Yurash Brett, Dixon Alana, Espinoza Carolina, Mikhailovsky Alexander, Chae Sangmin, Nakanotani Hajime, Adachi Chihaya, Nguyen Thuc-Quyen
Center for Polymers and Organic Solids (CPOS) and Department of Chemistry & Biochemistry, University of California, Santa Barbara, CA, 93106, USA.
Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.
Adv Mater. 2022 Feb;34(5):e2103976. doi: 10.1002/adma.202103976. Epub 2021 Dec 14.
As in many fields, the most exciting endeavors in photon upconversion research focus on increasing the efficiency (upconversion quantum yield) and performance (anti-Stokes shift) while diminishing the cost of production. In this vein, studies employing metal-free thermally activated delayed fluorescence (TADF) sensitizers have garnered increased interest. Here, for the first time, the strategy of ternary photon upconversion is utilized with the TADF sensitizer 2,4,5,6-tetrakis(carbazol-9-yl)isophthalonitrile (4CzIPN), resulting in a doubling of the upconversion quantum yield in comparison to the binary system employing p-terphenyl as the emitter. In this ternary blend, the sensitizer 4CzIPN is paired with an intermediate acceptor, 1-methylnaphthalene, in addition to the emitter molecule, p-terphenyl, yielding a normalized upconversion quantum yield of 7.6% while maintaining the 0.83 eV anti-Stokes shift. These results illustrate the potential benefits of utilizing this strategy of energy-funneling, previously used only with heavy-metal based sensitizers, to increase the performance of these photon upconversion systems.
与许多领域一样，光子上转换研究中最令人兴奋的努力集中在提高效率（上转换量子产率）和性能（反斯托克斯位移），同时降低生产成本。在这方面，采用无金属热活化延迟荧光（TADF）敏化剂的研究引起了越来越多的关注。在此，首次将三元光子上转换策略与TADF敏化剂2,4,5,6-四（咔唑-9-基）间苯二甲腈（4CzIPN）一起使用，与采用对三联苯作为发射体的二元体系相比，上转换量子产率提高了一倍。在这种三元共混物中，敏化剂4CzIPN除了与发射体分子对三联苯配对外，还与中间受体1-甲基萘配对，在保持0.83 eV反斯托克斯位移的同时，归一化上转换量子产率达到7.6%。这些结果说明了利用这种能量漏斗策略（以前仅用于基于重金属的敏化剂）来提高这些光子上转换系统性能的潜在好处。
