Solar cell electrode
View Patent ↗A method of manufacturing a solar cell electrode comprising steps of: preparing a semiconductor substrate, applying a conductive paste onto the light receiving side of the semiconductor substrate, wherein the conductive paste comprises (i) a conductive powder, (ii) a glass frit, (iii) an organic polymer comprising an elastomer and (iv) an organic solvent; and firing the applied conductive paste.
1. A method of manufacturing a fine line solar cell electrode comprising steps of:
preparing a semiconductor substrate,
applying a conductive paste onto the light receiving side of the semiconductor substrate, wherein the conductive paste comprises (i) a conductive powder, (ii) a glass frit, (iii) an organic polymer comprising an elastomer and (iv) an organic solvent, wherein the elastomer is thermoplastic, wherein the elastomer is selected from the group consisting of acrylic elastomer, ethylene acrylic elastomer, polyisoprene elastomer, styrene elastomer, polyester elastomer, butadiene elastomer, polyisobutylene elastomer, polyisobutylene-isoprene elastomer, nitrile-butadiene elastomer, polynitrile elastomer, ethylene-propylene elastomer, ethylene propylene diene elastomer, polyurethane-polyether block elastomer, polyamide-polyether block copolymer, siloxane elastomers, ethylene-propylene elastomer, isoprene elastomer, nitrile elastomer, natural elastomer, poly(ethylene-co-methyl acrylate) elastomer and a mixture of said elastomers, wherein the elastomer is 6 to 90 wt % based on the weight of the organic polymer; and
firing the applied conductive paste to form the fine line solar cell electrode with a width of 10 to 60 μm.
2. The method of claim 1 , wherein the elastomer has glass transition temperature of −5 to −50° C.
3. The method of claim 1 , wherein mooney viscosity (ML 1+4 ) at 100° C. of the elastomer is 10 to 50.
4. The method of claim 1 , wherein the organic polymer is 0.01 to 5.0 wt %, based on the weight of the conductive paste.
5. The method of claim 1 , wherein the conductive powder is 40 to 95 wt % and the glass frit is 0.5 to 8 wt %, based on the weight of the conductive paste.
6. The method of claim 1 , wherein the elastomer is a copolymer of ethylene and acrylic acid or a copolymer of ethylene and acrylic acid ester that are further polymerized with a monomer with a cross-linkable group.
7. The method of claim 1 , wherein the fine line solar cell electrode has a width of 20 to 45 μm.
8. The method of claim 1 , wherein the organic polymer further comprises one or more of an ester of hydrogenated rosin, an epoxy resin, a polyester resin, an ethylene-vinyl acetate copolymer, an ethyl cellulose, or a mixture thereof.
9. The method of claim 1 , wherein the viscosity of the conductive paste is 200 to 500 Pa·s.
10. A conductive paste comprising (i) a conductive powder, (ii) a glass frit, (iii) an organic polymer comprising elastomer and (iv) an organic solvent, wherein the elastomer is thermoplastic, wherein the elastomer is selected from the group consisting of acrylic elastomer, ethylene acrylic elastomer, polyisoprene elastomer, styrene elastomer, polyester elastomer, butadiene elastomer, polyisobutylene elastomer, polyisobutylene-isoprene elastomer, nitrile-butadiene elastomer, polynitrile elastomer, ethylene-propylene elastomer, ethylene propylene diene elastomer, polyurethane-polyether block elastomer, polyamide-polyether block copolymer, siloxane elastomers, ethylene-propylene elastomer, isoprene elastomer, nitrile elastomer, natural elastomer, poly(ethylene-co-methyl acrylate) elastomer and a mixture of said elastomers, wherein the elastomer is 6 to 90 wt % based on the weight of the organic polymer and the conductive paste is capable of being formed into a fine line solar cell electrode with a width of 10 to 60 μm.
11. The method of claim 1 , wherein the applying of the conductive paste comprises screen printing.
12. The method of claim 1 , wherein the elastomer is an ethylene acrylic elastomer.
13. The conductive paste of claim 10 , wherein the elastomer is an ethylene acrylic elastomer.
14. The conductive paste of claim 10 , wherein the elastomer is a copolymer of ethylene and acrylic acid or a copolymer of ethylene and acrylic acid ester that are further polymerized with a monomer with a cross-linkable group.
15. The conductive paste of claim 10 , wherein the conductive powder is 40 to 95 wt %, the glass frit is 0.5 to 8 wt %, the organic polymer is 0.01 to 5.0 wt %, the organic solvent is 3.0 to 13.0 wt %, based on the weight of the conductive paste.
16. The conductive paste of claim 10 , wherein the elastomer has a glass transition temperature of −5 to −50° C.
17. The conductive paste of claim 10 , wherein mooney viscosity (ML 1+4 ) at 100° C. of the elastomer is 10 to 50.
18. The conductive paste of claim 10 , wherein the organic polymer further comprises one or more of an ester of hydrogenated rosin, an epoxy resin, a polyester resin, an ethylene-vinyl acetate copolymer, an ethyl cellulose, or a mixture thereof.
19. The conductive paste of claim 10 , wherein the viscosity of the conductive paste is 200 to 500 Pa·s.