Orange-red and saturated red thermally activated delayed fluorescent dendrimers for non-doped solution-processed OLEDs

• Published in: Dyes and pigments 2022-07, Vol.203, p.110385, Article 110385
• Main Authors: He, Yuting, Zhou, Deyun, Zhang, Cheng, Yan, Hao, Chai, Yongshuai
• Format: Article
• Language: English
• Subjects: Non-doped solution-processed; Orange-red and saturated red; Organic light-emitting diode; Thermally activated delayed fluorescence
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2022.110385

Two thermally activated delayed fluorescence (TADF) dendritic emitters with orange-red and saturated red emission, respectively, were obtained by coupled diphenylamine-carbazole dendron groups as donor with di(pyridin-3-yl)methanone as accepter. The two TADF dendrimers of tBuDPACz-DPyM and MeODPACz-DPyM exhibited small energy gaps between the singlet and triplet excited states (0.04 vs 0.03 eV). As a consequence, the tBuDPACz-DPyM non-doped solution-processed organic light-emitting devices (OLED) exhibited high current efficiency of 2.36 cd A−1 and external quantum efficiency of 1.82% with low turn-on voltage 3.4 V as well as a lower efficiency roll-off. Moreover, Commission Internationale de L'Éclairage (CIE) coordinates of two OLED devices were (0.56, 0.43) and (0.62, 0.37) for tBuDPACz-DPyM and MeODPACz-DPyM respectively. [Display omitted] •Two red dendritic TADF emitters were synthesized and investigated.•The EL spectra of the tow dendrimers exhibited orange-red and saturated red emission.•Non-doped solution processed orange-red OLED achieved CEmax up to 2.36 cd A−1.