Diphenylanthracene-based trimeric systems for efficient photon upconversion through triplet–triplet annihilation

Abstract

Photon upconverting materials allow energy modulation 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 cm⁻²), is limited 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 volumes or having several triplets within the acceptor molecule may make the annihilation process molecular diffusion-free, thus improving both the abovementioned highly desirable factors. Herein, we demonstrated the synthesis and TTA-UC properties of trimeric diphenylanthracene and phenylanthracene-based materials that exhibit triplet–triplet annihilation-based upconversion with efficiency of up to 5.6% in dilute donor–acceptor conditions (∼ μM).