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CN-122002909-A - Back contact solar cell and photovoltaic module

CN122002909ACN 122002909 ACN122002909 ACN 122002909ACN-122002909-A

Abstract

The invention relates to the technical field of photovoltaics, in particular to a back contact solar cell and a photovoltaic module. The back contact solar cell comprises a substrate, wherein first areas and first areas are formed on a backlight surface of the substrate and are alternately arranged at intervals along the X direction, a third area is formed in a gap between each two adjacent first areas, a first doping layer is formed in each first area, a second doping layer is formed in each second area, a third doping layer is formed in each third area, the doping concentration of the third doping layer is respectively larger than the doping concentration of the first doping layer and the doping concentration of the second doping layer, and the third doping layer is respectively electrically connected with the adjacent first doping layer and the adjacent second doping layer. Compared with the prior art, the arrangement of the third doped layer is beneficial to generating leakage current under lower reverse bias voltage, so that the hot spot temperature of the component is remarkably reduced, the reliability of a single battery and the component is improved, and the phenomenon of abnormal concentration of the reverse leakage current can be avoided.

Inventors

  • LIU YADONG
  • SUN BO
  • LI YUNLIANG
  • PAN BINBIN
  • Xing Zhicong

Assignees

  • TCL中环新能源科技股份有限公司

Dates

Publication Date
20260508
Application Date
20260211

Claims (13)

  1. 1. A back contact solar cell, comprising a substrate (1), wherein a first region (11) and a second region (12) are formed on a backlight surface of the substrate (1) and alternately arranged at intervals along an X direction, and a third region (13) is formed by gaps between the adjacent first region (11) and second region (12), characterized in that a first doping layer (21) is formed in each first region (11), a second doping layer (22) is formed in each second region (12), and a third doping layer (23) is formed in each third region (13); one of the first doped layer (21) and the second doped layer (22) is P-type doped and the other is N-type doped, the third doped layer (23) is P-type doped or N-type doped, and the doping concentration of the third doped layer (23) is respectively greater than the doping concentration of the first doped layer (21) and the doping concentration of the second doped layer (22); The third doped layer (23) is electrically connected with the adjacent first doped layer (21) and the adjacent second doped layer (22) respectively.
  2. 2. The back contact solar cell according to claim 1, characterized in that the ratio of the doping concentration of the third doped layer (23) to the doping concentration of the first doped layer (21) is 10:1-200:1, and/or, The ratio of the doping concentration of the third doped layer (23) to the doping concentration of the second doped layer (22) is between 10:1 and 200:1, and/or, The peak doping concentration of the first doping layer (21) is 1e 18-5 e19cm < -3 >, and/or, The peak doping concentration of the second doping layer (22) is 0.5e18-3e19 cm < -3 >, and/or, The peak doping concentration of the third doping layer (23) is 1e 19-1 e21cm < -3 >.
  3. 3. The back contact solar cell according to claim 1, wherein the area ratio of the individual third areas (13) to the backlight surface is in the range of 0.1 to 2%, and/or, The thickness of the third doped layer (23) is greater than the thickness of the first doped layer (21) and the thickness of the second doped layer (22), respectively.
  4. 4. A back contact solar cell according to claim 3, characterized in that the thickness of the third doped layer (23) is 0.1-2 um, and/or, The thickness of the first doped layer (21) is 0.1-0.3 um, and/or, The thickness of the second doped layer (22) is 0.05-0.25 um, and/or, The width of the third doped layer (23) is 0.5-20 um.
  5. 5. The back contact solar cell according to claim 1, wherein the third doped layer (23) has a first side and a second side in a width direction of the third doped layer (23), the first side being at least partially bonded to the first doped layer (21) and the second side being at least partially bonded to the second doped layer (22), or, Each third region (13) is internally provided with a third doped semiconductor layer (43), the third doped semiconductor layers (43) are stacked and arranged on the corresponding third doped layers (23), each third doped semiconductor layer (43) comprises a plurality of first contact protrusions (431) and a plurality of second contact protrusions (432), the plurality of first contact protrusions (431) are attached to the adjacent first doped layers (21), and the plurality of second contact protrusions (432) are attached to the adjacent second doped layers (22).
  6. 6. The back contact solar cell according to claim 5, wherein the third doped layer (23) is divided into a first contact portion (231), a second contact portion (232) and a spacer portion (233) along a length direction thereof, the first contact portion (231) and the second contact portion (232) are alternately distributed, each adjacent first contact portion (231) and each adjacent second contact portion (232) are connected by the spacer portion (233), each first contact portion (231) is attached to an adjacent first doped layer (21), each second contact portion (232) is attached to an adjacent second doped layer (22), and each spacer portion (233) is formed as a gap between each adjacent first doped layer (21) and each adjacent second doped layer (22).
  7. 7. The back contact solar cell according to claim 5, characterized in that the backlight surface is provided with a third doped semiconductor layer (43) on each of the third regions (13), respectively, the third doped semiconductor layer (43) being provided on the corresponding third doped layer (23) in a stack, the third doped semiconductor layer (43) comprising a plurality of first contact protrusions (431) and a plurality of second contact protrusions (432), wherein: The first contact protrusions (431) are arranged at intervals along the Y direction and are attached to the adjacent first doping layers (21); The second contact protrusions (432) are arranged at intervals along the Y direction and are attached to the adjacent second doping layers (22); The first contact protrusions (431) and the second contact protrusions (432) are alternately distributed on the corresponding third doped layer (23) at intervals; The Y direction is the extending direction of each doped layer, and the Y direction is perpendicular to the X direction.
  8. 8. The back contact solar cell according to claim 1, wherein the doping concentration of the third doped layer (23) is graded along the width direction of the third doped layer (23), or, Along the width direction of the third doping layer (23), the doping concentration of the third doping layer (23) increases from two sides to the middle.
  9. 9. The back contact solar cell according to claim 1, wherein the doping type of the third doped layer (23) is the same as that of the first doped layer (21), the third doped layer (23) is attached to one side of the first doped layer (21) which is close to each other, the third doped layer (23) and one side of the second doped layer (22) which is close to each other have an electrical gap therebetween, or, The doping types of the third doping layer (23) and the second doping layer (22) are the same, the third doping layer (23) is attached to one surface of the second doping layer (22) which is close to each other, and an electric gap is reserved between one surface of the third doping layer (23) and one surface of the first doping layer (21) which is close to each other; wherein, the gap width d of the electric gap is less than or equal to 0.05um.
  10. 10. The back contact solar cell according to claim 1, wherein said first regions (11) and said second regions (12) are alternately arranged in an interdigitated manner along said X-direction, or, The first regions (11) and the second regions (12) are arranged in parallel and alternately along the X direction, or, The first area (11) and the second area (12) are respectively formed by a plurality of island-shaped sub-areas which are regularly arranged, and the shapes of the sub-areas comprise one or more of a circle, a rectangle, a regular polygon and an irregular polygon.
  11. 11. The back contact solar cell according to claim 1, wherein the first region (11) and the second region (12) are separated by a trench, which constitutes the third region (13), the third doped layer (23) being arranged in the trench, and/or, The third doped layer (23) is locally distributed in the third region (13).
  12. 12. The back contact solar cell according to claim 1, wherein within each of the first regions (11), the first doped layer (21) is covered with one or more of a first interface passivation layer (31), a first doped semiconductor layer (41), a first transparent conductive oxide layer (51) and a first metal electrode (61) in sequence, and/or, Within each of the second regions (12), the second doped layer (22) is covered with one or more of a second interface passivation layer (32), a second doped semiconductor layer (42), a second transparent conductive oxide layer (52), and a second metal electrode (62) in sequence.
  13. 13. A photovoltaic module comprising a back contact solar cell according to any one of claims 1 to 12.

Description

Back contact solar cell and photovoltaic module Technical Field The invention relates to the technical field of photovoltaics, in particular to a back contact solar cell and a photovoltaic module. Background The back contact solar cell refers to a cell in which both positive and negative metal electrodes are on the back of the cell and the front is not shielded by the metal electrodes. Compared with a double-sided contact battery, the back contact battery has higher short-circuit current and photoelectric conversion efficiency, and is one of the technical directions for realizing the high-efficiency crystalline silicon battery at present. From the aspect of photoelectric conversion performance of the battery, two adjacent doped semiconductor layers of the back contact solar battery are required to be separated due to different polarities, and the two doped semiconductor layers are generally separated by a groove and a film layer to inhibit forward leakage, so that the battery has higher photoelectric conversion efficiency in a forward voltage region. From the aspect of cell reliability, the resistance between two adjacent doped semiconductor layers of the back contact solar cell is larger, and the corresponding reverse breakdown voltage is larger, so that the risk of hot spots of the cell is higher. The problem of hot spot reliability of the battery can cause a very large potential hazard to the safety of the component products. The existing back contact solar cell generally electrically connects a plurality of uniformly dispersed local positions between two adjacent doped semiconductor layers to form a plurality of uniformly dispersed leakage channels, so that reverse breakdown voltage is reduced, and hot spot risk is reduced to a certain extent. However, the back contact solar cell has the problems that if the number of the leakage channels is too large, carrier recombination is increased, so that the photoelectric conversion efficiency of the cell is lost, and if the number of the leakage channels is too small, reverse leakage is easily concentrated, and the risk of hot spots still exists. Disclosure of Invention The invention aims to provide a back contact solar cell and a photovoltaic module with the back contact solar cell, so as to improve the hot spot risk of the cell in the prior art. In order to achieve the above purpose, the present invention adopts the following technical scheme: A back contact solar cell comprises a substrate, wherein first areas and second areas are formed on the back surface of the substrate, the first areas and the second areas are alternately arranged at intervals along the X direction, gaps between the adjacent first areas and second areas form third areas, a first doping layer is formed in each first area, a second doping layer is formed in each second area, and a third doping layer is formed in each third area; One of the first doping layer and the second doping layer is P-type doped, the other is N-type doped, the third doping layer is P-type doped or N-type doped, and the doping concentration of the third doping layer is respectively larger than the doping concentration of the first doping layer and the doping concentration of the second doping layer; the third doped layer is electrically connected with the adjacent first doped layer and the adjacent second doped layer respectively. Compared with the prior art, the back contact solar cell provided by the application has the advantages that (1) the arrangement of the third doped layer is favorable for generating leakage current under lower reverse bias voltage, so that the hot spot temperature of a component is obviously reduced, the reliability of a single cell and the component is improved, (2) the concentration gradient between the third doped layer and the first doped layer and the concentration gradient between the third doped layer and the second doped layer can generate diffusion barriers, so that the transverse movement of carriers of the first doped layer and the second doped layer to the third doped layer can be restrained, the photoelectric conversion efficiency of the cell is ensured, and (3) the third doped layer forms a large-area reverse leakage channel between the first doped layer and the second doped layer, so that the hot spot risk caused by reverse leakage current concentration is relieved. In some embodiments, the ratio of the doping concentration of the third doped layer to the doping concentration of the first doped layer is 10:1 to 200:1, and/or, The ratio of the doping concentration of the third doping layer to the doping concentration of the second doping layer is 10:1-200:1, and/or, The peak doping concentration of the first doping layer is 1e 18-5 e19cm < -3 >, and/or, The peak doping concentration of the second doping layer is 0.5e18-3e19 cm < -3 >, and/or, The peak doping concentration of the third doping layer is 1e 19-1 e21cm < -3 >. The higher the doping concentration ratio of the third