Material for organic electroluminescent device, organic electroluminescent device including the same and preparation method of triarylamine derivatives

Provided are a material for an organic electroluminescent device having a high emission efficiency and an organic electroluminescent device including the same. The material for an organic electroluminescent device according to the present disclosure is represented by Formula 1: in which dibenzoheterole groups are coupled to a phenyl group of a triarylamine at the ortho positions relative to the nitrogen atom. The polarity of the molecule may be increased due to the heteroatoms of the dibenzoheterole groups, and the energy gap (e.g., HOMO-LUMO gap) of the molecule may be increased due to the large steric distortion of the molecule around the amine group. Accordingly, the emission efficiency of an organic EL device may be improved in the blue emission region.