Photovoltaic element, producing method therefor, and solar cell modules

• US 20010054436A1
• Filed: 06/22/2001
• Published: 12/27/2001
• Est. Priority Date: 06/27/2000
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Takabayashi, Akiharu, Mukai, Takaaki, Fukae, Kimitoshi
• Granted Patent: US 6,613,973 B2
• Time in Patent Office: Days
• US Class Current: 136/256
• 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: H01L 31/022475 composed of indium tin oxide [ITO]
• CPC Class Codes: H01L 31/056 the light-reflecting means being of the back surface reflector [BSR] type
• CPC Class Codes: H01L 31/075 the potential barriers being only of the PIN type, e.g. amorphous silicon PIN solar cells
• CPC Class Codes: H01L 31/202 including only elements of Group IV of the Periodic Table
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A photoelectric conversion layer 13, a transparent electrode layer 14, an insulating layer 15, and a back electrode layer 16 are successively formed in this order on a conductive substrate 11 having a through-hole 17 formed therein, and the transparent electrode layer 14 and the back electrode layer 16 are electrically communicated with each other through the through-hole 17 so as to provide a photovoltaic element in which no grid is employed and improve the productivity and the production yield.

Claims

1. A photovoltaic element comprising:

a conductive substrate having a through-hole;

a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate; and

an insulating layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate, wherein the photoelectric conversion layer and the transparent electrode layer are formed continuously from the major surface on the light-receiving face side to at least a part of an inner wall face of the through-hole;

the insulating layer and the back electrode layer are formed continuously from the major surface of the non-light-receiving face side to at least a part of the inner wall face of the through-hole;

the photoelectric conversion layer, the transparent electrode layer, the insulating layer, and the back electrode layer are successively stacked in this order in at least a part of the inner wall face of the through-hole; and

the transparent electrode layer and the back electrode layer are electrically communicated through the through-hole.

2. The photovoltaic element according to

claim 1

, wherein the photoelectric conversion layer is continuously formed from the major surface on the light-receiving face side to at least a part of the major surface of the non-light-receiving face side through the through-hole.

3. The photovoltaic element according to

claim 1

, wherein the conductive substrate is so arranged as to leave burr or burr residues generated following the formation of the through-hole of the conductive substrate mainly on the non-light-receiving face side.

4. The photovoltaic element according to

claim 1

, wherein a shape of the through-hole is approximately circular as viewed from the major surface side and satisfies that T/D is 1 or lower, wherein T denotes a thickness of the conductive substrate and D denotes a hole diameter of the through-hole.

5. The photovoltaic element according to

claim 1

, wherein a shape of the through-hole is approximately rectangular as viewed from the major surface side and satisfies that T/L is 1 or lower, wherein T denotes a thickness of the conductive substrate and L denotes a width of the through-hole in a shorter side.

6. The photovoltaic element according to

claim 1

, wherein a back reflection layer is provided between the conductive substrate and the photoelectric conversion layer and the back reflection layer is formed continuously from the major surface of the light-receiving face side to at least a part of the inner wall face of the through-hole.

7. The photovoltaic element according to

claim 1

, wherein a back reflection layer is provided between the conductive substrate and the photoelectric conversion layer and the back reflection layer is formed continuously from the major surface of the light-reciving face side to at least a part of the major surface on the non-light-receiving face side through the through-hole.

8. The photovoltaic element according to

claim 6

, wherein the back reflection layer is composed of a metal layer and a semiconductor layer.

9. The photovoltaic element according to

claim 1

, wherein the photoelectric conversion layer has any one selected from the group consisting of a PN junction, a PIN junction, a hetero junction and a Schottky barrier.

10. The photovoltaic element according to claim 1, wherein the photoelectric conversion layer is made of an amorphous, crystalline, or their mixture-phase material.

11. The photovoltaic element according to

claim 1

, wherein the photoelectric conversion layer is composed of any one selected from the group consisting of an amorphous silicon-based semiconductor, a microcrystalline silicon-based semiconductor, a polycrystalline silicon-based semiconductor, and polycrystalline compound-based semiconductor.

12. The photovoltaic element according to

claim 1

, wherein the conductive substrate is made of a flexible metal sheet.

24. A solar cell module comprising a photovoltaic elements as claimed in

claim 1

and a sealing material, wherein at least a part of the photovoltaic element is covered with the sealing material.

13. A method of producing a photovoltaic element comprising a conductive substrate having a through-hole, a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate, and an insulating layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate;

the method comprising a first step of successively forming the photoelectric conversion layer and the transparent electrode on the major surface of the light-receiving face side of the conductive substrate and on an inner wall face of the through-hole and a second step of successively forming the insulating layer and the back electrode layer on the major surface of the non-light-receiving face side of the conductive substrate and on the inner wall face of the through-hole.

14. The method according to

claim 13

, further comprising a step of producing the conductive substrate having the through-hole by perforating a through-hole in a conductive substrate, where burr to be generated in through-hole formation is mainly generated on the non-light-receiving face side of the conductive substrate.

15. The method according to

claim 14

, wherein the step of forming the through-hole is a punching step using dies comprising a punch and a die which is conducted by punching the conductive substrate from the light-receiving face side while arranging the punch on the light-receiving face side of the conductive substrate and the die on the non-light-receiving face side.

16. The method according to

claim 14

, wherein the step of forming the through-hole is a laser processing step which is conducted by irradiation of laser beam from the light-receiving face side of the conductive substrate.

17. The method according to

claim 14

, further comprising a step of removing burr generated in the through-hole formation between the step of forming the through-hole and the first step.

18. The method according to

claim 17

, wherein the step of removing the burr is carried out by electrolytic polishing.

19. The method according to

claim 13

, wherein formation of the photoelectric conversion layer in the first step is carried out by a chemical vapor deposition method.

20. The method according to

claim 13

, further comprising a step of selectively removing the transparent electrode layer is inserted between the first step and the second step.

21. The method according to

claim 13

, wherein a short-circuit point removal step of restoring short-circuit fault is inserted between the first step and the second step.

22. The method according to

claim 21

, wherein the short-circuit point removal step is carried out by causing electrolytic reaction by applying voltage between the conductive substrate and a counter electrode in an electrolytic solution.

23. The method according to

claim 13

, wherein formation of the insulating layer in the second step is carried out by a chemical vapor deposition method.

25. A photovoltaic element comprising:

a conductive substrate having a through-hole;

a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of a light-receiving face side of the conductive substrate;

a rectification layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate;

wherein the photoelectric conversion layer and the transparent electrode layer are formed continuously from the major surface of the light-receiving face side to at least a part of an inner wall face of the through-hole;

the rectification layer and the back electrode layer are formed continuously from the major surface of the non-light-receiving face side to at least a part of the inner wall face of the through-hole;

the transparent electrode layer and the back electrode layer are electrically communicated with each other through the through-hole; and

rectification characteristics of the rectification layer is in an inverse direction to a voltage of a photoelectric motive force of the photoelectric conversion layer.

26. The photovoltaic element according to

claim 25

, wherein the photoelectric conversion layer is continuously formed from the major surface of the light-receiving face side to at least a part of the major surface of the non-light-receiving face side through the through-hole.

27. The photovoltaic element according to

claim 25

, wherein the conductive substrate is so arranged as to generate burr or burr residues to be generated in the formation of the through-hole of the conductive substrate mainly on the non-light-receiving face side.

28. The photovoltaic element according to

claim 25

, wherein a shape of the through-hole is approximately circular as viewed from the major surface side and satisfies that T/D is 1 or lower, wherein T denotes a thickness of the conductive substrate and D denotes a hole diameter of the through-hole.

29. The photovoltaic element according to

claim 25

, wherein a shape of the through-hole is approximately rectangular as viewed from the major surface side and satisfies that T/L is 1 or lower, wherein T denotes a thickness of the conductive substrate and L denotes a width of the through-hole in a shorter side thereof.

30. The photovoltaic element according to

claim 25

, further comprising a back reflection layer between the conductive substrate and the photoelectric conversion layer, wherein the back reflection layer is formed continuously from the major surface of the light-receiving face side to at least a part of the inner wall face of the through-hole.

31. The photovoltaic element according to

claim 25

, further comprising a back reflection layer between the conductive substrate and the photoelectric conversion layer, wherein the back reflection layer is formed continuously from the major surface of the light-receiving face side to at least a part of the major surface of the non-light-receiving face side through the through-hole.

32. The photovoltaic element according to

claim 30

, wherein the back reflection layer is composed of a metal layer and a semiconductor layer.

33. The photovoltaic element according to

claim 25

, wherein the rectification layer has any one selected from the group consisting of a PN junction, a PIN junction, a hetero junction and a Schottky barrier.

34. The photovoltaic element according to

claim 25

, wherein the rectification layer is composed of amorphous, crystalline, or their mixture-phase material.

35. The photovoltaic element according to

claim 25

, wherein the rectification layer is composed of any one selected from the group consisting of an amorphous silicon-based semiconductor, a microcrystalline silicon-based semiconductor, a polycrystalline silicon-based semiconductor, and a polycrystalline compound-based semiconductor.

36. The photovoltaic element according to

claim 25

, wherein the photoelectric conversion layer has any one selected from the group consisting of a PN junction, a PIN junction, a hetero junction and a Schottky barrier.

37. The photovoltaic element according to

claim 25

, wherein the photoelectric conversion layer is composed of amorphous, crystalline, or their mixture-phase material.

38. The photovoltaic element according to

claim 25

, wherein the photoelectric conversion layer is composed of any one selected from the group consisting of an amorphous silicon-based semiconductor, a microcrystalline silicon-based semiconductor, a polycrystalline silicon-based semiconductor, and a polycrystalline compound-based semiconductor.

39. The photovoltaic element according to

claim 25

, wherein the conductive substrate is made of a flexible metal sheet.

51. A solar cell module comprising a photovoltaic element as claimed in

claim 25

and a sealing material, wherein at least a part of the photovoltaic element is covered with the sealing material.

40. A method of producing a photovoltaic element comprising a conductive substrate having a through-hole, a transparent electrode layer and a photoelectric conversion layer in this order from a light-receiving face side of the conductive substrate on a major surface of the light-receiving face side of the conductive substrate, and a rectification layer and a back electrode layer in this order from the light-receiving face side on a major surface of a non-light-receiving face side of the conductive substrate;

the method comprising a first step of successively forming the photoelectric conversion layer and the transparent electrode on the major surface of the light-receiving face side of the conductive substrate and on an inner wall face of the through-hole and a second step of successively forming the rectification layer and the back electrode layer on a major surface of a non-light-receiving face side of the conductive substrate and on the inner wall face of the through-hole.

41. The method according to

claim 40

, further comprising a step of producing the conductive substrate having the through-hole by perforating a through-hole in a conductive substrate, wherein the through-hole is formed so as to generate burr to be generated in the through-hole formation mainly on the non-light-receiving face side of the conductive substrate.

42. The method according to

claim 41

, wherein the step of forming the through-hole is a punching step using dies comprising a punch and a die which is conducted by punching the conductive substrate from the light-receiving face side while arranging the punch on the light-receiving face side of the conductive substrate and the die on the non-light-receiving face side.

43. The method according to

claim 41

, wherein the step of forming the through-hole is a laser processing step which is conducted by irradiation of laser beam from the light-receiving face side of the conductive substrate.

44. The method according to

claim 41

, further comprising a step of removing the burr generated in the through-hole formation between the step of forming the through-hole and the first step.

45. The method according to

claim 44

, wherein the step of removing the burr is carried out by electrolytic polishing.

46. The method according to

claim 40

, wherein the formation of the photoelectric conversion layer in the first step is carried out by a chemical vapor deposition method.

47. The method according to

claim 40

, further comprising a step of selectively removing the transparent electrode layer between the first step and the second step.

48. The method according to

claim 40

, further comprising a short-circuit point removal step of restoring short-circuit fault between the first step and the second step.

49. The method according to

claim 47

, wherein the short-circuit point removal step is carried out by causing electrolytic reaction by applying a voltage between the conductive substrate and a counter electrode in an electrolytic solution.

50. The method according to

claim 40

, wherein formation of the rectification layer in the second step is carried out by a chemical vapor deposition method.