EP-4579761-B1 - SOLAR CELL, METHOD FOR PREPARING SOLAR CELL, AND PHOTOVOLTAIC MODULE

Inventors

• ZHANG, XIAOWEN
• YU, Ding
• ZHAO, Xiangyun
• CHAI, Jialei
• LI, WENQI
• YANG, JIE
• ZHENG, Peiting

Dates

Publication Date

20260506

Application Date

20240315

Claims (15)

1. A solar cell, comprising: a substrate (100) having a first surface (1), wherein the first surface includes first regions (11) and second region (12) alternatingly arranged in a first direction; a first passivation contact structure (101) formed on the first regions and the second regions; second passivation contact structures (102) formed on the first passivation contact structure, the second passivation contact structures including at least one respective second passivation contact structure corresponding to a respective first region of the first regions, wherein each of the at least one respective second passivation contact structure has an orthographic projection on the first surface in the respective first region; first passivation films (103) formed on the first passivation contact structure, wherein each of the first passivation films has an orthographic projection on the first surface in a respective one of the second regions; and first electrodes (104) extending in a second direction perpendicular to the first direction, wherein the first electrodes include a respective first electrode formed over the at least one respective second passivation contact structure, the respective first electrode covers a top surface and at least part of two opposing sidewalls of each of the at least one respective second passivation contact structure in the first direction, and is in electrical contact with the at least one respective second passivation contact structure.
2. The solar cell according to claim 1, wherein the respective first electrode includes a plurality of conductive extensions, and the plurality of conductive extensions include: first conductive extensions, wherein the first conductive extensions penetrate each of the at least one respective second passivation contact structure to extend into the first passivation contact structure; and second conductive extensions extending into each of the at least one respective second passivation contact structure.
3. The solar cell according to claim 2, wherein the first passivation contact structure includes a first tunneling layer and a first doped conductive layer stacked in a direction away from the substrate, and the first conductive extensions extend into a partial thickness of the first doped conductive layer.
4. The solar cell according to claim 2, wherein the second conductive extensions include: first conductive sub-extensions extending into each of the at least one respective second passivation contact structure from the top surface of each of the at least one respective second passivation contact structure; second conductive sub-extensions extending into each of the at least one respective second passivation contact structure from the two opposing sidewalls of each of the at least one respective second passivation contact structure.
5. The solar cell according to claim 4, wherein each of the at least one respective second passivation contact structure includes a second tunneling layer, a second doped conductive layer and an amorphous silicon layer stacked in a direction away from the substrate, and wherein the first conductive sub-extensions include: a first plurality of first conductive sub-extensions extending into the amorphous silicon layer; and a second plurality of first conductive sub-extensions extending into the second doped conductive layer.
6. The solar cell according to any one of claims 2 to 5, wherein the respective first electrode further includes: a glass frit layer covering the top surface and the at least part of two opposing sidewalls of each of the at least one respective second passivation contact structure, wherein the plurality of conductive extensions are formed in the glass frit layer and extend from the glass frit layer to each of the at least one respective second passivation contact structure; and a slurry body layer formed on the glass frit layer, wherein the slurry body layer includes a material of the plurality of conductive extensions.
7. The solar cell according to claim 1 or claim 2, wherein the respective first electrode covers two opposing sidewalls of each of the at least one respective second passivation contact structure in the first direction and a portion of a top surface of the first passivation contact structure, and the first passivation films include a respective first passivation film having a sidewall facing the at least one respective second passivation contact structure and in contact with a portion of the respective first electrode formed on the two opposing sidewalls of each of the at least one respective second passivation contact structure.
8. The solar cell according to claim 7, wherein the respective first electrode includes a plurality of conductive extensions, and the plurality of conductive extensions include: third conductive extensions, wherein the third conductive extensions extend from the top surface of the first passivation contact structure into a partial thickness of the first passivation contact structure to be in electrical contact with the first passivation contact structure.
9. The solar cell according to claim 1 or claim 2, wherein the respective first electrode covers a part of two opposing sidewalls of each of the at least one respective second passivation contact structure, and a portion of the respective first electrode covering the part of two opposing sidewalls of each of the at least one respective second passivation contact structure is formed between two adjacent first passivation films.
10. The solar cell according to claim 1, wherein the first passivation contact structure includes a first tunneling layer and a first doped conductive layer stacked in a direction away from the substrate, and each of the at least one respective second passivation contact structure includes a second tunneling layer, a second doped conductive layer, and an amorphous silicon layer stacked in the direction away from the substrate; and wherein the first doped conductive layer has a thickness that is less than a thickness of the second doped conductive layer.
11. The solar cell according to claim 10, wherein the first doped conductive layer has a material including at least one of amorphous silicon, polysilicon, and silicon carbide, and the second doped conductive layer has a material including at least one of amorphous silicon, polysilicon, and silicon carbide.
12. The solar cell according to claim 1, wherein the second passivation contact structures are arranged at intervals in the first direction, and each of the second passivation contact structures extends in the second direction.
13. The solar cell according to claim 1, wherein the second passivation contact structures are arranged at intervals in both the first direction and the second direction.
14. A method for preparing a solar cell, comprising: providing a substrate having a first surface, wherein the first surface includes first regions and second regions alternatingly arranged in a first direction; forming a first passivation contact structure on the first regions and the second regions; forming second passivation contact structures on the first passivation contact structure, the second passivation contact structures including at least one respective second passivation contact structure corresponding to a respective first region of the first regions, wherein each of the at least one respective second passivation contact structure has an orthographic projection on the first surface in the respective first region; forming first passivation films on the first passivation contact structure, wherein each of the first passivation films has an orthographic projection on the first surface in a respective one of the second regions; and forming first electrodes extending in a second direction perpendicular to the first direction, wherein the first electrodes include a respective first electrode formed over the at least one respective second passivation contact structure, the respective first electrode covers a top surface and at least part of two opposing sidewalls of each of the at least one respective second passivation contact structure in the first direction, and is in electrical contact with the at least one respective second passivation contact structure.
15. A photovoltaic module, comprising: at least one cell string each formed by connecting a plurality of solar cells according to any one of claims 1 to 13; at least one encapsulation layer each configured to cover a surface of a respective cell string; and at least one cover plate each configured to cover a surface of a respective encapsulating adhesive film facing away from the respective cell string.

Description

TECHNICAL FIELD Embodiments of the present disclosure relate in general to the field of solar cells, and more specifically to a solar cell, a method for preparing a solar cell and a photovoltaic module. BACKGROUND Solar cells have good photovoltaic conversion capabilities. In tunnel oxide passivating contacts (TOPCON) cells, a passivation contact structure is prepared on one of the surfaces of the substrate for inhibiting carrier recombination on the surface of the substrate in the solar cell and providing good conductivity for majority carriers. Electrodes are also formed in the solar cell in order to transport and collect the generated carriers. The electrodes are in electrical contact with the passivated contact structure to collect the carriers. The ability of the electrodes to collect the carriers is critical to photovoltaic conversion performance of the solar cell. However, conventional solar cells have low photoelectric conversion efficiency. WO 2017/004624 A1 discloses a solar cell with second passivation contact structures formed on first regions of the substrate, passivation films formed on second regions of the substrate, and first electrodes covering the top surface and part of the sidewalls of the second passivation contact structures. US 2022/158003 A1 discloses a solar cell with a first passivation contact structure, second passivation contact structures formed on first regions of the substrate, passivation films formed on second regions of the substrate, and first electrodes covering the top surface of the second passivation contact structures. SUMMARY Some embodiments of the present disclosure provide a solar cell and a photovoltaic module, which are at least conducive to photoelectric conversion efficiency of the solar cell. Some embodiments of the present disclosure provide a solar cell, including: a substrate having a first surface, where the first surface includes first regions and second regions alternatingly arranged in a first direction; a first passivation contact structure formed on the first regions and the second regions; second passivation contact structures formed on the first passivation contact structure, the second passivation contact structures including at least one respective second passivation contact structure corresponding to a respective first region of the first regions, where each of the at least one respective second passivation contact structure has an orthographic projection on the first surface in the respective first region; first passivation films formed on the first passivation contact structure, where each of the first passivation films has an orthographic projection on the first surface in a respective one of the second regions; and first electrodes extending in a second direction perpendicular to the first direction, where the first electrodes include a respective first electrode formed over the at least one respective second passivation contact structure, the respective first electrode covers a top surface and at least part of two opposing sidewalls of each of the at least one respective second passivation contact structure in the first direction, and is in electrical contact with the at least one respective second passivation contact structure. In some embodiments, the respective first electrode includes a plurality of conductive extensions, and the plurality of conductive extensions include: first conductive extensions, where the first conductive extensions penetrate each of the at least one respective second passivation contact structure to extend into the first passivation contact structure; and second conductive extensions extending into each of the at least one respective second passivation contact structure. In some embodiments, the first passivation contact structure includes a first tunneling layer and a first doped conductive layer stacked in a direction away from the substrate, and the first conductive extensions extend into a partial thickness of the first doped conductive layer. In some embodiments, the second conductive extensions include: first conductive sub-extensions extending into each of the at least one respective second passivation contact structure from the top surface of each of the at least one respective second passivation contact structure; second conductive sub-extensions extending into each of the at least one respective second passivation contact structure from the two opposing sidewalls of each of the at least one respective second passivation contact structure. In some embodiments, each of the at least one respective second passivation contact structure includes a second tunneling layer, a second doped conductive layer and an amorphous silicon layer stacked in a direction away from the substrate, and where the first conductive sub-extensions include: a first plurality of first conductive sub-extensions extending into the amorphous silicon layer; and a second plurality of first conductive sub-extensions extending into the se