Automated Research Platform for Development of Triplet-Triplet Annihilation Photon Upconversion Systems

Area of Science:

• Photochemistry
• Materials Science
• Chemical Engineering

Background:

• Triplet-triplet annihilation photon upconversion (TTA-UC) is crucial for energy, 3D printing, and photopharmacology.
• Optimization of TTA-UC systems is hindered by precise concentration tuning requirements and oxygen sensitivity.

Purpose of the Study:

• To develop an automated, high-throughput platform for TTA-UC system discovery and optimization.
• To generate comprehensive concentration maps of critical TTA-UC parameters.
• To identify and analyze loss mechanisms in TTA-UC systems.

Main Methods:

• An automated, high-throughput platform was designed and implemented.
• The platform performed 100 concentration scans within two hours.
• Key parameters like quantum yield, triplet energy transfer efficiency, and threshold intensity were mapped.

Main Results:

• High sensitizer concentrations led to quantum yield losses due to sensitizer triplet self-quenching and sensitizer-triplet-triplet annihilation.
• Reverse triplet energy transfer (RTET) at elevated sensitizer levels increased upconversion losses and excitation thresholds.
• Loss mechanisms were confirmed in novel sensitizer-annihilator pairs, indicating areas for molecular design improvement.

Conclusions:

• The automated platform accelerates TTA-UC research and optimization.
• Understanding loss mechanisms like self-quenching and RTET is vital for improving TTA-UC efficiency.
• The platform is applicable to other photochemical studies requiring low oxygen and high laser excitation.