Transparent conductive electrode stack containing carbon-containing material

Abstract

A transparent conductive electrode stack containing a work function adjusted carbon-containing material is provided. Specifically, the transparent conductive electrode stack includes a layer of a carbon-containing material and a layer of a work function modifying material. The presence of the work function modifying material in the transparent conductive electrode stack shifts the work function of the layer of carbon-containing material to a higher value for better hole injection into the OLED device as compared to a transparent conductive electrode that includes only a layer of carbon-containing material and no work function modifying material.

1 . A transparent conductive electrode stack comprising:
 a layer of a carbon-containing material comprising a planar sheet of graphene; and   a layer of a work function modifying material located on an exposed surface of the layer of the carbon-containing material.   
     
     
         2 .- 3 . (canceled) 
     
     
         4 . The transparent conductive electrode of  claim 1 , wherein said layer of work function modifying material comprises at least one of a metal oxide, a conductive polymer, a metal, and an array of metal dots. 
     
     
         5 . The transparent conductive electrode of  claim 1 , wherein said layer of work function modifying material comprises a metal oxide selected from the group consisting of MoO 3 , W 2 O 5 , Al 2 O 3 , V 2 O 5  and combinations or multilayers thereof. 
     
     
         6 . The transparent conductive electrode of  claim 1 , wherein said layer of work function modifying material comprises a conductive polymer selected from aromatic compounds containing no heteroatoms, aromatic compounds containing a nitrogen heteroatom, aromatic compounds containing a sulfur heteroatom, polymeric compounds containing double bonds and/or aromatic compounds that also contain double bonds. 
     
     
         7 . The transparent conductive electrode of  claim 6 , wherein said conductive polymer is a polyaniline or poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate). 
     
     
         8 . The transparent conductive electrode of  claim 1 , wherein said layer of work function modifying material comprises a metal film or an array of metal dots, wherein said metal film and said array of metal dots includes as a metal one of Au, Pd, Pt, W, Ag, and Al. 
     
     
         9 . The transparent conductive electrode of  claim 1 , wherein said layer of work function modifying material is located above said layer of carbon-containing material. 
     
     
         10 . An organic light emitting diode (OLED) device comprising:
 a substrate;   a transparent conductive electrode stack located on an exposed surface of the substrate;   a layer of electroluminescent material located above the transparent conductive electrode stack;   a layer of a cathode material located on an exposed surface of the layer of electroluminescent material, wherein said transparent conductive electrode stack comprises a layer of a carbon-containing material comprising a planar sheet of graphene, and a layer of a work function modifying material located on an exposed surface of the layer of carbon-containing material.   
     
     
         11 . The OLED device of  claim 10 , wherein said substrate is transparent and is comprised of glass or a plastic. 
     
     
         12 .- 13 . (canceled) 
     
     
         14 . The OLED device of  claim 10 , wherein said layer of work function modifying material comprises at least one of a metal oxide, a conductive polymer, a metal, and an array of metal dots. 
     
     
         15 . The OLED device of  claim 10 , wherein said layer of work function modifying material comprises a metal oxide selected from the group consisting of MoO 3 , W 2 O 5 , Al 2 O 3 , V 2 O 5  and combinations or multilayers thereof. 
     
     
         16 . The OLED device of  claim 10 , wherein said wherein said layer of work function modifying material comprises a conductive polymer selected from aromatic compounds containing no heteroatoms, aromatic compounds containing a nitrogen heteroatom, aromatic compounds containing a sulfur heteroatom, polymeric compounds containing double bonds and/or aromatic compounds that also contain double bonds. 
     
     
         17 . The OLED device of  claim 16 , wherein said conductive polymer is a polyaniline or poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate). 
     
     
         18 . The OLED device of  claim 10 , wherein said layer of work function modifying material comprises a metal film or an array of metal dots, wherein said metal film and said array of metal dots includes as a metal one of Au, Pd, Pt, W, Ag, and Al. 
     
     
         19 . The OLED device of  claim 18 , wherein said layer of work function modifying material is located above said layer of carbon-containing material. 
     
     
         20 . The OLED device of  claim 10 , wherein said layer of electroluminescent material is selected from the group consisting of polyp-phenylenvinylene) (PPV), poly(naphthalene vinylenes) (PNVs), tris(2-phenyl pyridine)iridium (Ir(ppy) 3 ), and tris (8-oxychinolinato) aluminum (Alq 3 ). 
     
     
         21 . The OLED device of  claim 10 , wherein said layer of cathode material comprises aluminum (Al), calcium (Ca), magnesium (Mg) or a combination thereof. 
     
     
         22 . The OLED device of  claim 10 , wherein said layer of cathode material comprises a stack of LiF and Al. 
     
     
         23 . The transparent conductive electrode stack of  claim 1 , wherein said planar sheet of graphene contacts an entirety surface of said layer of said work function modifying material. 
     
     
         24 . The transparent conductive electrode stack of  claim 1 , wherein said planar sheet of graphene contains four entirely vertical sidewalls, an entirely planar top surface and an entirely planar bottom surface. 
     
     
         25 . The OLED device of  claim 10 , wherein said planar sheet of graphene contacts an entirety surface of said layer of said work function modifying material. 
     
     
         26 . The OLED device of  claim 10 , wherein said planar sheet of graphene contains four entirely vertical sidewalls, an entirely planar top surface and an entirely planar bottom surface.