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Updated: Oct 3, 2025
11:26
Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light
Published on: September 12, 2014
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Approaching the Spin-Statistical Limit in Visible-to-Ultraviolet Photon Upconversion
Axel Olesund1, Jessica Johnsson1, Fredrik Edhborg1
1Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296 Gothenburg, Sweden.
Journal of the American Chemical Society
|February 17, 2022
Summary
This study achieved a record 16.8% quantum yield for visible-to-ultraviolet (UV) triplet-triplet annihilation photon upconversion (TTA-UC), nearing the theoretical limit. This breakthrough advances TTA-UC applications in areas like solar energy and photochemistry.
Area of Science:
- Photochemistry
- Materials Science
- Physical Chemistry
Background:
- Triplet-triplet annihilation photon upconversion (TTA-UC) converts low-energy photons to higher-energy ones, crucial for applications in biology and solar energy.
- Existing visible-to-ultraviolet (UV) TTA-UC systems struggle to achieve high quantum yields, typically below 10%.
Purpose of the Study:
- To investigate novel annihilator molecules for efficient visible-to-UV TTA-UC.
- To explore the performance of TTA-UC using the sensitizer 2,3,5,6-tetra(9H-carbazol-9-yl)benzonitrile (4CzBN).
Main Methods:
- Screening six different annihilator molecules paired with the sensitizer 4CzBN.
- Measuring internal TTA-UC quantum yields (ΦUC,g).
- Developing a new method using time-resolved emission for determining TTA rate constants.
Main Results:
- Achieved a record internal TTA-UC quantum yield of 16.8% for 1,4-bis((triisopropylsilyl)ethynyl)naphthalene, approaching the 20% spin-statistical limit.
- Demonstrated high ΦUC,g above 12% for three other annihilators, including the novel use of 2,5-diphenylfuran.
- Successfully implemented a simplified method for TTA rate constant determination.
Conclusions:
- This work establishes a new benchmark for visible-to-UV TTA-UC efficiency.
- The findings pave the way for developing highly efficient TTA-UC systems for high-energy photochemical reactions and advanced solar energy conversion.
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