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Switching Photon Upconversion by Using Photofluorochromic Annihilator with Low-Lying Triplet
Jianlei Han1, Jian Zhang2, Yonghong Shi1
1CAS Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology (NCNST), ZhongGuanCun BeiYiTiao, Beijing 100190, P. R. China.
The Journal of Physical Chemistry Letters
|March 23, 2021
Summary
Researchers developed responsive photon upconversion materials using photofluorochromic diarylethenes. These materials enable switchable triplet-triplet annihilation upconversion (TTA-UC) between "on" and "off" states via light irradiation.
Area of Science:
- Materials Science
- Photochemistry
- Organic Electronics
Background:
- Photon upconversion via triplet-triplet annihilation (TTA-UC) offers high quantum yields and low thresholds.
- Integrating responsiveness into TTA-UC systems is challenging, particularly for excited triplet state annihilators.
Purpose of the Study:
- To synthesize and investigate photofluorochromic annihilators derived from fluorescent diarylethenes.
- To demonstrate light-switchable TTA-UC systems with responsive annihilators.
Main Methods:
- Synthesis of novel turn-on mode fluorescent diarylethenes based on 1,2-bis(2-ethyl-1-benzothiophen-1,1-dioxide-3-yl)perfuorocyclopentene.
- Photophysical characterization including photochromism and photofluorochromism.
- Investigation of TTA-UC using near-infrared ruthenium phthalocyanine as a sensitizer.
Main Results:
- Successful synthesis of diarylethene-based annihilators exhibiting photochromism and photofluorochromism.
- Observation of TTA-UC under 730 nm excitation with emission between 500-700 nm when sensitized by ruthenium phthalocyanine.
- Demonstration of "on" and "off" switching of TTA-UC by alternating UV and visible light irradiation.
Conclusions:
- Photofluorochromic diarylethenes can serve as responsive annihilators for TTA-UC.
- This work enables the development of light-controlled upconversion systems with tunable emission properties.
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