Solar cell, passivation contact structure thereof, cell module and photovoltaic system

Abstract

The present disclosure is applicable to the technical field of solar cells, and provides a solar cell, a passivation contact structure thereof, a cell module, and a photovoltaic system. The solar cell passivation contact structure comprises, successively stacked on the surface of a silicon substrate, a first passivation layer, a first doped polysilicon layer, a second passivation layer, and a second doped polysilicon layer, wherein the average grain size of the first doped polysilicon layer is greater than the average grain size of the second doped polysilicon layer. The solar cell passivation contact structure of the present disclosure uses the first passivation layer and the second passivation layer to jointly stop impurities from inwardly diffusing into the silicon substrate, which can improve the passivation effect of the solar cell, thereby improving cell efficiency. In addition, the second doped polysilicon layer has a denser structure than that of the first doped polysilicon layer, which can reduce the risk of an electrode paste burning through the doped polysilicon layers, and the combination loss of the electrode paste, thereby helping to improve the production yield of cells and improving cell efficiency.

Description

Solar cell and passivation contact structure thereof, cell assembly and photovoltaic system

[0001] Cross-reference to Related Applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202411097440.3, filed on August 9, 2024, and entitled "Solar cell and passivation contact structure thereof, cell assembly and photovoltaic system", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of solar cells, in particular to a solar cell and passivation contact structure thereof, cell assembly and photovoltaic system. BACKGROUND

[0004] With the increasing depletion of fossil fuels, it is necessary to find a new type of clean and sustainable energy, and solar energy is undoubtedly the most common and clean renewable energy in the field of vision. Solar cells are devices that convert light energy directly into electrical energy using photovoltaic effect. Solar cells mainly include bifacial solar cells and back contact solar cells. In order to improve the passivation effect of bifacial solar cells and back contact solar cells, a passivation contact structure is needed to be set at the electrode position to improve the cell efficiency.

[0005] In the prior art, the P region of the bifacial solar cell and the back contact solar cell is provided with a P-type doped polysilicon layer, the electrode of the P region is in contact with the P-type doped polysilicon layer, the N region is provided with an N-type doped polysilicon layer, and the electrode of the N region is in contact with the N-type doped polysilicon layer. However, whether it is a bifacial solar cell or a back contact solar cell, the passivation contact structure used in the P region and the N region is usually a single layer of doped polysilicon layer and a single layer of passivation layer. In the solar cell preparation process, the introduced impurities are easy to diffuse into the inside of the silicon substrate, resulting in poor passivation effect of the solar cell and affecting the efficiency of the solar cell. Moreover, the electrode paste is easy to burn through the doped polysilicon layer, affecting the production yield of the cell.

[0006] DISCLOSURE

[0007] The present disclosure provides a solar cell passivation contact structure, which aims to solve the problem of poor passivation effect of the prior art solar cell passivation contact structure and the problem of electrode paste easily burning through the doped polysilicon layer, affecting the production yield of the cell.

[0008] The present disclosure is achieved in this way, providing a solar cell passivation contact structure, comprising a first passivation layer, a first doped polysilicon layer, a second passivation layer, and a second doped polysilicon layer, which are sequentially stacked on the surface of a silicon substrate.

[0009] The average grain size of the first doped polysilicon layer is greater than that of the second doped polysilicon layer.

[0010] In some embodiments, the doping polarity of the first doped polysilicon layer is the same as or opposite to that of the second doped polysilicon layer.

[0011] In some embodiments, the deposition temperature of the first doped polysilicon layer is greater than the deposition temperature of the second doped polysilicon layer.

[0012] In some embodiments, the diffusion temperature of the first doped polysilicon layer is greater than the diffusion temperature of the second doped polysilicon layer.

[0013] In some embodiments, the deposition temperature of the first doped polysilicon layer is 595–630°C, and the deposition temperature of the second doped polysilicon layer is 545–585°C.

[0014] In some embodiments, the diffusion temperature of the first doped polysilicon layer is 750–950°C, and the diffusion temperature of the second doped polysilicon layer is 700–900°C.

[0015] In some embodiments, the ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 0.2 to 1.

[0016] In some embodiments, both the first doped polysilicon layer and the second doped polysilicon layer are P-type doped polysilicon, and the thickness of the first passivation layer is less than the thickness of the second passivation layer.

[0017] In some embodiments, both the first doped polysilicon layer and the second doped polysilicon layer are P-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer and the second doped polysilicon layer is 80 to 210 nanometers.

[0018] In some embodiments, both the first doped polysilicon layer and the second doped polysilicon layer are P-type doped polysilicon, and the sum of the thickness of the first passivation layer and the thickness of the second passivation layer is 1.5 to 4.0 nanometers.

[0019] In some embodiments, both the first doped polysilicon layer and the second doped polysilicon layer are N-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer and the second doped polysilicon layer is 60 to 200 nanometers.

[0020] In some embodiments, both the first doped polysilicon layer and the second doped polysilicon layer are N-type doped polysilicon, and the sum of the thickness of the first passivation layer and the thickness of the second passivation layer is 1.2 to 3.8 nanometers.

[0021] In some embodiments, it also includes:

[0022] The third passivation layer is disposed on the side of the second doped polysilicon layer that is away from the silicon substrate.

[0023] In some embodiments, the first and second doped polysilicon layers are both P-type doped polysilicon, the first passivation layer has a thickness smaller than the second passivation layer, and the first passivation layer has a thickness smaller than the third passivation layer.

[0024] In some embodiments, the first and second doped polysilicon layers are both N-type doped polysilicon, the first passivation layer has a thickness larger than the second passivation layer, and the first passivation layer has a thickness larger than the third passivation layer.

[0025] In some embodiments, further comprising:

[0026] a third doped polysilicon layer disposed on a side of the third passivation layer facing away from the silicon substrate.

[0027] In some embodiments, the sum of the thickness of the second doped polysilicon layer and the thickness of the third doped polysilicon layer is larger than the thickness of the first doped polysilicon layer.

[0028] In some embodiments, the sum of the thickness of the first doped polysilicon layer, the thickness of the second doped polysilicon layer, and the thickness of the third doped polysilicon layer is 40-230 nanometers.

[0029] In some embodiments, the deposition temperature of the first doped polysilicon layer is larger than the deposition temperature of the second doped polysilicon layer, and the deposition temperature of the first doped polysilicon layer is larger than the deposition temperature of the third doped polysilicon layer.

[0030] In some embodiments, the first, second, and third doped polysilicon layers are all P-type doped polysilicon, and the sum of the thickness of the first passivation layer, the thickness of the second passivation layer, and the thickness of the third passivation layer is 1.6-5 nanometers.

[0031] In some embodiments, the thickness of the first passivation layer is larger than 0.8 nanometers.

[0032] In some embodiments, the first, second, and third doped polysilicon layers are all N-type doped polysilicon, and the sum of the thickness of the first passivation layer, the thickness of the second passivation layer, and the thickness of the third passivation layer is 1.4-4.5 nanometers.

[0033] In some embodiments, the thickness of the first passivation layer is larger than 0.6 nanometers.

[0034] The present disclosure also provides a solar cell, comprising:

[0035] a silicon substrate having a surface provided with a P region and an N region;

[0036] a first passivation contact structure disposed on the P region;

[0037] a second passivated contact structure disposed in the N region;

[0038] The first passivated contact structure and the second passivated contact structure are both the solar cell passivated contact structure as described above, the first doped polysilicon layer of the first passivated contact structure is P-type doped polysilicon, and the first doped polysilicon layer of the second passivated contact structure is N-type doped polysilicon.

[0039] In some embodiments, further comprising:

[0040] a first electrode disposed in the P region, the first electrode being in contact with the second doped polysilicon layer of the first passivated contact structure;

[0041] a second electrode disposed in the N region, the second electrode being in contact with the second doped polysilicon layer of the second passivated contact structure.

[0042] In some embodiments, the thickness of the first passivation layer of the first passivated contact structure is less than the thickness of the second passivation layer of the first passivated contact structure.

[0043] In some embodiments, the thickness of the first passivation layer of the second passivated contact structure is greater than the thickness of the second passivation layer of the second passivated contact structure.

[0044] In some embodiments, the thickness of the second passivation layer of the first passivated contact structure is less than the thickness of the second passivation layer of the second passivated contact structure.

[0045] In some embodiments, the thickness of the first passivation layer of the first passivated contact structure is greater than the thickness of the first passivation layer of the second passivated contact structure.

[0046] In some embodiments, the solar cell is a back contact solar cell, and the P region and the N region are located on the same side of the silicon substrate.

[0047] In some embodiments, the solar cell is a bifacial solar cell, and the P region and the N region are located on opposite sides of the silicon substrate, respectively.

[0048] The present disclosure also provides a battery assembly comprising the solar cell as described above.

[0049] The present disclosure also provides a photovoltaic system comprising the battery assembly as described above.

[0050] The solar cell passivation contact structure provided by the present disclosure comprises a first passivation layer, a first doped polysilicon layer, a second passivation layer and a second doped polysilicon layer which are sequentially stacked on the surface of a silicon substrate. The first passivation layer and the second passivation layer jointly block the inward diffusion of impurities into the silicon substrate, thereby reducing the inward diffusion of impurities into the silicon substrate, avoiding excessive impurities from diffusing into the interior of the silicon substrate, improving the passivation effect of the solar cell, and thus improving the cell efficiency. Moreover, the average grain size of the first doped polysilicon layer of the solar cell passivation contact structure of the present disclosure is larger than the average grain size of the second doped polysilicon layer, so that the structure of the second doped polysilicon layer is more compact than that of the first doped polysilicon layer. The compactness of the second doped polysilicon layer can be improved, the second doped polysilicon layer has a certain blocking effect on electrode paste, the risk of electrode paste burning through the doped polysilicon layer can be reduced, and the electrode paste composite loss can be reduced, which is conducive to improving the cell production yield and improving the cell efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a cross-sectional view of a solar cell passivation contact structure according to an embodiment of the present disclosure;

[0052] Fig. 2 is a cross-sectional view of a solar cell passivation contact structure according to another embodiment of the present disclosure;

[0053] Fig. 3 is a cross-sectional view of a solar cell according to another embodiment of the present disclosure;

[0054] Fig. 4 is a cross-sectional view of another solar cell according to another embodiment of the present disclosure;

[0055] Fig. 5 is a cross-sectional view of a solar cell according to another embodiment of the present disclosure;

[0056] Fig. 6 is a cross-sectional view of another solar cell according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present disclosure and do not limit the present disclosure.

[0058] The solar cell passivation contact structure provided by the embodiments of the present disclosure includes a first passivation layer, a first doped polysilicon layer, a second passivation layer and a second doped polysilicon layer which are sequentially stacked on the surface of a silicon substrate. The first passivation layer and the second passivation layer jointly block impurity inward diffusion into the silicon substrate, so that the impurity inward diffusion into the silicon substrate can be reduced, the excessive impurity diffusion into the interior of the silicon substrate can be avoided, the passivation effect of the solar cell can be improved, and thus the cell efficiency can be improved. Moreover, the average grain size of the first doped polysilicon layer of the solar cell passivation contact structure is greater than the average grain size of the second doped polysilicon layer, so that the structure of the second doped polysilicon layer is more compact than that of the first doped polysilicon layer, the compactness of the second doped polysilicon layer can be improved, the second doped polysilicon layer has a certain blocking effect on electrode paste, the risk of electrode paste burning through the doped polysilicon layer can be reduced, the electrode paste composite loss can be reduced, and the cell production yield and the cell efficiency can be improved.

[0059] Embodiment one

[0060] Referring to FIG. 1, the present disclosure provides a solar cell passivation contact structure, which includes a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3 and a second doped polysilicon layer 4 which are sequentially stacked on the surface of a silicon substrate 10.

[0061] The average grain size of the first doped polysilicon layer 2 is greater than the average grain size of the second doped polysilicon layer 4.

[0062] In the embodiments of the present disclosure, the solar cell passivation contact structure includes a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3 and a second doped polysilicon layer 4 which are sequentially stacked on the surface of a silicon substrate 10. The first passivation layer 1 and the second passivation layer 3 jointly block impurity inward diffusion into the silicon substrate 10, so that the impurity inward diffusion into the silicon substrate 10 can be reduced, the excessive impurity diffusion into the interior of the silicon substrate 10 can be avoided, the passivation effect of the solar cell can be improved, and thus the cell efficiency can be improved. Moreover, the average grain size of the first doped polysilicon layer 2 of the solar cell passivation contact structure is greater than the average grain size of the second doped polysilicon layer 4, so that the structure of the second doped polysilicon layer 4 is more compact than that of the first doped polysilicon layer 2, the compactness of the second doped polysilicon layer 4 can be improved, the second doped polysilicon layer 4 has a certain blocking effect on electrode paste, the risk of electrode paste burning through the doped polysilicon layer can be reduced, the electrode paste composite loss can be reduced, and the cell production yield and the cell efficiency can be improved.

[0063] In the embodiment, the average grain size of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be measured by an X-ray diffraction (XRD) instrument, a scanning electronic microscopy (SEM) instrument or a transmission electron microscope (TEM) instrument.

[0064] In the embodiment, the average grain size of the first doped polysilicon layer 2 is greater than the average grain size of the second doped polysilicon layer 4. It can be understood that the average value of all grain sizes of the first doped polysilicon layer 2 in a unit area is greater than the average value of all grain sizes of the second doped polysilicon layer 4 in a unit area. That is, in a unit area, the number of grains in the second doped polysilicon layer 4 is greater and the grain size is smaller, so that the density of the second doped polysilicon layer 4 can be improved.

[0065] In actual application, in the preparation process of the first doped polysilicon layer 2 and the second doped polysilicon layer 4, intrinsic amorphous silicon can be deposited first, and then the intrinsic amorphous silicon is doped and diffused to obtain doped amorphous silicon. By adjusting the difference between the deposition temperature and the diffusion temperature of the first doped polysilicon layer 2 and the second doped polysilicon layer 4, the average grain size of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be controlled correspondingly.

[0066] As an embodiment of the present disclosure, the deposition temperature of the first doped polysilicon layer 2 is greater than the deposition temperature of the second doped polysilicon layer 4.

[0067] In the embodiment, the deposition temperature of the first doped polysilicon layer 2 is greater than the deposition temperature of the second doped polysilicon layer 4, so that the average grain size of the first doped polysilicon layer 2 is greater than the average grain size of the second doped polysilicon layer 4. At the same time, since the deposition temperature of the first doped polysilicon layer 2 is closer to the deposition temperature of the first passivation layer 1, the difference between the deposition temperature of the first passivation layer 1 and the deposition temperature of the first doped polysilicon layer 2 is smaller than the difference between the deposition temperature of the first passivation layer 1 and the deposition temperature of the second doped polysilicon layer 4. After the first passivation layer 1 is deposited, the deposition equipment does not need to be cooled and then the first doped polysilicon layer 2 is deposited, so that the process time can be shortened and the production efficiency can be improved.

[0068] As an embodiment of the present disclosure, the deposition temperature of the first doped polysilicon layer 2 is 595-630°C, and the deposition temperature of the second doped polysilicon layer 4 is 545-585°C.

[0069] The deposition temperature of the first doped polysilicon layer 2 is the temperature of depositing intrinsic amorphous silicon of the first doped polysilicon layer 2; and the deposition temperature of the second doped polysilicon layer 4 is the temperature of depositing intrinsic amorphous silicon of the second doped polysilicon layer 4. The deposition temperatures of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be set according to actual needs, as long as the deposition temperature of the first doped polysilicon layer 2 is greater than the deposition temperature of the second doped polysilicon layer 4.

[0070] As an embodiment of the present disclosure, the diffusion temperature of the first doped polysilicon layer 2 is greater than the diffusion temperature of the second doped polysilicon layer 4.

[0071] The diffusion temperature of the first doped polysilicon layer 2 is the temperature of diffusing intrinsic amorphous silicon of the first doped polysilicon layer 2 to form the first doped polysilicon layer 2; and the diffusion temperature of the second doped polysilicon layer 4 is the temperature of diffusing intrinsic amorphous silicon of the second doped polysilicon layer 4 to form the second doped polysilicon layer 4. The diffusion temperatures of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be set according to actual needs, as long as the diffusion temperature of the first doped polysilicon layer 2 is greater than the diffusion temperature of the second doped polysilicon layer 4.

[0072] As an embodiment of the present disclosure, the diffusion temperature of the first doped polysilicon layer 2 is 750-950℃, and the diffusion temperature of the second doped polysilicon layer 4 is 700-900℃.

[0073] In the embodiment, the diffusion temperatures of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be set according to actual needs, as long as the diffusion temperature of the first doped polysilicon layer 2 is greater than the diffusion temperature of the second doped polysilicon layer 4.

[0074] In the embodiment, the diffusion temperature of the first doped polysilicon layer 2 is 750-950℃, and the diffusion temperature of the second doped polysilicon layer 4 is 700-900℃, so as to ensure that the grain size of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 is within a relatively optimal range, which can not only achieve a relatively high passivation effect, but also can make the second doped polysilicon layer 4 have a relatively high density, so that the second doped polysilicon layer 4 has a good blocking effect on electrode paste, reduces the risk of electrode paste burning through the doped polysilicon layer, and is beneficial to improving the production yield and the battery efficiency.

[0075] As an optional embodiment of the present disclosure, the deposition temperature and the diffusion temperature of the first doped polysilicon layer 2 are greater than the deposition temperature and the diffusion temperature of the second doped polysilicon layer 4, which is more conducive to increasing the difference between the average grain size of the first doped polysilicon layer 2 and the average grain size of the second doped polysilicon layer 4.

[0076] In the embodiments of the present disclosure, the silicon substrate 10 can be a P-type silicon substrate 10 or an N-type silicon substrate 10. The surface of the silicon substrate 10 can be a back light surface or a light surface of a solar cell.

[0077] The solar cell passivation contact structure in the embodiments of the present disclosure can be applied to a back contact solar cell or a bifacial solar cell. The second doped polysilicon layer 4 is used to form a contact with an electrode of the solar cell.

[0078] In the embodiments of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 have the same or opposite doping polarity. Preferably, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 have the same doping polarity, which can better improve the passivation effect of the solar cell. For example, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type doped polysilicon containing P-type dopants, or the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both N-type doped polysilicon containing N-type dopants.

[0079] As an embodiment of the present disclosure, the first passivation layer 1 includes one or a combination of silicon oxide, silicon oxynitride, and silicon nitride.

[0080] In the embodiments, the first passivation layer 1 uses the above-mentioned materials, which can achieve good barrier effect of impurities and good passivation effect.

[0081] As an embodiment of the present disclosure, the second passivation layer 3 includes one or a combination of silicon oxide, silicon oxynitride, silicon nitride, and silicon carbide.

[0082] As an embodiment of the present disclosure, the thickness ratio of the first doped polysilicon layer 2 to the second doped polysilicon layer 4 is 0.2-1.

[0083] In the embodiments, the thickness of the first doped polysilicon layer 2 is smaller than that of the second doped polysilicon layer 4. Since the conventional solar cell passivation contact structure has only a single doped polysilicon layer, the single doped polysilicon layer is used for passivation, current lateral transmission, and ohmic contact with the electrode. In the embodiments of the present disclosure, the first doped polysilicon layer 2 is used to achieve the original passivation effect, and the second doped polysilicon layer 4 is used to achieve current lateral transmission and ohmic contact with the electrode. Therefore, the thickness of the first doped polysilicon layer 2 can be reduced to achieve good passivation effect. Since the thicker the second doped polysilicon layer 4 is, the smaller the lateral transmission resistance is, the second doped polysilicon layer 4 can achieve good current lateral transmission and ohmic contact with the electrode by being thickened. Meanwhile, the doping concentration of the dopants of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be adjusted to adapt to the ohmic contact and passivation effect of the solar cell.

[0084] In the embodiment, the ratio of the thickness of the first doped polysilicon layer 2 to the thickness of the second doped polysilicon layer 4 can be set according to actual needs; for example, the ratio of the thickness of the first doped polysilicon layer 2 to the thickness of the second doped polysilicon layer 4 can be one of 0.2, 0.3, 0.4, 0.5, 0.7, 0.8, 0.9, and 1.0.

[0085] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type doped polysilicon, and the thickness of the first passivation layer 1 is less than the thickness of the second passivation layer 3.

[0086] In the embodiment, by reducing the thickness of the first passivation layer 1, the passivation effect of the P region of the solar cell is improved, and the cell efficiency is improved.

[0087] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both N-type doped polysilicon, and the thickness of the first passivation layer 1 is greater than the thickness of the second passivation layer 3.

[0088] In the embodiment, since the N-type dopant of the N-type doped polysilicon has good diffusion effect, increasing the thickness of the first passivation layer 1 can improve the passivation effect without reducing the diffusion effect.

[0089] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 is 80-210 nanometers, which can achieve good passivation effect of the P region of the solar cell and reduce production cost.

[0090] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type doped polysilicon, and the sum of the thicknesses of the first passivation layer 1 and the second passivation layer 3 is 1.5-4.0 nanometers, which can achieve good passivation effect of the P region of the solar cell.

[0091] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both N-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 is 60-200 nanometers.

[0092] In the embodiment, the solar cell passivation contact structure is applied to a solar cell, which can reduce the parasitic absorption of the N region of the solar cell, thereby improving the cell efficiency and reducing the production cost.

[0093] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both N-type doped polysilicon, the sum of the thickness of the first passivation layer 1 and the thickness of the second passivation layer 3 is 1.2-3.8 nanometers, and a good passivation effect of the N region of the solar cell is achieved.

[0094] Embodiment two

[0095] Please refer to FIG. 2, on the basis of the first embodiment, the passivation contact structure of the solar cell of the present embodiment further comprises:

[0096] The third passivation layer 5 is arranged on the side of the second doped polysilicon layer 4 away from the silicon substrate 10.

[0097] In the present embodiment, by arranging the third passivation layer 5 on the surface of the second doped polysilicon layer 4 away from the silicon substrate 10, the third passivation layer 5 can be used to block the inward diffusion of impurities into the silicon substrate 10, further block the inward diffusion of impurities into the silicon substrate 10, and further improve the passivation effect of the passivation contact structure of the solar cell.

[0098] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type doped polysilicon, the thickness of the first passivation layer 1 is less than the thickness of the second passivation layer 3, and the thickness of the first passivation layer 1 is less than the thickness of the third passivation layer 5, so that the thickness of the first passivation layer 1 is smaller than the thickness of the second passivation layer 3 and the third passivation layer 5, and the passivation effect of the P region of the solar cell is further improved.

[0099] As an embodiment of the present disclosure, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both N-type doped polysilicon, the thickness of the first passivation layer 1 is greater than the thickness of the second passivation layer 3, and the thickness of the first passivation layer 1 is greater than the thickness of the third passivation layer 5, so as to ensure that the first passivation layer 1 of the N region of the solar cell has a good passivation effect.

[0100] As an embodiment of the present disclosure, it further comprises:

[0101] The third doped polysilicon layer 6 is arranged on the side of the third passivation layer 5 away from the silicon substrate 10.

[0102] In the present embodiment, by adding the third doped polysilicon layer 6, the passivation effect of the passivation contact structure of the solar cell can be further improved. The doping polarity of the third doped polysilicon layer 6 is the same as that of the first doped polysilicon layer 2 and the second doped polysilicon layer 4. The electrode of the solar cell contacts the second doped polysilicon layer 4 through the third doped polysilicon layer 6 and the third passivation layer 5. Of course, the electrode of the solar cell can also directly contact the third doped polysilicon layer 6.

[0103] As an embodiment of the present disclosure, the sum of the thickness of the second doped polysilicon layer 4 and the thickness of the third doped polysilicon layer 6 is greater than the thickness of the first doped polysilicon layer 2, which can achieve better passivation effect and has good effect of blocking electrode paste to prevent electrode paste from burning through the doped polysilicon layer.

[0104] As an embodiment of the present disclosure, the sum of the thickness of the first doped polysilicon layer 2, the thickness of the second doped polysilicon layer 4 and the thickness of the third doped polysilicon layer 6 is 40-230 nanometers, which makes the doped polysilicon layer have better passivation effect, reduces parasitic absorption and reduces cost.

[0105] As an embodiment of the present disclosure, the deposition temperature of the first doped polysilicon layer 2 is greater than the deposition temperature of the second doped polysilicon layer 4, and the deposition temperature of the first doped polysilicon layer 2 is greater than the deposition temperature of the third doped polysilicon layer 6.

[0106] In the embodiment, since the deposition temperature of the first doped polysilicon layer 2 is higher than that of the second doped polysilicon layer 4 and the third doped polysilicon layer 6, the deposition temperature of the first doped polysilicon layer 2 and the first passivation layer 1 is small, and the deposition of the first doped polysilicon layer 2 does not need to wait for the cooling of the deposition equipment, which can improve the deposition speed and improve the production efficiency.

[0107] As an embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 are all P-type doped polysilicon, and the sum of the thickness of the first passivation layer 1, the second passivation layer 3 and the third passivation layer 5 is 1.6-5 nanometers, which makes the P region of the solar cell have better passivation effect.

[0108] As an embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 are all P-type doped polysilicon, and the thickness of the first passivation layer 1 is greater than 0.8 nanometers, which makes the first passivation layer 1 of the P region of the solar cell have good passivation effect.

[0109] As another embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 are all N-type doped polysilicon, and the sum of the thickness of the first passivation layer 1, the second passivation layer 3 and the third passivation layer 5 is 1.4-4.5 nanometers.

[0110] As an embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 are all N-type doped polysilicon, and the thickness of the first passivation layer 1 is greater than 0.6 nanometers, which makes the first passivation layer 1 of the N region of the solar cell have good passivation effect.

[0111] Embodiment three

[0112] Please refer to FIG. 3 and FIG. 4, the embodiment provides a solar cell, comprising:

[0113] a silicon substrate 10, a surface of the silicon substrate 10 is provided with a P region 101 and an N region 102;

[0114] a first passivation contact structure 11 provided on the P region 101;

[0115] a second passivation contact structure 12 provided on the N region 102;

[0116] The first passivation contact structure 11 and the second passivation contact structure 12 are both the passivation contact structure of the solar cell of the above-mentioned embodiment one. Specifically, the first passivation contact structure 11 and the second passivation contact structure 12 respectively comprise a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3 and a second doped polysilicon layer 4 which are sequentially stacked on the surface of the silicon substrate 10. Exemplarily, the first doped polysilicon layer 2 of the first passivation contact structure 11 is P-type doped polysilicon, and the first doped polysilicon layer 2 of the second passivation contact structure 12 is N-type doped polysilicon.

[0117] As shown in FIG. 3, as one embodiment of the application, the solar cell is a back contact solar cell, and the P region 101 and the N region 102 are located on the same side of the silicon substrate 10. The silicon substrate 10 comprises a front surface 105 and a back surface 106 which is provided opposite to the front surface 105, the front surface 105 of the silicon substrate 10 is the light-receiving surface of the back contact solar cell, the back surface 106 of the silicon substrate 10 is the back surface of the back contact solar cell, and the P region 101 and the N region 102 are both located on the back surface of the silicon substrate 10.

[0118] The P region 101 and the N region 102 are both multiple, and the multiple P regions 101 and the multiple N regions 102 are sequentially and alternately spaced, and an isolation region 103 is provided between adjacent P regions 101 and N regions 102. The isolation region 103 can be a groove or a gap.

[0119] As shown in FIG. 3, the above-mentioned back contact solar cell further comprises a first electrode 7 provided on the P region 101, the first electrode 7 being in contact with the second doped polysilicon layer 4 of the first passivation contact structure 11; and a second electrode 8 provided on the N region 102, the second electrode 8 being in contact with the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0120] As shown in FIG. 4, as another embodiment of the application, the solar cell is a bifacial solar cell, and the P region 101 and the N region 102 are respectively located on opposite sides of the silicon substrate 10. Among them, the silicon substrate 10 includes a front surface 105 and a back surface 106 opposite to the front surface 105, the front surface 105 of the silicon substrate 10 is the light-receiving surface of the back contact solar cell, the back surface 106 of the silicon substrate 10 is the back light surface of the bifacial solar cell, and one of the P region 101 and the N region 102 is located on the front surface 105 of the silicon substrate 10, and the other is located on the back surface 106 of the silicon substrate 10.

[0121] Among them, the P region 101 in FIG. 4 is located on the back surface 106 of the silicon substrate 10, and the N region 102 is located on the front surface 105 of the silicon substrate 10. Among them, the P region 101 can completely cover the back surface 106 of the silicon substrate 10, or only cover part of the back surface 106 of the silicon substrate 10; the N region 102 can completely cover the front surface of the silicon substrate 10, or only cover part of the front surface 105 of the silicon substrate 10. The P region 101 and the N region 102 can also be multiple. Preferably, the P region 101 covers part of the back surface 106 of the silicon substrate 10, and the adjacent two P regions 101 are spaced apart from each other; the N region 102 only covers part of the front surface 105 of the silicon substrate 10, and the adjacent two N regions 102 are spaced apart from each other, which can reduce the light parasitic absorption.

[0122] Among them, as shown in FIG. 4, the bifacial solar cell includes a first passivation contact structure 11 provided on the P region 101 and a second passivation contact structure 12 provided on the N region 102. Specifically, the first passivation contact structure 11 and the second passivation contact structure 12 respectively include a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3 and a second doped polysilicon layer 4 which are sequentially stacked on the surface of the silicon substrate 10.

[0123] In this embodiment, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 of the first passivation contact structure 11 are both P-type doped polysilicon, and the first doped polysilicon layer 2 and the second doped polysilicon layer 4 of the second passivation contact structure 12 are both N-type doped polysilicon.

[0124] As one embodiment of the present disclosure, it further includes:

[0125] The first electrode 7 provided on the P region 101, the first electrode 7 being in contact with the second doped polysilicon layer 4 of the first passivation contact structure 11;

[0126] The second electrode 8 provided on the N region 102, the second electrode 8 being in contact with the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0127] In the embodiment, the first passivation contact structure 11 and the second passivation contact structure 12 both achieve the passivation effect by using the first doped polysilicon layer 2, and achieve the current lateral transmission effect and ohmic contact effect with the electrode by using the second doped polysilicon layer 4.

[0128] As an embodiment of the present disclosure, the thickness of the first doped polysilicon layer 2 of the first passivation contact structure 11 is less than the thickness of the second doped polysilicon layer 4 of the first passivation contact structure 11; and the thickness of the first doped polysilicon layer 2 of the second passivation contact structure 12 is less than the thickness of the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0129] In the embodiment, since the thickness of the first doped polysilicon layer 2 is thinned, the first doped polysilicon layer 2 can achieve good passivation effect; and since the thicker the second doped polysilicon layer 4 is, the smaller the lateral transmission resistance is, the second doped polysilicon layer 4 can achieve good current lateral transmission effect and ohmic contact effect with the electrode by thickening the second doped polysilicon layer 4, and the doping concentration of the dopant of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be adjusted to adapt to the ohmic contact and passivation effect of the solar cell.

[0130] As an embodiment of the present disclosure, the sum of the thicknesses of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 of the first passivation contact structure 11 is greater than the sum of the thicknesses of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0131] In the embodiment, the sum of the thicknesses of the first doped polysilicon layer 2 of the first passivation contact structure 11 and the second doped polysilicon layer 4 of the first passivation contact structure 11 is greater than the sum of the thicknesses of the first doped polysilicon layer 2 of the second passivation contact structure 12 and the second doped polysilicon layer 4 of the second passivation contact structure 12, so that the total thickness of the doped polysilicon layer of the P region is greater than the total thickness of the doped polysilicon layer of the N region, which is beneficial to improving the efficiency of the solar cell.

[0132] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the first passivation contact structure 11 is less than the thickness of the second passivation layer 3 of the first passivation contact structure 11; and the thickness of the first passivation layer 1 of the second passivation contact structure 12 is greater than the thickness of the second passivation layer 3 of the second passivation contact structure 12, which is beneficial to the diffusion of the P-type dopant of the P region and ensures good passivation effect of the P region and the N region.

[0133] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the second passivation contact structure 12 is greater than the thickness of the second passivation layer 3 of the second passivation contact structure 12, which is beneficial to improving the passivation effect of the second passivation contact structure 12.

[0134] As an embodiment of the present disclosure, the thickness of the second passivation layer 3 of the first passivation contact structure 11 is less than the thickness of the second passivation layer 3 of the second passivation contact structure 12, which is conducive to improving the passivation effect of the P region and thus improving the battery efficiency.

[0135] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the first passivation contact structure 11 is greater than the thickness of the first passivation layer 1 of the second passivation contact structure 12, which is conducive to achieving good passivation effects of both the P region and the N region.

[0136] Embodiment Four

[0137] Please refer to FIG. 5 and FIG. 6, the present embodiment provides a solar cell, comprising:

[0138] a silicon substrate 10, the surface of the silicon substrate 10 is provided with a P region 101 and an N region 102;

[0139] a first passivation contact structure 11 provided on the P region 101;

[0140] a second passivation contact structure 12 provided on the N region 102;

[0141] wherein, the first passivation contact structure 11 and the second passivation contact structure 12 are both the solar cell passivation contact structure of the above-mentioned embodiment two. Specifically, the first passivation contact structure 11 and the second passivation contact structure 12 respectively comprise a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3, a second doped polysilicon layer 4, a third passivation layer 5 and a third doped polysilicon layer 6 which are sequentially stacked on the surface of the silicon substrate 10. Exemplarily, the first doped polysilicon layer 2 of the first passivation contact structure 11 is P-type doped polysilicon, and the first doped polysilicon layer 2 of the second passivation contact structure 12 is N-type doped polysilicon.

[0142] As shown in FIG. 5, as an embodiment of the present disclosure, the solar cell is a back contact solar cell, and the P region 101 and the N region 102 are located on the same side of the silicon substrate 10. Wherein, the silicon substrate 10 comprises a front surface 105 and a back surface 106 opposite to the front surface 105, the front surface 105 of the silicon substrate 10 is the light-receiving surface of the back contact solar cell, the back surface 106 of the silicon substrate 10 is the back surface of the back contact solar cell, and the P region 101 and the N region 102 are both located on the back surface of the silicon substrate 10.

[0143] wherein, the P region 101 and the N region 102 are both multiple, the multiple P regions 101 and the multiple N regions 102 are sequentially and alternately spaced, and the adjacent P region 101 and N region 102 are provided with an isolation region 103. The isolation region 103 can be a groove or a gap.

[0144] As shown in FIG. 5, the back contact solar cell further comprises a first electrode 7 disposed on the P region 101, the first electrode 7 being in contact with the second doped polysilicon layer 4 of the first passivation contact structure 11; and a second electrode 8 disposed on the N region 102, the second electrode 8 being in contact with the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0145] As shown in FIG. 6, as another embodiment of the present disclosure, the solar cell is a bifacial solar cell, and the P region 101 and the N region 102 are respectively located on opposite sides of the silicon substrate 10. The silicon substrate 10 comprises a front surface 105 and a back surface 106 opposite to the front surface 105, the front surface 105 of the silicon substrate 10 being a light-receiving surface of the bifacial solar cell, and the back surface 106 of the silicon substrate 10 being a back surface of the bifacial solar cell. One of the P region 101 and the N region 102 is located on the front surface 105 of the silicon substrate 10, and the other is located on the back surface 106 of the silicon substrate 10.

[0146] The P region 101 and the N region 102 can be multiple. Preferably, the P region 101 covers part of the back surface 106 of the silicon substrate 10, and adjacent two P regions 101 are spaced apart from each other. The N region 102 covers part of the front surface 105 of the silicon substrate 10, and adjacent two N regions 102 are spaced apart from each other, which can reduce parasitic light absorption.

[0147] As shown in FIG. 6, the bifacial solar cell comprises the first passivation contact structure 11 disposed on the P region 101 and the second passivation contact structure 12 disposed on the N region 102. Specifically, the first passivation contact structure 11 and the second passivation contact structure 12 each comprise a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3, a second doped polysilicon layer 4, a third passivation layer 5 and a third doped polysilicon layer 6 which are sequentially stacked on the surface of the silicon substrate 10.

[0148] In this embodiment, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 of the first passivation contact structure 11 are all P-type doped polysilicon, and the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 of the second passivation contact structure 12 are all N-type doped polysilicon.

[0149] As one embodiment of the present disclosure, the bifacial solar cell further comprises:

[0150] The first electrode 7 is arranged in the P region 101, and the first electrode 7 is in contact with the second doped polysilicon layer 4 of the first passivation contact structure 11.

[0151] The second electrode 8 is arranged in the N region 102, and the second electrode 8 is in contact with the second doped polysilicon layer 4 of the second passivation contact structure 12.

[0152] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the first passivation contact structure 11 is less than the thickness of the second passivation layer 3 of the first passivation contact structure 11, and the thickness of the first passivation layer 1 of the first passivation contact structure 11 is less than the thickness of the third passivation layer 5 of the first passivation contact structure 11, which can further improve the passivation effect of the P region 101.

[0153] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the second passivation contact structure 12 is greater than the thickness of the second passivation layer 3 of the second passivation contact structure 12, and the thickness of the first passivation layer 1 of the second passivation contact structure 12 is greater than the thickness of the third passivation layer 5 of the second passivation contact structure 12, which can further improve the passivation effect of the N region 102.

[0154] As an embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 of the first passivation contact structure 11 are all P-type doped polysilicon, and the sum of the thicknesses of the first passivation layer 1, the second passivation layer 3 and the third passivation layer 5 of the first passivation contact structure 11 is 1.6-5 nanometers.

[0155] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the first passivation contact structure 11 is greater than 0.8 nanometer, which realizes good passivation effect of the first passivation layer 1 of the P region 101.

[0156] As an embodiment of the present disclosure, the first doped polysilicon layer 2, the second doped polysilicon layer 4 and the third doped polysilicon layer 6 of the second passivation contact structure 12 are all N-type doped polysilicon, and the sum of the thicknesses of the first passivation layer 1, the second passivation layer 3 and the third passivation layer 5 of the second passivation contact structure 12 is 1.4-4.5 nanometers.

[0157] As an embodiment of the present disclosure, the thickness of the first passivation layer 1 of the second passivation contact structure 12 is greater than 0.6 nanometer, which realizes good passivation effect of the first passivation layer 1 of the N region 102.

[0158] Embodiment five

[0159] The present disclosure also provides a battery assembly, which comprises the solar cell of the above-mentioned embodiment three or embodiment four. It should be noted that the battery assembly has the same or similar beneficial effects as the solar cell, and the relevant parts between the two can be referred to each other. In order to avoid repetition, it will not be described here.

[0160] Embodiment six

[0161] The photovoltaic system provided by the embodiments of the present disclosure includes the battery assembly of the above-mentioned embodiment five. It should be noted that the photovoltaic system has the same or similar beneficial effects as the above-mentioned solar cell, and the related parts between the two can be referred to each other. In order to avoid repetition, it will not be described here.

[0162] The solar cell passivation contact structure provided by the embodiments of the present disclosure includes a first passivation layer 1, a first doped polysilicon layer 2, a second passivation layer 3, and a second doped polysilicon layer 4 which are sequentially stacked on the surface of the silicon substrate 10. The first passivation layer 1 and the second passivation layer 3 are used to jointly block the impurity from diffusing into the silicon substrate 10, so that the impurity can be reduced from diffusing into the silicon substrate 10, and the excessive impurity can be prevented from diffusing into the inside of the silicon substrate 10, so that the passivation effect of the solar cell can be improved, and the battery efficiency can be improved. Moreover, the average grain size of the first doped polysilicon layer 2 of the solar cell passivation contact structure of the present disclosure is greater than the average grain size of the second doped polysilicon layer 4, so that the structure of the second doped polysilicon layer 4 is more compact than that of the first doped polysilicon layer 2. The compactness of the second doped polysilicon layer 4 can be improved, so that the second doped polysilicon layer 4 has a certain blocking effect on the electrode paste, the risk of the electrode paste burning through the doped polysilicon layer can be reduced, the electrode paste composite loss can be reduced, and the battery production yield and the battery efficiency can be improved.

[0163] The above only describes the preferred embodiments of the present disclosure and should not be used to limit the present disclosure. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present disclosure should be included in the protection scope of the present disclosure.

Claims

1. A solar cell passivated contact structure, comprising a first passivation layer, a first doped polysilicon layer, a second passivation layer, and a second doped polysilicon layer, which are sequentially stacked on a surface of a silicon substrate. wherein The average grain size of the first doped polysilicon layer is greater than that of the second doped polysilicon layer.

2. The solar cell passivated contact structure of claim 1, wherein, The doping polarity of the first doped polysilicon layer is the same as or opposite to that of the second doped polysilicon layer.

3. The solar cell passivated contact structure of claim 1, wherein, The deposition temperature of the first doped polysilicon layer is greater than that of the second doped polysilicon layer.

4. The passivated contact solar cell structure of claim 1, wherein, The diffusion temperature of the first doped polysilicon layer is greater than that of the second doped polysilicon layer.

5. The passivated contact solar cell structure of claim 1, wherein, The deposition temperature of the first doped polysilicon layer is 595-630℃, and the deposition temperature of the second doped polysilicon layer is 545-585℃.

6. The solar cell passivated contact structure of claim 1, wherein, The diffusion temperature of the first doped polysilicon layer is 750-950℃, and the diffusion temperature of the second doped polysilicon layer is 700-900℃.

7. The passivated contact solar cell structure of claim 1, wherein, The thickness ratio of the first doped polysilicon layer to the second doped polysilicon layer is 0.2-1.

8. The solar cell passivated contact structure of claim 1, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both P-type doped polysilicon, and the thickness of the first passivation layer is less than that of the second passivation layer.

9. The passivated contact solar cell structure of claim 1, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both P-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer and the second doped polysilicon layer is 80-210nm.

10. The passivated contact structure for a solar cell of claim 1, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both P-type doped polysilicon, and the sum of the thicknesses of the first passivation layer and the second passivation layer is 1.5-4.0nm.

11. The passivated contact solar cell structure of claim 1, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both N-type doped polysilicon, and the sum of the thicknesses of the first doped polysilicon layer and the second doped polysilicon layer is 60-200nm.

12. The passivated contact solar cell structure of claim 1, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both N-type doped polysilicon, and the sum of the thicknesses of the first passivation layer and the second passivation layer is 1.2-3.8nm.

13. The passivated contact solar cell structure of claim 1, wherein, Further comprising: a third passivation layer disposed on a side of the second doped polysilicon layer away from the silicon substrate.

14. The passivated contact structure for a solar cell of claim 13, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both P-type doped polysilicon, the thickness of the first passivation layer is less than that of the second passivation layer, and the thickness of the first passivation layer is less than that of the third passivation layer.

15. The passivated contact structure for a solar cell of claim 13, wherein, The first doped polysilicon layer and the second doped polysilicon layer are both N-type doped polysilicon, the thickness of the first passivation layer is greater than that of the second passivation layer, and the thickness of the first passivation layer is greater than that of the third passivation layer.

16. The passivated contact structure for a solar cell of claim 13, wherein, Further comprising: a third doped polysilicon layer disposed on a side of the third passivation layer away from the silicon substrate.

17. The passivated contact structure for a solar cell of claim 16, wherein, The sum of the thicknesses of the second doped polysilicon layer and the third doped polysilicon layer is greater than that of the first doped polysilicon layer.

18. The passivated contact structure for a solar cell of claim 16, wherein, The sum of the thicknesses of the first doped polysilicon layer, the second doped polysilicon layer, and the third doped polysilicon layer is 40-230nm.

19. The passivated contact solar cell structure of claim 16, wherein, The deposition temperature of the first doped polysilicon layer is greater than the deposition temperature of the second doped polysilicon layer, and the deposition temperature of the first doped polysilicon layer is greater than the deposition temperature of the third doped polysilicon layer.

20. The solar cell passivated contact structure of claim 16, wherein, The first doped polysilicon layer, the second doped polysilicon layer and the third doped polysilicon layer are all P-type doped polysilicon, and the sum of the thicknesses of the first passivation layer, the second passivation layer and the third passivation layer is 1.6-5 nm.

21. The passivated contact solar cell structure of claim 20, wherein, The thickness of the first passivation layer is greater than 0.8 nm.

22. The passivated contact solar cell structure of claim 16, wherein, The first doped polysilicon layer, the second doped polysilicon layer and the third doped polysilicon layer are all N-type doped polysilicon, and the sum of the thicknesses of the first passivation layer, the second passivation layer and the third passivation layer is 1.4-4.5 nm.

23. The passivated contact solar cell structure of claim 22, wherein, The thickness of the first passivation layer is greater than 0.6 nm.

24. A solar cell, comprising: a silicon substrate, a surface of the silicon substrate being provided with a P region and an N region; a first passivated contact structure provided at the P region; a second passivated contact structure provided at the N region; wherein the first passivated contact structure and the second passivated contact structure are both the passivated contact structure of any one of claims 1-23, the first doped polysilicon layer of the first passivated contact structure is P-type doped polysilicon, and the first doped polysilicon layer of the second passivated contact structure is N-type doped polysilicon.

25. The solar cell of claim 24, wherein, further comprising: a first electrode provided at the P region, the first electrode being in contact with the second doped polysilicon layer of the first passivated contact structure; a second electrode provided at the N region, the second electrode being in contact with the second doped polysilicon layer of the second passivated contact structure.

26. The passivated contact solar cell structure of claim 24, wherein, The thickness of the first passivation layer of the first passivated contact structure is less than the thickness of the second passivation layer of the first passivated contact structure.

27. The passivated contact solar cell structure of claim 24, wherein, The thickness of the first passivation layer of the second passivated contact structure is greater than the thickness of the second passivation layer of the second passivated contact structure.

28. The passivated contact solar cell structure of claim 24, wherein, The thickness of the second passivation layer of the first passivated contact structure is less than the thickness of the second passivation layer of the second passivated contact structure.

29. The passivated contact solar cell structure of claim 24, wherein, The thickness of the first passivation layer of the first passivated contact structure is greater than the thickness of the first passivation layer of the second passivated contact structure.

30. The solar cell of claim 24, wherein, The solar cell is a back contact solar cell, and the P region and the N region are located on the same side of the silicon substrate.

31. The solar cell of claim 24, wherein, The solar cell is a bifacial solar cell, and the P region and the N region are located on opposite sides of the silicon substrate, respectively.

32. A battery assembly, comprising the solar cell of any one of claims 24-31.

33. A photovoltaic system, comprising the battery assembly of claim 32.

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