Application of compound blue for white OLED

Used as a blue emitter, fluorescent dye 4,4′-bis(9-ethyl-3-carbazovinylene)-1,1′-biphenyl (BCzVBi) is compounded with Bis[2-(2-hydroxyphenyl)-pyridine]beryllium(Bepp2) to yield high efficiency. When combined with green and red phosphorescent emitting layers, a broad band white light organic light-emitting diodes are obtained and studied. In this device, both singlet and triplet excitons can be harvested to generate white color. Through device structure optimization, a high efficiency of 20.8 cd/A, which corresponds to an external quantum efficiency of 11.3% has been achieved.