Crystal Microplate by Ultrafast Photoemission Electron Microscopy
| Autor: | Ju Wang, Lun Dai, Y. B. Li, Qihuang Gong, Hong Yang, Xiaofang Li, Haoran Yu, Aiqin Hu, Guowei Lu, Shufeng Wang, Wei Liu |
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| Rok vydání: | 2021 |
| Předmět: |
Condensed Matter::Quantum Gases
Materials science business.industry Mechanical Engineering Bioengineering 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics law.invention Trap (computing) Photoemission electron microscopy Electron transfer law Femtosecond Optoelectronics General Materials Science Physics::Atomic Physics 0210 nano-technology business Single crystal Nanoscopic scale Electron cooling Perovskite (structure) |
| Zdroj: | Nano Letters. 21:2932-2938 |
| ISSN: | 1530-6992 1530-6984 |
| Popis: | For versatile lead-halide perovskite materials, their trap states, both in the bulk and at the surface, significantly influence optoelectronic behaviors and the performance of the materials and devices. Direct observation of the trap dynamics at the nanoscale is necessary to understand and improve the device design. In this report, we combined the femtosecond pump-probe technique and photoemission electron microscopy (PEEM) to investigate the trap states of an inorganic perovskite CsPbBr3 single-crystal microplate with spatial-temporal-energetic resolving capabilities. Several shallow trap sites were identified within the microplate, while the deep traps were resolved throughout the surface. The results revealed high-defect tolerance to the shallow traps, while the surface dynamics were dominated by the surface deep traps. The ultrafast PEEM disclosed a full landscape of fast electron transfer and accumulation of the surface trap states. These discoveries proved the excellent electronic properties of perovskite materials and the importance of surface optimization. |
| Databáze: | OpenAIRE |
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