Solar cell half-piece passivation coating method and solar cell

Abstract

The invention provides a solar cell half-piece passivation coating method and a solar cell, a material box comprises a cover plate, a bottom plate and a side plate, the material of the cover plate and the bottom plate comprises a conductive material, the material of the side plate comprises an insulating material, a plurality of stacked cell pieces are arranged in the material box, at least one cell piece is in contact with the cover plate, and at least one cell piece is in contact with the insulating material. At least one battery piece is in contact with the bottom plate, the hydrogen passivation cavity comprises a heating cavity, a process cavity and a discharging cavity which are sequentially communicated, and the method comprises the steps that a material box is conveyed to the heating cavity, so that the heating cavity heats the material box; and the heated material box is conveyed to a process cavity, ATM gas is introduced into the process cavity so as to conduct film coating on the cutting faces of the multiple battery pieces, and in the film coating process of the multiple cutting faces, voltage is provided for the cover plate and the bottom plate so as to activate hydrogen ions in the multiple battery pieces. The problem that in the prior art, the passivation efficiency is low due to the fact that the passivation process duration of the half battery piece is long is solved.

Description

Technical Field

[0001] The present application relates to the technical field of half-cell passivation, and in particular to a half-cell passivation coating method for a solar cell and a solar cell. Background Art

[0002] Existing ALD (Atomic Layer Deposition) passivation machine: The ALD passivation machine includes automatic loading, main machine, and automatic unloading. The front-end dicing machine cuts the whole battery into half pieces and then enters the automatic loading port of the ALD machine, and then is conveyed by the belt to the regularization area. The four-axis robot takes the piece and puts it into the regularizer to regularize the half piece into the material box. A material box is filled with 860 pieces. After the material box is filled, the cover is covered (the cover width is greater than the half piece width to ensure that the first and last pieces are not circumferentially plated), flipped 90° so that the cut surface faces up, and embedded in the boat by the six-axis robot. Each boat can embed 12 material boxes, and every two boats are stacked on the boat trailer and enter the furnace tube. The furnace door is closed, the temperature in the furnace tube is increased, and ATM gas is introduced for a 3-hour coating process. After the process is completed, it is taken out of the furnace and cooled for 1 hour before automatic unloading. Process conditions: 1) Original furnace tubes: three furnace tubes are arranged side by side, and a single furnace tube is used for heating and coating process; 2) Original gas flow direction: four nozzles spray to the furnace door, and then bounce from the furnace door to the material box in the boat. Because there is a 0.3mm gap on the side of the material box, the gas enters horizontally from the gap, coats the cut surface, and then is discharged from the tail of the furnace.

[0003] The existing equipment can only meet the process requirements of cutting surface coating efficiency improvement, and there is no half-cell efficiency improvement method. The process structure design is single, resulting in a long process time and low efficiency for half-cell batteries. Summary of the invention

[0004] The main purpose of the present application is to provide a half-cell passivation coating method for a solar cell and a solar cell, so as to solve the problem in the prior art that the passivation process of a half-cell cell takes a long time, resulting in low passivation efficiency.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a method for passivation coating of half a solar cell is provided, wherein a material box comprises a cover plate, a bottom plate and a side plate connecting the cover plate and the bottom plate, the materials of the cover plate and the bottom plate both comprise conductive materials, the material of the side plate comprises insulating materials, a plurality of cells are arranged in the material box, and a hydrogen passivation chamber comprises a heating chamber, a process chamber and a material discharge chamber which are sequentially connected, the method comprising: transferring the material box to the heating chamber so that the heating chamber heats the material box; transferring the heated material box to the process chamber, and introducing ATM gas into the process chamber to coat the cut surfaces of the plurality of cells, and in the process of coating the plurality of cut surfaces, providing voltage to the cover plate and the bottom plate to activate hydrogen ions in the plurality of cells; when the coating of the plurality of cells is completed, transferring the material box to the material discharge chamber to discharge the material box.

[0006] Optionally, providing voltage to the cover plate and the base plate includes: a first power-on step: applying a forward bias to the cover plate and the base plate; a stop step: stopping powering the cover plate and the base plate when the power-on time reaches a first predetermined time; a second power-on step: continuing to apply a forward bias to the cover plate and the base plate when the stop time reaches a second predetermined time; and a cycle step: repeating the first power-on step, the stop step and the second power-on step in sequence for a predetermined number of times.

[0007] Optionally, applying a forward bias voltage to the cover plate and the bottom plate includes: applying a first voltage to the cover plate and applying a second voltage to the bottom plate, wherein the voltage difference between the first voltage and the second voltage is 10V to 12V.

[0008] Optionally, the warming chamber includes a warming chamber body, an infrared lamp tube located in the warming chamber body, and a first air inlet passing through the warming chamber body, the infrared lamp tube is located on one side of the first air inlet, and the material box is transferred to the warming chamber so that the warming chamber heats the material box, including: transferring the material box to the warming chamber body to heat the material box with the air inlet lamp tube, and passing an inert gas into the warming chamber body through the first air inlet to heat the material box with the inert gas.

[0009] Optionally, there are four side panels, the side panel closest to the cutting surface is the target side panel, the process chamber includes a second air inlet, and the material box is transferred to the heating chamber body, including: flipping the cutting surface to a direction intersecting with the air inlet direction of the second air inlet, and removing the target side panel, and transferring the material box after removing the target side panel to the heating chamber body, and introducing ATM gas into the process chamber, including: introducing the ATM gas into the process chamber through the second air inlet so that the ATM gas is blown toward the cutting surface.

[0010] Optionally, transferring the heated material box to the process chamber includes: when the temperature of the material box reaches 100° C., transferring the material box from the temperature rising chamber to the process chamber.

[0011] Optionally, the materials of the cover plate and the bottom plate independently include aluminum, and the material of the side plate includes graphene, and the material box is transferred to the material discharge chamber, including: transferring the material box from the process chamber to the material discharge chamber, so that the material discharge chamber cools the material box and discharges the cooled material box.

[0012] Optionally, there are a plurality of material boxes, and transferring the material boxes to the temperature rising chamber comprises: placing the plurality of material boxes in a graphite boat; and transferring the graphite boat to the temperature rising chamber.

[0013] Optionally, introducing the ATM gas into the process chamber includes: introducing trimethylaluminum gas and water vapor into the process chamber, so that the trimethylaluminum gas and the water vapor react to obtain an aluminum oxide film.

[0014] According to another aspect of the present application, a solar cell is provided, wherein the solar cell is prepared by using any one of the methods for half-cell passivation coating of a solar cell.

[0015] Applying the technical solution of the present application, the material box includes a cover plate, a bottom plate and a side plate. The materials of the cover plate and the bottom plate include conductive materials, and the material of the side plate includes insulating materials. Multiple battery cells are arranged in the material box. First, the material box is transferred to the heating chamber so that the heating chamber heats the material box. Then, the heated material box is transferred to the process chamber, and ATM gas is introduced into the process chamber to coat the cut surfaces of the multiple battery cells. In the process of coating the multiple cut surfaces, voltage is provided to the cover plate and the bottom plate to activate hydrogen ions in the multiple battery cells. Finally, when the multiple battery cells have completed coating, the material box is transferred to the unloading chamber to unload the material box. Compared with the problem of long passivation process time for half-cell and resulting in low passivation efficiency in the prior art, the present application provides voltage to the cover plate and the bottom plate during the coating process of the cell, which will form an electric field inside the cell. This electric field can accelerate the movement of hydrogen ions, making it easier for them to reach the surface of the cell (that is, the hydrogen ions in the cell are activated), thereby achieving the effect of hydrogen passivation. In other words, the present application combines the coating and hydrogen passivation processes, shortens the process time, and ensures a high passivation efficiency for the half-cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting part of the present application are used to provide a further understanding of the present application. The exemplary embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1 A schematic diagram of a process for passivation coating of a half-cell solar cell provided in accordance with an embodiment of the present application is shown;

[0018] Figure 2 A schematic structural diagram of a material box provided with a plurality of battery cells according to an embodiment of the present application is shown;

[0019] Figure 3 A schematic structural diagram of a hydrogen passivation chamber provided according to an embodiment of the present application is shown;

[0020] Figure 4 A schematic structural diagram of another material box provided with a plurality of battery cells according to an embodiment of the present application is shown;

[0021] Figure 5 A method of providing a Figure 4 A schematic diagram of the structure of the material box after the target side plate is removed;

[0022] Figure 6 A method according to an embodiment of the present application is shown. Figure 4 A schematic diagram of the structure of the material box after adding the electrode plate;

[0023] Figure 7 A schematic diagram of a structure of transferring a material box to a temperature-raising chamber according to an embodiment of the present application is shown;

[0024] Figure 8 A schematic diagram of a structure of transferring a material box into a process chamber according to an embodiment of the present application is shown;

[0025] Fig. 9 A schematic diagram of a structure of transferring a material box to a material discharge cavity according to an embodiment of the present application is shown;

[0026] Fig.10 A schematic structural diagram of a solar cell provided according to an embodiment of the present application is shown.

[0027] The above drawings include the following reference numerals:

[0028] 10. Material box; 11. Battery cell; 12. Temperature rising chamber; 121. Temperature rising chamber body; 122. Infrared lamp tube; 123. First air inlet; 13. Process chamber; 14. Material unloading chamber; 15. Substrate; 16. Emitter layer; 17. Passivation layer; 18. Anti-reflection film; 19. Cover plate; 20. Bottom plate; 21. Cutting surface; 22. Target side plate; 23. Electrode plate; 231. First electrode plate; 232. Second electrode plate. DETAILED DESCRIPTION

[0029] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be intermediate elements. Moreover, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element through a third element.

[0032] As introduced in the background technology, the passivation process time of half-cell in the prior art is long, resulting in low passivation efficiency. To solve the above problem, the embodiments of the present application provide a half-cell passivation coating method for a solar cell and a solar cell.

[0033] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0034] Figure 1 1 is a flow chart of a half-cell passivation coating method for a solar cell according to an embodiment of the present application. Figure 4 and Figure 6 As shown, the material box 10 includes a cover plate 19, a bottom plate 20 and a side plate connecting the cover plate 19 and the bottom plate 20. The materials of the cover plate 19 and the bottom plate 20 are both conductive materials, and the material of the side plate is insulating material. A plurality of battery cells 11 are arranged in the material box 10. The hydrogen passivation chamber includes a heating chamber, a process chamber and a material discharge chamber which are connected in sequence, such as Figure 1 As shown, the method comprises the following steps:

[0035] Step S101, transferring the material box to the temperature rising chamber, so that the temperature rising chamber heats the material box;

[0036] Step S102, transferring the heated material box to the process chamber, and introducing ATM gas into the process chamber to coat the cut surfaces of the plurality of battery cells, and in the process of coating the cut surfaces, providing voltage to the cover plate and the bottom plate to activate hydrogen ions in the plurality of battery cells;

[0037] Step S103, when the plurality of battery cells have completed coating, the material box is transferred to the material unloading chamber to unload the material box.

[0038] According to the present embodiment, the material box includes a cover plate, a bottom plate and a side plate. The materials of the cover plate and the bottom plate include conductive materials, and the material of the side plate includes insulating materials. The material box is first transferred to the heating chamber so that the heating chamber heats the material box. Then, the heated material box is transferred to the process chamber, and ATM gas is introduced into the process chamber to coat the cut surfaces of multiple battery cells. In the process of coating the multiple cut surfaces, voltage is provided to the cover plate and the bottom plate to activate hydrogen ions in the multiple battery cells. Finally, when the multiple battery cells have completed coating, the material box is transferred to the unloading chamber to unload the material box. Compared with the problem of long passivation process time for half-cell and resulting in low passivation efficiency in the prior art, the present application provides voltage to the cover plate and the bottom plate during the coating process of the cell, which will form an electric field inside the cell. This electric field can accelerate the movement of hydrogen ions, making it easier for them to reach the surface of the cell (that is, the hydrogen ions in the cell are activated), thereby achieving the effect of hydrogen passivation. In other words, the present application combines the coating and hydrogen passivation processes, shortens the process time, and ensures a high passivation efficiency for the half-cell.

[0039] In addition, by using insulating side plates, it can be ensured that no direct current path is formed between the front and back sides of the battery cell during the power-on process (i.e., the front and back sides of half a battery cell are insulated during the power-on process). This can more accurately control the flow of current, so that the current mainly flows to the battery cell through the cover plate and the bottom plate, and will not be short-circuited or shunted by the side plates, thereby improving the uniformity and efficiency of the electric field during the coating process.

[0040] Specifically, the battery cell is a cut battery cell (i.e., a half-cell battery cell), and the cut surface is the cross section of the battery cell. In the material box, the battery cells are not in contact with each other (i.e., the material box is provided with a plurality of battery cells arranged at intervals). The width of the cover plate is greater than the width of the battery cell, which can ensure that the first and last cells are not circumferentially plated. The width represents the length in a predetermined direction, which is a direction perpendicular to the thickness of the battery cell. The first and last cells represent the battery cells located in the last row and the first row in the material box.

[0041] Specifically, a direct current voltage is applied to the cover plate and the bottom plate to achieve the effect of hydrogen passivation efficiencies. The hydrogen passivation chamber is a plate-type chamber.

[0042] It should be noted that under the action of the electric field, hydrogen ions will migrate from the inside of the cell to the surface. The hydrogen ions that reach the surface combine with defects on the cell surface (such as dangling bonds) to form stable hydrides. The process of combining with defects reduces surface defects and reduces the probability of electron-hole pairs recombination at these defects. By reducing surface recombination, the surface quality of the cell is improved, thereby improving the photoelectric conversion efficiency of the cell. In short, hydrogen ions in the cell can not only passivate surface defects, but also recombine with electron-hole pairs, reduce carrier recombination losses, and improve the photoelectric conversion efficiency of the cell.

[0043] Specifically, Figure 2 As shown, a plurality of battery cells 11 are arranged in the material box 10, and at this time the top plate (not shown) has not been covered.

[0044] Specifically, Figure 3 , Figure 7 , Figure 8 and Fig. 9 As shown, the hydrogen passivation chamber includes a temperature rising chamber 12 , a process chamber 13 and a material discharge chamber 14 , and the process chamber 13 includes a second air inlet 131 .

[0045] In an optional solution, the voltage is provided to the cover plate and the bottom plate, including: a first power-on step: applying a forward bias voltage to the cover plate and the bottom plate; a stop step: stopping the power-on of the cover plate and the bottom plate when the power-on time reaches a first predetermined time; a second power-on step: continuing to apply a forward bias voltage to the cover plate and the bottom plate when the stop time reaches a second predetermined time; a cycle step: repeating the first power-on step, the stop step, and the second power-on step for a predetermined number of times. In this embodiment, by periodically applying a forward bias voltage and stopping the power-on (i.e., power-on in multiple times), the hydrogen ions in the battery cell can be more effectively activated, thereby improving the efficiency of the passivation coating.

[0046] In actual application, those skilled in the art may set the first predetermined time length, the second predetermined time length and the predetermined number of times according to experience.

[0047] In the embodiment of the present application, a DC voltage is applied to the cover plate and the bottom plate for a total of 8 times (i.e., the predetermined number of times is 3), and the first predetermined duration is 300s to 400s. In each stop step, the second predetermined duration may be the same or different, and the present application does not impose any specific restrictions on this; for example, the interval between the first power-on and the second power-on is 10s, and the interval between the second power-on and the third power-on is 15s.

[0048] Specifically, Figure 6As shown, an electrode plate 23 may be added to the material box 10 (i.e., the cover plate 19 contacts the first electrode plate 231, and the bottom plate 20 contacts the second electrode plate 232), and a forward bias is applied to the first electrode plate 231 and the second electrode plate 232, thereby activating hydrogen ions in the battery cell 11. Specifically, the cover plate and the bottom plate are clamped by the electrode plates.

[0049] According to some exemplary embodiments of the present application, applying a forward bias to the cover plate and the bottom plate includes: applying a first voltage to the cover plate and applying a second voltage to the bottom plate, wherein the voltage difference between the first voltage and the second voltage is 10 V to 12 V. In this embodiment, by applying the first voltage to the cover plate and the second voltage to the bottom plate, and maintaining a voltage difference of 10 V to 12 V between the two voltages, the hydrogen ions in the battery cell can be further effectively activated, and the hydrogen passivation efficiency can be further improved.

[0050] Specifically, a forward bias voltage is applied to the cover plate and the bottom plate (ie, the first voltage is greater than the second voltage). Specifically, the current of the forward bias voltage is 8A to 10A.

[0051] In other embodiments, Figure 3 , Figure 7 , Figure 8 and Fig. 9 As shown, the above-mentioned heating chamber 12 includes a heating chamber body 121, an infrared lamp tube 122 located in the above-mentioned heating chamber body 121, and a first air inlet 123 that penetrates the above-mentioned heating chamber body 121, and the above-mentioned infrared lamp tube 122 is located on one side of the above-mentioned first air inlet 123. The above-mentioned material box is transferred to the above-mentioned heating chamber so that the above-mentioned heating chamber heats the above-mentioned material box, including: transferring the above-mentioned material box to the above-mentioned heating chamber body to heat the above-mentioned material box with the above-mentioned air inlet lamp tube, and passing the inert gas into the above-mentioned heating chamber body through the above-mentioned first air inlet, so as to heat the above-mentioned material box with the above-mentioned inert gas. In this embodiment, the infrared lamp tube heating is combined with the auxiliary heating of the inert gas, so that the material box can be heated quickly, the heating efficiency is improved, thereby further shortening the process time, and further improving the passivation efficiency of the half-cell cell. In addition, the inert gas environment can reduce oxidation and pollution, which is beneficial to the quality and performance protection of the solar cell.

[0052] According to other exemplary embodiments of the present application, Figure 4 As shown, there are four side panels, and the side panel closest to the cutting surface 21 is the target side panel 22. Figure 4 , Figure 5 and Figure 7As shown, the process chamber 13 includes a second air inlet 131, and the material box 10 is transferred to the temperature-raising chamber body 121, including: turning the cut surface 21 to a direction intersecting with the air inlet direction of the second air inlet 131, removing the target side plate 22, and transferring the material box 10 after removing the target side plate 22 to the temperature-raising chamber body 121. The ATM gas is introduced into the process chamber, including: through the second air inlet, the ATM gas is introduced into the process chamber so that the ATM gas is blown toward the cut surface. In this embodiment, by turning the cut surface to a direction intersecting with the air inlet direction of the second air inlet, and removing the target side plate, it can be ensured that the ATM gas is blown toward the cut surface of the battery cell more directly and evenly, thereby further improving the efficiency and uniformity of the coating.

[0053] Specifically, the target side plate is removed to prevent the ATM gas from passing through the middle of the material box top plate (i.e., the target side plate) and the cross section (i.e., the cutting surface), thereby avoiding serious accumulation of coating sources on the cross section, resulting in uneven coating, and ultimately leading to poor winding and large fluctuations in efficiency gain, thereby solving the problems of poor winding and uneven coating on the front and back of the battery cell.

[0054] Specifically, the cut surface 21 is turned over to a direction intersecting with the air intake direction of the second air intake port 131, and the material box 10 with a plurality of battery cells 11 is provided after removing the target side plate (not shown). Figure 5 , Figure 7 , Figure 8 and Fig. 9 shown.

[0055] Specifically, Figure 5 The cover plate 19 and the bottom plate 20 in Figure 4 and Figure 6 The cover plate 19 and the base plate 20 are the same.

[0056] Specifically, Figure 7 As shown, the material box 10 provided with the battery cells 11 is transferred to the temperature raising chamber 12. Figure 8 As shown, the material box 10 provided with the battery cells 11 is transferred from the temperature raising chamber 12 to the process chamber 13. Fig. 9 As shown, the material box 10 provided with the battery cells 11 is transferred from the process chamber 13 to the material discharge chamber 14 .

[0057] Specifically, Figures 7 to 9 The material box 10 provided with the battery cell 11 is Figure 5 A material box 10 with battery cells 11 is provided in the embodiment.

[0058] In some other optional solutions of the present application, transferring the heated material box to the process chamber includes: transferring the material box from the heating chamber to the process chamber when the temperature of the material box reaches 100° C. In this embodiment, by ensuring that the material box reaches 100° C. before being transferred to the process chamber, it can be ensured that the temperature requirements of the battery cell during the coating process are met, further improving the quality and efficiency of the coating.

[0059] Specifically, when the temperature of the material box reaches 100° C. and the temperature difference between the upper and lower parts of the material box is not greater than 40° C., the material box is transferred from the temperature rising chamber to the process chamber.

[0060] In some further optional schemes of the present application, the materials of the cover plate and the bottom plate independently include aluminum, the material of the side plate includes graphene, and the material box is transferred to the material discharge chamber, including: transferring the material box from the process chamber to the material discharge chamber, so that the material discharge chamber cools the material box, and discharges the cooled material box. In this embodiment, the cover plate and the bottom plate are made of aluminum material, which has good electrical conductivity and thermal conductivity, which helps to achieve effective current conduction and heat management during the passivation coating process. The graphene material ensures the insulation and high hardness of the side plate, and the high thermal conductivity of graphene also helps to quickly transfer heat. By transferring the material box from the process chamber to the material discharge chamber for cooling, the temperature of the material box can be effectively controlled to ensure that the battery cell will not be damaged due to excessive temperature after coating, and it also helps to improve production efficiency.

[0061] Specifically, in the embodiment of the present application, the cooling time is 1 hour.

[0062] In other embodiments, there are multiple material boxes, and transferring the material boxes to the temperature-raising chamber includes: placing the multiple material boxes in a graphite boat; transferring the graphite boat to the temperature-raising chamber. In this embodiment, by placing multiple material boxes in a graphite boat, more battery cells can be processed at one time, thereby further improving production efficiency and processing capacity.

[0063] Specifically, when unloading, the boat (i.e., graphite boat) comes out of the unloading chamber, and the automated robot takes the boat loading box to the test loading, and the boat is automatically transferred back to the loading end under the cavity of the unloading chamber, ending a process flow.

[0064] In some other optional schemes of the present application, the ATM gas is introduced into the process chamber, including: introducing trimethylaluminum gas and water vapor into the process chamber, so that the trimethylaluminum gas and the water vapor react to obtain an aluminum oxide film. In this embodiment, by introducing trimethylaluminum gas and water vapor into the process chamber, the two gases react chemically inside the process chamber to generate an aluminum oxide film, which is a good passivation layer that can effectively protect the cut surface of the solar cell, reduce surface recombination, and improve the photoelectric conversion efficiency of the cell.

[0065] Specifically, the heating chamber has a first furnace door and a second furnace door relative to each other, the process chamber has a third furnace door and a fourth furnace door relative to each other, and the unloading chamber has a fifth furnace door and a sixth furnace door relative to each other. When transferring the material box to the heating chamber, the first furnace door needs to be opened; when transferring the material box from the heating chamber to the process chamber, the second furnace door and the third furnace door need to be opened; when transferring the material box from the heating chamber to the unloading chamber, the fourth furnace door and the fifth furnace door need to be opened; when unloading the material box, the sixth furnace door needs to be opened.

[0066] Specifically, the main purpose of this application is to improve the efficiency of half a cell and shorten the process time by combining the coating and hydrogen passivation processes by changing the process method of passivating half a cell, the coating efficiency is increased by 0.3%+, the hydrogen passivation efficiency is increased by 0.1%+, and the process time is shortened by 30%; at the same time, the material box style and air intake method are changed to improve the utilization rate of automatic cell loading and unloading and reduce the process gas consumption, reduce winding plating and improve the yield (winding plating yield increased by 0.02%). In this application, the hydrogen passivation chamber has a high utilization rate, short process time, and improved winding plating yield. The efficiency improvement comes from two aspects: cross-section passivation efficiency gain and hydrogen passivation efficiency gain.

[0067] Specifically, the half-cell passivation coating method for solar cells of the present application is used to passivate the cut cells (i.e., half-cell cells). Compared with before passivation, the parameter gain of the cells after passivation is shown in Table 1.

[0068] Table 1

[0069] parameter Eta Voc(V) Isc(A) FF Gain 0.39％ 0.0025 0.0064 0.694

[0070] Specifically, in Table 1, Eta is efficiency, Voc is open circuit voltage, Isc is short circuit current, and FF is fill factor. The gain in Table 1 refers to the difference between the value before and after passivation.

[0071] The embodiment of the present application further provides a solar cell, which is prepared by using any of the above-mentioned half-cell passivation coating methods for solar cells.

[0072] In the above embodiment, the solar cell is prepared by a half-cell passivation coating method for solar cell, wherein the material box comprises a cover plate, a bottom plate and a side plate, the materials of the cover plate and the bottom plate both comprise conductive materials, and the material of the side plate comprises insulating materials, firstly, the material box is transferred to the heating chamber so that the heating chamber heats the material box, and then the heated material box is transferred to the process chamber, and ATM gas is introduced into the process chamber to coat the cut surfaces of multiple cells, and in the process of coating the multiple cut surfaces, voltage is provided to the cover plate and the bottom plate to activate hydrogen ions in the multiple cells, and finally, when the multiple cells have completed coating, the material box is transferred to the unloading chamber to unload the material box. Compared with the problem of long passivation process time for half-cell and resulting in low passivation efficiency in the prior art, the present application provides voltage to the cover plate and the bottom plate during the coating process of the cell, which will form an electric field inside the cell. This electric field can accelerate the movement of hydrogen ions, making it easier for them to reach the surface of the cell (that is, the hydrogen ions in the cell are activated), thereby achieving the effect of hydrogen passivation. In other words, the present application combines the coating and hydrogen passivation processes, shortens the process time, and ensures a high passivation efficiency for the half-cell.

[0073] Specifically, Fig.10 As shown, the solar cell comprises a substrate 15, an emitter layer 16, a passivation layer 17 and an anti-reflection film 18 which are stacked in sequence, wherein the material of the passivation layer 17 comprises Al2O3.

[0074] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0075] In the half-cell passivation coating method for solar cells of the present application, the material box includes a cover plate, a bottom plate and side plates, the materials of the cover plate and the bottom plate both include conductive materials, and the material of the side plates includes insulating materials. First, the material box is transferred to the heating chamber so that the heating chamber heats the material box, and then the heated material box is transferred to the process chamber, and ATM gas is introduced into the process chamber to coat the cut surfaces of multiple cells. In the process of coating the multiple cut surfaces, voltage is provided to the cover plate and the bottom plate to activate hydrogen ions in the multiple cells. Finally, when the multiple cells have completed coating, the material box is transferred to the unloading chamber to unload the material box. Compared with the problem of long passivation process time for half-cell and resulting in low passivation efficiency in the prior art, the present application provides voltage to the cover plate and the bottom plate during the coating process of the cell, which will form an electric field inside the cell. This electric field can accelerate the movement of hydrogen ions, making it easier for them to reach the surface of the cell (that is, the hydrogen ions in the cell are activated), thereby achieving the effect of hydrogen passivation. In other words, the present application combines the coating and hydrogen passivation processes, shortens the process time, and ensures a high passivation efficiency for the half-cell.

[0076] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for passivation coating of half a solar cell, characterized in that: The material box includes a cover plate, a bottom plate and a side plate connecting the cover plate and the bottom plate, the materials of the cover plate and the bottom plate both include conductive materials, the material of the side plate includes insulating materials, a plurality of battery cells are arranged in the material box, the hydrogen passivation chamber includes a temperature rising chamber, a process chamber and a material discharge chamber which are connected in sequence, and the method includes: Transferring the material box to the temperature rising chamber so that the temperature rising chamber heats the material box; The heated material box is transferred to the process chamber, and ATM gas is introduced into the process chamber to coat the cut surfaces of the plurality of battery cells, and in the process of coating the cut surfaces, a voltage is provided to the cover plate and the bottom plate to activate hydrogen ions in the plurality of battery cells; When the coating of the plurality of battery cells is completed, the material box is transferred to the unloading chamber to unload the material from the material box.

2. The method for passivation coating of half a solar cell according to claim 1, characterized in that: Providing voltage to the cover plate and the bottom plate, comprising: The first power-on step: applying a forward bias voltage to the cover plate and the bottom plate; Stopping step: when the power-on time reaches a first predetermined time, stopping powering the cover plate and the bottom plate; A second power-on step: when the stop time reaches a second predetermined time, continuing to apply a forward bias voltage to the cover plate and the bottom plate; Cycle step: repeating the first power-on step, the stop step and the second power-on step in sequence for a predetermined number of times.

3. The method for passivation coating of half a solar cell according to claim 2, characterized in that: Applying a forward bias voltage to the cover plate and the bottom plate comprises: A first voltage is applied to the cover plate, and a second voltage is applied to the bottom plate, wherein a voltage difference between the first voltage and the second voltage is 10V to 12V.

4. The method for passivation coating of half a solar cell according to claim 1, characterized in that: The heating chamber comprises a heating chamber body, an infrared lamp located in the heating chamber body, and a first air inlet penetrating the heating chamber body, wherein the infrared lamp is located on one side of the first air inlet, and the material box is transferred to the heating chamber so that the heating chamber heats the material box, including: The material box is transferred to the heating chamber body so as to be heated by the air inlet lamp, and an inert gas is introduced into the heating chamber body through the first air inlet so as to be heated by the inert gas.

5. The method for passivation coating of half a solar cell according to claim 4, characterized in that: There are four side plates, the side plate closest to the cutting surface is the target side plate, the process chamber includes a second air inlet, The material box is transferred to the temperature rising chamber body, including: turning the cut surface to a direction intersecting with the air intake direction of the second air intake port, removing the target side plate, and transferring the material box after removing the target side plate to the temperature rising chamber body, The step of introducing the ATM gas into the process chamber comprises: introducing the ATM gas into the process chamber through the second gas inlet so that the ATM gas is blown toward the cutting surface.

6. The method for passivation coating of half a solar cell according to claim 1, characterized in that: The heated material box is transferred to the process chamber, comprising: When the temperature of the material box reaches 100° C., the material box is transferred from the temperature increasing chamber to the process chamber.

7. The method for passivation coating of half a solar cell according to claim 1, characterized in that: The materials of the cover plate and the bottom plate independently include aluminum, the material of the side plate includes graphene, and the material box is transferred to the material discharge cavity, including: The material box is transferred from the process chamber to the material unloading chamber, so that the material unloading chamber cools the material box and unloads the cooled material box.

8. The method for passivation coating of half a solar cell according to claim 1, characterized in that: There are multiple material boxes, and the material boxes are transferred to the temperature rising chamber, including: placing a plurality of the material boxes in a graphite boat; The graphite boat is transferred to the temperature raising chamber.

9. The method for passivation coating of half a solar cell according to claim 1, characterized in that: Introducing the ATM gas into the process chamber comprises: Trimethylaluminum gas and water vapor are introduced into the process chamber so that the trimethylaluminum gas and the water vapor react to obtain an aluminum oxide film.

10. A solar cell, characterized in that: The solar cell is prepared by the half-cell passivation coating method for a solar cell according to any one of claims 1 to 9.

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