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

Abstract

The present disclosure is applicable to the technical field of solar cells, and provides a solar cell, a solar cell passivation contact structure, a cell assembly, and a photovoltaic system. The solar cell passivation contact structure comprises a first passivation layer, a first doped polysilicon layer, a first barrier layer, and a second doped polysilicon layer that are sequentially stacked on the surface of a silicon substrate; the doping polarity of the first doped polysilicon layer is the same as the doping polarity of the second doped polysilicon layer; and the thickness of the first passivation layer is greater than the thickness of the first barrier layer. The solar cell passivation contact structure provided by the present disclosure is additionally provided with a first barrier layer and a second doped polysilicon layer, and a first passivation layer and the first barrier layer are used to jointly prevent impurities from diffusing into a silicon substrate, so that the inward diffusion of the impurities into the silicon substrate is reduced, and thus the passivation effect of the solar cell can be significantly improved, thereby improving the cell efficiency.

Description

A solar cell and its passivated contact structure, cell module and photovoltaic system

[0001] This disclosure takes priority from the patent application filed on July 9, 2024, application number 2024109113526 entitled "A Solar Cell and Passivated Contact Structure Thereof, Battery Module and Photovoltaic System", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of solar cell technology, specifically to a solar cell and its passivated contact structure, cell module and photovoltaic system. Background Technology

[0003] Solar cells utilize the photovoltaic effect of semiconductors to convert sunlight into electrical energy. Solar cells mainly include bifacial solar cells and back-contact solar cells. Back-contact solar cells, with both positive and negative electrodes located on the back of the cell, completely avoid the shading caused by metal grid lines on the front surface, thus eliminating optical losses and significantly improving cell conversion efficiency, compared to bifacial solar cells.

[0004] In the related technologies known to the inventors, the passivation contact structure of solar cells typically includes a passivation layer and a doped polycrystalline silicon layer sequentially stacked on the surface of a silicon substrate. The metal electrode of the solar cell contacts the doped polycrystalline silicon layer to achieve passivation. However, the passivation contact structure of solar cells is usually configured as a combination of a single doped polycrystalline silicon layer and a single passivation layer. During the solar cell fabrication process, especially during the metallization process to form the metal electrode, impurities in the metal electrode, such as iron, copper, cobalt, nickel, and chromium, can easily diffuse into the silicon substrate, resulting in poor passivation performance of the passivation contact structure and affecting the efficiency of the solar cell. Summary of the Invention

[0005] This disclosure provides a solar cell and its passivated contact structure, a cell module, and a photovoltaic system, aiming to solve the problem of poor passivation effect of the passivation contact structure in solar cells, which affects cell efficiency, in the related technologies known to the inventors.

[0006] This disclosure is implemented by providing a passivation contact structure for a solar cell, comprising a first passivation layer, a first doped polycrystalline silicon layer, a first barrier layer, and a second doped polycrystalline silicon layer sequentially stacked on the surface of a silicon substrate, wherein the doping polarity of the first doped polycrystalline silicon layer is the same as that of the second doped polycrystalline silicon layer; wherein the thickness of the first passivation layer is greater than the thickness of the first barrier layer.

[0007] Preferably, the ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 10, and not equal to 1.

[0008] Preferably, the ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 4, and not equal to 1.

[0009] Preferably, the ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 2, but not equal to 1.

[0010] Preferably, the thickness of the first passivation layer is 0.5 to 5 nanometers, and the thickness of the first barrier layer is 0.2 to 4.5 nanometers.

[0011] Preferably, the first passivation layer has holes, and the first doped polysilicon layer contacts the silicon substrate through the holes in the first passivation layer.

[0012] Preferably, the first barrier layer has holes, and the second doped polysilicon layer passes through the holes in the first barrier layer and contacts the first doped polysilicon layer.

[0013] Preferably, both the first passivation layer and the first barrier layer are provided with pores, and the pore density of the first passivation layer is less than that of the first barrier layer.

[0014] Preferably, both the first passivation layer and the first barrier layer are provided with pores, and the average pore diameter of the first passivation layer is smaller than the average pore diameter of the first barrier layer.

[0015] Preferably, the first passivation layer comprises one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, and silicon nitride containing boron, phosphorus or gallium.

[0016] Preferably, the first barrier layer comprises one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, silicon nitride containing boron, phosphorus or gallium, oxygen-rich silicon containing boron, phosphorus or gallium, and nitrogen-rich silicon containing boron, phosphorus or gallium.

[0017] Preferably, the oxygen content of the oxygen-enriched silicon is 1×10⁻⁶. 19 atoms / cm 3 above.

[0018] Preferably, the nitrogen content of the nitrogen-rich silicon is 1×10⁻⁶. 19 atoms / cm 3 above.

[0019] Preferably, the first passivation layer, the first doped polysilicon layer, the first barrier layer, and the second doped polysilicon layer are all doped with group IIIA or group VA elements; the doping concentration of the second doped polysilicon layer is greater than the doping concentration of the first doped polysilicon layer.

[0020] Preferably, the doping concentration of the first passivation layer is less than or equal to the doping concentration of the first barrier layer.

[0021] Preferably, the thickness of the first doped polysilicon layer is greater than the thickness of the second doped polysilicon layer.

[0022] Preferably, the ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 1 to 50.

[0023] Preferably, the ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 2 to 50.

[0024] Preferably, the ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 5 to 50.

[0025] Preferably, the ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 10 to 50.

[0026] Preferably, the thickness of the first doped polycrystalline silicon layer is 30-350 nanometers, and the thickness of the second doped polycrystalline silicon layer is 5-150 nanometers.

[0027] Preferably, the thickness of the first doped polysilicon layer is less than the thickness of the second doped polysilicon layer.

[0028] Preferred options also include:

[0029] The second barrier layer is disposed on the side of the second doped polysilicon layer opposite to the silicon substrate.

[0030] Preferably, the thickness of the second barrier layer is less than or equal to the thickness of the first barrier layer.

[0031] Preferred options also include:

[0032] A third doped polysilicon layer is disposed on the side of the second barrier layer opposite to the silicon substrate, and the doping polarity of the third doped polysilicon layer is the same as or opposite to that of the second doped polysilicon layer.

[0033] Preferred options also include:

[0034] The third barrier layer is disposed on the side of the third doped polysilicon layer opposite to the silicon substrate.

[0035] Preferred options also include:

[0036] A fourth doped polysilicon layer is disposed on the side of the third barrier layer opposite to the silicon substrate, and the doping polarity of the fourth doped polysilicon layer is the same as or opposite to the doping polarity of the second doped polysilicon layer.

[0037] Preferably, the thickness of the third barrier layer is less than or equal to the thickness of the second barrier layer.

[0038] Preferably, both the first barrier layer and the second doped polysilicon layer are intermittently disposed on the first doped polysilicon layer.

[0039] Preferably, the thicknesses of the first doped polysilicon layer, the second doped polysilicon layer, the third doped polysilicon layer, and the fourth doped polysilicon layer decrease sequentially.

[0040] Preferred options also include:

[0041] A first metal electrode is disposed on the second doped polysilicon layer, and the first metal electrode is in contact with the second doped polysilicon layer.

[0042] Preferably, the first metal electrode passes through the second doped polysilicon layer, and the first barrier layer contacts the first doped polysilicon layer.

[0043] Preferably, the width of the first metal electrode in the first doped polysilicon layer region is smaller than the width of the first metal electrode in the second doped polysilicon layer region.

[0044] This disclosure also provides a solar cell, including a silicon substrate, the silicon substrate including a light-facing surface and a back-lighting surface disposed opposite to the light-facing surface, the light-facing surface and / or the back-lighting surface being provided with the above-described solar cell passivation contact structure.

[0045] Preferably, the solar cell is a back-contact solar cell, and the back surface of the back-contact solar cell is provided with a P region and an N region, and at least one of the P region and the N region is provided with the passivation contact structure of the solar cell.

[0046] Preferably, the P region is provided with the solar cell passivation contact structure, the N region is provided with a third passivation layer and a sixth doped polycrystalline silicon layer disposed on the side of the third passivation layer facing away from the silicon substrate; the first doped polycrystalline silicon layer of the solar cell passivation contact structure in the P region is P-type doped polycrystalline silicon, and the sixth doped polycrystalline silicon layer is N-type doped polycrystalline silicon.

[0047] Preferably, both the P-region and the N-region are provided with the solar cell passivation contact structure, wherein the first doped polycrystalline silicon layer of the solar cell passivation contact structure in the P-region is P-type doped polycrystalline silicon, and the first doped polycrystalline silicon layer of the solar cell passivation contact structure in the N-region is N-type doped polycrystalline silicon.

[0048] This disclosure also provides a battery assembly including the solar cell described above.

[0049] This disclosure also provides a photovoltaic system including the aforementioned battery module.

[0050] This disclosure provides a passivation contact structure for a solar cell, comprising a first passivation layer, a first doped polycrystalline silicon layer, a first barrier layer, and a second doped polycrystalline silicon layer sequentially stacked on the surface of a silicon substrate. By adding the first barrier layer and the second doped polycrystalline silicon layer on the surface of the first doped polycrystalline silicon layer, the combined blocking effect of the first passivation layer and the first barrier layer prevents excessive impurities from the metal electrode from diffusing into the silicon substrate, thereby reducing impurities in the metal electrode. For example, impurities such as iron, copper, cobalt, nickel, and chromium in the metal electrode can diffuse into the silicon substrate, significantly improving the passivation effect of the solar cell and thus improving the cell efficiency. Furthermore, the first barrier layer can block the paste of the metal electrode, reducing the burn-through depth of the paste and preventing the metal electrode from burning through the first barrier layer and entering the first doped polycrystalline silicon layer, thereby improving the cell yield.

[0051] Furthermore, the thickness of the first passivation layer is set to be greater than the thickness of the first barrier layer. By thinning the thickness of the first barrier layer, it is easier for doped atoms in the first and second doped polycrystalline silicon layers to diffuse through the first barrier layer. Doped atoms from the one with a higher doping concentration in the first and second doped polycrystalline silicon layers can diffuse through the first barrier layer to the one with a lower doping concentration in the first and second doped polycrystalline silicon layers. This allows for better adjustment of the doping concentration of the first and second doped polycrystalline silicon layers, further improving the passivation effect of the passivation contact structure of the solar cell. This achieves both the blocking effect of the first barrier layer on impurities in the metal electrode and the burn-through of the metal electrode paste, and facilitates the adjustment of the doping concentration between the first and second doped polycrystalline silicon layers, achieving a balance between the two effects and further improving the efficiency of the solar cell. Attached Figure Description

[0052] Figure 1 is a partial structural schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 1 of this disclosure;

[0053] Figure 2 is a schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 1 of this disclosure;

[0054] Figure 3 is a schematic diagram of another passivated contact structure for a solar cell provided in Embodiment 1 of this disclosure;

[0055] Figure 4 is a schematic diagram of another passivation contact structure for a solar cell provided in Embodiment 1 of this disclosure;

[0056] Figure 5 is a partial schematic diagram of the passivated contact structure of the solar cell shown in Figure 4;

[0057] Figure 6 is a partial structural schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 2 of this disclosure;

[0058] Figure 7 is a schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 2 of this disclosure;

[0059] Figure 8 is a schematic diagram of another passivation contact structure for a solar cell provided in Embodiment 2 of this disclosure;

[0060] Figure 9 is a partial structural schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 3 of this disclosure;

[0061] Figure 10 is a schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 3 of this disclosure;

[0062] Figure 11 is a schematic diagram of another passivation contact structure for a solar cell provided in Embodiment 3 of this disclosure;

[0063] Figure 12 is a partial structural schematic diagram of a passivated contact structure for a solar cell provided in Embodiment 4 of this disclosure;

[0064] Figure 13 is a schematic diagram of a solar cell provided in Embodiment 5 of this disclosure;

[0065] Figure 14 is a schematic diagram of a solar cell provided in Embodiment Six of this disclosure;

[0066] Figure 15 is a schematic diagram of a solar cell provided in Embodiment 7 of this disclosure;

[0067] Figure 16 is a schematic diagram of a solar cell provided in Embodiment 8 of this disclosure;

[0068] Figure 17 is a top view of a solar cell provided in Embodiment 9 of this disclosure;

[0069] Figure 18 is a cross-sectional view along the AA direction in Figure 17;

[0070] Figure 19 is a schematic cross-sectional view along the BB direction in Figure 17.

[0071] The above figures include the following reference numerals: 10, substrate; 1, first passivation layer; 2, first doped polysilicon layer; 3, first barrier layer; 4, second doped polysilicon layer; 5, second barrier layer; 6, third doped polysilicon layer; 7, third barrier layer; 8, fourth doped polysilicon layer; 9, groove; 11, first metal electrode; 14, second passivation layer; 15, fifth doped polysilicon layer; 17, second metal electrode; 19, third metal electrode; 20, third passivation layer; 21, sixth doped polysilicon layer; 22, isolation region; 25, P-region; 26, N-region; 28, fourth metal electrode; 100, opening; 101, light-facing surface; 102, backlighting surface. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this disclosure.

[0073] This disclosure provides a passivation contact structure for a solar cell, comprising a first passivation layer, a first doped polycrystalline silicon layer, a first barrier layer, and a second doped polycrystalline silicon layer sequentially stacked on the surface of a silicon substrate. By adding the first barrier layer and the second doped polycrystalline silicon layer to the surface of the first doped polycrystalline silicon layer, the first barrier layer acts as a barrier against impurities in the metal electrode, preventing excessive impurities from diffusing into the silicon substrate and reducing the inward diffusion of impurities from the metal electrode into the silicon substrate. This significantly improves the passivation effect of the solar cell, thereby increasing the cell efficiency. Furthermore, the first barrier layer acts as a barrier against the paste of the metal electrode, reducing the burn-through depth of the paste and preventing the metal electrode from burning through into the silicon substrate, thus improving the cell yield. Moreover, the thickness of the first passivation layer is set to be greater than the thickness of the first barrier layer, which not only achieves the barrier effect against impurities in the metal electrode and burn-through of the metal electrode paste, but also facilitates the adjustment of the doping concentration between the first doped polycrystalline silicon layer and the second doped polycrystalline silicon layer, thereby further improving the efficiency of the solar cell.

[0074] Example 1

[0075] Referring to Figures 1-4, this embodiment of the present disclosure provides a passivation contact structure for a solar cell, including a first passivation layer 1, a first doped polycrystalline silicon layer 2, a first barrier layer 3, and a second doped polycrystalline silicon layer 4 sequentially stacked on the surface of a silicon substrate 10. The doping polarity of the first doped polycrystalline silicon layer 2 is the same as that of the second doped polycrystalline silicon layer 4. The thickness d4 of the first passivation layer 1 is greater than the thickness d5 of the first barrier layer 3.

[0076] In this embodiment, the silicon substrate 10 can be a P-type silicon substrate or an N-type silicon substrate. The surface of the silicon substrate 10 can be the light-facing side or the back-facing side of the solar cell.

[0077] In this embodiment, a passivation contact structure for a solar cell includes a first passivation layer 1, a first doped polycrystalline silicon layer 2, a first barrier layer 3, and a second doped polycrystalline silicon layer 4 sequentially stacked on the surface of a silicon substrate 10. By adding the first barrier layer 3 and the second doped polycrystalline silicon layer 4 to the surface of the first doped polycrystalline silicon layer 2, the combined blocking effect of the first passivation layer 1 and the first barrier layer 3 prevents excessive impurities from the metal electrode from diffusing into the silicon substrate, thus reducing the inward diffusion of impurities from the metal electrode into the silicon substrate. This significantly improves the passivation effect of the solar cell, thereby increasing the cell efficiency. Furthermore, the first barrier layer 3 can block the paste of the metal electrode, reducing the burn-through depth of the metal electrode paste and preventing the metal electrode from burning through the first barrier layer 3 and entering the silicon substrate. The impurities include, but are not limited to, impurities such as iron, copper, cobalt, nickel, and chromium in the metal electrode.

[0078] Furthermore, by setting the thickness of the first passivation layer 1 to be greater than the thickness of the first barrier layer 3, and by thinning the thickness of the first barrier layer 3, the doped atoms of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4 can diffuse more easily through the first barrier layer 3. The doped atoms of the one with a higher doping concentration in the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4 can diffuse through the first barrier layer 3 to the one with a lower doping concentration in the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4. This allows for better adjustment of the doping concentration of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4, which can further improve the passivation effect of the passivation contact structure of the solar cell. This achieves both the blocking effect of the first barrier layer 3 on impurities in the metal electrode and the burn-through of the metal electrode paste, and facilitates the adjustment of the doping concentration between the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4, achieving a balance between the two effects, thereby further improving the efficiency of the solar cell. In addition, in practical applications, the passivation effect can be further optimized by adjusting the doping concentration and thickness of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4. This can give the passivation contact structure of the solar cell a better passivation effect and effectively improve the efficiency of the solar cell.

[0079] In this embodiment, the thickness d4 of the first passivation layer 1 is greater than the thickness d5 of the first barrier layer 3, meaning that the first passivation layer 1 closer to the silicon substrate 10 is thicker. This can further improve the passivation effect of the passivation contact structure of the solar cell. At the same time, it facilitates the diffusion of doped atoms of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4 through the first barrier layer 3, allowing for better adjustment of the doping concentration of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4. This can further improve the passivation effect of the passivation contact structure of the solar cell and effectively improve the efficiency of the solar cell.

[0080] In this embodiment, the doping polarity of the first doped polysilicon layer 2 and the second doped polysilicon layer 4 are both P-type or N-type. For example, both the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be doped with boron, or both the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can be doped with phosphorus.

[0081] As an embodiment of this disclosure, the first passivation layer 1, the first doped polysilicon layer 2, the first barrier layer 3, and the second doped polysilicon layer 4 are all doped with group IIIA or group VA elements; the doping concentration of the second doped polysilicon layer 4 is greater than the doping concentration of the first doped polysilicon layer 2.

[0082] In this embodiment, when the passivation contact structure of the solar cell is disposed in the P region of the solar cell, the first passivation layer 1, the first doped polycrystalline silicon layer 2, the first barrier layer 3, and the second doped polycrystalline silicon layer 4 are all doped with group IIIA elements; when the passivation contact structure of the solar cell is disposed in the N region of the solar cell, the first passivation layer 1, the first doped polycrystalline silicon layer 2, the first barrier layer 3, and the second doped polycrystalline silicon layer 4 are all doped with group VA elements.

[0083] In this embodiment, the doping concentration of the second doped polysilicon layer 4 is greater than that of the first doped polysilicon layer 2. The second doped polysilicon layer 4 and the first doped polysilicon layer 2 form a high-low junction, providing field-effect passivation. Moreover, the higher doping concentration of the second doped polysilicon layer 4 compared to the first doped polysilicon layer 2 facilitates the formation of a good ohmic contact between the second doped polysilicon layer 4 and the metal electrode, thereby improving the passivation effect of the solar cell's passivation contact structure, reducing current loss, and ultimately improving cell efficiency. Alternatively, in other embodiments, the doping concentration of the second doped polysilicon layer 4 may be less than or equal to the doping concentration of the first doped polysilicon layer 2.

[0084] As an embodiment of this disclosure, the doping concentration of the first passivation layer 1 is less than or equal to the doping concentration of the first barrier layer 3.

[0085] In this embodiment, the doping concentration of the first passivation layer 1 is less than or equal to the doping concentration of the first barrier layer 3, which is beneficial to improving the passivation effect of the first passivation layer 1. In some other embodiments, the doping concentration of the first passivation layer 1 may also be greater than the doping concentration of the first barrier layer 3.

[0086] As a preferred embodiment of this disclosure, the doping concentration of the first passivation layer 1 is lower than the doping concentration of the first barrier layer 3, which is beneficial to improving the ability of the first barrier layer 3 to block impurities from entering the silicon substrate 10.

[0087] As one embodiment of this disclosure, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is 1 to 10, and is not equal to 1.

[0088] In this embodiment, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is greater than 1 and less than or equal to 10. This ensures that the first passivation layer 1 and the first barrier layer 3 effectively block impurities and prevent the metal electrode paste from burning through. It also facilitates the adjustment of the doping concentration between the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4, enabling the passivation contact structure of the solar cell to have a good passivation effect. Furthermore, it facilitates the preparation of the first passivation layer 1 and the first barrier layer 3.

[0089] Specifically, the thickness d4 of the first passivation layer 1 and the thickness d5 of the first barrier layer 3 can be flexibly set, as long as the thickness d4 of the first passivation layer 1 is greater than the thickness d5 of the first barrier layer 3. The ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 can be: 1.01, or 1.5, or 2.0, or 2.4, or 3.0, or 3.5, or 4, or 4.5, or 5, or 5.5, or 6, or 7, or 8, or 9, or 10.

[0090] As one embodiment of this disclosure, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is 1 to 4, and is not equal to 1.

[0091] In this embodiment, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is greater than 1 and less than or equal to 4. This ensures that the first passivation layer 1 and the first barrier layer 3 have good impurity blocking and passivation effects, and also makes it easier to prepare the first passivation layer 1 and the first barrier layer 3.

[0092] As one embodiment of this disclosure, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is 1 to 2, and is not equal to 1.

[0093] In this embodiment, the ratio of the thickness d4 of the first passivation layer 1 to the thickness d5 of the first barrier layer 3 is greater than 1 and less than or equal to 2, which further reduces the thickness difference between the first passivation layer 1 and the first barrier layer 3, making it easier to prepare the first passivation layer 1 and the first barrier layer 3, and achieving good impurity blocking effect and good passivation effect of the first passivation layer 1 and the first barrier layer 3.

[0094] As one embodiment of this disclosure, the thickness d4 of the first passivation layer 1 is 0.5 to 5 nanometers, and the thickness d5 of the first barrier layer 3 is 0.2 to 4.5 nanometers. Furthermore, the thicknesses d4 of the first passivation layer 1 and d5 of the first barrier layer 3 are not limited to these ranges, and the thicknesses of the first passivation layer 1 and the first barrier layer 3 can be flexibly set as needed.

[0095] In this embodiment, provided that the thickness d4 of the first passivation layer 1 is greater than the thickness d5 of the first barrier layer 3, the thickness d4 of the first passivation layer 1 can be: 0.5 nm, or 1 nm, or 1.5 nm, or 2.0 nm, or 2.5 nm, or 2.8 nm, or 3.0 nm, or 3.2 nm, or 3.5 nm, or 3.8 nm, or 4.0 nm, or 4.2 nm, or 4.5 nm, or 5 nm.

[0096] In this embodiment, the thickness d5 of the first barrier layer 3 can be: 0.2 nanometers, or 0.5 nanometers, or 1 nanometer, or 1.5 nanometers, or 2.0 nanometers, or 2.5 nanometers, or 2.8 nanometers, or 3.0 nanometers, or 3.2 nanometers, or 3.5 nanometers, or 3.8 nanometers, or 4.0 nanometers, or 4.2 nanometers, or 4.5 nanometers.

[0097] As one embodiment of this disclosure, the first passivation layer 1 has holes (not shown), and the first doped polysilicon layer 2 contacts the silicon substrate 10 through the holes in the first passivation layer 1.

[0098] In this embodiment, the holes on the first passivation layer 1 penetrate vertically through the first passivation layer 1. An inner expansion layer is also provided inside the silicon substrate 10, and the first doped polycrystalline silicon layer 2 contacts the inner expansion layer inside the silicon substrate 10 through the holes on the first passivation layer 1. The contact between the first doped polycrystalline silicon layer 2 and the silicon substrate 10 via the holes on the first passivation layer 1 facilitates contact, reduces current loss, and improves battery conversion efficiency.

[0099] As one embodiment of this disclosure, the first barrier layer 3 is provided with holes, and the second doped polysilicon layer 4 passes through the holes in the first barrier layer 3 and contacts the first doped polysilicon layer 2.

[0100] In this embodiment, the holes in the first barrier layer 3 penetrate vertically through the first barrier layer 3. The second doped polycrystalline silicon layer 4 contacts the first doped polycrystalline silicon layer 2 through the holes in the first barrier layer 3, which facilitates contact between the second doped polycrystalline silicon layer 4 and the first doped polycrystalline silicon layer 2, reduces current loss, and improves cell conversion efficiency. Moreover, the holes in the first barrier layer 3 facilitate the passage of doped atoms from the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4, making it easier to adjust the doping concentration between the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4, thereby further improving the efficiency of the solar cell.

[0101] The pores in the first passivation layer 1 and the first barrier layer 3 can be formed by chemical etching, dry etching, or thermal diffusion shock, depending on the actual application requirements, and are not specifically limited here. When viewed from a top-down angle, the first passivation layer 1 and the first barrier layer 3 exhibit a porous structure, while when viewed from a cross-sectional angle, they show a multi-channel structure. Optionally, the pore size of the first passivation layer 1 and the first barrier layer 3 is less than 10 μm.

[0102] As an embodiment of this disclosure, both the first passivation layer 1 and the first barrier layer 3 are provided with pores, and the pore density of the first passivation layer 1 is less than the pore density of the first barrier layer 3.

[0103] In this embodiment, the pore density of the first passivation layer 1 is less than that of the first barrier layer 3. This can be understood as the number of pores in the first passivation layer 1 per unit area being less than the number of pores in the first barrier layer 3. Because the pore density of the first passivation layer 1 is less than that of the first barrier layer 3, the conductivity of the first passivation layer 1 and the first barrier layer 3 can be sequentially enhanced, which is beneficial to improving the gettering effect of the silicon substrate 10 and thus improving battery efficiency.

[0104] As an embodiment of this disclosure, both the first passivation layer 1 and the first barrier layer 3 are provided with holes, and the average hole diameter of the first passivation layer 1 is smaller than the average hole diameter of the first barrier layer 3.

[0105] In this design, the pore diameters of the pores in the first passivation layer 1 can be equal or unequal; similarly, the pore diameters of the pores in the first barrier layer 3 can be equal or unequal. The average pore diameter of the pores in the first passivation layer 1 can be understood as the average pore diameter of all pores in the first passivation layer 1; the average pore diameter of the pores in the first barrier layer 3 can be understood as the average pore diameter of all pores in the first barrier layer 3. By setting the average pore diameter of the pores in the first passivation layer 1 to be smaller than the average pore diameter of the pores in the first barrier layer 3, the passivation effect of the first passivation layer 1 on the back side of the silicon substrate 10 is improved, which is beneficial to improving battery efficiency.

[0106] As an embodiment of this disclosure, the first passivation layer 1 includes one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, and silicon nitride containing boron, phosphorus or gallium.

[0107] In this embodiment, the first passivation layer 1 can be silicon oxide containing boron, phosphorus, or gallium, or silicon oxynitride containing boron, phosphorus, or gallium, or silicon nitride containing boron, phosphorus, or gallium; alternatively, the first passivation layer 1 can be any combination of silicon oxide containing boron, phosphorus, or gallium, silicon oxynitride containing boron, phosphorus, or gallium, or silicon nitride containing boron, phosphorus, or gallium. Using the above-mentioned materials, the first passivation layer 1 can achieve both good impurity blocking effect and good passivation effect.

[0108] As an embodiment of this disclosure, the first barrier layer 3 includes one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, silicon nitride containing boron, phosphorus or gallium, oxygen-rich silicon containing boron, phosphorus or gallium, and nitrogen-rich silicon containing boron, phosphorus or gallium.

[0109] In this embodiment, the first barrier layer 3 can be silicon oxide containing boron, phosphorus, or gallium; silicon oxynitride containing boron, phosphorus, or gallium; silicon nitride containing boron, phosphorus, or gallium; oxygen-rich silicon containing boron, phosphorus, or gallium; or nitrogen-rich silicon containing boron, phosphorus, or gallium. The first barrier layer 3 can also be any combination of silicon oxide containing boron, phosphorus, or gallium; silicon oxynitride containing boron, phosphorus, or gallium; silicon nitride containing boron, phosphorus, or gallium; oxygen-rich silicon containing boron, phosphorus, or gallium; or nitrogen-rich silicon containing boron, phosphorus, or gallium. The use of the above-mentioned materials in the first barrier layer 3 achieves both good impurity blocking and good passivation effects.

[0110] As one embodiment of this disclosure, the oxygen content of the oxygen-enriched silicon is 1×10⁻⁶. 19 atoms / cm 3 above.

[0111] In this embodiment, when the first barrier layer 3 comprises oxygen-rich silicon containing boron, phosphorus, or gallium, the oxygen content of the oxygen-rich silicon is 1×10⁻⁶. 19 atoms / cm 3 The above can improve the effect of the first barrier layer 3 in blocking impurities.

[0112] As an embodiment of this disclosure, when the first barrier layer 3 comprises nitrogen-rich silicon containing boron, phosphorus, or gallium, the nitrogen content of the nitrogen-rich silicon is 1 × 10⁻⁶. 19 atoms / cm 3 The above can improve the effect of the first barrier layer 3 in blocking impurities.

[0113] As an embodiment of this disclosure, the thickness d1 of the first doped polysilicon layer 2 is greater than the thickness d2 of the second doped polysilicon layer 4.

[0114] In this embodiment, the thickness d1 of the first doped polycrystalline silicon layer 2 is greater than the thickness d2 of the second doped polycrystalline silicon layer 4. This makes the doped polycrystalline silicon layer near the silicon substrate 10 thicker, which is beneficial to further improve the passivation effect of the passivation contact structure of the solar cell.

[0115] In another embodiment of the present invention, the thickness d1 of the first doped polysilicon layer 2 is less than the thickness d2 of the second doped polysilicon layer 4, which can enhance the burn-through barrier effect of the second doped polysilicon layer 4 on the metal electrode paste and prevent the metal electrode paste from burning through into the first doped polysilicon layer 2. In some other embodiments, the thickness d1 of the first doped polysilicon layer 2 may also be equal to the thickness d2 of the second doped polysilicon layer 4.

[0116] As an embodiment of this disclosure, the ratio of the thickness d1 of the first doped polysilicon layer 2 to the thickness d2 of the second doped polysilicon layer 4 is 1 to 50.

[0117] In this embodiment, the ratio of the thickness d1 of the first doped polycrystalline silicon layer 2 to the thickness d2 of the second doped polycrystalline silicon layer 4 is greater than or equal to 1 and less than or equal to 50, which can ensure a good passivation effect of the passivation contact structure of the solar cell.

[0118] Specifically, the thickness d1 of the first doped polysilicon layer 2 and the thickness d2 of the second doped polysilicon layer 4 can be flexibly set, as long as the ratio of the thickness d1 of the first doped polysilicon layer 2 to the thickness d2 of the second doped polysilicon layer 4 is between 1 and 50. For example, the ratio of the thickness d1 of the first doped polysilicon layer 2 to the thickness d2 of the second doped polysilicon layer 4 can be: 1, 3, 5, 6, 8, 10, 12, 14, 15, 16, 17, 19, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 46, 48, or 50.

[0119] As an embodiment of this disclosure, the ratio of the thickness d1 of the first doped polysilicon layer 2 to the thickness d2 of the second doped polysilicon layer 4 is 2 to 50.

[0120] In this embodiment, the ratio of the thickness d1 of the first doped polycrystalline silicon layer 2 to the thickness d2 of the second doped polycrystalline silicon layer 4 is greater than or equal to 2 and less than or equal to 50. This ensures that the difference between the thickness d1 of the first doped polycrystalline silicon layer 2 and the thickness d2 of the second doped polycrystalline silicon layer 4 is within a better range, which can ensure a better passivation effect of the passivation contact structure of the solar cell and facilitate the preparation of the first doped polycrystalline silicon layer 2 and the second doped polycrystalline silicon layer 4.

[0121] As an embodiment of this disclosure, the ratio of the thickness d1 of the first doped polysilicon layer 2 to the thickness d2 of the second doped polysilicon layer 4 is 5 to 50.

[0122] In this embodiment, the ratio of the thickness d1 of the first doped polycrystalline silicon layer 2 to the thickness d2 of the second doped polycrystalline silicon layer 4 is greater than or equal to 5 and less than or equal to 50. This makes the difference between the thickness d1 of the first doped polycrystalline silicon layer 2 and the thickness d2 of the second doped polycrystalline silicon layer 4 larger, which can further improve the passivation effect of the passivation contact structure of the solar cell.

[0123] As one embodiment of this disclosure, the ratio of the thickness of the first doped polysilicon layer 2 to the thickness of the second doped polysilicon layer 4 is 10 to 50.

[0124] In this embodiment, the ratio of the thickness d1 of the first doped polycrystalline silicon layer 2 to the thickness d2 of the second doped polycrystalline silicon layer 4 is greater than or equal to 10 and less than or equal to 50. Further increasing the difference between the thickness d1 of the first doped polycrystalline silicon layer 2 and the thickness d2 of the second doped polycrystalline silicon layer 4 can further improve the passivation effect of the passivation contact structure of the solar cell.

[0125] As an embodiment of this disclosure, the thickness d1 of the first doped polysilicon layer 2 is 30-350 nanometers, and the thickness d2 of the second doped polysilicon layer 4 is 5-150 nanometers.

[0126] In this embodiment, the thickness d1 of the first doped polysilicon layer 2 can be any value within the range of 30 to 350 nanometers, and the thickness d2 of the second doped polysilicon layer 4 can be any value within the range of 5 to 150 nanometers. For example, the thickness d1 of the first doped polysilicon layer 2 can be 30 nanometers, and the thickness d2 of the second doped polysilicon layer 4 can be 5 nanometers; or, the thickness d1 of the first doped polysilicon layer 2 can be 300 nanometers, and the thickness d2 of the second doped polysilicon layer 4 can be 30 nanometers; or, for another example, the thickness d1 of the first doped polysilicon layer 2 can be 350 nanometers, and the thickness d2 of the second doped polysilicon layer 4 can be 150 nanometers.

[0127] As an embodiment of this disclosure, the first barrier layer 3 and the second doped polysilicon layer 4 are both in a continuous, full-surface structure covering the first doped polysilicon layer 2, that is, the first barrier layer 3 and the second doped polysilicon layer 4 cover the entire surface of the first doped polysilicon layer 2, which can achieve full-surface passivation.

[0128] Referring to Figure 2, the passivation contact structure of the solar cell in this embodiment further includes:

[0129] A first metal electrode 11 is disposed on the second doped polysilicon layer 4, and the first metal electrode 11 is in contact with the second doped polysilicon layer 4.

[0130] In this embodiment, since the first barrier layer 3 and the second doped polysilicon layer 4 can block the paste of the first metal electrode 11, preventing the first metal electrode 11 from burning through the first barrier layer 3 and entering the first doped polysilicon layer 2, the first metal electrode 11 only contacts the second doped polysilicon layer 4, and the depth of the first metal electrode 11 entering the second doped polysilicon layer 4 is less than the thickness of the second doped polysilicon layer 4. Furthermore, since the first doped polysilicon layer 2 and the second doped polysilicon layer 4 have the same doping polarity, the first metal electrode 11 directly contacts the second doped polysilicon layer 4, and there is no pre-set opening between the second doped polysilicon layer 4 and the first barrier layer 3. Therefore, the first doped polysilicon layer 2 and the second doped polysilicon layer 4 can have a good blocking effect.

[0131] Please refer to Figure 3. As another embodiment of this disclosure, the first metal electrode 11 passes through the second doped polysilicon layer 4 and the first barrier layer 3 and contacts the first doped polysilicon layer 2.

[0132] In this embodiment, during the metallization process of the first metal electrode 11, the first metal electrode 11 may pass through the second doped polysilicon layer 4, the first barrier layer 3, and contact the first doped polysilicon layer 2, so that the first metal electrode 11 simultaneously contacts the second doped polysilicon layer 4, the first barrier layer 3, and the first doped polysilicon layer 2. Since the second doped polysilicon layer 4 and the first barrier layer 3 do not have pre-set openings, the first metal electrode 11 is in close contact with the second doped polysilicon layer 4 and the first barrier layer 3, which can also ensure that the second doped polysilicon layer 4 and the first barrier layer 3 effectively block impurities.

[0133] Please refer to Figures 4 and 5. As an embodiment of this disclosure, the width of the first metal electrode 11 in the region of the first doped polysilicon layer 2 is smaller than the width of the first metal electrode 11 in the region of the second doped polysilicon layer 4.

[0134] The width of the first metal electrode 11 in the region of the first doped polysilicon layer 2 can be any width of the first metal electrode 11 in the region of the first doped polysilicon layer 2 along the horizontal direction L; the width of the first metal electrode 11 in the region of the second doped polysilicon layer 4 can also be any width of the first metal electrode 11 in the region of the second doped polysilicon layer 4 along the horizontal direction L. Preferably, the width of the first metal electrode 11 in the region of the first doped polysilicon layer 2 is the width W1 of the first metal electrode 11 in the region of the first doped polysilicon layer 2 along the horizontal direction L away from the surface of the first passivation layer 1; the width of the first metal electrode 11 in the region of the second doped polysilicon layer 4 is the width W2 of the first metal electrode 11 in the region of the second doped polysilicon layer 4 along the horizontal direction L away from the surface of the first passivation layer 1.

[0135] In this embodiment, due to the blocking effect of the second doped polysilicon layer 4 and the first barrier layer 3, the burn-through depth of the first metal electrode 11 can be blocked, so that the first metal electrode 11 gradually decreases from the surface of the second doped polysilicon layer 4 away from the first passivation layer 1 towards the first doped polysilicon layer 2. This can prevent the first metal electrode 11 from entering and burning through the first passivation layer 1, and prevent the first metal electrode 11 from directly contacting the silicon substrate 10.

[0136] Example 2

[0137] Please refer to Figure 6. Based on Embodiment 1, the passivation contact structure of the solar cell in this embodiment further includes:

[0138] The second barrier layer 5 is disposed on the side of the second doped polysilicon layer 4 that is away from the silicon substrate 10.

[0139] In this embodiment, by providing a second barrier layer 5 on the surface of the second doped polycrystalline silicon layer 4 away from the silicon substrate 10, the second barrier layer 5 can further block the diffusion of impurities from the metal electrode into the silicon substrate 10, and the second barrier layer 5 can further block the paste of the metal electrode, thereby further improving the passivation effect of the passivation contact structure of the solar cell.

[0140] As one embodiment of this disclosure, the thickness of the second barrier layer 5 is less than or equal to the thickness of the first barrier layer 3.

[0141] In this embodiment, the thickness of the second barrier layer 5 can be less than or equal to the thickness of the first barrier layer 3. In other embodiments, the thickness of the second barrier layer 5 can also be greater than the thickness of the first barrier layer 3. The material of the second barrier layer 5 can be the same as or different from the material of the first barrier layer 3.

[0142] As one embodiment of this disclosure, it also includes:

[0143] The third doped polysilicon layer 6 is disposed on the side of the second barrier layer 5 facing away from the silicon substrate 10. The doping polarity of the third doped polysilicon layer 6 is the same as or opposite to the doping polarity of the second doped polysilicon layer 4.

[0144] In this embodiment, by adding a second barrier layer 5 and a third doped polycrystalline silicon layer 6, the second barrier layer 5, the first barrier layer 3, and the first passivation layer 1 are used to jointly prevent impurities from the metal electrode from expanding into the silicon substrate 10. Furthermore, the second barrier layer 5 and the first barrier layer 3 jointly prevent the paste of the metal electrode from burning through, thereby further improving the passivation effect of the passivation contact structure of the solar cell. Moreover, the third doped polycrystalline silicon layer 6 can further enhance the passivation effect of the passivation contact structure of the solar cell.

[0145] The doping polarity of the third doped polysilicon layer 6 can be the same as or opposite to that of the second doped polysilicon layer 4.

[0146] Referring to Figure 7, the doping polarity of the third doped polysilicon layer 6 is the same as that of the second doped polysilicon layer 4, meaning that the doping polarities of the third doped polysilicon layer 6, the second doped polysilicon layer 4, and the first doped polysilicon layer 2 are all P-type or N-type. In this case, no opening is needed on the third doped polysilicon layer 6, and the first metal electrode 11 can contact the third doped polysilicon layer 6. Alternatively, the first metal electrode 11 can also pass through the third doped polysilicon layer 6 to contact the second doped polysilicon layer 4 or the first doped polysilicon layer 2.

[0147] Referring to Figure 8, the doping polarity of the third doped polysilicon layer 6 is opposite to that of the second doped polysilicon layer 4. That is, if the doping polarity of the second doped polysilicon layer 4 and the first doped polysilicon layer 2 is P-type, then the doping polarity of the third doped polysilicon layer 6 is N-type; or, if the doping polarity of the second doped polysilicon layer 4 and the first doped polysilicon layer 2 is N-type, then the doping polarity of the third doped polysilicon layer 6 is P-type. In this case, the third doped polysilicon layer 6 and the second barrier layer 5 are provided with an opening 100, through which the first metal electrode 11 passes and contacts the second doped polysilicon layer 4 or the first doped polysilicon layer 2.

[0148] Example 3

[0149] Referring to Figure 9, based on Embodiment 2, the passivation contact structure of the solar cell in this embodiment further includes:

[0150] The third barrier layer 7 is disposed on the side of the third doped polysilicon layer 6 that is away from the silicon substrate 10.

[0151] In this embodiment, by providing a third barrier layer 7 on the surface of the third doped polycrystalline silicon layer 6 away from the silicon substrate 10, the third barrier layer 7 can further block impurities of the metal electrode from expanding into the silicon substrate 10, and the third barrier layer 7 can further block the paste of the metal electrode, thereby further improving the passivation effect of the passivation contact structure of the solar cell.

[0152] As one embodiment of this disclosure, it also includes:

[0153] The fourth doped polysilicon layer 8 is disposed on the side of the third barrier layer 7 facing away from the silicon substrate 10. The doping polarity of the fourth doped polysilicon layer 8 is the same as or opposite to the doping polarity of the second doped polysilicon layer 4.

[0154] In this embodiment, by adding a third barrier layer 7 and a fourth doped polycrystalline silicon layer 8, the third barrier layer 7, the second barrier layer 5, the first barrier layer 3, and the first passivation layer 1 are used to jointly block the impurities of the metal electrode from expanding into the silicon substrate 10, which can further improve the passivation effect of the passivation contact structure of the solar cell; moreover, the fourth doped polycrystalline silicon layer 8 can further enhance the passivation effect of the passivation contact structure of the solar cell.

[0155] The doping polarity of the fourth doped polysilicon layer 8 is the same as that of the third doped polysilicon layer 6, and the doping polarity of the fourth doped polysilicon layer 8 can be the same as or opposite to that of the second doped polysilicon layer 4 and the first doped polysilicon layer 2.

[0156] Referring to Figure 10, when the doping polarity of the fourth doped polysilicon layer 8 and the third doped polysilicon layer 6 is the same as that of the second doped polysilicon layer 4 and the first doped polysilicon layer 2, no opening needs to be provided on the fourth doped polysilicon layer 8 and the third doped polysilicon layer 6, and the first metal electrode 11 can contact the fourth doped polysilicon layer 8; of course, an opening can also be provided on the fourth doped polysilicon layer 8, and the first metal electrode 11 can pass through the opening 100 to contact the third doped polysilicon layer 6; alternatively, an opening can be provided on the fourth doped polysilicon layer 8 and the third doped polysilicon layer 6, and the first metal electrode 11 can pass through the opening to contact the second doped polysilicon layer 4 or the first doped polysilicon layer 2.

[0157] Referring to Figure 11, when the doping polarity of the fourth doped polysilicon layer 8 is opposite to that of the second doped polysilicon layer 4 and the first doped polysilicon layer 2, openings 100 are provided on the fourth doped polysilicon layer 8, the third barrier layer 7, the third doped polysilicon layer 6, and the first barrier layer 3. The first metal electrode 11 passes through the openings 100 and contacts the second doped polysilicon layer 4. Of course, the first metal electrode 11 can also continue to pass through the second doped polysilicon layer 4 and the first barrier layer 3 to contact the first doped polysilicon layer 2.

[0158] As one embodiment of this disclosure, the thickness of the third barrier layer 7 is less than or equal to the thickness of the second barrier layer 5.

[0159] In this embodiment, the thickness of the third barrier layer 7 can be less than or equal to the thickness of the second barrier layer 5. In other embodiments, the thickness of the third barrier layer 7 can also be greater than the thickness of the second barrier layer 5. The material of the third barrier layer 7 can be the same as or different from the material of the first barrier layer 3.

[0160] In other embodiments, the surface of the fourth doped polysilicon layer 8 away from the silicon substrate 10 may also be superimposed with one or more barrier layers and one or more doped polysilicon layers, forming a stacked structure in which barrier layers and doped polysilicon layers are alternately arranged, so as to further improve the passivation effect of the battery.

[0161] Example 4

[0162] Please refer to Figure 12. Based on any one of the embodiments from Embodiment 1 to Embodiment 3, the first barrier layer 3 and the second doped polycrystalline silicon layer 4 of the passivation contact structure of the solar cell in this embodiment are both discontinuous, so that the first barrier layer 3 and the second doped polycrystalline silicon layer 4 only cover a part of the area of ​​the first doped polycrystalline silicon layer 2.

[0163] In this embodiment, both the first barrier layer 3 and the second doped polysilicon layer 4 are discontinuous, full-surface structures.

[0164] The first barrier layer 3 and the second doped polysilicon layer 4 are intermittently disposed on the first doped polysilicon layer 2, resulting in localized passivation of the first barrier layer 3 and the second doped polysilicon layer 4. Both the first barrier layer 3 and the second doped polysilicon layer 4 are block-shaped and disposed on the first doped polysilicon layer 2. Grooves 9 are formed between adjacent first barrier layers 3 and adjacent second doped polysilicon layers 4. A first metal electrode 11 is located in the groove 9 region and contacts the first doped polysilicon layer 2; the first metal electrode 11 is located in the second doped polysilicon layer 4 region and contacts the second doped polysilicon layer 4.

[0165] The passivated contact structure of the solar cell in this embodiment can be applied to bifacial solar cells as well as back-contact solar cells.

[0166] In this embodiment, the passivation effect can be further enhanced by using the first barrier layer 3 and the second doped polycrystalline silicon layer 4, and the area of ​​the first barrier layer 3 and the second doped polycrystalline silicon layer 4 can be reduced, which can reduce the absorption of light by the doped polycrystalline silicon layer, thereby reducing parasitic absorption and improving battery efficiency. On the other hand, during the metallization process of the solar cell, since the slurry of the first metal electrode 11 can be blocked between adjacent first barrier layers 3 and between adjacent second doped polycrystalline silicon layers 4, the slurry deposition at the corresponding non-second doped polycrystalline silicon layer 4 position of the first metal electrode 11 can be thicker, that is, the slurry deposition in the groove 9 region is thicker. Therefore, the thickness of the region of the first metal electrode 11 corresponding to the non-second doped polycrystalline silicon layer 4 is greater than the thickness of the region of the first metal electrode 11 corresponding to the second doped polycrystalline silicon layer 4, which increases the welding pull of the metal electrode and improves conductivity and battery stability.

[0167] Example 5

[0168] Referring to Figure 13, this embodiment provides a solar cell, including a silicon substrate 10. The silicon substrate 10 includes a light-facing surface 101 and a backlight surface 102 disposed opposite to the light-facing surface 101. The light-facing surface and / or the backlight surface are provided with a solar cell passivation contact structure of any one of the embodiments of Embodiments 1 to 4, which can improve the passivation effect of the solar cell and thus improve the cell efficiency.

[0169] In this embodiment, the solar cell is a bifacial solar cell. Both the light-facing surface 101 and the back-lighting surface 102 of the silicon substrate 10 can be provided with the above-mentioned solar cell passivation contact structure, or only the light-facing surface 101 or the back-lighting surface 102 of the silicon substrate 10 can be provided with the above-mentioned solar cell passivation contact structure.

[0170] In this embodiment, the solar cell's light-facing surface 101 and / or back-light-facing surface 102 are provided with the solar cell passivation contact structure of any of the embodiments in Embodiments 1 to 4, which can give the back side of the solar cell a better passivation effect and improve the cell efficiency.

[0171] For ease of explanation, Figure 13 only illustrates that both the light-facing surface 101 and the back-lighting surface 102 of the solar cell are provided with the solar cell passivation contact structure of Embodiment 1 described above. Multiple solar cell passivation contact structures are provided on both the light-facing surface 101 and the back-lighting surface 102 of the solar cell. The doping polarity of the first doped polycrystalline silicon layer 2 of each solar cell passivation contact structure on the light-facing surface 101 is the same, and the doping polarity of the first doped polycrystalline silicon layer 2 of each solar cell passivation contact structure on the back-lighting surface 102 is the same. Furthermore, the doping polarity of the first doped polycrystalline silicon layer 2 of each solar cell passivation contact structure on the light-facing surface 101 is opposite to that of the first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure on the back-lighting surface 102.

[0172] In this embodiment, the back surface 102 of the solar cell utilizes the above-mentioned passivation contact structure of the solar cell, which can give the solar cell a good passivation effect and improve the cell efficiency.

[0173] In this embodiment, the first metal electrode 11 of the solar cell passivation contact structure on the light-facing surface 101 contacts the second doped polysilicon layer 4 or the first doped polysilicon layer 2 of the solar cell passivation contact structure on the light-facing surface 101; the first metal electrode 11 of the solar cell passivation contact structure on the back-lighting surface 102 contacts the second doped polysilicon layer 4 or the first doped polysilicon layer 2 of the solar cell passivation contact structure on the back-lighting surface 102. One of the first metal electrode 11 on the light-facing surface 101 and the first metal electrode 11 on the back-lighting surface 102 is a positive electrode, and the other is a negative electrode.

[0174] In this embodiment, both the light-facing surface 101 and the back-lighting surface 102 of the solar cell are provided with the above-mentioned solar cell passivation contact structure, which can reduce the inward diffusion of impurities from the metal electrodes of the light-facing surface 101 and the back-lighting surface 102 into the silicon substrate 10, so that both the light-facing surface 101 and the back-lighting surface 102 have better passivation effect, improve the efficiency of the solar cell, and prevent the metal electrodes of the light-facing surface 101 and the back-lighting surface 102 from burning through into the silicon substrate 10, thereby improving the cell yield.

[0175] In this embodiment, an isolation region may be provided between the first doped polysilicon layers 2 of the two adjacent passivation contact structures of the light-facing surface 101 and the backlight surface 102 to isolate them from each other, or no isolation region may be provided, and the first doped polysilicon layers 2 of the two adjacent passivation contact structures of the solar cells may be in contact with each other, which is not limited here.

[0176] Example 6

[0177] Referring to Figure 14, this embodiment provides a solar cell, including a silicon substrate 10. The silicon substrate 10 includes a light-facing surface 101 and a backlight surface 102 disposed opposite to the light-facing surface 101. The light-facing surface 101 is locally provided with a solar cell passivation contact structure of any one of the embodiments of Embodiment 1 to Embodiment 4, which can improve the passivation effect of the solar cell and thus improve the cell efficiency.

[0178] In this embodiment, the solar cell is a bifacial solar cell. The light-facing surface 101 is locally provided with the solar cell passivation contact structure of any one of the embodiments 1 to 4 described above. It can be understood that only a part of the light-facing surface 101 is provided with the above-mentioned solar cell passivation contact structure, and other areas can be provided with other passivation contact structures.

[0179] As an embodiment of the present invention, a second passivation layer 14 is provided on the light-facing surface 101 in the area where the solar cell passivation contact structure is not provided, and a fifth doped polycrystalline silicon layer 15 is provided on the side of the second passivation layer 14 facing away from the silicon substrate 10. The doping polarity of the fifth doped polycrystalline silicon layer 15 is the same as that of the first doped polycrystalline silicon layer 2.

[0180] In this embodiment, a second passivation layer 14 is provided on the area of ​​the light-facing surface 101 that does not have a passivation contact structure for solar cells, and a fifth doped polycrystalline silicon layer 15 is provided on the back side of the second passivation layer 14. The second passivation layer 14 and the fifth doped polycrystalline silicon layer 15 form another passivation contact structure to passivate the area that does not have a passivation contact structure for solar cells, which can further improve the passivation effect of the battery.

[0181] In this embodiment, the doping polarity of the fifth doped polysilicon layer 15 is the same as that of the first doped polysilicon layer 2. This can be understood as follows: if the doping polarity of the first doped polysilicon layer 2 in the passivation contact structure of the solar cell is P-type, then the doping polarity of the fifth doped polysilicon layer 15 is P-type; or, if the doping polarity of the first doped polysilicon layer 2 in the passivation contact structure of the solar cell is N-type, then the doping polarity of the fifth doped polysilicon layer 15 is N-type.

[0182] In a preferred embodiment of this invention, the thickness of the fifth doped polysilicon layer 15 is greater than or equal to the thickness of the first doped polysilicon layer 2 of the passivation contact structure of the solar cell on the light-facing surface 101. In this embodiment, the solar cell further includes:

[0183] A second metal electrode 17 is provided on the light-facing surface 101, and the second front metal electrode 17 is in contact with the fifth doped polysilicon layer 15.

[0184] In this process, the first metal electrode 11 of the passivation contact structure of the solar cell on the light-facing surface 101 is in contact with the second doped polycrystalline silicon layer 4 or the first doped polycrystalline silicon layer 2, and the first metal electrode 11 of the light-facing surface 101 and the second metal electrode 17 of the light-facing surface 101 have the same polarity.

[0185] In this embodiment, the back surface 102 of the solar cell can also be provided with the solar cell passivation contact structure of any one of the embodiments 1 to 4 above, or other passivation contact structures can be provided.

[0186] As an embodiment of the present invention, the backlight surface 102 is locally provided with a solar cell passivation contact structure of any one of the above embodiments one to four, and the first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure on the backlight surface 102 has the opposite doping polarity to the first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure on the light-facing surface 101.

[0187] As an embodiment of the present invention, the backlight surface 102 is provided with a third passivation layer 20 and a sixth doped polycrystalline silicon layer 21 on the side of the third passivation layer 20 facing away from the silicon substrate 10, corresponding to the area where the solar cell passivation contact structure is not provided. The doping polarity of the sixth doped polycrystalline silicon layer 21 is the same as that of the first doped polycrystalline silicon layer 2.

[0188] In a preferred embodiment of the present invention, the thickness of the sixth doped polycrystalline silicon layer 21 is greater than or equal to the thickness of the first doped polycrystalline silicon layer 2 of the passivation contact structure of the solar cell on the backlight surface 102.

[0189] As one embodiment of this disclosure, the solar cell includes:

[0190] A third metal electrode 19 is disposed on the backlight surface 102, and the third metal electrode 19 is in contact with the sixth doped polysilicon layer 21.

[0191] In this embodiment, the first metal electrode 11 of the passivation contact structure of the solar cell on the backlight surface 102 is in contact with the second doped polycrystalline silicon layer 4 or the first doped polycrystalline silicon layer 2; wherein, the first metal electrode 11 and the third metal electrode 19 of the backlight surface 102 have the same polarity.

[0192] As an embodiment of this disclosure, the first doped polysilicon layer 2 of the solar cell passivation contact structure on the light-facing surface 101 and the fifth doped polysilicon layer 15 on the light-facing surface 101 can be spaced apart or in contact with each other. The first doped polysilicon layer 2 of the solar cell passivation contact structure on the back-lighting surface 102 and the sixth doped polysilicon layer 21 on the back-lighting surface 102 can be spaced apart or in contact with each other.

[0193] Example 7

[0194] Referring to Figure 15, this embodiment provides a solar cell, including a silicon substrate 10. The silicon substrate 10 includes a light-facing surface 101 and a backlight surface 102 disposed opposite to the light-facing surface 101. The backlight surface 102 is provided with a solar cell passivation contact structure of any one of the embodiments of the above embodiments one to four, which can improve the passivation effect of the solar cell, thereby improving the cell efficiency.

[0195] As an embodiment of this disclosure, the solar cell is a back-contact solar cell. The back surface 102 of the back-contact solar cell is provided with a P-region and an N-region. Both the P-region and the N-region are provided with a solar cell passivation contact structure of any one of the embodiments of the above embodiments one to four. The first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure in the P-region is P-type doped polycrystalline silicon, and the first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure in the N-region is N-type doped polycrystalline silicon.

[0196] In this embodiment, the solar cell is a back-contact solar cell. The back surface 102 of the back-contact solar cell is alternately provided with P region 25 and N region 26. The P region 25 and N region 26 are respectively provided with the solar cell passivation contact structure of any one of the above embodiments one to four. The doping polarity of the first doped polycrystalline silicon layer 2 of the two adjacent solar cell passivation contact structures on the back surface 102 is opposite, that is, the doping polarity of the first doped polycrystalline silicon layer 2 of the P region and the N region is opposite.

[0197] In this embodiment, both the P-region 25 and N-region 26 of the backlight surface 102 of the solar cell are provided with the solar cell passivation contact structure of any one of the embodiments 1 to 4 described above. Since the solar cell passivation contact structure of both the P-region 25 and N-region 26 includes a first barrier layer 3, the first barrier layer 3 can reduce the inward diffusion of impurities from the metal electrodes of the P-region 25 and N-region 26 into the silicon substrate 10, so that both the P-region 25 and N-region 26 have better passivation effects, improving the efficiency of the back contact solar cell. Moreover, the first barrier layer 3 can prevent the metal electrodes of the P-region 25 and N-region 26 from burning through into the silicon substrate 10, thereby improving the cell yield. In addition, the solar cell passivation contact structure of both the P-region 25 and N-region 26 includes at least two layers of doped polycrystalline silicon, which is beneficial to simultaneously improve the passivation effect of the P-region 25 and N-region 26.

[0198] In this embodiment, an isolation region 22 is provided between the first doped polycrystalline silicon layers 2 of two adjacent solar cell passivation contact structures, that is, an isolation region 22 is provided between the P region 25 and the N region 26. Specifically, the isolation region 22 can be a trench or a gap, maintaining a distance between the solar cell passivation contact structures of the P region 25 and the N region 26, and maintaining a distance between the first doped polycrystalline silicon layers 2 of two adjacent solar cell passivation contact structures, thus achieving good isolation between the first doped polycrystalline silicon layers 2 of the two adjacent solar cell passivation contact structures.

[0199] Example 8

[0200] Referring to Figure 16, this embodiment provides a solar cell, including a silicon substrate 10. The silicon substrate 10 includes a light-facing surface 101 and a backlight surface 102 disposed opposite to the light-facing surface 101. The backlight surface 102 is locally provided with a solar cell passivation contact structure of any one of the embodiments of Embodiment 1 to Embodiment 4 described above.

[0201] In this embodiment, the solar cell is a back-contact solar cell. The back surface 102 of the back-contact solar cell is provided with alternating P-regions 25 and N-regions 26. One of the P-regions and the N-region is provided with a solar cell passivation contact structure according to any one of the embodiments 1 to 4 above. The back surface 102 of the silicon substrate 10 is provided with multiple solar cell passivation contact structures, and the doping polarities of the first doped polycrystalline silicon layer 2 of two adjacent solar cell passivation contact structures are opposite.

[0202] The backlight surface 102 is locally provided with the solar cell passivation contact structure of any one of the above embodiments 1 to 4. It can be understood that only a part of the backlight surface 102 is provided with the above-mentioned solar cell passivation contact structure, and other parts can be provided with other passivation contact structures.

[0203] As one embodiment of this application, the P-region 25 of the backlight surface 102 is provided with the solar cell passivation contact structure of any one of the embodiments 1 to 4 described above. The N-region 26 of the backlight surface 102 is provided with a third passivation layer 20 and a sixth doped polycrystalline silicon layer 21 disposed on the side of the third passivation layer 20 facing away from the silicon substrate 10. The doping polarity of the sixth doped polycrystalline silicon layer 21 is opposite to the doping polarity of the first doped polycrystalline silicon layer 2. Alternatively, the N-region may be provided with the solar cell passivation contact structure of any one of the embodiments 1 to 4 described above.

[0204] In this embodiment, the first doped polycrystalline silicon layer 2 of the solar cell passivation contact structure in the P region 25 is P-type doped polycrystalline silicon, and the sixth doped polycrystalline silicon layer 21 is N-type doped polycrystalline silicon. Only the P region 25 is provided with the above-mentioned solar cell passivation contact structure. The P region 25 utilizes the first barrier layer 3 to block impurities and metal electrode paste from the metal electrode, which can reduce the inward diffusion of impurities from the metal electrode into the silicon substrate 10. Furthermore, the P region 25 can utilize the first barrier layer 3 to prevent the metal electrode paste from burning through into the silicon substrate 10.

[0205] As an embodiment of this application, the sum of the thicknesses of the first doped polysilicon layer and the second doped polysilicon layer 4 of the solar cell passivation contact structure in region P 25 is less than the thickness of the sixth doped polysilicon layer in region N 26. Because region P 25 is provided with a first barrier layer 3, the thickness of the doped polysilicon layer in the solar cell passivation contact structure of region P 25 can be reduced. While utilizing the first barrier layer 3 to prevent the metal electrode from burning through the slurry and to block impurities in the metal electrode, the thickness of the first doped polysilicon layer 2 in region P 25 is simultaneously reduced, which helps to lower costs and reduce parasitic absorption in the doped polysilicon layer of region P 25, thus improving cell efficiency.

[0206] In one embodiment of this application, the thickness of the sixth doped polycrystalline silicon layer 21 in the N-region 26 is greater than the thickness of the first doped polycrystalline silicon layer 2 in the solar cell passivation contact structure of the P-region 25. In this embodiment, the back surface 102 of the solar cell utilizes this solar cell passivation contact structure, which can give the back side of the solar cell a good passivation effect and improve the cell efficiency.

[0207] As one embodiment of this disclosure, the solar cell further includes:

[0208] A fourth metal electrode 28 is disposed on the backlight surface 102, and the fourth metal electrode 28 is in contact with the sixth doped polysilicon layer 21.

[0209] In this embodiment, the first metal electrode 11 of the passivation contact structure of the solar cell on the backlight surface 102 is in contact with the second doped polycrystalline silicon layer 4 or the first doped polycrystalline silicon layer 2. The first metal electrode 11 of the backlight surface 102 has the opposite polarity to the fourth metal electrode 28 of the backlight surface 102.

[0210] As an embodiment of this application, the depth to which the first metal electrode 11 enters the second doped polysilicon layer 4 is greater than the depth to which the fourth metal electrode 28 enters the sixth doped polysilicon layer 21.

[0211] In this embodiment, since the depth of the first metal electrode 11 in the P region 25 into the second doped polysilicon layer 4 is greater than the depth of the fourth metal electrode 28 in the N region 26 into the sixth doped polysilicon layer 21, the contact area between the first metal electrode 11 and the second doped polysilicon layer 4 in the P region 25 is increased, and the contact resistance between the first metal electrode 11 and the second doped polysilicon layer 4 is reduced, which is beneficial to improving the battery efficiency. At the same time, since the P region 25 is provided with the above-mentioned solar cell passivation contact structure, the P region 25 can use the first barrier layer 3 to block the paste burn-through depth of the first metal electrode 11, preventing the paste of the first metal electrode 11 from entering the first doped polysilicon layer 2 or the silicon substrate. Therefore, it can not only improve the contact performance between the first metal electrode 11 and the second doped polysilicon layer 4 in the P region 25, but also control the paste burn-through depth of the first metal electrode 11 in the P region 25.

[0212] As an embodiment of this disclosure, an isolation region 22 is provided between P-region 25 and N-region 26. Specifically, the isolation region 22 can be a trench or a gap. The isolation region 22 isolates P-region 25 and N-region 26 from each other, achieving good isolation between them. An isolation region 22 is also provided between the sixth doped polysilicon layer 21 and the first doped polysilicon layer 2. Specifically, the isolation region 22 can be a trench or a gap. The isolation region 22 isolates the sixth doped polysilicon layer 21 from the first doped polysilicon layer 2, preventing contact between them and achieving good isolation between them.

[0213] Example 9

[0214] Please refer to Figures 17-19. This embodiment provides a solar cell, including a silicon substrate 10. The silicon substrate 10 includes a light-facing surface 101 and a backlight surface 102 disposed opposite to the light-facing surface 101. The light-facing surface 101 and / or the backlight surface 102 are provided with the solar cell passivation contact structure of the above embodiment four.

[0215] In this embodiment, the solar cell can be a bifacial solar cell or a back-contact solar cell. For ease of explanation, Figures 17-19 only show the solar cell with its light-facing surface 101 having the passivation contact structure described in Embodiment 4. Of course, the back-facing surface 102 of the solar cell can also have the passivation contact structure described in Embodiment 4.

[0216] In this embodiment, since both the first barrier layer 3 and the second doped polycrystalline silicon layer 4 of the solar cell passivation contact structure are discontinuous, they are intermittently disposed on the first doped polycrystalline silicon layer 2. The first metal electrode 11 of the solar cell passivation contact structure is in contact with either the second doped polycrystalline silicon layer 4 or the first doped polycrystalline silicon layer 2.

[0217] In this embodiment, the first barrier layer 3 and the second doped polycrystalline silicon layer 4 can further enhance the passivation effect while reducing the area of ​​the first barrier layer 3 and the second doped polycrystalline silicon layer 4, thereby reducing the absorption of light by the doped polycrystalline silicon layer, reducing parasitic absorption, and improving cell efficiency. On the other hand, during the metallization process of the solar cell, since the adjacent first barrier layers 3 and the adjacent second doped polycrystalline silicon layers 4 can form a barrier to the paste of the first metal electrode 11, the thickness of the region D of the first metal electrode 11 corresponding to the non-second doped polycrystalline silicon layer 4 is greater than the thickness of the region C of the first metal electrode 11 corresponding to the second doped polycrystalline silicon layer 4. That is, the paste deposition of the first metal electrode 11 is thicker at the position of the first metal electrode 11 corresponding to the non-second doped polycrystalline silicon layer 4, which is conducive to increasing the welding pull of the first metal electrode 11, improving the conductivity of the first metal electrode 11 and the stability of the solar cell.

[0218] Example 10

[0219] This application also provides a battery assembly including the solar cell described in the above embodiments. It should be noted that this battery assembly has the same or similar beneficial effects as the back-contact solar cell described above, and the related aspects between the two can be referred to each other; to avoid repetition, they will not be repeated here.

[0220] Example 11

[0221] This application also provides a photovoltaic system, which includes the battery module of Embodiment Nine above. It should be noted that this photovoltaic system has the same or similar beneficial effects as the solar cell described above, and the related aspects between the two can be referred to each other; to avoid repetition, they will not be repeated here.

[0222] This disclosure provides a passivation contact structure for a solar cell, including...

[0223] A first passivation layer, a first doped polycrystalline silicon layer, a first barrier layer, and a second doped polycrystalline silicon layer are sequentially stacked on the surface of a silicon substrate. By adding the first barrier layer and the second doped polycrystalline silicon layer on the surface of the first doped polycrystalline silicon layer, the combined blocking effect of the first passivation layer and the first barrier layer prevents excessive impurities from the metal electrode from diffusing into the silicon substrate, thus reducing impurities in the metal electrode. For example, impurities such as iron, copper, cobalt, nickel, and chromium in the metal electrode can diffuse into the silicon substrate, which can significantly improve the passivation effect of the solar cell, thereby improving the cell efficiency. In addition, the first barrier layer can also block the paste of the metal electrode, reduce the burn-through depth of the paste of the metal electrode, and prevent the metal electrode from burning through the first barrier layer and entering the first doped polycrystalline silicon layer, thereby improving the cell yield.

[0224] Furthermore, the thickness of the first passivation layer is set to be greater than the thickness of the first barrier layer. By thinning the thickness of the first barrier layer, it is easier for doped atoms in the first and second doped polycrystalline silicon layers to diffuse through the first barrier layer. Doped atoms from the one with a higher doping concentration in the first and second doped polycrystalline silicon layers can diffuse through the first barrier layer to the one with a lower doping concentration in the first and second doped polycrystalline silicon layers. This allows for better adjustment of the doping concentration of the first and second doped polycrystalline silicon layers, further improving the passivation effect of the passivation contact structure of the solar cell. This achieves both the blocking effect of the first barrier layer on impurities in the metal electrode and the burn-through of the metal electrode paste, and facilitates the adjustment of the doping concentration between the first and second doped polycrystalline silicon layers, achieving a balance between the two effects and further improving the efficiency of the solar cell.

[0225] The above are merely preferred embodiments of this disclosure and are not intended to limit this disclosure. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A passivated contact structure for a solar cell, wherein, The material comprises a first passivation layer, a first doped polysilicon layer, a first barrier layer, and a second doped polysilicon layer, which are sequentially stacked on the surface of a silicon substrate. The doping polarity of the first doped polysilicon layer is the same as that of the second doped polysilicon layer. The thickness of the first passivation layer is greater than that of the first barrier layer.

2. The passivated contact structure for solar cells according to claim 1, wherein, The ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 10, and is not equal to 1.

3. The passivated contact structure for solar cells according to claim 1, wherein, The ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 4, and is not equal to 1.

4. The passivated contact structure for solar cells according to claim 1, wherein, The ratio of the thickness of the first passivation layer to the thickness of the first barrier layer is 1 to 2, but not equal to 1.

5. The passivated contact structure for a solar cell according to claim 1, wherein, The thickness of the first passivation layer is 0.5 to 5 nanometers, and the thickness of the first barrier layer is 0.2 to 4.5 nanometers.

6. The passivated contact structure for a solar cell according to claim 1, wherein, The first passivation layer has holes, and the first doped polysilicon layer contacts the silicon substrate through the holes in the first passivation layer.

7. The passivated contact structure for a solar cell according to claim 1, wherein, The first barrier layer has holes, and the second doped polysilicon layer passes through the holes in the first barrier layer and contacts the first doped polysilicon layer.

8. The passivated contact structure for a solar cell according to claim 1, wherein, Both the first passivation layer and the first barrier layer have pores, and the pore density of the first passivation layer is less than that of the first barrier layer.

9. The passivated contact structure for a solar cell according to claim 1, wherein, Both the first passivation layer and the first barrier layer are provided with pores, and the average pore diameter of the first passivation layer is smaller than the average pore diameter of the first barrier layer.

10. The passivated contact structure for a solar cell according to claim 1, wherein, The first passivation layer comprises one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, and silicon nitride containing boron, phosphorus or gallium.

11. The passivated contact structure for a solar cell according to claim 1, wherein, The first barrier layer comprises one or a combination of silicon oxide containing boron, phosphorus or gallium, silicon oxynitride containing boron, phosphorus or gallium, silicon nitride containing boron, phosphorus or gallium, oxygen-rich silicon containing boron, phosphorus or gallium, and nitrogen-rich silicon containing boron, phosphorus or gallium.

12. The passivated contact structure for a solar cell according to claim 11, wherein, The oxygen content of the oxygen-enriched silicon is 1×10⁻⁶. 19 atoms / cm 3 above.

13. The passivated contact structure for a solar cell according to claim 11, wherein, The nitrogen content of the nitrogen-rich silicon is 1×10⁻⁶. 19 atoms / cm 3 above.

14. The passivated contact structure for a solar cell according to claim 1, wherein, The first passivation layer, the first doped polysilicon layer, the first barrier layer, and the second doped polysilicon layer are all doped with group IIIA or group VA elements; the doping concentration of the second doped polysilicon layer is greater than the doping concentration of the first doped polysilicon layer.

15. The passivated contact structure for a solar cell according to claim 14, wherein, The doping concentration of the first passivation layer is less than or equal to the doping concentration of the first barrier layer.

16. The passivated contact structure for a solar cell according to claim 1, wherein, The thickness of the first doped polysilicon layer is greater than the thickness of the second doped polysilicon layer.

17. The passivated contact structure for a solar cell according to claim 1, wherein, The ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 1 to 50.

18. The passivated contact structure for a solar cell according to claim 17, wherein, The ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 2 to 50.

19. The passivated contact structure for a solar cell according to claim 18, wherein, The ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 5 to 50.

20. The passivated contact structure for a solar cell according to claim 16, wherein, The ratio of the thickness of the first doped polysilicon layer to the thickness of the second doped polysilicon layer is 10 to 50.

21. The passivated contact structure for a solar cell according to claim 16, wherein, The thickness of the first doped polycrystalline silicon layer is 30–350 nanometers, and the thickness of the second doped polycrystalline silicon layer is 5–150 nanometers.

22. The passivated contact structure for a solar cell according to claim 1, characterized in that, The thickness of the first doped polysilicon layer is less than the thickness of the second doped polysilicon layer.

23. The passivated contact structure for a solar cell according to claim 1, wherein, Also includes: The second barrier layer is disposed on the side of the second doped polysilicon layer opposite to the silicon substrate.

24. The passivated contact structure for a solar cell according to claim 23, wherein, The thickness of the second barrier layer is less than or equal to the thickness of the first barrier layer.

25. The passivated contact structure for a solar cell according to claim 23, wherein, Also includes: A third doped polysilicon layer is disposed on the side of the second barrier layer opposite to the silicon substrate, and the doping polarity of the third doped polysilicon layer is the same as or opposite to that of the second doped polysilicon layer.

26. The passivated contact structure for a solar cell according to claim 25, wherein, Also includes: The third barrier layer is disposed on the side of the third doped polysilicon layer opposite to the silicon substrate.

27. The passivated contact structure for a solar cell according to claim 26, wherein, Also includes: A fourth doped polysilicon layer is disposed on the side of the third barrier layer opposite to the silicon substrate, and the doping polarity of the fourth doped polysilicon layer is the same as or opposite to the doping polarity of the second doped polysilicon layer.

28. The passivated contact structure for a solar cell according to claim 27, wherein, The thickness of the third barrier layer is less than or equal to the thickness of the second barrier layer.

29. The passivated contact structure for a solar cell according to claim 1, wherein, Both the first barrier layer and the second doped polysilicon layer are intermittently disposed on the first doped polysilicon layer.

30. The passivated contact structure for a solar cell according to claim 27, wherein, The thicknesses of the first doped polysilicon layer, the second doped polysilicon layer, the third doped polysilicon layer, and the fourth doped polysilicon layer decrease sequentially.

31. The passivated contact structure for a solar cell according to claim 1, wherein, Also includes: A first metal electrode is disposed on the second doped polysilicon layer, and the first metal electrode is in contact with the second doped polysilicon layer.

32. The passivated contact structure for a solar cell according to claim 31, wherein, The first metal electrode passes through the second doped polysilicon layer, and the first barrier layer contacts the first doped polysilicon layer.

33. The passivated contact structure for a solar cell according to claim 32, wherein, The width of the first metal electrode in the first doped polysilicon layer region is smaller than the width of the first metal electrode in the second doped polysilicon layer region.

34. A solar cell, wherein, The device includes a silicon substrate, the silicon substrate comprising a light-facing surface and a backlight surface disposed opposite to the light-facing surface, the light-facing surface and / or the backlight surface being provided with a solar cell passivation contact structure as described in any one of claims 1 to 33.

35. The solar cell according to claim 34, wherein, The solar cell is a back-contact solar cell, and the back surface of the back-contact solar cell is provided with a P region and an N region, and at least one of the P region and the N region is provided with the passivation contact structure of the solar cell.

36. The solar cell according to claim 35, characterized in that, The P region is provided with the solar cell passivation contact structure, the N region is provided with a third passivation layer, and a sixth doped polycrystalline silicon layer is provided on the side of the third passivation layer facing away from the silicon substrate; the first doped polycrystalline silicon layer of the solar cell passivation contact structure in the P region is P-type doped polycrystalline silicon, and the sixth doped polycrystalline silicon layer is N-type doped polycrystalline silicon.

37. The solar cell according to claim 35, characterized in that, Both the P-region and the N-region are provided with the solar cell passivation contact structure. The first doped polycrystalline silicon layer of the solar cell passivation contact structure in the P-region is P-type doped polycrystalline silicon, and the first doped polycrystalline silicon layer of the solar cell passivation contact structure in the N-region is N-type doped polycrystalline silicon.

38. A battery assembly, wherein, Including the solar cell as described in any one of claims 34 to 37.

39. A photovoltaic system, wherein, Includes the battery assembly as described in claim 38.

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