Abstract
Although colloidal quantum dots (QDs) exhibit excellent photostability under mild excitation, intense illumination makes their emission increasingly intermittent, eventually leading to photobleaching. We study fluorescence of two commonly used types of QDs under pulsed excitation with varying power and repetition rate. The photostability of QDs is found to improve dramatically at low repetition rates, allowing for prolonged optical saturation of QDs without apparent photodamage. This observation suggests that QD blinking is facilitated by absorption of light in a transient state with a microsecond decay time. Enhanced photostability of generic quantum dots under intense illumination opens up new prospects for fluorescence microscopy and spectroscopy.
Original language | English |
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Pages (from-to) | 8778-8782 |
Number of pages | 5 |
Journal | ACS nano |
Volume | 6 |
Issue number | 10 |
DOIs | |
Publication status | Published - Oct 23 2012 |
Keywords
- fluorophore photostability
- quantum dot blinking
- saturable fluorescence
ASJC Scopus subject areas
- Materials Science(all)
- Engineering(all)
- Physics and Astronomy(all)