Abstract
Triplet-triplet annihilation upconversion (TTA-UC) with near-infrared (NIR) photosensitizers is highly desirable for a variety of emerging applications. However, the development of NIR-to-blue TTA-UC with a large anti-Stokes shift is extremely challenging because of the energy loss during the intersystem crossing (ISC). Here, we develop the first NIR-absorbing B,N-heteroarene-based sensitizer (BNS) with multi-resonance thermally activated delayed fluorescence (MR-TADF) characters to achieve efficient NIR-to-blue TTA-UC. The small energy gap between the singlet and triplet excited states (0.14 eV) of BNS suppresses the ISC energy loss, and its long-delayed fluorescence lifetime (115 μs) contributes to efficient triplet energy transfer. As a result, the largest anti-Stokes shift (1.03 eV) among all heavy-atom-free NIR-activatable TTA-UC systems is obtained with a high TTA-UC quantum yield of 2.9 % (upper limit 50 %).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
