Conductive paste and grid electrode for silicon solar cells

Abstract

A conductive paste for grid electrodes in solar cells includes a conductive component, glass frit, and resin binder, wherein the conductive component is selected from the group consisting of (i) silver particles and metal particles selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co, (ii) alloy particles comprising silver and metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co, and (iii) silver particles and core-shell particles in which a metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co is coated on the surface of silver or copper.

1 . A conductive paste for grid electrodes in solar cells, the conductive paste comprising a conductive component, glass frit, and resin binder, wherein
 the conductive component is selected from the group consisting of:   
       (i) silver particles and metal particles selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co; 
       (ii) alloy particles comprising silver and metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co and 
       (iii) silver particles and core-shell particles in which a metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co is coated on a surface of silver or copper. 
     
     
         2 . A conductive paste for grid electrodes in solar cells according to  claim 1 , wherein the conductive component is silver particles and metal particles are selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co. 
     
     
         3 . A conductive paste for grid electrodes in solar cells according to  claim 2 , wherein the metal particles are palladium particles. 
     
     
         4 . A conductive paste for grid electrodes in solar cells according to  claim 2 , wherein a content of the metal particles is 0.01 to 10 wt %, based on the total amount of the paste. 
     
     
         5 . A conductive paste for grid electrodes in solar cells according to  claim 1 , wherein the conductive component is alloy particles comprising silver and metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co. 
     
     
         6 . A conductive paste for grid electrodes in solar cells according to  claim 5 , wherein the alloy particles are Ag—Pd particles. 
     
     
         7 . A conductive paste for grid electrodes in solar cells according to  claim 5 , wherein a content of the alloy particles is 0.01 to 20 wt %, based on the total amount of the paste. 
     
     
         8 . A conductive paste for grid electrodes in solar cells according to  claim 1 , wherein the conductive component is silver particles and core-shell particles in which a metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co is coated on a surface of silver or copper. 
     
     
         9 . A conductive paste for grid electrodes in solar cells according to  claim 8 , wherein the core-shell particles are particles in which palladium is coated on a surface of silver. 
     
     
         10 . A conductive paste for grid electrodes in solar cells according to  claim 8 , wherein a content of the core-shell particles is 0.01 to 20 wt %, based on the total amount of the paste. 
     
     
         11 . A method for producing a solar cell electrode, comprising the steps of:
 applying a paste according to  claim 1  on at least part of a light-receiving surface of a semiconductor substrate, and   firing the electrode paste.   
     
     
         12 . A method for producing a solar cell electrode according to  claim 11 , wherein the firing step is carried out in a firing furnace in which a width of the a moving belt in the firing furnace is at least 20 cm. 
     
     
         13 . A solar cell electrode formed on a sunlight-receiving surface, comprising as conductive particles (i) silver particles and metal particles selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co, (ii) alloy particles comprising silver and metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co, or (iii) silver particles and core-shell particles in which a metal selected from the group consisting of Pd, Ir, Pt, Ru, Ti, and Co is coated on a surface of silver or copper.