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CN-122028541-A - Method for preparing silver bismuth sulfur film based on molecular formula ink knife coating

CN122028541ACN 122028541 ACN122028541 ACN 122028541ACN-122028541-A

Abstract

The invention discloses a method for preparing a silver bismuth sulfur film based on molecular formula ink knife coating, and belongs to the technical field of photoelectric materials. The invention adopts a knife coating method, can realize the coating technology of large-scale production, does not need complicated vacuum equipment, combines molecular-level precursor solution, and can obtain the AgBiS 2 film with high crystallinity, uniformity and compactness by precisely controlling the knife coating process parameters and the annealing process parameters. In addition, the silver source, the bismuth source and the sulfur source are dissolved in the organic solvent according to a specific molar ratio to form a clear molecular-level precursor solution, so that uniform mixing of reactants on a molecular level is ensured, precipitation or agglomeration is avoided, the thickness of the film can be flexibly and accurately regulated, specific requirements of different photoelectric devices on the thickness of the light absorption layer are met, the overall environmental friendliness is high, and the development trend of a green photoelectric technology is met.

Inventors

  • GU ENING
  • ZHANG ZIXIAN
  • FAN TING
  • Zeng Xinjuan
  • HUANG JINKUN
  • LONG ZHENZHEN

Assignees

  • 佛山大学

Dates

Publication Date
20260512
Application Date
20260325

Claims (10)

  1. 1. A method for preparing a silver bismuth sulfur film based on molecular formula ink knife coating, which is characterized by comprising the following steps: s1, cleaning a substrate, namely carrying out surface treatment on a fluorine-doped tin oxide substrate; s2, preparing a precursor solution, namely dissolving a silver source, a bismuth source and a sulfur source in an organic solvent according to a proportion, and stirring until the mixture is clear to obtain a molecular-grade precursor solution; S3, blade coating to form a film, namely uniformly coating the precursor solution on the surface of the cleaned fluorine-doped tin oxide substrate, and controlling blade coating process parameters to form a uniform wet film; s4, annealing treatment, namely placing the fluorine doped tin oxide substrate coated with the wet film on a heating table for annealing treatment, so that the precursor is converted into an AgBiS 2 film; S5, repeating the steps S3 and S4 for a plurality of times to regulate and control the thickness of the film.
  2. 2. The method of claim 1, wherein in step S1, the surface is post-plasma treated by ultrasonic cleaning, nitrogen blow-drying.
  3. 3. The method of claim 1, wherein in step S2, the molar ratio of the silver source, the bismuth source and the sulfur source is (1-1.2): 1 (2.5-2.75).
  4. 4. The method according to claim 1, wherein in step S2, the molar ratio of the silver source, bismuth source and sulfur source is 1:1:2.5.
  5. 5. A method according to claim 3, wherein in step S2, the concentration of silver ions in the molecular-level precursor solution is 0.25 mol/L to 0.3 mol/L.
  6. 6. The method according to claim 1, wherein in step S2, the organic solvent is at least one of dimethylformamide, dimethyl sulfoxide or 2-methoxyethanol.
  7. 7. The method according to claim 1, wherein in step S3, the precursor solution is used in an amount of 4 μl/cm 2 ~7.5 µL/cm 2 .
  8. 8. The method according to claim 1, wherein in the step S3, the height of the doctor blade is 0.15 mm to 0.4 mm, the doctor blade temperature is 20 ℃ to 80 ℃, and the doctor blade speed is 15 cm/min to 70 cm/min.
  9. 9. The method according to claim 1, wherein in the step S4, the annealing treatment process is that 1 min-3 min of heating treatment is performed at 60-65 ℃ and 2 min-5 min of heating treatment is performed at 200-400 ℃.
  10. 10. The silver-bismuth-sulfur film prepared by the method according to any one of claims 1-9, wherein the silver-bismuth-sulfur film is attached to a fluorine-doped tin oxide substrate and has a high-crystallinity, uniform and compact microstructure.

Description

Method for preparing silver bismuth sulfur film based on molecular formula ink knife coating Technical Field The invention relates to the technical field of photoelectric materials, in particular to a method for preparing a silver bismuth sulfur film based on molecular formula ink knife coating. Background AgBiS 2 is used as a novel inorganic photovoltaic absorption layer material, and has ideal optical band gap, extremely high light absorption coefficient, good stability and environment-friendly element composition, so that the AgBiS 2 has attracted wide attention in the field of thin film solar cells in recent years. Fluorine doped tin oxide (FTO) conductive glass is widely used as a transparent conductive substrate for optoelectronic devices due to its high light transmittance, excellent conductivity and excellent chemical and thermal stability, and is particularly suitable for the construction of double-sided and semitransparent solar cells. Therefore, the preparation of the high-quality AgBiS 2 film on the FTO substrate is a key premise for realizing the high-efficiency low-cost application of the AgBiS 2 film. At present, an absorption layer of the high-efficiency AgBiS 2 thin-film solar cell is mostly prepared by adopting a spin coating method, and a precursor of the absorption layer is usually nanocrystalline ink subjected to complex synthesis and ligand exchange treatment. Specifically, agBiS 2 nanocrystals are usually synthesized by high temperature injection and subjected to ligand exchange (e.g., using short chain ligands such as 3-mercaptopropionic acid, ethanedithiol, etc. instead of oleic acid) to improve their charge transport properties. The process involves multiple steps of synthesis, purification and exchange operations, and is complex, time consuming and costly. In addition, the obtained nanocrystalline ink has poor stability, is easy to agglomerate, and is difficult to meet the requirements of industrial production on material consistency and repeatability. Although the spin coating method is widely applied to small-area film formation in a laboratory, the material utilization rate is low (usually lower than 20%), and more than 80% of precursor solution is thrown away from a substrate in the film formation process, so that serious waste is caused. Meanwhile, the spin coating process is operated intermittently, is difficult to be compatible with continuous and large-area production modes (such as a roll-to-roll process), and limits the industrialized popularization of the spin coating process. The knife coating method is used as a large-scale coating technology, has the advantages of simple process, high material utilization rate, low cost, adaptation to continuous production and the like, and has good application prospect in the fields of organic photovoltaics and perovskite solar cells. However, no research report of preparing an AgBiS 2 film on an FTO substrate by combining a knife coating method with molecular ink is currently seen. To achieve this objective, the key technical difficulties are to develop AgBiS 2 molecular precursor solution with suitable rheological properties and stability, optimize blade coating process parameters (such as blade height, coating speed, substrate temperature, etc.) to control wet film spreading and crystallization behavior, and establish a heat treatment system matched with the blade coating process to obtain AgBiS 2 film with high crystallinity, phase purity, compactness and good adhesion to FTO. Therefore, the invention aims to provide a method for preparing an AgBiS 2 film on an FTO conductive substrate based on molecular ink and a knife coating process, which solves the problems of complex process, low material utilization rate, poor ink stability, difficulty in large scale and the like in the prior art and provides a feasible technical path for low-cost and large-area preparation of an AgBiS 2 film solar cell. Disclosure of Invention Based on the above, in order to solve one of the above technical problems, the invention provides a method for preparing a silver bismuth sulfur film based on molecular formula ink knife coating, which comprises the following specific technical scheme: A method for preparing a silver bismuth sulfur film based on molecular formula ink blade coating, comprising the following steps: s1, cleaning a substrate, namely carrying out surface treatment on a fluorine-doped tin oxide substrate; s2, preparing a precursor solution, namely dissolving a silver source, a bismuth source and a sulfur source in an organic solvent according to a proportion, and stirring until the mixture is clear to obtain a molecular-grade precursor solution; S3, blade coating to form a film, namely uniformly coating the precursor solution on the surface of the cleaned fluorine-doped tin oxide substrate, and controlling blade coating process parameters to form a uniform wet film; s4, annealing treatment, namely placing the fluorine doped tin oxide sub