# US 12,191,404 B2 · Solar cell having conductive contacts in alignment with recast signatures

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- Number: US 12,191,404 B2
- Document ID: US12191404B2
- Status: Granted
- Kind: B2
- Application number: 17/498,979
- Filed: 2021-10-12
- Published: 2022-01-27
- Granted: 2025-01-07
- Earliest claimed: 2009-12-01
- Assignees: Maxeon Solar Pte. Ltd.
- Applicants: Maxeon Solar Pte. Ltd.
- Inventors: Gabriel Harley; David D. Smith; Peter John Cousins
- Web page: https://patentgrep.com/patent/US12191404B2

## CPC

- H10F 77/935: {for photovoltaic devices or modules}
- H10F 10/146: {Back-junction photovoltaic cells, e.g. having interdigitated base-emitter regions on the back side}
- H10F 77/219: {Arrangements for electrodes of back-contact photovoltaic cells}
- Y02E 10/546: Polycrystalline silicon PV cells
- Y02E 10/547: Monocrystalline silicon PV cells
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The formation of solar cell contacts using a laser is described. A method of fabricating a back-contact solar cell includes forming a poly-crystalline material layer above a single-crystalline substrate. The method also includes forming a dielectric material stack above the poly-crystalline material layer. The method also includes forming, by laser ablation, a plurality of contacts holes in the dielectric material stack, each of the contact holes exposing a portion of the poly-crystalline material layer; and forming conductive contacts in the plurality of contact holes.

## Claims

### Claim 1

A solar cell comprising:
a first dielectric layer above a silicon substrate;
a material layer above the first dielectric layer, the material layer having a first doped region and a plurality of recast signatures;
a second dielectric layer above the material layer; and
a plurality of conductive contacts through the second dielectric layer with each of the plurality of conductive contacts being in alignment with one of the plurality of recast signatures in the material layer.

### Claim 2 (depends on 1)

The solar cell of claim 1, wherein the first dielectric layer comprises a tunnel oxide.

### Claim 3 (depends on 1)

The solar cell of claim 1, the second dielectric layer comprises silicon nitride.

### Claim 4 (depends on 3)

The solar cell of claim 3, further comprising a third dielectric layer disposed between the material layer and the second dielectric layer, the third dielectric layer comprising silicon dioxide.

### Claim 5 (depends on 1)

The solar cell of claim 1, wherein the material layer comprises poly-crystalline silicon.

### Claim 6 (depends on 1)

The solar cell of claim 1, further comprising a second doped region in the material layer.

### Claim 7 (depends on 1)

The solar cell of claim 1, wherein the silicon substrate comprises single-crystalline silicon.

### Claim 8 (depends on 1)

The solar cell of claim 1, wherein the solar cell is a back-contact solar cell.

### Claim 9

A solar cell comprising:
a first dielectric layer disposed on a silicon substrate;
a poly-crystalline silicon layer disposed on the first dielectric layer, the poly-crystalline silicon layer having a doped region and a recast signature in the doped region;
a second dielectric layer above the poly-crystalline silicon layer; and
a plurality of conductive contacts through the second dielectric layer, a conductive contact of the plurality of conductive contacts being in alignment with the recast signature.

### Claim 10 (depends on 9)

The solar cell of claim 9, wherein the first dielectric layer comprises a tunnel oxide.

### Claim 11 (depends on 9)

The solar cell of claim 9, wherein the second dielectric layer comprises silicon nitride.

### Claim 12 (depends on 11)

The solar cell of claim 11, further comprising a third dielectric layer disposed between the poly-crystalline silicon layer and the second dielectric layer, the third dielectric layer comprising silicon dioxide.

### Claim 13 (depends on 9)

The solar cell of claim 9, wherein the silicon substrate comprises single-crystalline silicon.

### Claim 14 (depends on 9)

The solar cell of claim 9, wherein the solar cell is a back-contact solar cell.

### Claim 15

A solar cell comprising:
a first dielectric layer disposed on a silicon substrate;
a poly-crystalline silicon layer disposed on the first dielectric layer, the poly-crystalline silicon layer having a doped region and a plurality of recast signatures;
a dielectric material stack disposed on the poly-crystalline silicon layer; and
a plurality of conductive contacts through the dielectric material stack, each conductive contact of the plurality of conductive contacts being in alignment with a recast signature of the plurality of recast signatures.

### Claim 16 (depends on 15)

The solar cell of claim 15, wherein the dielectric material stack comprises a silicon nitride layer that is disposed on the poly-crystalline silicon layer.

### Claim 17 (depends on 16)

The solar cell of claim 16, wherein the dielectric material stack comprises a silicon dioxide layer that is disposed between the poly-crystalline silicon layer and the silicon nitride layer.

### Claim 18 (depends on 15)

The solar cell of claim 15, wherein the first dielectric layer comprises tunnel oxide that is directly on the silicon substrate.

### Claim 19 (depends on 15)

The solar cell of claim 15, wherein the silicon substrate comprises a single-crystalline substrate.

### Claim 20 (depends on 15)

The solar cell of claim 15, wherein the solar cell is a back-contact solar cell.