CN103474128B - A kind of method of preparing copper-indium-galliun-selenium film solar cell - Google Patents

Abstract

The invention discloses a kind of method of preparing copper-indium-galliun-selenium film solar cell, comprise: (1) starches composite conducting molybdenum by serigraphy, blade coating or is sprayed on ceramic substrate, then through 150-250 DEG C of oven dry, 450-1150 DEG C heat treatment and 150-250 DEG C of annealing, make back electrode, this composite conducting molybdenum slurry comprises the component of following weight portion: molybdenum powder 50-80 weight portion, lead-free glass powder 5-15 weight portion, organic carrier 10-25 weight portion and the additive 5-10 weight portion of particle diameter 0.01-50 μ m; Wherein organic carrier comprises that mass ratio is epoxy resin and the organic solvent of 1-5:9-20, and additive comprises appropriate NaOH, thickener, plasticizer and surfactant; (2) on the basis of above-mentioned back electrode, prepare copper-indium-galliun-selenium film solar cell. The composite conducting molybdenum slurry that method of the present invention is used can adopt antivacuum technology of preparing to prepare the back electrode of copper-indium-galliun-selenium film solar cell, and technique is simple, reduces manufacturing cost.

Description

A kind of method for preparing copper indium gallium selenide thin film solar cell

technical field

The invention belongs to the field of preparation of solar cell electrodes, and in particular relates to a method for preparing copper indium gallium selenium thin film solar cells.

Background technique

In today's increasingly serious energy crisis, the research and application of new energy is becoming increasingly important. As an important part of the new energy industry, solar energy has the advantages of being clean, pollution-free, inexhaustible, safe and harmless. CIGS solar cells have the characteristics of stable performance, strong radiation resistance, low production cost, environmental protection and high efficiency, and may become the next generation of commercialized thin-film solar cells. However, the solar energy industry still has disadvantages such as high cost and instability. In my country, the application of solar energy is basically still in large-scale power stations, and large-scale power stations are basically distributed in areas with low population density such as Northwest China. In other regions of my country, Especially in big cities there are few applications. As a promising and important direction for the development of today's solar energy industry, BIPV can well solve the application of solar energy in urban areas. At present, building integrated photovoltaics mainly integrates silicon-based and other solar panels on the surface of buildings such as roofs. This method will not only increase additional costs, but also affect the appearance.

Contents of the invention

The purpose of the present invention is to overcome the defects of the prior art and provide a method for preparing copper indium gallium selenium thin film solar cells.

Technical scheme of the present invention is as follows:

A method for preparing a copper indium gallium selenide thin film solar cell, comprising:

(1) The composite conductive molybdenum paste is screen printed, scraped or sprayed on the ceramic substrate, then dried at 150-250°C, heat treated at 450-1150°C and annealed at 150-250°C to obtain the back electrode, The composite conductive molybdenum paste comprises the following components by weight:

Wherein the organic carrier includes an epoxy resin and an organic solvent with a mass ratio of 1-5:9-20, the additive includes an appropriate amount of NaOH, a thickener, a plasticizer and a surfactant, and the epoxy resin is E44 and E51 epoxy resin One or mixed, the organic solvent includes polyethylene glycol 200, the organic solvent is composed of polyethylene glycol 200, polyethylene glycol 400 and terpineol, wherein the mass ratio of terpineol to polyethylene glycol 200 is 0 -30:55-100, the mass ratio of polyethylene glycol 400 and polyethylene glycol 200 is 0-15:55-100;

(2) A copper indium gallium selenide thin film solar cell is prepared on the basis of the above-mentioned back electrode.

NaOH is mainly used to provide sodium element to promote the grain growth of copper indium gallium selenide film, which is beneficial to improve the efficiency of solar cells; thickener is a rheological additive, and its main function is to adjust the viscosity of conductive paste Degree and plasticity, improve cohesion.

The molybdenum powder with a particle size of 0.01-50 μm: when the molybdenum powder particles used are too large, during the sintering process of the molybdenum paste, the bonding between the molybdenum particles is not tight enough, the film layer is rough, there are many sintering defects, and the performance of the electrode When the particle size of molybdenum powder is too small, due to the large surface energy, the particles are more likely to agglomerate and not easy to disperse, and it is not easy to print and level when the content is above a certain fixed content, the electrode preparation is difficult, and the cost is correspondingly greatly increased.

The lead-free glass powder enables the molybdenum slurry to connect, tighten and fix the molybdenum particles of the conductive phase during the heat treatment process, forming a dense conductive film and firmly bonding the entire film layer and the substrate. In addition, the addition of the glass powder can improve the performance of the conductive paste system in various aspects, such as making the components of the conductive paste disperse more uniformly; the selection of the percentage composition of the glass powder can also adjust the heat treatment temperature of the molybdenum paste, and the heat treatment temperature of the preparation is 400-1200 Molybdenum paste used at ℃.

The epoxy resin is one or a mixture of E44 and E51 epoxy resins. It has excellent adhesion, anti-oxidation, and corrosion resistance. It can also adjust the viscosity of the slurry. In addition, it can be modified by adding a small amount of polyurethane to make it easier to cure.

The organic solvent includes polyethylene glycol 200, and the organic solvent is composed of polyethylene glycol 200, polyethylene glycol 400 and terpineol, wherein the mass ratio of terpineol to polyethylene glycol 200 is 0-30:55-100 , the mass ratio of polyethylene glycol 400 to polyethylene glycol 200 is 0-15:55-100. The organic solvents mentioned above are non-toxic and have good wettability to molybdenum powder. They can evenly wrap the molybdenum powder particles to facilitate the uniform dispersion of the molybdenum powder particles, so that the conductive paste is not easy to agglomerate and precipitate. Among them, terpineol is colorless It is a viscous liquid with a boiling point of 220.85°C. It contains oxygen atoms in its structure, which can reduce the aggregation of molybdenum nano-sized particles. At the same time, it can also control the volatilization speed when the slurry is dried, preventing the coating film from partially evaporating too fast. Uneven shrinkage leads to cracking; polyethylene glycol with a relatively low molecular weight has wide compatibility with various solvents, and is a good solvent and solubilizer, making the entire slurry system mix more uniformly and controlling the drying rate of the slurry And the solubility of additives such as thickeners. In addition, polyethylene glycol-400 is also a defoamer, which can prevent bubbles from appearing on the liquid surface during the stirring process. Polyethylene glycol-200 is also used as a humectant and viscosity thinner. If the viscosity of the slurry is too high, it can Add polyethylene glycol-200 to adjust. During the sintering process, these solvents can be gradually volatilized or decomposed to avoid voids on the surface and inside of the film layer, and will evaporate completely at a certain temperature without residual ash.

In a preferred embodiment of the present invention, the thickener is one or a mixture of ethyl cellulose, butyl cellulose, hydroxyethyl cellulose and methyl hydroxyethyl cellulose; not only can make pulp Thickening of the slurry, it has a certain mechanical strength after sintering, and it can also make the slurry not easy to oxidize and precipitate, improve the rheology of the slurry, and endow the conductive slurry with excellent mechanical properties and storage stability. After volatilization, a tough film is formed, which can be thermally decomposed and escaped without residual ash at high temperature (above about 300°C).

The plasticizer is an organic polymer plasticizer with flexible groups;

The surfactant includes one or a mixture of ethanol, toluene, sorbitan trioleate, and lecithin. Among them, sorbitan trioleate has good compatibility in organic media, which improves the wettability of organic solvents. In addition, the higher hydroxyl value and molecular weight can ensure the suspension of more metal particles while adsorbing them. The stability of molybdenum powder has a promoting effect; ethanol has good wettability to molybdenum powder particles, and has good solubility to other additives such as ethyl cellulose.

In a preferred embodiment of the present invention, the plasticizer includes dibutyl phthalate, polyester plasticizer or polyol ester plasticizer. The plasticizer mentioned above can increase the plasticity of the polymer and the viscosity of the conductive paste, so as to achieve the purpose of optimizing the leveling, thixotropy and processability of the conductive paste.

Finally, according to different application conditions, such as different substrates, other flow control agents, gelling agents, thixotropic agents and other additives can be added to change the rheological and thixotropic properties of the conductive paste.

The beneficial effects of the present invention are:

1. Compared with the prior art, the composite conductive molybdenum paste used in the method of the present invention can adopt non-vacuum preparation technology to prepare the back electrode of copper indium gallium selenium thin film solar cell, that is, adopt screen printing method, spraying method or scraping method The coating method has simple process and reduces manufacturing cost.

2. The solar cells prepared in the present invention can be directly integrated on building materials, which is beneficial to realize building integration of photovoltaics.

3. The molybdenum film formed on the ceramic by the composite conductive molybdenum paste prepared by the present invention is resistant to high temperature, and is convenient for high temperature treatment when preparing other layers of copper indium gallium selenide.

Description of drawings

Fig. 1 is one of the scanning electron micrographs of the composite conductive molybdenum paste prepared in Example 1 of the present invention on a ceramic substrate after heat treatment at 1100°C;

Fig. 2 is the second scanning electron microscope photo of the composite conductive molybdenum paste prepared in Example 1 of the present invention after heat treatment at 1100°C on the ceramic substrate;

Fig. 3 is one of the scanning electron micrographs of the composite conductive molybdenum paste prepared in Example 2 of the present invention on a ceramic substrate after heat treatment at 900°C;

Fig. 4 is the second scanning electron micrograph of the composite conductive molybdenum paste prepared in Example 2 of the present invention after heat treatment at 900°C on the ceramic substrate.

detailed description

The technical solutions of the present invention will be further illustrated and described below through specific embodiments.

Example 1

Mix 7g molybdenum powder (particle size 0.01-50μm), 0.5g glass powder (lead-free glass powder), 0.5g terpineol, 1g polyethylene glycol-200, 0.25g polyethylene glycol-400, 0.1g epoxy Resin E44 (or E51), 0.005g NaOH, 0.1g ethyl cellulose, 0.01g dibutyl phthalate, 0.03g Span 85 (sorbitan trioleate), 0.5g ethanol, 0.005g silicone oil Put them together and mix evenly to prepare a composite conductive molybdenum paste.

Molybdenum paste is screen-printed or scraped-coated on a ceramic substrate, dried at 200°C, then heat-treated at 1100°C for 0.5 hour, and kept at 200°C for 2 hours to prepare a conductive molybdenum film electrode (ie, the back electrode). By using a scanning electron microscope (SEM) to observe their surface and cross-section (as shown in Figure 1 and Figure 2), use a four-probe resistance tester to measure the sheet resistance of the film for characterization, and calculate the resistivity. Adopt the American Society for Testing Materials (American Society for Testing Materials, ASTM) standard test method ASTM-D3359-08, Standard Test Methods for Measuring Adhesion by Tape Test to carry out the adhesion test and characterization of the film, and the test results are shown in Table 1 below:

Table 1 Sample resistivity and adhesion test results

Continue to prepare copper indium gallium selenide thin film solar cell on the conductive molybdenum thin film electrode.

Example 2

Mix 7g molybdenum powder (particle size 0.01-50μm), 0.5g glass powder (lead-free glass powder), 0.5g terpineol, 1g polyethylene glycol-200, 0.25g polyethylene glycol-400, 0.1g epoxy Resin E44 (or E51), 0.005g NaOH, 0.1g ethyl cellulose, 0.01g dibutyl phthalate, 0.03g Span 85 (sorbitan trioleate), 0.5g ethanol, 0.005g silicone oil Put them together and mix evenly to prepare a composite conductive molybdenum paste.

Molybdenum paste was screen-printed or scraped-coated on a ceramic substrate, dried at 200°C, then heat-treated at 900°C for 0.5 hours, and kept at 200°C for 2 hours to prepare a conductive molybdenum film electrode. By using a scanning electron microscope (SEM) to observe their surface and cross-section (as shown in Figure 3 and Figure 4), use a four-probe resistance tester to measure the sheet resistance of the film for characterization, and calculate the resistivity. Adopt American Society for Testing Materials (American Society for Testing Materials, ASTM) standard test method ASTM-D3359-08, StandardTestMethodsforMeasuringAdhesionbyTapeTest to carry out the adhesion test characterization of the film, the test results are shown in Table 2 below:

Table 2 Sample resistivity and adhesion test results

Continue to prepare copper indium gallium selenide thin film solar cell on the conductive molybdenum thin film electrode.

Those skilled in the art can adjust in the following process conditions, and obtain the same or close technical effect with the above-mentioned embodiment:

Annealing temperature 150-250°C;

Described organic solvent also comprises terpineol and/or polyethylene glycol 400, and the mass ratio of terpineol and polyethylene glycol 200 is 0-30:55-100, and the mass ratio of polyethylene glycol 400 and polyethylene glycol 200 The mass ratio is 0-15:55-100.

The thickener is one or mixed in ethyl cellulose, butyl cellulose, hydroxyethyl cellulose and methyl hydroxyethyl cellulose;

The plasticizer is an organic polymer plasticizer with flexible groups, preferably including dibutyl phthalate, polyester plasticizer or polyol ester plasticizer;

The surfactant includes one or a mixture of ethanol, toluene, sorbitan trioleate, and lecithin.

The above is only a preferred embodiment of the present invention, so the scope of the present invention cannot be limited accordingly, that is, equivalent changes and modifications made according to the patent scope of the present invention and the content of the specification should still be covered by the present invention In the range.

Claims (3)

1. a method of preparing copper-indium-galliun-selenium film solar cell, is characterized in that: comprising:

(1) composite conducting molybdenum is starched by serigraphy, blade coating or is sprayed on ceramic substrate, then through 150-250 DEG COven dry, 450-1150 DEG C heat treatment and 150-250 DEG C of annealing, make back electrode, and this composite conducting molybdenum is starched by following weight portionComponent composition:

Wherein organic carrier comprises that mass ratio is epoxy resin and the organic solvent of 1-5:9-20, and additive comprises in right amountNaOH, thickener, plasticizer and surfactant, epoxy resin is a kind of or mixing in E44 and E51 epoxy resin,Organic solvent comprises Macrogol 200, and organic solvent is made up of Macrogol 200, PEG400 and terpinol, itsThe mass ratio of middle terpinol and Macrogol 200 is 0-30:55-100, the quality of PEG400 and Macrogol 200Than being 0-15:55-100;

(2) on the basis of above-mentioned back electrode, prepare copper-indium-galliun-selenium film solar cell.

2. a kind of method of preparing copper-indium-galliun-selenium film solar cell as claimed in claim 1, is characterized in that: instituteStating thickener is a kind of or mixing in ethyl cellulose, butyl cellulose, hydroxyethylcellulose and methyl hydroxyethylcellulose;Described plasticizer is the organic polymer plasticizer with flexible group; Described surfactant comprises ethanol, toluene, sorbA kind of or mixing in alcohol acid anhydride trioleate, lecithin.

3. a kind of method of preparing copper-indium-galliun-selenium film solar cell as claimed in claim 2, is characterized in that: instituteState plasticizer and comprise dibutyl phthalate, polyesters plasticizer or polyalcohol ester plasticizer.