Sensitized electrophosphorescence of infrared emission diode based on copper phthalocyanine by an ytterbium complex

By inserting a layer of (dibenzoylmethanato)(3)-(bathophenanthroline)-ytterbium (Yb-C) between copper phthalocyanine (CuPc) emitting layer and electron transport layer, intense and broadband electroluminescence (EL) were achieved at 930-1300 nm spectral region in a phosphorescent EL device. The intensity and bandwidth are increased by about 50 and 4 times, respectively, compared with the EL device without Yb-C layer. The improvement in the EL intensity and band broadening were attributed to the energy transfer from Yb-C to CuPc and the overlapping of the Yb3+ near-infrared emission band with the CuPc emission band. (c) 2007 American Institute of Physics.