Efficient, Color-stable and Long-lived White Organic Light-emitting Diode Utilizing Phosphorescent Molecular-Aggregates

White organic light-emitting diodes have the potential to become the new form of solid-state lighting used in housing and commericial buildings. Highly efficient and stable single-stack hybrid white organic light-emitting diode (WOLED) devices are developed using two emissive layers, one with amber colored phosphorescent molecular aggregate emission from the Pd (II) complex, Pd(II) 7-(3-(pyridine-2-yl-κN)phenoxy-κC)(benzo-κC)([c]benzo[4,5]imidazo-κN)[1,2-a][1,5]naphthyridine, Pd3O8-Py5, and the other with blue fluorescence emission. An optimized device structure achieved high color stability under various current densities, an external quantum efficiency (EQE) of 45.5%, a power efficiency of 97.4 Lm W^-1, and an estimated LT₉₅ (operational time to 95% of the initial luminance) of 50,744 hours at an initial luminance of 1000 cd m^-2.