An n-type host with a high triplet energy level and wide bandgap for RGB phosphorescent OLEDs

We applied 4,6-Bis(3,5-di(pyridin-2-yl)phenyl)-2-methylpyrimidine (B2PyMPM), a material with a wide bandgap and excellent electron mobility, as the host for the emissive layer in red, green, and blue organic phosphorescence-emitting devices. In the case of red emission, it exhibited a stable and outstanding external quantum efficiency (EQE) of 10.2% along with color coordinates (0.68, 0.31), indicating its potential as a candidate material for smartphone displays. For green and blue emissions, relatively low electroluminescence characteristics were observed due to insufficient energy transfer. With a high triplet energy level (T₁) of 2.89 eV, B2PyMPM holds promise for use with other phosphorescent dopants in the future.