Molecular engineering of blue diphenylsulfone-based emitter with aggregation-enhanced emission and thermally activated delayed fluorescence characteristics: impairing intermolecular electron-exchange interactions using steric hindrance

•An asymmetrical blue emitter with TADF, AEE and weak intermolecular electron-exchange interactions behaviors is demonstrated.•The relationship between structure and photo-induced and electro-induced behaviors was studied at the molecular perspective.•The efficiencies of blue non-doped OLED were 20.3 % and 47.4 cd/A.