Quantum size effect and surface defect passivation in size-controlled CsPbBr3 quantum dots
| Autor: | Xiaobo Kong, Mingxu Wang, Wenzhi Wang, Fangying Juan, Haoming Wei, Bingqiang Cao, Fan Xu, Jinkai Li |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Potential well
Materials science Photoluminescence Passivation business.industry Band gap Mechanical Engineering Metals and Alloys 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Mechanics of Materials Quantum dot Femtosecond Ultrafast laser spectroscopy Materials Chemistry Optoelectronics 0210 nano-technology business Absorption (electromagnetic radiation) |
| Zdroj: | Journal of Alloys and Compounds. 831:154834 |
| ISSN: | 0925-8388 |
| Popis: | Luminescent CsPbBr3 quantum dots (QDs) with adjustable size and bandgap were grown by controlling the synthesis temperature in this paper. As the synthesis temperature increases, the QD size becomes larger and then smaller. The corresponding absorption and steady-state photoluminescence spectrum indicate that the QD band gap becomes smaller and then larger, which is a typical quantum confinement effect. Time-resolved photoluminescence spectrum and femtosecond transient absorption spectrum (fs-TAS) show that the non-radiative recombination probability of photocarriers in small QDs is small it has few defects, indicating that the ligand molecules adsorbed on the surface of QDs effectively passivate the surface defects of CsPbBr3. Finally, the hot-phonon bottleneck effect of CsPbBr3 QDs is revealed by the kinetic curves fitting of fs-TAS and the cooling kinetic process of hot carriers is also discussed in detail. This work provides new insights on size-dependent photophysical properties of CsPbBr3 QDs. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect