Purely organic Vis-to-UV upconversion with an excited annihilator singlet beyond 4 eV†
The conversion of visible light into high-energy UV photons via sensitized triplet–triplet annihilation (TTA-UC) could pave the way for several energy-demanding applications. However, only a handful of annihilator chromophores for Vis-to-UV upconversion are known and the current limit for the excited-state energy of the UV emitter in TTA-UC schemes is below 4 eV, i.e., in the spectral region (>310 nm) where the sun still provides a considerable photon flux. Herein, we present a novel biphenyl-based annihilator with a highly fluorescent singlet state at 4.04 eV. This annihilator can be combined with a widely-used TADF sensitizer to yield an efficient blue-light (2.77 eV) driven upconversion system with unprecedented properties.
- This article is part of the themed collections: 2022 Journal of Materials Chemistry C Most Popular Articles and Materials for thermally activated delayed fluorescence and/or triplet fusion upconversion