Patent ID: 7727690

Claim:
A random copolymer having an iridium complex and carbazole derivative, represented by the following Formula 4: [Formula 4] wherein a molecular weight of the random co-polymer is 1000 to 900000, x+y is 100, and n is 1 to 10, respectively, and wherein the ligand is selected from the group consisting of structures described in the following Table Ligand Name Structure 2-Phenyl-pyridine 2-p-Tolyl-pyridine 2-(4-Fluoro-phenyl)-pyridine 2-(2,4-Difluoro-phenyl)-pyridine Benzo[α]quinoline 1-Phenylisoquinoline 1-Naphthalen-2-yl-isoquinoline 2-Thiophen-2-yl-pyridine 2-Phenyl-benzothiozole 2-Phenyl-benzoenzooxezole 4-(5-ethylthio)-1H-tetrazol-1-yl)- 2-fluorobenzonitrile 2-Biphenyl-4-yl-pyridine