Metal-free and purely organic phosphorescent light-emitting diodes using phosphorescence harvesting hosts and organic phosphorescent emitters

Pure organic based phosphorescent light-emitting diodes have been developed using Br modified 2,7-dibromophenanthrene-9,10-dione (27PNDO) as an emitter and Br modified 6,11-dibromodibenzo[f,h]quinoxaline (27QNX) as a host to harvest triplet excitons of the Br modified organic emitters for phosphorescent emission. The Br modified 27PNDO emitter showed phosphorescent emission with an external quantum efficiency of 0.11% by doping in the phosphorescence harvesting 27QNX host in the light-emitting devices. Pure organic phosphorescent light-emitting diodes were demonstrated using the 27PNDO emitter and phosphorescence harvesting 27QNX host.