A sky-blue fluorescent small molecule for non-doped OLED using solution-processing

Abstract

Fluorescent molecule 9,9-bis(4-bromobutyl)-2,7-bis(4-(1,2,2-triphenylvinyl)phenyl)-9H-fluorene, TPEF, comprising a fluorene unit and two tetraphenylethene moieties, has been utilized to serve as a sky-blue emitter in a solution-processed non-doped organic light-emitting diode (OLED), and its optical and electrical properties are investigated. The TPEF is an aggregation-induced emission (AIE)-active molecule. It is nearly non-emissive when dissolved in solution while emits strong fluorescence in solid state, indicating that it could be a promising candidate for electrofluorescence use. The solution-processed TPEF-based OLED with a simple non-doped structure exhibits sky-blue fluorescence emission, showing a maximum luminance of 2618 cd m⁻², a maximum current efficiency of 4.55 cd A⁻¹, and a maximum external quantum efficiency (EQE) of 2.17%.