Nanoparticle composite layer and preparation method thereof, front light absorption structure and TOPCon battery

Abstract

The embodiment of the invention provides a nanoparticle composite layer and a preparation method thereof, a front light absorption structure and a TOPCon cell, and relates to the technical field of solar cells. The invention relates to a nano-particle composite layer. Materials of the nano-particle composite layer comprise yttrium vanadate nano-particles doped with trivalent europium and trivalent bismuth and silver nano-particles. Under the interaction of trivalent europium, trivalent bismuth, yttrium vanadate nanoparticles and silver nanoparticles, the nanoparticle composite layer can form a localized surface plasma resonance enhanced light-emitting frequency-reducing nanomaterial, so that high-energy ultraviolet photons can be efficiently converted into low-energy photons with specific wavelength, the absorption of ultraviolet rays is effectively reduced optically, and the light-emitting efficiency is improved. The ultraviolet induced degradation (UVID) is obviously reduced; when the nano-particle composite layer is applied to the solar cell, the ultraviolet attenuation resistance of the solar cell can be effectively improved, and the photoelectric conversion efficiency of the solar cell is not affected.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a nanoparticle composite layer and a preparation method thereof, a front light absorption structure and a TOPCon cell. Background Art

[0002] UV resistance degradation refers to the ability of a material or device to resist UV radiation, that is, the ability to maintain stable performance under UV radiation. UV-induced degradation (UVID) refers to the performance degradation of a material or device caused by UV radiation. UV resistance degradation includes UV-induced degradation (UVID), and UV resistance is a specific manifestation of UV resistance.

[0003] The Renewable Energy Test Center (RETC) has identified seven important reliability tests, one of which is the UV-induced degradation (UVID) test. According to the standards of RETC (Renewable Energy Test Center), any maximum power degradation greater than or equal to 5% is considered a red light result. That is, when a power degradation of 5% or more is shown in the UV-induced degradation (UVID) test, it will be marked as a potential reliability problem. Currently, many solar cells show a power degradation of 5% or more in the UV-induced degradation (UVID) test, and it is urgent to pay attention to and improve the anti-UV degradation performance of solar cells.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] The embodiments of the present application provide a nanoparticle composite layer and a preparation method thereof, a front light absorption structure and a TOPCon cell that can effectively improve the anti-ultraviolet attenuation performance of a solar cell, so as to solve or alleviate the technical problems raised above.

[0006] To achieve the above purpose, this application adopts the following technical solutions: A nanoparticle composite layer, the material of which comprises trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles.

[0007] In some embodiments, the thickness of the nanoparticle composite layer is 1-10 μm.

[0008] In some embodiments, the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles are prepared by using yttrium vanadate as a matrix material and doping trivalent europium ions and trivalent bismuth ions; wherein the ratio of the doping concentration of the trivalent europium ions to the doping concentration of the trivalent bismuth ions is 1 to 5.

[0009] In some of the embodiments, in the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, the doping concentration of the trivalent bismuth ions is 0.4-1.2 mol %.

[0010] In some embodiments, the weight ratio of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to the silver nanoparticles is 1-5.

[0011] In some embodiments, the particle size of the silver nanoparticles is 1-10 nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 50-100 nm.

[0012] In some embodiments, the silver nanoparticles are loaded on the outer surface of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles.

[0013] The present application also provides a method for preparing a nanoparticle composite layer, comprising: Loading silver nanoparticles onto the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to form trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles with the silver nanoparticles loaded on the surface; The trivalent europium-doped and trivalent bismuth-doped yttrium vanadate nanoparticles with the silver nanoparticles on the surface are coated on a substrate to form the nanoparticle composite layer.

[0014] The present application also provides a front light absorption structure, the front light absorption structure comprising: an aluminum oxide layer, a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Or, the front light absorption structure comprises: a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Or, the front light absorption structure comprises: a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Wherein, the first nanoparticle composite layer is selected from the above-mentioned nanoparticle composite layer, or is prepared by the above-mentioned preparation method.

[0015] In some embodiments, the first silicon nitride layer includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer than the third sub-silicon nitride layer; and the refractive indices of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; And / or, the silicate oxynitride layer includes a first sub-silicate oxynitride layer and a second sub-silicate oxynitride layer stacked in sequence; the first sub-silicate oxynitride layer is closer to the first silicon nitride layer than the second sub-silicate oxynitride layer; and the refractive index of the first sub-silicate oxynitride layer is higher than the refractive index of the second sub-silicate oxynitride layer.

[0016] In some embodiments, the refractive index of the first silicon nitride layer is 2.25-2.35, the refractive index of the second silicon nitride layer is 2.15-2.20, and the refractive index of the third silicon nitride layer is 2.05-2.10; The refractive index of the first silicate oxynitride layer is 1.90-1.95, and the refractive index of the second silicate oxynitride layer is 1.90-1.95.

[0017] The present application also provides a TOPCon cell, wherein the back side of the TOPCon cell comprises a first silicon oxide layer, an n+ type doped polysilicon layer, a second silicon oxide layer, an n++ type doped polysilicon layer, a second silicon nitride layer, and a second nanoparticle composite layer stacked in sequence; The second nanoparticle composite layer is selected from the above-mentioned nanoparticle composite layer, or is prepared by the above-mentioned preparation method; the first silicon oxide layer is closer to the silicon substrate of the TOPCon battery than the second nanoparticle composite layer.

[0018] In some embodiments, the second silicon nitride layer includes a first sublayer, a second sublayer, and a third sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the third sublayer; and the refractive indices of the first sublayer, the second sublayer, and the third sublayer decrease in sequence; Or, the second silicon nitride layer includes a first sublayer, a second sublayer, a third sublayer, and a fourth sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the fourth sublayer; and the refractive indices of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer decrease in sequence.

[0019] In some embodiments, when the second silicon nitride layer includes the first sublayer, the second sublayer, and the third sublayer stacked in sequence, the refractive index of the first sublayer is 2.25-2.35, the refractive index of the second sublayer is 2.15-2.20, and the refractive index of the third sublayer is 2.05-2.10; When the second silicon nitride layer includes the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer stacked in sequence, the refractive index of the first sublayer is 2.25~2.35, the refractive index of the second sublayer is 2.20~2.25, the refractive index of the third sublayer is 2.15~2.20, and the refractive index of the fourth sublayer is 2.10~2.15.

[0020] The above technical solution adopted in the embodiment of the present application may have the following advantages: A nanoparticle composite layer of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles is used as the material of the nanoparticle composite layer. Under the interaction of trivalent europium, trivalent bismuth, yttrium vanadate nanoparticles and silver nanoparticles, a localized surface plasmon resonance enhanced luminescence frequency-reducing nanomaterial can be formed, thereby efficiently converting high-energy ultraviolet photons into low-energy photons of a specific wavelength, effectively reducing the absorption of ultraviolet rays optically, and significantly reducing ultraviolet induced attenuation (UVID); using the nanoparticle composite layer on a solar cell can effectively improve the anti-ultraviolet attenuation performance of the solar cell without affecting the photoelectric conversion efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0022] Figure 1 It is a schematic diagram of the structure of the TOPCon battery provided in the embodiment of the present application; Figure 2 is a structural schematic diagram of a front light absorption structure provided in an embodiment of the present application; Figure 3 is a schematic diagram of the structure of the nanoparticle composite layer provided in an embodiment of the present application; Figure 4 is a picture of a TOPCon battery provided with a nanoparticle composite layer provided in an embodiment of the present application; Description of reference numerals: 1. Nanoparticle composite layer; 10. N-type substrate silicon; 11. P-type emitter; 12. Aluminum oxide layer; 13. First silicon nitride layer; 14. Silica oxynitride layer; 15. Silicon dioxide layer; 16. First nanoparticle composite layer; 21. First silicon oxide layer; 22. n+ type doped polysilicon layer; 23. Second silicon oxide layer; 24. n++ type doped polysilicon layer; 25. Second silicon nitride layer; 26. Second nanoparticle composite layer. DETAILED DESCRIPTION

[0023] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0024] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0025] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0028] The present application aims to provide a nanoparticle composite layer and a preparation method thereof, a front light absorption structure and a TOPCon cell. A nanoparticle composite layer of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles is used as the material of the nanoparticle composite layer. Under the interaction of trivalent europium, trivalent bismuth, yttrium vanadate nanoparticles and silver nanoparticles, a localized surface plasmon resonance enhanced luminescence frequency reduction nanomaterial can be formed, thereby being able to efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, effectively reducing the absorption of ultraviolet rays optically, and significantly reducing ultraviolet induced attenuation (UVID); using the nanoparticle composite layer on a solar cell can effectively improve the anti-ultraviolet attenuation performance of the solar cell without affecting the photoelectric conversion efficiency of the solar cell.

[0029] Below, exemplary embodiments of the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0030] The present application provides a nanoparticle composite layer 1, wherein the material of the nanoparticle composite layer 1 includes trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles. Figure 3 The picture of the TOPCon battery provided with the nanoparticle composite layer 1 is shown in FIG. Figure 4 In the embodiment of the present application, the nanoparticle composite layer 1 may also include other functional layers to achieve specific functions.

[0031] In the embodiment of the present application, the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) is doped with trivalent europium (Eu 3+ ) and trivalent bismuth (Bi 3+ ) of yttrium vanadate (YVO 4 ) phosphor, yttrium vanadate nanoparticles doped with trivalent europium and trivalent bismuth and silver nanoparticles together form a localized surface plasmon resonance enhanced luminescence subtraction nanomaterial (YVO 4 :Eu 3+ ,Bi 3+ @Ag), yttrium vanadate (YVO) in europium-doped bismuth-doped yttrium vanadate nanoparticles 4 ) is the matrix, trivalent europium (Eu 3+ ) as an activator provides characteristic luminescence, while trivalent bismuth (Bi 3+ ) as a co-dopant can enhance the 3+ ) luminous efficiency; the materials of the nanoparticle composite layer include trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, silver nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ @Ag), under the interaction of trivalent europium, trivalent bismuth, yttrium vanadate nanoparticles and silver nanoparticles, it can efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, effectively reduce the absorption of ultraviolet rays optically, and significantly reduce ultraviolet induced attenuation (UVID).

[0032] In the embodiments of the present application, the preparation method of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles can be selected from one or more of a low-temperature wet chemical precipitation method, a precipitation method, a high-temperature solid phase method, and a Pechini-type sol-gel method.

[0033] In the embodiments of the present application, when the nanoparticle composite layer is used on a solar cell, the nanoparticle composite layer can be arranged on the front side of the solar cell, or on the back side of the solar cell, or on both the front side and the back side of the solar cell; the nanoparticle composite layer can be arranged as needed; the nanoparticle composite layer is arranged on the solar cell, which can effectively improve the anti-ultraviolet attenuation performance of the solar cell, and does not affect the photoelectric conversion efficiency of the solar cell. It should be noted that the nanoparticle composite layer can be used on various types of solar cells, such as monocrystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, perovskite solar cells, etc.

[0034] In some embodiments, the thickness of the nanoparticle composite layer is 1 to 10 μm (e.g., 1 μm, 2 μm, 4 μm, 6 μm, 8 μm, 10 μm). In the embodiments of the present application, the thickness of the nanoparticle composite layer is controlled to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet light, thereby further reducing ultraviolet induced attenuation (UVID).

[0035] In some of the embodiments, trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles are prepared by using yttrium vanadate as a matrix material and doping trivalent europium ions and trivalent bismuth ions; wherein the ratio of the doping concentration of the trivalent europium ions to the doping concentration of the trivalent bismuth ions is 1 to 5 (for example, 1:1, 3:1, 5:1).

[0036] In the embodiment of the present application, the doping concentration of trivalent europium ions and trivalent bismuth ions is controlled to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID).

[0037] In some of the embodiments, in the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, the doping concentration of trivalent bismuth ions is 0.4-1.2 mol % (eg, 0.4 mol %, 0.6 mol %, 0.8 mol %, 1.0 mol %, 1.2 mol %).

[0038] In the embodiment of the present application, the specific calculation method of the doping concentration of trivalent europium ions and trivalent bismuth ions can refer to the calculation of molar percentage: molar percentage = (molar number of specific component / total molar number of mixture) × 100%. For example, a mixture contains 10 moles of component A and 20 moles of component B, then the molar percentage of component A = (10 / 30) × 100% ≈ 33.33%; that is, the concentration of component A in the mixture is 33.33 mol%. Similarly, the doping concentration of trivalent europium ions and trivalent bismuth ions can be calculated.

[0039] In the embodiment of the present application, the doping concentration of trivalent europium ions and trivalent bismuth ions is controlled to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID).

[0040] In some embodiments, the weight ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is 1 to 5 (eg, 1:1, 3:1, 5:1).

[0041] In the embodiments of the present application, the ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is controlled to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID).

[0042] In some embodiments, the particle size of the silver nanoparticles is 1-10 nm (e.g., 1 nm, 2 nm, 4 nm, 6 nm, 8 nm, 10 nm), and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 50-100 nm (e.g., 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm).

[0043] In the embodiments of the present application, the particle sizes of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles are controlled to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID).

[0044] In some embodiments, the silver nanoparticles are loaded on the outer surface of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles.

[0045] In the embodiment of the present application, silver nanoparticles are loaded on the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, which plays a role in optimizing the material structure of the nanoparticle composite layer, facilitating more efficient conversion of high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID).

[0046] The present application also provides a method for preparing a nanoparticle composite layer, comprising: Loading silver nanoparticles onto the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to form trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles with silver nanoparticles loaded on the surface; The trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles with silver nanoparticles on the surface are coated on a substrate to form a nanoparticle composite layer.

[0047] In the embodiment of the present application, the method for loading silver nanoparticles on the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles can be: 1) loading trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) and silver nanoparticles (Ag) are dispersed in alcohol; 2) ultrasonic oscillation and mixing at a specific frequency at room temperature for 1H; 3) silver nanoparticles (Ag) are adsorbed onto trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) surface, forming surface-loaded silver nanoparticles-doped trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ Other methods can also be used to load silver nanoparticles on the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles.

[0048] In the embodiment of the present application, silver nanoparticles are loaded on the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, which plays a role in optimizing the material structure of the nanoparticle composite layer, facilitating more efficient conversion of high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID).

[0049] The present application also provides a front light absorption structure, including a first nanoparticle composite layer 16, wherein the first nanoparticle composite layer 16 is selected from the above-mentioned nanoparticle composite layer, or is prepared by the above-mentioned preparation method.

[0050] In some embodiments, the front light absorption structure includes: an aluminum oxide layer 12, a first silicon nitride layer 13, a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence, as shown in FIG. Figure 2 shown.

[0051] In some embodiments, the front light absorption structure includes: a first silicon nitride layer 13, a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence.

[0052] In some embodiments, the front light absorption structure includes: a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence.

[0053] In the embodiment of the present application, for a battery having an aluminum oxide layer and a silicon nitride layer on the front, such as a TOPCon battery, the front light absorption structure may include a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; for a battery having no aluminum oxide layer and a silicon nitride layer on the front, the front light absorption structure may include an aluminum oxide layer, a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; for a battery having an aluminum oxide layer but no silicon nitride layer on the front, the front light absorption structure may include a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; the interaction between the layers can further reduce ultraviolet induced attenuation (UVID).

[0054] In an embodiment of the present application, the thickness of the aluminum oxide layer can be 3.5-6.5nm, and the preparation method of the aluminum oxide layer can be one or more of the atomic layer deposition (ALD) method and the co-precipitation method; the thickness of the first silicon nitride layer can be 40-50nm, and the preparation method of the first silicon nitride layer can be one or more of the chemical vapor deposition (CVD) method and the physical vapor deposition (PVD) method; the thickness of the silicate oxynitride layer can be 10-20nm, and the preparation method of the silicate oxynitride layer can be a plasma enhanced chemical vapor deposition (PECVD) method; the thickness of the silicon dioxide layer can be 5-10nm, and the preparation method of the silicon dioxide layer can be one or more of the chemical vapor deposition (CVD) method, the atomic layer deposition (ALD) method, and the physical vapor deposition (PVD) method; the thickness of the first nanoparticle composite layer can be 15-25nm, and the preparation method of the first nanoparticle composite layer can be a coating method.

[0055] In the embodiment of the present application, when the front light absorption structure is used on the solar cell, the nanoparticle composite layer is arranged on the front of the solar cell. The first nanoparticle composite layer is used in conjunction with the aluminum oxide layer, the first silicon nitride layer and other layers. On the one hand, it is convenient to assist the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also promote light absorption, thereby improving the photoelectric conversion efficiency of the solar cell.

[0056] In some embodiments, the first silicon nitride layer includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer than the third sub-silicon nitride layer; and the refractive indices of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; And / or, the silicate oxynitride layer includes a first sub-silicate oxynitride layer and a second sub-silicate oxynitride layer stacked in sequence; the first sub-silicate oxynitride layer is closer to the first silicon nitride layer than the second sub-silicate oxynitride layer; and the refractive index of the first sub-silicate oxynitride layer is higher than the refractive index of the second sub-silicate oxynitride layer.

[0057] In the embodiment of the present application, the structure of the first silicon nitride layer is optimized. On the one hand, it is convenient to assist the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thus improve the photoelectric conversion efficiency of solar cells.

[0058] In the embodiment of the present application, the structure of the silicate oxynitride layer is optimized. On the one hand, it is convenient to assist the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thus improve the photoelectric conversion efficiency of solar cells.

[0059] In some embodiments, the refractive index of the first silicon nitride sub-layer is 2.25-2.35, the refractive index of the second silicon nitride sub-layer is 2.15-2.20, and the refractive index of the third silicon nitride sub-layer is 2.05-2.10; The refractive index of the first silicate oxynitride sub-layer is 1.90-1.95, and the refractive index of the second silicate oxynitride sub-layer is 1.90-1.95.

[0060] In the embodiments of the present application, the refractive index of each layer is optimized to enhance the anti-reflection effect, promote light absorption, and thus enhance the photoelectric conversion efficiency of the solar cell.

[0061] The present application also provides a TOPCon cell, wherein the back side of the TOPCon cell comprises a first silicon oxide layer, an n+ type doped polysilicon layer, a second silicon oxide layer, an n++ type doped polysilicon layer, a second silicon nitride layer, and a second nanoparticle composite layer stacked in sequence; The second nanoparticle composite layer is selected from the above-mentioned nanoparticle composite layer, or is prepared by the above-mentioned preparation method; the first silicon oxide layer is closer to the silicon substrate of the TOPCon battery than the second nanoparticle composite layer.

[0062] In an embodiment of the present application, the thickness of the first silicon oxide layer may be 0.65-1.5 nm, and the preparation method of the first silicon oxide layer may be one or more of a chemical vapor deposition (CVD) method and a magnetron sputtering method; the thickness of the n+ type doped polysilicon layer may be 20-30 nm, and the preparation method of the n+ type doped polysilicon layer may be a low pressure chemical vapor deposition (LPCVD) method; the thickness of the second silicon oxide layer may be 0.5-0.6 nm, and the preparation method of the second silicon oxide layer may be one or more of a chemical vapor deposition (CVD) method and a magnetron sputtering method; the thickness of the n++ type doped polysilicon layer may be 60-70 nm, and the preparation method of the n++ type doped polysilicon layer may be a low pressure chemical vapor deposition (LPCVD) method; the thickness of the second silicon nitride layer may be 70-80 nm, and the preparation method of the second silicon nitride layer may be one or more of a chemical vapor deposition (CVD) method and a physical vapor deposition (PVD) method; the thickness of the second nanoparticle composite layer may be 15-25 nm, and the preparation method of the second nanoparticle composite layer may be a coating method.

[0063] In the embodiments of the present application, the n+ type doped polysilicon layer refers to a phosphorus-doped polysilicon layer deposited on the back of the silicon wafer. This polysilicon layer is in contact with the n-type silicon substrate to form an n+ / n high-low junction structure, which reduces the recombination loss at the silicon substrate interface and provides good conduction performance for carriers. The n++ type doped polysilicon layer refers to a polysilicon layer with a higher doping concentration. That is, the n+ type doped polysilicon layer is a polysilicon layer with a relatively low doping concentration, while the n++ type doped polysilicon layer is a polysilicon layer with a higher doping concentration. Both play a role in reducing carrier recombination and improving battery performance in the TOPCon battery structure.

[0064] In the embodiment of the present application, the front side of the TOPCon cell may include a P-type emitter, an aluminum oxide layer, and a silicon nitride layer stacked in sequence; the P-type emitter is closer to the silicon substrate of the TOPCon cell than the silicon nitride layer. In addition, in the embodiment of the present application, a second nanoparticle composite layer may also be included, the second nanoparticle composite layer is disposed on the silicon nitride layer, and the second nanoparticle composite layer is further away from the silicon substrate of the TOPCon cell than the silicon nitride layer.

[0065] In the embodiment of the present application, the second nanoparticle composite layer is used in conjunction with the first silicon oxide layer, the second silicon oxide layer and other layers. On the one hand, it is convenient to assist the second nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also promote light absorption, thereby improving the photoelectric conversion efficiency of solar cells.

[0066] In some embodiments, the second silicon nitride layer includes a first sublayer, a second sublayer, and a third sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the third sublayer; and the refractive indices of the first sublayer, the second sublayer, and the third sublayer decrease in sequence; Or, the second silicon nitride layer includes a first sublayer, a second sublayer, a third sublayer, and a fourth sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the fourth sublayer; and the refractive indices of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer decrease in sequence.

[0067] In the embodiment of the present application, the structure of the second silicon nitride layer is optimized. On the one hand, it is convenient to assist the second nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, and thus further reduce ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thus improve the photoelectric conversion efficiency of solar cells.

[0068] In some embodiments, when the second silicon nitride layer includes a first sublayer, a second sublayer, and a third sublayer stacked sequentially, the refractive index of the first sublayer is 2.25-2.35, the refractive index of the second sublayer is 2.15-2.20, and the refractive index of the third sublayer is 2.05-2.10; When the second silicon nitride layer includes a first sublayer, a second sublayer, a third sublayer, and a fourth sublayer stacked in sequence, the refractive index of the first sublayer is 2.25~2.35, the refractive index of the second sublayer is 2.20~2.25, the refractive index of the third sublayer is 2.15~2.20, and the refractive index of the fourth sublayer is 2.10~2.15.

[0069] In the embodiments of the present application, the refractive index of each layer is optimized to enhance the anti-reflection effect, promote light absorption, and thus enhance the photoelectric conversion efficiency of the solar cell.

[0070] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0071] Example 1 A TOPCon battery, such as Figure 1As shown, it includes: an N-type substrate silicon 10, the front side of the N-type substrate silicon 10 includes a P-type emitter 11, an aluminum oxide layer 12, a first silicon nitride layer 13, a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence, the first nanoparticle composite layer 16 is closer to the light receiving surface than the aluminum oxide layer 12, that is, the aluminum oxide layer 12 is closer to the N-type substrate silicon 10 than the first nanoparticle composite layer 16; the first silicon nitride layer 13 includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer 12 than the third sub-silicon nitride layer; the refractive index of the first sub-silicon nitride layer is 2.25, the refractive index of the second sub-silicon nitride layer is 2.15, and the refractive index of the third sub-silicon nitride layer is 2.05 ; The refractive indexes of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; the thickness of the first sub-silicon nitride layer is 15nm, the thickness of the second sub-silicon nitride layer is 15nm, and the thickness of the third sub-silicon nitride layer is 10nm; the silicate oxynitride layer 14 includes a first sub-siliconate oxynitride layer and a second sub-siliconate oxynitride layer stacked in sequence; the first sub-siliconate oxynitride layer is closer to the first silicon nitride layer 13 than the second sub-siliconate oxynitride layer; the refractive index of the first sub-siliconate oxynitride layer is 1.95, and the refractive index of the second sub-siliconate oxynitride layer is 1.90; the refractive index of the first sub-siliconate oxynitride layer is higher than the refractive index of the second sub-siliconate oxynitride layer; the thickness of the first sub-siliconate oxynitride layer is 10nm, and the thickness of the second sub-siliconate oxynitride layer is 10nm; The back side of the N-type substrate silicon 10 includes a first silicon oxide layer 21, an n+ type doped polysilicon layer 22, a second silicon oxide layer 23, an n++ type doped polysilicon layer 24, a second silicon nitride layer 25, and a second nanoparticle composite layer 26 which are stacked in sequence; the second silicon nitride layer 25 includes a first sublayer, a second sublayer, and a third sublayer which are stacked in sequence; the first sublayer is closer to the n++ type doped polysilicon layer 24 than the third sublayer; the refractive index of the first sublayer is 2.25, the refractive index of the second sublayer is 2.15, and the refractive index of the third sublayer is 2.05; the refractive indices of the first sublayer, the second sublayer, and the third sublayer decrease in sequence; the thickness of the first sublayer is 20nm, the thickness of the second sublayer is 20nm, and the thickness of the third sublayer is 30nm.

[0072] The specific preparation process of TOPCon battery is as follows: (1) Cleaning and texturing: cleaning the contaminants on the surface of the N-type substrate silicon 10, polishing the surface of the silicon wafer, and forming a velvet structure; (2) Front boron diffusion: Boron element is diffused on the N-type substrate silicon 10 to form a pn junction and obtain a P-type emitter 11.

[0073] (3) Borosilicate glass (BSG) removal + alkali polishing: remove the borosilicate glass layer on the surface of the silicon wafer to prepare for the subsequent passivation layer deposition.

[0074] (4) Deposition and preparation of a first silicon oxide layer 21 as a tunneling layer: nitrous oxide (N 2 O) gas as the raw material gas, and a 1nm tunnel oxide layer (SiO x ), obtaining a first silicon oxide layer 21.

[0075] (5) Preparation of phosphorus-doped polysilicon layer by back diffusion: Silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) as the raw material gas, using PECVD method to deposit a 20nm n+ doped polysilicon layer 22 on the back; using nitrous oxide (N 2 O) gas as the raw material gas, and a 0.5 nm tunnel oxide layer (SiO x ), obtain the second silicon oxide layer 23; with silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) is used as the raw material gas, and a 60nm n++ type doped polysilicon layer 24 is deposited on the back side using the PECVD method.

[0076] (6) PSG removal + RCA cleaning: remove the PSG layer on the back and clean it.

[0077] (7) Plasma-enhanced atomic layer deposition (PEALD) technology: trimethylaluminum (TMA), water vapor (H 2 O) and inert gas as raw materials, a 4nm aluminum oxide layer 12 is deposited on the front side of the silicon wafer.

[0078] (8) PECVD coating of silicon nitride anti-reflection film on the front and back: Silane (SiH 4 ), nitrous oxide (N 2 O) is used as the raw material gas, and a silicon nitride film is deposited on the front and back sides of the silicon wafer using the PECVD method to form a 40nm first silicon nitride layer 13 on the front side of the silicon wafer and a 70nm second silicon nitride layer 25 on the back side of the silicon wafer.

[0079] (9) Silane (SiH 4 ), ammonia (NH 3 ), nitrous oxide (N 2 O) as the raw material gas, using the PECVD method to deposit a 20nm silicate oxynitride layer 14 (SiON) on the front side of the silicon wafer; using silane (SiH 4 ), nitrous oxide (N 2O) as the raw material gas, and a 5 nm silicon dioxide layer 15 (SiO 2 ); Silicon dioxide layer 15 (SiO 2 ) has a refractive index of 1.65; (10) The mixed dispersion is applied to the front and back sides of the silicon wafer respectively, and a first nanoparticle composite layer 16 with a thickness of 1 μm is prepared on the front side of the silicon wafer, and a second nanoparticle composite layer 26 with a thickness of 1 μm is prepared on the back side of the silicon wafer. The preparation method of the mixed dispersion is as follows: 1) Yttrium vanadate nanoparticles doped with trivalent europium and trivalent bismuth (YVO 4 :Eu 3+ ,Bi 3+ ) and silver nanoparticles (Ag) are dispersed in alcohol; 2) ultrasonic oscillation and mixing at a specific frequency at room temperature for 1H; 3) silver nanoparticles (Ag) are adsorbed onto trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) surface, forming surface-loaded silver nanoparticles-doped trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ @Ag) composite structure to obtain a mixed dispersion; wherein the ratio of the doping concentration of trivalent europium ions to the doping concentration of trivalent bismuth ions is 1:1; the doping concentration of trivalent bismuth ions is 0.4 mol%; the weight ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is 1:1; the particle size of the silver nanoparticles is 1 nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 100 nm; (11) Screen printing: Prepare the front and rear electrodes by screen printing technology; (12) Sintering: Good ohmic contact is formed through high temperature sintering.

[0080] Example 2 A TOPCon battery, such as Figure 1As shown, it includes: an N-type substrate silicon 10, the front side of the N-type substrate silicon 10 includes a P-type emitter 11, an aluminum oxide layer 12, a first silicon nitride layer 13, a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence, the first nanoparticle composite layer 16 is closer to the light receiving surface than the aluminum oxide layer 12, that is, the aluminum oxide layer 12 is closer to the N-type substrate silicon 10 than the first nanoparticle composite layer 16; the first silicon nitride layer 13 includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer 12 than the third sub-silicon nitride layer; the refractive index of the first sub-silicon nitride layer is 2.35, the refractive index of the second sub-silicon nitride layer is 2.20, and the refractive index of the third sub-silicon nitride layer is 2.10 ; The refractive indexes of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; the thickness of the first sub-silicon nitride layer is 15nm, the thickness of the second sub-silicon nitride layer is 15nm, and the thickness of the third sub-silicon nitride layer is 10nm; the silicate oxynitride layer 14 includes a first sub-siliconate oxynitride layer and a second sub-siliconate oxynitride layer stacked in sequence; the first sub-siliconate oxynitride layer is closer to the first silicon nitride layer 13 than the second sub-siliconate oxynitride layer; the refractive index of the first sub-siliconate oxynitride layer is 1.95, and the refractive index of the second sub-siliconate oxynitride layer is 1.92; the refractive index of the first sub-siliconate oxynitride layer is higher than the refractive index of the second sub-siliconate oxynitride layer; the thickness of the first sub-siliconate oxynitride layer is 10nm, and the thickness of the second sub-siliconate oxynitride layer is 10nm; The back side of the N-type substrate silicon 10 includes a first silicon oxide layer 21, an n+ type doped polysilicon layer 22, a second silicon oxide layer 23, an n++ type doped polysilicon layer 24, a second silicon nitride layer 25, and a second nanoparticle composite layer 26 which are stacked in sequence; the second silicon nitride layer 25 includes a first sublayer, a second sublayer, and a third sublayer which are stacked in sequence; the first sublayer is closer to the n++ type doped polysilicon layer 24 than the third sublayer; the refractive index of the first sublayer is 2.35, the refractive index of the second sublayer is 2.20, and the refractive index of the third sublayer is 2.10; the refractive indices of the first sublayer, the second sublayer, and the third sublayer decrease in sequence; the thickness of the first sublayer is 20nm, the thickness of the second sublayer is 20nm, and the thickness of the third sublayer is 30nm.

[0081] The specific preparation process of TOPCon battery is as follows: (1) Cleaning and texturing: cleaning the contaminants on the surface of the N-type substrate silicon 10, polishing the surface of the silicon wafer, and forming a velvet structure; (2) Front boron diffusion: Boron element is diffused on the N-type substrate silicon 10 to form a pn junction and obtain a P-type emitter 11.

[0082] (3) Borosilicate glass (BSG) removal + alkali polishing: remove the borosilicate glass layer on the surface of the silicon wafer to prepare for the subsequent passivation layer deposition.

[0083] (4) Deposition and preparation of a first silicon oxide layer 21 as a tunneling layer: nitrous oxide (N 2 O) gas as the raw material gas, and a 1nm tunnel oxide layer (SiO x ), obtaining a first silicon oxide layer 21.

[0084] (5) Preparation of phosphorus-doped polysilicon layer by back diffusion: Silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) as the raw material gas, using PECVD method to deposit a 20nm n+ doped polysilicon layer 22 on the back; using nitrous oxide (N 2 O) gas as the raw material gas, and a 0.5 nm tunnel oxide layer (SiO x ), obtain the second silicon oxide layer 23; with silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) is used as the raw material gas, and a 60nm n++ type doped polysilicon layer 24 is deposited on the back side using the PECVD method.

[0085] (6) PSG removal + RCA cleaning: remove the PSG layer on the back and clean it.

[0086] (7) Plasma-enhanced atomic layer deposition (PEALD) technology: trimethylaluminum (TMA), water vapor (H 2 O) and inert gas as raw materials, a 4nm aluminum oxide layer 12 is deposited on the front side of the silicon wafer.

[0087] (8) PECVD coating of silicon nitride anti-reflection film on the front and back: Silane (SiH 4 ), nitrous oxide (N 2 O) is used as the raw material gas, and a silicon nitride film is deposited on the front and back sides of the silicon wafer using the PECVD method to form a 40nm first silicon nitride layer 13 on the front side of the silicon wafer and a 70nm second silicon nitride layer 25 on the back side of the silicon wafer.

[0088] (9) Silane (SiH 4 ), ammonia (NH 3 ), nitrous oxide (N 2 O) as the raw material gas, using the PECVD method to deposit a 20nm silicate oxynitride layer 14 (SiON) on the front side of the silicon wafer; using silane (SiH 4 ), nitrous oxide (N 2O) as the raw material gas, and a 5 nm silicon dioxide layer 15 (SiO 2 ); Silicon dioxide layer 15 (SiO 2 ) has a refractive index of 1.65; (10) The mixed dispersion is applied to the front and back sides of the silicon wafer respectively, and a first nanoparticle composite layer 16 with a thickness of 10 μm is prepared on the front side of the silicon wafer, and a second nanoparticle composite layer 26 with a thickness of 10 μm is prepared on the back side of the silicon wafer. The preparation method of the mixed dispersion is as follows: 1) Yttrium vanadate nanoparticles doped with trivalent europium and trivalent bismuth (YVO 4 :Eu 3+ ,Bi 3+ ) and silver nanoparticles (Ag) are dispersed in alcohol; 2) ultrasonic oscillation and mixing at a specific frequency at room temperature for 1H; 3) silver nanoparticles (Ag) are adsorbed onto trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) surface, forming surface-loaded silver nanoparticles-doped trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ @Ag) composite structure to obtain a mixed dispersion; wherein the ratio of the doping concentration of trivalent europium ions to the doping concentration of trivalent bismuth ions is 5:1; the doping concentration of trivalent bismuth ions is 1.2 mol%; the weight ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is 5:1; the particle size of the silver nanoparticles is 10 nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 100 nm; (11) Screen printing: Prepare the front and rear electrodes by screen printing technology; (12) Sintering: Good ohmic contact is formed through high temperature sintering.

[0089] Example 3 A TOPCon battery, such as Figure 1As shown, it includes: an N-type substrate silicon 10, the front side of the N-type substrate silicon 10 includes a P-type emitter 11, an aluminum oxide layer 12, a first silicon nitride layer 13, a silicate oxynitride layer 14, a silicon dioxide layer 15, and a first nanoparticle composite layer 16 stacked in sequence, the first nanoparticle composite layer 16 is closer to the light receiving surface than the aluminum oxide layer 12, that is, the aluminum oxide layer 12 is closer to the N-type substrate silicon 10 than the first nanoparticle composite layer 16; the first silicon nitride layer 13 includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer 12 than the third sub-silicon nitride layer; the refractive index of the first sub-silicon nitride layer is 2.25, the refractive index of the second sub-silicon nitride layer is 2.15, and the refractive index of the third sub-silicon nitride layer is 2.05 ; The refractive indexes of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; the thickness of the first sub-silicon nitride layer is 15 nm, the thickness of the second sub-silicon nitride layer is 15 nm, and the thickness of the third sub-silicon nitride layer is 10 nm; the silicate oxynitride layer 14 includes a first sub-siliconate oxynitride layer and a second sub-siliconate oxynitride layer stacked in sequence; the first sub-siliconate oxynitride layer is closer to the first silicon nitride layer 13 than the second sub-siliconate oxynitride layer; the refractive index of the first sub-siliconate oxynitride layer is 1.93, and the refractive index of the second sub-siliconate oxynitride layer is 1.90; the refractive index of the first sub-siliconate oxynitride layer is higher than the refractive index of the second sub-siliconate oxynitride layer; the thickness of the first sub-siliconate oxynitride layer is 10 nm, and the thickness of the second sub-siliconate oxynitride layer is 10 nm; The back side of the N-type substrate silicon 10 includes a first silicon oxide layer 21, an n+ type doped polysilicon layer 22, a second silicon oxide layer 23, an n++ type doped polysilicon layer 24, a second silicon nitride layer 25, and a second nanoparticle composite layer 26 stacked in sequence; the second silicon nitride layer 25 includes a first sublayer, a second sublayer, a third sublayer, and a fourth sublayer stacked in sequence; the first sublayer is closer to the n++ type doped polysilicon layer 24 than the fourth sublayer; the refractive index of the first sublayer is 2.25, the refractive index of the second sublayer is 2.20, the refractive index of the third sublayer is 2.15, and the refractive index of the fourth sublayer is 2.10; the refractive indices of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer decrease in sequence; the thickness of the first sublayer is 20nm, the thickness of the second sublayer is 20nm, the thickness of the third sublayer is 15nm, and the thickness of the fourth sublayer is 15m.

[0090] The specific preparation process of TOPCon battery is as follows: (1) Cleaning and texturing: cleaning the contaminants on the surface of the N-type substrate silicon 10, polishing the surface of the silicon wafer, and forming a velvet structure; (2) Front boron diffusion: Boron element is diffused on the N-type substrate silicon 10 to form a pn junction and obtain a P-type emitter 11.

[0091] (3) Borosilicate glass (BSG) removal + alkali polishing: remove the borosilicate glass layer on the surface of the silicon wafer to prepare for the subsequent passivation layer deposition.

[0092] (4) Deposition and preparation of a first silicon oxide layer 21 as a tunneling layer: nitrous oxide (N 2 O) gas as the raw material gas, and a 1nm tunnel oxide layer (SiO x ), obtaining a first silicon oxide layer 21.

[0093] (5) Preparation of phosphorus-doped polysilicon layer by back diffusion: Silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) as the raw material gas, using PECVD method to deposit a 20nm n+ doped polysilicon layer 22 on the back; using nitrous oxide (N 2 O) gas as the raw material gas, and a 0.5 nm tunnel oxide layer (SiO x ), obtain the second silicon oxide layer 23; with silane (SiH 4 ), hydrogen (H 2 ), phosphine (PH 3 ) is used as the raw material gas, and a 60nm n++ type doped polysilicon layer 24 is deposited on the back side using the PECVD method.

[0094] (6) PSG removal + RCA cleaning: remove the PSG layer on the back and clean it.

[0095] (7) Plasma-enhanced atomic layer deposition (PEALD) technology: trimethylaluminum (TMA), water vapor (H 2 O) and inert gas as raw materials, a 4nm aluminum oxide layer 12 is deposited on the front side of the silicon wafer.

[0096] (8) PECVD coating of silicon nitride anti-reflection film on the front and back: Silane (SiH 4 ), nitrous oxide (N 2 O) is used as the raw material gas, and a silicon nitride film is deposited on the front and back sides of the silicon wafer using the PECVD method to form a 40nm first silicon nitride layer 13 on the front side of the silicon wafer and a 70nm second silicon nitride layer 25 on the back side of the silicon wafer.

[0097] (9) Silane (SiH 4 ), ammonia (NH 3 ), nitrous oxide (N 2 O) as the raw material gas, using the PECVD method to deposit a 20nm silicate oxynitride layer 14 (SiON) on the front side of the silicon wafer; using silane (SiH 4), nitrous oxide (N 2 O) as the raw material gas, and a 5 nm silicon dioxide layer 15 (SiO 2 ); Silicon dioxide layer 15 (SiO 2 ) has a refractive index of 1.65; (10) The mixed dispersion is applied to the front and back sides of the silicon wafer respectively, and a first nanoparticle composite layer 16 with a thickness of 10 μm is prepared on the front side of the silicon wafer, and a second nanoparticle composite layer 26 with a thickness of 10 μm is prepared on the back side of the silicon wafer. The preparation method of the mixed dispersion is as follows: 1) Yttrium vanadate nanoparticles doped with trivalent europium and trivalent bismuth (YVO 4 :Eu 3+ ,Bi 3+ ) and silver nanoparticles (Ag) are dispersed in alcohol; 2) ultrasonic oscillation and mixing at a specific frequency at room temperature for 1H; 3) silver nanoparticles (Ag) are adsorbed onto trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ ) surface, forming surface-loaded silver nanoparticles-doped trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles (YVO 4 :Eu 3+ ,Bi 3+ @Ag) composite structure to obtain a mixed dispersion; wherein the ratio of the doping concentration of trivalent europium ions to the doping concentration of trivalent bismuth ions is 3:1; the doping concentration of trivalent bismuth ions is 0.8mol%; the weight ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is 3:1; the particle size of the silver nanoparticles is 2nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 80nm; (11) Screen printing: Prepare the front and rear electrodes by screen printing technology; (12) Sintering: Good ohmic contact is formed through high temperature sintering.

[0098] Example 4 The TOPCon cell of Example 4 was prepared by referring to the preparation method of Example 1, except that the first silicon nitride layer 13 was different. The first silicon nitride layer 13 in Example 4 had only one layer, a refractive index of 2.25, and a thickness of 40 nm.

[0099] Example 5 The TOPCon cell of Example 5 was prepared by referring to the preparation method of Example 1, except that the silicate oxynitride layer 14 was different. The silicate oxynitride layer 14 in Example 5 had only one layer, a refractive index of 1.90, and a thickness of 20 nm.

[0100] Example 6 The TOPCon cell of Example 6 is prepared by referring to the preparation method of Example 1, except that the silicate oxynitride layer 14 and the first silicon nitride layer 13 are different; the silicate oxynitride layer 14 in Example 6 has only one layer, a refractive index of 1.90, and a thickness of 20 nm; the first silicon nitride layer 13 in Example 6 has only one layer, a refractive index of 2.25, and a thickness of 40 nm.

[0101] Example 7 The TOPCon cell of Example 7 was prepared by referring to the preparation method of Example 1, except that the second silicon nitride layer 25 was different. The second silicon nitride layer 25 in Example 7 had only one layer, a refractive index of 2.15, and a thickness of 70 nm.

[0102] Example 8 The TOPCon cell of Example 8 is prepared by referring to the preparation method of Example 1, with the only difference being that the silicate oxynitride layer 14, the first silicon nitride layer 13 and the second silicon nitride layer 25 are all different; the silicate oxynitride layer 14 in Example 8 has only one layer, a refractive index of 1.90 and a thickness of 20 nm; the first silicon nitride layer 13 in Example 8 has only one layer, a refractive index of 2.25 and a thickness of 40 nm; the second silicon nitride layer 25 in Example 8 has only one layer, a refractive index of 2.15 and a thickness of 70 nm.

[0103] Example 9 The TOPCon battery of Example 9 was prepared by referring to the preparation method of Example 1, except that the thickness of the second nanoparticle composite layer 26 of Example 9 was 4 μm; the thickness of the first nanoparticle composite layer 16 of Example 9 was 4 μm.

[0104] Example 10 The TOPCon battery of Example 10 was prepared by referring to the preparation method of Example 1, except that the thickness of the second nanoparticle composite layer 26 of Example 10 was 6 μm; the thickness of the first nanoparticle composite layer 16 of Example 10 was 6 μm.

[0105] Embodiment 11 The TOPCon battery of Example 11 is prepared by referring to the preparation method of Example 1, except that the TOPCon battery of Example 11 does not have the second nanoparticle composite layer 26 .

[0106] Example 12 The TOPCon battery of Example 12 is prepared by referring to the preparation method of Example 1, except that the TOPCon battery of Example 12 does not have the first nanoparticle composite layer 16 .

[0107] Example 13 The TOPCon battery of Example 13 was prepared by referring to the preparation method of Example 1, except that the preparation method of the mixed dispersion of Example 13 was as follows: yttrium vanadate nanoparticles doped with trivalent europium and trivalent bismuth (YVO 4 :Eu 3+ ,Bi 3+ ) and silver nanoparticles (Ag) were dispersed in alcohol and only mixed evenly (no surface-loaded silver nanoparticles were formed) 4 :Eu 3+ ,Bi 3+ @Ag) composite structure), to obtain a mixed dispersion; wherein, the ratio of the doping concentration of trivalent europium ions to the doping concentration of trivalent bismuth ions is 1:1; the doping concentration of trivalent bismuth ions is 0.4mol%; the weight ratio of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to silver nanoparticles is 1:1; the particle size of the silver nanoparticles is 1nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 50nm.

[0108] Embodiment 14 The TOPCon cell of Example 14 is prepared by referring to the preparation method of Example 1, with the only difference being that the TOPCon cell of Example 14 does not have a silicate oxynitride layer 14, and the TOPCon cell of Example 14 does not have a silicon dioxide layer 15; that is, the front side of the TOPCon cell in Example 14 includes a P-type emitter 11, an aluminum oxide layer 12, a first silicon nitride layer 13, and a first nanoparticle composite layer 16 stacked in sequence.

[0109] Comparative Example 1 The TOPCon cell of Comparative Example 1 is prepared by referring to the preparation method of Example 1, with the only difference being that the second nanoparticle composite layer 26 is not provided on the back of the TOPCon cell of Comparative Example 1, and the silicate oxynitride layer 14, the silicon dioxide layer 15, and the first nanoparticle composite layer 16 are not provided on the front of the TOPCon cell of Comparative Example 1; that is, the front of the TOPCon cell in Comparative Example 1 includes a P-type emitter 11, an aluminum oxide layer 12, and a first silicon nitride layer 13 stacked in sequence, and the back of the TOPCon cell includes a first silicon oxide layer 21, an n+ type doped polysilicon layer 22, a second silicon oxide layer 23, an n++ type doped polysilicon layer 24, and a second silicon nitride layer 25 stacked in sequence.

[0110] The following is a performance test of the TOPCon batteries provided in Examples 1-14 of the present application and Comparative Example 1. The test results are shown in Table 1.

[0111] Table 1 Performance test results of TOPCon batteries of Examples 1-14 and Comparative Example 1

[0112] Referring to the battery performance test results of Examples 1-14 and Comparative Example 1, it can be seen that a nanoparticle composite layer containing trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles and silver nanoparticles is used as a nanoparticle composite layer. Under the interaction of trivalent europium, trivalent bismuth, yttrium vanadate nanoparticles and silver nanoparticles, a localized surface plasmon resonance enhanced luminescence frequency reduction nanomaterial can be formed, thereby efficiently converting high-energy ultraviolet photons into low-energy photons of a specific wavelength, effectively reducing the absorption of ultraviolet rays optically, and significantly reducing ultraviolet induced attenuation (UVID); using the nanoparticle composite layer on a solar cell can effectively improve the anti-ultraviolet attenuation performance of the solar cell without affecting the photoelectric conversion efficiency of the solar cell.

[0113] Referring to the battery performance test results of Example 1 and Example 14, it can be seen that optimizing the front light absorption structure and utilizing the interaction between the layers can, on the one hand, assist the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reduce the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also promote light absorption, thereby improving the photoelectric conversion efficiency of solar cells.

[0114] Referring to the battery performance test results of Example 1 and Example 13, it can be seen that loading silver nanoparticles on the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles plays a role in optimizing the material structure of the nanoparticle composite layer, facilitating more efficient conversion of high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID).

[0115] With reference to the battery performance test results of Examples 1-3, Example 8, Example 6 and Example 4, it can be seen that optimizing the structure of the first silicon nitride layer 13, on the one hand, facilitates assisting the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thereby improve the photoelectric conversion efficiency of solar cells.

[0116] With reference to the battery performance test results of Examples 1-3, Example 8, Example 6 and Example 5, it can be seen that optimizing the structure of the silicate oxynitride layer 14, on the one hand, facilitates assisting the first nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thereby improve the photoelectric conversion efficiency of solar cells.

[0117] Referring to the battery performance test results of Examples 1-3, Example 8 and Example 7, it can be seen that optimizing the structure of the second silicon nitride layer 25 is, on the one hand, convenient for assisting the second nanoparticle composite layer to more efficiently convert high-energy ultraviolet photons into low-energy photons of a specific wavelength, further optically reducing the absorption of ultraviolet rays, thereby further reducing ultraviolet induced attenuation (UVID); on the other hand, it can also play a role in anti-reflection, promote light absorption, and thus improve the photoelectric conversion efficiency of solar cells. It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. 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. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself. For example, if a device in a drawing is inverted, a device described as "above" or "over" other devices or structures would then be oriented "below" or "beneath" the other devices or structures. Thus, the exemplary term "above" can encompass both "above" and "below." The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0118] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0119] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0120] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0121] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A nanoparticle composite layer, characterized in that: The materials of the nano-particle composite layer include trivalent europium-doped trivalent bismuth-doped yttrium vanadate nano-particles and silver nano-particles.

2. The nanoparticle composite layer according to claim 1, characterized in that The thickness of the nanoparticle composite layer is 1-10 μm.

3. The nanoparticle composite layer according to claim 1, characterized in that The trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles are prepared by taking yttrium vanadate as a matrix material and doping trivalent europium ions and trivalent bismuth ions; wherein the ratio of the doping concentration of the trivalent europium ions to the doping concentration of the trivalent bismuth ions is 1-5.

4. The nanoparticle composite layer according to claim 1, characterized in that In the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles, the doping concentration of the trivalent bismuth ions is 0.4-1.2 mol %.

5. The nanoparticle composite layer according to claim 1, characterized in that: The weight ratio of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to the silver nanoparticles is 1-5.

6. The nanoparticle composite layer according to claim 1, characterized in that The particle size of the silver nanoparticles is 1-10 nm, and the particle size of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles is 50-100 nm.

7. The nanoparticle composite layer according to any one of claims 1 to 6, characterized in that The silver nanoparticles are loaded on the outer surface of the trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles.

8. A method for preparing a nanoparticle composite layer, characterized in that: include: Loading silver nanoparticles onto the outer surface of trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles to form trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles with the silver nanoparticles loaded on the surface; The trivalent europium-doped trivalent bismuth-doped yttrium vanadate nanoparticles with the silver nanoparticles on the surface are coated on a substrate to form a nanoparticle composite layer.

9. A front light absorption structure, characterized in that: The front light absorption structure comprises: an aluminum oxide layer, a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Or, the front light absorption structure comprises: a first silicon nitride layer, a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Or, the front light absorption structure comprises: a silicate oxynitride layer, a silicon dioxide layer, and a first nanoparticle composite layer stacked in sequence; Wherein, the first nanoparticle composite layer is selected from the nanoparticle composite layer described in any one of claims 1 to 7, or is prepared by the method for preparing a nanoparticle composite layer according to claim 8.

10. The front light absorption structure according to claim 9, characterized in that: The first silicon nitride layer includes a first sub-silicon nitride layer, a second sub-silicon nitride layer, and a third sub-silicon nitride layer stacked in sequence; the first sub-silicon nitride layer is closer to the aluminum oxide layer than the third sub-silicon nitride layer; and the refractive indices of the first sub-silicon nitride layer, the second sub-silicon nitride layer, and the third sub-silicon nitride layer decrease in sequence; And / or, the silicate oxynitride layer includes a first sub-silicate oxynitride layer and a second sub-silicate oxynitride layer stacked in sequence; the first sub-silicate oxynitride layer is closer to the first silicon nitride layer than the second sub-silicate oxynitride layer; and the refractive index of the first sub-silicate oxynitride layer is higher than the refractive index of the second sub-silicate oxynitride layer.

11. The front light absorption structure according to claim 10, characterized in that: The refractive index of the first silicon nitride layer is 2.25-2.35, the refractive index of the second silicon nitride layer is 2.15-2.20, and the refractive index of the third silicon nitride layer is 2.05-2.10; The refractive index of the first silicate oxynitride layer is 1.90-1.95, and the refractive index of the second silicate oxynitride layer is 1.90-1.

95.

12. A TOPCon battery, characterized in that: The back side of the TOPCon cell includes a first silicon oxide layer, an n+ type doped polysilicon layer, a second silicon oxide layer, an n++ type doped polysilicon layer, a second silicon nitride layer, and a second nanoparticle composite layer stacked in sequence; The second nanoparticle composite layer is selected from the nanoparticle composite layer described in any one of claims 1 to 6, or is prepared by the preparation method of the nanoparticle composite layer described in claim 7; the first silicon oxide layer is closer to the silicon substrate of the TOPCon battery than the second nanoparticle composite layer.

13. The TOPCon battery according to claim 12, characterized in that The second silicon nitride layer includes a first sublayer, a second sublayer, and a third sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the third sublayer; and the refractive indices of the first sublayer, the second sublayer, and the third sublayer decrease in sequence; Or, the second silicon nitride layer includes a first sublayer, a second sublayer, a third sublayer, and a fourth sublayer stacked in sequence; the first sublayer is closer to the n++-type doped polysilicon layer than the fourth sublayer; and the refractive indices of the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer decrease in sequence.

14. The TOPCon battery according to claim 13, characterized in that When the second silicon nitride layer includes the first sublayer, the second sublayer, and the third sublayer stacked in sequence, the refractive index of the first sublayer is 2.25-2.35, the refractive index of the second sublayer is 2.15-2.20, and the refractive index of the third sublayer is 2.05-2.10; When the second silicon nitride layer includes the first sublayer, the second sublayer, the third sublayer, and the fourth sublayer stacked in sequence, the refractive index of the first sublayer is 2.25~2.35, the refractive index of the second sublayer is 2.20~2.25, the refractive index of the third sublayer is 2.15~2.20, and the refractive index of the fourth sublayer is 2.10~2.15.

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