Electron-emitting element, fluorescent light-emitting element, and image displaying device

Abstract

A principal object of the present invention is to provide efficiently an electron-emitting element demonstrating performance equal or superior to that attained with the conventional technology. The electron-emitting element of the present invention comprises: (a) a substrate, (b) a lower electrode layer provided on the substrate, (c) an electron-emitting layer provided on the lower electrode layer, and (d) a control electrode layer so disposed as not to be in contact with the electron-emitting layer, wherein the electron-emitting layer comprises an electron-emitting material for emitting electrons in an electric field, (1) the electron-emitting material being a porous body having a 3D-network structure skeleton, (2) the 3D-network structure skeleton being composed on an inner portion and a surface portion, (3) the surface portion comprising an electron-emitting component, (4) the inner portion being occupied by (i) at least one of an insulating material and a semiinsulating material, (ii) an empty space, or (iii) at least one of an insulating material and a semiinsulating material and an empty space.

1 . An electron-emitting element comprising: (a) a substrate, (b) a lower electrode layer provided on said substrate, (c) an electron-emitting layer provided on said lower electrode layer, and (d) a control electrode layer so disposed as not to be in contact with said electron-emitting layer, 
 wherein said electron-emitting layer comprises an electron-emitting material for emitting electrons in an electric field;    (1) said electron-emitting material being a porous body having a 3D-network structure skeleton, (2) the 3D-network structure skeleton being composed of an inner portion and a surface portion, (3) the surface portion comprising an electron-emitting component, (4) the inner portion being occupied by (i) at least one of an insulating material and a semiinsulating material, (ii) an empty space, or (iii) an empty space and at least one of an insulating material and a semiinsulating material.    
     
     
         2 . The electron-emitting element according to  claim 1 , wherein said electron-emitting material is exposed on the surface of said electron-emitting layer.  
     
     
         3 . The electron-emitting element according to  claim 2 , wherein said electron-emitting layer consist of an electron-emitting material for emitting electrons in an electric field.  
     
     
         4 . The electron-emitting element according to  claim 1 , wherein said electron-emitting layer has electric conductivity.  
     
     
         5 . The electron-emitting element according to  claim 1 , wherein said electron-emitting layer is obtained by baking a coating film of a paste containing a powdered electron-emitting material.  
     
     
         6 . The electron-emitting element according to  claim 1 , wherein the substantially entire inner portion is composed of an inorganic oxide.  
     
     
         7 . The electron-emitting element according to  claim 1 , wherein the substantially entire inner portion is composed of an empty space.  
     
     
         8 . The electron-emitting element according to  claim 1 , wherein the electron-emitting component is a carbon material.  
     
     
         9 . The electron-emitting element according to  claim 8 , wherein the carbon material has one or more π bonds.  
     
     
         10 . The electron-emitting element according to  claim 8 , wherein the carbon material contains graphite as the main component.  
     
     
         11 . A fluorescent light-emitting element comprising an anode portion having a fluorescent layer and an electron-emitting element, said anode portion and electron-emitting element being so disposed that the electrons emitted from said electron-emitting element cause said fluorescent layer to emit light, wherein said electron-emitting element is the element according to  claim 1 .  
     
     
         12 . An image displaying device comprising an anode portion having a fluorescent layer and a plurality of electron-emitting elements disposed two-dimensionally, said anode portion and electron-emitting elements being so disposed that the electrons emitted from said electron-emitting elements cause said fluorescent layer to emit light, wherein said electron-emitting element is the element claimed in  claim 1 .  
     
     
         13 . A method for manufacturing an electron-emitting material, (1) the electron-emitting material being a porous body having a 3D-network structure skeleton, (2) the 3D-network structure skeleton being composed on an inner portion and a surface portion, (3) the surface portion comprising an electron-emitting component, (4) the inner portion being composed of (i) at least one of an insulating material and a semiinsulating material, (ii) an empty space, or (iii) an empty space and at least one of an insulating material and a semiinsulating material, 
 wherein the method comprises a step A of obtaining an electron-emitting material composed of a carbon-containing material by adding a carbon material to a gel of an inorganic oxide having a 3D-network structure skeleton.    
     
     
         14 . The manufacturing method according to  claim 13 , further comprising a step of removing the inorganic oxide partially or entirely from the carbon-containing material.  
     
     
         15 . The manufacturing method according to  claim 13 , wherein a dry gel is used as the gel of the inorganic oxide and the step of obtaining a porous body as the carbon-containing material by adding a carbon material to the dry gel is implemented as the step A.  
     
     
         16 . The manufacturing method according to  claim 13 , wherein the carbon precursor contains an organic polymer.  
     
     
         17 . The manufacturing method according to  claim 14 , wherein a carbon precursor contains an organic polymer.  
     
     
         18 . The manufacturing method according to  claim 16 , wherein the organic polymer has one or more carbon-carbon unsaturated bonds.  
     
     
         19 . The manufacturing method according to  claim 16 , wherein the organic polymer has one or more aromatic rings.  
     
     
         20 . The manufacturing method according to  claim 16 , wherein the organic polymer is at least one of phenolic resins, polyimides, and polyacrylonitrile.  
     
     
         21 . A method for manufacturing an electron-emitting material, (1) the electron-emitting material being a porous body having a 3D-network structure skeleton, (2) the 3D-network structure skeleton being composed of an inner portion and a surface portion, (3) the surface portion comprising an electron-emitting component, (4) the inner portion being composed of (i) at least one of an insulating material and a semiinsulating material, (ii) an empty space, or (iii) an empty space and at least one of an insulating material and a semiinsulating material, 
 wherein the method comprises a step B of obtaining an electron-emitting material composed of a carbon-containing material by adding a carbon precursor to a gel of an inorganic oxide having a 3D-network structure skeleton and carbonizing the carbon precursor containing gel thus obtained.    
     
     
         22 . The manufacturing method according to  claim 21 , further comprising a step of removing the inorganic oxide partially or entirely from the carbon precursor containing gel.  
     
     
         23 . The manufacturing method according to  claim 21 , wherein a wet gel is used as the gel of the inorganic oxide and a step of obtaining a porous body as the carbon-containing material by adding a carbon precursor to said wet gel and drying the carbon precursor containing gel thus obtained to obtain a carbon precursor containing dry gel, and then carbonizing said dry gel is carried out as the step B.  
     
     
         24 . The manufacturing method according to  claim 22 , wherein a wet gel is used as the gel of the inorganic oxide and a step of obtaining a porous body as the carbon-containing material by adding a carbon precursor to said wet gel, removing the inorganic oxide partially or entirely from the carbon precursor containing gel thus obtained, and then carbonizing the obtained material is carried out as the step B.  
     
     
         25 . The manufacturing method according to  claim 21 , wherein the carbon precursor contains an organic polymer.  
     
     
         26 . The manufacturing method according to  claim 22 , wherein the carbon precursor contains one or more types of organic polymer.  
     
     
         27 . The manufacturing method according to  claim 25 , wherein the organic polymer has one or more carbon-carbon unsaturated bonds.  
     
     
         28 . The manufacturing method according to  claim 25 , wherein the organic polymer has one or more aromatic rings.  
     
     
         29 . The manufacturing method according to  claim 25 , wherein the organic polymer is at least one of phenolic resins, polyimides, and polyacrylonitrile.