单一集团非指数光发电群从宽带白发光矿中衰变
Joseph E Thomaz1, Kurt P Lindquist1, Hemamala I Karunadasa1,2
1Department of Chemistry, Stanford University, Stanford, California 94305, United States.
Journal of the American Chemical Society
|September 10, 2020
概括
在 (EDBE) PbBr4 矿中,白光发射源于单一的自我捕获激子组合,而不是多个不同的状态. 快速的结构波动创建了一个广泛的光谱,平均衰变动态,揭示了矿光发机制的洞察力.
科学领域:
- 材料科学
- 固态物理
- 摄影化学
背景情况:
- 层状化矿 (Pb-X) 在紫外线激发时呈现白光辐射,这一现象具有重大科学意义.
- 之前的研究表明, (110) 矿中的宽带光发光 (PL) 源于具有不同衰变动态的多种自我捕获的激发点.
- 了解精确的发射机制对于开发先进的光电子材料至关重要.
研究的目的:
- 阐明层状 (110) 矿,特别是 (EDBE) PbBr4中白光发射背后的机制.
- 研究单晶和薄膜的光发光衰变的时间依赖性.
- 为了区分单组发射和多个激发状态,促进宽带PL.
主要方法:
- 使用与时间相关的单光子计数 (TCSPC) 来分析单晶体的光发衰变.
- 进行了长时间 (高达100 ns) 的光谱线形状分析.
- 单晶和螺旋涂层膜之间的衰变动态的比较.
主要成果:
- 在 (EDBE) PbBr4单晶中,白光发射衰变表现为一个单一的组合,在初始快速衰变后,其发射线形状保持不变.
- 建议快速的局部结构波动导致自我捕获激子 (STEs) 经历广泛的能量范围,从而导致广泛的PL.
- 虽然表现出时间平均单元组合动态,但晶体PL衰变是三指数的,表明缺陷参与; 电影显示更快,非指数的衰变.
结论:
- 在 (EDBE) PbBr4 中的宽带排放源于受到快速环境波动影响的单一时间平均组合.
- 观察到的PL衰变动态与单个集合一致,反驳了多个独立衰变激发状态的假设.
- 晶体和薄膜之间的衰变动力学差异突出了形态学对光电子特性的影响.
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