Texturing and cleaning method of heterojunction solar cell

A solar cell and heterojunction technology, applied in circuits, photovoltaic power generation, electrical components, etc., can solve the problems of unclean cleaning, affecting the electrical performance of the cell, and insufficient reaction, so as to improve the passivation effect and reduce the EL defect. rate, improve the effect of Voc and FF

CN110993724AInactive Publication Date: 2020-04-10JINENG CLEAN ENERGY TECH LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2020-04-10
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a texturing and cleaning method for a heterojunction solar cell. The texturing and cleaning method sequentially comprises the following steps: pre-cleaning a silicon wafer, roughly polishing and texturing the silicon wafer, carrying out texturing surface smoothing treatment, carrying out alkali cleaning, carrying out acid cleaning, and carrying out DHF cleaning and drying.According to the cleaning method, after alkali cleaning is adjusted to smoothing treatment, due to the fact that acid cleaning is adopted for smoothing treatment, alkali cleaning is added after acid cleaning, residual acid cleaning liquid before cleaning can be neutralized, and marks formed before cleaning can be removed in a slight corrosion mode. Through the optimized texturing process, the optimal cleaning effect can be achieved, an EL reject ratio is effectively reduced, and the Voc and FF of the heterojunction cell are improved.
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Description

Technical field

[0001] The invention belongs to the field of photovoltaic solar cell manufacturing, and relates to a texturing cleaning method for heterojunction solar cells. Background technique

[0002] Solar photovoltaic power generation has great application prospects. At present, high-efficiency crystalline silicon cells have become the mainstream of market research and development. Heterojunction battery, which adopts amorphous silicon / crystalline silicon heterojunction structure, is a high-efficiency crystalline silicon solar cell that can be realized at low cost. The texturing cleaning process is a crucial step in the manufacturing process of heterojunction solar cells and has a significant impact on the electrical properties of the finished cells. Therefore, optimizing the wet chemical treatment technology of the silicon wafer surface to reduce the defects and impurities introduced by the unclean surface of the silicon wafer, thereby reducing the carrier recombination l...

Examples

Embodiment 1

[0039] A method for fabricating and cleaning heterojunction solar cells, the specific operation steps are as follows:

[0040] (1) Wafer pre-cleaning: use ammonia and H 2 O 2 The mixed solution is washed for 180s at 70℃; the mass percentage of ammonia in the mixed solution is 2%, H 2 O 2 The mass percentage is 4%;

[0041] (2) Rough polishing: clean the silicon wafers cleaned in step (1) with an alkaline solution at 80°C for 60 seconds; the alkaline solution is KOH, and the mass percentage of KOH is 10%;

[0042] (3) Texturing: the silicon wafer after rough polishing in step (2) is treated with an alkali solution and alcohol additives at 70°C for 600s; the alkali solution is KOH, and the mass percentage of KOH is 5%;

[0043] (4) Smooth surface treatment: Use HF and HNO on the silicon wafer after step (3). 3 The mixed solution is treated at 5℃ for 60s; the mass percentage of HF in the mixed solution is 0.9%, HNO 3 The mass percentage is 50%;

[0044] (5) Alkaline cleaning: use ammonia w...

Embodiment 2

[0050] A method for fabricating and cleaning heterojunction solar cells, the specific operation steps are as follows:

[0051] (1) Wafer pre-cleaning: use ammonia and H 2 O 2 The mixed solution is cleaned at 80℃ for 300s; the mass percentage of ammonia in the mixed solution is 3%, H 2 O 2 The mass percentage is 6%;

[0052] (2) Rough polishing: Use an alkaline solution to clean the silicon wafer after step (1) at 90°C for 180s; NaOH solution, the mass percentage of NaOH is 13%;

[0053] (3) Texturing: the silicon wafer after rough polishing in step (2) is treated with an alkali solution and alcohol additives at 80°C for 800s; the alkali solution is a NaOH solution, and the mass percentage of NaOH is 8%;

[0054] (4) Smooth surface treatment: Use HF and HNO on the silicon wafer after step (3). 3 The mixed solution is treated at 15°C for 100s; the mass percentage of HF in the mixed solution is 1.5%, HNO 3 The mass percentage is 70%;

[0055] (5) Alkaline cleaning: use ammonia water and H ...

Embodiment 3

[0061] A method for fabricating and cleaning heterojunction solar cells, the specific operation steps are as follows:

[0062] (1) Wafer pre-cleaning: use ammonia and H 2 O 2 The mixed solution is cleaned at 80℃ for 300s; the mass percentage of ammonia in the mixed solution is 5%, H 2 O 2 The mass percentage is 7%;

[0063] (2) Rough polishing: use an alkaline solution to clean the silicon wafer after step (1) at 90°C for 180s; the alkaline solution is a KOH solution, and the mass percentage of KOH is 15%;

[0064] (3) Texturing: The silicon wafer after rough polishing in step (2) is treated with an alkaline solution and alcohol additives at 80°C for 700s; the alkaline solution is a KOH solution, and the mass percentage of KOH is 6%;

[0065] (4) Smooth surface treatment: Use HF and HNO on the silicon wafer after step (3). 3 The mixed liquor is treated at 20℃ for 180s; the mass percentage of HF in the mixed liquor is 2.0%, HNO 3 The mass percentage is 80%;

[0066] (5) Alkaline cleaning...