Photovoltaic cell with light reflection structure, photovoltaic module and photovoltaic system

Abstract

The invention relates to the technical field of photoelectricity, in particular to a photovoltaic cell with a light reflection structure, a photovoltaic module and a system, and the photovoltaic cell comprises a semiconductor substrate which is used for absorbing light energy and generating current; the fine grid metal conductive electrode is arranged on the surface of the semiconductor substrate and is used for collecting current on the surface of the semiconductor substrate; the main grid metal guide wire is vertically connected with the fine grid metal conductive electrode and is used for collecting the current on the fine grid metal conductive electrode and outputting the current; and the plurality of metal reflecting layers are used for reflecting light energy penetrating through the semiconductor substrate to the semiconductor substrate, and the metal reflecting layers only cover areas among the fine grid metal conductive electrodes. According to the invention, on the basis of the formation of the semiconductor substrate, the fine grid metal conductive electrode and the main grid metal guide wire and the action of light energy, the light energy penetrating through the semiconductor substrate can be reflected back to the semiconductor substrate after reaching the metal reflecting layer, so that the full utilization of the light energy is realized.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic technologies, and particularly to a photovoltaic cell with a light reflection structure. Background Art

[0002] As a sunrise industry, the optoelectronic technology industry is experiencing unprecedented development globally. Especially in China, both the market scale and technological innovation show strong growth momentum. A photovoltaic cell, also known as a solar cell, is a device that can directly convert solar energy into electrical energy.

[0003] The patent document with the publication number CN117976776A discloses a battery chip, which includes a monocrystalline silicon layer. There is a matte structure layer on one side of the monocrystalline silicon layer, and a polished structure layer on the other side of the monocrystalline silicon layer. The preparation method adopted includes polishing and cleaning a semiconductor substrate; performing an oxidation treatment on the first surface of the semiconductor substrate to form an oxide film on the first surface; performing a phosphorus source treatment on the second surface of the semiconductor substrate to purify impurities in the semiconductor substrate; performing a texturing operation on the semiconductor substrate, forming a polished structure layer on the first surface under the isolation of the oxide film, and forming a structure layer different from the first surface on the second surface of the semiconductor substrate; removing impurities and the oxide film on the semiconductor substrate by pickling; depositing silicon layers on the first surface and the second surface of the semiconductor substrate respectively; depositing transparent conductive film layers on the silicon layers of the semiconductor substrate respectively, and then printing and curing to obtain the battery chip.

[0004] However, in the existing battery chips, the first surface of the semiconductor substrate is processed to form a polished structure layer, which directly acts on the semiconductor substrate, with high operation difficulty, and the contact area between the printed electrode and the surface of the semiconductor substrate is reduced, resulting in low current collection efficiency. Summary of the Invention

[0005] Therefore, the present invention provides a photovoltaic cell with a light reflection structure, which can make the transmitted light re-enter the battery chip by setting a metal reflection layer, improve the light energy utilization rate, and greatly enhance the current collection efficiency due to the large contact area between the electrode and the semiconductor substrate.

[0006] To achieve the above object, on the one hand, the present invention provides a photovoltaic cell with a light reflection structure, including:

[0007] A semiconductor substrate for absorbing light energy and generating current;

[0008] A plurality of fine grid metal conductive electrodes arranged in parallel on the surface of the semiconductor substrate for collecting the current on the surface of the semiconductor substrate;

[0009] A metal reflective layer, used to reflect light energy transmitted through the semiconductor substrate to the semiconductor substrate, the metal reflective layer covering the area between the fine-grid metal conductive electrodes;

[0010] The semiconductor substrate has a first surface, the first surface is close to the metal reflective layer, and the orthographic projection area of the metal reflective layer on the semiconductor substrate is the area of the first surface of the semiconductor substrate minus the orthographic projection area of the fine gate metal conductive electrode on the semiconductor substrate.

[0011] Furthermore, it also includes a main grid metal wire, which is connected to the fine grid metal conductive electrode to collect the current on the fine grid metal conductive electrode and output it. A plurality of the fine grid metal conductive electrodes are arranged between any two adjacent main grid metal wires. The metal reflective layer does not cover the main grid metal wires, and the arrangement density of the fine grid metal conductive electrodes is greater than the arrangement density of the main grid metal wires.

[0012] Furthermore, it also includes a transparent conductive film layer for conducting the current generated by the semiconductor substrate.

[0013] Furthermore, the transparent conductive film layer is an ITO film, and the material of the fine grid metal conductive electrode and the main grid metal conductive wire is a metal element or a metal alloy.

[0014] Furthermore, the metal reflective layer is an aluminum layer, a silver layer, a nickel layer or a metal alloy layer.

[0015] Furthermore, it also includes a magnesium fluoride layer, which is used to cooperate with the metal reflective layer to form a multi-medium reflective film.

[0016] Furthermore, the metal reflective layer is single-sided reflective, and the reflective surface of the metal reflective layer is arranged on a side close to the semiconductor substrate.

[0017] Furthermore, the thickness of the semiconductor substrate is between 70 mm and 250 mm.

[0018] In a second aspect, the present invention further provides a photovoltaic module, comprising a photovoltaic cell having a light reflection structure, wherein adjacent photovoltaic cells are electrically connected by main grid metal wires.

[0019] In a third aspect, the present invention further provides a photovoltaic system, comprising the above-mentioned photovoltaic module.

[0020] Compared with the prior art, the beneficial effect of the present invention lies in that the basis for the interaction with light energy is formed by the semiconductor substrate, the fine-grid metal conductive electrode and the main-grid metal conductive wire. In actual applications, light enters the semiconductor substrate to excite electrons in the semiconductor substrate. Since the actual thickness of the semiconductor substrate is small, the light can penetrate more easily. Therefore, a metal reflective layer is provided on the other surface of the semiconductor substrate close to the side of the semiconductor substrate for reflection, so that the light energy passing through the semiconductor substrate can be reflected back to the semiconductor substrate after reaching the metal reflective layer, thereby achieving full utilization of light energy, effectively exciting electrons in the semiconductor substrate, and generating more electrical energy to be collected by the fine-grid metal conductive electrode, thereby improving the efficiency of light energy utilization.

[0021] In particular, the gate layer structure can achieve a current guiding effect and effectively collect the current formed on the surface of the semiconductor substrate. Due to the good conductivity of the copper wire and the aluminum wire, the current formed by the directional movement of electrons excited by light energy on the surface of the semiconductor substrate can be effectively collected. In the embodiment of the present invention, the gate layer structure can not only serve as the basis for setting up the metal reflective layer, but also take into account the role of the conductive electrode, which greatly saves the preparation raw materials and can effectively reduce the production cost.

[0022] In particular, the fine-grid metal conductive electrodes are distributed between the main grid metal wires, so that the current generated by the photogenerated electrons on the surface of the cell can be collected more quickly, and the distance that the current is conducted on the fine-grid metal conductive electrodes is shortened, thereby reducing the loss of the current during the transmission process. The fine-grid metal conductive electrodes arranged on the back of the semiconductor substrate cover part of the surface of the cell, so that the photogenerated current can be collected more fully, and the photoelectric conversion efficiency of the cell can be improved. Since the fine-grid metal conductive electrodes make the current transmission path shorter, the resistance loss of the current on the fine-grid metal conductive electrodes is relatively small, which improves the overall efficiency of the cell. The fine-grid metal conductive electrodes are usually made of highly conductive metal materials, which can effectively transmit the current from the surface of the cell to the main grid metal wires, further reducing the resistance loss. In the main grid metal wire-free technology, metal wires are used to connect the cell. After the number of main grid metal wires increases, the fine-grid metal conductive electrodes can be made thinner, which can reduce the use of high-cost materials such as silver paste, thereby reducing the manufacturing cost of the cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the side structure of a photovoltaic cell with a light reflection structure in an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of a grid layer structure in a photovoltaic cell with a light reflection structure in an embodiment of the present invention;

[0025] Figure 3Schematic plan view of a photovoltaic cell with a light reflection structure in an embodiment of the present invention.

[0026] Reference numerals:

[0027] 1, semiconductor substrate; 2, main grid metal wire; 3, metal reflection layer; 4, fine grid metal conductive electrode; 5, transparent conductive thin film layer. Detailed implementation manners

[0028] In order to make the objectives and advantages of the present invention clearer, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0030] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0031] In addition, it should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] Please refer to Figure 1 As shown, the photovoltaic cell with a light reflection structure provided by the embodiment of the present invention includes:

[0033] A semiconductor substrate 1 for absorbing light energy and generating current;

[0034] Fine grid metal conductive electrodes 4 are arranged in parallel on the surface of the semiconductor substrate for collecting the current on the surface of the semiconductor substrate;

[0035] The main grid metal wire 2 is connected to the fine grid metal conductive electrode, and is used to collect and output the current on the fine grid metal conductive electrode. A plurality of the fine grid metal conductive electrodes are arranged between any two adjacent main grid metal wires. The metal reflective layer does not cover the main grid metal wire, and the setting density of the fine grid metal conductive electrode is greater than that of the main grid metal wire;

[0036] A plurality of metal reflective layers 3 are used to reflect the light energy transmitted through the semiconductor substrate back to the semiconductor substrate, and the metal reflective layer covers the area between the fine grid metal conductive electrodes;

[0037] The semiconductor substrate has a first surface, the first surface is close to the metal reflective layer, and the orthographic projection area of the metal reflective layer on the semiconductor substrate is the area of the first surface of the semiconductor substrate minus the orthographic projection area of the fine grid metal conductive electrode on the semiconductor substrate.

[0038] Specifically, the photovoltaic cell with a light reflection structure provided by the embodiment of the present invention includes a semiconductor substrate, a grid structure layer and a metal reflective layer. In practical applications, grid structure layers are arranged on both sides of the semiconductor substrate, or a grid layer structure can be arranged on the surface of the semiconductor substrate, or other setting modes can be adopted, which will not be enumerated one by one here. The grid structure layer is used to collect and output the current on the surface of the semiconductor substrate to ensure the efficient collection of the current on the surface of the semiconductor substrate. The grid structure layer includes main grid metal wires and fine grid metal conductive electrodes. In the actual preparation process, the main grid metal wires are usually printed on the surface of the semiconductor substrate, and then the fine grid metal conductive electrodes are printed. The fine grid metal conductive electrodes are lapped on the main grid metal wires. Usually, the setting density of the fine grid metal conductive electrodes is large, which can collect the current formed on the surface of the semiconductor substrate due to the action of light energy to the greatest extent. However, if the density is too large, it will affect the area of the metal reflective layer and make it smaller, resulting in less reflected light. Therefore, the density of the fine grid metal conductive electrodes in the embodiment of the present invention cannot be too large, and the problems of both the reflection area and the collection efficiency need to be considered. The metal reflective layer is arranged on the side of the grid structure layer away from the semiconductor substrate, and the metal reflective layer covers the area between the fine grid metal conductive electrodes, so that the main grid metal wires can be electrically connected to other main grid metal wires, thereby forming a battery string and greatly improving the photovoltaic power generation. In addition, by arranging a metal reflective layer on the first surface of the semiconductor substrate and ensuring that the orthographic projection area of the metal reflective layer is the area of the first surface of the semiconductor substrate minus the orthographic projection areas of the fine grid metal conductive electrodes and the main grid metal wires, the metal reflective layer basically covers the semiconductor substrate, which can effectively reduce the light projection loss, reflect it back into the semiconductor substrate as much as possible, increase the light propagation path in the semiconductor substrate, improve the light absorption rate, and thus improve the photoelectric conversion efficiency of the photovoltaic cell. In the embodiment of the present invention, the first surface can be the back surface of the semiconductor substrate.

[0039] In an optional embodiment, gate structure layers are provided on the upper and lower surfaces of the semiconductor substrate, and a metal reflective layer is provided on the side of the gate structure layer away from the semiconductor substrate. The side of the metal reflective layer close to the semiconductor substrate is used for reflection, and the side of the metal reflective layer away from the semiconductor substrate is transparent, so that light can pass through the metal reflective layer and the gate layer structure to reach the semiconductor substrate, thereby achieving the excitation of the state of electrons in the semiconductor substrate, and then moving in a directed manner to form current.

[0040] In another optional embodiment, a gate layer structure is provided on one surface of the semiconductor substrate, and the gate layer structure includes a vertically arranged fine gate metal conductive electrode and a main gate metal wire, wherein the fine gate metal conductive electrode and the main gate metal wire are both arranged on one surface of the semiconductor substrate, and the fine gate metal conductive electrode and the main gate metal wire are respectively connected to a negative electrode and a positive electrode, thereby realizing the extraction of current from the surface of the semiconductor substrate. By providing a metal reflective layer on the semiconductor substrate, and the metal reflective layer does not cover the gate layer structure, light entering from the other surface of the semiconductor substrate can return to the semiconductor substrate under the action of the metal reflective layer after passing through the semiconductor substrate, thereby realizing the reuse of light, improving the excitation of electrons in the semiconductor substrate by light, and improving the light utilization efficiency.

[0041] Specifically, the embodiment of the present invention forms a basis for the interaction with light energy through a semiconductor substrate, a fine-grid metal conductive electrode and a main-grid metal conductive wire. In actual applications, light enters the semiconductor substrate to excite electrons in the semiconductor substrate. Since the actual thickness of the semiconductor substrate is relatively small, light can penetrate more easily. Therefore, a metal reflective layer is provided on the other surface of the semiconductor substrate close to the side of the semiconductor substrate for reflection, so that the light energy passing through the semiconductor substrate can be reflected back to the semiconductor substrate after reaching the metal reflective layer, thereby achieving full utilization of light energy, effectively exciting electrons in the semiconductor substrate, and generating more electrical energy, which is then collected by the fine-grid metal conductive electrode, thereby improving the efficiency of light energy utilization.

[0042] Specifically, the fine grid metal conductive electrode and the main grid metal conductive wire are made of a single metal or a metal alloy.

[0043] Specifically, in an optional embodiment of the present invention, a photovoltaic cell with a light reflective structure includes a semiconductor substrate, and a gate layer structure is arranged on both sides of the semiconductor substrate, and the main grid metal wire in the gate layer structure is a copper wire, and the fine grid metal conductive electrode is an aluminum wire, other metal wire or conductive paste, which is not limited here, and a metal reflective layer covering the aluminum wire, and the metal reflective layer covers the fine grid metal conductive electrode made of aluminum wire. Therefore, the gate layer structure can realize the current conduction function and effectively collect the current formed on the surface of the semiconductor substrate. Due to the good conductivity of copper wire and aluminum wire, the current formed by the directional movement of electrons excited by light energy on the surface of the semiconductor substrate can be effectively collected. In the embodiment of the present invention, the gate layer structure can not only serve as the basis for setting the metal reflective layer, but also take into account the role of the conductive electrode, which greatly saves the preparation raw materials and can effectively reduce the production cost.

[0044] In actual application, when sunlight passes through the gate layer structure arranged on the first surface of the semiconductor substrate, the sunlight interacts with the semiconductor substrate to excite the electrons therein into an excited state. The electrons in the excited state are unstable and can generate current once they move in a directed manner. However, due to the small thickness of the semiconductor substrate, the sunlight will directly pass through the semiconductor substrate and cannot fully interact with the semiconductor substrate, thereby generating fewer electrons. However, since a metal reflective layer is also arranged on the gate layer structure arranged on the second surface of the semiconductor substrate, the sunlight after transmission can be reflected again by the metal reflective layer and then return to the semiconductor substrate to interact with the semiconductor substrate again. After the sunlight interacts with the semiconductor substrate and is emitted from the semiconductor substrate, a metal reflective layer can also be arranged on the side of the gate layer structure arranged on the first surface of the semiconductor substrate close to the semiconductor substrate, and then metal reflective layers are arranged on the upper and lower surfaces of the semiconductor substrate, so that the sunlight can be captured by the semiconductor substrate and fully utilized to excite the electrons therein, thereby generating more electrical energy to be drained and utilized by the gate layer structure, thereby effectively improving the utilization efficiency of sunlight.

[0045] Specifically, it also includes a transparent conductive film layer 5 for conducting the current generated by the semiconductor substrate. The transparent conductive film layer is an ITO film. The metal reflective layer is a single-sided reflective layer, and the reflective surface of the metal reflective layer is arranged on a side close to the semiconductor substrate.

[0046] Specifically, the ITO film in the embodiment of the present invention can be used as a substrate for the gate layer structure. Due to its transparent properties, light can penetrate into the semiconductor substrate, and can also collect and transmit electrons, thereby improving the utilization efficiency of sunlight.

[0047] Specifically, in another alternative embodiment of the present invention, a photovoltaic cell with a light reflection structure includes a semiconductor substrate, an ITO film, a grid layer structure, and a metal reflection layer. Generally, the ITO film is disposed on the side of the fine grid metal conductive electrode close to the semiconductor substrate. The ITO film is close to the semiconductor substrate and is uniformly and closely arranged on the surface of the semiconductor substrate, capable of capturing all the electrons on the surface of the semiconductor substrate. In practical applications, the metal reflection layer is a single-sided reflection layer, which can transmit sunlight unidirectionally into the grid layer structure and the ITO film to reach the semiconductor substrate when receiving sunlight. After the sunlight penetrates the semiconductor substrate and enters the grid layer structure provided with the metal reflection layer, at this time, using the metal reflection layer with a single-sided reflection film structure, there is still a chance to re-utilize the sunlight by the semiconductor substrate through the ITO film again, thereby effectively improving the transmittance of sunlight and the utilization efficiency of sunlight.

[0048] Specifically, the photovoltaic cell with a light reflection structure in the embodiment of the present invention further includes a magnesium fluoride layer, which is used to cooperate with the metal reflection layer to form a multi-media reflection film.

[0049] Specifically, in practical applications, the magnesium fluoride layer and the metal reflection layer are arranged adjacent to each other to form a multi-media reflection film. When sunlight passes through the semiconductor substrate and enters the multi-media reflection film formed by the magnesium fluoride layer and the metal reflection layer, since the refractive index of magnesium fluoride is less than that of the metal reflection layer, reflection is formed at the interface between the two, causing the sunlight to re-enter the semiconductor substrate, thereby realizing the effective utilization of light energy.

[0050] Specifically, by arranging the magnesium fluoride layer and the metal reflection layer adjacent to each other to form a multi-media reflection film, when the light exits the semiconductor substrate and enters the magnesium fluoride layer, a reflection interface will be formed at the interface between the magnesium fluoride layer and the metal reflection layer, and the light can be reflected back into the semiconductor substrate. This structural design can increase the propagation path of light in the battery, thereby improving the light absorption rate and further enhancing the photoelectric conversion efficiency of the battery.

[0051] Specifically, the metal reflection layer is an aluminum layer, a silver layer, a nickel layer, or a metal alloy layer.

[0052] Specifically, in practical applications, the metal reflection layer can be an aluminum layer, a silver layer, or a nickel layer, as long as it can perform reflection. Preferably, an aluminum layer is used as the metal reflection layer, which can save costs.

[0053] Specifically, a plurality of the fine grid metal conductive electrodes are arranged between any two adjacent main grid metal wires.

[0054] Specifically, the fine grid metal conductive electrodes are distributed between the main grid metal wires, enabling the current generated by photo-generated electrons on the surface of the cell to be collected more quickly. The conduction distance of the current on the fine grid metal conductive electrodes is shortened, thereby reducing the loss of current during transmission. The fine grid metal conductive electrodes cover a part of the surface of the cell, which can collect photo-generated current more fully and improve the photoelectric conversion efficiency of the cell. Since the fine grid metal conductive electrodes make the current transmission path shorter and the resistance loss of the current on the fine grid metal conductive electrodes is relatively small, the overall efficiency of the cell is improved. The fine grid metal conductive electrodes are usually made of metal materials with high conductivity and can effectively transmit the current from the surface of the cell to the main grid metal wires, further reducing the resistance loss. In the multi-main grid metal wire technology, after the number of main grid metal wires increases, the fine grid metal conductive electrodes can be made thinner, which can reduce the use of high-cost materials such as silver paste and thus reduce the manufacturing cost of the cell.

[0055] Specifically, the thickness of the semiconductor substrate is between 70 mm and 250 mm.

[0056] Specifically, the thickness of the semiconductor substrate affects its heat conduction performance. A thicker semiconductor substrate can better conduct the heat generated by the device to the heat dissipation system, thereby improving the heat management efficiency and ensuring the stable operation of the device in a high-temperature environment. By reasonably setting the thickness of the semiconductor substrate, the thermal resistance between the semiconductor substrate and the radiator is effectively reduced, making it easier for the heat to be conducted from the semiconductor substrate to the radiator and further improving the heat dissipation effect. The thickness of the semiconductor substrate is set between 70 mm and 250 mm to comprehensively consider various factors such as mechanical strength, heat management, electrical performance, manufacturing process compatibility, and cost-benefit balance to meet the requirements of different application scenarios and ensure the performance and reliability of the semiconductor device.

[0057] Example 1

[0058] The photovoltaic cell with a light reflection structure provided by an embodiment of the present invention includes a semiconductor substrate, a grid structure layer, and a metal reflection layer. The metal reflection layer is disposed between the semiconductor substrate and the grid structure layer, on the side of the grid structure layer close to the semiconductor substrate, and the metal reflection layer covers the fine grid metal conductive electrodes of the grid structure layer and the area therebetween. This structural design aims to improve the utilization rate of light, reduce the reflection loss of light, and thus improve the photoelectric conversion efficiency. Generally, in practical applications, an ITO film for absorbing photoelectrons is further disposed between the semiconductor substrate and the grid layer structure. The high transmittance and low reflectivity characteristics of the ITO film ensure that more light can enter the semiconductor substrate and be absorbed, reducing the light scattering and reflection losses. By optimizing the preparation process of the ITO film, its resistivity can be reduced, the series resistance can be decreased, and the current transmission efficiency can be improved, thereby enhancing the electrical performance of the cell. By optimizing the light reflection structure, the photoelectric conversion efficiency, stability, and environmental adaptability of the photovoltaic cell are significantly improved, while the production cost is reduced. This structural design is applicable not only to various forms of cell but also to the construction of high-efficiency tandem cells.

[0059] Embodiment 2

[0060] The photovoltaic cell with a light reflection structure provided by an embodiment of the present invention includes a semiconductor substrate, a grid structure layer, a first metal reflection layer, an ITO film, and a second metal reflection layer. The ITO film is disposed between the semiconductor substrate and the grid layer structure. The first metal reflection layer is disposed on the side of the grid structure layer close to the semiconductor substrate, and the second metal reflection layer is disposed on the side of the ITO film close to the grid structure layer. The first metal reflection layer and the second metal reflection layer are both single-sided reflection layers. Through the multi-layer film structure, high light transmittance can be achieved on one side, while high reflectivity can be achieved on the other side. For example, based on the film structure of fluorine-doped tin oxide / silver / fluorine-doped tin oxide, high transmittance (average transmittance of 82.52%) can be achieved in the visible light band, and high reflectivity (average reflectivity of 81.46%) can be achieved in the infrared band, thus meeting the requirements of light transmission on one side and light reflection on the other side. The first metal reflection layer and the second metal reflection layer reflect the light that passes through the cell back into the cell, increasing the opportunities for multiple reflections and absorptions of light in the cell, thereby improving the utilization rate of light, and further increasing the current formed on the cell surface and improving the photoelectric conversion efficiency. The present invention is applicable to various forms of cell, including the cells in the prior art, the cells including the grid layer structure, and the cells only including the fine grid metal conductive electrodes, and has wide applicability. The embodiments of the present invention are applicable not only to single cells but also to cell strings, and can achieve higher photoelectric conversion efficiency. By optimizing the light reflection structure, the photoelectric conversion efficiency, stability, and environmental adaptability of the photovoltaic cell are significantly improved, while the production cost is reduced.

[0061] Embodiment 3

[0062] The photovoltaic cell with a light reflection structure provided by an embodiment of the present invention includes a semiconductor substrate, an ITO thin film, and a metal reflection layer. The metal reflection layer is disposed on one side of the ITO thin film close to the semiconductor substrate. A metal reflection layer is plated behind the ITO thin film by means of vacuum coating such as thermal evaporation or magnetron sputtering. These two methods are used to form a reflective surface on the ITO thin film to return the light transmitted through the semiconductor substrate. In this way, the light can be reflected and then absorbed by the semiconductor substrate again, thereby improving the light illumination efficiency. The semiconductor substrate can usually be a silicon substrate. At this time, the metal reflection layer can also play a role in current conduction and can be regarded as a fine grid metal conductive electrode to collect and export the current on the semiconductor substrate, improving the utilization efficiency of light energy.

[0063] In practical applications, the components on both sides of the semiconductor substrate are symmetrically arranged with the semiconductor substrate as the center in a mirror image manner, enabling the semiconductor substrate to be reflected multiple times between the two metal reflection layers, thereby improving the utilization efficiency of light energy.

[0064] An embodiment of the present invention further provides a photovoltaic module, including a photovoltaic cell with a light reflection structure, and adjacent photovoltaic cells are electrically connected by main grid metal conducting wires.

[0065] Specifically, in the actual preparation process, the metal reflection layer covers the fine grid metal conductive electrode and the area therebetween, while the main grid metal conducting wire is reserved because the main grid metal conducting wire needs to be connected in series during electrical connection. Usually, after leaving the position of the main grid metal conducting wire, the metal reflection layer can be plated. Fine grid metal conductive electrodes for collecting photo-generated electrons are fabricated on the front and back surfaces of the battery chip, so that a number of uniformly arranged fine grid metal conductive electrodes are formed on the front and back surfaces of the battery chip; the fine grid metal conductive electrodes are perpendicular to the main grid metal conducting wire; in the specific implementation process, a number of main grid metal conducting wires capable of converging the fine grid metal conductive electrodes and leading them out from the battery chip are formed by means of hot pressing.

[0066] Specifically, in the photovoltaic module provided by the embodiment of the present invention, fine grid metal conductive electrodes for collecting photo-generated electrons are fabricated on the front and back surfaces of the cell, and the fine grids are perpendicularly arranged with respect to the main grids, which can more effectively collect photo-generated carriers, reduce the recombination of carriers, and thus improve the photoelectric conversion efficiency of the cell. By forming the main grid metal leads through electrical connection, compared with the traditional printed main grids, the resistance of the main grids can be reduced, and the loss of current during transmission can be decreased, further improving the output power of the cell. The metal reflective layer covers the fine grid metal conductive electrodes, which can protect the fine grids and prevent them from being damaged during subsequent processes, improving the stability and reliability of the cell. On the premise of retaining the main grid metal leads, through reasonable design and processes, the complexity of the cell electrode structure is reduced, making the overall structure of the cell more concise, which is conducive to improving the production efficiency and quality control of the cell. By adopting the combination of fine grid metal conductive electrodes and main grid metal leads, compared with the traditional all-silver paste printed electrodes, the amount of silver paste can be significantly reduced, thereby reducing the production cost of the cell. After leaving the position for the main grid metal leads, the metal reflective layer is plated, and this precise process control can improve the material utilization rate, reduce material waste, and further lower the cost. Combining the preparation of the metal reflective layer with the formation of the electrodes reduces some process steps, making the entire production process of the cell more concise and efficient, which helps to improve the production efficiency. The process of hot pressing the metal leads to form the main grid metal leads is easy to realize automated operation, which can improve the production consistency and stability, meet the requirements of large-scale automated production, and further enhance the production efficiency.

[0067] The embodiment of the present invention also provides a photovoltaic system, including the above-mentioned photovoltaic module.

[0068] The photovoltaic system in the embodiment of the present invention includes a photovoltaic module and can achieve the same technical effects, which will not be elaborated herein.

[0069] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0070] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photovoltaic cell with a light reflection structure, characterized in that, include: The semiconductor substrate absorbs light energy and generates electric current; A plurality of fine-grid metal conductive electrodes are arranged in parallel on the surface of the semiconductor substrate to collect current on the surface of the semiconductor substrate; A metal reflective layer, used to reflect light energy transmitted through the semiconductor substrate to the semiconductor substrate, the metal reflective layer covering the area between the fine-grid metal conductive electrodes; The semiconductor substrate has a first surface, which is close to the metal reflective layer. The orthographic projection area of the metal reflective layer on the semiconductor substrate is the area of the first surface of the semiconductor substrate minus the orthographic projection area of the fine gate metal conductive electrode and the main gate metal wire on the semiconductor substrate.

2. The photovoltaic cell with a light reflection structure according to claim 1, wherein The main grid metal wire is connected to the fine grid metal conductive electrode to collect and output the current on the fine grid metal conductive electrode. A plurality of the fine grid metal conductive electrodes are arranged between any two adjacent main grid metal wires. The metal reflective layer does not cover the main grid metal wire. The arrangement density of the fine grid metal conductive electrodes is greater than the arrangement density of the main grid metal wire.

3. The photovoltaic cell with a light reflection structure according to claim 1, characterized in that, It also includes a transparent conductive film layer for conducting the current generated by the semiconductor substrate.

4. The photovoltaic cell with a light reflection structure according to claim 1, characterized in that, The transparent conductive film layer is an ITO film, and the material of the fine grid metal conductive electrode and the main grid metal conductive wire is a metal element or a metal alloy.

5. The photovoltaic cell with a light reflection structure according to any one of claims 1-4, characterized in that, The metal reflective layer is an aluminum layer, a silver layer, a nickel layer or a metal alloy layer.

6. The photovoltaic cell with a light reflection structure according to claim 3, characterized in that, It also includes a magnesium fluoride layer, which is used to cooperate with the metal reflection layer to form a multi-medium reflection film.

7. The photovoltaic cell with a light reflection structure according to claim 1, characterized in that, The metal reflection layer is single-sided reflective, and the reflection surface of the metal reflection layer is arranged on a side close to the semiconductor substrate.

8. The photovoltaic cell with a light reflection structure according to claim 2, characterized in that, The thickness of the semiconductor substrate is between 70 mm and 250 mm.

9. A photovoltaic module, characterized in that, The invention comprises a photovoltaic cell with a light reflection structure as claimed in any one of claims 1 to 8, wherein adjacent photovoltaic cells are electrically connected by main grid metal wires.

10. A photovoltaic system, characterized in that, Comprising the photovoltaic module as claimed in claim 9.

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