Anomalous Emission Shift of CdSe/CdS/ZnS Quantum Dots at Cryogenic Temperatures

被引：14

作者：

Liu, Shaojie ^{[1
,2
]}

Shu, Yufei ^{[1
,2
]}

Zhu, Meiyi ^{[1
,2
]}

Qin, Haiyan ^{[1
,2
]}

Peng, Xiaogang ^{[1
,2
]}

机构：

[1] Zhejiang Univ, Key Lab Excited State Mat Zhejiang Prov, Hangzhou 310027, Peoples R China

[2] Zhejiang Univ, Dept Chem, Hangzhou 310027, Peoples R China

来源：

NANO LETTERS | 2022年 / 22卷 / 07期

基金：

中国国家自然科学基金;

关键词：

quantum dots; temperature-dependent emission energy; exciton fi ne structure; electron; phonon coupling; EXCITON FINE-STRUCTURE; BAND-EDGE EXCITON; DEPENDENT PHOTOLUMINESCENCE; RECOMBINATION DYNAMICS; DARK-EXCITON; NANOCRYSTALS; SPECTRUM; INTERMITTENCY; SPECTROSCOPY; SIZE;

D O I：

10.1021/acs.nanolett.2c00220

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The band-gap energy of most bulk semiconductors tends to increase as the temperature decreases. However, non-monotonic temperature dependence of the emission energy has been observed in semiconductor quantum dots (QDs) at cryogenic temperatures. Here, using stable and highly efficient CdSe/CdS/ZnS QDs as the model system, we quantitatively reveal the origins of the anomalous emission red-shift (-8 meV) below 40 K by correlating ensemble and single QD spectroscopy measurements. About one-quarter of the anomalous red-shift (-2.2 meV) is caused by the temperature-dependent population of the band-edge exciton fine levels. The enhancement of electronoptical phonon coupling caused by the increasing population of dark excitons with temperature decreases contributes an -3.4 meV red-shift. The remaining -2.4 meV red-shift is attributed to temperaturedependent electron-acoustic phonon coupling.

引用

页码：3011 / 3017

页数：7

共 54 条

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