Rational bridging affording luminogen with AIE features and high field effect mobility

Abstract

Linear and starburst emissive materials constructed by multiple triphenylamine (TPA) groups are extensively used in optoelectronic devices owing to their luminescence and good charge transport properties. Usual connecting units such as single bonds and benzene rings, however, normally generate chromophores with aggregation-caused quenching properties, which limit their applications. The creation of TPA derivatives with both effective charge transport and efficient emission is thus of significant importance. Herein, rational bridging of four TPA units by an ethylene group affords 4TPAE with aggregation-induced emission (AIE) characteristics and a high solid-state efficiency up to unity. Its spin-coated film can work as a p-type semiconductor with a field effect mobility of 4.43 × 10⁻⁴ cm² V⁻¹ s⁻¹. Its OLED devices also perform excellently, whose maximal current efficiency (CE_max) and external quantum efficiency (EQE_max) are as high as 12.2 cd A⁻¹ and 4.9%, respectively. These results have obvious implications for the fabrication of novel multifunctional materials consisting of multiple TPA segments.