Solar cell with back reflector and photovoltaic module

Abstract

The utility model is suitable for the technical field of solar cells, and particularly relates to a solar cell with a back reflector and a photovoltaic assembly, the solar cell comprises a cell main body, the cell main body comprises a light-facing surface and a backlight surface opposite to the light-facing surface; the plurality of electrodes are arranged on the backlight surface and are in contact with the battery main body; the back reflector is arranged on the backlight face and located in the area where the electrodes are not arranged, the back reflector comprises a first dielectric layer and a second dielectric layer which are alternately stacked, and the refractive index of the first dielectric layer is larger than that of the second dielectric layer. According to the solar cell with the back reflector, the back reflector is arranged on the backlight surface of the cell main body, so that the back reflector and the cell main body of the solar cell do not need to be independently prepared and then assembled, and the preparation process is simpler; moreover, the back reflector is formed by overlapping the first dielectric layer and the second dielectric layer with different refractive indexes, so that the reflection effect of the back surface of the solar cell on the transmitted light of the solar cell can be improved, and the cell efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, and particularly relates to a solar cell with a back reflector and a photovoltaic module. Background Art

[0002] Solar energy is an inexhaustible renewable energy source, which is of great significance to environmental protection. The effective utilization of solar energy has become the consensus of mankind. The utilization of solar energy, especially photovoltaic power generation technology, is the most promising renewable energy technology. Solar cells have the advantages of low energy consumption, rich and pollution-free raw materials, and easy large-area production, and have been industrialized. The products are widely used in fields such as ground photovoltaic power stations, building integrated photovoltaics, and rooftop power stations.

[0003] In the prior art, in order to improve the reflectivity of the light transmitted through the front surface of the solar cell at the back surface and improve the utilization efficiency of sunlight, it is usually necessary to set a back reflector to reflect the light transmitted through the front surface of the solar cell. Generally, when the solar cell is encapsulated into a photovoltaic module, a back reflector is set on the back plate, and then the back reflector, the back plate and the solar cell are assembled to obtain a photovoltaic module. However, since the solar cell itself does not have a back reflector, the back reflector and the solar cell need to be separately prepared and then assembled, and the preparation process is complex; moreover, the existing back reflector is usually a reflector plate (such as an aluminum plate), and the reflection effect of the back reflector on the light transmitted through the solar cell is poor, resulting in low sunlight utilization efficiency of the solar cell. Summary of the Utility Model

[0004] The utility model provides a solar cell with a back reflector, aiming to solve the problems in the prior art that the solar cell and the back reflector are separately arranged, the preparation process is complex, and the reflection effect of the back reflector on the light transmitted through the solar cell is poor.

[0005] The utility model is realized as follows. A solar cell with a back reflector is provided, including:

[0006] A battery body, the battery body including a light-facing surface and a light-backing surface oppositely arranged with the light-facing surface;

[0007] A plurality of electrodes arranged on the light-backing surface and in contact with the battery body;

[0008] A back reflector arranged on the light-backing surface and located in a region where the electrodes are not arranged, the back reflector including an alternately stacked first dielectric layer and a second dielectric layer, and the refractive index of the first dielectric layer being greater than that of the second dielectric layer.

[0009] Preferably, the solar cell is a back-contact solar cell, and insulation is formed between the back reflector and the adjacent electrodes.

[0010] Preferably, it further includes:

[0011] An insulating layer provided on the back reflector, and the insulating layer at least includes a first region located between the side surface of the back reflector and the adjacent electrode.

[0012] Preferably, the insulating layer further includes a second region covering the side of the back reflector away from the backlight surface.

[0013] Preferably, the insulating layer is a single layer or a stack of one or both of a silicon nitride layer and a silicon oxide layer.

[0014] Preferably, the thickness of the insulating layer is 5 to 200 nanometers.

[0015] Preferably, the second dielectric layer is a single layer or a stack of one or both of a silicon dioxide layer and a gallium aluminum arsenide layer; the first dielectric layer is a single layer or a stack of at least two of an amorphous silicon layer, a titanium dioxide layer, an antimony trisulfide layer, and a gallium arsenide layer.

[0016] Preferably, the thickness ratio of the first dielectric layer to the second dielectric layer is 1:2.

[0017] Preferably, the second dielectric layer is a silicon dioxide layer, and the first dielectric layer is an amorphous silicon layer.

[0018] Preferably, the thickness of the first dielectric layer is 60 nanometers, and the thickness of the second dielectric layer is 125 nanometers.

[0019] Preferably, the thickness of the first dielectric layer is 25 nanometers, and the thickness of the second dielectric layer is 125 nanometers.

[0020] Preferably, the number of the back reflectors is multiple, and the back reflectors and the electrodes are alternately arranged at intervals in sequence.

[0021] Preferably, the number of periods of the alternating stacking of the first dielectric layer and the second dielectric layer of the back reflector is greater than or equal to 2.

[0022] Preferably, it further includes:

[0023] A back surface passivation layer provided on the backlight surface, the back reflector is provided on the back surface passivation layer, and the electrode passes through the back surface passivation layer to contact the battery body.

[0024] Preferably, the back surface passivation layer is a single layer or a stack of at least two of a silicon nitride layer, a silicon oxide layer, and an aluminum oxide layer.

[0025] The present utility model further provides a photovoltaic module, including the above-mentioned solar cell having a back reflector.

[0026] A solar cell with a back reflector provided by an embodiment of the present invention sets the back reflector in the area of the backlight surface of the battery body where no electrode is provided, so that the back reflector is integrally arranged on the backlight surface of the battery body. When preparing the solar cell, the back reflector can be prepared on the backlight surface of the battery body at the same time. The back reflector of the solar cell and the battery body do not need to be separately prepared and then assembled, and the preparation process is simpler; moreover, the back reflector includes alternately stacked second dielectric layers and first dielectric layers, and the refractive index of the first dielectric layer is greater than that of the second dielectric layer. By using the second dielectric layer and the first dielectric layer with different refractive indices to form the back reflector, the reflection effect of the backlight of the solar cell on the light transmitted through the solar cell can be improved, the light utilization efficiency of the solar cell can be improved, and thus the battery efficiency can be improved. Description of the Drawings

[0027] Figure 1 It is a schematic diagram of a solar cell with a back reflector provided by an embodiment of the present invention. Detailed Embodiments

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] A solar cell with a back reflector provided by an embodiment of the present invention sets the back reflector in the area of the backlight surface of the battery body where no electrode is provided, so that the back reflector is integrally arranged on the backlight surface of the battery body. When preparing the solar cell, the back reflector can be prepared on the backlight surface of the battery body at the same time. The back reflector is a part of the structure of the solar cell. There is no need to separately prepare and then assemble the back reflector and the battery body of the solar cell, and the preparation process is simpler; moreover, the back reflector includes alternately stacked first dielectric layers and second dielectric layers, and the refractive index of the first dielectric layer is greater than that of the second dielectric layer. By using the second dielectric layer and the first dielectric layer with different refractive indices to form the back reflector, the reflection effect of the backlight of the solar cell on the light transmitted through the solar cell can be improved, the light utilization efficiency of the solar cell can be improved, and thus the battery efficiency can be improved.

[0030] Please refer to Figure 1 , a solar cell 100 with a back reflector provided by an embodiment of the present invention includes:

[0031] A battery body 1, the battery body 1 includes a light-facing surface 11 and a backlight surface 12 oppositely arranged with respect to the light-facing surface 11;

[0032] A plurality of electrodes 13 arranged on the backlight surface 12 and spaced apart from each other in sequence;

[0033] A back reflector 2 is disposed on the backlight surface 12 and in a region where the non-setting electrode 13 is not located. The back reflector 2 includes a first dielectric layer 21 and a second dielectric layer 22 that are alternately stacked, and the refractive index of the first dielectric layer 21 is greater than that of the second dielectric layer 22.

[0034] In an embodiment of the present invention, the solar cell can be a back-contact solar cell or a double-sided contact solar cell. The light-facing surface 11 is the side of the battery body 1 facing the light, and the backlight surface 11 is the side of the battery body 1 facing away from the light.

[0035] Among them, the structure of the battery body 1 is the structure of a back-contact solar cell or a double-sided contact solar cell with the electrode 13 removed, and the battery body 1 can be any existing back-contact solar cell or double-sided contact solar cell.

[0036] For example, taking the solar cell as a back-contact solar cell, the battery body 1 includes:

[0037] A silicon substrate, and a P region and an N region are provided on the backlight surface 12 of the silicon substrate;

[0038] A first tunneling passivation layer provided in the P region and a second tunneling passivation layer provided in the N region;

[0039] A P-type doping layer provided on the side of the first tunneling passivation layer facing away from the silicon substrate and an N-type doping layer provided on the side of the second tunneling passivation layer facing away from the silicon substrate.

[0040] Among them, the electrode 13 at the P region position is in contact with the P-type doping layer, and the electrode 13 at the N region position is in contact with the N-type doping layer.

[0041] In an embodiment of the present invention, a solar cell with a back reflector is provided with a back reflector 2 in a region where the non-setting electrode 13 is not located on the backlight surface 12 of the battery body 1, so that the back reflector 2 is integrally provided on the backlight surface 12 of the battery body 1. When preparing the solar cell, the back reflector 2 can be prepared on the backlight surface 12 of the battery body 1 at the same time. The back reflector 2 of the solar cell and the battery body 1 do not need to be separately prepared and then assembled, and the preparation process is simpler; moreover, the back reflector 2 is formed by alternately stacking a first dielectric layer 21 and a second dielectric layer 22 with two different refractive indexes, so that the refractive indexes of the first dielectric layer 21 and the second dielectric layer 22 are set in a high-low-high-low periodicity or the refractive indexes of the first dielectric layer 21 and the second dielectric layer 22 are set in a low-high-low-high periodicity, greatly improving the reflection effect of the light transmitted through the solar cell on the back surface of the solar cell, improving the light utilization efficiency of the solar cell, and thus improving the battery efficiency. In particular, the reflectivity of the back reflector 2 to sunlight with a wavelength in the range of 700 to 1100 nm can be improved, and the sunlight reflectivity can be as high as 99%.

[0042] In the embodiment of the present invention, the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 may be overlapped in such a manner that the first dielectric layer 21 and the second dielectric layer 22 are alternately arranged in sequence along the direction from the light-facing surface 11 to the backlight surface 12; in addition, the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 may be overlapped in such a manner that the second dielectric layer 22 and the first dielectric layer 21 are alternately arranged in sequence along the direction from the light-facing surface 11 to the backlight surface 12. Figure 1 FIG. 2 only illustrates the situation in which the first dielectric layer 21 and the second dielectric layer 22 are alternately arranged in sequence from the light-facing surface 11 to the backlight surface 12 .

[0043] In the embodiment of the present invention, the refractive index of the first dielectric layer 21 and the second dielectric layer 22 can be specifically set according to actual conditions. In actual applications, the greater the difference in refractive index between the first dielectric layer 21 and the second dielectric layer 22, the better the back reflector 2 reflects light transmitted through the solar cell. As an optional embodiment, the refractive index of the first dielectric layer 21 is at least twice the refractive index of the second dielectric layer 22, which can better achieve the back reflector 2's reflection effect on light transmitted through the solar cell.

[0044] In an embodiment of the present invention, the back reflector 2 is arranged in an area of the backlight surface 12 where the electrode 13 is not arranged, so that the arrangement of the back reflector 2 will not block the electrode 13, and thus will not affect the screen printing process of the electrode 13. It is compatible with the electrode 13 printing process of traditional solar cells, and the back reflector 2 does not affect the subsequent welding of the electrode 13, thereby facilitating the welding of the electrode 13.

[0045] As an embodiment of the present invention, there are multiple back reflectors 2 , and the back reflectors 2 and the electrodes 13 are alternately arranged in sequence.

[0046] In this embodiment, the number of back reflectors 2 matches the number of electrodes 13 , and one back reflector 2 is disposed between every two adjacent electrodes 13 . Figure 1 Only two electrodes 13 and three back reflectors 2 are shown, and a back reflector 2 is provided on both sides of each electrode 13. Figure 1 The structures of the back reflectors 2 shown in FIG are identical. Of course, the structures of the back reflectors 2 can be identical or different. Preferably, the structures of the back reflectors 2 are identical, which facilitates simultaneous processing and preparation of the back reflectors 2, thereby reducing production costs.

[0047] In this embodiment, multiple back reflectors 2 and multiple electrodes 13 are alternately arranged in sequence, so that adjacent electrodes 13 are isolated by the back reflectors 2, which is beneficial for the multiple back reflectors 2 to reflect the transmitted light from the front of the solar cell, thereby improving the light utilization efficiency of the solar cell and thus improving the battery efficiency.

[0048] As an embodiment of the present utility model, the solar cell is a back-contact solar cell, and insulation is formed between the back reflector 2 and the adjacent electrode 13.

[0049] In this embodiment, the solar cell is a back-contact solar cell. The polarities of two adjacent electrodes 13 located on the backlight surface 12 are different, that is, one of the two adjacent electrodes 13 is a positive electrode and the other is a negative electrode 13. Among them, insulation is formed between the back reflector 2 and the adjacent electrode 13, so as to prevent the back reflector 2 from contacting and conducting electricity with the adjacent electrode 13, realize insulation between the two adjacent electrodes 13, prevent the two adjacent electrodes 13 from being conducted through the back reflector 2, and improve the working reliability of the battery.

[0050] As an embodiment of the present utility model, it further includes:

[0051] An insulating layer 3 provided on the back reflector 2, and the insulating layer 3 is at least located in a first region 31 between the side surface of the back reflector 2 and the adjacent electrode 13.

[0052] In this embodiment, isolation is formed between the side surface of the back reflector 2 and the electrode 13 through the first region 31 of the insulating layer 3, which can achieve good insulation between the back reflector 2 and the electrode 13 and maintain the working reliability of the battery. In addition, a gap can also be provided between the side surface of the back reflector 2 and the electrode 13, and the gap can also be used to realize insulation between the back reflector 2 and the adjacent electrode 13.

[0053] As an embodiment of the present utility model, the first region 31 of the insulating layer 3 completely wraps all side surfaces of the back reflector 2, which can further improve the insulation reliability between the side surface of the back reflector 2 and the electrode 13.

[0054] As an embodiment of the present utility model, the insulating layer 3 is one or a stack of two of a silicon nitride layer and a silicon oxide layer.

[0055] In this embodiment, the insulating layer 3 can specifically be one of a silicon nitride layer and a silicon oxide layer, or a stacked structure of a silicon nitride layer and a silicon oxide layer. Preferably, the insulating layer 3 is a layer of silicon nitride layer. By using the good insulation effect of silicon nitride, good insulation between the back reflector 2 and the electrode 13 can be achieved, and it is convenient for the processing and preparation of the insulating layer 3.

[0056] As an embodiment of the present utility model, the thickness of the insulating layer 3 is 5 to 200 nanometers, which can not only achieve good insulation between the back reflector 2 and the electrode 13, but also facilitate the processing and preparation of the insulating layer 3.

[0057] As an embodiment of the present utility model, the insulating layer 3 further includes a second region 32 covering the side of the back reflector 2 away from the backlight surface 12.

[0058] In this embodiment, the second region 32 of the insulating layer 3 is used to insulate and protect the side of the back reflector 2 away from the battery body 1, that is, the second region 32 of the insulating layer 3 insulates and protects the back of the back reflector 2, so that the second region 32 and the first region 31 completely cover the side and the back of the back reflector 2, which can further improve the insulation effect between the back reflector 2 and the electrode 13; moreover, the second region 32 and the first region 31 are integrally formed, and the insulating layer 3 can be deposited and prepared at one time, which is convenient for the preparation and processing of the insulating layer 3.

[0059] As an embodiment of the present invention, the battery body 1 further includes:

[0060] A back passivation layer 4 provided on the back of the backlight surface 12, the back reflector 2 is provided on the back passivation layer 4, and the electrode 13 passes through the back passivation layer 4 to contact the battery body 1.

[0061] In this embodiment, by providing the back passivation layer 4 on the backlight surface 12 of the battery body 1 and using the back passivation layer 4 to passivate the back of the battery body 1, the passivation effect of the solar cell can be improved and the battery efficiency can be enhanced. Of course, the back passivation layer 4 may not be provided on the backlight surface 12, and the back reflector 2 may be directly provided on the backlight surface 12.

[0062] As an embodiment of the present invention, the back passivation layer 4 is one or at least two of a silicon nitride layer, a silicon oxide layer or an aluminum oxide layer stacked.

[0063] As an embodiment of the present invention, the second dielectric layer 22 is a stack of one or two of a silicon dioxide layer, a gallium aluminum arsenide layer; the first dielectric layer 21 is a stack of one or at least two of an amorphous silicon layer, a titanium dioxide layer, a stibnite layer, a gallium arsenide layer.

[0064] In this embodiment, the combination of the second dielectric layer 22 and the first dielectric layer 21 can be flexibly set, and it is only necessary to satisfy that the refractive index of the first dielectric layer 21 is greater than that of the second dielectric layer 22. For example, the second dielectric layer 22 is a silicon dioxide layer and the first dielectric layer 21 is an amorphous silicon layer. The second dielectric layer 22 is a gallium aluminum arsenide layer and the first dielectric layer 21 is an amorphous silicon layer. Also for example, the second dielectric layer 22 is a gallium aluminum arsenide layer and the first dielectric layer 21 is a gallium arsenide layer. Of course, the second dielectric layer 22 can be a stacked structure of two of a silicon dioxide layer and a gallium aluminum arsenide layer, and the first dielectric layer 21 can be a stacked structure of at least two of an amorphous silicon layer, a titanium dioxide layer, a stibnite layer, a gallium arsenide layer, and the function of the back reflector 2 can also be realized.

[0065] As a preferred embodiment of the present invention, the second dielectric layer 22 is a silicon dioxide layer and the first dielectric layer 21 is an amorphous silicon layer.

[0066] In this embodiment, a silicon dioxide layer is used as the second dielectric layer 22, and an amorphous silicon layer is used as the first dielectric layer 21. The amorphous silicon layer and the silicon dioxide layer are alternately stacked to form a back reflector 2, which can improve the reflectivity of the back reflector 2 for sunlight with wavelengths in the range of 700 - 1100 nm, greatly enhancing the reflection effect of the back surface of the solar cell on the light transmitted through the solar cell, improving the light utilization efficiency of the solar cell, and thus enhancing the cell efficiency.

[0067] As an embodiment of the present utility model, the thickness ratio of the first dielectric layer 21 to the second dielectric layer 22 is 1:2, which is beneficial to further improving the reflection effect of the back reflector 2 on the light transmitted through the solar cell, improving the light utilization efficiency of the solar cell, and thus enhancing the cell efficiency.

[0068] As an embodiment of the present utility model, the second dielectric layer 22 is a silicon dioxide layer, and the first dielectric layer 21 is an amorphous silicon layer; the thickness of the first dielectric layer 21 is 60 nanometers, and the thickness of the second dielectric layer 22 is 125 nanometers.

[0069] In this embodiment, with this thickness combination of the first dielectric layer 21 and the second dielectric layer 22, it can be well adapted to sunlight with wavelengths in the range of 750 - 1100 nanometers, and the reflectivity of sunlight with wavelengths in the range of 750 - 1100 nanometers can reach more than 99%.

[0070] As an embodiment of the present utility model, the second dielectric layer 22 is a silicon dioxide layer, and the first dielectric layer 21 is an amorphous silicon layer; the thickness of the first dielectric layer 21 is 25 nanometers, and the thickness of the second dielectric layer 22 is 125 nanometers.

[0071] In this embodiment, with this thickness combination of the first dielectric layer 21 and the second dielectric layer 22, the back reflector 2 can be well adapted to sunlight with wavelengths in the range of 500 - 800 nanometers, and the reflectivity of sunlight with wavelengths in the range of 500 - 800 nanometers can reach more than 90%.

[0072] As an embodiment of the present utility model, the number of alternating stacking cycles of the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 is greater than or equal to 2.

[0073] In this embodiment, it can be understood that one cycle is formed by superposing the first dielectric layer 21 and the second dielectric layer 22 once. The first dielectric layer 21 and the second dielectric layer 22 form a light-reflecting unit. Superposing the first dielectric layer 21 and the second dielectric layer 22 once increases one light-reflecting unit, that is, each back reflector 2 includes at least two superposed light-reflecting units. The number of cycles of alternately superposing the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 is greater than or equal to 2, which can ensure a good light reflection effect. Preferably, the number of cycles of alternately superposing the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 is greater than or equal to 2 and less than or equal to 5, which can not only ensure a good light reflection effect, but also reduce the processing cost of the back reflector 2. Among them, Figure 1 The number of cycles of alternately superposing the first dielectric layer 21 and the second dielectric layer 22 of the back reflector 2 shown in it is equal to 5.

[0074] When preparing the solar cell with a back reflector provided in this embodiment, first prepare the cell body 1 by using the conventional solar cell preparation process, then deposit the back passivation layer 4 on the back of the cell body 1, and then alternately deposit the first dielectric layer 21 and the second dielectric layer 22 on the back passivation layer 4 in sequence. Use the laser grooving process to groove in the printed electrode 13 area to remove the first dielectric layer 21, the second dielectric layer 22 and the back passivation layer 4 corresponding to the electrode 13 area. Deposit the insulating layer 3 on the back of the first dielectric layer 21 and the second dielectric layer 22, use the laser grooving process in the printed electrode area to remove the local insulating layer 3, and then print the electrode 13 or directly burn through the back passivation layer 4 with the paste to print the electrode 13 in the electrode area, so that the electrode 13 forms an ohmic contact with the cell body 1, forming a solar cell with a back reflector, realizing a simple process and a low cost.

[0075] The embodiment of the present invention also provides a photovoltaic module, including the above-mentioned solar cell 100 with a back reflector. It should be noted that this photovoltaic module has the same or similar beneficial effects as the solar cell 100 with a back reflector, and the relevant parts between the two can be referred to each other. To avoid repetition, it will not be elaborated here. Moreover, since the solar cell 100 itself has a back reflector 2, when the solar cell 100 forms a photovoltaic module, there is no need to assemble a back reflector additionally, which can simplify the assembly process of the photovoltaic module and improve the assembly efficiency of the photovoltaic module.

[0076] In an embodiment of the present utility model, a solar cell with a back reflector is provided. A back reflector 2 is provided in a region of the backlight surface 12 where no electrode 13 is provided, such that the back reflector 2 is integrally provided on the backlight surface 12 of the battery body 1. When manufacturing the solar cell, the back reflector 2 can be manufactured on the backlight surface 12 of the battery body 1 simultaneously. The back reflector 2 of the solar cell and the battery body 1 do not need to be separately manufactured and then assembled, and the manufacturing process is simpler. Moreover, by using the overlapping of the second dielectric layer 22 and the first dielectric layer 21 with two different refractive indices to form the back reflector 2, the reflection effect of the light transmitted through the solar cell on the back of the solar cell can be improved, the light utilization efficiency of the solar cell can be enhanced, and thus the battery efficiency can be improved.

[0077] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A solar cell with a back reflector, characterized in that, Comprising: A battery body, the battery body including a light-facing surface and a backlight surface oppositely disposed to the light-facing surface; A plurality of electrodes disposed on the backlight surface and in contact with the battery body; A back reflector disposed on the backlight surface and in a region where the electrodes are not disposed, the back reflector including alternately stacked first dielectric layers and second dielectric layers, and the refractive index of the first dielectric layer being greater than that of the second dielectric layer.

2. The solar cell with a back reflector according to claim 1, characterized in that, The solar cell is a back-contact solar cell, and insulation is formed between the back reflector and the adjacent electrodes.

3. The solar cell with a back reflector according to claim 2, characterized in that, Further comprising: An insulating layer disposed on the back reflector, the insulating layer at least including a first region located between the side surface of the back reflector and the adjacent electrodes.

4. The solar cell with a back reflector according to claim 3, characterized in that, The insulating layer further includes a second region covering a side of the back reflector away from the backlight surface.

5. The solar cell with a back reflector according to claim 3, characterized in that, The insulating layer is one or a stack of two of a silicon nitride layer and a silicon oxide layer.

6. The solar cell with a back reflector according to claim 3, characterized in that, The thickness of the insulating layer is 5 to 200 nanometers.

7. The solar cell with a back reflector according to claim 1, characterized in that, The second dielectric layer is one or a stack of two of a silicon dioxide layer and a gallium aluminum arsenide layer; the first dielectric layer is one or a stack of at least two of an amorphous silicon layer, a titanium dioxide layer, a stibnite layer, and a gallium arsenide layer.

8. The solar cell with a back reflector according to claim 1, characterized in that, The thickness ratio of the first dielectric layer to the second dielectric layer is 1:

2.

9. The solar cell with a back reflector according to claim 1, characterized in that, The second dielectric layer is a silicon dioxide layer, and the first dielectric layer is an amorphous silicon layer.

10. The solar cell with a back reflector according to claim 9, characterized in that, The thickness of the first dielectric layer is 60 nanometers, and the thickness of the second dielectric layer is 125 nanometers.

11. The solar cell with a back reflector according to claim 9, characterized in that, The thickness of the first dielectric layer is 25 nanometers, and the thickness of the second dielectric layer is 125 nanometers.

12. The solar cell with a back reflector according to claim 1, characterized in that, The number of the back reflectors is plural, and the back reflectors and the electrodes are alternately and spacedly disposed in sequence.

13. The solar cell with a back reflector according to claim 1, characterized in that, The number of cycles of alternately stacking the first dielectric layer and the second dielectric layer of the back reflector is greater than or equal to 2.

14. The solar cell with a back reflector according to claim 1, characterized in that, Further comprising: A back surface passivation layer disposed on the backlight surface, the back reflector being disposed on the back surface passivation layer, and the electrodes passing through the back surface passivation layer to be in contact with the battery body.

15. The solar cell with a back reflector according to claim 14, characterized in that, The back surface passivation layer is one or a stack of at least two of a silicon nitride layer, a silicon oxide layer, and an aluminum oxide layer.

16. A photovoltaic module, characterized in that, Including the solar cell with a back reflector according to any one of claims 1 to 15.

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