氧通过脱离离子化稳定了CdSe/CdS核心/外量子点的光发光
Zhuang Hu1, Shaojie Liu1, Haiyan Qin1
1Center for Chemistry of Novel & High-Performance Materials, and Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China.
Journal of the American Chemical Society
|February 12, 2020
概括
氧气通过促进高效的激子状态来增强化/硫化 (CdSe/CdS) 核心/外量子点的光发光 (PL). 这种效应对于稳定各种应用中的QD性能至关重要.
科学领域:
- 材料科学
- 量子点技术
- 摄影化学
背景情况:
- 量子点 (QD) 具有独特的光发光 (PL) 特性,对它们的环境敏感.
- 氧在QD光物理中的作用是复杂的,需要详细的研究.
- 了解这些相互作用是优化 QD 应用程序的关键.
研究的目的:
- 系统地研究氧气对CdSe/CdS核心/外量子点的光发光效应的定量影响.
- 阐明氧介导脱离离子和稳定QD状态的机制.
- 为了比较氧气对平面CdSe QD和核心/外结构的影响.
主要方法:
- 使用高质量的CdSe/CdS核心/外QD的精确的光谱特征.
- 在单点和整体水平上 (在基板和溶液中) 进行了系统研究.
- 在光刺激过程中改变氧气压力,以观察PL和脱离离率的变化.
主要成果:
- 在核心/外QD中,氧气可促进及时的脱离离子,从低效的三离子状态转变为高效的单激子状态.
- 增加的氧气压力增加了自发和光脱离率,但对光电离率的影响很小.
- 对于CdSe和CdSe/CdS QD,氧气稳定了PL,但仅对普通CdSeQD观察到不可逆转的光腐蚀.
结论:
- 氧气在稳定CdSe/CdS核心/外量子点中的光发光起着至关重要的作用.
- 对于防止不可逆转的光腐蚀而言,高质量的表皮的存在至关重要.
- 这些发现强调了外完整性对于强大的QD应用程序的重要性.
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