阅读说明：本技术 一种用于perc晶硅太阳能电池背面银浆的玻璃粉及制备方法 (Glass powder for silver paste on back of PERC crystalline silicon solar cell and preparation method ) 是由 卢波 项永亮 谢继峰 程晨琛 陈卫龙 于 2021-10-14 设计创作，主要内容包括：本公开提供了一种用于PERC晶硅太阳能电池背面银浆的玻璃粉,所述玻璃粉包括按以下重量百分比的组分：1-30％的PbO；1-30％的Bi-(2)O-(3)；20-45％的Si-(2)O；5-20％的MnO-(2)；10-30％的CuO；0.1-5％的Li-(2)O、Na-(2)O或K-(2)O中的一种或几种；0-5％的MgO、CaO或BaO中的一种或几种；0.5-10％的添加剂；上述组分重量百分比之和为100％。本公开的玻璃粉能够适用于PERC晶硅太阳能电池,具有高常规拉力、高老化拉力、高开路电压和转换效率,对PERC晶体硅片背面钝化层具有弱腐蚀,同时能制成银含量较低的背面银浆(50-65％)。(The present disclosure provides a glass powder for a silver paste on the back of a PERC crystalline silicon solar cell, the glass powder comprising the following components by weight: 1-30% of PbO; 1-30% of Bi 2 O 3 (ii) a 20-45% of Si 2 O; 5-20% MnO 2 (ii) a 10-30% of CuO; 0.1-5% of Li 2 O、Na 2 O or K 2 One or more of O; 0-5% of one or more of MgO, CaO and BaO; 0.5-10% of additives; the sum of the weight percentages of the components is 100 percent. The glass powder disclosed by the invention can be suitable for the PERC crystalline silicon solar cell, has high conventional tension, high aging tension, high open-circuit voltage and conversion efficiency, has weak corrosion on a passivation layer on the back of the PERC crystalline silicon wafer, and can be made into back silver paste (50-65%) with lower silver content.)

1. The glass powder for the silver paste on the back of the PERC crystalline silicon solar cell is characterized by comprising the following components in percentage by weight: 1-30% of PbO; 1-30% of Bi₂O₃(ii) a 20-45% of Si₂O; 5-20% MnO₂(ii) a 10-30% of CuO; 0.1-5% of Li₂O、Na₂O or K₂One or more of O; 0-5% of one or more of MgO, CaO and BaO; 0.5-10% of additives; the sum of the weight percentages of the components is 100 percent.

2. The glass frit according to claim 1, wherein the additive is one or more of boron oxide, titanium oxide, chromium oxide, cobalt and cobalt oxide, nickel and nickel oxide, zinc oxide, zirconium oxide, niobium oxide, molybdenum oxide, tellurium oxide, cerium oxide, tantalum oxide and tungsten oxide.

3. The glass frit according to claim 2, wherein the glass frit comprises the following components in percentage by weight: 10-25% of PbO; 5-20% of Bi₂O₃(ii) a 25-40% of Si₂O; 7% MnO₂(ii) a 15% of CuO; 5% of Li₂O; 1% of Cr₂O₃(ii) a 2% of ZnO.

4. The glass frit according to claim 3, whichIs characterized in that the glass powder comprises the following components in percentage by weight: 25% of PbO; 5% of Bi₂O₃(ii) a 40% of Si₂O; 7% MnO₂(ii) a 15% of CuO; 5% of Li₂O; 1% of Cr₂O₃(ii) a 2% of ZnO.

5. The glass frit according to claim 1, wherein the glass frit has a glass transition temperature of 500-600 ℃ and an average particle size of 0.1-12 μm.

6. The preparation method of the glass powder for the silver paste on the back of the PERC crystalline silicon solar cell is characterized by comprising the following steps:

step 1.1, adding the raw materials in proportion, operating a stainless steel grinder for 1-5min, and uniformly mixing to obtain uniform raw materials for later use;

step 1.2, putting the raw material prepared in the step 1.1 into a corundum crucible, then placing the corundum crucible into a box-type resistance furnace, preserving the heat for 30-60min at 1300-1400 ℃, forming uniform and clear glass liquid, and then pouring the glass liquid into deionized water for water quenching to obtain glass slag;

step 1.3, placing the glass slag prepared in the step 1.2 in an oven to be dried for 10-12h to obtain dry glass slag;

step 1.4, putting the dry glass slag prepared in the step 1.3 into a crusher to prepare fine glass slag with D50 of 15-25 mu m, and sieving the fine glass slag to disperse the fine glass slag;

step 1.5, the fine glass slag obtained in the step 1.4 is milled by airflow with the flow rate of 0.50MPa-1.0MPa to prepare glass powder with the D50 diameter of 1.5-5 mu m;

and step 1.6, placing the glass powder prepared in the step 1.5 in an oven to be dried for 10-12h until the water content is less than 0.3%, and sieving and dispersing to obtain uniform glass powder.

7. The method according to claim 6, wherein in step 1.2, the corundum crucible is maintained in the box-type resistance furnace at 1350 ℃.

8. A method according to claim 6, wherein in step 1.2, the corundum crucible is held in the box-type resistance furnace for 45 min.

9. The preparation method of the silver paste for the back of the PERC crystalline silicon solar cell is characterized by comprising the following steps:

step 2.1, preparing the glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell according to any one of claims 1 to 5;

step 2.2, preparing the prepared glass powder, silver powder and organic carrier according to a certain proportion, and then putting the mixture into a planetary mixer to be uniformly mixed; grinding the uniformly stirred premixed slurry by using a three-roll mill to prepare silver paste for the back of the PERC crystalline silicon solar cell; the glass powder, the silver powder and the organic carrier respectively comprise the following components in percentage by weight: 1-3% of glass powder, 50-65% of silver powder and 32-49% of organic carrier.

10. The production method according to claim 9, wherein the silver powder is a spherical powder having a D50 particle size of 0.7 to 1.5 μm.

11. The method of claim 9, wherein the organic vehicle comprises the following components in weight percent: 3.0-7.0% of resin, 92.0-96.9% of solvent and 0.1-1.0% of auxiliary agent.

12. The PERC crystalline silicon solar cell is characterized in that the PERC crystalline silicon solar cell is prepared by printing the silver paste on the back surface of the PERC crystalline silicon solar cell as claimed in claim 9 onto a PERC cell piece and sintering.

Technical Field

The disclosure relates to the technical field of manufacturing processes of electronic devices and materials thereof, in particular to glass powder for a silver paste on the back of a PERC crystalline silicon solar cell and a preparation method thereof.

Background

The global energy is in shortage day by day, and the development and utilization of more efficient clean energy are more urgent. Photovoltaic power generation is a technology for directly converting light energy into electric energy by utilizing the photovoltaic effect of a semiconductor interface, and is favored by various manufacturers due to the advantages of no pollution, large market space and the like. In recent years, the material cost and the production cost are reduced to be close to the freezing point, and the competitiveness can be improved only by reducing the unit consumption and improving the conversion efficiency of the battery, so that the competitive power is not eliminated by the market.

PERC back passivation technique is to use high quality passivation layer Al₂O₃And SiNx laminated dielectric films replace conventional aluminum back fields. The method has the advantages of reducing the recombination of effective carriers on the back surface of the battery, improving open-circuit voltage, improving long-wave response, increasing short current and finally improving the conversion efficiency of the battery. Due to the reduction of the unit price of the silicon material and the higher battery conversion efficiency, the silicon material becomes the mainstream of the prior art and is selected by various manufacturers.

Due to the special technology of the PERC back silver battery, the passivation layer on the back cannot be corroded too much, and the corrosion is too deep to influence the open-circuit voltage, the reverse resistance and the like, so that the conversion efficiency of the whole battery is reduced, and the conventional back system for deepening the corrosion and improving the tensile force of the crystalline silicon battery is not suitable. The back silver paste needs to provide reliable tension and aging tension, and the contact surface needs to be corroded to a certain degree, which is a technical difficulty of the back silver paste of the PERC battery at the present stage. At present, cell manufacturers are bound to reduce corrosion of the passivation layer to the maximum extent under the condition of maintaining reliability in order to improve production efficiency, reduce the consumption of raw materials and reduce the thickness of the cell and the passivation layer on the back surface. In view of the above, the inventors research and design a glass frit for a silver paste on the back surface of a PERC crystalline silicon solar cell and a preparation method thereof.

Disclosure of Invention

In order to solve the problem that the back corrosion is reduced and the reliability is kept under the condition that the thickness of a passivation layer on the back of a PERC cell is reduced, the disclosure provides glass powder for the back silver paste of the PERC crystalline silicon solar cell and a preparation method thereof. The glass powder has high conventional tension, high aging tension, high open-circuit voltage and conversion efficiency, has weak corrosion on a passivation layer on the back of a PERC crystal silicon wafer, and can be prepared into back silver paste (50-65%) with lower silver content.

The technical scheme adopted by the disclosure for solving the technical problem is as follows:

the glass powder for the silver paste on the back of the PERC crystalline silicon solar cell comprises the following components in percentage by weight: 1-30% of PbO; 1-30% of Bi₂O₃(ii) a 20-45% of Si₂O; 5-20% MnO₂(ii) a 10-30% of CuO; 0.1-5% of Li₂O、Na₂O or K₂One or more of O; 0-5% of one or more of MgO, CaO and BaO; 0.5-10% of additives; the sum of the weight percentages of the components is 100 percent.

As a preferred mode of embodiment, the additive is one or more of boron oxide, titanium oxide, chromium oxide, cobalt and cobalt oxide, nickel and nickel oxide, zinc oxide, zirconium oxide, niobium oxide, molybdenum oxide, tellurium oxide, cerium oxide, tantalum oxide and tungsten oxide.

As a preferred mode of embodiment, the glass powder comprises the following components in percentage by weight: 10-25% of PbO; 5-20% of Bi₂O₃(ii) a 25-40% of Si₂O; 7% MnO₂(ii) a 15% of CuO; 5% of Li₂O; 1% of Cr₂O₃(ii) a 2% of ZnO.

As a preferred mode of embodiment, the glass powder comprises the following components in percentage by weight: 25% of PbO; 5% of Bi₂O₃(ii) a 40% of Si₂O; 7% MnO₂(ii) a 15% of CuO; 5% of Li₂O; 1% of Cr₂O₃(ii) a 2% of ZnO.

Advantages as examplesFirst, the glass transition temperature (T) of the glass frit_g) 500 ℃ and 600 ℃, and the average particle size is 0.1-12 μm.

A preparation method of glass powder for a silver paste on the back of a PERC crystalline silicon solar cell comprises the following steps:

step 1.1, adding the raw materials in proportion, operating a stainless steel grinder for 1-5min, and uniformly mixing to obtain uniform raw materials for later use;

step 1.2, putting the raw material prepared in the step 1.1 into a corundum crucible, then placing the corundum crucible into a box-type resistance furnace, preserving the heat for 30-60min at 1300-1400 ℃, forming uniform and clear glass liquid, and then pouring the glass liquid into deionized water for water quenching to obtain glass slag;

step 1.3, placing the glass slag prepared in the step 1.2 in an oven to be dried for 10-12h to obtain dry glass slag;

step 1.4, putting the dry glass slag prepared in the step 1.3 into a crusher to prepare fine glass slag with D50 of 15-25 mu m, and sieving the fine glass slag to disperse the fine glass slag;

and step 1.5, performing jet milling on the fine glass slag prepared in the step 1.4 at the flow rate of 0.50-1.0 MPa to prepare glass powder with the D50 size of 1.5-5 mu m.

And step 1.6, placing the glass powder prepared in the step 1.5 in an oven to be dried for 10-12h until the water content is less than 0.3%, and sieving and dispersing to obtain uniform glass powder.

As a preferred mode of embodiment, in step 1.2, the temperature of the corundum crucible held in the box-type resistance furnace is 1350 ℃.

As a priority mode of embodiment, in the step 1.2, the heat preservation time of the corundum crucible in the box type resistance furnace is 45 min.

The invention also provides a preparation method of the silver paste for the back of the PERC crystalline silicon solar cell, which comprises the following steps:

step 2.1, preparing the glass powder for the silver paste on the back of the PERC crystalline silicon solar cell;

step 2.2, preparing the prepared glass powder, silver powder and organic carrier according to a certain proportion, and then putting the mixture into a planetary mixer to be uniformly mixed; grinding the uniformly stirred premixed slurry by using a three-roll mill to prepare silver paste for the back of the PERC crystalline silicon solar cell; the glass powder, the silver powder and the organic carrier respectively comprise the following components in percentage by weight: 1-3% of glass powder, 50-65% of silver powder and 32-49% of organic carrier.

As a preferred mode of embodiment, in step 2.2, the silver powder is spherical powder of D500.7-1.5 μm.

As a preferred mode of embodiment, in step 2.2, the organic vehicle comprises the following components in percentage by weight: 3.0-7.0% of resin, 92.0-96.9% of solvent and 0.1-1.0% of auxiliary agent. The resin is preferably ethyl cellulose, the solvent is preferably terpineol and decaglycol ester, and the auxiliary agent is a dispersing agent.

The disclosure also provides a PERC crystalline silicon solar cell, wherein the PERC crystalline silicon solar cell is prepared by printing silver paste on the back of the PERC crystalline silicon solar cell to a PERC cell piece and sintering the PERC crystalline silicon solar cell piece.

After adopting above-mentioned technical scheme, this disclosed beneficial effect does:

1) the glass powder for the silver paste on the back of the PERC crystalline silicon solar cell disclosed by the disclosure takes alkali metal and alkaline earth metal as fluxing agents to improve Si₂And (4) the content of O. The glass powder has higher viscosity under the high-temperature condition, and the fluidity of the glass at the high temperature is reduced, so that the conventional tension, the aging tension, the open-circuit voltage and the conversion efficiency are improved, and the corrosion to a passivation layer is reduced. Transition metal oxide MnO₂Is an oxidizing agent in the glass, can accelerate the clarification of molten glass and is helpful for melting the glass. The high CuO exists in an ion form after the PERC is sintered with the silver-backed glass powder, so that the glass and the silver powder are combined compactly, which is beneficial to improving the welding tension of the back electrode, and the back silver paste (50-65%) with lower silver content can be prepared. PbO and Bi₂O₃Heavy metal oxides can form glasses with lower melt viscosities and melting points. The components form the integral scheme of the glass powder, and the integral scheme is mutually cooperated, so that unexpected technical effects in the aspects of tension, open-circuit voltage, conversion efficiency and the like are achieved, and the glass powder is incomparable with commercially available products.

2) The glass powder for the silver paste on the back of the PERC crystalline silicon solar cell is prepared by jet milling, and has a particle size grading function compared with the conventional process, and can separate glass powder with extremely small particle size, especially nano-level. The tiny and nano-scale glass powder is caused by the fact that the hardness of the glass after phase splitting is reduced, and is easy to sinter and aggravate the damage to the passivation layer in the sintering process, so that the glass powder which is uniform in particle size distribution and free of tiny and nano-scale glass powder is prepared by grinding glass slag through air flow, the corrosion to the passivation layer can be weakened, and therefore the open-circuit voltage and the conversion efficiency are improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the disclosure and together with the description serve to explain the principles of the disclosure.

FIG. 1 is an electroluminescence test chart of a comparative example.

FIG. 2 is an electroluminescence test chart of example 1.

FIG. 3 is an electroluminescence test chart of example 2.

FIG. 4 is an electroluminescence test chart of example 3.

FIG. 5 is an electroluminescence test chart of example 4.

FIG. 6 is an electroluminescence test chart of example 5.

Detailed Description

The present disclosure will be described in further detail with reference to the following embodiments. It is to be understood that the specific embodiments described herein are for purposes of illustration only and are not to be construed as limitations of the present disclosure.

It should be noted that the embodiments and features of the embodiments in the present disclosure may be combined with each other without conflict. The present disclosure will be described in detail with reference to embodiments.

Example 1

The glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell is shown in table 1, wherein the weight percentages of the raw material components in example 1 are as follows.

Example 2

The glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell is shown in table 1, wherein the weight percentages of the raw material components in example 2 are shown in the following table.

Example 3

The glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell in example 3 comprises the following raw material components in percentage by weight as shown in table 1.

Example 4

The glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell in example 4 comprises the following raw material components in percentage by weight, as shown in table 1.

Example 5

The glass powder for the silver paste on the back surface of the PERC crystalline silicon solar cell in example 5 comprises the following raw material components in percentage by weight, as shown in table 1.

Table 1 examples 1-5 weight percent of each raw material component

In the above embodiment:

further, Si₂O is used as a main raw material of the glass powder, so that the viscosity of the glass powder in a high-temperature state can be improved, the corrosion of the glass to a passivation layer is reduced, and meanwhile, the tensile force can be improved.

Further, Li₂O，Na₂O，K₂O and MgO, CaO, BaO are fluxes of glass, which may be carbonates, and Li₂O，Na₂O can also be replaced by LiF, NaF.

Further, Bi₂O₃And PbO may be replaced by its corresponding fluoride.

Example 6

A preparation method of glass powder for a silver paste on the back of a PERC crystalline silicon solar cell comprises the following steps:

1) the raw materials are added in proportion, and a stainless steel grinder is used for running for 1min to be uniformly mixed, so that uniform raw materials are obtained for later use.

2) And (2) putting the raw material prepared in the step (1) into a corundum crucible, putting the corundum crucible into a box-type resistance furnace, preserving heat for 45min at 1350 ℃ to form uniform and clear glass liquid, and then pouring the glass liquid into deionized water for water quenching to obtain glass slag.

3) And (3) placing the glass slag prepared in the step (2) into an oven to be dried for 12 hours.

4) And (4) placing the dried glass slag prepared in the step (3) into a grinder to be ground for 2min, sieving the ground glass slag by a 200-mesh sieve to disperse large particles, and then re-grinding the glass slag until the large particles completely pass through the sieve.

5) And (4) carrying out jet milling on the fine glass slag prepared in the step (4) at the flow rate of 0.80 Mpa.

6) And (5) drying the glass paste prepared in the step (5) in an oven for 12 hours until the water content is less than 0.3%, and sieving and dispersing to obtain uniform glass powder.

Example 7

A preparation method of glass powder for a silver paste on the back of a PERC crystalline silicon solar cell comprises the following steps:

1) -6) procedure as in example 6;

7) mixing the prepared glass powder, silver powder and organic carrier in proportion, and then putting into a planetary mixer to be uniformly stirred; and grinding the uniformly stirred premixed slurry by using a three-roll mill to prepare the silver paste for the back of the PERC crystalline silicon solar cell. The preferable preparation proportion in this step is silver powder: 60%, organic vehicle: 38%, glass frit: 2.0 percent.

In the above embodiment:

further, the silver powder was spherical powder having D50 of 0.85.

Furthermore, the organic carrier is 4% of ethyl cellulose, 20% of terpineol, 75.5% of dodecyl alcohol and 0.5% of dispersant.

Example 8

PERC crystalline silicon solar cell

The silver paste prepared in example 7 was printed on the PERC cell by a screen printing process, respectively, and sintered to obtain the PERC solar cell.

Specifically, 166X 166mm PERC crystalline silicon solar cells can be used, and the rear silver paste is printed on the cells through a 325-mesh screen, so that the PERC crystalline silicon solar cells are prepared according to the process.

And (3) testing the battery performance:

the results of the electrical property test (HALM tester) and the welding tension test (0.35mm round wire solder strip, oven temperature 150 ℃/30min) of the prepared battery piece are shown in the table 2, and the electroluminescent tester (EL) is used as a comparative example, wherein the comparative example is a product on sale, and the main component of the glass powder is Bi₂O₃，Si₂O，CuO，Li₂O, etc., and the results are shown in FIGS. 1 to 6.

Table 2 PERC crystalline silicon solar cell electrical properties and tensile data

Therefore, compared with the comparative examples, the conversion efficiency (Eta) of the examples 1 to 5 of the disclosure is improved, which is reflected in VOC and obvious Rsh; the tensile force and the oven tensile force are both greater than 5N to meet the requirements; meanwhile, as can be seen from fig. 1 to 6, the blackening degree of the back electrode position is obviously improved compared with the comparative example, and the corrosion of the back passivation layer can be reduced by the glass powder provided by the invention.

In the description herein, reference to the description of the terms "one embodiment/mode," "some embodiments/modes," "example," "specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment/mode or example is included in at least one embodiment/mode or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to be the same embodiment/mode or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments/modes or examples. Furthermore, the various embodiments/aspects or examples and features of the various embodiments/aspects or examples described in this specification can be combined and combined by one skilled in the art without conflicting therewith.

It will be understood by those skilled in the art that the foregoing embodiments are merely for clarity of illustration of the disclosure and are not intended to limit the scope of the disclosure. Other variations or modifications may occur to those skilled in the art, based on the foregoing disclosure, and are still within the scope of the present disclosure.