Discharge electrode

Abstract

Heretofore, silicon nitride film formed by low pressure plasma CVD has been used for an antireflection film of a solar battery. But it is difficult to reduce the production cost of a solar battery, because, in a low pressure process, facility cost and process cost are expensive. As disclosed, a nitride film is formed by atmospheric pressure plasma CVD using dielectric barrier discharge generated by a plasma head where a plurality of plasma head unit parts is installed in parallel to generate plasma by applying electric field or magnetic field via a dielectric member. Stable glow discharge is formed even under atmospheric pressure by dielectric barrier discharge. And nitride film deposition under atmospheric pressure and low cost production of a solar battery is materialized by using dielectric barrier discharge and by reacting different plasmas generated from plasma supply openings laying side-by-side.

1 . A discharge electrode composed of a ceramic member having a hollow portion where an electrode wire is placed without contact with the ceramic member. 
     
     
         2 . The discharge electrode according to  claim 1 , wherein the hollow portion is in vacuum state. 
     
     
         3 . The discharge electrode according to  claim 1 , wherein gas is enclosed in the hollow portion and the gas is noble gas. 
     
     
         4 . The discharge electrode according to  claim 3 , wherein the pressure in the hollow portion is reduced to less than or equal to 250 Torr. 
     
     
         5 . The discharge electrode according to  claim 3 , wherein the noble gas is Ar or Ne. 
     
     
         6 . The discharge electrode according to  claim 1 , wherein one terminal of the electrode wire was connected to a metal foil, the end of the metal foil functions as an external extraction terminal, and the metal foil is sealed in contact with narrowed part of the ceramic member. 
     
     
         7 . The discharge electrode according to  claim 1 , wherein the electrode wire is made of Ni or Ni alloy. 
     
     
         8 . The discharge electrode according to  claim 1 , wherein the electrode wire is made of W including Th or ThO. 
     
     
         9 . The discharge electrode according to  claim 8 , wherein the content of Th is less than or equal to 4 weight %. 
     
     
         10 . The discharge electrode according to  claim 1 , wherein the electrode wire is formed with coil-like shape. 
     
     
         11 . The discharge electrode according to  claim 1 , wherein a layer made of emitter material is formed on the surface of the electrode wire, and the emitter material is material with smaller work function than the material of the electrode. 
     
     
         12 . The discharge electrode according to  claim 11 , wherein the emitter material is material with perovskite-type crystal structure. 
     
     
         13 . The discharge electrode according to  claim 11 , wherein the emitter material is more than or equal to one chemical compound selected from the chemical compound group comprising TiSrO, MgO, TiO. 
     
     
         14 . The discharge electrode according to  claim 11 , wherein the emitter layer is formed by a process wherein material of emitter layer is torn into pieces in a mortar, and resultant powder is solved in water, and the solution mixed with glue is coated on the surface of the electrode wire, and emitter layer is formed by sintering of coated wire. 
     
     
         15 . The discharge electrode according to  claim 11 , wherein the emitter layer is formed by MOCVD. 
     
     
         16 . The discharge electrode according to  claim 6 , wherein the metal foil is made of Mo or Mo alloy. 
     
     
         17 . The discharge electrode according to  claim 4 , wherein the noble gas is Ar or Ne. 
     
     
         18 . The discharge electrode according to  claim 5 , wherein one terminal of the electrode wire was connected to a metal foil, the end of the metal foil functions as an external extraction terminal, and the metal foil is sealed in contact with narrowed part of the ceramic member. 
     
     
         19 . The discharge electrode according to  claim 6 , wherein the electrode wire is made of Ni or Ni alloy. 
     
     
         20 . The discharge electrode according to  claim 7 , wherein the electrode wire is made of W including Th or ThO.