CN-122002908-A - Back contact battery, preparation method of back contact battery and photovoltaic module

Abstract

The application relates to a back contact battery, a preparation method of the back contact battery and a photovoltaic module. The substrate has a first side including first and second regions alternately arranged. The tunneling layer is arranged in the first area, and the first doped semiconductor layer is arranged on one side of the tunneling layer far away from the substrate. The doped field region is located in the first region, and the doped field region and the first doped semiconductor layer both have a first doping element. The second region is provided with a groove concavely arranged relative to the first region, one part of the amorphous layer is arranged on the second region, and the other part of the amorphous layer is arranged on one side of the first doped semiconductor layer away from the substrate. The second doped semiconductor layer is arranged on one side of the amorphous layer far away from the substrate and is provided with a second doping element with different doping types from the first doping element. The depth of the doped field region is less than the depth of the recess. The passivation performance of the first region can be improved, and the passivation performance of the second region can be simultaneously improved.

Inventors

• LI HUIMIN
• CHANG BINBIN
• DAI HUIZHEN
• DUAN WEIYUAN

Assignees

• 浙江晶科能源有限公司

Dates

Publication Date

20260508

Application Date

20260408

Claims (19)

1. 1. A back contact battery, comprising: a substrate having a first face and a second face disposed opposite in a first direction, the first face including first and second regions alternately arranged; the tunneling layer is arranged in the first area; the first doped semiconductor layer is arranged on one side of the tunneling layer away from the substrate; the doped field region and the first doped semiconductor layer are provided with first doping elements; An amorphous layer provided in the second region with a recess recessed with respect to the first region, a part of the amorphous layer being provided on the second region, and another part of the amorphous layer being provided on a side of the first doped semiconductor layer remote from the substrate, and The second doped semiconductor layer is arranged on one side of the amorphous layer, which is far away from the substrate, and is provided with a second doping element with a doping type different from that of the first doping element; The depth of the doped field region is smaller than the depth of the groove.
2. 2. The back contact cell of claim 1, wherein a sum of a thickness of the tunneling layer, a thickness of the first doped semiconductor layer, and a depth of the doped field region is less than a depth of the recess.
3. 3. The back contact cell of claim 1, wherein the ratio of the depth of the recess to the depth of the doped field region is 5-100.
4. 4. The back contact cell of claim 1, wherein the depth of the doped field region is 100nm-1000nm.
5. 5. The back contact battery of claim 1, wherein the depth of the grooves is 1 μιη -10 μιη.
6. 6. The back contact cell of any of claims 1-5, wherein a doping concentration of the first doping element in the first doped semiconductor layer is greater than a doping concentration of the first doping element in the doped field region.
7. 7. The back contact cell of any of claims 1-5, wherein the doped field region comprises a first doped sub-region and a second doped sub-region, the first doped sub-region being disposed closer to the first face than the second doped sub-region along the first direction; The doping concentration of the first doping element in the first doping sub-region is greater than the doping concentration of the first doping element in the second doping sub-region.
8. 8. The back contact cell of claim 7, wherein the doped field region further comprises a third doped sub-region located between the first doped sub-region and the second doped sub-region along the first direction; the doping concentration of the first doping element in the first doping sub-region is greater than the doping concentration of the first doping element in the third doping sub-region, and the doping concentration of the first doping element in the third doping sub-region is greater than the doping concentration of the first doping element in the second doping sub-region.
9. 9. The back contact cell of any of claims 1-5, wherein a doping concentration of the first doping element in the tunneling layer is greater than a doping concentration of the first doping element in the doped field region, and/or The doping concentration of the first doping element in the tunneling layer is greater than the doping concentration of the first doping element in the first doped semiconductor layer.
10. 10. The back contact battery of any of claims 1-5, wherein the ratio of the doping concentration of the first doping element in the doped field region to the doping concentration of the second doping element in the second doped semiconductor layer is 0.1-10.
11. 11. The back contact battery of any of claims 1-5, wherein the first doped semiconductor layer and the second doped semiconductor layer differ in crystalline phase.
12. 12. The back contact battery of any of claims 1-5, wherein the first doped semiconductor layer comprises a middle portion and edge portions on either side of the middle portion; a part of the amorphous layer is arranged on one side of the edge part, which is away from the substrate; the doping concentration of the first doping element in the intermediate portion is greater than the doping concentration of the first doping element in the edge portion.
13. 13. The back contact battery of any one of claims 1-5, wherein the back contact battery further comprises: a first transparent conductive layer arranged on one side of the first doped semiconductor layer far away from the substrate and electrically connected with the first doped semiconductor layer, and/or The second transparent conductive layer is arranged on one side of the second doped semiconductor layer far away from the substrate and is electrically connected with the second doped semiconductor layer.
14. 14. The back contact cell of claim 13, further comprising a first electrode disposed on a side of the first transparent conductive layer remote from the first doped semiconductor layer, wherein the first electrode is not in contact with the doped field region.
15. 15. The back contact battery of any one of claims 1-5, wherein the second region has a first pyramid-like structure and the second face has a second pyramid-like structure; The first pyramidal structure has a smaller size than the second pyramidal structure.
16. 16. The back contact battery of any of claims 1-5, further comprising a first passivation layer and a first anti-reflection layer disposed on the second face.
17. 17. A method of making a back contact battery comprising: Providing a substrate, wherein the substrate is provided with a first surface and a second surface which are oppositely arranged along a first direction, and the first surface comprises a first area and a second area which are alternately arranged; forming an initial tunneling layer on the first face; forming a first semiconductor layer on one side of the initial tunneling layer away from the substrate; diffusing a first doping element into the first semiconductor layer to form an initial doping field region at the first face; Forming a groove on the second region, and removing the initial tunneling layer, the first semiconductor layer and the initial doping field region at the part of the second region to obtain a tunneling layer, a first doping semiconductor layer and a doping field region; forming an amorphous layer and forming a second doped semiconductor layer arranged on one side of the amorphous layer away from the substrate; Wherein a portion of the amorphous layer is disposed on the second region, and another portion of the amorphous layer is disposed on a side of the first doped semiconductor layer away from the substrate; The second doped semiconductor layer has a second doping element of a different doping type from the first doping element; The depth of the doped field region is smaller than the depth of the groove.
18. 18. The method according to claim 17, wherein the first doping element is diffused into the first semiconductor layer at a diffusion temperature of 700 ℃ to 1000 ℃ and/or a diffusion time of 5min to 60min.
19. 19. A photovoltaic module comprising the back contact cell of any one of claims 1 to 16 or a back contact cell prepared by the method of preparing a back contact cell of any one of claims 17 to 18.

Description

Back contact battery, preparation method of back contact battery and photovoltaic module Technical Field The application relates to the technical field of solar cells, in particular to a back contact cell, a preparation method of the back contact cell and a photovoltaic module. Background A back contact cell (BC cell for short) is a solar cell technology in which positive and negative metal contacts are all integrated on the back surface. In the related art, how to improve passivation performance of the back contact battery is one of the future development directions. Disclosure of Invention Based on this, it is necessary to provide a back contact battery, a method of manufacturing the back contact battery, and a photovoltaic module to improve passivation performance of the back contact battery. According to a first aspect of the present application, there is provided a back contact battery comprising a substrate, a tunneling layer, a first doped semiconductor layer, a doped field region, an amorphous layer and a second doped semiconductor layer. The substrate has a first face and a second face disposed opposite in a first direction, the first face including first and second regions alternately arranged. The tunneling layer is arranged in the first area, and the first doped semiconductor layer is arranged on one side of the tunneling layer far away from the substrate. The doped field region is located in the first region, and the doped field region and the first doped semiconductor layer both have a first doping element. The second region is provided with a groove concavely arranged relative to the first region, one part of the amorphous layer is arranged on the second region, and the other part of the amorphous layer is arranged on one side of the first doped semiconductor layer away from the substrate. The second doped semiconductor layer is arranged on one side of the amorphous layer far away from the substrate and is provided with a second doping element with different doping types from the first doping element. The depth of the doped field region is less than the depth of the recess. In one embodiment, the sum of the thickness of the tunneling layer, the thickness of the first doped semiconductor layer and the depth of the doped field region is less than the depth of the recess. In one embodiment, the ratio of the depth of the recess to the depth of the doped field region is 5-100. In one embodiment, the depth of the doped field region is 100nm-1000nm. In one embodiment, the grooves have a depth of 1 μm to 10 μm. In one embodiment, the doping concentration of the first doping element in the first doped semiconductor layer is greater than the doping concentration of the first doping element in the doped field region. In one embodiment, the doped field region comprises a first doped sub-region and a second doped sub-region, the first doped sub-region is arranged closer to the first face than the second doped sub-region along the first direction, and the doping concentration of the first doping element in the first doped sub-region is greater than the doping concentration of the first doping element in the second doped sub-region. In one embodiment, the doped field region further comprises a third doped region located between the first doped region and the second doped region in the first direction, the doping concentration of the first doping element in the first doped region being greater than the doping concentration of the first doping element in the third doped region, and the doping concentration of the first doping element in the third doped region being greater than the doping concentration of the first doping element in the second doped region. In one embodiment, the doping concentration of the first doping element in the tunneling layer is greater than the doping concentration of the first doping element in the doped field region, and/or the doping concentration of the first doping element in the tunneling layer is greater than the doping concentration of the first doping element in the first doped semiconductor layer. In one embodiment, the ratio of the doping concentration of the first doping element in the doping field region to the doping concentration of the second doping element in the second doped semiconductor layer is 0.1-10. In one embodiment, the first doped semiconductor layer and the second doped semiconductor layer have different crystalline phases. In one embodiment, the first doped semiconductor layer comprises a middle portion and edge portions located on two sides of the middle portion, a part of the amorphous layer is arranged on one side, away from the substrate, of the edge portion, and the doping concentration of the first doping element in the middle portion is larger than that of the first doping element in the edge portion. In one embodiment, the back contact battery further comprises a first transparent conductive layer and a second transparent conductive layer, wherein