Solar cell metallizations containing metal additive

Patent metadata

Field	Value
Publication number	US-9466738-B2
Application number	US-201113881395-A
Country	US
Kind code	B2
Filing date	Oct 27, 2011
Priority date	Oct 28, 2010
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

Paste compositions, methods of making a paste composition, and methods of making a solar cell contact are disclosed. The paste composition can contain silver, a glass frit, a metal additive and an organic vehicle system. The metal additive is at least one selected from the group consisting of yttrium, an organo-vanadium compound, organo-antimony compound, organo-phosphorus compound, and an organo-yttrium compound. The paste can be used for making a solar cell contact.

First claim

What is claimed is:

1. A method of making a solar cell contact, comprising;
applying a paste to a silicon substrate, the paste comprising:
silver particles at about 50 wt % or more and about 92 wt % or less of the paste composition;
a glass frit portion at about 1 wt % or more and about 15 wt % or less of the paste composition; and
a metal additive selected from the group consisting of vanadyl acetylacetonates present in an amount effective to reduce a resistance of the solar cell contact, wherein the amount of the metal additive is about 0.01 wt % to about 5 wt % of the paste; and

heating the paste to sinter the silver particles and fuse the glass frit.

2. The method of claim 1 , wherein the paste composition comprises the metal additive at about 0.02 wt % or more and about 1 wt % or less of the paste composition.

3. The method of claim 1 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of vanadium alkoxides, vanadyl alkoxides, antimony alkoxides, and yttrium alkoxides.

4. The method of claim 1 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of vanadium acetylacetonates, antimony acetylacetonates, and yttrium acetylacetonates.

5. The method of claim 1 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of metal 2-methylhexanoate, metal 2-ethylhexanoate, and metal 2-propylhexanoate thereof, where the metal is vanadium, antimony, or yttrium.

6. The method of claim 1 , wherein the paste further includes a second metal additive comprising one or more organo-metal compounds selected from the group consisting of a vanadium, antimony, phosphorus, yttrium, cobalt, nickel, zirconium, tin, zinc or lithium organo-metal compound.

7. A paste composition, comprising:
silver at about 50 wt % or more and about 92 wt % or less of the paste composition;
a glass frit portion at about 1 wt % or more and about 15 wt % or less of the paste composition; and
a metal additive selected from the group consisting of vanadyl acetylacetonates in an amount effective to reduce a resistance of a solar cell contact formed from the paste composition, wherein the amount of the metal additive is about 0.01 wt % to about 5 wt % of the paste composition.

8. A solar cell contact formed by firing a paste composition according to claim 7 .

9. The paste composition of claim 7 , wherein the paste composition comprises the metal additive at about 0.02 wt % or more and about 3 wt % or less of the paste composition.

10. The paste composition of claim 7 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of vanadium alkoxides, vanadyl alkoxides, antimony alkoxides, and yttrium alkoxides.

11. The paste composition of claim 7 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of vanadium acetylacetonates, antimony acetylacetonates, and yttrium acetylacetonates.

12. The paste composition of claim 7 , wherein the paste further comprises one or more organo-metal compounds selected from the group consisting of metal 2-methylhexanoate, metal 2-ethylhexanoate, and metal 2-propylhexanoate where the metal is vanadium, antimony, or yttrium.

13. The paste composition of claim 7 , further including a second metal additive comprising one or more organo-metal compounds selected from the group consisting of a cobalt, nickel, zirconium, tin, zinc or lithium organo-metal compound, or mixtures thereof.

14. The paste composition of claim 7 , wherein the silver comprises a mixture of spherical and flake shaped powders.

15. The paste composition of claim 7 , wherein the silver comprises a mixture of irregular shape particles and colloidal silver.

16. The paste composition of claim 7 , wherein said glass frit has the following composition:
PbO 52-88 wt %; SiO 2 0.5-15 wt %; Al 2 O 3 0.5-10 wt %; ZnO 0-22 wt %; Ta 2 O 5 0-8 wt %; ZrO 2 0-10 wt %; P 2 O 5 0-8 wt %; Li 2 O+K 2 O+Na 2 O 0-15 wt %; B 2 O 3 0-12 wt %; and Fe 2 O 3 +Co 2 O 3 +CuO+MnO 2 0-25 wt %, wherein all weight percentages are based upon 100% total weight of the glass frit portion.

17. The paste composition of claim 7 wherein said glass frit portion comprises a mixture of two or more glass frits.

18. The paste composition of claim 7 wherein said glass frit portion is cadmium-free and lead-free.

19. The paste composition of claim 18 , wherein said glass frit portion includes the following composition:
Bi 2 O 3 +SiO 2 30-62 wt %; ZnO 0-34 wt %; TiO 2 0-22 wt %; Li 2 O 0-10 wt %; Na 2 O 0-23 wt %; K 2 O 0-13 wt %; P 2 O 5 0-10 wt %; Sb 2 O 5 +V 2 O 5 0-13 wt %; ZrO 2 0-8 wt %; F 0-5 wt %; and Fe 2 O 3 +Co 2 O 3 +CuO+MnO 2 0-25 wt %, wherein all weight percentages are based upon 100% total weight of the glass frit portion.

20. The paste composition of claim 7 wherein said glass frit portion includes the following composition:
Bi 2 O 3 55-99 wt %; B 2 O 3 1-15 wt %; SiO 2 0-20 wt %; ZnO 0-13 wt %; K 2 O 0-12 wt %; Li 2 O 0-10 wt %; Nb 2 O 5 +Ta 2 O 5 0-10 wt %; and Fe 2 O 3 +Co 2 O 3 +CuO+MnO2 0-25 wt %, wherein all weight percentages are based upon 100% total weight of the glass frit portion.

Assignees

• Yang Yi
• Shaikh Aziz S
• Sridharan Srinivasan
• Heracus Precious Metals North America Conshohocken LLC

Inventors

• Yang Yi
• Shaikh Aziz S
• Sridharan Srinivasan

Classifications

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F10/00

  Individual photovoltaic cells, e.g. solar cells (electrolytic light-sensitive devices, e.g. dye-sensitised solar cells, H01G9/20) · CPC title

• H10F77/211 Primary

  for photovoltaic cells · CPC title

• H10F77/20

  Electrodes · CPC title

• H10F77/00 Primary

  Constructional details of devices covered by this subclass (constructional details of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title