Passivated contact solar cell, preparation method thereof and photovoltaic module

Abstract

The embodiment of the invention provides a passivation contact solar cell, a preparation method thereof and a photovoltaic module. The passivation contact solar cell comprises a silicon substrate which comprises a first surface and a second surface which are oppositely arranged; the first passivation layer is located on the second surface and is provided with a first region and a second region; the gallium-doped polycrystalline silicon layer and the first mask layer are located in the first region and stacked in the first direction; the boron-doped polycrystalline silicon layer and the second mask layer are located in the second region and are stacked in the first direction; the second passivation layer is located on the surface of the first mask layer and the surface of the second mask layer; and the first antireflection layer is positioned on the surface of the second passivation layer. According to the embodiment of the invention, by arranging the gallium-doped polycrystalline silicon layer, the B-O composite defect can be reduced, so that the passivation performance of the P-type polycrystalline silicon is improved, by arranging the boron-doped polycrystalline silicon layer, the improvement of the passivation performance is realized, the additional high metal contact resistivity is avoided, and the high-performance solar cell is realized.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a passivated contact solar cell and a preparation method thereof and a photovoltaic module. Background Art

[0002] Tunneling oxide passivation contact (TOPCon) technology is a representative passivation contact technology. Its key feature is to grow an ultra-thin nano-silicon oxide layer on the surface of the silicon wafer to eliminate the dangling bonds on the surface, and prepare a layer of heavily doped polysilicon on the ultra-thin silicon oxide to achieve the field passivation effect. However, due to the presence of BO composite defects, the P-type polysilicon structure of the cell exhibits poor passivation performance, and the conversion efficiency of the TOPCon cell is mainly limited by the poor passivation quality.

[0003] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0004] The embodiments of the present application provide a passivated contact solar cell and a preparation method and a photovoltaic module, aiming to solve the problem that the existing TOPCon cell exhibits poor passivation performance of the cell's P-type polysilicon structure due to BO composite defects, thereby affecting the conversion efficiency.

[0005] In a first aspect, an embodiment of the present application provides a passivated contact solar cell, comprising: The silicon substrate comprises a first surface and a second surface which are arranged opposite to each other; a first passivation layer located on the second surface, wherein the first passivation layer has a first region and a second region; A gallium-doped polysilicon layer and a first mask layer located in the first region and stacked along a first direction; A boron-doped polysilicon layer and a second mask layer located in the second region and stacked along the first direction; a second passivation layer located on a surface of the first mask layer and a surface of the second mask layer; A first anti-reflection layer is located on the surface of the second passivation layer, wherein the first anti-reflection layer has a metallized region and a non-metallized region, and the metallized region corresponds to the second region.

[0006] Optionally, a first electrode is further included, wherein the first electrode sequentially penetrates the first anti-reflection layer, the second passivation layer, and the second mask layer, and is in ohmic contact with the boron-doped polysilicon layer.

[0007] Optionally, the boron doping concentration in the boron-doped polysilicon layer is 1E18-1E19cm -3 , the thickness of the boron-doped polysilicon layer is 30-150nm.

[0008] Optionally, the gallium doping concentration in the gallium-doped polysilicon layer is 1E16-1E19cm -3 , the thickness of the gallium-doped polysilicon layer is 30-150nm.

[0009] Optionally, in the direction from the second surface to the first surface, a third passivation layer, a phosphorus-doped polysilicon layer, a second anti-reflection layer, and a second electrode are sequentially stacked on the first surface.

[0010] Optionally, the third passivation layer includes at least one of silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide and titanium oxide.

[0011] In a second aspect, an embodiment of the present application provides a method for preparing a passivated contact solar cell, the method comprising: Providing a silicon substrate, the silicon substrate comprising a first surface and a second surface disposed opposite to each other; Depositing a first passivation layer on the second surface, wherein the first passivation layer has a first region and a second region; depositing an initial boron-doped polysilicon layer on the surface of the first passivation layer; forming a second mask layer on the initial boron-doped polysilicon layer located in the second region; Using the second mask layer, removing the initial boron-doped polysilicon layer located in the first region to form a boron-doped polysilicon layer; depositing an initial gallium-doped polysilicon layer on a first surface of the silicon substrate on which the boron-doped polysilicon layer is formed; forming a first mask layer on the initial gallium-doped polysilicon layer located in the first region; Using the first mask layer, removing the initial gallium-doped polysilicon layer located in the second region to form a gallium-doped polysilicon layer; A first anti-reflection layer is deposited on the boron-doped polysilicon layer and the gallium-doped polysilicon layer.

[0012] Optionally, the preparation method further comprises: Depositing a third passivation layer on the first surface of the silicon substrate; Depositing a phosphorus-doped polysilicon layer on the surface of the third passivation layer; Depositing a second anti-reflection layer on the surface of the phosphorus-doped polysilicon layer; A second electrode is formed on a surface of the second anti-reflection layer.

[0013] Optionally, when depositing the second passivation layer, trimethylaluminum is reacted with oxygen or nitrous oxide at a reaction temperature of 200-350°C.

[0014] In a third aspect, an embodiment of the present application provides a photovoltaic assembly, including the above-mentioned passivated contact solar cell.

[0015] The above technical solution adopted in the embodiment of the present application may have the following advantages: According to the above-mentioned passivated contact solar cell, by dividing the first surface of the silicon substrate into a metallized area and a non-metallized area, and only providing a gallium-doped polysilicon layer in the non-metallized area, using gallium (Ga) as a p-type dopant can reduce BO composite defects, thereby improving the passivation performance of the front P-type polysilicon. At the same time, since the contact resistivity between gallium and metal is higher than the contact resistivity between the boron layer and metal, a boron-doped polysilicon layer is provided in the metallized area, thereby achieving an improvement in passivation performance, avoiding the additional high metal contact resistivity, and realizing a high-performance solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0017] Figure 1 Schematic diagram of the structure of a TOPCon solar cell provided in one embodiment of the present application.

[0018] Description of reference numerals: 110-silicon substrate; 120-third passivation layer; 130-phosphorus-doped polysilicon layer; 140-second anti-reflection layer; 150-first passivation layer; 160-boron-doped polysilicon layer; 170-second mask layer; 180-gallium-doped polysilicon layer; 190-first mask layer; 200-second passivation layer; 210-first anti-reflection layer; 220-first electrode; 230-second electrode, S1-first surface; S2-second surface. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0020] It should be understood that when an element or layer is referred to as "on", "under", "adjacent to", "connected to" or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as "directly on", "under", "directly adjacent to", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part. When discussing a second element, component, region, layer or section, it does not necessarily mean that the first element, component, region, layer or section must be present.

[0021] In this application, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] The embodiment of the present application aims to design a new passivation contact structure, in which the metallized region of the passivation contact structure corresponds to the boron-doped polysilicon layer, and the non-metallized region of the passivation contact structure corresponds to the gallium-doped polysilicon layer, and the boron-doped polysilicon layer and the gallium-doped polysilicon layer do not contain phosphorus, which can effectively reduce BO composite defects, thereby improving the passivation performance of P-type polysilicon. At the same time, since the contact resistivity between gallium and metal is higher than the contact resistivity between the boron layer and metal, a boron-doped polysilicon layer is provided in the metallized region, which can achieve the improvement of the passivation performance while avoiding the additional high contact resistivity of the metal, thereby realizing a high-performance solar cell.

[0024] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0025] like Figure 1 As shown, the embodiment of the present application provides a passivated contact solar cell, which includes: a silicon substrate 110, including a first surface S1 and a second surface S2 arranged opposite to each other; a first passivation layer 150 located on the second surface S2, the first passivation layer 150 having a first region and a second region; a gallium-doped polysilicon layer 180 and a first mask layer 190 located in the first region and stacked in sequence along a first direction; a boron-doped polysilicon layer 160 and a second mask layer 170 located in the second region and stacked in sequence along the first direction; a second passivation layer 200 located on the surface of the first mask layer 190 and the surface of the second mask layer 170; a first anti-reflection layer 210 located on the surface of the second passivation layer 200, the first anti-reflection layer 210 having a metallized region and a non-metallized region, the metallized region corresponding to the second region. The direction from the first surface S1 to the second surface S2 is the first direction.

[0026] In some embodiments, the first surface S1 refers to the light-receiving surface, and the second surface S2 refers to the backlight surface. The light-receiving surface can be understood as the outermost surface of the solar cell facing the sunlight, and the backlight surface can also be understood as the outermost surface facing away from the sunlight.

[0027] The silicon substrate 110 is used to receive incident light and generate photogenerated carriers. The silicon substrate 110 includes but is not limited to a doped semiconductor substrate made of silicon or germanium. For example, in some embodiments, the material of the silicon substrate 110 can be a doped single crystal silicon material. Further, the doping element of the silicon substrate 110 can be N-type or P-type. When the doping type of the silicon substrate 110 is N-type doping, the corresponding dopant can include any one or more of phosphorus (P), arsenic (As), bismuth (Bi) and antimony (Sb) in the V group elements; when the doping type of the silicon substrate 110 is P-type doping, the corresponding dopant can include any one or more of boron (B), aluminum (Al), gallium (Ga) and indium (In) in the III group elements. In addition, in some embodiments, the first surface S1 and the second surface S2 of the silicon substrate 110 will also have certain morphological changes based on the morphology of the battery film layer and other features. For example, the light-receiving surface may be a velvet structure; a portion of the backlight surface may be a planar structure, and another portion of the backlight surface may also be a velvet structure.

[0028] In some embodiments, in the direction from the second surface S2 to the first surface S1 , the third passivation layer 120 , the phosphorus-doped polysilicon layer 130 , the second anti-reflection layer 140 , and the second electrode 230 are sequentially stacked on the first surface S1 .

[0029] The third passivation layer 120 is located on the surface of the first surface S1, that is, the third passivation layer 120 is located on the surface of the light-receiving surface of the silicon substrate 110. By setting the third passivation layer 120, the recombination of carriers on the substrate surface can be reduced, thereby increasing the open circuit voltage of the solar cell and improving the photoelectric conversion efficiency of the solar cell.

[0030] Specifically, the third passivation layer 120 can saturate the dangling bonds on the substrate surface, reduce the interface defect state density of the first surface S1 of the silicon substrate 110, thereby reducing the recombination center of the first surface S1 of the substrate to reduce the carrier recombination rate. The material of the third passivation layer 120 can be a dielectric material, for example, the third passivation layer 120 at least includes one of silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide and titanium oxide. Among them, the dielectric material can contain doping elements of the same type as the doping elements of the substrate. In addition, the thickness of the third passivation layer 120 is less than or equal to 3 nanometers. Exemplarily, the thickness of the third passivation layer 120 can be 3nm, 2nm, 1nm, 0.5nm, etc.

[0031] The phosphorus-doped polysilicon layer 130 is located on the surface of the third passivation layer 120 away from the silicon substrate 110. The thickness of the phosphorus-doped polysilicon layer 130 is 30 nanometers to 150 nanometers. Exemplarily, the thickness of the phosphorus-doped polysilicon layer 130 can be 30nm, 90nm, 150nm, etc.

[0032] In some embodiments, the second anti-reflection layer 140 may be one of silicon nitride, silicon oxynitride, and silicon oxide films, and the second anti-reflection layer 140 may include one or more layers of silicon nitride, silicon oxynitride, and silicon oxide films.

[0033] In some embodiments, the thickness of the second passivation layer 200 is 1-2 nm. For example, the thickness of the second passivation layer 200 may be 1 nm, 1.5 nm, 2 nm, etc.

[0034] The boron-doped polysilicon layer 160 is located on the surface of the first passivation layer 150 away from the silicon substrate 110. The boron doping concentration in the boron-doped polysilicon layer 160 is 1E18-1E19cm-3. If the boron doping concentration in the boron-doped polysilicon layer 160 is too high, the composite defects will be aggravated. If the boron doping concentration in the boron-doped polysilicon layer 160 is too low, the contact resistance will be increased, affecting the contact performance. By controlling the boron doping concentration in the boron-doped polysilicon layer 160 within a suitable concentration range, the passivation performance of the polysilicon layer can be ensured. For example, in some embodiments, the boron doping concentration in the boron-doped polysilicon layer 160 can be 1E18cm-3. -3 、5.5E18cm -3 、1E19cm -3 The thickness of the boron-doped polysilicon layer 160 is 30-150 nm. If the thickness of the boron-doped polysilicon layer 160 is too thick, parasitic absorption will be serious. If the thickness of the boron-doped polysilicon layer 160 is too thin, the contact will be poor. By controlling the thickness of the boron-doped polysilicon layer 160 within a suitable range, the boron doping concentration in the boron-doped polysilicon layer 160 can be maintained at a moderate level, while avoiding the high metal contact resistivity caused by the provision of the gallium-doped polysilicon layer 180.

[0035] The gallium-doped polysilicon layer 180 is located on the non-metallized area and stacked on the first passivation layer 150. The gallium doping concentration in the gallium-doped polysilicon layer 180 is 1E16-1E19 cm -3If the gallium doping concentration in the gallium-doped polysilicon layer 180 is too high, the contact resistance between gallium and metal will increase, affecting the contact performance. If the gallium doping concentration in the gallium-doped polysilicon layer 180 is too low, the passivation effect will be poor. By controlling the gallium doping concentration in the gallium-doped polysilicon layer 180 within a suitable range, the BO composite defects can be effectively reduced, thereby improving the passivation performance of P-type polysilicon. The thickness of the gallium-doped polysilicon layer 180 is 30-150nm. If the thickness of the gallium-doped polysilicon layer 180 is too thick, parasitic absorption will be serious. If the thickness of the gallium-doped polysilicon layer 180 is too thin, the passivation effect will be poor. By controlling the thickness of the gallium-doped polysilicon layer 180 within a suitable range, the boron doping concentration in the boron-doped polysilicon layer 160 can be maintained at a moderate level while avoiding excessive contact resistance that affects the contact. For example, the gallium doping concentration in the gallium-doped polysilicon layer 180 can be 1E16cm -3 、1E17cm -3 、1E18cm -3 、1E19cm -3 .

[0036] In some embodiments, the first electrode 220 sequentially penetrates the first anti-reflection layer 210, the second passivation layer 200, and the second mask layer 170, and makes ohmic contact with the boron-doped polysilicon layer 160. The second electrode 230 sequentially penetrates the second anti-reflection layer 140, and makes ohmic contact with the phosphorus-doped polysilicon layer 130, so as to further improve the metal contact, which is beneficial to the gain fill factor.

[0037] In some embodiments, the material of the first electrode 220 and the second electrode 230 includes but is not limited to one or more of aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), silver (Ag), copper (Cu) and tin (Sn). In the embodiment of the present application, the first electrode 220 and the second electrode 230 can be metal gate lines.

[0038] The passivated contact solar cell provided in the embodiment of the present application has a metallized region of the passivated contact structure corresponding to the boron-doped polysilicon layer 160, and a non-metallized region corresponding to the gallium-doped polysilicon layer 180. By using gallium (Ga) as a p-type dopant, BO composite defects can be reduced, and the passivation performance of the P-type polysilicon can be improved. At the same time, since the contact resistivity between gallium and metal is higher than the contact resistivity between the boron layer and metal, the boron-doped polysilicon layer 160 is provided in the metallized region, thereby achieving an improvement in the passivation performance and avoiding the additional high metal contact resistivity, thereby achieving a high-performance solar cell.

[0039] The present application also provides a method for preparing the above-mentioned passivated contact solar cell, the method comprising: Providing a silicon substrate, the silicon substrate comprising a first surface and a second surface disposed opposite to each other; Depositing a first passivation layer on the second surface, the first passivation layer having a first region and a second region; depositing an initial boron-doped polysilicon layer on the surface of the first passivation layer; forming a second mask layer on the initial boron-doped polysilicon layer located in the second region; Using the second mask layer, removing the initial boron-doped polysilicon layer located in the first region to form a boron-doped polysilicon layer; depositing an initial gallium-doped polysilicon layer on a first surface of the silicon substrate on which the boron-doped polysilicon layer is formed; forming a first mask layer on the initial gallium-doped polysilicon layer located in the first region; Using the first mask layer, removing the initial gallium-doped polysilicon layer located in the second region to form a gallium-doped polysilicon layer; A first anti-reflection layer is deposited on the boron-doped polysilicon layer and the gallium-doped polysilicon layer.

[0040] In some embodiments, after depositing the structure on the front side of the silicon substrate, the preparation method further comprises: depositing a third passivation layer on the first surface of the silicon substrate; depositing a phosphorus-doped polysilicon layer on the surface of the third passivation layer; Depositing a second anti-reflection layer on the surface of the phosphorus-doped polysilicon layer; A second electrode is formed on a surface of the second anti-reflection layer.

[0041] In some embodiments, when depositing the second passivation layer, trimethylaluminum is reacted with oxygen or nitrous oxide at a reaction temperature of 200-350°C.

[0042] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0043] [Example 1] (1) introducing N2O at a flow rate of 11000 sccm, a deposition temperature of 400°C, a pressure of 10000 mtor, and a deposition time of 275 s to deposit a first passivation layer on the second surface of the silicon substrate; (2) SiH4, H2, and diborane were introduced at flow rates of 5000 sccm, 12000 sccm, and 225 sccm, respectively, at a deposition temperature of 400°C, a pressure of 10000 mtor, and a deposition time of 275 s to deposit an initial boron-doped polysilicon layer on the surface of the first passivation layer; (3) Patterning the metallized area of ​​the initial boron-doped polysilicon layer is performed through a second mask layer, and the boron-doped polysilicon layer located in the non-metallized area is etched using a sodium hydroxide solution to remove the initial boron-doped polysilicon layer in the non-metallized area to form a boron-doped polysilicon layer. The boron doping concentration of the obtained boron-doped polysilicon layer is about 1E18 cm -3 , thickness is 30nm; (4) SiH4, H2, and trimethylgallium were introduced at flow rates of 10000 sccm, 13000 sccm, and 255 sccm, respectively, with a deposition temperature of 400°C, a pressure of 10000 mtor, and a deposition time of 260 s to deposit an initial gallium-doped polysilicon layer on the entire surface of the first passivation layer; (5) Patterning is performed in the non-metallized area of ​​the gallium-doped polysilicon layer through the first mask layer, and the gallium-doped polysilicon layer in the metallized area is etched using a sodium hydroxide solution to remove the initial gallium-doped polysilicon layer in the metallized area to form a gallium-doped polysilicon layer. The gallium doping concentration of the obtained gallium-doped polysilicon layer is 1E16cm -3 , thickness is 30nm; (6) introducing trimethylaluminum and water at flow rates of 55 sccm and 55 sccm, respectively, at a deposition temperature of 300° C. for a deposition time of 100-1500 s, to deposit a second passivation layer on the entire surface of the boron-doped polysilicon layer and the gallium-doped polysilicon layer on the first surface of the silicon substrate; (7) introducing SiH4 and NH3 at flow rates of 5500 sccm and 5500 sccm, respectively, at a deposition temperature of 400°C, a pressure of 4000 mtor, and a deposition time of 210 s to deposit a first anti-reflection layer on the entire surface of the second passivation layer; (8) metallizing the front side of the silicon substrate to deposit a first electrode; (9) introducing N2O at a flow rate of 11000 sccm, a deposition temperature of 400°C, a pressure of 10000 mtor, and a deposition time of 260 s to deposit a third passivation layer on the second surface of the silicon substrate; (10) SiH4, H2, and PH3 were introduced at flow rates of 5000 sccm, 13000 sccm, and 500 sccm, respectively, at a deposition temperature of 400°C, a pressure of 4000 mtor, and a deposition time of 310 s to deposit a phosphorus-doped polysilicon layer on the surface of the third passivation layer; (11) introducing SiH4 and NH3 at flow rates of 5000 sccm and 11000 sccm, respectively, at a deposition temperature of 400°C, a pressure of 4000 mtor, and a deposition time of 255 s to deposit a second anti-reflection layer on the surface of the phosphorus-doped polysilicon layer; (14) Depositing a second electrode on the surface of the second anti-reflection layer.

[0044] [Example 2] - [Example 5] The passivated contact solar cells of Examples 2 to 5 were prepared by referring to the preparation method of Example 1, except that the gallium source flow rate and deposition time when depositing the gallium-doped polysilicon layer in step (4) were changed to adjust the gallium doping concentration and thickness of the gallium-doped polysilicon layer, and the boron source flow rate and deposition time when depositing the boron-doped polysilicon layer in step (2) were changed to adjust the boron doping concentration and thickness of the boron-doped polysilicon layer, as shown in Table 1 below.

[0045] Table 1

[0046] In order to more clearly illustrate the technical effects of the embodiments of the present application, the present application also points out the passivated contact solar cells of [Comparative Example 1]-[Comparative Example 2].

[0047] [Comparative Example 1] The passivated contact solar cell of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that the gallium-doped polysilicon layer was deleted, that is, a boron-doped polysilicon layer was stacked on the first passivation layer regardless of the non-metallized area or the metallized area.

[0048] [Comparative Example 2] The passivated contact solar cell of Comparative Example 2 was prepared by referring to the preparation method of Example 1, except that the boron-doped polysilicon layer was deleted, that is, a gallium-doped polysilicon layer was stacked on the first passivation layer regardless of the non-metallized area or the metallized area.

[0049] The following is a performance test of the passivated contact solar cells provided in Examples 1-5 of the present application and Comparative Examples 1-2, so as to obtain the open circuit voltage Voc, short circuit current density Jsc, fill factor FF, and photoelectric conversion efficiency PCE of the corresponding passivated contact solar cells. The test results are shown in Table 2 below.

[0050] Table 2

[0051] Data result analysis: According to Table 2, compared with Comparative Example 1 and Comparative Example 2, the open circuit voltage, fill factor and photoelectric conversion efficiency of the passivated contact solar cells prepared in Examples 1-5 of the present application are significantly improved, which shows that the passivated contact solar cells in Examples 1-5 of the present application divide the first surface of the silicon substrate into a metallized area and a non-metallized area, and only provide a gallium-doped polysilicon layer in the non-metallized area, and provide a boron-doped polysilicon layer in the metallized area, which can effectively improve the passivation performance, reduce the contact resistivity, and thus improve the battery performance.

[0052] In summary, in the passivated contact solar cell in the embodiment of the present application, the metallized region of the passivated contact structure corresponds to the boron-doped polysilicon layer, and the non-metallized region corresponds to the gallium-doped polysilicon layer. By using gallium (Ga) as a p-type dopant, BO composite defects can be reduced, and the passivation performance of P-type polysilicon can be improved. At the same time, since the contact resistivity between gallium and metal is higher than the contact resistivity between the boron layer and metal, a boron-doped polysilicon layer is provided in the metallized region, thereby achieving an improvement in the passivation performance and avoiding the additional high metal contact resistivity, thereby achieving a high-performance solar cell.

[0053] An embodiment of the present application provides a photovoltaic module (not shown), including the above-mentioned passivated contact solar cell.

[0054] The embodiment of the present application can provide a photovoltaic system, including the photovoltaic components in any of the above embodiments. The advantages of the above photovoltaic components are also possessed by the photovoltaic system, which will not be repeated here. The above photovoltaic system has a wide range of applications, not only limited to photovoltaic power stations, such as ground power stations, rooftop power stations and water power stations, but also includes various equipment and devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars and solar buildings. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be used in all fields where solar energy is required for power generation. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components may form multiple photovoltaic arrays. The photovoltaic array is connected to a junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0055] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0056] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0057] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0058] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A passivated contact solar cell, characterized in that: include: The silicon substrate comprises a first surface and a second surface which are arranged opposite to each other; a first passivation layer located on the second surface, wherein the first passivation layer has a first region and a second region; A gallium-doped polysilicon layer and a first mask layer located in the first region and stacked along a first direction; A boron-doped polysilicon layer and a second mask layer located in the second region and stacked along the first direction; a second passivation layer located on a surface of the first mask layer and a surface of the second mask layer; A first anti-reflection layer is located on the surface of the second passivation layer, wherein the first anti-reflection layer has a metallized region and a non-metallized region, and the metallized region corresponds to the second region.

2. The passivated contact solar cell according to claim 1, characterized in that: The invention also includes a first electrode, wherein the first electrode sequentially penetrates the first anti-reflection layer, the second passivation layer, and the second mask layer, and is in ohmic contact with the boron-doped polysilicon layer.

3. The passivated contact solar cell according to claim 1, characterized in that: The boron doping concentration in the boron-doped polysilicon layer is 1E18-1E19cm -3 , the thickness of the boron-doped polysilicon layer is 30-150nm.

4. The passivated contact solar cell according to claim 1, characterized in that: The gallium doping concentration in the gallium-doped polysilicon layer is 1E16-1E19cm -3 , the thickness of the gallium-doped polysilicon layer is 30-150nm.

5. The passivated contact solar cell according to any one of claims 1 to 4, characterized in that: In the direction from the second surface to the first surface, a third passivation layer, a phosphorus-doped polysilicon layer, a second anti-reflection layer, and a second electrode are sequentially stacked on the first surface.

6. The passivated contact solar cell according to claim 5, characterized in that: The third passivation layer includes at least one of silicon oxide, amorphous silicon, polycrystalline silicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide and titanium oxide.

7. A method for preparing a passivated contact solar cell, characterized in that: The preparation method comprises: Providing a silicon substrate, the silicon substrate comprising a first surface and a second surface disposed opposite to each other; Depositing a first passivation layer on the second surface, wherein the first passivation layer has a first region and a second region; depositing an initial boron-doped polysilicon layer on the surface of the first passivation layer; forming a second mask layer on the initial boron-doped polysilicon layer located in the second region; Using the second mask layer, removing the initial boron-doped polysilicon layer located in the first region to form a boron-doped polysilicon layer; depositing an initial gallium-doped polysilicon layer on a first surface of the silicon substrate on which the boron-doped polysilicon layer is formed; forming a first mask layer on the initial gallium-doped polysilicon layer located in the first region; Using the first mask layer, removing the initial gallium-doped polysilicon layer located in the second region to form a gallium-doped polysilicon layer; A second passivation layer is deposited on the boron-doped polysilicon layer and the gallium-doped polysilicon layer.

8. The method for preparing a passivated contact solar cell according to claim 7, characterized in that: The preparation method further comprises: Depositing a third passivation layer on the first surface of the silicon substrate; Depositing a phosphorus-doped polysilicon layer on the surface of the third passivation layer; Depositing a second anti-reflection layer on the surface of the phosphorus-doped polysilicon layer; A second electrode is formed on a surface of the second anti-reflection layer.

9. The method for preparing a passivated contact solar cell according to claim 8, characterized in that: When depositing the second passivation layer, trimethylaluminum is reacted with oxygen or nitrous oxide at a reaction temperature of 200-350°C.

10. A photovoltaic module, characterized in that: A passivated contact solar cell comprising the method of any one of claims 1 to 6.

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