Redox-mediated reversible modulation of the photoluminescence of single quantum dots  

作　　者：李颖 刘仁威 马丽 范苏娜 李辉 胡书新 李明 

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics and Chinese Academy of Sciences Key Laboratory of Soft Matter Physics,Institute of Physics,Chinese Academy of Sciences [2]College of Materials Science and Engineering,Jilin University

出　　处：《Chinese Physics B》2015年第7期575-581,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.10904164,61275192,and 11104328)

摘　　要：Precise control over the photoluminescence（PL） of single quantum dots（QDs） is important for their practical applications. We show that the PL of individual Cd Se/Zn S core/shell QDs can be effectively enhanced and continuously modulated by electrochemically manipulating the electron transfer（ET） between the QDs and the attached redox-active ligands such as 2-mercaptoethanol（BME）. We found that i） the ET from BME to the QDs＇ surface trap states suppresses the blinking of the QDs, ii） the ET from the QDs＇ conduction band to the oxidization product results in dimmed PL when BME is oxidized,and iii） further oxidization of BME results in a significant PL brightening. The single particle measurements help us unveil the important features hidden in ensemble measurements and understand the underlying mechanism of the PL modulation.The results also suggest a simple yet efficient method to produce bright and non-blinking QDs and offer opportunities for further development of high resolution fluorescent bioimaging and nanodevices.Precise control over the photoluminescence（PL） of single quantum dots（QDs） is important for their practical applications. We show that the PL of individual Cd Se/Zn S core/shell QDs can be effectively enhanced and continuously modulated by electrochemically manipulating the electron transfer（ET） between the QDs and the attached redox-active ligands such as 2-mercaptoethanol（BME）. We found that i） the ET from BME to the QDs＇ surface trap states suppresses the blinking of the QDs, ii） the ET from the QDs＇ conduction band to the oxidization product results in dimmed PL when BME is oxidized,and iii） further oxidization of BME results in a significant PL brightening. The single particle measurements help us unveil the important features hidden in ensemble measurements and understand the underlying mechanism of the PL modulation.The results also suggest a simple yet efficient method to produce bright and non-blinking QDs and offer opportunities for further development of high resolution fluorescent bioimaging and nanodevices.

关 键 词：quantum dots photoluminescence modulation redox electron transfer 

分 类 号：O471.1[理学—半导体物理]