Molecular orientation of a new anthracene derivative for highly-efficient blue fluorescence OLEDs

Abstract

A new anthracene derivative of 9,10-bis(2,5-dimethyl-4-(naphthalen-2-yl)phenyl)-2,3-diphenylanthracene (BDNPA) was designed and synthesized as a non-doped blue emitter in organic light emitting diodes (OLEDs). BDNPA has highly rigid structure and thermal stability with decomposition temperature (corresponding to 5% weight loss) of 490°C, because p-naphthyl xylene groups in 9,10-positions were highly twisted to anthracene core due to steric hindrance of xylene groups, and because the 2,3-diphenyl groups were also twisted about 45–49° to anthracene. OLEDs with BDNPA non-doped emitter showed high efficiency of 5.21cd/A due to the carrier mobility with well-aligned π-stacking structure toward out-of-plane by the face-on orientation by grazing incidence X-ray diffraction.