IMPROVING THE PERFORMANCE OF PHOSPHORESCENT BASED WHITE POLYMER LIGHT EMITTING DEVICES USING IRIDIUM COMPLEXES

Polymer White-light-emitting devices WPLEDs with single layer structures are fabricated by the spincoating method. The device structure used here is indium-tin-oxide(ITO)/polyethylene dioxythiophene(PEDOT:PSS)/polymer blend/Ca/Al, whose blend consists poly N-vinylcarbazole(PVK) hole transporting host polymer, an electron transporting materials 2-4-biphenylyl-5-tert-butylphenyl1,3,4-oxadiazole(PBD), doped with blue emitting and orange light emitting Ir complexes. The white light emission with CIE coordinates of (0.33, 0.36) is achieved in a large voltage range, the maximal luminance efficiency of 1.8 cd/A is obtained at 6V, and the maximal brightness is 3000 cd/m2 at 9 V.