Crystalline silicon photovoltaic cell with novel boron expansion shallow junction, preparation method and device

Abstract

The invention discloses a crystalline silicon photovoltaic cell with a novel boron expansion shallow junction, a preparation method and a device, the crystalline silicon photovoltaic cell comprises a silicon wafer, the surface of the silicon wafer is alternately provided with a deep junction region and a shallow junction region, the depth of the deep junction region is greater than 200nm, the depth of the shallow junction region is less than 80nm, the surface of the silicon wafer is also provided with grid-shaped metal grid lines, and the grid-shaped metal grid lines are arranged on the surface of the silicon wafer. The metal grid lines comprise main grid lines parallel to the deep junction region and auxiliary grid lines vertically staggered with the main grid lines, and the main grid lines protrude out of the surface of the shallow junction region. By arranging the shallow junction region of which the doping depth is less than 80nm, the solar cell has the characteristics of high light transmission and low recombination, is beneficial to sunlight penetration, improves the light utilization rate, reduces the number of holes and consumed electrons, thereby improving the cell efficiency, and meanwhile, by arranging the deep junction region of which the depth is greater than 200nm formed by high doping and deep diffusion, the solar cell has the characteristic of low resistance, thereby improving the cell efficiency. The hole transmission efficiency is ensured, the mode of reducing the grid line spacing is avoided, and the production cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic cells, and in particular to a crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction, and a preparation method and device thereof. Background Art

[0002] Crystalline silicon photovoltaic cells are solar cells made of semiconductor materials. Their working principle is to use the photoelectric material to absorb light energy and then undergo photoelectron conversion reaction. The existing crystalline silicon photovoltaic cells can basically meet daily usage needs, but there are still some shortcomings that need to be improved.

[0003] Patent document CN110634973A disclosed a new type of crystalline silicon solar cell on December 31, 2019, and its technical solution includes: a first back N-type silicon and a back N-type silicon, the first back N-type silicon and the back N-type silicon are alternately connected, and the phosphorus doping concentration of the first back N-type silicon is greater than the phosphorus doping concentration of the back N-type silicon; its beneficial effect is: under the premise of ensuring the passivation effect of the positive surface of the P-type silicon wafer, the boron diffusion process is avoided, the preparation process is simplified, and in addition, the recombination rate of the back N-type silicon area is reduced to improve the battery efficiency. The crystalline silicon photovoltaic cell described in the patent is a full back electrode contact structure, and there is no metal grid line on the front.

[0004] In the existing crystalline silicon photovoltaic cells where the positive and negative electrode grid lines are located on the front and back sides respectively, grid lines are arranged on the front side of the cell for hole transmission. By reducing the width and spacing of the grid lines, the efficiency of the cell can be improved. However, when the grid line spacing is reduced, the number of grid lines per unit area increases, which is not conducive to reducing costs. In addition, the surface boron diffusion depth of the crystalline silicon photovoltaic cell also affects the cell efficiency. The current boron diffusion depth of the crystalline silicon photovoltaic cell is usually set to a consistent depth greater than 500nm to balance the requirements of low resistance and high light transmittance and low recombination. Therefore, there is an urgent need for a crystalline silicon photovoltaic cell with a new type of boron diffusion shallow junction, a preparation method and a device to solve the above problems. Summary of the invention

[0005] The object of the present invention is to provide a crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction, a preparation method and a device to solve the above-mentioned deficiencies in the prior art.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A crystalline silicon photovoltaic cell with a novel boron-expanded shallow junction comprises a silicon wafer, wherein deep junction regions and shallow junction regions are alternately arranged on the surface of the silicon wafer, wherein the depth of the deep junction region is greater than 200nm, and the depth of the shallow junction region is less than 80nm. Grid-shaped metal grid lines are also arranged on the surface of the silicon wafer, wherein the metal grid lines comprise main grid lines parallel to the deep junction regions and auxiliary grid lines perpendicularly intersecting the main grid lines, and wherein the main grid lines protrude from the surface of the shallow junction regions.

[0008] A preparation method for producing the crystalline silicon photovoltaic cell with the novel boron-diffused shallow junction comprises the following steps of processing the front side of the cell:

[0009] S1: Diffusing boron on the front side of the silicon wafer to be processed;

[0010] S2: The front side of the silicon wafer obtained in S1 is heavily doped with SE laser;

[0011] S3: The surface of the silicon wafer obtained in S2 is oxidized to form BSG, and then the back of the silicon wafer is subjected to BSG removal and alkali polishing;

[0012] S4: using PECVD to deposit a tunnel oxide layer and doped amorphous silicon on the back of the silicon wafer obtained in S3;

[0013] S5: performing annealing and crystallization treatment on the silicon wafer obtained in S4, so that the doped amorphous silicon is crystallized into a doped polysilicon film, and distinct alternating deep junction regions and shallow junction regions are formed on the front side of the silicon wafer;

[0014] S6: The silicon wafer obtained in S5 is cleaned by a tank RCA to remove the polysilicon coating on the edge and the front side, and the front BSG layer is cleaned by an HF acid tank;

[0015] S7: depositing aluminum oxide and silicon nitride layers on the front and back sides of the silicon wafer obtained in S6;

[0016] S8: Screen printing and drying of silver paste on the front side of the silicon wafer obtained in S7;

[0017] S9: sintering and light injection on the front side of the silicon wafer obtained in S8;

[0018] S10: Perform LECO treatment on the front side of the silicon wafer obtained in S9 to form a silver-silicon alloy contact between the silicon wafer and the front metal grid line.

[0019] A device, which is used in S8 of the novel boron-expanded shallow junction crystalline silicon photovoltaic cell preparation method, comprises a printing bin and a transport bin, one end of the transport bin is butted against the lower side of the printing bin, a first transport platform and a second transport platform are horizontally movable in the transport bin, the first transport platform and the second transport platform move relative to each other to enter and exit the printing bin respectively, a first mold base is fixedly arranged on the first transport platform, a second mold base is liftably arranged on the second transport platform, a linkage assembly is arranged on the second transport platform, during the movement of the second transport platform in and out of the printing bin, the linkage assembly keeps the second mold base at a lowered height, and at both ends of the moving stroke of the second transport platform, the linkage assembly keeps the second mold base flush with the height of the first mold base.

[0020] Preferably, the inner wall of the transport bin is fixedly provided with a first track and a second track which are parallel to each other in an upper and lower direction, the side wall of the first transport platform is provided with a first sliding sleeve which matches the first track, and the side wall of the second transport platform is provided with a second sliding sleeve which matches the second track.

[0021] Preferably, a plurality of rolling teeth rotatably connected to the inner wall of the transport bin are arranged between the first rail and the second rail, and the same rolling belt is sleeved on the rolling teeth on the same side, the upper side of the rolling belt is fixedly connected to the first sliding sleeve, and the lower side of the rolling belt is fixedly connected to the second sliding sleeve.

[0022] Preferably, a plurality of guide pillars are provided at the bottom of the second mold base, and a guide sleeve movably connected to the guide pillars is fixedly provided on the second transport platform, and the guide pillars move up and down along the guide sleeves.

[0023] Preferably, the linkage assembly includes a support rod hinged on the second transport platform, the upper end of the support rod is movably connected to the second mold base, a linkage part is arranged for lifting and lowering on the second transport platform, the upper end of the linkage part is movably connected to the support rod, a linkage rod is fixedly arranged at the lower end of the linkage part, a cross beam is arranged in the transport bin, and a linkage groove matching the linkage rod is arranged on the cross beam.

[0024] Preferably, the first mold base and the second mold base are both provided with a workpiece groove, a top block is provided in the workpiece groove which can be raised and lowered, and the first mold base and the second mold base are both provided with a trigger component for triggering the top block to rise, and the trigger component is triggered when the first mold base or the second mold base is away from one end of the printing chamber during the moving stroke.

[0025] Preferably, the trigger assembly includes a trigger groove arranged at the lower side of the workpiece groove, a trigger rod is elastically and movably arranged in the trigger groove, an extrusion block is arranged on the trigger rod, and an extrusion groove wedge-shapedly matched with the extrusion block is arranged at the lower end of the top block, and the trigger rod can movably extend one end of the first mold base or the second mold base to move outside the printing bin, and an abutment corresponding to the trigger rod is arranged on the inner side of the end of the transport bin outside the printing bin.

[0026] Preferably, the abutment member is provided with a through hole matching the trigger rod, and the abutment member is elastically provided with a stopper for blocking the through hole.

[0027] In the above technical solution, the beneficial effects of the present invention are:

[0028] The crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction has a shallow junction region with a doping depth of less than 80nm, and has the characteristics of high light transmittance and low recombination, which is conducive to the passage of sunlight, improves the light utilization rate, reduces the number of holes, and reduces the consumption of electrons, thereby improving the battery efficiency. At the same time, by setting a deep junction region with a depth greater than 200nm formed by high doping and deep diffusion, it has the characteristics of low resistance, ensures the hole transmission efficiency, avoids the use of a method of reducing the grid line spacing, and reduces the production cost.

[0029] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0030] This application document provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0032] Figure 1 A schematic diagram of a cross-sectional structure of a battery provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a battery plan structure provided by an embodiment of the present invention;

[0034] Figure 3 A schematic diagram of the overall structure of a device provided by an embodiment of the present invention;

[0035] Figure 4 A schematic diagram of the overall structure of a transport warehouse provided in an embodiment of the present invention;

[0036] Figure 5 A schematic diagram of a side cross-sectional structure of a device provided in an embodiment of the present invention;

[0037] Figure 6 The embodiment of the present invention provides Figure 5 A schematic diagram of the enlarged structure at A in the middle;

[0038] Figure 7 The embodiment of the present invention provides Figure 5 A schematic diagram of the enlarged structure at B in the middle;

[0039] Figure 8 The embodiment of the present invention provides Figure 5 Schematic diagram of the enlarged structure at C in the middle;

[0040] Fig. 9 A schematic diagram of a side cross-sectional structure of a device provided in an embodiment of the present invention;

[0041] Fig.10 A schematic diagram of a front cross-sectional structure of a device provided in an embodiment of the present invention;

[0042] Fig.11 The embodiment of the present invention provides Fig.10 Schematic diagram of the enlarged structure at D in the middle.

[0043] Description of reference numerals:

[0044] 1. Deep junction area; 2. Shallow junction area; 3. Metal grid line; 4. Printing chamber; 5. Transport chamber; 6. First transport platform; 7. Second transport platform; 8. First die base; 9. Second die base; 10. First track; 11. Second track; 12. First slide sleeve; 13. Second slide sleeve; 14. Rolling gear; 15. Rolling belt; 16. Guide column; 17. Guide sleeve; 18. Support rod; 19. Linkage member; 20. Linkage rod; 21. Crossbeam; 22. Linkage groove; 23. Workpiece groove; 24. Top block; 25. Trigger groove; 26. Trigger rod; 27. Abutment; 28. Perforation; 29. ​​Stopper; 30. Extrusion block; 31. Extrusion groove; 32. First sliding pin; 33. First sliding frame; 34. Second sliding pin; 35. Second sliding frame. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0046] See also Figure 1-2 A crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction provided in an embodiment of the present invention comprises a silicon wafer, a deep junction region 1 and a shallow junction region 2 are alternately arranged on the surface of the silicon wafer, the depth of the deep junction region 1 is greater than 200nm, and the depth of the shallow junction region 2 is less than 80nm, and a grid-shaped metal grid line 3 is also arranged on the surface of the silicon wafer, the metal grid line 3 comprises a main grid line parallel to the deep junction region 1 and a secondary grid line perpendicular to the main grid line, and the main grid line protrudes from the surface of the shallow junction region 2.

[0047] Specifically, the deep junction region 1 and the shallow junction region 2 are parallel lines, and the width of each deep junction region 1 is consistent and the spacing between each adjacent deep junction region 1 is consistent; the width of each main grid line is consistent and the spacing between each adjacent main grid line is consistent; the width of each auxiliary grid line is consistent and the spacing between each adjacent auxiliary grid line is consistent; the main grid line and the deep junction region 1 do not have to be strictly aligned; the setting of the depth of the deep junction region 1 being greater than 200nm can have a low resistance value, help form a hole transmission path, and ensure the hole transmission efficiency; the setting of the depth of the shallow junction region being less than 80nm can have the characteristics of high light transmittance and low recombination, which is conducive to the passage of sunlight, improves light utilization, and reduces the number of holes, reduces electron consumption, thereby improving battery efficiency.

[0048] Compared with the prior art, a crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction proposed in an embodiment of the present invention has the characteristics of high light transmittance and low recombination by setting a shallow junction region with a doping depth of less than 80nm, which is conducive to the passage of sunlight, improves the light utilization rate, reduces the number of holes, reduces the consumption of electrons, and thus improves the battery efficiency. At the same time, a deep junction region with a depth greater than 200nm formed by high doping and deep diffusion is set, which has the characteristics of low resistance, ensures the hole transmission efficiency, avoids the use of a method of reducing the gate line spacing, and reduces the production cost.

[0049] A preparation method for producing the above-mentioned crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction comprises the following steps of processing the front side of the cell:

[0050] S1: Diffusing boron on the front side of the silicon wafer to be processed;

[0051] S2: The front side of the silicon wafer obtained in S1 is heavily doped with SE laser;

[0052] S3: The surface of the silicon wafer obtained in S2 is oxidized to form BSG, and then the back of the silicon wafer is subjected to BSG removal and alkali polishing;

[0053] S4: using PECVD to deposit a tunnel oxide layer and doped amorphous silicon on the back of the silicon wafer obtained in S3;

[0054] S5: performing annealing and crystallization treatment on the silicon wafer obtained in S4, so that the doped amorphous silicon is crystallized into a doped polysilicon film, and a deep junction region 1 and a shallow junction region 2 are formed on the front side of the silicon wafer, which are clearly alternating;

[0055] S6: The silicon wafer obtained in S5 is cleaned by a tank RCA to remove the polysilicon coating on the edge and the front side, and the front BSG layer is cleaned by an HF acid tank;

[0056] S7: depositing aluminum oxide and silicon nitride layers on the front and back sides of the silicon wafer obtained in S6;

[0057] S8: Screen printing and drying of silver paste on the front side of the silicon wafer obtained in S7;

[0058] S9: sintering and light injection on the front side of the silicon wafer obtained in S8;

[0059] S10: Perform LECO treatment on the front side of the silicon wafer obtained in S9 to form a silver-silicon alloy contact between the silicon wafer and the front metal grid line 3.

[0060] Specifically, SE laser heavy doping in S2 can achieve a doping depth of more than 200nm, promoting the formation of deep junction area 1; and the formation of shallow junction area 2 is achieved by shortening the annealing time in S3 and S5; laser enhanced contact optimization (LECO) technology accurately helps to form silver-silicon alloy contact between the metal gate line 3 and the silicon wafer, greatly reducing the contact resistance.

[0061] See also Figure 3-11 , a device, which is used in S8 of the above-mentioned novel boron-expanded shallow junction crystalline silicon photovoltaic cell preparation method, includes a printing bin 4 and a transport bin 5, one end of the transport bin 5 is docked at the lower side of the printing bin 4, and a first transport platform 6 and a second transport platform 7 are horizontally movable in the transport bin 5, and the first transport platform 6 and the second transport platform 7 move relative to each other to enter and exit the printing bin 4 respectively, a first mold base 8 is fixedly arranged on the first transport platform 6, and a second mold base 9 is liftably arranged on the second transport platform 7, and a linkage component is arranged on the second transport platform 7. During the movement of the second transport platform 7 in and out of the printing bin 4, the linkage component keeps the second mold base 9 at a lowered height, and at both ends of the moving stroke of the second transport platform 7, the linkage component keeps the second mold base 9 flush with the first mold base 8.

[0062] Specifically, the printing bin 4 is provided with a prior art silver paste printing mechanism, which is not shown in the figure. The lower part of the silver paste printing mechanism is set as a printing position. The first transport platform 6 and the second transport platform 7 on the transport bin 5 move the first mold base 8 and the second mold base 9 to the printing position alternately through relative movement. After one printing, the first transport platform 6 and the second transport platform 7 alternate positions again, thereby achieving a group of battery cells being printed at the printing position while another group of battery cells can be taken away outside the printing bin 4 and replaced with a new group of battery cells to be processed. The first mold base 8 and the second mold base 9 are used to carry the battery cells to be printed and processed; the first mold base 8 is fixed at a height on the first transport platform 6, and the height corresponds to one end in the printing bin 4 during the moving stroke of the first transport platform 6, so that the first mold base 8 on it corresponds to the printing position; under the setting of the linkage component: at both ends of the moving stroke of the second transport platform 7, the second mold base 9 corresponds to the highest position of the lifting stroke, and the height is level with the height of the first mold base 8, and in the moving stroke of the second transport platform 7, the height of the second mold base 9 corresponds to one end in the printing bin 4, and the printing position; the lowest position of the lifting stroke of the second mold base 9 is lower than the height setting of the first transport platform 6; when the first transport platform 6 and the second transport platform 7 are close, the height of the second mold base 9 decreases, and when the first transport platform 6 and the second transport platform 7 are about to overlap vertically, the second mold base 9 is at the lowest position of the lifting stroke and maintains this position.

[0063] In actual use of the above technical solution, the first transport platform 6 and the second transport platform 7 move relative to each other. When the first transport platform 6 is at one end of the transport bin 5 outside the printing bin 4, the second transport platform 7 is at one end of the transport bin 5 inside the printing bin 4. At this time, the second mold base 9 rises to the highest position to correspond to the printing position under the action of the linkage component. The silver paste printing mechanism can perform silver paste screen printing on the battery cells carried by the second mold base 9. At the same time, the first mold base 8 is outside the printing bin 4 and close to the edge of the transport bin 5, which can facilitate the removal and replacement of a new group of battery cells to be processed; then the first transport platform 6 moves toward the direction inside the printing bin 4, and the second transport platform 7 moves outside the printing bin 4. At this time, the proximity of the first transport platform 6 and the second transport platform 7 causes the second mold base 9 to lower its height under the action of the linkage component. When the first transport platform 6 and the second transport platform 7 are about to overlap vertically, the second mold base 9 is at the lowest position of the lifting stroke and maintains this position, so that the second mold base 9 can smoothly avoid the first transport platform 6. When the first transport platform 6 carries the first mold base 8 to the corresponding printing position, the second transport platform 7 moves to one end of the transport bin 5 outside the printing bin 4. At this time, the second mold base 9 is raised to the highest position under the action of the linkage assembly to be flush with the height of the first mold base 8. Therefore, the silver paste printing mechanism can perform silver paste screen printing processing on the battery cells carried by the first mold base 8. At the same time, the second mold base 9 is outside the printing bin 4 and close to the edge of the transport bin 5, which can easily remove and replace a new group of battery cells to be processed; this is repeated to achieve uninterrupted switching of the dual platforms, greatly improving the printing processing efficiency of the battery cells.

[0064] As the preferred technical solution of this embodiment, the inner wall of the transport warehouse 5 is fixedly provided with a first rail 10 and a second rail 11 which are parallel to each other in the upper and lower directions, the side wall of the first transport platform 6 is provided with a first sleeve 12 which matches the first rail 10, and the side wall of the second transport platform 7 is provided with a second sleeve 13 which matches the second rail 11. Specifically, the first rail 10 is composed of two parallel rod bodies, and is symmetrically arranged on two opposite sides of the inner wall of the transport warehouse 5. The two opposite side walls of the first transport platform 6 are both provided with a first sleeve 12, and the first sleeve 12 may preferably be C-shaped and engaged with the first rail 10; the second rail 11 is composed of another two parallel rod bodies, and is symmetrically arranged on two opposite sides of the inner wall of the transport warehouse 5. The two opposite side walls of the second transport platform 7 are both provided with a second sleeve 13, and the second sleeve 13 may preferably be C-shaped and engaged with the second rail 11; the first rail 10 and the second rail 11 are arranged with a gap in the upper and lower parts.

[0065] As the preferred technical solution of this embodiment, a plurality of rolling gears 14 rotatably connected to the inner wall of the transport bin 5 are arranged between the first track 10 and the second track 11, and the same rolling belt 15 is sleeved on the rolling gears 14 on the same side, and the upper side of the rolling belt 15 is fixedly connected to the first sleeve 12, and the lower side of the rolling belt 15 is fixedly connected to the second sleeve 13. Specifically, the rolling gears 14 are driven by a servo motor, and the two groups of rolling gears 14 on both sides rotate synchronously in the same direction, so that the rolling belts 15 on both sides driven by them have the same movement direction and speed; when the rolling belt 15 rolls, the upper and lower parts move in opposite directions, and then the first transport platform 6 and the second transport platform 7 are driven to move in opposite directions through the first sleeve 12 and the second sleeve 13 respectively, that is, the first transport platform 6 and the second transport platform 7 move relative to each other.

[0066] As a preferred technical solution of this embodiment, a plurality of guide pillars 16 are arranged at the bottom of the second mold base 9, and a guide sleeve 17 movably connected to the guide pillar 16 is fixedly arranged on the second transport platform 7, and the guide pillar 16 moves up and down along the guide sleeve 17. Specifically, the guide pillar 16 and the guide sleeve 17 are arranged vertically, and the guide pillar 16 and the guide sleeve 17 can preferably be four groups, which are correspondingly arranged at the four corners of the second mold base 9; the arrangement of the guide pillar 16 and the guide sleeve 17 limits the lifting and lowering movement of the second mold base 9 relative to the second transport platform 7.

[0067] As the preferred technical scheme of this embodiment, the linkage assembly includes a support rod 18 hinged on the second transport platform 7, the upper end of the support rod 18 is movably connected to the second mold base 9, a linkage member 19 is arranged on the second transport platform 7 for lifting and lowering, the upper end of the linkage member 19 is movably connected to the support rod 18, and a linkage rod 20 is fixedly arranged on the lower end of the linkage member 19, a crossbeam 21 is arranged in the transport bin 5, and a linkage groove 22 matching the linkage rod 20 is arranged on the crossbeam 21, specifically, a first sliding pin 32 is fixedly arranged on the upper end of the support rod 18, and a first sliding frame 33 matching the first sliding pin 32 is arranged at the bottom of the second mold base 9; the swing of the support rod 18 around the lower end changes the height of its upper end, and then the second mold base 9 is lifted and lowered by the first sliding pin 32 and the first sliding frame 33; the linkage member 19 can be lifted and lowered and movably penetrates the second transport platform 7, a second sliding pin 34 is fixedly arranged on the support rod 18, and a second sliding frame 35 matching the second sliding pin 34 is arranged on the upper end of the linkage member 19; The swing of the rod 18 changes the height of the second sliding pin 34, and then the linkage member 19 is lifted and lowered through the second sliding frame 35; the crossbeam 21 is arranged along the moving direction of the second transport platform 7; the linkage groove 22 is arranged to be tilted upward by a certain height at both ends of the middle level. When the linkage rod 20 corresponds to the two ends of the linkage groove 22, the height is the highest, that is, the linkage member 19 is in the highest position. At this time, the corresponding support rod 18 swings upward by a certain height, so that the second mold base 9 is in the highest position of the lifting stroke; when the linkage rod 20 corresponds to the middle horizontal part of the linkage groove 22, the linkage member 19 is in the lowest position, and then the linkage support rod 18 reduces the swing height downward, and then the second mold base 9 is linked to the lowest position of the lifting stroke; the range corresponding to the horizontal position of the linkage rod 20 and the linkage groove 22 covers the overlapping range of the first transport platform 6 and the second transport platform 7, thereby ensuring that when the first transport platform 6 and the second transport platform 7 are about to overlap or overlap, the second mold base 9 is kept in the lowest position to avoid interference movement.

[0068] In another embodiment of the present invention, a workpiece groove 23 is provided on the first mold base 8 and the second mold base 9, and a top block 24 is provided in the workpiece groove 23 which can be raised and lowered. A trigger component for triggering the top block 24 to rise is provided in the first mold base 8 and the second mold base 9, and the trigger component is triggered when the first mold base 8 or the second mold base 9 is far away from one end of the printing chamber 4 during the moving stroke. Specifically, a plurality of workpiece grooves 23 can be provided, arranged in a rectangular array, and the workpiece grooves 23 match the shape of the battery cell to be processed; the top block 24 can lift the battery cell to be processed in the workpiece groove 23 to achieve separation; the automatic triggering of the trigger component can realize that the battery cell to be processed is automatically lifted to separate from the workpiece groove 23 when it is printed and moved out of the printing chamber 4, so as to facilitate grasping; the lifting function of the top block 24 allows the battery cell to be processed to enter and exit the workpiece groove 23 in a lifting manner, thereby greatly reducing the gap between the workpiece groove 23 and the battery cell to be processed, and reducing the occurrence of silver paste filling problems.

[0069] As a preferred technical solution of this embodiment, the trigger assembly includes a trigger groove 25 arranged at the lower side of the workpiece groove 23, a trigger rod 26 is elastically and movably arranged in the trigger groove 25, an extrusion block 30 is arranged on the trigger rod 26, and an extrusion groove 31 wedge-shapedly matched with the extrusion block 30 is arranged at the lower end of the top block 24. The trigger rod 26 can movably extend out of the first mold base 8 or the second mold base 9 to move outside the printing bin 4, and an abutment 27 corresponding to the trigger rod 26 is arranged on the inner side of the end of the transport bin 5 outside the printing bin 4. Specifically, the trigger groove 25 is arranged in both the first mold base 8 and the second mold base 9, and the water The trigger groove 25 is arranged flat, and the extension direction of both ends of the trigger groove 25 is consistent with the extension direction of both ends of the transport bin 5; the trigger groove 25 is open at one end facing the outside of the transport bin 5, and the other end is closed and provided with a first elastic member to abut against the trigger rod 26, thereby making the trigger rod 26 maintain the tendency of extending out of the first mold base 8 or the second mold base 9 to move out of the printing bin 4; a through groove connection is provided between the workpiece groove 23 and the trigger groove 25, the lower end of the top block 24 is slidably connected in the through groove, and the extrusion block 30 extends upward into the through groove; the abutment 27 is horizontally protruding and extending on the inner side of the end of the transport bin 5 away from the printing bin 4. In actual use of the present technical solution, when the first transport platform 6 or the second transport platform 7 moves to the end of the transport bin 5 away from the printing bin 4 after moving out of the printing bin 4, the height of the first mold base 8 or the second mold base 9 is consistent, so that the end of the trigger rod 26 on the first mold base 8 or the second mold base 9 extending out of the trigger groove 25 is horizontally corresponding to the abutment 27. When the first transport platform 6 or the second transport platform 7 moves to the end of the transport bin 5 away from the printing bin 4, the trigger rod 26 is blocked by the abutment 27 and moves back into the trigger groove 25, thereby driving the extrusion block 30 to wedge-extrude the extrusion groove 31, thereby causing the top block 24 to automatically rise, and lift up the battery cell in the workpiece groove 23 to automatically detach from the workpiece groove 23.

[0070] As a preferred technical solution of this embodiment, a through hole 28 matching the trigger rod 26 is provided on the abutment 27, and a block 29 for blocking the through hole 28 is elastically provided on the abutment 27. Specifically, the through hole 28 can be used for the trigger rod 26 to pass through; sliders are provided on opposite sides of the block 29, a groove matching the block 29 is provided on the abutment 27, a slide groove matching the slider is provided on the inner wall of the groove, and a second elastic member connected to the upper end of the slider is provided in the slide groove, and the second elastic member prevents the slider from moving upward; preferably, the upper end of the block 29 is bent toward the outside of the transport bin 5 for easy operation. In actual use of the present technical solution, when a new battery cell to be processed is to be replaced in the workpiece slot 23, the block 29 can be pulled upward first so that the block 29 no longer blocks the through hole 28. As a result, the trigger rod 26 is not blocked by the block 29 and elastically extends out of the trigger slot 25, that is, passes through the through hole 28. As a result, the height of the top block 24 can be lowered, and the new battery cell to be processed can be placed flat in the workpiece slot 23. Subsequently, the block 29 is released, and the block 29 can be against the upper side of the trigger rod 26. When the first transport platform 6 or the second transport platform 7 moves into the printing chamber 4 again, the trigger rod 26 moves accordingly and slides out of the block 29, and the block 29 automatically moves down and resets under the elastic force.

[0071] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions 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 crystalline silicon photovoltaic cell with a novel boron-extended shallow junction, comprising a silicon wafer, characterized in that: The surface of the silicon wafer is alternately provided with deep junction areas (1) and shallow junction areas (2), the depth of the deep junction areas (1) being greater than 200 nm, and the depth of the shallow junction areas (2) being less than 80 nm. The surface of the silicon wafer is also provided with grid-shaped metal gate lines (3), the metal gate lines (3) comprising main gate lines parallel to the deep junction areas (1) and secondary gate lines perpendicularly intersecting the main gate lines, the main gate lines protruding from the surface of the shallow junction areas (2).

2. A preparation method for producing the crystalline silicon photovoltaic cell with a novel boron-diffused shallow junction as claimed in claim 1, characterized in that: The following battery front processing steps are included: S1: Diffusing boron on the front side of the silicon wafer to be processed; S2: The front side of the silicon wafer obtained in S1 is heavily doped with SE laser; S3: The surface of the silicon wafer obtained in S2 is oxidized to form BSG, and then the back of the silicon wafer is subjected to BSG removal and alkali polishing; S4: using PECVD to deposit a tunnel oxide layer and doped amorphous silicon on the back of the silicon wafer obtained in S3; S5: performing annealing and crystallization treatment on the silicon wafer obtained in S4, so that the doped amorphous silicon is crystallized into a doped polysilicon film, and a deep junction region (1) and a shallow junction region (2) are formed on the front side of the silicon wafer in alternating distinct directions; S6: The silicon wafer obtained in S5 is cleaned by a tank RCA to remove the polysilicon coating on the edge and the front side, and the front BSG layer is cleaned by an HF acid tank; S7: depositing aluminum oxide and silicon nitride layers on the front and back sides of the silicon wafer obtained in S6; S8: Screen printing and drying of silver paste on the front side of the silicon wafer obtained in S7; S9: sintering and light injection on the front side of the silicon wafer obtained in S8; S10: LECO treatment is performed on the front side of the silicon wafer obtained in S9, so that a silver-silicon alloy contact is formed between the silicon wafer and the surface metal grid line (3).

3. A device used in S8 of the method for preparing a novel boron-diffused shallow junction crystalline silicon photovoltaic cell according to claim 2, characterized in that: The invention comprises a printing bin (4) and a transport bin (5), one end of the transport bin (5) is butted against the lower side of the printing bin (4), a first transport platform (6) and a second transport platform (7) are horizontally movable in the transport bin (5), one high and one low, the first transport platform (6) and the second transport platform (7) are relatively movable to enter and exit the printing bin (4), a first mold base (8) is fixedly arranged on the first transport platform (6), a second mold base (9) is liftably arranged on the second transport platform (7), a linkage assembly is arranged on the second transport platform (7), during the process of the second transport platform (7) moving in and out of the printing bin (4), the linkage assembly keeps the second mold base (9) at a lowered height, and at both ends of the moving stroke of the second transport platform (7), the linkage assembly keeps the second mold base (9) flush with the first mold base (8) in height.

4. The device according to claim 3, characterized in that The inner wall of the transport bin (5) is fixedly provided with a first track (10) and a second track (11) which are parallel to each other in an upper and lower direction; the side wall of the first transport platform (6) is provided with a first sliding sleeve (12) which matches the first track (10); and the side wall of the second transport platform (7) is provided with a second sliding sleeve (13) which matches the second track (11).

5. The device according to claim 4, characterized in that A plurality of rolling teeth (14) rotatably connected to the inner wall of the transport bin (5) are arranged between the first track (10) and the second track (11); a same rolling belt (15) is sleeved on the rolling teeth (14) on the same side; the upper side of the rolling belt (15) is fixedly connected to the first sliding sleeve (12); and the lower side of the rolling belt (15) is fixedly connected to the second sliding sleeve (13).

6. The device according to claim 3, characterized in that A plurality of guide pillars (16) are arranged at the bottom of the second mold base (9), and a guide sleeve (17) movably sleeved with the guide pillars (16) is fixedly arranged on the second transport platform (7), and the guide pillars (16) are movable up and down along the guide sleeve (17).

7. The device according to claim 3, characterized in that The linkage assembly comprises a support rod (18) hinged on the second transport platform (7), the upper end of the support rod (18) is movably connected to the second mold base (9), a linkage member (19) is provided on the second transport platform (7) for lifting, the upper end of the linkage member (19) is movably connected to the support rod (18), a linkage rod (20) is fixedly provided at the lower end of the linkage member (19), a crossbeam (21) is provided in the transport bin (5), and a linkage groove (22) matching the linkage rod (20) is provided on the crossbeam (21).

8. The device according to claim 3, characterized in that The first die base (8) and the second die base (9) are both provided with a workpiece groove (23), a top block (24) is provided in the workpiece groove (23) and can be raised and lowered, and a trigger component for triggering the top block (24) to rise is provided in the first die base (8) and the second die base (9), and the trigger component is triggered when the first die base (8) or the second die base (9) is at one end away from the printing chamber (4) during the moving stroke.

9. The device according to claim 8, characterized in that The trigger assembly comprises a trigger groove (25) arranged at the lower side of the workpiece groove (23), a trigger rod (26) being elastically and movably arranged in the trigger groove (25), an extrusion block (30) being arranged on the trigger rod (26), an extrusion groove (31) being wedge-shapedly matched with the extrusion block (30) being arranged at the lower end of the top block (24), one end of the trigger rod (26) being movably extended out of the first die base (8) or the second die base (9) to move outside the printing bin (4), and an abutment member (27) corresponding to the trigger rod (26) being arranged on the inner side of one end of the transport bin (5) outside the printing bin (4).

10. The device according to claim 9, characterized in that The abutment member (27) is provided with a through hole (28) matching the trigger rod (26), and a stopper (29) for blocking the through hole (28) is elastically provided on the abutment member (27).

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