Preparation method of solar cell structure and solar cell structure

Abstract

The invention provides a preparation method of a solar cell structure and the solar cell structure. The preparation method comprises the following steps: providing a cell substrate which is provided with a light receiving surface; forming an organic anti-reflection layer on one side, with the light receiving surface, of the cell substrate; and printing conductive slurry on one side, far away from the cell substrate, of the organic anti-reflection layer by adopting a printing technology, carrying out heat treatment on the conductive slurry, the conductive slurry containing an organic solvent, and dissolving part of the organic anti-reflection layer by the organic solvent to form a conductive electrode which penetrates through the organic anti-reflection layer and is in contact with the cell substrate. According to the solar cell structure, the phenomenon that the conductive electrode is covered with an insulating material corresponding to the organic anti-reflection layer is avoided, and therefore the problem that in the prior art, the charge transmission capacity of a metal grid line (conductive electrode) of the solar cell structure is poor is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a method for preparing a solar cell structure and a solar cell structure. Background Art

[0002] For perovskite / crystalline silicon tandem cells, the preparation process of perovskite / crystalline silicon tandem cells in the prior art usually first prepares the functional layers of each perovskite cell on the crystalline silicon cell, and then sequentially evaporates the top electrode and the anti-reflection layer with insulating properties, such as magnesium fluoride, on the side of the functional layer of the perovskite cell away from the crystalline silicon cell.

[0003] It can be seen that the preparation process of the metal electrode and the anti-reflection film in the prior art is to prepare the metal electrode first and then prepare the anti-reflection film. However, this preparation process is only applicable to small-area perovskite / crystalline silicon stacked cells, and is not applicable to large-area mass-produced perovskite / crystalline silicon stacked cells; furthermore, since the anti-reflection layer is electrically insulating, and the anti-reflection layer is formed after the metal grid line in the preparation process of the existing metal grid line / anti-reflection layer structure, the insulating material will cover the metal grid line during the formation of the anti-reflection layer, and the insulating material covering the metal grid line will affect the electrical contact between the metal grid line and the perovskite / crystalline silicon cell, so the prepared metal grid line / anti-reflection film structure will reduce the ability of the metal grid line to transmit charge.

[0004] Therefore, a new preparation process for the organic anti-reflection layer / metal grid line structure is urgently needed to reduce the front reflection of the perovskite / crystalline silicon stacked cell while ensuring the ability of the metal grid line to transmit charges. Summary of the invention

[0005] The main purpose of the present invention is to provide a method for preparing a solar cell structure and a solar cell structure, so as to solve the problem of poor transmission capability of metal grid lines of the solar cell structure in the prior art.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, a method for preparing a solar cell structure is provided, comprising: providing a cell substrate, the cell substrate having a light-receiving surface; forming an organic anti-reflection layer on a side of the cell substrate having the light-receiving surface; using a printing technique to print a conductive paste on a side of the organic anti-reflection layer away from the cell substrate and heat-treating the conductive paste, wherein the conductive paste contains an organic solvent, and the organic solvent dissolves a portion of the organic anti-reflection layer to form a conductive electrode that penetrates the organic anti-reflection layer and contacts the cell substrate.

[0007] Optionally, before the step of forming the organic anti-reflection layer, the preparation method further comprises: forming a transparent conductive layer on the side of the battery substrate having the light-receiving surface, so that the transparent conductive layer is located between the battery substrate and the organic anti-reflection layer.

[0008] Optionally, the printing technique includes any one of screen printing, gravure printing and inkjet printing.

[0009] Optionally, the temperature of the heat treatment is 50°C to 200°C.

[0010] According to another aspect of the present invention, there is provided a solar cell structure prepared by the above-mentioned method for preparing a solar cell structure, comprising: a cell substrate having a light-receiving surface; an organic anti-reflection layer located on a side of the cell substrate having the light-receiving surface; and a conductive electrode penetrating the organic anti-reflection layer and arranged in contact with the cell substrate.

[0011] Optionally, the solar cell structure further includes: a transparent conductive layer located between the cell substrate and the organic anti-reflection layer, and the conductive electrode penetrates the organic anti-reflection layer to the transparent conductive layer.

[0012] Optionally, the refractive index of the organic anti-reflection layer is 1.2-1.6.

[0013] Optionally, the organic anti-reflection layer is an ethylene-vinyl acetate copolymer layer.

[0014] Optionally, the cell substrate includes any one of a perovskite cell, a crystalline silicon cell and a crystalline silicon / perovskite stacked cell.

[0015] Optionally, the conductive electrode is a metal electrode, and the material of the metal electrode includes any one of gold, silver, copper and aluminum.

[0016] By applying the technical solution of the present invention, a method for preparing a solar cell structure is provided. When a cell substrate is provided, an organic anti-reflection layer is first formed on one side of the light-receiving surface of the cell substrate so that the organic anti-reflection layer covers the entire light-receiving surface of the cell substrate. Since the conductive paste used to form the conductive electrode contains an organic solvent, in the step of printing the conductive paste on the side of the organic anti-reflection layer away from the cell substrate by using a printing technique, the organic solvent in the conductive paste can dissolve the portion of the organic anti-reflection layer in contact with the conductive paste during the printing process. Therefore, when the organic anti-reflection layer in the contact area is completely removed, the conductive paste can penetrate the organic anti-reflection layer and contact the cell substrate. Then, the conductive paste that penetrates the organic anti-reflection layer to the cell substrate is heat-treated, thereby forming a conductive electrode that penetrates the organic anti-reflection layer to the cell substrate. It can be seen that in the process of forming a conductive electrode and an organic anti-reflection layer, the present application first forms an organic anti-reflection layer to achieve the effect of reducing the reflection of the light-receiving surface of the solar cell structure, and then forms a conductive electrode that penetrates the organic anti-reflection layer to avoid the phenomenon that the conductive electrode is covered with an insulating material corresponding to the organic anti-reflection layer. Therefore, through the present application, the problem of poor charge transmission ability of the metal grid line (conductive electrode) of the solar cell structure in the prior art can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 A schematic cross-sectional structure diagram of forming a transparent conductive layer and an organic anti-reflection layer on a solar cell substrate in a method for preparing a solar cell structure according to an embodiment of the present invention is shown;

[0019] Figure 2 Shown in Figure 1 A schematic diagram of a cross-sectional structure after printing wet gate lines based on the structure shown;

[0020] Figure 3 Shown in Figure 2 A schematic cross-sectional structure diagram of a conductive electrode formed by heat treating a wet gate line based on the structure shown.

[0021] The above drawings include the following reference numerals:

[0022] 10. Cell substrate; 101. Crystalline silicon bottom cell; 102. Spacer layer; 103. Hole transport layer; 104. Perovskite absorption layer; 105. Electron transport layer; 20. Organic anti-reflection layer; 30. Transparent conductive layer; 401. Wet grid line; 40. Conductive electrode. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] As described in the background technology, for perovskite / crystalline silicon stacked cells, the preparation process of perovskite / crystalline silicon stacked cells in the prior art usually first prepares the functional layers of each perovskite cell on the crystalline silicon cell, and then sequentially evaporates the top electrode and the anti-reflection layer with insulating properties, such as magnesium fluoride, on the side of the functional layer of the perovskite cell away from the crystalline silicon cell. It can be seen that the preparation process for the metal electrode and the anti-reflection film in the prior art is to first prepare the metal electrode and then prepare the anti-reflection film. However, this preparation process is only suitable for small-area perovskite / crystalline silicon stacked cells, and is not suitable for large-area mass-produced perovskite / crystalline silicon stacked cells; furthermore, since the anti-reflection layer is electrically insulating, and the anti-reflection layer is formed after the metal grid line in the preparation process of the existing metal grid line / anti-reflection layer structure, the insulating material will cover the metal grid line in the process of forming the anti-reflection layer, and then the insulating material covered on the metal grid line will affect the electrical contact between the metal grid line and the perovskite / crystalline silicon cell, so the prepared metal grid line / anti-reflection film structure will reduce the ability of the metal grid line to transmit charge. On this basis, in order to solve the problem that the existing metal grid line / anti-reflection film structure reduces the charge transmission capacity of the metal grid line, the present application provides a method for preparing a solar cell structure and a solar cell structure.

[0027] In some optional embodiments, a method for preparing a solar cell structure is provided, the method comprising: providing a cell substrate 10, wherein the cell substrate 10 has a light-receiving surface; forming an organic anti-reflection layer 20 on one side of the cell substrate 10 having the light-receiving surface, such as Figure 1 As shown; a conductive paste (such as Figure 2 The conductive paste is heat treated, wherein the conductive paste contains an organic solvent, and the organic solvent dissolves part of the organic anti-reflection layer 20 to form a conductive electrode penetrating the organic anti-reflection layer and contacting the battery substrate, as shown in FIG. Figure 3 shown.

[0028] Specifically, the battery substrate 10 may include a crystalline silicon battery, a perovskite battery and a stacked battery, wherein the stacked battery may include but is not limited to a crystalline silicon / perovskite stacked battery and a full perovskite stacked battery.

[0029] Alternatively, if Figure 1 As shown, in the case where the above-mentioned battery substrate 10 is a crystalline silicon / perovskite stacked battery, the battery substrate 10 may include a stacked crystalline silicon bottom battery 101, a spacer layer 102, a hole transport layer 103, a perovskite absorption layer 104 and an electron transport layer 105.

[0030] Furthermore, the above-mentioned crystalline silicon bottom cell 101 may include but is not limited to a rear emitter passivation cell (PERT), a tunneling oxide passivation cell (TOPCon), a heterojunction cell (HJT), an N-type all-back electrode contact cell (N-IBC), and a P-type all-back electrode contact cell (P-IBC).

[0031] Furthermore, the material of the spacer layer 102 may be a transparent conductive oxide (ITO), which may include but is not limited to indium tin oxide (ITO), indium zinc oxide (IZO) and aluminum-doped zinc oxide (AZO).

[0032] Furthermore, the material of the hole transport layer 103 may include, but is not limited to, spiro-dimethylthieno[3,2-b]thiophene polymer (Spiro-OMeTAD), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA), poly(3,4-ethylenedioxythiophene)-poly(p-styrenesulfonic acid) (PEDOT:PSS) and nickel oxide (NiO x ).

[0033] Furthermore, the perovskite absorption layer 104 may include but is not limited to CsPbI 2 Br perovskite thin film, CsPbIBr 2 Perovskite thin film layer, CsPbI 3 Perovskite thin film layer or CsPbBr 3 Any of the perovskite thin film layers;

[0034] Furthermore, the material of the electron transport layer 105 may include but is not limited to tin oxide (SnO 2 )、ZnO、TiO 2 ), (6,6)-phenyl C71 butyric acid methyl ester (PCBM) and C 60 wait.

[0035] In some optional embodiments, such as Figure 1As shown, before the step of forming the above-mentioned organic anti-reflection layer 20, the above-mentioned preparation method also includes: forming a transparent conductive layer 30 on the side of the above-mentioned battery substrate 10 having the above-mentioned light-receiving surface, so that the above-mentioned transparent conductive layer 30 is located between the above-mentioned battery substrate 10 and the above-mentioned organic anti-reflection layer 20.

[0036] Specifically, the transparent conductive layer 30 in this embodiment may include, but is not limited to, any one of an indium tin oxide (ITO) layer, an indium zinc oxide (IZO) layer, and an aluminum-doped zinc oxide (AZO) layer.

[0037] In the above embodiment, after the transparent conductive layer 30 is formed on the light-receiving side of the battery substrate 10, since the transparent conductive layer 30 is located between the battery substrate 10 and the organic anti-reflection layer 20, the conductive electrode 40 can penetrate the organic anti-reflection layer 20 to the transparent conductive layer 30. Further, in the case where the conductive electrode 40 collects the current from the battery substrate 10, since the transparent conductive layer 30 is evenly distributed on the surface of the battery substrate 10 having the light-receiving side, the current on the entire surface of the battery substrate 10 can be evenly collected, thereby improving the current collection capacity of the conductive electrode 40. In addition, since the material corresponding to the functional film layer of the battery substrate 10 in contact with the organic anti-reflection layer 20 can be an organic material, by arranging the above transparent conductive layer 30 between the functional film layer of the battery substrate 10 and the organic anti-reflection layer 20, it is also avoided that the conductive paste dissolves the functional film layer of the battery substrate 10 in the process of dissolving the organic anti-reflection layer 20, thereby improving the overall performance of the solar cell structure.

[0038] Specifically, the material forming the organic anti-reflection layer 20 is an organic material, that is, the organic anti-reflection layer 20 in the present application can be dissolved in an organic solvent.

[0039] Alternatively, the organic material may include, but is not limited to, ethylene-vinyl acetate copolymer (EVA), poly(sodium 4-styrene sulfonate) (PSS), and dimethyldiallylammonium chloride homopolymer (PDAC).

[0040] Optionally, the organic anti-reflection layer 20 may be formed by a solution process.

[0041] For example, in the step of forming the organic anti-reflection layer 20 on the side of the battery substrate 10 having the light-receiving surface, an organic solution corresponding to the organic anti-reflection layer 20 is first prepared, and then the organic solution can be coated on the side of the battery substrate 10 having the light-receiving surface by a coating process, and the organic solution is cured to form the organic anti-reflection layer 20. Further, the coating process can include but is not limited to any one of spin coating, blade coating, slit coating and spray coating.

[0042] The organic solvent in the organic solution may be the same as or different from the organic solvent in the conductive paste. It should be noted that the organic solvent in the conductive paste needs to be able to dissolve the organic material corresponding to the organic anti-reflection layer 20. For example, when the organic material of the organic anti-reflection layer 20 is the ethylene-vinyl acetate copolymer, the organic solvent in the conductive paste may include, but is not limited to, one or more of ethanol, ethylene glycol, and 4-tert-butyl cyclohexyl acetate.

[0043] Furthermore, after the step of forming the above-mentioned organic anti-reflection layer 20, the present application can directly print a conductive paste containing an organic solvent on the side of the organic anti-reflection layer 20 away from the battery substrate 10, so that in the process of preparing the conductive electrode 40, the organic solvent in the conductive paste can directly dissolve the portion of the organic anti-reflection layer 20 that contacts the conductive paste (specifically, in the direction perpendicular to the light-receiving surface of the battery substrate 10, the conductive paste can dissolve the organic anti-reflection layer 20, so that for the organic anti-reflection layer 20 and the battery substrate 10, an opening that exposes the light-receiving surface of the battery substrate 10 can be formed in the organic anti-reflection layer 20). Then, when the organic anti-reflection layer 20 corresponding to the portion in contact with the conductive paste is completely dissolved, the conductive paste can directly contact the surface of the battery substrate 10 having the light-receiving surface. It can be seen that the above-mentioned opening and the printing of the conductive paste are formed in the same process step. Furthermore, to form a conductive electrode, the conductive paste may be heat treated while in contact with the surface of the battery substrate having the light-receiving surface, thereby removing the organic solvent in the conductive paste and curing the conductive paste to form the conductive electrode 40 .

[0044] It should be noted that it takes a certain amount of time for the conductive paste to dissolve the organic anti-reflection layer 20, that is, after printing the conductive paste to the surface of the organic anti-reflection layer 20 away from the battery substrate 10 and before forming the heat-treated conductive paste, the conductive paste is in a wet paste containing an organic solvent, and the wet paste corresponds to the wet grid line 401 in the solar cell structure, such as Figure 2 shown.

[0045] Specifically, the conductive paste may be printed onto the surface of the organic anti-reflection layer 20 away from the battery substrate 10 by printing technology. Optionally, the printing technology may include but is not limited to any one of screen printing, gravure printing and inkjet printing.

[0046] In some optional embodiments, such as Figure 3 As shown, the conductive electrode 40 may be a metal electrode, and the material of the metal electrode may include but is not limited to any one of gold (Au), silver (Ag), copper (Cu) and aluminum (Al).

[0047] Specifically, the temperature of the heat treatment may be 50°C to 200°C.

[0048] In the above embodiment, when a battery substrate 10 is provided, an organic anti-reflection layer 20 is first formed on the side of the battery substrate 10 having a light-receiving surface, so that the organic anti-reflection layer 20 covers the entire light-receiving surface of the battery substrate 10. Since the conductive paste used to form the conductive electrode 40 contains an organic solvent, in the step of printing the conductive paste on the side of the organic anti-reflection layer 20 away from the battery substrate 10 using a printing technique, the organic solvent in the conductive paste can dissolve the portion of the organic anti-reflection layer 20 in contact with the conductive paste during the printing process. Therefore, when the organic anti-reflection layer 20 in the above-mentioned contact area is completely removed, the conductive paste can penetrate the organic anti-reflection layer 20 and contact the battery substrate 10. Then, the conductive paste that penetrates the organic anti-reflection layer 20 to the battery substrate 10 is heat-treated, thereby forming a conductive electrode that penetrates the organic anti-reflection layer 20 to the battery substrate 10. It can be seen that in the process flow of forming the conductive electrode 40 and the organic anti-reflection layer 20, the organic anti-reflection layer 20 is first formed to achieve the effect of reducing the reflection of the light-receiving surface of the solar cell structure, and then the conductive electrode 40 that penetrates the organic anti-reflection layer 20 is formed, avoiding the phenomenon that the conductive electrode 40 is covered with the insulating material corresponding to the organic anti-reflection layer 20. Therefore, through the present application, the problem of poor charge transmission ability of the metal grid line (conductive electrode 40) of the solar cell structure in the prior art can be solved.

[0049] According to another aspect of the present application, there is also provided a solar cell structure prepared by using any one of the above solar cell structures, such as Figure 3 As shown, the solar cell structure may include: a cell substrate 10 having a light-receiving surface; an organic anti-reflection layer 20 located on a side of the cell substrate 10 having the light-receiving surface; a conductive electrode 40 penetrating the organic anti-reflection layer 20 and arranged in contact with the cell substrate 10, wherein the conductive electrode 40 may be formed by printing a conductive paste on a side of the organic anti-reflection layer 20 away from the cell substrate 10 using a printing technique and then heat-treating the conductive paste, wherein the conductive paste contains an organic solvent, and the organic solvent dissolves a portion of the organic anti-reflection layer 20.

[0050] Optionally, a transparent conductive layer 30 may be provided between the organic anti-reflection layer 20 of the solar cell structure and the cell substrate 10 , and the transparent conductive layer 30 is at least used to enhance the current collection capability of the solar cell structure.

[0051] In the above embodiment, since the conductive electrode 40 of the solar cell structure prepared by the above-mentioned method for preparing the solar cell structure will not be covered with the insulating material corresponding to the organic anti-reflection layer 20, the conductive electrode 40 of the solar cell structure can have good electrical contact with the functional film layer of the battery substrate 10 below (or the transparent conductive layer 30 located between the battery substrate 10 and the organic anti-reflection layer 20), and can also be used to achieve good electrical contact with the contact probe or the welding strip, thereby solving the problem of electrical contact of the metal grid line (conductive electrode 40) in the actual large-scale production of the solar cell structure.

[0052] In some optional embodiments, in order to improve the photoelectric conversion efficiency of the solar cell, the refractive index of the organic anti-reflection layer 20 may be 1.2 to 1.6.

[0053] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0054] The present application provides a method for preparing a solar cell structure. In the case of providing a cell substrate, an organic anti-reflection layer is first formed on one side of the light-receiving surface of the cell substrate, so that the organic anti-reflection layer covers the entire light-receiving surface of the cell substrate. Since the conductive paste used to form the conductive electrode contains an organic solvent, in the step of printing the conductive paste on the side of the organic anti-reflection layer away from the cell substrate by using a printing technology, the organic solvent in the conductive paste can dissolve the portion of the organic anti-reflection layer in the contact area with the conductive paste during the printing process. Therefore, when the organic anti-reflection layer in the above-mentioned contact area is completely removed, the conductive paste can penetrate the organic anti-reflection layer and contact the cell substrate. Then, the conductive paste that penetrates the organic anti-reflection layer to the cell substrate is heat-treated, thereby forming a conductive electrode that penetrates the organic anti-reflection layer to the cell substrate. It can be seen that in the process of forming a conductive electrode and an organic anti-reflection layer, the present application first forms an organic anti-reflection layer to achieve the effect of reducing the reflection of the light-receiving surface of the solar cell structure, and then forms a conductive electrode that penetrates the organic anti-reflection layer to avoid the phenomenon that the conductive electrode is covered with an insulating material corresponding to the organic anti-reflection layer. Therefore, through the present application, the problem of poor charge transmission ability of the metal grid line (conductive electrode) of the solar cell structure in the prior art can be solved.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a solar cell structure, characterized in that: include: Providing a battery substrate, wherein the battery substrate has a light-receiving surface; forming an organic anti-reflection layer on a side of the battery substrate having the light-receiving surface; A conductive paste is printed on a side of the organic anti-reflection layer away from the battery substrate by using a printing technique and the conductive paste is heat-treated. The conductive paste contains an organic solvent that dissolves part of the organic anti-reflection layer to form a conductive electrode that penetrates the organic anti-reflection layer and contacts the battery substrate.

2. The preparation method according to claim 1, characterized in that: Before the step of forming the organic anti-reflection layer, the preparation method further comprises: A transparent conductive layer is formed on the side of the battery substrate having the light receiving surface, so that the transparent conductive layer is located between the battery substrate and the organic anti-reflection layer.

3. The preparation method according to claim 1, characterized in that: The printing technique includes any one of screen printing, gravure printing and inkjet printing.

4. The preparation method according to claim 1, characterized in that: The temperature of the heat treatment is 50°C to 200°C.

5. A solar cell structure prepared by the method for preparing a solar cell structure according to any one of claims 1 to 4, characterized in that: include: A battery substrate having a light-receiving surface; An organic anti-reflection layer, located on a side of the cell substrate having the light-receiving surface; The conductive electrode penetrates the organic anti-reflection layer and is arranged in contact with the battery substrate.

6. The solar cell structure according to claim 5, characterized in that: The solar cell structure further comprises: The transparent conductive layer is located between the battery substrate and the organic anti-reflection layer, and the conductive electrode penetrates through the organic anti-reflection layer to the transparent conductive layer.

7. The solar cell structure according to claim 5, characterized in that: The refractive index of the organic anti-reflection layer is 1.2-1.

6.

8. The solar cell structure according to claim 5, characterized in that: The organic anti-reflection layer is an ethylene-vinyl acetate copolymer layer.

9. The solar cell structure according to claim 5, characterized in that: The cell substrate includes any one of a perovskite cell, a crystalline silicon cell and a crystalline silicon / perovskite stacked cell.

10. The solar cell structure according to claim 5, characterized in that: The conductive electrode is a metal electrode, and the material of the metal electrode includes any one of gold, silver, copper and aluminum.

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