Phosphorus diffusion equipment source quantity control method and phosphorus diffusion equipment

Abstract

The invention is suitable for the technical field of battery preparation, and provides a phosphorus diffusion equipment source quantity control method and phosphorus diffusion equipment. According to the method, when a diffusion process is carried out on a battery to be produced by utilizing phosphorus diffusion equipment, the real-time concentration of phosphorus pentoxide in a tail gas pipe in the phosphorus diffusion equipment is obtained, and the phosphorus source introduction amount of the phosphorus diffusion equipment is controlled to be the corresponding introduction amount according to the real-time concentration of phosphorus pentoxide and different preset concentration threshold values. According to the invention, accurate control of the source quantity can be realized, the performance of the photovoltaic cell is improved, and the waste of the phosphorus source is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of battery preparation, and in particular to a method for controlling the flow rate of a phosphorus diffusion device and a phosphorus diffusion device. Background Art

[0002] The main process steps for preparing photovoltaic cells include: texturing, diffusion, cleaning, etching, coating, printing and sintering. Among them, the diffusion process is the key process for preparing the battery PN junction and producing the photovoltaic effect. The traditional phosphorus diffusion method is to put the silicon wafer into a diffusion furnace, and pass oxygen and nitrogen carrying phosphorus oxychloride into the diffusion furnace (source), so that phosphorus oxychloride and oxygen react at high temperature to deposit phosphorus atoms on the surface of the silicon wafer, and after reaching the preset time, stop passing the source and maintain the preset temperature, so that the phosphorus atoms on the surface of the silicon wafer diffuse into the inside of the silicon wafer to form a PN junction and complete the diffusion process.

[0003] In this process, in order to ensure that sufficient phosphorus source is deposited on the surface of the silicon wafer, a longer source-on time is usually set, resulting in excessive input of phosphorus source and supersaturated phosphorus deposition on the surface of the silicon wafer, forming an electrically inactive diffusion dead layer on the surface of the silicon wafer, reducing the photoelectric conversion efficiency of the photovoltaic cell. In addition, under high-temperature source-on conditions, the phosphorus deposited on the surface of the silicon wafer also diffuses into the interior of the silicon wafer, resulting in poor uniformity of phosphorus source diffusion, reducing the performance of the photovoltaic cell, and causing waste of phosphorus source. Summary of the invention

[0004] The embodiments of the present application provide a method for controlling the amount of phosphorus diffusion equipment and a phosphorus diffusion equipment to solve the technical problems in the related art of excessive amount of source flow leading to poor performance of photovoltaic cells and waste of phosphorus source.

[0005] In a first aspect, an embodiment of the present application provides a method for controlling the flow rate of a phosphorus diffusion device, comprising:

[0006] When a phosphorus diffusion device is used to perform a diffusion process on a battery to be produced, obtaining a real-time concentration of phosphorus pentoxide in a tail gas pipe in the phosphorus diffusion device;

[0007] According to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0008] In a possible implementation, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds includes:

[0009] When the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, controlling the phosphorus source flow rate to be the primary flow rate;

[0010] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, controlling the phosphorus source flow rate to be the secondary flow rate;

[0011] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0012] Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

[0013] In a possible implementation, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds includes:

[0014] Obtaining the type of the battery to be produced; wherein the type of the battery to be produced includes a low-resistance battery and a high-resistance battery; the low-resistance battery is a battery whose square resistance is lower than a preset square resistance threshold, and the high-resistance battery is a battery whose square resistance is higher than a preset square resistance threshold;

[0015] According to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0016] In a possible implementation, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide, and the different concentration thresholds includes:

[0017] If the type of the battery to be produced is a low-resistance battery, when the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the first concentration threshold, and the primary flow rate is the first flow rate;

[0018] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the second concentration threshold, and the secondary flow rate is the second flow rate;

[0019] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0020] Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

[0021] In a possible implementation, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds includes:

[0022] If the type of the battery to be produced is a high-resistance battery, when the real-time concentration of phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the third concentration threshold, and the primary flow rate is the third flow rate;

[0023] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the fourth concentration threshold, and the secondary flow rate is the fourth flow rate;

[0024] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0025] Among them, the third concentration threshold is smaller than the first concentration threshold, and the fourth concentration threshold is smaller than the second concentration threshold; the third flux is smaller than the first flux, and the fourth flux is smaller than the second flux.

[0026] In a possible implementation, the method further includes:

[0027] Obtaining the number of silicon wafers included in the battery to be produced;

[0028] Accordingly, according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to be a corresponding flow rate includes:

[0029] According to the number of silicon wafers, a preset number threshold, the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0030] In a possible implementation, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the number of silicon wafers, a preset number threshold, the real-time concentration of phosphorus pentoxide, and different preset concentration thresholds includes:

[0031] When the number of silicon wafers is less than or equal to the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to be the corresponding flow rate;

[0032] When the number of silicon wafers is greater than the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be the product of the corresponding source flow rate and a preset coefficient;

[0033] The preset coefficient is greater than 1 and is proportional to the number of silicon wafers.

[0034] In a second aspect, an embodiment of the present application provides a phosphorus diffusion device, including: a phosphorus diffusion device body, a concentration measuring instrument and a controller; the phosphorus diffusion device body includes an exhaust pipe for discharging exhaust gas generated in a diffusion process;

[0035] The concentration measuring instrument is used to collect the real-time concentration of phosphorus pentoxide in the tail gas pipe in the phosphorus diffusion equipment body;

[0036] The controller is used to obtain the real-time concentration of phosphorus pentoxide collected by the concentration measuring instrument when the phosphorus diffusion equipment performs a diffusion process on the battery to be produced; and control the phosphorus source flow rate of the phosphorus diffusion equipment to be the corresponding flow rate according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds.

[0037] In a possible implementation, the phosphorus diffusion equipment body further includes: a temperature reduction device;

[0038] The cooling device is arranged on the tail gas pipe and is used for cooling the tail gas in the tail gas pipe.

[0039] In a possible implementation, the tailpipe includes a first tailpipe and a second tailpipe; the cooling device includes a spiral tube and a cooling chamber arranged outside the spiral tube:

[0040] The air inlet of the spiral tube is arranged on one side of the cooling chamber and communicated with one end of the first tail gas pipe, and the air outlet of the spiral tube is arranged on the other side of the cooling chamber and communicated with one end of the second tail gas pipe;

[0041] A water inlet is arranged on one side of the cooling cavity, and a water outlet is arranged on the other side of the cooling cavity.

[0042] In a third aspect, an embodiment of the present application provides a phosphorus diffusion equipment source flow control device, comprising:

[0043] The acquisition module is used to obtain the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion device when the phosphorus diffusion device is used to perform a diffusion process on the battery to be produced.

[0044] The control module is used to control the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds.

[0045] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for controlling the source flow rate of a phosphorus diffusion device as described in any one of the first aspects is implemented.

[0046] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0047] The phosphorus diffusion equipment source flow control method and phosphorus diffusion equipment provided in the embodiments of the present application obtain the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion equipment when the phosphorus diffusion equipment is used to perform a diffusion process on a battery to be produced, so as to control the phosphorus source source flow of the phosphorus diffusion equipment to be the corresponding source flow according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, thereby achieving accurate control of the source flow, improving the performance of photovoltaic cells, and avoiding waste of phosphorus sources.

[0048] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0050] Figure 1 is a schematic structural diagram of a phosphorus diffusion device provided in one embodiment of the present application;

[0051] Figure 2 It is a structural schematic diagram of a cooling device provided in one embodiment of the present application;

[0052] Figure 3 It is a flow chart of a method for controlling the flow rate of a phosphorus diffusion device provided in one embodiment of the present application;

[0053] Figure 4 It is a structural schematic diagram of a source flow control device for phosphorus diffusion equipment provided in one embodiment of the present application. DETAILED DESCRIPTION

[0054] The present application is described more clearly below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the effects of the present application, but are not intended to limit the present application in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present application. These all fall within the scope of protection of the present application.

[0055] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0056] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0057] In the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0058] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0059] In addition, the “plurality” mentioned in the embodiments of the present application should be interpreted as two or more.

[0060] The traditional phosphorus diffusion method places the silicon wafer into the phosphorus diffusion equipment to complete the diffusion process. The reaction steps and corresponding reaction equations of the diffusion process are as follows:

[0061] 1. Phosphorus oxychloride (POCl3) decomposes at high temperature to generate phosphorus pentachloride (PCl5) and phosphorus pentoxide (P2O5). The reaction formula is as follows:

[0062]

[0063] 2. Phosphorus pentachloride (PCl5) is difficult to decompose. It reacts with oxygen (O2) to generate phosphorus pentoxide (P2O5) and releases chlorine (Cl2). The reaction formula is as follows:

[0064]

[0065] 3. Phosphorus pentoxide (P2O5) reacts with silicon at the diffusion temperature to generate silicon dioxide (SiO2) and phosphorus atoms (P). The reaction formula is as follows:

[0066] 2P2O5+5Si=5SiO2+4P↓

[0067] It can be obtained that the comprehensive reaction equation corresponding to the diffusion process is:

[0068] 4POCl3+3O2+5Si=6Cl2+5SiO2+4P↓

[0069] However, in order to ensure that sufficient phosphorus source is deposited on the surface of the silicon wafer, the traditional phosphorus diffusion method usually sets a longer source-on time, resulting in excessive phosphorus source being introduced, which reduces the performance of the photovoltaic cell.

[0070] In order to accurately control the flow rate of phosphorus source, improve the performance of photovoltaic cells and reduce the waste of phosphorus source, the inventors have discovered that the state of phosphorus diffusion reaction in the diffusion furnace can be judged by the concentration of phosphorus pentoxide in the exhaust gas generated in the diffusion process. That is, the flow rate of phosphorus diffusion equipment can be controlled by measuring the concentration of phosphorus pentoxide in the exhaust gas and based on the above-mentioned phosphorus pentoxide concentration and a preset concentration threshold, so as to achieve accurate control of the flow rate, improve the performance of photovoltaic cells and avoid waste of phosphorus source.

[0071] Figure 1 Schematic diagram of the structure of a phosphorus diffusion device provided in one embodiment of the present application. Figure 1 As shown, the phosphorus diffusion device comprises a phosphorus diffusion device body, a concentration measuring instrument 9 and a controller 4. The phosphorus diffusion device body comprises an exhaust pipe 2 for discharging exhaust gas generated in the diffusion process.

[0072] The concentration measuring instrument 9 is used to collect the real-time concentration of phosphorus pentoxide in the tail gas pipe 2 in the phosphorus diffusion device body.

[0073] The controller 4 is used to obtain the real-time concentration of phosphorus pentoxide collected by the concentration measuring instrument 9 when the phosphorus diffusion equipment performs a diffusion process on the battery to be produced, and control the phosphorus source flow rate of the phosphorus diffusion equipment to a corresponding flow rate according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds.

[0074] Among them, the phosphorus diffusion equipment body includes not only the tail gas pipe 2, but also a diffusion furnace 1 (such as a quartz furnace tube), an air intake pipe, a flow meter corresponding to the air intake pipe, a quartz boat, a heating device and a temperature measuring thermocouple (not shown). The air intake pipe includes an oxygen air intake pipe 31, a nitrogen air intake pipe 32 and a nitrogen air intake pipe 33 carrying phosphorus oxychloride. Correspondingly, the flow meter includes an oxygen flow meter 5, a first nitrogen flow meter 6 and a second nitrogen flow meter 7. The controller 4 controls the flux of oxygen by controlling the oxygen flow meter 5, controls the flux of nitrogen by controlling the first nitrogen flow meter 6, and controls the flux of nitrogen carrying phosphorus oxychloride by controlling the second nitrogen flow meter 7, that is, controls the flux of the phosphorus source. The quartz boat is used to carry silicon wafers, the heating device is arranged to wrap around the diffusion furnace 1, and is used to heat the diffusion furnace 1. The temperature measuring thermocouple is arranged inside the diffusion furnace 1, and is used to measure the internal temperature of the diffusion furnace 1.

[0075] The concentration measuring instrument 9 may adopt a high-precision electrochemical principle sensor, and the measurement accuracy is less than or equal to ±3% FS.

[0076] As mentioned above, the controller 4 controls the phosphorus source flow rate of the phosphorus diffusion device to be the corresponding flow rate, that is, the phosphorus source flow rate is controlled by controlling the second nitrogen flow meter 7. In addition, the controller 4 is also used to control the flux of oxygen by controlling the oxygen flow meter 5, control the flux of nitrogen by controlling the first nitrogen flow meter 6, and control the heating device, etc.

[0077] In addition, the working temperature of the concentration measuring instrument 9 is relatively low, usually less than a temperature threshold such as 70°C. Once the temperature exceeds the temperature threshold, the measurement accuracy of the concentration measuring instrument 9 will decrease. In the phosphorus diffusion reaction, the temperature of the exhaust gas in the exhaust pipe 2 can reach more than 300°C. Therefore, in order to ensure that the concentration measuring instrument 9 can work normally and accurately, some measures can be taken to reduce the temperature of the exhaust gas.

[0078] In some embodiments, reference Figure 1 The phosphorus diffusion device body may further include: a cooling device 8 , which is disposed on the tail gas pipe 2 and is used to cool the tail gas in the tail gas pipe 2 .

[0079] In this embodiment, in order to more accurately measure the real-time concentration of phosphorus pentoxide in the tail pipe 2, an additional cooling device 8 such as a cooling fan or a water cooling device can be provided to cool the exhaust gas in the tail pipe 2 and reduce the exhaust gas to below the temperature threshold. The cooling device 8 is arranged before the concentration measuring instrument 9 according to the exhaust gas flow direction, so that the concentration measuring instrument 9 can measure the real-time concentration of phosphorus pentoxide after cooling, thereby improving the measurement accuracy.

[0080] In some embodiments, the tailpipe 2 includes a first tailpipe and a second tailpipe, and the cooling device 8 includes a spiral tube 81 and a cooling chamber 82 disposed outside the spiral tube 81. The air inlet of the spiral tube 81 is disposed on one side of the cooling chamber 82 and communicates with one end of the first tailpipe, and the air outlet of the spiral tube 81 is disposed on the other side of the cooling chamber 82 and communicates with one end of the second tailpipe. A water inlet is disposed on one side of the cooling chamber 82, and a water outlet is disposed on the other side of the cooling chamber 82.

[0081] In this embodiment, one end of the cooling device 8 is connected to the first tail gas pipe, and the other end is connected to the second tail gas pipe, so that the tail gas enters the cooling device 8 after passing through the first tail gas pipe, and enters the second tail gas pipe after being cooled in the cooling device 8. Figure 2 A cooling chamber 82 is arranged outside the spiral tube 81 of the cooling device 8, and the cooling chamber 82 is provided with a water inlet and a water outlet. The exhaust gas in the spiral tube 81 is cooled by circulating cooling water, and the spiral structure of the spiral tube 81 can prolong the residence time of the exhaust gas in the cooling water, improve the cooling efficiency, and increase the cooling effect.

[0082] Combine the following Figure 1 and Figure 2 ,refer to Figure 3 A method for controlling the flow rate of a phosphorus diffusion device according to an exemplary embodiment of the present application will be described.

[0083] Figure 3 It is a flow chart of a method for controlling the flow rate of a phosphorus diffusion device provided in one embodiment of the present application.

[0084] like Figure 3 As shown, the method in the embodiment of the present application may include:

[0085] Step 301: When a phosphorus diffusion device is used to perform a diffusion process on a battery to be produced, the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion device is obtained.

[0086] In this embodiment, the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion device can be obtained by a concentration measuring instrument. The battery to be produced is a photovoltaic cell to be prepared.

[0087] Step 302: According to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0088] Exemplarily, the preset concentration threshold is determined according to the concentration of phosphorus pentoxide in the tail gas under various states of the diffusion process when the phosphorus source is not excessive in the diffusion process, that is, when no supersaturated phosphorus is deposited on the surface of the silicon wafer and no diffusion dead layer is formed on the surface of the silicon wafer. And the corresponding source flow is determined according to the source flow under various states of the diffusion process when the phosphorus source is not excessive in the diffusion process, that is, when no supersaturated phosphorus is deposited on the surface of the silicon wafer and no diffusion dead layer is formed on the surface of the silicon wafer.

[0089] In a possible implementation manner, in this embodiment, when controlling the phosphorus source flow rate of the phosphorus diffusion device to be the corresponding flow rate, steps A1 to A3 may be performed.

[0090] A1. When the real-time concentration of phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow is controlled to be the primary flow.

[0091] A2. When the real-time concentration of phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow is controlled to be the secondary flow.

[0092] A3. When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stop the source. Among them, the primary concentration threshold is less than the secondary concentration threshold, and the primary source flow is greater than the secondary source flow.

[0093] For example, in the early stage of the phosphorus diffusion reaction, phosphorus pentoxide generated by phosphorus oxychloride and oxygen reacts with the surface of the silicon wafer. At this time, the concentration of phosphorus pentoxide in the tail gas emitted by the phosphorus diffusion reaction is low, and the phosphorus source flow rate can be controlled to be a larger value. When the phosphorus atom concentration on the surface of the silicon wafer is saturated, the phosphorus diffusion reaction proceeds to the inside of the silicon wafer. At this time, the phosphorus diffusion reaction speed slows down, and the concentration of phosphorus pentoxide in the exhaust gas emitted begins to rise. At this time, the phosphorus source flow rate can be controlled to be reduced. When the concentration of phosphorus pentoxide rises to a certain threshold, the phosphorus diffusion reaction is completed, and the flow rate can be controlled to stop.

[0094] Here, the primary concentration threshold can be determined according to the concentration of phosphorus pentoxide in the tail gas emitted by the phosphorus diffusion reaction when the phosphorus atom concentration is saturated, and the primary source flow can be determined according to the source flow of the phosphorus diffusion reaction when the phosphorus atom concentration is saturated. The secondary concentration threshold can be determined according to the concentration of phosphorus pentoxide in the tail gas under various states of the diffusion process when the phosphorus source is not excessive in the diffusion process, that is, when no supersaturated phosphorus is deposited on the silicon wafer surface and no diffusion dead layer is formed on the silicon wafer surface, and the secondary source flow can be determined according to the source flow of the phosphorus diffusion reaction when the phosphorus source is not excessive in the diffusion process, that is, when no supersaturated phosphorus is deposited on the silicon wafer surface and no diffusion dead layer is formed on the silicon wafer surface.

[0095] In addition, the preset concentration threshold and source flow rate are also related to the type of battery to be produced. Therefore, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment, the type of battery to be produced can also be considered.

[0096] In a possible implementation, this embodiment can obtain the type of battery to be produced when controlling the phosphorus source flow rate of the phosphorus diffusion equipment to be a corresponding flow rate, and control the phosphorus source flow rate of the phosphorus diffusion equipment to be a corresponding flow rate according to the type of battery to be produced, the real-time concentration of phosphorus pentoxide and different concentration thresholds.

[0097] Among them, the types of batteries to be produced include low-resistance batteries and high-resistance batteries. Low-resistance batteries are batteries with a square resistance lower than a preset square resistance threshold, and high-resistance batteries are batteries with a square resistance higher than a preset square resistance threshold. Here, the preset square resistance threshold is related to the battery preparation process, etc. Under different battery preparation processes, the classification of low-resistance batteries and high-resistance batteries is different. For example, under a certain battery preparation process, the preset square resistance threshold can be 150Ω / sq.

[0098] In some embodiments, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment to be the corresponding flow rate, when the type of battery to be produced is a low-resistance battery, when the real-time concentration of phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the first concentration threshold, and the primary flow rate is the first flow rate.

[0099] When the real-time concentration of phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow is controlled to be the secondary flow; the secondary concentration threshold is the second concentration threshold, and the secondary flow is the second flow.

[0100] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, the source is stopped; wherein, the primary concentration threshold is less than the secondary concentration threshold, and the primary source amount is greater than the secondary source amount.

[0101] In some embodiments, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment to be a corresponding flow rate, when the type of battery to be produced is a high-resistance battery, when the real-time concentration of phosphorus pentoxide is less than the first-level concentration threshold, the phosphorus source flow rate is controlled to be the first-level flow rate; the first-level concentration threshold is the third concentration threshold, and the first-level flow rate is the third flow rate.

[0102] When the real-time concentration of phosphorus pentoxide is greater than or equal to the first-level concentration threshold and less than the second-level concentration threshold, the phosphorus source flow is controlled to be the second-level flow; the second-level concentration threshold is the fourth concentration threshold, and the second-level flow is the fourth flow.

[0103] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stop the source; wherein, the third concentration threshold is less than the first concentration threshold, and the fourth concentration threshold is less than the second concentration threshold; the third source amount is less than the first source amount, and the fourth source amount is less than the second source amount.

[0104] In this embodiment, a smaller square resistance requires more flux, because increasing the flux of the phosphorus source can increase the phosphorus concentration on the surface of the silicon wafer, thereby reducing the square resistance. The square resistance of a low-resistance battery is smaller than that of a high-resistance battery. Therefore, when producing low-resistance batteries and high-resistance batteries, the third flux when producing high-resistance batteries is smaller than the first flux when producing low-resistance batteries, and the fourth flux when producing high-resistance batteries is smaller than the second flux when producing low-resistance batteries.

[0105] Optionally, when producing low-resistance batteries, the concentration of phosphorus pentoxide corresponding to when the phosphorus atom concentration on the silicon wafer surface is saturated is higher than the concentration of phosphorus pentoxide corresponding to when the phosphorus atom concentration on the silicon wafer surface is saturated when producing high-resistance batteries. Therefore, the third concentration threshold is less than the first concentration threshold, and the fourth concentration threshold is less than the second concentration threshold.

[0106] A simple example is that when the battery to be produced is a low-resistance battery, when the concentration of phosphorus pentoxide is less than 300ppm, the phosphorus source flow rate is controlled to be 800sccm; when the concentration of phosphorus pentoxide is greater than or equal to 300ppm and less than 600ppm, the phosphorus source flow rate is controlled to be 500sccm; when the concentration of phosphorus pentoxide is greater than or equal to 600ppm, the source flow is stopped.

[0107] When the battery to be produced is a high-resistance battery, when the concentration of phosphorus pentoxide is less than 200ppm, the phosphorus source flow rate is controlled to be 700sccm; when the concentration of phosphorus pentoxide is greater than or equal to 200ppm and less than 500ppm, the phosphorus source flow rate is controlled to be 400sccm; when the concentration of phosphorus pentoxide is greater than or equal to 500ppm, the source flow is stopped.

[0108] In addition, the preset concentration threshold and source flow rate are also related to the number of silicon wafers of the battery to be produced. Therefore, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment, the number of silicon wafers of the battery to be produced can also be considered.

[0109] In some embodiments, the number of silicon wafers included in the battery to be produced can also be obtained. Accordingly, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment to be the corresponding flow rate, the phosphorus source flow rate of the phosphorus diffusion equipment can be controlled to be the corresponding flow rate based on the number of silicon wafers, the preset number threshold, the real-time concentration of phosphorus pentoxide and the preset different concentration thresholds.

[0110] Exemplarily, when the number of silicon wafers is less than or equal to a preset number threshold, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding source flow rate according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds.

[0111] When the number of silicon wafers is greater than a preset number threshold, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be the product of the corresponding flow rate and a preset coefficient according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds. The preset coefficient is greater than 1 and is proportional to the number of silicon wafers.

[0112] In this embodiment, the more silicon wafers there are, the greater the required source flow. The preset quantity threshold can be determined based on the critical quantity value when the source flow changes greatly with the number of silicon wafers. For example, the preset quantity threshold can be 100. When the number of silicon wafers of the battery to be produced is less than or equal to 100, the phosphorus source flow is controlled to be the corresponding source flow. When the number of silicon wafers of the battery to be produced is greater than 100, the phosphorus source flow is controlled to be the product of the corresponding source flow and the preset coefficient, that is, on the basis of the corresponding source flow, the source flow is increased. For example, for the same type of battery to be produced, when the number of silicon wafers is 100, the phosphorus source flow is controlled to be the corresponding source flow Y, and when the number of silicon wafers is 200, the phosphorus source flow is controlled to be the product of the corresponding source flow Y and the preset coefficient 1.2, that is, the phosphorus source flow is increased by 20% on the basis of the corresponding source flow Y.

[0113] In this embodiment, when controlling the phosphorus source flow rate of the phosphorus diffusion equipment, the number of silicon wafers of the battery to be produced is also taken into consideration, so that more accurate control of the source flow rate can be achieved.

[0114] The method for controlling the flow rate of a phosphorus diffusion device provided in the embodiment of the present application obtains the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion device when the phosphorus diffusion device is used to perform a diffusion process on a battery to be produced, thereby controlling the flow rate of the phosphorus source of the phosphorus diffusion device to a corresponding flow rate according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, thereby achieving accurate control of the flow rate, improving the performance of photovoltaic cells, and avoiding waste of phosphorus sources.

[0115] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0116] Figure 4 Schematic diagram of the structure of a phosphorus diffusion equipment source flow control device provided in one embodiment of the present application. Figure 4 As shown, the phosphorus diffusion equipment source flow control device provided in this embodiment may include: an acquisition module 401 and a control module 402.

[0117] The acquisition module 401 is used to acquire the real-time concentration of phosphorus pentoxide in the tail gas pipe of the phosphorus diffusion device when the phosphorus diffusion device is used to perform a diffusion process on the battery to be produced.

[0118] The control module 402 is used to control the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds.

[0119] In a possible implementation, the control module 402 is further configured to:

[0120] When the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, controlling the phosphorus source flow rate to be the primary flow rate;

[0121] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, controlling the phosphorus source flow rate to be the secondary flow rate;

[0122] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0123] Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

[0124] In a possible implementation, the control module 402 is further configured to:

[0125] Obtaining the type of the battery to be produced; wherein the type of the battery to be produced includes a low-resistance battery and a high-resistance battery; the low-resistance battery is a battery whose square resistance is lower than a preset square resistance threshold, and the high-resistance battery is a battery whose square resistance is higher than a preset square resistance threshold;

[0126] According to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0127] In a possible implementation, the control module 402 is further configured to:

[0128] If the type of the battery to be produced is a low-resistance battery, when the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the first concentration threshold, and the primary flow rate is the first flow rate;

[0129] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the second concentration threshold, and the secondary flow rate is the second flow rate;

[0130] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0131] Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

[0132] In a possible implementation, the control module 402 is further configured to:

[0133] If the type of the battery to be produced is a high-resistance battery, when the real-time concentration of phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the third concentration threshold, and the primary flow rate is the third flow rate;

[0134] When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the fourth concentration threshold, and the secondary flow rate is the fourth flow rate;

[0135] When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source;

[0136] Among them, the third concentration threshold is smaller than the first concentration threshold, and the fourth concentration threshold is smaller than the second concentration threshold; the third flux is smaller than the first flux, and the fourth flux is smaller than the second flux.

[0137] In a possible implementation, the acquisition module 401 is further configured to:

[0138] Obtaining the number of silicon wafers included in the battery to be produced;

[0139] Accordingly, the control module 402 is also used for:

[0140] According to the number of silicon wafers, a preset number threshold, the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

[0141] In a possible implementation, the control module 402 is further configured to:

[0142] When the number of silicon wafers is less than or equal to the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to be the corresponding flow rate;

[0143] When the number of silicon wafers is greater than the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be the product of the corresponding source flow rate and a preset coefficient;

[0144] The preset coefficient is greater than 1 and is proportional to the number of silicon wafers.

[0145] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0146] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for controlling the flow rate of a phosphorus diffusion device, characterized in that: The method comprises: When a phosphorus diffusion device is used to perform a diffusion process on a battery to be produced, obtaining a real-time concentration of phosphorus pentoxide in a tail gas pipe in the phosphorus diffusion device; According to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

2. The phosphorus diffusion equipment source flow control method according to claim 1, characterized in that: According to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate includes: When the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, controlling the phosphorus source flow rate to be the primary flow rate; When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, controlling the phosphorus source flow rate to be the secondary flow rate; When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source; Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

3. The phosphorus diffusion equipment source flow control method according to claim 1, characterized in that: According to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate includes: Obtaining the type of the battery to be produced; wherein the type of the battery to be produced includes a low-resistance battery and a high-resistance battery; the low-resistance battery is a battery whose square resistance is lower than a preset square resistance threshold, and the high-resistance battery is a battery whose square resistance is higher than a preset square resistance threshold; According to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

4. The phosphorus diffusion equipment source flow control method according to claim 3, characterized in that: According to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate includes: If the type of the battery to be produced is a low-resistance battery, when the real-time concentration of the phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the first concentration threshold, and the primary flow rate is the first flow rate; When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the second concentration threshold, and the secondary flow rate is the second flow rate; When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source; Among them, the primary concentration threshold is smaller than the secondary concentration threshold, and the primary source amount is larger than the secondary source amount.

5. The phosphorus diffusion equipment source flow control method according to claim 4, characterized in that: According to the type of the battery to be produced, the real-time concentration of the phosphorus pentoxide and the different concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate includes: If the type of the battery to be produced is a high-resistance battery, when the real-time concentration of phosphorus pentoxide is less than the primary concentration threshold, the phosphorus source flow rate is controlled to be the primary flow rate; the primary concentration threshold is the third concentration threshold, and the primary flow rate is the third flow rate; When the real-time concentration of the phosphorus pentoxide is greater than or equal to the primary concentration threshold and less than the secondary concentration threshold, the phosphorus source flow rate is controlled to be the secondary flow rate; the secondary concentration threshold is the fourth concentration threshold, and the secondary flow rate is the fourth flow rate; When the real-time concentration of phosphorus pentoxide is greater than or equal to the secondary concentration threshold, stopping the source; Among them, the third concentration threshold is smaller than the first concentration threshold, and the fourth concentration threshold is smaller than the second concentration threshold; the third flux is smaller than the first flux, and the fourth flux is smaller than the second flux.

6. The method for controlling the flow rate of phosphorus diffusion equipment according to any one of claims 1 to 5, characterized in that: The method further comprises: Obtaining the number of silicon wafers included in the battery to be produced; Accordingly, according to the real-time concentration of the phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to be a corresponding flow rate includes: According to the number of silicon wafers, a preset number threshold, the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be a corresponding flow rate.

7. The method for controlling the flow rate of phosphorus diffusion equipment according to claim 6, characterized in that: The controlling the phosphorus source flow rate of the phosphorus diffusion device to a corresponding flow rate according to the number of silicon wafers, the preset number threshold, the real-time concentration of phosphorus pentoxide and the preset different concentration thresholds includes: When the number of silicon wafers is less than or equal to the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, controlling the phosphorus source flow rate of the phosphorus diffusion device to be the corresponding flow rate; When the number of silicon wafers is greater than the preset number threshold, according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds, the phosphorus source flow rate of the phosphorus diffusion device is controlled to be the product of the corresponding source flow rate and the preset coefficient; The preset coefficient is greater than 1 and is proportional to the number of silicon wafers.

8. A phosphorus diffusion device, characterized in that: include: A phosphorus diffusion device body, a concentration measuring instrument and a controller; the phosphorus diffusion device body includes an exhaust pipe for discharging exhaust gas generated in the diffusion process; The concentration measuring instrument is used to collect the real-time concentration of phosphorus pentoxide in the tail gas pipe in the phosphorus diffusion equipment body; The controller is used to obtain the real-time concentration of phosphorus pentoxide collected by the concentration measuring instrument when the phosphorus diffusion equipment performs a diffusion process on the battery to be produced; and control the phosphorus source flow rate of the phosphorus diffusion equipment to be the corresponding flow rate according to the real-time concentration of phosphorus pentoxide and different preset concentration thresholds.

9. The phosphorus diffusion device according to claim 8, characterized in that The phosphorus diffusion equipment body also includes: a temperature reduction device; The cooling device is arranged on the tail gas pipe and is used for cooling the tail gas in the tail gas pipe.

10. The phosphorus diffusion device according to claim 9, characterized in that: The tailpipe includes a first tailpipe and a second tailpipe; the cooling device includes a spiral tube and a cooling chamber arranged outside the spiral tube: The air inlet of the spiral tube is arranged on one side of the cooling chamber and communicated with one end of the first tail gas pipe, and the air outlet of the spiral tube is arranged on the other side of the cooling chamber and communicated with one end of the second tail gas pipe; A water inlet is arranged on one side of the cooling cavity, and a water outlet is arranged on the other side of the cooling cavity.

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