Heterojunction battery and preparation method and application thereof

Abstract

The invention relates to a heterojunction battery and a preparation method and application thereof. The preparation method of the heterojunction battery comprises the following steps: after ITO thin film layer deposition and printing metal electrode treatment are sequentially carried out on the surface of the battery main body to form the battery, hydrophilic modification treatment is carried out on the surface of the battery, so that a hydrophilic group is formed on the ITO thin film layer deposited on the surface of the battery. The technical problem to be solved is how to provide the preparation method of the heterojunction battery, so that the problems of adhesive layer falling, adhesive force reduction and the like caused by environmental influence in the use process of the prepared heterojunction battery are relieved and even avoided.

Description

Technical Field

[0001] The present invention belongs to the field of heterojunction batteries, and in particular relates to a heterojunction battery and a preparation method and application thereof. Background Art

[0002] Heterojunction cells, also known as HJT cells, are usually able to effectively improve the photoelectric conversion efficiency, reduce carrier recombination, and thus improve the overall performance of the cell. Therefore, they have attracted much attention in recent years. The traditional heterojunction cell preparation process includes: texturing and cleaning, amorphous silicon thin film deposition, TCO thin film deposition, and electrode metallization. Among them, the deposition of transparent conductive oxide film (TCO) (such as indium tin oxide (ITO) or aluminum zinc oxide (AZO)) on both sides of the cell can not only build a series resistance when collecting current, but also play a role in anti-reflection similar to the silicon nitride layer on the crystalline silicon cell, thereby forming a higher open circuit voltage and improving the cell conversion efficiency or the electrochemical performance of the cell.

[0003] However, during use, heterojunction cells with an ITO thin film layer deposited on the surface are easily affected by environmental factors (including but not limited to light, air temperature and humidity, etc.), which may cause problems such as glue layer shedding and decreased adhesion, thereby affecting the use of heterojunction cells. Summary of the invention

[0004] The main purpose of the present invention is to provide a heterojunction battery and its preparation method and application. The technical problem to be solved is how to provide a preparation method for a heterojunction battery so that the prepared heterojunction battery can reduce or even avoid problems such as glue layer shedding and decreased adhesion caused by the environment during use.

[0005] The purpose of the present invention and the technical problem to be solved are achieved by adopting the following technical solutions. According to a method for preparing a heterojunction battery proposed by the present invention, the method comprises the following steps:

[0006] ITO thin film layers are sequentially deposited on the surface of the battery body, and after metal electrodes are printed to form a battery, the battery surface is subjected to hydrophilic modification treatment to form hydrophilic groups on the ITO thin film layer deposited on the battery surface.

[0007] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0008] Preferably, in the aforementioned preparation method, a plasma cleaning device is used to perform plasma cleaning treatment on the battery surface to modify the hydrophilicity of the battery surface.

[0009] Preferably, in the aforementioned preparation method, the atmosphere introduced into the plasma cleaning equipment is a mixture of any one or more of nitrogen, argon, oxygen and air.

[0010] Preferably, in the aforementioned preparation method, the voltage used by the plasma cleaning equipment is 10-150V and the current is 0.2-2A.

[0011] Preferably, in the aforementioned preparation method, the air flow velocity of the plasma cleaning equipment is 8 to 12 m / s.

[0012] Preferably, in the aforementioned preparation method, the cleaning time of the plasma cleaning treatment is 1 to 60 minutes.

[0013] The purpose of the present invention and the technical problems solved therein are also achieved by the following technical solutions: According to the heterojunction battery proposed by the present invention, an ITO thin film layer is deposited on the surface of the battery, and the side of the ITO thin film layer bonded to the packaging material has a hydrophilic group.

[0014] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0015] Preferably, in the aforementioned battery, the hydrophilic groups are hydroxyl groups and hydrocarbon groups.

[0016] Preferably, in the aforementioned battery, the hydrophilic group is obtained by the method described in the aforementioned scheme.

[0017] The purpose of the present invention and the technical problems solved therein are also achieved by adopting the following technical solutions: The heterojunction battery described in the above solutions of the present invention can be applied to the fields of renewable energy and semiconductor materials.

[0018] By means of the above technical solution, the heterojunction battery and its preparation method and application proposed by the present invention have at least the following advantages:

[0019] The present invention provides a heterojunction battery and a preparation method thereof. For a battery body with an ITO thin film layer deposited on the surface, after a metal is printed on the battery body to form a battery, a hydrophilic modification treatment is performed on the battery surface to form a hydrophilic group on the ITO thin film layer deposited on the battery surface, thereby improving the hydrophilicity of the battery surface, thereby improving the adhesion between the battery surface and the packaging material, and reducing or even avoiding the problems of glue layer shedding and decreased adhesion caused by the battery being affected by the environment.

[0020] Preferably, the present invention pre-treats the battery surface by plasma cleaning after the prepared heterojunction battery is screen-printed and cured and before the battery is packaged, thereby changing the hydrophobic surface of the ITO thin film layer deposited on the battery surface into a hydrophilic surface without introducing foreign pollutants, thereby improving the adhesion between ITO and the packaging material.

[0021] Preferably, the present invention further reduces or even avoids the influence of the metal electrode printed on the battery surface on the hydrophilicity of the battery surface during the plasma cleaning pretreatment process by regulating the atmosphere, voltage, current and air flow velocity etc. used in the plasma cleaning equipment during the plasma cleaning process, thereby improving the overall performance and quality of the battery.

[0022] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a battery prepared in an embodiment;

[0024] Figure 2 This is a flow chart for preparing the battery of Example 5. DETAILED DESCRIPTION

[0025] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a heterojunction battery and its preparation method and application proposed by the present invention in combination with the accompanying drawings and preferred embodiments. Its specific implementation method, structure, characteristics and effects are described in detail as follows.

[0026] The inventors have discovered through research that when the surface deposited layer of a heterojunction battery is a special inert metal oxide indium tin oxide (referred to as "ITO") thin film layer, the battery surface is highly hydrophobic. During the packaging process, the adhesion between the battery surface and conventional packaging materials such as EVA and POE materials is poor, resulting in the heterojunction battery with an ITO thin film layer deposited on the surface being easily detached and having reduced adhesion after composite aging of the battery surface adhesive layer under the influence of diverse environmental factors.

[0027] Based on the above findings, the inventors tried to change the hydrophobic surface of the heterojunction battery with a surface-deposited ITO thin film layer and the packaging material into a hydrophilic interface, so as to improve the bonding ability between the adhesive film and the battery surface, thereby reducing or even avoiding the problems of heterojunction batteries, such as the easy falling off and decreased adhesion of the battery surface adhesive layer after composite aging under the influence of environmental factors.

[0028] In some embodiments, the inventor deposits an ITO film layer on the surface of the prepared battery body, and further prints a metal electrode to form a battery, and then further performs a hydrophilic treatment on the battery surface to form a hydrophilic group on the ITO film layer deposited on the battery surface, thereby avoiding contamination of the ITO film layer that forms the hydrophilic group during the printing of the electrode on the battery surface, and avoiding the situation where the printed electrode may increase the hydrophobicity of the battery surface, thereby avoiding the effect of affecting the adhesion between the battery surface and the film material. Therefore, the technical solution of the present invention can ensure that the hydrophilicity of the battery surface is significantly improved after the battery surface is treated with hydrophilic modification, ensuring that the adhesion between the battery surface and the film material is improved, thereby avoiding the situation where the film falls off and the adhesion decreases during the use of the battery due to the influence of environmental diversity, which affects the stability of the battery.

[0029] Preferably, the inventors further, in some embodiments, use plasma cleaning treatment to change the interface between the surface deposition layer of the heterojunction battery and the packaging material into a hydrophilic interface without introducing foreign contaminants as much as possible. This not only solves the technical problem to be solved by the present invention, but also avoids the process method of hydrophilic modification of the battery surface affecting the battery's conductivity and other properties, thereby making the prepared battery of better quality.

[0030] In view of the above, the present invention provides a method for preparing a heterojunction battery, which comprises the following steps:

[0031] First, the battery body is subjected to a surface deposition ITO conductive oxide film treatment in sequence, and an ITO transparent conductive oxide film layer (referred to as "ITO film layer") is formed on the surface of the battery to achieve the functions of conducting electricity, reducing reflection, and protecting the crystalline silicon film and / or amorphous silicon film inside the battery. The surface deposited ITO film layer of the present invention can be deposited on one side or on both sides.

[0032] In the aforementioned technical solution, in some embodiments, the method for preparing the battery body comprises the following steps:

[0033] 1) Take an N-type silicon wafer for texturing and cleaning; first use an alkaline substance (such as sodium hydroxide or other alkaline substances) to etch the surface of the silicon wafer, and then use the RCA cleaning process to clean the silicon wafer to remove the residual alkaline substance, and at the same time, the oxide layer on the surface of the silicon wafer can be removed. The present invention uses the anisotropic etching principle of alkaline substances on N-type silicon wafers to form a pyramid shape on the surface of the silicon wafer, increase the light absorption area, and improve the photoelectric conversion efficiency of the battery; use the RCA cleaning process to clean the silicon wafer to provide a clean surface for subsequent coating operations.

[0034] 2) Amorphous silicon deposition: depositing an intrinsic amorphous silicon film and a doped amorphous silicon film on the surface of the N-type silicon wafer processed in step 1) to form a PN junction.

[0035] Furthermore, the present invention forms a metal electrode by printing on the surface of the ITO thin film layer deposited on the surface of the battery body, thereby forming a battery. In some embodiments, a fixed screen pattern is used to accurately print silver paste on the surface of the ITO film layer of the battery, and after the pattern printing is completed, it is cured to form a conductive circuit so as to effectively lead out the current generated by the battery. The process conditions involved in the process of screen printing the metal gate electrode of the present invention are not specifically limited, and conventional methods can be used.

[0036] Preferably, in the above scheme, the thickness of the amorphous silicon layer on the light-receiving side is 6-8nm; the thickness of the amorphous silicon layer on the backlight side is 5-6nm; the thickness of the P-type doped amorphous silicon layer on the light-receiving side is 8-10nm; the thickness of the N-type doped amorphous silicon layer on the backlight side is 5-7nm; the thickness of the ITO layer is 90-120nm. The metal gate electrode is a silver electrode.

[0037] Furthermore, the battery after the surface deposition of the ITO thin film layer and the printing of the metal electrode is subjected to a hydrophilic modification treatment so that hydrophilic groups are formed on the ITO thin film layer deposited on the battery surface to improve the hydrophilicity of the battery surface.

[0038] Preferably, in some embodiments, the battery surface is treated by plasma cleaning, so that the hydrophilicity of the battery surface is improved without introducing foreign debris. This is not only beneficial to the adhesion of the battery surface to the adhesive film, so as to reduce or even avoid problems such as adhesive film shedding and decreased adhesion caused by environmental influences on the battery, but also the hydrophilic modification treatment method does not introduce foreign matter, thereby avoiding the influence on the electrochemical properties of the battery such as the conductivity, thereby improving the quality of the battery.

[0039] In order to make the ITO thin film layer deposited on the surface of the heterojunction battery prepared by the present invention have good hydrophilicity, and to avoid the influence of the metal electrode printed on the surface of the battery during the plasma cleaning process of the battery surface, the present invention strictly controls the atmosphere introduced into the plasma cleaning equipment during the plasma cleaning process. Preferably, in some embodiments, the atmosphere can be a mixture of any one or more of nitrogen, argon, oxygen, and air; further preferably, the atmosphere is a mixture of any one or more of nitrogen, argon, and oxygen; the atmosphere pressure is standard atmospheric pressure. Optimizing the above atmosphere is not only conducive to the easy formation of hydrophilic groups on the ITO thin film layer on the surface of the battery, but also avoids the influence on the metal electrode printed on the surface of the battery as much as possible.

[0040] In order to further make the surface hydrophilicity of the deposited layer of the heterojunction battery prepared by the present invention good and avoid affecting the electrode on the ITO film, the present invention strictly controls the voltage and current of the plasma cleaning equipment during the plasma cleaning process. Preferably, in some embodiments, the voltage of the plasma cleaning equipment during the plasma cleaning process is 10 to 150V, and the current is 0.2 to 2A. If the voltage and current of the plasma cleaning equipment during the cleaning process exceed the required range of voltage and current described in the present invention, the quality of the prepared heterojunction battery may be affected. For example, if the voltage and current are too large, it is easy to impact the metal electrode, resulting in defects on the electrode surface; if the voltage and current are too small, the design requirements of the present invention may not be met.

[0041] In other embodiments, the air flow velocity of the plasma cleaning equipment during the plasma cleaning process is 8 to 12 m / s, which avoids affecting the metal electrode and the ITO film layer while meeting the requirements of the present invention, thereby avoiding affecting the quality of the prepared battery.

[0042] In other embodiments, it is further preferred that the plasma cleaning time for the battery surface is 1 to 60 minutes, so as to avoid affecting the metal electrode and the ITO film layer while meeting the requirements of the present invention, thereby avoiding affecting the quality of the prepared battery.

[0043] The preparation method of the heterojunction battery provided by the present invention adopts a plasma cleaning pretreatment method after the prepared heterojunction battery is screen-printed and cured and before the battery is packaged, so as to change the hydrophobic surface of the ITO surface into a hydrophilic surface without introducing foreign pollutants, so as to improve the adhesion between the ITO and the packaging material, so that during use, the problems of the adhesive layer falling off and the decrease of the adhesion force caused by the environment are reduced or even avoided; the process is simple, the threshold for mass production is low, the preparation cost is low, the production efficiency is high, and it is helpful to realize large-scale production.

[0044] In view of the above, some embodiments of the present invention further provide a heterojunction battery, wherein an ITO thin film layer is deposited on the surface of the battery, and a hydrophilic group modification is introduced on the side of the ITO film layer bonded to the packaging material to improve the hydrophilicity of the battery surface, thereby improving the adhesion between the battery surface and the packaging material, reducing or even avoiding the occurrence of phenomena such as glue layer shedding and decreased adhesion during the use of the battery.

[0045] Furthermore, in some embodiments, preferably, the hydrophilic groups introduced on the side where the ITO film layer is bonded to the packaging material are hydroxyl groups and hydrocarbon groups, that is, the surface of the ITO film layer is modified by hydroxyl groups and hydrocarbon groups, and the obtained ITO film layer has good surface hydrophilicity and strong bonding between the ITO film layer and the packaging material.

[0046] Furthermore, in some embodiments, the hydrophilic groups are obtained by using the heterojunction battery preparation method described in the aforementioned scheme from the hydrophilic groups on the side where the ITO film layer is bonded to the packaging material. This method is used to introduce hydrophilic groups on the side where the ITO film layer is bonded to the packaging material to avoid introducing other pollutants, thereby helping to ensure the quality of the prepared battery.

[0047] Furthermore, some embodiments provide a heterojunction battery, which further includes:

[0048] N-type silicon wafer;

[0049] An amorphous silicon layer, a P-type doped amorphous silicon layer, an ITO film layer, and a metal electrode are sequentially arranged on the light-receiving surface of the N-type silicon wafer;

[0050] An amorphous silicon layer, an N-type doped amorphous silicon layer, an ITO film layer and a metal electrode are sequentially arranged on the backlight surface of the N-type silicon wafer.

[0051] In some embodiments, the amorphous silicon layer may be amorphous P-type or amorphous N-type.

[0052] In other embodiments, other TCO films are disposed between the P-type doped amorphous silicon layer and the ITO film layer; other TCO films are also disposed between the N-type doped amorphous silicon layer and the ITO film layer.

[0053] The heterojunction battery of the aforementioned solution of the present invention can be applied to the fields of renewable energy and semiconductor materials.

[0054] The present invention will be further described below in conjunction with specific embodiments, but this should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by technicians in this field based on the above-mentioned contents of the present invention still fall within the scope of protection of the present invention.

[0055] Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art. Unless otherwise defined, the technical terms or scientific terms used should have the common meanings understood by ordinary technicians in the field to which the present invention belongs.

[0056] Example 1

[0057] This embodiment prepares a heterojunction battery and a preparation method thereof, comprising the following steps:

[0058] 1) Texturing and cleaning: Take an N-type silicon wafer, use sodium hydroxide to etch the silicon wafer to form a pyramid shape, and use the RCA cleaning process to clean the silicon wafer.

[0059] 2) Amorphous silicon deposition: Intrinsic amorphous silicon film and doped amorphous silicon film are deposited on the surface of N-type silicon wafer to form a PN junction.

[0060] 3) ITO film deposition: depositing an ITO transparent conductive oxide film on the surface of the battery treated in step 2).

[0061] 4) Screen printing of metal gate electrode: Use a fixed screen pattern to accurately print silver paste onto the surface of the ITO film layer of the battery, and solidify it to form a conductive circuit;

[0062] 5) Plasma cleaning: The battery treated in step 4) is plasma cleaned by plasma cleaning equipment. The plasma cleaning equipment is set with the following process conditions: under nitrogen conditions, gas flow rate 10m / s, working current 0.2A, voltage 10V, plasma cleaning 60min, and HJT battery is obtained. Figure 1 As shown:

[0063] The battery comprises an N-type silicon wafer 1, on which the light-receiving side and the backlight side of the N-type silicon wafer are respectively provided with amorphous silicon layers 2 and 3, a P-type doped amorphous silicon layer 5 is arranged on the amorphous silicon layer on the light-receiving side of the N-type silicon wafer, an N-type doped amorphous silicon layer 4 is arranged on the amorphous silicon layer on the backlight side, an ITO film layer 6 is arranged on both the P-type doped amorphous silicon layer and the N-type doped amorphous silicon layer, and a metal gate electrode 7 is arranged on each of the ITO film layers.

[0064] The thickness of the amorphous silicon layer on the light-receiving side is 6nm; the thickness of the amorphous silicon layer on the backlight side is 5nm; the thickness of the P-type doped amorphous silicon layer on the light-receiving side is 10nm; the thickness of the N-type doped amorphous silicon layer on the backlight side is 7nm; the thickness of the ITO film layer is 100nm. The metal gate electrode is a silver electrode.

[0065] The battery prepared in this example was subjected to the following tests:

[0066] 1. Water contact angle test: Use a contact angle meter to perform the contact angle test.

[0067] 2. Peel strength with EVA: According to the common test method for peel strength, the battery cell and the front side of the EVA film are partially isolated with a non-stick material, and the preformed parts are placed in a 145°C laminator for 17 minutes for cross-linking treatment. After the laminated sample is cooled for 2 hours, the peel strength between the film and the battery cell is tested.

[0068] 3. Battery electrical performance testing: Use IV test method to test the battery's open circuit voltage (Voc), fill factor (FF), and short circuit current (Isc).

[0069] The test indicators are shown in Table 1.

[0070] Example 2

[0071] This embodiment prepares a heterojunction battery and a preparation method thereof, comprising the following steps:

[0072] 1) Texturing and cleaning: Take an N-type silicon wafer, use sodium hydroxide to etch the silicon wafer to form a pyramid shape, and use the RCA cleaning process to clean the silicon wafer.

[0073] 2) Amorphous silicon deposition: Intrinsic amorphous silicon film and doped amorphous silicon film are deposited on the surface of N-type silicon wafer to form a PN junction.

[0074] 3) ITO film deposition: depositing an ITO transparent conductive oxide film on the surface of the battery treated in step 2).

[0075] 4) Screen printing of metal gate electrode: Use a fixed screen pattern to accurately print silver paste onto the surface of the ITO film layer of the battery, and solidify it to form a conductive circuit;

[0076] 5) Plasma cleaning: The battery treated in step 4) is plasma cleaned by a plasma cleaning device. The plasma cleaning device is set with the following process conditions: under argon conditions, a gas flow rate of 10 m / s, a working current of 0.2 A, a voltage of 50 V, and plasma cleaning for 30 min to obtain a HJT battery.

[0077] The battery body is the same as that in Example 1, and the remaining steps and parameters are the same as those in Example 1.

[0078] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0079] Example 3

[0080] This embodiment prepares a heterojunction battery and a preparation method thereof, comprising the following steps:

[0081] 1) Texturing and cleaning: Take an N-type silicon wafer, use potassium hydroxide to etch the silicon wafer to form a pyramid shape, and use the RCA cleaning process to clean the silicon wafer.

[0082] 2) Amorphous silicon deposition: Intrinsic amorphous silicon film and doped amorphous silicon film are deposited on the surface of N-type silicon wafer to form a PN junction.

[0083] 3) ITO film deposition: depositing an ITO transparent conductive oxide film on the surface of the battery treated in step 2).

[0084] 4) Screen printing of metal gate electrode: Use a fixed screen pattern to accurately print silver paste onto the surface of the ITO film layer of the battery, and solidify it to form a conductive circuit;

[0085] 5) Plasma cleaning: The battery treated in step 4) is plasma cleaned by a plasma cleaning device. The plasma cleaning device is set with the following process conditions: under nitrogen conditions, a gas flow rate of 10 m / s, a working current of 0.2 A, a voltage of 10 V, and plasma cleaning for 60 min to obtain a HJT battery.

[0086] The battery body is the same as that in Example 1, and the remaining steps and parameters are the same as those in Example 1.

[0087] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0088] Example 4

[0089] This embodiment prepares a heterojunction battery and a preparation method thereof, comprising the following steps:

[0090] 1) Texturing and cleaning: Take an N-type silicon wafer, use sodium hydroxide to etch the silicon wafer to form a pyramid shape, and use the RCA cleaning process to clean the silicon wafer.

[0091] 2) Amorphous silicon deposition: Intrinsic amorphous silicon film and doped amorphous silicon film are deposited on the surface of N-type silicon wafer to form a PN junction.

[0092] 3) ITO film deposition: depositing an ITO transparent conductive oxide film on the surface of the battery treated in step 2).

[0093] 4) Screen printing of metal gate electrode: Use a fixed screen pattern to accurately print silver paste onto the surface of the ITO film layer of the battery, and solidify it to form a conductive circuit;

[0094] 5) Plasma cleaning: The battery treated in step 4) is plasma cleaned by plasma cleaning equipment. The plasma cleaning equipment is set with the following process conditions: under argon conditions, gas flow rate 12m / s, working current 2A, voltage 150V, plasma cleaning 10min, and HJT battery is obtained.

[0095] The battery body is the same as that in Example 1, and the remaining steps and parameters are the same as those in Example 1.

[0096] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0097] Example 5

[0098] The difference between this embodiment and embodiment 1 is that, in the process of preparing the battery body, in this embodiment, after amorphous silicon is deposited to form a PN junction in step 2), a zinc oxide aluminum (AZO) thin film layer is deposited on the surface of the battery body, and then an ITO thin film layer is further deposited on the zinc oxide aluminum (AZO) thin film layer.

[0099] The remaining steps and parameters are the same as in Example 1.

[0100] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0101] Example 6

[0102] This embodiment prepares a heterojunction battery and its preparation method, which is different from the embodiment 1 in that the battery body has the same structure as the embodiment 1. Among them, the thickness of the amorphous silicon layer on the light-receiving side of the battery is 8nm; the thickness of the amorphous silicon layer on the backlight side is 6nm; the thickness of the P-type doped amorphous silicon layer on the light-receiving side is 8nm; the thickness of the N-type doped amorphous silicon layer on the backlight side is 6nm; the thickness of the ITO film layer is 120nm. The metal grid electrode is a silver electrode.

[0103] The remaining steps and parameters are the same as in Example 1.

[0104] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0105] Example 7

[0106] The difference between this embodiment and embodiment 1 is that, during the preparation of the battery, after the ITO film is deposited and before the step of screen printing the metal gate electrode, the battery surface is plasma cleaned.

[0107] The battery body is the same as that in Example 1, and the remaining steps and parameters are the same as those in Example 1.

[0108] The detection indexes and methods are the same as those in Example 1. The detection results are shown in Table 1.

[0109] Comparative Example 1

[0110] The difference between this comparative example and Example 1 is that the plasma cleaning step is not performed. The remaining steps and parameters are the same as those in Example 1, and the detection indicators and methods are the same as those in Example 1. The test results are shown in Table 1.

[0111] Comparative Example 2

[0112] The difference between this comparative example and Example 1 is that the plasma cleaning process is: under oxygen conditions, the gas flow rate is 10 m / s, the working current is 2.5 A, the voltage is 160 V, and the plasma cleaning time is 60 min. The remaining steps and parameters are the same as in Example 1, and the detection indicators and methods are the same as in Example 1. The test results are shown in Table 1.

[0113] Comparative Example 3

[0114] The difference between this comparative example and Example 1 is that the plasma cleaning process is: under ammonia conditions, the gas flow rate is 10 m / s, the working current is 0.2 A, the voltage is 10 V, and the plasma cleaning is 60 min. The remaining steps and parameters are the same as in Example 1, and the detection indicators and methods are the same as in Example 1. The test results are shown in Table 1.

[0115] Table 1 Test results of indicators of various embodiments and comparative examples

[0116] Group Water drop angle (°) (N / cm) V(V) I(A) FF(%) Example 1 30 230.1 0.7402 9.118 83.88 Example 2 28 240.5 0.7421 9.116 83.76 Example 3 45 201.4 0.7430 9.116 83.72 Example 4 40 205.3 0.7408 9.117 83.81 Example 5 31 232.2 0.7415 9.115 83.84 Example 6 30 232.5 0.7403 9.116 83.95 Example 7 63 192.6 0.7431 9.116 82.97 Comparative Example 1 85 165.1 0.7427 9.117 82.88 Comparative Example 2 40 154.3 0.7406 9.115 82.79 Comparative Example 3 80 162.8 0.7408 9.114 82.73

[0117] Through the examples and Table 1, Figure 1 It can be seen that by using the heterojunction battery and the preparation method thereof provided by the present invention, the water drop angle of the heterojunction battery formed is significantly reduced, and the peel strength with EVA is basically above 200N / cm, which significantly improves the bonding strength between the surface deposition layer of the heterojunction battery and the packaging material, so that during use, the problems of glue layer shedding and decreased adhesion caused by environmental influences are reduced or even avoided.

[0118] Furthermore, it can be seen from the comparative examples that in the heterojunction battery prepared by the preparation method of the heterojunction battery provided by the present invention, if the voltage and current exceed the range required by the present invention during the plasma cleaning process, for example, the voltage and current are too large, defects will be generated on the electrode surface, thereby affecting the quality of the battery.

[0119] Furthermore, in the process of plasma cleaning of the heterojunction battery prepared by the method for preparing the heterojunction battery provided by the present invention, if the atmosphere uses ammonia, the problem of enhanced lipophilicity of the polymer surface will occur, which is caused by the increase in the number of nitrogen-containing groups during the reaction process.

[0120] The technical features in the claims and / or the specification of the present invention may be combined, and the combination is not limited to the combination obtained by reference in the claims. The technical solution obtained by combining the technical features in the claims and / or the specification is also within the protection scope of the present invention.

[0121] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a heterojunction battery, characterized in that: It includes the following steps: ITO thin film layers are sequentially deposited on the surface of the battery body, and after metal electrodes are printed to form a battery, the battery surface is subjected to hydrophilic modification treatment to form hydrophilic groups on the ITO thin film layer deposited on the battery surface.

2. The preparation method according to claim 1, characterized in that: The battery surface is plasma cleaned by using a plasma cleaning device to modify the hydrophilicity of the battery surface.

3. The preparation method according to claim 2, characterized in that: The atmosphere introduced into the plasma cleaning equipment is any one or more mixtures of nitrogen, argon, oxygen and air.

4. The preparation method according to claim 2, characterized in that: The plasma cleaning equipment uses a voltage of 10 to 150 V and a current of 0.2 to 2 A.

5. The preparation method according to claim 4, characterized in that: The air flow velocity of the plasma cleaning equipment is 8-12 m / s.

6. The preparation method according to any one of claims 2 to 5, characterized in that: The cleaning time of the plasma cleaning process is 1 to 60 minutes.

7. A heterojunction battery, characterized in that: An ITO film layer is deposited on the surface of the battery, and a side of the ITO film layer bonded to the packaging material has a hydrophilic group.

8. The battery according to claim 7, characterized in that The hydrophilic groups are hydroxyl groups and hydrocarbon groups.

9. The battery according to claim 7, characterized in that The hydrophilic group is obtained by the method according to any one of claims 1 to 6.

10. The heterojunction battery according to any one of claims 1 to 9, which can be applied in the fields of renewable energy and semiconductor materials.

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