Production process of solar cell and solar cell

Abstract

The present invention provides a production process of a solar cell and a solar cell, specifically relating to the technical field of solar cell preparation. The production process of the solar cell includes the following steps: forming a silicon oxide layer in the patterned area of the cell precursor, and then annealing, nickel plating, metallizing, and sintering in sequence to obtain the solar cell. In the production process of the solar cell provided by the present invention, the formed silicon oxide layer is used as a passivation contact layer to reduce the surface recombination of silicon; the nickel layer is directly disposed on the silicon oxide layer, and local contact is formed with silicon through sintering to form a local passivation contact structure solar cell, reducing metal recombination, reducing the reverse saturation current, and increasing the open-circuit voltage of the solar cell. The annealing process causes internal stress in the silicon oxide, thereby generating nano-scale pores, providing a current path for the nickel plating process, and ensuring the smooth progress of the subsequent process.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell preparation, and in particular to a production process of a solar cell and a solar cell. Background Art

[0002] At present, the copper interconnection technology of crystalline silicon solar cells generally uses laser or mask methods for patterning, removing part of the antireflection layer on the surface of the cell precursor, and exposing the silicon in the area to be metallized. Then, metal stacks such as nickel / copper / tin are deposited on the silicon substrate in sequence as electrodes, and nickel contacts with silicon to form a good ohmic contact. Different from the "dot-like" contact areas where silver paste / silver-aluminum paste generates silver barbs / silver-aluminum barbs inward on the surface of the silicon substrate, the contact between nickel and silicon is a surface contact in the entire metallized area. Therefore, the copper interconnection technology has a lower contact resistance compared with silver paste.

[0003] The contact area between nickel and silicon is larger than that of silver paste, resulting in a lower contact resistance, but at the same time, it also causes a higher metal recombination, leading to an increase in the reverse saturation current J 0 of the solar cell, and making the open-circuit voltage of the copper interconnection solar cell relatively low.

[0004] In view of this, the present invention is particularly proposed. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a production process of a solar cell, aiming to solve at least one of the above technical problems in the prior art.

[0006] Another purpose of the present invention is to provide a solar cell.

[0007] In order to achieve the above purposes of the present invention, the following technical solutions are specifically adopted:

[0008] The first aspect of the present invention provides a production process of a solar cell, including the following steps:

[0009] Form an oxide silicon layer in the patterned area of the cell precursor, and then anneal, nickel-plate, metallize, and sinter in sequence to obtain a solar cell.

[0010] Further, the oxide silicon layer is formed by thermal oxidation growth or vapor deposition.

[0011] Preferably, the vapor deposition includes physical vapor deposition or chemical vapor deposition, preferably chemical vapor deposition.

[0012] Preferably, the thickness of the oxide silicon layer is 2.5 nm to 4.5 nm.

[0013] Preferably, the sintering method is laser-assisted sintering.

[0014] Preferably, the bias voltage for the laser-assisted sintering is 0V to 15V.

[0015] Preferably, the current for the laser-assisted sintering is 3A to 10A.

[0016] Further, the process of thermal oxidation growth is as follows:

[0017] Place the battery precursor in a high-temperature furnace, introduce oxygen to carry out a thermal oxidation reaction to form a silicon oxide layer.

[0018] Preferably, the flow rate of the oxygen is 500 sccm to 3000 sccm.

[0019] Preferably, the temperature of the thermal oxidation reaction is 800°C to 1200°C.

[0020] Preferably, the time of the thermal oxidation reaction is 2 min to 1 h.

[0021] Further, the process of chemical vapor deposition is as follows:

[0022] Use the battery precursor as a template in the deposition equipment, and introduce silane and N 2 O for vapor deposition under nitrogen protection.

[0023] Preferably, the flow rate of the silane is 100 sccm to 1000 sccm.

[0024] Preferably, the flow rate of the N 2 O is 100 sccm to 1000 sccm.

[0025] Preferably, the temperature of the chemical vapor deposition is 400°C to 800°C.

[0026] Preferably, the time of the chemical vapor deposition is 20 min to 1 h.

[0027] Further, the temperature of the annealing is 950°C to 1100°C.

[0028] Preferably, the time of the annealing is 1 min to 10 min.

[0029] Further, the methods of nickel plating include electroplating, photo-induced plating, electroless plating, or physical vapor deposition.

[0030] Preferably, the thickness of the nickel layer formed by nickel plating is 1 μm to 3 μm.

[0031] Further, the materials for metallization are copper, tin, or silver.

[0032] Preferably, the thickness of the metal electrode obtained after metallization is 5 μm to 15 μm.

[0033] Further, the silicon substrate is subjected to laser film opening or masking and then chemically etched to form a patterned groove, obtaining a battery precursor.

[0034] Preferably, the width of the patterned groove is 5 μm to 50 μm.

[0035] The second aspect of the present invention provides a solar cell, which is produced by using the production process described in the first aspect.

[0036] Compared with the prior art, the present invention has at least the following beneficial effects:

[0037] In the production process of the solar cell provided by the present invention, the formed silicon oxide layer is used as a passivation contact layer to reduce the surface recombination of silicon; the nickel layer is directly disposed on the silicon oxide layer, and a local passivation contact structure with local contact is formed by sintering, thereby reducing metal recombination, reducing the reverse saturation current, and increasing the open circuit voltage of the solar cell. The annealing process causes internal stress in the silicon oxide, and then nano-scale holes are generated, providing a current path for the nickel plating process and ensuring the smooth progress of the subsequent process.

[0038] Due to the advantages of the above production process, the solar cell provided by the present invention has a reduced reverse saturation current, an increased open circuit voltage, an increased conversion efficiency, and an extended lifespan of the solar cell. Detailed Embodiments

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Apparently, the described embodiments are only a part rather than all of the embodiments of the present invention.

[0040] Hereinafter, the terms "including", "having", and their cognates that may be used in various embodiments of the present invention are only intended to represent a specific feature, number, step, operation, element, component, or combination of the foregoing items, and should not be construed as first excluding the existence or adding the possibility of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing items.

[0041] According to the production process of the solar cell provided by the first aspect of the present invention, the following steps are included:

[0042] An silicon oxide layer is formed in the patterned area of the battery precursor, and then annealed, nickel plated, metallized, and sintered in sequence to obtain a solar cell.

[0043] The production process of the solar cell provided by the present invention uses the formed silicon oxide layer as a passivation contact layer to reduce the surface recombination of silicon; the nickel layer is directly disposed on the silicon oxide layer, and a local passivation contact structure with local contact is formed through sintering, thereby reducing metal recombination, reducing the reverse saturation current, and increasing the open-circuit voltage of the solar cell. The annealing process causes internal stress in the silicon oxide, and then nano-scale pores are generated, providing a current path for the nickel plating process and ensuring the smooth progress of the subsequent process.

[0044] Further, the silicon oxide layer is formed by thermal oxidation growth or chemical vapor deposition. The silicon oxide can passivate the silicon exposed in the patterned area and reduce surface recombination; nickel silicide is formed by sintering to make nickel and silicon form nickel silicide, and the local passivation contact structure with local contact greatly reduces metal recombination and increases the open-circuit voltage of the solar cell.

[0045] Preferably, the chemical vapor deposition includes physical vapor deposition or chemical vapor deposition, and preferably chemical vapor deposition.

[0046] Preferably, the thickness of the silicon oxide layer is 2.5 nm to 4.5 nm.

[0047] Within this thickness range, the passivation effect of the silicon oxide layer can reach the best, and the probability of the electron tunneling effect on both sides of the oxide layer can be greatly reduced. When the thickness of the silicon oxide layer is less than 2.5 nm, the generated silicon oxide layer is too thin, and the electron tunneling probability on both sides of the oxide layer increases significantly. Electron tunneling becomes the main mechanism for carrier transport between the silicon substrate and the metal electrode, and the current transmission cross-sectional area between the silicon substrate and the metal electrode increases, resulting in that the photocurrent density passing through the nano-scale pores during the laser-assisted sintering process is not enough to reach the temperature for generating nickel silicide, and a good nickel-silicon contact cannot be formed; when the thickness of the silicon oxide layer is greater than 4.5 nm, the generated silicon oxide layer is too thick, which is not conducive to the annealing process, and the formed nano-scale pores cannot penetrate the entire silicon oxide layer, resulting in that the photocurrent during the laser-assisted sintering process cannot be at the silicon-nickel contact interface, nickel silicide cannot be formed, and a good nickel-silicon contact cannot be formed.

[0048] Typical but non-limiting, the thickness of the silicon oxide layer can be, for example, 2.5 nm, 3 nm, 3.5 nm, 4 nm or 4.5 nm, or any value within the range of 2.5 nm to 4.5 nm.

[0049] Preferably, the sintering method is laser-assisted sintering. The laser can induce the generation of a high-density current. After applying a bias voltage between the metal electrode and the silicon substrate, the current passes through the nano-scale pores between nickel and silicon to generate local high temperature, causing the nickel to react with the silicon in the silicon oxide to form nickel silicide with a nano-scale size in a dot-like distribution.

[0050] Nickel silicide with nanoscale dimensions forms good ohmic contacts while minimally damaging the passivation effect of the silicon oxide layer, and enables the metal electrode to have a low contact resistance. At the same time, nickel silicide can improve the bonding force of the metal electrode. After the formation of nickel silicide, due to the reduction in resistance, the heat generated by the current decreases. At the same time, nickel silicide has a high thermal conductivity, and the heat is quickly dissipated. The molten area solidifies to form a near-nanoscale size and is distributed in a dot pattern. Compared with the nickel silicide formed by thermal annealing, the distribution is more uniform, the size is smaller, and the passivation effect of the silicon oxide layer is retained.

[0051] Preferably, the bias voltage of the laser-assisted sintering is 0V to 15V.

[0052] Preferably, the current of the laser-assisted sintering is 3A to 10A.

[0053] When the bias voltage of the laser-assisted sintering is higher than 15V and the current is greater than 10A, the temperature generated by the current passing through the nanoscale holes exceeds the temperature required for the formation of nickel silicide, resulting in excessive formation of nickel silicide and an increase in the depth of nickel entering silicon, increasing the damage to the silicon substrate. When the bias voltage exceeds 15V, it is easily broken down under the forward bias of the PN junction, thus damaging the quality of the PN junction.

[0054] Typically but not restrictively, the bias voltage of the laser-assisted sintering can be, for example, 1V, 3V, 5V, 7V, 9V, 11V, 13V or 15V, or any value within the range of 0V to 15V; the current of the laser-assisted sintering can be, for example, 3A, 4A, 5A, 6A, 7A, 8A, 9A or 10A, or any value within the range of 3A to 10A.

[0055] Furthermore, the process of thermal oxidation growth is as follows:

[0056] Place the battery precursor in a high-temperature furnace and introduce oxygen to carry out a thermal oxidation reaction to form a silicon oxide layer.

[0057] Preferably, the flow rate of the oxygen is 500 sccm to 3000 sccm.

[0058] Typically but not restrictively, the flow rate of the oxygen can be, for example, 500 sccm, 700 sccm,

[0059] 1000 sccm, 1500 sccm, 2000 sccm, 2500 sccm or 3000 sccm, or any value within the range of 500 sccm to 3000 sccm.

[0060] Preferably, the temperature of the thermal oxidation reaction is 800°C to 1200°C.

[0061] Typically but not restrictively, the temperature of the thermal oxidation reaction can be, for example, 800 °C, 900 °C, 1000 °C, 1100 °C or 1200 °C, or any value within the range of 800 °C to 1200 °C.

[0062] Preferably, the time of the thermal oxidation reaction is 2 min to 1 h.

[0063] Typically but not restrictively, the time of the thermal oxidation reaction can be, for example, 2 min, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 1 h, or any value within the range of 2 min to 1 h.

[0064] The flow rate of oxygen, the temperature and time of the thermal oxidation reaction affect the thickness of the generated silicon oxide, and the specific parameters can be adjusted according to the required thickness of the silicon oxide.

[0065] Further, the process of the chemical vapor deposition is as follows:

[0066] Using the battery precursor as a template in the deposition equipment, silane and N 2 O are introduced for vapor deposition under nitrogen protection.

[0067] Preferably, the flow rate of the silane is 100 sccm to 1000 sccm.

[0068] Typically but not restrictively, the flow rate of the silane can be, for example, 100 sccm, 300 sccm, 500 sccm, 700 sccm, 900 sccm or 1000 sccm, or any value within the range of 100 sccm to 1000 sccm.

[0069] Preferably, the flow rate of the N 2 O is 100 sccm to 1000 sccm.

[0070] Typically but not restrictively, the flow rate of the N 2 O can be, for example, 100 sccm, 300 sccm, 500 sccm, 700 sccm, 900 sccm or 1000 sccm, or any value within the range of 100 sccm to 1000 sccm.

[0071] Preferably, the temperature of the chemical vapor deposition is 400 °C to 800 °C.

[0072] Typically but not restrictively, the temperature of the chemical vapor deposition can be, for example, 400 °C, 500 °C, 600 °C, 700 °C or 800 °C, or any value within the range of 400 °C to 800 °C.

[0073] Preferably, the time of the chemical vapor deposition is 5 min to 1 h.

[0074] Typically but not limited thereto, the time of the chemical vapor deposition can be, for example, 5 min, 10 min, 20 min, 30 min, 40 min, 50 min or 1 h, or can be any value within the range of 5 min to 1 h.

[0075] Silicon oxide has insulating properties and it is impossible to directly electroplate a nickel metal layer thereon. Through the annealing process, due to internal stress, the silicon oxide layer will generate nano-scale pores with a certain density for electron flow. These pores provide current paths for the electroplating process, enabling nickel to be deposited on the silicon oxide layer by electroplating.

[0076] Furthermore, the temperature of the annealing is 950 °C to 1100 °C.

[0077] Preferably, the time of the annealing is 1 min to 10 min.

[0078] When the annealing temperature is lower than 950 °C and the time is less than 1 min, it will result in insufficient overall heat, and the density of the nano-scale pores generated in the silicon oxide layer is low, and a good nickel-silicon contact cannot be formed after laser-assisted sintering; when the annealing temperature is higher than 1100 °C and the time is greater than 10 min, it will cause the silicon oxide layer to crack, the size and density of the nano-scale pores increase, and the passivation effect of the silicon oxide layer decreases.

[0079] Typically but not limited thereto, the annealing temperature can be, for example, 950 °C, 1000 °C, 1050 °C or 1100 °C, or can be any value within the range of 950 °C to 1100 °C.

[0080] Typically but not limited thereto, the annealing time can be, for example, 1 min, 3 min, 5 min, 7 min, 9 min or 10 min, or can be any value within the range of 1 min to 10 min.

[0081] Furthermore, the method of nickel plating includes electroplating, photo-induced plating, electroless plating or physical vapor deposition.

[0082] Preferably, the thickness of the nickel layer formed by nickel plating is 1 μm to 3 μm.

[0083] Typically but not limited thereto, the nickel layer thickness can be, for example, 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm, or can be any value within the range of 1 μm to 3 μm.

[0084] Furthermore, the material for metallization is copper, tin or silver.

[0085] Preferably, the thickness of the metal electrode obtained after metallization is 5 μm to 15 μm.

[0086] Typically but not limited thereto, the thickness of the metal electrode can be, for example, 5 μm, 7 μm, 9 μm, 11 μm, 13 μm or 15 μm, or can be any value within the range of 5 μm to 15 μm.

[0087] Further, the silicon substrate is subjected to laser film opening or masking and then chemically etched to form a patterned groove, thereby obtaining a battery precursor.

[0088] Preferably, the width of the patterned groove is 5 μm to 50 μm.

[0089] The second aspect of the present invention provides a solar cell produced by using the production process described in the first aspect.

[0090] Due to the advantages of the above production process, the solar cell provided by the present invention has a reduced reverse saturation current, an increased open-circuit voltage, an increased conversion efficiency, and an extended lifespan.

[0091] The present invention will be further described below through specific examples and comparative examples. However, it should be understood that these examples are only for more detailed description and should not be construed as limiting the present invention in any way. For the raw materials used in the examples and comparative examples of the present invention, those without specific conditions are carried out according to conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0092] Example 1

[0093] This example provides a production process for a solar cell, and the specific steps are as follows:

[0094] 1. The silicon substrate is subjected to laser film opening to form a patterned groove, wherein the width of the patterned groove is 20 μm, thereby obtaining a battery precursor.

[0095] 2. The battery precursor is placed in a quartz core tube, and the core tube is heated by a heater of an oxidation furnace, and oxygen is introduced to perform a dry thermal oxidation reaction to generate a 2.5-nm-thick silicon oxide layer.

[0096] Among them, the flow rate of oxygen is 800 sccm; the temperature of the thermal oxidation reaction is 800 °C, and the time is 50 min.

[0097] 3. The battery precursor deposited with silicon oxide is subjected to high-temperature annealing, and the annealing temperature is 1000 °C and the time is 5 min.

[0098] 4. The annealed battery precursor is placed in an electroplating nickel solution for nickel plating, taken out after completion, washed with water and dried to obtain a 2-μm-thick nickel layer.

[0099] 5. Continue the electroplating copper process to obtain a metallized solar cell.

[0100] 6. Perform laser-assisted sintering on the metallized solar cell to form nanoscale nickel silicide.

[0101] Among them, the bias voltage of the laser-assisted sintering is 8V, and the current is 7A.

[0102] Example 2

[0103] This example provides a production process for a solar cell, and the specific steps are as follows:

[0104] 1. Perform laser film opening on the silicon substrate to form a patterned groove, where the width of the patterned groove is 10 μm, to obtain a battery precursor.

[0105] 2. Place the battery precursor in a quartz core tube, heat the core tube using the heater of the oxidation furnace, introduce oxygen, and perform a dry heat oxidation reaction to generate a 4.5 nm thick silicon oxide layer.

[0106] Among them, the flow rate of oxygen is 2000 sccm; the temperature of the thermal oxidation reaction is 1200 °C, and the time is 2 min.

[0107] 3. Anneal the battery precursor deposited with silicon oxide at a temperature of 1100 °C for 1 min.

[0108] 4. Place the annealed battery precursor in an electroplating nickel solution for nickel plating, take it out after completion, wash it with water and dry it to obtain a 1 μm thick nickel layer.

[0109] 5. Continue the electroplating copper process to obtain a metallized solar cell.

[0110] 6. Perform laser-assisted sintering on the metallized solar cell to form nanoscale nickel silicide.

[0111] Among them, the bias voltage of the laser-assisted sintering is 15V, and the current is 3A.

[0112] Example 3

[0113] This example provides a production process for a solar cell, and the specific steps are as follows:

[0114] 1. Perform laser film opening on the silicon substrate to form a patterned groove, where the width of the patterned groove is 50 μm, to obtain a battery precursor.

[0115] 2. Place the battery precursor in a quartz core tube, heat the core tube using the heater of the oxidation furnace, introduce oxygen, and perform a dry heat oxidation reaction to generate a 3 nm thick silicon oxide layer.

[0116] Among them, the flow rate of oxygen is 1000 sccm; the temperature of the thermal oxidation reaction is 1000 °C, and the time is 3 min.

[0117] 3. Anneal the battery precursor deposited with silicon oxide at a high temperature. The annealing temperature is 950 °C, and the time is 10 min.

[0118] 4. Place the annealed battery precursor in an electroplating nickel solution for nickel plating. After completion, take it out, wash it with water and dry it to obtain a nickel layer with a thickness of 3 μm.

[0119] 5. Continue the electroplating copper process to obtain a metallized solar cell.

[0120] 6. Perform laser-assisted sintering on the metallized solar cell to form nanoscale nickel silicide.

[0121] Among them, the bias voltage of the laser-assisted sintering is 5 V, and the current is 10 A.

[0122] Example 4

[0123] This example provides a production process of a solar cell. Different from Example 1, the generation method of silicon oxide is chemical vapor deposition. The specific steps are as follows:

[0124] In the deposition equipment, use the battery precursor as a template, and introduce silane and N 2 O for vapor deposition under nitrogen protection.

[0125] Among them, the flow rate of silane is 500 sccm, and the flow rate of N 2 O is 500 sccm. The temperature of the chemical vapor deposition is 600 °C, and the time is 20 min.

[0126] The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0127] Example 5

[0128] This example provides a production process of a solar cell. Different from Example 1, the generation method of silicon oxide is chemical vapor deposition. The specific steps are as follows:

[0129] In the deposition equipment, use the battery precursor as a template, and introduce silane and N 2 O for vapor deposition under nitrogen protection.

[0130] Among them, the flow rate of silane is 1000 sccm, and the flow rate of N 2 O is 1000 sccm. The temperature of the chemical vapor deposition is 400 °C, and the time is 1 h.

[0131] The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0132] Example 6

[0133] This example provides a production process for a solar cell. Different from Example 1, in step 2, the battery precursor is placed in a quartz core tube, and the core tube is heated by the heater of the oxidation furnace. Nitrogen and oxygen are introduced to carry out a dry thermal oxidation reaction to form a 1-nm-thick silicon oxide layer.

[0134] Among them, the flow rate of nitrogen is 1000 sccm, and the flow rate of oxygen is 2000 sccm; the temperature of the thermal oxidation reaction is 800 °C, and the time is 20 min.

[0135] The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0136] Example 7

[0137] This example provides a production process for a solar cell. Different from Example 1, in step 2, the battery precursor is placed in a quartz core tube, and the core tube is heated by the heater of the oxidation furnace. Nitrogen and oxygen are introduced to carry out a dry thermal oxidation reaction to form a 7-nm-thick silicon oxide layer.

[0138] Among them, the flow rate of nitrogen is 1000 sccm, and the flow rate of oxygen is 2000 sccm; the temperature of the thermal oxidation reaction is 900 °C, and the time is 30 min.

[0139] The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0140] Example 8

[0141] This example provides a production process for a solar cell. Different from Example 1, the bias voltage of the laser-assisted sintering is 20 V, and the current is 7 A. The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0142] Example 9

[0143] This example provides a production process for a solar cell. Different from Example 1, the bias voltage of the laser-assisted sintering is 8 V, and the current is 20 A. The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0144] Example 10

[0145] This example provides a production process for a solar cell. Different from Example 1, in step 4, the annealed battery precursor is placed in a electroless nickel plating solution for electroless nickel plating. The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0146] Comparative Example 1

[0147] This comparative example provides a production process for a solar cell. Different from Example 1, step 2 is omitted, and nickel is directly plated on the patterned area of the cell precursor. The remaining steps are the same as those in Example 1 and will not be elaborated here.

[0148] Comparative Example 2

[0149] This comparative example provides a production process for a solar cell. Different from Example 1, step 3 is omitted, and nickel plating is directly carried out on the silicon oxide layer. Since silicon oxide is insulating, a current path cannot be formed, and a nickel layer cannot be deposited, resulting in the failure of solar cell preparation.

[0150] Comparative Example 3

[0151] This example provides a production process for a solar cell. Different from Example 1, step 6 is omitted, and the remaining steps are the same as those in Example 1 and will not be elaborated here.

[0152] Test Example

[0153] The solar cells provided by the examples and comparative examples were subjected to performance tests.

[0154] Specifically, under the conditions of AM1.5, light intensity of 1000 W, and temperature of 25 °C, the electrical performance of solar cell wafers of the same scale was tested, and J was tested using Sinton Suns-Voc under the same set conditions. 0metal The results obtained are shown in Table 1 below.

[0155] Table 1

[0156]

[0157]

[0158] Among them, Uoc is the open-circuit voltage, and J 0 metal is the reverse saturation current caused by the increase in the carrier recombination rate due to metal-semiconductor contact.

[0159] As can be seen from Table 1, the technology of the present invention and the solar cells produced using this technology have a local passivation contact structure, reducing the J of the solar cell. 0 metal Therefore, it has a more excellent open-circuit voltage and higher power generation efficiency of the solar cell.

[0160] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the technical field of the present invention can still modify the technical solutions described in the foregoing embodiments or easily conceive of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described therein.

Claims

1. A production process for solar cells, characterized in that: The following steps are involved: forming a silicon oxide layer in the patterned area of ​​the cell precursor, using the formed silicon oxide layer as a passivation contact layer, and then sequentially annealing, nickel plating, metallization, and sintering to obtain a solar cell; The sintering method is laser-assisted sintering; the bias voltage of the laser-assisted sintering is 0V~15V, and the current is 3A~10A; The thickness of the silicon oxide layer is 2.5 nm to 4.5 nm; The annealing temperature is 950° C. to 1100° C., and the annealing time is 1 min to 10 min.

2. The production process according to claim 1, characterized in that: The silicon oxide layer is formed by thermal oxygen growth or vapor deposition.

3. The production process according to claim 2, characterized in that: The vapor deposition includes physical vapor deposition or chemical vapor deposition.

4. The production process according to claim 2, characterized in that: The vapor deposition is chemical vapor deposition.

5. The production process according to claim 2, characterized in that: The process of the thermal oxygen growth is: The battery precursor is placed in a high-temperature furnace and oxygen is introduced to perform a thermal oxidation reaction to form a silicon oxide layer.

6. The production process according to claim 5, characterized in that: The flow rate of the oxygen gas is 500 sccm to 3000 sccm.

7. The production process according to claim 5, characterized in that: The temperature of the thermal oxidation reaction is 800°C to 1200°C.

8. The production process according to claim 5, characterized in that: The thermal oxidation reaction time is 2min~1h.

9. The production process according to claim 4, characterized in that: The process of chemical vapor deposition is: The battery precursor is used as a template in the deposition equipment, and silane and N2O are introduced under nitrogen protection for vapor deposition.

10. The production process according to claim 9, characterized in that: The flow rate of the silane is 100 sccm~1000 sccm.

11. The production process according to claim 9, characterized in that: The flow rate of N2O is 100sccm~1000sccm.

12. The production process according to claim 4, characterized in that: The temperature of the chemical vapor deposition is 400°C to 800°C.

13. The production process according to claim 4, characterized in that: The chemical vapor deposition time is 5 minutes to 1 hour.

14. The production process according to any one of claims 1 to 13, characterized in that: The nickel plating method includes electroplating, light-induced plating, chemical plating or physical vapor deposition.

15. The production process according to any one of claims 1 to 13, characterized in that: The thickness of the nickel layer formed by nickel plating is 1μm~3μm.

16. The production process according to any one of claims 1 to 13, characterized in that: The metallized material is copper, tin or silver.

17. The production process according to any one of claims 1 to 13, characterized in that: The thickness of the metal electrode obtained after metallization is 5μm~15μm.

18. The production process according to any one of claims 1 to 13, characterized in that: The silicon substrate is laser-cut or masked and then chemically etched to form patterned grooves to obtain a battery precursor.

19. The production process according to claim 18, characterized in that: The width of the patterned groove is 5 μm-50 μm.

20. A solar cell, characterized in that: The product is produced by the production process described in any one of claims 1 to 19.

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