Device and method for improving efficiency of solar cell through low-temperature rapid pretreatment

Abstract

The invention discloses a device and method for improving the efficiency of a solar cell through low-temperature rapid pretreatment, and belongs to the technical field of solar cells, the device comprises a device shell, a conveying belt and an ultraviolet light-emitting device, the conveying belt penetrates through the device shell, and the ultraviolet light-emitting device is arranged in the device shell, and the method comprises the steps that a TOPCon solar cell is prepared, a TOPCon solar cell is placed on a conveying belt, when the TOPCon solar cell moves into a device shell, an ultraviolet light-emitting device is started to carry out ultraviolet light irradiation on the front face of the TOPCon solar cell, and after the TOPCon solar cell is conveyed out of the device shell through the conveying belt, laser-assisted sintering is carried out. The device cost and the power cost are reduced, and the low-temperature rapid ultraviolet radiation pretreatment can break weak Si-H bonds in the battery and improve the passivation performance of the battery, so that the efficiency of the battery is improved, and the anti-UV attenuation performance of the TOPCon solar battery and the assembly can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and particularly relates to a device and method for improving the efficiency of solar cells by low-temperature rapid pretreatment. Background Art

[0002] The manufacturing of TOPCon solar cells includes processes such as cleaning and texturing, diffusion, oxidation, annealing, PE-Poly, ALD, PECVD, screen printing, etc. The conventional electrode preparation technical route for TOPCon solar cells is screen printing + sintering + light injection annealing + laser-assisted sintering. The required light intensity for light injection annealing is 10 - 60 kWh / m 2 , and the temperature is above 600 °C, resulting in high equipment and electricity costs; TOPCon solar cells have the advantages of high mass production efficiency (the theoretical limit efficiency is 28.7%, higher than the theoretical limit efficiency of HJT, which is 27.5%), excellent passivation effect, compatibility of the manufacturing process with existing production lines, and mature technology. However, TOPCon solar cells and modules are sensitive to ultraviolet-induced degradation (UVID). Summary of the Invention

[0003] To solve the problems raised in the above background art, the present invention provides a device and method for improving the efficiency of solar cells by low-temperature rapid pretreatment, so as to solve the problems of high electricity cost in the annealing process in the prior art and the sensitivity of TOPCon solar cells and modules to ultraviolet-induced degradation (UVID).

[0004] To achieve the above object, the present invention provides the following technical solutions: A device for improving the efficiency of solar cells by low-temperature rapid pretreatment, comprising: A device housing; the device housing is a box structure made of light-tight material, and each of two opposite side surfaces of the device housing is provided with a transmission through hole; A conveyor belt; the conveyor belt passes through the two transmission through holes in sequence and penetrates through the device housing. The TOPCon solar cell is placed on the conveyor belt, and the conveyor belt is used to drive the TOPCon solar cell through the device housing; An ultraviolet light-emitting device; the ultraviolet light-emitting device is arranged on the inner top surface of the device housing, and the light-emitting end of the ultraviolet light-emitting device points to the conveyor belt. The light irradiation intensity of the ultraviolet light-emitting device is 100 - 300 W / m 2 .

[0005] Preferably, the ultraviolet light-emitting device is at least one ultraviolet lamp.

[0006] Preferably, the ultraviolet rays emitted by the ultraviolet lamp include two types, UVA and UVB, wherein UVB accounts for 3 - 9%, and the wavelength is 280 - 400 nm.

[0007] A method for improving the efficiency of solar cells by low-temperature rapid pretreatment, comprising the following steps: S1: Prepare a TOPCon solar cell; S2: Place the TOPCon solar cell on a conveyor belt, and the conveyor belt drives the TOPCon solar cell to move into the device housing; S3: Turn on the ultraviolet light emitting device to irradiate the front side of the TOPCon solar cell located in the device housing with ultraviolet light; S4: After the TOPCon solar cell irradiated with ultraviolet light is sent out of the device housing through the conveyor belt, perform laser-assisted sintering.

[0008] Preferably, S1 specifically includes the following steps: S1.1: Prepare an n-type silicon substrate, texture the silicon substrate, remove surface impurities, and form a pyramid structure; S1.2: Perform boron diffusion on the front side of the silicon substrate to form a boron diffusion doping layer; S1.3: Perform high-temperature oxidation on the front side of the silicon substrate, and advance the PN junction on the boron diffusion doping layer to form boron-silicon glass BSG; S1.4: Remove the boron-silicon glass BSG deposited around the back side of the silicon substrate and perform polishing treatment; S1.5: Sequentially deposit a tunneling oxide layer and a phosphorus-doped polysilicon layer on the back side of the silicon substrate by plasma-enhanced chemical vapor deposition technology; S1.6: Remove the phosphorus-silicon glass on the front side and edges of the silicon substrate by the RCA process; S1.7: Then form a double-layer structure of alumina and silicon nitride on both the front and back sides of the silicon substrate by atomic layer deposition and plasma-enhanced chemical vapor deposition technologies; S1.8: Screen-print the front and back electrodes of the silicon substrate and perform high-temperature sintering.

[0009] Preferably, in S3, the ultraviolet light irradiation intensity is 100 - 300 W / m 2 , the irradiation time is 10 - 60 s, and the temperature is room temperature.

[0010] Preferably, in S4, the deflection voltage during laser-assisted sintering is set to 10 - 15 V, the laser power is set to 20% - 35%, and the time is 1 - 1.5 s.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This application optimizes the screen process of the battery. By replacing the photo-injection annealing process with low-temperature rapid ultraviolet irradiation pretreatment, the equipment cost and power cost are reduced. This application breaks the weak Si-H bonds inside the battery through low-temperature rapid ultraviolet irradiation pretreatment, improves the passivation performance of the battery, thereby increasing the battery efficiency, and can improve the anti-UV attenuation performance of TOPCon solar cells and modules. Description of the Drawings

[0012] Figure 1 It is a schematic structural diagram of the device of this application; Figure 2 It is a graph showing the change of minority carrier lifetime of the blue film after coating after low-temperature rapid ultraviolet irradiation pretreatment; The marks in the figure are: 1 - Device housing; 2 - Conveyor belt; 3 - TOPCon solar cell; 4 - Ultraviolet lamp; 5 - Transmission through-hole. Detailed Embodiments

[0013] To facilitate the understanding of the technical content of the present invention by those skilled in the art, the present invention will be further described in detail below with reference to the drawings and specific examples. It should be understood that the specific examples described herein are only used to explain the present invention and are not used to limit the present invention.

[0014] As Figure 1 shown, a device for improving the efficiency of a solar cell by low-temperature rapid pretreatment includes: Device housing 1; The device housing 1 is a box structure made of light-tight material, and each of the two opposite side surfaces of the device housing 1 is provided with a transmission through-hole 5; Conveyor belt 2; The conveyor belt 2 passes through the two transmission through-holes 5 in sequence and is arranged through the device housing 1. The TOPCon solar cell 3 is placed on the conveyor belt 2, and the conveyor belt 2 is used to drive the TOPCon solar cell 3 through the device housing 1; Ultraviolet light emitting device; The ultraviolet light emitting device is arranged on the inner top surface of the device housing 1, and the light emitting end of the ultraviolet light emitting device points to the conveyor belt 2. The light irradiation intensity of the ultraviolet light emitting device is 200W / m 2 , and the ultraviolet light emitting device is two ultraviolet lamps 4, and the ultraviolet rays emitted by the ultraviolet lamps 4 have a wavelength of 365nm.

[0015] A method for improving the efficiency of a solar cell by low-temperature rapid pretreatment includes the following steps: S1: Prepare the TOPCon solar cell 3, specifically: S1.1: Prepare an n-type silicon substrate, texture the silicon substrate, remove surface impurities, and form a pyramid structure; S1.2: Perform boron diffusion on the front surface of the silicon substrate to form a boron diffusion doping layer; S1.3: Perform high-temperature oxidation on the front side of the silicon substrate to promote the formation of a PN junction on the boron diffusion doping layer to form borosilicate glass BSG; S1.4: Remove the borosilicate glass BSG plated around the back side of the silicon substrate and perform polishing treatment; S1.5: Sequentially deposit a tunneling oxide layer and a phosphorus-doped polysilicon layer on the back side of the silicon substrate by plasma-enhanced chemical vapor deposition technology; S1.6: Remove the phosphosilicate glass on the front side and edges of the silicon substrate by RCA process; S1.7: Then form a double-layer structure of alumina and silicon nitride on both the front and back sides of the silicon substrate by atomic layer deposition and plasma-enhanced chemical vapor deposition technology; S1.8: Screen-print the front and back electrodes of the silicon substrate and perform high-temperature sintering.

[0016] S2: Place the TOPCon solar cell 3 on the conveyor belt 2, and the conveyor belt 2 drives the TOPCon solar cell 3 to move into the device housing 1; S3: Turn on the ultraviolet light emitting device to irradiate the front side of the TOPCon solar cell 3 located in the device housing 1 with ultraviolet light. The ultraviolet light irradiation intensity is 200W / m 2 , the irradiation time is 30s, and the temperature is room temperature; S4: After the TOPCon solar cell 3 irradiated with ultraviolet light is sent out of the device housing 1 through the conveyor belt 2, perform laser-assisted sintering. The deflection voltage during laser-assisted sintering is set to 12V, the laser power is set to 25%, and the time is 1s.

[0017] This application optimizes the screen process of the battery. By replacing the photo-injection annealing process with low-temperature rapid ultraviolet irradiation pretreatment, the equipment cost and power cost are reduced. This application breaks the weak Si-H bonds inside the battery through low-temperature rapid ultraviolet irradiation pretreatment, improves the passivation performance of the battery, thereby improving the battery efficiency, and can improve the anti-UV attenuation performance of the TOPCon solar cell 3 and components. As Figure 2 shown, at an implantation concentration of 1E15cm -3 , after ultraviolet irradiation for 10s and 30s, the minority carrier lifetime of the blue film increases from 1377μs to 2843 and 2893μs. It can be seen that after the blue film is coated and pretreated with low-temperature rapid ultraviolet irradiation, the minority carrier lifetime is significantly improved.

Claims

1. A device for improving the efficiency of solar cells by low-temperature rapid pretreatment, characterized in that: include: Device housing (1); the device housing (1) is a box structure made of opaque material, and a transmission through hole (5) is respectively provided on two opposite sides of the device housing (1); A conveyor belt (2); the conveyor belt (2) passes through two conveying through holes (5) in sequence and penetrates the device housing (1); a TOPCon solar cell (3) is placed on the conveyor belt (2); and the conveyor belt (2) is used to drive the TOPCon solar cell (3) to pass through the device housing (1); Ultraviolet light emitting device; The ultraviolet light emitting device is arranged on the inner top surface of the device housing (1), the light emitting end of the ultraviolet light emitting device is arranged to point toward the conveyor belt (2), and the light irradiation intensity of the ultraviolet light emitting device is 100-300W / m 2 .

2. The device for improving solar cell efficiency by low temperature rapid pretreatment according to claim 1, characterized in that: The ultraviolet light emitting device is at least one ultraviolet lamp (4).

3. The device for improving solar cell efficiency by low temperature rapid pretreatment according to claim 2, characterized in that: The ultraviolet rays emitted by the ultraviolet lamp (4) include two types: UVA and UVB. Among them, UVB accounts for 3-9% and has a wavelength of 280-400nm.

4. A method for improving the efficiency of solar cells by low-temperature rapid pretreatment, applied to the device for improving the efficiency of solar cells by low-temperature rapid pretreatment as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Preparation of TOPCon solar cells (3); S2: placing the TOPCon solar cell (3) on the conveyor belt (2), and the conveyor belt (2) drives the TOPCon solar cell (3) to move into the device housing (1); S3: turning on the ultraviolet light emitting device to irradiate the front side of the TOPCon solar cell (3) located in the device housing (1) with ultraviolet light; S4: After the TOPCon solar cell (3) irradiated with ultraviolet light is sent out of the device housing (1) via a conveyor belt (2), laser-assisted sintering is performed.

5. The method for improving solar cell efficiency by low temperature rapid pretreatment according to claim 4, characterized in that: S1 specifically includes the following steps: S1.1: Prepare an n-type silicon substrate, perform texturing on the silicon substrate, remove surface impurities, and form a pyramid structure; S1.2: Diffusing boron on the front side of the silicon substrate to form a boron diffusion doping layer; S1.3: High temperature oxidation is performed on the front side of the silicon substrate to promote the PN junction on the boron diffusion doped layer to form borosilicate glass (BSG); S1.4: Remove the borosilicate glass (BSG) coated on the back of the silicon substrate and perform polishing; S1.5: depositing a tunnel oxide layer and a phosphorus-doped polysilicon layer in sequence on the back side of the silicon substrate by plasma enhanced chemical vapor deposition technology; S1.6: Remove the phosphosilicate glass on the front and edge of the silicon substrate by RCA process; S1.7: Then, a double-layer structure of aluminum oxide and silicon nitride is formed on both the front and back sides of the silicon substrate by atomic layer deposition and plasma enhanced chemical vapor deposition technology; S1.8: Screen print the front and back electrodes of the silicon substrate and perform high temperature sintering.

6. The method for improving solar cell efficiency by low temperature rapid pretreatment according to claim 4, characterized in that: In S3, the UV radiation intensity is 100-300W / m 2 , irradiation time is 10-60s, and temperature is room temperature.

7. The method for improving solar cell efficiency by low temperature rapid pretreatment according to claim 4, characterized in that: In S4, the deflection voltage during laser-assisted sintering was set to 10-15 V, the laser power was set to 20%-35%, and the time was 1-1.5 s.

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