压力对化纳米晶体的结构和光学性能的影响
Guanjun Xiao1, Ye Cao1, Guangyu Qi1
1State Key Laboratory of Superhard Materials, College of Materials Science and Engineering, Jilin University , Changchun 130012, People's Republic of China.
Journal of the American Chemical Society
|July 7, 2017
概括
使用高压来设计化纳米晶体 (CsPbBr3NCs) 的带隙,显示在1.2GPa的相位过渡. 这种方法提高了光伏应用的太阳光谱吸收率.
科学领域:
- 材料科学
- 凝聚物质物理学
- 纳米技术
背景情况:
- 金属化物矿 (MHP) 对光电子和太阳能电池具有前景.
- 在MHP中带隙工程对于实际应用至关重要,但仍然具有挑战性.
研究的目的:
- 研究高压对化纳米晶体 (CsPbBr3NCs) 的光学和结构性质的影响.
- 了解CsPbBr3NC中的压力诱导带隙工程背后的机制.
主要方法:
- 使用稳态光发光和吸收光谱的高压实验.
- 分析电子带结构和结构变化的第一原则计算.
主要成果:
- 在大约1.2GPa时发生了CsPbBr3NC的相变,由光学光谱的不连续性证明.
- 压力诱导带隙缩小和延长载波寿命,增强太阳光谱的吸收.
- 在纳米立方体,纳米线和批量CsPbBr3中观察到形态依赖的相位过渡和带隙转移.
结论:
- 高压是一种有效的工具来定制CsPbBr3NC的带隙和结构.
- 结构修改,包括PbBr6八面体内的结合长度和角度,决定了带隙工程.
- 在较高的压力下,Jahn-Teller效应会导致直接到间接的带隙过渡.
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