High-efficiency white organic light-emitting devices with a non-doped yellow phosphorescent emissive layer

Abstract

Highly efficient phosphorescent white organic light-emitting devices (PHWOLEDs) with a simple structure of ITO/TAPC (40nm)/mCP:FIrpic (20nm, x wt.%)/bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2′] iridium (acetylacetonate) (tbt)2Ir(acac) (y nm)/Bphen (30nm)/Mg:Ag (200nm) have been developed, by inserting a thin layer of non-doped yellow phosphorescent (tbt)2Ir(acac) between doped blue emitting layer (EML) and electron transporting layer. By changing the doping concentration of the blue EML and the thickness of the non-doped yellow EML, a PHWOLED comprised of higher blue doping concentration and thinner yellow EML achieves a high current efficiency of 31.7cd/A and Commission Internationale de l'Eclairage coordinates of (0.33, 0.41) at a luminance of 3000cd/m2 could be observed.