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CN-121568468-B - Back contact solar cell

CN121568468BCN 121568468 BCN121568468 BCN 121568468BCN-121568468-B

Abstract

The application provides a back contact solar cell which comprises a silicon substrate, a first metal grid line, a second metal grid line, a first passivation layer, a second passivation layer and a protection layer, wherein the first metal grid line and the second metal grid line are arranged on the back surface of the silicon substrate, a protection layer accommodating area is formed between adjacent parts of the first metal grid line and the second metal grid line at intervals, the first passivation layer is arranged on the front surface of the silicon substrate, the second passivation layer is arranged on the back surface of the silicon substrate and is positioned in the protection layer accommodating area, the protection layer is arranged on the surface of the first passivation layer, the orthographic projection of the protection layer on the back surface of the silicon substrate is positioned in the orthographic projection of the protection layer accommodating area on the back surface of the silicon substrate, the distances h1 of the protection layer, h2 of one end, away from the second passivation layer, of the second metal grid line and the second passivation layer are respectively, and h3 of one end, away from the second passivation layer, of the first metal grid line meets h1> h2, h1> h3. The metal grid lines on the back of the stacked back contact solar cell are not easy to scratch the front suede.

Inventors

  • Lei Huayong
  • CHEN XIANZHI
  • Deng Mingzhang
  • LI ZHONGLAN

Assignees

  • 通威太阳能（成都）有限公司

Dates

Publication Date
20260505
Application Date
20260123

Claims (11)

  1. 1. The back contact solar cell is characterized by comprising a silicon substrate, a first metal grid line, a second metal grid line, a first passivation layer, a second passivation layer and a protective layer; the first metal grid line and the second metal grid line are arranged on the back surface of the silicon substrate, and a protective layer accommodating area is formed between adjacent parts of the first metal grid line and adjacent parts of the second metal grid line at intervals; the first passivation layer is arranged on the front surface of the silicon substrate, and the second passivation layer is arranged on the back surface of the silicon substrate and is positioned in the protective layer accommodating area; The protective layer is arranged on the surface of the first passivation layer, which is away from the silicon substrate, the orthographic projection of the protective layer on the back surface of the silicon substrate is positioned in the orthographic projection range of the protective layer accommodating area on the back surface of the silicon substrate, the thickness of the protective layer is h1, the distance between one end of the first metal grid line, which is away from the second passivation layer, and the second passivation layer is h2, the distance between one end of the second metal grid line, which is away from the second passivation layer, and the second passivation layer is h3, and the requirements of h1> h2, and h1> h3 are met; The back contact solar cell further comprises a protection frame, the protection frame is arranged on the front face of the silicon substrate, the protection layer is arranged in the protection frame, all orthographic projections of the first metal grid lines and the second metal grid lines on the front face of the silicon substrate are all located in an orthographic projection range of the protection frame on the front face of the silicon substrate, when the back contact solar cells are stacked up and down, the protection frame can enclose the first metal grid lines and the second metal grid lines on the back face of the silicon substrate in the protection frame, and the thickness of the protection frame is larger than or equal to that of the protection layer.
  2. 2. The back contact solar cell of claim 1, further comprising a third passivation layer disposed in at least a portion of a side surface of the silicon substrate, and wherein the back contact solar cell is rectangular or rectangular-like in shape when the back contact solar cell comprises the third passivation layer.
  3. 3. The back contact solar cell according to claim 1, wherein the protective layer accommodating region has a width d2, the distance between the protective frame and the edge of the silicon substrate in the first direction is B, the distance between the protective frame and the edge of the silicon substrate in the second direction is C, and 0.2d2≤B≤10d2, and 0.2d2≤C≤8d2 are satisfied; The first direction is a direction perpendicular to the first metal grid line in a plane where the front surface of the silicon substrate is located, and the second direction is parallel to the first metal grid line.
  4. 4. The back contact solar cell of any one of claims 1-3, wherein the materials of the protective layer and the protective frame each independently comprise one or more of an acrylic resin, an epoxy resin, and a silicone resin.
  5. 5. The back contact solar cell of any one of claims 1-3, wherein a sum of orthographic projected areas of the protective layer and the protective frame on the front surface of the silicon substrate is 0.5% -3% of the front surface area of the silicon substrate.
  6. 6. The back contact solar cell of any one of claims 1-3, wherein a width of the protective frame is greater than or equal to a width of the protective layer.
  7. 7. The back contact solar cell of claim 6, wherein the protective frame has a width of 30-350 μιη; and/or the width of the protective layer is 30-350 μm.
  8. 8. The back contact solar cell of any one of claims 1-3, wherein the protective layer has a width d1, the protective layer receiving region has a width d2, and 0.02d2< d1<0.8d2 is satisfied.
  9. 9. The back contact solar cell of any one of claims 1-3, wherein h2 is greater than h3 and h1_h2=1 μm to 30 μm.
  10. 10. A back contact solar cell according to any of claims 1-3, wherein part of said protective layer accommodating area is provided with one or more of said protective layers in the orthographic projection area of the front side of the silicon substrate.
  11. 11. The back contact solar cell according to any one of claims 1 to 3, wherein the orthographic projection shape of each protective layer on the front surface of the silicon substrate is any one of a continuous straight line type, a rectangular shape arranged at intervals, a dot shape arranged at intervals, a square shape arranged at intervals, and a star shape arranged at intervals.

Description

Back contact solar cell Technical Field The application relates to the technical field of photovoltaics, in particular to a back contact solar cell. Background For a conventional double-sided metallized solar cell, the front side is generally provided with a suede structure of a pyramid, and the heights of metal grid lines on the front side and the back side are higher than those of passivation film layers, so that the double-sided metallized solar cell can be directly stacked, the solar cell cannot be scratched due to friction to the passivation film layers to influence the cell efficiency and the cell yield, and the suede structure of the pyramid cannot be damaged due to direct stacking to reduce the light trapping effect and the passivation effect of the double-sided metallized solar cell. However, when the back contact solar cell needs to be stacked, the back metal grid line may scratch the pyramid suede surface on the front surface and the passivation film layer on the front surface, so as to adversely affect the efficiency and yield of the cell. Disclosure of Invention Based on the technical scheme, the application provides a back contact solar cell, and aims to solve the technical problem that after the back contact solar cell is stacked, a back metal electrode scratches a front suede and a passivation film layer, so that the yield and efficiency of the cell are affected. The technical scheme provided by the application is as follows: According to a first aspect of the present application, there is provided a back contact solar cell comprising a silicon substrate, a first metal gate line, a second metal gate line, a first passivation layer, a second passivation layer and a protective layer; the first metal grid line and the second metal grid line are arranged on the back surface of the silicon substrate, and a protective layer accommodating area is formed between adjacent parts of the first metal grid line and adjacent parts of the second metal grid line at intervals; the first passivation layer is arranged on the front surface of the silicon substrate, and the second passivation layer is arranged on the back surface of the silicon substrate and is positioned in the protective layer accommodating area; The protective layer is arranged on the surface of the first passivation layer, which is away from the silicon substrate, the orthographic projection of the protective layer on the back surface of the silicon substrate is positioned in the orthographic projection range of the protective layer accommodating area on the back surface of the silicon substrate, the thickness of the protective layer is h1, the distance between one end of the first metal grid line, which is away from the second passivation layer, and the second passivation layer is h2, the distance between one end of the second metal grid line, which is away from the second passivation layer, and the second passivation layer is h3, and the requirements of h1> h2 and h1> h3 are met. In some embodiments, the back contact solar cell further comprises a protection frame, the protection frame is arranged on the front surface of the silicon substrate, the protection layer is located in the protection frame, and all orthographic projections of the first metal grid lines and the second metal grid lines on the front surface of the silicon substrate are located in an orthographic projection range of the protection frame on the front surface of the silicon substrate. In some embodiments, the thickness of the protective frame is greater than or equal to the thickness of the protective layer. In some embodiments, the back contact solar cell further comprises a third passivation layer disposed on at least a portion of the side surface of the silicon substrate, and when the back contact solar cell comprises the third passivation layer, the back contact solar cell is rectangular or rectangular-like in shape. In some embodiments, the width of the protective layer accommodating area is d2, the distance between the protective frame and the edge of the silicon substrate in the first direction is B, the distance between the protective frame and the edge of the silicon substrate in the second direction is C, 0.2d2≤B10d2 and 0.2d2≤C8d2 are met, wherein the first direction is the direction perpendicular to the first metal grid line in the plane of the front surface of the silicon substrate, and the second direction is parallel to the first metal grid line. In some of these embodiments, the materials of the protective layer and the protective frame each independently include one or more of an acrylic resin, an epoxy resin, and a silicone resin. In some embodiments, the sum of the orthographic projection area of the protective layer and the protective frame on the front surface of the silicon substrate is 0.5% -3% of the front surface area of the silicon substrate. In some embodiments, the width of the protective frame is greater than or equal to the width of the prot