Solar cell

Patent metadata

Field	Value
Publication number	US-9627557-B2
Application number	US-201314033653-A
Country	US
Kind code	B2
Filing date	Sep 23, 2013
Priority date	Mar 25, 2011
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

The solar cell ( 1 ) of the present invention is provided with an n-side electrode ( 14 ), a p-side electrode ( 15 ), and a photoelectric conversion unit ( 20 ) having a first main surface ( 20 a ) and a second main surface ( 20 b ). The first main surface ( 20 a ) includes an n-type surface ( 20 an ) and a p-type surface ( 20 ap ). The photoelectric conversion unit ( 20 ) has a semiconductor substrate ( 10 ) and a semiconductor layer ( 12 n ). The semiconductor substrate ( 10 ) has first and second main surfaces ( 10 b, 10 a ). The semiconductor layer ( 12 n ) is arranged on a portion of the first main surface ( 10 b ). The semiconductor layer ( 12 n ) constitutes either the n-type surface ( 20 an ) or the p-type surface ( 20 ap ). The semiconductor layer ( 12 n ) includes a relatively thick portion ( 12 n 1 ) and a relative thin portion ( 12 n 2 ). The n-side electrode ( 14 ) or the p-side electrode ( 15 ) is arranged on at least the relatively thin portion ( 12 n 2 ) of the semiconductor layer ( 12 n ). The solar cell of the present invention, by means of the aforementioned configuration, is able to extend the lifetime of the minor carriers by means of the relatively thick portion ( 12 n 1 ), to maintain low resistance between the semiconductor substrate ( 10 ) and the n-side electrode ( 14 ) by means of the relatively thin portion ( 12 n 2 ), and to increase hole and electron collection efficiency.

First claim

What is claimed is:

1. A solar cell comprising:
a photoelectric conversion unit having a first main surface including an n-type surface and a p-type surface, and a second main surface,
an n-side electrode connected electrically to the n-type surface, and
a p-side electrode connected electrically to the p-type surface, wherein the photoelectric conversion unit comprises:
a crystalline type semiconductor substrate having first and second main surfaces,
an amorphous semiconductor layer arranged on a portion of the first main surface of the photoelectric conversion unit and constituting either the n-type surface or the p-type surface, and
an insulating layer provided on a portion of the amorphous semiconductor layer;

wherein the amorphous semiconductor layer includes a thick portion positioned between the crystalline type semiconductor substrate and the insulating layer and covered with the insulating layer and a thinner portion that is exposed from the insulating layer,
wherein the thinner portion of the amorphous semiconductor layer does not overlap with the insulating layer when seen in a direction orthogonal to the first main surface of the crystalline type semiconductor substrate,
wherein an interface surface between the amorphous semiconductor layer and the crystalline type semiconductor substrate is flat without having a textured structure, and
wherein one of either the n-side electrode or the p-side electrode contacts on at least the thinner portion of the amorphous semiconductor layer.

2. The solar cell according to claim 1 , wherein the amorphous semiconductor layer contains hydrogen.

3. The solar cell according to claim 1 , wherein each of the n-side electrode and the p-side electrode includes a plurality of finger portions extending in a first direction and arranged at intervals in a second direction perpendicular to the first direction,
the thinner portion of the amorphous semiconductor layer being provided beneath the finger portions.

4. The solar cell according to claim 3 , wherein each of the n-side electrode and the p-side electrode further includes a collector portion connected electrically to the plurality of finger portions,
the thinner portion of the amorphous semiconductor layer being provided beneath the collector portion of the n-side electrode.

5. The solar cell according to claim 1 , wherein the photoelectric conversion unit has an additional semiconductor layer arranged in gaps on the first main surface of the crystalline type semiconductor substrate in which the amorphous semiconductor layer is not arranged,
a portion of the additional semiconductor layer covers an edge of the insulating layer, and
the insulating layer is sandwiched by the portion of the additional semiconductor layer and the amorphous semiconductor layer.

6. The solar cell according to claim 5 , wherein the entire first main surface of the crystalline type semiconductor substrate is substantially covered by the amorphous semiconductor layer and the additional semiconductor layer.

7. The solar cell according to claim 1 , wherein the thinner portion and the thick portion of the amorphous silicon layer are outside of the crystalline type semiconductor substrate with reference to the first main surface thereof.

8. A solar cell comprising:
a photoelectric conversion unit having a first main surface including an n-type surface and a p-type surface, and a second main surface,
an n-side electrode connected electrically to the n-type surface, and
a p-side electrode connected electrically to the p-type surface;
wherein the photoelectric conversion unit comprises:
a crystalline type semiconductor substrate having first and second main surfaces,
an amorphous semiconductor layer arranged on a portion of the first main surface of the photoelectric conversion unit and constituting either the n-type surface or the p-type surface, and
an insulating layer provided on a portion of the amorphous semiconductor layer;

wherein the amorphous semiconductor layer includes a thick portion positioned between the crystalline type semiconductor substrate and the insulating layer and covered with the insulating layer and a thinner portion that is exposed from the insulating layer,
wherein the thinner portion of the amorphous semiconductor layer does not overlap with the insulating layer when seen in a direction orthogonal to the first main surface of the crystalline type semiconductor substrate,
wherein an interface surface between the amorphous semiconductor layer and the crystalline type semiconductor substrate is flat without having a textured structure,
wherein one of either the n-side electrode or the p-side electrode contacts on at least the thinner portion of the amorphous semiconductor layer,
wherein the photoelectric conversion unit has an additional semiconductor layer arranged in gaps on the first semiconductor main surface in which the amorphous semiconductor layer is not arranged,
wherein the additional semiconductor layer includes a thick portion and a thinner portion, and
wherein the other of either the n-side electrode or the p-side electrode contacts on at least the thinner portion of the additional semiconductor layer.

9. The solar cell according to claim 8 , wherein the additional semiconductor layer contains hydrogen.

10. The solar cell according to claim 8 , wherein the thinner portion and the thick portion of the amorphous silicon layer are outside of the crystalline type semiconductor substrate with reference to the first main surface thereof.

Assignees

• Sanyo Electric Co
• Panasonic Ip Man Co Ltd

Inventors

• Arimoto Mamoru
• Hirayama Yasuko
• Mishima Takahiro
• Fujita Kazunori

Classifications

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title

• H01L31/0747

  Electricity · mapped topic

• H01L31/022441 Primary

  Electricity · mapped topic

• H01L31/02245

  Electricity · mapped topic

• H01L31/0682

  Electricity · mapped topic