# US 9,437,768 B2 · Photoelectric conversion device

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

- Number: US 9,437,768 B2
- Document ID: US9437768B2
- Status: Granted
- Kind: B2
- Application number: 13/615,700
- Filed: 2012-09-14
- Published: 2013-04-04
- Granted: 2016-09-06
- Earliest claimed: 2011-09-30
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Yoichiro Numasawa; Yasushi Maeda; Yoshikazu Hiura; Shunpei Yamazaki
- Inventors: Yoichiro Numasawa; Yasushi Maeda; Yoshikazu Hiura; Shunpei Yamazaki
- Web page: https://patentgrep.com/patent/US9437768B2

## CPC

- H10F 10/16: Photovoltaic cells having only PN heterojunction potential barriers
- H10F 10/166: the Group IV-IV heterojunctions being heterojunctions of crystalline and amorphous materials, e.g. silicon heterojunction [SHJ] photovoltaic cells
- H10F 71/121: {The active layers comprising only Group IV materials}
- H10F 77/1226: comprising multiple Group IV elements, e.g. SiC
- 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 photoelectric conversion device with low resistance loss and high conversion efficiency is provided. The photoelectric conversion device includes a first silicon semiconductor layer and a second silicon semiconductor layer between a pair of electrodes. The first silicon semiconductor layer is provided over one surface of a crystalline silicon substrate having one conductivity type and has a conductivity type opposite to that of the crystalline silicon substrate, and the second silicon semiconductor layer is provided on the other surface of the crystalline silicon substrate and has a conductivity type which is the same as that of the crystalline silicon substrate. Further, the first silicon semiconductor layer and the second silicon semiconductor layer each have a carrier concentration varying in the film thickness direction.

## Claims

### Claim 1

A photoelectric conversion device comprising:
a first electrode;
a second electrode;
a crystalline silicon substrate having one conductivity type between the first electrode and the second electrode;
a first silicon semiconductor layer between the crystalline silicon substrate and the first electrode, the first silicon semiconductor layer having a conductivity type opposite to that of the crystalline silicon substrate;
a light-transmitting conductive film between the first silicon semiconductor layer and the first electrode; and
a second silicon semiconductor layer between the crystalline silicon substrate and the second electrode, the second silicon semiconductor layer having the same conductivity type as the crystalline silicon substrate,
wherein the first silicon semiconductor layer comprises a first region, a second region under the first region, and a third region under the second region,
wherein the first silicon semiconductor layer comprises an impurity element imparting a conductivity type,
wherein a concentration of the impurity element is constant in the third region,
wherein a concentration of the impurity element in the second region monotonically increases in a film thickness direction from a third region side to a first region side,
wherein a concentration of the impurity element is constant in the first region, and
wherein the second silicon semiconductor layer is in contact with the second electrode.

### Claim 2 (depends on 1)

The photoelectric conversion device according to claim 1,
wherein the crystalline silicon substrate has n-type conductivity, the first silicon semiconductor layer has p-type conductivity, and the second silicon semiconductor layer has n-type conductivity.

### Claim 3 (depends on 1)

The photoelectric conversion device according to claim 1,
wherein the crystalline silicon substrate is a single-crystal silicon substrate.

### Claim 4

A photoelectric conversion device comprising:
a first electrode;
a second electrode;
a crystalline silicon substrate having one conductivity type between the first electrode and the second electrode;
a first silicon semiconductor layer having a conductivity type opposite to that of the crystalline silicon substrate between the crystalline silicon substrate and the first electrode;
a light-transmitting conductive film between the first silicon semiconductor layer and the first electrode; and
a second silicon semiconductor layer having the same conductivity type as the crystalline silicon substrate between the crystalline silicon substrate and the second electrode,
wherein the second silicon semiconductor layer comprises a first region, a second region over the first region, and a third region over the second region,
wherein the second silicon semiconductor layer comprises an impurity element imparting a conductivity type,
wherein a concentration of the impurity element is constant in the third region,
wherein a concentration of the impurity element in the second region monotonically increases in a film thickness direction from a third region side to a first region side,
wherein a concentration of the impurity element is constant in the first region, and
wherein the second silicon semiconductor layer is in contact with the second electrode.

### Claim 5 (depends on 4)

The photoelectric conversion device according to claim 4,
wherein the crystalline silicon substrate has n-type conductivity, the first silicon semiconductor layer has p-type conductivity, and the second silicon semiconductor layer has n-type conductivity.

### Claim 6 (depends on 4)

The photoelectric conversion device according to claim 4,
wherein a dark conductivity of the first silicon semiconductor layer is greater than or equal to 1×10−10 S/cm and less than or equal to 1×10−5 S/cm.

### Claim 7 (depends on 4)

The photoelectric conversion device according to claim 4,
wherein a dark conductivity of the second silicon semiconductor layer is greater than or equal to 1×10−9 S/cm and less than or equal to 1×10−4 S/cm.

### Claim 8 (depends on 4)

The photoelectric conversion device according to claim 4,
wherein the crystalline silicon substrate is a single-crystal silicon substrate.

### Claim 9

A photoelectric conversion device comprising:
a first electrode;
a second electrode;
a crystalline silicon substrate having one conductivity type between the first electrode and the second electrode;
a first silicon semiconductor layer having a conductivity type opposite to that of the crystalline silicon substrate between the crystalline silicon substrate and the first electrode;
a light-transmitting conductive film between the first silicon semiconductor layer and the first electrode; and
a second silicon semiconductor layer having the same conductivity type as the crystalline silicon substrate between the crystalline silicon substrate and the second electrode,
wherein the first silicon semiconductor layer comprises a first region, a second region under the first region, and a third region under the second region,
wherein the first silicon semiconductor layer comprises a first impurity element imparting a conductivity type,
wherein a concentration of the first impurity element is constant in the third region,
wherein a concentration of the first impurity element in the second region monotonically increases in a film thickness direction from a third region side to a first region side,
wherein a concentration of the first impurity element is constant in the first region
wherein the second silicon semiconductor layer comprises a fourth region, a fifth region over the fourth region, and a sixth region over the fifth region,
wherein the second silicon semiconductor layer comprises a second impurity element imparting a conductivity type,
wherein a concentration of the second impurity element is constant in the sixth region,
wherein a concentration of the second impurity element in the second region monotonically increases in a film thickness direction from a sixth region side to a fourth region side,
wherein a concentration of the second impurity element is constant in the fourth region, and
wherein the second silicon semiconductor layer is in contact with the second electrode.

### Claim 10 (depends on 9)

The photoelectric conversion device according to claim 9,
wherein the first region of the first silicon semiconductor layer is in contact with the light-transmitting conductive film, and
wherein the third region of the first silicon semiconductor layer is in contact with the crystalline silicon substrate.

### Claim 11 (depends on 10)

The photoelectric conversion device according to claim 10,
wherein the fourth region of the second silicon semiconductor layer is in contact with the second electrode, and
wherein the sixth region of the second silicon semiconductor layer is in contact with the crystalline silicon substrate.

### Claim 12 (depends on 9)

The photoelectric conversion device according to claim 9,
wherein the fourth region of the second silicon semiconductor layer is in contact with the second electrode, and
wherein the sixth region of the second silicon semiconductor layer is in contact with the crystalline silicon substrate.

### Claim 13 (depends on 9)

The photoelectric conversion device according to claim 9,
wherein the crystalline silicon substrate has n-type conductivity, the first silicon semiconductor layer has p-type conductivity, and the second silicon semiconductor layer has n-type conductivity.

### Claim 14 (depends on 9)

The photoelectric conversion device according to claim 9, wherein the crystalline silicon substrate is a single-crystal silicon substrate.