# US 2014/0196777 A1 · Solar cell and method for manufacturing the same

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0196777 A1
- Document ID: US20140196777A1
- Status: Published application
- Kind: A1
- Application number: 14/151,345
- Filed: 2014-01-09
- Published: 2014-07-17
- Earliest claimed: 2013-01-16
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Dohwan YANG; Juhong YANG; Ilhyoung JUNG; Jinah KIM
- Web page: https://patentgrep.com/patent/US20140196777A1

## CPC

- H10F 10/13: Photovoltaic cells having absorbing layers comprising graded bandgaps
- H10F 10/146: {Back-junction photovoltaic cells, e.g. having interdigitated base-emitter regions on the back side}
- H10F 71/121: {The active layers comprising only Group IV materials}
- H10F 71/128: {Annealing}
- H10F 77/311: {for photovoltaic cells}
- Y02E 10/547: Monocrystalline silicon PV cells
- 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
- 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

A solar cell and a method for manufacturing the solar cell are discussed. An embodiment of the method includes forming an emitter region containing impurities of a second conductive type opposite a first conductive type at a back surface of a semiconductor substrate containing impurities of the first conductive type, forming a passivation layer paste containing impurities of the first conductive type on the emitter region, selectively performing a thermal process on a first partial area of the passivation layer paste to form a back surface field region containing impurities of the first conductive type at a partial area of the emitter region, forming a plurality of openings in partial areas of the passivation layer paste to form a passivation layer, forming a first electrode connected to the emitter region, and forming a second electrode connected to the back surface field region.

## Claims

### Claim 1

A method for manufacturing a solar cell comprising:
forming an emitter region containing impurities of a second conductive type opposite a first conductive type at a back surface of a semiconductor substrate containing impurities of the first conductive type;
forming a passivation layer paste containing impurities of the first conductive type on the emitter region;
selectively performing a thermal process on a first partial area of the passivation layer paste to form a back surface field region containing impurities of the first conductive type at a partial area of the emitter region;
forming a plurality of openings in a second partial area of the passivation layer paste positioned on the emitter region and a third partial area of the passivation layer paste positioned on the back surface field region to form a passivation layer;
forming a first electrode connected to the emitter region; and
forming a second electrode connected to the back surface field region.

### Claim 2 (depends on 1)

The method of claim 1, wherein in the forming of the passivation layer paste, a concentration of the impurities of the first conductive type contained in the passivation layer paste is higher than a concentration of the impurities of the second conductive type contained in the emitter region.

### Claim 3 (depends on 1)

The method of claim 1, wherein the passivation layer paste contains aluminum oxide (AlOx).

### Claim 4 (depends on 1)

The method of claim 1, wherein in the forming of the passivation layer paste, a formation thickness of the passivation layer paste is about 10 nm to 25 nm.

### Claim 5 (depends on 1)

The method of claim 1, wherein the forming of the back surface field region includes diffusing the impurities of the first conductive type contained in the passivation layer paste into the partial area of the emitter region by selectively irradiating a laser beam onto the partial area of the passivation layer paste to form the back surface field region.

### Claim 6 (depends on 1)

The method of claim 1, wherein the emitter region is formed at a process temperature of 800° C. to 900° C.

### Claim 7 (depends on 6)

The method of claim 6, wherein the forming of the emitter region includes diffusing impurities of the second conductive type into the back surface of the semiconductor substrate using a process gas containing impurities of the second conductive type in a diffusion furnace.

### Claim 8 (depends on 7)

The method of claim 7, wherein the process gas includes POCl3 gas.

### Claim 9 (depends on 5)

The method of claim 5, wherein the forming of the plurality of openings in the passivation layer paste includes selectively irradiating the laser beam onto the second partial area of the passivation layer paste positioned on the emitter region and the third partial area of the passivation layer paste positioned on the back surface field region to form the plurality of openings.

### Claim 10 (depends on 9)

The method of claim 9, wherein a power of the laser beam used to form the plurality of openings in the passivation layer paste is greater than a power of the laser beam used to form the back surface field region.

### Claim 11 (depends on 1)

The method of claim 1, wherein the forming of the plurality of openings in the passivation layer paste includes:
forming a mask having a plurality of openings on the passivation layer paste; and
etching the first and second partial areas of the passivation layer paste exposed through the plurality of openings of the mask to form the plurality of openings in the passivation layer paste.

### Claim 12

A solar cell comprising:
a semiconductor substrate containing impurities of a first conductive type;
an emitter region which is positioned at a partial area of a back surface of the semiconductor substrate and contains impurities of a second conductive type opposite the first conductive type;
a back surface field region which is positioned at a remaining partial area of the back surface of the semiconductor substrate and contains impurities of the first conductive type at a concentration higher than the semiconductor substrate;
a passivation layer which is positioned on the emitter region and the back surface field region, has a plurality of openings exposing the emitter region and the back surface field region, and contains impurities of the first conductive type;
a first electrode connected to the emitter region; and
a second electrode connected to the back surface field region.

### Claim 13 (depends on 12)

The solar cell of claim 12, wherein the passivation layer contains aluminum oxide (AlOx).

### Claim 14 (depends on 12)

The solar cell of claim 12, wherein a thickness of the passivation layer is 10 nm to 25 nm.

### Claim 15 (depends on 12)

The solar cell of claim 12, wherein a concentration of the impurities of the first conductive type contained in the passivation layer is higher than a concentration of the impurities of the second conductive type contained in the emitter region.