Visible to near-infrared organic light-emitting diodes using phosphorescent materials by solution process

The characteristics of visible to near-infrared OLEDs with co-doping three phosphorescent dyes, iridium (III) bis(2-(4,6-difluorephenyl)pyridinato-N,C(2)') (FIrpic). tris(I-phenylisoquinoline)iridium(III) (Ir(piq)(3)), Pt-tetraphenyltetrabenzoporphyrin (Pt(tpbp)) in poly(N-vinylcarbazole) host as blue, red and near-infrared emitters are investigated. Visible to near-infrared OLEDs covering the wavelength range from 450 to 850 nm were achieved. The device with 11.7 wt.% FIrpic, 0.3 wt.% Ir(piq)(3) and 0.1 wt.% Pt(tpbp) showed white light emission of CIE (0.34, 0.39). The co-doping results in efficient cascade energy transfer from host through Ir complexes. For 0.1 wt.% Pt(tpbp), the optimal device exhibited the maximum output power of 3 mW/cm(2), maximum luminance of 2900 cd/m(2) and the maximum efficiency of 7 cd/A. (C) 2009 Elsevier B.V. All rights reserved.