Photoluminescence Blinking and Biexciton Auger Recombination in Single Colloidal Quantum Dots with Sharp and Smooth Core/Shell Interfaces.
Photoluminescence Blinking and Biexciton Auger Recombination in Single Colloidal Quantum Dots with Sharp and Smooth Core/Shell Interfaces.
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DOI：
10.1021/acs.jpclett.0c03065
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发表时间：
2020-12
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影响因子：
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通讯作者：
Wenli Guo;Jialun Tang;Guofeng Zhang;Bin Li;Changgang Yang;Ruiyun Chen;Chengbing Qin;Jianyong Hu;Haizheng Zhong;Liantuan Xiao;Suotang Jia
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文献类型：
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作者：
Wenli Guo;Jialun Tang;Guofeng Zhang;Bin Li;Changgang Yang;Ruiyun Chen;Chengbing Qin;Jianyong Hu;Haizheng Zhong;Liantuan Xiao;Suotang Jia
在单胶体量子点中，光滑的核/壳界面是否能减少俄歇复合并抑制光致发光（PL）闪烁，目前还没有一致的结论。本文通过比较CdxZn1-xSeyS1-y/ZnS核/壳量子点的单点PL谱，研究了核/壳界面对PL闪烁和双激子俄格复合的影响。当考虑不同的PL闪烁机制时，这种不一致性可以得到澄清。对于出现俄歇闪烁的单量子点，光滑的核/壳界面势可以通过减少俄歇复合来抑制PL闪烁。相比之下，我们发现具有光滑核/壳界面的带边载流子（BC）闪烁量子点的双激子俄歇复合率略有降低，但PL闪烁活性增加。这是因为光滑的界面电位不能减少电子向表面态转移所引起的PL闪烁；然而，有可能增加电子波函数离域，以降低双激子俄歇复合率。
There is an inconsistence on whether a smooth core/shell interface can reduce Auger recombination and suppress photoluminescence (PL) blinking in single colloidal quantum dots (QDs). Here, we investigate the influence of a core/shell interface on PL blinking and biexciton Auger recombination by comparing the single-dot PL spectra of CdxZn1-xSeyS1-y/ZnS core/shell QDs with sharp and smooth interfaces. The inconsistence can be clarified when considering different PL blinking mechanisms. For the single QDs showing Auger blinking, a smooth core/shell interface potential can suppress PL blinking through reducing the Auger recombination. In contrast, we find slightly reduced biexciton Auger recombination rates but increased PL blinking activities in the band-edge carrier (BC)-blinking QDs with the smooth core/shell interface. This is because the smooth interface potential cannot reduce the PL blinking caused by the transfer of electrons to the surface states; however, there is potential to increase electron wave function delocalization for reducing the biexciton Auger recombination rate.