Film coating substrate and preparation method and application thereof

Abstract

The invention provides a film coating substrate and a preparation method and application thereof, the film coating substrate comprises a film coating area and an edge area, the edge area is provided with at least two adjacent grooves around the film coating area, an isolation belt is arranged between the adjacent grooves, and the isolation belt is arranged between the adjacent grooves. The top of the isolation strip is higher than a plane where a target film layer is connected with the coating area, and the top of the isolation strip is lower than the top of the target film layer; wherein after target film layers are deposited in the film coating area and the edge area, the target film layer in the film coating area is integrally connected with the target film layer in the groove close to the film coating area, and the isolation belt separates the target film layers in the adjacent grooves. By designing the structure of the film-coated substrate, crack propagation is blocked, the propagation depth of cracks is effectively reduced, a special edge sealing process is combined, a water and oxygen invasion channel is effectively improved, the water and oxygen blocking effect is improved, and the edge clearing distance is reduced.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, and relates to a coating substrate, its preparation method, and its application. Background Technology

[0002] Currently, the efficiency of perovskite solar cells is gradually approaching that of crystalline silicon, reaching 26.7%, but this is primarily limited to small-area applications. However, when the area of ​​perovskite is increased to 1000 cm², further progress is needed. 2 Or, at scales exceeding one square meter, the coating quality of perovskite significantly deteriorates, leading to a corresponding decrease in cell efficiency. Larger areas often result in uneven film thickness, bubbles, voids, and cracks. This is primarily because perovskite is coated, and due to the fluid properties of the solution, it's difficult to maintain a perfectly consistent liquid injection volume between the coating front and back ends. Furthermore, the liquid surface at the coating front is exposed to air for a longer time than at the coating back. These differences in liquid injection volume, film thickness, and exposure time to air typically cause defects such as cracks, peeling, and streaks at the coating front during crystallization. This results in excessively large edge-clearing distances in perovskite cells, leading to efficiency losses.

[0003] To address the aforementioned issues, a pre-coating area is typically set up during the coating process. However, setting up a pre-coating area in industrial production is not only time-consuming but also requires timely cleaning, making it difficult to implement in continuous production.

[0004] CN113649701A discloses a laser edge-cleaning method and apparatus for solar cells. The method includes performing a first irradiation operation, using a first laser to scribing and dividing the thin film layer of the cell along a preset contour direction, dividing the thin film layer into effective and ineffective regions; and performing a second irradiation operation, using a second laser to remove the thin film layer in the ineffective regions. When using the method of this invention for edge cleaning, the first irradiation operation is performed first, followed by the second irradiation operation.

[0005] CN116896906A discloses a method for preparing a perovskite solar cell, a perovskite solar cell, and photovoltaic equipment. The preparation method includes: preparing a cell substrate, which includes: preparing a perovskite thin film using a wet process. Subsequently, the perovskite thin film is laser-cleaned using a laser beam.

[0006] The above solutions alleviate the problems by adjusting the process, but they cannot completely solve the problem. The edge clearing distance cannot be effectively shortened, and this method also complicates the coating process, which is not conducive to production. Summary of the Invention

[0007] The purpose of this invention is to provide a coating substrate, its preparation method, and its application. This invention designs the structure of the coating substrate to prevent crack propagation, effectively reducing the crack propagation depth. Combined with a special edge sealing process, it effectively enhances the channels for water and oxygen intrusion, improves the water and oxygen barrier effect, and reduces the edge cleaning distance.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a coating substrate, the coating substrate including a coating area and an edge area, the edge area having at least two adjacent grooves surrounding the coating area, an isolation strip being provided between the adjacent grooves, the top of the isolation strip being higher than the height of the plane where the target film layer is connected to the coating area, and the top of the isolation strip being lower than the top height of the target film layer;

[0010] Wherein, after the target film layer is deposited in the coating area and the edge area, the target film layer in the coating area is integrally connected with the target film layer in the groove near the coating area, and the isolation strip separates the target film layers in the adjacent groove.

[0011] The "around" mentioned in this invention does not necessarily have to form a complete circle around the coating area. It can be just one side of the coating area or multiple sides of the coating area. The deposition conditions of the target film are exactly the same in the coating area and the edge area, so that the thickness of the film to be deposited per unit horizontal area in the coating area and the edge area is the same. That is, if there is no groove in the edge area, the coating area and the edge area will form a target film of the same thickness.

[0012] For thin films prone to cracking at the film edge, the coating substrate described in this invention utilizes grooves and isolation strips to prevent crack propagation, reducing the width of the cracked area and thus improving coating quality. The coating substrate can be etched with grooves of appropriate width and depth according to the target film thickness, and isolation strips of appropriate height can be prepared in the area between the grooves. This invention, through a special design of the coating substrate, prevents crack propagation, effectively reducing the crack depth and thus reducing the edge cleaning distance. The coating substrate can prevent edge cracks, stringing, and other defects from further propagating inwards, improving the edge quality of the thin film, while also further reducing the edge cleaning size and increasing the effective power generation area.

[0013] Preferably, the cross-sectional shape of the isolation strip is a gradually changing shape that is narrower at the top and wider at the bottom.

[0014] Preferably, the cross-sectional shape of the groove is a gradually changing shape that is wider at the top and narrower at the bottom.

[0015] Preferably, the gradient shape is trapezoidal.

[0016] The present invention sets the cross-sectional shape of the isolation strip and the cross-sectional shape of the groove to be trapezoidal, which facilitates etching.

[0017] Preferably, the depth of the groove is 1 to 20 μm, for example: 1 μm, 5 μm, 10 μm, 15 μm or 20 μm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] Preferably, the opening width of the groove is 10 to 800 μm, for example: 10 μm, 20 μm, 100 μm, 500 μm or 800 μm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0019] Preferably, the height of the isolation strip is 0.2–1 μm, for example: 0.2 μm, 0.3 μm, 0.5 μm, 0.8 μm, or 1 μm, etc., and is not limited to the listed values; other unlisted values ​​within this range are also applicable. It should be noted that the height of the isolation strip can refer to the vertical distance between the top of the isolation strip and the top of the groove.

[0020] A perovskite solar cell typically comprises a substrate layer, a bottom electrode layer, a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a top electrode layer. The thickness of the bottom electrode layer is generally 50–500 nm, the thickness of the first carrier transport layer is generally 10–100 nm, and the thickness of the perovskite thin film is generally 300–700 nm. The aforementioned limitations on the groove depth, groove opening width, and separator height make the corresponding coating substrates more suitable for preparing perovskite thin films of the thickness required for perovskite solar cells.

[0021] The height of the isolation strip in this invention is the height exceeding the plane of the coating substrate, that is, the height of the isolation strip above the top of the groove.

[0022] Preferably, the material of the insulating strip includes any one or a combination of at least two of the following: silicon dioxide, FTO, ITO, KrF photoresist, ArF photoresist, acrylonitrile-butadiene-styrene copolymer (ABS), polylactic acid, or polycarbonate.

[0023] Secondly, the present invention provides a method for preparing a thin film, the method comprising:

[0024] A target film layer is deposited using a coating substrate as described in the first aspect, the target film layer covering the coating area and the edge area.

[0025] Preferably, the target film is a perovskite film.

[0026] Thirdly, the present invention provides a method for preparing a perovskite photovoltaic module, the method comprising the following steps:

[0027] A perovskite thin film is deposited over the coating area and edge area of ​​the coating substrate described in the first aspect, wherein the coating substrate includes a first base layer, and the coating area of ​​the coating substrate further includes a bottom electrode layer and a first carrier transport layer sequentially stacked on one side of the first base layer.

[0028] A second carrier transport layer and a top electrode layer are sequentially deposited on the surface of the perovskite thin film away from the coating substrate;

[0029] The perovskite thin film, second carrier transport layer and top electrode layer deposited in the edge region are removed to expose the first substrate layer and groove in the edge region of the coated substrate, and then encapsulated to obtain a perovskite photovoltaic module.

[0030] It should be noted that for the edge region, the coating substrate may only include the first base layer, or it may include a bottom electrode layer and a first carrier transport layer, similar to the coating region. Whether or not it includes a bottom electrode layer and a first carrier transport layer is not limited in this application. However, regardless of the case, the grooves and isolation strips of the coating substrate must meet the requirements of this application for the coating substrate. If the edge region of the coating substrate has a bottom electrode layer and a first carrier transport layer, then before encapsulation, it is generally necessary to remove both the bottom electrode layer and the first carrier transport layer in the edge region to expose the first base layer, thereby achieving a better encapsulation effect.

[0031] The first substrate layer can refer to the substrate that provides support for the perovskite cell. It can generally be a glass substrate or a solar cell, such as a silicon solar cell or a perovskite cell, thereby preparing a stacked module.

[0032] The fabrication of the perovskite photovoltaic module described in this invention includes multiple steps, such as laser scribing. This application mainly focuses on the improvements made to the prior art. As for steps unrelated to the improvements, those skilled in the art can choose to use the solutions in the prior art according to actual needs, and will not be elaborated upon.

[0033] Preferably, the encapsulation includes: depositing silicon oxynitride on the surface of the top electrode layer in the coating region, on the surface of the first substrate in the exposed edge region, and in the groove, so that the silicon oxynitride layer and the first substrate form a sealing structure.

[0034] Preferably, the first carrier transport layer is an electron transport layer and the second carrier transport layer is a hole transport layer. Alternatively, the first carrier transport layer is a hole transport layer and the second carrier transport layer is an electron transport layer.

[0035] The material of the electron transport layer described in this invention is not limited; for example, it can be a fullerene derivative, PCBM. The material of the hole transport layer is not limited; for example, it can be nickel oxide. The material of the perovskite thin film is not limited; for example, it can be MA. 0.5 FA 0.5 PbI3. The material of the top electrode layer is not limited; for example, it can be copper.

[0036] This invention employs a special encapsulation process (depositing silicon oxynitride), combined with a coating substrate of a specific structure to extend the water and oxygen diffusion path and change the water and oxygen diffusion direction, which can further improve the water and oxygen barrier capability of the thin film encapsulation, thereby achieving the removal of butyl glue, saving costs and reducing the edge cleaning distance.

[0037] Fourthly, the present invention provides a perovskite photovoltaic module, which is prepared by the preparation method described in the third aspect.

[0038] Preferably, the width of the edge region is 2 to 3 mm, for example: 2 mm, 2.2 mm, 2.5 mm, 2.8 mm or 3 mm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, the thickness of the silicon oxynitride layer is 1 to 20 μm, for example: 1 μm, 3 μm, 5 μm, 10 μm, 15 μm or 20 μm, etc., and is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) This invention designs the structure of the coating substrate to block crack propagation, effectively reducing the crack propagation depth. Combined with a special edge sealing process, it effectively enhances the channels for water and oxygen intrusion, improves the water and oxygen barrier effect, and reduces the edge cleaning distance.

[0042] (2) The method described in this invention can shorten the propagation length of thin film cracks in perovskite photovoltaic modules from more than 3 mm to less than 1.5 mm, effectively shortening the crack length and reducing the edge clearing distance. Attached Figure Description

[0043] Figure 1 This is a cross-sectional schematic diagram of the coating substrate described in an embodiment of the present invention. 1 is a glass substrate covered with an FTO transparent conductive layer, 2 is a groove, and 3 is an isolation strip.

[0044] Figure 2This is a cross-sectional schematic diagram of the perovskite component described in the application example of the present invention. 1 is the coating substrate, 2 is the groove, 3 is the isolation strip, 4 is the silicon oxynitride capping layer, 5 is the hole transport layer, 6 is the perovskite light-absorbing layer, 7 is the electron transport layer, and 8 is the electrode layer.

[0045] Figure 3 This is a schematic diagram illustrating the transverse spread of cracks in the perovskite component described in Example 1. Detailed Implementation

[0046] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0047] Example 1

[0048] This embodiment provides a coating substrate, which includes a glass substrate covered with an FTO transparent conductive layer. A cross-sectional schematic diagram of the coating substrate is shown below. Figure 1 As shown, the edge region of the glass substrate 1 covered with the FTO transparent conductive layer is provided with two adjacent inverted trapezoidal grooves 2, and an isolation strip 3 is provided between the two adjacent grooves 2. The material of the isolation strip 3 is silicon dioxide.

[0049] The thickness b of the FTO transparent glass is 2.2 mm, the depth a of the groove 2 is 1 μm, the opening width is 150 μm, and the height of the isolation strip 3 is 0.3 μm.

[0050] Example 2

[0051] This embodiment provides a coating substrate, which includes a glass substrate, an FTO transparent conductive layer and a hole transport layer stacked sequentially. The edge of the glass substrate 1 covering the FTO transparent conductive layer is provided with two adjacent inverted trapezoidal grooves 2, and an isolation strip 3 is provided between the two adjacent grooves 2. The material of the isolation strip 3 is KrF photoresist.

[0052] The FTO glass has a thickness b of 2.2 mm, the groove 2 has a depth a of 2 μm and an opening width of 80 μm, and the isolation strip 3 has a height of 0.5 μm.

[0053] Example 3

[0054] This embodiment provides a coating substrate, which includes a glass substrate, an FTO transparent conductive layer and a hole transport layer stacked sequentially. The edge of the glass substrate 1 covering the FTO transparent conductive layer is provided with two adjacent inverted trapezoidal grooves 2, and an isolation strip 3 is provided between the two adjacent grooves 2. The material of the isolation strip 3 is ABS.

[0055] The FTO glass has a thickness b of 2.2 mm, the groove 2 has a depth a of 15 μm and an opening width of 600 μm, and the isolation strip 3 has a height of 1 μm.

[0056] Example 4

[0057] The only difference between this embodiment and Embodiment 1 is that the groove is rectangular in shape; all other conditions and parameters are exactly the same as in Embodiment 1.

[0058] Comparative Example 1

[0059] The only difference between this comparative example and Example 2 is that only one groove is provided, and an isolation strip is provided on the inner edge of the groove near the transparent conductive layer. All other conditions and parameters are exactly the same as in Example 2.

[0060] Comparative Example 2

[0061] The only difference between this comparative example and Example 2 is that no isolation zone is set up; all other conditions and parameters are exactly the same as in Example 2.

[0062] Comparative Example 3

[0063] This comparative example does not modify the structure of the FTO transparent conductive layer; that is, it does not include grooves.

[0064] An example of the application of this invention is 1.2 × 0.6 m. 2 Take perovskite components as an example.

[0065] Application Example 1

[0066] This application example provides a perovskite component, which is prepared by the following method:

[0067] A perovskite light-absorbing layer, an electron transport layer, and an electrode layer were sequentially prepared on the coating substrate described in Example 2 to obtain a semi-finished device.

[0068] Silicon oxynitride is deposited on the surface of the semi-finished device to obtain the perovskite module. The silicon oxynitride completely covers the perovskite active layer of the semi-finished device and the areas not covered by the perovskite active layer, forming a silicon oxynitride capping layer 4. A cross-sectional schematic diagram of the perovskite module is shown below. Figure 2 As shown;

[0069] The thickness of the FTO transparent conductive layer is 300 nm, and the hole transport layer 5 is made of NiO. x The thickness is 30 nm, and the material of the perovskite light-absorbing layer 6 is MA. 0.5 FA 0.5 The material of the PbI3 layer is 550 nm thick, the electron transport layer 7 is made of PCBM with a thickness of 20 nm, and the material of the electrode layer 8 is Cu with a thickness of 100 nm.

[0070] A schematic diagram of the transverse spread of the fracture-resistant cracks in the perovskite component is shown below. Figure 3 As shown.

[0071] Application Example 2

[0072] The only difference between this application example and application example 1 is that the coating substrate described in example 3 is used, while the other conditions and parameters are exactly the same as in application example 1.

[0073] Application Example 3

[0074] The only difference between this application example and application example 1 is that the coating substrate described in example 4 is used, while the other conditions and parameters are exactly the same as in application example 1.

[0075] Comparative Application Example 1

[0076] The only difference between this comparative application example and application example 1 is that the coating substrate described in comparative example 1 is used, while the other conditions and parameters are exactly the same as in application example 1.

[0077] Comparative Application Example 2

[0078] The only difference between this comparative application example and application example 1 is that the coating substrate described in comparative example 2 is used, while the other conditions and parameters are exactly the same as in application example 1.

[0079] Comparative Application Example 3

[0080] The only difference between this comparative application example and application example 1 is that the coating substrate described in comparative example 3 is used, while the other conditions and parameters are exactly the same as in application example 1.

[0081] Performance testing:

[0082] After perovskite coating and pre-annealing, five locations were evenly selected along the long side of the perovskite film, and the distance the crack extended from the edge of the perovskite film inward was measured. The specific data are as follows, and the test results are shown in Table 1. The units of the values ​​in the table are mm.

[0083] Table 1

[0084]

[0085] As can be seen from Table 1, based on Application Example 1, Application Example 2 and Comparative Application Example 3, the crack propagation length was significantly reduced (up to within 1.5 mm) after adopting the groove design and isolation strip design, effectively achieving the crack blocking effect.

[0086] A comparison of Application Example 1 and Application Example 3 shows that if the groove of the coating substrate of the present invention is a rectangular groove, the step difference is large, which will cause cracks or holes to be generated in the perovskite during the coating process, thereby increasing the crack length. Setting the groove of the coating substrate as trapezoidal or inverted trapezoidal helps to reduce the generation of cracks.

[0087] A comparison of Example 1 and Comparative Application Example 1 shows that the two-groove design, particularly the groove on the inner side of the isolation strip, is necessary. This groove prevents new cracks from forming on the inner side of the isolation strip and allows the isolation strip to effectively separate the coatings on both sides without requiring a very high height. Thus, together with the isolation strip and the groove on the outer side of the isolation strip, it hinders crack propagation. The inner side of the isolation strip refers to the side of the isolation strip furthest from the edge of the coating substrate, while the outer side refers to the side of the isolation strip closest to the edge of the coating substrate. However, if the height of the isolation strip is too large, it may affect the coating effect.

[0088] As can be seen from the comparison between Example 1 and Comparative Application Example 2, the isolation strip design in the edge region of the coating substrate described in this invention can block the crack propagation at the top of the film and reduce the width of the crack area.

[0089] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A coating substrate, characterized in that, The coating substrate includes a coating area and an edge area. The edge area has at least two adjacent grooves around the coating area. An isolation strip is provided between the adjacent grooves. The top of the isolation strip is higher than the plane where the target film layer is connected to the coating area, and the top of the isolation strip is lower than the top of the target film layer. Wherein, after the target film layer is deposited in the coating area and the edge area, the target film layer in the coating area is integrally connected with the target film layer in the groove near the coating area, and the isolation strip separates the target film layers in the adjacent groove.

2. The coating substrate as described in claim 1, characterized in that, The cross-sectional shape of the isolation strip is a gradually changing shape that is narrower at the top and wider at the bottom; Preferably, the cross-sectional shape of the groove is a gradually changing shape that is wider at the top and narrower at the bottom; Preferably, the gradient shape is trapezoidal.

3. The coating substrate as described in claim 1 or 2, characterized in that, The depth of the groove is 1–20 μm; Preferably, the opening width of the groove is 10–800 μm; Preferably, the height of the isolation strip is 0.2–1 μm; Preferably, the material of the isolation strip includes any one or a combination of at least two of the following: silicon dioxide, FTO, ITO, KrF photoresist, ArF photoresist, acrylonitrile-butadiene-styrene copolymer, polylactic acid, or polycarbonate.

4. A method for preparing a thin film, characterized in that, The preparation method includes: The target film is deposited using the coating substrate as described in any one of claims 1-3, the target film covering the coating area and the edge area.

5. The preparation method according to claim 4, characterized in that, The target film is a perovskite thin film.

6. A method for preparing a perovskite photovoltaic module, characterized in that, The preparation method includes: A perovskite thin film is deposited over the coating area and edge area of ​​the coating substrate according to any one of claims 1-3, wherein the coating substrate includes a first base layer, and the coating area of ​​the coating substrate further includes a bottom electrode layer and a first carrier transport layer sequentially stacked on one side of the first base layer. A second carrier transport layer and a top electrode layer are sequentially deposited on the surface of the perovskite thin film away from the coating substrate; The perovskite thin film, second carrier transport layer and top electrode layer deposited in the edge region are removed to expose the first substrate layer and groove in the edge region of the coated substrate, and then encapsulated to obtain a perovskite photovoltaic module.

7. The method for preparing a perovskite photovoltaic module as described in claim 6, characterized in that, The package includes: Silicon oxynitride is deposited on the surface of the top electrode layer in the coating area, the surface of the first base layer in the exposed edge area, and in the groove, so that the silicon oxynitride layer and the first base layer form a sealing structure.

8. The method for preparing a perovskite photovoltaic module as described in claim 6 or 7, characterized in that, The packaging process includes: Silicon oxynitride is deposited on the surface of the top electrode layer in the coating area, the surface of the coating substrate in the exposed edge area, and in the groove, so that the silicon oxynitride layer and the coating substrate form a sealed structure.

9. A perovskite photovoltaic module, characterized in that, The perovskite photovoltaic module is prepared by the preparation method according to any one of claims 6-8.

10. The perovskite photovoltaic module as described in claim 9, characterized in that, The width of the edge region is 2-3 mm; Preferably, the thickness of the silicon oxynitride layer is 1–20 μm.

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