Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Shell-dependent Blinking of CdSe-Based Core/Shell Nanocrystals

Published

Author(s)

Seung Koo Shin, Bonghwan Chon, Sung Jun Lim, Wonjung Kim, Hyeong G. Kang, Taiha Joo, Jeeseong C. Hwang

Abstract

Blinking of zinc-blende CdSe-based core/shell nanocrystals are studied as a function of shell materials. CdSe/ZnS, CdSe/ZnSe/ZnS, and CdSe/CdS/ZnS core/shell nanocrystals are prepared by epitaxial growth of two-to-six monolayers (MLs) of shell materials over the same green-emitting CdSe core. The time trace of blinking is recorded for single nanocrystals on a borosilicate cover glass. Both on- and off-time distributions are fit to the power law. The off-time exponents are grouped in the range of 1.45-1.70, whereas the on-time exponents are spread in the range of 1.84-2.11. The on-time duration significantly varies with shell material and thickness. As the thickness of ZnS shell increases from four-to-six MLs in CdSe/ZnS nanocrystals, the on-time duration decreases with concomitant increases in the off-time duration. On the other hand, as the shell composition and structure are changed to CdS(2ML)/ZnS(4ML), the power-law statistics remains almost identical to that of CdSe/ZnS(4ML) nanocrystals; on the contrary, the ZnSe(2ML)/ZnS(4ML) double shell over the CdSe core shortens the on-time duration. The shell-dependent power-law exponents suggest that blinking of single nanocrystals can be suppressed by reducing interfacial defects and extending the conduction band to the shell.
Citation
Physical Chemistry Chemical Physics
Volume
12

Keywords

quantum dot, nanocrystal, core-shell

Citation

Shin, S. , Chon, B. , Lim, S. , Kim, W. , Kang, H. , Joo, T. and Hwang, J. (2010), Shell-dependent Blinking of CdSe-Based Core/Shell Nanocrystals, Physical Chemistry Chemical Physics, [online], https://doi.org/10.1039/b924917f (Accessed February 21, 2024)
Created May 9, 2010, Updated October 12, 2021