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

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.