Organic light-emitting device with improved layer structure

Abstract

An organic light emitting device having a cathode, an anode and an organic layer structure disposed between the cathode and the anode, the organic layer structure comprising a hole injection layer doped with a p-type dopant, a hole transport layer, an emissive layer and an electron transport layer doped with an n-type dopant, wherein all of the layers in the organic layer structure are substantially made from the same organic host material. In particular, the organic host material is a bipolar organic material such as a derivative of fused aromatic rings. The emissive layer can be doped with a fluorescent dye or a phosphorescent dye.

1 - 9 . (canceled)  
     
     
         10 . A method for improving a process for fabricating an organic light emitting device, the device comprising a cathode, an anode, and an organic layer structure disposed between the cathode and the anode, the organic layer structure comprising a hole transport layer disposed adjacent to the anode, an electron transport layer disposed adjacent to the cathode and an emissive layer disposed between the hole transport layer and the electron transport layer, said method comprising: 
 providing an organic host material for use in the hole transport layer, the emissive layer and the electron transport layer;    doping the electron transport layer with at least one n-type dopant; and    doping the emissive layer with a luminescent dopant.    
     
     
         11 . The method of  claim 10 , further comprising 
 doping the hole transport layer with at least one p-type dopant.    
     
     
         12 . The method of  claim 10 , wherein the hole transport layer comprises a hole injection layer made substantially from the organic host material disposed adjacent to the anode, said method further comprising: 
 doping the hole injection layer with at least one p-type dopant.    
     
     
         13 . The method of  claim 10 , wherein the luminescent dopant comprises a fluorescent dopant.  
     
     
         14 . The method of  claim 10 , wherein the luminescent dopant comprises a phosphorescent dopant.  
     
     
         15 - 23 . (canceled)