TBC solar cell and preparation method thereof

Abstract

The invention provides a TBC solar cell and a preparation method thereof. The method for preparing the TBC solar cell comprises the steps that a tunneling oxide layer and a first intrinsic amorphous silicon layer are sequentially deposited on the back face of a silicon substrate; first doping source deposition, propelling, second doping source deposition and cooling treatment are carried out on the surface, away from the silicon substrate, of the first intrinsic amorphous silicon layer, doping of the first intrinsic amorphous silicon layer is achieved, a p-type doped polycrystalline silicon layer is obtained, and oxygen is introduced in the process of the first doping source deposition and the second doping source deposition; in the p + region, a first glass layer is formed on the surface, far away from the silicon substrate, of the p-type doped polycrystalline silicon layer; taking the first glass layer as a mask, and removing the corresponding p-type doped polycrystalline silicon layer and tunneling oxide layer in the n + region; forming an n-type doped polycrystalline silicon layer in the n + region; a positive electrode is formed in the p + region, and a negative electrode is formed in the n + region. According to the preparation method, the process window is relatively wide, the preparation efficiency and the yield of the battery can be improved, and the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a TBC solar cell and a preparation method thereof. Background Art

[0002] With the rapid development of photovoltaic technology, the conversion efficiency of crystalline silicon solar cells has increased year by year. At present, the mainstream TOPCon cells have almost replaced the P-type bifacial PERC cells to become the mainstream product of the solar cell manufacturing industry. At the same time, various manufacturers have also begun to develop the next generation of cells that are more efficient than TOPCon cells. Among them, TBC solar cells stand out with many advantages such as high conversion efficiency and high compatibility with TOPCon cell production lines. Many manufacturers in the industry have begun to increase their investment in the research and development and production of TBC cells. The production technology of TBC solar cells is complicated, the requirements are high, and the production cost is high. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide a method for preparing a TBC solar cell, which has a high preparation efficiency.

[0004] In one aspect of the present invention, the present invention provides a method for preparing a TBC solar cell. According to an embodiment of the present invention, the method for preparing a TBC solar cell includes: depositing a tunneling oxide layer and a first intrinsic amorphous silicon layer on the back of a silicon substrate in sequence; performing a first deposition doping source, a push-up, a second deposition doping source, and a temperature reduction treatment on the surface of the first intrinsic amorphous silicon layer away from the silicon substrate to achieve doping of the first intrinsic amorphous silicon layer to obtain a p-type doped polycrystalline silicon layer, wherein oxygen is introduced during the first deposition doping source and the second deposition doping source process; in the p+ region, a first glass layer is formed on the surface of the p-type doped polycrystalline silicon layer away from the silicon substrate; using the first glass layer as a mask, the corresponding p-type doped polycrystalline silicon layer and the tunneling oxide layer in the n+ region are removed; forming an n-type doped polycrystalline silicon layer in the n+ region; forming a positive electrode in the p+ region and a negative electrode in the n+ region. Therefore, in the process of forming a p-type doped polysilicon layer by p-type ion doping, two-step doping source deposition of a first deposition doping source and a second deposition doping source is required, but oxygen only needs to be introduced during the two-step deposition process, and no further additional oxygen is required during the advancement and cooling processes. In this way, the amount of oxygen introduced can be reduced and the cost can be reduced; and the second deposition doping source can also be used for the subsequent formation of the first glass layer.

[0005] According to an embodiment of the present invention, the conditions for depositing the first doping source include: a deposition temperature of 800-860° C.; a deposition pressure of 100-200 mbar; an oxygen flow rate of 100-600 sccm; and a deposition rate of the doping source of 150-220 sccm.

[0006] According to an embodiment of the present invention, the conditions for depositing the second doping source include: a deposition temperature of 800-860° C.; a deposition pressure of 100-150 mbar; an oxygen flow rate of 10-200 sccm; and a deposition amount of the doping source of 20-120 sccm.

[0007] According to an embodiment of the present invention, the pushing temperature is 920-970° C., and the pushing time is 200-3000 s.

[0008] According to an embodiment of the present invention, the method for forming the first glass layer is: irradiating laser light only on the p+ region, and forming the first glass layer using doping ions of the second deposition doping source and oxygen in the air.

[0009] According to an embodiment of the present invention, the conditions for laser irradiation are as follows: the spot overlap rate is 5-10%; the line overlap rate is 10-30%; and the power is 5-10W.

[0010] According to an embodiment of the present invention, the p-type doped polysilicon layer and the tunneling oxide layer corresponding to the n+ region are removed by wet etching, and the wet etching conditions are: alkali volume ratio is 10-18%, temperature is 65-80°C, and time is 120-200 seconds.

[0011] According to an embodiment of the present invention, the step of forming the n-type doped polysilicon layer in the n+ region includes: depositing a second intrinsic amorphous silicon layer in the n+ region and the p+ region; depositing a third doping source and advancing on the surface of the second intrinsic amorphous silicon layer away from the silicon substrate to obtain the n-type doped polysilicon layer, and forming a second glass layer on the surface of the n-type doped polysilicon layer; laser removing the second glass layer in the p+ region; and etching and removing the corresponding n-type doped polysilicon layer in the p+ region using the second glass layer in the n+ region as a mask.

[0012] According to an embodiment of the present invention, before forming the positive electrode and the negative electrode, it also includes: texturing the front side of the silicon substrate to obtain a texturing structure; removing the remaining first glass layer in the p+ region and the remaining second glass layer in the n+ region on the back side; depositing a front passivation layer and a back passivation layer on the front and back sides respectively; and depositing a front anti-reflection layer and a back anti-reflection layer on the front and back sides respectively.

[0013] In another aspect of the present invention, the present invention provides a TBC solar cell. According to an embodiment of the present invention, the TBC solar cell is prepared by the method described above. Therefore, the TBC solar cell prepared by the above preparation method has good working performance, high preparation efficiency, and a better collaborative process window of the implementation steps in the preparation process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0015] Figure 1 is a flow chart of a method for preparing a TBC solar cell in one embodiment of the present invention;

[0016] Figures 2 to 12 It is a schematic diagram of the structure of preparing a TBC solar cell in another embodiment of the present invention. DETAILED DESCRIPTION

[0017] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0018] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0019] In one aspect of the present invention, the present invention provides a method for preparing a TBC solar cell. Figure 1 , a method for preparing a TBC solar cell comprises:

[0020] S100: A tunneling oxide layer 20 and a first intrinsic amorphous silicon layer 31 are sequentially deposited on the back side of the silicon substrate 10. The schematic diagram of the structure can be referred to Figure 2 .

[0021] In some embodiments of the present invention, the tunneling oxide layer 20 can be prepared by deposition methods such as chemical vapor deposition (such as low pressure chemical vapor deposition LPCVD), magnetron sputtering, etc. In some specific embodiments, the tunneling oxide layer 20 is formed by reacting pure oxygen at a temperature of 550 to 640° C. for 50 to 3000 seconds using LPCVD. The thickness of the tunneling oxide layer can be 1.2 to 1.8 nm.

[0022] In some embodiments of the present invention, the first intrinsic amorphous silicon layer 31 can be prepared by deposition methods such as chemical vapor deposition (such as low pressure chemical vapor deposition LPCVD), magnetron sputtering, etc. In some specific embodiments, the first intrinsic amorphous silicon layer 31 is formed by LPCVD at 500-640° C. by decomposition and deposition of silane. The thickness of the first intrinsic amorphous silicon layer 31 can be 100-600 nm.

[0023] In some embodiments of the present invention, before depositing the tunneling oxide layer, the back surface of the silicon substrate can be pretreated in advance. Specifically, the surface of the silicon substrate can be treated with alkali and additives (such as alkali and hydrogen peroxide) to remove contamination on the surface of the silicon substrate and eliminate structural damage on the surface, thereby forming a good interface morphology.

[0024] S200: Performing a first deposition doping source, advancing, a second deposition doping source, and a temperature reduction process on the first intrinsic amorphous silicon layer 31 away from the silicon substrate 10 to achieve doping of the first intrinsic amorphous silicon layer to obtain a p-type doped polysilicon layer 32, wherein oxygen is introduced during the first deposition doping source and the second deposition doping source process. The structural schematic diagram can be referred to Figure 3 .

[0025] In this step, two steps of doping source deposition, namely the first deposition doping source and the second deposition doping source, are required. However, oxygen only needs to be introduced during the two-step deposition process, and no additional oxygen needs to be introduced during the advancement and cooling process. The oxygen introduced in the above method is sufficient to react with the doping source to achieve doping of the first intrinsic amorphous silicon layer. There is no need to introduce additional oxygen to form the first glass layer. In this way, the amount of oxygen introduced can be reduced, thereby reducing costs.

[0026] In some specific embodiments, the first deposition doping source and the second deposition doping source may be a deposition boron source, such as BCl 3 , that is, the first intrinsic amorphous silicon layer is doped with boron.

[0027] According to some embodiments of the present invention, the deposition temperature of the first deposition doping source is 800-860°C, such as 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, etc. In some specific embodiments, the temperature of the first deposition doping source may be 800-840°C; according to some embodiments of the present invention, the deposition pressure during the first deposition doping source process is 100-200mbar, such as 100mbar, 110mbar, 120mbar, 130mbar, 140mbar, 150mbar, 160mbar, 170mbar, 180mbar, 190mbar, 200mbar, etc.; according to some embodiments of the present invention, the oxygen flow rate during the first deposition doping source process is 100-600sccm, For example, it is 100sccm, 150sccm, 200sccm, 250sccm, 300sccm, 350sccm, 400sccm, 450sccm, 500sccm, 550sccm, 600sccm, etc. According to some embodiments of the present invention, the deposition amount of the doping source in the first deposition doping source process is 150-220sccm, for example, 150sccm, 160sccm, 170sccm, 180sccm, 190sccm, 200sccm, 210sccm, 220sccm, etc. Under the above deposition conditions, it is helpful to obtain a p-type doped polysilicon layer 32 with better quality by doping.

[0028] According to some embodiments of the present invention, the advancing temperature is 920-970° C., such as 920° C., 925° C., 930° C., 935° C., 940° C., 945° C., 950° C., 955° C., 960° C., 965° C., 970° C., etc., and the advancing time is 200-3000s, such as 200s, 500s, 1000s, 1200s, 1500s, 1800s, 2000s, 2200s, 2400s, 2600s, 2800s, 3000s, etc. Thus, under the above conditions, the doping of the first intrinsic amorphous silicon layer by the first deposited doping source can be efficiently achieved.

[0029] According to some embodiments of the present invention, the deposition temperature of the second deposition doping source is 800-860°C, such as 800°C, 810°C, 820°C, 830°C, 840°C, 850°C, 860°C, etc. In some specific embodiments, the temperature of the second deposition doping source can be 800-840°C; according to some embodiments of the present invention, the deposition pressure in the second deposition doping source process is 100-150mbar, such as 100mbar, 110mbar, 120mbar, 130mbar, 140mbar, 150mbar, etc.; according to some embodiments of the present invention, the oxygen flow rate in the second deposition doping source process is 10-200sccm, such as 10sccm, 20sccm, 50sccm, 80sccm, 100sccm, 120sccm, 150sccm, 180sccm, 200sccm, etc.; according to some embodiments of the present invention, the deposition amount of the doping source in the second deposition doping source process is 20-120sccm, such as 20sccm, 40sccm, 50sccm, 60sccm, 70sccm, 80sccm, 90sccm, 100sccm, 110sccm, 120sccm, etc. It can be seen that compared with the first deposition doping source, the oxygen flux and deposition amount of the second deposition doping source are both less, that is, a light second deposition is sufficient to form the first glass layer, which can reduce the difficulty and cost of the process conditions.

[0030] According to some embodiments of the present invention, the temperature reduction process is to reduce the temperature of the deposition equipment from the advancing temperature to the temperature required for deposition in the subsequent step.

[0031] S300: In the p+ region, a first glass layer 41 is formed on the surface of the p-type doped polysilicon layer 32 away from the silicon substrate 10. The structural diagram can be referred to Figure 3 If a boron doping source is used, the first glass layer is borosilicate glass (BSG).

[0032] According to some embodiments of the present invention, the method for forming the first glass layer is: irradiating laser light only in the p+ region, and forming the first glass layer using doping ions of the second deposition doping source and oxygen in the air. In some specific embodiments, in a laser, the surface of the second deposition doping source is acted on by laser light, and the second deposition doping source is used to deposit ions and oxygen in the air to form the first glass layer on the surface of the p-type doped polysilicon layer. Since the laser is irradiated only in the p-region, the first glass layer is formed only in the p+ region in this step, and no glass layer is formed in the n+ region. In this way, there is no need to use laser to pattern the glass layer and remove the glass layer in the n+ region, thereby simplifying the process flow. Moreover, compared with laser patterning, laser heat is used to form the first glass layer in a specific p+ region in this step. The power of the laser used is small, the energy consumption is low, the equipment cost can be greatly reduced, and the production efficiency is high. Furthermore, in the process of forming the first glass layer, only a small amount of oxygen in the air is needed to form the first glass layer. Compared with the method in the prior art that forms the first glass layer by using a large amount of oxygen during the first deposition doping source, advancement and cooling process, the method of the present invention can greatly reduce the amount of oxygen used and simplify the process flow. At the same time, compared with the method of laser mold opening (laser patterning of the glass layer), the method of the present invention greatly reduces the power required for the laser, greatly reduces the laser cost, and widens the process window.

[0033] According to some embodiments of the present invention, the spot overlap rate of the laser irradiation is 5-10%, such as 5%, 6%, 7%, 8%, 9%, 10%, etc.; the line overlap rate of the laser irradiation is 10-30%, such as 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.; the power of the laser irradiation is 5-10W, such as 5W, 6W, 7W, 8W, 9W, 10W, etc. It can be seen that in the process of laser forming the first glass layer, the required laser energy is low, which can greatly reduce the laser cost.

[0034] S400: Using the first glass layer 41 as a mask, remove the corresponding p-type doped polysilicon layer 32 and the tunneling oxide layer 20 in the n+ region. The structural diagram can be referred to Figure 4 .

[0035] According to some embodiments of the present invention, the p-type doped polysilicon layer and the tunneling oxide layer corresponding to the n+ region are removed by wet etching, and an etching solution of alkali and additives is used, wherein the volume ratio of alkali is 10-18%, such as 10%, 11%, 12%, 13%, 4%, 15%, 16%, 17%, 18%, etc., the etching temperature is 65-80°C, and the etching time is 120-200 seconds, such as 120s, 130s, 140s, 150s, 160s, 170s, 180s, 190s, 200s, etc. It can be seen that in the process of the present invention, the etching time of this step is short, which helps to improve the efficiency of the overall process.

[0036] In some embodiments of the present invention, the collaborative process window for implementing the operations between the above steps S200 to S400 is relatively wide, which helps to improve the overall preparation efficiency and yield of the TBC battery.

[0037] S500: forming an n-type doped polysilicon layer 52 in the n+ region. The schematic diagram of the structure can be referred to Figure 5 , Figure 6 , Figure 7 and Figure 8 .

[0038] According to some embodiments of the present invention, referring to Figure 5 and Figure 6 The step of forming an n-type doped polysilicon layer in the n+ region comprises:

[0039] S510: Depositing a second intrinsic amorphous silicon layer 51 in the n+ region and the p+ region, such as Figure 5 shown.

[0040] In some embodiments of the present invention, the second intrinsic amorphous silicon layer 51 can be prepared by chemical vapor deposition (such as low pressure chemical vapor deposition LPCVD), magnetron sputtering and other deposition methods. In some specific embodiments, the second intrinsic amorphous silicon layer 51 is formed by silane decomposition deposition at 500-640° C. using LPCVD. The thickness of the second intrinsic amorphous silicon layer 51 can be 50-500 nm.

[0041] S520: performing a third deposition doping source on the surface of the second intrinsic amorphous silicon layer 51 away from the silicon substrate 10, and advancing to obtain an n-type doped polysilicon layer 52, and forming a second glass layer 42 on the surface of the n-type doped polysilicon layer 52, such as Figure 6 shown.

[0042] In some specific embodiments, the third deposition doping source may be a deposition phosphorus source, that is, phosphorus is used to dope the second intrinsic amorphous silicon layer. Simultaneously, phosphorus silicon glass (PSG), that is, the second glass layer 42 , is formed on the surface of the n-type doped polysilicon layer 52 .

[0043] According to some embodiments of the present invention, the deposition temperature of the third deposition doping source is 860-920°C, such as 860°C, 870°C, 880°C, 890°C, 900°C, 910°C, 920°C, etc.; according to some embodiments of the present invention, the deposition pressure during the third deposition doping source process is 100-200mbar, such as 100mbar, 110mbar, 120mbar, 130mbar, 140mbar, 150mbar, 160mbar, 170mbar, 180mbar. , 190mbar, 200mbar, etc.; according to some embodiments of the present invention, the deposition amount of the doping source in the third deposition doping source process is 500-2000sccm, such as 500sccm, 800sccm, 1000sccm, 1200sccm, 1400sccm, 1500sccm, 1600sccm, 1800sccm, 2000sccm, etc.; according to some embodiments of the present invention, the oxygen flow rate in the third deposition doping source process is 1 / 3-2 / 3 of the deposition amount of the doping source. Under the above deposition conditions, it is helpful to obtain a better quality n-type doped polysilicon layer 52 by doping.

[0044] According to some embodiments of the present invention, a large amount of oxygen still needs to be passed during the above-mentioned advancement process to facilitate the formation of the second glass layer. There is no special requirement for the specific amount of oxygen passed during the advancement process, and those skilled in the art can flexibly select it according to actual needs and existing technical means, and no limitation is imposed here.

[0045] S530: laser mold opening to remove the second glass layer 42 in the p+ region, and only the second glass layer 42 in the n+ region is retained, such as Figure 7 shown.

[0046] In this step, the second glass layer 42 in the p+ region is removed by laser mold opening, wherein the spot overlap rate of laser irradiation is 15-25% (for example, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.), the line overlap rate of laser irradiation is 20-40% (for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc.), and the power of laser irradiation is 25-38W (for example, 25W, 26W, 27W, 28W, 29W, 30W, 31.4W, 32W, 33W, 34W, 35W, 36W, 37W, 38W, etc.). In this way, the patterning of the second glass layer can be effectively achieved under the above conditions without damaging other structures.

[0047] S540: Using the second glass layer 42 in the n+ region as a mask, the corresponding n-type doped polysilicon layer 52 in the p+ region is removed by etching, that is, the n-type doped polysilicon layer 52 is formed only in the n+ region. Figure 8 shown.

[0048] According to some embodiments of the present invention, the n-type doped polysilicon layer 52 corresponding to the p+ region is removed by wet etching, using a conventional etching solution of alkali and additives, wherein the volume ratio of alkali is 1-2%, such as 1%, 1.5%, 2%, etc., the etching temperature is 60-75°C, and the etching time is 200-400 seconds.

[0049] According to an embodiment of the present invention, the method for preparing a TBC solar cell further comprises the following steps:

[0050] S550: Texturing the front side of the silicon substrate 10 to obtain a suede structure. The schematic diagram of the structure can be referred to Fig. 9 In some embodiments of the present invention, there is no special requirement for the specific method of front surface texturing, and those skilled in the art can flexibly select it according to actual needs and existing technical means, and no limitation is imposed here. In some embodiments, texturing can be performed by alkali solution.

[0051] S560: Remove the remaining first glass layer 41 in the p+ region and the remaining second glass layer 52 in the n+ region on the back side. Fig.10 shown.

[0052] In some embodiments, the first glass layer and the second glass layer may be removed by hydrofluoric acid.

[0053] S580: Depositing a front passivation layer 61 and a back passivation layer 62 on the front and back sides respectively. Fig.11 shown.

[0054] S590: Depositing a front anti-reflection layer 71 and a back anti-reflection layer 72 on the front and back sides respectively, such as Fig.11 shown.

[0055] In some embodiments of the present invention, the specific method of depositing the passivation layer 60 and the anti-reflection layer 70 includes, but is not limited to, chemical vapor deposition and magnetron sputtering. The material of the passivation layer includes, but is not limited to, aluminum oxide; the material of the anti-reflection layer includes, but is not limited to, silicon nitride, silicon oxide, silicon oxynitride, titanium oxide, and the like. The anti-reflection layer may be a single-layer structure or a multi-layer stacked structure. Those skilled in the art may flexibly design it according to actual needs.

[0056] S600: forming a positive electrode 81 in the p+ region and a negative electrode 82 in the n+ region, such as Fig.12 shown.

[0057] In another aspect of the present invention, the present invention provides a TBC solar cell. According to an embodiment of the present invention, the TBC solar cell is prepared by the method described above. Therefore, the TBC solar cell prepared by the above preparation method has good working performance, and the collaborative process window of the implementation steps in the preparation process is wide, which helps to improve the preparation efficiency and yield of the TBC cell, and helps to reduce the production cost.

[0058] According to the embodiments of the present invention, there are no restrictions on the application fields of the above-mentioned TBC solar cells, and those skilled in the art can flexibly select according to actual needs. For example, the above-mentioned TBC solar cells can be applied to photovoltaic power generation systems, that is, the above-mentioned TBC solar cell sheets are used to construct photovoltaic modules, which are widely used in various photovoltaic power generation systems such as solar power stations and rooftop solar panels.

[0059] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0060] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0061] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a TBC solar cell, characterized in that: include: Depositing a tunneling oxide layer and a first intrinsic amorphous silicon layer in sequence on the back side of the silicon substrate; Performing a first deposition doping source, a push-up, a second deposition doping source, and a temperature reduction process on a surface of the first intrinsic amorphous silicon layer away from the silicon substrate to achieve doping of the first intrinsic amorphous silicon layer to obtain a p-type doped polycrystalline silicon layer, wherein oxygen is introduced during the first deposition doping source and the second deposition doping source process; In the p+ region, forming a first glass layer on a surface of the p-type doped polysilicon layer away from the silicon substrate; Using the first glass layer as a mask, removing the corresponding p-type doped polysilicon layer and the tunneling oxide layer in the n+ region; forming an n-type doped polysilicon layer in the n+ region; A positive electrode is formed in the p+ region, and a negative electrode is formed in the n+ region.

2. The method according to claim 1, characterized in that: The conditions for the first deposition of dopant sources include: The deposition temperature is 800-860°C; The deposition pressure is 100-200 mbar; The oxygen flow rate is 100-600sccm; The deposition amount of the doping source is 150-220 sccm.

3. The method according to claim 1, characterized in that The conditions of the second deposition doping source include: The deposition temperature is 800-860°C; The deposition pressure is 100-150 mbar; The oxygen flow rate is 10-200 sccm; The deposition amount of the doping source is 20-120 sccm.

4. The method according to claim 1, characterized in that: The pushing temperature is 920-970° C., and the pushing time is 200-3000 s.

5. The method according to claim 1, characterized in that The method for forming the first glass layer is: irradiating laser light only on the p+ region, and using doping ions of the second deposition doping source and oxygen in the air to form the first glass layer.

6. The method according to claim 5, characterized in that The laser irradiation conditions meet: The spot overlap rate is 5-10%; Line overlap is 10-30%; The power is 5-10W.

7. The method according to claim 1, characterized in that The p-type doped polysilicon layer and the tunneling oxide layer corresponding to the n+ region are removed by wet etching, and the wet etching conditions are: alkali volume ratio is 10-18%, temperature is 65-80° C., and time is 120-200 seconds.

8. The method according to claim 1, characterized in that The step of forming the n-type doped polysilicon layer in the n+ region comprises: Depositing a second intrinsic amorphous silicon layer on the n+ region and the p+ region; Depositing a third doping source and advancing the second intrinsic amorphous silicon layer on a surface away from the silicon substrate to obtain the n-type doped polysilicon layer, and forming a second glass layer on the surface of the n-type doped polysilicon layer; removing the second glass layer in the p+ region by laser; The n-type doped polysilicon layer corresponding to the p+ region is etched and removed using the second glass layer in the n+ region as a mask.

9. The method according to claim 8, characterized in that Before forming the positive electrode and the negative electrode, the method further comprises: Forming a velvet surface on the front side of the silicon substrate to obtain a velvet surface structure; removing the remaining first glass layer in the p+ region and the remaining second glass layer in the n+ region on the back side; Depositing a front passivation layer and a back passivation layer on the front and back sides respectively; A front anti-reflection layer and a back anti-reflection layer are deposited on the front side and the back side respectively.

10. A TBC solar cell, characterized in that: The invention is prepared by the method according to any one of claims 1 to 9.

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