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CN-121985631-A - Back contact solar cell

CN121985631ACN 121985631 ACN121985631 ACN 121985631ACN-121985631-A

Abstract

The application relates to a back contact solar cell, which comprises a semiconductor substrate and a passivation antireflection film, wherein a backlight surface of the semiconductor substrate is provided with a doped region, the doped region is provided with a tunneling oxide layer and a doped layer arranged on one side of the tunneling oxide layer far away from the semiconductor substrate, the passivation antireflection film comprises a first passivation antireflection film arranged on one side of the doped layer far away from the tunneling oxide layer, the doped region is provided with a tower-shaped texture structure, the tower-shaped texture structure comprises a top surface, a bottom surface and a side wall connected between the top surface and the bottom surface, the thickness of the first passivation antireflection film on the top surface and the bottom surface is larger than the thickness of the side wall, and the passivation antireflection film on the top surface and the bottom surface is larger than the passivation antireflection film on the side wall based on different crystal surface compositions on the doped region of the backlight surface, so as to meet different passivation and antireflection requirements on the doped region.

Inventors

  • LI WENBIN
  • WU CHENGKUN
  • REN YONG
  • CHEN DESHUANG

Assignees

  • 横店集团东磁股份有限公司

Dates

Publication Date
20260505
Application Date
20251212

Claims (10)

  1. 1. The utility model provides a back contact solar cell, includes semiconductor base member and passivation anti-reflection film, the back of the body face of semiconductor base member has the doped region, the doped region is equipped with tunnel oxide layer and locates tunnel oxide layer keeps away from the doped layer of semiconductor base member one side, its characterized in that, passivation anti-reflection film is including locating the doped layer is kept away from first passivation anti-reflection film of tunnel oxide layer one side, the doped region has tower base form texture, tower base form texture include top surface, bottom surface and connect in the top surface with the lateral wall between the bottom surface, first passivation anti-reflection film is in the top surface and the thickness of bottom surface is all greater than the thickness of lateral wall.
  2. 2. The back contact solar cell of claim 1, wherein the first passivation anti-reflection film has a thickness of 70nm to 110nm and a refractive index of 2.0 to 2.2.
  3. 3. The back contact solar cell of claim 1, wherein the doped regions are provided in plurality, the backlight has an isolation region for isolating adjacent doped regions, and the passivation anti-reflection film further comprises a second passivation anti-reflection film provided in the isolation region.
  4. 4. The back contact solar cell of claim 3, wherein the second passivation anti-reflection film has a thickness of 40nm to 70nm and a refractive index of 2.1 to 2.4.
  5. 5. The back contact solar cell of claim 3, wherein the thickness of the second passivation anti-reflection film at the bottom of the isolation region is d 1 and the thickness of the second passivation anti-reflection film at the sides of the isolation region is d 2 ,1＜d 1 / d 2 <2.
  6. 6. The back contact solar cell of claim 3, wherein the isolation region bottom has a plurality of pyramid-like textures, the pyramid-like textures comprise conical surfaces, a portion between adjacent pyramid-like textures is a substrate, and a thickness of the second passivation anti-reflection film at the conical surfaces is smaller than a thickness at the substrate.
  7. 7. The back contact solar cell of claim 3, wherein the first passivation anti-reflection film has a thickness D 1 , the second passivation anti-reflection film has a thickness D 2 ,1＜D 1 / D 2 <3, the first passivation anti-reflection film has a refractive index n 1 , and the second passivation anti-reflection film has a refractive index n 2 ,1＜n 2 / n 1 <1.3.
  8. 8. The back contact solar cell of claim 1, wherein the passivation and antireflection film further comprises a third passivation and antireflection film arranged on the light-facing surface of the semiconductor substrate, the thickness of the third passivation and antireflection film is 65 nm-90 nm, and the refractive index of the third passivation and antireflection film is 1.9-2.1; The first passivation antireflection film has a thickness D 1 , the third passivation antireflection film has a thickness D 3 ,1＜D 1 / D 3 <2, the first passivation antireflection film has a refractive index n 1 , and the third passivation antireflection film has a refractive index n 3 ,1＜n 1 / n 3 <1.5.
  9. 9. The back contact solar cell of claim 8, wherein the semiconductor substrate has a side surface connecting the light-facing surface and the back surface, the passivation and antireflection film further comprises a fourth passivation and antireflection film provided on the side surface, the fourth passivation and antireflection film has a thickness of 100nm to 160nm and a refractive index of 2.0 to 2.1; The first passivation anti-reflection film thickness is D 1 , the third passivation anti-reflection film thickness is D 3 , and the fourth passivation anti-reflection film thickness is D 4 ,0.5＜D 4 /（D 1 +D 3 ) <1.
  10. 10. The back contact solar cell according to any one of claims 1 to 9, wherein the refractive index and thickness of the passivation anti-reflection film at any position satisfy 80≤n×d≤350; wherein n is the refractive index of the passivation anti-reflection film, d is the thickness of the passivation anti-reflection film, and the unit is nm.

Description

Back contact solar cell Technical Field The application relates to the technical field of solar cells, in particular to a back contact solar cell. Background In the preparation process of the back contact solar cell, the back surface of the semiconductor substrate is required to be provided with different types of doped regions so as to realize the core electrical function of the cell. To avoid signal interference between the various doped regions, each doped region is typically physically isolated by an isolation region. To ensure light absorption efficiency, the doped region surface generally has a tower-like texture. However, the structure has obvious morphology difference, and the top, the side wall and the bottom of the structure have different parameter requirements on the passivation anti-reflection film. In the conventional passivation process, the prepared passivation anti-reflection film mostly adopts a single material system and preparation parameters, and cannot meet the requirements of the doped region on the back of the substrate on different passivation and anti-reflection. Disclosure of Invention Based on this, it is necessary to provide a back contact solar cell, and optimize and improve the passivation and antireflection film to meet different passivation and antireflection requirements of different parts of the back doped region. The application provides a back contact solar cell, which comprises a semiconductor substrate and a passivation antireflection film, wherein a backlight surface of the semiconductor substrate is provided with a doped region, the doped region is provided with a tunneling oxide layer and a doped layer arranged on one side of the tunneling oxide layer far away from the semiconductor substrate, the passivation antireflection film comprises a first passivation antireflection film arranged on one side of the doped layer far away from the tunneling oxide layer, the doped region is provided with a tower-shaped texture structure, the tower-shaped texture structure comprises a top surface, a bottom surface and a side wall connected between the top surface and the bottom surface, and the thickness of the first passivation antireflection film on the top surface and the bottom surface is larger than that of the side wall. It can be understood that the passivation and antireflection film thickness of the doped region of the backlight surface is subjected to region customization, and the passivation and antireflection film thickness of the side wall of the tower-shaped texture structure is configured to be smaller than the thickness of the top surface and the bottom surface, so that different requirements of different parts of the doped region on passivation and antireflection are met. In one embodiment, the thickness of the first passivation anti-reflection film is 70 nm-110 nm, and the refractive index is 2.0-2.2. In one embodiment, the doped regions are provided in plurality, the backlight surface is provided with an isolation region for isolating adjacent doped regions, and the passivation anti-reflection film further comprises a second passivation anti-reflection film arranged in the isolation region. In one embodiment, the thickness of the second passivation anti-reflection film is 40 nm-70 nm, and the refractive index is 2.1-2.4. In one embodiment, the thickness of the second passivation and anti-reflection film at the bottom of the isolation region is d 1, and the thickness of the second passivation and anti-reflection film at the side of the isolation region is d 2,1＜d1/ d2 <2. In one embodiment, the bottom of the isolation region is provided with a plurality of pyramid-shaped texture structures, the pyramid-shaped texture structures comprise conical surfaces, a part between adjacent pyramid-shaped texture structures is a substrate, and the thickness of the second passivation anti-reflection film on the conical surfaces is smaller than that of the second passivation anti-reflection film on the substrate. In one embodiment, the first passivation anti-reflection film has a thickness D 1, the second passivation anti-reflection film has a thickness D 2,1＜D1/ D2 <3, the first passivation anti-reflection film has a refractive index n 1, and the second passivation anti-reflection film has a refractive index n 2,1＜n2/ n1 <1.3. In one embodiment, the passivation and antireflection film further comprises a third passivation and antireflection film arranged on the light-facing surface of the semiconductor substrate, wherein the thickness of the third passivation and antireflection film is 65-90 nm, and the refractive index of the third passivation and antireflection film is 1.9-2.1; The first passivation antireflection film has a thickness D 1, the third passivation antireflection film has a thickness D 3,1＜D1/ D3 <2, the first passivation antireflection film has a refractive index n 1, and the third passivation antireflection film has a refractive index n 3,1＜n1/ n3 <1.5. In one