Bright white organic light-emitting diode

A very bright white organic light-emitting diode (OLED) was realized by using a bright blue-emitting layer, 1,7-diphenyl-4-biphenyl-3,5-dimethyl-1,7-dihydrodipyrazolo[3,4-b;4('),3(')-e]pyridine (PAP-Ph), together with a 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyry)-4H-pyran (DCM)-doped Alq [tris(8-hydroxyquinolinato) aluminum (III)] layer to provide blue, red, and green emission for color mixing. By appropriately controlling the layer thickness, the white light OLED achieved good performance of 24 700 cd/m(2) at 15 V, 1.93 lm/W at 6.5 V, and > 300 cd/m(2) at 7.7 mA/cm(2). The Commission Internationale de l'Eclairage coordinates of the emitted light are quite stable at voltages from 6 to 12 V, ranging from (0.35, 0.34) to (0.34, 0.35). (C) 2001 American Institute of Physics.