High-efficiency back contact silicon solar cell and photovoltaic module

Abstract

This invention discloses a high-efficiency back-contact silicon solar cell and photovoltaic module, belonging to the field of solar cell technology. The structure includes a silicon substrate. The front side of the silicon substrate, from the inside out, includes a front surface passivation layer and an anti-reflection layer. The back side of the silicon substrate adopts a partitioned design, including a periodically arranged first doped region, a floating gate region, and a second doped region, with the floating gate region located between the first and second doped regions. The floating gate region includes n floating gate portions and n+1 isolation portions, where n≥1 and n is a positive integer. Each floating gate portion includes a floating gate disposed on the outer surface of the first passivation layer. Isolation portions isolate the floating gate portions from each other, from the floating gate portion to the first doped region, and from the floating gate portion to the second doped region. This invention optimizes the lateral transport path of photogenerated carriers in the solar cell through the floating gate design, suppresses carrier recombination behavior, improves the utilization rate of photogenerated carriers, and ultimately further improves the photoelectric conversion efficiency of the back-contact solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a high-efficiency back-contact silicon solar cell and photovoltaic module. Background Technology

[0002] Photovoltaic technology is a crucial technological means to achieve energy structure transformation and move towards sustainable development. Among these technologies, silicon solar cells are currently the mainstream product in the photovoltaic market. Over the past few decades, the structure of silicon solar cells has evolved from aluminum back surface field (Al-BSF) solar cells to passivated emitter and back-mounted (PERC) solar cells, and then to tunneling silicon oxide passivated contact (TOPCon), heterojunction (HJT), and back contact (BC) solar cells, with the photoelectric conversion efficiency of these devices gradually improving. Looking at the development of silicon solar cell structures, it can be seen that its essence lies in continuously optimizing the generation, transport, and recombination behavior of charge carriers. Therefore, how to further optimize the generation, transport, and recombination behavior of charge carriers is key to designing the next generation of high-efficiency silicon solar cell structures.

[0003] Chinese patent document CN120187160A discloses a back-contact solar cell with a dual passivation structure. The front side, from the outside in, comprises: an anti-reflection film, a textured surface, and an N-type monocrystalline silicon wafer. The back side is divided into a back field region, an emitter region, and an isolation region between the back field region and the emitter region. The back field region, from the outside in, comprises: a metal electrode, an anti-reflection film, a second phosphorus-doped polycrystalline silicon layer, a second tunneling oxide layer, a first phosphorus-doped polycrystalline silicon layer, a first tunneling oxide layer, and an N-type monocrystalline silicon wafer. The emitter region, from the outside in, comprises: a metal electrode, an anti-reflection film, a transparent conductive film, a boron-doped amorphous silicon layer, an intrinsic amorphous silicon layer, and an N-type monocrystalline silicon wafer. The isolation region, from the outside in, comprises: an anti-reflection film, a textured surface, and an N-type monocrystalline silicon wafer. This invention can significantly improve the conversion efficiency of back-contact solar cells.

[0004] Chinese patent document CN118763131A discloses a solar cell comprising a silicon substrate. The back side of the silicon substrate includes alternating first and second doped regions, with an isolation region between adjacent first and second doped regions. In a first target region on the surface of a first textured structure, the average lateral dimension of the first target micro-unit structure is d1 target. The front side of the silicon substrate has a second micro-unit structure, and multiple second micro-unit structures form a second textured structure. In a second target region on the surface of the second textured structure, the average lateral dimension of the second target micro-unit structure is d2 target. Since d1 target < d2 target, the utilization rate of light can be improved, thereby improving the photoelectric conversion efficiency of the back-contact solar cell.

[0005] Chinese patent document CN119894152A discloses a passivated contact back-contact solar cell. This cell comprises a crystalline silicon substrate. The front side of the crystalline silicon substrate is a passivation antireflection layer, and the back side, from the inside out, consists of a first tunneling layer, a first polycrystalline silicon layer, a second tunneling layer, a second polycrystalline silicon layer, a passivation layer, and a metal electrode. The first polycrystalline silicon layer includes a first n+ polycrystalline silicon region, a first p+ polycrystalline silicon region, and a first isolation region. The second polycrystalline silicon layer includes a second n+ polycrystalline silicon region, a second p+ polycrystalline silicon region, and a second isolation region. The boron doping concentration in the first p+ polycrystalline silicon region is lower than that in the second p+ polycrystalline silicon region, and the phosphorus doping concentration in the first n+ polycrystalline silicon region is lower than that in the second n+ polycrystalline silicon region. This invention can simultaneously achieve low metal contact recombination, low non-metal contact region recombination, and low contact resistivity, thereby improving the cell's open-circuit voltage and conversion efficiency.

[0006] While the aforementioned technologies optimize carrier and light management, developing novel back-contact solar cells based on these technologies is crucial for achieving higher theoretical efficiency limits. Summary of the Invention

[0007] This invention provides a high-efficiency back-contact silicon solar cell. By introducing a floating grid design into the silicon solar cell, the lateral transport path of photogenerated carriers is optimized, the recombination behavior of carriers is suppressed, the utilization rate of photogenerated carriers is improved, and ultimately the photoelectric conversion efficiency of the back-contact solar cell is further improved.

[0008] The specific technical solution adopted is as follows: A high-efficiency back-contact silicon solar cell includes a silicon substrate. The front side of the silicon substrate includes a front surface passivation layer and an anti-reflection layer from the inside to the outside. The back side of the silicon substrate adopts a partitioned design, and a first passivation layer is disposed on its surface. The back side of the silicon substrate includes a periodically arranged first doped region, a floating gate region, and a second doped region, with the floating gate region located between the first doped region and the second doped region; The floating gate region includes n floating gate portions and n+1 isolation portions, where n≥1 and n is a positive integer; the floating gate portion includes a floating gate disposed on the outer surface of the first passivation layer; the floating gate portions are isolated from each other, from the floating gate portion to the first doped region, and from the floating gate portion to the second doped region through the isolation portions; When the silicon substrate is n-type doped, the work function of the floating gate is less than the work function of the silicon substrate; When the silicon substrate is p-type doped, the work function of the floating gate is greater than the work function of the silicon substrate; The first doped region includes a first doped semiconductor layer and a metal electrode disposed on the outer surface of the first passivation layer; The second doped region includes a second doped semiconductor layer and a metal electrode disposed on the outer surface of the first passivation layer.

[0009] In this invention, the floating gate structure differs from the first and second doped semiconductor layers. The floating gate does not contact the metal electrode, and its function also differs from the first and second doped semiconductor layers. It is not used for collecting photogenerated carriers, but rather to generate an electric field in the silicon substrate to optimize the transport path of photogenerated carriers. That is, the floating gate does not directly contact the silicon substrate, metal electrode, first doped region, or second doped region, resembling an isolated island, yet its physical properties are similar to those of a gate, hence the name "floating gate." Introducing a floating gate design into silicon solar cells can improve the photoelectric conversion efficiency of back-contact solar cells.

[0010] Furthermore, when the silicon substrate is n-type doped, the lateral width of the first doped region in each periodic cell must be greater than the sum of the lateral widths of the floating gate region and the second doped region; when the silicon substrate is p-type doped, the lateral width of the second doped region in each periodic cell must be greater than the sum of the lateral widths of the floating gate region and the first doped region; in each periodic cell, the lateral width of the first doped region is 1~1000 μm, the lateral width of the second doped region is 1~1000 μm, in the floating gate region, the lateral width of each floating gate is 0.005~100 μm, and the lateral width of each isolation portion is 0.005~100 μm.

[0011] Specifically, the thickness of the front surface passivation layer is 0.001-10 μm, the thickness of the antireflection layer is 0.001-10 μm, and the material of the front surface passivation layer includes, but is not limited to, aluminum oxide, silicon oxide, etc.; the material of the antireflection layer includes, but is not limited to, hydrogenated silicon nitride, hydrogenated silicon oxynitride, etc.

[0012] Specifically, the thickness of the first passivation layer is 0.0001-0.1 μm, and the material of the first passivation layer includes, but is not limited to, silicon oxide, hafnium oxide, hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, aluminum oxide, silicon nitride, silicon oxynitride, etc., which can passivate the dangling bonds on the surface of the silicon substrate.

[0013] Optionally, in the first doped region, a first doped semiconductor layer, a transparent conductive layer, and a metal electrode are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer; in the second doped region, a second doped semiconductor layer, a transparent conductive layer, and a metal electrode are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer.

[0014] Furthermore, the thickness of the first doped semiconductor layer is 0.001-1 μm, the thickness of the second doped semiconductor layer is 0.001-1 μm, and the thickness of the transparent conductive layer is 0.001-1 μm.

[0015] The work function of the material in the first doped semiconductor layer is greater than that of the silicon substrate, including but not limited to boron-doped polycrystalline silicon, boron-doped hydrogenated amorphous silicon, and boron-doped hydrogenated microcrystalline silicon; the work function of the material in the second doped semiconductor layer is less than that of the silicon substrate, including but not limited to phosphorus-doped polycrystalline silicon, phosphorus-doped hydrogenated amorphous silicon, and phosphorus-doped hydrogenated microcrystalline silicon.

[0016] The material for the transparent conductive layer is specifically selected as indium tin oxide or aluminum-doped zinc oxide.

[0017] Optionally, in the first doped region, a first doped semiconductor layer, a second passivation layer, and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer, and a metal electrode is disposed on the outer surface of the first doped semiconductor layer; in the second doped region, a second doped semiconductor layer, a second passivation layer, and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer, and a metal electrode is disposed on the outer surface of the second doped semiconductor layer; in the floating gate portion, a second passivation layer and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the floating gate.

[0018] Furthermore, the thickness and material settings of the first doped semiconductor layer and the second doped semiconductor layer are the same as described above. The thickness of the second passivation layer is 0.0001-0.1 μm, and the thickness of the auxiliary back reflector layer is 0.001-10 μm. The material of the second passivation layer includes, but is not limited to, silicon oxide, hafnium oxide, hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, aluminum oxide, silicon nitride, and silicon oxynitride. The material of the auxiliary back reflector layer includes, but is not limited to, hydrogenated silicon nitride and hydrogenated silicon oxynitride.

[0019] Preferably, the thickness of the floating gate is 0.001-100 μm, and the material of the floating gate can be boron-doped polycrystalline silicon, phosphorus-doped polycrystalline silicon, boron-doped hydrogenated amorphous silicon, or phosphorus-doped hydrogenated amorphous silicon, with a doping concentration of 1×10⁻⁶. 16 -1×10 20 cm -3 .

[0020] The present invention also provides a photovoltaic module, the structure of which includes the aforementioned high-efficiency back-contact silicon solar cell.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The floating grid design proposed in this invention in silicon solar cells further optimizes the transport path of photogenerated carriers near the surface of the silicon substrate corresponding to the isolation region between the positive and negative electrodes (first doped region and second doped region), and more effectively separates electron and hole currents in space, thereby suppressing the recombination behavior of electron-hole pairs.

[0022] (2) The floating grid design introduced in the present invention in silicon solar cells can alleviate the optical loss caused by the positive and negative electrodes (first doped region and second doped region) to a certain extent. On the one hand, the width of the positive and negative electrodes can be reduced by the reasonable design of the floating grid width, thereby reducing parasitic absorption. On the other hand, the probability of incident light being reflected on the back of the cell can be increased by the reasonable selection of the floating grid material, thereby further improving the utilization rate of the absorption layer (silicon substrate) for incident light.

[0023] (3) Introducing a floating grid design into a back-contact silicon solar cell can further improve the photoelectric conversion efficiency of the solar cell. Attached Figure Description

[0024] Figure 1 This is a typical structural diagram of a high-efficiency back-contact silicon solar cell in this invention.

[0025] Figure 2 This is a schematic diagram of the structure of the two solar cells in Example 1.

[0026] Figure 3 This is a schematic diagram of the electric field distribution on the back of the two types of solar cells in Example 1.

[0027] Figure 4 This is a schematic diagram of the distribution of holes and electron currents on the back side during the operation of the two types of solar cells in Example 1.

[0028] Figure 5 The curves showing the efficiency of the high-efficiency back-contact silicon solar cell in Example 1 as a function of floating gate doping concentration are shown.

[0029] Figure 6 This is a schematic diagram of the structure of the two types of solar cells in Example 2.

[0030] Reference numerals in the attached figures: 1 is the antireflection layer, 2 is the front surface passivation layer, 3 is the silicon substrate, 4 is the first passivation layer, 5 is the first doped semiconductor layer, 6 is the floating gate, 7 is the second doped semiconductor layer, 8 is the second passivation layer, 9 is the auxiliary back reflection layer, 10 is the metal electrode, 11 is the first doped region, 12 is the floating gate region, 13 is the second doped region, and 14 is the transparent conductive layer. Detailed Implementation

[0031] To make the objectives, features, and advantages of this invention more apparent and understandable, a detailed description is provided below through specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. Technical features in various embodiments of the invention can be combined appropriately without mutual conflict.

[0032] Unless otherwise specified, the operating methods in the following examples are generally performed under conventional conditions or as recommended by the manufacturer. Contents not described in detail in this specification are prior art known to those skilled in the art. Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0033] A representative structural schematic diagram of the high-efficiency back-contact silicon solar cell provided by this invention is shown below. Figure 1 As shown, it includes a silicon substrate 3. The front side of the silicon substrate 3 includes a front surface passivation layer 2 and an anti-reflection layer 1 from the inside to the outside. The back side of the silicon substrate 3 adopts a partitioned design, and a first passivation layer 4 is provided on its surface. The back side of the silicon substrate includes a first doped region 11, a floating gate region 12, and a second doped region 13 arranged in a periodic manner, with the floating gate region 12 located between the first doped region 11 and the second doped region 13. The floating gate region 12 includes n floating gate portions and n+1 isolation portions. In the figure, n=2. The floating gate portion includes a floating gate 6 disposed on the outer surface of the first passivation layer 4. The floating gate portions are isolated from each other, from the floating gate portion to the first doped region, and from the floating gate portion to the second doped region through the isolation portions. In the first doped region 11, a first doped semiconductor layer 5, a second passivation layer 8, and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4, and a metal electrode is disposed on the outer surface of the first doped semiconductor layer 5; in the second doped region 13, a second doped semiconductor layer 7, a second passivation layer 8, and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4, and a metal electrode is disposed on the outer surface of the second doped semiconductor layer 7; in the floating gate portion, a second passivation layer 8 and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the floating gate 6.

[0034] When the silicon substrate is n-type doped, the work function of the floating gate is less than the work function of the silicon substrate; in each periodic cell, the lateral width of the first doped region must be greater than the sum of the lateral widths of the floating gate region and the second doped region.

[0035] When the silicon substrate is p-type doped, the work function of the floating gate is greater than the work function of the silicon substrate; in each periodic cell, the lateral width of the second doped region must be greater than the sum of the lateral widths of the floating gate region and the first doped region.

[0036] Example 1 like Figure 2 As shown, the left figure is a schematic diagram of a conventional back-contact solar cell structure, and the right figure is a schematic diagram of a high-efficiency back-contact silicon solar cell structure obtained in this embodiment.

[0037] Specifically, in this embodiment, the back-contact solar cell includes a silicon substrate 3. The front surface of the silicon substrate 3, from the inside out, includes a front surface passivation layer 2 and an antireflection layer 1. The antireflection layer 1 is silicon nitride with a thickness of 20 nm, prepared using plasma-enhanced chemical vapor deposition (PECVD). The front surface passivation layer 2 is aluminum oxide with a thickness of 5 nm, prepared using atomic deposition (ALD). The silicon substrate 3 is n-type doped with phosphorus as the dopant, and the doping concentration is 5 × 10⁻⁶. 14 cm -3 The back side of the silicon substrate adopts a partitioned design, including a periodically arranged first doped region 11, a floating gate region 12, and a second doped region 13. A first passivation layer 4 is disposed on its surface. The first passivation layer 4 is hydrogenated amorphous silicon with a thickness of 5 nm and is prepared by PECVD.

[0038] In the first doped region 11, a first doped semiconductor layer 5, a transparent conductive layer 14 and a metal electrode 10 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4; in the second doped region 13, a second doped semiconductor layer 7, a transparent conductive layer 14 and a metal electrode 10 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4.

[0039] In each periodic unit, the first doped semiconductor layer 5 is p-type doped hydrogenated amorphous silicon, with boron as the dopant and a doping concentration of 1×10⁻⁶. 19 cm -3 The first doped semiconductor layer 5 has a work function greater than that of the silicon substrate 3, a thickness of 5 nm, and is prepared using PECVD. The second doped semiconductor layer 7 is n-type doped hydrogenated amorphous silicon, with phosphorus as the dopant and a doping concentration of 1 × 10⁻⁶. 19 cm -3 The work function of the second doped semiconductor layer 7 is less than that of the silicon substrate 3, and its thickness is 5 nm. It is prepared using PECVD. The transparent conductive layer 14 is made of indium tin oxide and has a thickness of 50 nm. It is also prepared using PECVD. The electrode 10 is made of silver and is prepared using screen printing. The width of the first doped region 11 is 300 μm, and the width of the second doped region 13 is 200 μm.

[0040] Compared to the conventional back-contact solar cell shown in the left figure, this invention adds a floating gate region between the first and second doped regions on the back side of the silicon substrate. Specifically, the floating gate 6 is n-type doped hydrogenated amorphous silicon, with phosphorus as the dopant and a doping concentration of 1×10⁻⁶. 14 cm -3 ~ 1×10 20 cm -3The thickness is 5 nm, and it is prepared by PECVD. The width is 50 µm, the number of floating gates is 1, and the distance of the floating gate from the first doped region and the second doped region (the lateral width of the isolation part) is 4 µm.

[0041] Figure 3 To adopt Figure 2 The diagrams illustrate the electric field distribution on the back side of two solar cells obtained from the two designs. The top diagram shows a conventional back-contact solar cell, and the bottom diagram shows the high-efficiency back-contact silicon solar cell of this invention. Since the floating gate is made of n-type doped hydrogenated amorphous silicon, its work function is smaller than that of the silicon substrate, thus generating an electric field between the silicon substrate and the floating gate. After adding the floating gate between the first and second doped regions, the electric field intensity in the near-surface region of the back side of the silicon substrate between the first and second doped regions significantly increases. In particular, the electric field generated by the floating gate in the silicon substrate can cover the entire floating gate region, including the isolation region between the floating gate and the two doped regions.

[0042] Figure 4 To adopt Figure 2 The diagrams illustrate the electron and hole current distributions on the back side of two solar cells obtained from the two designs. The top diagram shows a conventional back-contact solar cell, and the bottom diagram shows the high-efficiency back-contact silicon solar cell of this invention. Because the floating grid region alters the electric field distribution near the surface of the corresponding silicon substrate, the transport path of photogenerated carriers near the surface also changes. In conventional back-contact solar cells, the transport paths of electrons and holes overlap significantly in the silicon substrate corresponding to the isolation region, especially in the near-surface region. However, in the high-efficiency back-contact silicon solar cell, the electric field introduced by the floating grid effectively separates the transport paths of electrons and holes near the surface, thereby reducing the probability of electron-hole recombination.

[0043] Figure 5 This is the curve showing the change in efficiency of a high-efficiency back-contact silicon solar cell with the floating gate doping concentration in this embodiment. It can be seen that the cell efficiency increases with the increase of the floating gate doping concentration. When the floating gate doping concentration reaches 1×10⁻⁶... 18 cm -3 At that time, compared with conventional back-contact solar cells, its photoelectric conversion efficiency increased from 26.7% to 27.31%. Subsequently, when the doping concentration was increased, the photoelectric conversion efficiency no longer showed a significant improvement.

[0044] Example 2 like Figure 6 As shown, the left figure is a schematic diagram of a conventional back-contact solar cell structure, and the right figure is a schematic diagram of a high-efficiency back-contact silicon solar cell structure obtained in this embodiment.

[0045] Specifically, in this embodiment, the back-contact solar cell includes a silicon substrate 3. The front side of the silicon substrate 3, from the inside out, includes a front surface passivation layer 2 and an antireflection layer 1. The antireflection layer 1 is silicon nitride with a thickness of 20 nm, prepared using PECVD. The front surface passivation layer 2 is aluminum oxide with a thickness of 5 nm, prepared using ALD. The silicon substrate 3 is n-type doped with phosphorus as the dopant, and the doping concentration is 5 × 10⁻⁶. 14 cm -3 The back side of the silicon substrate adopts a partitioned design, including a periodically arranged first doped region 11, a floating gate region 12, and a second doped region 13. A first passivation layer 4 is disposed on its surface. The first passivation layer 4 is tunneling silicon oxide with a thickness of 1.2 nm.

[0046] In the first doped region 11, a first doped semiconductor layer 5, a second passivation layer 8, and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4, and a metal electrode is disposed on the outer surface of the first doped semiconductor layer 5; in the second doped region 13, a second doped semiconductor layer 7, a second passivation layer 8, and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer 4, and a metal electrode is disposed on the outer surface of the second doped semiconductor layer 7; in the floating gate portion, a second passivation layer 8 and an auxiliary back reflection layer 9 are sequentially disposed from the inside to the outside on the outer surface of the floating gate 6.

[0047] The first doped semiconductor layer 5 is p-type doped polycrystalline silicon, with boron as the dopant and a doping concentration of 1×10⁻⁶. 20 cm -3 The first doped semiconductor layer, with a thickness of 120 nm, was prepared using PECVD. Its work function is greater than that of the silicon substrate. The second doped semiconductor layer 7 is n-type doped polycrystalline silicon, with phosphorus as the dopant and a doping concentration of 1 × 10⁻⁶. 20 cm -3 The second doped semiconductor layer is 120 nm thick and is prepared by PECVD. The work function of the material in the second doped semiconductor layer is less than that of the silicon substrate. The second passivation layer 8 is aluminum oxide with a thickness of 3 nm and is prepared by ALD. The auxiliary back reflection layer 9 is silicon nitride with a thickness of 20 nm and is prepared by PECVD.

[0048] Specifically, compared to the conventional back-contact solar cell shown in the left figure, the high-efficiency back-contact silicon solar cell adds a floating gate region between the first and second doped regions. Floating gate 6 is n-type doped polycrystalline silicon, with phosphorus as the dopant and a doping concentration of 1×10⁻⁶. 20 cm -3The thickness is 120 nm. The work function of the floating gate is less than that of the silicon substrate. The number of floating gates is 1. The distance (width of the isolation portion) of the floating gate from the first doped region and the second doped region is 4 µm. The width of the first doped region 11 is 300 μm, the width of the second doped region 13 is 200 μm, and the width of the floating gate portion in the floating gate region is 50 μm.

[0049] Specifically, in this embodiment, the photoelectric conversion efficiency of the high-efficiency back-contact silicon solar cell reaches 26.5%, which is 0.4% higher than that of the conventional back-contact solar cell without a floating grid region.

[0050] The embodiments described above provide a detailed explanation of the technical solutions of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency back-contact silicon solar cell, characterized in that, The high-efficiency back-contact silicon solar cell includes a silicon substrate. The front side of the silicon substrate includes a front surface passivation layer and an anti-reflection layer from the inside to the outside. The back side of the silicon substrate adopts a partitioned design, and a first passivation layer is provided on its surface. The back side of the silicon substrate includes a periodically arranged first doped region, a floating gate region, and a second doped region, with the floating gate region located between the first doped region and the second doped region; The floating gate region includes n floating gate portions and n+1 isolation portions, where n≥1 and n is a positive integer; the floating gate portion includes a floating gate disposed on the outer surface of the first passivation layer; the floating gate portions are isolated from each other, from the floating gate portion to the first doped region, and from the floating gate portion to the second doped region through the isolation portions; When the silicon substrate is n-type doped, the work function of the floating gate is less than the work function of the silicon substrate; When the silicon substrate is p-type doped, the work function of the floating gate is greater than the work function of the silicon substrate; The first doped region includes a first doped semiconductor layer and a metal electrode disposed on the outer surface of the first passivation layer; The second doped region includes a second doped semiconductor layer and a metal electrode disposed on the outer surface of the first passivation layer.

2. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, When the silicon substrate is n-type doped, the lateral width of the first doped region in each periodic cell must be greater than the sum of the lateral widths of the floating gate region and the second doped region; When the silicon substrate is p-type doped, the lateral width of the second doped region in each periodic cell must be greater than the sum of the lateral widths of the floating gate region and the first doped region; In each periodic cell, the lateral width of the first doped region is 1~1000 μm, the lateral width of the second doped region is 1~1000 μm, the lateral width of each floating gate in the floating gate region is 0.005~100 μm, and the lateral width of each isolation part is 0.005~100 μm.

3. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, The material of the passivation layer on the front surface is selected from alumina or silicon oxide; the material of the antireflection layer is selected from hydrogenated silicon nitride or hydrogenated silicon oxynitride.

4. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, The material of the first passivation layer is selected from silicon oxide, hafnium oxide, hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, aluminum oxide, silicon nitride, or silicon oxynitride.

5. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, In the first doped region, a first doped semiconductor layer, a transparent conductive layer, and a metal electrode are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer; in the second doped region, a second doped semiconductor layer, a transparent conductive layer, and a metal electrode are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer.

6. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, In the first doped region, a first doped semiconductor layer, a second passivation layer, and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer, and a metal electrode is disposed on the outer surface of the first doped semiconductor layer; in the second doped region, a second doped semiconductor layer, a second passivation layer, and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the first passivation layer, and a metal electrode is disposed on the outer surface of the second doped semiconductor layer; in the floating gate portion, a second passivation layer and an auxiliary back reflection layer are sequentially disposed from the inside to the outside on the outer surface of the floating gate.

7. The high-efficiency back-contact silicon solar cell according to claim 5 or 6, characterized in that, The work function of the first doped semiconductor layer is greater than that of the silicon substrate, and is selected from boron-doped polycrystalline silicon, boron-doped hydrogenated amorphous silicon, or boron-doped hydrogenated microcrystalline silicon; the work function of the second doped semiconductor layer is less than that of the silicon substrate, and is selected from phosphorus-doped polycrystalline silicon, phosphorus-doped hydrogenated amorphous silicon, or phosphorus-doped hydrogenated microcrystalline silicon.

8. The high-efficiency back-contact silicon solar cell according to claim 6, characterized in that, The material of the second passivation layer is selected from silicon oxide, hafnium oxide, hydrogenated amorphous silicon, hydrogenated microcrystalline silicon, aluminum oxide, silicon nitride, or silicon oxynitride; the material of the auxiliary back reflective layer is selected from hydrogenated silicon nitride or hydrogenated silicon oxynitride.

9. The high-efficiency back-contact silicon solar cell according to claim 1, characterized in that, The floating gate is made of boron-doped polycrystalline silicon, phosphorus-doped polycrystalline silicon, boron-doped hydrogenated amorphous silicon, or phosphorus-doped hydrogenated amorphous silicon.

10. A photovoltaic module, characterized in that, The structure includes the high-efficiency back-contact silicon solar cell as described in claim 1.

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