Efficient White Organic Light-Emitting Diodes with Dual Blue Emitting Layer

Abstract

We have demonstrated efficient phosphorescent white organic light-emitting diodes (PHWOLEDs) by using iridium (III) bis(1-phenyl(quinolinato-N,C2')) acetylacetonate doped in 4,4,4-tris(N-carbazolyl)-triphenylamine as phosphorescent red emitting layer and iridium (III) bis[(4,6-di-fluoropheny)-pyridinato-N,C2] picolinate doped in dual blue-emitting layer (D-BEML), N,N'-dicarbazolyl-3,5-benzene and 2,2',2 ''''-(1,3,5-benzenetryl) tris(1-phenyl)- 1H-benzimidazol, respectively. D-BEML structure have broad exciton formation zone than single BEML. The optimized PHWOLEDs showed an external quantum efficiency of 5.93%, current efficiency of 11.54 cd/A, and Commission Internationale de L'Eclairage coordinates of (0.45, 0.37) at 1000 cd/m(2).