Gautam Prakalp, Siddiqui Iram, Blazevicius Dovydas, Krucaite Gintare, Tavgeniene Daiva, Jou Jwo-Huei, Grigalevicius Saulius
Department of Materials Science and Engineering, National Tsing Hua University, No. 101, Section 2, Guangfu Rd., East District, Hsinchu 30013, Taiwan.
Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Plentas 19, LT50254 Kaunas, Lithuania.
Nanomaterials (Basel). 2023 Apr 19;13(8):1408. doi: 10.3390/nano13081408.
Organic light-emitting diodes (OLEDs) have played a vital role in showing tremendous technological advancements for a better lifestyle, due to their display and lighting technologies in smartphones, tablets, television, and automotive industries. Undoubtedly, OLED is a mainstream technology and, inspired by its advancements, we have designed and synthesized the bicarbazole-benzophenone-based twisted donor-acceptor-donor (D-A-D) derivatives, namely DB13, DB24, DB34, and DB43, as bi-functional materials. These materials possess high decomposition temperatures (>360 °C) and glass transition temperatures (~125 °C), a high photoluminescence quantum yield (>60%), wide bandgap (>3.2 eV), and short decay time. Owing to their properties, the materials were utilized as blue emitters as well as host materials for deep-blue and green OLEDs, respectively. In terms of the blue OLEDs, the emitter DB13-based device outperformed others by showing a maximum EQE of 4.0%, which is close to the theoretical limit of fluorescent materials for a deep-blue emission (CIE = 0.09). The same material also displayed a maximum power efficacy of 45 lm/W as a host material doped with a phosphorescent emitter Ir(ppy). Furthermore, the materials were also utilized as hosts with a TADF green emitter (4CzIPN) and the device based on DB34 displayed a maximum EQE of 11%, which may be attributed to the high quantum yield (69%) of the host DB34. Therefore, the bi-functional materials that are easily synthesized, economical, and possess excellent characteristics are expected to be useful in various cost-effective and high-performance OLED applications, especially in displays.
有机发光二极管（OLED）凭借其在智能手机、平板电脑、电视和汽车行业的显示及照明技术，在展现推动美好生活的巨大技术进步方面发挥了至关重要的作用。毫无疑问，OLED是一项主流技术，受其进步的启发，我们设计并合成了基于联咔唑-二苯甲酮的扭曲供体-受体-供体（D-A-D）衍生物，即DB13、DB24、DB34和DB43，作为双功能材料。这些材料具有高分解温度（>360°C）和玻璃化转变温度（约125°C）、高光致发光量子产率（>60%）、宽带隙（>3.2 eV）以及短衰减时间。由于它们的这些特性，这些材料分别被用作蓝色发光体以及深蓝色和绿色OLED的主体材料。就蓝色OLED而言，基于发光体DB13的器件表现优于其他器件，其最大外量子效率（EQE）为4.0%，接近深蓝色发射荧光材料的理论极限（CIE = 0.09）。同样的材料作为掺杂磷光发光体Ir(ppy)的主体材料时，还展现出45 lm/W的最大功率效率。此外，这些材料还被用作具有热激活延迟荧光（TADF）绿色发光体（4CzIPN）的主体材料，基于DB34的器件显示出最大EQE为11%，这可能归因于主体DB34的高量子产率（69%）。因此，这些易于合成、经济且具有优异特性的双功能材料有望用于各种具有成本效益和高性能的OLED应用，尤其是在显示器方面。
