Organic electroluminescent devices

Abstract

An organic electroluminescent (EL) device comprising at least one luminescent layer of an organic compound, the luminescent layer being positioned between a cathode electrode and an anode electrode opposed to the cathode electrode, and an organic layer positioned adjacent to the cathode electrode, in which the organic layer is constituted from an organic metal complex compound containing at least one of alkali metal ions, alkali earth metal ions and rare earth metal ions, and the cathode electrode is constituted from a metal capable of reducing the metal ion in the complex compound, in vacuum, to the corresponding metal. The cathode electrode can be formed from a low cost and stable metal which is well-known as the wiring material. The EL device ensures a diminished energy barrier in an electron injection from the cathode electrode into the luminescent layer, a lowered driving voltage, and a high efficiency and luminescence.

What is claimed is:  
     
         1 . An organic electroluminescent device comprising: 
 at least one luminescent layer constituted from an organic compound, the luminescent layer being positioned between a cathode electrode and an anode electrode opposed to the cathode electrode; and    an organic layer positioned adjacent to said cathode electrode,    in which said organic layer is constituted from an organic metal complex compound containing at least one member selected from the group consisting of an alkali metal ion, an alkali earth metal ion and a rare earth metal ion, and    said cathode electrode comprises a metal capable of reducing the metal ion contained in said complex compound, in vacuum, to the corresponding metal.    
     
     
         2 . The organic electroluminescent device according to  claim 1 , in which the metal used in said cathode electrode is any one of aluminum, zirconium, titanium, yttrium, scandium and silicon.  
     
     
         3 . The organic electroluminescent device according to  claim 1 , in which the metal used in said cathode electrode is an alloy containing at least one of aluminum, zirconium, titanium, yttrium, scandium and silicon.