Photoelectric conversion device

• US 20060090790A1
• Filed: 02/09/2005
• Published: 05/04/2006
• Est. Priority Date: 10/29/2004
• Status: Abandoned Application

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Sakai, Satoshi, Kobayashi, Yasuyuki, Satake, Koji
• Application Number:
  US11/053,667
• Publication Number:
  US 20060090790A1
• Time in Patent Office: Days
• US Class Current: 136/256
• CPC Class Codes: H01L 31/02168 the coatings being antireflective or having enhancing optical properties for the solar cells
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H01L 31/022466 made of transparent conductive layers, e.g. TCO, ITO layers
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

A photoelectric conversion device is composed of a substrate, a lower electrode layer formed to cover the substrate, and a first semiconductor layer formed on the lower electrode. The lower electrode layer includes a first matrix formed of transparent conductive material, and light scattering granules embedded within the first matrix.

Claims

1. A photoelectric conversion device comprising:

a substrate;

a lower electrode layer formed to cover said substrate; and

a first semiconductor layer formed on said lower electrode layer,

wherein said lower electrode layer includes;

a first matrix formed of transparent conductive material, and

light scattering granules embedded within said first matrix.

2. The photoelectric conversion device according to claim 1, wherein said lower electrode layer is in contact with said first semiconductor layer on a contact face, and

wherein said contact face is substantially flat.

3. The photoelectric conversion device according to claim 2, wherein a difference between relative refractive indexes of said first matrix and second light scattering granules is 2.0 or less.

4. The photoelectric conversion device according to claim 2, wherein said light scattering granules are formed of insulating material.

5. The photoelectric conversion device according to claim 2, wherein said light scattering granules are formed of one selected form a group consisting of titanium oxide, diamond, silicon oxide, magnesium fluoride, magnesium oxide, zinc oxide, and lithium tantalate.

6. The photoelectric conversion device according to claim 2, wherein said light scattering granules comprises:

first and second light scattering granules formed of different materials having different relative refractive indexes.

7. The photoelectric conversion device according to claim 2, wherein an average of external dimensions of said light scattering granules ranges from 60 to 2000 nm, where said light scattering granules are each approximated by an ellipsoid having a major axis, and said external dimensions are each defined as being twice the average of a distance between said major axis and a surface of associated one of said light scattering granules.

8. The photoelectric conversion device according to claim 2, wherein said average of said external dimensions of said light scattering granules is equal to or less than 1200 nm.

9. The photoelectric conversion device according to claim 2, wherein said average of said external dimensions of said light scattering granules is equal to or more than 300 nm.

10. The photoelectric conversion device according to claim 2, wherein an average of diameters of said light scattering granules ranges from 60 to 2000 nm, where said diameters are each defined as being twice the average of a distance between a center and a surface of associated one of said light scattering granules.

11. The photoelectric conversion device according to claim 10, wherein said average of said diameters is equal to or less than 1200 nm.

12. The photoelectric conversion device according to claim 10, wherein said average of said diameters is equal to or more than 300 nm.

13. The photoelectric conversion device according to claim 10, wherein a difference between maximum and minimum values of said diameters is equal to or less than 120 nm.

14. The photoelectric conversion device according to claim 2, wherein an average of spacing lengths of said light scattering granules is equal to or less than 4000 nm, where said spacing lengths of said light scattering granules are each defined as being a distance between centers of adjacent two of said light scattering granules.

15. The photoelectric conversion device according to claim 14, wherein said average of said spacing lengths is equal to or less than 2400 nm.

16. The photoelectric conversion device according to claim 2, wherein a ratio δ

_AVE/d_AVE, which is defined as being a ratio of a average spacing length δ

_AVE of said light scattering granules to an average diameter d_AVE, is equal to or less than 20, where said average spacing length δ

_AVE is defined as being the average of spacing lengths of said light scattering granules with said spacing lengths of said light scattering granules each defined as being a distance between centers of adjacent two of said light scattering granules, and said average diameter d_AVE defined as being the average of diameters of said light scattering granules, with said diameters each defined as being twice the average of a distance between a center and a surface of associated one of said light scattering granules.

17. The photoelectric conversion device according to claim 16, wherein said ratio δ

_AVE/d_AVE is equal to or less than 4.

18. The photoelectric conversion device according to claim 14, wherein a difference between maximum and minimum values of said spacing lengths is equal to or less than 120 nm.

19. The photoelectric conversion device according to claim 2, wherein a distance between said light scattering granules and said contact face is equal to or less than 50 nm.

20. The photoelectric conversion device according to claim 2, wherein a distance between said light scattering granules and said contact face is equal to or less than 30 nm.

21. The photoelectric conversion device according to claim 2, wherein said light scattering granules are positioned in contact with said contact face.

22. The photoelectric conversion device according to claim 1, further comprising:

an intermediate layer formed on said first semiconductor layer; and

a second semiconductor layer formed on said intermediate layer,

wherein said intermediate layer includes;

a second matrix formed of transparent conductive material, and

light scattering granules embedded within said second matrix.

23. The photoelectric conversion device according to claim 22, wherein said intermediate layer is in contact with said second semiconductor layer on another contact face, and

wherein said another contact face is substantially flat.

24. The photoelectric conversion device according to claim 1, further comprising:

an upper electrode layer formed to cover said first semiconductor layer,

wherein said upper electrode layer includes;

a third matrix formed of transparent conductive material, and

light scattering granules embedded within said third matrix.

25. The photoelectric conversion device according to claim 1, wherein said first semiconductor layer is formed on selected from a group consisting of silicon, SiC, and SiGe.

26. A photoelectric conversion device comprising:

a substrate;

a first semiconductor layer formed to cover an upper surface of said substrate;

a second semiconductor layer formed to cover an upper surface of said first semiconductor layer; and

an intermediate layer disposed between said first and second semiconductor layers,

wherein said intermediate layer includes;

a matrix formed of transparent conductive material, and

light scattering granules embedded within said matrix.

27. A substrate structure used for a photoelectric conversion device, said substrate structure comprising:

a substrate; and

a lower electrode layer formed to cover said substrate,

wherein said lower electrode layer includes;

a matrix formed of transparent conductive material, and

light scattering granules embedded within said matrix.

28. A method for fabricating a substrate structure used for a photoelectric conversion device, said method comprising:

covering a substrate with a first layer formed of transparent conductive material;

applying a solution containing a precursor of said transparent conductive material and light scattering granules onto said first layer; and

sintering said solution to complete a second layer on said first layer, said second layer includes a matrix and said light scattering granules embedded within said matrix.