Passivated contact solar cell, method of making and photovoltaic module

Abstract

The embodiment of the present application provides a kind of passivated contact solar cell and its preparation method and photovoltaic module.The passivated contact solar cell includes: silicon base, including oppositely arranged first surface and second surface;First passivation layer located in the second surface, first passivation layer has first area and second area;Doped gallium polysilicon layer, first mask layer are located in first area and are stacked along the first direction;Doped boron polysilicon layer, second mask layer are located in second area and are stacked along the first direction;Second passivation layer located in the surface of first mask layer and the surface of second mask layer;First anti-reflection layer located in the surface of second passivation layer.The embodiment of the present application can reduce B-O complex defects by being provided with doped gallium polysilicon layer, to improve the passivation performance of P-type polysilicon, by setting doped boron polysilicon layer, to further realize the improvement of passivation performance, also avoid the metal high contact resistivity caused by extra, realize high-performance solar cell.

Description

TECHNICAL FIELD

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

[0002] Tunnel oxide passivated contact (TOPCon) technology is a representative passivation contact technology, and its key feature is to grow an ultra-thin nanometer silicon oxide layer on the surface of a silicon wafer to eliminate dangling bonds on the surface, and to prepare a heavily doped polysilicon layer on the ultra-thin silicon oxide layer to achieve field passivation effect. However, due to the existence of B-O complex defects, the P-type polysilicon structure of the battery exhibits poor passivation performance, and the conversion efficiency of the TOPCon battery is mainly limited by the poor passivation quality.

[0003] It should be noted that the above content is not necessarily prior art, and is not used to limit the patent protection scope of the present application. SUMMARY

[0004] The embodiments of the present application provide a passivated contact solar cell, a preparation method thereof and a photovoltaic module, aiming to solve the problem that the existing TOPCon battery has poor passivation performance due to B-O complex defects in the P-type polysilicon structure of the battery, thereby affecting the conversion efficiency.

[0005] In a first aspect, the embodiments of the present application provide a passivated contact solar cell, comprising:

[0006] A silicon substrate comprising a first surface and a second surface arranged opposite to each other;

[0007] A first passivation layer located on the second surface, the first passivation layer having a first region and a second region thereon;

[0008] A gallium-doped polysilicon layer and a first mask layer located in the first region and stacked along a first direction;

[0009] A boron-doped polysilicon layer and a second mask layer located in the second region and stacked along the first direction;

[0010] A second passivation layer located on the surface of the first mask layer and the surface of the second mask layer;

[0011] A first anti-reflection layer located on the surface of the second passivation layer, the first anti-reflection layer having a metallized region and a non-metallized region, and the metallized region corresponding to the second region.

[0012] Optionally, it further comprises a first electrode, the first electrode penetrating the first anti-reflection layer, the second passivation layer and the second mask layer in sequence and being in ohmic contact with the boron-doped polysilicon layer.

[0013] Optionally, the boron doping concentration in the boron-doped polysilicon layer is 1E18-1E19 cm -3 , and the thickness of the boron-doped polysilicon layer is 30-150 nm.

[0014] Optionally, the gallium doping concentration in the gallium-doped polysilicon layer is 1E16-1E19 cm -3 , and the thickness of the gallium-doped polysilicon layer is 30-150 nm.

[0015] Optionally, in the direction in which the second surface points to the first surface, the first surface is sequentially stacked with a third passivation layer, a phosphorus-doped polysilicon layer, a second anti-reflection layer, and a second electrode.

[0016] Optionally, the third passivation layer at least includes one of silicon oxide, amorphous silicon, polysilicon, silicon carbide, silicon nitride, silicon oxynitride, aluminum oxide, and titanium oxide.

[0017] In a second aspect, the embodiments of the present application provide a preparation method of a passivated contact solar cell, and the preparation method comprises:

[0018] providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged oppositely;

[0019] depositing a first passivation layer on the second surface, the first passivation layer having a first region and a second region;

[0020] depositing an initial boron-doped polysilicon layer on the surface of the first passivation layer;

[0021] forming a second mask layer on the initial boron-doped polysilicon layer located in the second region;

[0022] removing the initial boron-doped polysilicon layer located in the first region by using the second mask layer to form a boron-doped polysilicon layer;

[0023] depositing an initial gallium-doped polysilicon layer on the first surface of the silicon substrate on which the boron-doped polysilicon layer is formed;

[0024] forming a first mask layer on the initial gallium-doped polysilicon layer located in the first region;

[0025] removing the initial gallium-doped polysilicon layer located in the second region by using the first mask layer to form a gallium-doped polysilicon layer;

[0026] depositing a first anti-reflection layer on the boron-doped polysilicon layer and the gallium-doped polysilicon layer.

[0027] Optionally, the preparation method further comprises:

[0028] depositing a third passivation layer on the first surface of the silicon substrate.

[0029] depositing a phosphorus-doped polysilicon layer on a surface of the third passivation layer;

[0030] depositing a second anti-reflective layer on a surface of the phosphorus-doped polysilicon layer;

[0031] forming a second electrode on a surface of the second anti-reflective layer.

[0032] Optionally, when depositing the second passivation layer, trimethylaluminum reacts with oxygen or nitrous oxide, and the reaction temperature is 200-350°C.

[0033] In a third aspect, the embodiments of the present application provide a photovoltaic module, comprising the passivated contact solar cell described above.

[0034] The embodiments of the present application can have the following advantages by using the technical solutions described above:

[0035] According to the passivated contact solar cell described above, the first surface of the silicon substrate is divided into a metallized area and a non-metallized area, and a gallium-doped polysilicon layer is arranged only in the non-metallized area. Using gallium (Ga) as a p-type dopant can reduce B-O complex 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 that between a boron layer and metal, a boron-doped polysilicon layer is arranged in the metallized area, thereby improving the passivation performance and avoiding the additional high contact resistivity of metal, and achieving a high-performance solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0036] In the drawings, like reference numerals refer to like elements throughout the various drawings. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating principles of the application. It should be understood that the drawings are merely depictions of some embodiments of the application and should not be construed as limiting the scope of the application.

[0037] Figure 1 FIG. 1 is a structural schematic diagram of a TOPCon solar cell according to an embodiment of the present application.

[0038] Legend of reference numerals:

[0039] 110-silicon substrate; 120-third passivation layer; 130-phosphorus-doped polysilicon layer; 140-second anti-reflective 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-reflective layer; 220-first electrode; 230-second electrode; S1-first surface; S2-second surface. DETAILED DESCRIPTION

[0040] Embodiments of the present application are described in detail below with reference to the accompanying drawings. In the drawings, the size of layers, regions, elements and the relative sizes of the same can be exaggerated for clarity. The same or similar components are denoted by the same or similar reference numerals throughout the drawings. The embodiments described below are exemplary only, and are not intended to limit the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other under the condition of no conflict.

[0041] It should be understood that when an element or layer is referred to as being "on", "under", "adjacent", "connected to" or "coupled to" another element or layer, it can be directly on, under, adjacent, connected or coupled to the other element or layer or intervening elements or layers can be present. In contrast, when an element is referred to as being "directly on", "directly under", "directly adjacent", "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present application. Similarly, a second element, component, region, layer or section discussed below could be termed a first element, component, region, layer or section without departing from the teachings of the present application.

[0042] In the present application, unless specifically defined otherwise and limited, the terms "set", "mounted", "connected", "linked", "fixed" and the like should be interpreted broadly, for example, can be fixedly connected, can be detachably connected, or integrated; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise specifically defined. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] It is to be understood that the terms "first", "second", and the like, used in the description and the claims of the present application as well as the above description of the drawings merely refer to categories and do not require or imply any particular order or sequence of any of the steps, actions, or elements. It is to be understood that the terms so used are interchangeable under appropriate circumstances and embodiments of the application described herein are capable of producing more than one contemplated effect. Also, the terms "comprise", "comprising", "include", "including", and the like, used in the description and the claims of the present application, are used where appropriate as synonymous for "comprises essentially" or "comprises / including essentially all", such that it is understood that aspects of the application are not limited to any single step, element, ingredient, etc. described, but rather, additional or other steps, elements, ingredients, etc. can be present.

[0044] The embodiments of the present application aim to effectively reduce B-O complex defects by designing a brand-new passivation contact structure, the metallized region of the passivation contact structure corresponds to the boron-doped polysilicon layer, 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 elements, thereby improving the passivation performance of the P-type polysilicon, and at the same time, since the contact resistivity between gallium and metal is higher than that between the boron layer and metal, the boron-doped polysilicon layer is arranged in the metallized region, which can realize the improvement of the passivation performance while avoiding the additional high contact resistivity of metal, and realize a high-performance solar cell.

[0045] Hereinafter, example embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the example embodiments can be implemented in various manners, and should not be interpreted as being limited only to the embodiments set forth herein.

[0046] As shown in Figure 1 The embodiments of the present application provide a passivation contact solar cell, which comprises: a silicon substrate 110, comprising a first surface S1 and a second surface S2 arranged oppositely; 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 arranged in the first region and stacked in a first direction; a boron-doped polysilicon layer 160 and a second mask layer 170 arranged in the second region and stacked in 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; and 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, and the metallized region corresponding to the second region. Wherein, the direction from the first surface S1 to the second surface S2 is the first direction.

[0047] In some embodiments, the first surface S1 refers to a light-receiving surface, and the second surface S2 refers to a back light surface. The light-receiving surface can be understood as the outermost surface of the solar cell facing the sunlight, and the back light surface can also be understood as the outermost surface facing away from the sunlight.

[0048] The silicon base 110 is used to receive incident light and generate photo-generated carriers, and the silicon base 110 includes but is not limited to a doped semiconductor substrate made of silicon or germanium, etc. For example, in some embodiments, the material of the silicon base 110 can be a doped single crystal silicon material. Further, the doping element of the silicon base 110 can be N-type or P-type. When the doping type of the silicon base 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 group V elements. When the doping type of the silicon base 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 group III elements. In addition, in some embodiments, the first surface S1 and the second surface S2 of the silicon base 110 can also have certain topography changes based on the topography of the characteristics of the cell film layer, etc. For example, the light-receiving surface can be a textured structure, and part of the back light surface can be a planar structure, and another part of the back light surface can also be a textured structure.

[0049] In some embodiments, in the direction from the second surface S2 to the first surface S1, the first surface S1 is sequentially stacked with the third passivation layer 120, the phosphorus-doped polycrystalline silicon layer 130, the second anti-reflection layer 140, and the second electrode 230.

[0050] The third passivation layer 120 is located on the surface of the first surface S1, i.e., the third passivation layer 120 is located on the surface of the light-receiving surface of the silicon base 110. By arranging 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.

[0051] 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 base 110, and thus reduce the recombination centers of the first surface S1 of the substrate to reduce the recombination rate of carriers. 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 the same type of doping element as the doping element of the substrate. In addition, the thickness of the third passivation layer 120 is less than or equal to 3 nanometers. For example, the thickness of the third passivation layer 120 can be 3 nm, 2 nm, 1 nm, 0.5 nm, etc.

[0052] The phosphorus-doped polysilicon layer 130 is located on the surface of the third passivation layer 120 away from the silicon substrate 110, and the thickness of the phosphorus-doped polysilicon layer 130 is 30 nm to 150 nm. For example, the thickness of the phosphorus-doped polysilicon layer 130 can be 30 nm, 90 nm, 150 nm, etc.

[0053] In some embodiments, the second anti-reflective layer 140 can be one of silicon nitride, silicon oxynitride, and silicon oxide film, and the second anti-reflective layer 140 can include one or more layers of silicon nitride, silicon oxynitride, and silicon oxide film.

[0054] 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 can be 1 nm, 1.5 nm, 2 nm, etc.

[0055] The boron-doped polysilicon layer 160 is located on the surface of the first passivation layer 150 away from the silicon substrate 110, and the boron doping concentration in the boron-doped polysilicon layer 160 is 1E18-1E19 cm-3. If the boron doping concentration in the boron-doped polysilicon layer 160 is too high, it will exacerbate the recombination defects. If the boron doping concentration in the boron-doped polysilicon layer 160 is too low, it will make the contact resistance high, 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 1E18 cm -3 , 5.5E18 cm -3 , 1E19 cm -3 , etc. 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, the 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 within a suitable range, while the additional high metal contact resistance caused by the setting of the gallium-doped polysilicon layer 180 can be avoided.

[0056] The gallium-doped polysilicon layer 180 is located on the non-metalized area and stacked on the first passivation layer 150. The gallium doping concentration in the gallium-doped polysilicon layer 180 is 1E16-1E19 cm -3, if the gallium doping concentration in the gallium-doped polysilicon layer 180 is too high, the contact resistance between gallium and metal will be high, affecting the contact performance, and 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, B-O complex defects can be effectively reduced, thereby improving the passivation performance of the 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, and 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 within a suitable range, while avoiding excessive contact resistance affecting the contact. Exemplarily, the gallium doping concentration in the gallium-doped polysilicon layer 180 can be 1E16cm -3 , 1E17cm -3 , 1E18cm -3 , 1E19cm -3 .

[0057] In some embodiments, the first electrode 220 sequentially penetrates the first anti-reflective layer 210, the second passivation layer 200, and the second mask layer 170, and is in ohmic contact with the boron-doped polysilicon layer 160, and the second electrode 230 sequentially penetrates the second anti-reflective layer 140 and is in ohmic contact with the phosphorus-doped polysilicon layer 130, to further improve the metal contact and facilitate the gain fill factor.

[0058] 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 embodiments of the present application, the first electrode 220 and the second electrode 230 can be metal gate lines.

[0059] The passivated contact solar cell provided by the embodiments 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, B-O complex defects can be reduced, and the passivation performance of the P-type polysilicon can be improved. 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 arranged in the metallized region, thereby improving the passivation performance and avoiding the additional high metal contact resistivity, and a high-performance solar cell is achieved.

[0060] The embodiments of the present application also provide a preparation method of the passivated contact solar cell described above, which comprises:

[0061] providing a silicon substrate, the silicon substrate comprising a first surface and a second surface arranged opposite to each other;

[0062] depositing a first passivation layer on the second surface, the first passivation layer having a first region and a second region;

[0063] depositing an initial boron-doped polysilicon layer on the surface of the first passivation layer;

[0064] forming a second mask layer on the initial boron-doped polysilicon layer located in the second region;

[0065] removing the initial boron-doped polysilicon layer located in the first region by using the second mask layer to form a boron-doped polysilicon layer;

[0066] depositing an initial gallium-doped polysilicon layer on the first surface of the silicon substrate on which the boron-doped polysilicon layer is formed;

[0067] forming a first mask layer on the initial gallium-doped polysilicon layer located in the first region;

[0068] removing the initial gallium-doped polysilicon layer located in the second region by using the first mask layer to form a gallium-doped polysilicon layer;

[0069] depositing a first anti-reflection layer on the boron-doped polysilicon layer and the gallium-doped polysilicon layer.

[0070] In some embodiments, after the structure on the front surface of the silicon substrate is deposited, the preparation method further comprises:

[0071] depositing a third passivation layer on the first surface of the silicon substrate;

[0072] depositing a phosphorus-doped polysilicon layer on the surface of the third passivation layer;

[0073] depositing a second anti-reflection layer on the surface of the phosphorus-doped polysilicon layer;

[0074] forming a second electrode on the surface of the second anti-reflection layer.

[0075] In some embodiments, when depositing the second passivation layer, trimethylaluminum is reacted with oxygen or dinitrogen monoxide, and the reaction temperature is 200-350°C.

[0076] The following specific embodiments further illustrate the present application, but should not be construed as limiting the present application. Modifications or substitutions to the methods, steps or conditions of the present application, which do not depart from the spirit and essence of the present application, are intended to be within the scope of the present application.

[0077]

Example 1

[0078] (1) N2O is introduced at a flow rate of 11000 seem, the deposition temperature is 400°C, the pressure is 10000 mtor, and the deposition time is 275 s, to deposit a first passivation layer on the second surface of the silicon substrate;

[0079] (2) SiH4, H2, diborane are respectively introduced at a flow rate of 5000 sccm, 12000 sccm, 225 sccm, the deposition temperature is 400 ℃, the pressure is 10000 mtor, and the deposition time is 275 s, so as to deposit an initial boron-doped polysilicon layer on the surface of the first passivation layer;

[0080] (3) The initial boron-doped polysilicon layer in the metallized region is patterned through the second mask layer, and the boron-doped polysilicon layer in the non-metallized region is etched using a sodium hydroxide solution, so as to remove the initial boron-doped polysilicon layer in the non-metallized region, thereby forming a boron-doped polysilicon layer, and the boron doping concentration of the obtained boron-doped polysilicon layer is about 1E18 cm-2, and the thickness is 30 nm; -3

[0081] (4) SiH4, H2, trimethylgallium are respectively introduced at a flow rate of 10000 sccm, 13000 sccm, 255 sccm, the deposition temperature is 400 ℃, the pressure is 10000 mtor, and the deposition time is 260 s, so as to deposit an initial gallium-doped polysilicon layer on the entire surface of the first passivation layer;

[0082] (5) The initial gallium-doped polysilicon layer in the non-metallized region is patterned through the first mask layer, and the gallium-doped polysilicon layer in the metallized region is etched using a sodium hydroxide solution, so as to remove the initial gallium-doped polysilicon layer in the metallized region, thereby forming a gallium-doped polysilicon layer, and the gallium doping concentration of the obtained gallium-doped polysilicon layer is 1E16 cm-2, and the thickness is 30 nm; -3

[0083] (6) Trimethylaluminum and water are respectively introduced at a flow rate of 55 sccm, 55 sccm, the deposition temperature is 300 ℃, and the deposition time is 100-1500 s, so as 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;

[0084] (7) SiH4 and NH3 are respectively introduced at a flow rate of 5500 sccm, 5500 sccm, the deposition temperature is 400 ℃, the pressure is 4000 mtor, and the deposition time is 210 s, so as to deposit a first antireflection layer on the entire surface of the second passivation layer;

[0085] (8) The front surface of the silicon substrate is metallized to deposit a first electrode;

[0086] (9) N2O is introduced at a flow rate of 11000 sccm, the deposition temperature is 400 ℃, the pressure is 10000 mtor, and the deposition time is 260 s, so as to deposit a third passivation layer on the second surface of the silicon substrate;

[0087] ​​(10) flow rate of 5000 seem, 13000 seem, 500 seem of SiH4, H2, PH3 respectively, deposition temperature is 400℃, pressure is 4000mtor, deposition time is 310s, to deposit a phosphorus-doped polysilicon layer on the surface of the third passivation layer;

[0088] (11) flow rate of 5000 seem, 11000 seem of SiH4 and NH3 respectively, deposition temperature is 400℃, pressure is 4000mtor, deposition time is 255s, to deposit a second anti-reflective layer on the surface of the phosphorus-doped polysilicon layer;

[0089] (14) depositing a second electrode on the surface of the second anti-reflective layer.

[0090]

Example 2

Example 5

[0091] The passivated contact solar cells of Examples 2-5 are prepared according to the preparation method of Example 1, except that the flow rate of the gallium source and the deposition time when depositing the gallium-doped polysilicon layer in step (4) are changed to adjust the gallium doping concentration and thickness of the gallium-doped polysilicon layer, and the flow rate of the boron source and the deposition time when depositing the boron-doped polysilicon layer in step (2) are changed to adjust the boron doping concentration and thickness of the boron-doped polysilicon layer, as shown in Table 1 below.

[0092] Table 1

[0093]

[0094] 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

[0095]

Comparative Example 1

[0096] The passivated contact solar cell of Comparative Example 1 is prepared according to the preparation method of Example 1, except that the gallium-doped polysilicon layer is deleted, i.e. the boron-doped polysilicon layer is stacked on the first passivation layer regardless of the non-metallized area or the metallized area.

[0097]

Comparative Example 2

[0098] The passivated contact solar cell of Comparative Example 2 is prepared according to the preparation method of Example 1, except that the boron-doped polysilicon layer is deleted, i.e. the gallium-doped polysilicon layer is stacked on the first passivation layer regardless of the non-metallized area or the metallized area.

[0099] The passivated contact solar cells provided in Embodiments 1-5 and Comparative Examples 1-2 of the present application were subjected to performance tests, 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, and the test results are shown in Table 2 below.

[0100] Table 2

[0101]

[0102] 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 Embodiments 1-5 of the present application are all significantly improved, which indicates that the passivated contact solar cells in Embodiments 1-5 of the present application can effectively improve the passivation performance and reduce the contact resistivity, thereby improving the cell performance, by dividing the first surface of the silicon substrate into a metallized region and a non-metallized region, and only setting a gallium-doped polysilicon layer in the non-metallized region, and setting a boron-doped polysilicon layer in the metallized region.

[0103] In summary, in the passivated contact solar cells in the embodiments of the present application, the metallized region of the passivation 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, the B-O complex 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 that between the boron layer and metal, the boron-doped polysilicon layer is set in the metallized region, thereby improving the passivation performance, avoiding the additional high metal contact resistivity, and achieving a high-performance solar cell.

[0104] The embodiments of the present application provide a photovoltaic module (not shown), which comprises the passivated contact solar cell described above.

[0105] The photovoltaic system can be applied to a photovoltaic power generation system. The photovoltaic system can include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array can be an array combination of a plurality of photovoltaic modules. For example, a plurality of photovoltaic modules can form a plurality of photovoltaic arrays. The photovoltaic array is connected to the combiner box. The combiner box can combine the current generated by the photovoltaic array. The combined current flows through the inverter to convert into alternating current required by a power grid, and then is connected to the power grid to realize solar power supply.

[0106] It should be noted that the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. The orientation terms "inner" and "outer" refer to the inner and outer of the profile of each component itself. For example, if the device in the drawing is inverted, the device described as "above" or "on" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, 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 herein are interpreted accordingly.

[0107] It should also be noted that "one embodiment", "another embodiment", "embodiment", and the like in the present application refer to specific features, structures, or characteristics described in conjunction with the embodiment, which are included in at least one embodiment described generally in the present application. The same expression appearing in several 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 implementation of such feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of the present application.

[0108] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0109] It also needs to be explained that the above is only the preferred embodiment of the present application, and does not limit the patent protection scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification and drawings, or direct or indirect application 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 by, include: A silicon substrate, including a first surface and a second surface disposed opposite to each other; A first passivation layer is located on the second surface, and the first passivation layer has a first region and a second region; A gallium-doped polysilicon layer and a first mask layer are stacked in the first region and along the first direction; A boron-doped polycrystalline silicon layer and a second mask layer are stacked in the second region and along the first direction; A second passivation layer located on the surface of the first mask layer and the surface of the second mask layer; A first anti-reflective layer on the surface of the second passivation layer, the first anti-reflective layer having a metalized region and a non-metalized region, the metalized region corresponding to the second region; the boron doping concentration in the boron-doped polysilicon layer is 1E18-1E19 cm -3 The gallium doping concentration in the gallium-doped polysilicon layer is 1E16-1E19 cm -3 .

2. The passivated contact solar cell of claim 1, wherein, It also includes a first electrode, which sequentially penetrates the first antireflection layer, the second passivation layer, and the second mask layer, and makes ohmic contact with the boron-doped polycrystalline silicon layer.

3. The passivated contact solar cell of claim 1, wherein, The thickness of the boron-doped polycrystalline silicon layer is 30-150 nm.

4. The passivated contact solar cell of claim 1, wherein, The thickness of the gallium-doped polycrystalline silicon layer is 30-150 nm.

5. The passivated contact solar cell according to any 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 polycrystalline silicon layer, a second antireflection layer, and a second electrode are sequentially stacked on the first surface.

6. The passivated contact solar cell of claim 5, wherein, 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 of producing a passivated contact solar cell as claimed in any one of claims 1 to 6, characterised in that, The preparation method includes: A silicon substrate is provided, the silicon substrate including a first surface and a second surface disposed opposite to each other; A first passivation layer is deposited on the second surface, the first passivation layer having a first region and a second region; An initial boron-doped polycrystalline silicon layer is deposited on the surface of the first passivation layer; A second mask layer is formed on the initial boron-doped polysilicon layer located in the second region; Using the second mask layer, the initial boron-doped polysilicon layer located in the first region is removed to form a boron-doped polysilicon layer; An initial gallium-doped polysilicon layer is deposited on the first surface of the silicon substrate on which the boron-doped polysilicon layer is formed; A first mask layer is formed on the initial gallium-doped polysilicon layer located in the first region; Using the first mask layer, the initial gallium-doped polysilicon layer located in the second region is removed 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 of claim 7, wherein the method further comprises: The preparation method further includes: A third passivation layer is deposited on the first surface of the silicon substrate; A phosphorus-doped polycrystalline silicon layer is deposited on the surface of the third passivation layer; A second antireflection layer is deposited on the surface of the phosphorus-doped polycrystalline silicon layer; A second electrode is formed on the surface of the second antireflective layer.

9. The method of claim 8, wherein the method further comprises: 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 by, Including passivated contact solar cells as described in any one of claims 1-6.

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