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WO-2026092396-A1 - BC BATTERY, MODULE AND SYSTEM

WO2026092396A1WO 2026092396 A1WO2026092396 A1WO 2026092396A1WO-2026092396-A1

Abstract

The present disclosure provides a BC battery, a module and a system. An extension section of an insulating dielectric layer, a first doped layer and a silicon substrate form a deposition space at a preset position. The extension section, the first doped layer and the silicon substrate form a closed profile at a first cross-section. An electric-leakage doped portion in the deposition space forms an electric-leakage contact with the first doped layer and a conductive contact with a first extension portion of a second doped layer.

Inventors

  • YANG, Tianzi
  • LIU, Shengpu
  • CHEN, JUN
  • YU, Tianshui
  • SONG, Banghao
  • WANG, YONGQIAN
  • CHEN, GANG

Assignees

  • 珠海富山爱旭太阳能科技有限公司
  • 浙江爱旭太阳能科技有限公司
  • 广东爱旭科技有限公司
  • 天津爱旭太阳能科技有限公司
  • 深圳爱旭数字能源技术有限公司
  • 滁州爱旭太阳能科技有限公司

Dates

Publication Date
20260507
Application Date
20251027
Priority Date
20241101

Claims (20)

  1. A back-contact battery, comprising: A silicon substrate having opposing front and back sides, the back side including a plurality of first regions and a plurality of second regions arranged alternately along a first direction, and a spacer region between the first regions and the second regions, the first regions, the second regions and the spacer region all extending along a second direction, the second direction intersecting the first direction; A first doped layer disposed on the first region; An insulating dielectric layer is disposed on at least a portion of the first doped layer. At a predetermined position in the spacer region, the insulating dielectric layer has an extension extending out of the first region and bending at least partially toward the side where the silicon substrate is located. The end of the extension at least partially overlaps the spacer region, so that the extension, the first doped layer, and the silicon substrate together form a deposition space. In a first cross-section along the first direction, the extension, the first doped layer, and the silicon substrate together form a closed pattern. A leakage doped portion, wherein the leakage doped portion is disposed within the deposition space and forms a leakage contact with the first doped layer, and the polarity of the leakage doped portion is opposite to that of the first doped layer; and A second doped layer is disposed on a portion of the second region and the spacer region, the polarity of the second doped layer being opposite to that of the first doped layer. At the preset position, the second doped layer has a first extension extending over at least a portion of the extension, the first extension being in conductive contact with the leakage doped portion, and the first extension also extending along the first extension to cover at least a portion of the portion of the insulating dielectric layer corresponding to the first doped layer.
  2. According to claim 1, the back contact battery has a through hole formed on the extension, and the first extension makes conductive contact with the leakage doped portion through the through hole.
  3. According to claim 1, in a second cross section along the first direction, the end of the extension is suspended over the spacer region, the extension, together with the first doped layer and the silicon substrate, forms a non-closed pattern with an opening, the second doped layer and the leakage doped portion are in conductive contact at the opening, and the first cross section and the second cross section are parallel to each other in the second direction.
  4. According to claim 1, the back contact battery, wherein, in the second direction, the extension has a first portion with its end overlapping the spacer region and a second portion with its end suspended in the spacer region, the second portion having a gap with the surface of the spacer region, and the second doped layer making conductive contact with the leakage doped portion through the gap.
  5. According to claim 4, the gap between the second portion and the surface of the spacer region is 5nm-800nm.
  6. According to claim 1, the back contact battery has a cavity in the third cross section along the first direction.
  7. According to claim 6, the outer diameter of the cavity is 10nm-500nm.
  8. According to claim 1, the back contact battery, wherein the angle between the surface of the first doped layer and the leakage doped portion forming a leakage contact and the surface of the first region is an acute angle, and the surface of the first doped layer and the leakage doped portion forming a leakage contact has a first recessed region.
  9. According to claim 8, the back contact battery, wherein the surface on which the first doped layer and the leakage doped portion form a leakage contact is a curved surface.
  10. According to claim 1, the back contact battery, wherein the first doped layer has a second extension extending along the first direction and suspended over the spacer region, the insulating dielectric layer covers the surface of the second extension facing away from the silicon substrate, the extension segment and the second extension together form the deposition space, and the leakage doped portion forms a leakage contact with the second extension.
  11. According to claim 10, the back contact battery satisfies at least one of the following: the leakage doped portion and the surface of the second extension toward the spacer region form a leakage contact; the leakage doped portion and the end face of the second extension in the first direction form a leakage contact.
  12. According to claim 11, the back contact battery, wherein the leakage doped portion and the end face of the second extension portion form a leakage contact in the first direction, the angle between the end face of the second extension portion and the surface of the first region is an acute angle, and the end face of the second extension portion has a second recessed region.
  13. According to claim 10, the back contact battery, wherein the extension length of the second extension in the first direction is 0.1 μm-3 μm.
  14. According to claim 1, the back contact battery is provided with a first dielectric layer on the surface where the first doped layer and the leakage doped portion form a leakage contact, and the leakage doped portion and the first doped layer form a leakage contact through the first dielectric layer.
  15. According to claim 1, the back contact battery is provided with a second dielectric layer at least at the preset position on the spacer region, the end of the extension is at least partially overlapped on the second dielectric layer, and the leakage doped portion is also provided on the second dielectric layer.
  16. According to claim 1, the back contact battery, wherein at a fourth cross-section along the first direction, the extension has an overlap portion that overlaps the spacer region, and the second doped layer and the leakage doped portion are separated by the extension.
  17. According to the back contact battery of claim 16, the portion of the silicon substrate covered by the overlapping portion has a length of less than 150 nm in the first direction.
  18. According to the back contact battery of claim 16, wherein, at the fourth cross-section, the overlap portion is a discontinuous structure, such that the overlap portion at the fourth cross-section includes a first portion close to the leakage doped portion and a second portion spaced apart from the first portion; The second doped layer is conductive to the silicon substrate at the gap between the first portion and the second portion.
  19. According to the back contact battery of claim 18, the portion of the silicon substrate correspondingly covered by the first portion has a length of less than 150 nm in the first direction.
  20. According to claim 1, in the first direction, the silicon substrate has a silicon wafer extension that extends and is suspended over the spacer region, the silicon wafer extension is also provided with the first doped layer, the cross-sectional profile of the silicon wafer extension is triangular, and the angle between the surface of the silicon wafer extension facing the spacer region and the surface of the first region is an acute angle.

Description

BC batteries, components and systems Cross-reference of related applications This disclosure claims priority to Chinese patent application No. 202422676897.1, filed on November 1, 2024, with the China National Intellectual Property Administration, entitled “Back Contact Battery, Battery Module and Photovoltaic System”, the entire contents of which are incorporated herein by reference. Technical Field This disclosure relates to the field of solar cell technology, and more particularly to a back-contact cell, a cell module, and a photovoltaic system. Background Technology Currently, in solar cells, back contact cells (BC cells) are a type of cell in which both the emitter and base contact electrodes are placed on the back (not the front) of the cell. The front of the cell is not obstructed by any metal electrodes, thus effectively improving the efficiency of back contact cells. During module operation, when external obstructions block the solar cells, hot spots can appear on the blocked cells. At high temperatures, this can easily lead to carbonization of the encapsulation film and even cause a fire. In back-contact solar cells of relevant technologies, two different doped layers are typically electrically connected at a local location to form a leakage point, reducing the reverse breakdown voltage and thus improving the hot spot resistance and reducing the risk of hot spots. However, while current back-contact solar cells can improve hot spot resistance, they also result in poor performance and low conversion efficiency. Therefore, how to improve the heat spot resistance of back contact batteries while ensuring their conversion efficiency has become a technical problem that engineers urgently need to solve. Public content This disclosure provides a back-contact battery, a battery module, and a photovoltaic system. This disclosure is implemented as follows: the back contact battery of the embodiments of this disclosure includes: The silicon substrate has a front side and a back side, the back side including a plurality of first regions and a plurality of second regions arranged alternately along a first direction, and a spacer region between the first regions and the second regions, the first regions, the second regions and the spacer region all extending along a second direction, the second direction intersecting the first direction; The first doped layer is disposed on the first region; An insulating dielectric layer is disposed on at least a portion of the first doped layer. At a predetermined location in the spacer region, the insulating dielectric layer has an extension that extends out of the first region and bends at least partially toward the side where the silicon substrate is located. The end of the extension is at least partially overlapped on the spacer region so that the extension, the first doped layer, and the silicon substrate together form a deposition space. In a first cross-section along the first direction, the extension, the first doped layer, and the silicon substrate together form a closed pattern. The leakage doped portion is disposed within the deposition space and forms a leakage contact with the first doped layer; the polarity of the leakage doped portion is opposite to that of the first doped layer. A second doped layer is disposed on a portion of the second region and the spacer region. The polarity of the second doped layer is opposite to that of the first doped layer. At a predetermined position, the second doped layer has a first extension that extends and covers at least a portion of the extension. The first extension is in conductive contact with the leakage doped portion. The first extension also extends along the first extension and covers at least a portion of the portion of the insulating dielectric layer corresponding to the first doped layer. In some embodiments, a through hole is formed on the extension, and the first extension makes conductive contact with the leakage doped portion through the through hole. In some embodiments, at a second cross section along the first direction, the end of the extension is suspended over the spacer region, the extension, together with the first doped layer and the silicon substrate, forms a non-closed pattern with an opening, the second doped layer and the leakage doped portion are in conductive contact at the opening, and the first cross section and the second cross section are parallel to each other in the second direction. In some embodiments, in the second direction, the extension has a first portion with its end overlapping the spacer region and a second portion with its end suspended over the spacer region, the second portion having a gap with the surface of the spacer region, and the second doped layer making conductive contact with the leakage doped portion through the gap. In some embodiments, the gap between the second portion and the surface of the spacer region is 5nm-800nm. In some embodiments, a cavity is provided withi