Lead-tellurium inorganic reaction systems

Abstract

An inorganic reaction system comprising a lead-tellurium-zinc composition of Formula (I): Pb a —Te b —Zn f -M d -O e , wherein 0<a, b, d, or f≦1, the sum of a, b, d and f is 1, 0≦d≦0.5, 0<f≦0.2, a:b is between about 10:90 and about 90:10, (a+f+d):b is between about 10:90 and about 90:10, M is one or more elements, and e is a number sufficient to balance the Pb, Te, Zn, and M components.

1 . An inorganic reaction system comprising a lead-tellurium-zinc composition of Formula (I):
   Pb a —Te b —Zn f -M d -O e ,
   wherein 0<a, b, d, or f≦1, the sum of a, b, d and f is 1, 0≦d≦0.5, 0<f≦0.2, a:b is between about 10:90 and about 90:10, (a+f+d):b is between about 10:90 and about 90:10, M is one or more elements, and e is a number sufficient to balance the Pb, Te, Zn, and M components.   
     
     
         2 . An inorganic reaction system comprising a lead-tellurium-magnesium composition of Formula (II):
   Pb a —Te b —(Mg w —Ca x —Sr y —Ba z )-M d -O e ,
   wherein 0<a, b, or d≦1, 0≦w, x, y, z≦1, w+x+y+z=c, at least one of w, x, y and z is greater than zero, the sum of a, b, c and d is 1, 0<c≦0.2, 0≦d≦0.5, a:b is between about 10:90 and about 90:10, (a+c+d):b is between about 10:90 and about 90:10, M is one or more elements, and e is a number sufficient to balance the Pb, Te, Mg—Ca—Sr—Ba and M components.   
     
     
         3 . An inorganic reaction system comprising a lead-tellurium-magnesium-zinc composition of Formula (III):
   Pb a —Te b —(Mg w —Ca x —Sr y —Ba z )—Zn f -M d -O e ,
   wherein 0<a, b, d, or f≦1, 0≦w, x, y, z≦1, w+x+y+z=c, at least one of w, x, y, and z is greater than zero, the sum of a, b, c, d and f is 1, 0<c≦0.2, 0<f≦0.2, 0≦d≦0.5, a:b is between about 10:90 and about 90:10, (a+c+f+d):b is between about 10:90 and about 90:10, M is one or more elements, and e is a number sufficient to balance the Pb, Te, Mg—Ca—Sr—Ba, Zn, and M components.   
     
     
         4 . The inorganic reaction system according to  claim 1 , where d is 0≦d≦0.4. 
     
     
         5 . The inorganic reaction system according to  claim 1 , wherein a:b is between about 20:80 and about 80:20. 
     
     
         6 . The inorganic reaction system according to  claim 2 , wherein 0<c≦0.1. 
     
     
         7 . The inorganic reaction system according to  claim 1 , wherein 0<f≦0.1. 
     
     
         8 . The inorganic reaction system according to  claim 1 , wherein the inorganic reaction system is formed from at least about 5 wt % lead-containing compound, preferably at least 8 wt %, and no more than about 45 wt % lead-containing compound, preferably no more than about 40 wt %, and most preferably no more than about 38 wt %, based upon 100% total weight of the inorganic reaction system. 
     
     
         9 . The inorganic reaction system according to  claim 1 , wherein the inorganic reaction system is formed from at least about 20 wt % tellurium-containing compound, preferably at least about 30 wt %, and no more than about 70 wt % tellurium-containing composition, and preferably no more than about 60 wt %, based upon 100% total weight of the inorganic reaction system. 
     
     
         10 . The inorganic reaction system according to  claim 1 , wherein the inorganic reaction system is formed no more than about 15 wt % zinc-containing compound, magnesium-containing compound, or both, and preferably no more than about 10 wt %, based upon 100% total weight of the inorganic reaction system. 
     
     
         11 . The inorganic reaction system according to  claim 1 , wherein M is selected from the group consisting of boron, aluminum, gallium, silicon, germanium, tin, phosphorus, antimony, niobium, tantalum, vanadium, titanium, molybdenum, tungsten, chromium, silver, halides, chalcogenides, alkaline metals, alkaline earth metals, and rare earth metals. 
     
     
         12 . The inorganic reaction system according to  claim 1 , wherein the inorganic reaction system further comprises bismuth. 
     
     
         13 . An electroconductive paste comprising:
 metallic particles;   at least one of the inorganic reaction systems according to  claim 1 ; and   an organic vehicle.   
     
     
         14 . The electroconductive paste composition according to  claim 13 , wherein the paste composition comprises at least about 50 wt % metallic particles, preferably at least about 60 wt %, more preferably at least about 70 wt %, and most preferably at least about 80 wt %, and no more than about 95 wt % of metallic particles, based upon 100% total weight of the paste. 
     
     
         15 . The electroconductive paste composition according to  claim 13 , wherein the metallic particles are selected from the group consisting of silver, aluminum, gold, copper, nickel, and alloys or mixtures thereof, preferably silver. 
     
     
         16 . The electroconductive paste composition according to  claim 13 , wherein the paste composition comprises at least about 0.1 wt % of the IRS system, preferably at least about 0.5 wt %, and no more than about 10 wt %, more preferably no more than about 5 wt %, and most preferably no more than about 3 wt %, based upon 100% total weight of the paste. 
     
     
         17 . The electroconductive paste composition according to  claim 13 , wherein the paste composition comprises at least about 0.01 wt % organic vehicle, and no more than about 50 wt %, preferably no more than about 30 wt %, and most preferably no more than about 20 wt %, based upon 100% total weight of the paste. 
     
     
         18 . The electroconductive paste composition according to  claim 13 , wherein the organic vehicle comprises an organic solvent and one or more of a binder, surfactant, and thixotropic agent, or any combination thereof. 
     
     
         19 . The electroconductive paste composition according to  claim 18 , wherein the organic solvent is selected from the group consisting of carbitol, terpineol, hexyl carbitol, texanol, butyl carbitol, butyl carbitol acetate, dimethyladipate glycol ether, and any combination thereof. 
     
     
         20 . The electroconductive paste composition according  claim 18 , wherein the binder is selected from the group consisting of ethyl cellulose, phenolic resin, polyacrylic acid, polyvinyl butyral, polyester resin, polycarbonate, polyethylene resin, polyurethane resin, rosin derivative, and any combination thereof. 
     
     
         21 . The electroconductive paste composition according to  claim 18 , wherein the surfactant is selected from the group consisting of polyethylene oxide, polyethylene glycol, benzotriazole, poly(ethyleneglycol)acetic acid, lauric acid, oleic acid, capric acid, myristic acid, linoleic acid, stearic acid, palmitic acid, stearate salts, palmitate salts, and any combination thereof. 
     
     
         22 . A solar cell produced by applying an electroconductive paste according to  claim 13  to a silicon wafer and firing the silicon wafer. 
     
     
         23 . The solar cell according to  claim 22 , wherein the electroconductive paste is applied to an antireflective coating on a surface of the silicon wafer. 
     
     
         24 . A solar cell module comprising electrically interconnected solar cells according to  claim 22 . 
     
     
         25 . A method of producing a solar cell, comprising the steps of:
 providing a silicon wafer having a front side and a backside;   applying an electroconductive paste according to  claim 13  to the silicon wafer; and   firing the silicon wafer.   
     
     
         26 . The method of producing a solar cell according to  claim 25 , wherein the electroconductive paste is applied to the front side of the silicon wafer.