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 930–1300nm 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.