Heterojunction silicon cell and preparation method thereof

Abstract

The invention relates to the technical field of heterojunction silicon cells, in particular to a heterojunction silicon cell and a preparation method thereof. The front surface and the back surface of the monocrystalline silicon wafer are provided with silicon thin film layers; the first transparent conductive film and the second transparent conductive film are mounted on the silicon thin film layer; the metal grid lines are respectively arranged on the surfaces of the first transparent conductive film and the second transparent conductive film far away from the silicon thin film layer; the cerium dioxide transparent conductive film is installed between the metal grid line and the first transparent conductive film so as to increase absorption of the first transparent conductive film to ultraviolet light. According to the invention, a layer of very thin cerium dioxide thin film can be introduced in the middle of the transparent conductive film, so that the absorption of the conductive film to ultraviolet light is effectively increased, the ultraviolet light absorbed by the silicon thin film is reduced, the probability that silicon-hydrogen bonds in the silicon thin film are damaged is greatly reduced, and the long-term stability of the battery performance is improved.

Description

Technical Field

[0001] This invention relates to the field of heterojunction silicon solar cell technology, and in particular to a heterojunction silicon solar cell and its preparation method. Background Technology

[0002] To achieve better returns, photovoltaic power plants are placing higher demands on the long-term stability of monocrystalline silicon modules, and heterojunction modules also need further improvements in stability. Monocrystalline silicon modules generally suffer from significant UV degradation. To mitigate this, in addition to improving module materials and processes, it is also necessary to analyze the structure and function of the cells, thereby leading to improvements in materials and related processes.

[0003] Existing heterojunction silicon solar cells mainly suffer from the following shortcomings: (1) The ultraviolet degradation of existing heterojunction silicon cells will cause the breakage of silicon-hydrogen bonds in silicon thin films.

[0004] (2) Transparent conductive films all use high transmittance materials. Although this increases the short-circuit current, the transmittance of ultraviolet rays also increases accordingly, which is detrimental to the stability of silicon thin film materials. Summary of the Invention

[0005] The present invention aims to at least improve one of the technical problems existing in the prior art. To this end, the present invention proposes a heterojunction silicon solar cell.

[0006] The technical solution of the present invention is as follows: A heterojunction silicon solar cell, comprising: A monocrystalline silicon wafer, with a silicon thin film layer on both the front and back sides; A first transparent conductive film is mounted on the silicon thin film layer on the front side of the single crystal silicon wafer; A second transparent conductive film is mounted on the silicon thin film layer on the back side of the single-crystal silicon wafer; Metal grid lines are respectively mounted on the surfaces of the first transparent conductive film and the second transparent conductive film, which are far from the silicon thin film layer; A cerium dioxide transparent conductive film is installed between the metal grid lines and the first transparent conductive film to increase the absorption of ultraviolet light by the first transparent conductive film.

[0007] Furthermore, the present invention provides a second heterojunction silicon solar cell, which further includes: A third transparent conductive film is installed between the cerium dioxide transparent conductive film and the metal grid lines.

[0008] Furthermore, the present invention provides a third type of heterojunction silicon solar cell, in which a cerium dioxide thin film replaces the cerium dioxide transparent conductive film, wherein the cerium dioxide thin film is mounted on the surface of the first transparent conductive film adjacent to the metal grid lines.

[0009] In one possible technical solution, the thickness of the cerium dioxide transparent conductive film is further 10nm to 20nm. Cerium dioxide films have poor conductivity; if the thickness is too thick, it will affect the sheet resistance of the film surface, which is detrimental to the ohmic contact of the electrodes. Furthermore, due to the multilayer film structure, the thickness of different films needs to be appropriately adjusted. If it is too thin, optical interference (related to refractive index and film thickness) will occur, causing a change in the color of the battery surface.

[0010] In one possible technical solution, the thickness of the cerium dioxide film is further 10 nm to 20 nm.

[0011] A method for fabricating a heterojunction silicon solar cell, wherein the method for fabricating a first heterojunction silicon solar cell includes: S11: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S12: Deposit a first transparent conductive film of 80nm to 90nm on the front silicon thin film surface of the first substrate to obtain a second substrate, wherein the first transparent conductive film and the second transparent conductive film are both ITO thin films; S13: Continue to deposit a 10nm~20nm cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S14: Pattern and print grid lines on the front and back sides of the third substrate to prepare metal grid lines and obtain a complete battery cell.

[0012] A method for fabricating a heterojunction silicon solar cell, wherein the method for fabricating a second heterojunction silicon solar cell includes: S21: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S22: A first transparent conductive film of 30nm to 40nm is deposited on the front silicon thin film surface of the first substrate to obtain a second substrate, wherein the first transparent conductive film and the second transparent conductive film are both ITO thin films; S23: Continue to deposit a 10nm~20nm cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S24: Continue to deposit a third transparent conductive film of 40nm to 50nm on the surface of the cerium dioxide transparent conductive film to obtain the fourth substrate; S25: The grid lines are patterned and printed on the front and back sides of the fourth substrate to prepare metal grid lines and obtain a complete battery cell.

[0013] A method for preparing a heterojunction silicon solar cell, wherein the method for preparing a third heterojunction silicon solar cell includes: S31: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S32: Deposit a first transparent conductive film of 80nm to 90nm on the front silicon thin film surface of the first substrate to obtain a second substrate; S33: Pattern and print the grid lines on the front and back sides of the second substrate to prepare metal grid lines and obtain the third substrate; S34: Place the third substrate face up on the carrier and place a mask matching the printed pattern on the upper surface of the third substrate to protect the metal grid lines; at this time, continue to deposit a 10nm~20nm cerium dioxide thin film on the surface of the third substrate to obtain a complete battery cell.

[0014] According to the heterojunction silicon solar cell and its preparation method of the present invention, a very thin cerium dioxide film can be introduced in the middle of the transparent conductive film, which effectively increases the absorption of ultraviolet light by the conductive film and reduces the ultraviolet light absorbed by the silicon film, thereby greatly reducing the probability of silicon-hydrogen bonds in the silicon film being broken, and thus improving the long-term stability of the battery performance.

[0015] A system for fabricating a heterojunction silicon solar cell, comprising an apparatus for implementing the above-described method for fabricating a heterojunction silicon solar cell.

[0016] A computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the above-described method for preparing a heterojunction silicon solar cell.

[0017] A computer storage medium, characterized in that the computer storage medium stores instructions, which, when executed on a computer, cause the computer to perform the above-described method for preparing a heterojunction silicon solar cell. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a heterojunction silicon solar cell according to Embodiment 1 of the present invention; Figure 2 This is a flowchart illustrating the fabrication process of a heterojunction silicon solar cell according to Embodiment 1 of the present invention. Figure 3 This is a schematic diagram of the structure of a heterojunction silicon solar cell according to Embodiment 2 of the present invention; Figure 4 This is a flowchart illustrating the fabrication process of a heterojunction silicon solar cell according to Embodiment 2 of the present invention. Figure 5 This is a schematic diagram of the heterojunction silicon solar cell according to Embodiment 3 of the present invention; Figure 6 This is a flowchart illustrating the fabrication process of a heterojunction silicon solar cell according to Embodiment 3 of the present invention.

[0020] Figure label: The components include a single-crystal silicon wafer 100, a silicon thin film layer 200, a first transparent conductive film 300, a second transparent conductive film 400, a metal grid line 500, a cerium dioxide transparent conductive film 600, a third transparent conductive film 700, and the cerium dioxide thin film 800. Detailed Implementation

[0021] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] The terms "first," "second," "third," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects and not to describe a particular order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, it may include a series of steps or units, or optionally, steps or units not listed, or other steps or units inherent to these processes, methods, products, or devices.

[0025] The accompanying drawings show only the portions relevant to this application, not all of them. Before discussing exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe operations (or steps) as sequential processes, many of these operations may be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations may be rearranged. The process may be terminated when its operation is completed, but may also have additional steps not included in the drawings. The process may correspond to a method, function, procedure, subroutine, subprogram, etc.

[0026] Example 1 like Figure 1 As shown, this embodiment provides a heterojunction silicon solar cell, which includes: A monocrystalline silicon wafer 100 has a silicon thin film layer 200 on both its front and back sides; A first transparent conductive film 300 is mounted on the silicon thin film layer 200 on the front side of the single crystal silicon wafer 100; A second transparent conductive film 400 is mounted on the silicon thin film layer 200 on the back side of the single crystal silicon wafer 100; Metal grid lines 500 are respectively mounted on the surfaces of the first transparent conductive film 300 and the second transparent conductive film 400, which are far away from the silicon thin film layer 200; A cerium dioxide transparent conductive film 600 is installed between the metal grid line 500 and the first transparent conductive film 300 to increase the absorption of ultraviolet light by the first transparent conductive film 300.

[0027] like Figure 2 As shown, this embodiment also provides a method for preparing a heterojunction silicon solar cell, wherein the method for preparing the first heterojunction silicon solar cell includes: S11: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S12: Deposit a first transparent conductive film of 80nm to 90nm on the front silicon thin film surface of the first substrate to obtain a second substrate, wherein the first transparent conductive film and the second transparent conductive film are both ITO thin films; S13: Continue to deposit a 10nm~20nm cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S14: Pattern and print grid lines on the front and back sides of the third substrate to prepare metal grid lines and obtain a complete battery cell.

[0028] Example 2 like Figure 3 As shown, this embodiment provides a second type of heterojunction silicon solar cell, including: A monocrystalline silicon wafer 100 has a silicon thin film layer 200 on both its front and back sides; A first transparent conductive film 300 is mounted on the silicon thin film layer 200 on the front side of the single crystal silicon wafer 100; A second transparent conductive film 400 is mounted on the silicon thin film layer 200 on the back side of the single crystal silicon wafer 100; Metal grid lines 500 are respectively mounted on the surfaces of the first transparent conductive film 300 and the second transparent conductive film 400, which are far away from the silicon thin film layer 200; A cerium dioxide transparent conductive film 600 is installed between the metal grid line 500 and the first transparent conductive film 300 to increase the absorption of ultraviolet light by the first transparent conductive film 300; A third transparent conductive film 700 is installed between the cerium dioxide transparent conductive film 600 and the metal grid line 500.

[0029] It should be noted that in the above embodiments, the thickness of the cerium dioxide transparent conductive film 600 is 10nm to 20nm.

[0030] like Figure 4 As shown, this embodiment also provides a method for preparing a heterojunction silicon solar cell, wherein the method for preparing a second heterojunction silicon solar cell includes: S21: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S22: A first transparent conductive film of 30nm to 40nm is deposited on the front silicon thin film surface of the first substrate to obtain a second substrate, wherein the first transparent conductive film and the second transparent conductive film are both ITO thin films; S23: Continue to deposit a 10nm~20nm cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S24: Continue to deposit a third transparent conductive film of 40nm to 50nm on the surface of the cerium dioxide transparent conductive film to obtain the fourth substrate; S25: The grid lines are patterned and printed on the front and back sides of the fourth substrate to prepare metal grid lines and obtain a complete battery cell.

[0031] Example 3 like Figure 5 As shown, this embodiment provides a third type of heterojunction silicon solar cell, including: A monocrystalline silicon wafer 100 has a silicon thin film layer 200 on both its front and back sides; A first transparent conductive film 300 is mounted on the silicon thin film layer 200 on the front side of the single crystal silicon wafer 100; A second transparent conductive film 400 is mounted on the silicon thin film layer 200 on the back side of the single crystal silicon wafer 100; Metal grid lines 500 are respectively mounted on the surfaces of the first transparent conductive film 300 and the second transparent conductive film 400, which are far away from the silicon thin film layer 200; A cerium dioxide thin film 800 is mounted on the surface of the first transparent conductive film 300 adjacent to the metal grid line 500, and the thickness of the cerium dioxide thin film 800 is 10 nm to 20 nm.

[0032] It should be noted that in the above three embodiments, the cerium dioxide transparent conductive film 600 and the cerium dioxide film 800 have the same thickness range of 10nm to 20nm. This is mainly because the conductivity of cerium dioxide films is relatively poor. If the thickness is too thick, it will affect the sheet resistance of the film surface, which is not conducive to the ohmic contact of the electrodes. In addition, since it is a multilayer film structure, the thickness of different films needs to be appropriately adjusted. If it is too thin, optical interference will occur (related to refractive index and film thickness), causing changes in the color of the battery surface.

[0033] like Figure 6 As shown, this embodiment also provides a method for preparing a heterojunction silicon solar cell, wherein the method for preparing a third type of heterojunction silicon solar cell includes: S31: Deposit a 100nm second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S32: Deposit a first transparent conductive film of 80nm to 90nm on the front silicon thin film surface of the first substrate to obtain a second substrate; S33: Pattern and print the grid lines on the front and back sides of the second substrate to prepare metal grid lines and obtain the third substrate; S34: Place the third substrate face up on the carrier and place a mask matching the printed pattern on the upper surface of the third substrate to protect the metal grid lines; at this time, continue to deposit a 10nm~20nm cerium dioxide thin film on the surface of the third substrate to obtain a complete battery cell.

[0034] To verify the technical effect of the present invention, heterojunction silicon solar cells with structures from two embodiments of this application were tested, and the test results are compared with those of the prior art as follows: In summary, the technical solution of introducing a very thin cerium dioxide film in the middle of the transparent conductive film based on the present invention can effectively increase the absorption of ultraviolet light by the conductive film and reduce the ultraviolet light absorbed by the silicon film compared with the prior art. This greatly reduces the probability of silicon-hydrogen bonds in the silicon film being broken, thereby improving the long-term stability of battery performance.

[0035] According to the heterojunction silicon solar cell and its preparation method of the present invention, a very thin cerium dioxide film can be introduced in the middle of the transparent conductive film, which effectively increases the absorption of ultraviolet light by the conductive film and reduces the ultraviolet light absorbed by the silicon film, thereby greatly reducing the probability of silicon-hydrogen bonds in the silicon film being broken, and thus improving the long-term stability of the battery performance.

[0036] Example 4 This embodiment provides a fabrication system for heterojunction silicon solar cells, wherein the above-mentioned fabrication method for heterojunction silicon solar cells is implemented.

[0037] The heterojunction silicon solar cell fabrication system in this application embodiment can be a device, or a component, integrated circuit, or chip in a terminal. The device can be a mobile electronic device or a non-mobile electronic device. For example, mobile electronic devices can be mobile phones, tablets, laptops, PDAs, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc., while non-mobile electronic devices can be servers, network-attached storage (NAS), personal computers (PCs), etc. This application embodiment does not impose specific limitations.

[0038] The fabrication system for a heterojunction silicon solar cell in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit the specific operating system used.

[0039] The heterojunction silicon solar cell fabrication system provided in this application embodiment can realize all the processes implemented by the heterojunction silicon solar cell fabrication method in the above embodiment. To avoid repetition, it will not be described again here.

[0040] According to the heterojunction silicon solar cell fabrication system of the present invention, a very thin cerium dioxide film can be introduced in the middle of the transparent conductive film, which effectively increases the absorption of ultraviolet light by the conductive film and reduces the ultraviolet light absorbed by the silicon film, thereby greatly reducing the probability of silicon-hydrogen bonds in the silicon film being broken, and thus improving the long-term stability of the battery performance.

[0041] Optionally, this application embodiment also provides an electronic device, including a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the various processes of the above-described method embodiment for preparing a heterojunction silicon solar cell and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0042] This application also provides a readable storage medium storing a program or instructions. When the program or instructions are executed by a processor, they implement the various processes of the above-described method for preparing a heterojunction silicon solar cell and achieve the same technical effect. To avoid repetition, they will not be described again here.

[0043] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0045] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0046] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0047] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A heterojunction silicon solar cell, characterized by, include: A single-crystal silicon wafer (100) has a silicon thin film layer (200) on both its front and back sides. A first transparent conductive film (300) is mounted on the silicon thin film layer (200) on the front side of the single crystal silicon wafer (100); A second transparent conductive film (400) is mounted on the silicon thin film layer (200) on the back side of the single crystal silicon wafer (100); Metal grid lines (500) are respectively mounted on the surfaces of the first transparent conductive film (300) and the second transparent conductive film (400) away from the silicon thin film layer (200); A cerium dioxide transparent conductive film (600) is installed between the metal grid line (500) and the first transparent conductive film (300) to increase the absorption of ultraviolet light by the first transparent conductive film (300).

2. The heterojunction silicon solar cell according to claim 1, characterized in that, Also includes: A third transparent conductive film (700) is installed between the cerium dioxide transparent conductive film (600) and the metal grid line (500).

3. The heterojunction silicon solar cell according to claim 1, characterized in that, The cerium dioxide transparent conductive film (600) of claim 1 is replaced with a cerium dioxide film (800), wherein the cerium dioxide film (800) is mounted on the surface of the first transparent conductive film (300) adjacent to the metal grid line (500).

4. The heterojunction silicon solar cell according to claim 2, characterized in that, The thickness of the cerium dioxide transparent conductive film (600) is 10nm to 20nm.

5. The heterojunction silicon solar cell according to claim 3, characterized in that, The thickness of the cerium dioxide thin film (800) is 10 nm to 20 nm.

6. A method for fabricating a heterojunction silicon solar cell, characterized in that, For preparing the heterojunction silicon solar cell as described in claim 1, comprising: S11: Deposit a second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S12: Deposit a first transparent conductive film on the front silicon thin film surface of the first substrate to obtain a second substrate; S13: Continue to deposit a cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S14: Pattern and print grid lines on the front and back sides of the third substrate to prepare metal grid lines and obtain a complete battery cell.

7. A method for fabricating a heterojunction silicon solar cell, characterized in that, For preparing the heterojunction silicon solar cell as described in claim 2, comprising: S21: Deposit a second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S22: Deposit a first transparent conductive film on the front silicon thin film surface of the first substrate to obtain a second substrate; S23: Continue to deposit a cerium dioxide transparent conductive film on the surface of the first transparent conductive film to obtain the third substrate; S24: Continue to deposit a third transparent conductive film on the surface of the cerium dioxide transparent conductive film to obtain a fourth substrate. S25: The grid lines are patterned and printed on the front and back sides of the fourth substrate to prepare metal grid lines and obtain a complete battery cell.

8. A method for fabricating a heterojunction silicon solar cell, characterized in that, For preparing the heterojunction silicon solar cell as described in claim 3, comprising: S31: Deposit a second transparent conductive film on the back silicon film surface of the already deposited silicon thin film substrate to obtain the first substrate; S32: Deposit a first transparent conductive film on the front silicon thin film surface of the first substrate to obtain a second substrate; S33: Pattern and print the grid lines on the front and back sides of the second substrate to prepare metal grid lines and obtain the third substrate; S34: Place the third substrate face up on the carrier and place a mask matching the printed pattern on the upper surface of the third substrate; at this time, continue to deposit a cerium dioxide film on the surface of the third substrate face up to obtain a complete battery cell.

9. A fabrication system for a heterojunction silicon solar cell, characterized in that, A method for fabricating a heterojunction silicon solar cell as described in any one of claims 6 to 8.

10. A computer device, characterized in that, It includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the method for preparing a heterojunction silicon solar cell as described in any one of claims 6 to 8.

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