Transparent conductive articles and methods of making same

Abstract

A lightweight, flexible, plastic substrate used to construct displays, including flat panel displays, to package materials and for electro luminescence lamps is coated with at least one layer, such that the substrate has desired barrier and electrode characteristics. The display medium of the flat panel display is protected from oxygen and moisture in order to avoid degradation with the coating. The layer with barrier and electrode characteristics has both a low enough resistance to function as an electrode for the display, and low oxygen and moisture permeability. For lower permeability and/or higher conductivity, multiple alternating layers of barrier materials and conductive materials are applied. The barrier material includes at least one of a thin metallic film, an organic polymer, a thin transparent dielectric, a thin transparent metal nitride, and a thin transparent conductive oxide. The conductive material includes at least one of a thin transparent conductive oxide, a thin transparent metallic film, and a thin transparent metal nitride. Preferably there is a Polymer Multi Layer (PML) processed base coat deposited over the substrate. The base coat produces substrate smoothing, and more importantly, in combination with another layer, the base coat improves vapor barrier properties. In the preferred embodiment, a PML processed top coat barrier layer is deposited before the coating contacts a surface, such as a roller. The PML processed top coat also excludes moisture (water vapor) and atmospheric gases that chemically degrade the device performance.

1 . An article comprising a flexible plastic substrate coated with multiple layers of transparent conductive metal nitride separated by one or more layers of polymer, the article being sufficiently flexible to be processable in a web coater.  
   
   
       2 . An article comprising a flexible plastic substrate coated with multiple layers of transparent conductive metal separated by one or more layers of polymer.  
   
   
       3 . An article comprising a flexible substrate, at least one layer of polymer and an optically enhanced transparent conductive three layer configuration comprising adjacent layers of: 
 a) conductive oxide, metal, and conductive oxide;    b) conductive oxide, metal nitride, and conductive oxide;    c) metal nitride, metal, and metal nitride; or d) conductive oxide, metal, and metal oxide.    
   
   
       4 . An article according to  claim 3  wherein the conductive layers are electrically connected in parallel.  
   
   
       5 . An article according to  claim 3  comprising a conductive oxide layer of one or more of cadmium oxide, tin oxide, indium oxide, zinc oxide, gallium-containing oxide, and magnesium oxide, which oxides may be doped or undoped.  
   
   
       6 . An article according to  claim 3  comprising a metal nitride layer of one or more nitride of a Group III or IV element of the Periodic Table.  
   
   
       7 . A process for fabricating an article comprising: 
 a) providing a flexible plastic substrate, which optionally has a hard coat; and    b) depositing over the substrate multiple layers of transparent conductive oxide that are separated by one or more layers of in-situ polymerized organic monomer.    
   
   
       8 . A process according to  claim 7  further comprising applying a polymeric base coat to smooth the substrate prior to deposition of transparent conductive oxide.  
   
   
       9 . A process according to  claim 7  further comprising heating the substrate during or after deposition of transparent conductive oxide.  
   
   
       10 . A process according to  claim 7  further comprising depositing transparent conductive oxide in a hydrogen-containing plasma.  
   
   
       11 . A process according to  claim 7  wherein the multiple layers are deposited in a single vacuum chamber.  
   
   
       12 . A process according to  claim 7  further comprising electrically connecting the transparent conductive oxide layers in parallel.  
   
   
       13 . A process according to  claim 7  comprising contacting the transparent conductive oxide layers with a roller without causing cracking or crazing of the conductive oxide layers sufficient to reduce conductivity.  
   
   
       14 . A process for fabricating an article comprising: 
 a) providing a flexible plastic substrate; and    b) depositing over the substrate a layer of in-situ polymerized organic monomer and an optically enhanced transparent conductive three layer configuration comprising layers of conductive oxide, metal nitride or dielectric; metal or metal nitride; and conductive oxide, metal nitride or dielectric.    
   
   
       15 . A process according to  claim 14  further comprising electrically connecting the conductive layers in parallel.  
   
   
       16 . An article according to  claim 3  wherein tile transparent conductive three layer configuration comprises adjacent layers of conductive oxide, conductive metal nitride, and conductive oxide.  
   
   
       17 . An article according to  claim 3  wherein the transparent conductive three layer configuration comprises adjacent layers of silicon nitride, metal, and another metal nitride.  
   
   
       18 . An article according to  claim 3  comprising: 
 a) a first transparent conductive three layer configuration and    b) a layer of transparent conductive oxide or a second transparent conductive three layer configuration    separated by one or more layers of polymer.    
   
   
       19 . An article according to  claim 1  wherein the article is roll-to-roll processable.