Efficient and bright blue-emitting phosphorescent materials

Abstract

A new type of ancillary ligand for blue-emitting heteroleptic iridium complexes has been successfully developed. New ligands, 3-(trifluoromethyl)-5-( pyridin-2-yl)-1,2,4-triazolate and 5( pyridin-2-yl)-tetrazolate, show stronger blue-shifting power than that of the picolate of Flrpic [ iridium (III) bis(4,6-difluorophenylpyridinato) picolate]. Organic light-emitting diodes (OLEDs) fabricated with a new complex, Flrtaz [ iridium ( III) bis( 4,6-difluorophenylpyridinato)( 5-(pyridine-2-yl)-1,2,4-triazolate) or FlrN4 [(iridium ( III) bis( 4,6-difluorophenylpyridinato)( 5-(pyridin-2-yl)-tetrazolate], as the blue dopant in the host of mCP [ 1,3- bis(9-carbazolyl) benzene], exhibit near-saturated blue electrophosphorescence with Commision Internale de l'Eclairage (CIEx,y) coordinates of (0.14, 0.18) and ( 0.15, 0.24), respectively.