Rational Design of Perylenediimide‐Substituted Triphenylethylene to Electron Transporting Aggregation‐Induced Emission Luminogens (AIEgens) with High Mobility and Near‐Infrared Emission

• Published in: Advanced functional materials 2018-03, Vol.28 (11), p.n/a
• Main Authors: Zhao, Zheng, Gao, Simin, Zheng, Xiaoyan, Zhang, Pengfei, Wu, Wenting, Kwok, Ryan T. K., Xiong, Yu, Leung, Nelson L. C., Chen, Yuncong, Gao, Xike, Lam, Jacky W. Y., Tang, Ben Zhong
• Format: Article
• Language: English
• Subjects: Agglomeration; aggregation‐induced emission; Electron mobility; Electron transport; Electrons; Emission analysis; Materials science; Molecular conformation; Near infrared radiation; near‐infrared emission; Optical properties; Optoelectronics; organic field‐effect transistors; Organic materials; perylenediimide; Semiconductor devices; tetraphenylethylene; Transistors
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201705609

Organic materials with both high electron mobility and strong solid‐state emission are rare although for their importance to advanced organic optoelectronics. In this paper, triphenylethylenes with varying number of perylenediimide (PDI) unit (TriPE‐nPDIs, n = 1−3) are synthesized and their optical and charge‐transporting properties are systematically investigated. All the molecules exhibit strong solid‐stated near infrared (NIR) emission and some of them exhibit aggregation‐enhanced emission characteristics. Organic field‐effect transistors (OFETs) using TriPE‐nPDIs are fabricated. TriPE‐3PDI shows the best performance with maximum quantum yield of ≈30% and optimized electron mobility of over 0.01 cm2 V−1 s−1, which are the highest values among aggregation‐induced emission luminogens with NIR emissions reported so far. Photophysical property investigation and theoretical calculation indicate that the molecular conformation plays an important role on the optical properties of TriPE‐nPDI, while the result from film microstructure study reveals that the film crystallinity influences greatly their OFET device performance. N‐type semiconductors with high electron mobility, strong near‐infrared emission are constructed from aggregation‐induced emission luminogen (AIEgen) and perylenediimide (PDI). The effect of PDI substitution on their optical and charge‐transporting properties is investigated. The current work provides important clues for constructing high mobility semiconducting emitters and demonstrates the great potential of AIEgens in organic photoelectronics.