Single emitting layer white organic light-emitting device with high color stability to applied voltage
A new type of white organic light-emitting device has been fabricated incorporating a single light-emitting layer of bis(2-methyl-8-quinolinolato) (para-phenylphenolato) aluminum (III) (BAlq) doped with 2,5,8,11-tetra-tert-butylperylene (TBPe) and 5,6,11,12-tetraphenyl-naphthacene (rubrene). The configuration of the device was ITO/PVK:TPD/BAlq:TBPe:rubrene/Alq3/Mg:Ag. By adjusting the proportion of the dopants (TBPe and rubrene) in the light-emitting layer, white light with Commission Internationale de lEclairage (CIE) coordinates of (0.34,0.39) was obtained at an applied voltage of 8V; the change of emission spectra was minimal when the voltage increased from 5 to 20V. The device exhibited a maximum external quantum efficiency of 0.68% and a brightness of 1020cd/m2 at 8V, the brightness increasing to 5723cd/m2 at 17V.
tbpe rubrene cie oled