Solar cell and photovoltaic module

Abstract

The utility model relates to the technical field of solar cells, and discloses a solar cell and a photovoltaic assembly. The functional layer is arranged on the silicon substrate, and the functional layer comprises at least one of a silicon nitride layer, a silicon oxynitride layer or a silicon oxide layer; the ultraviolet-proof layer is arranged on the surface of the side, away from the silicon substrate, of the functional layer, and the ultraviolet-proof layer is a zinc oxide layer. The solar cell has relatively high ultraviolet resistance, so that the long-term stability of the solar cell is ensured, the service life of the solar cell is prolonged, and the photoelectric conversion performance of the solar cell is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar cell technical field especially relates to a solar cell, photovoltaic module. BACKGROUND

[0002] The energy of ultraviolet is higher, and the solar cell is under the irradiation of ultraviolet for a long time, which not only causes the surface of the solar cell to produce cracks and the roughness to be high, but also causes the internal reaction of the solar cell, so that the structural stability of the solar cell is poor, thereby the service life and photoelectric conversion efficiency of the solar cell are shortened to a high degree. SUMMARY

[0003] The utility model discloses a solar cell, photovoltaic module, the solar cell has higher anti ultraviolet performance to guarantee the long -term stability of solar cell, help to improve its service life and photoelectric conversion performance.

[0004] In a first aspect, the embodiments of the present application disclose a solar cell, which comprises:

[0005] A silicon substrate;

[0006] A functional layer, which is arranged on the silicon substrate, and comprises at least one of a silicon nitride layer, a silicon oxynitride layer or a silicon oxide layer;

[0007] An ultraviolet-proof layer, which is arranged on the side surface of the functional layer away from the silicon substrate, and is a zinc oxide layer.

[0008] Further, the thickness of the ultraviolet-proof layer is 2nm-5nm.

[0009] Further, the zinc oxide layer is a crystal zinc oxide layer, and the particle size of the crystal in the crystal zinc oxide layer is 30nm-80nm.

[0010] Further, the refractive index of the ultraviolet-proof layer is 2.32-2.48, and the visible light transmittance of the ultraviolet-proof layer is 85%-95%; and / or,

[0011] The band gap of the ultraviolet-proof layer is 3.12eV-3.35eV.

[0012] Further, the functional layer comprises a first functional layer and a second functional layer, the first functional layer is arranged on the light-receiving surface of the silicon substrate, and the second functional layer is arranged on the back surface of the silicon substrate.

[0013] The anti-ultraviolet layer comprises a first anti-ultraviolet layer and a second anti-ultraviolet layer, the first anti-ultraviolet layer is arranged on the side surface of the first functional layer away from the silicon substrate, and the second anti-ultraviolet layer is arranged on the side surface of the second functional layer away from the silicon substrate.

[0014] Further, the back surface of the silicon substrate is further provided with a passivation contact structure between the second functional layer and the silicon substrate, wherein the passivation contact structure comprises a dielectric layer and a doped layer on the side surface of the dielectric layer away from the silicon substrate, and the doped layer is a carbon-doped polysilicon layer.

[0015] Further, the doped layer comprises a first doped layer and a second doped layer, and the passivation contact structure comprises the dielectric layer, the first doped layer, a barrier layer and the second doped layer in sequence along the direction from the silicon substrate to the anti-ultraviolet layer, and the material of the barrier layer comprises at least one of silicon oxide, magnesium fluoride, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide.

[0016] Further, the solar cell further comprises a first diffusion layer and a passivation layer arranged in sequence between the silicon substrate and the first functional layer, and the solar cell further comprises a second diffusion layer arranged between the passivation contact structure and the silicon substrate, wherein the conductive type of one of the first diffusion layer and the second diffusion layer is N type and the conductive type of the other is P type.

[0017] The solar cell further comprises a first electrode arranged on the side surface of the first anti-ultraviolet layer away from the silicon substrate and a second electrode arranged on the side surface of the second anti-ultraviolet layer away from the silicon substrate, wherein one of the first electrode and the second electrode is a positive electrode and the other is a negative electrode.

[0018] In a second aspect, the embodiments of the present application disclose a photovoltaic module, comprising the solar cell of any one of the first aspect.

[0019] Compared with the prior art, the present application has at least the following beneficial effects:

[0020] The present application provides a solar cell, which comprises a silicon substrate, and a functional layer and an anti-ultraviolet layer arranged in sequence on the silicon substrate. Since the material of the functional layer comprises at least one of silicon nitride, silicon oxynitride or silicon oxide, the performance of the functional layer is seriously attenuated due to the influence of ultraviolet rays. By further arranging the anti-ultraviolet layer, which is a zinc oxide layer, the anti-ultraviolet layer can effectively resist ultraviolet rays, thereby reducing the adverse effects of ultraviolet rays on the functional layer to a higher degree, and improving the photoelectric conversion efficiency and service life of the solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the embodiments will be briefly introduced as follows. Obviously, the drawings described in the following embodiments are only some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art based on these drawings without creative labor are within the protection scope of the present application.

[0022] Figure 1 is a structural schematic diagram of a first solar cell provided by the embodiments of the present application;

[0023] Figure 2 is a structural schematic diagram of a second solar cell provided by the embodiments of the present application;

[0024] Figure 3 is a structural schematic diagram of a third solar cell provided by the embodiments of the present application.

[0025] Icon: 1, silicon substrate; 2, functional layer; 21, first functional layer; 211, silicon nitride layer; 212, silicon oxynitride layer; 213, silicon oxide layer; 22, second functional layer; 3, ultraviolet-proof layer; 31, first ultraviolet-proof layer; 32, second ultraviolet-proof layer; 4, passivation contact structure; 41, dielectric layer; 42, doped layer; 421, first doped layer; 422, second doped layer; 43, barrier layer; 5, first diffusion layer; 6, passivation layer; 7, second diffusion layer; 8, first electrode; 9, second electrode. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor are within the protection scope of the present application.

[0027] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "transverse", "longitudinal" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0028] Furthermore, in addition to indicating direction or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this utility model according to the specific circumstances.

[0029] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0030] The technical solution provided by this utility model will be further described below with reference to the embodiments and accompanying drawings.

[0031] Ultraviolet radiation has high energy intensity. Under ultraviolet radiation, some materials of solar cells will age and decompose, resulting in more defects in the solar cells, damaging the crystal structure of the solar cells, affecting the passivation effect of functional layers, and leading to an increase in carrier recombination and dangling bonds, thereby affecting the lifespan and photoelectric conversion efficiency of solar cells.

[0032] Currently, production lines reduce the amount of ultraviolet (UV) radiation transmitted to the solar cells by encapsulating UV-resistant materials on the cells. However, this method places high demands on the encapsulation process, increasing the difficulty of module manufacturing and quality control. This results in poor process stability, making it difficult to effectively improve the UV resistance of the solar cells. Furthermore, the difference in the coefficient of thermal expansion between the encapsulation material and the materials within the solar cell can generate stress during temperature changes, potentially leading to solar cell cracking or encapsulation failure, thus affecting the performance of the solar cells.

[0033] Based on the above problems, this application provides a solar cell with high UV resistance, thereby ensuring the long-term stability of the solar cell and helping to improve its service life and photoelectric conversion performance.

[0034] Firstly, embodiments of this application disclose a solar cell, such as... Figure 1 As shown, the solar cell includes:

[0035] Silicon substrate 1;

[0036] Functional layer 2 is disposed on silicon substrate 1, and functional layer 2 includes at least one of silicon nitride layer 211, silicon oxynitride layer 212 or silicon oxide layer 213.

[0037] The anti-ultraviolet layer 3 is arranged on the side surface of the functional layer 2 away from the silicon substrate 1, and the anti-ultraviolet layer 3 is a zinc oxide layer.

[0038] The solar cell of the present application comprises a silicon substrate 1, and a functional layer 2 and an anti-ultraviolet layer 3 arranged on the silicon substrate 1 in sequence, wherein the functional layer 2 comprises at least one of a silicon nitride layer 211, a silicon oxynitride layer 212 or a silicon oxide layer 213, so that the material in the functional layer 2 will be decomposed under the long-term effect of ultraviolet light, thereby affecting the passivation effect of the functional layer 2. By further arranging the anti-ultraviolet layer on the functional layer 2, and the anti-ultraviolet layer 3 being a zinc oxide layer, the zinc oxide layer has the effect of blocking ultraviolet light, reducing the content of ultraviolet light transmitted into the solar cell, avoiding the influence of ultraviolet light on the functional layer 2, and ensuring that the functional layer 2 has a high passivation effect, which is conducive to improving the service life and photoelectric conversion efficiency of the solar cell.

[0039] Further, the thickness of the anti-ultraviolet layer 3 is 2nm-5nm. At this thickness, the anti-ultraviolet layer 3 can effectively block ultraviolet light, reduce the content of ultraviolet light transmitted into the solar cell, effectively avoid the aging and performance degradation of the solar cell, improve the long-term reliability of the solar cell, and at this thickness, the influence on the transmittance of visible light is small, ensuring that there is enough visible light to pass through, maintaining a high photoelectric conversion efficiency.

[0040] Further, the zinc oxide layer is a crystalline zinc oxide layer, and the particle size of the crystal 3a in the crystalline zinc oxide layer is 30nm-80nm. When the particle size of the crystal in the zinc oxide layer is within the above range, it is more conducive to increasing the refractive index of the anti-ultraviolet layer, thereby further reducing the content of ultraviolet light entering the solar cell, and effectively ensuring the long-term reliability of the solar cell.

[0041] In addition, the refractive index of the anti-ultraviolet layer 3 of the present application is 2.32-2.48, and the visible light transmittance of the anti-ultraviolet layer 3 is 85%-95%. When the refractive index of the anti-ultraviolet layer 3 is within the above range, it is conducive to reducing the content of ultraviolet light entering the solar cell, ensuring the passivation effect of the passivation layer; and by controlling the refractive index within the above range, it is also conducive to improving the passing rate of visible light, ensuring that the visible light passing rate of the anti-ultraviolet layer 3 is within the above range, so that the solar cell can effectively realize the conversion of solar energy, and it is conducive to improving the photoelectric conversion efficiency and service life of the solar cell.

[0042] In addition, the band gap of the anti-ultraviolet layer 3 is 3.12eV-3.35eV. When the band gap is within the above range, the anti-ultraviolet layer 3 can release the absorbed ultraviolet light in other forms, thereby having the effect of resisting ultraviolet light.

[0043] Further, the functional layer 2 is at least one of a carbon-doped silicon nitride layer 211, a carbon-doped silicon oxynitride layer 212, or a carbon-doped silicon oxide layer 213. Since the carbon element is doped in the layer structure of the functional layer 2, hydrogen escape is avoided, the enrichment of hydrogen elements and interface defects at the interface are reduced, the passivation effect is improved, and the performance of the solar cell is improved.

[0044] In a first alternative embodiment, referring back to Figure 1 , the functional layer 2 is arranged on both the light-receiving surface and the back surface of the silicon substrate 1, i.e., the functional layer 2 includes a first functional layer 21 and a second functional layer 22, the first functional layer 21 is arranged on the light-receiving surface of the silicon substrate 1, and the second functional layer 22 is arranged on the back surface of the silicon substrate 1.

[0045] The anti-ultraviolet layer 3 includes a first anti-ultraviolet layer 31 and a second anti-ultraviolet layer 32, the first anti-ultraviolet layer 31 is arranged on the side surface of the first functional layer 21 away from the silicon substrate 1, and the second anti-ultraviolet layer 32 is arranged on the side surface of the second functional layer 22 away from the silicon substrate 1.

[0046] In a second alternative embodiment, as shown in Figure 2 , the functional layer 2 is arranged on only one side surface of the silicon substrate 1, i.e., arranged on the light-receiving surface of the silicon substrate 1 or arranged on the back surface of the silicon substrate 1, and therefore the anti-ultraviolet layer 3 is also arranged on the one side surface of the silicon substrate 1.

[0047] In a third alternative embodiment, as shown in Figure 3 , the functional layer 2 is arranged on both the light-receiving surface and the back surface of the silicon substrate 1, i.e., the functional layer 2 includes a first functional layer 21 and a second functional layer 22, the first functional layer 21 is arranged on the light-receiving surface of the silicon substrate 1, and the second functional layer 22 is arranged on the back surface of the silicon substrate 1; and the anti-ultraviolet layer 3 is arranged on the first functional layer 21 or arranged on the second functional layer 22.

[0048] When the anti-ultraviolet layer 3 is arranged on both side surfaces of the silicon substrate 1, it not only increases the blocking of ultraviolet light on the light-receiving surface, but also helps to increase the blocking of ultraviolet light reflected from the ground on the back surface, thereby greatly improving the anti-ultraviolet performance of the solar cell and improving the performance of the solar cell.

[0049] Further, the back surface of the silicon substrate 1 is further provided with a passivation contact structure 4, the passivation contact structure 4 is located between the second functional layer 22 and the silicon substrate 1, wherein the passivation contact structure 4 includes a dielectric layer 41 and a doped layer 42 arranged on the side surface of the dielectric layer 41 away from the silicon substrate 1, and the doped layer 42 is a carbon-doped polysilicon layer.

[0050] It should be noted that the passivation contact structure 4 provides a good interface passivation effect for the solar cell, and the material of the dielectric layer 41 can include various dielectric materials, such as at least one of silicon oxide, magnesium fluoride, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide. Preferably, the dielectric layer 41 is a silicon oxide layer formed of silicon oxide, because the silicon oxide layer has excellent passivation performance, can minimize the recombination loss of minority carriers on the surface of the silicon substrate 1, and is a thin film with excellent durability to subsequent high-temperature processes.

[0051] The dielectric layer 41 acts as a potential barrier for electrons and holes, and can be combined with the doped layer 42 to form the passivation contact structure 4 to prevent the passage of minority carriers. The dielectric layer 41 can also have a pinhole channel effect, allowing the free movement of carriers within the solar cell, and selectively passing majority carriers through the heavily doped doped layer 42, which helps to reduce the recombination loss of minority carriers. In addition, the dielectric layer 41 can act as a diffusion barrier to prevent the diffusion of doped elements in the doped layer 42 to the silicon substrate 1. Furthermore, controlling the thickness of the dielectric layer 41 to be 0.5-4 nm helps to reduce the transmission resistance of the carriers and improve the efficiency of their transmission.

[0052] Since the doped layer 42 is a carbon-doped polycrystalline silicon layer, it can suppress the escape of hydrogen elements, reduce contact resistance, avoid the transition crystallization of the doped layer 42, alleviate the stress concentration phenomenon during the process, reduce the problem of film explosion of the doped layer 42, reduce the defects of the doped layer 42, and improve the yield and photoelectric conversion performance of the solar cell.

[0053] Optionally, the doped layer 42 includes a first doped layer 421 and a second doped layer 422, and the passivation contact structure 4 includes, in order from the silicon substrate 1 to the anti-ultraviolet layer 3, the dielectric layer 41, the first doped layer 421, a barrier layer 43, and the second doped layer 422. The material of the barrier layer 43 includes at least one of silicon oxide, magnesium fluoride, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide.

[0054] When the passivation contact structure 4 has the above structure, the transmission distance of the doped elements in the second doped layer 422 can be effectively increased, and the content of the doped elements diffusing to the silicon substrate 1 can be suppressed, which helps to reduce Auger recombination and improve the photoelectric conversion efficiency of the solar cell.

[0055] Further, the solar cell further includes a first diffusion layer 5 and a passivation layer 6 arranged in order between the silicon substrate 1 and the first functional layer 21, and the solar cell further includes a second diffusion layer 7 arranged between the passivation contact structure 4 and the silicon substrate 1, wherein the first diffusion layer 5 and the second diffusion layer 7 have one layer of N-type and the other layer of P-type.

[0056] The solar cell further comprises a first electrode 8 arranged on the surface of the first ultraviolet-proof layer 31 away from the silicon substrate 1, and a second electrode 9 arranged on the surface of the second ultraviolet-proof layer 32 away from the silicon substrate 1, wherein one of the first electrode 8 and the second electrode 9 is a positive electrode and the other is a negative electrode.

[0057] The second diffusion layer 7 refers to a region of the silicon substrate 1 with doped elements, and specifically, due to the high-temperature promotion during the annealing process, part of the doped elements will diffuse into part of the region of the silicon substrate 1, so that the silicon substrate 1 in the region is a silicon substrate 1 doped with doped elements.

[0058] In a second aspect, the embodiments of the present application disclose a photovoltaic module, comprising the solar cell of the first aspect.

[0059] The photovoltaic module comprises a solar cell string, and the solar cell string is made by welding a plurality of solar cells through a solder strip, and the ultraviolet-proof layer in the solar cell of the present application is arranged below the electrode, so as not to affect the stability of the solder strip welding, to ensure the effectiveness of the solder strip and electrode welding, thereby helping to improve the performance of the photovoltaic module.

[0060] The above has introduced in detail the solar cell and the photovoltaic module disclosed by the embodiments of the present application, and the principles and implementation manners of the present application have been described by applying specific examples. The above embodiment is only used to help understand the solar cell and the photovoltaic module: meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation manner and application range will be changed, and the above description should not be understood as the limitation of the present application.

Claims

1. A solar cell, characterized by, The solar cell comprises: a silicon substrate; a functional layer provided on the silicon substrate, the functional layer comprising at least one of a silicon nitride layer, a silicon oxynitride layer or a silicon oxide layer; an ultraviolet-proof layer provided on a side surface of the functional layer away from the silicon substrate, the ultraviolet-proof layer being a zinc oxide layer.

2. The solar cell according to claim 1, characterized in that, The thickness of the ultraviolet-proof layer is 2 nm-5 nm.

3. The solar cell according to claim 1, characterized in that, The zinc oxide layer is a crystalline zinc oxide layer, and the particle size of the crystals in the crystalline zinc oxide layer is 30 nm-80 nm.

4. The solar cell according to claim 1, characterized in that, The refractive index of the ultraviolet-proof layer is 2.32-2.48, and the visible light transmittance of the ultraviolet-proof layer is 85%-95%; and / or, The band gap of the ultraviolet-proof layer is 3.12 eV-3.35 eV.

5. The solar cell according to claim 1, characterized in that, The functional layer is at least one of a carbon-doped silicon nitride layer, a carbon-doped silicon oxynitride layer or a carbon-doped silicon oxide layer.

6. The solar cell according to claim 1, characterized in that, The functional layer comprises a first functional layer and a second functional layer, the first functional layer being provided on a light-receiving surface of the silicon substrate, and the second functional layer being provided on a back surface of the silicon substrate; The ultraviolet-proof layer comprises a first ultraviolet-proof layer and a second ultraviolet-proof layer, the first ultraviolet-proof layer being provided on a side surface of the first functional layer away from the silicon substrate, and the second ultraviolet-proof layer being provided on a side surface of the second functional layer away from the silicon substrate.

7. The solar cell according to claim 6, characterized in that The back surface of the silicon substrate is further provided with a passivation contact structure between the second functional layer and the silicon substrate, wherein the passivation contact structure comprises a dielectric layer and a doped layer provided on a side surface of the dielectric layer away from the silicon substrate, and the doped layer is a carbon-doped polysilicon layer.

8. The solar cell according to claim 7, characterized in that, The doped layer comprises a first doped layer and a second doped layer, and the passivation contact structure comprises, in sequence, the dielectric layer, the first doped layer, a barrier layer and the second doped layer in the direction from the silicon substrate to the ultraviolet-proof layer, and the material of the barrier layer comprises at least one of silicon oxide, magnesium fluoride, silicon nitride, silicon oxynitride, aluminum oxide or titanium oxide.

9. The solar cell according to claim 6, characterized in that, The solar cell further comprises a first diffusion layer and a passivation layer provided in sequence between the silicon substrate and the first functional layer, and further comprises a second diffusion layer provided between the passivation contact structure and the silicon substrate, wherein the first diffusion layer and the second diffusion layer are of one of N type and the other of P type. The solar cell further comprises a first electrode provided on a side surface of the first ultraviolet-proof layer away from the silicon substrate, and a second electrode provided on a side surface of the second ultraviolet-proof layer away from the silicon substrate, wherein one of the first electrode and the second electrode is a positive electrode and the other is a negative electrode.

10. A photovoltaic module, characterized by The solar cell comprises: The solar cell of any one of claims 1-9.

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