Crystalline silicon solar cell and preparation method thereof

Abstract

The invention discloses a crystalline silicon solar cell and a preparation method thereof. The crystalline silicon solar cell may include: a crystalline silicon substrate; the first intrinsic silicon-containing film layer is arranged on the main surface of the crystalline silicon substrate; the first doped silicon-containing film layer is arranged on the outer side of the first intrinsic silicon-containing film layer and comprises first doped atoms, the conduction type of the first doped atoms is opposite to that of second doped atoms contained in the crystalline silicon substrate, and the first doped silicon-containing film layer does not completely cover the first intrinsic silicon-containing film layer; the first transparent conductive film layer is arranged on the outer side of the first intrinsic silicon-containing film layer which is not covered by the first doped silicon-containing film layer and is in direct contact with the first intrinsic silicon-containing film layer; the second transparent conductive film layer is arranged on the outer side of the first doped silicon-containing film layer and is in direct contact with the first doped silicon-containing film layer; the first doped silicon-containing film layer and the second transparent conductive film layer are electrically isolated from the first transparent conductive film layer. The battery is simple in structure, the process complexity can be reduced, and structural damage caused by the preparation process is reduced.

Description

Technical Field

[0001] This invention relates to a crystalline silicon solar cell and its fabrication method. Background Technology

[0002] Heterojunction solar cells combine the advantages of crystalline and amorphous silicon solar cells, featuring low processing temperature, high conversion efficiency, and good high-temperature characteristics. In particular, heterojunction cells with a fully back-side electrode structure, in addition to these advantages, eliminate the shading of sunlight by the front-side grid lines, increasing the absorption efficiency of incident light. However, existing heterojunction cell structures are relatively complex, and their fabrication processes are also complex. The fabrication process for heterojunction cells with a fully back-side electrode structure is even more complex, making them prone to higher levels of process damage. Summary of the Invention

[0003] In view of this, the present invention provides a crystalline silicon solar cell and a method for preparing the same, which effectively simplifies the structure of the crystalline silicon solar cell and reduces process damage.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a crystalline silicon solar cell, comprising: Crystalline silicon substrate; A first intrinsic silicon-containing film layer is disposed on the main surface of the crystalline silicon substrate; A first doped silicon-containing film layer containing first doped atoms is disposed on the outside of the first intrinsic silicon-containing film layer and in direct contact with the first intrinsic silicon-containing film layer. The first doped atom has the opposite conductivity type to the second doped atom contained in the crystalline silicon substrate. The first doped silicon-containing film layer does not completely cover the first intrinsic silicon-containing film layer. A first transparent conductive film layer is disposed on the outside of the first intrinsic silicon-containing film layer that is not covered by the first doped silicon-containing film layer and is in direct contact with the first intrinsic silicon-containing film layer. And a second transparent conductive film layer disposed on the outside of the first doped silicon-containing film layer and in direct contact with the first doped silicon-containing film layer; The first doped silicon-containing film layer and the second transparent conductive film layer are both electrically isolated from the first transparent conductive film layer.

[0005] Secondly, embodiments of the present invention provide a method for preparing a crystalline silicon solar cell, comprising: Step 1: Provide a crystalline silicon substrate; Step 2: Form a first intrinsic silicon-containing film layer on the main surface of the crystalline silicon substrate; Step 3: Form a first doped silicon-containing film layer containing a first doped atom on the outside of the first intrinsic silicon-containing film layer. The first doped atom has the opposite conductivity type to the second doped atom contained in the crystalline silicon substrate. The first doped silicon-containing film layer does not completely cover the first intrinsic silicon-containing film layer. Step 4: A first transparent conductive film layer in direct contact with the first intrinsic silicon-containing film layer is formed on the outside of the first intrinsic silicon-containing film layer, and a second transparent conductive film layer in direct contact with the first doped silicon-containing film layer is formed on the outside of the first doped silicon-containing film layer, wherein the first doped silicon-containing film layer and the second transparent conductive film layer are electrically isolated from the first transparent conductive film layer.

[0006] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects: The crystalline silicon solar cell provided in this invention comprises a crystalline silicon substrate, a first intrinsic silicon-containing film layer, and a first doped silicon-containing film layer containing first doped atoms disposed outside the first intrinsic silicon-containing film layer and in direct contact with it. The first doped atoms have the opposite conductivity type to the second doped atoms contained in the crystalline silicon substrate. The crystalline silicon substrate, the first intrinsic silicon-containing film layer, and the first doped silicon-containing film layer are combined to form a PiN junction. Furthermore, the first transparent conductive film layer directly collects the charge carriers generated by the crystalline silicon substrate. The first intrinsic silicon-containing film layer passivates the surface of the crystalline silicon substrate, thereby improving the charge carrier collection capability of the first transparent conductive film layer. In other words, a heterogeneous crystalline silicon solar cell is obtained by combining the crystalline silicon substrate, the first intrinsic silicon-containing film layer, the first doped silicon-containing film layer, the first transparent conductive film layer, and the second transparent conductive film layer. This effectively simplifies the structure of the heterogeneous crystalline silicon solar cell and effectively reduces the process damage of the heterogeneous crystalline silicon solar cell. Attached Figure Description

[0007] Figure 1 This is a cross-sectional schematic diagram of a back-contact heterojunction solar cell based on existing technology. Figure 2 This is a schematic diagram of the structural changes corresponding to the fabrication process of back-contact heterojunction solar cells based on existing technologies; Figure 3 This is a cross-sectional schematic diagram of a crystalline silicon solar cell with a first structure provided according to an embodiment of the present invention; Figure 4 This is a cross-sectional schematic diagram of a crystalline silicon solar cell with a second structure provided according to an embodiment of the present invention; Figure 5 This is a cross-sectional schematic diagram of a crystalline silicon solar cell with a third structure provided according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the main process of a method for preparing a crystalline silicon solar cell according to an embodiment of the present invention; Figure 7 This is a schematic cross-sectional view of the structural changes corresponding to steps S603, S6041, and S6042 of the preparation method according to an embodiment of the present invention.

[0008] The attached figures are labeled as follows: 10 - Crystalline silicon substrate; 11 - First main surface; 12 - Second main surface; 20 - First intrinsic silicon-containing film layer; 20' - Tunneling oxide layer; 30 - First doped silicon-containing film layer; 30' - Doped polycrystalline silicon layer; 30'' - Silicon nitride layer; 40 - First transparent conductive film layer; 50 - Second transparent conductive film layer; 60 - Isolation region; 61 - First isolation region; 62 - Second isolation region; 70 - Passivation layer; 80 - Anti-reflection layer; 91 - First metal electrode; 92 - Second metal electrode. Detailed Implementation

[0009] For existing heterojunction solar cells (especially hybrid back-contact solar cells, such as P-type functional regions with heterojunction structures and N-type functional regions with tunneling oxide passivation contact structures), an intrinsic amorphous silicon film layer is generally formed on the surface of a crystalline silicon substrate 10, and a doped silicon-containing film layer is formed on the outside of the intrinsic amorphous silicon film layer. This forms a PiN junction with the crystalline silicon substrate 10, and the first type of charge carrier (such as holes) is collected through the doped silicon-containing film layer. In the non-PiN junction region, a doped polycrystalline silicon layer is generally formed to collect the second type of charge carrier (such as electrons). The first type of charge carrier is the opposite of the second type of charge carrier. Because doped silicon-containing layers and doped polycrystalline silicon layers are completely different, they need to be fabricated separately. During fabrication, multiple laser etching steps and partial wet etching are required to remove excess film. These multiple laser etching steps and partial wet etching can result in some excess film not being completely removed, potentially damaging the doped silicon-containing layer or the doped polycrystalline silicon layer and affecting the performance of the heterojunction solar cell. For example, taking an existing back-contact heterojunction solar cell as an example... Figure 1 As shown, the structure of existing back-contact heterojunction solar cells generally includes: a crystalline silicon substrate 10, a first intrinsic amorphous silicon film layer 20 and a tunneling oxide layer 20' arranged alternately and spaced apart on the back side of the crystalline silicon substrate 10, a first doped silicon-containing film layer 30 disposed outside the first intrinsic amorphous silicon film layer 20, a doped polycrystalline silicon layer 30' disposed outside the tunneling oxide layer 20', a second transparent conductive film layer 50 disposed outside the first doped silicon-containing film layer 30, a first transparent conductive film layer 40 disposed outside the doped polycrystalline silicon layer 30', a first metal electrode 91 disposed outside the second transparent conductive film layer 50, and a second metal electrode 92 disposed outside the first transparent conductive film layer 40. Regarding this... Figure 1 The existing back-contact heterojunction solar cell structure shown is fabricated as follows: Figure 2The structural changes shown are as follows: Step S201: First, a tunneling oxide layer 20' and a doped polysilicon layer 30' are sequentially stacked on the entire back side of the crystalline silicon substrate 10 (e.g., an N-type crystalline silicon substrate), and a silicon nitride layer 30'' is formed outside the doped polysilicon layer 30' (e.g., a phosphorus-doped polysilicon layer). Step S202: The silicon nitride layer 30'' and a portion of the doped polysilicon layer 30' corresponding to the P-type region are removed by laser. Step S203: The remaining doped polysilicon layer 30' and tunneling oxide layer 20' corresponding to the P-type region are removed by alkaline cleaning, and a textured surface is formed on the surface of the crystalline silicon substrate 10 corresponding to the P-type region, resulting in a tunneling oxide layer 20', a doped polysilicon layer 30', and a silicon nitride layer 30'' stacked from the inside out, with only the N-type region and the isolation region remaining. Step S204: A first intrinsic amorphous silicon film layer 20 and a first doped silicon-containing film layer 30 are sequentially stacked outside the silicon nitride layer 30'' in the P-type region, the isolation region, and the N-type region. Step S205: The first intrinsic amorphous silicon film layer 20, the first doped silicon-containing film layer 30, and the silicon nitride layer 30'' corresponding to the N-type region are removed by laser. It is evident that the existing fabrication process for heterojunction solar cells is cumbersome. Furthermore, the laser etching process in step S202 easily damages the surface of the crystalline silicon substrate 10, and the laser etching process in step S205 easily damages the crystalline silicon substrate 10, the doped polycrystalline silicon layer 30', and the tunneling oxide layer 20', resulting in structural damage to the heterojunction solar cell.

[0010] To address the complex fabrication processes and structural damage associated with existing heterojunction solar cells due to their intricate structures, this invention provides a novel crystalline silicon solar cell and its fabrication method. Specifically, the novel crystalline silicon solar cell provided in this invention is a heterojunction solar cell.

[0011] It should be noted that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. It is worth noting that the first main surface 11 and the second main surface 12 of the crystalline silicon substrate 10 involved in the embodiments of this invention are two main surfaces of the crystalline silicon substrate 10 that are opposite to each other. In the embodiments of this invention, if the first main surface 11 corresponds to the back side of the crystalline silicon substrate 10, then the second main surface 12 generally corresponds to the front side of the crystalline silicon substrate 10; if the first main surface 11 corresponds to the front side of the crystalline silicon substrate 10, then the second main surface 12 generally corresponds to the back side of the crystalline silicon substrate 10.

[0012] Specifically, embodiments of the present invention provide a novel crystalline silicon solar cell and its fabrication method. Figures 3 to 5 This diagram shows a cross-sectional view of a novel crystalline silicon solar cell structure provided in an embodiment of the present invention. Figures 3 to 5 As shown, the crystalline silicon solar cell may include: A crystalline silicon substrate 10; a first intrinsic silicon-containing film layer 20 disposed on the main surface of the crystalline silicon substrate 10; a first doped silicon-containing film layer 30 disposed outside the first intrinsic silicon-containing film layer 20 and containing first doped atoms, wherein the first doped atoms have the opposite conductivity type to the second doped atoms contained in the crystalline silicon substrate 10, and the first doped silicon-containing film layer 30 does not completely cover the first intrinsic silicon-containing film layer 20; a first transparent conductive film layer 40 disposed outside the first intrinsic silicon-containing film layer 20 not covered by the first doped silicon-containing film layer 30 and in direct contact with the first intrinsic silicon-containing film layer 20; and a second transparent conductive film layer 50 disposed outside the first doped silicon-containing film layer 30; wherein the first doped silicon-containing film layer 30 and the second transparent conductive film layer 50 are both electrically isolated from the first transparent conductive film layer 40.

[0013] The silicon substrate 10 can be an N-type silicon substrate doped with N-type dopant atoms (phosphorus and / or antimony atoms) or a P-type silicon substrate doped with P-type dopant atoms (boron and / or gallium atoms). Preferably, the silicon substrate 10 is an N-type silicon substrate.

[0014] The primary function of the first intrinsic silicon-containing film layer 20 is to provide hydrogen (H) atoms to the surface of the crystalline silicon substrate 10, thereby passivating the surface of the crystalline silicon substrate 10 and reducing defects on the surface of the crystalline silicon substrate 10.

[0015] In this context, the conductivity type of the first doped atom and the second doped atom are opposite. Generally, if the first doped atom is a P-type doped atom such as boron and / or gallium (for collecting / transporting hole carriers), then the second doped atom is an N-type doped atom such as phosphorus and / or antimony (for collecting / transporting electron carriers); conversely, if the first doped atom is an N-type doped atom such as phosphorus and / or antimony (for collecting / transporting electron carriers), then the second doped atom is a P-type doped atom such as boron and / or gallium (for collecting / transporting hole carriers). For example, if the silicon substrate 10 is an N-type silicon substrate, then the first doped silicon film layer 30 is a P-type doped silicon film layer containing P-type doped atoms; if the silicon substrate 10 is a P-type silicon substrate, then the first doped silicon film layer 30 is an N-type doped silicon film layer containing N-type doped atoms.

[0016] For example, the first doped silicon-containing film layer is in direct contact with the first intrinsic silicon-containing film layer 20, and the structure of this crystalline silicon solar cell is simple.

[0017] The crystalline silicon solar cell provided in this embodiment of the invention comprises a crystalline silicon substrate 10, a first intrinsic silicon-containing film layer 20, and a first doped silicon-containing film layer 30 containing first doped atoms disposed outside the first intrinsic silicon-containing film layer 20 and in direct contact with the first intrinsic silicon-containing film layer 20. The first doped atoms have the opposite conductivity type to the second doped atoms contained in the crystalline silicon substrate 10, so that the crystalline silicon substrate 10, the first intrinsic silicon-containing film layer 20, and the first doped silicon-containing film layer 30 cooperate to form a PiN junction. Furthermore, the first transparent conductive film layer 40 directly collects the charge carriers generated by the crystalline silicon substrate 10, and the first intrinsic silicon-containing film layer 20 passivates the main surface of the crystalline silicon substrate 10, thereby improving the charge carrier collection capability of the first transparent conductive film layer 40. Compared to existing heterojunction solar cells, the heterojunction solar cell provided in this embodiment of the invention uses a combination of a crystalline silicon substrate 10, a first intrinsic silicon-containing film layer 20, a first doped silicon-containing film layer 30, a first transparent conductive film layer 40, and a second transparent conductive film layer 50, omitting functional film layers such as tunneling passivation layers and doped polycrystalline silicon layers. Therefore, the structure provided in this embodiment of the invention effectively simplifies the structure of heterojunction crystalline silicon solar cells and effectively reduces process damage to heterojunction crystalline silicon solar cells.

[0018] Furthermore, due to the simple structure of crystalline silicon solar cells, the manufacturing process of crystalline silicon solar cells can be effectively simplified, facilitating large-scale production and reducing the production cost of crystalline silicon solar cells.

[0019] In addition, since the crystalline silicon solar cell provided in this embodiment of the invention has a simple structure, requires less investment in fixed equipment, and has relatively low operating costs, the production cost of crystalline silicon solar cells is further reduced.

[0020] Furthermore, the combined use of laser patterning and chemical etching to remove the damage layer on the surface of the silicon substrate 10 causes height issues in the P-type and N-type regions, such as... Figure 1 The height difference shown in the prior art, in order to facilitate subsequent photovoltaic module fabrication, the lower surfaces of the first metal electrode 91 and the second metal electrode 92 set in the P-type region and the N-type region are kept as flush as possible, and the region with lower height ( Figure 1 The left-hand region shown consumes more metal paste. Compared with the structure provided by the prior art, the crystalline silicon solar cell provided by the embodiment of the present invention does not have a damage layer on the surface of the crystalline silicon substrate 10, and eliminates the height difference between the P-type region and the N-type region, thereby reducing the consumption of metal paste. In addition, during the printing of metal electrodes, the elimination of the height difference between the P-type region and the N-type region can reduce the pressure on the printing screen, thereby effectively increasing the life of the screen used for printing metal electrodes, and further reducing the cost of production equipment.

[0021] The crystalline silicon solar cells provided in this invention mainly have three structures.

[0022] Specifically, regarding the first structure of the crystalline silicon solar cell provided in the embodiments of the present invention, it can be as follows: Figure 3 As shown, a first intrinsic silicon-containing film layer 20 is disposed on the first main surface 11 and the second main surface 12 of the crystalline silicon substrate 10. Correspondingly, a first doped silicon-containing film layer 30 is disposed on the outside of the first intrinsic silicon-containing film layer 20 on the first main surface 11; a first transparent conductive film layer 40 is disposed on the outside of the first intrinsic silicon-containing film layer 20 on the second main surface 12.

[0023] For the first structure of the crystalline silicon solar cell, the first intrinsic silicon-containing film layer 20 disposed on the first main surface 11, the first doped silicon-containing film layer 30 disposed on its outer side and the second transparent conductive film layer 50 together can serve as the front side of the crystalline silicon solar cell. Correspondingly, the first intrinsic silicon-containing film layer 20 and the first transparent conductive film layer 40 disposed on the second main surface 12 together serve as the back side of the crystalline silicon solar cell.

[0024] In addition, for the first structure of the crystalline silicon solar cell, the first intrinsic silicon-containing film layer 20 and the first transparent conductive film layer 40 disposed on the second main surface 12 can also be used as the front side of the crystalline silicon solar cell. Correspondingly, the first intrinsic silicon-containing film layer 20 disposed on the first main surface 11, the first doped silicon-containing film layer 30 on its outer side and the second transparent conductive film layer 50 are used as the back side of the crystalline silicon solar cell.

[0025] Regarding the first structure of the aforementioned crystalline silicon solar cell, regardless of whether the PiN junction is disposed on the front or back side of the crystalline silicon solar cell, the combination of the crystalline silicon substrate 10, the first intrinsic silicon-containing film layer 20 disposed on the first main surface 11, and the first doped silicon-containing film layer 30 on its outer side not only forms the PiN junction of the crystalline silicon solar cell, but also passivates the first main surface 11 of the crystalline silicon substrate 10 by the first intrinsic silicon-containing film layer 20 and the first doped silicon-containing film layer 30 on its outer side, reducing defects and carrier recombination on the first main surface 11 and improving the carrier transport capability of the crystalline silicon solar cell. Furthermore, the combination of the first intrinsic silicon-containing film layer 20 and the first transparent conductive film layer 40 on the second main surface 12 not only collects / transmits carriers of the crystalline silicon solar cell, but also passivates the second main surface 12 of the crystalline silicon substrate 10 by the first intrinsic silicon-containing film layer 20, reducing defects and carrier recombination on the second main surface 12 and improving the carrier transport capability of the crystalline silicon solar cell.

[0026] In addition, for the second and third structures of crystalline silicon solar cells, further details can be made as follows: Figure 4 and Figure 5As shown, a first intrinsic silicon-containing film layer 20 is disposed on the first main surface 11 of the crystalline silicon substrate 10; a first doped silicon-containing film layer 30 and a first transparent conductive film layer 40 are arranged alternately and at intervals outside the first intrinsic silicon-containing film layer 20. Specifically, for the second and third structures of the crystalline silicon solar cell, the first main surface 11 of the crystalline silicon substrate 10 corresponds to the back surface of the crystalline silicon solar cell. It is worth noting that... Figure 4 and Figure 5 Only a portion of a crystalline silicon solar cell is shown as an example; based on this, those skilled in the art can understand the complete structure of a crystalline silicon solar cell.

[0027] The region between the adjacent first doped silicon-containing film layer 30 and the first transparent conductive film layer 40 is the isolation region 60.

[0028] Regardless of whether it is the second or third structure of the crystalline silicon solar cell, for example, if the crystalline silicon substrate 10 is an N-type silicon substrate, the region corresponding to the first doped silicon-containing film layer 30 is a P-type region, and the region corresponding to the first transparent conductive film layer 40 is an N-type region; if the crystalline silicon substrate 10 is a P-type silicon substrate, the region corresponding to the first doped silicon-containing film layer 30 is an N-type region, and the region corresponding to the first transparent conductive film layer 40 is a P-type region, that is, an isolation region 60 is provided between the N-type region and the P-type region for electrically isolating the N-type region and the P-type region.

[0029] In addition, regardless of whether it is the second or third structure of the crystalline silicon solar cell, the first intrinsic silicon-containing film layer 20 is disposed throughout the first main surface 11 of the crystalline silicon substrate 10, that is, the first intrinsic silicon-containing film layer 20 penetrates the N-type region, the P-type region and the isolation region 60. By disposing the first intrinsic silicon-containing film layer 20 on the entire first main surface 11 of the crystalline silicon substrate 10, the surface defects and surface carrier recombination of the crystalline silicon substrate 10 are reduced, thereby improving the surface passivation performance of the N-type and P-type regions of the crystalline silicon solar cell.

[0030] Whether it's the second or third structure of crystalline silicon solar cells, such as Figure 4 and Figure 5As shown, the width ratio (D1:D2) between the width D1 of the first doped silicon-containing film layer 30 and the width D2 of the first transparent conductive film layer 40 is 1:1 to 2:1, and the direction of the width is the direction in which the first doped silicon-containing film layer 30 and the first transparent conductive film layer 40 are arranged alternately and at intervals. For example, this width ratio can be 1:1, 1.2:1, 1.5:1, 1.8:1, or 2:1, etc. Preferably, the width ratio (D1:D2) between the width D1 of the first doped silicon-containing film layer 30 and the width D2 of the first transparent conductive film layer 40 is 2:1. On the one hand, by controlling the range of this width ratio, the area of ​​the PN junction region can be effectively increased, improving carrier collection capability and cell efficiency. On the other hand, by controlling the width ratio (D1:D2) within the range of 1:1 to 2:1, it is feasible in terms of manufacturing process. However, further increasing the width ratio (D1:D2) (i.e., a width ratio greater than 2:1) is detrimental to the controllability of the width D2 of the first transparent conductive film layer 40. Therefore, by controlling the width ratio (D1:D2) within the range of 1:1 to 2:1, the controllability and alignment accuracy of the crystalline silicon solar cell fabrication process can be effectively guaranteed, and the crystalline silicon solar cell can be guaranteed to have a relatively high process window. In addition, a wider width D1 of the first doped silicon-containing film layer 30 can improve the current and photoelectric conversion efficiency of the crystalline silicon solar cell. Further research found that further increasing the width ratio (D1:D2) above 2:1 did not significantly improve the photoelectric conversion efficiency of the crystalline silicon solar cell, but instead increased the manufacturing difficulty. A width ratio (D1:D2) below 1:1 leads to lower cell efficiency.

[0031] Whether it's the second or third structure of crystalline silicon solar cells, such as Figure 4 and Figure 5 As shown, an isolation region 60 is provided on the outer side of the first intrinsic silicon-containing film layer 20, between the adjacent first doped silicon-containing film layer 30 and the first transparent conductive film layer 40. The isolation region 60 electrically isolates the first doped silicon-containing film layer 30 and the first transparent conductive film layer 40.

[0032] Preferably, the width of the isolation zone 60 (e.g.) Figure 4 The width D3 of the isolation zone 60 shown is... Figure 5 The width (D31+D32) of the isolation region 60 shown can be 1μm to 200μm. For example, the width of the isolation region 60 can be 1μm, 5μm, 10μm, 50μm, 80μm, 100μm, 120μm, 150μm, 180μm, or 200μm, etc. By controlling the width of the isolation region 60, the fabrication accuracy of the crystalline silicon solar cell can be ensured, a wider process window can be guaranteed, and short circuits in the crystalline silicon solar cell can be avoided.

[0033] Specifically, the structure of isolation zone 60 can be of two types.

[0034] A second structure for a crystalline silicon solar cell includes a first type of isolation region 60. The structure of this first isolation region 60 is as follows: Figure 4 As shown, the first type of isolation region 60 is provided with only the first intrinsic silicon-containing film layer 20. The structure of the first type of isolation region 60 can effectively prevent short circuits in crystalline silicon solar cells and improve the carrier collection efficiency of crystalline silicon solar cells.

[0035] A third structure for crystalline silicon solar cells includes a second type of isolation region 60. The structure of this second isolation region 60 is as follows: Figure 5 As shown, the isolation region 60 may include: a first isolation region 61 and a second isolation region 62 arranged side by side, wherein, compared to the second isolation region 62, the first isolation region 61 is closer to the first doped silicon-containing film layer 30; compared to the first isolation region 61, the second isolation region 62 is closer to the first transparent conductive film layer 40; the second transparent conductive film layer 50 extends from the outside of the first doped silicon-containing film layer 30 to the outside of the first intrinsic silicon-containing film layer 20 corresponding to the first isolation region 61, and the second transparent conductive film layer 50 does not extend to the second isolation region 62.

[0036] By setting a first isolation region 61 and a second isolation region 62, the second transparent conductive film layer 50 corresponding to the first isolation region 61 can protect the edge of the first doped silicon film layer 30 during the fabrication process of crystalline silicon solar cells, avoiding damage to the edge of the first doped silicon film layer 30 during the fabrication process, thereby reducing process damage to crystalline silicon solar cells and improving the efficiency and carrier collection capability of crystalline silicon solar cells.

[0037] Preferably, such as Figure 5 As shown, the width D31 of the first isolation region 61 is 1 μm to 100 μm. For example, the width D31 of the first isolation region 61 can be 1 μm, 5 μm, 10 μm, 20 μm, 50 μm, 80 μm, or 100 μm, etc. By controlling the width D31 of the first isolation region 61, the fabrication process control precision and a wider process window can be ensured, while minimizing the impact of the first isolation region 61 on the first doped silicon-containing film layer 30.

[0038] Preferably, such as Figure 5 As shown, the width D32 of the second isolation region 62 is 1 μm to 100 μm. For example, the width D32 of the second isolation region 62 can be 1 μm, 5 μm, 10 μm, 20 μm, 50 μm, 80 μm, or 100 μm, etc. By controlling the width D32 of the second isolation region 62, the fabrication process control precision and a wider process window can be ensured, while also guaranteeing electrical isolation between the first doped silicon-containing film layer 30 and the first transparent conductive film layer 40.

[0039] Furthermore, for any of the first, second, and third structures of the aforementioned crystalline silicon solar cell, the first intrinsic silicon-containing film layer 20 may be one or more of microcrystalline silicon, nanocrystalline silicon, amorphous silicon, silicon oxide, and silicon carbide, and may be a single-layer film or a stacked film. Preferably, the thickness of the first intrinsic silicon-containing film layer 20 may be 1 nm to 15 nm. For example, the thickness of the first intrinsic silicon-containing film layer 20 may be 1 nm, 2 nm, 5 nm, 8 nm, 10 nm, 12 nm, or 15 nm, etc. By controlling the composition and thickness of the first intrinsic silicon-containing film layer 20, the passivation effect of the first intrinsic silicon-containing film layer 20 on the surface of the crystalline silicon solar cell can be effectively improved.

[0040] Furthermore, the first doped silicon-containing film 30 may be one or more of microcrystalline silicon, nanocrystalline silicon, amorphous silicon, silicon oxide, and silicon carbide, doped with first dopant atoms. The first doped silicon-containing film 30 may be a single layer or a stacked layer. Preferably, the thickness of the first intrinsic silicon-containing film 20 may be 1 nm to 15 nm. Additionally, the doping concentration of the first doped silicon-containing film 30 may be 1 × 10⁻⁶. 17 atoms / cm 2 ~1×10 20 atoms / cm 2 For example, the thickness of the first doped silicon-containing film 30 can be 1 nm, 5 nm, 10 nm, 20 nm, 25 nm, 30 nm, 40 nm, 45 nm, or 50 nm, etc. The doping concentration of the first doped silicon-containing film 30 can be 1 × 10⁻⁶. 17 atoms / cm 2 5×10 17 atoms / cm 2 3×10 18 atoms / cm 2 8×10 18 atoms / cm 2 5×10 19 atoms / cm 2 9×10 19 atoms / cm 2 Or 1×10 20 atoms / cm 2 By controlling the thickness of the first doped silicon-containing film 30, the carrier collection capability of the first doped silicon-containing film 30 can be effectively guaranteed.

[0041] Furthermore, for any of the first, second, and third structures of the aforementioned crystalline silicon solar cell, the work function of the first transparent conductive film layer 40 is generally 3.0 eV to 4.0 eV. For example, the work function of the first transparent conductive film layer 40 can be 3.0 eV, 3.2 eV, 3.5 eV, 3.8 eV, or 4.0 eV, etc. By controlling the work function of the first transparent conductive film layer 40, a better fit is formed between the stacked structure of the first transparent conductive film layer 40 and the first intrinsic silicon-containing film layer 20 and the stacked structure of the first doped silicon-containing film layer 30 and the first intrinsic silicon-containing film layer 20. Even if the doped polycrystalline silicon layer is omitted between the first transparent conductive film layer 40 and the first intrinsic silicon-containing film layer 20, the carrier transport capability of the crystalline silicon solar cell can still be effectively improved.

[0042] The first transparent conductive film layer 40 may be one or more metal oxides or metal nitrides containing doped atoms. The first transparent conductive film layer 40 may be a single layer or a stacked layer. The metal oxide may be one or more of indium oxide, tin oxide, zinc oxide, cadmium oxide, and titanium oxide. The metal nitride may be titanium nitride. The doped atoms in the first transparent conductive film layer 40 may be one or more of indium, tin, calcium, aluminum, cadmium, zinc, cerium, and fluorine. Preferably, the first transparent conductive film layer 40 is an N-type transparent conductive film layer.

[0043] Furthermore, for any of the first, second, and third structures of the aforementioned crystalline silicon solar cell, the second transparent conductive film layer 50 can be a single-layer or stacked film layer doped with one or more metal oxides or metal nitrides. The metal oxide is one or more of indium oxide, tin oxide, zinc oxide, cadmium oxide, and titanium oxide, and the metal nitride is titanium nitride. The first transparent conductive film layer 40 contains one or more doped atoms of indium, tin, calcium, aluminum, cadmium, zinc, cerium, and fluorine. The second transparent conductive film layer 50 can be made of the same material as the first transparent conductive film layer 40, or it can be made of a different material.

[0044] Furthermore, regarding the second and third structures of the aforementioned crystalline silicon solar cells, such as... Figure 4 and Figure 5 As shown, the crystalline silicon solar cell may also include a passivation layer 70 disposed on the second main surface 12 of the crystalline silicon substrate 10.

[0045] The passivation layer 70 can have various structures.

[0046] Specifically, the first structure of the passivation layer 70 may be composed of one or more materials selected from silicon oxide, aluminum oxide, gallium oxide, and titanium oxide, and the passivation layer 70 may be a single-layer film or a multilayer film. The thickness of the passivation layer 70 may be 1 nm to 15 nm. For example, the thickness of the passivation layer 70 may be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, or 15 nm, etc.

[0047] Alternatively, the passivation layer 70 may have a second intrinsic silicon-containing film layer. The thickness of the second intrinsic silicon-containing film layer may be 1 nm to 15 nm. For example, the thickness of the second intrinsic silicon-containing film layer may be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, or 15 nm, etc.

[0048] Additionally, the third structure of the passivation layer 70 may include: a second intrinsic silicon-containing film layer with a thickness of 1 nm to 15 nm, and a second doped silicon-containing film layer with a thickness of 0.5 nm to 30 nm containing second doped atoms, stacked on the outside of the second intrinsic silicon-containing film layer. For example, the thickness of the second intrinsic silicon-containing film layer may be 1 nm, 3 nm, 5 nm, 8 nm, 10 nm, 12 nm, or 15 nm, etc. The thickness of the second doped silicon-containing film layer may be 0.5 nm, 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm, etc. The second intrinsic silicon-containing film layer may be one or more of microcrystalline silicon, nanocrystalline silicon, amorphous silicon, silicon oxide, and silicon carbide, and may be a single-layer film layer or a multilayer film layer. The second doped silicon-containing film layer may be doped with second doped atoms and may include one or more of microcrystalline silicon, nano-silicon, amorphous silicon, silicon oxide and silicon carbide. The second doped silicon-containing film layer may be a single layer or a stacked layer.

[0049] By providing a passivation layer 70 to the second main surface 12 of the crystalline silicon substrate 10, the second main surface 12 of the crystalline silicon substrate 10 can be effectively passivated to improve the photoelectric conversion efficiency of the crystalline silicon solar cell.

[0050] Furthermore, regarding the second and third structures of the aforementioned crystalline silicon solar cells, such as... Figure 4 and Figure 5As shown, the crystalline silicon solar cell may further include an antireflection layer 80 stacked outside the passivation layer 70. The antireflection layer 80 comprises one or more of silicon nitride, silicon oxynitride, magnesium oxide, and lithium fluoride. The antireflection layer 80 can be a single layer or a multilayer film. The thickness of the antireflection layer 80 can be 1 nm to 300 nm. For example, the antireflection layer 80 can be 1 nm, 5 nm, 10 nm, 20 nm, 50 nm, 80 nm, 100 nm, 120 nm, 150 nm, 200 nm, 250 nm, or 300 nm. By setting the antireflection layer 80, the reflected light from the crystalline silicon solar cell can be effectively reduced, improving the light utilization rate and photoelectric conversion efficiency of the crystalline silicon solar cell.

[0051] Furthermore, such as Figures 3 to 5 As shown, the crystalline silicon solar cell may further include: a first metal electrode 91 electrically connected to the first transparent conductive film layer 40; and a second metal electrode 92 electrically connected to the second transparent conductive film layer 50.

[0052] Furthermore, embodiments of the present invention provide a method for fabricating a crystalline silicon solar cell. Specifically, this method for fabricating a crystalline silicon solar cell relates to the method for fabricating a crystalline silicon solar cell provided in any of the above embodiments. Figure 6 As shown, the method for fabricating this crystalline silicon solar cell may include the following steps: Step S601: Provide a crystalline silicon substrate 10.

[0053] The silicon substrate 10 can be an N-type silicon substrate or a P-type silicon substrate. Preferably, the silicon substrate 10 is an N-type silicon substrate.

[0054] Step S602: Form a first intrinsic silicon-containing film layer 20 on the main surface of the crystalline silicon substrate 10.

[0055] Specifically, regarding the above Figure 3 The first structure of the provided crystalline silicon solar cell may include step S602 in which a first intrinsic silicon-containing film layer 20 is formed on the first main surface 11 and the second main surface 12 of the crystalline silicon substrate 10.

[0056] In response to the above Figure 4 The second structure of the provided crystalline silicon solar cell and Figure 5 The third structure of the crystalline silicon solar cell shown may include step S602, which may include forming a first intrinsic silicon-containing film layer 20 on the first main surface 11 of the crystalline silicon substrate 10.

[0057] In addition, regarding the above Figure 4 The second structure of the provided crystalline silicon solar cell and Figure 5The third structure of the crystalline silicon solar cell shown in step S602 can also simultaneously form a second intrinsic silicon-containing film layer on the second main surface 12 of the crystalline silicon substrate 10.

[0058] Step S603: A first doped silicon film layer 30 containing first doped atoms is formed on the outside of the first intrinsic silicon film layer 20, which is in direct contact with the first intrinsic silicon film layer 20. The first doped atoms have the opposite conductivity type to the second doped atoms contained in the crystalline silicon substrate 10. The first doped silicon film layer 30 does not completely cover the first intrinsic silicon film layer 20.

[0059] Specifically, regarding the above Figure 3 The first structure of the provided crystalline silicon solar cell, in a specific embodiment of step S603, may include: forming a first doped silicon-containing film layer 30 on the outer side of the first intrinsic silicon-containing film layer 20 on the first main surface 11.

[0060] In addition, regarding the above Figure 4 The second structure of the provided crystalline silicon solar cell and Figure 5 The third structure of the crystalline silicon solar cell shown may include step S603 in the following specific implementation: forming a first doped silicon-containing film layer 30 with spacing on the outside of the first intrinsic silicon-containing film layer 20.

[0061] Specifically, a first doped silicon-containing film 30 can be formed by combining a mask with chemical deposition. This mask covers, for example... Figure 7 The exposed area of ​​the first intrinsic silicon-containing film layer 20 in the structure formed in step S603 shown.

[0062] In this context, the conductivity type of the first doped atom and the second doped atom are opposite. Generally, if the first doped atom is a P-type doped atom such as boron and / or gallium (for collecting / transporting hole carriers), then the second doped atom is an N-type doped atom such as phosphorus and / or antimony (for collecting / transporting electron carriers); conversely, if the first doped atom is an N-type doped atom such as phosphorus and / or antimony (for collecting / transporting electron carriers), then the second doped atom is a P-type doped atom such as boron and / or gallium (for collecting / transporting hole carriers). For example, if the silicon substrate 10 is an N-type silicon substrate, then the first doped silicon film layer 30 is a P-type doped silicon film layer containing P-type doped atoms; if the silicon substrate 10 is a P-type silicon substrate, then the first doped silicon film layer 30 is an N-type doped silicon film layer containing N-type doped atoms.

[0063] Step S604: A first transparent conductive film layer 40 is formed on the outside of the first intrinsic silicon-containing film layer 20, which is in direct contact with the first intrinsic silicon-containing film layer 20, and a second transparent conductive film layer 50 is formed on the outside of the first doped silicon-containing film layer 30, which is in direct contact with the first doped silicon-containing film layer 30, wherein the first doped silicon-containing film layer 30 and the second transparent conductive film layer 50 are both electrically isolated from the first transparent conductive film layer 40.

[0064] In response to the above Figure 4 The second structure of the provided crystalline silicon solar cell and Figure 5 The third structure of the crystalline silicon solar cell shown includes step S604, which may specifically include: Step S6041: forming a transparent conductive film layer outside the first doped silicon-containing film layer 30 and outside the exposed area of ​​the first intrinsic silicon-containing film layer 20; Step S6042: removing the portion of the transparent conductive film layer near the first intrinsic silicon-containing film layer 20 corresponding to the exposed area, resulting in a first transparent conductive film layer 40 remaining in the exposed area, and a second transparent conductive film layer 50 stacked outside the first doped silicon-containing film layer 30. The structural changes corresponding to steps S6041 and S6042 are as follows: Figure 7 As shown. In step S6042, the portion of the transparent conductive film layer near the first intrinsic silicon-containing film layer 20 corresponding to the exposed area can be removed by laser etching. The laser energy used in this step is relatively low (for example, the laser power used in this step can be 0.5W~20W, such as 0.5W, 1W, 4W, 5W, 8W, 10W, 15W, 18W or 20W, etc.). The presence of the first intrinsic silicon-containing film layer 20 can absorb the low-energy laser and avoid laser damage to the crystalline silicon substrate 10.

[0065] Furthermore, regarding step S604, regardless of whether it is the second or third structure of the crystalline silicon solar cell, the width ratio (D1:D2) between the width D1 of the first doped silicon-containing film layer 30 and the width D2 of the first transparent conductive film layer 40 is controlled to be 1:1 to 2:1. For example, this width ratio can be 1:1, 1.2:1, 1.5:1, 1.8:1, or 2:1, etc. Preferably, the width ratio (D1:D2) between the width D1 of the first doped silicon-containing film layer 30 and the width D2 of the first transparent conductive film layer 40 is 2:1. By controlling the width ratio (D1:D2) within the range of 1:1 to 2:1, this width ratio (D1:D2) is technically achievable. However, further increasing the width ratio (D1:D2) is detrimental to the controllability of the width D2 of the first transparent conductive film layer 40. Therefore, by controlling the width ratio (D1:D2) within the range of 1:1 to 2:1, the controllability and alignment accuracy of the crystalline silicon solar cell fabrication process can be effectively guaranteed, and a relatively high process window can be ensured for the crystalline silicon solar cell. In addition, a wider width D1 of the first doped silicon-containing film layer 30 can improve the current and photoelectric conversion efficiency of the crystalline silicon solar cell. Further research found that further increasing the width ratio (D1:D2) above 2:1 did not significantly improve the photoelectric conversion efficiency of the crystalline silicon solar cell.

[0066] Furthermore, regarding step S604, the width of the control isolation zone 60 is (e.g.) Figure 4 The width D3 of the isolation zone 60 shown is... Figure 5 The width (D31+D32) of the isolation region 60 shown can be 1μm to 200μm. For example, the width of the isolation region 60 can be 1μm, 5μm, 10μm, 50μm, 80μm, 100μm, 120μm, 150μm, 180μm, or 200μm, etc. By controlling the width of the isolation region 60, the fabrication accuracy of the crystalline silicon solar cell can be ensured, a wider process window can be guaranteed, and short circuits in the crystalline silicon solar cell can be avoided.

[0067] and Figure 2 Compared to the structure shown, Figure 6 The preparation method provided by the embodiments of the present invention effectively simplifies the preparation process and reduces the process damage to crystalline silicon solar cells, making it easier for large-scale production.

[0068] The performance of the crystalline silicon solar cells prepared by the preparation method provided in this invention is described in detail below with reference to the test results of the embodiments and comparative examples.

[0069] Comparative products adopt Figure 2 The product prepared by the process shown is the product of the example. Figure 6 The steps shown prepare Figure 4The product shown. In the comparative example, the parameters used in the same process as in the embodiment are the same (such as the parameters used for depositing the first intrinsic silicon-containing film layer 20, the process of depositing the transparent conductive film layer, and the process of grooving the transparent conductive film layer are all the same).

[0070] By performing IV tests on the comparative and exemplary products, the open-circuit voltage (Voc), short-circuit current density (Isc), fill factor (FF), and conversion efficiency (Eff) of the comparative and exemplary products were obtained, as shown in Table 1 below.

[0071] Table 1

[0072] As can be seen from Table 1, the structure provided by the embodiments of the present invention can achieve a higher Isc compared with the comparative example. Although the Voc, FF, and Eff of the products prepared in the embodiments are slightly lower than those in the comparative example, the process used to prepare the products in the embodiments is simpler, requires less equipment investment, fewer steps, and less materials, resulting in a significant cost reduction. That is, the cost savings outweigh the battery efficiency loss, which is conducive to improving profitability.

[0073] The above steps are provided only to help understand the method, structure, and core ideas of this invention. Those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A crystalline silicon solar cell, characterized in that, include: Crystalline silicon substrate (10); A first intrinsic silicon-containing film layer (20) is disposed on the main surface of the crystalline silicon substrate (10). A first doped silicon film layer (30) is disposed outside the first intrinsic silicon film layer (20) and contains a first doped atom. The first doped atom has the opposite conductivity type to the second doped atom contained in the crystalline silicon substrate (10). The first doped silicon film layer (30) does not completely cover the first intrinsic silicon film layer (20). A first transparent conductive film layer (40) is disposed on the outside of the first intrinsic silicon-containing film layer (20) which is not covered by the first doped silicon-containing film layer (30) and is in direct contact with the first intrinsic silicon-containing film layer (20); and, A second transparent conductive film layer (50) is disposed on the outside of the first doped silicon film layer (30). The first doped silicon-containing film layer (30) and the second transparent conductive film layer (50) are both electrically isolated from the first transparent conductive film layer (40).

2. The crystalline silicon solar cell according to claim 1, characterized in that, The first intrinsic silicon-containing film layer (20) is disposed on the first main surface (11) and the second main surface (12) of the crystalline silicon substrate (10). The first doped silicon-containing film layer (30) is disposed on the outer side of the first intrinsic silicon-containing film layer (20) on the first main surface (11); The first transparent conductive film layer (40) is disposed on the outside of the first intrinsic silicon-containing film layer (20) on the second main surface (12).

3. The crystalline silicon solar cell according to claim 1, characterized in that, The first intrinsic silicon-containing film layer (20) is disposed on the first main surface of the crystalline silicon substrate (10); The first doped silicon-containing film layer (30) and the first transparent conductive film layer (40) are arranged alternately and at intervals on the outside of the first intrinsic silicon-containing film layer (20); Preferably, the width ratio of the first doped silicon-containing film layer (30) to the first transparent conductive film layer (40) is 1:1 to 2:1, and the direction of the width is the direction in which the first doped silicon-containing film layer (30) and the first transparent conductive film layer (40) are arranged alternately and at intervals.

4. The crystalline silicon solar cell according to claim 3, characterized in that, An isolation region (60) is provided on the outside of the first intrinsic silicon-containing film layer (20) and between the first doped silicon-containing film layer (30) and the first transparent conductive film layer (40). Preferably, the width of the isolation region (60) is 1 μm to 200 μm.

5. The crystalline silicon solar cell according to claim 4, characterized in that, The isolation zone (60) includes: a first isolation zone (61) and a second isolation zone (62) arranged side by side. The first isolation region (61) is closer to the first doped silicon film layer (30) than the second isolation region (62); The second isolation region (62) is closer to the first transparent conductive film layer (40) than the first isolation region (61); The second transparent conductive film layer (50) extends from the outside of the first doped silicon-containing film layer (30) to the outside of the first intrinsic silicon-containing film layer (20) corresponding to the first isolation region (61), and the second transparent conductive film layer (50) does not extend to the second isolation region (62). Preferably, the width of the first isolation region (61) is 1μm to 100μm; Preferably, the width of the second isolation zone (62) is 1μm to 100μm.

6. The crystalline silicon solar cell according to any one of claims 3 to 5, characterized in that, Also includes: A passivation layer (70) disposed on the second main surface of the crystalline silicon substrate (10); Preferably, the thickness of the passivation layer (70) is 1 nm to 15 nm; more preferably, the material of the passivation layer (70) includes one or more of silicon oxide, aluminum oxide, gallium oxide, and titanium oxide, and the passivation layer (70) is a single layer film or a stacked film; or, the passivation layer (70) is a second intrinsic silicon-containing film layer. or, The passivation layer (70) disposed on the second main surface of the crystalline silicon substrate (10) includes a second intrinsic silicon-containing film layer with a thickness of 1 nm to 15 nm and a second doped silicon-containing film layer with a thickness of 0.5 nm to 30 nm containing second doped atoms stacked on the outside of the second intrinsic silicon-containing film layer. Preferably, the second intrinsic silicon-containing film layer comprises one or more of microcrystalline silicon, nano-silicon, amorphous silicon, silicon oxide, and silicon carbide, and the second intrinsic silicon-containing film layer is a single-layer film layer or a stacked film layer. Preferably, the second doped silicon-containing film layer is doped with the second doping atoms and includes one or more of microcrystalline silicon, nano-silicon, amorphous silicon, silicon oxide and silicon carbide, and the second doped silicon-containing film layer is a single layer or a stacked layer. Preferably, the crystalline silicon solar cell further includes an antireflection layer (80) stacked on the outside of the passivation layer (70), wherein the material of the antireflection layer (80) includes one or more of silicon nitride, silicon oxynitride, silicon oxide, magnesium oxide and lithium fluoride, and the antireflection layer (80) is a single layer or a stacked film layer; Preferably, the thickness of the antireflective layer (80) is 1 nm to 300 nm.

7. The crystalline silicon solar cell according to any one of claims 1 to 5, characterized in that, The work function of the first transparent conductive film layer (40) is 3.0 eV to 4.0 eV.

8. The crystalline silicon solar cell according to any one of claims 1 to 5, characterized in that, The first intrinsic silicon-containing film layer (20) comprises one or more of microcrystalline silicon, nano-silicon, amorphous silicon, silicon oxide and silicon carbide, and the first intrinsic silicon-containing film layer (20) is a single layer or a stacked layer. Preferably, the thickness of the first intrinsic silicon-containing film layer (20) is 1 nm to 15 nm; And / or, The first doped silicon-containing film layer (30) is doped with the first doped atoms and includes one or more of microcrystalline silicon, nano-silicon, amorphous silicon, silicon oxide and silicon carbide. The first doped silicon-containing film layer (30) is a single layer or a stacked layer. Preferably, the thickness of the first doped silicon-containing film layer (30) is 1 nm to 50 nm; And / or, The first transparent conductive film layer (40) is one or more metal oxides or metal nitrides including doped atoms. The first transparent conductive film layer (40) is a single layer or a stacked film layer. The metal oxide is one or more of indium oxide, tin oxide, zinc oxide, cadmium oxide and titanium oxide. The metal nitride is titanium nitride. The doped atoms contained in the first transparent conductive film layer (40) are one or more of indium, tin, calcium, aluminum, cadmium, zinc, cerium and fluorine. And / or, The second transparent conductive film layer (50) is one or more metal oxides or metal nitrides including doped atoms. The second transparent conductive film layer (50) is a single layer or a stacked film layer. The metal oxide is one or more of indium oxide, tin oxide, zinc oxide, cadmium oxide and titanium oxide. The metal nitride is titanium nitride. The first transparent conductive film layer (40) contains one or more of indium, tin, calcium, aluminum, cadmium, zinc, cerium and fluorine as doped atoms. And / or, The crystalline silicon solar cell also includes: A first metal electrode (91) electrically connected to the first transparent conductive film layer (40). A second metal electrode (92) electrically connected to the second transparent conductive film layer (50); And / or, The crystalline silicon substrate (10) is an N-type crystalline silicon substrate; and / or, The first doped silicon-containing film layer (30) is in direct contact with the first intrinsic silicon-containing film layer (20).

9. A method for preparing a crystalline silicon solar cell, characterized in that, include: Step 1: Provide a crystalline silicon substrate (10); Step 2: Form a first intrinsic silicon-containing film layer (20) on the main surface of the crystalline silicon substrate (10); Step 3: A first doped silicon film layer (30) containing a first doped atom is formed on the outside of the first intrinsic silicon film layer (20). The first doped atom has the opposite conductivity type to the second doped atom contained in the crystalline silicon substrate (10). The first doped silicon film layer (30) does not completely cover the first intrinsic silicon film layer (20). Step 4: A first transparent conductive film layer (40) is formed on the outside of the first intrinsic silicon-containing film layer (20) and is in direct contact with the first intrinsic silicon-containing film layer (20), and a second transparent conductive film layer (50) is formed on the outside of the first doped silicon-containing film layer (30), wherein the first doped silicon-containing film layer (30) and the second transparent conductive film layer (50) are electrically isolated from the first transparent conductive film layer (40).

10. The method for preparing a crystalline silicon solar cell according to claim 9, characterized in that, Step 2 includes: forming the first intrinsic silicon-containing film layer (20) on the first main surface (11) and the second main surface (12) of the crystalline silicon substrate (10); Step 3 includes: forming the first doped silicon film layer (30) on the outside of the first intrinsic silicon film layer (20) on the first main surface (11). or, Step 2 includes: forming the first intrinsic silicon-containing film layer (20) on the first main surface of the crystalline silicon substrate (10); Step 3 includes: forming a first doped silicon film layer (30) with spacing on the outside of the first intrinsic silicon film layer (20); Preferably, Step 4 includes: Step 41: A transparent conductive film is formed on the outside of the first doped silicon-containing film layer (30) and on the outside of the exposed area of ​​the first intrinsic silicon-containing film layer (20); Step 42: Remove the portion of the transparent conductive film layer corresponding to the exposed area that is close to the first intrinsic silicon-containing film layer (20) to obtain the first transparent conductive film layer (40) remaining in the exposed area and the second transparent conductive film layer (50) stacked on the outside of the first doped silicon-containing film layer (30); preferably, step 42 uses a laser with a power of 0.5W~20W to remove the portion of the transparent conductive film layer corresponding to the exposed area that is close to the first intrinsic silicon-containing film layer (20); preferably, the width of the laser-removed portion is 1μm~100μm.

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