Oxygen Stabilizes Photoluminescence of CdSe/CdS Core/Shell Quantum Dots via Deionization

被引:68
作者
Hu, Zhuang [1 ,2 ]
Liu, Shaojie [1 ,2 ]
Qin, Haiyan [1 ,2 ]
Zhou, Jianhai [1 ,2 ]
Peng, Xiaogang [1 ,2 ]
机构
[1] Zhejiang Univ, Ctr Chem Novel & High Performance Mat, Hangzhou 310027, Peoples R China
[2] Zhejiang Univ, Dept Chem, Hangzhou 310027, Peoples R China
基金
中国国家自然科学基金;
关键词
FLUORESCENCE INTERMITTENCY; AUGER RECOMBINATION; BLINKING; NANOCRYSTALS; ELECTRON; LUMINESCENCE; GENERATION; DEPENDENCE; INTENSITY; ENSEMBLE;
D O I
10.1021/jacs.9b11978
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
By taking advantage of well-defined spectroscopic signatures of high-quality CdSe/CdS core/shell QDs, the effects of oxygen on photoluminescence (PL) of QDs were studied systematically and quantitatively at both single-dot and ensemble simple picture. With a sufficient amount of oxygen in the system(on substrate and in solution) levels, which reveals a unified yet during photoexcitation, the core/shell QDs in all forms would be deionized timely from the photogenerated and inefficient trion state back to the efficient single-exciton state, with superoxide radicals as the reduction product of oxygen. Under a given excitation power, rates of both spontaneous deionization and photodeionization channels increased by increasing the oxygen pressure, but photoionization of the QDs was barely affected by the oxygen pressure. While stabilizing PL by oxygen was identified for both CdSe plain core and CdSe/CdS core/shell QDs, irreversible photocorrosion was only observed for CdSe plain core QDs, suggesting the importance of high-quality epitaxial shells for QDs in various applications.
引用
收藏
页码:4254 / 4264
页数:11
相关论文
共 56 条
[1]   Semiconductor clusters, nanocrystals, and quantum dots [J].
Alivisatos, AP .
SCIENCE, 1996, 271 (5251) :933-937
[3]   The effects of chemisorption on the luminescence of CdSe quantum dots [J].
Bullen, C ;
Mulvaney, P .
LANGMUIR, 2006, 22 (07) :3007-3013
[4]  
Chen O, 2013, NAT MATER, V12, P445, DOI [10.1038/NMAT3539, 10.1038/nmat3539]
[5]   Photo-activated luminescence of CdSe quantum dot monolayers [J].
Cordero, SR ;
Carson, PJ ;
Estabrook, RA ;
Strouse, GF ;
Buratto, SK .
JOURNAL OF PHYSICAL CHEMISTRY B, 2000, 104 (51) :12137-12142
[6]   Probing the "Dark" Fraction of Core-Shell Quantum Dots by Ensemble and Single Particle pH-Dependent Spectroscopy [J].
Durisic, Nela ;
Godin, Antoine G. ;
Walters, Derrel ;
Gruetter, Peter ;
Wiseman, Paul W. ;
Heyes, Colin D. .
ACS NANO, 2011, 5 (11) :9062-9073
[7]   Random telegraph signal in the photoluminescence intensity of a single quantum dot [J].
Efros, AL ;
Rosen, M .
PHYSICAL REVIEW LETTERS, 1997, 78 (06) :1110-1113
[8]  
Efros AL, 2016, NAT NANOTECHNOL, V11, P661, DOI [10.1038/nnano.2016.140, 10.1038/NNANO.2016.140]
[9]   Magneto-optical properties of trions in non-blinking charged nanocrystals reveal an acoustic phonon bottleneck [J].
Fernee, Mark J. ;
Sinito, Chiara ;
Louyer, Yann ;
Potzner, Christian ;
Tich-Lam Nguyen ;
Mulvaney, Paul ;
Tamarat, Philippe ;
Lounis, Brahim .
NATURE COMMUNICATIONS, 2012, 3
[10]   Emission intensity dependence and single-exponential behavior in single colloidal quantum dot fluorescence lifetimes [J].
Fisher, BR ;
Eisler, HJ ;
Stott, NE ;
Bawendi, MG .
JOURNAL OF PHYSICAL CHEMISTRY B, 2004, 108 (01) :143-148