Solar cell

• US 10,181,534 B2
• Filed: 03/16/2015
• Issued: 01/15/2019
• Est. Priority Date: 03/17/2014
• Status: Active Grant

• Current Assignee: Jingao Solar Company Limited (JA Solar Technology Co., Ltd.)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Chung, Indo, Shim, Seunghwan, Jung, Ilhyoung, Nam, Jeongbeom
• Primary Examiner(s): Mowla, Golam
• Application Number:
  US14/659,053
• Publication Number:
  US 20150263193A1
• Time in Patent Office: 1,401 Days
• CPC Class Codes: H01L 31/02167 for solar cells
• CPC Class Codes: H01L 31/02168 the coatings being antireflective or having enhancing optical properties for the solar cells
• CPC Class Codes: H01L 31/022433 Particular geometry of the grid contacts
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/0682 back-junction, i.e. rearside emitter, solar cells, e.g. interdigitated base-emitter regions back-junction 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: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/1868 Passivation
• 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

Discussed is a solar cell includes a semiconductor substrate, a conductive type region including a first conductive type region and a second conductive type region formed on one surface of the semiconductor substrate, an electrode including a first electrode and a second electrode, wherein the first electrode is connected to the first conductive type region and the second electrode is connected to the second conductive type region, and a passivation layer formed on the conductive type region. The passivation layer includes at least one of silicon nitride and silicon carbide.

Claims

1. A solar cell, comprising:

a semiconductor substrate;

a conductive type region comprising a first conductive type region and a second conductive type region formed on one surface of the semiconductor substrate;

an electrode comprising a first electrode and a second electrode, wherein the first electrode is connected to the first conductive type region and the second electrode is connected to the second conductive type region; and

a passivation layer formed on the conductive type region,

wherein the passivation layer includes at least one of silicon nitride and silicon carbide,

wherein the electrode further comprises;

an adhesive layer being in contact with the conductive type region and being electrically conductive;

an electrode layer formed on the adhesive layer; and

a ribbon-connected layer formed on the electrode layer,

wherein at least a part of the electrode layer has a width smaller than a width of the adhesive layer and the ribbon-connected layer, and

wherein the adhesive layer has a coefficient of thermal expansion between a coefficient of thermal expansion of the first and second conductive type regions and a coefficient of thermal expansion of a portion of the electrode layer adjacent to the adhesive layer.

2. The solar cell according to claim 1, wherein the passivation layer comprises a silicon nitride layer including the silicon nitride and has a refractive index of about 2.1 to about 2.2.

3. The solar cell according to claim 2, further comprising:

an insulating layer formed on the other surface from the one surface of the semiconductor substrate, wherein the insulating layer includes the silicon nitride and has a refractive index smaller than the refractive index of the passivation layer.

4. The solar cell according to claim 1, wherein the passivation layer comprises a silicon carbide layer including the silicon carbide, and has a refractive index of about 1.5 to 2.0.

5. The solar cell according to claim 4, wherein the silicon carbide layer has an amorphous structure.

6. The solar cell according to claim 4, wherein the silicon carbide layer is hydrophobic.

7. The solar cell according to claim 1, wherein the passivation layer is formed of a single layer of one of the silicon nitride and the silicon carbide.

8. The solar cell according to claim 1, wherein the passivation layer comprises:

a first layer formed on the conductive type region and comprising the silicon nitride; and

a second layer formed on the first layer and comprising the silicon carbide.

9. The solar cell according to claim 8, wherein a refractive index of the first layer is larger than a refractive index of the second layer.

10. The solar cell according to claim 8, wherein the first layer has a thickness the same as or larger than a thickness of the second layer.

11. The solar cell according to claim 10, wherein a ratio of the second layer:

the first layer is about 1;

1 to about 1;

4, or

the first layer has a thickness of about 50 nm to about 200 nm and the second layer has a thickness of about 10 nm to about 50 nm.

12. The solar cell according to claim 1, wherein the passivation layer includes an opening corresponding to the electrode, and

the electrode is formed on a bottom surface of the opening, on a side surface of the passivation layer adjacent to the opening, and on the passivation layer adjacent to the opening.

13. The solar cell according to claim 12, wherein the adhesive layer is in contact with a bottom surface of the opening, with the side surface of the passivation layer adjacent to the opening, and with the passivation layer adjacent to the opening.

14. The solar cell according to claim 13, wherein the adhesive layer comprises a metal having a transparency.

15. The solar cell according to claim 1, wherein the passivation layer includes an opening corresponding to the electrode, and

the electrode has a side surface having an undercut.

16. The solar cell according to claim 15, wherein the undercut has a width of about 1 μ

m to about 10 μ

m.

17. The solar cell according to claim 1, further comprising:

a tunneling layer formed between the one surface of the semiconductor substrate and the conductive type region.

18. The solar cell according to claim 1, further comprising:

a barrier region formed between the first conductive type region and the second conductive type region.

19. The solar cell according to claim 1, wherein at least a part of the electrode layer is adjacent to the adhesive layer.

20. The solar cell according to claim 1, wherein the adhesive layer is thinner than the passivation layer, and

wherein a thickness of the adhesive layer is about 5 nm to 50 nm.