在WSe2单层中以缺陷为媒介的电荷载体捕获和非辐射重组
Journal of the American Chemical Society
|June 28, 2019
概括
二氧化 (WSe2) 单层中的空位显著减缓了电荷重组,增强了太阳能设备的潜力. 其他缺陷,如空隙加速重组,突出缺陷工程的重要性.
科学领域:
- 材料科学
- 凝聚物质物理学
- 计算化学
背景情况:
- 在过渡金属二化物 (TMD) 单层中进行非辐射电荷载体重组阻碍了太阳能应用.
- TMD单层中的缺陷是电荷重组的关键位置,需要更深入地了解它们的影响.
研究的目的:
- 在原始和有缺陷的二单层中量化研究电荷载体动力学.
- 阐明受特定缺陷影响的重组机制:Se空位,W空位和SeW反位.
主要方法:
- 使用第一原理计算来模拟电荷载体动态.
- 分析的重点是内在缺陷对WSe2单层的重组率和机制的影响.
主要成果:
- 预计空缺会通过减少声模式强度,使重组率降低一个数量级.
- 发现空位会使重组加速超过一个数量级,包括电荷捕获和陷辅助重组.
- SeW抗体还通过不同的机制加速重组,包括浅层电子捕获和同时浅层/深层捕获辅助重组.
结论:
- WSe2单层中的明显缺陷对电荷载体重组动力学有独特的影响.
- 减轻W空缺的材料工程对于推进基于WSe2的光活性装置至关重要.
- 了解缺陷特定的重组机制对于设计高性能太阳能转换技术至关重要.
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