Four-Fold Enhancement of the Activation Energy for Nonradiative Decay of Excitons in PbSe/CdSe Core/Shell versus PbSe Colloidal Quantum Dots

被引：54

作者：

Abel, Keith A. ^{[1
]}

Qiao, Haijun ^{[2
]}

Young, Jeff F. ^{[2
]}

van Veggel, Frank C. J. M. ^{[1
]}

机构：

[1] Univ Victoria, Dept Chem, Victoria, BC V8W 3V6, Canada

[2] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada

来源：

JOURNAL OF PHYSICAL CHEMISTRY LETTERS | 2010年 / 1卷 / 15期

基金：

加拿大自然科学与工程研究理事会; 加拿大创新基金会;

关键词：

NANOCRYSTALS; SPECTROSCOPY;

D O I：

10.1021/jz1007565

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

PbSe/CdSe core/shell quantum dots (QDs) were prepared and investigated as thick films using temperature-dependent photoluminescence. In addition to increased photostability, the CdSe shell leads to a four-fold increase of the activation energy for nonradiative exciton decay for the core/shell QDs compared to that for the bare PbSe QDs. The onset for exponential decay of luminescence is similar to 240 K in the core/shell samples. From further analysis of the temperature-dependent photoluminescence shift and emission line width, we find that the cation exchange reaction broadens the QD size distribution and increases the temperature-independent state broadening. However, the temperature-dependent contribution to the line shape of the core/shell QDs is similar to that in the cores.

引用

页码：2334 / 2338

页数：5