Interdigitated back contact metal-insulator-semiconductor solar cell with printed oxide tunnel junctions

• US 11,125,389 B2
• Filed: 04/24/2020
• Issued: 09/21/2021
• Est. Priority Date: 12/20/2016
• Status: Active Grant

• Current Assignee: Zhejiang Kaiying New Materials Co., Ltd.
• Original Assignee: Zhejiang Kaiying New Materials Co., Ltd.
• Inventors: Hilali, Mohamed M.
• Primary Examiner(s): Mershon, Jayne L
• Application Number:
  US16/857,627
• Publication Number:
  US 20200248869A1
• Time in Patent Office: 515 Days
• CPC Class Codes: F17C 2201/0109 with exteriorly curved end-piece
• CPC Class Codes: F17C 2201/0157 Polygonal
• CPC Class Codes: F17C 2201/052 large (>1000 m3)
• CPC Class Codes: F17C 2203/012 on or in the wall, e.g. ribs
• CPC Class Codes: F17C 2221/033 Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
• CPC Class Codes: F17C 2223/0161 cryogenic, e.g. LNG, GNL, PLNG
• CPC Class Codes: F17C 2270/01 for fluid transport or storage
• CPC Class Codes: F17C 3/02 with provision for thermal insulation thermal insulation in general F16L59/00 ; refrigerators F25D; insulation specially adapted for cryogenic vessels F17C13/001; tank vehicles B60P3/22; railway tank wagons B61D5/00
• CPC Class Codes: H01L 31/022441 Electrode arrangements specially adapted for back-contact solar cells
• CPC Class Codes: H01L 31/02363 of the semiconductor body itself, e.g. textured active layers
• CPC Class Codes: H01L 31/035272 characterised by at least one potential jump barrier or surface barrier
• CPC Class Codes: H01L 31/03529 Shape of the potential jump barrier or surface barrier
• 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 31/072 the potential barriers being only of the PN heterojunction type
• CPC Class Codes: H01L 31/18 Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells

Abstract

Screen-printable metallization pastes for forming thin oxide tunnel junctions on the back-side surface of solar cells are disclosed. Interdigitated metal contacts can be deposited on the oxide tunnel junctions to provide all-back metal contact to a solar cell.

Claims

1. A method of forming a solar cell interconnect, comprising:

depositing a positively charged dielectric paste on a first region of a back surface of a silicon substrate to form a positively charged oxide layer, wherein the positively charged dielectric paste comprises a positively charged oxide;

depositing a negatively charged dielectric paste on a second region of the back surface of the silicon substrate to form a negatively charged oxide layer, wherein the negatively charged dielectric paste comprises a negatively charged oxide;

curing the positively charged oxide layer and the negatively charged oxide layer under conditions sufficient to form positively charged oxide tunnel junction regions and negatively charged oxide tunnel junction regions;

depositing a first gridline metallization paste on the positively charged oxide tunnel junction regions and depositing a second gridline metallization paste on the negatively charged oxide tunnel junction regions; and

curing the deposited first gridline metallization paste to form a positive electrode and curing the deposited second gridline metallization paste to form a negative electrode,

wherein each of the first gridline metallization paste and the second gridline metallization paste independently comprises;

a metal, a metal alloy, or a combination thereof; and

a metallic glass.

2. The method of claim 1, wherein the negatively charged oxide comprises silicon oxide.

3. The method of claim 1, wherein the positively charged oxide comprises aluminum oxide.

4. The method of claim 1, wherein, after curing, each of the positively charged oxide layer and the negatively charged oxide layer independently has a thickness from 1 Å

to 45 Å

.

5. The method of claim 1, wherein the metallic glass comprises ZrCuNiAl, CuZr, CuZrAl, CuZrAg, CuZrAlAg, CuZrAlAgNi, CuZrAlNi, ZrTiNbCuNiAl, MgZn, MgCu, MgNi, MgNiY, MgCa, AlNiYLa, AlMg, AlMgCa, TiZrCuNi, NiNbZrTiPt, AlNiLa, ZrCuTiNiBe, MgCuYAg, AlLiCu, AlYFe, AgMgCa, AgMgCaCu, or a combination of any of the foregoing.

6. The method of claim 1, wherein the metal or metal alloy comprises copper, zirconium, aluminum, silver, nickel, or a combination of any of the foregoing.

7. The method of claim 1, wherein the metallic glass comprises an amorphous content from 50 wt % to about 99.9 wt %, wherein wt % is based on a total weight of the metallic glass.

8. The method of claim 1, wherein the metallic glass comprises a crystalline content from 1 wt % to 50 wt %, wherein wt % is based on a total weight of the metallic glass.

9. The method of claim 1, wherein each of the positive electrode grid and the negative electrode grid independently comprises silver, a silver alloy, copper, a copper alloy, or a combination of any of the foregoing.

10. The method of claim 1, wherein curing the positively charged oxide layer and curing the negatively charged oxide layer comprises exposing the positively charged oxide layer and the negatively charged oxide layer to a temperature up to 450°

C.

11. The method of claim 1, wherein curing the first gridline metallization paste and curing the second gridline metallization paste comprises exposing the first gridline metallization paste and the second gridline metallization paste to a temperature from 300°

C. to 500°

C.

12. The method of claim 1, wherein the first gridline metallization paste and the second metallization paste comprise the same composition.

13. The method of claim 1, wherein,

depositing the first gridline metallization paste and the second gridline metallization paste comprises depositing simultaneously;

and

curing the first gridline metallization paste and the second metallization paste comprises curing simultaneously.