How Exciton and Single Carriers Block the Excitonic Transition in Two-Dimensional Cadmium Chalcogenide Nanoplatelets
How Exciton and Single Carriers Block the Excitonic Transition in Two-Dimensional Cadmium Chalcogenide Nanoplatelets
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DOI：
10.1021/acs.nanolett.0c02461
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发表时间：
2020-08-12
期刊：
影响因子：
10.8
通讯作者：
Lian, Tianquan
中科院分区：
文献类型：
--
作者：
Li, Qiuyang;He, Sheng;Lian, Tianquan
硫族镉纳米片具有独特的性质，在激光、发光二极管和光催化等领域具有巨大的应用潜力。然而，带边激子和单载流子（电子和空穴）态的确切性质仍然不清楚，即使它们影响这些材料的关键特性和应用。在此，我们研究了单载流子（电子或空穴）态对镉硫属化物NPL单激子态相空间填充的贡献。与泵的注量依赖TA的研究和选择性的电子去除，我们确定，一个单一的电子和空穴状态，分别贡献85%和12%，在CdSe/ZnS核/壳NPLs的激子跃迁的阻塞。这些观察结果可以合理化的带边激子和单载流子状态的2D NPL，显着不同的量子点的模型。
Cadmium chalcogenide nanoplatelets (NPLs) possess unique properties and have shown great potential in lasing, light-emitting diodes, and photocatalytic applications. However, the exact natures of the band-edge exciton and single carrier (electron and hole) states remain unclear, even though they affect the key properties and applications of these materials. Herein, we study the contribution of a single carrier (electron or hole) state to phase space filling of single exciton states of cadmium chalcogenide NPLs. With pump fluence dependent TA study and selective electron removal, we determine that a single electron and hole states contribute 85% and 12%, respectively, to the blocking of the excitonic transition in CdSe/ZnS core/shell NPLs. These observations can be rationalized by a model of band-edge exciton and single carrier states of 2D NPLs that differs significantly from that of quantum dots.