# US 5,700,467 A · Amorphous silicon carbide film and photovoltaic device using the same

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- Number: US 5,700,467 A
- Document ID: US5700467A
- Status: Granted
- Kind: A
- Application number: 08/619,327
- Filed: 1996-03-21
- Granted: 1997-12-23
- Earliest claimed: 1995-03-23
- Assignees: Sanyo Electric Co., Ltd.
- Inventors: Masaki Shima; Norihiro Terada
- Web page: https://patentgrep.com/patent/US5700467A

## CPC

- H10F 10/172: comprising multiple PIN junctions, e.g. tandem cells
- H10F 10/17: Photovoltaic cells having only PIN junction potential barriers
- H10F 71/1035: {having multiple Group IV elements, e.g. SiGe or SiC}
- H10F 77/1665: {including Group IV-IV materials, e.g. SiGe or SiC}
- Y02E 10/548: Amorphous 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

In the present invention, the optical band gap Eg (eV) of an amorphous silicon carbide film has the following relationship with the content of hydrogen C.sub.H (at. %) and the content of carbon C.sub.C (at. %) in the film: Eg=a+bC.sub.H /100+cC.sub.C /100, where a, b, and c are respectively in the ranges of 1.54.ltoreq.a.ltoreq.1.60, 0.55.ltoreq.b.ltoreq.0.65, and -0.65.ltoreq.c.ltoreq.-0.55, whereby the defect density in the amorphous silicon carbide film can be significantly reduced.

## Claims

### Claim 1

An amorphous silicon carbide semiconductor, wherein
the optical band gap Eg (eV) of the semiconductor has the following relationship with the content of hydrogen C.sub.H (at. %) and the content of carbon C.sub.C (at. %) in the semiconductor:
Eg=a+bC.sub.H /100+cC.sub.C /100,
where a, b, and c are respectively in the ranges of 1.54.ltoreq.a.ltoreq.1.60, 0.55.ltoreq.b.ltoreq.0.65, and -0.65.ltoreq.c.ltoreq.-0.55.

### Claim 2 (depends on 1)

The amorphous silicon carbide semiconductor according to claim 1, wherein
the content of hydrogen C.sub.H in said semiconductor is in the range of 10 to 30 at. %.

### Claim 3

A photovoltaic device comprising a power generating portion comprising a p-type amorphous semiconductor layer, an i-type amorphous semiconductor layer, and an n-type amorphous semiconductor layer, wherein
said i-type amorphous semiconductor layer comprises an amorphous silicon carbide film whose optical band gap Eg (eV) has the following relationship with the content of hydrogen C.sub.H (at. %) and the content of carbon C.sub.C (at. %) in the film:
Eg=a+bC.sub.H /100+cC.sub.C /100,
where a, b, and c are respectively in the ranges of 1.54.ltoreq.a.ltoreq.1.60, 0.55.ltoreq.b.ltoreq.0.65, and -0.65.ltoreq.c.ltoreq.-0.55.

### Claim 4 (depends on 3)

The photovoltaic device according to claim 3, wherein
the content of hydrogen C.sub.H in said amorphous silicon carbide film is in the range of 10 to 30 at. %.

### Claim 5

A photovoltaic device comprising a power generating portion comprising a p-type amorphous semiconductor layer, an i-type amorphous semiconductor layer, and an n-type amorphous semiconductor layer, wherein
a buffer layer comprising an intrinsic amorphous semiconductor material is provided between said p-type amorphous semiconductor layer and the i-type layer, and
said buffer layer comprises an amorphous silicon carbide film whose optical band gap Eg (eV) has the following relationship with the content of hydrogen C.sub.H (at. %) and the content of carbon C.sub.C (at. %) in the film:
Eg=a+bC.sub.H /100+cC.sub.C /100,
where a, b, and c are respectively in the ranges of 1,54.ltoreq.a.ltoreq.1.60, 0.55.ltoreq.b.ltoreq.0.65, and -0.65.ltoreq.c.ltoreq.-0.55.

### Claim 6 (depends on 5)

The photovoltaic device according to claim 5, wherein
the content of hydrogen C.sub.H in said amorphous silicon carbide film is in the range of 10 to 30 at. %.

### Claim 7 (depends on 5)

The photovoltaic device according to claim 5, wherein
a plurality of power generating portions are laminated.

### Claim 8

A photovoltaic device comprising a plurality of power generating portions laminated together, each portion comprising a p-type amorphous semiconductor layer, an i-type amorphous semiconductor layer, and an n-type amorphous semiconductor layer, wherein
said i-type amorphous semiconductor layer of said power generating portion positioned on the side of light incidence comprises an amorphous silicon carbide film whose optical band gap Eg (eV) has the following relationship with the content of hydrogen C.sub.H (at. %) and the content of carbon C.sub.C (at. %) in the film:
Eg=a+bC.sub.H /100+cC.sub.C /100,
wherein a, b, and c are respectively in the ranges of 1.54.ltoreq.a.ltoreq.1.60, 0.55.ltoreq.b.ltoreq.0.65, and -0.65.ltoreq.c.ltoreq.-0.55.

### Claim 9 (depends on 8)

The photovoltaic device according to claim 8, wherein
the content of hydrogen C.sub.H in said amorphous silicon carbide film is in the range of 10 to 30 at. %.