Solar cell, manufacturing method thereof, and photovoltaic module

Patent metadata

Field	Value
Publication number	US-11804564-B2
Application number	US-202217737908-A
Country	US
Kind code	B2
Filing date	May 5, 2022
Priority date	Sep 16, 2021
Publication date	Oct 31, 2023
Grant date	Oct 31, 2023

Abstract

Provided is a solar cell, including: an N-type semiconductor substrate having a front surface and a rear surface opposite to the front surface; a boron diffusion layer arranged on the front surface of the N-type semiconductor substrate, a first passivation layer is provided on a surface of the boron diffusion layer, and a first electrode is provided passing through the first passivation layer to form an electrical connection with the N-type semiconductor substrate; and a phosphorus-doped polysilicon layer arranged on the rear surface of the N-type semiconductor substrate. A silicon oxide layer containing nitrogen and phosphorus is provided between the rear surface of the N-type semiconductor substrate and the phosphorus-doped polysilicon layer, a second passivation layer is provided on a surface of the phosphorus-doped polysilicon layer, and a second electrode is provided passing through the second passivation layer to form an electrical connection with the phosphorus-doped polysilicon layer.

First claim

What is claimed is:

1. A solar cell, comprising:
an N-type semiconductor substrate having a front surface and a rear surface opposite to the front surface;
a boron diffusion layer arranged on the front surface of the N-type semiconductor substrate, wherein a first passivation layer is provided on a surface of the boron diffusion layer, and a first electrode is provided passing through the first passivation layer to form an electrical connection with the N-type semiconductor substrate; and
a phosphorus-doped polysilicon layer arranged on the rear surface of the N-type semiconductor substrate, wherein a silicon oxide layer containing nitrogen and phosphorus is provided between the rear surface of the N-type semiconductor substrate and the phosphorus-doped polysilicon layer, a second passivation layer is provided on a surface of the phosphorus-doped polysilicon layer, and a second electrode is provided passing through the second passivation layer to form an electrical connection with the phosphorus-doped polysilicon layer,
wherein the silicon oxide layer comprises a first oxide sub-layer, a second oxide sub-layer, and a third oxide sub-layer, wherein the first oxide sub-layer is a nitrogen-doped silicon oxide layer, the second oxide sub-layer is made of silicon dioxide, and the third oxide sub-layer is a phosphorus-doped silicon oxide layer.

2. The solar cell according to claim 1 , wherein at least one of the first oxide sub-layer, the second oxide sub-layer, and the third oxide sub-layer contains Al and/or Ta.

3. The solar cell according to claim 1 , wherein the nitrogen-doped silicon oxide layer includes SiO x N y , where y/(x+y)<15%, and/or a doping concentration of nitrogen in the nitrogen-doped silicon oxide layer decreases from the N-type semiconductor substrate to the phosphorus-doped polysilicon layer.

4. The solar cell according to claim 1 , wherein the first oxide sub-layer has a thickness in a range from 1 Å to 2 Å.

5. The solar cell according to claim 1 , wherein a doping concentration of phosphorus in the phosphorus-doped silicon oxide layer is in a range from 1×10 10 cm −3 to 1×10 18 cm −3 , and/or a doping concentration of phosphorus in the phosphorus-doped silicon oxide layer increases from the N-type semiconductor substrate to the phosphorus-doped polysilicon layer.

6. The solar cell according to claim 1 , wherein the third oxide sub-layer has a thickness in a range from 2 Å to 3 Å.

7. The solar cell according to claim 1 , wherein the second oxide sub-layer has a thickness in a range from 8 Å to 10 Å, and/or the second oxide sub-layer has a pinhole density in a range from 10 −6 to 10 −3 .

8. The solar cell according to claim 1 , wherein a sum of thicknesses of the first oxide sub-layer, the second oxide sub-layer, and the third oxide sub-layer is less than or equal to 16 Å.

9. The solar cell according to claim 1 , wherein the phosphorus-doped polysilicon layer has a doping concentration in a range from 1×10 19 cm −3 to 1×10 21 cm −3 .

10. The solar cell according to claim 1 , wherein the first passivation layer includes at least one of silicon nitride, silicon oxynitride, and aluminum oxide, and/or the second passivation layer comprises at least one of silicon nitride, silicon oxynitride, and aluminum oxide.

11. The solar cell according to claim 1 , wherein the first electrode is a silver electrode or a silver/aluminum electrode, and/or the second electrode is a silver electrode.

12. A method for manufacturing a solar cell, comprising:
performing boron diffusion on a front surface of an N-type semiconductor substrate after the N-type semiconductor substrate is textured, to form a boron diffusion layer;
forming an oxide layer containing nitrogen and phosphorus on a rear surface of the N-type semiconductor substrate;
depositing a polysilicon layer on a surface of the oxide layer containing nitrogen and phosphorus, and performing secondary phosphorus diffusion on the polysilicon layer, to form a phosphorus-doped polysilicon layer;
forming a second passivation layer on a surface of the phosphorus-doped polysilicon layer;
forming a first passivation layer on a surface of the boron diffusion layer, and forming a first electrode by passing through the first passivation layer to be electrically connected to the boron diffusion layer; and
forming a second electrode by passing through the second passivation layer to be electrically connected to the phosphorus-doped polysilicon layer,
wherein the oxide layer comprises a first oxide sub-layer, a second oxide sub-layer, and a third oxide sub-layer, wherein the first oxide sub-layer is a nitrogen-doped silicon oxide layer, the second oxide sub-layer is made of silicon dioxide, and the third oxide sub-layer is a phosphorus-doped silicon oxide layer.

13. The method according to claim 12 , wherein forming an oxide layer containing nitrogen and phosphorus comprises:
during oxidization, performing primary phosphorus diffusion on an oxidized product to form the third oxide sub-layer; continuing the oxidization to form the second oxide sub-layer after the third oxide sub-layer is formed, wherein the second oxide sub-layer is provided between the third oxide sub-layer and the N-type semiconductor substrate; continuing the oxidization after the second oxide sub-layer is formed, and during the oxidization, performing nitrogen diffusion on the oxidized product to form the first oxide sub-layer, wherein the first oxide sub-layer is provided between the second oxide sub-layer and the N-type semiconductor substrate.

14. The method according to claim 12 , wherein continuing oxidization to form the second oxide sub-layer after the third oxide sub-layer comprises:
after O 2 is introduced at a flow rate in a range from 8 L/min to 10 L/min for 3 min to 5 min, stopping the introduction and performing oxidization, wherein a temperature of the oxidization is in a range from 500° C. to 530° C., and a time of the oxidization is in a range from 350 s to 450 s.

15. The method according to claim 12 , wherein continuing oxidization after the second oxide sub-layer is formed, and during the oxidization, performing nitrogen diffusion on an oxidized product to form the first oxide sub-layer comprises:
using a mixture of O 2 and N 2 O with a volume ratio of (2-4):1 as a doping source, introducing the mixture at a flow rate in a range from 8 L/min to 10 L/min for 3 min to 5 min, and performing nitrogen diffusion on the oxidized product after the introduction stops, wherein a temperature of the nitrogen diffusion is in a range from 500° C. to 530° C., and a time of the nitrogen diffusion is in a range from 40 s to 60 s.

16. The method according to claim 12 , wherein performing primary phosphorus diffusion on an oxidized product to form the third oxide sub-layer comprises:
using a phosphorus source as a doping source, introducing O 2 at a flow rate in a range from 10 L/min to 12 L/min for 3 min to 5 min, and performing primary phosphorus diffusion on the oxidized product after the introduction stops, wherein a temperature of the primary phosphorus diffusion is in a range from 780° C. to 820° C., and a time of the primary phosphorus diffusion is in a range from 50 s to 60 s.

17. A photovoltaic module, comprising a plurality of solar cell strings, wherein each of the plurality of solar cell strings comprises a plurality of solar cells, and at least one of the plurality of solar cells comprises:
an N-type semiconductor substrate having a front surface and a rear surface opposite to the front surface;
a boron diffusion layer arranged on the front

Assignees

• Jinko Solar Co Ltd

Inventors

• Qu Jiahua
• Jin Jingsheng
• Zhang Linan

Classifications

• H10F10/12

  Photovoltaic cells having only metal-insulator-semiconductor [MIS] potential barriers · CPC title

• H10F77/1226

  comprising multiple Group IV elements, e.g. SiC · CPC title

• H10F71/137

  Batch treatment of the devices · CPC title

• H10F77/315

  the coatings being antireflective or having enhancing optical properties · CPC title

• H10F77/311 Primary

  for photovoltaic cells · CPC title