Chan Chin-Yiu, Lee Yi-Ting, Mamada Masashi, Goushi Kenichi, Tsuchiya Youichi, Nakanotani Hajime, Adachi Chihaya
Center for Organic Photonics and Electronics Research (OPERA), Kyushu University Motooka, Nishi Fukuoka 819-0395 Japan
International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan.
Chem Sci. 2022 Jun 8;13(26):7821-7828. doi: 10.1039/d2sc02478k. eCollection 2022 Jul 6.
This work reports a new acceptor for constructing donor-acceptor type (D-A type) blue thermally activated delayed fluorescence (TADF) emitters with narrowed charge-transfer (CT) emissions. A new acceptor core, carbazole-2-carbonitrile (CCN), is formed by the fusion of carbazole and benzonitrile. Three D-A type TADF emitters based on the CCN acceptor, namely 3CzCCN, 3MeCzCCN, and 3PhCzCCN, have been successfully synthesized and characterized. These emitters show deep-blue emissions from 439 to 457 nm with high photoluminescence quantum yields of up to 85% in degassed toluene solutions. Interestingly, all CCN-based deep-blue TADF emitters result in narrow CT emissions with full-width at half-maximums (FWHMs) of less than 50 nm in toluene solutions, which are pretty narrower compared with those of typical D-A type TADF emitters. Devices based on these emitters show high maximum external quantum efficiencies of up to 17.5%.
这项工作报道了一种新型受体，用于构建具有窄化电荷转移（CT）发射的供体-受体型（D-A型）蓝色热激活延迟荧光（TADF）发光体。一种新型受体核心，咔唑-2-腈（CCN），由咔唑和苄腈融合而成。基于CCN受体的三种D-A型TADF发光体，即3CzCCN、3MeCzCCN和3PhCzCCN，已成功合成并表征。这些发光体在脱气甲苯溶液中发出439至457nm的深蓝色光，光致发光量子产率高达85%。有趣的是，所有基于CCN的深蓝色TADF发光体在甲苯溶液中的CT发射都很窄，半高宽（FWHM）小于50nm，与典型的D-A型TADF发光体相比要窄得多。基于这些发光体的器件显示出高达17.5%的高最大外量子效率。
