Systems and method for manufacturing solar cell paste

Abstract

Provided in one embodiment is a method of making paste for solar cells. The method can include forcing silver through a feed tube coupled to a hydrodynamic cavitation chamber using an air-driven piston. The method can include subjecting the silver to hydrodynamic cavitation in the hydrodynamic cavitation chamber by using a hydraulic pump to pass the silver sequentially through a primary orifice, a secondary orifice, and a final orifice within the hydrodynamic cavitation chamber to produce the paste for the solar cells. The silver can include up to three unique silver powders having a total particle size distribution from 0.1 microns to 10 microns. A first silver powder can have a first average particle size of 1.5 um, a second silver powder having a second average particle size of 0.5 um, and a third silver powder having a third average particle size of 0.2 um.

What is claimed: 
     
         1 . A solar cell paste manufactured according to a method comprising:
 providing an electrically conductive material;   forcing the electrically conductive material through an orifice of a hydrodynamic cavitation chamber; and   subjecting the electrically conductive material in the hydrodynamic cavitation chamber to a hydrodynamic cavitation process by passing the electrically conductive material sequentially through a primary orifice, a secondary orifice, and a final orifice within the hydrodynamic cavitation chamber to make a composition.   
     
     
         2 . The method of  claim 1 , wherein providing comprises providing the electrically conductive material that includes at least one glass material. 
     
     
         3 . The method of  claim 1 , wherein providing comprises providing the electrically conductive material that comprises at least one of Ag, Pd, Au, Pt, Ni, Cu, Ru, or an alloy thereof. 
     
     
         4 . The method of  claim 1 , wherein providing comprises providing the electrically conductive material that comprises at least one of carbon black, graphene, carbon nanotubes, and graphite. 
     
     
         5 . The method of  claim 1 , wherein forcing comprises forcing the electrically conductive material through the orifice of the hydrodynamic cavitation chamber such that a viscosity of the composition is lower than the electrically conductive material. 
     
     
         6 . The method of  claim 1 , wherein subjecting comprises subjecting the electrically conductive material having a first viscosity to the hydrodynamic cavitation process in the hydrodynamic cavitation chamber by passing the electrically conductive material sequentially through the primary orifice, the secondary orifice, and the final orifice within the hydrodynamic cavitation chamber to make the composition having a second viscosity that is lower than the first viscosity. 
     
     
         7 . The method of  claim 1 , wherein subjecting comprises subjecting the electrically conductive material having a first viscosity to the hydrodynamic cavitation process in the hydrodynamic cavitation chamber by passing the electrically conductive material sequentially through the primary orifice, the secondary orifice, and the final orifice within the hydrodynamic cavitation chamber to make the composition having a second viscosity that is higher than the first viscosity. 
     
     
         8 . The method of  claim 1 , wherein subjecting further comprises:
 heating the electrically conductive material to a temperature between 38° C. and 48° C.; and   pressurizing the electrically conductive material to a pressure between 4,500 pounds per square inch (PSI) and 45,000 PSI.   
     
     
         9 . A composition for solar cell paste having a viscosity of at least 1 Kcps at 25° C., comprising:
 an organic solvent; 
 a polymer material; and 
 particles comprising an electrically conductive material dispersed throughout the composition, the composition having a conductivity less than 2 micro-ohm·cm and a sintering temperature less than 450 C. 
 
     
     
         10 . The composition of  claim 9 , wherein the electrically conductive material comprises at least one of Ag, Pd, Au, Pt, Ni, Cu, Ru, or an alloy thereof. 
     
     
         11 . The composition of  claim 9 , wherein the electrically conductive material comprises at least one of carbon black, graphene, carbon nanotubes, and graphite. 
     
     
         12 . The composition of  claim 9 , wherein the organic solvent comprises at least one of ester alcohol and alpha terpineol. 
     
     
         13 . The composition of  claim 9 , wherein the polymer material comprises at least one of a resin, a thixotropic agent, a lubricant, a plasticizer, and a wax. 
     
     
         14 . The composition of  claim 9 , wherein the composition comprises a first glass material. 
     
     
         15 . The composition of  claim 14 , wherein the first glass material comprises borosilicate. 
     
     
         16 . The composition of  claim 14 , wherein the first glass material has at least one of the following:
 a softening temperature between 400° C. and 460° C.;   a glass transition temperature between 320° C. and 385° C.; and   an average particle size between 0.1 microns and 3 microns.   
     
     
         17 . The composition of  claim 14 , wherein the composition comprises:
 3.5 to 6.0 wt. % of the first glass material;   80 to 88 wt. % of the particles comprising the electrically conductive material;   10.8 to 14.4 wt. % of the organic solvent; and   1.2 to 1.6 wt. % of the polymer material.   
     
     
         18 . The composition of  claim 14 , wherein the composition comprises:
 3.5 to 6.0 wt. % of the first glass material;   65 to 75 wt. % of the particles comprising the electrically conductive material;   18 to 27 wt. % of the organic solvent; and   2 to 3 wt. % of the polymer material.   
     
     
         19 . The composition of  claim 14 , wherein the composition comprises a second glass material that is different from the first glass material. 
     
     
         20 . The composition of  claim 19 , wherein the first glass material has a first transition temperature, wherein the second glass material has a second transition temperature higher than the first transition temperature, and wherein a weight ratio of the first glass material and the second glass material in the composition is 8:1.