Diphenylanthracene-based Trimeric Systems for Efficient Photon Upconversion through Triplet-Triplet Annihilation

Abstract

Photon upconverting materials allow the modulation of energy of the incident photon by emitting photons that are higher in energy than the absorbed ones. Triplet-triplet annihilation-based photon upconversion (TTA-UC) which can operate under much milder light intensities (≤ mW/cm²) is challenged by low upconversion quantum yields and higher threshold excitation intensities in dilute solutions. It has been proposed that creating large densities of triplets in small volume or having several triplets within the acceptor molecule may make annihilation process to be molecular difusion-free, thus improve both of the above highly desirable factors. Herein, we have demonstrated the synthesis and TTA-UC properties of trimeric diphenylanthracene and phenylanthracene-based materials that exhibit triplet-triplet annihilation-based upconversion with upconversion efficiency up to 5.6% in dilute donor-acceptor conditions (~μM).