Photoelectric conversion device

Patent metadata

Field	Value
Publication number	US-9437768-B2
Application number	US-201213615700-A
Country	US
Kind code	B2
Filing date	Sep 14, 2012
Priority date	Sep 30, 2011
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

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.

First claim

What is claimed is:

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.

2. 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.

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

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.

5. 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.

6. 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.

7. 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.

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

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.

10. 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.

11. 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.

12. 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.

13. 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.

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

Assignees

• Numasawa Yoichiro
• Maeda Yasushi
• Hiura Yoshikazu
• Yamazaki Shunpei
• Semiconductor Energy Lab

Inventors

• Numasawa Yoichiro
• Maeda Yasushi
• Hiura Yoshikazu
• Yamazaki Shunpei

Classifications

• H10F77/1226

  comprising multiple Group IV elements, e.g. SiC · CPC title

• H10F71/121

  The active layers comprising only Group IV materials · 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

• H10F10/00

  Individual photovoltaic cells, e.g. solar cells (electrolytic light-sensitive devices, e.g. dye-sensitised solar cells, H01G9/20) · CPC title

• H10F10/16 Primary

  Photovoltaic cells having only PN heterojunction potential barriers · CPC title