Bypassing the statistical limit of singlet generation in sensitized upconversion using fluorinated conjugated systems

Area of Science:

• Photochemistry
• Materials Science
• Organic Chemistry

Background:

• Photon upconversion via triplet-triplet annihilation (TTA) converts low-energy light to higher energy photons.
• Efficient TTA requires effective annihilator molecules, which are currently limited.
• Applications in technologies are hindered by the scarcity of efficient annihilator moieties.

Purpose of the Study:

• Synthesize and evaluate novel fluorinated chromophores for TTA.
• Investigate phenazine and acridine derivatives as potential TTA annihilators.
• Explore new strategies for developing efficient TTA materials.

Main Methods:

• Synthesis of two new fluorinated chromophores (phenazine and acridine-based).
• Experimental characterization of upconverted emission and TTA efficiency.
• Quantum mechanical modeling to understand the photophysical processes.

Main Results:

• Both synthesized chromophores demonstrated upconverted emission, acting as TTA annihilators.
• The acridine-based chromophore exhibited superior TTA yield compared to established model systems.
• Experimental and computational data revealed an alternative pathway for generating upconverted states.

Conclusions:

• Novel fluorinated acridine and phenazine derivatives are effective TTA annihilators.
• The acridine derivative shows promising high TTA efficiency for potential applications.
• Fine-tuning high-energy triplet states offers a new development route for TTA materials.