CN-122002966-A - Back contact battery and photovoltaic module

CN122002966ACN 122002966 ACN122002966 ACN 122002966ACN-122002966-A

Abstract

The application relates to the technical field of solar cells, in particular to a back contact cell and a photovoltaic module, which can simplify the preparation process, wherein the back contact cell comprises a semiconductor substrate, a first electrode, a second electrode, a third electrode and a first electrode, wherein the semiconductor substrate comprises a first surface and a second surface, the first surface comprises a first area, a second area and a third area, a doped crystal silicon area is formed on the surface of the first area, the doped crystal silicon area is formed by adding a doping agent into the semiconductor substrate, and the third area is positioned between the first area and the second area; the first unit structure is arranged in the first area and comprises a first passivation structure arranged on the doped crystalline silicon area, the first passivation structure also covers the third area, the second unit structure is arranged in the second area and comprises an amorphous silicon layer, a doped amorphous silicon layer and a conductive film which are sequentially arranged, the first electrode is electrically contacted with the doped crystalline silicon area, and the second electrode is electrically contacted with the doped amorphous silicon layer.

Inventors

ZHANG TENGXI
LI HUIMIN
FENG XIU
XU MENGLEI
ZHANG XINYU
YANG JIE

Assignees

晶科能源(海宁)有限公司

Dates

Publication Date: 20260508
Application Date: 20251027

Claims (11)

1. A back contact battery, comprising: The semiconductor substrate comprises a first surface and a second surface which are arranged in a back-to-back manner, wherein the first surface comprises a first area, a second area and a third area, a doped crystal silicon area is formed in the surface of the first area, the doped crystal silicon area is formed by adding a dopant into the semiconductor substrate, and the third area is positioned between the first area and the second area; The first unit structure is arranged in the first area, comprises a first passivation structure arranged on the doped crystal silicon area along the direction away from the first surface, and also covers the third area; The second unit structure is arranged in the second area and comprises an amorphous silicon layer, a doped amorphous silicon layer and a conductive film which are sequentially arranged along the direction away from the first surface; a first electrode in electrical contact with the doped crystalline silicon region, and A second electrode in electrical contact with the doped amorphous silicon layer; Wherein the first passivation structure in the third region is divided into a first portion and a second portion along a direction parallel to the first surface, wherein the second portion overlies the second cell structure.
2. The back contact battery of claim 1, wherein the width of the second portion is 10-50 μιη in a direction parallel to the first surface.
3. The back contact battery of claim 1, wherein the amorphous silicon layer has a thickness of 2-20nm, the doped amorphous silicon layer has a thickness of 10-50nm, and the conductive film has a thickness of 30-150nm.
4. The back contact cell of claim 1, wherein the first passivation structure comprises a conductive film disposed on the doped crystalline silicon region.
5. The back contact battery of claim 1, wherein the second surface is provided with a second passivation structure.
6. The back contact battery of claim 5, wherein the second passivation structure comprises an aluminum oxide layer and a silicon-based thin film layer disposed on the second surface in sequence.
7. The back contact cell of claim 6, wherein the silicon-based thin film layer is one or more combinations of silicon nitride, silicon oxide, silicon oxynitride, and the like.
8. The back contact battery of claim 6, wherein the alumina layer has a thickness of 1-20nm.
9. The back contact battery of claim 1, wherein the first surface has a textured structure thereon.
10. The back contact battery of claim 1, wherein the second surface has a textured structure thereon.
11. A photovoltaic module comprising a back contact cell according to any one of claims 1-10.

Description

Back contact battery and photovoltaic module The application relates to a back contact battery, a preparation method thereof and a photovoltaic module, which are applied by the applicant in 2025, 10 and 27 days, and are divided application of China patent application with the application number 2025115436793. Technical Field The application relates to the technical field of solar cells, in particular to a back contact cell and a photovoltaic module. Background The photovoltaic power generation is a system for directly converting solar energy into electric energy by utilizing a solar cell according to the photovoltaic effect principle, wherein the basic structure of the solar cell is a large-area plane PN junction. When sunlight irradiates on the PN junction, the PN junction absorbs light energy to excite electrons and holes, and then voltage is generated in the PN junction, so that photoelectric conversion is realized. Therefore, the core structure for realizing solar energy and electric energy conversion in the crystalline silicon battery is a PN junction. In photovoltaic power generation, HBC (Hybrid Back Contact) is an IBC cell technology and HJT (heterojunction) -stacked photovoltaic cell technology, and when the back surface is designed, an N region and a P region are arranged in an interdigital manner, and a Gap region is arranged between the N region and the P region. The design of the back passivation structure is related to the generated power of the photovoltaic cell. Disclosure of Invention The applicant finds that the P region is usually passivated by intrinsic amorphous silicon and boron doped amorphous silicon, the N region is passivated by intrinsic amorphous silicon and phosphorus doped amorphous silicon, the Gap region is passivated by aluminum oxide and silicon nitride, and the P region, the Gap region and the N region are respectively passivated by different film layers, thus the process is complicated. And the intrinsic amorphous silicon passivation structures of the P region and the N region have weaker UV resistance and are more easily damaged by UV in daily use, so that the generated power is reduced. Based on this, there is a need to propose a back contact cell which facilitates a simple passivation process, and also a photovoltaic module. In one aspect, the back contact battery comprises a semiconductor substrate, a first unit structure, a second unit structure and a second electrode, wherein the first surface and the second surface are oppositely arranged, the first surface comprises a first area, a second area and a third area, a doped crystalline silicon area is formed on the surface of the first area, the doped crystalline silicon area is formed by adding a doping agent into the semiconductor substrate, the third area is positioned between the first area and the second area, the first unit structure is arranged in the first area along the direction away from the first surface and comprises a first passivation structure arranged on the doped crystalline silicon area, the first passivation structure also covers the third area, the second unit structure is arranged in the second area along the direction away from the first surface and comprises an amorphous silicon layer, a doped amorphous silicon layer and a conducting film which are sequentially arranged, the first electrode is electrically contacted with the doped crystalline silicon area, the second electrode is electrically contacted with the doped amorphous silicon layer along the direction parallel to the first surface, and the second unit structure is partially covered in the first area and the second unit structure. In some embodiments, the second portion has a width of 10-50 μm in a direction parallel to the first surface. In some embodiments, the amorphous silicon layer has a thickness of 2-20nm, the doped amorphous silicon layer has a thickness of 10-50nm, and the conductive film has a thickness of 30-150nm. In some embodiments, the first passivation structure includes a conductive film disposed on the doped crystalline silicon region. In some embodiments, the second surface is provided with a second passivation structure. In some embodiments, the second passivation structure includes an aluminum oxide layer and a silicon-based thin film layer disposed on the second surface in sequence. In some embodiments, the silicon-based thin film layer is one or more combinations of silicon nitride, silicon oxide, silicon oxynitride, and the like. In some embodiments, the alumina layer has a thickness of 1-20nm. In some embodiments, the first surface has a pile structure thereon. In some embodiments, the second surface has a pile structure thereon. In another aspect of the application, a photovoltaic module is provided that includes the back contact cell. In the present application, the first passivation structure covers both the first region and the third region. In this way, the passivation film layers on the first and third regi