CN-115842064-B - HJT solar cell and preparation method thereof

CN115842064BCN 115842064 BCN115842064 BCN 115842064BCN-115842064-B

Abstract

The application discloses a HJT solar cell and a preparation method thereof, wherein the preparation method comprises the steps of providing a heterojunction cell substrate, and depositing transparent conductive oxide layers on two sides of the heterojunction cell substrate; preparing a transparent conductive oxide layer, preparing a mask layer on the surface of the transparent conductive oxide layer, carrying out graphical opening treatment on the mask layer to form a mask layer with graphical openings, sequentially carrying out roughening, presoaking and metal activating treatment on the graphical openings of the mask layer in a dark environment to obtain a pretreated heterojunction battery substrate, and sequentially carrying out pre-plating, oxidation removal, copper electroplating, film stripping and chemical tinning treatment on the pretreated heterojunction battery substrate to obtain the HJT solar battery. According to the method, PVD (physical vapor deposition) sputtering of a copper seed layer and etching are not needed on the two sides of the battery, discharge of copper-containing wastewater is avoided, TCO damage caused by etching of the copper seed layer is reduced, invalid line width shielding areas are reduced, and the defects of the traditional technology are overcome.

Inventors

HU GUANGBAO
LI JIAN
YU CAO

Assignees

苏州迈为科技股份有限公司

Dates

Publication Date: 20260512
Application Date: 20230207

Claims (9)

1. A method of fabricating a HJT solar cell, the method comprising the steps of: providing a heterojunction cell substrate, and depositing transparent conductive oxide layers on both sides of the heterojunction cell substrate; manufacturing a mask layer on the surface of the transparent conductive oxide layer; carrying out graphical opening treatment on the mask layer to form a mask layer with graphical openings; Under a dark environment, sequentially performing roughening, presoaking and metal activation treatment on the graphical opening of the mask layer to prepare a pretreated heterojunction battery substrate; sequentially performing pre-plating, oxidation removal, copper electroplating, film stripping and chemical tinning treatment on the pre-treated heterojunction battery substrate to obtain HJT solar batteries; the pre-plating adopts chemical pre-plating.
2. The method according to claim 1, wherein the roughening treatment comprises placing the heterojunction cell substrate with the patterned opening in an acid solution with a mass concentration of 3% -15%, and treating at 35 ℃ -90 ℃ for 30 s-200 s.
3. The method according to claim 1, wherein the pre-dip treatment comprises placing the roughened heterojunction cell substrate in a pre-dip solution, and treating at 20-30 ℃ for 30-300 s; the prepreg solution comprises 150-350 g/L of sodium sulfate, 150-250 mL/L of 50% sulfuric acid solution and 2-4 g/L of sulfur compounds.
4. The production method according to claim 1, wherein the metal activation treatment is a palladium activation treatment, a platinum activation treatment, a ruthenium activation treatment, a silver activation treatment, or a zinc activation treatment.
5. The method of claim 4, wherein the metal activation treatment comprises placing the pre-impregnated heterojunction cell substrate in an activation solution comprising a stabilizer, an acid, and a metal salt of the corresponding acid ion; The stabilizer is one or more selected from malic acid, citric acid, lactic acid, propionic acid, glycolic acid, triethanolamine, glycine, thiourea, 4-methylpyridine, sodium dodecyl sulfate and potassium iodide; the acid is selected from one or more of nitric acid, sulfuric acid, hydrochloric acid, chloric acid, perchloric acid and methanesulfonic acid.
6. The method of claim 1, wherein the preplating is preplating, preplating or preplating.
7. The preparation method according to claim 1, wherein the deoxidation process comprises the steps of placing the heterojunction battery substrate subjected to the pretreatment in an deoxidation solution for reaction at 20-30 ℃ for 30-200 s; the deoxidization solution is an HF solution.
8. The method according to claim 1, wherein the electrolytic copper plating process comprises placing the deoxidized heterojunction cell substrate in an electrolytic copper plating solution, and reacting for 100 s-1200 s at 20 ℃ to 30 ℃ to form a copper electrode; The copper electroplating solution comprises 90-180 g/L of copper sulfate and 90-180 g/L of sulfuric acid.
9. HJT solar cell, characterized in that it is produced by the production method according to any one of claims 1 to 8.

Description

HJT solar cell and preparation method thereof Technical Field The application relates to the technical field of solar cells, in particular to a HJT solar cell and a preparation method thereof. Background HJT solar cells are a new type of solar cells, and have become a new hot spot in the solar field in recent years. The electrode of the traditional HJT solar cell is usually printed with a positive electrode, a negative electrode and an electric field on the surface of a silicon wafer by adopting a screen printing process through low-temperature silver-aluminum paste, but the unit consumption of the silver paste is too high and the cost is high due to the high resistivity of the low-temperature silver paste. In order to reduce the cost, researchers have further proposed a seed copper electroplating process, in which a seed layer is plated on the surface of a silicon wafer TCO by PVD sputtering to improve the contact characteristics, because the adhesion of directly electroplated metal on the transparent conductive oxide layer (TCO) is poor and the metal is easily detached. However, in order to avoid the short circuit of the battery piece and expose the TCO layer, the redundant copper seed layer needs to be removed in the subsequent process, and the etching of the copper seed layer often brings a series of problems of the emission of copper-containing wastewater in the later stage, the damage to the TCO, the actual shielding width of the grid line being far greater than the width of the grid line, the excessively large ineffective line width shielding area and the like, so that the progress of the industrialized application of the heterojunction battery is limited. Disclosure of Invention Based on the method, the HJT solar cell and the preparation method thereof are provided, and the PVD (physical vapor deposition) sputtering copper seed layer and etching are not needed on the two sides of the cell, so that the discharge of copper-containing wastewater is avoided, TCO (transparent conductive oxide) damage caused by etching of the copper seed layer is reduced, an invalid line width shielding area is reduced, and the defects of the traditional technology are overcome. In a first aspect of the present application, there is provided a method for manufacturing HJT solar cells, comprising the steps of: Providing a heterojunction battery substrate, and depositing transparent conductive oxide layers on two sides of the heterojunction battery substrate; manufacturing a mask layer on the surface of the transparent conductive oxide layer; carrying out graphical opening treatment on the mask layer to form a mask layer with graphical openings; Under dark environment, sequentially coarsening, presoaking and activating metals at the graphical opening of the mask layer to obtain a pretreated heterojunction battery substrate; and sequentially performing pre-plating, oxidation removal, copper electroplating, film stripping and chemical tinning treatment on the pre-treated heterojunction cell substrate to obtain the HJT solar cell. In some embodiments, roughening includes placing the heterojunction cell substrate with the patterned opening in an acid solution with a mass concentration of 3% -15%, and treating at 35 ℃ -90 ℃ for 30 s-200 s. In some embodiments, the pre-dip treatment comprises placing the roughened heterojunction cell substrate in a pre-dip solution, and treating at 20-30 ℃ for 30-300 s; the prepreg solution comprises 150-350 g/L of sodium sulfate, 150-250 mL/L of 50% sulfuric acid solution and 2-4 g/L of sulfur compound. In some embodiments, the sulfur-based compound is selected from sodium propanesulfonate and thiourea. In some embodiments, the metal activation treatment is selected from palladium activation treatment, platinum activation treatment, ruthenium activation treatment, silver activation treatment, or zinc activation treatment. In some embodiments, the metal activation treatment comprises placing the pre-impregnated heterojunction cell substrate in an activation solution and treating at 20 ℃ to 30 ℃ for 30s to 300s. In some embodiments, the activation solution comprises a stabilizer, a metal salt of an acid with the corresponding acid ion; The stabilizer is one or more selected from malic acid, citric acid, lactic acid, propionic acid, glycolic acid, triethanolamine, glycine, thiourea, potassium iodide, 4-methylpyridine and sodium dodecyl sulfate; The acid is selected from one or more of nitric acid, sulfuric acid, hydrochloric acid, chloric acid, perchloric acid and methylsulfonic acid. In some embodiments, the activating solution comprises 5mg/L to 80mg/L of palladium sulfate, 3mg/L to 25mg/L of 4-methylpyridine, 1mg/L to 40mg/L of sodium dodecyl sulfate, 1mg/L to 40mg/L of sodium sulfate, and 18mL/L to 22mL/L of 50% sulfuric acid solution. In some embodiments, the preplating is preplating, or preplating. In some embodiments, the pre-plating is electroless pre-plating. In some embodiments, the nicke