Molecular Crystals and Liquid Crystals, Vol.530, 230-238, 2010
Properties of Phosphorescence Polymer Light Emitting Diodes with PVK: Ir(ppy)(3): PFO:Ir(pq)(2)acac Emission Layer
Phosphorescence polymer LEDs (PhPLEDs) with the structure of ITO/PED-OT:PSS/PVK:Ir(ppy)(3):PFO:Ir(pq)(2)acac/TPBI/LiF/Al were fabricated to investigate the effects of the doping concentration of Ir(pq)(2)acac on the electrical and optical properties of the devices. PVK(poly-vinylcarbazole) and Ir(ppy)(3) [tris(2-phenylpyridine) iridium(III)] polymers were used as the host and guest materials, respectively. PFO[poly(9,9-dioctylfluorene)] and Ir(pq)(2)(acac) [bis(2-phenyl-1-quinoline)iridiumacetyl acetonate] were also introduced as blue and red component guest materials for the white emission. The concentration ratio of PVK: Ir(ppy)(3):PFO was fixed at 100:2.0:1.0 vol%. The Ir(pq)(2)acac concentration in the emission layer was varied from 1.0 to 5.0 vol%. White PhPLEDs were obtained for the samples with 5.0 vol% of Ir(pq) 2acac, for which the luminance and current density were about 2530 cd/m(2) and 720 mA/cm(2) at 8V, respectively. The CIE color coordinates were x, y = 0.33, 0.33, showing a pure white color.
Keywords:CIE color coordinates;Ir(ppy)(3);Ir(pq)(2)acac;luminance;phosphorescence;polymer light emitting diode;PVK;white emission