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Enhancing the statistical probability factor in triplet-triplet annihilation photon upconversion via TIPS
Lukas Naimovičius1,2,3, Manvydas Dapkevičius2, Edvinas Radiunas2
1Institute of Materials Science of Barcelona (ICMAB-CSIC), Universitat Autònoma de Barcelona Bellaterra Barcelona 08193 Spain kasper.moth-poulsen@upc.edu pbharmoria@icmab.es.
Chemical Science
|October 16, 2025
Summary
Triisopropylsilyl (TIPS) functionalization significantly boosts red-to-green photon upconversion efficiency in new perylene derivatives. This enhancement stems from improved singlet generation and broad upconversion capabilities, crucial for biological applications.
Area of Science:
- Photochemistry
- Materials Science
- Organic Chemistry
Background:
- Triplet-triplet annihilation photon upconversion (TTA-UC) is a promising technology for light manipulation.
- Optimizing annihilator properties is key to improving TTA-UC efficiency and expanding its applications.
- The spin statistical probability factor (f) critically influences singlet generation efficiency in TTA-UC.
Purpose of the Study:
- To investigate the impact of triisopropylsilyl (TIPS) functionalization on perylene (PY) annihilators for TTA-UC.
- To synthesize and characterize a novel green-emitting TIPS-functionalized perylene derivative (TIPS-PY).
- To evaluate the spin statistical probability factor and overall efficiency of TIPS-PY in TTA-UC.
Main Methods:
- Synthesis of 3,9-bis((triisopropylsilyl)ethynyl)perylene (TIPS-PY).
- Measurement of photophysical properties including fluorescence quantum yield and triplet energy (T1).
- Determination of the spin statistical probability factor (f) and TTA-UC quantum yield.
- Computational analysis using TheoDORE for excited state characterization.
Main Results:
- A record red-to-green TTA-UC quantum yield of 13.7% was achieved with TIPS-PY.
- TIPS-PY exhibits a high fluorescence quantum yield (95%) and a reduced triplet energy (1.29 eV).
- The spin statistical probability factor (f = 39.2% ± 2.4%) for TIPS-PY is superior to other annihilators in the 470-570 nm range.
- Computational analysis revealed increased singlet-like character in the triplet-pair state of TIPS-PY.
- TIPS-PY demonstrated efficient upconversion of 730 nm light, suitable for the phototherapeutic window.
Conclusions:
- TIPS functionalization is a highly effective strategy for enhancing TTA-UC performance in perylene derivatives.
- The improved singlet generation efficiency, attributed to increased singlet-like character in the triplet-pair state, is a key factor in the high quantum yield.
- TIPS-PY shows significant potential for applications requiring efficient photon upconversion, particularly in biological contexts due to its broad upconversion range.
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