A novel white organic electroluminescent device based on a thin LiF interlayer

A novel white organic electroluminescent device was fabricated by inserting a thin lithium fluoride (LiF) layer in the emitting layer (tris-(8-hydroxyquinoline) aluminum (Alq3)). The electroluminescence device with the configuration indium tin oxide (ITO)/N,N′-diphenyl-N,N′-bis(l-napthyl)-1,1′-biphenyl-4,4′-diamine (NPB; 45 nm)/tris-(8-hydroxyquinoline) aluminum (Alq3; x nm)/LiF (0.3 nm)/Alq3 ((45 − x) nm)/Al (150 nm) showed expanded electroluminescence (EL) spectra. The spectra contain tricolor, so this should be a simple method to realize white light emitting. We also elucidated the mechanism of expanded EL spectra formation and investigated the properties of these devices.