The application of halogenated 3,3′-dimethyl-9,9′-bianthracene derived materials in deep-blue OLEDs

3,3′-dimethyl-9,9′-bianthracene (MBAn) is a non-donor-acceptor type bipolar deep blue fluorophore with a twisted conformation that can effectively prevent π-π stacking quenching, thereby enhancing the luminescence efficiency. And the introduction of halogen elements can increase the electron affinity of the material, thus effectively improving the electron mobility of the material, which contributes to the better optoelectronic performance of organic light-emitting diodes (OLEDs). Five MBAn derivatives were synthesized by altering the positions and numbers of halogen substituents on the two phenyl rings attached to the MBAn core at positions 9 and 9'. The photophysical, electrochemical, thermal stability and theoretical studies of these five derivatives were carried out. The OLED using 10,10′-bis(4-chlorophenyl)-3,3′-dimethyl-9,9′-bianthracene (MBAn-4-Cl) as the emitter shows a comparable electroluminescence spectrum peaked at 440 nm (FWHM = 52 nm) and a maximum external quantum efficiency (EQEmax) of 5.25% at Commission Internationale de l’Éclairage (CIE) coordinates of (0.143, 0.067), which matches the National Television Standards Committee (NTSC) standard (0.14, 0.08) very well.