| 초록 |
High efficiency green thermally activated delayed fluorescence (TADF) organic light emitting diodes were developed using mixed host emitting layer. A high external quantum efficiency (EQE) was achieved by mixing hole and electron transport host materials for the charge balance. 4,4’-di(9H-carbazol-9-yl)biphenyl and 1,3-bis(N-carbazolyl)benzene were used as hole transport host materials and 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene and 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene(BmPyPb) were used as electron transport materials. A Mixed host device of mCP:BmPyPb doped with (4s,6s)-2,4,5,6-tetra(9H-carbazol-9-yl)isophthalonitrile showed a maximum EQE of 28.6% and power efficiency of 56.6 lm/W. |
