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US-20260130004-A1 - BACK-CONTACT SOLAR CELL, CELL ASSEMBLY, AND PHOTOVOLTAIC SYSTEM

US20260130004A1US 20260130004 A1US20260130004 A1US 20260130004A1US-20260130004-A1

Abstract

A back-contact solar cell, a cell assembly, and a photovoltaic system are provided. First busbars of a back-contact solar cell are in contact with first finger pre-plated layers, and second busbars are in contact with second finger pre-plated layers. A first conductive connector and a second conductive connector are respectively arranged on two ends of each first busbar and two ends of each second busbar. The first conductive connector is connected to the ends of all the first busbars facing away from the second conductive connector, and the second conductive connector is connected to the ends of all the second busbars facing away from the first conductive connector.

Inventors

  • Yongqian Wang
  • Gang Chen

Assignees

  • ZHEJIANG AIKO SOLAR TECHNOLOGY CO., LTD.
  • GUANGDONG AIKO SOLAR TECHNOLOGY CO., LTD.
  • TIANJIN AIKO SOLAR TECHNOLOGY CO., LTD.
  • ZHUHAI FUSHAN AIKO SOLAR TECHNOLOGY CO., LTD.

Dates

Publication Date
20260507
Application Date
20251231
Priority Date
20230727

Claims (20)

  1. 1 . A back-contact solar cell, comprising a substrate and at least one back electrode structure arranged on a backlight surface of the substrate, wherein the at least one back electrode structure comprises: a plurality of first fingers and a plurality of second fingers sequentially and alternately arranged at intervals in a first direction, wherein each first finger comprises a first finger pre-plated layer which forms an ohmic contact with the substrate and a first finger electroplated layer plated on the first finger pre-plated layer, and each second finger comprises a second finger pre-plated layer which forms an ohmic contact with the substrate and a second finger electroplated layer plated on the second finger pre-plated layer; a plurality of first busbars and a plurality of second busbars sequentially and alternately arranged at intervals in a second direction, wherein the first direction intersects the second direction, the plurality of first busbars are in contact with first finger pre-plated layers, the plurality of first fingers are disconnected at the plurality of second busbars, the plurality of second busbars are in contact with second finger pre-plated layers, and the second fingers are disconnected at the plurality of first busbars; and a first conductive connector and a second conductive connector, wherein the first conductive connector and the second conductive connector are respectively arranged on two ends of each first busbar and two ends of each second busbar, the first conductive connector is connected to ends of all the plurality of first busbars facing away from the second conductive connector, and the second conductive connector is connected to ends of all the plurality of second busbars facing away from the first conductive connector.
  2. 2 . The back-contact solar cell according to claim 1 , wherein a width of the first conductive connector is greater than a width of the first finger pre-plated layer, and a width of the second conductive connector is greater than a width of the second finger pre-plated layer.
  3. 3 . The back-contact solar cell according to claim 1 , wherein a width of the first finger pre-plated layer is 0.03 mm to 1 mm, and a width of the first conductive connector is 0.1 mm to 10 mm.
  4. 4 . The back-contact solar cell according to claim 3 , wherein the width of the first finger pre-plated layer is 0.03 mm to 0.6 mm, and the width of the first conductive connector is 0.1 mm to 5 mm.
  5. 5 . The back-contact solar cell according to claim 1 , wherein a width of the second finger pre-plated layer is 0.03 mm to 1 mm, and a width of the second conductive connector is 0.1 mm to 10 mm.
  6. 6 . The back-contact solar cell according to claim 5 , wherein the width of the second finger pre-plated layer is 0.03 mm to 0.6 mm, and the width of the second conductive connector is 0.1 mm to 5 mm.
  7. 7 . The back-contact solar cell according to claim 1 , wherein both the first conductive connector and the second conductive connector are parallel to the first finger pre-plated layers and the second finger pre-plated layers.
  8. 8 . The back-contact solar cell according to claim 1 , wherein at least one of following is satisfied: the first conductive connector forms an ohmic contact with the substrate; the second conductive connector forms an ohmic contact with the substrate.
  9. 9 . The back-contact solar cell according to claim 1 , wherein the backlight surface of the substrate has a plurality of electrode arrangement regions in the first direction, and the back electrode structure is arranged in each electrode arrangement region.
  10. 10 . The back-contact solar cell according to claim 9 , wherein in two adjacent back electrode structures, second conductive connectors of the two back electrode structures are adjacent to each other.
  11. 11 . The back-contact solar cell according to claim 10 , wherein, in the two adjacent back electrode structures, two adjacent second conductive connectors are of an integrally formed structure.
  12. 12 . The back-contact solar cell according to claim 9 , wherein in two adjacent back electrode structures, the first conductive connector of one of the back electrode structures is adjacent to the second conductive connector of an other back electrode structure.
  13. 13 . The back-contact solar cell according to claim 9 , wherein, in two adjacent back electrode structures, the first busbars of one of the back electrode structures are aligned with the first busbars of an other back electrode structure one to one in the first direction, and the second busbars of one of the back electrode structures are aligned with the second busbars of the other back electrode structure one to one in the first direction; or the first busbars of one of the back electrode structures are aligned with the second busbars of the other back electrode structure one to one in the first direction, and the second busbars of one of the back electrode structures are aligned with the first busbars of the other back electrode structure one to one in the first direction.
  14. 14 . The back-contact solar cell according to claim 1 , wherein the first finger pre-plated layer and the second finger pre-plated layer each comprise a seed layer, wherein the seed layer is formed by a physical vapor deposition method.
  15. 15 . The back-contact solar cell according to claim 14 , wherein a composition of the seed layer contains copper, aluminum, or nickel.
  16. 16 . The back-contact solar cell according to claim 1 , wherein the first finger pre-plated layer and the second finger pre-plated layer are formed by a light-induced electroplating method or an electroless plating method.
  17. 17 . The back-contact solar cell according to claim 16 , wherein a composition of the first finger pre-plated layer and the second finger pre-plated layer contains copper or nickel.
  18. 18 . The back-contact solar cell according to claim 1 , wherein each first busbar comprises a first busbar pre-plated layer in contact with the first finger pre-plated layer and a first busbar electroplated layer plated on the first busbar pre-plated layer, the first busbar pre-plated layer is in contact with the first conductive connector; and each second busbar comprises a second busbar pre-plated layer in contact with the second finger pre-plated layer and a second busbar electroplated layer plated on the second busbar pre-plated layer, the second busbar pre-plated layer is in contact with the second conductive connector.
  19. 19 . A cell assembly, comprising a plurality of back-contact solar cells comprising the back-contact solar cell according to claim 1 .
  20. 20 . A photovoltaic system, comprising the cell assembly according to claim 19 .

Description

CROSS-REFERENCES TO RELATED APPLICATIONS The present application is a continuation application of International Application No.: PCT/CN2023/113866, filed on Aug. 18, 2023, which claims priority to Chinese Patent Application No. 202310934646.6, filed on Jul. 27, 2023, the disclosure of all of which is hereby incorporated by reference in their entirety. TECHNICAL FIELD The present disclosure relates to the technical field of solar batteries, and in particular, to a back-contact solar cell, a cell assembly, and a photovoltaic system BACKGROUND A back-contact solar cell is a solar cell in which both P-regions and N-regions are arranged on a back surface of a cell, and a front surface of the cell is not blocked by any metal electrode, which may effectively increase the short-circuit current of the cell and improve the efficiency of the cell. The P-regions and the N-regions on the back surface are alternately arranged, fingers are arranged on the P-regions and the N-regions, and these fingers are connected to busbars of the corresponding polarity. In order to avoid short circuits, a design is typically used where the fingers are connected to the busbars of the same polarity and disconnected at the busbars of different polarities. For example, the positive fingers are disconnected at the negative busbars, and the negative fingers are disconnected at the positive busbars. That is, the fingers have a discontinuous design and are divided into a plurality of finger segments. In the related art, the fingers of the back-contact solar cell may be formed using an electroplating design. For example, a discontinuous finger metal layer may be arranged in advance in regions where the fingers are required, and then an electroplated layer may be formed by performing electroplating (e.g., copper electroplating) on the finger metal layer using an electroplating device, thereby forming the final fingers. However, in such a case, since the fingers have a discontinuous design, each finger is divided into a plurality of independent finger segments. In the electroplating process, in order to ensure that all the finger segments have an electroplated layer, it is necessary to sequentially and respectively connect a cathode of the electroplating device to each independent finger segment or sequentially connect the busbars that are connected to and in contact with the finger segments, so that the electroplated layer is plated on all the finger segments. The electroplating process is relatively complex and the electroplating efficiency is relatively low. SUMMARY The present disclosure provides a back-contact solar cell, a cell assembly, and a photovoltaic system, aiming to solve the technical problems of a relatively complex electroplating process and relatively low electroplating efficiency during the electroplating of back electrodes in existing back-contact solar cells. The present disclosure is implemented as follows: a back-contact solar cell provided by the embodiments of the present disclosure includes a substrate and at least one back electrode structure arranged on a backlight surface of the substrate, and the at least one back electrode structure includes a plurality of first fingers and a plurality of second fingers sequentially and alternately arranged at intervals in a first direction, where each first finger includes a first finger pre-plated layer which forms an ohmic contact with the substrate and a first finger electroplated layer plated on the first finger pre-plated layer, and each second finger includes a second finger pre-plated layer which forms an ohmic contact with the substrate and a second finger electroplated layer plated on the second finger pre-plated layer;a plurality of first busbars and a plurality of second busbars sequentially and alternately arranged at intervals in a second direction, where the first direction intersects the second direction, the plurality of first busbars are in contact with first finger pre-plated layers, the plurality of first fingers are disconnected at the plurality of second busbars, the plurality of second busbars are in contact with second finger pre-plated layers, and the second fingers are disconnected at the plurality of first busbars; anda first conductive connector and a second conductive connector, where the first conductive connector and the second conductive connector are respectively arranged on two ends of each first busbar and two ends of each second busbar, the first conductive connector is connected to ends of all the plurality of first busbars facing away from the second conductive connector, and the second conductive connector is connected to ends of all the plurality of second busbars facing away from the first conductive connector. In some exemplary embodiments, a width of the first conductive connector is greater than a width of the first finger pre-plated layer, and a width of the second conductive connector is greater than a width of the second finger pre-plat