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Discovery of Key TIPS‐Naphthalene for Efficient Visible‐to‐UV Photon Upconversion under Sunlight and Room Light **
Author(s) -
Harada Naoyuki,
Sasaki Yoichi,
Hosoyamada Masanori,
Kimizuka Nobuo,
Yanai Nobuhiro
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202012419
Subject(s) - photon upconversion , photochemistry , quantum yield , visible spectrum , sunlight , chemistry , fluorescence , optoelectronics , quantum efficiency , naphthalene , materials science , doping , optics , physics , organic chemistry
While many studies have been done on triplet–triplet annihilation‐based photon upconversion (TTA‐UC) to produce visible light with high efficiency, the efficient TTA‐UC from visible to UV light, despite its importance for a variety of solar and indoor applications, remains a challenging task. Here, we report the highest visible‐to‐UV TTA‐UC efficiency of 20.5 % based on the discovery of an excellent UV emitter, 1,4‐bis((triisopropylsilyl)ethynyl)naphthalene (TIPS‐Nph). TIPS‐Nph is an acceptor with desirable features of high fluorescence quantum yield and high singlet generation efficiency by TTA. TIPS‐Nph has a low enough triplet energy level to be sensitized by Ir(C6) 2 (acac), a superior donor that does not quench UV emission. The combination of TIPS‐Nph and Ir(C6) 2 (acac) realizes the efficient UV light production even with weak light sources such as an AM 1.5 solar simulator and room LEDs.