Abstract: The present invention relates to a platinum complex as the following formula (I): Xn (I) wherein X, n, R1, R2, R3,R4, R5, X1, X2, L1, and L2 are defined the same as the specification. The present invention also further provides an organic light-emitting device using the same. The complexes of the present invention exhibit enhanced emission quantum yields, and short phosphorescence radiative lifetimes in the range of several microseconds so as to be applied in high efficiency OLEDs.

Abstract: The present invention discloses a phosphorescent tris-chelated transition metal complex comprising i) two identical non-conjugated cyclometalated ligands being incorporated into a coordination sphere thereof with a transition metal, and one ligated chromophore being incorporated into the coordination sphere; or ii) one non-conjugated cyclometalated ligand forming a coordination sphere thereof with a transition metal, and two ligated chromophores being incorporated into the coordination sphere, wherein the metal is iridium, platinum, osmium or ruthenium, and the ligated chromophore possesses a relatively lower energy gap in comparison with that of the non-conjugated cyclometalated ligand, the latter afforded an effective barrier for inhibiting the ligand-to-ligand charge transfer process, so that a subsequent radiative decay from an excited state of these transition complexes will be confined to the single ligated chromophore.