TOPCon battery, photovoltaic module and laminated battery
By setting an alumina layer on the polysilicon layer on the back of the TOPCon battery, the problem of poor anti-reflection effect is solved and the conversion efficiency of the battery is improved.
Patent Information
- Application Number
- CN202421733622.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-08-01
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The anti-reflection effect on the back of the existing TOPCon batteries is poor, resulting in a reduced battery conversion efficiency.
Alumina layer is provided on the polysilicon layer on the back of the battery to increase the anti-reflection effect.
By providing an alumina layer on the polysilicon layer, the conversion efficiency of the back of the battery is improved.
Smart Images
Figure CN223182584U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of solar power generation, and particularly relates to a TOPCon battery, a photovoltaic module and a tandem battery. Background Art
[0002] A solar cell is a device that directly converts light energy into electrical energy through the photovoltaic effect or the photochemical effect. The working principle of a photovoltaic effect solar cell is as follows: sunlight shines on a semiconductor p-n junction, forming new hole-electron pairs. Under the action of the p-n junction electric field, holes flow from the n-region to the p-region, and electrons flow from the p-region to the n-region. After connecting the circuit, an electric current is formed.
[0003] The main structural components of a conventional TOPCon (Tunnel Oxide Passivated Contact) battery include an upper electrode, a passivation layer, an emitter layer, a substrate, a diffusion doping layer, a passivated contact structure and a lower electrode. Among them, the passivated contact structure can block the recombination of minority carrier holes and improve the open-circuit voltage and short-circuit current of the battery. However, the antireflection effect of existing TOPCon batteries is poor, reducing the conversion efficiency of the battery. Summary of the Utility Model
[0004] An embodiment of the utility model provides a TOPCon battery, aiming at solving the problem that the conversion efficiency of the existing TOPCon battery is reduced due to the poor antireflection effect on the back surface of the battery.
[0005] An embodiment of the utility model is implemented as follows. A TOPCon battery includes:
[0006] A silicon substrate;
[0007] A tunneling layer disposed on the back surface of the silicon substrate;
[0008] A polysilicon layer disposed on the side surface of the tunneling layer away from the silicon substrate; and
[0009] An alumina layer disposed on the side surface of the polysilicon layer away from the tunneling layer, and the alumina layer is disposed in at least a partial area of the polysilicon layer.
[0010] Further, a diffusion doping layer is disposed on the back surface of the silicon substrate, and a tunneling layer is disposed on the side surface of the diffusion doping layer away from the silicon substrate.
[0011] Further, the TOPCon battery further includes a back electrode connected to the polysilicon layer.
[0012] Further, the diffusion doping layer is disposed in a partial area on the back surface of the silicon substrate.
[0013] Further, the tunneling layer is disposed in a partial area of the diffusion doping layer.
[0014] Further, the TOPCon cell further includes a back passivation layer disposed on a side of the alumina layer away from the polysilicon layer.
[0015] Further, an emitter layer and a front electrode connected to the emitter layer are disposed on the front side of the silicon substrate.
[0016] Further, a front passivation layer is disposed on a side of the emitter layer away from the silicon substrate.
[0017] Further, the front passivation layer and the back passivation film include at least one of silicon nitride, alumina, silicon oxynitride, and silicon oxide.
[0018] In a second aspect, the present application further provides a photovoltaic module including the TOPCon cell as described above.
[0019] In a third aspect, the present application further provides a tandem cell including a perovskite cell and the TOPCon cell as described above.
[0020] The beneficial effect of the present application is that the TOPCon cell of the present application includes a silicon substrate, a tunneling layer, a polysilicon layer, and an alumina layer. Among them, the tunneling layer is disposed on the back side of the silicon substrate, the polysilicon layer is disposed on a side of the tunneling layer away from the silicon substrate, the alumina layer is disposed on a side of the polysilicon layer away from the tunneling layer, and the alumina layer is disposed in at least a part of the polysilicon layer. Through the above arrangement, an alumina layer is disposed on at least a part of the polysilicon layer on the back side of the cell, increasing the antireflection effect and improving the conversion efficiency of the back side of the cell. Description of the Drawings
[0021] Figure 1 is a schematic structural diagram of a silicon substrate of an embodiment of the TOPCon cell provided by the present application;
[0022] Figure 2 is a schematic structural diagram of an embodiment of the TOPCon cell provided by the present application with an alumina layer disposed on the back side;
[0023] Figure 3 is a schematic structural diagram of an embodiment of the TOPCon cell provided by the present application with an alumina layer disposed on a partial area of the back side;
[0024] Figure 4 is a schematic structural diagram of an embodiment of the TOPCon cell provided by the present application. Detailed Embodiments
[0025] In order to make the objectives, technical solutions and advantages of the present utility model more clear and understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.
[0026] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model.
[0027] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless otherwise specifically defined.
[0028] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection or an integral connection; it may be a mechanical connection, an electrical connection or a connection capable of mutual communication; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0029] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath" and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is lower than that of the second feature.
[0030] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.
[0031] The TOPCon battery of the present application includes a silicon substrate, a tunneling layer, a polysilicon layer, and an alumina layer. Among them, the tunneling layer is disposed on the back surface of the silicon substrate, the polysilicon layer is disposed on a side surface of the tunneling layer away from the silicon substrate, the alumina layer is disposed on a side surface of the polysilicon layer away from the tunneling layer, and the alumina layer is disposed in at least a part of the polysilicon layer. Through the above settings, an alumina layer is disposed on at least a part of the polysilicon layer on the back surface of the battery, increasing the antireflection effect and improving the conversion efficiency of the back surface of the battery.
[0032] Embodiment 1
[0033] As Figures 1 to 4 shown, an embodiment of the present application provides a TOPCon battery, including:
[0034] A silicon substrate 100;
[0035] A tunneling layer 200 disposed on the back surface 120 of the silicon substrate 100;
[0036] A polysilicon layer 300 disposed on a side surface of the tunneling layer 200 away from the silicon substrate 100; and
[0037] An alumina layer 400 disposed on a side surface of the polysilicon layer 300 away from the tunneling layer 200, and the alumina layer 400 is disposed in at least a part of the polysilicon layer 300.
[0038] In implementation, the TOPCon cell provided by this application refers to Tunnel Oxide Passivated Contact, that is, an oxide layer passivated contact cell.
[0039] Optionally, the TOPCon cell provided by this application refers to a single-sided TOPCon cell, that is, a passivated contact structure composed of a layer of ultra-thin silicon oxide (1 nm - 2 nm) and a layer of doped polysilicon film is provided on the back surface 120 of the cell.
[0040] In implementation, the silicon substrate 100 is a silicon wafer. The silicon substrate 100 can be a P-type silicon wafer or an N-type silicon wafer, without limitation.
[0041] In implementation, there is no essential difference in the power generation principles of solar cell wafers using P-type silicon wafers or N-type silicon wafers. Both are based on the PN junction for the separation of photo-generated carriers.
[0042] Optionally, by doping a donor impurity (such as a pentavalent element like phosphorus) into a semiconductor, an N-type semiconductor material is obtained; by doping an acceptor impurity (such as a trivalent element like boron) into a semiconductor, a P-type semiconductor material is obtained.
[0043] Diffusing a pentavalent element, such as phosphorus, on a P-type semiconductor material to form an n+ / p-type structure solar cell is a P-type cell wafer; implanting a trivalent element, such as boron, on an N-type semiconductor material to form a p+ / n-type structure solar cell is an N-type cell wafer.
[0044] Optionally, as Figure 1 shown, the silicon substrate 100 is in sheet or plate form, having opposite front surface 110 and back surface 120. Usually, the front surface 110 of the silicon substrate 100 can be regarded as the light-receiving surface of the solar cell wafer. Similarly, the back surface 120 of the silicon substrate 100 can be regarded as the backlight surface of the solar cell wafer.
[0045] On the back surface 120 of the silicon substrate 100, a tunneling layer 200, a polysilicon layer 300, and an alumina layer 400 are sequentially arranged in a direction away from the silicon substrate 100. That is to say, the tunneling layer 200 is arranged on the back surface 120 of the silicon substrate 100, the polysilicon layer 300 is arranged on the back surface 120 of the tunneling layer 200, and the alumina layer 400 is arranged on the back surface 120 of the polysilicon layer 300.
[0046] Optionally, the tunneling layer 200 refers to an ultrathin tunneling oxide layer (SiO2) with a thickness of less than 5 nm, preferably 0.5 nm to 2 nm, such as 0.5 nm, 1 nm, 1.5 nm, or 2 nm, etc., which is not limited herein. The polysilicon layer 300 refers to a doped polysilicon layer, and the doping type of the polysilicon layer 300 can be determined according to the type of the silicon substrate 100. For example, when the silicon substrate 100 is an N-type silicon wafer, the polysilicon layer 300 is a phosphorus-doped polysilicon layer.
[0047] In some alternative embodiments, the alumina layer 400 is disposed on at least a portion of the polysilicon layer 300. During implementation, the alumina layer 400 can be disposed over the entire back surface 120 of the polysilicon layer 300, as Figure 2 shown, or can be disposed on a partial area of the back surface 120 of the polysilicon layer 300, as Figure 3 shown. The alumina layer 400, i.e., the alumina thin film disposed on the back surface 120 of the polysilicon layer 300, can enhance the antireflection effect.
[0048] The TOPCon cell of the present application includes a silicon substrate 100, a tunneling layer 200, a polysilicon layer 300, and an alumina layer 400. Among them, the tunneling layer 200 is disposed on the back surface 120 of the silicon substrate 100, the polysilicon layer 300 is disposed on a side surface of the tunneling layer 200 away from the silicon substrate 100, the alumina layer 400 is disposed on a side surface of the polysilicon layer 300 away from the tunneling layer 200, and the alumina layer 400 is disposed on at least a portion of the polysilicon layer 300. Through the above arrangement, an alumina layer 400 is disposed on at least a portion of the polysilicon layer 300 on the back surface 120 of the cell, enhancing the antireflection effect and improving the conversion efficiency of the back surface 120 of the cell.
[0049] In some alternative embodiments, as Figure 4 shown, an emitter layer 500 and a diffusion doping layer 600 are respectively disposed on the front surface 110 and the back surface 120 of the silicon substrate 100, wherein the emitter layer 500 is connected to the front electrode 710.
[0050] Optionally, the emitter layer 500 and the diffusion doping layer 600 refer to doping layers formed by further doping on the basis of the silicon substrate 100. Exemplarily, taking the silicon substrate 100 as an N-type silicon wafer as an example, boron can be doped on the front surface 110 of the silicon substrate 100 to form the emitter layer 500. At this time, the emitter layer 500 can be regarded as a p+ layer, and phosphorus is doped on the back surface 120 of the silicon substrate 100 to obtain the diffusion doping layer 600. The diffusion doping layer 600 can be formed by separate diffusion or can be formed by diffusion of the polysilicon layer 300 into the silicon substrate 100, which is not limited herein.
[0051] By providing a passivation contact structure on the back surface 120 of the battery, the recombination of minority carrier holes can be blocked, and the open-circuit voltage and short-circuit current of the battery can be increased. Among them, the ultra-thin tunneling layer 200 allows majority carrier electrons to tunnel into the polysilicon layer 300 while blocking the recombination of minority carrier holes. The good passivation effect of the ultra-thin tunneling layer 200 and the polysilicon layer 300 causes the energy band on the surface of the silicon wafer to bend, thereby forming a field passivation effect. The probability of electron tunneling increases significantly, the contact resistance decreases, the open-circuit voltage and short-circuit current of the battery are increased, and thus the conversion efficiency of the battery is improved.
[0052] In some possible embodiments, the diffusion doping layer 600 is disposed in a partial region of the back surface 120 of the silicon substrate 100. That is to say, the diffusion doping layer 600 and the silicon substrate 100 are in partial contact, reducing the surface recombination in the non-contact region.
[0053] In some possible embodiments, the tunneling layer 200 is disposed in a partial region of the diffusion doping layer 600. That is to say, the tunneling layer 200 and the diffusion doping layer 600 are in partial contact, which can effectively reduce the contact recombination.
[0054] In some possible embodiments, the TOPCon battery provided by the present application further includes a front passivation layer 810 and a back passivation layer 820. The front passivation layer 810 is disposed on a side of the emitter layer 500 away from the silicon substrate 100, and the back passivation layer 820 is disposed on a side of the alumina layer 400 away from the polysilicon layer 300.
[0055] Both the front passivation layer 810 and the back passivation layer 820 are passivation antireflection thin films. The passivation antireflection thin film is used to improve the photoelectric conversion efficiency and stability of the solar cell, reduce the surface damage and oxidation reaction of the solar cell, and extend the service life of the solar cell.
[0056] During implementation, the front electrode 710 is connected to the emitter layer 500 after passing through the front passivation layer 810, and the back electrode 720 is connected to the polysilicon layer 300 after passing through the back passivation layer 820.
[0057] In some embodiments, the connection of the back electrode 720 to the polysilicon layer 300 can be in contact with the surface of the polysilicon layer 300 or extend into the interior of the polysilicon layer 300, but not in contact with the tunneling layer 200.
[0058] In some other alternative embodiments, the back electrode 720 burns through the back passivation layer 820 and then contacts the polysilicon layer 300. Some metal crystals of the metal paste penetrate into the polysilicon layer 300. That is, the metal electrode is in contact with the polysilicon layer 300 and some metal crystals are formed in the polysilicon layer 300, but no metal crystals are formed in the tunneling layer 200. Through the above arrangement, the metal crystals can help the carriers move to the metal electrode more easily, improving the efficiency of the solar cell.
[0059] Optionally, the front passivation layer 810 and the back passivation layer 820 include at least one of silicon nitride, aluminum oxide, silicon oxynitride, and silicon oxide, without limitation. Preferably, the front passivation layer 810 and / or the back passivation layer 820 can adopt aluminum oxide to ensure the light absorption rate.
[0060] Embodiment 2
[0061] In some alternative embodiments, the present application provides a photovoltaic module, including the TOPCon cell as described above.
[0062] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the structure and implementation principle of the photovoltaic module described above can refer to the corresponding structure and implementation principle in the foregoing Embodiment 1, and will not be elaborated here.
[0063] The TOPCon cell of the present application includes a silicon substrate 100, a tunneling layer 200, a polysilicon layer 300, and an aluminum oxide layer 400. Among them, the tunneling layer 200 is disposed on the back surface 120 of the silicon substrate 100, the polysilicon layer 300 is disposed on a side surface of the tunneling layer 200 away from the silicon substrate 100, the aluminum oxide layer 400 is disposed on a side surface of the polysilicon layer 300 away from the tunneling layer 200, and the aluminum oxide layer 400 is disposed in at least part of the area of the polysilicon layer 300. Through the above arrangement, an aluminum oxide layer 400 is disposed on at least part of the area of the polysilicon layer 300 on the back surface 120 of the cell, increasing the antireflection effect and improving the conversion efficiency of the back surface 120 of the cell.
[0064] Embodiment 3
[0065] In some embodiments, the present application further provides a tandem cell, including a perovskite cell and the TOPCon cell as described above.
[0066] During implementation, the perovskite cell, i.e., perovskite solar cells, is a solar cell that uses an organic metal halide semiconductor of the perovskite type as a light-absorbing material. The tandem cell provided by the present application is a perovskite-silicon-based tandem solar cell. The perovskite-silicon-based tandem cell utilizes the broadband gap structure characteristics of the perovskite cell material. By disposing the perovskite cell material above the silicon-based cell, it can absorb high-energy photons in the short wavelength band that are difficult for the silicon-based cell to absorb, thereby maximizing the utilization of the incident sunlight, and further improving the conversion efficiency of the photovoltaic cell, and having a higher theoretical efficiency limit, which will not be elaborated here.
[0067] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the structure and implementation principle of the tandem cell described above can refer to the corresponding structure and implementation principle in the foregoing Embodiments 1 to 2, and will not be elaborated here.
[0068] The TOPCon battery of the present application includes a silicon substrate 100, a tunneling layer 200, a polysilicon layer 300, and an alumina layer 400. Among them, the tunneling layer 200 is disposed on the back surface 120 of the silicon substrate 100, the polysilicon layer 300 is disposed on a side surface of the tunneling layer 200 away from the silicon substrate 100, the alumina layer 400 is disposed on a side surface of the polysilicon layer 300 away from the tunneling layer 200, and the alumina layer 400 is disposed in at least a partial area of the polysilicon layer 300. Through the above arrangement, the alumina layer 400 is disposed on at least a partial area of the polysilicon layer 300 on the back surface 120 of the battery, increasing the antireflection effect and improving the conversion efficiency of the back surface 120 of the battery.
[0069] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A TOPCon battery, characterized in that, Comprising: A silicon substrate; A tunneling layer disposed on the back surface of the silicon substrate; A polysilicon layer disposed on a side surface of the tunneling layer away from the silicon substrate; And An alumina layer disposed on a side surface of the polysilicon layer away from the tunneling layer, the alumina layer being disposed in at least a partial area of the polysilicon layer.
2. The TOPCon battery according to claim 1, characterized in that, A diffusion doping layer is disposed on the back surface of the silicon substrate, and the tunneling layer is disposed on a side surface of the diffusion doping layer away from the silicon substrate.
3. The TOPCon battery according to any one of claims 1 to 2, characterized in that The TOPCon cell further includes a back electrode connected to the polysilicon layer.
4. The TOPCon battery according to claim 2, wherein The diffusion doping layer is disposed in a partial area on the back surface of the silicon substrate.
5. The TOPCon battery according to claim 2 or 4, characterized in that, The tunneling layer is disposed in a partial area of the diffusion doping layer.
6. The TOPCon battery according to claim 1, wherein The TOPCon cell further includes a back passivation layer, and the back passivation layer is disposed on a side surface of the alumina layer away from the polysilicon layer.
7. The TOPCon battery according to claim 6, wherein An emitter layer and a front electrode connected to the emitter layer are disposed on the front surface of the silicon substrate.
8. The TOPCon cell according to claim 7, characterized in that, A front passivation layer is disposed on a side of the emitter layer away from the silicon substrate.
9. A photovoltaic module, characterized in that, Comprising the TOPCon cell according to any one of claims 1 to 8.
10. A stacked battery, characterized in that, Comprising a perovskite cell and the TOPCon cell according to any one of claims 1 to 8.