Solar cell and solar cell preparation method

Abstract

The invention relates to the technical field of solar energy, particularly provides a solar cell and a preparation method of the solar cell, and aims to solve the problem that the photoelectric conversion efficiency of the solar cell is affected due to the fact that an existing transparent electrode cannot effectively balance conductivity and light transmittance. In order to achieve the purpose, the solar cell comprises a first transparent conductive layer, a first transmission layer, an active layer, a second transmission layer, a light interference buffer layer, a second transparent conductive layer and a first light interference film layer which are sequentially arranged on the surface of one side of a substrate, the light interference buffer layer, the second transparent conductive layer and the first light interference film layer form a multi-layer anti-reflection structure; the refractive index of the first light interference film layer and the refractive index of the light interference buffer layer are both smaller than the refractive index of the second transparent conductive layer. According to the scheme, the first light interference film layer, the second transparent conductive layer and the light interference buffer layer form a low-refractive-index-high-refractive-index-low-refractive-index alternating multi-layer anti-reflection structure, the electric conductivity is guaranteed, meanwhile, light reflection can be effectively reduced, and the light transmittance is improved.

Description

Technical Field

[0001] This application relates to the field of solar energy technology, and specifically provides a solar cell and a method for manufacturing the solar cell. Background Art

[0002] The optoelectronic properties of the transparent electrode are one of the key factors affecting the efficiency of solar cells. An ideal transparent electrode should meet the following conditions: excellent optical transmittance in the visible and near-infrared regions, low resistivity, good chemical stability, and compatibility with adjacent layers. For example, transparent conductive oxides meet the above conditions, and transparent conductive oxides are used as transparent electrodes in related perovskite solar cells.

[0003] However, there are still some problems in the application of transparent conductive oxides in perovskite solar cells. To improve the conductivity, it is necessary to increase the thickness of the transparent conductive oxide, but this increase in thickness will lead to a decrease in light transmittance, thereby affecting the photoelectric conversion efficiency of perovskite solar cells. Summary of the Invention

[0004] This application aims to solve the above technical problems, that is, to solve the problem that the existing transparent electrode cannot effectively balance the conductivity and light transmittance, affecting the photoelectric conversion efficiency of solar cells.

[0005] In a first aspect, this application provides a solar cell, which includes a first transparent conductive layer, a first transport layer, an active layer, a second transport layer, a light interference buffer layer, a second transparent conductive layer, and a first light interference film layer sequentially arranged on one side surface of a substrate. The light interference buffer layer, the second transparent conductive layer, and the first light interference film layer form a multi-layer antireflection structure;

[0006] Wherein, the refractive indices of the first light interference film layer and the light interference buffer layer are both less than the refractive index of the second transparent conductive layer.

[0007] In some embodiments, the solar cell further includes a light interference stack structure, and the light interference stack structure is arranged on the surface of the first light interference film layer away from the second transparent conductive layer;

[0008] The light interference stack structure includes at least one group of second light interference film layers and third light interference film layers alternately stacked in the direction away from the second transparent conductive layer of the first light interference film layer. The refractive index of the third light interference film layer is less than the refractive index of the adjacent second light interference film layer, and the refractive index of the first light interference film layer is less than the refractive index of the adjacent second light interference film layer.

[0009] In some embodiments, when the optical interference stack structure includes multiple sets of second optical interference film layers and third optical interference film layers alternately stacked in a direction away from the second transparent conductive layer of the first optical interference film layer, the second optical interference film layers in different sets are the same or different, and the third optical interference film layers in different sets are the same or different.

[0010] In some embodiments, the optical interference buffer layer is made of at least one of an aluminum oxide layer and a tin oxide layer.

[0011] In some embodiments, the thickness of the optical interference buffer layer is 10 - 50 nm.

[0012] In some embodiments, the second optical interference film layer is made of at least one of a titanium oxide film layer, a niobium oxide film layer, a yttrium fluoride film layer, a tantalum oxide film layer, and a hafnium oxide film layer.

[0013] In some embodiments, the third optical interference film layer or the first optical interference film layer is made of at least one of a silicon oxide film layer, a silicon nitride film layer, a magnesium fluoride film layer, and a silicon-aluminum mixture film layer.

[0014] In some embodiments, the thickness of the second transparent conductive layer is 30 - 200 nm.

[0015] In some embodiments, the solar cell further includes an antireflection layer disposed between the substrate and the first transparent conductive layer.

[0016] In a second aspect, the present application provides a method for manufacturing a solar cell, which includes:

[0017] Forming a first transparent conductive layer, a first transport layer, an active layer, a second transport layer, an optical interference buffer layer, a second transparent conductive layer, and a first optical interference film layer on a substrate in sequence;

[0018] Wherein, the optical interference buffer layer, the second transparent conductive layer, and the first optical interference film layer form a multilayer antireflection structure, and the refractive indices of the first optical interference film layer and the optical interference buffer layer are both less than the refractive index of the second transparent conductive layer.

[0019] In some embodiments, the method further includes:

[0020] Forming an optical interference stack structure on a surface of the first optical interference film layer away from the second transparent conductive layer;

[0021] The optical interference stack structure includes at least one set of second optical interference film layers and third optical interference film layers alternately stacked in a direction away from the second transparent conductive layer of the first optical interference film layer, and the refractive index of the second optical interference film layer is greater than the refractive index of the third optical interference film layer.

[0022] In the case of adopting the above technical solution, the present application can provide a solar cell, which includes a first transparent conductive layer, a first transport layer, an active layer, a second transport layer, a light interference buffer layer, a second transparent conductive layer, and a first light interference film layer sequentially arranged on one surface of a substrate. The light interference buffer layer, the second transparent conductive layer, and the first light interference film layer form a multi-layer antireflection structure; wherein, the refractive indices of the first light interference film layer and the light interference buffer layer are both less than the refractive index of the second transparent conductive layer. In this solution, the first light interference film layer, the second transparent conductive layer, and the light interference buffer layer form a multi-layer antireflection structure with alternating low refractive index - high refractive index - low refractive index. While ensuring the conductivity, it can effectively reduce light reflection, improve the light transmittance, and broaden the effective wavelength range of the antireflection effect through the multi-layer interference effect. Description of the Drawings

[0023] The following describes the preferred embodiments of the present application with reference to the drawings, in which:

[0024] Figure 1 is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present application;

[0025] Figure 2 is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present application, provided with a light interference stacking structure;

[0026] Figure 3 is a schematic cross-sectional structure diagram of a solar cell provided by another embodiment of the present application, provided with a light interference stacking structure;

[0027] Figure 4 is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present application, provided with an antireflection layer;

[0028] Figure 5 is a schematic cross-sectional structure diagram of a solar cell provided by another embodiment of the present application;

[0029] Figure 6 is a schematic flow chart of a method for preparing a solar cell provided by an embodiment of the present application;

[0030] Figure 7 is a schematic flow chart of a method for preparing a solar cell provided by another embodiment of the present application;

[0031] Figure 8 is a schematic flow chart of a method for preparing a solar cell provided by another embodiment of the present application;

[0032] Figure 9 shows a schematic comparison diagram of the overall transmittance of the composite film on the upper surface of the active layer in the 380nm - 1200nm band between a solar cell prepared by a conventional process and a solar cell provided by the present application. Detailed implementation manners

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Apparently, the described embodiments are some but not all of the embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0034] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present disclosure belongs. The terms "first", "second", and similar terms used in the present disclosure do not denote any order, quantity, or importance, but are only used to distinguish different components. The terms "including", "comprising", or similar terms mean that the elements or items appearing before the term cover the elements or items listed after the term and their equivalents, without excluding other elements or items.

[0035] Based on the description in the background art section, when a transparent conductive oxide is used as the transparent electrode of a perovskite solar cell, in order to improve the conductivity, it is necessary to increase the thickness of the transparent conductive oxide. However, this increase in thickness will result in a decrease in transmittance, thereby affecting the photoelectric conversion efficiency of the perovskite solar cell.

[0036] In view of this, the present application provides a solar cell. The solar cell forms a multi-layer antireflection structure with a second transparent conductive layer, an optical interference buffer layer adjacent to the second transparent conductive layer, and an odd-numbered layer optical interference film layer. In the multi-layer antireflection structure, the refractive indices of the even-numbered layers are arranged in a low-high-low pattern with respect to their two adjacent layers, which can increase the film thickness of the second transparent conductive layer and improve the conductivity while increasing the transmittance, thereby enhancing the performance of the solar cell.

[0037] See Figure 1 as shown in Figure 1 FIG. is a schematic cross-sectional structure diagram of a solar cell provided by an embodiment of the present application. It may include a first transparent conductive layer 11, a first transport layer 12, an active layer 13, a second transport layer 14, an optical interference buffer layer 15, a second transparent conductive layer 16, and a first optical interference film layer 17 sequentially disposed on one side surface of a substrate 10. The optical interference buffer layer 15, the second transparent conductive layer 16, and the first optical interference film layer 17 form a multi-layer antireflection structure.

[0038] Among them, the refractive indices of the first optical interference film layer 17 and the optical interference buffer layer 15 are both less than the refractive index of the second transparent conductive layer 16.

[0039] That is, in this embodiment, it is shown that on the surface of the second transparent conductive layer 16 away from the substrate 10, only one layer of optical interference film layer, i.e., the first optical interference film layer 17, is provided. The optical interference buffer layer 15, the second transparent conductive layer 16, and the first optical interference film layer 17 form a multi-layer antireflection structure with a low-high-low refractive index arrangement, which is beneficial to reducing light reflection and improving light transmittance while ensuring high conductivity, thereby improving the performance of the solar cell. In addition, by combining with the second transparent conductive layer in the solar cell to form a multi-layer antireflection structure, it is beneficial to simplify the process flow of forming the multi-layer antireflection structure and reduce the influence of the multi-layer antireflection structure on the structure or stability of the solar cell.

[0040] In the embodiment of the present application, the substrate 10, the first transparent conductive layer 11, the first transport layer 12, the active layer 13, the second transport layer 14, and the second transparent conductive layer 16 can adopt materials that can realize the functions of the corresponding layers of the solar cell.

[0041] In some embodiments, the first transport layer 12 can be a hole transport layer, and the second transport layer 14 can be an electron transport layer; in other embodiments, the first transport layer 12 can be an electron transport layer, and the second transport layer 14 can be a hole transport layer.

[0042] In some embodiments, the active layer 13 can adopt perovskite materials.

[0043] In some embodiments, the first transparent conductive layer 11 and the second transparent conductive layer 16 can adopt TCO (Transparent Conductive Oxide), and in some embodiments, TCO can include at least one of indium tin oxide ITO, indium zinc oxide IZO, indium tungsten oxide IWO, aluminum-doped zinc oxide AZO, and tin fluoride oxide TFO.

[0044] In some embodiments, the optical interference buffer layer 15 can adopt a material for realizing the corresponding function of the second transport layer 14, but is different from the material adopted by the second transport layer 14. By setting the optical interference buffer layer 15, on the one hand, it can be used to form a multi-layer antireflection structure and improve light transmittance, and on the other hand, it can play a buffering role and improve the overall stability and anti-deformation ability of the solar cell.

[0045] In some embodiments, the optical interference buffer layer 15 can adopt at least one of an alumina layer and a tin oxide layer.

[0046] In some embodiments, the first optical interference film layer 17 can adopt a transparent material with a refractive index greater than the refractive index of air and less than the refractive index of the second transparent conductive layer 16.

[0047] In some embodiments, the first optical interference film layer 17 is at least one of a silicon oxide film layer, a silicon nitride film layer, a magnesium fluoride film layer, and a silicon-aluminum mixture film layer.

[0048] In some embodiments, the layer thicknesses of the respective layers in the solar cell can be flexibly set based on requirements.

[0049] In some embodiments, the thickness of the second transparent conductive layer 16 can be set based on the requirement of conductivity. In some embodiments, the thickness of the second transparent conductive layer 16 can be 30 - 200 nm.

[0050] In some embodiments, the thicknesses of the optical interference buffer layer 15 and the first optical interference film layer 17 can be set in coordination with the thickness of the second transparent conductive layer 16 to achieve an antireflection effect on light within a desired wavelength range.

[0051] In some embodiments, the thickness of the optical interference buffer layer 15 can be 10 - 50 nm.

[0052] The above is a solar cell provided by an embodiment of the present application, which includes a first transparent conductive layer 11, a first transport layer 12, an active layer 13, a second transport layer 14, an optical interference buffer layer 15, a second transparent conductive layer 16, and a first optical interference film layer 17 sequentially arranged on one side surface of a substrate 10. The optical interference buffer layer 15, the second transparent conductive layer 16, and the first optical interference film layer 17 form a multilayer antireflection structure; wherein, the refractive indices of the first optical interference film layer 17 and the optical interference buffer layer 15 are both less than the refractive index of the second transparent conductive layer 16. In this solution, the first optical interference film layer 17, the second transparent conductive layer 16, and the optical interference buffer layer 15 form a multilayer antireflection structure with an alternating arrangement of low refractive index - high refractive index - low refractive index. While ensuring conductivity, it can effectively reduce light reflection, improve light transmittance, and broaden the effective wavelength range of the antireflection effect through the multilayer interference effect.

[0053] See Figure 2 and Figure 3 shown in Figure 2 and Figure 3 are schematic cross-sectional structure diagrams of a solar cell provided with an optical interference stack structure according to an embodiment of the present application. Among them, the optical interference stack structure and the first interference buffer layer 17 form an odd number of optical interference film layers, and further combine with the second transparent conductive layer 16 and the optical interference buffer layer 17 to form a more-layered antireflection structure. And in this multilayer antireflection structure, the refractive indices of the even layers and their two adjacent layers are arranged in a low - high - low pattern, which can further improve the light transmittance.

[0054] Figure 2 and Figure 3 The solar cells corresponding to the corresponding embodiments can all be realized based on Figure 1 the corresponding solar cell, and are the same asFigure 1 compared with the corresponding solar cell Figure 2 and Figure 3 the solar cell provided by the corresponding embodiment may further include an optical interference stack structure 21, and the optical interference stack structure 21 is disposed on the surface of the first optical interference film layer 17 away from the second transparent conductive layer 16.

[0055] The optical interference stack structure 21 includes at least one group of second optical interference film layers 211 and third optical interference film layers 212 alternately stacked in the direction away from the second transparent conductive layer 16 of the first optical interference film layer 17. The refractive index of the third optical interference film layer 212 is less than that of the adjacent second optical interference film layer 211, and the refractive index of the first optical interference film layer 17 is less than that of the adjacent second optical interference film layer 211.

[0056] By providing at least one group of optical interference stack structures 21 with alternating low and high refractive indices, the optical interference stack structure 21, the first optical interference film layer 17, the second transparent conductive layer 16, and the optical interference buffer layer 15 further form a multi-layer antireflection structure, which is beneficial to achieving antireflection effects in different optical wavelength ranges.

[0057] In some embodiments, referring to Figure 2 as shown Figure 2 exemplarily shows that the optical interference stack structure 21 includes a group of second optical interference film layers 211 and third optical interference film layers 212 alternately stacked, wherein the second optical interference film layer 211 is disposed on the surface of the first optical interference film layer 17 away from the second transparent conductive layer 16, and the third optical interference film layer 212 is disposed on the surface of the second optical interference film layer 211 away from the first optical interference film layer 17.

[0058] Wherein, the refractive index of the third optical interference film layer 212 is less than that of the second optical interference film layer 211, and the refractive index of the first optical interference film layer 17 is less than that of the second optical interference film layer 211. The refractive indices of the third optical interference film layer 212, the second optical interference film layer 211, the first optical interference film layer 17, the second transparent conductive layer 16, and the optical interference buffer layer 15 are arranged in a low-high-low-high-low trend.

[0059] In some embodiments, the second optical interference film layer 211 may be at least one of a titanium oxide film layer, a niobium oxide film layer, a yttrium fluoride film layer, a tantalum oxide film layer, and a hafnium oxide film layer.

[0060] In some embodiments, the third optical interference film layer 212 may be at least one of a silicon oxide film layer, a silicon nitride film layer, a magnesium fluoride film layer, and a silicon-aluminum mixture film layer.

[0061] In some other embodiments, the second optical interference film layer 211 may be made of a material with a refractive index greater than 2, and the third optical interference film layer 212 may be made of a material with a refractive index less than 2.

[0062] In the embodiments of the present application, the thicknesses of the second optical interference film layer 211 and the third optical interference film layer 212 can both be flexibly set based on actual requirements.

[0063] In some embodiments, referring to Figure 3 as shown Figure 3 exemplarily shows that the optical interference stack structure 21 includes multiple groups of second optical interference film layers 211 and third optical interference film layers 212 alternately stacked in a direction away from the second transparent conductive layer 16 on one side of the first optical interference film layer 17. Among them, the second optical interference film layer 211 is disposed on the surface of the first optical interference film layer 17 away from the second transparent conductive layer 16.

[0064] Among them, the refractive index of the third optical interference film layer 212 is less than that of the adjacent second optical interference film layer 211. The second optical interference film layer 211 adjacent to the third optical interference film layer 212 may include the second optical interference film layer of the same group as it, or include the second optical interference film layer of the same group as it and the second optical interference film layer of a different group adjacent to it. As an example, when the optical interference stack structure 21 includes two groups of second optical interference film layers 211 and third optical interference film layers 212 alternately stacked, in the direction away from the second transparent conductive layer 16 on one side of the first optical interference film layer 17, in sequence, the second optical interference film layer 211 is disposed on the first layer, the third optical interference film layer 212 is disposed on the second layer, the second optical interference film layer 211 is disposed on the third layer, and the third optical interference film layer 212 is disposed on the fourth layer. The refractive index of the third optical interference film layer 212 disposed on the second layer is less than the refractive indices of the second optical interference film layer 211 disposed on the first layer of the same group and the second optical interference film layer 211 disposed on the third layer of an adjacent and different group. The refractive index of the third optical interference film layer 212 disposed on the fourth layer is less than the refractive index of the second optical interference film layer 211 disposed on the third layer of the same group.

[0065] The refractive index of the first optical interference film layer 17 is less than that of the adjacent second optical interference film layer 211. Based on the above example, that is, the refractive index of the first optical interference film layer 17 is less than the refractive index of the second optical interference film layer 211 disposed on the first layer adjacent to it.

[0066] In this embodiment, at least one optical interference stack structure 21 with a low refractive index - high refractive index periodic arrangement is formed. After combining the first optical interference film layer 17, the second transparent conductive layer 16, and the optical interference buffer layer 15, an antireflection structure with a low - high alternating periodic refractive index arrangement and both outermost layers being low refractive index layers is obtained.

[0067] It should be noted that in the embodiments of the present application, "low" or "high" when describing the refractive index arrangement trend may refer to the refractive index of a corresponding layer being "low" or "high" relative to its adjacent layer.

[0068] In some embodiments, when the optical interference stack structure 21 includes multiple sets of second optical interference film layers 211 and third optical interference film layers 212 that are alternately stacked in a direction away from the second transparent conductive layer 16 of the first optical interference film layer 17, the second optical interference film layers 211 in different sets may be the same or different, and the third optical interference film layers 212 in different sets may be the same or different.

[0069] In some embodiments, the materials of the second optical interference film layers 211 in different sets may be the same or different.

[0070] In some embodiments, the second optical interference film layer 211 may adopt at least one of a titanium oxide film layer, a niobium oxide film layer, a yttrium fluoride film layer, a tantalum oxide film layer, and a hafnium oxide film layer.

[0071] In some embodiments, the materials of the third optical interference film layers 212 in different sets may be the same or different.

[0072] In some embodiments, the third optical interference film layer 212 may adopt at least one of a silicon oxide film layer, a silicon nitride film layer, a magnesium fluoride film layer, and a silicon-aluminum mixture film layer.

[0073] In some other embodiments, the second optical interference film layer 211 may adopt a material with a refractive index greater than 2, and the third optical interference film layer 212 may adopt a material with a refractive index less than 2.

[0074] In the embodiments of the present application, the thicknesses of the second optical interference film layers 211 and the third optical interference film layers 212 in different sets can be flexibly set based on actual requirements.

[0075] The above is the solar cell provided by another embodiment of the present application, which can achieve the same beneficial effects as the Figure 1 corresponding embodiment, and by setting the optical interference stack structure on the basis of the Figure 1 corresponding embodiment, more layers of antireflection results can be further formed to achieve antireflection effects in different optical wavelength ranges.

[0076] In some other embodiments, in order to further improve the light transmittance, the solar cell may also be provided with an antireflection layer. For specific details, please refer to the description of the following embodiments. It should be noted that this embodiment can be implemented based on any of the above embodiments. Here, it is described by taking the implementation based on the Figure 1 corresponding embodiment as an example.

[0077] See Figure 4 as shown in Figure 4It is a schematic cross-sectional structure diagram of a solar cell provided with an antireflection layer according to an embodiment of the present application.

[0078] On the basis of this, the solar cell further includes an antireflection layer 41 disposed between the substrate 10 and the first transparent conductive layer 11. Figure 1 On the basis of this, the solar cell further includes an antireflection layer 41 disposed between the substrate 10 and the first transparent conductive layer 11.

[0079] Among them, the refractive index of the antireflection layer 41 can be greater than the refractive index of the substrate 10 and less than the refractive index of the first transparent conductive layer 11 to play an antireflection role.

[0080] In some embodiments, the solar cell may further include a plurality of scribing grooves to divide the entire solar cell into a plurality of independent sub-cell units and connect the plurality of sub-cell units in series. For specific details, please refer to the description of the following embodiments. It should be noted that this embodiment can be implemented based on any of the above embodiments. Here, it is described by taking the implementation based on Figure 1 the corresponding embodiment as an example.

[0081] Referring to Figure 5 , Figure 5 It is a schematic cross-sectional structure diagram of a solar cell provided by another embodiment of the present application. The solar cell further includes a first scribing groove P1 penetrating through the first transparent conductive layer 11, a second scribing groove P2 penetrating through the first transparent conductive layer 11, the first transmission layer 12, the active layer 13, the second transmission layer 14, and the optical interference buffer layer 15, and a third scribing groove P3 penetrating through the first transparent conductive layer 11, the first transmission layer 12, the active layer 13, the second transmission layer 14, the optical interference buffer layer 15, and the second transparent conductive layer 16.

[0082] The second transparent conductive layer 16 covers the optical interference buffer layer 15 and the second scribing groove P2, and the first optical interference film layer 17 covers the second transparent conductive layer 16 and the third scribing groove P3.

[0083] On the other hand, the present application provides a method for manufacturing a solar cell. Referring to Figure 6 shown in Figure 6 It is a schematic flowchart of a method for manufacturing a solar cell provided by an embodiment of the present application, which may include:

[0084] Step S61: Sequentially form a first transparent conductive layer 11, a first transmission layer 12, an active layer 13, a second transmission layer 14, an optical interference buffer layer 15, a second transparent conductive layer 16, and a first optical interference film layer 17 on the substrate 10.

[0085] Among them, the optical interference buffer layer 15, the second transparent conductive layer 16, and the first optical interference film layer 17 form a multilayer antireflection structure, and the refractive indices of the first optical interference film layer 17 and the optical interference buffer layer 15 are both less than the refractive index of the second transparent conductive layer 16.

[0086] In some embodiments, the first transparent conductive layer 11, the first transport layer 12, the active layer 13, and the second transport layer 14 are sequentially formed on the substrate 10, and can be prepared by conventional processes for the corresponding layers in the art.

[0087] In some embodiments, forming the optical interference buffer layer 15 may be to form the optical interference buffer layer 15 on the second transport layer 14 by using the ALD (Atomic Layer Deposition) process.

[0088] In some embodiments, the second transparent conductive layer 16 and the first optical interference film layer 17 may be sequentially formed on the optical interference buffer layer 15 by using magnetron sputtering.

[0089] Among them, each layer can be set in the same manner as the corresponding layer in the Figure 1 corresponding embodiment, and achieve the same beneficial effects as the Figure 1 corresponding embodiment.

[0090] In other embodiments, as Figure 7 shown, Figure 7 is a schematic flow chart of a method for preparing a solar cell provided in another embodiment of the present application. The method includes:

[0091] Step S71: Sequentially form a first transparent conductive layer 11, a first transport layer 12, an active layer 13, a second transport layer 14, an optical interference buffer layer 15, a second transparent conductive layer 16, and a first optical interference film layer 17 on the substrate 10.

[0092] The technical details of this step can refer to the description of step S61 in the above Figure 6 and will not be elaborated here.

[0093] Step S72: Form an optical interference stack structure 21 on the surface of the first optical interference film layer 17 on the side away from the second transparent conductive layer 16.

[0094] In some embodiments, the optical interference stack structure 21 can be formed on the surface of the first optical interference film layer 17 on the side away from the second transparent conductive layer 16 by using magnetron sputtering.

[0001] The interference stack structure 21 can be set in the same way as the interference stack structure in the above Figure 2 or Figure 3 corresponding embodiment, such as Figure 2 or Figure 3As shown, the optical interference stack structure 21 may include at least one set of second optical interference film layers 211 and third optical interference film layers 212 that are alternately stacked in a direction away from the second transparent conductive layer 16 on one side of the first optical interference film layer 17. The refractive index of the second optical interference film layer 211 is greater than that of the third optical interference film layer 212. This can further improve the light transmittance and broaden the effective wavelength range of the antireflection effect through the multi-layer interference effect.

[0002] In some other embodiments, before forming the first transparent conductive layer 11 on the substrate 10, the method may further include: forming an antireflection layer 41 on the substrate 10. This is to further improve the light transmittance and thus improve the photoelectric conversion efficiency of the solar cell.

[0003] In some embodiments, referring to Figure 8 as shown, Figure 8 is a schematic flowchart of a method for manufacturing a solar cell provided in another embodiment of the present application. The method may further include:

[0004] Step S81: Form a first transparent conductive layer 11 on the substrate 10;

[0005] Step S82: Laser-etch the first transparent conductive layer 11 to form a first scribing groove P1;

[0006] Step S83: Form a first transport layer 12 covering the first transparent conductive layer 11 and the first scribing groove P1;

[0007] Step S84: Sequentially form an active layer 13, a second transport layer 14, and an optical interference buffer layer 15 on the first transport layer 12;

[0008] Step S85: Laser-etch the first transparent conductive layer 11, the first transport layer 12, the active layer 13, the second transport layer 14, and the optical interference buffer layer 15 to form a second scribing groove P2;

[0009] Step S86: Form a second transparent conductive layer 16 covering the optical interference buffer layer 15 and the second scribing groove P2;

[0010] Step S87: Laser-etch the first transparent conductive layer 11, the first transport layer 12, the active layer 13, the second transport layer 14, the optical interference buffer layer 15, and the second transparent conductive layer 16 to form a third scribing groove P3;

[0011] Step S88: Form a first optical interference film layer 17 covering the second transparent conductive layer 16 and the third scribing groove P3.

[0012] In some embodiments, step S81 may specifically be to form FTO on the substrate 10 by magnetron sputtering as the first transparent conductive layer 11.

[0013] In some embodiments, the thickness of the FTO can be 100 nm.

[0014] In some embodiments, step S82 can specifically be to etch the first transparent conductive layer 11 using a 532 nm green laser to form a first scribing groove P1.

[0015] In some embodiments, step S83 can specifically be to form a first transmission layer 12 covering the first transparent conductive layer 11 and the first scribing groove P1 by magnetron sputtering.

[0016] In some embodiments, the first transmission layer 12 can be a hole transport layer, and the hole transport layer can be made of nickel oxide (NiOx). In other embodiments, the hole transport layer can also be made of other materials that can achieve the same function.

[0017] In some embodiments, forming the active layer 13 on the first transmission layer 12 in step S84 can specifically be to form the active layer 13 on the first transmission layer 12 by bar coating.

[0018] In some embodiments, forming the active layer 13 on the first transmission layer 12 by bar coating can specifically be: preparing a 0.6 M (moles per liter) concentration of FAPbI3 (formamidinium iodide-based perovskite), dissolving it in a DMF (N,N-dimethylformamide) / DMSO (dimethyl sulfoxide) solvent with a volume ratio of 4:1, using a coating rate of 6 mm / s (millimeters per second) for coating, then using a nitrogen gun to blow air to remove the excess solvent until it turns dark yellow, and then annealing at 150 °C for 15 min.

[0019] In some embodiments, forming the second transmission layer 14 in step S84 can specifically be to form the second transmission layer 14 by vacuum evaporation.

[0020] In some embodiments, when the first transmission layer 12 is a hole transport layer, the second transmission layer 14 can be an electron transport layer.

[0021] In some embodiments, the thickness of the second transmission layer 14 can be 25 nm.

[0022] In some embodiments, forming the optical interference buffer layer 15 in step S84 can specifically be to form the optical interference buffer layer 15 on the second transmission layer 14 using ALD technology.

[0023] In some embodiments, the optical interference buffer layer 15 can be made of alumina material.

[0024] In some embodiments, the thickness of the optical interference buffer layer 15 can be 15 nm.

[0025] In some embodiments, step S85 may specifically be to use a green laser to etch the first transparent conductive layer 11, the first transport layer 12, the active layer 13, the second transport layer 14, and the optical interference buffer layer 15 to form a second scribing groove P2.

[0026] In some embodiments, step S86 may specifically be to use magnetron sputtering to form a second transparent conductive layer 16 covering the optical interference buffer layer 15 and the second scribing groove P2.

[0027] In some embodiments, the second transparent conductive layer 16 may be made of ITO material.

[0028] In some embodiments, the thickness of the second transparent conductive layer 16 may be 70 nm.

[0029] In some embodiments, step S87 may specifically be to use a red laser to etch the first transparent conductive layer 11, the first transport layer 12, the active layer 13, the second transport layer 14, the optical interference buffer layer 15, and the second transparent conductive layer 16 to form a third scribing groove P3.

[0030] Step S88 may specifically be to use magnetron sputtering to form a first optical interference film layer 17 covering the second transparent conductive layer 16 and the third scribing groove P3.

[0031] In some embodiments, the first optical interference film layer 17 may be made of silicon dioxide material, and the thickness of the first optical interference film layer 17 may be 35 nm.

[0032] In other embodiments, as Figure 2 shown, a second optical interference film layer 211 and a third optical interference film layer 212 may also be formed on the first optical interference film layer 17.

[0033] In some embodiments, the second optical interference film layer 211 may be made of titanium dioxide material. The thickness of the second optical interference film layer 211 may be 10 nm.

[0034] In some embodiments, the third optical interference film layer 212 may be made of magnesium fluoride material.

[0035] The thickness of the third optical interference film layer 212 may be 120 nm.

[0036] In some embodiments, the method may further include laser edge cleaning and encapsulation testing of the solar cell.

[0037] The solar cell provided by this application can effectively improve the light transmittance. Refer to Figure 9 shown, Figure 9The figure shows a comparison schematic diagram of the overall transmittance of the composite film on the upper surface of the active layer in the 380nm - 1200nm band for a solar cell prepared by a conventional process and a solar cell provided in this application. Among them, the thinner black line represents the transmittance curve corresponding to the solar cell prepared by the conventional process, and the thicker black line represents the transmittance curve corresponding to the solar cell provided in this application. The abscissa in the figure represents the wavelength, and the ordinate represents the transmittance. The upper surface refers to the surface of the active layer on the side away from the substrate.

[0038] It should be noted that the multi-layer antireflection structure or the multi-layer antireflection structure combined with the optical interference stacking structure 21 provided in this application can also be adaptively applied to crystalline silicon-perovskite tandem devices and perovskite-perovskite tandem devices, and achieve the same beneficial effects as the solar cell of this proposal.

[0039] So far, the technical solution of this application has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of this application is obviously not limited to these specific embodiments. Without departing from the principle of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of this application.

Claims

1. A solar cell, characterized in that: The invention comprises a first transparent conductive layer, a first transmission layer, an active layer, a second transmission layer, a light interference buffer layer, a second transparent conductive layer and a first light interference film layer which are sequentially arranged on a surface of one side of a substrate, wherein the light interference buffer layer, the second transparent conductive layer and the first light interference film layer form a multi-layer anti-reflection structure; The refractive indexes of the first light interference film layer and the light interference buffer layer are both smaller than the refractive index of the second transparent conductive layer.

2. The solar cell according to claim 1, characterized in that The solar cell further comprises a light interference stacking structure, and the light interference stacking structure is arranged on a surface of the first light interference film layer away from the second transparent conductive layer; The optical interference stacking structure includes at least one group of second optical interference film layers and third optical interference film layers alternately stacked in a direction away from the second transparent conductive layer on the first optical interference film layer, the refractive index of the third optical interference film layer is smaller than the refractive index of the second optical interference film layer adjacent to it, and the refractive index of the first optical interference film layer is smaller than the refractive index of the second optical interference film layer adjacent to it.

3. The solar cell according to claim 2, characterized in that: When the optical interference stacking structure includes multiple groups of second optical interference film layers and third optical interference film layers alternately stacked in a direction away from the first optical interference film layer on the side of the second transparent conductive layer, the second optical interference film layers in different groups are the same or different, and the third optical interference film layers in different groups are the same or different.

4. The solar cell according to any one of claims 1 to 3, characterized in that The optical interference buffer layer is made of at least one of an aluminum oxide layer and a tin oxide layer.

5. The solar cell according to any one of claims 1 to 3, characterized in that The thickness of the optical interference buffer layer is 10-50 nm.

6. The solar cell according to any one of claims 2 or 3, characterized in that: The second light interference film layer is at least one of a titanium oxide film layer, a niobium oxide film layer, an yttrium fluoride film layer, a tantalum oxide film layer and a hafnium oxide film layer.

7. The solar cell according to any one of claims 2 or 3, characterized in that: The third light interference film layer or the first light interference film layer is made of at least one of a silicon oxide film layer, a silicon nitride film layer, a magnesium fluoride film layer and a silicon-aluminum mixture film layer.

8. The solar cell according to any one of claims 1 to 3, characterized in that: The thickness of the second transparent conductive layer is 30-200 nm.

9. The solar cell according to claim 1, characterized in that: The solar cell further includes an anti-reflection layer disposed between the substrate and the first transparent conductive layer.

10. A method for preparing a solar cell, characterized in that: include: A first transparent conductive layer, a first transmission layer, an active layer, a second transmission layer, a light interference buffer layer, a second transparent conductive layer and a first light interference film layer are sequentially formed on a substrate; The light interference buffer layer, the second transparent conductive layer and the first light interference film layer form a multi-layer anti-reflection structure, and the refractive indexes of the first light interference film layer and the light interference buffer layer are both smaller than the refractive index of the second transparent conductive layer.

11. The method according to claim 10, characterized in that The method further comprises: forming an optical interference stacking structure on a surface of the first optical interference film layer away from the second transparent conductive layer; The optical interference stacking structure includes at least one group of second optical interference film layers and third optical interference film layers alternately stacked in a direction away from the second transparent conductive layer on the first optical interference film layer, and the refractive index of the second optical interference film layer is greater than the refractive index of the third optical interference film layer.

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