Can Exciton-Delocalizing Ligands Facilitate Hot Hole Transfer from Semiconductor Nanocrystals?
Can Exciton-Delocalizing Ligands Facilitate Hot Hole Transfer from Semiconductor Nanocrystals?
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DOI：
10.1021/acs.jpcc.6b08178
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发表时间：
2016-12
影响因子：
3.7
通讯作者：
Michael S. Azzaro;Mark C. Babin;Shannon K. Stauffer;G. Henkelman;S. Roberts
中科院分区：
文献类型：
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作者：
Michael S. Azzaro;Mark C. Babin;Shannon K. Stauffer;G. Henkelman;S. Roberts
激子离域配体（EDL）引起了研究人员的兴趣，因为它们能够让电荷载流子扩散到半导体纳米晶体（NC）的配体壳中。通过增加载流子表面可及性，EDL 可以促进在弛豫到能带边缘之前从 NC 中提取高度光激发的载流子，这一过程可以提高基于 NC 的光催化剂和光捕获系统的性能。然而，热载流子提取必须与载流子冷却竞争，载流子和 EDL 之间更强的相互作用可以加速载流子冷却。该报告描述了 EDL 苯基二硫代氨基甲酸酯 (PTC) 对 CdSe NC 的电子和空穴冷却速率的影响。使用状态分辨瞬态吸收光谱，我们发现 PTC 处理可将孔冷却速度加快 1.7 倍。然而，在用醋酸镉 (II) 进一步处理这些 NC 后，孔冷却速率恢复到 PTC 处理之前测量的值，但这些 NC 仍...
Exciton-delocalizing ligands (EDLs) are of interest to researchers due to their ability to allow charge carriers to spread into the ligand shell of semiconductor nanocrystals (NCs). By increasing charge carrier surface accessibility, EDLs may facilitate the extraction of highly photoexcited carriers from NCs prior to their relaxation to the band edge, a process that can boost the performance of NC-based photocatalysts and light harvesting systems. However, hot carrier extraction must compete with carrier cooling, which could be accelerated by the stronger interaction of charge carriers and EDLs. This report describes the influence of the EDL phenyldithiocarbamate (PTC) on the electron and hole cooling rates of CdSe NCs. Using state-resolved transient absorption spectroscopy, we find that PTC treatment accelerates hole cooling by a factor of 1.7. However, upon further treatment of these NCs with cadmium(II) acetate, the hole cooling rate reverts to the value measured prior to PTC treatment, yet these NCs m...