Back contact solar cell and photovoltaic module

Patent metadata

Field	Value
Publication number	US-2026075981-A1
Application number	US-202519316541-A
Country	US
Kind code	A1
Filing date	Sep 2, 2025
Priority date	Sep 12, 2024
Publication date	Mar 12, 2026
Grant date	—

Abstract

The present application discloses a back contact solar cell and a photovoltaic module. In one example, a back contact solar cell includes a semiconductor substrate, a first doped semiconductor part, a second doped semiconductor part, a first dielectric passivation layer, and a second dielectric passivation layer. Each of the first dielectric passivation layer and the second dielectric passivation layer includes a first passivation sub-layer having a field passivation function. A conductivity type of the first doped semiconductor part is opposite to that of fixed charges of the first passivation sub-layer. A thickness of the first passivation sub-layer included in the first dielectric passivation layer is greater than a thickness of the first passivation sub-layer included in the second dielectric passivation layer. Each of the first dielectric passivation layer and the second dielectric passivation layer further includes a second passivation sub-layer having a chemical passivation function.

First claim

What is claimed is:

1 . A back contact solar cell, comprising: a semiconductor substrate, a first doped semiconductor part, a second doped semiconductor part, a first dielectric passivation layer, and a second dielectric passivation layer, wherein a conductivity type of the first doped semiconductor part is opposite to a conductivity type of the second doped semiconductor part, wherein each of the first dielectric passivation layer and the second dielectric passivation layer comprises a first passivation sub-layer having a field passivation function, and wherein the conductivity type of the first doped semiconductor part is opposite to a conductivity type of fixed charges of the first passivation sub-layer,
wherein the semiconductor substrate comprises a first surface and a second surface opposite to each other, wherein along a direction parallel to the first surface, the first doped semiconductor part and the second doped semiconductor part are alternately distributed on the first surface, wherein the first dielectric passivation layer covers a side of the first doped semiconductor part facing away from the semiconductor substrate, and the second dielectric passivation layer covers a side of the second doped semiconductor part facing away from the semiconductor substrate, wherein a thickness of the first passivation sub-layer comprised in the first dielectric passivation layer is greater than a thickness of the first passivation sub-layer comprised in the second dielectric passivation layer, and wherein each of the first dielectric passivation layer and the second dielectric passivation layer further comprises a second passivation sub-layer having a chemical passivation function, wherein the second passivation sub-layer is disposed on a side of the first passivation sub-layer facing away from the semiconductor substrate, wherein a material of the second passivation sub-layer comprised in the first dielectric passivation layer is different from a material of the first passivation sub-layer comprised in the first dielectric passivation layer, and wherein a material of the second passivation sub-layer comprised in the second dielectric passivation layer is different from a material of the first passivation sub-layer comprised in the second dielectric passivation layer.

2 . The back contact solar cell according to claim 1 , wherein under a same test condition, a photometric luminance (PL) value of a part on a back surface of the back contact solar cell corresponding to the second doped semiconductor part is greater than a PL value of a part on the back surface of the back contact solar cell corresponding to the first doped semiconductor part.

3 . The back contact solar cell according to claim 1 , wherein the thickness of the first passivation sub-layer is greater than or equal to 2 nm and less than or equal to 15 nm.

4 . The back contact solar cell according to claim 1 , wherein a thickness of the second passivation sub-layer comprised in the first dielectric passivation layer is less than a thickness of the second passivation sub-layer comprised in the second dielectric passivation layer.

5 . The back contact solar cell according to claim 1 , wherein a difference between a thickness of the second passivation sub-layer comprised in the second dielectric passivation layer and a thickness of the second passivation sub-layer comprised in the first dielectric passivation layer is greater than or equal to 0.5 nm and less than or equal to 5 nm.

6 . The back contact solar cell according to claim 1 , wherein a thickness of the second passivation sub-layer is greater than or equal to 50 nm and less than or equal to 160 nm.

7 . The back contact solar cell according to claim 1 , wherein a thickness of the first dielectric passivation layer is less than a thickness of the second dielectric passivation layer.

8 . The back contact solar cell according to claim 1 , wherein a ratio of a thickness of the first dielectric passivation layer to a thickness of the second dielectric passivation layer is greater than or equal to 0.9 and less than or equal to 1.1.

9 . The back contact solar cell according to claim 1 , wherein a thickness of the first dielectric passivation layer and a thickness of the second dielectric passivation layer is greater than or equal to 52 nm and less than or equal to 175 nm.

10 . The back contact solar cell according to claim 1 , wherein the first passivation sub-layer is an aluminum oxide layer,
wherein under a test condition in which an exposure time is 0.2s and a light intensity is 1 sun:
a PL value corresponding to the side of the first passivation sub-layer comprised in the first dielectric passivation layer that faces away from the semiconductor substrate is greater than or equal to 5000; and
a PL value corresponding to the side of the first passivation sub-layer comprised in the second dielectric passivation layer that faces away from the semiconductor substrate is greater than or equal to 16500.

11 . The back contact solar cell according to claim 1 , wherein the first passivation sub-layer is an aluminum oxide layer, and
wherein under a test condition in which an exposure time is 0.2s and a light intensity is 1 sun, a ratio of a PL value corresponding to the side of the first passivation sub-layer comprised in the second dielectric passivation layer that faces away from the semiconductor substrate to a PL value corresponding to the side of the first passivation sub-layer comprised in the first dielectric passivation layer that faces away from the semiconductor substrate is greater than or equal to 2.5 and less than or equal to 3.4.

12 . The back contact solar cell according to claim 1 , wherein a surface reflectance of the side of the first doped semiconductor part facing away from the semiconductor substrate is greater than a surface reflectance of the side of the second doped semiconductor part facing away from the semiconductor substrate.

13 . The back contact solar cell according to claim 12 , wherein a side of the first doped semiconductor part facing away from the semiconductor substrate has a first texture structure, and a side of the second doped semiconductor part facing away from the semiconductor substrate has a second texture structure, and wherein a one-dimensional size of the first texture structure is different from a one-dimensional size of the second texture structure.

14 . The back contact solar cell according to claim 1 , wherein the first doped semiconductor part is a P-type doped semiconductor part, and the second doped semiconductor part is an N-type doped semiconductor part, and
wherein a doping concentration of a dopant in the first doped semiconductor part is less than a doping concentration of a dopant in the second doped semiconductor part, and wherein a thickness of the first doped semiconductor part is greater than a thickness of the second doped semiconductor part.

15 . The back contact solar cell according to claim 1 , wherein the first passivation sub-layer comprised in the first dielectric passivation layer comprises a hydrogen-containing passivation layer, and wherein a portion of the hydrogen-containing passivation layer has micro-structures.

16 . The back contact solar cell according to claim 15 , wherein the first passivation sub-layer comprised in the first dielectric passivation layer and the first passivation sub-layer comprised in the second dielectric passivation layer each comprise the hydrogen-containing passivation layer, and
wherein a distribution density of the micro-structures in the first passivation sub-layer comp

Assignees

• Longi Green Energy Technology Co Ltd

Inventors

• Li Zhenguo
• Tong Hongbo
• Sun Zhanfeng
• Yu Long
• Li Jinyu

Classifications

• H10F19/908

  for back-contact photovoltaic cells · CPC title

• H02S50/15

  using optical means, e.g. using electroluminescence · CPC title

• H10F77/219

  Arrangements for electrodes of back-contact photovoltaic cells · CPC title

• H10F10/166

  the Group IV-IV heterojunctions being heterojunctions of crystalline and amorphous materials, e.g. silicon heterojunction [SHJ] photovoltaic cells · CPC title

• H10F10/165

  the heterojunctions being Group IV-IV heterojunctions, e.g. Si/Ge, SiGe/Si or Si/SiC photovoltaic cells · CPC title