Efficient Green Organic Light-Emitting Devices Based on a Solution-Processable Starburst Molecule

We develop high efficiency solution-processed pure green organic light-emitting devices using a starburst molecule7,7',7"-（5,5,10,10,15,15-hexahexyl-10,15-dihydro-5H-diindeno[l,2-a:1',2'-c]fiuorene-2!7,12-triyl）tris(4-(4-（9Hcarbazol-9-yl）phenyl)benzo[c][l,2,5]thiadiazole)（TRcz）doped 2-methyl-9,10-di（2-naphthyl）anthracene（MADN）as the emitting layers.The electroluminescence properties of the devices with different doping concentrations are investigated.With the increasing doping concentration from 0.5wt%to 5wt%,the maximum efficiency changes from 4.8 cd/A to 8.4 cd/A.Under the optimal concentration of 4wt%,the device shows pure green emission at516nm with a chromaticity coordinate of（0.30,0.59）as well as a high brightness of 19900cd/m2 and a high efficiency of 10.1cd/A,which are better than 11490cd/m2 and 4.2cd/A obtained in the undoped device.