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US 7,030,413 B2Granted
Photovoltaic device with intrinsic amorphous film at junction, having varied optical band gap through thickness thereof
AssigneeSanyo Electric Co., Ltd.
InventorsNoboru Nakamura, Mikio Taguchi, Kunihiro Kawamoto
Life of this patent
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Abstract
In a photovoltaic device comprising a thin intrinsic amorphous semiconductor film inserted in a junction portion of a crystalline semiconductor substrate and an amorphous semiconductor film which have conductive types reverse to each other, an optical band gap of the intrinsic amorphous semiconductor film is expanded on a side in contact with the amorphous semiconductor film.
Claims15
A photovoltaic device comprising:
- a crystalline semiconductor substrate of a first conductivity type, wherein said substrate is a principal power generating layer of said photovoltaic device;
- a non-intrinsic amorphous semiconductor film of said first conductivity type or of a second conductivity type opposite said first conductivity type;
- and
- an intrinsic amorphous semiconductor film having a thickness of 20 to 250 Å and being interposed directly between said substrate and said non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film has a varied optical band gap with a first optical band gap value on a first side of said intrinsic amorphous semiconductor film contacting said substrate and a second optical band gap value greater than said first optical band gap value on a second side of said intrinsic amorphous semiconductor film contacting said non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film comprises at least a first intrinsic amorphous semiconductor layer being an amorphous silicon layer along said first side having said first optical band gap value and a second intrinsic amorphous semiconductor layer along said second side having said second optical band gap value;
- and
- wherein said second intrinsic amorphous semiconductor layer is a layer selected from the group consisting of an amorphous silicon carbide layer, an amorphous silicon oxide layer, and an amorphous silicon nitride layer.
5 more elements
A photovoltaic device comprising:
- a crystalline semiconductor substrate of a first conductivity type, wherein said substrate is a principal power generating layer of said photovoltaic device;
- a non-intrinsic amorphous semiconductor film of a second conductivity type opposite said first conductivity type;
- and
- an intrinsic amorphous semiconductor film having a thickness of 20 to 250 Å and being interposed directly between said substrate and said non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film has a varied optical band gap with a first optical band gap value on a first side of said intrinsic amorphous semiconductor film contacting said substrate and a second optical band gap value greater than said first optical band gap value on a second side of said intrinsic amorphous semiconductor film contacting said non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film comprises at least a first intrinsic amorphous semiconductor layer being an amorphous silicon layer along said first side having said first optical band gap value and a second intrinsic amorphous semiconductor layer along said second side having said second optical band gap value;
- and
- wherein said amorphous silicon layer of said first intrinsic amorphous semiconductor layer is a first amorphous silicon layer containing a first content of hydrogen, and said second intrinsic amorphous semiconductor layer comprises a second amorphous silicon layer containing a second constant of hydrogen greater than said first content of hydrogen.
5 more elements
A photovolteic device comprising:
- a crystalline semiconductor substrate of a first conductivity type, wherein said substrate is a principal power generating layer of said photovoltaic device;
- a first non-intrinsic amorphous semiconductor film of said first conductivity type;
- and
- a first intrinsic amorphous semiconductor film having a thickness of 20 to 250 Å and being interposed directly between a first side of said substrate and said first non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film has a varied optical band gap with a first optical band gap value on a first side of said intrinsic amorphous semiconductor film contacting said substrate and a second optical band gap value greater than said first optical band gap value on a second side of said intrinsic amorphous semiconductor film contacting said non-intrinsic amorphous semiconductor film;
- wherein said intrinsic amorphous semiconductor film comprises at least a first intrinsic amorphous semiconductor layer being an amorphous silicon layer along said first side having said first optical band gap value and a second intrinsic amorphous semiconductor layer along said second side having said second optical ban gap value;
- and
- wherein said amorphous silicon layer of said first intrinsic amorphous semiconductor layer is a first amorphous silicon layer containing a first content of hydrogen, and said second intrinsic amorphous semiconductor layer comprises a second amorphous silicon layer containing a second content of hydrogen greater than said first content of hydrogen.
5 more elements
Dependencies are inferred from the claim text.