Triplet-Fusion Upconversion Using a Rigid Tetracene Homodimer

Abstract

We demonstrate that a structurally rigid, weakly coupled molecular dimer can replace traditional monomeric annihilators for triplet fusion upconversion (TUC) in solution by observing emitted photons (λ = 540 nm) from a norbornyl-bridged tetracene homodimer following excitation of a triplet sensitizer at λ = 730 nm. Intriguingly, steadystate spectroscopy, kinetic simulations, and Stern−Volmer quenching experiments show that the dimer exhibits qualitatively different photophysics than its parent monomer: it is less effective at diffusion-mediated triplet exciton transfer, but it fuses extracted triplets more efficiently. Our results support the development of composite triplet-fusion platforms that go beyond diffusion-mediated triplet extraction, ultimately circumventing the concentration dependence of solution-phase TUC.

Designs of Singlet Fission Chromophores with a Diazadiborinine Framework**

“…The corresponding species, including the unmodified 2, are candidates of triplet-fusion upconversion to form a singlet exciton, which is of great interest in infrared sensing, photocatalysis, and development of light-emitting diodes. [70,71] In Section S.3, we discuss possible synthetic routes for the designed structures. The introduction of donors and acceptors certainly complicates the synthesis.…”

Discovery of Key TIPS‐Naphthalene for Efficient Visible‐to‐UV Photon Upconversion under Sunlight and Room Light**

“…(TTA-UC) has the potential to efficiently convert lowerenergy photons into higher-energy photons at a weak excitation intensity. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] TTA-UC occurs in multi-chromophore systems wherein the excited triplet energy of a donor (sensitizer) is transferred to an acceptor (emitter), and sensitized acceptor triplets annihilate to show an upconverted emission (Figure 1 a).…”

Engineering 3D perovskites for photon interconversion applications

“…By using tightly bound transmitter ligands, and state-of-theart zwitterionic ligands to reduce the surface trap states further advancements are near. Dimerized annihilators can further boost the UC efficiency by increasing the probability of TTA within the triplet lifetime [91,92]. As the emission wavelength of perovskite NCs can be tuned up to~3 eV, UC deep into the UV is feasible.…”