Highly efficient white organic electroluminescence device based on a phosphorescent orange material doped in a blue host emitter†
Abstract
A high-efficiency and pure white OLED has been realized by only doping one novel phosphorescent orange-light-emitting complex (bzq)2Ir(dipba) into a suitable deep-blue-emitting fluorescent complex Bepp2 as an emissive layer. The highest efficiency for white OLEDs with a simple HTL-EML-ETL architecture, with a peak power efficiency (PE) of 48.8 lm W−1 and a peak external quantum efficiency (EQE) of 27.8%, has been realized by employing both singlet and triplet excitons for emission. The PE and EQE at the applicable brightness of 1000 cd m−2 are 37.5 lm W−1 and 36.8%, respectively.