Highly Efficient and Unusual Structure White Organic Light-emitting Devices Based on Phosphorescence Sensitized 5,6,11,12-tetraphenylnaphthacene

摘要

Highly efficient and unusual structures white organic light-emitting devices were fabricated based on phosphorescence sensitized 5,6,11,12-tetraphenylnaphthacene. The device structure was ITO / NPB (30 nm)/CBP: 10% DPVBi (10 nm)/CBP (5 nm) /CBP:x% Ir(ppy)_3 : y% rubrene (20 nm)/ CBP (5 nm)/ CBP: 10% DPVBi (10 nm)/BCP (10 nm)/ Alq_3 (30 nm)/LiF(0.5 nm)/Al, where NPB is N,N '-bis-^s(1-naphthyl)-^sN,N ' -diphenyl -1, 1 '- biphenyl-4,4 '-diamine as a hole transporting layer, CBP 4,4,N,N'-dicarbazolebiphenyl as host,DPVBi is 4,4 '-bis(2,2 -diphenyl vinyl)-1,1 '-biphenyl as blue fluorescent dye, Rubrene is 5,6,11,12,-tetraphenylnaphthacene as fluorescent dye,Ir(ppy)3 is factris (2-phenylpyridine) iridium as phosphorescent sensitizer .BCP is 2,9-dimethyl-4,7-diphenyl-l,10-phenanthroline as hole-blocking layer, and Alq_3 is tris(8-hydroxyquinoline) aluminum as an electron-transporting layer. In this device, phosphorescent emissive layer was sandwiched between two blue fluorescent doped ones. This architecture allowed for resonant energy transfer from both the host singlet and triplet energy levels that minimized exchange energy losses. Thus, a WOLED with a maximum luminous efficiency of 11.63 cd/A, a maximum power efficiency of 7.37 lm/W, a maximum luminance of 31770cd/m~2 , and Commission Internationale de L'Eclairage coordinates of (0.34.0.36) was achieved.