Battery production method and battery structure

Abstract

The application relates to a battery preparation method and a battery structure. The battery preparation method comprises the following steps: providing an N-type silicon substrate; forming first and second spaced-apart passivation contact structures on the back surface of the N-type silicon substrate to obtain a first form body; texturing the first form body, and in the drying process of the texturing and passivation process, wet ozone or wet oxygen is introduced to form a first passivation film in the form of silicon oxide on the front and back surfaces of the first form body; and forming an electrode assembly on the side of the first passivation film away from the N-type silicon substrate. The preparation of the battery is completed through the above arrangement, and the first passivation film in the form of silicon oxide is formed on the front and back surfaces of the first form body by introducing wet ozone or wet oxygen in the drying step in the texturing and passivation process, so that the surface defect density of the N-type silicon substrate after texturing is effectively reduced, the surface passivation effect of the N-type silicon substrate is enhanced, and higher battery conversion efficiency is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic power generation, in particular to a cell preparation method and a cell structure. BACKGROUND

[0002] A solar cell is a kind of semiconductor device that can convert solar energy into electric energy, and a lower degree of electric cost has been the goal pursued by the solar cell industry.

[0003] The current solar cell combines TOPCon technology with IBC technology, combines the high short-circuit current of IBC technology and the excellent passivation contact characteristics of TOPCon technology, so that the solar cell forms an interdigital patterned structure on the back surface. Such a structure can improve the conversion efficiency of the cell through a good passivation structure. However, the passivation effect of the back surface of the current solar cell is poor, which limits the conversion efficiency of the cell. SUMMARY

[0004] Therefore, it is necessary to provide a cell preparation method and a cell structure in view of the problem that the passivation effect of the back surface of the current solar cell is poor, which limits the conversion efficiency of the cell.

[0005] A cell preparation method, the cell preparation method comprising the following steps:

[0006] providing an N-type silicon substrate;

[0007] forming a first passivation contact structure and a second passivation contact structure arranged at intervals on the back surface of the N-type silicon substrate to obtain a first morphology body;

[0008] texturing the first morphology body, and in a drying process of the texturing process, wet ozone or wet oxygen is introduced to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body;

[0009] forming an electrode assembly on the side of the first passivation film away from the N-type silicon substrate.

[0010] In one embodiment, the humidity ratio in the wet ozone or the wet oxygen is 30%-70%.

[0011] In one embodiment, the temperature range of the drying process is 90°-200°.

[0012] In one embodiment, after the "texturing the first morphology body, and in a drying process of the texturing process, wet ozone or wet oxygen is introduced to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body", and before the "forming an electrode assembly on the side of the first passivation film away from the N-type silicon substrate", the method further comprises:

[0013] forming a second passivation film on the surface of the first passivation film.

[0014] In one embodiment, the second passivation film comprises at least one of aluminum oxide, silicon nitride, and silicon oxynitride.

[0015] In one embodiment, the step of "forming a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body in the drying process of the texturing process" specifically comprises the following steps:

[0016] performing acid etching on the front surface of the first morphology body to expose the front surface topography of the N-type silicon substrate;

[0017] performing front texturing on the first morphology body, while etching the spacing region between the first passivation contact structure and the second passivation contact structure to also form a pyramid texture in the spacing region;

[0018] performing cleaning and drying on the textured first morphology body to obtain the first passivation film;

[0019] forming a second passivation film on the surface of the first passivation film to obtain a semi-finished product.

[0020] In one embodiment, the step of "performing cleaning and drying on the textured first morphology body to obtain the first passivation film" specifically comprises the following steps:

[0021] washing off chemical residues on the first morphology body with pure water;

[0022] slowly pulling the first morphology body with pure water to ensure that the surface of the first morphology body is clean;

[0023] drying the clean first morphology body through a drying device, and introducing wet ozone or wet oxygen during the drying process or after drying the first morphology body to form the first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body.

[0024] In one embodiment, the step of "forming a first passivation contact structure and a second passivation contact structure spaced apart on the back surface of the N-type silicon substrate to obtain a first morphology body" specifically comprises the following steps:

[0025] sequentially depositing a first tunneling oxide layer and a first polysilicon layer on the back surface of the N-type silicon substrate;

[0026] performing boron diffusion on the first polysilicon layer, and forming a borosilicate glass layer on the first polysilicon layer;

[0027] The first patterning process is performed to remove part of the borosilicate glass layer, and the area where the borosilicate glass layer is removed is an N area;

[0028] The N area is etched to expose the topography of the N-type silicon substrate corresponding to the N area, thereby obtaining an initial morphology body.

[0029] In one embodiment, after the step of "etching the N area to expose the topography of the N-type silicon substrate corresponding to the N area, thereby obtaining an initial morphology body", the following steps are further included:

[0030] A second tunneling oxide layer and a second polysilicon layer are sequentially deposited on the outer layer of the initial morphology body;

[0031] Phosphorus is diffused in the second polysilicon layer, and a phosphosilicate glass layer is formed on the second polysilicon layer;

[0032] A second patterning process is performed on the first tunneling oxide layer, the first polysilicon layer, the second tunneling oxide layer, and the second polysilicon layer to form the first passivation contact structure and the second passivation contact structure arranged at intervals.

[0033] The above battery preparation method is completed through a doping process, a texturing and passivation process, and a metallization preparation process. In the drying step in the texturing and passivation process, wet ozone or wet oxygen is introduced to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body, effectively reducing the surface defect density of the N-type silicon substrate after texturing, enhancing the surface passivation effect of the N-type silicon substrate, and thus obtaining higher battery conversion efficiency.

[0034] The application also provides a battery structure prepared by the battery preparation method of any one of the above embodiments, the battery structure comprising:

[0035] An N-type silicon substrate having a front surface and a back surface arranged oppositely, the back surface of the N-type silicon substrate being distributed with a doped layer, the doped layer including a first deposition area, a second deposition area, and an interval area between the two;

[0036] A pyramid texture formed on the front surface of the N-type silicon substrate and the interval area;

[0037] A passivation layer including a first passivation film covering the pyramid texture and the doped layer, the first passivation film being silicon oxide;

[0038] An electrode assembly including a first electrode and a second electrode, the first electrode being in contact with the first deposition area through the passivation layer on the back surface, and the second electrode being in contact with the second deposition area through the passivation layer on the back surface. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 Flow chart of the battery preparation method provided in the present application.

[0040] Figure 2 Structure diagram of the preparation flow of the initial form provided in the present application.

[0041] Figure 3 Structure diagram of the preparation flow of the first form provided in the present application.

[0042] Figure 4 Structure diagram of the preparation flow of the semi-finished product provided in the present application.

[0043] Figure 5 Schematic diagram of the first passivation film preparation device provided in the present application.

[0044] Figure 6 Schematic diagram of the battery structure provided in the present application.

[0045] Wherein:

[0046] 10, battery structure; 20, first passivation film preparation device; 21, ozone generator; 22, water tank; 23, defoaming device; 30, drying device; 40, first form; 50, initial form; 60, semi-finished product;

[0047] 100, N-type silicon substrate; 110, front surface; 120, back surface;

[0048] 200, doped layer; 210, first deposition area; 211, first tunneling oxide layer; 212, first polysilicon layer; 2121, borosilicate glass layer; 220, second deposition area; 221, second tunneling oxide layer; 222, second polysilicon layer; 2221, phosphosilicate glass layer; 230, spacing area;

[0049] 300, pyramid velvet;

[0050] 400, passivation layer; 410, first passivation film; 420, second passivation film;

[0051] 500, electrode assembly; 510, first electrode; 520, second electrode. DETAILED DESCRIPTION

[0052] In order to make the above objectives, features and advantages of the present application more clear and comprehensible, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of different ways beyond the specific embodiments described herein and by one of ordinary skill in the art without departing from the spirit and scope of the present application, and it is therefore intended that all such variations be considered as falling within the scope of the present application. It should be understood that the use of the terms "include", "comprise" or "contain" herein should not be understood as limiting the present application to the features or steps described herein, but rather the use of these terms is intended to cover the presence of the features or steps described herein as well as the presence of other features or steps not described herein.

[0053] In the description of the present application, it should be understood that, if these terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0054] In addition, if these terms "first", "second" appear, these terms are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features referred to. Therefore, the features defined with "first", "second" can include at least one of the features explicitly or implicitly. In the description of the present application, if the term "a plurality of" appears, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0055] In the present application, unless otherwise explicitly specified and limited, if the terms "mount", "connect", "connect", "fix" and the like appear, these terms should be interpreted broadly. For example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0056] In the present application, unless specifically defined and limited otherwise, if there is a description of a first feature "on" or "under" a second feature, etc., it can mean that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature "over", "above" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only means that the first feature is horizontally higher than the second feature. The first feature "under", "below" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only means that the first feature is horizontally lower than the second feature.

[0057] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or there can be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be an intermediate element. If present, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in the present application are for illustrative purposes only and do not represent the only implementation.

[0058] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 a flow chart of a battery preparation method in an embodiment of the present application is shown, Figure 2 a preparation flow structure schematic diagram of an initial form body in an embodiment of the present application is shown, Figure 3 a preparation flow structure schematic diagram of a first form body in an embodiment of the present application is shown, Figure 4 a preparation flow structure schematic diagram of a semi-finished product provided by an embodiment of the present application is shown.

[0059] The battery preparation method provided by an embodiment of the present application comprises the following steps:

[0060] Step S1, providing an N-type silicon substrate 100, in specific settings, the N-type silicon substrate 100 has oppositely arranged front surface 110 and back surface 120, the front surface 110 is used for facing the sun, i.e. the light-receiving surface, and the back surface 120 is used for facing away from the sun, i.e. the back surface, in specific use, the front surface 110 and the back surface 120 of the N-type silicon substrate 100 are both polished;

[0061] Step S2, forming a first passivation contact structure and a second passivation contact structure arranged at intervals on the back surface 120 of the N-type silicon substrate 100, to obtain Figure 3The first morphology body 40 shown, in a specific setting, generally forms the first passivation contact structure and the second passivation contact structure through a doping process, and the first passivation contact structure and the second passivation contact structure play a better passivation effect on the N-type silicon substrate 100, so as to improve the photoelectric conversion efficiency of the formed solar cell;

[0062] Step S3, referring to Figure 4 The first morphology body 40 is textured, and wet ozone or wet oxygen is introduced in the drying process of the texturing process to form a first passivation film 410 in the form of silicon oxide on the front surface 110 and the back surface 120 of the first morphology body 40. Through the above setting, the oxidation ability of wet ozone or wet oxygen is used to form silicon oxide on the front surface 110 and the back surface 120 of the first morphology body 40, so as to enhance the passivation effect on the surface of the N-type silicon substrate and reduce the defect density on the surface of the N-type silicon substrate after texturing;

[0063] Step S4, forming an electrode assembly on the side of the first passivation film 410 away from the N-type silicon substrate 100 to complete the preparation of the cell.

[0064] The above cell preparation method completes the preparation of the cell through a doping process, a texturing and passivation process, and a metallization preparation process. And by introducing wet ozone or wet oxygen in the drying step in the texturing and passivation process to form a first passivation film 410 in the form of silicon oxide on the front surface 110 and the back surface 120 of the first morphology body 40, the surface defect density of the N-type silicon substrate after texturing is effectively reduced, the surface passivation effect of the N-type silicon substrate is enhanced, and higher cell conversion efficiency is obtained.

[0065] Taking wet ozone as an example, in order to more conveniently introduce wet ozone in the drying process of the texturing process, an embodiment of the present application provides a first passivation film preparation device 20 as shown. Figure 5 The first passivation film preparation device 20 includes an ozone generator 21, a water tank 22 and a defoaming device 23 connected in sequence. In a specific setting, the defoaming device 23 is connected to a drying device 30, and the drying device 30 is provided with a first morphology body 40. In specific use, oxygen is introduced into the ozone generator 21 to generate ozone, and the ozone is passed through the water tank 22 to dissolve part of the ozone in the water in the water tank 22. The part not dissolved in water is collected through the defoaming device 23 and then enters the drying device 30. The defoaming device 23 is used to filter the water vapor of the wet ozone, so that the wet ozone enters the drying device 30 after retaining a set humidity.

[0066] To form the compact first passivation film 410, in one preferred embodiment, the humidity in the wet ozone or wet oxygen accounts for 30%-70%. It should be noted that the above account is obtained by the applicant through repeated experiments. When the humidity in the wet ozone or wet oxygen accounts for 30%-70%, the surface of the first morphology body 40 forms the compact first passivation film 410, and the thickness of the first passivation film 410 ranges between 0.01 nm and 1 nm, so as to enhance the passivation effect on the surface of the N-type silicon substrate and reduce the defect density of the N-type silicon substrate after texturing.

[0067] It should be emphasized that ozone decomposes less at low temperature and has strong oxidation ability. With the increase of oxidation temperature, on the one hand, the decomposition of ozone is strengthened, which leads to the weakening of oxidation ability and the decrease of the thickness of the first passivation film 410. On the other hand, with the strengthening of ozone decomposition, the number of oxygen atoms increases. When the oxidation temperature continues to increase, the oxygen atoms not involved in the reaction participate in oxidation, and the thickness of the first passivation film 410 increases. In order to form the first passivation film 410 with a suitable thickness to enhance the passivation effect, in one preferred embodiment, the temperature range of the drying process is 90°-200°. In the specific setting, the drying time is set to 500s-900s, and the ozone concentration ranges between 0.5ppm and 10ppm. Through the above setting, the first passivation film 410 with a thickness ranging between 0.01 nm and 1 nm can be formed on the surface of the first morphology body 40, so as to enhance the passivation effect on the surface of the N-type silicon substrate and reduce the defect density of the N-type silicon substrate after texturing.

[0068] Again referring to Figure 4 , in order to further enhance the passivation effect, in one preferred embodiment, after step S3 and before step S4, a second passivation film 420 is further formed on the surface of the first passivation film 410. In the specific setting, the second passivation film 420 includes at least one of aluminum oxide, silicon nitride, and silicon oxynitride. It should be emphasized that when the second passivation film 420 is selected as aluminum oxide, ALD deposition technology can be used to deposit aluminum oxide on the surface of the first passivation film 410. The silicon oxide first passivation film 410 can promote the release of the field passivation effect of the second passivation film 420, so as to have the advantages of both in the passivation performance, obtain a relatively low defect state, improve the open-circuit voltage of the battery, and further obtain a higher battery conversion efficiency.

[0069] Please refer to Figure 2 , in order to more conveniently prepare the initial morphology body 50 for subsequent preparation of the first morphology body, in one preferred embodiment, in step S2, the following steps are specifically included:

[0070] Step S21, the back surface 120 of the N-type silicon substrate 100 is sequentially deposited with a first tunneling oxide layer 211 and a first polysilicon layer 212. In a specific operation, the polished N-type silicon substrate 100 is passed through a deposition device to deposit the first tunneling oxide layer 211, and then the first tunneling oxide layer 211 is further deposited with the first polysilicon layer 212. The thickness of the first tunneling oxide layer 211 is preferably 1.2-2 nm, and the thickness of the first polysilicon layer 212 is preferably 100-400 nm. Step S22, boron diffusion is performed on the first polysilicon layer 212 to form a borosilicate glass layer 2121 on the first polysilicon layer 212. The thickness of the borosilicate glass layer 2121 is preferably 30-100 nm. In a specific operation, the boron diffusion can be performed in a high-temperature diffusion device. Step S23, a first patterning process is performed to remove part of the borosilicate glass layer 2121, and the area where the borosilicate glass layer 2121 is removed is the N area. In a specific arrangement, the borosilicate glass layer 2121 in the N area can be removed by laser. The area between two adjacent N areas is the P area. Step S24, the N area is etched to expose the topography of the N-type silicon substrate 100 corresponding to the N area, thereby obtaining an initial morphology body 50. In a specific arrangement, the N area can be etched by alkali etching.

[0071] In combination Figure 3 As shown in the drawings, in order to more conveniently prepare the first morphology body 40 from the initial morphology body 50, specifically, after step S24, the following steps are further included:

[0072] Step S24, the outer layer of the initial morphology body 50 is sequentially deposited with a second tunneling oxide layer 221 and a second polysilicon layer 222 to deposit the second polysilicon layer 222 on the surface of the second tunneling oxide layer 221. The thickness of the second tunneling oxide layer 221 is preferably 1.2-2 nm, and the thickness of the second polysilicon layer 222 is preferably 100-400 nm. Step S24, phosphorus diffusion is performed on the second polysilicon layer 222 to form a phosphosilicate glass layer 2221 on the second polysilicon layer 222. The thickness of the phosphosilicate glass layer 2221 is preferably 30-100 nm. Step S24, a second patterning process is performed on the first tunneling oxide layer 211, the first polysilicon layer 212, the second tunneling oxide layer 221, and the second polysilicon layer 222 to form first and second spaced apart passivation contact structures. The second patterning process can be laser. Specifically, the phosphosilicate glass layer 2221 corresponding to all P areas and part of the phosphosilicate glass layer 2221 corresponding to the N area can be removed by laser, so that there is a spacing area 230 between the borosilicate glass layer 2121 and the phosphosilicate glass layer 2221, corresponding to the gap between the first and second passivation contact structures, thereby obtaining the first morphology body 40.

[0073] It should be emphasized that the texturing structure can increase the surface area of the battery piece, thereby increasing the generation and collection of photo-generated carriers and improving the conversion efficiency of the battery. In combination with the above Figure 4 As shown, in order to more conveniently texturize the first morphology body 40, a preferred embodiment in step S3 specifically includes the following steps:

[0074] Step S31, acid etching the front surface 110 of the first morphology body 40 to expose the topography of the front surface 110 of the N-type silicon substrate 100, through the above setting, to eliminate the plating around inevitably formed on the front surface 110 of the N-type silicon substrate 100 in step S2, and in the specific setting, acid etching is performed after mixing nitric acid, hydrofluoric acid and sulfuric acid, wherein the range of nitric acid is 300g / L-400g / L, the range of hydrofluoric acid is 50g / L-100g / L, and the range of sulfuric acid is 60g / L-150g / L;

[0075] Step S32, texturing the front surface 110 of the first morphology body 40, while etching the interval region between the first passivation contact structure and the second passivation contact structure, to form a pyramid texture 300 in the interval region, and in the specific operation: first, using sodium hydroxide and hydrogen peroxide to pre-clean the first morphology body 40 after acid etching; then washing with water to wash away the chemical residues on the first morphology body 40; then through sodium hydroxide and additives to form a pyramid texture 300 structure on the front surface 110 of the first morphology body 40 and the interval region between the first passivation contact structure and the second passivation contact structure, while removing the corresponding second tunnel oxide layer and second polysilicon layer 222 on the P region; in order to ensure the smooth progress of the subsequent film plating process, the chemical residues are then washed with pure water, and then sodium hydroxide and hydrogen peroxide are used to react with the additives to clean the surface of the first morphology body 40, and then the surface is cleaned by acid washing with hydrofluoric acid solution to remove the borosilicate glass layer 2121 on the P region and the phosphosilicate glass layer 2221 on the N region, making the surface cleaner;

[0076] It should be noted that the texturing process in step S32 involves acidic and alkaline solutions, so after the pyramid texture 300 is formed, the first morphology body 40 after texturing is cleaned and dried through step S33, and in the specific cleaning process: the chemical residues on the first morphology body 40 are washed away with pure water; then the first morphology body 40 is slowly pulled up with pure water to ensure that the surface of the first morphology body 40 is clean; in the specific drying process: by introducing wet ozone or wet oxygen, a first passivation film 410 in the form of silicon oxide is simply and quickly formed on the front surface 110 and back surface 120 of the first morphology body 40, which can effectively reduce the surface defect density of the N-type silicon substrate after texturing and enhance the surface passivation effect of the N-type silicon substrate. In addition, wet ozone or wet oxygen can also be introduced to form the first passivation film 410 after the first morphology body 40 is dried.

[0077] And to enhance the passivation effect, a second passivation film 420 is formed on the surface of the first passivation film 410 through step S34, and the second passivation film 420 can be selected as aluminum oxide. Through the above arrangement, the first passivation film 410 in the form of silicon oxide can promote the release of the field passivation effect of the second passivation film 420, so as to have the advantages of both in the passivation performance, obtain a relatively low defect state, and improve the open circuit voltage of the battery, and further obtain a higher battery conversion efficiency. In a specific arrangement, the thickness of the second passivation film 420 can be selected as 6nm.

[0078] It should be noted that after the second passivation film 420 is formed on the surface of the first passivation film 410, a semi-finished product 60 is obtained. Subsequently, silver paste can be screen printed to form an ohmic contact for facilitating current output, and then a battery is obtained through sintering.

[0079] The application also provides a battery structure 10 prepared by the battery preparation method of any one of the above embodiments. Figure 6 As shown in the drawings, Figure 6 A schematic diagram of a battery structure 10 in an embodiment of the application is shown. The above battery structure 10 includes an N-type silicon substrate 100, a pyramid texturing 300, a passivation layer 400, and an electrode assembly 500.

[0080] The N-type silicon substrate 100 has oppositely arranged front and back surfaces 110 and 120, and the back surface 120 of the N-type silicon substrate 100 is distributed with a doped layer 200. The doped layer 200 includes a first deposition area 210, a second deposition area 220, and a spacing area 230 therebetween. In a specific arrangement, the first deposition area 210 includes a first tunneling oxide layer 211 and a boron-doped first polysilicon layer 212, and the second deposition area 220 includes a second tunneling oxide layer 221 and a phosphorus-doped second polysilicon layer 222. The pyramid texturing 300 is formed on the front surface 110 and the spacing area 230 of the N-type silicon substrate 100.

[0081] The passivation layer 400 includes a first passivation film 410 covering the pyramid texturing 300 and the doped layer 200, and the first passivation film 410 is silicon oxide. In a specific arrangement, the passivation layer 400 further includes a second passivation film 420, and the second passivation film 420 covers the outer side of the first passivation film 410. The second passivation film 420 can be selected as aluminum oxide. Through the above arrangement, the first passivation film 410 in the form of silicon oxide can promote the release of the field passivation effect of the second passivation film 420, so as to have the advantages of both in the passivation performance, obtain a relatively low defect state, and improve the open circuit voltage of the battery, and further obtain a higher battery conversion efficiency.

[0082] The electrode assembly 500 includes a first electrode 510 and a second electrode 520, the first electrode 510 being in contact with the first deposition region 210 through the passivation layer 400 on the back surface 120, and the second electrode 520 being in contact with the second deposition region 220 through the passivation layer 400 on the back surface 120. In a specific arrangement, one end of the first electrode 510 is in contact with the boron-doped first polysilicon layer 212 in the first deposition region 210, and the other end of the first electrode 510 extends out of the first deposition region 210; one end of the second electrode 520 is in contact with the phosphorus-doped second polysilicon layer 222 in the second deposition region 220, and the other end of the second electrode 520 extends out of the second deposition region 220.

[0083] The battery structure 10 described above, by arranging the first passivation film 410 including the pyramid-textured surface 300 and the doped layer 200, the first passivation film 410 being silicon oxide, enhances the surface passivation effect of the N-type silicon substrate 100, and further obtains higher battery conversion efficiency.

[0084] The technical features of the above-described embodiments can be combined in any manner. To make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, but as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0085] The above-described embodiments only express several implementation manners of the present application, and the description is relatively specific and detailed, but it should not be understood as a limitation on the patent scope of the application. It should be pointed out that for ordinary skilled persons in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the protection scope of the present application. Therefore, the patent protection scope of the present application should be subject to the appended claims.

Claims

1. A method of battery production, characterized by, The battery preparation method comprises the following steps: providing an N-type silicon substrate; forming a first passivation contact structure and a second passivation contact structure at intervals on the back surface of the N-type silicon substrate to obtain a first morphology body; texturing the first morphology body, and introducing humid ozone or humid oxygen in a drying process of the texturing process to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body; forming an electrode assembly on the side of the first passivation film away from the N-type silicon substrate; the humidity in the humid ozone or the humid oxygen accounts for 30%-70%; the thickness of the first passivation film ranges between 0.01 nm and 1 nm.

2. The battery production method according to claim 1, wherein the drying time ranges between 500 s and 900 s.

3. The battery production method according to claim 1, wherein the temperature of the drying process ranges between 90° and 200°.

4. The battery production method according to claim 1, wherein after the "texturing the first morphology body, and introducing humid ozone or humid oxygen in a drying process of the texturing process to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body", and before the "forming an electrode assembly on the side of the first passivation film away from the N-type silicon substrate", further comprising: forming a second passivation film on the surface of the first passivation film.

5. The battery production method according to claim 4, wherein the second passivation film comprises at least one of aluminum oxide, silicon nitride and silicon oxynitride.

6. The battery production method according to claim 1, wherein in the "texturing the first morphology body, and introducing humid ozone or humid oxygen in a drying process of the texturing process to form a first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body", specifically comprising the following steps: acid etching the front surface of the first morphology body to expose the front surface topography of the N-type silicon substrate; front surface texturing the first morphology body, and etching the interval region between the first passivation contact structure and the second passivation contact structure to also form a pyramid texture in the interval region; cleaning and drying the first morphology body after texturing to obtain the first passivation film; forming a second passivation film on the surface of the first passivation film to obtain a semi-finished product.

7. The battery production method according to claim 6, wherein in the "cleaning and drying the first morphology body after texturing to obtain the first passivation film", specifically comprising the following steps: washing away chemical residues on the first morphology body with pure water; slowly pulling the first morphology body with pure water to ensure that the surface of the first morphology body is clean; drying the clean first morphology body through a drying device, and introducing humid ozone or humid oxygen in the drying process or after drying the first morphology body to form the first passivation film in the form of silicon oxide on the front surface and the back surface of the first morphology body.

8. The battery production method according to claim 1, wherein in the "forming a first passivation contact structure and a second passivation contact structure at intervals on the back surface of the N-type silicon substrate to obtain a first morphology body", specifically comprising the following steps: sequentially depositing a first tunneling oxide layer and a first polysilicon layer on the back surface of the N-type silicon substrate; diffusing boron on the first polysilicon layer to form a borosilicate glass layer on the first polysilicon layer; removing part of the borosilicate glass layer through first patterning processing, and the area where the borosilicate glass layer is removed is an N area; etching the N region to expose the topography of the N-type silicon substrate corresponding to the N region, thereby obtaining an initial morphological body.

9. The battery production method according to claim 8, wherein After the step of "etching the N region to expose the topography of the N-type silicon substrate corresponding to the N region, thereby obtaining an initial morphological body", the method further comprises the following steps: sequentially depositing a second tunneling oxide layer and a second polysilicon layer on the outer layer of the initial morphological body; performing phosphorus diffusion on the second polysilicon layer to form a phosphorus-silicon glass layer on the second polysilicon layer; performing a second patterning process on the first tunneling oxide layer, the first polysilicon layer, the second tunneling oxide layer and the second polysilicon layer to form the first passivation contact structure and the second passivation contact structure arranged in an interval.

10. A battery structure produced by the method of any one of claims 1 to 9, characterized by The battery structure comprises: an N-type silicon substrate having a front surface and a back surface arranged oppositely, the back surface of the N-type silicon substrate being distributed with a doped layer, the doped layer comprising a first deposition area, a second deposition area and an interval area between the first deposition area and the second deposition area; a pyramid texture formed on the front surface of the N-type silicon substrate and the interval area; a passivation layer comprising a first passivation film covering the pyramid texture and the doped layer, the first passivation film being silicon oxide; an electrode assembly comprising a first electrode and a second electrode, the first electrode being in contact with the first deposition area through the passivation layer on the back surface, and the second electrode being in contact with the second deposition area through the passivation layer on the back surface.

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