Organic–inorganic heterojunction light emitting diodes based on poly(p-phenylene vinylene)/cadmium sulfide thin films

We report on a solution processed novel electroluminescent heterostructure device consisting of an inorganic semiconductor, CdS, and a polymer emitter, poly(p-phenylene vinylene) (PPV). This configuration provides the advantage of excellent charge transporting properties of an inorganic semiconductor and the high luminescence quantum efficiency of an organic emitter. The electroluminescence spectrum obtained from this hetrostructure device is similar to the emission spectrum of pure PPV. Even with aluminum electrode, we have achieved stable electroluminescence at very low threshold voltage (3 V) and overall quantum efficiency of about 1% in these devices. The device emitted bright electroluminescence radiation (150 cd/m2) at a driving voltage of 10 V under the forward bias condition.

[1]  D. Hammer,et al.  Lifetime of the P-selectin-carbohydrate bond and its response to tensile force in hydrodynamic flow , 1995, Nature.

[2]  M. Bawendi,et al.  Electroluminescence from CdSe quantum‐dot/polymer composites , 1995 .

[3]  Akira J. Ikushima,et al.  Observation of degradation processes of Al electrodes in organic electroluminescence devices by electroluminescence microscopy, atomic force microscopy, scanning electron microscopy, and Auger electron spectroscopy , 1994 .

[4]  Siegfried Karg,et al.  Transient electroluminescence in poly(p-phenylenevinylene) light-emitting diodes , 1994 .

[5]  M. Berggren,et al.  Thermal control of near‐infrared and visible electroluminescence in alkyl‐phenyl substituted polythiophenes , 1994 .

[6]  D. Braun,et al.  Photo- and electroluminescence efficiency in poly(dialkoxy-p-phenylenevinylene) , 1994 .

[7]  Qibing Pei,et al.  Efficient blue electroluminescence from a fluorinated polyquinoline , 1994 .

[8]  F. E. Karasz,et al.  Electroluminescence of pure poly(N‐vinylcarbazole) and its blends with a multiblock copolymer , 1994 .

[9]  A. Alivisatos,et al.  Light-emitting diodes made from cadmium selenide nanocrystals and a semiconducting polymer , 1994, Nature.

[10]  Andreas Greiner,et al.  Electroluminescence from polymer blends and molecularly doped polymers , 1994 .

[11]  Stephen R. Forrest,et al.  Electroluminescence from trap‐limited current transport in vacuum deposited organic light emitting devices , 1994 .

[12]  P. K. Nair,et al.  Conversion of chemically deposited photosensitive CdS thin films to n‐type by air annealing and ion exchange reaction , 1994 .

[13]  R. H. Friend,et al.  Efficient light-emitting diodes based on polymers with high electron affinities , 1993, Nature.

[14]  F. E. Karasz,et al.  Blue-light electroluminescence from p-phenylene vinylene-based copolymers , 1993 .

[15]  Tadashi Kusumoto,et al.  Novel structure of organic electroluminescence cells with conjugated oligomers , 1993 .

[16]  Katsutoshi Nagai,et al.  Organic electroluminescent devices based on molecularly doped polymers , 1992 .

[17]  A. Heeger,et al.  Electroluminescence and electrical transport in poly(3‐octylthiophene) diodes , 1992 .

[18]  A. Heeger,et al.  Flexible light-emitting diodes made from soluble conducting polymers , 1992, Nature.

[19]  R. W. Gymer,et al.  Chemical tuning of electroluminescent copolymers to improve emission efficiencies and allow patterning , 1992, Nature.

[20]  Bruno Ullrich,et al.  Realization of a blue-light-emitting device using poly(p-phenylene)†‡ , 1992 .

[21]  R. N. Marks,et al.  Light-emitting diodes based on conjugated polymers , 1990, Nature.

[22]  A. Heeger,et al.  Visible light emission from semiconducting polymer diodes , 1991 .

[23]  P. S. Vincett,et al.  Electrical conduction and low voltage blue electroluminescence in vacuum-deposited organic films , 1982 .

[24]  W. G. Schneider,et al.  RECOMBINATION RADIATION IN ANTHRACENE CRYSTALS , 1965 .