White organic light-emitting devices based on fac tris(2-phenylpyridine) iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

摘要

We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' -biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure isITO/2T-NATA (20 nm)/ NPBX (20 nm)/ CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/ NPBX (5 nm)/DPVBi (30 nm)/ Alq(30nm)/LiF(0.5 nm)/Al. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescentmaterial, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)-N,N' –diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively.When the concentration of Ir (ppy)3 is 6wt%, the maximum luminance is 24960 cd/m2 at an applied voltage of 15 V, and themaximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.