Size Engineering of Trap Effects in Oxidized and Hydroxylated ZnSe Quantum Dots

被引：26

作者：

Min, Jingjing ^{[1
,2
]}

Zhang, Ying ^{[1
,2
]}

Zhou, Yamei ^{[1
,2
]}

Xu, Dangdang ^{[1
,2
]}

Garoufalis, Christos S. ^{[3
]}

Zeng, Zaiping ^{[1
,2
]}

Shen, Huaibin ^{[1
,2
]}

Baskoutas, Sotirios ^{[3
]}

Jia, Yu ^{[1
,2
,4
,5
]}

Du, Zuliang ^{[1
,2
]}

机构：

[1] Henan Univ, Collaborat Innovat Ctr Nano Funct Mat & Applicat, Minist Educ, Key Lab Special Funct Mat, Kaifeng 475001, Henan, Peoples R China

[2] Henan Univ, Sch Mat Sci & Engn, Kaifeng 475001, Henan, Peoples R China

[3] Univ Patras, Mat Sci Dept, Patras 26504, Greece

[4] Zhengzhou Univ, Int Lab Quantum Funct Mat Henan, Zhengzhou 450001, Henan, Peoples R China

[5] Zhengzhou Univ, Sch Phys & Engn, Zhengzhou 450001, Henan, Peoples R China

来源：

NANO LETTERS | 2022年 / 22卷 / 09期

关键词：

Exciton; Quantum Dot; Density Functional Theory; Time-Dependent Density Functional Theory; HIGHLY EFFICIENT; ENERGY-TRANSFER; SURFACE; STATES;

D O I：

10.1021/acs.nanolett.2c00118

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Environmentally friendly blue-emitting ZnSe quan-tum dots (QDs) are in high demand for next-generation light-emitting devices. Yet, they suffer longstanding optical instabilityissues under aerobic conditions. Herein, we have demonstrated theexistence of oxidization or hydroxylation on the QD surface whenQDs are subjected to oxygen exposure, which potentiallyintroduces highly localized in-gap states. Those states result in adense number of surface-related, weak-intensity"dark"excitonstates at the emission edge. Remarkably, there exists a criticaldiameter (Dc approximate to 8.5 nm) at which the deepest trap level reachesresonance with the highest occupied molecular orbital state.Beyond this critical diameter, the effects of those trap states areminimized, and the emission edge is dominated by high-intensity,bulk-to-bulk-like"bright"exciton states. The present work provides a novel strategy for designing highly stable QD emitters via sizeengineering, which are broadly applicable to other closely related QD systems

引用

页码：3604 / 3611

页数：8

共 34 条

[1] Surface States Mediate Triplet Energy Transfer in Nanocrystal-Acene Composite Systems [J].