# US 12,015,091 B2 · Conductive paste and method for producing TOPCon solar cell

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- Number: US 12,015,091 B2
- Document ID: US12015091B2
- Status: Granted
- Kind: B2
- Application number: 17/014,412
- Filed: 2020-09-08
- Published: 2022-03-10
- Granted: 2024-06-18
- Earliest claimed: 2020-09-08
- Assignees: Toyo Aluminium Kabushiki Kaisha
- Applicants: Toyo Aluminium Kabushiki Kaisha
- Inventors: Naoya Morishita; Marwan Dhamrin
- Web page: https://patentgrep.com/patent/US12015091B2

## CPC

- H10F 77/211: {for photovoltaic cells}
- B22F 9/008: {Rapid solidification processing}
- H01B 1/24: the conductive material comprising carbon-silicon compounds, carbon or silicon
- H10F 71/128: {Annealing}
- H10F 77/219: {Arrangements for electrodes of back-contact photovoltaic cells}
- Y02E 10/50: Photovoltaic [PV] energy
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

This invention provides a conductive paste and a method for producing a TOPCon solar cell, by which a TOPCon solar cell can be produced by a simple method, and additionally, a TOPCon solar cell can be constructed with excellent conversion efficiency. Specifically, the invention provides a conductive paste for use as a back electrode for TOPCon solar cells, the conductive paste comprising aluminum-silicon alloy particles, an organic vehicle, and a glass powder, the aluminum-silicon alloy particles having a silicon concentration of 25 wt % or more and 40 wt % or less.

## Claims

### Claim 1

A conductive paste for use as a back electrode for a TOPCon solar cell, the conductive paste comprising aluminum-silicon alloy particles, an organic vehicle, and a glass powder, the aluminum-silicon alloy particles having a silicon concentration of 25 wt % or more and 40 wt % or less,
the content of the aluminum-silicon alloy particles in the conductive paste being 50 wt % or more,
the content of the components of the conductive paste other than the aluminum-silicon alloy particles, the organic vehicle, and the glass powder being 5 wt % or less,
the glass powder comprising at least one member selected from the group consisting of lead (Pb), bismuth (Bi), vanadium (V), boron (B), tin (Sn), phosphorus (P), zinc (Zn), and a lead-free glass powder, and
the lead-free glass powder being at least one member selected from the group consisting of bismuth-based, vanadium-based, tin-phosphorus-based, zinc-borosilicate-based, and alkali-borosilicate-based glass powders.

### Claim 2 (depends on 1)

The conductive paste according to claim 1, wherein the aluminum-silicon alloy particles have a volume average particle size of 1 to 10 μm.

### Claim 3 (depends on 1)

A method for producing a TOPCon solar cell by using the conductive paste according to claim 1, the method comprising:
step 1 of applying the conductive paste comprising aluminum-silicon alloy particles to a surface of a silicon substrate on a side opposite to a light-receiving surface side;
step 2 of applying a silver paste composition to a surface of the silicon substrate on the light-receiving surface side; and
step 3 of sintering the silicon substrate at a sintering temperature of 700° C. or higher after steps 1 and 2.

### Claim 4 (depends on 3)

The production method according to claim 3, wherein the sintering temperature in step 3 is 900° C. or lower.