Hybrid passivation back contact solar cell and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, and discloses a hybrid passivation back contact solar cell and a preparation method thereof. The preparation method comprises the following steps: providing a substrate layer comprising a light receiving surface and a backlight surface, wherein the backlight surface comprises first areas and second areas which are alternately arranged; first passivation contact structures are formed in the first region, each first passivation contact structure comprises a tunneling oxide layer and a doped polycrystalline silicon layer which are arranged in a stacked mode, and an isolation groove exposing the second region is formed between every two adjacent first passivation contact structures; a second passivation contact structure is formed in at least the second area, the second passivation contact structure comprises an intrinsic amorphous silicon layer and a doped amorphous silicon layer which are arranged in a stacked mode, the intrinsic amorphous silicon layer further covers part of the doped polycrystalline silicon layer of the first area, and the doped amorphous silicon layer covers the intrinsic amorphous silicon layer of the second area; the first electrode is connected with the doped amorphous silicon, and the second electrode is connected with the doped amorphous silicon layer. The first passivation contact structure is covered with a single layer of intrinsic amorphous silicon layer, the passivation performance of the surface of the doped polycrystalline silicon layer is effectively improved, and the risk of short circuit conduction is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of solar cells, and in particular to a hybrid passivated back contact solar cell and a preparation method thereof. Background Art

[0002] Back-contact solar cells (BC cells for short) are a technology that transfers all positive and negative electrodes to the back of the cell. There are no grid lines blocking the front, which can effectively improve light absorption efficiency and reduce current loss. With the continuous development of solar cell technology, hybrid back-contact cells that combine back-contact solar cell technology with other types of solar cell technology have received widespread attention. For example, the tunneling oxide passivated back contact cell (TBC cell for short), which is formed by combining the tunneling oxide passivated contact solar cell (TOPCon cell for short) technology with the BC cell technology, applies the tunneling oxide passivated contact structure of the TOPCon cell to the back contact structure. All electrodes are prepared on the back of the cell. While retaining the high current advantage of the BC cell's front side, it also further improves the cell's open circuit voltage and photoelectric conversion efficiency.

[0003] In back-contact cells, the performance of the doping layer directly determines the cell's photoelectric conversion efficiency. This is especially true in TBC cells, where the p-type doped layer (p-poly) is weaker than the n-type doped layer (n-poly) in both passivation and contact performance. However, significant process optimization is difficult to achieve. To this end, the industry has begun adopting heterojunction passivation contact technology with intrinsic amorphous silicon / p-type doped amorphous silicon to replace the traditional p-type passivation contact structure, thereby forming a hybrid (or hybrid) passivated back-contact solar cell. However, the specific structure and preparation process of this hybrid integrated cell based on the TOPCon cell format and heterojunction cell format are not yet mature, making it difficult to optimize and improve the overall cell performance and photoelectric conversion efficiency. Summary of the Invention

[0004] In view of this, the present disclosure provides a hybrid passivated back-contact solar cell and a preparation method thereof to solve the problem that the cell performance and photoelectric conversion efficiency of existing back-contact solar cells are difficult to optimize and improve.

[0005] In a first aspect, the present disclosure provides a method for preparing a hybrid passivated back contact solar cell, comprising: Providing a base layer, the base layer comprising a light-receiving surface and a backlight surface disposed opposite to each other, the backlight surface comprising first areas and second areas arranged alternately; forming a first passivation contact structure in the first region, the first passivation contact structure comprising a stacked tunneling oxide layer and a doped polysilicon layer, wherein the tunneling oxide layer is relatively close to the backlight surface; forming isolation trenches between adjacent first passivation contact structures, wherein the isolation trenches expose the second region; forming a second passivation contact structure in at least the second region, the second passivation contact structure comprising a stacked intrinsic amorphous silicon layer and a doped amorphous silicon layer, the intrinsic amorphous silicon layer being relatively close to the backlight surface; the intrinsic amorphous silicon layer also covering a portion of the doped polycrystalline silicon layer in the first region, and the doped amorphous silicon layer covering the intrinsic amorphous silicon layer in the second region; A first electrode and a second electrode are formed, wherein the first electrode is connected to the doped amorphous silicon layer, and the second electrode is connected to the doped amorphous silicon layer.

[0006] In an optional embodiment, forming a first passivation contact structure in the first region includes: forming an initial tunneling oxide layer on the entire backlight surface; forming an initial intrinsic polysilicon layer on the initial tunneling oxide layer; performing a first doping process on the initial intrinsic polysilicon layer to form an initial doped polysilicon layer; The initial tunneling oxide layer and the initial doped polysilicon layer on the second region are removed to form the tunneling oxide layer and the doped polysilicon layer on the first region and the isolation trench exposing the second region.

[0007] In an optional embodiment, in the step of forming the first passivation contact structure in the first region, before forming the initial tunneling oxide layer on the entire backlight surface, the method further includes: performing a first ultraviolet oxidation treatment on the surface of the second region to form a first stop layer, wherein the initial tunneling oxide layer covers the first stop layer and the surface of the first region; Removing the initial tunneling oxide layer and the initial doped polysilicon layer located on the second region further includes: removing the first stop layer.

[0008] In an optional embodiment, forming a second passivation contact structure in at least the second region includes: forming an initial intrinsic amorphous silicon layer on the entire backlight side, wherein the initial intrinsic amorphous silicon layer covers the surface of the isolation groove and the surface of the doped polysilicon layer; forming an initial doped amorphous silicon layer on the initial intrinsic amorphous silicon layer; The entire initial doped amorphous silicon layer and part of the initial intrinsic amorphous silicon layer located in the first region are removed to form an intrinsic amorphous silicon layer and a doped amorphous silicon layer. A window is formed in the intrinsic amorphous silicon layer located in the first region, and the window exposes part of the doped polycrystalline silicon layer; the doped amorphous silicon layer is located on the intrinsic amorphous silicon layer in the second region.

[0009] In an optional embodiment, in the step of forming the second passivation contact structure in at least the second region, before forming the initial intrinsic amorphous silicon layer on the entire surface of the backlight side, the step further includes: performing a second ultraviolet oxidation treatment on a portion of the surface of the doped polycrystalline silicon layer to form a second stop layer; the initial intrinsic amorphous silicon layer covers the surface of the isolation trench, the surface of the doped amorphous silicon layer, and the surface of the second stop layer; After forming an initial intrinsic amorphous silicon layer on the entire backlight side and before forming an initial doped amorphous silicon layer on the initial intrinsic amorphous silicon layer, the method further includes: performing a third ultraviolet oxidation treatment on a portion of the surface of the initial doped amorphous silicon layer located on the first region to form a third stop layer, wherein a projection of the doped amorphous silicon layer not covered by the third stop layer on the first region is located within a projection of the second stop layer on the first region; Removing the entire initial doped amorphous silicon layer and a portion of the initial intrinsic amorphous silicon layer located on the first region further includes: removing the second stop layer and the third stop layer.

[0010] In an optional embodiment, the process parameters of the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment are the same, and the process energy density and oxygen flow rate of the third ultraviolet oxidation treatment are less than the process energy density and oxygen flow rate of the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment.

[0011] In an optional embodiment, in the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200-400 nm, the energy density range is 0.5-5 J / cm2, the scanning speed range of the ultraviolet laser is 100-1000 mm / s, and the oxygen flow rate range of the oxygen-containing atmosphere is 10-50 L / min; In the third ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200~400 nm, the energy density range is 0.2~2 J / cm2, the scanning speed range of the ultraviolet laser is 100~1000 mm / s, and the oxygen flow range of the oxygen-containing atmosphere is 5~20 L / min.

[0012] In an optional embodiment, after forming a second passivation contact structure in at least the second region and before forming the first electrode and the second electrode, it also includes: forming a first transparent conductive layer and a second transparent conductive layer on one side of the backlight surface, the first transparent conductive layer is located in the first region and covers at least the doped polycrystalline silicon layer, and the second transparent conductive layer is located in the second region and covers at least the doped amorphous silicon layer; the first electrode is located on the first transparent conductive layer, and the second electrode is located on the second transparent conductive layer.

[0013] In an optional embodiment, after forming the first passivation contact structure in the first region and before forming the second passivation contact structure in at least the second region, the method further includes: disposing a passivation anti-reflection layer on the light-receiving surface of the base layer.

[0014] In the second aspect, the present disclosure also provides a hybrid passivation back contact solar cell, comprising: a base layer, a first passivation contact structure, a second passivation contact structure, a first electrode and a second electrode, the base layer comprising a light-receiving surface and a backlight surface arranged opposite to each other, the backlight surface comprising a first region and a second region arranged alternately; the first passivation contact structure is located in the first region, comprising a stacked tunneling oxide layer and a doped polycrystalline silicon layer, the tunneling oxide layer is arranged relatively close to the backlight surface, and an isolation groove is provided between adjacent first passivation contact structures, and the isolation groove exposes the second region; the second passivation contact structure is located at least in the second region, comprising a stacked intrinsic amorphous silicon layer and a doped amorphous silicon layer, the intrinsic amorphous silicon layer is arranged relatively close to the backlight surface, the intrinsic amorphous silicon layer also covers part of the doped polycrystalline silicon layer located in the first region, and the doped amorphous silicon layer covers the intrinsic amorphous silicon layer located in the second region; the first electrode is connected to the doped amorphous silicon, and the second electrode is connected to the doped amorphous silicon layer.

[0015] Beneficial effect: In the hybrid passivated back-contact solar cell disclosed in the present invention, the first area of ​​the backlight surface of the substrate layer forms a first passivation contact structure of a first polarity, and the first passivation contact structure includes a tunneling oxide layer and a doped polycrystalline silicon layer of a TOPCon cell-related structure; the second area of ​​the backlight surface of the substrate layer forms a second passivation contact structure of a second polarity, and the second passivation contact structure includes an intrinsic amorphous silicon layer and a doped amorphous silicon layer of a heterojunction cell-related structure, wherein the intrinsic amorphous silicon layer also covers part of the surface of the first passivation contact structure, that is, the first passivation contact structure of this embodiment is also covered with an intrinsic amorphous silicon layer, but not with the doped amorphous silicon layer; finally, a first electrode is provided to be connected to the doped polycrystalline silicon layer of the first passivation contact structure, and a second electrode is provided to be connected to the doped amorphous silicon layer of the second passivation contact structure.

[0016] Compared with the double-layer structure of the intrinsic amorphous silicon layer and the doped amorphous silicon layer covering the first passivation contact structure in the conventional solution, this embodiment only covers the first passivation contact structure in the form of a TOPCon cell with a single-layer structure of the intrinsic amorphous silicon layer. On the one hand, the single-layer intrinsic amorphous silicon layer can effectively reduce the interface state density on the surface of the doped polycrystalline silicon in the first passivation contact structure, reduce carrier recombination, and greatly improve the passivation performance of the surface of the doped polycrystalline silicon layer. If the doped amorphous silicon layer is introduced, the high defect density caused by doping will reversely increase the interface recombination, which will affect the passivation. effect; on the other hand, the introduced doped amorphous silicon layer may also generate a parasitic barrier with the doped polycrystalline silicon layer, hindering carrier transmission, while only using the intrinsic amorphous silicon layer can maintain a smooth band structure and reduce the carrier transmission resistance; in addition, a single layer of intrinsic amorphous silicon layer covering the doped polycrystalline silicon surface can also reduce the contact area between passivation contact structures of different polarities, reducing the risk of short-circuit conduction and leakage, and the conductive parts of the first passivation contact structure and the second passivation contact structure are relatively small in area on their respective side parts, which can form an anti-hot spot structure at the battery end. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 1 is a schematic flow chart of a method for preparing a hybrid passivated back contact solar cell according to an embodiment of the present disclosure; Figure 2 is a schematic structural diagram of a base layer according to an embodiment of the present disclosure; Figure 3 This is a schematic structural diagram of an embodiment of the present disclosure after a first stop layer, an initial tunneling oxide layer, an initial doped polysilicon layer, and a first protective layer are formed on the backlight surface of the base layer; Figure 4 is a schematic structural diagram after forming a first passivation contact structure according to an embodiment of the present disclosure; Figure 5 is a schematic structural diagram of an embodiment of the present disclosure after a second stop layer is formed on the doped polysilicon layer; Figure 6 is a schematic structural diagram of an embodiment of the present disclosure after an initial intrinsic amorphous silicon layer is formed on a backlight surface and a third stop layer is formed thereon; Figure 7 is a schematic structural diagram of an embodiment of the present disclosure after an initial doped amorphous silicon layer and a second protective layer are formed on the initial intrinsic amorphous silicon layer; Figure 8 2 is a schematic structural diagram of a second passivation contact structure formed after removing the second protective layer, the initial doped amorphous silicon layer located in the first region, and a portion of the initial intrinsic amorphous silicon layer according to an embodiment of the present disclosure; Figure 9 This is a schematic diagram of the structure after an initial transparent conductive layer is formed on one side of the backlight surface of the embodiment of the present disclosure; Figure 10 This is a schematic structural diagram of forming a first transparent conductive layer and a second transparent conductive layer after the initial transparent conductive layer is grooved and isolated according to an embodiment of the present disclosure; Figure 11 It is a schematic diagram of the complete structure of the hybrid passivated back contact solar cell according to an embodiment of the present disclosure.

[0019] Description of reference numerals: 1. Base layer; 11. Light-receiving surface; 111. Velvet structure; 12. Backlight surface; A. First region; B. Second region; 2. First passivation contact structure; 21. Tunneling oxide layer; 21a. Initial tunneling oxide layer; 22. Doped polysilicon layer; 22a. Initial doped polysilicon layer; 23a. Initial intrinsic polysilicon layer; 24a. First protective layer; 3. Isolation trough; 4. Second passivation contact structure; 41. Intrinsic amorphous silicon layer; 41a. Initial intrinsic amorphous silicon layer; 411. First sublayer; 412. Second sublayer; 413. Window; 42. Doped amorphous silicon layer; 43a. Second protective layer; 51. First electrode; 52. Second electrode; 61. First transparent conductive layer; 62. Second transparent conductive layer; 6a. Initial transparent conductive layer; 7. First stop layer; 8. Second stop layer; 9. The third stop layer; 10. Passivation anti-reflection layer. DETAILED DESCRIPTION

[0020] The present disclosure will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are intended only to illustrate the present disclosure and are not intended to limit it. It should also be noted that, for ease of description, the drawings only illustrate some, but not all, structures relevant to the present disclosure. In the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion about the concepts of the present disclosure. The accompanying drawings illustrate various schematic diagrams of structures according to embodiments of the present disclosure. These figures are not drawn to scale; certain details are exaggerated and may be omitted for clarity. The shapes, relative sizes, and positional relationships of the various regions and layers shown in the figures are merely illustrative and may vary in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions based on actual needs. In the context of the present disclosure, when a layer / element is referred to as being "on" another layer / element, the layer / element may be directly on the other layer / element, or an intervening layer / element may exist between them. In addition, if a layer / element is "on" another layer / element in one orientation, then when the orientation is reversed, the layer / element would be "below" the other layer / element.

[0021] refer to Figures 1 to 11 This embodiment provides a method for preparing a hybrid passivated back contact solar cell. Figure 1 Schematic diagram of the preparation method, the preparation method specifically comprises the following steps: In step S101 , a base layer 1 is provided. The base layer 1 includes a light-receiving surface 11 and a backlight surface 12 that are oppositely arranged. The backlight surface 12 includes first areas A and second areas B that are alternately arranged.

[0022] refer to Figure 1 and Figure 2 The aforementioned base layer 1 can be a silicon substrate. For example, an N-type silicon wafer cut with diamond wire is selected and then placed in an alkaline polishing bath for 6-8 minutes of double-side polishing at a temperature range of 75-85°C. The polishing removes 3-7 μm of silicon wafer thickness and 0.35-0.45 g of thinning to obtain a silicon substrate. On the backlight surface 12 side, the base layer 1 forms first regions A and second regions B of different polarities. Specifically, one of the first regions A and second regions B is a p-region, and the other is an n-region. The first regions A and second regions B are arranged alternately.

[0023] In step S102, a first passivation contact structure 2 is formed in the first region A. The first passivation contact structure 2 includes a stacked tunneling oxide layer 21 and a doped polysilicon layer 22. The tunneling oxide layer 21 is arranged relatively close to the backlight surface 12. Isolation trenches 3 are formed between adjacent first passivation contact structures 2, and the isolation trenches 3 expose the second region B.

[0024] For example, a first passivation contact structure 2 of a TOPCon cell type is prepared in the first area A of the backlight surface 12. That is, the first passivation contact structure 2 includes a tunneling oxide layer 21 on the surface of the first area A and a doped polysilicon layer 22 disposed on the tunneling oxide layer 21. Correspondingly, an isolation trench 3 exposing the second area B is formed between adjacent first passivation contact structures 2, as shown in FIG. Figure 4 The first passivation contact structure 2 can be either n-type or p-type. In this embodiment, the first passivation contact structure 2 is described as n-type.

[0025] In step S103, a second passivation contact structure 4 is formed in at least the second region B. The second passivation contact structure 4 includes an intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42 that are stacked. The intrinsic amorphous silicon layer 41 is arranged relatively close to the backlight surface 12; the intrinsic amorphous silicon layer 41 also covers a portion of the doped polycrystalline silicon layer 22 located in the first region A, and the doped amorphous silicon layer 42 covers the intrinsic amorphous silicon layer 41 located in the second region B.

[0026] For example, on the basis of having formed the first passivation contact structure 2, the second passivation contact structure 4 is further prepared in the second area B exposed by the isolation groove 3 on the side of the backlight surface 12. The second passivation contact structure 4 adopts an intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42 of a heterojunction battery type, wherein the intrinsic amorphous silicon layer 41 includes a second sublayer 412 located in the second area B and a first sublayer 411 of the partially doped polycrystalline silicon layer 22 extending to cover the first area A, but the doped amorphous silicon layer 42 is only provided on the second sublayer 412 of the intrinsic amorphous silicon layer 41 located in the second area B, as shown in FIG. Figure 8 Similarly, the second passivation contact structure 4 can be of n-type or p-type. In this embodiment, the second passivation contact structure 4 is described as p-type.

[0027] In step S104 , a first electrode 51 and a second electrode 52 are formed. The first electrode 51 is connected to the doped polysilicon layer 22 , and the second electrode 52 is connected to the doped amorphous silicon layer 42 .

[0028] Specifically, a low-temperature paste is first printed on the first passivation contact structure 2 on the first region A, and then sintered at 100-250°C with the doped polysilicon layer 22 of the first region A to form a first electrode 51 in ohmic contact with the doped polysilicon layer 22. Similarly, a low-temperature paste is printed on the second passivation contact structure 4 on the second region B, and then sintered at 100-250°C with the doped amorphous silicon layer 42 of the second region B to form a second electrode 52 in ohmic contact with the doped amorphous silicon layer 42, as shown in FIG. Figure 11 .

[0029] In summary, in the preparation method of the hybrid passivated back contact solar cell of the present embodiment, a first passivation contact structure 2 of a first polarity is first formed in the first area A of the backlight surface 12 of the substrate layer 1, and the first passivation contact structure 2 includes a tunneling oxide layer 21 and a doped polycrystalline silicon layer 22 of a TOPCon battery-related structure; then a second passivation contact structure 4 of a second polarity is formed in the second area B of the backlight surface 12 of the substrate layer 1, and the second passivation contact structure 4 includes an intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42 of a heterojunction battery-related structure, wherein the intrinsic amorphous silicon layer 41 also covers part of the surface of the first passivation contact structure 2, that is, the first passivation contact structure 2 of the present embodiment is also covered with the intrinsic amorphous silicon layer 41, but not the doped amorphous silicon layer 42; finally, a first electrode 51 is set to be connected to the doped polycrystalline silicon layer 22 of the first passivation contact structure 2, and a second electrode 52 is set to be connected to the doped amorphous silicon layer 42 of the second passivation contact structure 4.

[0030] Compared with the double-layer structure of the intrinsic amorphous silicon layer 41 and the doped amorphous silicon layer 42 covering the first passivation contact structure 2 in the conventional solution, this embodiment only covers the first passivation contact structure 2 in the form of a TOPCon cell with a single-layer structure of the intrinsic amorphous silicon layer 41. On the one hand, the single-layer intrinsic amorphous silicon layer 41 can effectively reduce the interface state density on the surface of the doped polycrystalline silicon layer 22 in the first passivation contact structure 2, reduce carrier recombination, and greatly improve the passivation performance of the surface of the doped polycrystalline silicon layer 22. If the doped amorphous silicon layer 42 is introduced, the high defect density caused by the doping will reversely increase the interface recombination, which will affect the On the other hand, the introduced doped amorphous silicon layer 42 may also generate a parasitic barrier with the doped polycrystalline silicon layer 22, hindering carrier transmission, while only using the intrinsic amorphous silicon layer 41 can maintain a smooth band structure and reduce the carrier transmission resistance; in addition, the single-layer intrinsic amorphous silicon layer 41 covers the surface of the doped polycrystalline silicon layer 22, which can also reduce the contact area between the passivation contact structures of different polarities and reduce the risk of short-circuit conduction and leakage. Moreover, the conductive parts of the first passivation contact structure 2 and the second passivation contact structure 4 are relatively small in area on their respective side parts, which can form a hot spot protection structure at the battery end.

[0031] Regarding the configuration of the passivation contact structure in a back-contact solar cell, even with conventional film layers, whether or not they overlap and the overlapping area will have a significant impact on the cell performance. Therefore, a comparative cell and a cell of this embodiment were selected for electrical performance testing. The passivation contact structure of the comparative cell is a conventional scheme, i.e., a double-layer structure of an intrinsic amorphous silicon layer and a doped amorphous silicon layer covering the first passivation contact structure in the first area of ​​the backlight surface, while the cell of this embodiment is a single-layer structure of an intrinsic amorphous silicon layer covering the first passivation contact structure in the first area of ​​the backlight surface. Based on this, the electrical performance test data obtained for the comparative cell and the cell of this embodiment are as follows:

[0032] As can be seen from the table above, the battery of this embodiment has a conversion efficiency ( η )、Open circuit voltage( V oc )、Short-circuit current density( J sc ), fill factor ( FF ) and the reverse saturation current ( Irev ) That is, the leakage parameters and other current performance parameters are better than those of the comparative battery. That is, the single-layer structure of the battery of this embodiment, which only covers the intrinsic amorphous silicon layer, can not only further passivate the surface of the doped polysilicon layer, but also reduce the risk of short circuit between the doped amorphous silicon layer and the doped polysilicon layer. Therefore, the performance of the battery of this embodiment is higher than that of the comparative battery, and the leakage value is also lower. In addition, since the coverage area of ​​the doped amorphous silicon layer is reduced, the parasitic absorption of the backlight surface will also decrease, and the optical performance of the battery ( J sc ) will be further improved.

[0033] refer to Figure 3 In one embodiment, the step S102 of forming the first passivation contact structure 2 in the first region A includes: Step S1021 : forming an initial tunneling oxide layer 21 a on the entire backlight surface 12 .

[0034] For example, an ultrathin layer of silicon oxide is deposited entirely on the backlight surface 12 of the substrate layer 1 using low-pressure chemical vapor deposition (LPCVD) technology to form an initial tunneling oxide layer 21a. The deposition process involves an oxygen flow rate ranging from 10,000 to 80,000 sccm, a temperature ranging from 400°C to 800°C, and a deposition time ranging from 200 to 1,000 seconds. The thickness of the formed initial tunneling oxide layer 21a ranges from 1 to 10 nm.

[0035] Step S1022 , forming an initial intrinsic polysilicon layer 23 a on the initial tunneling oxide layer 21 a .

[0036] Exemplarily, a layer of polysilicon is deposited on the initial tunneling oxide layer 21a using low-pressure chemical vapor deposition (LPCVD) technology to form the initial intrinsic polysilicon layer 23a. The deposition process involves a monosilane (SiH4) flow rate ranging from 300 to 2000 sccm, a temperature range of 500 to 700°C, a time range of 2 to 4 hours, and an operating pressure range of 100 to 500 mTorr. The resulting initial intrinsic polysilicon layer 23a has a thickness ranging from 100 to 300 nm.

[0037] Step S1023 : performing a first doping process on the initial intrinsic polysilicon layer 23 a to form an initial doped polysilicon layer 22 a .

[0038] For example, a phosphorus doping treatment is performed on the initial intrinsic polysilicon layer 23a, transforming the inner layer of the initial intrinsic polysilicon layer 23a into the initial doped polysilicon layer 22a. Simultaneously, a phosphorus-silicate glass (PSG) layer is formed on the surface of the initial intrinsic polysilicon layer 23a, serving as the first protective layer 24a. The phosphorus-doping treatment is specifically as follows: a mixture of phosphorus oxychloride (POCl3) and oxygen is introduced and diffused at a temperature range of 750-850°C for 5-30 minutes. The nitrogen-carried phosphorus oxychloride has a flow rate of 500-1200 sccm, and the oxygen has a flow rate of 500-1000 sccm. Oxygen is then introduced for oxidation advancement at a temperature range of 850-950°C for 20-60 minutes. The oxygen flow rate is then in the range of 1000-10000 sccm, resulting in a phosphorus-silicate glass layer with a thickness of 30-70 nm.

[0039] In step S1024 , the initial tunneling oxide layer 21 a and the initial doped polysilicon layer 22 a on the second region B are removed to form the tunneling oxide layer 21 and the doped polysilicon layer 22 in the first region A, and the isolation trench 3 exposing the second region B.

[0040] For example, a laser process is first used to pattern and groove the borosilicate glass layer in the second area B corresponding to the backlight surface 12, as well as the light-receiving surface 11 and part of the borosilicate glass layer formed on the sidewall, to pave the way for subsequent cleaning and texturing. The conditions for the above-mentioned laser process patterning and grooving are as follows: using a picosecond laser or a femtosecond laser, setting the laser wavelength range to 200~400 nm, the laser energy density range to 10~50 J / cm2, the scanning speed range to 40000~50000 mm / s, and using air or an inert gas atmosphere. Then, a wet cleaning method is used to remove the initial doped polysilicon layer 22a and the initial tunneling oxide layer 21a exposed by the borosilicate glass layer. Specifically, on the one hand, the wet cleaning process can not only remove the diffusion structure layer plated around the light-receiving surface 11 and the sidewall surface, but also form a light-trapping velvet structure 111 on the light-receiving surface 11. On the other hand, for the side of the backlight surface 12, the diffusion structure layer in the exposed second area B after the laser process can be effectively removed during the wet cleaning process. For the non-laser process-treated area of ​​the backlight surface 12 of the base layer 1, due to the presence of the borosilicate glass layer, the diffusion structure layer at the bottom can be protected during the wet cleaning process, and finally the tunneling oxide layer 21 and the doped polysilicon layer 22 located in the first area A that are not damaged are obtained, that is, the first passivation contact structure 2 is obtained in the first area A. In the wet cleaning process, potassium hydroxide solution is used for alkaline cleaning. The concentration range of potassium hydroxide solution is 1.5~1.8 wt%, the cleaning temperature range is 80~85 ℃, and the time range is 6~12 min. Finally, the borosilicate glass layer remaining on the surface is further removed by acid cleaning. Hydrofluoric acid can be used for acid cleaning to obtain the following Figure 4 A first passivation contact structure 2 is shown.

[0041] Furthermore, in the above-mentioned step S102 of forming the first passivation contact structure 2 in the first region A, before forming the initial tunneling oxide layer 21a on the entire backlight surface 12, the step further includes: performing a first ultraviolet oxidation treatment on the surface of the second region B to form a first stop layer 7, and the initial tunneling oxide layer 21a covers the first stop layer 7 and the surface of the first region A. Then, removing the initial tunneling oxide layer 21a and the initial doped polysilicon layer 22a located on the second region B further includes: removing the first stop layer 7.

[0042] refer to Figure 3Specifically, a first stop layer 7 is pre-formed on the second region B through a first UV oxidation treatment. This ensures that etching stops at the first stop layer 7 during the wet cleaning process, limiting the etching depth in the second region B to typically less than 3 μm. This also maintains a polished surface on the second region B. This not only facilitates uniform deposition of the intrinsic amorphous silicon layer 41 and the doped amorphous silicon layer 42 on the second region B, improving passivation performance, but also enhances the internal reflection of incident light within the cell, thereby improving the cell's optical performance. Furthermore, the first stop layer 7 is removed simultaneously during the final acid cleaning process to remove the borosilicate glass layer.

[0043] refer to Figures 5 to 8 In one embodiment, the step S103 of forming the second passivation contact structure 4 in at least the second region B specifically includes: In step S1031 , an initial intrinsic amorphous silicon layer 41 a is formed on the entire surface of the backlight surface 12 . The initial intrinsic amorphous silicon layer 41 a covers the surface of the isolation trench 3 and the surface of the doped polysilicon layer 22 .

[0044] refer to Figure 6 For example, a plate-type chemical vapor deposition (CVD) technique is used to deposit an initial intrinsic amorphous silicon layer 41a on the backlight surface 12 side of the base layer 1, wherein the power density during the deposition process ranges from 10 to 500 mW / cm2, the gas flow ratio of silane (SiH4) and hydrogen (H2) ranges from 1:1 to 1:10, the gas pressure ranges from 10 to 500 Pa, and the temperature ranges from 100 to 250°C. The thickness of the formed initial intrinsic amorphous silicon layer 41a ranges from 3 to 20 nm.

[0045] Step S1032 , forming an initial doped amorphous silicon layer 42 on the initial intrinsic amorphous silicon layer 41 a .

[0046] refer to Figure 7For example, an initial doped amorphous silicon layer 42 is deposited on the initial intrinsic amorphous silicon layer 41a, and a second protective layer 43a is formed on the initial doped amorphous silicon layer 42. The second protective layer 43a is silicon oxide, and the initial doped amorphous silicon layer 42 is a boron-doped amorphous silicon layer. The deposition process parameters for forming the initial doped amorphous silicon layer 42 are as follows: a power density ranging from 20 to 300 mW / cm2, a gas flow ratio of silane to hydrogen ranging from 1:10 to 1:100, a gas flow ratio of diborane (B2H6) to silane (SiH4) ranging from 100:1 to 3:1, a gas pressure ranging from 50 to 500 Pa, and a temperature ranging from 100°C to 250°C. The resulting initial doped amorphous silicon layer 42 has a thickness ranging from 10 to 50 nm. The preparation process parameters for forming the second protective layer 43a are as follows: power density range is 50-300 mW / cm2, oxygen flow rate range is 100-1000 sccm, temperature range is 100-250°C, and the thickness of the formed second protective layer 43a ranges from 5 to 20 nm.

[0047] In step S1033, all of the initial doped amorphous silicon layer 42 and part of the initial intrinsic amorphous silicon layer 41a located in the first region A are removed to form an intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42. A window 413 is formed in the intrinsic amorphous silicon layer 41 located in the first region A, and the window 413 exposes part of the doped polycrystalline silicon layer 22; the doped amorphous silicon layer 42 is located on the intrinsic amorphous silicon layer 41 in the second region B.

[0048] refer to Figure 8For example, a laser process is first used to pattern and groove the second protective layer 43a in the first region A corresponding to the backlight surface 12. The second protective layer 43a in the second region B protects the structures in the second region B during the subsequent wet cleaning process. The specific conditions for this laser patterning groove are: using a picosecond laser or a femtosecond laser, setting the laser wavelength to a range of 200-400 nm, the laser energy density to a range of 10-50 J / cm2, the scanning speed to a range of 40,000-50,000 mm / s, and using an air or inert gas atmosphere. Afterwards, a wet cleaning method is used to remove the doped amorphous silicon layer 42 and part of the intrinsic amorphous silicon layer 41 exposed by the second protective layer 43a, so that the intrinsic amorphous silicon layer 41 corresponding to the first region A forms a window 413 exposing the doped polycrystalline silicon layer 22. The part that does not need to be cleaned and removed can be selectively protected by a shielding structure such as a mask, thereby achieving selective partial removal. This wet cleaning process can effectively remove the doped amorphous silicon layer 42 and part of the intrinsic amorphous silicon layer 41 in the first region A exposed after laser treatment, and finally obtain the intrinsic amorphous silicon layer 41 and the doped amorphous silicon layer 42 located in the second region B that are not damaged. At the same time, the single-layer structure of the intrinsic amorphous silicon layer 41 is retained on the doped polycrystalline silicon layer 22 in the first region A, thereby enhancing the passivation performance, and thus obtaining the first passivation contact structure 2. In this step, the wet cleaning process uses a potassium hydroxide solution for alkaline cleaning. The concentration of the potassium hydroxide solution ranges from 1.9 to 2.2 wt%, the cleaning temperature ranges from 70 to 85°C, and the cleaning time ranges from 1 to 5 minutes. The solution concentration, cleaning temperature, and cleaning time are strictly controlled to ensure the desired morphological properties of the intrinsic amorphous silicon layer 41. Finally, an acid cleaning is performed to further remove any remaining second protective layer 43a. The acid cleaning solution can be hydrofluoric acid.

[0049] Furthermore, in the above-mentioned step S103 of forming the second passivation contact structure 4 in at least the second region B, before the step S103 of forming the initial intrinsic amorphous silicon layer 41a on the entire surface of the backlight surface 12, it also includes: performing a second ultraviolet oxidation treatment on a portion of the surface of the doped polycrystalline silicon layer 22 to form a second stop layer 8; the initial intrinsic amorphous silicon layer 41a covers the surface of the isolation groove 3, the surface of the doped amorphous silicon layer 42 and the surface of the second stop layer 8.

[0050] refer to Figure 5 A second stop layer 8 is formed in advance on the surface of a portion of the doped polysilicon layer 22 in the first region A through a second ultraviolet oxidation treatment, so that after the subsequent laser removal process and wet cleaning process, the surface of the doped polysilicon layer 22 can be accurately etched without causing the doped polysilicon layer 22 to be removed simultaneously, thereby ensuring the reliability of the connection between the subsequent first electrode 51 and the doped polysilicon layer 22.

[0051] After step S1031 of forming an initial intrinsic amorphous silicon layer 41a on the entire surface of one side of the backlight surface 12, and before step S1032 of forming an initial doped amorphous silicon layer 42 on the initial intrinsic amorphous silicon layer 41a, the method further includes: performing a third ultraviolet oxidation treatment on a portion of the surface of the initial doped amorphous silicon located on the first area A to form a third stop layer 9, and the projection of the doped amorphous silicon layer 42 not covered by the third stop layer 9 on the first area A is located within the projection of the second stop layer 8 on the first area A.

[0052] refer to Figure 6 A third stop layer 9 is formed on the surface of a portion of the initial intrinsic polysilicon layer 23a in the first region A through a third UV oxidation treatment. Within the first region A, the projected area of ​​the third stop layer 9 is greater than or equal to the area not covered by the projected area of ​​the second stop layer 8. Therefore, during the subsequent wet cleaning process, the initial doped amorphous silicon layer 42 in the first region A and the initial intrinsic amorphous silicon layer 41a in the area not covered by the third stop layer 9 are removed, while the initial intrinsic amorphous silicon layer 41a covered by the third stop layer 9 remains. Furthermore, the second stop layer 8 prevents corrosion of the doped polysilicon layer 22 at the window 413 in the initial intrinsic amorphous silicon layer 41a, thus ensuring the integrity of the doped polysilicon layer 22. This reduces the risk of subsequent large-scale short circuit leakage between the first passivation contact structure 2 in the first region A and the second passivation contact structure 4 in the second region B. Furthermore, the intrinsic amorphous silicon layer 41 remaining on the doped polysilicon layer 22 further improves the passivation performance.

[0053] On this basis, the above-mentioned removal of the entire initial doped amorphous silicon layer 42 and a portion of the initial intrinsic amorphous silicon layer 41a located on the first region A further includes: removing the second stop layer 8 and the third stop layer 9. In other words, the formed second stop layer 8 and the third stop layer 9 are removed simultaneously when the second protective layer 43a is removed in the above-mentioned final acid cleaning process.

[0054] In one embodiment, the process parameters of the first and second ultraviolet oxidation treatments are the same, and the process energy density and oxygen flow rate of the third ultraviolet oxidation treatment are smaller than those of the first and second ultraviolet oxidation treatments.

[0055] Compared with the first and second ultraviolet oxidation treatments, the third ultraviolet oxidation treatment has a lower energy density and less oxygen flow. This is mainly because when the initial doped amorphous silicon and part of the initial intrinsic amorphous silicon corresponding to the first area A are finally removed, the wet process used has a relatively short processing time and does not require a thicker third stop layer 9 for protection. At the same time, the initial intrinsic amorphous silicon layer 41a is also thin. If a thicker third stop layer 9 is grown on its surface, it will affect the thin film properties of the initial intrinsic amorphous silicon layer 41a.

[0056] Specifically, in the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200-400 nm, the energy density range is 0.5-5 J / cm2, the scanning speed range of the ultraviolet laser is 100-1000 mm / s, and the oxygen flow rate range of the oxygen-containing atmosphere is 10-50 L / min; In the third ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200~400 nm, the energy density range is 0.2~2 J / cm2, the scanning speed range of the ultraviolet laser is 100~1000 mm / s, and the oxygen flow range of the oxygen-containing atmosphere is 5~20 L / min.

[0057] Within the above parameter range, the first stop layer 7, the second stop layer 8 and the third stop layer 9 formed have good film properties themselves, which can effectively protect the target structural layer. At the same time, it is also convenient for subsequent process removal to avoid affecting the continued deposition of other subsequent structural layers, thereby improving the overall structural performance of the battery.

[0058] In one embodiment, reference Figures 9 to 11 , after step S103 of forming the second passivation contact structure 4 in at least the second region B and before step S104 of forming the first electrode 51 and the second electrode 52, the method further includes: forming a first transparent conductive layer 61 and a second transparent conductive layer 62 on one side of the backlight surface 12, the first transparent conductive layer 61 being located in the first region A and at least covering the doped polycrystalline silicon layer 22, the second transparent conductive layer 62 being located in the second region B and at least covering the doped amorphous silicon layer 42; the first electrode 51 being located on the first transparent conductive layer 61, and the second electrode 52 being located on the second transparent conductive layer 62.

[0059] refer to Figure 9 First, physical vapor deposition (PVD) or reactive plasma deposition (RPD) is used to deposit an initial transparent conductive layer 6a on the entire surface of the backlight surface 12. This initial transparent conductive layer 6a can be one or more of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), indium tungsten oxide (IWO), indium cerium oxide (ICO), or indium zinc oxide (IZO). Furthermore, the thickness of the initial transparent conductive layer 6a is typically set between 50 and 200 nm, the refractive index ranges from 1.5 to 2.5, and the sheet resistance is 30 to 300 Ω / □. Subsequently, to prevent direct conduction between the first passivation contact structure 2 in the first region A and the second passivation contact structure 4 in the second region B, a laser process is used to cut and segment the initial transparent conductive layer 6a to isolate the structures of different polarity regions. This results in a first transparent conductive layer 61 located in the first region A and connected to the first passivation contact structure 2, and a second transparent conductive layer 62 located in the second region B and connected to the second passivation contact structure 4, as shown in FIG. Figure 10The laser process conditions in this step are as follows: using a picosecond laser or a femtosecond laser, setting the laser wavelength range to 200-400 nm, the laser energy density range to 10-50 J / cm2, the scanning speed range to 40,000-50,000 mm / s, using air or an inert gas atmosphere, and finally printing a low-temperature paste on the first transparent conductive layer 61 and the second transparent conductive layer 62 respectively to achieve sintering, thereby obtaining the first electrode 51 and the second electrode 52, as shown. Figure 11 The first transparent conductive layer 61 and the second transparent conductive layer 62 help reduce the transmission loss of charge directly from the passivation contact structure to the electrode, thereby increasing the output power of the battery and thus improving the photoelectric conversion efficiency. At the same time, they can also improve the weather resistance of the battery and extend its service life.

[0060] refer to Figures 4 to 8 In one embodiment, after step S102 of forming the first passivation contact structure 2 in the first area A and before step S103 of forming the second passivation contact structure 4 in at least the second area B, it also includes: setting a passivation anti-reflection layer 10 on the light-receiving surface 11 of the base layer 1.

[0061] It can be known that, during the process of preparing the first passivation contact structure 2 in step S102, the wet cleaning process will simultaneously form a pyramid-shaped velvet structure 111 on the light-receiving surface 11 of the battery. Figure 4 On this basis, in this embodiment, the plate-type atomic layer deposition (ALD) technology and plasma enhanced chemical vapor deposition (PECVD) technology are used to deposit and form the passivation anti-reflection layer 10 on the light-receiving surface 11 of the base layer 1 . First, an aluminum oxide film is formed on the light-receiving surface 11 of the treated substrate layer 1 using a plate-type ALD deposition technology. The aluminum oxide film is generated by the reaction of trimethylaluminum (Al(CH3)3) with water vapor, with a thickness ranging from 8 to 10 nm and a process temperature controlled between 220 and 280°C. Then, a silicon nitride film is deposited on the aluminum oxide film using a PECVD device. The silicon nitride film has a thickness ranging from 80 to 120 nm and a refractive index ranging from 1.9 to 2.1. The reaction gases in the tubular cavity of the device are SiH4 and NH3, the operating pressure range is 1500 to 1700 mTorr, the power range is 10,000 to 15,000 W, the temperature range is 400 to 600°C, the gas flow rate of SiH4 is 900 to 2000 sccm, the gas flow rate of NH3 is 7000 to 12000 sccm, and the deposition time range is 5 to 20 min. The passivation anti-reflection layer 10 on the light-receiving surface 11 adopts a stacked structure of aluminum oxide film and silicon nitride film, which not only reduces the surface carrier recombination of the light-receiving surface 11, but also greatly enhances the light absorption capacity of the light-receiving surface 11 of the battery, thereby improving the photoelectric conversion efficiency of the battery.

[0062] refer to Figure 11 The present embodiment provides a hybrid passivated back contact solar cell, which is manufactured by the above-mentioned method for manufacturing a hybrid passivated back contact solar cell, and includes: a base layer 1, a first passivated contact structure 2, a second passivated contact structure 4, a first electrode 51 and a second electrode 52, wherein the base layer 1 includes a light-receiving surface 11 and a backlight surface 12 arranged opposite to each other, and the backlight surface 12 includes a first area A and a second area B arranged alternately; the first passivated contact structure 2 is located in the first area A, and includes a stacked tunneling oxide layer 21 and a doped polysilicon layer 22, and the tunneling oxide layer 21 is relatively close to the backlight surface 12. The first passivation contact structure 2 is provided with an isolation trench 3 between adjacent first passivation contact structures 2, and the isolation trench 3 exposes the second region B; the second passivation contact structure 4 is located at least in the second region B, and includes a stacked intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42, the intrinsic amorphous silicon layer 41 is relatively close to the backlight surface 12, the intrinsic amorphous silicon layer 41 also covers a portion of the doped polycrystalline silicon layer 22 located in the first region A, and the doped amorphous silicon layer 42 covers the intrinsic amorphous silicon layer 41 located in the second region B; the first electrode 51 is connected to the doped polycrystalline silicon layer 22, and the second electrode 52 is connected to the doped amorphous silicon layer 42.

[0063] Specifically, in the hybrid passivated back contact solar cell of the present embodiment, the first area A of the backlight surface 12 of the substrate layer 1 forms a first passivation contact structure 2 of a first polarity, and the first passivation contact structure 2 includes a tunneling oxide layer 21 and a doped polycrystalline silicon layer 22 of a TOPCon cell-related structure; the second area B of the backlight surface 12 of the substrate layer 1 forms a second passivation contact structure 4 of a second polarity, and the second passivation contact structure 4 includes an intrinsic amorphous silicon layer 41 and a doped amorphous silicon layer 42 of a heterojunction cell-related structure, wherein the intrinsic amorphous silicon layer 41 also covers part of the surface of the first passivation contact structure 2, that is, the first passivation contact structure 2 of the present embodiment is also covered with the intrinsic amorphous silicon layer 41, but not the doped amorphous silicon layer 42.

[0064] Compared with the double-layer structure of the intrinsic amorphous silicon layer 41 and the doped amorphous silicon layer 42 covering the first passivation contact structure 2 in the conventional solution, this embodiment only covers the first passivation contact structure 2 in the form of a TOPCon cell with a single-layer structure of the intrinsic amorphous silicon layer 41. On the one hand, the single-layer intrinsic amorphous silicon layer 41 can effectively reduce the interface state density on the surface of the doped polycrystalline silicon layer 22 in the first passivation contact structure 2, reduce carrier recombination, and greatly improve the passivation performance of the surface of the doped polycrystalline silicon layer 22. If the doped amorphous silicon layer 42 is introduced, the high defect density caused by the doping will reversely increase the interface recombination, which will affect the On the other hand, the introduced doped amorphous silicon layer 42 may also generate a parasitic barrier with the doped polycrystalline silicon layer 22, hindering carrier transmission, while only using the intrinsic amorphous silicon layer 41 can maintain a smooth band structure and reduce the carrier transmission resistance; in addition, the single-layer intrinsic amorphous silicon layer 41 covers the surface of the doped polycrystalline silicon layer 22, which can also reduce the contact area between the passivation contact structures of different polarities and reduce the risk of short-circuit conduction and leakage. Moreover, the conductive parts of the first passivation contact structure 2 and the second passivation contact structure 4 are relatively small in area on their respective side parts, which can form a hot spot protection structure at the battery end.

[0065] The further functional description of each of the above structures is the same as that of the above corresponding embodiments and will not be repeated here.

[0066] While the above description does not provide detailed technical details regarding the patterning and etching of each layer, those skilled in the art will appreciate that various technical means can be employed to form layers, regions, and the like in desired shapes. Furthermore, those skilled in the art may devise methods that differ from those described above to form the same structure. Furthermore, while each embodiment has been described separately, this does not mean that the measures in each embodiment cannot be advantageously combined.

[0067] Although the embodiments of the present disclosure have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for preparing a hybrid passivated back contact solar cell, characterized in that: include: Providing a base layer, the base layer comprising a light-receiving surface and a backlight surface disposed opposite to each other, the backlight surface comprising first areas and second areas arranged alternately; forming a first passivation contact structure in the first region, the first passivation contact structure comprising a stacked tunneling oxide layer and a doped polysilicon layer, the tunneling oxide layer being relatively close to the backlight surface; forming isolation trenches between adjacent first passivation contact structures, the isolation trenches exposing the second region; forming a second passivation contact structure in at least the second region, the second passivation contact structure comprising a stacked intrinsic amorphous silicon layer and a doped amorphous silicon layer, the intrinsic amorphous silicon layer being relatively close to the backlight surface; the intrinsic amorphous silicon layer also covering a portion of the doped polycrystalline silicon layer in the first region, and the doped amorphous silicon layer covering the intrinsic amorphous silicon layer in the second region; A first electrode and a second electrode are formed, wherein the first electrode is connected to the doped polysilicon layer, and the second electrode is connected to the doped amorphous silicon layer.

2. The method for preparing a hybrid passivated back contact solar cell according to claim 1, wherein: The forming of a first passivation contact structure in the first region includes: forming an initial tunneling oxide layer on the entire backlight surface; forming an initial intrinsic polysilicon layer on the initial tunneling oxide layer; performing a first doping process on the initial intrinsic polysilicon layer to form an initial doped polysilicon layer; The initial tunneling oxide layer and the initial doped polysilicon layer located on the second region are removed to form the tunneling oxide layer and the doped polysilicon layer located in the first region, and the isolation trench is exposed in the second region.

3. The method for preparing a hybrid passivated back contact solar cell according to claim 2, wherein: In the step of forming a first passivation contact structure in the first region, Before forming the initial tunneling oxide layer on the entire backlight surface, the method further includes: performing a first ultraviolet oxidation treatment on the surface of the second region to form a first stop layer, wherein the initial tunneling oxide layer covers the first stop layer and the surface of the first region; The removing of the initial tunneling oxide layer and the initial doped polysilicon layer on the second region further includes: removing the first stop layer.

4. The method for preparing a hybrid passivated back contact solar cell according to claim 3, wherein: The forming of a second passivation contact structure in at least the second region includes: forming an initial intrinsic amorphous silicon layer on the entire surface of the backlight side, wherein the initial intrinsic amorphous silicon layer covers the surface of the isolation trench and the surface of the doped polysilicon layer; forming an initial doped amorphous silicon layer on the initial intrinsic amorphous silicon layer; All of the initial doped amorphous silicon layer and part of the initial intrinsic amorphous silicon layer located in the first region are removed to form the intrinsic amorphous silicon layer and the doped amorphous silicon layer. The intrinsic amorphous silicon layer located in the first region forms a window, and the window exposes part of the doped polycrystalline silicon layer; the doped amorphous silicon layer is located on the intrinsic amorphous silicon layer in the second region.

5. The method for preparing a hybrid passivated back contact solar cell according to claim 4, characterized in that: In the step of forming a second passivation contact structure in at least the second region, Before forming the initial intrinsic amorphous silicon layer on the entire backlight side, the method further includes: performing a second ultraviolet oxidation treatment on a portion of the surface of the doped polysilicon layer to form a second stop layer; the initial intrinsic amorphous silicon layer covers the surface of the isolation trench, the surface of the doped amorphous silicon layer, and the surface of the second stop layer; After forming an initial intrinsic amorphous silicon layer on the entire surface of one side of the backlight surface and before forming an initial doped amorphous silicon layer on the initial intrinsic amorphous silicon layer, the method further includes: performing a third ultraviolet oxidation treatment on a portion of the surface of the initial doped amorphous silicon layer located on the first region to form a third stop layer, wherein a projection of the doped amorphous silicon layer not covered by the third stop layer on the first region is located within a projection of the second stop layer on the first region; Removing the entirety of the initial doped amorphous silicon layer and a portion of the initial intrinsic amorphous silicon layer located on the first region further includes: removing the second stop layer and the third stop layer.

6. The method for preparing a hybrid passivated back contact solar cell according to claim 5, characterized in that: The process parameters of the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment are the same, and the process energy density and oxygen flow rate of the third ultraviolet oxidation treatment are smaller than those of the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment.

7. The method for preparing a hybrid passivated back contact solar cell according to claim 6, characterized in that: In the first ultraviolet oxidation treatment and the second ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200-400 nm, the energy density range is 0.5-5 J / cm2, the scanning speed range of the ultraviolet laser is 100-1000 mm / s, and the oxygen flow rate range of the oxygen-containing atmosphere is 10-50 L / min; In the third ultraviolet oxidation treatment, the wavelength range of the ultraviolet laser is 200~400 nm, the energy density range is 0.2~2 J / cm2, the scanning speed range of the ultraviolet laser is 100~1000 mm / s, and the oxygen flow range of the oxygen-containing atmosphere is 5~20 L / min.

8. The method for preparing a hybrid passivated back contact solar cell according to any one of claims 1 to 7, characterized in that: After forming the second passivation contact structure in at least the second region and before forming the first electrode and the second electrode, the method further includes: A first transparent conductive layer and a second transparent conductive layer are formed on one side of the backlight surface, wherein the first transparent conductive layer is located in the first region and at least covers the doped polycrystalline silicon layer, and the second transparent conductive layer is located in the second region and at least covers the doped amorphous silicon layer; the first electrode is located on the first transparent conductive layer, and the second electrode is located on the second transparent conductive layer.

9. The method for preparing a hybrid passivated back contact solar cell according to claim 8, characterized in that: After forming a first passivation contact structure in the first region and before forming a second passivation contact structure in at least the second region, the method further includes: disposing a passivation anti-reflection layer on the light-receiving surface of the base layer.

10. A hybrid passivated back contact solar cell, characterized in that: include: a base layer, the base layer comprising a light-receiving surface and a backlight surface opposite to each other, the backlight surface comprising first areas and second areas alternately arranged; a first passivation contact structure located in the first region, the first passivation contact structure comprising a stacked tunneling oxide layer and a doped polysilicon layer, the tunneling oxide layer being relatively close to the backlight surface; and an isolation trench being defined between adjacent first passivation contact structures, the isolation trench exposing the second region; a second passivation contact structure, located at least in the second region, the second passivation contact structure comprising a stacked intrinsic amorphous silicon layer and a doped amorphous silicon layer, the intrinsic amorphous silicon layer being relatively close to the backlight surface; the intrinsic amorphous silicon layer also covering a portion of the doped polycrystalline silicon layer located in the first region, and the doped amorphous silicon layer covering the intrinsic amorphous silicon layer located in the second region; A first electrode and a second electrode, the first electrode is connected to the doped polysilicon layer, and the second electrode is connected to the doped amorphous silicon layer.

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