Expanding the Anti-Stokes Shift of TTA-UC to 1.04 eV by Chemical Tuning of BODIPY-Based Organic Photosensitizers
Chunying Fan, Xiaofeng Wei, Wanhua Wu, Cheng Yang
Abstract
A series of BODIPY-derivatives B-1 ∼ B-5 were synthesized as metal-free photosensitizers in triplet–triplet annihilation (TTA) upconversion (UC) with the purpose of finely tuning the excited state properties to reduce the energy loss during intersystem crossing (ISC), and hence to expand the anti-Stokes shift of TTA-UC. It was revealed that B-5 showed a Δ E ST of as small as 0.28 eV, thus, providing a large anti-Stokes shift of 1.04 eV in TTA-UC with organic sensitizers. A deep red-blue upconversion emission with UC quantum yields of up to 10.7% (out of a 50% maximum) was observed.
Topics & Concepts
Intersystem crossingStokes shiftBODIPYChemistryPhoton upconversionExcited statePhotochemistryAnnihilationFluorescenceAtomic physicsOrganic chemistrySinglet stateOpticsPhysicsIonQuantum mechanicsLuminescence and Fluorescent MaterialsOrganic Light-Emitting Diodes ResearchNanoplatforms for cancer theranostics