Wu Xiugang, Huang Jing-Wei, Su Bo-Kang, Wang Sai, Yuan Li, Zheng Wei-Qiong, Zhang Hu, Zheng You-Xuan, Zhu Weiguo, Chou Pi-Tai
School of Materials Science and Engineering, Jiangsu Collaboration Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, China.
Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
Adv Mater. 2022 Jan;34(1):e2105080. doi: 10.1002/adma.202105080. Epub 2021 Oct 24.
Circularly polarized thermally activated delayed fluorescence (CP-TADF) and multiple-resonance thermally activated delayed fluorescence (MR-TADF), which exhibit novel circularly polarized luminescence and excellent color fidelity, respectively, have gained immense popularity. In this study, integrated CP-TADF and MR-TADF (CPMR-TADF) are prepared by strategic design and synthesis of asymmetrical peripherally locked enantiomers, which are separated and denoted as (P,P″,P″)-/(M,M″,M″)-BN4 and (P,P″,P″)-/(M,M″,M″)-BN5 and exhibit TADF and circularly polarized light (CPL) properties. As the entire molecular frame participates in the frontier molecular orbitals, the resulting helical chirality of (+)/(-)-BN4- and (+)/(-)-BN5-based solution-processed organic light-emitting diodes (OLEDs) helps in achieving a narrow full width at half maximum (FWHM) of 49/49 and 48/48 nm and a high maximum external quantum efficiency (EQE) of 20.6%/19.0% and 22.0%/26.5%, respectively. Importantly, unambiguous circularly polarized electroluminescence signals with dissymmetry factors (g ) of +3.7 × 10 /-3.1 × 10 (BN4) and +1.9 × 10 /-1.6 × 10 (BN5) are obtained. The results indicate successful exploitation of CPMR-TADF-emitter-based OLEDs to exhibit three characteristics: high efficiency, color purity, and circularly polarized light.
圆偏振热激活延迟荧光（CP-TADF）和多共振热激活延迟荧光（MR-TADF）分别展现出新颖的圆偏振发光和出色的色彩保真度，因而广受欢迎。在本研究中，通过对不对称外围锁定对映体进行策略性设计与合成，制备出了集成CP-TADF和MR-TADF（CPMR-TADF），它们被分离并标记为（P，P″，P″）-/(M，M″，M″)-BN4和（P，P″，P″）-/(M，M″，M″)-BN5，并展现出TADF和圆偏振光（CPL）特性。由于整个分子框架参与前沿分子轨道，基于（+）/（-）-BN4和（+）/（-）-BN5的溶液处理有机发光二极管（OLED）所产生的螺旋手性有助于实现半高宽（FWHM）分别为49/49和48/48 nm的窄带宽以及分别为20.6%/19.0%和22.0%/26.5%的高最大外量子效率（EQE）。重要的是，获得了不对称因子（g）分别为+3.7×10 /-3.1×10（BN4）和+1.9×10 /-1.6×10（BN5）的明确圆偏振电致发光信号。结果表明成功开发了基于CPMR-TADF发射体的OLED，以展现出高效率、高色纯度和圆偏振光这三个特性。
