Method of manufacturing a solar cell by texturing a principal surface using an alkaline solution

Patent metadata

Field	Value
Publication number	US-9419168-B2
Application number	US-201414477965-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Mar 8, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A method of manufacturing a solar cell including a crystalline semiconductor substrate, includes: etching or washing at least part of a first principal surface of the substrate by treatment with an aqueous alkaline solution; and depositing a p-type semiconductor layer containing boron on at least part of a second principal surface of the substrate before the treatment with the aqueous alkaline solution.

First claim

The invention claimed is:

1. A method of manufacturing a solar cell including a substrate made of a crystalline semiconductor material, comprising:
depositing a p-type semiconductor layer containing boron on at least part of a first principal surface of the substrate, thereby protecting the at least part of the first principal surface to a subsequent etching or washing step;
etching or washing at least part of a second principal surface of the substrate by subjecting the at least part of the second principal surface to a treatment with an aqueous alkaline solution;
patterning the p-type semiconductor layer by removing a part of the p-type semiconductor layer after the treatment with the aqueous alkaline solution; and
forming electrodes on the pattered p-type semiconductor layer and on an exposed area that is exposed through the removed part of the p-type semiconductor layer, respectively, and
forming a semiconductor junction,
wherein
the semiconductor junction forming step comprises:
removing the p-type semiconductor layer; and

forming a new semiconductor layer containing boron at a lower concentration than that in the p-type semiconductor layer, on the first principal surface to form the semiconductor junction, after the removing step.

2. The method according to claim 1 , wherein the etching or washing step is a step of anisotropically etching the at least part of the second principal surface of the substrate with the aqueous alkaline solution.

3. The method according to claim 1 , wherein the solar cell is a back contact solar cell.

4. The method according to claim 1 , wherein silicon nitride film is not used to protect the substrate from the etching or washing step.

5. A method of manufacturing a solar cell including a substrate made of a crystalline semiconductor material, comprising:
depositing a p-type amorphous silicon layer containing boron on at least part of a first principal surface of the substrate, thereby protecting the at least part of the first principal surface to a subsequent etching or washing step;
etching or washing at least part of a second principal surface of the substrate by subjecting the at least part of the second principal surface to a treatment with an aqueous alkaline solution; and
patterning the p-type amorphous silicon layer by removing a part of the p-type amorphous silicon layer after the treatment with the aqueous alkaline solution; and
forming electrodes on the pattered p-type amorphous silicon layer and on an exposed area that is exposed through the removed part of the p-type amorphous silicon layer, respectively; and
forming a semiconductor junction,

wherein the semiconductor junction forming step comprises:
removing the p-type amorphous silicon layer; and
forming a new semiconductor layer on the first principal surface to form the semiconductor junction, after the removing step,

wherein
the new semiconductor layer contains boron, and
a boron concentration in the new semiconductor layer is lower than a boron concentration in the p-type amorphous silicon layer.

6. The method according to claim 5 , wherein the etching or washing step is a step of anisotropically etching the at least part of the second principal surface of the substrate with the aqueous alkaline solution.

7. The method according to claim 5 , wherein the solar cell construction is a back contact solar cell.

8. The method according to claim 5 , wherein silicon nitride film is not used to protect the substrate from the etching or washing step.

Assignees

• Sanyo Electric Co
• Panasonic Ip Man Co Ltd

Inventors

• Nakasu Masato
• Sotani Naoya
• Kirihata Yutaka

Classifications

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• H10F77/707

  of the substrates or of layers on substrates, e.g. textured ITO layer on a glass substrate · CPC title

• H10F77/219 Primary

  Arrangements for electrodes of back-contact photovoltaic cells · CPC title

• H10F77/148

  Shapes of potential barriers · CPC title

• H10F10/166

  the Group IV-IV heterojunctions being heterojunctions of crystalline and amorphous materials, e.g. silicon heterojunction [SHJ] photovoltaic cells · CPC title