Twisted-terphenyl conjugated carbazole derivatives with aggregation-induced emission enhancement for deep-blue fluorescence in the solid state

• Published in: Dyes and pigments 2023-05, Vol.213, p.111177, Article 111177
• Main Authors: Geng, Sinuo, Li, Huihui, Shen, Ziqiu, Zhong, Ziting, Feng, Xin Jiang, Lu, Hua
• Format: Article
• Language: English
• Subjects: Aggregation-induced emission enhancement; Deep-blue fluorescence; Organic light-emitting diodes; Solid-state; Twisted
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2023.111177

Scarcity of highly efficient, stable and pure deep-blue chromophores is a key impact on application of OLEDs. In this study, four bipolar molecules were designed and synthesized using carbazolyl as donor and oxadiazole/triazole as acceptors via a twisted terphenyl bridge substituted with trimethylsilyl group. These materials show high thermal/morphological stabilities and deep-blue emission benefited by the twisted structures with high fluorescent efficiency in the solid states. The dual emission properties are well tuned via different acceptors and conjugation sites with aggregation-induced emission enhancement. Electroluminescent device using p-CSiTO as a dopant was fabricated and this device emits deep-blue light at 437 nm with Commission Internationale de l’Eclairage (CIEx',y) of (0.159, 0.110) and good colour purity with full width half maximum (FWHM) of 66 nm. [Display omitted] •Highly twisted molecules help to construct deep-blue organic emitters.•Aggregation-induced emission enhancement is achieved by twisted molecules.•Dual emission properties are well tuned via different acceptors and conjugation sites.•A molecular design strategy was introduced for deep-blue organic emitters.