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Auger Ionization Beats Photo‐Oxidation of Semiconductor Quantum Dots: Extended Stability of Single‐Molecule Photoluminescence
Author(s) -
Yamashita Shinichi,
Hamada Morihiko,
Nakanishi Shunsuke,
Saito Hironobu,
Nosaka Yoshio,
Wakida Shinichi,
Biju Vasudevanpillai
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201501131
Subject(s) - auger , auger effect , photoluminescence , quantum dot , ionization , singlet oxygen , optoelectronics , photochemistry , materials science , chemistry , atomic physics , oxygen , ion , physics , organic chemistry
Despite the bright and tuneable photoluminescence (PL) of semiconductor quantum dots (QDs), the PL instability induced by Auger recombination and oxidation poses a major challenge in single‐molecule applications of QDs. The incomplete information about Auger recombination and oxidation is an obstacle in the resolution of this challenge. Here, we report for the first time that Auger‐ionized QDs beat self‐sensitized oxidation and the non‐digitized PL intensity loss. Although high‐intensity photoactivation insistently induces PL blinking, the transient escape of QDs into the ultrafast Auger recombination cycle prevents generation of singlet oxygen ( 1 O 2 ) and preserves the PL intensity. By the detection of the NIR phosphorescence of 1 O 2 and evaluation of the photostability of single QDs in aerobic, anaerobic, and 1 O 2 scavenger‐enriched environments, we disclose relations of Auger ionization and 1 O 2 ‐mediated oxidation to the PL stability of single QDs, which will be useful during the formulation of QD‐based single‐molecule imaging tools and single‐photon devices.