Solar cell substrate, solar cell and electrical device

Abstract

This application discloses a substrate for a solar cell, a solar cell, and an electrical device. The substrate includes a first substrate, a second substrate, and a sealing film. The first substrate includes a first refractive portion. The second substrate is stacked on one side of the first substrate and includes a second refractive portion. The refractive index of the second substrate is greater than that of the first substrate. Along the direction from the first substrate to the second substrate, the cross-section of the first refractive portion gradually decreases, and the cross-section of the second refractive portion gradually increases. At least a portion of the second refractive portion is located on the periphery of the first refractive portion. The sealing film is disposed between the first and second refractive portions. In the thickness direction of the first and second substrates, the cross-sectional shape of the sealing film is adapted to the contour shape of the first refractive portion facing the second substrate and the contour shape of the second refractive portion facing the first substrate.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a solar cell substrate, a solar cell and an electrical device. Background Art

[0002] The development of semiconductor technology plays a vital role in the progress of the electronics industry. As a new type of semiconductor, perovskite has many advantages such as long carrier diffusion length, high defect tolerance, adjustable band gap, and large absorption coefficient. Compared with traditional organic and inorganic semiconductors, perovskite has a simple preparation process and low cost, which has great advantages in the semiconductor field. Up to now, the efficiency of perovskite solar cells has exceeded 26%, and T95 has exceeded thousands of hours. In addition, it has been studied and applied in light-emitting diodes, detectors, lasers, etc. As an emerging semiconductor material, perovskite shows great potential.

[0003] Currently, the photoelectric conversion efficiency of perovskite cells is low. Summary of the invention

[0004] The purpose of the present application is to provide a solar cell substrate, a solar cell and an electrical device, which can improve the photoelectric conversion efficiency of the cell.

[0005] In a first aspect, the present application provides a substrate for a solar cell, comprising a first substrate and a second substrate, the first substrate comprising a first refractive portion; the second substrate is stacked on one side of the first substrate, the second substrate comprising a second refractive portion, wherein a refractive index of the second substrate is greater than a refractive index of the first substrate, and along a direction from the first substrate toward the second substrate, a cross-section of the first refractive portion gradually decreases, and a cross-section of the second refractive portion gradually increases, and at least a portion of the second refractive portion is located on a peripheral side of the first refractive portion; the substrate also comprises a sealing film, the sealing film is arranged between the first refractive portion and the second refractive portion, and in a thickness direction of the first substrate and the second substrate, a cross-sectional shape of the sealing film is adapted to a contour shape of the first refractive portion toward the second substrate side and a contour shape of the second refractive portion toward the first substrate side.

[0006] In some embodiments, in the thickness direction of the first substrate and the second substrate, the cross-sectional shape of the first refractive portion and / or the second refractive portion is any one of a triangle, a semicircle, a semi-ellipse, and a trapezoid.

[0007] In some embodiments, the first refractive portion and / or the second refractive portion is any one of a triangular prism structure, a triangular pyramid structure, and a cone structure.

[0008] In some embodiments, the number of first refraction parts and the number of second refraction parts are respectively plural, the multiple first refraction parts and the multiple second refraction parts are arranged in an array along a direction parallel to the first substrate and the second substrate, and one second refraction part is located between two adjacent first refraction parts.

[0009] In some embodiments, the first substrate also includes a first main body, and the multiple first refractive parts are respectively arranged on the side of the first main body facing the second refractive part; and / or, the second substrate also includes a second main body, and the multiple second refractive parts are arranged on the side of the second main body facing the first refractive part.

[0010] In some embodiments, the thickness L1 of the sealing film satisfies 1 nm≤L1≤1000 nm.

[0011] In some embodiments, the refractive index of the sealing film is greater than the refractive index of the first substrate and less than the refractive index of the second substrate;

[0012] In some embodiments, the refractive index N1 of the first substrate satisfies: 1.4≤N1≤1.64, the refractive index N2 of the sealing film satisfies: 1.6≤N2≤1.65, and the refractive index N3 of the second substrate satisfies: 1.6≤N3≤1.9.

[0013] In some embodiments, the material of the first substrate and / or the second substrate includes an organic material; and / or the material of the sealing film includes an inorganic material;

[0014] In some embodiments, the material of the first substrate includes at least one of PET and PMMA; and / or, the material of the sealing film includes at least one of Al2O3 and SiO2; and / or, the material of the second substrate includes at least one of PEN and CPI.

[0015] In some embodiments, along a direction parallel to the first substrate, a width L2 of the first refractive portion away from the second substrate side satisfies: 100 nanometers ≤ L2 ≤ 300 nanometers, and along a thickness direction of the first substrate, a height H1 of the first refractive portion satisfies: 100 nanometers ≤ H1 ≤ 600 nanometers; and / or, along a direction parallel to the second substrate, a width L3 of the second refractive portion away from the first substrate satisfies: 100 nanometers ≤ L3 ≤ 300 nanometers, and along a thickness direction of the second substrate, a height H2 of the second refractive portion satisfies: 100 nanometers ≤ H2 ≤ 600 nanometers.

[0016] A second aspect of the present application provides a solar cell, comprising any of the above substrates and a battery cell, wherein the battery cell is arranged on a side of the second substrate of the substrate away from the first substrate, and the battery cell comprises a first electrode, a photosensitive layer, and a second electrode arranged in a stacked manner.

[0017] In some embodiments, the first electrode is located between the substrate and the photosensitive layer, and the refractive index of the first electrode is greater than the refractive index of the second substrate;

[0018] Preferably, the refractive index N4 of the first electrode satisfies: 1.8≤N4≤2.1.

[0019] A third aspect of the present application provides an electrical device, comprising the above-mentioned solar cell.

[0020] The embodiments of the present application provide a substrate, a battery and an electrical device for a solar cell, wherein the substrate comprises a first substrate and a second substrate, wherein the first substrate comprises a first refractive portion, the second substrate is stacked on one side of the first substrate, the second substrate comprises a second refractive portion, the refractive index of the second substrate is greater than the refractive index of the first substrate, and since at least part of the second refractive portion is located on the peripheral side of the first refractive portion, and along the direction from the first substrate to the second substrate, the cross-section of the first refractive portion gradually decreases, and the cross-section of the second refractive portion gradually increases, therefore, the refractive index of the substrate can increase gradually in the direction from the first substrate to the second substrate, at this time, the side of the first refractive portion facing the second refractive portion and the side of the second refractive portion facing the first refractive portion can both be used to refract light to change the propagation path of the light, reduce the amount of light directly reflected at the junction of the first substrate and the second substrate, so that more light can pass through the substrate, thereby improving the light transmittance of the substrate, and thereby improving the photoelectric conversion efficiency of the solar cell. In addition, a sealing film is arranged between the first refractive part and the second refractive part, so that the cross-section of the sealing film in the thickness direction of the first substrate and the second substrate can be adapted to the contour shape of the first refractive part facing the second substrate, and also to the contour shape of the second refractive part facing the first substrate. At this time, the sealing film is approximately concave-convex, which can increase the contact area between the sealing film and the first substrate and the second substrate on the one hand, thereby improving its sealing performance, and on the other hand, can also improve the bending performance of the sealing film, so that the sealing film can evenly disperse the stress it is subjected to, and reduce the risk of cracks or even breakage due to stress concentration. When the substrate is a flexible substrate, the sealing film can adapt to the bending of the substrate in various shapes and angles to ensure its sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A schematic cross-sectional view of a substrate provided in some embodiments of the present application;

[0023] Figure 2 A top view of a first substrate or a second substrate in a substrate provided in some embodiments of the present application;

[0024] Figure 3 Another top view of the first substrate or the second substrate in the substrate provided in some embodiments of the present application;

[0025] Figure 4 Another top view of the first substrate or the second substrate in the substrate provided in some embodiments of the present application;

[0026] Figure 5 A graph showing a change in the refractive index of a solar cell provided in some embodiments of the present application;

[0027] Figure 6 A schematic cross-sectional view of a substrate provided in some other embodiments of the present application;

[0028] Figure 7 A schematic diagram of the structure of an electron beam winding coating device provided in some embodiments of the present application;

[0029] Figure 8 A schematic cross-sectional view of a solar cell provided in some embodiments of the present application.

[0030] The figures are as follows:

[0031] Substrate 10 ; first substrate 11 ; first refraction portion 111 ; first main body portion 112 ; second substrate 12 ; second refraction portion 121 ; second main body portion 122 ; sealing film 13 ; battery cell 20 ; first electrode 21 ; photosensitive layer 22 ; second electrode 23 ; flexible packaging cover 30 . DETAILED DESCRIPTION

[0032] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0033] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0034] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0035] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of this application. In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0036] See also Figure 1 In a first aspect, the present application provides a substrate 10 for a solar cell, comprising a first substrate 11 and a second substrate 12, wherein the first substrate 11 comprises a first refractive portion 111; the second substrate 12 is stacked on one side of the first substrate 11, and the second substrate 12 comprises a second refractive portion 121, wherein a refractive index of the second substrate 12 is greater than a refractive index of the first substrate 11, and along a direction from the first substrate 11 to the second substrate 12, a cross-section of the first refractive portion 111 gradually decreases, and a cross-section of the second refractive portion 121 gradually increases, and at least a portion of the second refractive portion 121 is located on the peripheral side of the first refractive portion 111.

[0037] The substrate 10 includes a first substrate 11 and a second substrate 12. The first substrate 11 and the second substrate 12 can be a hard substrate made of materials such as glass or plastic, or can be a flexible substrate made of materials such as polyethersulfone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyarylate, polyimide (PI), polycarbonate (PC) or cellulose acetate propionate (CAP).

[0038] Specifically, when the battery cell 20 of the solar cell is arranged on the side of the second substrate 12 away from the first substrate 11, light is transmitted from the air through the first substrate 11 and the second substrate 12 in sequence to the battery cell 20. Therefore, setting the refractive index of the second substrate 12 to be greater than the refractive index of the first substrate 11 can reduce the refractive index difference between the air and the substrate 10 and the refractive index difference between the substrate 10 and the battery cell 20, thereby facilitating light propagation and improving light transmittance.

[0039] It should be noted that when at least part of the second refractive portion 121 is located on the peripheral side of the first refractive portion 111, the second refractive portion 121 can be arranged around the outer peripheral side of the first refractive portion 111, or at least part of the second refractive portion 121 can also be arranged on one side of the first refractive portion 111 along a direction parallel to the first substrate 11 and the second substrate 12, which is not limited in this embodiment. Along the direction parallel to the first substrate 11 and the second substrate 12, the first refractive portion 111 and the second refractive portion 121 can be arranged at intervals. At this time, a filling medium can be arranged in the gap between the first refractive portion 111 and the second refractive portion 121, and the refractive index of the filling medium is between the refractive index of the first refractive portion 111 and the refractive index of the second refractive portion 121; or the first refractive portion 111 and the second refractive portion 121 can also be arranged in close contact, that is, the side of the first refractive portion 111 facing the second refractive portion 121 is in close contact with the side of the second refractive portion 121 facing the first refractive portion 111. It should be noted that, in this embodiment, the cross-section of the first refractive portion 111 refers to the cross-section of the first refractive portion 111 on the plane where the length direction and the width direction of the first substrate 11 are located, and the cross-section of the second refractive portion 121 refers to the cross-section of the second refractive portion 121 on the plane where the length direction and the width direction of the second substrate 12 are located.

[0040] The inventors have found that the reason why the photoelectric conversion efficiency of solar cells is low is that a large amount of incident light is lost at the substrate 10. When the light enters the cell through the substrate 10, it is easily reflected by the substrate 10, resulting in light loss. Therefore, the embodiment of the present application provides a substrate 10 for a solar cell, which includes a first substrate 11 and a second substrate 12. The first substrate 11 includes a first refractive portion 111. The second substrate 12 is stacked on one side of the first substrate 11. The second substrate 12 includes a second refractive portion 121. The refractive index of the second substrate 12 is greater than the refractive index of the first substrate 11. Moreover, since at least part of the second refractive portion 121 is located on the peripheral side of the first refractive portion 111, and along the direction from the first substrate 11 to the second substrate 12, the cross-section of the first refractive portion 111 gradually decreases, and the cross-section of the second refractive portion 121 gradually increases. Therefore, the substrate The refractive index of the board 10 can increase gradually in the direction from the first substrate 11 to the second substrate 12, which can reduce the amount of light reflected by the substrate and improve the light transmittance of the substrate. At the same time, the side of the first refractive portion 111 toward the second refractive portion 121 and the side of the second refractive portion 121 toward the first refractive portion 111 can be used to refract light to change the propagation path of the light and reduce the amount of light directly reflected at the junction of the first substrate 11 and the second substrate 12, so that more light can pass through the substrate 10, further improving the light transmittance of the substrate 10, and thereby improving the photoelectric conversion efficiency of the solar cell.

[0041] It can be understood that the structure of the substrate 10 in this embodiment can be similar to the moth-eye structure, which can refract the light multiple times to effectively reduce the reflection of the light, thereby increasing the transmittance of the light.

[0042] It should be noted that, during the preparation of the substrate 10, a first substrate 11 having a preset shape can be first formed by a compression molding process, so that the first substrate 11 includes a first refractive portion 111, and the cross-section of the first refractive portion 111 gradually decreases along the direction from the first substrate 11 to the second substrate 12; then, a second refractive portion 121 is formed on the first refractive portion 111. For example, the second refractive portion 121 can be formed on the first refractive portion 111 by a coating process, a compression molding process, and a deposition process, so that at least a portion of the second refractive portion 121 is located on the peripheral side of the first refractive portion 111, and the cross-section of the second refractive portion 121 gradually increases along the direction from the first substrate 11 to the second substrate 12.

[0043] In some embodiments, in the thickness direction of the first substrate 11 and the second substrate 12 , the cross-sectional shape of the first refractive portion 111 and / or the second refractive portion 121 is any one of a triangle, a semicircle, a semi-ellipse, and a trapezoid.

[0044] It should be noted that the cross-sectional shape of the first refractive portion 111 and the cross-sectional shape of the second refractive portion 121 may be the same or different, and this embodiment does not limit this. When the cross-sectional shape of the first refractive portion 111 and / or the second refractive portion 121 is a triangle or a trapezoid, the side of the first refractive portion 111 facing the second refractive portion 121 and / or the side of the second refractive portion 121 facing the first refractive portion 111 is an inclined plane, and when the cross-sectional shape of the first refractive portion 111 and / or the second refractive portion 121 is a semicircular, semi-elliptical, etc., the side of the first refractive portion 111 facing the second refractive portion 121 and / or the side of the second refractive portion 121 facing the first refractive portion 111 is a curved surface.

[0045] In these embodiments, by reasonably selecting the cross-sectional shape of the first refractive portion 111 and / or the second refractive portion 121, the substrate 10 can adapt to different light refraction requirements and improve the refraction effect of the side of the first refractive portion 111 facing the second refractive portion 121 and the side of the second refractive portion 121 facing the first refractive portion 111 on the light.

[0046] See also Figure 2-Figure 4 Preferably, the first refractive portion 111 and / or the second refractive portion 121 is any one of a triangular prism structure, a triangular pyramid structure and a cone structure, so that by reasonably selecting the shape of the first refractive portion 111 and / or the second refractive portion 121, the refraction effect of light is further improved, thereby improving the transmittance of the substrate 10.

[0047] It should be noted that the first refractive portion 111 and the second refractive portion 121 may be respectively Figure 2 In the triangular prism structure shown, when the second refractive portion 121 is arranged on the peripheral side of the first refractive portion 111, the first refractive portion 111 and the second refractive portion 121 are alternately arranged in a direction parallel to the substrate 10. When the light is transmitted from the first substrate 11 to the second substrate 12, the light is first incident on the first refractive portion 111 from the side of the first substrate 11 away from the second substrate 12, and is successively refracted into the second refractive portion 121 through the refraction effect of the first refractive portion 111 toward the side surface of the second refractive portion 121 and the refraction effect of the second refractive portion 121 toward the surface of the first refractive portion 111, and then passes through the second refractive portion 121 and is transmitted to the battery unit 20 for photoelectric conversion. In this process, the substrate 10 can be similar to the moth-eye structure, and can refract the light multiple times to effectively reduce the reflection of the light, increase the light transmittance of the substrate 10, and improve the photoelectric conversion efficiency of the solar cell.

[0048] Please continue reading Figure 1-Figure 5 In some embodiments, the number of the first refractive portions 111 and the number of the second refractive portions 121 are respectively multiple, and the multiple first refractive portions 111 and the multiple second refractive portions 121 are arranged in an array along a direction parallel to the first substrate 11 and the second substrate 12, and a second refractive portion 121 is located between two adjacent first refractive portions 111 to increase the probability of light refraction and further improve the transmittance of the substrate 10.

[0049] It should be noted that the number of first refractive parts 111 and the number of second refractive parts 121 can be reasonably selected in practical applications, and this embodiment does not limit this. The shapes of the multiple first refractive parts 111 can be the same or different, and the shapes of the multiple second refractive parts 121 can be the same or different.

[0050] A second refractive portion 121 is located between two adjacent first refractive portions 111, and a plurality of second refractive portions 121 can be arranged along the circumference of a first refractive portion 111. The shape of the second refractive portion 121 can be adapted to the shape of the gap between the two adjacent first refractive portions 111, so that the side of the first refractive portion 111 can be close to the side of the second refractive portion 121, that is, there is no gap between the first refractive portion 111 and the second refractive portion 121, thereby ensuring that the refractive index of the substrate 10 increases gradually along the direction from the first substrate 11 to the second substrate 12. Exemplarily, when the first refractive portion 111 is a conical structure, if two adjacent first refractive portions 111 are arranged in sequence, the second refractive portion 121 located between the two adjacent first refractive portions 111 can also be approximately a conical structure; or, if the two adjacent first refractive portions 111 are spaced by a preset distance, the second refractive portion 121 located between the two adjacent first refractive portions 111 can be approximately an inverted trapezoidal structure, and it is only necessary to ensure that there is no gap between the first refractive portion 111 and the second refractive portion 121.

[0051] Please continue reading Figure 1 Preferably, the first substrate 11 also includes a first main body portion 112, and the plurality of first refractive portions 111 are respectively arranged on one side of the first main body portion 112 facing the second refractive portion 121, so that the plurality of first refractive portions 111 are connected by the first main body portion 112, thereby improving the structural stability of the substrate 10.

[0052] Please continue reading Figure 1 Preferably, the second substrate 12 also includes a second main body portion 122, and a plurality of second refractive portions 121 are arranged on a side of the second main body portion 122 facing the first refractive portion 111, so that the plurality of second refractive portions 121 can be connected through the second main body portion 122 to further improve the structural stability of the substrate 10.

[0053] It should be noted that when the first substrate 11 includes a first main body portion 112 and the second substrate 12 includes a second main body portion 122, the first main body portion 112 and the second main body portion 122 are arranged relatively spaced apart, the first refractive portion 111 and the second refractive portion 121 are located between the first main body portion 112 and the second main body portion 122, and one second refractive portion 121 is located between two adjacent first refractive portions 111, that is, the multiple first refractive portions 111 and the multiple second refractive portions 121 are staggered and distributed along a direction parallel to the first substrate 11.

[0054] In some optional embodiments, the first main body portion 112 and the first refractive portion 111 are integrally formed, and the two are made of the same material and can be prepared using the same process to simplify the process steps.

[0055] In some optional embodiments, the second main body portion 122 and the second refractive portion 121 are integrally formed, and the two are made of the same material and can be prepared using the same process to simplify the process steps.

[0056] It should be noted that the same material means the same refractive index, therefore, the first main body portion 112 has the same refractive index as the first refractive portion 111, and the second main body portion 122 has the same refractive index as the second refractive portion 121. Figure 1 and Figure 5 In the substrate 10, the area of ​​the substrate 10 corresponding to the first main body 112 (ie Figure 1 and Figure 5 The refractive index of the first refractive portion 111 is constant, and the cross section of the first refractive portion 111 gradually decreases and the cross section of the second refractive portion 121 gradually increases along the direction from the first substrate 11 to the second substrate 12. Therefore, on the basis that the refractive index of the second substrate 12 is greater than the refractive index of the first substrate 11, the area between the first main body portion 112 and the second main body portion 122 of the substrate 10 (i.e. Figure 1 and Figure 5 The overall refractive index of the H2-H3 section in the substrate 10 gradually increases, and the area of ​​the substrate 10 corresponding to the second main body 122 (i.e. Figure 1 and Figure 5 The refractive index of the H3~H4 segment is constant.

[0057] See also Figure 6 In some embodiments, the substrate 10 further includes a sealing film 13, which is disposed between the first refractive portion 111 and the second refractive portion 121. In the thickness direction of the first substrate 11 and the second substrate 12, a cross-sectional shape of the sealing film 13 is adapted to a contour shape of the first refractive portion 111 toward the second refractive portion 121 and a contour shape of the second refractive portion 121 toward the first refractive portion 111.

[0058] In these embodiments, the sealing film 13 is generally a flexible film, which is extruded and arranged between the first refractive portion 111 and the second refractive portion 121, so that the cross-section of the sealing film 13 in the thickness direction of the first substrate 11 and the second substrate 12 can be adapted to the contour shape of the first refractive portion 111 facing the second substrate 12, and also adapted to the contour shape of the second refractive portion 121 facing the first substrate 11. At this time, the sealing film 13 is approximately concave and convex. On the one hand, the contact area between the sealing film 13 and the first substrate 11 and the second substrate 12 can be increased, thereby improving its sealing performance. On the other hand, the bending performance of the sealing film 13 can also be improved, so that the sealing film 13 can evenly disperse the stress it is subjected to, thereby reducing the risk of cracks or even breakage due to stress concentration. When the substrate 10 is a flexible substrate 10, the sealing film 13 can adapt to the bending of the substrate 10 in various shapes and angles to ensure its sealing effect.

[0059] It should be noted that when the substrate 10 includes a sealing film 13, during the preparation process of the substrate 10, a first substrate 11 with a preset shape can be first formed by a mold, so that the first substrate 11 includes a first refractive portion 111, and the cross-section of the first refractive portion 111 gradually decreases along the direction of the first substrate 11 toward the second substrate 12; then, the sealing film 13 can be formed on the first refractive portion 111. For example, the sealing film 13 can be formed on the first refractive portion 111 by atomic layer deposition technology or electron beam winding coating technology, so that the cross-sectional shape of the sealing film 13 in the thickness direction of the first substrate 11 and the second substrate 12 is adapted to the contour shape of the first refractive portion 111; finally, the second refractive portion 121 is formed on the side of the sealing film 13 away from the first refractive portion 111, so that the sealing film 13 is located between the first refractive portion 111 and the second refractive portion 121.

[0060] For example, in the case of Figure 7 In the process of forming the sealing film 13 by the electron beam winding coating equipment shown, the sealing film 13 material can be first placed in the crucible of the electron beam winding coating equipment, and the crucible is heated by an electron beam gun to evaporate the sealing film 13 material to the coating area. The material of the sealing film 13 can be a mixture of silicon dioxide and aluminum oxide. The evaporated sealing film 13 material is in a gas phase mixed state in the coating area, and is thus evaporated to the surface of the first refractive portion 111 to form the sealing film 13.

[0061] See also Figure 6 Preferably, the thickness L1 of the sealing film 13 satisfies 1 nm≤L1≤1000 nm, so as to ensure its sealing effect and bending performance.

[0062] It should be noted that the thickness of the sealing film 13 can be any value within the above range, such as 1 nanometer, 100 nanometers, 300 nanometers, 500 nanometers, 700 nanometers and 1000 nanometers, and this embodiment does not limit it. When the surface of the first refractive portion 111 facing the sealing film 13 is a plane, the thickness of the sealing film 13 refers to the dimension of the sealing film 13 in the direction perpendicular to the plane of the first refractive portion 111 facing the sealing film 13. When the surface of the first refractive portion 111 facing the sealing film 13 is a curved surface, the thickness of the sealing film 13 can be the dimension of the sealing film 13 in the normal direction corresponding to the curved surface.

[0063] In some embodiments, the refractive index of the sealing film 13 is greater than the refractive index of the first substrate 11 and less than the refractive index of the second substrate 12, so that the refractive index of the substrate 10 gradually increases from the first substrate 11 to the second substrate 12, so as to further improve the light transmittance of the substrate 10. It can be understood that the sealing film 13 is disposed between the first refractive portion 111 and the second refractive portion 121, and its refractive index is between the refractive index of the first refractive portion 111 and the refractive index of the second refractive portion 121. Therefore, the sealing film 13 can also refract light to a certain extent, change the propagation path of light, and further reduce the amount of light directly reflected in the substrate 10.

[0064] Preferably, the refractive index N1 of the first substrate 11 satisfies: 1.4≤N1≤1.64, the refractive index N2 of the sealing film 13 satisfies: 1.6≤N2≤1.65, and the refractive index N3 of the second substrate 12 satisfies: 1.6≤N3≤1.9, so that by reasonably setting the refractive indices of the first substrate 11, the sealing film 13 and the second substrate 12, the refractive indices of the three are adapted to further improve the light transmittance of the substrate 10.

[0065] It should be noted that the refractive index of the first substrate 11 is greater than or equal to 1.4 and less than or equal to 1.64. For example, the refractive index of the first substrate 11 may be 1.4, 1.45, 1.5, 1.53, 1.55, 1.6, 1.64, etc. The refractive index of the sealing film 13 is greater than or equal to 1.6 and less than or equal to 1.65. For example, the refractive index of the sealing film 13 may be 1.6, 1.61, 1.62, 1.64, 1.65, etc. The refractive index of the second substrate 12 is greater than or equal to 1.6 and less than or equal to 1.9. For example, the refractive index of the second substrate 12 may be 1.6, 1.65, 1.7, 1.8, 1.9, etc.

[0066] In some embodiments, the material of the first substrate 11 and / or the second substrate 12 includes an organic material, and / or the material of the sealing film 13 includes an inorganic material.

[0067] In these embodiments, the material of the first substrate 11 and / or the second substrate 12 includes an organic material, so that the substrate 10 can have good bending performance. And / or, the material of the sealing film 13 includes an inorganic material, so that the sealing film 13 has good sealing performance, can better isolate water and oxygen, thereby improving the service life and stability of the solar cell, and can also make the sealing film 13 have good flexible bending ability, can have good deformation ability during the bending process, reduce the risk of damage, and improve impact resistance.

[0068] Preferably, the material of the first substrate 11 includes at least one of PET (polyethylene terephthalate) and PMMA (polymethyl methacrylate); and / or, the material of the sealing film 13 includes at least one of Al2O3 and SiO2; and / or, the material of the second substrate 12 includes at least one of PEN (polyethylene naphthalate) and CPI (colorless polyimide).

[0069] In these embodiments, by properly setting the materials of the first substrate 11 and / or the second substrate 12, the first substrate 11 and / or the second substrate 12 can have good bending performance on the basis of ensuring the refractive index of the first substrate 11 and / or the second substrate 12. In addition, by properly setting the material of the sealing film 13, the sealing film 13 can have good sealing performance, and at the same time, the refractive index of the sealing film 13 can be adapted to the refractive index of the first refractive portion 111 and the refractive index of the second refractive portion 121, thereby ensuring the transmittance of the substrate 10.

[0070] In some optional embodiments, the material of the first substrate 11 includes PET, and the Young's modulus E1 of the first substrate 11 satisfies: 2000 MPa ≤ E1 ≤ 4000 MPa, thereby further improving the bending performance of the first substrate 11. For example, the Young's modulus of the first substrate 11 can be 2000 MPa, 2500 MPa, 3000 MPa, 3500 MPa, 4000 MPa, etc.

[0071] In some other optional embodiments, the material of the first substrate 11 includes PMMA, and the Young's modulus E2 of the first substrate 11 satisfies: 2800 MPa ≤ E2 ≤ 3300 MPa, thereby further improving the bending performance of the first substrate 11. Exemplarily, the Young's modulus of the first substrate 11 can be 2800 MPa, 2900 MPa, 3100 MPa, 3200 MPa, 3300 MPa, etc.

[0072] In some optional embodiments, the material of the second substrate 12 includes PEN, and the Young's modulus E3 of the second substrate 12 satisfies: 3000 MPa ≤ E3 ≤ 5000 MPa, thereby further improving the bending performance of the second substrate 12. For example, the Young's modulus of the second substrate 12 can be 3000 MPa, 3500 MPa, 4000 MPa, 4500 MPa, 5000 MPa, etc.

[0073] In some optional embodiments, the material of the second substrate 12 includes CPI, and the Young's modulus E4 of the second substrate 12 satisfies: 3000 MPa ≤ E4 ≤ 4000 MPa, thereby further improving the bending performance of the second substrate 12. For example, the Young's modulus of the second substrate 12 can be 3000 MPa, 3200 MPa, 3500 MPa, 3700 MPa, 4000 MPa, etc.

[0074] See also Figure 6 In some embodiments, along a direction parallel to the first substrate 11, a width L2 of the first refractive portion 111 away from the second substrate 12 satisfies: 100 nanometers ≤ L2 ≤ 300 nanometers, and along a thickness direction of the first substrate 11, a height H1 of the first refractive portion 111 satisfies: 100 nanometers ≤ H1 ≤ 600 nanometers; and / or, along a direction parallel to the second substrate 12, a width L3 of the second refractive portion 121 away from the first substrate 11 satisfies: 100 nanometers ≤ L3 ≤ 300 nanometers, and along a thickness direction of the second substrate 12, a height H2 of the second refractive portion 121 satisfies: 100 nanometers ≤ H2 ≤ 600 nanometers.

[0075] Since the cross-section of the first refractive portion 111 gradually decreases along the direction from the first substrate 11 to the second substrate 12, and the cross-section of the second refractive portion 121 gradually increases along the direction from the first substrate 11 to the second substrate 12, the width of the first refractive portion 111 on the side away from the second substrate 12 is the maximum width of the first refractive portion 111, and the width of the second refractive portion 121 on the side away from the first substrate 11 is the maximum width of the second refractive portion 121.

[0076] In these embodiments, by reasonably setting the width of the first refractive portion 111 away from the second substrate 12 and / or the width of the second refractive portion 121 away from the first substrate 11, the number of the first refractive portion 111 and the second refractive portion 121 can be reasonably adjusted on the basis of ensuring the refraction effect of the single first refractive portion 111 and the second refractive portion 121 on light, so as to improve the transmittance of the substrate 10. On this basis, by reasonably setting the height of the first refractive portion 111 and / or the second refractive portion 121, the inclination or curvature of the surface of the first refractive portion 111 facing the second refractive portion 121 and / or the surface of the second refractive portion 121 facing the first refractive portion 111 can be adjusted, so that the surface has good light refraction ability, thereby improving the light transmission performance of the first refractive portion 111 and / or the second refractive portion 121.

[0077] It should be noted that the width of the first refractive portion 111 and / or the second refractive portion 121 is greater than or equal to 100 nanometers and less than or equal to 300 nanometers, for example, the width may be 100 nanometers, 150 nanometers, 200 nanometers, 250 nanometers, 300 nanometers, etc. The height of the first refractive portion 111 and / or the second refractive portion 121 is greater than or equal to 100 nanometers and less than or equal to 600 nanometers, for example, the height may be 100 nanometers, 200 nanometers, 300 nanometers, 400 nanometers, 500 nanometers, 600 nanometers, etc.

[0078] See also Figure 8 In a second aspect, the present application provides a solar cell, comprising any of the above substrates 10 and a battery cell 20, wherein the battery cell 20 is arranged on the side of the second substrate 12 of the substrate 10 away from the first substrate 11, and the battery cell 20 comprises a first electrode 21, a photosensitive layer 22, and a second electrode 23 arranged in a stacked manner. The solar cell provided in the embodiment of the present application has the technical effects of the technical solutions of any of the above embodiments, and the structures identical or corresponding to the above embodiments and the explanations of the terms are not repeated here.

[0079] Specifically, in the battery cell 20, the first electrode 21 is arranged on the side of the second substrate 12 of the substrate 10 away from the first substrate 11, the photosensitive layer 22 is arranged on the side of the first electrode 21 away from the substrate 10, and the second electrode 23 is arranged on the side of the photosensitive layer 22 away from the substrate 10. When light passes through the substrate 10 and the first electrode 21 along the direction from the first substrate 11 to the second substrate 12 and irradiates the photosensitive layer 22, the photosensitive layer 22 can separate electron-hole pairs, and the electrons and holes can move toward the first electrode 21 and the second electrode 23 respectively under the action of the external electric field, thereby forming a current and realizing photoelectric conversion. The battery cell 20 is arranged on the substrate 10, so by improving the light transmittance of the substrate 10, more light can pass through the substrate 10 and irradiate the photosensitive layer 22 of the battery cell 20, so that the photosensitive layer 22 can separate more electron-hole pairs, thereby forming a larger current, so as to improve the photoelectric conversion efficiency of the battery cell 20.

[0080] It should be noted that the solar cell provided in the present application can be any type of cell capable of achieving photoelectric conversion. For example, the solar cell of the present application can be a perovskite cell, or a monocrystalline silicon cell or a polycrystalline silicon cell, which is not limited in this embodiment. In some optional embodiments, when the solar cell is a perovskite cell, the material of its photosensitive layer 22 can include a perovskite material to improve the photoelectric conversion efficiency and reduce the production cost.

[0081] In some optional embodiments, please continue to refer to Figure 8 The solar cell further includes a flexible packaging cover plate 30 disposed on a side of the battery unit 20 facing away from the substrate 10 .

[0082] In these embodiments, the battery cell 20 is arranged on the substrate 10. Since the substrate 10 includes the first substrate 11, the sealing film 13 and the second substrate 12, the first substrate 11 includes the first refractive portion 111, the second substrate 12 includes the second refractive portion 121, and the cross-section of the first refractive portion 111 gradually decreases and the cross-section of the second refractive portion 121 gradually increases along the direction from the first substrate 11 to the second substrate 12, and at least part of the second refractive portion 121 is located on the peripheral side of the first refractive portion 111, therefore, the refractive index of the substrate 10 can be increased in the direction from the first substrate 11 to the second substrate 12. The first refractive portion 111 and the second refractive portion 121 are gradually increased, which can reduce the amount of light reflected by the substrate and improve the light transmittance of the substrate. At the same time, the side of the first refractive portion 111 facing the second refractive portion 121 and the side of the second refractive portion 121 facing the first refractive portion 111 can be used to refract light to change the propagation path of the light and reduce the amount of light directly reflected at the junction of the first substrate 11 and the second substrate 12, so that more light can pass through the substrate 10 and be transmitted to the battery unit for photoelectric conversion, thereby further improving the light transmittance of the substrate 10 and improving the photoelectric conversion efficiency of the solar cell.

[0083] On this basis, by setting a flexible packaging cover plate 30 on the side of the battery unit 20 away from the substrate 10, and setting a sealing film 13 between the first refraction portion 111 and the second refraction portion 121, the sealing film 13 and the flexible packaging cover plate 30 can together realize flexible packaging of the solar cell to isolate external water and oxygen, avoid the external environment from affecting the battery performance, and improve the battery life and stability.

[0084] In some embodiments, the first electrode 21 is located between the substrate 10 and the photosensitive layer 22 , and the refractive index of the first electrode 21 is greater than the refractive index of the second substrate 12 .

[0085] The first electrode 21 is disposed on the second substrate 12 of the base plate 10. Light can sequentially pass through the first substrate 11, the sealing film 13, the second substrate 12 and the first electrode 21 and irradiate the photosensitive layer 22. Therefore, in these embodiments, by setting the refractive index of the first electrode 21 to be greater than the refractive index of the second substrate 12, it is possible to avoid total reflection of light at the interface between the second substrate 12 and the first electrode 21, thereby improving light transmittance. Figure 5 and Figure 8 In the solar cell, the second main body portion 122 (ie Figure 1 and Figure 5 The refractive index of the first electrode 21 (i.e. Figure 5 and Figure 8The refractive index of the H4~H5 segment in the second main body 122 is constant and greater than the refractive index of the second main body 122.

[0086] Preferably, the refractive index N4 of the first electrode 21 satisfies: 1.8≤N4≤2.1, so that the refractive index of the first electrode 21 and the second substrate 12 are matched to further improve the light transmittance.

[0087] The third aspect of the present application provides an electric device, including the solar cell. The electric device provided in the embodiment of the present application has the technical effect of the technical solution of any of the above embodiments, and the explanation of the same or corresponding structures and terms as the above embodiments will not be repeated here.

[0088] The power-consuming device may be any device that requires electric energy, for example, a mobile phone, tablet computer, laptop computer, PDA, in-vehicle electronic device, wearable device, ultramobile personal computer (UMPC), netbook or personal digital assistant (PDA) and other mobile devices, and may also be a personal computer (PC), television (TV), ATM or self-service machine and other non-mobile devices.

[0089] Although the embodiments disclosed in this application are as above, the contents described are only embodiments adopted for facilitating the understanding of this application and are not intended to limit the present invention. Any technician in the technical field to which this application belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in this application, but the scope of protection of this application shall still be subject to the scope defined in the attached claims.

[0090] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the replacement of other connection methods described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A substrate for a solar cell, characterized in that: include: A first substrate including a first refractive portion; A second substrate is stacked on one side of the first substrate, the second substrate includes a second refractive portion, wherein the refractive index of the second substrate is greater than the refractive index of the first substrate, and along the direction from the first substrate to the second substrate, the cross section of the first refractive portion gradually decreases, and the cross section of the second refractive portion gradually increases, and at least part of the second refractive portion is located on the peripheral side of the first refractive portion, so that the overall refractive index of the substrate increases gradually in the direction from the first substrate to the second substrate; A sealing film is arranged between the first refractive part and the second refractive part. In the thickness direction of the first substrate and the second substrate, the cross-sectional shape of the sealing film is adapted to the contour shape of the first refractive part facing the second substrate side and the contour shape of the second refractive part facing the first substrate side.

2. The substrate according to claim 1, characterized in that In the thickness direction of the first substrate and the second substrate, a cross-sectional shape of the first refractive portion and / or the second refractive portion is any one of a triangle, a semicircle, a semi-ellipse, and a trapezoid.

3. The substrate according to claim 2, characterized in that The first refractive portion and / or the second refractive portion is any one of a triangular prism structure, a triangular pyramid structure and a cone structure.

4. The substrate according to claim 1, characterized in that The number of the first refractive parts and the number of the second refractive parts are respectively multiple, the multiple first refractive parts and the multiple second refractive parts are arranged in an array along a direction parallel to the first substrate and the second substrate, and one second refractive part is located between two adjacent first refractive parts.

5. The substrate according to claim 4, characterized in that The first substrate further includes a first main body portion, and the plurality of first refractive portions are respectively arranged on a side of the first main body portion facing the second refractive portion; and / or, The second substrate further includes a second main body portion, and a plurality of second refractive portions are arranged on a side of the second main body portion facing the first refractive portions.

6. The substrate according to claim 1, characterized in that The thickness L1 of the sealing film satisfies: 1 nm≤L1≤1000 nm.

7. The substrate according to claim 1, characterized in that The refractive index of the sealing film is greater than the refractive index of the first substrate and less than the refractive index of the second substrate.

8. The substrate according to claim 7, characterized in that The refractive index N1 of the first substrate satisfies: 1.4≤N1≤1.64, the refractive index N2 of the sealing film satisfies: 1.6≤N2≤1.65, and the refractive index N3 of the second substrate satisfies: 1.6≤N3≤1.

9.

9. The substrate according to claim 1, characterized in that The material of the first substrate and / or the second substrate includes an organic material; and / or the material of the sealing film includes an inorganic material.

10. The substrate according to claim 9, characterized in that The material of the first substrate includes at least one of PET and PMMA; and / or, the material of the sealing film includes at least one of Al2O3 and SiO2; and / or, the material of the second substrate includes at least one of PEN and CPI.

11. The substrate according to any one of claims 1 to 5, characterized in that: Along a direction parallel to the first substrate, a width L2 of the first refractive portion away from the second substrate satisfies: 100 nanometers ≤ L2 ≤ 300 nanometers, and along a thickness direction of the first substrate, a height H1 of the first refractive portion satisfies: 100 nanometers ≤ H1 ≤ 600 nanometers; and / or, Along a direction parallel to the second substrate, a width L3 of the second refractive portion away from the first substrate satisfies: 100 nanometers ≤ L3 ≤ 300 nanometers, and along a thickness direction of the second substrate, a height H2 of the second refractive portion satisfies: 100 nanometers ≤ H2 ≤ 600 nanometers.

12. A solar cell, characterized in that: include: The substrate according to any one of claims 1 to 11; The battery cell is arranged on the side of the second substrate of the base plate away from the first substrate, and the battery cell includes a first electrode, a photosensitive layer and a second electrode which are stacked.

13. The solar cell according to claim 12, characterized in that: The first electrode is located between the substrate and the photosensitive layer, and the refractive index of the first electrode is greater than the refractive index of the second substrate.

14. The solar cell according to claim 13, characterized in that: The refractive index N4 of the first electrode satisfies: 1.8≤N4≤2.

1.

15. An electrical device, characterized in that: A solar cell comprising the solar cell described in any one of claims 12 to 14.

Images