Solar cell

• US 5,330,584 A
• Filed: 10/13/1992
• Issued: 07/19/1994
• Est. Priority Date: 10/17/1991
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hisamatsu, Tadashi, Matsutani, Toshinobu, Saga, Tatsuo
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US07/959,908
• Time in Patent Office: 644 Days
• Field of Search: 136/255
• US Class Current: 136/255
• CPC Class Codes: H01L 31/03529 Shape of the potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/0443 comprising bypass diodes integrated or directly associated with the devices, e.g. bypass diodes integrated or formed in or on the same substrate as the photovoltaic cells
• CPC Class Codes: H01L 31/068 the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
• CPC Class Codes: H01L 31/0693 the devices including, apart from doping material or other impurities, only AIIIBV compounds, e.g. GaAs or InP solar cells
• CPC Class Codes: Y02E 10/544 Solar cells from Group III-V materials
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A solar cell includes a first semiconductor region of a P type, a second semiconductor region of an N type in contact with the first semiconductor region so as to form a PN junction therebetween, and a third semiconductor region of a P⁺ type in contact with both the first and second semiconductor regions and having a higher impurity concentration than that of the first semiconductor region.

Claims

1. A solar cell, comprising:

a first semiconductor region of a first conductivity type;

a second semiconductor region of a second conductivity type in contact with said first semiconductor region so as to form a PN junction therebetween;

a third semiconductor region of the first conductivity type in contact with both said first and second semiconductor regions to form a bypass diode, said third semiconductor region having an impurity concentration higher than the impurity concentration of said first semiconductor region; and

an electrode comprising a plurality of spaced apart elements formed on a surface of said second semiconductor region,

wherein said third semiconductor region includes a plurality of island-like regions formed in said second semiconductor region each of said plurality of island-like regions being formed in the spaces between said spaced apart elements of said electrode without contacting said electrode.

2. The solar cell of claim 1, wherein said solar cell is selected from the group consisting of a BSF type and a BSFR type solar cell.

3. The solar cell of claim 1, wherein said semiconductor is selected from the group consisting of silicon and GaAs.

4. The solar cell of claim 1, wherein said first conductivity type is P type and said second conductivity type is N type.

5. The solar cell of claim 1, wherein said island-like regions are of circular cross section each having a diameter of 0.01 mm to 1.0 mm.

6. The solar cell of claim 1, wherein said island-like regions are of quadrilateral cross section with one side having a length of 0.01 mm to 1.0 mm.

7. A solar cell, comprising:

a first semiconductor region of a first conductivity type;

a second semiconductor region of a second conductivity type in contact with said first semiconductor region so as to form a PN junction therebetween;

a third semiconductor region of the first conductivity type in contact with both said first and second semiconductor regions to form a bypass diode, said third semiconductor region having an impurity concentration higher than the impurity concentration of said first semiconductor region; and

an electrode comprising a plurality of spaced apart elements formed on a surface of said second semiconductor region,

wherein said third semiconductor region comprises a plurality of island-like regions formed along a major portion of the periphery of said second semiconductor region and is formed without contacting said electrode.

8. The solar cell of claim 7 wherein said solar cell is selected from the group consisting of a BSF and BSFR type solar cell.

9. The solar cell of claim 7 wherein said semiconductor is selected from the group consisting of silicon and GaAs.

10. The solar cell of claim 7 wherein said first conductivity type is P type and said second conductivity type is N type.

11. The solar cell of claim 7 wherein said plurality of regions are of quadrilateral cross section with one side having a length of 0.01 mm to 1.0 mm.

12. A solar cell, comprising:

a first semiconductor region of a first conductivity type;

a second semiconductor region of a second conductivity type in contact with said first semiconductor region so as to form a PN junction therebetween;

a third semiconductor region of the first conductivity type in contact with both said first and second semiconductor regions to form a bypass diode, said third semiconductor region having an impurity concentration higher than the impurity concentration of said first semiconductor region; and

electrodes formed on a surface of said second semiconductor region,

wherein said third semiconductor region is formed as a plurality of well-like regions extending from said PN junction into said first semiconductor region and is formed without contacting said electrodes.

13. The solar cell of claim 12 wherein said solar cell is selected from the group consisting of a BSF and BSFR type solar cell.

14. The solar cell of claim 12 wherein said semiconductor is selected from the group consisting of silicon and GaAs.

15. The solar cell of claim 12 wherein said first conductivity type is P type and said second conductivity type is N type.

16. The solar cell of claim 12 wherein said well-like regions are of circular cross section each having a diameter of 0.01 mm to 1.0 mm.

17. The solar cell of claim 12 wherein said well-like regions are quadrilateral cross section with one side having a length of 0.01 mm to 1.0 mm.