Rectangular silicon wafer treatment process and application thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a rectangular silicon wafer treatment process and application thereof. The treatment process comprises the following steps: carrying out primary cleaning treatment and secondary cleaning treatment in sequence before texturing; wherein the reflectivity of the rectangular silicon wafer after the primary cleaning treatment is 30%-40%; and the reflectivity of the rectangular silicon wafer after the secondary cleaning treatment is 10%-20%. According to the rectangular silicon wafer treatment process and the application thereof provided by the invention, secondary cleaning is carried out after a conventional cleaning process, and the reflectivity of the rectangular silicon wafer after cleaning treatment is controlled, so that silicon powder on the surface of the silicon wafer can be effectively and thoroughly removed.

Description

Technical Field

[0001] The invention relates to the technical field of solar cells, and in particular to a processing technology for a rectangular silicon wafer and an application thereof. Background Art

[0002] In order to maximize the power of components under the same area, rectangular silicon wafers came into being, such as 191 mm × 182 mm and 210 mm × 182 mm. Compared with the conventional silicon wafers of 182 mm × 182 mm, these rectangular silicon wafers have a larger area, and the cutting channel temperature is higher during the fine-line cutting process (especially when using a wire diameter of 42 microns or less). A part of the silicon powder will be deposited and penetrated on the surface of the silicon wafer. After cleaning with conventional cleaning processes, the silicon powder that has penetrated on the surface of the silicon wafer cannot be completely removed, which can easily cause uneven distribution of the pyramid morphology after battery texturing, substandard reflectivity, and low battery efficiency.

[0003] In view of this, the present invention is proposed. Summary of the invention

[0004] In order to solve the problems in the prior art, the present invention provides a processing technology for a rectangular silicon wafer and its application.

[0005] Based on this, the present invention has the following technical solutions: In a first aspect, the present invention provides a processing process for a rectangular silicon wafer, comprising: performing a primary cleaning treatment and a secondary cleaning treatment in sequence before texturing; wherein, after the primary cleaning treatment, the reflectivity of the rectangular silicon wafer is 30%~40%; and after the secondary cleaning treatment, the reflectivity of the rectangular silicon wafer is 10%~20%.

[0006] According to a rectangular silicon wafer processing process provided by the present invention, the secondary cleaning process includes alkali washing the rectangular silicon wafer, performing anti-floating treatment at the same time, and then washing with water after alkali washing.

[0007] According to a rectangular silicon wafer treatment process provided by the present invention, during the alkali washing, the alkali solution is a potassium hydroxide solution or a sodium hydroxide solution; preferably, the concentration of the potassium hydroxide solution is 0.07wt%~0.3wt%; and / or the concentration of the sodium hydroxide solution is 0.05wt%~0.22wt%.

[0008] According to a rectangular silicon wafer processing process provided by the present invention, the anti-floating processing includes any of the following methods: Method 1: Use a flower basket with a pressure rod to hold the silicon wafer against floating; Method 2: Use a robotic arm with a pressure bar to prevent the silicon wafer from floating by moving the robotic arm.

[0009] According to a rectangular silicon wafer processing process provided by the present invention, a slow pull process is further included between the primary cleaning process and the secondary cleaning process; The time of the slow pull treatment is 100 to 200 seconds; The temperature of the slow pulling treatment is 70-80 degrees Celsius; The lifting speed of the slow pulling process is 2-2.6 cm / s.

[0010] According to a rectangular silicon wafer processing process provided by the present invention, the secondary cleaning process further includes a secondary slow pulling process; The time of the secondary slow pulling treatment is 100 to 200 seconds; The temperature of the secondary slow drawing treatment is 85-95 degrees Celsius; The lifting speed of the secondary slow pulling process is 1-1.5 cm / s.

[0011] According to a rectangular silicon wafer processing process provided by the present invention, the one-time cleaning process comprises: sequentially subjecting the rectangular silicon wafer to a first water wash, a detergent wash, a second water wash, a hydrogen peroxide wash and a third water wash.

[0012] According to a processing process for a rectangular silicon wafer provided by the present invention, the processing process comprises: sequentially subjecting the rectangular silicon wafer to a primary cleaning process, a primary slow pulling process, a secondary cleaning process, a secondary slow pulling process, drying, sorting and texturing.

[0013] Preferably, the treatment process includes: sequentially subjecting the rectangular silicon wafer to a first water wash, a detergent wash, a second water wash, a hydrogen peroxide wash, a third water wash, a slow pull treatment, an alkali wash, a fourth water wash, a second slow pull treatment, drying, sorting and texturing.

[0014] According to a rectangular silicon wafer processing process provided by the present invention, the first water washing time is 200-500 seconds, and the water washing temperature is 30-40 degrees Celsius; and / or, the cleaning time of the cleaning agent is 450 to 800 seconds, and the cleaning temperature of the cleaning agent is 50 to 60 degrees Celsius; And / or, the second washing time is 100-300 seconds, and the washing temperature is 40-50 degrees Celsius; And / or, the time of hydrogen peroxide cleaning is 150-300 seconds, and the temperature of hydrogen peroxide cleaning is 30-50 degrees Celsius; And / or, the third washing time is 400-800 seconds, and the washing temperature is 55-80 degrees Celsius; And / or, the time of one slow-pulling treatment is 100-200 seconds, and the temperature of one slow-pulling treatment is 80-95 degrees Celsius; And / or, the alkali washing time is 50 to 200 seconds, and the alkali washing temperature is 65 to 80 degrees Celsius; And / or, the fourth washing time is 200-500 seconds, and the fourth washing temperature is 20-40 degrees Celsius; and / or, the time of the secondary slow-drawing treatment is 100 to 200 seconds, and the temperature of the secondary slow-drawing treatment is 80 to 95 degrees Celsius; And / or, the hot air drying time is 300-600 seconds, and the hot air drying temperature is 90-100 degrees Celsius.

[0015] In a second aspect, the present invention provides application of the rectangular silicon wafer processing process in preparing solar cells.

[0016] The processing technology and application of the rectangular silicon wafer provided by the present invention can effectively and thoroughly remove silicon powder on the surface of the silicon wafer by performing secondary cleaning after a conventional cleaning process and controlling the reflectivity of the rectangular silicon wafer after the cleaning process. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Before texturing, the silicon wafer is cleaned using a conventional cleaning process, and the silicon powder that penetrates the surface cannot be completely removed, which easily causes uneven pyramid morphology distribution after texturing of the battery, substandard reflectivity, and low efficiency of the battery. The present invention finds that secondary cleaning after the conventional cleaning process and controlling the reflectivity of the rectangular silicon wafer after cleaning can effectively and completely remove the silicon powder on the surface of the silicon wafer.

[0019] In a first aspect, the present invention provides a processing process for a rectangular silicon wafer, comprising: performing a primary cleaning treatment and a secondary cleaning treatment in sequence before texturing; wherein, after the primary cleaning treatment, the reflectivity of the rectangular silicon wafer is 30%~40%; and after the secondary cleaning treatment, the reflectivity of the rectangular silicon wafer is 10%~20%.

[0020] In the present invention, the reflectivity of the rectangular silicon wafer after the one cleaning treatment can be any value of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, or a numerical range with any two of the above values ​​as endpoints.

[0021] After the secondary cleaning treatment, the reflectivity of the rectangular silicon wafer can be any value of 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a numerical range with any two of the above values ​​as endpoints.

[0022] According to a rectangular silicon wafer processing process provided by the present invention, the secondary cleaning process includes alkali washing the rectangular silicon wafer, performing anti-floating treatment at the same time, and then washing with water after alkali washing.

[0023] In the present invention, the silicon wafer is etched by alkali washing to achieve the reflectivity; at the same time, since hydrogen is generated after the alkali and the silicon wafer react, it adheres to the surface of the silicon wafer and easily lifts the silicon wafer, so anti-floating treatment is performed while the alkali washing is performed.

[0024] According to a rectangular silicon wafer processing process provided by the present invention, during the alkali washing, the alkali solution is a potassium hydroxide solution or a sodium hydroxide solution; preferably, the concentration of the potassium hydroxide solution is 0.07wt%~0.3wt%, specifically any one of 0.07wt%, 0.08wt%, 0.09wt%, 0.10wt%, 0.15wt%, 0.20wt%, 0.25wt%, 0.3wt%, or a numerical range with any two of the above values ​​as endpoints.

[0025] And / or the concentration of the sodium hydroxide solution is 0.05wt%~0.22wt%, specifically any value among 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.10wt%, 0.15wt%, 0.20wt%, 0.22wt%, or a numerical range with any two of the above values ​​as endpoints.

[0026] According to a rectangular silicon wafer processing process provided by the present invention, the anti-floating processing includes any of the following methods: Method 1: Use a flower basket with a pressure rod to hold the silicon wafer against floating; Method 2: Use a robotic arm with a pressure bar to prevent the silicon wafer from floating by moving the robotic arm.

[0027] According to a rectangular silicon wafer processing process provided by the present invention, a slow pull process is further included between the primary cleaning process and the secondary cleaning process; The time of the slow pull treatment is 100 to 200 seconds; The temperature of the slow pulling treatment is 70-80 degrees Celsius; The lifting speed of the slow pulling process is 2-2.6 cm / s.

[0028] In the present invention, the purpose of the slow pull treatment is to remove bubbles, residual dirt and large water droplets on the surface of the silicon wafer, and at the same time, it can also help to make the subsequent etching more uniform.

[0029] According to a rectangular silicon wafer processing process provided by the present invention, the secondary cleaning process further includes a secondary slow pulling process; The time of the secondary slow pulling treatment is 100 to 200 seconds; The temperature of the secondary slow drawing treatment is 85-95 degrees Celsius; The lifting speed of the secondary slow pulling process is 1-1.5 cm / s.

[0030] In the present invention, the purpose of the secondary slow pulling treatment is to remove bubbles on the surface of the silicon wafer and drain 70%-90% of the water on the surface of the silicon wafer.

[0031] According to a rectangular silicon wafer processing process provided by the present invention, the one-time cleaning process comprises: sequentially subjecting the rectangular silicon wafer to a first water wash, a detergent wash, a second water wash, a hydrogen peroxide wash and a third water wash.

[0032] In a specific implementation, the cleaning agent may be a mixture of water, a surfactant, a chelating agent, a penetrant and an alkali, or may be a cleaning agent conventionally used in the art, which is not limited herein.

[0033] In a specific implementation, the hydrogen peroxide cleaning uses hydrogen peroxide with a concentration of 10wt% to 20wt%.

[0034] According to a processing process for a rectangular silicon wafer provided by the present invention, the processing process comprises: sequentially subjecting the rectangular silicon wafer to a primary cleaning process, a primary slow pulling process, a secondary cleaning process, a secondary slow pulling process, drying, sorting and texturing.

[0035] Preferably, the treatment process includes: sequentially subjecting the rectangular silicon wafer to a first water wash, a detergent wash, a second water wash, a hydrogen peroxide wash, a third water wash, a slow pull treatment, an alkali wash, a fourth water wash, a second slow pull treatment, drying, sorting and texturing.

[0036] According to a rectangular silicon wafer processing process provided by the present invention, the first water washing time is 200-500 seconds, and the water washing temperature is 30-40 degrees Celsius; and / or, the cleaning time of the cleaning agent is 450 to 800 seconds, and the cleaning temperature of the cleaning agent is 50 to 60 degrees Celsius; And / or, the second washing time is 100-300 seconds, and the washing temperature is 40-50 degrees Celsius; And / or, the time of hydrogen peroxide cleaning is 150-300 seconds, and the temperature of hydrogen peroxide cleaning is 30-50 degrees Celsius; And / or, the third washing time is 400-800 seconds, and the washing temperature is 55-80 degrees Celsius; And / or, the time of a slow pull treatment is 100-200 seconds, the temperature of a slow pull treatment is 80-95 degrees Celsius; the lifting speed of the slow pull treatment is 1-2.6 cm / second; And / or, the alkali washing time is 50 to 200 seconds, and the alkali washing temperature is 65 to 80 degrees Celsius; And / or, the fourth washing time is 200-500 seconds, and the fourth washing temperature is 20-40 degrees Celsius; And / or, the time of the secondary slow-pulling treatment is 100 to 200 seconds, the temperature of the secondary slow-pulling treatment is 80 to 95 degrees Celsius; the lifting speed of the secondary slow-pulling treatment is 1 to 2.6 cm / s; And / or, the hot air drying time is 300-600 seconds, and the hot air drying temperature is 90-100 degrees Celsius.

[0037] According to a preferred embodiment of the present invention, the processing of the silicon wafer includes: S1: The rectangular silicon wafer is washed for the first time in a pure water overflow rinsing tank, the washing time is 200-500 seconds, and the washing temperature is 30-40 degrees Celsius; S2: After washing with water, the rectangular silicon wafer is cleaned in a cleaning agent tank. The cleaning time is 450 to 800 seconds. The cleaning temperature of the cleaning agent is 50 to 60 degrees Celsius. S3: After cleaning, the rectangular silicon wafer is washed for a second time in a pure water overflow rinsing tank, the washing time is 100 to 300 seconds, and the washing temperature is 40 to 50 degrees Celsius; S4: After washing, the rectangular silicon wafer is cleaned in a hydrogen peroxide tank for 150 to 300 seconds at a temperature of 30 to 50 degrees Celsius; wherein the concentration of hydrogen peroxide is 10wt% to 20wt%; S5: After cleaning, the rectangular silicon wafer is washed for the third time in a pure water overflow rinsing tank, the washing time is 400 to 800 seconds, and the washing temperature is 55 to 80 degrees Celsius; S6: After washing, the rectangular silicon wafer is subjected to a slow-pulling treatment in a slow-pulling tank, the time of the slow-pulling treatment is 100-200 seconds, the temperature of the slow-pulling treatment is 80-95 degrees Celsius, and the lifting speed of the slow-pulling treatment is 1-2.6 cm / s; S7: After washing, the rectangular silicon wafer is alkali-washed in an anti-floating wafer alkali-washing tank using a 0.07wt% to 0.3wt% potassium hydroxide aqueous solution. At the same time, a mechanical arm with a pressure rod is used to prevent the silicon wafer from floating by moving the mechanical arm; the alkali-washing time is 50 to 200 seconds, and the alkali-washing temperature is 65 to 80 degrees Celsius; S7: After the alkaline washing, the rectangular silicon wafer is washed for the fourth time in a pure water overflow rinsing tank, the washing time is 400-800 seconds, and the washing temperature is 55-80 degrees Celsius; the washing time is 200-500 seconds, and the washing temperature is 20-40 degrees Celsius; S8: After washing, the rectangular silicon wafer is subjected to a secondary slow-pulling treatment in a slow-pulling tank, the time of the secondary slow-pulling treatment is 100 to 200 seconds, the temperature of the secondary slow-pulling treatment is 80 to 95 degrees Celsius, and the lifting speed of the secondary slow-pulling treatment is 1 to 2.6 cm / s; S9: After slow pulling, the rectangular silicon wafer is dried in a drying tank. The hot air drying time is 300 to 600 seconds and the hot air drying temperature is 90 to 100 degrees Celsius.

[0038] In a second aspect, the present invention provides application of the rectangular silicon wafer processing process in preparing solar cells.

[0039] In order to further illustrate the technical solution of the present invention, the present invention also provides the following specific embodiments and comparative examples.

[0040] Unless otherwise specified, the various raw materials used in the examples and comparative examples are commercially available conventional raw materials, and the technical means used are conventional means well known to those skilled in the art.

[0041] Example 1 This embodiment provides a silicon wafer processing process, comprising the following steps: S1: The rectangular silicon wafer is washed for the first time in a pure water overflow rinsing tank, the washing time is 200 seconds, and the washing temperature is 30 degrees Celsius; S2: After washing with water, the rectangular silicon wafer is cleaned in a cleaning agent tank for 450 seconds at a cleaning temperature of 50 degrees Celsius; S3: After cleaning, the rectangular silicon wafer is rinsed for a second time in a pure water overflow rinsing tank, the washing time is 100 seconds, and the washing temperature is 40 degrees Celsius; S4: After washing, the rectangular silicon wafer is cleaned in a hydrogen peroxide tank for 150 seconds at a cleaning temperature of 40 degrees Celsius; wherein the concentration of hydrogen peroxide is 10wt%; S5: After cleaning, the rectangular silicon wafer is washed for a third time in a pure water overflow rinsing tank, the washing time is 400 seconds, and the washing temperature is 55 degrees Celsius; after one cleaning process, the reflectivity of the rectangular silicon wafer is 33%; S6: After washing, the rectangular silicon wafer is subjected to a slow-pulling treatment in a slow-pulling tank, the time of the slow-pulling treatment is 100 seconds, the temperature of the slow-pulling treatment is 70 degrees Celsius, and the lifting speed of the slow-pulling treatment is 2 cm / s; S7: After washing, the rectangular silicon wafer is alkali-washed in an anti-floating wafer alkali-washing tank using a 0.07wt% potassium hydroxide aqueous solution. At the same time, a mechanical arm with a pressure rod is used to prevent the silicon wafer from floating by moving the mechanical arm; the alkali-washing time is 50 seconds, and the alkali-washing temperature is 65 degrees Celsius; S8: After the alkaline washing, the rectangular silicon wafer is washed for the fourth time in a pure water overflow rinsing tank, the washing time is 400 seconds, and the washing temperature is 55 degrees Celsius; the washing time is 200 seconds, and the washing temperature is 20 degrees Celsius; after the second washing treatment, the reflectivity of the rectangular silicon wafer is 17.9%; S9: After washing, the rectangular silicon wafer is subjected to a secondary slow-pulling treatment in a slow-pulling tank. The time of the secondary slow-pulling treatment is 100 seconds, and the temperature of the secondary slow-pulling treatment is 85 degrees Celsius. The lifting speed of the secondary slow-pulling treatment is 1 cm / s. S10: After slow pulling, the rectangular silicon wafer is dried in a drying tank, the hot air drying time is 300 seconds, and the hot air drying temperature is 90 degrees Celsius.

[0042] Example 2 This embodiment provides a silicon wafer processing process, comprising the following steps: S1: The rectangular silicon wafer is washed for the first time in a pure water overflow rinsing tank, the washing time is 250 seconds, and the washing temperature is 35 degrees Celsius; S2: After washing with water, the rectangular silicon wafer is cleaned in a cleaning agent tank for 500 seconds at a cleaning temperature of 55 degrees Celsius; S3: After cleaning, the rectangular silicon wafer is rinsed for a second time in a pure water overflow rinsing tank, the rinsing time is 150 seconds, and the rinsing temperature is 45 degrees Celsius; S4: After washing, the rectangular silicon wafer is cleaned in a hydrogen peroxide tank for 200 seconds at a cleaning temperature of 45 degrees Celsius; wherein the concentration of hydrogen peroxide is 12wt%; S5: After cleaning, the rectangular silicon wafer is washed for a third time in a pure water overflow rinsing tank, the washing time is 450 seconds, and the washing temperature is 60 degrees Celsius; after one cleaning process, the reflectivity of the rectangular silicon wafer is 35%; S6: After washing, the rectangular silicon wafer is subjected to a slow-pulling treatment in a slow-pulling tank, the time of the slow-pulling treatment is 120 seconds, the temperature of the slow-pulling treatment is 75 degrees Celsius, and the lifting speed of the slow-pulling treatment is 2.5 cm / s; S7: After washing, the rectangular silicon wafer is alkaline washed in an anti-floating wafer alkaline washing tank using a 0.09% potassium hydroxide aqueous solution. At the same time, a mechanical arm with a pressure rod is used to prevent the silicon wafer from floating by moving the mechanical arm. The alkaline washing time is 55 seconds and the alkaline washing temperature is 70 degrees Celsius. S8: After the alkaline washing, the rectangular silicon wafer is washed for the fourth time in a pure water overflow rinsing tank, the washing time is 450 seconds, and the washing temperature is 55 degrees Celsius; the washing time is 250 seconds, and the washing temperature is 25 degrees Celsius; after the second washing treatment, the reflectivity of the rectangular silicon wafer is 17.5%; S9: After washing, the rectangular silicon wafer is subjected to a secondary slow-pulling treatment in a slow-pulling tank. The time of the secondary slow-pulling treatment is 120 seconds, and the temperature of the secondary slow-pulling treatment is 90 degrees Celsius. The lifting speed of the secondary slow-pulling treatment is 1.2 cm / s. S10: After slow pulling, the rectangular silicon wafer is dried in a drying tank, the hot air drying time is 350 seconds, and the hot air drying temperature is 93 degrees Celsius.

[0043] Example 3 This embodiment provides a silicon wafer processing process, which differs from Embodiment 1 only in that: during the alkaline washing in S7, a potassium hydroxide aqueous solution with a concentration of 0.3wt% is used for alkaline washing; after the secondary washing treatment, the reflectivity of the rectangular silicon wafer is 17.2%.

[0044] Example 4 This embodiment provides a silicon wafer processing process, which is different from the embodiment 1 only in that the conditions of the first slow pull process and the second slow pull process are the same. The slow pull process time is 120 seconds, the slow pull process temperature is 90 degrees Celsius, and the lifting speed of the slow pull process is 1.2 cm / s.

[0045] Example 5 This embodiment provides a silicon wafer processing process, which differs from Embodiment 1 only in that: during the alkaline washing in S7, a potassium hydroxide aqueous solution with a concentration of 0.5wt% is used for alkaline washing; after the secondary washing treatment, the reflectivity of the rectangular silicon wafer is 20.3%.

[0046] Comparative Example 1 This embodiment provides a silicon wafer processing process, which differs from Embodiment 1 only in that: a potassium hydroxide aqueous solution with a concentration of 2 wt % is used for alkaline washing; and after the secondary washing treatment, the reflectivity of the rectangular silicon wafer is 25.5%.

[0047] Test example The present invention tests the reflectivity of the silicon wafers prepared in the above-mentioned embodiments and comparative examples, and the results are shown in Table 1.

[0048] The detection method refers to GB / T 36540-2018.

[0049] Table 1

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these 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.

Claims

1. A process for processing a rectangular silicon wafer, characterized in that: include: Before texturing, a primary cleaning process and a secondary cleaning process are performed in sequence; wherein, after the primary cleaning process, the reflectivity of the rectangular silicon wafer is 30% to 40%; and after the secondary cleaning process, the reflectivity of the rectangular silicon wafer is 10% to 20%.

2. The rectangular silicon wafer processing process according to claim 1, characterized in that: The secondary cleaning process includes alkali cleaning the rectangular silicon wafer, performing anti-drifting treatment at the same time, and then washing with water after the alkali cleaning.

3. The process for processing a rectangular silicon wafer according to claim 2, characterized in that: During the alkali washing, the alkali solution is a potassium hydroxide solution or a sodium hydroxide solution; preferably, the concentration of the potassium hydroxide solution is 0.07wt%~0.3wt%; and / or the concentration of the sodium hydroxide solution is 0.05wt%~0.22wt%.

4. The process for processing a rectangular silicon wafer according to claim 2, characterized in that: The anti-drifting treatment includes any of the following methods: Method 1: Use a flower basket with a pressure rod to hold the silicon wafer against floating; Method 2: Use a robotic arm with a pressure bar to prevent the silicon wafer from floating by moving the robotic arm.

5. The process for processing a rectangular silicon wafer according to any one of claims 1 to 4, characterized in that: A slow pull process is also included between the primary cleaning process and the secondary cleaning process; The time of the slow pull treatment is 100 to 200 seconds; The temperature of the slow pulling treatment is 70-80 degrees Celsius; The lifting speed of the slow pulling process is 2-2.6 cm / s.

6. The process for processing a rectangular silicon wafer according to any one of claims 1 to 5, characterized in that: The secondary cleaning process also includes a secondary slow pulling process; The time of the secondary slow pulling treatment is 100 to 200 seconds; The temperature of the secondary slow drawing treatment is 85-95 degrees Celsius; The lifting speed of the secondary slow pulling process is 1-1.5 cm / s.

7. The process for processing a rectangular silicon wafer according to any one of claims 1 to 6, characterized in that: The one-time cleaning process includes: sequentially performing a first water wash, a cleaning agent wash, a second water wash, a hydrogen peroxide wash and a third water wash on the rectangular silicon wafer.

8. The process for processing a rectangular silicon wafer according to any one of claims 1 to 7, characterized in that: The processing process includes: sequentially performing a primary cleaning process, a primary slow pulling process, a secondary cleaning process, a secondary slow pulling process, drying, sorting and texturing on the rectangular silicon wafer; Preferably, the treatment process includes: sequentially subjecting the rectangular silicon wafer to a first water wash, a detergent wash, a second water wash, a hydrogen peroxide wash, a third water wash, a slow pull treatment, an alkali wash, a fourth water wash, a second slow pull treatment, drying, sorting and texturing.

9. The rectangular silicon wafer processing process according to claim 8, characterized in that: The first washing time is 200~500 seconds, and the washing temperature is 30~40 degrees Celsius; and / or, the cleaning time of the cleaning agent is 450 to 800 seconds, and the cleaning temperature of the cleaning agent is 50 to 60 degrees Celsius; And / or, the second washing time is 100-300 seconds, and the washing temperature is 40-50 degrees Celsius; And / or, the time of hydrogen peroxide cleaning is 150-300 seconds, and the temperature of hydrogen peroxide cleaning is 30-50 degrees Celsius; And / or, the third washing time is 400-800 seconds, and the washing temperature is 55-80 degrees Celsius; And / or, the time of one slow-pulling treatment is 100-200 seconds, and the temperature of one slow-pulling treatment is 80-95 degrees Celsius; And / or, the alkali washing time is 50 to 200 seconds, and the alkali washing temperature is 65 to 80 degrees Celsius; And / or, the fourth washing time is 200-500 seconds, and the fourth washing temperature is 20-40 degrees Celsius; and / or, the time of the secondary slow-drawing treatment is 100 to 200 seconds, and the temperature of the secondary slow-drawing treatment is 80 to 95 degrees Celsius; And / or, the hot air drying time is 300-600 seconds, and the hot air drying temperature is 90-100 degrees Celsius.

10. Application of the rectangular silicon wafer processing process according to any one of claims 1 to 9 in the preparation of solar cells.

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