Glass frits and methods of making, conductive pastes, methods of making, and solar cells

Abstract

The application relates to the technical field of solar cell materials, in particular to a glass frit and a preparation method thereof, a conductive paste, a preparation method thereof and a solar cell. The first aspect of the application provides a glass frit which comprises the following mass percentages of raw material components: 30-50% of lead oxide, 15-30% of boron oxide, 20-30% of silicon dioxide, 1-10% of di-aluminum trioxide, 0.5-5% of zinc oxide, 0-7% of nickel oxide or / and germanium oxide, 10-20% of a cobalt-containing compound. The cobalt-containing compound introduced in the glass powder can provide excellent static conductive performance, collect the micro-current of active substances, thereby greatly reduce the contact resistance, and meanwhile can improve the adhesion between the two, meanwhile, the glass powder is prepared by matching germanium oxide and nickel oxide, the contact resistance can be cooperatively reduced in the conductive paste system, the photoelectric conversion efficiency can be improved, and the open-circuit voltage of the battery can be improved.

Description

Technical Field

[0001] This application belongs to the field of solar cell material technology, and particularly relates to a glass material and its preparation method, a conductive paste, a preparation method, and a solar cell. Background Technology

[0002] In related technologies, silicon solar cells have an anti-reflective coating (mostly a silicon nitride film) on the silicon substrate. The anti-reflective coating has a grid pattern, and within the grid pattern is a front electrode formed from front-side conductive silver paste. In the manufacturing process of silicon solar cells, the anti-reflective coating is first deposited on the silicon substrate using methods such as vapor deposition. Then, the grid pattern is fabricated using photolithography or laser penetration through the anti-reflective coating. Subsequently, the front-side conductive silver paste is screen-printed into the grid lines. Sintering then etches the anti-reflective coating with the conductive silver paste, bringing it into contact with the silicon substrate. After sintering, the conductive silver paste forms a grid-like front electrode on the surface of the silicon substrate.

[0003] Specifically, the conductive silver paste used to manufacture the front electrode generally consists of three parts: a conductive phase (silver powder), an organic carrier, and a binder phase. The conductive phase, as the name suggests, conducts electricity. The organic carrier is a solution of polymers (such as resins and cellulose) dissolved in an organic solvent, serving as a carrier for the conductive and binder phases, dispersing and mixing them for screen printing. The binder phase includes glass powder, which melts after sintering following the printing of the conductive silver paste onto the anti-reflective film, and serves to etch the anti-reflective film and bond the conductive phase to the substrate. More specifically, after the conductive silver paste is screen-printed onto the silicon substrate, sintering the conductive silver paste and the silicon substrate is sufficient to molten the glass powder, thus etching the anti-reflective film and bringing the conductive phase in the conductive silver paste into contact with the silicon substrate (at this point, the silver powder, as the conductive phase, dissolves in the molten glass phase in the form of silver ions). Subsequently, the conductive silver paste shrinks into a solid, forming an electrical contact with the silicon substrate and creating a grid-like front electrode.

[0004] Therefore, as a crucial component of silver paste, the glass frit plays a vital role. It not only helps form silver-silicon ohmic contacts and provides solderability for silver electrodes, but also affects the sintering activity of silver powder. For silver-aluminum pastes in N-type solar cells, the glass frit is a key factor determining contact resistance, surface etching reaction, and the overall electrical performance of the cell. During the etching process, it is necessary to etch only the passivation layer that penetrates the surface, with minimal etching of the doped polycrystalline silicon layer, while forming excellent contact. Therefore, developing new and efficient glass frits is particularly important.

[0005] Currently, the silver-aluminum paste glass material for N-type crystalline silicon solar cells suffers from problems such as high sintering temperature, large surface recombination, and low photoelectric conversion efficiency. Existing improvement technologies focus on increasing ohmic contact, reducing recombination, increasing open voltage, and reducing contact resistance. Summary of the Invention

[0006] Technical issues

[0007] The technical problem to be solved by this application is to provide a glass material and its preparation method, a conductive paste, a preparation method and a solar cell, which aims to solve the problems of high sintering temperature, large surface recombination and low photoelectric conversion efficiency of existing silver-aluminum paste glass materials for N-type crystalline silicon solar cells.

[0008] Furthermore, this application also provides a conductive paste, a preparation method, and a solar cell.

[0009] Technical solutions

[0010] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0011] A glass frit for use in N-type crystalline silicon solar cells comprises the following raw material components in weight percentages:

[0012]

[0013]

[0014] Accordingly, a method for preparing a glass frit includes the following steps:

[0015] Weigh each component according to the mass percentage of each raw material contained in the glass material mentioned above;

[0016] The raw materials are mixed and melted to obtain glass material.

[0017] And, a conductive paste comprising conductive metal particles, and further comprising the glass frit described above or the glass frit prepared by the method described above.

[0018] Accordingly, a method for preparing a conductive paste includes the following steps: mixing conductive metal particles and glass frit to obtain a conductive paste.

[0019] And, an N-type TOPCon crystalline silicon solar cell, comprising the conductive paste described above, formed by curing.

[0020] Beneficial effects

[0021] Compared to existing technologies, the glass powder provided in this application provides trace elements by adjusting the compounding ratio of lead oxide, boron oxide, silicon dioxide, aluminum oxide, zinc oxide, nickel oxide, and / or germanium oxide, germanium oxide, and cobalt-containing compounds. Adding these special trace elements improves the electrical properties of the glass powder. Secondly, the cobalt-containing compounds introduced into the glass powder in this application provide excellent static conductivity, enabling the collection of microcurrents from active materials. When applied to N-type crystalline silicon solar cells, this significantly reduces contact resistance and improves adhesion to the doped silicon layer. Furthermore, when combined with germanium oxide and / or nickel oxide to form the glass powder, it synergistically reduces contact resistance and improves photoelectric conversion efficiency within the system. It also exhibits excellent contact performance with the silicon layer, increasing the open-circuit voltage of the N-type crystalline silicon solar cell, thereby enhancing the overall performance of the N-type crystalline silicon solar cell.

[0022] The glass frit preparation method provided in this application mainly consists of two steps. First, each component is weighed according to the mass percentage of each raw material contained in the glass frit as described above, which can lower the sintering temperature of the glass frit. Mixing the glass raw materials described above yields a highly dispersed glass raw material mixture, facilitating subsequent forming processes. Second, the raw materials are mixed and melted to form a liquid glass frit. The glass frit prepared by the above method exhibits low contact resistance, high photoelectric conversion efficiency, and excellent contact with the crystalline silicon layer in a silver paste system.

[0023] The conductive paste provided in this application, through the synergistic effect of conductive metal particles and the glass frit mentioned above, can reduce the contact resistance of the conductive paste and improve its photoelectric conversion efficiency. The conductive paste formed by the compounding of the glass frit and conductive agent in the embodiments of this application, wherein the conductive agent imparts conductive properties to the conductive paste, forming a conductive layer.

[0024] The conductive paste formed by the compounding of glass frit and conductive metal particles provided in this application has conductive properties imparted by a conductive agent, facilitating coating treatment to form a conductive layer. Specifically, because the glass frit described above has low metal-induced recombination, the open-circuit voltage of the conductive paste is increased, and it also possesses excellent contact resistivity at lower sintering temperatures. Furthermore, the cobalt-containing glass frit in this embodiment supports an ultra-thin polycrystalline silicon layer, exhibiting higher adhesion strength and reducing contact resistance.

[0025] The cobalt-containing glass powder of this application can be used to prepare the silver-aluminum paste on the front side of N-type crystalline silicon solar cells, which can improve the open-circuit voltage of N-type TOPCon crystalline silicon solar cells. The solar cells provided by this application include N-type TOPCon crystalline silicon solar cells, including conductive paste prepared by the above-described conductive paste preparation method, which can form a conductive layer after curing treatment. After curing treatment, the conductive paste will solidify or cross-link under certain conditions to form a three-dimensional network structure, in which conductive metal particles are dispersed, which has a certain shaping effect on the conductive metal particles, and can make the conductive agent densely packed, thereby improving its conductivity. The cobalt-containing compound introduced into the glass powder can provide excellent static conductivity, collect the microcurrent of the active material, thereby significantly reducing the contact resistance and improving the adhesion between the two. At the same time, the glass powder prepared together with germanium oxide and / or nickel oxide can synergistically reduce the contact resistance and improve the photoelectric conversion efficiency in the system. During the etching process, less polycrystalline silicon layer is etched, and it helps to improve the contact performance between the two. Attached Figure Description

[0026] Figure 1 A scanning electron microscope image of glass powder provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0030] It should be understood that, in the various embodiments of this application, the sequence number of each process does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the implementation regulations of this application.

[0031] The terminology used in the embodiments of this application is for the purpose of describing particular implementations only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the implementations of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0032] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0033] The terms "first" and "second" are used only to describe the purpose of distinguishing objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the provisions of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0034] The technical solution adopted in this application is as follows:

[0035] The first aspect of this application provides a glass frit comprising the following raw material components by mass percentage:

[0036]

[0037] In the first aspect, the glass powder provided in the embodiments of this application can provide some trace elements by adjusting the compound ratio of components such as lead oxide, boron oxide, silicon dioxide, aluminum oxide, zinc oxide, nickel oxide and / or germanium oxide, germanium oxide, and cobalt-containing compounds. Adding special trace elements to the glass powder can improve the electrical properties of the glass powder. Secondly, the cobalt-containing compound introduced into the glass powder in this application provides excellent static conductivity and can collect the microcurrent of the active material. When applied to N-type crystalline silicon solar cells, it can significantly reduce contact resistance and improve adhesion to the crystalline silicon layer. Furthermore, when combined with germanium oxide and / or nickel oxide to form the glass powder, it can synergistically reduce contact resistance and improve photoelectric conversion efficiency within the system. Consequently, during the etching process, less crystalline silicon layer is etched, and it exhibits excellent contact performance with the silicon layer, increasing the open-circuit voltage of the N-type crystalline silicon solar cell. This, in turn, improves the overall performance of the N-type crystalline silicon solar cell. For example, studies using the embodiments have shown that when the glass powder described above is applied to N-type crystalline silicon solar cells, the open-circuit voltage is 0.7004–0.7072 V, the fill factor (FF) is 81.39–81.72%, and the photoelectric conversion efficiency (Eta) is 24.19–24.35%.

[0038] In some embodiments, the glass material includes 30-50% lead oxide, 15-30% boron oxide, 20-30% silicon dioxide, 1-10% aluminum oxide, 0.5-5% zinc oxide, 0-5% nickel oxide, and 10-20% cobalt-containing compounds. In the embodiments of this application, the synergistic effect of nickel oxide and cobalt-containing compounds can further reduce contact resistance and improve photoelectric conversion efficiency.

[0039] In some embodiments, the glass material includes 30-50% lead oxide, 15-30% boron oxide, 20-30% silicon dioxide, 1-10% aluminum oxide, 0.5-5% zinc oxide, 0-2% germanium oxide, and 10-20% cobalt-containing compounds. In the embodiments of this application, the synergistic effect of germanium oxide and cobalt-containing compounds can further reduce contact resistance and improve photoelectric conversion efficiency.

[0040] In some embodiments, the glass material includes 30-50% lead oxide, 15-30% boron oxide, 20-30% silicon dioxide, 1-10% aluminum oxide, 0.5-5% zinc oxide, 0-7% nickel oxide and germanium oxide, and 10-20% cobalt-containing compounds. In the embodiments of this application, the synergistic effect of nickel oxide, germanium oxide, and cobalt-containing compounds can further reduce contact resistance and improve photoelectric conversion efficiency.

[0041] In some specific embodiments, the composition is 42% lead oxide, 16% boron oxide, 22% silicon dioxide, 2.5% aluminum oxide, 3% zinc oxide, 2% nickel oxide, 0.5% germanium oxide, and 12% cobalt-containing compounds.

[0042] In some embodiments, the cobalt-containing compound includes at least one of lithium cobalt oxide, sodium cobalt oxide, magnesium cobalt oxide, and lead cobalt oxide. As described above, the cobalt-containing compound is a layered functional material. The cobalt-containing compound introduced into the glass powder in this application embodiment is a layered functional material that provides excellent static conductivity, collects microcurrents from active materials, thereby significantly reducing contact resistance and improving adhesion between the active materials. In the system, it synergistically interacts with other components, further reducing contact resistance and improving photoelectric conversion efficiency.

[0043] The second aspect of this application provides a method for preparing glass frit, comprising the following steps:

[0044] Step S10: Weigh each component according to the mass percentage of each raw material contained in the glass material as described above;

[0045] Step S20: Mix and melt the raw materials to obtain glass material.

[0046] The glass frit preparation method provided in this application mainly consists of two steps. First, each component is weighed according to the mass percentage of each raw material contained in the glass frit as described above, which can lower the sintering temperature of the glass frit. Mixing the glass raw materials described above yields a highly dispersed glass raw material mixture, facilitating subsequent forming processes. Second, the raw materials are mixed and melted to form a liquid glass frit. The glass frit prepared by this method exhibits low contact resistance and high photoelectric conversion efficiency within the system.

[0047] In some embodiments, step S20 above is performed in a stepwise manner, including the mixing and melting processes.

[0048] In some embodiments, the step-by-step approach includes the following steps:

[0049] Step S21: The oxides, excluding those containing cobalt compounds, are subjected to preheating treatment, mixing treatment, and first melting treatment to obtain the first melt.

[0050] Step S22: Add a cobalt-containing compound to the first melt for mixing and a second melting process to obtain the second melt.

[0051] This application provides a step-by-step approach, mainly comprising two steps. The first step involves preheating, mixing, and performing a first melting treatment on oxides (excluding the cobalt-containing compound) to obtain a highly dispersed first melt. The second step involves adding the cobalt-containing compound to the first melt, performing a mixing treatment, and then performing a second melting treatment to finally obtain a liquid glass frit. This step-by-step approach to glass frit preparation saves resources during melting and ensures successful glass frit firing.

[0052] In some embodiments, the preheating temperature is 400–500°C, and the preheating time is 0.5–1 hour. In the above description, the first melting temperature is 900–950°C, and the holding time is 0.5–1 hour. In the above description, the second melting temperature is 1100–1150°C, and the holding time is 0.5–1 hour.

[0053] In some embodiments, the second melt is further subjected to water quenching to solidify it into glass fragments. The glass fragments are then ground and graded to obtain glass material of a predetermined particle size for use in conductive silver paste.

[0054] The third aspect of this application provides a conductive paste, including conductive metal particles, and also including the glass frit described above or the glass frit prepared by the method described above.

[0055] The conductive paste provided in this application embodiment, through the synergistic effect of conductive metal particles and the glass frit mentioned above, can reduce the contact resistance of the conductive paste and improve its photoelectric conversion efficiency. The conductive paste formed by the compounding of the glass frit and conductive agent provided in this application embodiment, wherein the conductive agent imparts conductive properties to the conductive paste, forming a conductive layer.

[0056] In some embodiments, an organic carrier is also included. The conductive slurry is formed by combining the organic carrier, conductive metal particles, and the glass material provided in the embodiments of this application. The conductive metal particles impart conductivity to the conductive slurry. After mixing with the organic carrier, it is convenient to coat the conductive slurry to form a conductive layer.

[0057] In some embodiments, the conductive metal includes aluminum powder and silver powder. The conductive metal provided in the above embodiments of this application, including aluminum powder and silver powder, can mitigate the shunting and recombination effects of N-type solar cells. The conductive paste formed by combining the aluminum powder and silver powder with the organic carrier imparts conductivity to the paste. The aluminum and silver powders, dispersed within the organic carrier, can adjust the viscosity of the paste, thus facilitating printing and coating the conductive paste to form a conductive layer. During subsequent sintering, the glass frit can lower the glass transition temperature of the conductive paste and enhance the glass's ability to melt silver at low temperatures. By adjusting the blending ratio of the glass frit, organic carrier, aluminum powder, and silver powder, the open-circuit voltage (Voc) and fill factor (FF) of the TOPCon cell can be further improved, thereby increasing the conversion efficiency of the solar cell and reducing the levelized cost of electricity (LCOE).

[0058] The fourth aspect of this application provides a method for preparing a conductive paste, comprising the following steps: mixing conductive metal particles and glass frit to obtain a conductive paste.

[0059] The conductive paste formed by the compounding of glass frit and conductive metal particles provided in the above embodiments of this application has conductive properties imparted to it by a conductive agent, facilitating coating treatment to form a conductive layer. Specifically, because the glass frit described above has low metal-induced recombination, the open-circuit voltage of the conductive paste is increased, and it also possesses excellent contact resistivity at lower sintering temperatures. Furthermore, the cobalt-containing glass frit in the embodiments of this application supports an ultra-thin polycrystalline silicon layer, exhibiting higher adhesion strength and reducing contact resistance.

[0060] The fifth aspect of this application provides an N-type TOPCon crystalline silicon solar cell, which is formed by curing the conductive paste described above.

[0061] The cobalt-containing glass powder of this application embodiment can be used to prepare silver-aluminum paste for the front side of solar cells, wherein the solar cells include N-type TOPCon crystalline silicon solar cells, which can improve the open-circuit voltage of the solar cells. Firstly, the conductive paste mentioned above, after curing, can form a conductive layer. Under certain conditions, the conductive paste, after curing, will solidify or cross-link to form a three-dimensional network structure, in which conductive metal particles are dispersed, providing a certain shaping effect on the conductive metal particles, allowing the conductive agent to be tightly packed, thereby improving its conductivity. Secondly, the cobalt-containing compound introduced into the glass powder can provide excellent static conductivity, collect the microcurrent of the active material, thereby significantly reducing contact resistance and improving the adhesion between the two. Thirdly, the glass powder prepared by combining germanium oxide and / or nickel oxide can synergistically reduce contact resistance and improve photoelectric conversion efficiency in the system, and has excellent contact performance with the doped polycrystalline silicon layer.

[0062] In some embodiments, the silver powder may have a particle size in the nanometer or micrometer range. For example, the silver powder may have a particle size of tens to hundreds of nanometers, or several micrometers to tens of micrometers. Alternatively, the silver powder may be a mixture of two or more types of silver powder with different particle sizes.

[0063] In some embodiments, the organic carrier imparts printable viscosity and rheological characteristics to the slurry composition by mechanically mixing it with the inorganic components in the composition for solar cell electrodes. The organic carrier may be any typical organic carrier for the composition for solar cell electrodes and may contain adhesive resins, solvents, etc.

[0064] To enable those skilled in the art to clearly understand the above-described implementation details and operations of this application, and to demonstrate the significant improvements in the performance of the glass material, preparation method, conductive paste, preparation method, and solar cell of the embodiments of this application, the following examples illustrate the above technical solutions.

[0065] Example 1

[0066] This embodiment provides a method for preparing glass powder, which includes the following steps:

[0067] Step S10: Weigh out the following components by weight percentage: 41% lead oxide, 18% boron oxide, 20% silicon dioxide, 2.5% aluminum oxide, 4% zinc oxide, 2% nickel oxide, and 0.5% germanium oxide.

[0068] Step S20: Place the above glass powder raw material in a mixer and mix evenly. Place the crucible containing the glass powder raw material in a muffle furnace and preheat at 500°C for 0.5 hours. Then heat to 950°C to melt and hold for 0.5 hours.

[0069] Step S30: Then add 12% cobalt-containing compound, which includes 8% lithium cobalt oxide and 4% sodium cobalt oxide, heat to 1150°C to melt, and hold at that temperature for 0.5 hours.

[0070] Step S40: The above glass melt is quenched with deionized water, and the quenched glass slag is crushed in an air jet mill. Cobalt-containing glass material is used for silver-aluminum paste in N-type crystalline silicon solar cells.

[0071] Example 2

[0072] This embodiment provides a method for preparing glass powder, which includes the following steps:

[0073] Step S10: Weigh out the following components by weight percentage: 42% lead oxide, 16% boron oxide, 22% silicon dioxide, 2.5% aluminum oxide, 3% zinc oxide, and 2.5% nickel oxide.

[0074] Step S20: Place the above glass powder raw material in a mixer and mix evenly. Place the crucible containing the glass powder raw material in a muffle furnace and preheat at 500°C for 0.5 hours. Then heat to 950°C to melt and hold for 0.5 hours.

[0075] Step S30: Then add 12% cobalt-containing compound, which includes 4% lithium cobalt oxide and 8% magnesium cobalt oxide, heat to 1150°C to melt, and hold at that temperature for 0.5 hours.

[0076] Step S40: The above glass melt is quenched with deionized water, and the quenched glass slag is crushed in an air jet mill. Cobalt-containing glass material is used for silver-aluminum paste in N-type crystalline silicon solar cells.

[0077] Example 3

[0078] This embodiment provides a method for preparing glass powder, which includes the following steps:

[0079] Step S10: Weigh out the following components by weight percentage: 42% lead oxide, 16% boron oxide, 22% silicon dioxide, 2.5% aluminum oxide, 3% zinc oxide, 2% nickel oxide, and 0.5% germanium oxide.

[0080] Step S20: Place the above glass powder raw material in a mixer and mix evenly. Place the crucible containing the glass powder raw material in a muffle furnace and preheat at 500°C for 0.5 hours. Then heat to 950°C to melt and hold for 0.5 hours.

[0081] Step S30: Then add 12% cobalt-containing compound, which includes 10% lead cobaltate and 2% magnesium cobaltate, heat to 1150°C to melt, and hold at that temperature for 0.5 hours.

[0082] Step S40: The above glass melt is quenched with deionized water, and the quenched glass slag is crushed in an air jet mill. Cobalt-containing glass material is used for silver-aluminum paste in N-type crystalline silicon solar cells.

[0083] Example 4

[0084] This embodiment provides a method for preparing glass powder, which includes the following steps:

[0085] Step S10: Weigh out the following components by weight percentage: 42% lead oxide, 16% boron oxide, 22% silicon dioxide, 2.5% aluminum oxide, 3% zinc oxide, and 2.5% germanium oxide.

[0086] Step S20: Place the above glass powder raw material in a mixer and mix evenly. Place the crucible containing the glass powder raw material in a muffle furnace and preheat at 500°C for 0.5 hours. Then heat to 950°C to melt and hold for 0.5 hours.

[0087] Step S30: Then add 12% of cobalt-containing compound, which includes 5% magnesium cobaltate and 7% sodium cobaltate, heat to 1150°C to melt, and hold at that temperature for 0.5 hours.

[0088] Step S40: The above glass melt is quenched with deionized water, and the quenched glass slag is crushed in an air jet mill. Cobalt-containing glass material is used for silver-aluminum paste in N-type crystalline silicon solar cells.

[0089] Example 5

[0090] This embodiment provides a method for preparing glass powder, which includes the following steps:

[0091] Step S10: Weigh out the following components by weight percentage: 45% lead oxide, 16% boron oxide, 21% silicon dioxide, 2.5% aluminum oxide, 1% zinc oxide, 2% nickel oxide, and 0.5% germanium oxide.

[0092] Step S20: Place the above glass powder raw material in a mixer and mix evenly. Place the crucible containing the glass powder raw material in a muffle furnace and preheat at 500°C for 0.5 hours. Then heat to 950°C to melt and hold for 0.5 hours.

[0093] Step S30: Then add 12% cobalt-containing compound, which includes 9% sodium cobaltate and 3% lead cobaltate, heat to 1150°C to melt, and hold at that temperature for 0.5 hours.

[0094] Step S40: The above glass melt is quenched with deionized water, and the quenched glass slag is crushed in an air jet mill. Cobalt-containing glass material is used for silver-aluminum paste in N-type crystalline silicon solar cells.

[0095] Example 6

[0096] This embodiment provides a silver paste, which comprises the following components in the indicated mass percentages:

[0097]

[0098] Example 7

[0099] This embodiment provides a silver paste, which comprises the following components in the indicated mass percentages:

[0100]

[0101] Example 8

[0102] This embodiment provides a silver paste, which comprises the following components in the indicated mass percentages:

[0103]

[0104] Example 9

[0105] This embodiment provides a silver paste, which comprises the following components in the indicated mass percentages:

[0106]

[0107]

[0108] Example 10

[0109] This embodiment provides a silver paste, which comprises the following components in the indicated mass percentages:

[0110]

[0111] Comparative Example 1

[0112] This comparative example provides a silver paste comprising the following components by mass percentage:

[0113]

[0114] Performance testing

[0115] Table 1 shows the composition of the silver paste used in Examples 6 to 9, as follows:

[0116] Table 1 Examples of silver paste preparation

[0117] mass ratio Example 6 Example 7 Example 8 Example 9 Example 10 Comparative Example 1 Silver powder 86％ 84％ 83％ 84％ 85％ 86％ aluminum powder 2％ 3％ 2％ 1％ 2％ 2％ glass powder 4％ 5％ 6％ 5％ 4％ 4％ organic carrier 8％ 8％ 9％ 10％ 9％ 8％

[0118] The silver paste from Examples 1 to 5 and Comparative Example 1 was printed on the front side of an N-type crystalline silicon solar cell, and its electrical performance was tested. The results are shown in Table 2.

[0119] Table 2 Electrical properties of silver paste

[0120]

[0121]

[0122] The silver pastes used in Examples 1 to 5 resulted in N-type crystalline silicon solar cells with open-circuit voltages of 0.7004–0.7072 V, fill factors (FF) of 81.39–81.72%, and photoelectric conversion efficiency (Eta) of 24.19–24.35%. The glass powder provided in this application, by adjusting the blending ratio of lead oxide, boron oxide, silicon dioxide, aluminum oxide, zinc oxide, nickel oxide, and / or germanium oxide, germanium oxide, and cobalt-containing compounds, can provide trace elements to improve its electrical properties. The cobalt-containing compound introduced into the glass powder in this application embodiment provides excellent static conductivity and can collect microcurrents from active materials. When applied to N-type crystalline silicon solar cells, it can significantly reduce contact resistance and improve adhesion to the doped polycrystalline silicon layer. At the same time, when combined with germanium oxide and / or nickel oxide to form glass powder, it can synergistically reduce contact resistance, improve photoelectric conversion efficiency and open-circuit voltage in the system, thereby significantly improving the overall performance of N-type crystalline silicon solar cells.

[0123] Figure 1 The image shows a scanning electron microscope (SEM) image of the glass powder obtained in Example 1. The glass powder has a uniform particle size and narrow distribution. Most of the modified glass powder particles are between 1.0 and 2.0 micrometers in size, which can form a dense sintered structure, making it suitable for use in the selection of silver-aluminum paste on the front side of N-type solar cells.

[0124] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A glass material, characterized in that, It comprises the following raw material components in the following mass percentages: Lead oxide 30-45%; Boron oxide 15-30%; 20-30% silicon dioxide; Aluminum oxide 1~10%; Zinc oxide 0.5~4%; Nickel oxide and / or germanium oxide 0~7%; Cobalt compounds 10-20%; The cobalt-containing compound includes at least one of lithium cobalt oxide, sodium cobalt oxide, magnesium cobalt oxide, and lead cobalt oxide. The nickel oxide and / or germanium oxide and the cobalt-containing compound work synergistically to reduce contact resistance, wherein the content of nickel oxide and / or germanium oxide is not 0.

2. The glass material as described in claim 1, characterized in that, The cobalt-containing compound is a layered functional material.

3. A method for preparing glass frit, characterized in that, Includes the following steps: Weigh each component according to the mass percentage of each raw material contained in the glass material as described in claim 1 or 2; The raw materials are mixed and melted to obtain the glass material.

4. The method for preparing the glass frit as described in claim 3, characterized in that, The mixing and melting processes are carried out in a step-by-step manner.

5. The method for preparing the glass frit as described in claim 4, characterized in that, The step-by-step approach includes the following steps: Oxides other than cobalt-containing compounds are preheated, mixed, and subjected to a first melting process to obtain a first melt. A cobalt-containing compound is added to the first melt for mixing and a second melting process to obtain a second melt.

6. The method for preparing the glass frit as described in claim 5, characterized in that, The preheating temperature is 400~500℃, and the preheating time is 0.5~1 hour.

7. The method for preparing the glass frit as described in claim 5 or 6, characterized in that, The temperature of the first melting treatment is 900~950℃, and the holding time is 0.5~1 hour.

8. The method for preparing the glass frit as described in claim 7, characterized in that, The temperature of the second melting treatment is 1100~1150℃, and the holding time is 0.5~1 hour.

9. A conductive paste, characterized in that, It includes conductive metal particles, and also includes glass frit prepared by the method of preparing glass frit according to claim 1 or any one of claims 3-8.

10. The conductive paste as described in claim 9, characterized in that, It also includes organic carriers.

11. The conductive paste as described in claim 9 or 10, characterized in that, The conductive metal includes aluminum powder and silver powder.

12. A method for preparing a conductive paste, characterized in that, The process includes the following steps: mixing glass frit, organic carrier, metallic silver powder and metallic aluminum powder to obtain the conductive paste; the glass frit is the glass frit as described in claim 1 or 2.

13. An N-type TOPCon crystalline silicon solar cell, characterized in that, It includes the conductive paste according to any one of claims 9 to 11, which is formed by curing.

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