Solar cell and its manufacturing method, electrical device

Abstract

A solar cell and its manufacturing method and application. The solar cell includes a substrate (100), an emitter layer (110), a first passivation layer (120), and a first anti-reflection layer (130) sequentially stacked on one side of the substrate (100), and a passivation contact structure (140) and a second anti-reflection layer (150) sequentially stacked on the other side of the substrate (100). The material of the first passivation layer (120) includes gallium oxide. The manufacturing method includes the steps of sequentially manufacturing the emitter layer (110), the first passivation layer (120), and the first anti-reflection layer (130) on one side of the substrate (100), and sequentially manufacturing the passivation contact structure (140) and the second anti-reflection layer (150) on the other side of the substrate (100). The solar cell is used as a power source.

Description

[Technical Field]

[0001] Priority information This invention claims priority to Chinese application No. 202310376099.4, filed on April 10, 2023, entitled "Solar Cell and Manufacturing Method Thereof, Electrical Device," the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to the field of battery technology, in particular to solar cells and their manufacturing methods, and electrical devices. [Background technology]

[0003] As the global energy system transitions toward a low-carbon society, the large-scale use of renewable energy and the clean, low-carbonization of conventional energy sources have become fundamental trends. Accelerating the development of renewable energy has become the mainstream direction of the global energy transition, with photovoltaic power generation being a key area. Solar cells, primarily large-area semiconductor photodiodes, are electronic components that convert solar energy directly into electrical energy through the photovoltaic effect. Photovoltaic materials absorb light energy, generating a photoelectric effect, converting it into electrical energy. Therefore, solar energy generation is also known as photovoltaics. P-type batteries are made from P-type silicon wafers, while N-type batteries are made from N-type silicon wafers. The main technological process for conventional P-type monocrystalline and polycrystalline batteries is aluminum backsurface field technology. Currently, the mainstream P-type monocrystalline battery technology is the Passivated Emitter and Rear Cell (PERC) technology. This technology has a simple manufacturing process and low cost. As P-type batteries gradually approach their conversion efficiency limits, N-type batteries are becoming the development direction for next-generation battery technology. N-type batteries have advantages such as high conversion efficiency, high bifacial rate, low temperature coefficient, and long carrier life.

[0004] The manufacturing technology for N-type TOPCon high-efficiency solar cells is a key technology for solar cells, and is key to improving the efficiency and reducing the cost of solar power generation. Currently, market demand for N-type TOPCon solar cells is strong and is reaching a peak. TOPCon (Tunnel Oxide Passivating Contacts) cells use an N-type silicon wafer. First, a 1-2 nm tunnel oxide layer is fabricated on the backside of the cell, and then a doped polysilicon layer is deposited. The two layers form a passivation contact structure, providing excellent interfacial passivation to the backside of the silicon wafer.

[0005] Traditionally, the manufacturing process for TOPCon high-efficiency solar cells requires the deposition of a dielectric passivation layer, typically an aluminum oxide layer, on the front side of the N-type silicon wafer after the formation of the tunnel oxide passivation contact structure to provide effective field passivation. However, although aluminum oxide is water-insoluble, it has strong water absorption, adsorption power, and catalytic activity, which makes it susceptible to water vapor intrusion into TOPCon solar cells during use, leading to cell failure. Summary of the Invention [Problem to be solved by the invention]

[0006] According to various embodiments of the present invention, a solar cell, a manufacturing method thereof, and applications thereof are provided, and the solar cell can maintain high conversion efficiency while having excellent reliability even when placed in a high-temperature, high-humidity environment for a long period of time. [Means for solving the problem]

[0007] The present invention provides a solar cell including a substrate, an emitter layer, a first passivation layer, and a first anti-reflection layer sequentially stacked on one surface of the substrate, and a passivation contact structure and a second anti-reflection layer sequentially stacked on the other surface of the substrate, wherein the material of the first passivation layer includes gallium oxide.

[0008] In one embodiment, the solar cell further includes a second passivation layer disposed between the passivation contact structure and the second anti-reflection layer, the material of the second passivation layer including gallium oxide.

[0009] In one embodiment, the passivation contact structure includes a tunnel oxide layer and a doped polysilicon layer stacked in sequence, the tunnel oxide layer facing one side of the substrate.

[0010] In one embodiment, the first anti-reflective layer and the second anti-reflective layer each independently include one or more of a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer.

[0011] In one embodiment, the first anti-reflection layer comprises a first silicon nitride layer, the first silicon nitride layer being in contact with the first passivation layer.

[0012] In one embodiment, the solar cell further includes a first electrode and a second electrode, the first electrode passing through the first passivation layer and the first anti-reflection layer to connect to the emitter layer, and the second electrode passing through the second anti-reflection layer to connect to the passivation contact structure.

[0013] Furthermore, the present invention further provides a method for manufacturing the above-mentioned solar cell, which includes the steps of sequentially fabricating the emitter layer, the first passivation layer, and the first anti-reflection layer on one side surface of the substrate, and sequentially fabricating the passivation contact structure and the second anti-reflection layer on the other side surface of the substrate.

[0014] In one embodiment, the first passivation layer is fabricated by one of atomic layer deposition, plasma enhanced chemical vapor deposition and physical vapor deposition.

[0015] In one embodiment, the conditions for manufacturing the first passivation layer and the second passivation layer by atomic layer deposition each independently include a reaction temperature of 210°C to 230°C and a reaction pressure of 20 torr to 35 torr in an atmosphere of 3000 sccm to 12000 sccm of trimethylgallium and 4000 sccm to 12000 sccm of ozone.

[0016] The present invention further provides an electrical device that includes the above solar cell as a power source.

[0017] The details of one or more embodiments of the invention are set forth in the drawings and description which follow. Other features, objects, and advantages of the invention will become apparent from the description, drawings, and claims. [Brief explanation of the drawings]

[0018] In order to more clearly explain the technical solutions of the embodiments of the present invention or the prior art, the drawings necessary for the description of the embodiments or the prior art will be briefly described below. The drawings in the following description are merely embodiments of the present invention, and it is obvious that those skilled in the art can derive other drawings based on these drawings without any creative work. [Figure 1] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; [Figure 2] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; [Figure 3] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; [Figure 4] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; [Figure 5] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; [Figure 6] 1 is a structural schematic diagram of a solar cell according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is clear that the described embodiments are only some of the embodiments of the present invention, not all of the embodiments. All other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without any creative work are also within the scope of protection of the present invention.

[0020] Additionally, the terms "first" and "second" are merely descriptive, without indicating or implying a relative importance or the number of technical features being presented. Thus, a feature qualified by "first" or "second" may expressly or imply the inclusion of at least one of the feature. In describing the present invention, "plurality" means at least two, e.g., two, three, etc., unless otherwise specifically limited. In describing the present invention, "several" means at least two, e.g., two, three, etc., unless otherwise specifically limited.

[0021] As used herein, terms such as "some embodiments" refer to embodiments of the invention that may provide beneficial effects in some cases. However, other embodiments may be preferred, in the same or other cases. Furthermore, the description of one or more preferred embodiments does not imply that other embodiments cannot be utilized, and is not intended to exclude other embodiments from the scope of the invention.

[0022] When a range of values ​​is disclosed herein, the range is considered continuous and includes the minimum value, the maximum value, and every value between the minimum and maximum values. Furthermore, when a range is an integer, it includes every integer between the minimum and maximum values ​​in the range. Also, when multiple ranges are provided to describe a feature or characteristic, these ranges are combinable. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges contained therein.

[0023] When describing positional relationships, unless otherwise specified, when a component, e.g., a layer, film, or substrate, is considered to be "on" another film layer, it may be directly on top of the other film layer, or there may be intermediate film layers present. Furthermore, when a layer is considered to be "below" another layer, it may be directly below, or there may be one or more intermediate film layers present. It should be understood that when a layer is considered to be "between" two layers, it may be the only layer between the two layers, or there may be one or more intermediate layers present.

[0024] The use of "comprising," "having," and "containing" in this description is intended to cover a non-exclusive package, and other elements may be added unless express limiting terms such as "only," "consisting of," etc. are used.

[0025] Unless stated to the contrary, singular terms may include plurals and are not to be construed as meaning one.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in the present specification are intended only to describe specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0027] 1, the present invention provides a solar cell 10, which includes a substrate 100, an emitter layer 110, a first passivation layer 120, and a first anti-reflection layer 130, which are sequentially stacked on one surface of the substrate 100, and a passivation contact structure 140 and a second anti-reflection layer 150, which are sequentially stacked on the other surface of the substrate 100. The material of the first passivation layer 120 includes gallium oxide.

[0028] The use of the above-mentioned gallium oxide material as the passivation layer material, which has a low interface state density and a high amount of fixed negative charge, ensures the strong interface field passivation required for the front surface of TOPCon solar cells and maintains high conversion efficiency. Furthermore, the above material also has excellent water-blocking stability, effectively avoiding the problem of increased contact resistance after the passivation layer absorbs water, which can lead to solar cell failure.

[0029] 2, the solar cell 10 further includes a second passivation layer 160. The material of the second passivation layer 160 includes gallium oxide.

[0030] In some embodiments, the material of the first passivation layer 120 and the material of the first passivation layer 120 are one-dimensional β-Ga 2 O 3 .

[0031] Furthermore, selecting gallium oxide as the material for the passivation layer can more effectively absorb ultraviolet light, reducing the H after the solar cell is exposed outdoors for a long period of time. + Improves the stability of the bond energy and + It improves the stability of passivation and effectively avoids the failure problem of solar cells under strong ultraviolet radiation. + The bond is the H produced in the reaction of SiH4, NH3, and (CH3)3Ga. + Refers to a bond.

[0032] In one specific example, the passivation contact structure 140 includes a tunnel oxide layer 141 and a doped polysilicon layer 142 that are stacked in sequence, with the tunnel oxide layer 141 facing one side of the substrate 100. In some embodiments, the tunnel oxide layer 141 contacts the substrate 100.

[0033] The substrate 100 is a silicon substrate 100 having a first conductivity type, the emitter layer 110 has a second conductivity type, and the doped polysilicon has the first conductivity type. The first conductivity type is N-type and the second conductivity type is P-type, or the first conductivity type is P-type and the second conductivity type is N-type.

[0034] Furthermore, the substrate 100 has a first conductivity type. The emitter layer 110, which has a second conductivity type, is fabricated by doping the substrate 100 with boron through diffusion. The doped polysilicon layer 142, which has the first conductivity type, is fabricated by doping polysilicon with phosphorus through diffusion.

[0035] Furthermore, the tunnel oxide layer 141 is a silicon oxide layer.

[0036] In some embodiments, first antireflective layer 130 and second antireflective layer 150 each independently comprise one or more of a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer.

[0037] In some embodiments, the first anti-reflective layer 130 includes one or more of a first silicon nitride layer 131, a silicon oxynitride layer 132, and a silicon oxide layer. In some embodiments, the first anti-reflective layer 130 includes the first silicon nitride layer 131 in contact with the first passivation layer 120.

[0038] In some embodiments, the second anti-reflective layer 150 includes a second silicon nitride layer 151. Specifically, the second silicon nitride layer contacts the second passivation layer 160.

[0039] In addition, by selecting gallium oxide as the first passivation layer 120 and forming a first gallium nitride layer on the first passivation layer 120, the stacked structure of the first anti-reflection layer 130 can strengthen the chemical passivation and field passivation of the cell surface, effectively improving the minority carrier lifetime and conversion efficiency of the solar cell.

[0040] In one specific example, the solar cell further includes a first electrode 170 and a second electrode 180. The first electrode 170 connects to the emitter layer 110 through the first passivation layer 120 and the first anti-reflection layer 130. The second electrode 180 connects to the passivation contact structure 140 through the second anti-reflection layer 150.

[0041] Furthermore, the material of the first electrode 170 and the material of the second electrode 180 each independently include silver, aluminum, and gold.

[0042] Furthermore, when silver or aluminum is selected as the metal electrode, it is often manufactured using a screen printing method with a metal paste. For example, if the passivation layer material is prone to water absorption, the alloy formed from the paste is prone to oxidation, increasing contact resistance and causing battery failure. However, the use of a passivation layer material with excellent water-blocking stability effectively reduces the sensitivity of TOPCon solar cells to high-temperature and high-humidity environments, effectively improving battery reliability.

[0043] Furthermore, the present invention further provides a method for manufacturing the above-mentioned solar cell, which includes the steps of sequentially manufacturing an emitter layer 110, a first passivation layer 120, and a first anti-reflection layer 130 on one side surface of the substrate 100, and sequentially manufacturing a passivation contact structure 140 and a second anti-reflection layer 150 on the other side surface of the substrate 100.

[0044] The surface of the first conductivity type silicon wafer is textured to remove surface damage and impurities caused during the silicon wafer cutting process, increase the bonding area through diffusion, and increase the surface area of ​​the battery cell. The reflectivity of the surface of the battery cell is reduced through the principle of optical confinement. The texture may be applied to one or both sides of the substrate 100 as needed. In some embodiments, the silicon wafer is N-type.

[0045] Further, a second conductivity type atom diffusion is performed on the front side of the substrate 100 to form an emitter layer 110 having the second conductivity type, followed by laser doping. In some embodiments, boron diffusion is performed on the surface of the substrate 100. The boron diffusion conditions include using BCl3 as a boron source and performing diffusion at a temperature of 950°C to 1000°C.

[0046] In addition, in a boron-diffused selective emitter (SE) structure battery, the contact area (electrode contact area) between the metal gate line and the silicon wafer on the boron-diffused surface is heavily doped, while the non-metallic contact area between the metal electrodes is lightly doped. This structure effectively reduces the contact resistance and metal intermetallicity in the metal area, increasing the open circuit voltage. It also reduces Auger recombination in the lightly doped non-metallic contact area, effectively improving short-wavelength quantum efficiency and thereby increasing the short-circuit current.

[0047] The method further includes subjecting the doped region to a high temperature process after the laser doping to restore the doped region to a high temperature.

[0048] In one specific example, after high-temperature recovery, borosilicate glass (BSG) wrapped around the edges and the backside of the substrate 100 is removed by a chain method. After this process, a groove-type backside polishing process is performed, in which the edges and backside of the substrate 100 are alkaline etched to remove the wrapping and polish the backside.

[0049] After the above steps, a tunnel oxide layer 141 and a polysilicon layer are sequentially formed on the other surface of the silicon wafer, i.e., the backside. Specifically, the tunnel oxide layer 141 and the polysilicon layer may be formed by, but not limited to, a low-pressure chemical vapor deposition (LPCVD) method. Furthermore, a phosphorus diffusion doping process is performed on the backside polysilicon layer to form a doped polysilicon layer 142, followed by an annealing process to crystallize the polysilicon.

[0050] In one specific example, after phosphorus diffusion and annealing, chains are used to remove wrapped phosphosilicate glass (PSG) from the edges and the other front side of the substrate 100. This is followed by trench polysilicon removal and an RCA clean, an industry standard wet cleaning process, followed by alkaline polishing to remove wrapped polysilicon from the front and edges, and hydrofluoric acid to remove borosilicate glass (BSG) from the front side.

[0051] In one specific example, before manufacturing the second anti-reflection layer 150, the passivation structure further includes a step of manufacturing a second passivation layer 160.

[0052] In one specific example, the first passivation layer 120 is fabricated by one of atomic layer deposition, plasma-enhanced chemical vapor deposition, and physical vapor deposition.

[0053] Furthermore, the methods for fabricating the first passivation layer 120 and the second passivation layer 160 are each independently selected from one of atomic layer deposition, plasma-enhanced chemical vapor deposition, and physical vapor deposition.

[0054] In some embodiments, the first passivation layer 120 and the second passivation layer 160 are fabricated by atomic layer deposition (ALD) using trimethylgallium and oxygen-containing materials.

[0055] Specifically, the steps for manufacturing the first passivation layer 120 and the second passivation layer 160 by atomic layer deposition include loading the boat, first evacuation, heating to the process temperature and subsequent heat retention, leak detection, pre-venting, trimethylgallium deposition, trimethylgallium thermal decomposition reaction, trimethylgallium cleaning treatment, first constant temperature, ozone deposition, ozone thermal decomposition reaction, ozone cleaning treatment, second constant temperature, second evacuation, furnace tube cleaning, returning to normal pressure, and loading the boat out.

[0056] In one specific embodiment, the step of depositing a gallium oxide passivation layer to a variable thickness includes repeatedly performing the steps of trimethylgallium deposition, trimethylgallium thermal decomposition, trimethylgallium rinsing, a first constant temperature, ozone deposition, ozone thermal decomposition, ozone rinsing, and a second constant temperature. The number of repetitions can be set as needed and is between 20 and 40 times. In some embodiments, the number of repetitions can be between 25 and 35 times, specifically, but not limited to, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, or 35 times.

[0057] In one specific example, the conditions for producing the first passivation layer 120 and the second passivation layer 160 by atomic layer deposition independently include a reaction temperature of 210°C to 230°C and a reaction pressure of 20 torr to 35 torr in an atmosphere of 3000 sccm to 12000 sccm of trimethylgallium and 4000 sccm to 12000 sccm of ozone.

[0058] Specifically, the board loading conditions include sending a silicon wafer into the device, a set time of 100 seconds to 140 seconds, and a set temperature of 230°C to 270°C.

[0059] Furthermore, the conditions for the first evacuation include a set time of 180 seconds to 240 seconds, a set temperature of 200°C to 240°C, and a set pressure after evacuation of 25 torr to 35 torr.

[0060] Furthermore, the conditions for heating to the process temperature and subsequent temperature maintenance include re-evacuating the device to the process set point, a set time of 280 s to 340 s, a set temperature of 200°C to 240°C, and a set pressure after evacuation of 25 torr to 35 torr.

[0061] Next, perform leak detection to detect whether the vacuum is leaking, so that the process effect can be easily ensured before introducing the process gas. The set time is 18s to 24s, the set temperature is 200°C to 240°C, and the set pressure after evacuation is 25torr to 35torr.

[0062] A pre-aeration treatment is performed. The conditions for the pre-aeration treatment include a set time of 8 seconds to 14 seconds, a flow rate of trimethylgallium of 8000 sccm to 12000 sccm, and a flow rate of ozone of 8000 sccm to 12000 sccm.

[0063] The conditions for trimethylgallium deposition include a trimethylgallium flow rate of 3000sccm to 8000sccm, a reaction pressure of 20torr to 30torr, a reaction temperature of 210°C to 230°C, and a set time of 2000ms to 6000ms.

[0064] Furthermore, the conditions for the trimethylgallium deposition include a trimethylgallium flow rate of 4000 sccm to 6000 sccm, a reaction pressure of 22 torr to 27 torr, a reaction temperature of 215°C to 225°C, and a set time of 3000 ms to 5000 ms.

[0065] The conditions for the trimethylgallium thermal decomposition reaction include a reaction pressure of 20 torr to 30 torr, a reaction temperature of 210°C to 230°C, and a set time of 2000 ms to 5000 ms.

[0066] In some embodiments, the conditions for the trimethylgallium thermal decomposition reaction include a reaction pressure of 22 torr to 27 torr, a reaction temperature of 210° C. to 230° C., and a set time of 2000 ms to 4000 ms.

[0067] The conditions for performing the cleaning treatment on trimethylgallium include an introduction flow rate of trimethylgallium of 8000sccm to 12000sccm, an introduction flow rate of ozone of 8000sccm to 12000sccm, a set pressure of 20torr to 30torr, a set temperature of 210°C to 230°C, and a set time of 4000ms to 8000ms.

[0068] Furthermore, the conditions for performing the cleaning treatment on trimethylgallium include an introduction flow rate of trimethylgallium of 9000sccm to 11000sccm, an introduction flow rate of ozone of 9000sccm to 11000sccm, a set pressure of 22torr to 27torr, a set temperature of 215°C to 225°C, and a set time of 5500ms to 7500ms.

[0069] The conditions for the first constant temperature include waiting until all the gas in the furnace tube is extracted, setting time 1000ms to 3000ms, setting pressure 25torr to 35torr, and setting temperature 210℃ to 230℃.

[0070] In one specific example, the conditions for the first constant temperature treatment include a set time of 1500 ms to 2500 ms, a set pressure of 28 torr to 32 torr, and a set temperature of 215°C to 225°C.

[0071] The conditions for ozone deposition include an ozone flow rate of 3000sccm to 8000sccm, a reaction pressure of 20torr to 30torr, a reaction temperature of 210℃ to 230℃, and a set time of 4000ms to 8000ms.

[0072] Furthermore, the conditions for ozone deposition include an ozone flow rate of 5000 sccm to 7000 sccm, a reaction pressure of 22 torr to 27 torr, a reaction temperature of 215°C to 225°C, and a set time of 5000 ms to 7000 ms.

[0073] The conditions for the ozone thermal decomposition reaction include a reaction pressure of 20 torr to 30 torr, a reaction temperature of 210°C to 230°C, and a set time of 300 ms to 700 ms.

[0074] Furthermore, the conditions for the ozone thermal decomposition reaction include a reaction pressure of 22 torr to 27 torr, a reaction temperature of 215°C to 225°C, and a set time of 400 ms to 600 ms.

[0075] The conditions for performing the cleaning treatment with ozone include an introduction flow rate of trimethylgallium of 8000sccm to 12000sccm, an introduction flow rate of ozone of 8000sccm to 12000sccm, a set pressure of 20torr to 30torr, a set temperature of 210°C to 230°C, and a set time of 2000ms to 6000ms.

[0076] In some embodiments, the conditions for performing the cleaning process with ozone include an introduction flow rate of trimethylgallium of 9000 sccm to 11000 sccm, an introduction flow rate of ozone of 9000 sccm to 11000 sccm, a set pressure of 22 torr to 27 torr, a set temperature of 215°C to 225°C, and a set time of 3000 ms to 5000 ms.

[0077] The conditions for the second constant temperature include waiting until all the gas in the furnace tube is extracted, setting time 1000ms to 3000ms, setting pressure 25torr to 35torr, and setting temperature 210℃ to 230℃.

[0078] Furthermore, the conditions for the second constant temperature treatment include a set time of 1500 ms to 2500 ms, a set pressure of 28 torr to 32 torr, and a set temperature of 210°C to 230°C.

[0079] After the second constant temperature, a second evacuation is performed. The conditions for the second evacuation include a set time of 10 seconds to 40 seconds, a set temperature of 220°C to 270°C, and a set pressure after evacuation of 15 torr to 25 torr.

[0080] The conditions for cleaning the furnace tube after the second evacuation and blowing out the residual gas in the furnace include a set time of 10 s to 30 s, a set temperature of 220°C to 270°C, a set pressure after evacuation of 15 torr to 25 torr, and an inert gas flow rate of 20,000 sccm to 30,000 sccm.

[0081] Thereafter, the device is returned to normal pressure setting, and the conditions for opening the furnace door include a set time of 100 to 300 seconds, a set temperature of 220 to 270°C, and an inert gas flow rate of 30,000 to 70,000 sccm.

[0082] Finally, the conditions for unloading the boat and removing the sample include a set time of 100 to 150 seconds and a set temperature of 220 to 270°C.

[0083] Furthermore, the first anti-reflection layer 130 and the second anti-reflection layer 150 may be manufactured by, but not limited to, plasma-enhanced chemical vapor deposition (PECVD).

[0084] Furthermore, the first electrode 170 and the second electrode 180 may be manufactured by a screen printing method, specifically by printing electrode paste on both sides of the substrate and sintering the electrodes to bring them into contact with each other, but this is not limiting.

[0085] After the first electrode 170 and the second electrode 180 are fabricated, the method further includes a step of injecting carriers to achieve hydrogen passivation and applying light incidence to perform a light attenuation prevention process.

[0086] Furthermore, there is provided an electric device powered by the solar cell, which may be, but is not limited to, a transformer, a reactor, a capacitor, a complex electric device, a breaker, a detector, a lightning arrester, a coupling capacitor, a power transmission line, a power cable, a grounding device, a generator, a phase modifier, an electric motor, a sealed busbar, and a thyristor.

[0087] Hereinafter, specific examples will be provided to further explain the solar cell according to the present invention.

[0088] Example 1 As shown in Figure 3, the present invention provides a solar cell. The solar cell includes an N-type silicon substrate, a P-type emitter layer formed by boron diffusion on one side of the N-type silicon substrate, a first passivation layer made of gallium oxide, a first anti-reflection layer formed by silicon nitride, silicon oxynitride, and silicon oxide on the first passivation layer, and a second anti-reflection layer formed by a tunnel oxide layer, a doped polysilicon layer formed by phosphorus diffusion, and silicon nitride on the other side of the N-type silicon substrate. The steps for forming the one-dimensional β-Ga2O3 structure of the first passivation layer are as follows: Step 1: The boat was loaded, and the silicon wafer was placed on an aluminum support jig. The wafer was then transferred to the ALD apparatus using a robot arm. The time was set to 120 s and the temperature to 250°C. Step 2: A vacuum was drawn and the furnace tube was vacuumed for the first time at a time of 200 s, a temperature of 220°C, and a pressure of 30 torr. Step 3: Heating was performed, and the pressure was evacuated to the process set point, and the furnace tube was kept at a constant temperature for 300 s, at a temperature of 220° C., and at a pressure of 30 torr. Step 4: Leak detection was performed to check whether the vacuum leaked or not to ensure the process effect before introducing the process gas. The time was 20 s, the temperature was 220 °C, and the pressure was 30 torr. Step 5: Pre-venting was performed on the gas line, and the pre-venting time was set to 10 seconds. Trimethyl gallium (TMGa) was introduced at a flow rate of 10,000 sccm, and ozone (O3) was introduced at a flow rate of 10,000 sccm. Step 6: Trimethylgallium (TMGa) was introduced and pyrolytically deposited for a time of 4000 ms at a temperature of 220° C., a pressure of 25 torr, and a flow rate of 5000 sccm. Step 7: The thermal decomposition reaction of trimethylgallium (TMGa) was allowed to stabilize, and the time was set to 3000 ms, the temperature to 220° C., and the pressure to 25 torr. Step 8: The trimethylgallium (TMGa) was subjected to a cleaning process, with the time set to 6500 ms, the temperature set to 220°C, the pressure set to 25 torr, the trimethylgallium (TMGa) introduced at a flow rate of 10000 sccm, and ozone (O3) introduced at a flow rate of 10000 sccm. Step 9: The temperature in the furnace tube was stabilized until the gas inside was completely extracted, and the time was set to 2000 ms, the temperature to 220°C, and the pressure to 30 torr. Step 10: Ozone (O3) was introduced for pyrolysis deposition, with the time set to 6000 ms, the temperature set to 220°C, the pressure set to 25 torr, and the ozone (O3) introduced at a flow rate of 6000 sccm. Step 11: The thermal decomposition reaction of ozone (O3) was allowed to stabilize, with the time set to 500 ms, the temperature set to 220°C, and the pressure set to 25 torr. Step 12: A cleaning process was performed with ozone (O3), with a time of 4000 ms, a temperature of 220°C, a pressure of 25 torr, trimethylgallium (TMGa) introduced at a flow rate of 10000 sccm, and ozone (O3) introduced at a flow rate of 10000 sccm. Step 13: The temperature was stabilized until the gas inside the furnace tube was completely extracted, and the time was set to 2000 ms, the temperature to 220°C, and the pressure to 30 torr. Steps 6 to 13 are one cycle reaction, and 30 cycles are required to deposit the gallium oxide medium layer. Step 14: A vacuum was applied to extract excess gas, the time was 25 s, the temperature was 250° C., and the pressure was 20 torr. Step 15: The furnace tube was cleaned and residual gas was blown out, the time was 15 seconds, the temperature was 250° C., the pressure was 20 torr, and the nitrogen gas flow rate was 25,000 sccm. Step 16: The pressure was returned to normal, the furnace door was prepared for opening, the time was set to 200 s, the temperature was set to 250°C, and N2 was introduced at a flow rate of 50,000 sccm. Step 17: The boat was removed, and the aluminum support jig was removed from the cavity of the ALD reactor by a robot arm. The time was set to 120 s and the temperature to 250°C.

[0089] Example 2 As shown in Figure 4, this example provides a solar cell. This solar cell is based on Example 1, in which gallium oxide is formed as a second passivation layer between the doped polysilicon layer and the second anti-reflection layer, and the manufacturing method of the second passivation layer is the same as that of the first passivation layer.

[0090] Example 3 As shown in Figure 5, this example provides a solar cell, which differs from Example 2 in that the structure of the first passivation layer and the first anti-reflection layer is a gallium oxide layer, a silicon nitride layer, and a silicon oxynitride layer that are sequentially stacked.

[0091] Example 4 As shown in Figure 6, the present invention provides a solar cell, which differs from Example 2 in that the structure of the first passivation layer and the first anti-reflection layer is a gallium oxide layer, a silicon nitride layer, and a silicon oxide layer that are sequentially stacked.

[0092] Comparative Example 1 This comparative example provides a solar cell, which differs from Example 1 in that the material of the first passivation layer is aluminum oxide.

[0093] Comparative Example 2 This comparative example provides a solar cell, which differs from Example 2 in that the materials of the first passivation layer and the second passivation layer are aluminum oxide.

[0094] Comparative Example 3 This comparative example provides a solar cell, which differs from Example 2 in that the structure of the first passivation layer and the first anti-reflection layer is a gallium oxide layer, a silicon oxynitride layer, and a silicon oxide layer stacked in sequence.

[0095] Comparative Example 4 This comparative example provides a solar cell, which differs from Example 2 in that the structure of the first passivation layer and the first anti-reflection layer is a gallium oxide layer and a silicon oxynitride layer stacked in sequence.

[0096] Comparative Example 5 This comparative example provides a solar cell, which differs from Example 2 in that the structure of the first passivation layer and the first anti-reflection layer is a gallium oxide layer and a silicon oxide layer that are sequentially stacked.

[0097] For the solar cells according to Examples 1 to 4 and Comparative Examples 1 to 5, parameters such as the solar cell conversion efficiency (Eta), open circuit voltage (Uoc), short circuit current (Isc), fill factor (FF), maximum operating voltage (Umpp), maximum operating current (Impp), maximum operating power (Pmpp), and power loss were measured. The measurement method was performed with reference to IEC TS 63202-3 Photovoltaic cells - Part 3: Measurement of current-voltage characteristics of bicial photovoltaic cells published by the International Electrotechnical Commission.

[0098] The conversion efficiencies of the solar cells according to the above examples and comparative examples were measured, and the results are shown in Table 1.

[0099] JPEG0007742500000001.jpg32170

[0100] According to Table 1, the introduction of gallium oxide media layer material did not affect the final conversion efficiency of the TOPCon solar cell, which remained high at a level of 25%.

[0101] Measurements were carried out on the solar cells according to the above-mentioned Examples and Comparative Examples at a temperature of 85° C. and a humidity of 85%. The results are shown in Table 2.

[0102] JPEG0007742500000002.jpg102170

[0103] Thus, after replacing the passivation layer material, the performance of TOPCon solar cells in high temperature and humidity environments is significantly improved, effectively improving the reliability of the device.

[0104] The solar cells according to the above examples and comparative examples were subjected to measurement of UV light attenuation for 200 hours, and the results are shown in Table 3.

[0105] JPEG0007742500000003.jpg49170

[0106] According to Table 3, after replacing the passivation layer material, the TOPCon solar cell maintains excellent device performance even when exposed to UV radiation for a long time.

[0107] Thus, gallium oxide, with its low interface state density and high fixed negative charge, not only ensures the strong interface field passivation required for the front surface of TOPCon solar cells, but also maintains the high conversion efficiency of TOPCon solar cells. Furthermore, the above material also has excellent water-blocking stability, effectively avoiding the problem of increased contact resistance after the passivation layer absorbs water, which can lead to solar cell failure. Selecting gallium oxide as the passivation layer material can effectively absorb ultraviolet light, reducing the H2O2 buildup after solar cells are exposed outdoors for long periods of time. + Improves the stability of the bond energy and + Improve the stability of passivation and effectively avoid the failure of solar cells under strong ultraviolet irradiation.

[0108] Furthermore, cell structures in which gallium oxide was installed as a passivation layer on both sides of the TOPCon solar cell substrate were compared, and the performance of the solar cells in Examples 2 to 4 and Comparative Examples 3 to 5 was measured by installing different first anti-reflection layer structures, with the measurement results shown in Table 4. The measurement results show that the composite passivation structure obtained by contacting gallium oxide in the passivation layer with silicon nitride in the anti-reflection layer strengthens the chemical passivation and field passivation of the cell surface, effectively improving the minority carrier lifetime and conversion efficiency of the solar cell.

[0109] JPEG0007742500000004.jpg45170

[0110] The technical features of the above-described embodiments can be combined in any manner. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described, but any combination of these technical features should be considered within the scope of the present specification unless they are inconsistent.

[0111] The above examples merely illustrate some embodiments of the present invention. Although the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model. It should be noted that a person skilled in the art can make several modifications and improvements without departing from the spirit of the present invention, and all of these fall within the scope of protection of the present application. Therefore, the patent protection scope of the present invention shall be governed by the appended claims.

[0112] Explanation of symbols 10. Solar Cells 100 boards 110 Emitter layer 120 First passivation layer 130 1st anti-reflection layer 131 First silicon nitride layer 132 Silicon oxynitride 133 Silicon oxide 140 Passivation Contact Structure 141 Tunnel oxide layer 142 doped polysilicon layer 150 Second anti-reflection layer 151 Second silicon nitride layer 160 Second passivation layer 170 1st electrode 180 2nd electrode

Claims

1. A solar cell, A substrate; an emitter layer, a first passivation layer, and a first anti-reflection layer sequentially stacked on one surface of the substrate; a passivation contact structure and a second anti-reflection layer sequentially stacked on the other surface of the substrate; the material of the first passivation layer includes gallium oxide; a second passivation layer disposed between the passivation contact structure and the second anti-reflection layer; A solar cell, wherein the material of the second passivation layer contains gallium oxide.

2. the passivation contact structure includes a tunnel oxide layer and a doped polysilicon layer stacked in sequence; 2. The solar cell according to claim 1, wherein the tunnel oxide layer is provided at a position closer to the substrate than the doped polysilicon layer.

3. The solar cell according to claim 1 , wherein the first anti-reflection layer and the second anti-reflection layer each independently include at least one of a silicon nitride layer, a silicon oxynitride layer, and a silicon oxide layer.

4. the first anti-reflection layer includes a first silicon nitride layer; 4. The solar cell of claim 3, wherein the first silicon nitride layer is in contact with the first passivation layer.

5. further comprising a first electrode and a second electrode; the first electrode passes through the first passivation layer and the first antireflection layer and is connected to the emitter layer; 5. The solar cell according to claim 1, wherein the second electrode penetrates the second anti-reflection layer and connects to the passivation contact structure.

6. A method for producing a solar cell according to any one of claims 1 to 4, comprising: forming the emitter layer, the first passivation layer, and the first anti-reflection layer sequentially on one side surface of the substrate; and sequentially forming the passivation contact structure and the second anti-reflection layer on the other surface of the substrate.

7. 7. The method of claim 6, wherein the first passivation layer is formed by one of atomic layer deposition, plasma enhanced chemical vapor deposition, and physical vapor deposition.

8. 7. The method for manufacturing a solar cell according to claim 6, wherein the conditions for manufacturing the first passivation layer and the second passivation layer by atomic layer deposition each independently include a reaction temperature of 210°C to 230°C and a reaction pressure of 20 torr to 35 torr in an atmosphere of 3000 sccm to 12000 sccm of trimethylgallium and 4000 sccm to 12000 sccm of ozone.

9. 1. An electrical device comprising: An electrical device comprising the solar cell according to any one of claims 1 to 4 as a power source.

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