Photovoltaic cell and method of fabricating the same

• US 20050062041A1
• Filed: 09/24/2004
• Published: 03/24/2005
• Est. Priority Date: 09/24/2003
• Status: Active Grant

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Asaumi, Toshio, Terakawa, Akira
• Granted Patent: US 7,199,395 B2
• Time in Patent Office: Days
• US Class Current: 257/53
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/0747 comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/548 Amorphous silicon PV cells

Abstract

An i-type amorphous silicon film and an anti-reflection film made of amorphous silicon nitride or the like are formed in this order on a main surface of an n-type single-crystalline silicon substrate. On a back surface of the n-type single-crystalline silicon substrate are provided a positive electrode and a negative electrode next to each other. The positive electrode includes an i-type amorphous silicon film, a p-type amorphous silicon film, a back electrode, and a collector electrode formed in this order on the back surface of the n-type single-crystalline silicon substrate. The negative electrode includes an i-type amorphous silicon film, an n-type amorphous silicon film, a back electrode, and a collector electrode formed in this order on the back surface of the n-type single-crystalline silicon substrate.

Claims

1. A photovoltaic cell comprising:

a crystal-based semiconductor having one face and another face;

an intrinsic first amorphous-based semiconductor film;

a second amorphous-based semiconductor film including impurities showing a first conductivity-type;

a first electrode;

a semiconductor layer including impurities showing another conductivity-type different from said one conductivity-type; and

a second electrode, wherein

said first amorphous-based semiconductor film, said second amorphous-based semiconductor film, and said first electrode are formed in this order on a first region of said one face of said crystal-based semiconductor, and

said semiconductor layer and said second electrode are formed in this order on a second region of said one face of said crystal-based semiconductor.

2. The photovoltaic cell according to claim 1, wherein

said crystal-based semiconductor includes impurities showing said one conductivity-type.

3. The photovoltaic cell according to claim 1, wherein

said semiconductor layer is a third amorphous-based semiconductor film including impurities showing said another conductivity-type,

the photovoltaic cell further comprising an intrinsic fourth amorphous-based semiconductor film provided between said crystal-based semiconductor and said third amorphous-based semiconductor film.

4. The photovoltaic cell according to claim 3, wherein

said first amorphous-based semiconductor film on said first region of said crystal-based semiconductor and said fourth amorphous-based semiconductor film on said second region are a continuous common amorphous-based semiconductor film.

5. The photovoltaic cell according to claim 4, wherein said second amorphous-based semiconductor film and said third amorphous-based semiconductor film are provided at a distance from each other,

the photovoltaic cell further comprising a protective layer provided on a surface of said common amorphous-based semiconductor film between said second amorphous-based semiconductor film and said third amorphous-based semiconductor film.

6. The photovoltaic cell according to claim 3, wherein

said first amorphous-based semiconductor film on said first region of said crystal-based semiconductor and said fourth amorphous-based semiconductor film on said second region are formed in contact with each other.

7. The photovoltaic cell according to claim 6, wherein

said second amorphous-based semiconductor film and said third amorphous-based semiconductor film are formed in contact with each other.

8. The photovoltaic cell according to claim 1, wherein

said first region and said second region are provided at a distance from each other,

the photovoltaic cell further comprising a protective layer provided on a surface of said crystal-based semiconductor between said first region and said second region.

9. The photovoltaic cell according to claim 1, wherein

said semiconductor layer is a doped layer in which said second region of said crystal-based semiconductor is doped with impurities showing said another conductivity-type.

10. The photovoltaic cell according to claim 1, wherein

said second amorphous-based semiconductor film is a doped layer in which said first amorphous-based semiconductor film is doped with impurities showing said another conductivity-type.

11. The photovoltaic cell according to claim 1, wherein

substantially the whole of said another face is a light-incident surface.

12. The photovoltaic cell according to claim 1, further comprising an anti-reflection film provided on the another face of said crystal-based semiconductor.

13. The photovoltaic cell according to claim 12, further comprising an intrinsic fifth amorphous-based semiconductor film provided between said another face of said crystal-based semiconductor and said anti-reflection film.

14. A photovoltaic cell comprising:

a crystal-based semiconductor having one face and another face;

an intrinsic first amorphous-based semiconductor film formed on said one face of said crystal-based semiconductor;

a second amorphous-based semiconductor film including impurities showing one conductivity-type;

a third amorphous-based semiconductor film including impurities showing another conductivity-type different from said one conductivity-type;

a first electrode; and

a second electrode, wherein

said second amorphous-based semiconductor film is formed on a first region of said first amorphous-based semiconductor film,

said third amorphous-based semiconductor film is formed on a second region of said first amorphous-based semiconductor film and said second amorphous-based semiconductor film,

said first electrode is formed on said third amorphous-based semiconductor film on top of said first region, and

said second electrode is formed on said third amorphous-based semiconductor film on top of said second region.

15. A photovoltaic cell comprising:

a crystal-based semiconductor having one face and another face;

an intrinsic first amorphous-based semiconductor film;

a second amorphous-based semiconductor film including impurities showing one conductivity-type;

a first electrode;

an intrinsic third amorphous-based semiconductor film;

a fourth amorphous-based semiconductor film including impurities showing another conductivity-type different from said one conductivity-type; and

a second electrode, wherein

said first amorphous-based semiconductor film is formed on a first region of the one face of said crystal-based semiconductor,

said second amorphous-based semiconductor film is formed on said first amorphous-based semiconductor film,

said first electrode is formed on said second amorphous-based semiconductor film,

said third amorphous-based semiconductor film is formed on a second region of said one face of said crystal-based semiconductor and said first electrode,

said fourth amorphous-based semiconductor film is formed on said third amorphous-based semiconductor film, and

said second electrode is formed on said fourth amorphous-based semiconductor film on top of said second region.

16. A method of fabricating a photovoltaic cell comprising the steps of:

forming an intrinsic first amorphous-based semiconductor film on a first region of one face of a crystal-based semiconductor;

forming a second amorphous-based semiconductor film including impurities showing one conductivity-type on said first amorphous-based semiconductor film;

forming a semiconductor layer including impurities showing another conductivity-type different from said one conductivity-type on a second region of said one face of said crystal-based semiconductor;

forming a first electrode on said second amorphous-based semiconductor film; and

forming a second electrode on said semiconductor layer.

17. The method of fabricating a photovoltaic cell according to claim 16, wherein

substantially the whole of the another face of said crystal-based semiconductor film is a light-incident surface.

18. The method of fabricating a photovoltaic cell according to claim 16, further comprising the step of forming an anti-reflection film on the another face of said crystal-based semiconductor.

19. A method of fabricating a photovoltaic cell comprising the steps of:

forming an intrinsic first amorphous-based semiconductor film on one face of a crystal-based semiconductor;

forming a second amorphous-based semiconductor film including impurities showing one conductivity-type on a first region of said first crystal-based semiconductor film;

forming a third amorphous-based semiconductor film including impurities showing another conductivity-type different from said one conductivity-type on a second region of said first amorphous-based semiconductor film and said second amorphous-based semiconductor film;

forming a first electrode on said third amorphous-based semiconductor film on top of said first region; and

forming a second electrode on said third amorphous-based semiconductor film on top of said second region.

20. A method of fabricating a photovoltaic cell comprising the steps of:

forming an intrinsic first amorphous-based semiconductor film on a first region of one face of a crystal-based semiconductor;

forming a second amorphous-based semiconductor film including impurities showing one conductivity-type on said first amorphous-based semiconductor film;

forming a first electrode on said second amorphous-based semiconductor film;

forming an intrinsic third amorphous-based semiconductor film on a second region of said one face of said crystal-based semiconductor and said first electrode;

forming a fourth amorphous-based semiconductor film including impurities showing another conductivity-type different from said one conductivity-type on said third amorphous-based semiconductor film; and

forming a second electrode on said fourth amorphous-based semiconductor film on top of said second region.