Influence of Emissive Hole-Transporting Materials on the Electrical and Luminescent Performance of Highly Efficient White-Light Organic Light-Emitting Diodes

摘要

An emissive hole-transporting material with a dopant was proposed for realizing highly efficient and relatively pure white-light organic light-emitting diode (OLED). The device structure included ITO/N, N′-diphenyl-N, N′-bis(1-naphthyl-phenyl)-(1,1′-biphenyl)-4, 4′-diamine (NPB)/NPB doped with 4-Dicyanomethylene-2-methyl-6-[2-(2, 3, 6, 7-tetra-hydro-1H, 5H-benzo[ij]-quinolizin-8-yl)vinyl]-4H-pyran (DCM2) (NPB:DCM2)/bathocuproine (BCP)/tris-(8-hydroxyquinoline) aluminum (Alq_3)/Mg:Ag. By appropriately controlling the DCM2 doping concentration as well as thickness of the blue-red-emitting layer of NPB:DCM2, the white-light OLED has a relatively stable white color even the operating voltages change from 9 to 18V.