A crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment

Abstract

The present invention discloses a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and a production device thereof, and relates to the technical field of crystalline silicon photovoltaic cells. The present invention adopts a sol-gel method to prepare a gel film, adopts a gel film thermal oxidation method to prepare a carbon-doped silicon oxide film, and sandwiches the carbon-doped silicon oxide film between a crystalline silicon substrate and a doped polycrystalline silicon film as a junction tunneling passivation layer to improve the performance of crystalline silicon photovoltaic cells. The patent improves the mixing effect of the sol and the cleanliness of the equipment through a unique stirring structure and a scraping and cleaning function, and provides effective technical support for the production of crystalline silicon photovoltaic cells. The stirring equipment includes a stirring kettle, and a power structure is installed on the top of the stirring kettle. The power is provided by a power member, and the stirring member in the stirring structure is driven to slide up and down and rotate and stir in the stirring kettle in cooperation with a reciprocating member and a rotating member, so as to achieve mixed stirring of multiple sols. A stirring rod with an adjustable stirring range is arranged in the stirring structure, and the stirring rod is adjusted by the bottom rod in the upper adjusting member to achieve scraping and cleaning of the inner wall of the stirring kettle.

Description

Technical Field

[0001] The present invention relates to crystalline silicon photovoltaic cell technology, and specifically to a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment. Background Art

[0002] It is well-known that for the gate dielectric of a field-effect transistor, in order to solve the problem of gate leakage, it is advisable to increase the dielectric constant (k value), and the k value of nitrogen-doped silicon oxide is higher than that of silicon oxide. For the tunneling passivation layer of a crystalline silicon photovoltaic cell and the insulating isolation layer between metal wires in a chip, in order to reduce capacitance and interference with the external electric field, it is advisable to reduce the k value. The k value of carbon-doped silicon oxide is lower than that of silicon oxide and is called a low-k material. Although the k value of nitrogen-doped silicon oxide is relatively high, its preparation difficulty is low and its ability to block boron atom diffusion is strong. Therefore, the industry is studying its feasibility as the positive tunneling passivation layer of a crystalline silicon photovoltaic cell. Compared with nitrogen-doped silicon oxide, carbon-doped silicon oxide is more beneficial to improving the performance as the tunneling passivation layer of a crystalline silicon photovoltaic cell.

[0003] Currently, silicon oxide is mostly used as the tunneling passivation layer of mass-produced crystalline silicon photovoltaic cells. However, the density of silicon oxide is only 2.2 g / cm 3 , and the small density results in insufficient compactness of blocking doped atoms, and also results in its inability to completely eliminate the surface dangling bonds of the crystalline silicon substrate, and also results in a high content of hydrogen atoms inside, causing the problem of photothermal attenuation.

[0004] The thermal oxidation method is a traditional process for preparing SiO x films. Although this method has a simple process and the prepared SiO x films have excellent electrical properties and can meet the needs of semiconductor device production in terms of both insulation performance and masking performance, this method is applied to the surface oxidation of single-crystalline silicon wafers and requires a relatively high temperature environment (1050 °C - 1100 °C). The process of making SiO x films by the sol-gel method is to first prepare sol A and sol B, mix the two sols together and stir well, reflux at 80 °C for about 3 - 5 h, and store at room temperature for use in coating. Then, in a clean, dry and constant temperature (20 °C - 25 °C) environment, the SiO x gel film is prepared by the dipping method, the pulling speed is controlled at 10 - 20 cm / min, and then the SiO x gel film is subjected to low-temperature calcination.

[0005] When preparing carbon-doped silicon oxide using the gel film thermal oxidation method in this patent, a stirring tank is required to mix and stir multiple sols. However, in current stirring tanks, when stirring the sols, a stirring shaft with an adjustable position is generally set inside the stirring tank for stirring. Due to the certain adhesiveness of the sols themselves, they are prone to adhering to the inner sidewall of the stirring tank. The sols adhering to the inner sidewall of the stirring tank cannot fully participate in the stirring and mixing, affecting the stirring and mixing effect of the sols. Summary of the Invention

[0006] The object of the present invention is to provide a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment to solve the above deficiencies in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solution: A carbon-doped silicon oxide thin film is sandwiched between a crystalline silicon substrate and a doped polysilicon thin film to be used as a junction region tunneling passivation layer to improve the performance of the crystalline silicon photovoltaic cell.

[0008] The carbon-doped silicon oxide thin film, as the tunneling passivation layer, plays a crucial role in the crystalline silicon photovoltaic cell of this patent. It can not only effectively block the diffusion of doped atoms between the crystalline silicon substrate and the doped polysilicon thin film, improving the stability of the cell, but also promote the transport of photo-generated carriers through its unique tunneling effect, thereby improving the photoelectric conversion efficiency of the cell. In addition, the introduction of carbon doping also reduces the dielectric constant of the silicon oxide thin film, reducing the capacitance effect and further enhancing the performance of the cell.

[0009] The tunneling passivation layer has various names in the field of photovoltaic cells, and these names all reflect its important position as a key layer with tunneling effect and passivation function in the cell structure. Whether it is a tunneling oxide layer, a tunnel passivation layer or a tunnel oxide layer, it emphasizes the role of this layer in promoting carrier tunneling and reducing interface defects.

[0010] As a further description of the above technical solution: The doped polysilicon thin film includes but is not limited to: n-type doping using phosphorus as the doping atom, p-type doping using boron or gallium as the doping atom.

[0011] The doped polysilicon thin film, as an important part of the crystalline silicon photovoltaic cell, its doping type (n-type or p-type) determines the conduction type and performance of the junction region. N-type doping is achieved by introducing phosphorus atoms, while p-type doping is achieved by introducing boron or gallium atoms. These doping atoms replace the positions of silicon atoms in the silicon lattice, thereby changing the conductivity of the material.

[0012] As a further description of the above technical solution: The relative dielectric constant of the carbon-doped silicon oxide is between 1 and 4, and the thickness of the carbon-doped silicon oxide thin film is 0 to 3 nanometers.

[0013] As a material with excellent properties, carbon-doped silica has broad application prospects in the field of photovoltaic cells. Its various names reflect different understandings of its performance characteristics and application requirements in different fields. The relative permittivity, as one of the important physical parameters of the material, has an important impact on the performance of the battery. By adjusting the carbon doping dosage and porosity structure, precise control of the relative permittivity of carbon-doped silica can be achieved, thus meeting the requirements of different application scenarios.

[0014] As a further description of the above technical solution: The preparation methods of carbon-doped silica include but are not limited to chemical vapor deposition, plasma enhancement, and thermal oxidation methods.

[0015] The thermal oxidation method is a traditional process for preparing SiO x films. Although this method has a simple process and the prepared SiO x films have excellent electrical properties and can meet the needs of semiconductor device production in terms of both insulation performance and masking performance, this method requires operation at a relatively high temperature environment (1050°C - 1100°C) for the surface oxidation of single-crystalline silicon wafers. The process of making SiO x films by the sol-gel method is to first prepare sol A and sol B, mix the two sols together and stir well, reflux at 80°C for about 3 - 5 h, and store at room temperature for use in coating. Then, in a clean, dry, and constant temperature (20°C - 25°C) environment, the SiO x gel films are prepared by the dipping method, the pulling speed is controlled at 10 - 20 cm / min, and then the SiO x gel films are subjected to low-temperature calcination. The prepared nano-porous SiO x thin films have the advantages of controllable structure, adjustable refractive index, high porosity, low dielectric constant, low thermal conductivity, high laser damage threshold, etc. They can be used on the surfaces of cathode ray tubes, large-screen displays, solar collectors, etc. as anti-glare and anti-reflection coatings, and can also be used in high-power laser systems as high-laser-damage antireflection films, and can also be used in microelectronic circuits and as high-performance transparent heat-insulating coatings, thus having very broad application prospects.

[0016] As a further description of the above technical solution: A production device for crystalline silicon photovoltaic cells with a novel tunneling passivation layer uses the sol-gel method to prepare gel films and the gel film thermal oxidation method to prepare carbon-doped silica films. It includes a stirring tank for mixing and stirring various sols during the production process. A power structure is installed at the top of the stirring tank, and a power component for providing power is arranged inside the power structure. The power component drives the stirring component in the stirring structure to slide up and down in the stirring tank while stirring the sols through its reciprocating motion in cooperation with a rotating part;

[0017] The stirring structure is provided with a stirring member for mixing and stirring multiple sols added into the stirring kettle. The stirring rod slides up and down in the power structure along with the movable rod, and at the same time, it cooperates with the bottom rod with a gradually increasing size from top to bottom arranged in the adjusting member to abut against one end of the stirring rod, so as to intermittently adjust the position of the stirring rod in the stirring kettle, and after being fully expanded, the other end of the stirring rod is attached to the inner side wall of the stirring kettle for scraping;

[0018] The inner bottom end of the bottom rod is telescopically installed with a scraping member through a lower adjusting member. The scraping member realizes the expansion and contraction of the scraping strip through the abutment of the lower adjusting member, so as to adjust the expansion width of the scraping strip, and when fully expanded, the scraping member scrapes the inner bottom side wall of the stirring kettle;

[0019] The power member cooperates with the reciprocating member to drive the stirring rod to slide up and down in the stirring kettle. At the same time, the rotating member drives the stirring rod to rotate and stir while sliding up and down in the stirring kettle, and it cooperates with the adjusting member and the lower adjusting member to abut against one end of the stirring rod inserted into the movable rod, so as to extrude and expand the stirring rod and the scraping strip, thereby realizing the expansion of the stirring rod, the scraping strip and the side plate in the stirring kettle, and realizing the stirring of the sol in the stirring kettle while being able to scrape and clean the sol adhered to the inner side wall of the reaction kettle.

[0020] There are rotating grooves formed around the inner bottom end of the movable rod. At the bottom end of the stirring rod, a rotating rod is rotatably inserted into the rotating groove through the rotating rod. One end of the stirring rod inserted into the movable rod is rotatably connected to a sliding column. The sliding column is slidably abutted against the surfaces of the bottom rod and the conical rod. The bottom end of the bottom rod is rotatably installed at the central position of the inner bottom of the stirring kettle through the inner and outer ring bearings arranged inside. The bottom rod is stacked by multiple cylinders and cones, and the outer diameter gradually increases from top to bottom. And around the surface of the cylinder connected to the bottom of each cone, grooves are recessed inwardly in cooperation with the position and size of the sliding column. An elastic plate with elastic deformation properties is arranged in the groove. By restricting the sliding column inserted into the groove, the restriction between the bottom end of the stirring rod and the bottom rod is realized through the rotation of the movable rod. Thus, the bottom rod is driven to rotate by the rotation of the movable rod, and the scraping bars and side plates installed on both sides of the bottom end of the bottom rod are rotated. Thus, while the stirring rod is stirring, the scraping bars and side plates arranged at the inner bottom of the stirring kettle can also realize the stirring function. At the same time, the scraping bar can scrape the inner bottom of the stirring kettle. A scraping bar is slidably inserted into the cone and cylinder at the bottommost end of the bottom rod. One end of the scraping bar inserted into the bottom rod is rotatably connected to the bottom end of the column through a rotating shaft. The terminal of the column is rotatably connected to the inner side wall of the bottom of the groove through a rotating shaft. And the top end of the column is rotatably connected to one end of the extrusion rod through a rotating shaft. The other end of the extrusion rod is fixedly connected to the elastic plate arranged in the groove opened on the surface of the cylinder at the bottommost end of the bottom rod. After the end of the stirring rod where the sliding column is installed slides to the surface of the cylinder with the largest size at the bottommost end of the bottom rod, at this time, the outside of the stirring rod is pressed against the inner side wall of the stirring kettle. At this time, further pressing on the stirring rod will press the force of the extrusion on the elastic plate. By pressing the elastic plate inward in the groove, the lever is moved away through the extrusion rod and the rotating column, and the scraping bar is pushed out of the bottom rod outward. Thus, the side plate arranged at one end of the scraping bar close to the inner side wall of the stirring kettle is expanded outward to fit against the inner side wall of the stirring kettle. The scraping bar scrapes the bottom of the stirring kettle in a fitting manner. At the same time, the side plate scrapes the position on the bottom of the stirring kettle that cannot be scraped by the stirring rod, preventing the sol adhered to the inner side wall of the stirring kettle from not being stirred and affecting the stirring effect between multiple sols. During the downward sliding of the movable rod, after inserting the conical rod at the top end of the bottom rod into the movable rod, the stirring rod rotatably installed at the bottom end of the movable rod can be in contact with the conical rod on the surface of the bottom rod and the guide rod used to connect multiple cones and cylinders inside the bottom rod. It is realized that the stirring range of multiple stirring rods gradually expands during the downward movement of the movable rod, and it expands until the stirring rod fits against the inner side wall of the stirring kettle. While the movable rod is lifted upward and stirred in the reverse direction, multiple stirring rods are contracted inward again. The stirring range of the stirring rods in the stirring kettle expands with the downward movement of the movable rod and shrinks with the upward movement of the movable rod, realizing the change of the stirring range and at the same time providing scraping and cleaning of the inner side wall of the stirring kettle.

[0021] As a further description of the above technical solution: The stirring member is powered by a power member and cooperates with a reciprocating member to change the position of the stirring rod by sliding up and down in the stirring kettle. At the same time, the rotating member drives the stirring rod to rotate while sliding up and down in the stirring kettle for stirring.

[0022] A power member is installed at the top of the stirring kettle. The power member includes a sole motor for providing a power source installed on one side of the top of the stirring kettle. The power output end of the motor is fixedly connected to a driving gear. The driving gear is installed on the top of the stirring kettle through a fixing frame. And a driven gear is meshed above the driving gear. A descending gear is fixedly installed on one side of the driving gear, and a rising gear is installed on one side of the driven gear. The driving gear and the descending gear have the same size. The rising gear and the descending gear are smaller in size than the driving gear and the driven gear. Only half of the surface area of the rising gear and the descending gear is provided with racks, and the other half area is smooth and the positions are opposite. The rising gear and the descending gear are meshed with the racks at intervals. Only the rising gear or the descending gear will be independently meshed on the surface of the rack. The bottom end of the rack is rotatably connected to a movable rod through a double-disk bearing. The movable rod is movably inserted into a sleeve fixedly installed on the inner top of the stirring kettle. A spiral groove in a spiral shape is opened on the inner side wall of the sleeve. A roller is slidably connected in the spiral groove. The roller can rotate independently but is fixedly installed on both sides of the outer surface of the movable rod. When the rack drives the movable rod to slide up and down in the sleeve, the roller slides in the spiral groove to drive the movable rod to rotate while sliding up and down. Through the effect of the movable rod sliding up and down and rotating in the stirring kettle, the stirring rod installed at the bottom end of the movable rod is driven to stir at different positions up and down in the stirring kettle. At the same time, through the contact between the upper adjusting member and the stirring member in the stirring structure, the stirring rod is stirred in different positions and different ranges are stirred, and the inner side wall of the stirring kettle is scraped.

[0023] As a further description of the above technical solution: The bottom rod arranged in the upper adjusting member is stacked by a plurality of cylinders and cones, and the outer diameter gradually increases from top to bottom. By sliding and contacting the end of the stirring rod inserted into the movable rod on the surface of the bottom rod, the stirring range of the stirring rod in the stirring kettle is adjusted. Finally, the stirring rod is used to scrape the inner side wall of the stirring kettle, so that the stirring rod not only provides stirring, but also realizes the function of scraping and cleaning the inner side wall of the stirring kettle.

[0024] As a further description of the above technical solution: The lower adjusting member is arranged in the cone at the bottom end of the bottom rod. The horizontally arranged U-shaped connecting rod structure inside drives the scraping strip and the side plate installed at the bottom of the stirring kettle to expand and contract at the bottom of the stirring kettle, so as to cooperate with stirring during the expansion and contraction process. At the same time, after complete expansion, the position that the stirring rod at the bottom end of the inner side wall of the stirring kettle cannot scrape is scraped, and the surface of the bottom of the stirring kettle is scraped.

[0025] As a further description of the above technical solution: The scraping bars provided inside the scraping member are telescopically installed on both sides of the inner bottom end of the bottom rod, and the bottom end of the bottom rod is installed on the inner bottom of the stirring kettle through inner and outer ring bearings, and the inner and outer ring bearings are arranged inside the bottom rod. The bottom end of the bottom rod is attached to the bottom surface of the stirring kettle to prevent a large amount of sol from seeping into the bottom rod.

[0026] In the above technical solution, a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment provided by the present invention. A sharp cone for facilitating insertion into the movable rod is provided at the top of the cylinder provided at the top end of the bottom rod, and an elastic scraping plate with a deformable ability and a size adapted to the inner diameter of the movable rod is provided at the position where the cone is connected to the cylinder.

[0027] When the movable rod slides downward and the bottom rod is inserted into the movable rod, the size of the elastic scraping plate is adapted to the inner side wall size of the movable rod and will fit the inner side wall of the movable rod. Therefore, there is a downward frictional force, which rotates the outer ring of the elastic scraping plate downward, so that the sol in the cavity provided at the bottom end of the movable rod for supplying the rotation of the stirring rod can be extruded outward under the extrusion of the bottom rod. The outer ring of the elastic scraping plate is downwardly guided, so that it will not affect the extrusion of the sol. And when the movable rod slides upward, the sol on the inner side wall of the cavity at the bottom end of the movable rod is scraped downward by the outer ring of the elastic scraping plate that fits the inner side wall of the bottom end of the movable rod.

[0028] The beneficial effects of the present invention are:

[0029] 1. Carbon doping of the silicon oxide tunneling passivation layer can increase its density, improve its density and defect passivation effect. At the same time, carbon doping also reduces the k value of the silicon oxide tunneling passivation layer, reduces its interference with the external electric field, and ensures the promoting effect of the external electric field in accelerating photo-generated carriers and enabling the carriers to tunnel;

[0030] 2. Through a unique stirring structure, the full mixing and stirring of various sols are realized, the problem that the sol adheres to the inner side wall of the stirring kettle and cannot fully participate in the stirring and mixing is solved, and the mixing uniformity of the sol is improved; The design of the stirring rod and the scraping member not only realizes the stirring of the sol, but also has the function of scraping and cleaning the inner side wall and the bottom of the stirring kettle, effectively preventing the residue and accumulation of the sol; The design of the bottom rod in the upper adjusting member enables the stirring range of the stirring rod to be adjustable during the stirring process, can adapt to different stirring requirements, and improves the flexibility and applicability of the equipment. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings.

[0032] Figure 1 It is a schematic structural diagram of a stirring kettle required for the production of carbon-doped silicon oxide by using the gel film thermal oxidation method provided by an embodiment of the present invention;

[0033] Figure 2 It is a schematic structural diagram of a bottom rod provided by an embodiment of the present invention;

[0034] Figure 3 It is a schematic structural diagram of the daily bouncing state (left) and the squeezed and sunken state (right) of the elastic plate arranged in the groove provided by an embodiment of the present invention;

[0035] Figure 4 It is a schematic structural diagram of the roller on the surface of the movable rod provided by an embodiment of the present invention;

[0036] Figure 5 It is a schematic structural diagram of a rack provided by an embodiment of the present invention;

[0037] Figure 6 It is a schematic structural diagram of the movable rod and the sleeve provided by an embodiment of the present invention;

[0038] Figure 7 It is a schematic structural diagram of the stirring rod inserted into the movable rod provided by an embodiment of the present invention;

[0039] Figure 8 It is a schematic structural diagram of the expanded scraping state (left) and the contracted stirring state (right) of the stirring rod installed at the bottom end of the movable rod provided by an embodiment of the present invention;

[0040] Figure 9 It is a schematic structural diagram of the multi-link connecting the scraping bar and the elastic plate in the bottom rod provided by an embodiment of the present invention;

[0041] Figure 10 It is a schematic structural diagram of the connection between the scraping bar, the column, the extrusion rod and the elastic plate provided by an embodiment of the present invention.

[0042] Explanation of reference numerals:

[0043] 7 - Stirring kettle; 29 - Elastic scraper

[0044] Power structure

[0045] Power components: 1 - Motor; 2 - Driven gear; 3 - Fixed frame; 18 - Driving gear

[0046] Reciprocating parts: 4 - rack; 17 - lifting gear; 19 - lowering gear

[0047] Rotating parts: 5 - sleeve; 6 - movable rod; 20 - roller; 22 - double - disk bearing; 23 - spiral groove

[0048] Stirring structure

[0049] Stirring parts: 8 - stirring rod; 21 - rotating groove

[0050] Upper adjusting parts: 9 - bottom rod; 12 - groove; 13 - elastic plate; 14 - tapered rod; 15 - guide rod; 24 - sliding column; 25 - rotating rod

[0051] Lower adjusting parts: 26 - extrusion rod; 27 - rotating shaft; 28 - column

[0052] Scraping parts: 10 - scraping strip; 11 - inner - outer ring bearing; 16 - side plate Specific implementation manners

[0053] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0054] Please refer to Figures 1-10 , an embodiment of the present invention provides a technical solution for a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment: including preparing a gel film by the sol - gel method, preparing a carbon - doped silicon oxide film by the thermal oxidation method of the gel film, and sandwiching the carbon - doped silicon oxide thin film between the crystalline silicon substrate and the doped polysilicon thin film as the tunneling passivation layer in the junction region to improve the performance of the crystalline silicon photovoltaic cell.

[0055] The carbon - doped silicon oxide thin film, as the tunneling passivation layer, plays a crucial role in the crystalline silicon photovoltaic cell. It can not only effectively block the diffusion of doped atoms between the crystalline silicon substrate and the doped polysilicon thin film, improving the stability of the cell, but also promote the transport of photo - generated carriers through its unique tunneling effect, thereby improving the photoelectric conversion efficiency of the cell. In addition, the introduction of carbon doping also reduces the dielectric constant of the silicon oxide thin film, reducing the capacitance effect and further enhancing the performance of the cell.

[0056] The tunneling passivation layer has various names in the field of photovoltaic cells, and these names all reflect its important position as the key layer with tunneling effect and passivation function in the cell structure. Whether it is the tunneling oxide layer, the tunnel passivation layer or the tunnel oxide layer, they all emphasize the role of this layer in promoting carrier tunneling and reducing interface defects.

[0057] In another embodiment provided by the present invention, preferably, the doped polysilicon thin film includes but is not limited to: n - type doping using phosphorus as the doping atom, p - type doping using boron or gallium as the doping atom.

[0058] As an important component of crystalline silicon photovoltaic cells, the doping type (n-type or p-type) of doped polysilicon thin films determines the conduction type and performance of the junction region. N-type doping is achieved by introducing phosphorus atoms, while p-type doping is achieved by introducing boron or gallium atoms. These doped atoms replace the positions of silicon atoms in the silicon lattice, thereby changing the conductivity of the material.

[0059] In another embodiment provided by the present invention, the relative dielectric constant of carbon-doped silicon oxide is between 1 and 4, and the thickness of the carbon-doped silicon oxide thin film is 0 to 3 nanometers.

[0060] As a material with excellent properties, carbon-doped silicon oxide has broad application prospects in the field of photovoltaic cells. Its various names reflect different understandings and application requirements of its performance characteristics in different fields. The relative dielectric constant, as one of the important physical parameters of the material, has an important impact on the performance of the battery. By adjusting the carbon doping dose and porosity structure, precise control of the relative dielectric constant of carbon-doped silicon oxide can be achieved, so as to meet the requirements of different application scenarios.

[0061] In another embodiment provided by the present invention, the preparation method of carbon-doped silicon oxide includes but is not limited to chemical vapor deposition, plasma enhancement, and thermal oxidation methods.

[0062] The thermal oxidation method is a traditional process for preparing SiO x films. Although this method has a simple process and the prepared SiO x films have excellent electrical properties and can meet the needs of semiconductor device production in terms of both insulation performance and masking performance, this method is applied to the surface oxidation of single crystal silicon wafers and requires a high-temperature environment (1050°C - 1100°C). The process of making SiO x films by the sol-gel method is to first prepare sol A and sol B, mix the two sols together and stir well, reflux at 80°C for about 3 - 5h, and store at room temperature for use in coating. Then, in a clean, dry, and constant-temperature (20°C - 25°C) environment, the SiO x gel film is prepared by the dipping method, the pulling speed is controlled at 10 - 20 cm / min, and then the SiO x gel film is subjected to low-temperature calcination. The prepared nanoporous SiO x thin films have the advantages of controllable structure, adjustable refractive index, high porosity, small dielectric constant, low thermal conductivity, high laser damage threshold, etc. They can be used on the surfaces of cathode ray tubes, large-screen displays, solar collectors, etc. as anti-glare and anti-reflection coatings, and can also be used in high-power laser systems as high-laser-damage antireflection films, and can also be used in microelectronic circuits and as high-performance transparent heat-insulating coatings, so they have very broad application prospects.

[0063] In yet another embodiment provided by the present invention, a crystalline silicon photovoltaic cell with a novel tunneling passivation layer and its production equipment are provided. The stirring member is powered by a power member and cooperates with a reciprocating member to change the position of the stirring rod 8 by sliding up and down in the stirring kettle 7. At the same time, the rotating member drives the stirring rod 8 to rotate and stir while sliding up and down in the stirring kettle 7.

[0064] A power member is installed at the top of the stirring kettle 7. The power member includes a single motor 1 for providing a power source installed on one side of the top of the stirring kettle 7. The power output end of the motor 1 is fixedly connected to the driving gear 18. The driving gear 18 is installed on the top of the stirring kettle 7 through a fixing frame 3. A driven gear 2 is meshed above the driving gear 18. A descending gear 19 is fixedly installed on one side of the driving gear 18. An ascending gear is installed on one side of the driven gear 2. The driving gear 18 and the descending gear 19 are of the same size. The ascending gear and the descending gear 19 are smaller in size than the driving gear 18 and the driven gear 2. Only half of the surface area of the ascending gear and the descending gear 19 is provided with a rack 4, and the other half area is smooth and the positions are opposite. The ascending gear and the descending gear 19 are meshed with the rack 4 at intervals. The surface of the rack 4 will only independently mesh with the ascending gear or the descending gear 19. The bottom end of the rack 4 is rotatably connected to a movable rod 6 through a double-disk bearing 22. The movable rod 6 is movably inserted into a sleeve 5 fixedly installed on the inner top of the stirring kettle 7. A spiral groove 23 is formed on the inner side wall of the sleeve 5. A roller 20 is slidably connected in the spiral groove 23. The roller 20 can rotate independently but is fixedly installed on both sides of the outer surface of the movable rod 6. When the rack 4 drives the movable rod 6 to slide up and down in the sleeve 5, the roller 20 slides in the spiral groove 23 to drive the movable rod 6 to rotate while sliding up and down. Through the effect of the movable rod 6 sliding up and down and rotating in the stirring kettle 7, the stirring rod 8 installed at the bottom end of the movable rod 6 is driven to stir at different positions in the stirring kettle 7. At the same time, through the contact between the upper adjusting member and the stirring member in the stirring structure, the stirring rod 8 stirs different ranges while stirring at different positions, and realizes scraping of the inner side wall of the stirring kettle 7.

[0065] In yet another embodiment provided by the present invention, it includes a stirring kettle 7 for mixing and stirring various sols during the preparation of a carbon-doped silicon oxide film using a gel film thermal oxidation method. A power structure is installed at the top of the stirring kettle 7. A power member for providing power is arranged in the power structure. The power member drives the stirring member in the stirring structure to stir the sol while sliding up and down in the stirring kettle 7 through its own reciprocating motion and cooperating with the rotating member;

[0066] The stirring structure is provided with a stirring member for mixing and stirring the various sols added to the stirring kettle 7. The stirring rod 8 slides up and down in the movable rod 6 as the movable rod 6 moves in the power structure. At the same time, the bottom rod 9, which is provided in the upper adjusting member and has a gradually increasing size from top to bottom, resists one end of the stirring rod 8, thereby intermittently adjusting the position of the stirring rod 8 in the stirring kettle 7. After fully expanding, the other end of the stirring rod 8 is attached to the inner wall of the stirring kettle 7 for scraping.

[0067] A scraper is telescopically mounted on the bottom end of the bottom rod 9 through a lower adjusting member, and the scraper can extend and retract the scraper bar 10 through the interference of the lower adjusting member, thereby adjusting the unfolded width of the scraper bar 10, and when fully unfolded, the scraper scrapes the inner side wall of the bottom end of the stirring tank 7;

[0068] The power part cooperates with the reciprocating part to drive the stirring rod 8 to slide up and down in the stirring kettle 7. At the same time, the rotating part drives the stirring rod 8 to slide up and down in the stirring kettle 7 while rotating and stirring, and cooperates with the upper adjusting part and the lower adjusting part to resist the stirring rod 8 inserted in one end of the movable rod 6, thereby squeezing and expanding the stirring rod 8 and the scraper 10, thereby realizing the expansion of the stirring rod 8, the scraper 10 and the side plate 16 in the stirring kettle 7, realizing the stirring of the sol in the stirring kettle 7 and scraping and cleaning the sol adhered to the inner wall of the reactor.

[0069] A rotating groove 21 is formed around the inner bottom end of the movable rod 6. The bottom end of the stirring rod 8 is rotatably inserted into the rotating groove 21 through a rotating rod 25. One end of the stirring rod 8 inserted into the movable rod 6 is rotatably connected with a sliding column 24. The sliding column 24 is slidably abutted against the surfaces of the bottom rod 9 and the conical rod 14. The bottom end of the bottom rod 9 is rotatably installed at the central position of the inner bottom of the stirring kettle 7 through an inner and outer ring bearing 11 arranged inside. The bottom rod 9 is stacked by a plurality of cylinders and cones, and the outer diameter gradually increases from top to bottom. Grooves 12 are recessed inwardly around the surface of the cylinder connected to the bottom of each cone to match the position and size of the sliding column 24. An elastic plate 13 with elastic deformation properties is arranged in the groove 12. By restricting the sliding column 24 inserted into the groove 12, the restriction between the bottom end of the stirring rod 8 and the bottom rod 9 is realized through the rotation of the movable rod 6. Thus, the bottom rod 9 is driven to rotate by the rotation of the movable rod 6, and the scraping strips 10 and the side plates 16 installed on both sides of the bottom end of the bottom rod 9 are rotated. Therefore, while the stirring rod 8 is stirring, the scraping strips 10 and the side plates 16 arranged at the inner bottom of the stirring kettle 7 can also realize the stirring function. At the same time, the scraping strip 10 can scrape the inner bottom of the stirring kettle 7. A scraping strip 10 is slidably inserted into the cone and the cylinder at the bottommost end of the bottom rod 9. One end of the scraping strip 10 inserted into the bottom rod 9 is rotatably connected to the bottom end of the column 28 through a rotating shaft 27. The terminal of the column 28 is rotatably connected to the inner bottom inner side wall of the groove 12 through a rotating shaft 27. The top end of the column 28 is rotatably connected to one end of the extrusion rod 26 through a rotating shaft 27. The other end of the extrusion rod 26 is fixedly connected to the elastic plate 13 arranged in the groove 12 formed on the surface of the cylinder at the bottommost end of the bottom rod 9. After one end of the stirring rod 8 installed with the sliding column 24 slides to the surface of the cylinder with the largest size at the bottommost end of the bottom rod 9, at this time, the outside of the stirring rod 8 is pressed against the inner side wall of the stirring kettle 7. At this time, further pressing on the stirring rod 8 will press the elastic plate 13 with the pressing force. By pressing the elastic plate 13 inward in the groove 12, the lever principle is realized through the extrusion rod 26 and the rotating column to drive the column 28, and the scraping strip 10 is pushed outwards from the bottom rod 9, so that the side plate 16 arranged at one end of the scraping strip 10 close to the inner side wall of the stirring kettle 7 is expanded outwards and attached to the inner side wall of the stirring kettle 7. The scraping strip 10 scrapes the bottom of the stirring kettle 7 by fitting, and at the same time, the side plate 16 scrapes the position on the bottom of the stirring kettle 7 that cannot be scraped by the stirring rod 8, preventing the sol adhered to the inner side wall of the stirring kettle 7 from not being stirred, which affects the stirring effect between multiple sols. During the downward sliding of the movable rod 6, after the conical rod 14 at the top end of the bottom rod 9 is inserted into the movable rod 6, the stirring rod 8 rotatably installed at the bottom end of the movable rod 6 can be in contact with the conical rod 14 on the surface of the bottom rod 9 and the guide rod 15 used to connect multiple cones and cylinders inside the bottom rod 9. It is realized that during the downward movement of the movable rod 6, the stirring range of the multiple stirring rods 8 gradually expands until the stirring rod 8 is attached to the inner side wall of the stirring kettle 7. When the movable rod 6 is lifted upwards and stirred in the reverse direction, the multiple stirring rods 8 are retracted inwards again.The stirring range of the stirring rod 8 in the stirring kettle 7 is enlarged as the movable rod 6 descends and reduced as the movable rod 6 ascends, so as to change the stirring range and simultaneously provide scraping and cleaning of the inner side wall of the stirring kettle 7.

[0070] In another embodiment provided by the present invention, the bottom rod 9 arranged in the upper adjusting member is stacked by a plurality of cylinders and cones, and the outer diameter gradually increases from top to bottom. By the sliding resistance of the surface of the bottom rod 9 against one end of the stirring rod 8 inserted into the movable rod 6, the stirring range of the stirring rod 8 in the stirring kettle 7 is adjusted, and finally the stirring rod 8 scrapes the inner side wall of the stirring kettle 7. While the stirring rod 8 provides stirring, the function of scraping and cleaning the inner side wall of the stirring kettle 7 is realized.

[0071] In another embodiment provided by the present invention, the lower adjusting member is arranged in the cone at the inner bottom end of the bottom rod 9. The horizontally arranged U-shaped connecting rod structure drives the scraping strip 10 and the side plate 16 installed at the bottom end of the stirring kettle 7 to expand and contract at the bottom of the stirring kettle 7, so as to cooperate with stirring during the expansion and contraction process. At the same time, after complete expansion, the position at the bottom end of the inner side wall of the stirring kettle 7 that cannot be scraped by the stirring rod 8 is scraped, and the surface of the bottom of the stirring kettle 7 is scraped.

[0072] In another embodiment provided by the present invention, the scraping strip 10 arranged in the scraping member is telescopically installed on both sides of the inner bottom end of the bottom rod 9, and the bottom end of the bottom rod 9 is installed on the bottom of the stirring kettle 7 through the inner and outer ring bearings 11, and the inner and outer ring bearings 11 are arranged inside the bottom rod 9. The bottom end of the bottom rod 9 is attached to the surface of the bottom of the stirring kettle 7 to prevent a large amount of sol from seeping into the bottom rod 9.

[0073] In another embodiment provided by the present invention, preferably, a cone with a sharp tip for inserting into the movable rod 6 is arranged on the top of the cylinder at the top end of the bottom rod 9, and an elastic scraping plate 29 with a deformable ability and a size adapted to the inner diameter of the movable rod 6 is arranged at the connection position between the cone and the cylinder.

[0074] When the movable rod 6 slides downward and the bottom rod 9 is inserted into the movable rod 6, the size of the elastic scraping plate 29 is adapted to the inner side wall of the movable rod 6 and will fit the inner side wall of the movable rod 6. Therefore, there is a downward frictional force, which rotates the outer ring of the elastic scraping plate 29 downward, so that the sol in the cavity for supplying the rotation of the stirring rod 8 opened at the bottom end of the movable rod 6 can be extruded outward under the extrusion of the bottom rod 9. The outer ring of the elastic scraping plate 29 is guided downward, so as not to affect the extrusion of the sol. When the movable rod 6 slides upward, the outer ring of the elastic scraping plate 29 with a downward outer ring fits the inner side wall of the bottom end of the movable rod 6 to scrape, and the sol on the inner side wall of the cavity at the bottom end of the movable rod 6 is scraped downward.

[0075] In the process of preparing carbon-doped silica by the gel film thermal oxidation method, a variety of prepared sol raw materials need to be put into the stirring kettle 7 for stirring and then reflux and other operations are carried out.

[0076] Start the motor 1. The motor 1 drives the driving gear 18 and the descending gear 19 to rotate clockwise. The driving gear 18 drives the driven gear 2 meshed above to rotate counterclockwise, and drives the ascending gear fixedly installed on one side to rotate counterclockwise through the driven gear 2. When the descending gear 19 rotates clockwise, the rack 4 arranged on the outer half circle of the descending gear 19 is meshed with the rack 4, so as to insert the rack 4 into the reaction kettle, and the bottom end of the rack 4 is inserted into the sleeve 5 arranged at the top of the reaction kettle through the movable rod 6 rotatably connected by the double-disc bearing 22. While the movable rod 6 slides downward, the rollers 20 arranged on both sides of the movable rod 6 will rotate and slide along the spiral groove 23 opened on the inner side of the sleeve 5, so as to drive the movable rod 6 to rotate while sliding downward in the stirring kettle 7, and drive the multi-group stirring rods 8 installed at the bottom end of the movable rod 6 to rotate and stir in the stirring kettle 7. After the descending gear 19 and the rack 4 are misaligned, at this time, the rack 4 drives the movable rod 6 and the stirring shaft to descend to the limit position. At this time, the ascending gear and the rack 4 are meshed, driving the rack 4 to slide upward, so that the movable rod 6 slides upward and rotates reversely in the stirring kettle 7, so that the stirring rods 8 rotate reversely and stir in the stirring kettle 7 while lifting the height position upward;

[0077] After the movable rod 6 slides downward to a certain position, the tapered rod 14 arranged at the top of the bottom rod 9 is inserted into the bottom end of the movable rod 6, and the tapered rod 14 and the surface of the bottom rod 9 are plugged into the bottom end of the movable rod 6. Through the change of the size of the bottom rod 9 itself, the sliding column 24 installed at one end of the stirring rod 8 plugged into the bottom end of the movable rod 6 is squeezed, thereby squeezing the stirring rod 8 and under the rotation of the rotating rod 25, the stirring rod 8 is installed in the stirring kettle 7. One end is rotated outward to expand, thereby increasing the stirring range of the stirring rod 8 in the stirring kettle 7, and while the sliding column 24 is inserted into the groove 12 opened on the surface of the bottom rod 9 and squeezes the elastic plate 13 inward, the sliding column 24 is restricted by the groove 12, so that the movable rod 6 drives the bottom rod 9 to rotate, so that the scraping strips 10 and the side plates 16 installed on both sides of the bottom end of the bottom rod 9 are also rotated and stirred at the bottom of the stirring kettle 7, and at the same time The scraper bar 10 scrapes the bottom of the stirring kettle 7. After the movable rod 6 is inserted into the guide rod 15 and the cylindrical surface at the bottom end of the bottom rod 9, the sliding column 24 rotates with the rotation of the movable rod 6 until it is inserted into the groove 12 and then squeezes the elastic plate 13 inward. The elastic plate 13 pushes the scraper bar 10 outward from the bottom rod 9 by a certain distance through the lever formed by the squeezing rod 26, the rotating shaft 27 and the column 28, so that the side plate 16 is attached to the inner wall of the stirring kettle 7, so that the bottom rod 9 is driven by the movable rod 6 to rotate under the cooperation of the inner and outer ring bearings 11. At this time, the stirring rod 8 also reaches the maximum expansion range. At this time, the stirring rod 8 is attached to the upper part of the inner wall of the stirring kettle 7, and the side plate 16 is attached to the lower part of the inner wall of the stirring kettle 7, so as to scrape the inner wall of the stirring kettle 7 and scrape the sol adhering to the inner wall of the stirring kettle 7 for stirring and mixing.

[0078] When the movable rod 6 meshes with the lifting gear 17 and slides upward, the bottom rod 9 and the stirring rod 8 are driven to rotate in the opposite direction. While sliding upward, the sliding column 24 will be kept in contact with the surface of the bottom rod 9 under the rotation of the rotating rod 25. At the same time, the elastic plate 13 at the bottom end of the bottom rod 9 rebounds, shrinking the scraper bar 10 into the bottom rod 9, and separating the side plate 16 from the inner wall of the stirring tank 7, and rotating the scraper bar 10 and the side plate 16 in the opposite direction. The stirring rod 8 will also separate from the inner wall of the stirring tank 7 and shrink as the size of the squeezing of the sliding column 24 by the bottom rod 9 changes, and rotate in the opposite direction for stirring at the same time, shrinking the stirring range of the stirring rod 8 and rotating in the opposite direction for stirring;

[0079] Move back and forth in sequence. During the downward movement of the movable rod 6 in the stirring kettle 7, the stirring rod 8 and the scraping strip 10 are stirred counterclockwise, and the stirring ranges of the stirring rod 8, the scraping strip 10 and the side plate 16 are expanded until they fit against the inner wall of the stirring kettle 7 for scraping. During the upward movement of the movable rod 6, the stirring rod 8, the scraping strip 10 and the side plate 16 are stirred clockwise, and the stirring ranges of the stirring rod 8, the scraping strip 10 and the side plate 16 are contracted. This can not only achieve the intermittent reciprocating adjustment of the stirring range, but also intermittently scrape the inner wall of the stirring kettle 7, preventing the sol attached to the inner wall of the stirring kettle 7 from being unable to fully participate in the stirring and thus unable to be repeatedly mixed, which affects the mixing effect of various sols.

[0080] Only some exemplary embodiments of the present invention have been described by way of illustration above. Without doubt, for those of ordinary skill in the art, the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and description are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A production device for crystalline silicon photovoltaic cells with a novel tunnel passivation layer, comprising a stirring kettle (7) for mixing and stirring a plurality of sols during the production process, wherein a power structure is installed on the top of the stirring kettle (7), wherein a power member for providing power is arranged in the power structure, wherein the power member drives a stirring member in the stirring structure to slide up and down in the stirring kettle (7) through its own reciprocating motion in cooperation with a rotating member, thereby stirring the sol, wherein: The stirring structure is provided with a stirring member for mixing and stirring the various sols added to the stirring kettle (7); the stirring rod (8) slides up and down in the movable rod (6) in the power structure along with the movable rod (6); and the bottom rod (9) provided in the upper adjustment member and increasing in size from top to bottom contacts one end of the stirring rod (8), thereby intermittently adjusting the position of the stirring rod (8) in the stirring kettle (7); and after being fully expanded, the other end of the stirring rod (8) is attached to the inner wall of the stirring kettle (7) for scraping; A scraper is retractably mounted on the bottom end of the bottom rod (9) via a lower adjusting member, and the scraper is retracted and retracted on the scraper bar (10) by the interference of the lower adjusting member, thereby adjusting the unfolded width of the scraper bar (10), and when fully unfolded, the scraper scrapes the inner side wall of the bottom end of the stirring kettle (7); The power member cooperates with the reciprocating member to drive the stirring rod (8) to slide up and down in the stirring kettle (7), and at the same time, the rotating member drives the stirring rod (8) to slide up and down in the stirring kettle (7) while rotating and stirring, and cooperates with the upper adjusting member and the lower adjusting member to resist the end of the stirring rod (8) inserted in the movable rod (6), thereby squeezing and expanding the stirring rod (8) and the scraper (10), thereby realizing the expansion of the stirring rod (8), the scraper (10) and the side plate (16) in the stirring kettle (7), realizing the stirring of the sol in the stirring kettle (7) and scraping and cleaning the sol adhered to the inner wall of the reaction kettle.

2. The production equipment of a crystalline silicon photovoltaic cell with a novel tunnel passivation layer according to claim 1, characterized in that: The stirring member provides power through the power member and cooperates with the reciprocating member to change the position of the stirring rod (8) by sliding up and down in the stirring kettle (7). At the same time, the stirring rod (8) is driven by the rotating member to slide up and down in the stirring kettle (7) while rotating and stirring.

3. The production equipment of a crystalline silicon photovoltaic cell with a novel tunnel passivation layer according to claim 2, characterized in that: The bottom rod (9) arranged in the upper adjustment member is in the form of a plurality of stacked cylinders and cones, and the outer diameter gradually increases from top to bottom. The surface of the bottom rod (9) is in sliding contact with one end of the stirring rod (8) inserted in the movable rod (6), so that the stirring range of the stirring rod (8) in the stirring kettle (7) is adjusted, and finally the stirring rod (8) scrapes the inner wall of the stirring kettle (7), so that the stirring rod (8) not only provides stirring, but also realizes the function of scraping and cleaning the inner wall of the stirring kettle (7).

4. The production equipment of a crystalline silicon photovoltaic cell with a novel tunnel passivation layer according to claim 3, characterized in that: The lower adjusting member is arranged in a cone at the bottom end of the bottom rod (9), and drives the scraper bar (10) and the side plate (16) installed at the bottom end of the stirring kettle (7) to expand and contract at the bottom of the stirring kettle (7) through a U-shaped connecting rod structure arranged in a transverse manner inside, so as to coordinate stirring during the expansion and contraction process. At the same time, after full expansion, the position of the bottom end stirring rod (8) on the inner side wall of the stirring kettle (7) that cannot be scraped is scraped, and the bottom surface of the stirring kettle (7) is scraped.

5. The production equipment of crystalline silicon photovoltaic cells with a novel tunnel passivation layer according to claim 4, characterized in that: The scraper strips (10) arranged in the scraper can be telescopically installed on both sides of the bottom end of the bottom rod (9), and the bottom end of the bottom rod (9) is installed on the bottom of the stirring kettle (7) through the inner and outer ring bearings (11), and the inner and outer ring bearings (11) are arranged inside the bottom rod (9), so that the bottom end of the bottom rod (9) is fitted with the bottom surface of the stirring kettle (7) to prevent a large amount of sol from penetrating into the bottom rod (9).

6. The production equipment of a crystalline silicon photovoltaic cell with a novel tunnel passivation layer according to claim 5, characterized in that: The top of the cylinder arranged at the top of the bottom rod (9) is provided with a sharp cone for easy insertion into the movable rod (6), and a deformable elastic scraper (29) with a size matching the inner diameter of the movable rod (6) is provided at the position where the cone and the cylinder are connected.

7. A crystalline silicon photovoltaic cell with a novel tunnel passivation layer, using a production device for a crystalline silicon photovoltaic cell with a novel tunnel passivation layer as claimed in any one of claims 1 to 6, characterized in that: The gel film is prepared by a sol-gel method, and the carbon-doped silicon oxide film is prepared by a gel film thermal oxidation method, including sandwiching the carbon-doped silicon oxide film between a crystalline silicon substrate and a doped polycrystalline silicon film as a junction tunneling passivation layer to improve the performance of crystalline silicon photovoltaic cells.

8. A crystalline silicon photovoltaic cell with a novel tunnel passivation layer according to claim 7, characterized in that: The doped polysilicon film includes n-type doping using phosphorus as the doping atom or p-type doping using boron and gallium as the doping atom. The relative dielectric constant of the carbon-doped silicon oxide is between 1 and 4, and the thickness of the carbon-doped silicon oxide film is 0 to 3 nanometers.

Images