A thin film photovoltaic module and its preparation method

Abstract

The present invention relates to a thin-film photovoltaic module and a preparation method thereof, belonging to the technical field of thin-film photovoltaic modules, in order to solve the problem that the P1 groove of the thin-film photovoltaic module in the prior art is filled with organic photoresist and cannot withstand high temperatures of 300°C to 700°C, thereby reducing the insulation performance at the P1 laser groove and limiting the process flow and process temperature of the module. The thin-film photovoltaic module comprises: a glass substrate, a transparent front electrode layer, a window layer, and an absorption layer stacked in sequence; a P1 laser groove; the P1 laser groove runs through the transparent front electrode layer, the window layer, and the absorption layer; the P1 laser groove is filled with an inorganic nanomaterial; and the melting point of the inorganic nanomaterial is greater than 300°C. The thin-film photovoltaic module provided by the present invention can improve the high temperature resistance of the module, so that the module still maintains a high photoelectric conversion efficiency when the temperature is greater than 300°C, which is conducive to the preparation of new products of thermally curved surface thin-film photovoltaic modules and new products of thin-film photovoltaic modules containing anti-reflection films.

Description

Technical Field

[0001] The present invention relates to the technical field of thin-film photovoltaic modules, and in particular to a thin-film photovoltaic module and a preparation method thereof. Background Art

[0002] The P1 laser groove of conventional thin-film photovoltaic modules is generally filled with organic photoresist and then UV-cured. Due to the poor high-temperature resistance of organic photoresist, carbonization will occur at temperatures >300°C. The result of carbonization is further deterioration of the insulation performance at the P1 laser groove, significantly reducing the photovoltaic conversion efficiency of the module. Therefore, the maximum temperature of the subsequent process after the P1 groove filling in the preparation of conventional thin-film photovoltaic modules does not exceed 300°C.

[0003] For some special thin-film photovoltaic module products or processes, it is necessary to perform high-temperature treatment of 300℃~700℃ after the P1 laser groove is filled. For example, the thin-film photovoltaic module is hot-bent to form a curved module, and the bending temperature of curved glass is 400℃~700℃; some module products will involve the preparation of subsequent anti-reflection films. Generally, the anti-reflection film needs to be heated and cured at a temperature of 400℃~700℃. However, conventional organic photoresists cannot withstand high temperatures of 300℃~700℃. In these special thin-film photovoltaic module products or processes, the insulation performance at the P1 laser groove will be reduced, thereby reducing the photoelectric conversion efficiency of the module. Obviously, the currently used organic photoresist filling process is not conducive to the development of some special new products with higher process temperatures. In addition, the poor high-temperature resistance of organic photoresists will also limit the process flow and process temperature of current conventional thin-film photovoltaic module products. For example, 400 o C~500 o The CdCl2 heat treatment process of C needs to be placed before the organic photoresist filling process. For example, the Cu doping process temperature after organic photoresist filling cannot be higher than 300 o C, these are not conducive to the optimization of component processing and performance.

[0004] Therefore, a solution is needed to select materials with good high temperature resistance to fill the P1 groove, which is beneficial to optimize the component process flow and process temperature, improve component efficiency and improve component appearance; in addition, it is also beneficial to the hot bending process of curved components and the preparation of new products. Summary of the invention

[0005] Therefore, the present invention provides a thin-film photovoltaic module and a preparation method thereof to solve the problem that the P1 groove of the thin-film photovoltaic module in the prior art is filled with organic photoresist and cannot withstand high temperatures of 300°C to 700°C, thereby reducing the insulation performance at the P1 laser groove, limiting the module process flow and process temperature, and the development of some new products and new processes that need to undergo high-temperature processes.

[0006] The present invention provides a thin-film photovoltaic module, comprising:

[0007] A glass substrate, a transparent front electrode layer, a window layer, and an absorption layer stacked in sequence;

[0008] P1 laser groove; the P1 laser groove penetrates the transparent front electrode layer, the window layer and the absorption layer;

[0009] The P1 laser groove is filled with inorganic nanomaterials; the melting point of the inorganic nanomaterials is greater than 300°C.

[0010] Optionally, the thin-film photovoltaic module further comprises:

[0011] A pinhole, wherein the pinhole penetrates the window layer and the absorption layer; and the pinhole is filled with the inorganic nanomaterial.

[0012] Optionally, the thin-film photovoltaic module further comprises:

[0013] A back contact layer, located on a surface of the absorption layer facing away from the window layer, wherein the back contact layer comprises copper;

[0014] A back electrode layer, located on a surface of the back contact layer facing away from the absorption layer;

[0015] P2 laser groove; the P2 laser groove penetrates the window layer, the absorption layer and the back contact layer; the P2 laser groove is filled with the material of the back electrode layer;

[0016] P3 laser groove; the P3 laser groove penetrates the window layer, the absorption layer, the back contact layer and the back electrode layer.

[0017] The present invention also provides a method for preparing a thin-film photovoltaic module, comprising the following steps:

[0018] Providing a glass substrate, on which a transparent front electrode layer, a window layer and an absorption layer are sequentially deposited;

[0019] forming a P1 laser groove, wherein the P1 laser groove penetrates the transparent front electrode layer, the window layer and the absorption layer;

[0020] The P1 laser groove is filled with an inorganic nano material; the melting point of the inorganic nano material is greater than 300°C.

[0021] Optionally, after the step of filling the P1 laser groove with inorganic nanomaterials, the step further includes:

[0022] forming a back contact layer on a surface of the absorption layer facing away from the window layer, wherein the back contact layer comprises copper;

[0023] forming a P2 laser groove, wherein the P2 laser groove penetrates the window layer, the absorption layer and the back contact layer;

[0024] Forming a back electrode layer on a surface of the back contact layer facing away from the absorption layer, wherein the back electrode layer also extends into and fills the P2 laser groove;

[0025] A P3 laser groove is formed, wherein the P3 laser groove penetrates the window layer and the absorption layer, the back contact layer and the back electrode layer.

[0026] Optionally, a first pinhole is formed simultaneously in the step of sequentially depositing a transparent front electrode layer, a window layer and an absorption layer on the glass substrate, wherein the first pinhole penetrates the window layer and the absorption layer and exposes the transparent front electrode layer;

[0027] The step of filling the P1 laser groove with inorganic nanomaterials comprises:

[0028] The P1 laser groove and the first pinhole are filled with the inorganic nanomaterial.

[0029] Optionally, the step of filling the P1 laser groove and the first pinhole with the inorganic nanomaterial includes:

[0030] Applying an inorganic nanomaterial solution on the surface of the absorption layer and in the P1 laser groove;

[0031] Perform low-temperature curing to volatilize the solvent and form an inorganic nanomaterial film layer;

[0032] Selective film removal is performed by immersing the low-temperature cured sample in a selective film removal solution to cause the inorganic nanomaterial film layer on the surface of the absorption layer to fall off, while the inorganic nanomaterial film layer in the P1 laser groove and at the first pinhole is retained.

[0033] Optionally, the coating method of the inorganic nanomaterial includes a wet film-forming process such as spin coating and roller coating;

[0034] The low temperature curing temperature is 100 o C~300 o C, the low temperature curing time is 5min~60min;

[0035] The selective film removal solution is an aqueous solution, an acid solution, an alkaline solution or a salt solution, and the concentration of the selective film removal solution is 0-30%; the immersion time of the selective film removal solution is 5s-10min.

[0036] Optionally, in the step of sequentially depositing a transparent front electrode layer, a window layer and an absorption layer on the glass substrate, a second pinhole is also formed simultaneously, wherein the second pinhole penetrates the absorption layer and exposes the window layer;

[0037] The step of filling the P1 laser groove and the first pinhole with the inorganic nanomaterial includes:

[0038] Performing a selective etching process on the window layer exposed at the position of the second pinhole, so that the second pinhole penetrates the window layer and the absorption layer and exposes the transparent front electrode layer;

[0039] The P1 laser groove, the first pinhole and the second pinhole are filled with the inorganic nanomaterial.

[0040] Optionally, the etching solution used in the selective etching process is an acidic solution;

[0041] The acidic solution includes one or more of hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid;

[0042] The concentration of the acidic solution is 1% to 70%, and the solvent of the acidic solution is water or alcohol.

[0043] Optionally, after the step of filling the P1 laser groove with inorganic nanomaterials, the step further includes:

[0044] A cadmium chloride heat treatment process is performed.

[0045] Optionally, the inorganic nanomaterial includes one or more of Si3N4, Al2O3, ZrO2, SiO2, and Ta2O5 nanoparticles;

[0046] The nanoparticle size in the inorganic nanomaterial is 1nm~1000nm;

[0047] The solvent of the inorganic nano material is water or alcohol.

[0048] The technical solution of the present invention has the following advantages:

[0049] (1) The thin-film photovoltaic module provided by the present invention uses inorganic nanomaterials with a melting point greater than 300°C to fill the P1 groove, which can improve the high temperature resistance of the P1 groove (can withstand temperatures >300°C), ensure the insulation performance of the P1 groove, and further improve the high temperature resistance of the module, so that the module can still maintain a high photoelectric conversion efficiency when the temperature is greater than 300°C, which is conducive to the preparation of new products of thermally curved surface thin-film photovoltaic modules and new products of thin-film photovoltaic modules containing anti-reflection films.

[0050] (2) The method for preparing a thin-film photovoltaic module provided by the present invention is used to prepare the thin-film photovoltaic module provided by the present invention. The inorganic nanomaterial with a melting point greater than 300°C is used to fill the P1 groove, which can improve the high temperature resistance of the P1 groove (can withstand temperatures >300°C), ensure the insulation performance of the P1 groove, and then improve the high temperature resistance of the module, so that the module can still maintain a high photoelectric conversion efficiency when the temperature is greater than 300°C, which is beneficial to the preparation of new products of thermally curved surface thin-film photovoltaic modules and new products of thin-film photovoltaic modules containing anti-reflection films, and at the same time, it is beneficial to optimize the position of the CdCl2 heat treatment process and the temperature of the Cu doping process in the module process flow, further improving the module efficiency and improving the appearance of the module.

[0051] (3) The method for preparing a thin-film photovoltaic module provided by the present invention utilizes the differences in material properties and bonding strength between inorganic nanomaterials and different structural layers to achieve the filling and insulation of the P1 laser groove and pinhole, greatly simplifying the complexity of the equipment and process.

[0052] (4) The method for preparing a thin-film photovoltaic module provided by the present invention first utilizes a selective single-film etching solution and a chemical etching process to etch the window layer at the second pinhole position, so that the second pinhole penetrates the window layer and the absorption layer and exposes the transparent front electrode layer. Then, an inorganic nanomaterial with a melting point greater than 300°C is used to fill the second pinhole, thereby achieving insulation at the second pinhole position, reducing the short-circuit point and impact caused by the second pinhole, and further improving the module efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 This is a schematic structural diagram of a thin-film photovoltaic module according to an embodiment of the present invention;

[0055] Figure 2 A schematic diagram of a process for preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0056] Figure 3 A schematic diagram of the structure of a first pinhole and a second pinhole in a method for preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0057] Figure 4 A schematic diagram of the structure of a conventional thin-film photovoltaic module obtained by a conventional thin-film photovoltaic module preparation process in the prior art;

[0058] Figure 5 A schematic diagram of the structure of etching a second pinhole in a process of preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0059] Figure 6 A schematic diagram of the preparation process of a conventional thin-film photovoltaic module in the prior art as a comparative example;

[0060] Figure 7 A schematic diagram of a specific process of a method for preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0061] Figure 8 A schematic diagram of the structure of a thin-film photovoltaic module obtained by a method for preparing a thin-film photovoltaic module in Example 3 of the present invention;

[0062] Fig. 9 A schematic diagram of a specific process of another method for preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0063] Fig.10 A schematic diagram of a specific process of another method for preparing a thin-film photovoltaic module according to an embodiment of the present invention;

[0064] Fig.11 The present invention is a schematic diagram of a specific process of another method for preparing a thin-film photovoltaic module according to an embodiment of the present invention.

[0065] Description of reference numerals:

[0066] 1-glass substrate; 2-transparent front electrode layer; 3-window layer; 4-absorption layer; 5-P1 laser slot; 6-pinhole; 7-back contact layer; 8-back electrode layer; 9-P2 laser slot; 10-P3 laser slot; 61-first pinhole; 62-second pinhole; 101-glass substrate; 102-transparent front electrode layer; 103-window layer; 104-absorption layer; 105-P1 laser slot; 107-back contact layer; 108-back electrode layer; 109-P2 laser slot; 110-P3 laser slot; 111-ultraviolet light source; 161-first pinhole; 162-second pinhole. DETAILED DESCRIPTION

[0067] In order to solve the problem that the P1 groove of the thin-film photovoltaic module in the prior art is filled with organic photoresist and cannot withstand high temperatures of 300°C to 700°C, thereby reducing the insulation performance at the P1 laser groove, limiting the module process flow and process temperature, and the development of some new products and new processes that need to undergo high-temperature processes, the present invention provides a thin-film photovoltaic module, including: a glass substrate, a transparent front electrode layer, a window layer, and an absorption layer stacked in sequence; a P1 laser groove; the P1 laser groove runs through the transparent front electrode layer, the window layer and the absorption layer; the P1 laser groove is filled with an inorganic nano material; the melting point of the inorganic nano material is greater than 300°C.

[0068] The present invention also provides a method for preparing a thin-film photovoltaic module, comprising the following steps: providing a glass substrate, depositing a transparent front electrode layer, a window layer and an absorption layer in sequence on the glass substrate; forming a P1 laser groove, wherein the P1 laser groove penetrates the transparent front electrode layer, the window layer and the absorption layer; and filling the P1 laser groove with an inorganic nanomaterial; wherein the melting point of the inorganic nanomaterial is greater than 300°C.

[0069] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that the terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0070] Example 1

[0071] refer to Figure 1 , this embodiment provides a thin-film photovoltaic module, including:

[0072] A glass substrate 1, a transparent front electrode layer 2, a window layer 3, and an absorption layer 4 are stacked in sequence;

[0073] P1 laser groove 5; the P1 laser groove 5 penetrates the transparent front electrode layer 2, the window layer 3 and the absorption layer 4;

[0074] The P1 laser groove 5 is filled with an inorganic nano material; the melting point of the inorganic nano material is greater than 300°C.

[0075] The thin-film photovoltaic module provided in this embodiment uses inorganic nanomaterials with a melting point greater than 300°C to fill the P1 groove, which can improve the high temperature resistance of the P1 groove (can withstand temperatures >300°C), ensure the insulation performance of the P1 groove, and then improve the high temperature resistance of the module, so that the module can still maintain a high photoelectric conversion efficiency when the temperature is greater than 300°C, which is conducive to the preparation of new products of thermally curved surface thin-film photovoltaic modules and new products of thin-film photovoltaic modules containing anti-reflection films.

[0076] Furthermore, in this embodiment, the thin-film photovoltaic module further includes:

[0077] A pinhole 6 , wherein the pinhole 6 penetrates the window layer 3 and the absorption layer 4 ; the pinhole 6 is filled with the inorganic nanomaterial.

[0078] The thin-film photovoltaic module provided in this embodiment uses inorganic nanomaterials with a melting point greater than 300° C. to fill the pinholes formed in the module preparation process, thereby achieving insulation at the pinhole positions and avoiding short circuits between the front and rear electrodes.

[0079] Furthermore, in this embodiment, the thin-film photovoltaic module further includes:

[0080] a back contact layer 7, located on a surface of the absorption layer 4 facing away from the window layer 3, wherein the back contact layer 7 comprises copper;

[0081] A back electrode layer 8, located on a surface of the back contact layer 7 facing away from the absorption layer 4;

[0082] P2 laser groove 9; the P2 laser groove 9 penetrates the window layer 3, the absorption layer 4 and the back contact layer 7; the P2 laser groove 9 is filled with the material of the back electrode layer 8;

[0083] P3 laser groove 10 ; the P3 laser groove 10 penetrates the window layer 3 , the absorption layer 44 , the back contact layer 7 , and the back electrode layer 8 .

[0084] Example 2

[0085] refer to Figure 2 The present invention also provides a method for preparing a thin-film photovoltaic module, which is used to prepare the thin-film photovoltaic module of the above-mentioned embodiment 1. The method comprises the following steps:

[0086] S101, providing a glass substrate 1, and sequentially depositing a transparent front electrode layer 2, a window layer 3 and an absorption layer 4 on the glass substrate;

[0087] S102, forming a P1 laser groove 5, wherein the P1 laser groove 5 penetrates the transparent front electrode layer 2, the window layer 3 and the absorption layer 4;

[0088] S103, filling the P1 laser groove 5 with an inorganic nano material; the melting point of the inorganic nano material is greater than 300°C.

[0089] In specific implementation, the steps of filling the P1 laser groove 5 with inorganic nanomaterials specifically include: first, using common wet coating techniques such as roller coating and spin coating to cover the liquid inorganic nanomaterial on the surface of the absorption layer and the P1 laser groove; then performing low-temperature curing to form the inorganic nanomaterial into a film, the solvent is basically volatilized, and the nanomaterial film is combined with the substrate; finally, selective film removal is performed, and the sample after low-temperature curing is immersed in a solution to cause the nanofilm material on the surface of the absorption layer to fall off, while the nanofilm material at the P1 laser groove 5 is retained.

[0090] In one example, the low-temperature curing temperature is 100°C to 500°C, and the curing time is 5min to 60min; the selective film removal solution is an aqueous solution, an acid solution, an alkaline solution, or a salt solution, and the immersion time is 5s to 10min. The acid solution includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc., the alkaline solution includes one or more of sodium hydroxide, potassium hydroxide, ammonia water, etc., and the salt solution includes one or more of sodium chloride, potassium chloride, potassium nitrate, etc., and the solution concentration is 0 to 30%.

[0091] The method for preparing a thin-film photovoltaic module provided in this embodiment is used to prepare the thin-film photovoltaic module provided by the present invention. The P1 groove is filled with an inorganic nanomaterial with a melting point greater than 300°C, which can improve the high temperature resistance of the P1 groove (can withstand temperatures >300°C), ensure the insulation performance of the P1 groove, and then improve the high temperature resistance of the module, so that the module can still maintain a high photoelectric conversion efficiency when the temperature is greater than 300°C, which is beneficial to the preparation of new products of thermally curved surface thin-film photovoltaic modules and new products of thin-film photovoltaic modules containing anti-reflection films, and is also beneficial to the optimization of the position of the CdCl2 heat treatment process and the temperature of the Cu doping process in the module process flow, further improving the module efficiency and improving the appearance of the module.

[0092] Furthermore, in some embodiments, the step of filling the P1 laser groove with inorganic nanomaterials further includes:

[0093] A back contact layer 7 is formed on a surface of the absorption layer 4 facing away from the window layer 3, wherein the back contact layer 7 comprises copper;

[0094] forming a P2 laser groove 9, wherein the P2 laser groove 9 penetrates the window layer 3, the absorption layer 4 and the back contact layer 7;

[0095] A back electrode layer 8 is formed on a surface of the back contact layer 7 facing away from the absorption layer 4, and the back electrode layer 8 also extends into and fills the P2 laser groove 9;

[0096] A P3 laser groove 10 is formed, and the P3 laser groove 10 penetrates the window layer 3 and the absorption layer 4 , the back contact layer 7 and the back electrode layer 8 .

[0097] In the preparation process of conventional thin-film photovoltaic modules, since the process temperature after the photoresist fills the P1 groove 5 needs to be lower than 300°C, the temperature of subsequent processes is limited. For example, the annealing temperature of the Cu-containing back contact layer 7 is limited to 200°C~300°C, which limits the optimization of processes such as Cu doping.

[0098] In the method for preparing the thin-film photovoltaic module provided in this embodiment, since the melting point of the inorganic nanomaterial filling the P1 laser groove 5 is greater than 300°C, the annealing temperature of the Cu-containing back contact layer 7 can reach above 300°C, so that the Cu-containing back contact layer 7 can adopt a high-temperature, short-time processing process, further optimizing the diffusion and distribution of Cu in the battery, thereby improving the average power of the module.

[0099] Furthermore, in some embodiments, Figure 3 As shown, the pinhole 6 of the thin-film photovoltaic module in Example 1 includes a first pinhole 61; the first pinhole 61 is simultaneously formed in the step of sequentially depositing the transparent front electrode layer 2, the window layer 3 and the absorption layer 4 on the glass substrate 1, and the first pinhole 61 penetrates the window layer 3 and the absorption layer 4, and exposes the transparent front electrode layer 2;

[0100] The step of filling the P1 laser groove 5 with inorganic nanomaterials includes:

[0101] The P1 laser groove 5 and the first pinhole 61 are filled with the inorganic nanomaterial.

[0102] In a specific implementation, the first pinhole 61 may be filled while the P1 laser groove 5 is filled with the inorganic nanomaterial.

[0103] Furthermore, in some embodiments, the step of filling the P1 laser groove 5 and the first pinhole 61 with the inorganic nanomaterial includes:

[0104] Applying an inorganic nano material solution on the surface of the absorption layer 4 and in the P1 laser groove 5;

[0105] Perform low-temperature curing to volatilize the solvent and form an inorganic nanomaterial film layer;

[0106] Selective film removal is performed by immersing the low-temperature cured sample in a selective film removal solution to remove the inorganic nanomaterial film layer on the surface of the absorption layer, while the inorganic nanomaterial film layer in the P1 laser groove 5 and at the first pinhole 61 is retained.

[0107] During the specific implementation, common wet coating techniques such as roller coating and spin coating are first used to cover the liquid inorganic nanomaterial on the surface of the absorption layer 4, the P1 laser groove 5 and the first pinhole 61; then low-temperature curing is performed to form an inorganic nanomaterial film to form an inorganic nanomaterial film layer. At this time, the solvent is basically evaporated to form an inorganic nanomaterial film layer combined with the substrate; finally, selective film removal is performed, and the low-temperature cured sample is immersed in a solution to cause the nanofilm material on the surface of the absorption layer 4 to fall off, while the nanofilm material at the P1 laser groove 5 and the first pinhole 61 is retained.

[0108] Furthermore, in some embodiments, the coating method of the inorganic nanomaterial includes a wet film-forming process such as spin coating and roller coating;

[0109] The low temperature curing temperature is 100 o C~300 o C, the low temperature curing time is 5min~60min;

[0110] The selective film removal solution is an aqueous solution, an acid solution, an alkaline solution or a salt solution, and the concentration of the selective film removal solution is 0-30%; the immersion time of the selective film removal solution is 5s-10min.

[0111] In specific implementation, the acid solution includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc., the alkaline solution includes one or more of sodium hydroxide, potassium hydroxide, ammonia water, etc., and the salt solution includes one or more of sodium chloride, potassium chloride, potassium nitrate, etc.

[0112] This embodiment utilizes the differences in material properties and bonding strength between inorganic nanomaterials and different structural layers, including thermal expansion coefficient, lattice parameters, adhesion, etc., and uses inorganic nanomaterials with a melting point greater than 300°C to fill the first pinhole 61 formed in the component preparation process. This can achieve insulation at the position of the first pinhole 61, avoid short circuits between the front and rear electrodes, further improve component efficiency, and greatly simplify the complexity of equipment and processes.

[0113] In one embodiment, the inorganic nanomaterial is Si3N4, and the material properties of the glass substrate, SnO2:F (FTO) conductive film, and cadmium telluride absorption layer 3 are different, resulting in different stresses in the Si3N4 nanofilm material formed on the glass substrate, FTO conductive film, and cadmium telluride absorption layer 4, and different bonding forces between the Si3N4 nanofilm material and the glass substrate, FTO conductive film, and cadmium telluride absorption layer 4; wherein, the stress of the Si3N4 nanofilm on the absorption layer 4 is large, and the bonding force between the Si3N4 nanofilm and the absorption layer 4 is weak; in the subsequent solution immersion process, such characteristics of large stress and weak adhesion are further amplified, thereby achieving the self-falling of the Si3N4 nanofilm material on the absorption layer; and the bonding force between the Si3N4 nanofilm and the glass substrate and FTO conductive film at the P1 laser groove 5 and the first pinhole 61 is strong, and the film layer does not fall off, thereby achieving selective filling and insulation.

[0114] Furthermore, in some embodiments, Figure 3 As shown, the pinhole 6 of the thin-film photovoltaic module in Example 1 further includes a second pinhole 62, and the second pinhole 62 is also formed simultaneously in the step of sequentially depositing the transparent front electrode layer 2, the window layer 3 and the absorption layer 4 on the glass substrate 1, and the second pinhole 62 penetrates the absorption layer 4 and exposes the window layer 3;

[0115] The step of filling the P1 laser groove 5 and the first pinhole 61 with the inorganic nanomaterial includes:

[0116] Performing a selective etching process on the window layer exposed at the position of the second pinhole 62, so that the second pinhole 62 penetrates the window layer 3 and the absorption layer 4 and exposes the transparent front electrode layer 2;

[0117] The P1 laser groove 5 , the first pinhole 61 and the second pinhole 62 are filled with the inorganic nanomaterial.

[0118] In a specific implementation, the first pinhole 61 and the second pinhole 62 may be filled while the P1 laser groove 5 is filled with the inorganic nanomaterial.

[0119] In a specific embodiment, the specific steps of the selective etching process are: immersing the glass substrate / transparent front electrode layer / window layer / absorption layer sample in an etching solution, because the etching solution does not react with the cadmium telluride absorption layer 4 or the etching rate is low, the etching solution reacts quickly with the cadmium sulfide or cadmium selenide window layer 3, and the etching rate of the window layer is high; using the difference in etching rates of different materials to achieve selective etching of the window layer 3 material, so that the second pinhole 62 penetrates the window layer 3 and the absorption layer 4, and exposes the transparent front electrode layer 2. In one example, the immersion time in the etching solution is 1min~30min.

[0120] In the conventional manufacturing process of thin-film photovoltaic modules, there is no relevant process for filling and plugging the second pinholes. Figure 4 As shown, in the preparation process of conventional thin-film photovoltaic modules, after the photoresist fills the P1 groove 105, it is necessary to irradiate with an ultraviolet light source 111 from the lower surface of the glass substrate 1 to cure the photoresist. For the second pinhole 162 that only exists in the absorption layer 104 (where all or part of the window layer 103 exists), since the ultraviolet light cannot penetrate the window layer 103 to reach the absorption layer 104, the photoresist cannot be cured, and thus cannot play a role in plugging the hole and insulating. This second pinhole 162 often becomes a potential short-circuit point in the battery, which will reduce the battery performance.

[0121] The method for preparing a thin-film photovoltaic module provided in this embodiment first uses a selective single-layer etching solution and a chemical etching process to etch the window layer 3 at the position of the second pinhole 62, so that the second pinhole 62 penetrates the window layer 3 and the absorption layer 4 and exposes the transparent front electrode layer 2. Figure 5 As shown; then, an inorganic nanomaterial with a melting point greater than 300°C is used to fill the second pinhole 62, which can achieve insulation at the position of the second pinhole 62, reduce the short-circuit point and impact caused by the second pinhole 62, and further improve the component efficiency.

[0122] Further, in some embodiments, the etching solution used in the selective etching process is an acidic solution;

[0123] The acidic solution includes one or more of hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid;

[0124] The concentration of the acidic solution is 1% to 70%, and the solvent of the acidic solution is water or alcohol.

[0125] Furthermore, in some embodiments, the step of filling the P1 laser groove 5, the first pinhole 61 and the second pinhole 62 with the inorganic nanomaterial includes: firstly, using common wet coating techniques such as roller coating and spin coating to cover the liquid inorganic nanomaterial on the surface of the absorption layer 4, the P1 laser groove 5, the first pinhole 61 and the second pinhole 62; then, performing low-temperature curing to form an inorganic nanomaterial film to form an inorganic nanomaterial film layer, at which time the solvent is basically evaporated to form an inorganic nanomaterial film layer combined with the substrate; finally, performing selective film removal, immersing the low-temperature cured sample in a solution, so that the nanofilm material on the surface of the absorption layer 4 falls off, and the nanofilm material at the P1 laser groove 5, the first pinhole 61 and the second pinhole 62 is retained.

[0126] In one example, the low-temperature curing temperature is 100°C to 500°C, and the curing time is 5min to 60min; the selective film removal solution is an aqueous solution, an acid solution, an alkaline solution, or a salt solution, and the immersion time is 5s to 10min. The acid solution includes one or more of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, etc., the alkaline solution includes one or more of sodium hydroxide, potassium hydroxide, ammonia water, etc., and the salt solution includes one or more of sodium chloride, potassium chloride, potassium nitrate, etc., and the solution concentration is 0 to 30%.

[0127] Furthermore, in some embodiments, the step of filling the P1 laser groove 5 with inorganic nanomaterials further includes:

[0128] A cadmium chloride heat treatment process is performed.

[0129] In the preparation process of conventional thin-film photovoltaic modules, since organic photoresists are not resistant to high temperatures, P1 laser etching and photoresist filling must be performed after the cadmium chloride heat treatment process. As a result, during the cadmium chloride heat treatment process, due to the exposure of the first pinhole 61 and the second pinhole 62, cadmium chloride is more likely to gather and diffuse there, resulting in uneven distribution and heat treatment of cadmium chloride, which not only affects the power generation efficiency of the module, but also produces a large number of tiny white spots on the light-receiving surface of the glass, affecting the appearance of the module.

[0130] The method for preparing the thin-film photovoltaic module provided in this embodiment advances the filling and insulation process of the P1 groove and pinhole to before the cadmium chloride heat treatment process, thereby eliminating the phenomenon of cadmium chloride aggregation at the first pinhole 61 and the second pinhole 62, reducing the impact of uneven distribution of cadmium chloride and heat treatment, reducing white spot formation and improving the appearance of the module.

[0131] Further, in some embodiments, the inorganic nanomaterial includes one or more of Si3N4, Al2O3, ZrO2, SiO2, and Ta2O5 nanoparticles;

[0132] The nanoparticle size in the inorganic nanomaterial is 1 nm to 1000 nm, such as 1 nm, 200 nm, 600 nm, 1000 nm, etc.;

[0133] The solvent of the inorganic nano material is water or alcohol.

[0134] In order to verify the effectiveness of the solution of this embodiment, the present invention also provides comparative examples and embodiments 3 to 6, comparing the differences between the conventional thin-film photovoltaic module preparation process and the specific preparation method of the thin-film photovoltaic module provided by the present invention.

[0135] Comparative Example

[0136] The comparative example is a conventional thin-film photovoltaic module preparation process in the prior art, referring to Figure 6 , including steps S201-S206:

[0137] S201, depositing an FTO layer (including a high-resistance layer such as SnO2) 102, a cadmium sulfide window layer 103 and a cadmium telluride absorption layer 104 on a glass substrate 101 in sequence, such as Figure 4 As shown;

[0138] S202, cadmium chloride heat treatment and phosphorus nitric acid dilute acid surface oxide layer corrosion;

[0139] S203, P1 laser etching 105 and photoresist filling and UV curing 111, to achieve filling and insulation at the position of the P1 laser groove 105 and the first pinhole 161;

[0140] S204, using a cleaning solution to clean and dry the uncured photoresist on the surface of the absorption layer 104, and then depositing and annealing a Cu-containing back contact layer 107 such as ZnTe:Cu, at a temperature of 260° C. for 30 minutes;

[0141] S205, P2 laser etching 109, depositing a metal back electrode layer 108 such as Mo and Al; P3 laser etching 110, using laser or sandblasting technology to clean the edges of the substrate and remove the edge film layer;

[0142] S206, the battery substrate is covered with packaging materials such as ethylene-vinyl acetate copolymer (EVA) film and back panels such as glass in sequence, and then put into a laminator or autoclave for packaging, and a junction box is installed to form a final component product.

[0143] The disadvantages of this comparative example are: (1) the photoresist filling needs to be carried out after the cadmium chloride heat treatment (the cadmium chloride treatment temperature is 400°C~450°C to avoid carbonization of the organic photoresist), and the diffusion and aggregation of cadmium chloride will be accelerated at the positions of the first pinhole 161 and the second pinhole 162, resulting in uneven distribution and heat treatment of cadmium chloride, and a large amount of white spots are generated on the glass surface of the component, affecting the appearance of the component; (2) the photoresist has no filling and insulation properties for the semi-transparent second pinhole 162; (3) the process temperature after the photoresist filling needs to be lower than 300°C, such as the annealing temperature of the Cu-containing back contact layer 107 is 200°C~300°C, which limits the process optimization such as Cu doping.

[0144] Example 3

[0145] Example 3 is a specific preparation method of a thin-film photovoltaic module provided by the present invention, referring to Figure 7 , including steps S301-S306:

[0146] S301, depositing an FTO layer (including a high-resistance layer such as SnO2) 2, a cadmium sulfide window layer 3 and a cadmium telluride absorption layer 4 on a glass substrate 1 in sequence, such as Figure 8 As shown;

[0147] S302, cadmium chloride heat treatment and phosphorus nitric acid dilute acid surface oxide layer corrosion;

[0148] S303, P1 laser etching 5, inorganic nano-Si3N4 material roller coating filling, 200 o C and solidify for 10 min, soak in 1% dilute hydrochloric acid solution for local demolding, and achieve filling and insulation at the position of P1 laser groove 5 and the first pinhole 61;

[0149] S304, washing with water and drying, and then depositing and annealing a Cu-containing back contact layer 7 such as ZnTe:Cu, etc., at a processing temperature of 260 o C. Time: 30 minutes;

[0150] S305, P2 laser etching 9, depositing a metal back electrode layer 8 such as Mo and Al; P3 laser etching 10, using laser or sandblasting to clean the edges of the substrate and remove the edge film layer;

[0151] S306, the battery substrate is covered with packaging materials such as EVA and back panels such as glass in sequence, and then put into a laminator or autoclave for packaging, and a junction box is installed to form a final component product.

[0152] The difference between Example 3 and the comparative example is that step S203 is P1 laser etching 5, inorganic nano-Si3N4 material roller coating filling, 200 oC and solidify for 10 minutes, soak in 1% dilute hydrochloric acid solution for local demolding, and achieve filling and insulation at the position of P1 laser groove 5 and the first pinhole 61. The other steps are the same.

[0153] The advantages of Example 3 compared to the comparative example are: the use of inorganic nanomaterials to fill the P1 groove 5 and the first pinhole 61 can ensure the insulation performance at the P1 groove 5 and the first pinhole 61, thereby improving the high temperature resistance of the component, so that the component can still maintain a high photoelectric conversion efficiency when the temperature is greater than 300°C, which can improve the component efficiency and improve the component appearance, which is beneficial to the optimization of the component process flow and process temperature, and is also beneficial to the hot bending process of curved thin-film photovoltaic components and the preparation of new products.

[0154] Example 4

[0155] Example 4 is another specific preparation method of a thin-film photovoltaic module provided by the present invention, referring to Fig. 9 , including steps S401-S406:

[0156] S401, depositing an FTO layer (including a high-resistance layer such as SnO2) 2, a cadmium sulfide window layer 3 and a cadmium telluride absorption layer 4 on a glass substrate 1 in sequence;

[0157] S402, cadmium chloride heat treatment, 30% concentrated hydrochloric acid etching, while removing the surface oxide, to achieve selective etching of the window layer 3 at the position of the second pinhole 62, such as Figure 5 As shown;

[0158] S403, P1 laser etching 5, inorganic nano-Al2O3 material roller coating filling, 150 o C and solidify for 15 minutes, and then soak in 3% nitric acid solution for local demolding to achieve filling and insulation at the positions of P1 laser groove 5, first pinhole 61 and second pinhole 62;

[0159] S404, washing with water and drying, depositing and annealing a Cu-containing back contact layer 7 such as ZnTe:Cu, etc., at a processing temperature of 260 o C. Time: 30 minutes;

[0160] S405, P2 laser etching 9, depositing a metal back electrode layer 8 such as Mo and Al; P3 laser etching 10, using laser or sandblasting to clean the edges of the substrate and remove the edge film layer;

[0161] S406, the battery substrate is covered with packaging materials such as EVA and back panels such as glass in sequence, and then put into a laminator or autoclave for packaging, and a junction box is installed to form a final component product.

[0162] The difference between Example 4 and Example 3 is that step S402 is a cadmium chloride heat treatment, 30% concentrated hydrochloric acid etching, while removing the surface oxide, to achieve selective etching of the window layer 3 at the position of the second pinhole 62; step S403 is P1 laser etching 5, inorganic nano-Al2O3 material roller coating filling, 150 o C and solidify for 15 minutes, and soak in 3% nitric acid solution for local demolding to achieve filling and insulation at the positions of P1 laser groove 5 and the first needle 61 and the second pinhole 62; the other steps are the same.

[0163] The advantages of Example 4 over Example 3 are: the filling and insulation of the second pinhole 62 can be achieved, the short circuit and its influence can be reduced, and the average power generation power of the component can be relatively increased by 2% to 3%.

[0164] Example 5

[0165] Example 5 is another specific method for preparing a thin-film photovoltaic module provided by the present invention, referring to Fig.10 , including steps S501-S506:

[0166] S501, depositing an FTO layer (including a high-resistance layer such as SnO2) 2, a cadmium sulfide window layer 3 and a cadmium telluride absorption layer 4 on a glass substrate 1 in sequence;

[0167] S502, heat treatment with cadmium chloride, etching with 50% concentrated hydrochloric acid, and selectively etching the window layer 3 at the position of the second pinhole 62 while achieving conventional surface oxide removal;

[0168] S503, P1 laser etching 5, inorganic nano ZrO2 material roller coating filling, 120 o C and solidify for 20 minutes, soak in 5% dilute hydrochloric acid / nitric acid solution for local demolding, and achieve filling and insulation at the positions of P1 laser groove 5, first pinhole 61 and second pinhole 62;

[0169] S504, washing with water and drying, and then depositing and annealing a Cu-containing back contact layer 7 such as ZnTe:Cu, etc., at a processing temperature of 350 o C. Time: 2 minutes;

[0170] S505, P2 laser etching 9, depositing a metal back electrode layer 8 such as Mo and Al; P3 laser etching 10, using laser or sandblasting to clean the edges of the substrate and remove the edge film layer;

[0171] S506, the battery substrate is covered with packaging materials such as EVA and back panels such as glass in sequence, and then put into a laminator or autoclave for packaging, and a junction box is installed to form a final component product.

[0172] The difference between Example 5 and Example 4 is that step S504 is water washing and drying, and the Cu-containing back contact layer 7 such as ZnTe:Cu is deposited and annealed at a temperature of 350 o C. Time: 2 min; other steps are the same.

[0173] The advantages of Example 5 over Example 4 are as follows: when the annealing temperature is increased to 350 o C, the annealing time is shortened from 50 min to 2 min. Therefore, the Cu-containing back contact layer 7 can adopt a high temperature and short time treatment process to further optimize the diffusion and distribution of Cu in the battery, and relatively improve the average power of the component by 3%.

[0174] Example 6

[0175] Example 6 is a specific method for preparing another thin-film photovoltaic module provided by the present invention, referring to Fig.11 , including steps S601-S607:

[0176] S601, depositing an FTO layer (including a high-resistance layer such as SnO2) 2, a cadmium sulfide window layer 3 and a cadmium telluride absorption layer 4 on a glass substrate 1 in sequence;

[0177] S602, performing 60% concentrated hydrochloric acid etching to achieve selective etching of the window layer 3 at the position of the second pinhole 62;

[0178] S603, P1 laser etching 5, inorganic nano-SiO2 material roller coating filling, 250 o C and solidify for 5 minutes, and then soak in 8% dilute phosphoric acid / nitric acid solution for local demolding to achieve filling and insulation at the positions of P1 laser groove 5, first pinhole 61 and second pinhole 62;

[0179] S604, heat treatment with cadmium chloride, corrosion of the surface oxide layer with dilute phosphoric and nitric acid, washing with water and drying;

[0180] S605, depositing and annealing a Cu-containing back contact layer 7 such as ZnTe:Cu, etc., at a temperature of 380 o C. Time: 1min;

[0181] S606, P2 laser etching 9, depositing a metal back electrode layer 8 such as Mo and Al; P3 laser etching 10, using laser or sandblasting to clean the edges of the substrate and remove the edge film layer;

[0182] S607, the battery substrate is covered with packaging materials such as EVA and back panels such as glass in sequence, and then put into a laminator or autoclave for packaging, and a junction box is installed to form the final component product.

[0183] The difference between Example 6 and Example 5 is that, in steps S602 to S604, the inorganic nanomaterial filling and insulation are advanced before the cadmium chloride heat treatment to achieve plugging of the first pinhole 61 and the second pinhole 62; the other steps are the same.

[0184] The advantages of Example 6 compared to Example 5 are: it can avoid the accumulation of cadmium chloride at the first pinhole 61 and the second pinhole 62, reduce the influence of cadmium chloride distribution and heat treatment layout, further improve component performance, and relatively increase the average power of the component by 2% to 3%; reduce the formation of white spots and improve the appearance of the component.

[0185] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for preparing a thin-film photovoltaic module, characterized in that: The following steps are involved: A glass substrate is provided, and a transparent front electrode layer, a window layer, and an absorption layer are sequentially deposited on the glass substrate; a first pinhole and a second pinhole are simultaneously formed in the step of sequentially depositing the transparent front electrode layer, the window layer, and the absorption layer on the glass substrate, wherein the first pinhole penetrates the window layer and the absorption layer and exposes the transparent front electrode layer; and the second pinhole penetrates the absorption layer and exposes the window layer; forming a P1 laser groove, wherein the P1 laser groove penetrates the transparent front electrode layer, the window layer and the absorption layer; The P1 laser groove is filled with an inorganic nanomaterial; the melting point of the inorganic nanomaterial is greater than 300° C.; the size of the nanoparticles in the inorganic nanomaterial is 1 nm to 1000 nm; The step of filling the P1 laser groove with inorganic nanomaterials comprises: Performing a selective etching process on the window layer exposed at the position of the second pinhole, so that the second pinhole penetrates the window layer and the absorption layer and exposes the transparent front electrode layer; Filling the P1 laser groove, the first pinhole and the second pinhole with the inorganic nanomaterial; The step of filling the P1 laser groove, the first pinhole and the second pinhole with the inorganic nanomaterial includes: Applying an inorganic nanomaterial solution on the surface of the absorption layer and in the P1 laser groove; Perform low-temperature curing to volatilize the solvent and form an inorganic nanomaterial film layer; Selective film removal is performed, and the sample after low-temperature curing is immersed in a selective film removal solution to make the inorganic nano material film layer on the surface of the absorption layer fall off, and the inorganic nano material film layer in the P1 laser groove, the first pinhole and the second pinhole is retained.

2. The method for preparing a thin-film photovoltaic module according to claim 1, characterized in that: After the step of filling the P1 laser groove with inorganic nanomaterials, the following steps are further included: forming a back contact layer on a surface of the absorption layer facing away from the window layer, wherein the back contact layer comprises copper; forming a P2 laser groove, wherein the P2 laser groove penetrates the window layer, the absorption layer and the back contact layer; Forming a back electrode layer on a surface of the back contact layer facing away from the absorption layer, wherein the back electrode layer also extends into and fills the P2 laser groove; A P3 laser groove is formed, wherein the P3 laser groove penetrates the window layer and the absorption layer, the back contact layer and the back electrode layer.

3. The method for preparing a thin-film photovoltaic module according to claim 2, characterized in that: The coating method of the inorganic nano material includes spin coating and roller coating; The low temperature curing temperature is 100 o C~300 o C, the low temperature curing time is 5min~60min; The selective film removal solution is an aqueous solution, an acid solution, an alkaline solution or a salt solution, and the concentration of the selective film removal solution is 0-30%; the immersion time of the selective film removal solution is 5s-10min.

4. The method for preparing a thin-film photovoltaic module according to claim 3, characterized in that: The etching solution used in the selective etching process is an acidic solution; The acidic solution includes one or more of hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid; The concentration of the acidic solution is 1% to 70%, and the solvent of the acidic solution is water or alcohol.

5. The method for preparing a thin-film photovoltaic module according to claim 1, characterized in that: After the step of filling the P1 laser groove with inorganic nanomaterials, the following steps are further included: A cadmium chloride heat treatment process is performed.

6. The method for preparing a thin-film photovoltaic module according to claim 1, characterized in that: The inorganic nanomaterial includes one or more of Si3N4, Al2O3, ZrO2, SiO2, and Ta2O5 nanoparticles; The solvent of the inorganic nano material is water or alcohol.

7. A thin-film photovoltaic module, characterized in that: The thin-film photovoltaic module is prepared by the method for preparing a thin-film photovoltaic module according to any one of claims 1 to 6, comprising: A glass substrate, a transparent front electrode layer, a window layer, and an absorption layer stacked in sequence; P1 laser groove; the P1 laser groove penetrates the transparent front electrode layer, the window layer and the absorption layer; A first pinhole; the first pinhole penetrates the window layer and the absorption layer; A second pinhole; the second pinhole penetrates the window layer and the absorption layer; The P1 laser groove, the first pinhole and the second pinhole are filled with inorganic nanomaterials; the melting point of the inorganic nanomaterials is greater than 300° C.; the size of the nanoparticles in the inorganic nanomaterials is 1 nm to 1000 nm.

Images