Etching method and system of solar cell

Abstract

The embodiment of the invention provides a solar cell etching method and system, and relates to the technical field of solar cells. The etching method of the solar cell comprises the following steps: dissociating positive ions and negative ions in dissociated gas by using laser to obtain dissociated ions; and etching the base material through the etching effect of the dissociated ions. Positive ions and negative ions in dissociated gas are dissociated by adopting laser, the substrate is etched by utilizing the etching effect of the dissociated ions, the etching depth is accurate and controllable, accurate patterning etching can be carried out, lateral etching and permeation etching can be greatly reduced, the etching process is free of metal ion pollution, the cleanliness is high, and the etching efficiency is high. The photoelectric conversion efficiency of the solar cell can be effectively improved, and a photoetching process and a laser wet etching process for the cell can be replaced.

Description

Technical Field

[0001] This application belongs to the technical field of solar cells, and particularly relates to an etching method and system for solar cells. Background Art

[0002] A solar cell is a semiconductor device that directly converts solar energy into electrical energy. Its working principle is based on the photoelectric effect of semiconductor materials, especially the photovoltaic effect of the PN junction. When light irradiates a solar cell, the energy of photons excites electrons to jump from the valence band to the conduction band, forming electron-hole pairs. These carriers are separated under the action of the built-in electric field, thereby generating voltage and current at both ends of the cell. Currently, the main methods for etching the thin film or crystal of a solar cell are laser etching, wet etching, and combined laser-wet etching.

[0003] The defects of laser etching are as follows: the action depth of the laser is difficult to control, which may damage or destroy the crystal structure or other structures, ultimately resulting in a large number of carrier recombination centers and reducing the photoelectric conversion efficiency of the solar cell. Wet etching has problems such as side etching, permeation etching of the thin film, and continuous etching pollution. Permeation etching (the etching solution not only vertically etches the material from above but also etches the material from the side, resulting in a "hollowing out" phenomenon of the etched pattern laterally) and side etching (side etching refers to the etching of the sidewalls of the material during the etching process, resulting in the widening of the etched pattern in the horizontal direction) will seriously affect the masking effect, and the pollution of metal ions will seriously affect the semiconductor structure performance, thereby reducing the photoelectric conversion efficiency of the solar cell. Combined laser-wet etching first uses a laser to modify the thin film and then performs wet etching. The modification of the thin film in the laser area leads to different wet etching rates in each area, realizing patterned etching. This method is beneficial for realizing patterned etching but has both the defects of laser etching and wet etching.

[0004] It should be noted that the above content is not necessarily prior art and does not limit the patent protection scope of this application. Summary of the Invention

[0005] Embodiments of this application provide an etching method and system for a solar cell with precisely controllable etching depth, capable of performing precise patterned etching, greatly reducing side etching and permeation etching, having no metal ion pollution during the etching process, high cleanliness, and effectively improving the photoelectric conversion efficiency of the solar cell, so as to solve or alleviate the above-mentioned technical problems.

[0006] To achieve the above object, this application adopts the following technical solutions: An etching method for a solar cell, comprising: dissociating positive ions and negative ions in the dissociated gas by using a laser to obtain dissociated ions; Etch the substrate by the etching action of the dissociated ions.

[0007] In some embodiments, the laser includes an ultrashort pulse width laser, and the wavelength range of the ultrashort pulse width laser is 355nm - 1064nm; The ultrashort pulse width laser includes one or more of picosecond laser and femtosecond laser.

[0008] In some embodiments, the dissociated gas includes one or more of sulfur hexafluoride, nitrogen trifluoride, trifluoromethane, and tetrafluoromethane.

[0009] In some embodiments, during the dissociation process of the dissociated gas: the dissociated gas is placed in a closed chamber, and the laser irradiates the closed chamber to dissociate positive ions and negative ions in the dissociated gas, obtaining dissociated ions.

[0010] In some embodiments, during the process of etching the substrate: an external electric field is applied to the dissociated ions, and the external electric field prompts the dissociated ions to impact the substrate along a predetermined direction and etch the substrate.

[0011] The embodiment of the present application also provides an etching system for a solar cell, including: A closed chamber for placing the dissociated gas and the substrate; A laser for emitting a laser, and the laser dissociates positive ions and negative ions in the dissociated gas in the closed chamber to obtain dissociated ions; the dissociated ions impact the substrate along a predetermined direction and etch the substrate.

[0012] In some embodiments, it further includes a scanning galvanometer; the scanning galvanometer is used to irradiate the laser emitted by the laser to a predetermined position.

[0013] In some embodiments, it further includes an electric field generator, and the electric field generator is used to apply an external electric field to the dissociated ions.

[0014] In some embodiments, it further includes a focusing mirror, and the focusing mirror is used to focus the laser emitted by the laser.

[0015] In some embodiments, it further includes a reflecting mirror; the reflecting mirror is used to reflect the laser emitted by the laser to a predetermined position.

[0016] The embodiment of the present application adopting the above technical solutions may include the following advantages: The positive ions and negative ions in the gas to be dissociated are dissociated by using a laser. By utilizing the etching effect of the dissociated ions, the substrate is etched. The etching depth is precisely controllable, precise patterning etching can be performed, and side etching and penetration etching can be greatly reduced. There is no metal ion pollution during the etching process, and the cleanliness is high. It can effectively improve the photoelectric conversion efficiency of solar cells and can replace the photolithography process and laser wet etching process used in batteries. Description of the Drawings

[0017] In the drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0018] Figure 1 is a schematic structural diagram of an etching system for a solar cell provided by an embodiment of the present application; Figure 2 is a schematic structural diagram of a perovskite solar cell module provided by an embodiment of the present application.

[0019] Description of the Reference Numerals: 1. Laser; 2. Reflecting mirror; 3. Scanning galvanometer; 4. Sealed chamber; 5. Focusing mirror; 6. Electric field generator; 7. Substrate; 11. Conductive substrate; 12. Hole transport layer; 13. Perovskite light absorption layer; 14. Electron transport layer; 15. Metal electrode. Detailed Embodiments

[0020] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Wherever the same or similar reference numerals are used throughout, the same or similar elements or elements having the same or similar functions are denoted. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application and should not be construed as limiting the present application. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0021] It should be understood that when an element or layer is referred to as "on", "adjacent to", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent to, connected, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as "directly on", "directly adjacent to", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or part from another element, component, region, layer, or part. Thus, without departing from the teachings of the present disclosure, the first element, component, region, layer, or part discussed below may be referred to as the second element, component, region, layer, or part. And when discussing the second element, component, region, layer, or part, it does not imply that there must be a first element, component, region, layer, or part in the present disclosure.

[0022] In this application, unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled", "fixed", etc. shall be construed broadly. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and do not necessarily describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products, or devices.

[0024] In this application, when it comes to numerical intervals (i.e., numerical ranges), unless otherwise specified, the distribution of the selectable numerical values within the numerical interval is considered continuous, and includes the two numerical endpoints of the numerical interval (i.e., the minimum value and the maximum value), as well as each numerical value between these two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers within the numerical interval, it includes the two endpoint integers of the numerical range, as well as each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all sub-ranges subsumed therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. The "numerical interval" is allowed to broadly include quantitative intervals such as percentage intervals, ratio intervals, ratio value intervals, etc.

[0025] This application aims to provide an etching method and system for solar cells, which dissociates positive ions and negative ions in a dissociable gas by using a laser, and uses the etching effect of the dissociated ions to etch a substrate. The etching depth is precisely controllable, precise patterning etching can be performed, and side etching and penetration etching can be greatly reduced. The etching process has no metal ion pollution and high cleanliness, can effectively improve the photoelectric conversion efficiency of solar cells, and can replace the photolithography process and laser wet etching process used in batteries.

[0026] Next, the exemplary embodiments of this application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments described herein.

[0027] The embodiment of this application provides an etching method for a solar cell, including: Using a laser to dissociate positive ions and negative ions in a dissociable gas to obtain dissociated ions; Etching the substrate through the etching effect of the dissociated ions.

[0028] In the embodiment of this application, laser radiation decomposes the molecules of the dissociable gas into fragments, and positive ions and negative ions are dissociated. Due to the momentum transfer of the laser, the dissociated positive ions and negative ions obtain kinetic energy. Therefore, the dissociated positive ions and negative ions can impact the substrate along a predetermined direction, thereby etching the substrate. It should be noted that the dissociable gas and the substrate can be replaced according to actual needs, as long as it is ensured that the dissociated ions can react and etch the target substrate.

[0029] In the embodiments of the present application, positive ions and negative ions in the gas to be dissociated are dissociated by laser, and the etching effect of the dissociated ions can be used to etch the thin film or crystal (silicon wafer) of the solar cell. The thin film of the solar cell that can be etched may include one or more of a passivation film, an aluminum oxide thin film, a transparent conductive film, a light-absorbing film layer, etc.; the types of solar cells that can be etched may include one or more of monocrystalline silicon solar cells, polycrystalline silicon solar cells, amorphous silicon solar cells, perovskite solar cells, and other solar cells.

[0030] In the embodiments of the present application, positive ions and negative ions in the gas to be dissociated are dissociated by laser, and then the positive ions and negative ions can be used simultaneously to perform reactive etching on the target substrate, or in the case of setting a specific electric field, the positive ions or negative ions can be used alone to perform reactive etching on the target substrate.

[0031] In the embodiments of the present application, the momentum of the laser is first transferred to the positive ions and negative ions, and then the positive ions and negative ions etch the substrate. Since a certain amount of momentum loss will occur during the momentum transfer process, this well solves the problem that the etching depth of the laser etching effect is too deep and it is easy to cause damage or destruction to other structures. Therefore, the etching depth of the method of the present application is more precisely controllable. In addition, under the method of the present application, only the laser action area can achieve the etching effect of positive ions and negative ions, and gas ionization does not occur in the non-laser action area, so etching cannot be achieved. Therefore, precise patterning etching can be performed, and side etching and penetration etching can be greatly reduced. There is no metal ion pollution during the etching process, the cleanliness is high, the photoelectric conversion efficiency of the solar cell can be effectively improved, and it can replace the photolithography process and the laser wet etching process used in the battery.

[0032] It should be noted that the momentum loss is equivalent to the effect of reducing speed. For example, when cutting an object at 10 mm / s and then cutting an object at 8 mm / s after deceleration, the speed decreases and the etching accuracy will increase. Specifically, when cutting at a low speed, the control system of the cutting equipment has more time to adjust and correct the cutting path, thereby reducing the deviation of the etching depth. After the speed decreases, the heat generated during the etching process relatively decreases, and the thermal deformation of the material also decreases accordingly. Generally speaking, the etching accuracy is higher.

[0033] In an alternative embodiment, the laser includes an ultra-short pulse width laser, and the wavelength range of the ultra-short pulse width laser is 355 nm to 1064 nm; The ultra-short pulse width laser includes one or more of picosecond laser and femtosecond laser.

[0034] In the embodiments of the present application, a suitable laser type and wavelength can be selected according to the absorption energy level of the gas to be dissociated. Taking SF6 (sulfur hexafluoride) gas as an example, it is easier to ionize SF6 (sulfur hexafluoride) gas using a 355 nm ultraviolet laser, and ionization is more likely to occur when using femtosecond laser compared to picosecond laser.

[0035] In an alternative embodiment, the gas to be dissociated includes one or more of sulfur hexafluoride, nitrogen trifluoride, trifluoromethane, and tetrafluoromethane.

[0036] In the embodiments of the present application, the selected gases to be dissociated can all dissociate into negatively charged fluoride ions. The negatively charged fluoride ions have a good etching effect on the substrate, the etching depth is more precisely controllable, precise patterning etching can be carried out, and side etching and penetration etching can be greatly reduced. There is no metal ion pollution during the etching process, the cleanliness is high, and the photoelectric conversion efficiency of the solar cell can be effectively improved.

[0037] In an alternative embodiment, during the dissociation process of the gas to be dissociated: the gas to be dissociated is placed in a closed chamber, and the laser irradiates the closed chamber to dissociate the positive and negative ions in the gas to be dissociated, obtaining dissociated ions.

[0038] In the embodiments of the present application, the laser irradiates in a closed gas atmosphere cavity. Taking SF6 (sulfur hexafluoride) gas as an example, under the huge energy release of the picosecond level of the ultrafast laser, SF6 molecules are instantaneously ionized to form positively charged sulfur ions and negatively charged fluoride ions. The etching effect on the substrate is better, the etching depth is more precisely controllable, precise patterning etching can be carried out, and side etching and penetration etching can be greatly reduced. There is no metal ion pollution during the etching process, the cleanliness is high, and the photoelectric conversion efficiency of the solar cell can be effectively improved.

[0039] In an alternative embodiment, during the process of etching the substrate: an external electric field is applied to the dissociated ions, and the dissociated ions are urged by the external electric field to impact the substrate along a predetermined direction and etch the substrate.

[0040] In the embodiments of the present application, taking SF6 (sulfur hexafluoride) gas as an example, after SF6 molecules are ionized to form positively charged sulfur ions and negatively charged fluoride ions, under the continuous action of the external electric field, the formed positive and negative ions are separated and accelerated respectively. The negatively charged fluoride ions will accelerate along the opposite direction of the electric field and finally linearly impact the surface of the substrate. Since the negatively charged fluoride ions can strongly etch the substrate, the etching process can be carried out continuously or interrupted at any time (by turning off the laser), thereby realizing etching with a precise depth. The etching effect of the negatively charged fluoride ions on the substrate can be strengthened, the etching depth is more precisely controllable, and precise patterning etching can be carried out. Side etching and penetration etching are greatly reduced. There is no metal ion pollution during the etching process, the cleanliness is high, and the photoelectric conversion efficiency of the solar cell can be effectively improved.

[0041] The embodiment of the present application also provides an etching system for a solar cell, including: A sealed chamber 4 for placing the dissociated gas and the substrate 7; A laser 1 for emitting laser light, which dissociates positive ions and negative ions in the dissociated gas in the sealed chamber 4 to obtain dissociated ions; the dissociated ions impact the substrate 7 along a predetermined direction and etch the substrate 7.

[0042] In the embodiment of the present application, the laser radiation is in the sealed chamber 4. Taking SF6 (sulfur hexafluoride) gas as an example, under the huge energy release of picosecond level of the ultrafast laser, SF6 molecules are instantaneously ionized to form positively charged sulfur ions and negatively charged fluorine ions. The etching effect of the substrate 7 is better, the etching depth is more precisely controllable, precise patterning etching can be carried out, and side etching and penetration etching can be greatly reduced. There is no metal ion pollution during the etching process, the cleanliness is high, and the photoelectric conversion efficiency of the solar cell can be effectively improved.

[0043] In an optional embodiment, it further includes a scanning galvanometer 3; the scanning galvanometer 3 is used to irradiate the laser emitted by the laser 1 to a predetermined position.

[0044] In the embodiment of the present application, it further includes a scanning galvanometer 3. The action position of the laser can be changed through the scanning galvanometer 3 to achieve selective laser radiation at different spatial positions, and then precise patterning etching can be carried out. The scanning galvanometer 3 can be arranged in the sealed chamber 4 or outside the sealed chamber 4, and the installation position of the scanning galvanometer 3 can be set according to actual needs.

[0045] In an optional embodiment, it further includes an electric field generator 6, and the electric field generator 6 is used to apply an external electric field to the dissociated ions. In the embodiment of the present application, the dissociated ions are urged to impact the substrate 7 along a predetermined direction through the external electric field, and then the substrate 7 is etched. The electric field generator 6 can be arranged in the sealed chamber 4 or outside the sealed chamber 4, and the installation position of the electric field generator 6 can be set according to actual needs. In order to better apply an external electric field to the dissociated ions, the electric field generator 6 can usually be arranged in the sealed chamber 4.

[0046] In the embodiment of the present application, taking SF6 (sulfur hexafluoride) gas as an example, after SF6 molecules are ionized to form positively charged sulfur ions and negatively charged fluoride ions, under the continuous action of an external electric field, the formed positive and negative ions are separated and accelerated respectively. The negatively charged fluoride ions will accelerate along the opposite direction of the electric field and finally linearly impact the surface of the substrate 7. Since the negatively charged fluoride ions can strongly etch the substrate 7, the etching process can be continuously carried out or interrupted at any time (just turn off the laser), thereby realizing etching with precise depth, strengthening the etching effect of the negatively charged fluoride ions on the substrate 7, making the etching depth more precisely controllable, and being able to perform precise patterned etching, greatly reducing side etching and penetration etching. The etching process has no metal ion pollution, high cleanliness, and can effectively improve the photoelectric conversion efficiency of solar cells.

[0047] In an alternative embodiment, it further includes a focusing mirror 5, and the focusing mirror 5 is used to focus the laser emitted by the laser 1.

[0048] In the embodiment of the present application, the focusing mirror 5 can be placed inside the sealed chamber 4 and between the substrate 7 and the laser 1. The focusing mirror 5 can also be placed outside the sealed chamber 4 and between the substrate 7 and the laser 1. Just set the installation position of the focusing mirror 5 according to actual needs.

[0049] In the embodiment of the present application, the focusing mirror 5 can focus the laser beam at the position of the dissociated gas. On the one hand, it can enhance the dissociation effect of the dissociated gas and strengthen the etching effect of the dissociated ions. On the other hand, it can refine the laser action area, thereby assisting in more precise patterned etching.

[0050] In an alternative embodiment, it further includes a reflecting mirror 2; the reflecting mirror 2 is used to reflect the laser emitted by the laser 1 to a predetermined position. In the embodiment of the present application, setting the reflecting mirror 2 can play a role in changing the laser transmission path and can be applicable to more usage scenarios. And there can be multiple groups of reflecting mirrors 2 to facilitate the laser to transmit along the required path, and thus be applicable to more usage scenarios. The reflecting mirror 2 is generally set outside the sealed chamber 4. Of course, the reflecting mirror 2 can also be set inside the sealed chamber 4 according to actual needs as long as it can change the laser transmission path as required.

[0051] The following specific embodiments further illustrate the present application in detail, but should not be construed as a limitation to the present application. Without departing from the spirit and essence of the present application, any modification or replacement of the methods, steps or conditions of the present application belongs to the scope of the present application.

[0052] Embodiment 1 An etching system for a solar cell, as Figure 1 shown, includes: A sealed chamber 4 for placing the dissociated gas and the substrate 7; Laser 1, which is used to emit laser light, is located outside the sealed chamber 4; Mirror 2 and scanning galvanometer 3, where mirror 2 is used to reflect the laser light emitted by laser 1 to scanning galvanometer 3; among them, mirror 2 is located between scanning galvanometer 3 and laser 1, and scanning galvanometer 3 is located outside the sealed chamber 4; Focusing lens 5, which is located inside the sealed chamber 4; the laser light emitted by laser 1 is reflected by mirror 2 to scanning galvanometer 3, and scanning galvanometer 3 then emits the laser light. Focusing lens 5 is used to focus the laser light emitted by scanning galvanometer 3 and emit the laser light to a specified position inside the sealed chamber 4, dissociating positive ions and negative ions in the dissociated gas inside the sealed chamber 4 to obtain dissociated ions; (it should be noted that in the case where mirror 2 and scanning galvanometer 3 are not provided, focusing lens 5 can be directly used to focus the laser light emitted by laser 1); Electric field generator 6, which is located inside the sealed chamber 4; the electric field generator 6 is used to apply an external electric field to the dissociated ions, and the external electric field is used to prompt the dissociated ions to impact the substrate 7 along a predetermined direction, thereby etching the substrate 7.

[0053] Reference Figure 2 , the specific preparation process of the perovskite solar cell module is as follows: Step S1: Provide a cleaned conductive substrate 11, etch the conductive substrate 11 to form P1 trenches, and obtain an etched substrate; the P1 trenches penetrate the conductive material layer of the conductive substrate 11; Step S2: Deposit a compound of nickel and oxygen (NiO x ) on the etched substrate as the hole transport layer 12, with a thickness of 40 nm; Step S3: Dissolve the perovskite material in an organic solvent to prepare a perovskite solution; among them, the structure of the perovskite material is Cs 0.05 MA 0.15 FA 0.8 Pb(I 0.75 Br 0.25 )3, and the specific formula of each component is: CsI (19.5 mg); MABr (25.1 mg); FAI (206.4 mg); PbI2 (484.1 mg); PbBr2 (165.1 mg); the concentration of the perovskite solution is 1.5 M (that is, there are 1.5 moles of perovskite material per liter of solution); Step S4: Spin-coat the perovskite solution on the hole transport layer 12, and then anneal it at 120 °C for 20 min to form a perovskite light absorption layer 13 with a thickness of 600 nm; Step S5: Use a thermal evaporation coater to evaporate a layer of fullerene (C60 1) As the electron transport layer 14, etching is performed to form P2 trenches; the P2 trenches sequentially penetrate the hole transport layer 12, the perovskite light absorption layer 13, and the electron transport layer 14; Step S6: Using the thermal evaporation method, deposit a layer of metallic silver as an electrode on the electron transport layer 14 to form a metal electrode 15, perform etching to form P3 trenches, and the P3 trenches penetrate the metal electrode 15 to prepare a perovskite solar cell module; Among them, the P1 trenches, P2 trenches, and P3 trenches are all etched using the above-mentioned etching system for solar cells. The specific etching method is: place the target cell in the sealed chamber 4, fill the sealed chamber 4 with a dissociated gas, use a laser to dissociate positive and negative ions in the dissociated gas to obtain dissociated ions; through the etching action of the dissociated ions, etch the substrate to form P1 trenches, P2 trenches, and P3 trenches respectively.

[0054] Examples 2 - 7 Refer to the preparation method of Example 1 to prepare the perovskite solar cell modules of Examples 2 - 7. The difference is only that the etching processes of the P1 trenches, P2 trenches, and P3 trenches in Examples 2 - 7 are different, and the etching process parameters of the P1 trenches, P2 trenches, and P3 trenches in Examples 2 - 7 are shown in Table 1.

[0055] Comparative Example 1 Refer to the preparation method of Example 1 to prepare the perovskite solar cell module of Comparative Example 1. The difference is only that the etching process of the P1 trenches, P2 trenches, and P3 trenches in Comparative Example 1 is laser etching, and the type of laser is ultraviolet 355nm picosecond laser.

[0056] Comparative Example 2 Refer to the preparation method of Example 1 to prepare the perovskite solar cell module of Comparative Example 2. The difference is only that the etching process of the P1 trenches, P2 trenches, and P3 trenches in Comparative Example 2 is laser etching, and the type of laser is ultraviolet 355nm picosecond laser.

[0057] Comparative Example 3 Refer to the preparation method of Example 1 to prepare the perovskite solar cell module of Comparative Example 3. The difference is only that the etching process of the P1 trenches, P2 trenches, and P3 trenches in Comparative Example 3 is plasma etching.

[0058] Table 1 Etching process parameters of P1 trenches, P2 trenches, and P3 trenches in Examples 2 - 7 Table 1

[0059] Next, performance tests were conducted on the perovskite solar cell modules provided in Examples 1-7 and Comparative Examples 1-3 of the present application, and the test results are shown in Table 2.

[0060] Table 2 Performance test results of perovskite solar cell modules in Examples 1-7 and Comparative Examples 1-3

[0061] Referring to the battery performance test results of Examples 1-7 and Comparative Examples 1-3, it can be seen that positive and negative ions in the dissociated gas are dissociated by laser, and the substrate is etched by the etching action of the dissociated ions. The etching depth is precisely controllable, precise patterning etching can be carried out, and side etching and penetration etching can be greatly reduced. The etching process is free of metal ion pollution, has a high cleanliness, and can effectively improve the photoelectric conversion efficiency of the solar cell.

[0062] Referring to the battery performance test results of Example 1 and Examples 3-4, it can be seen that an external electric field is applied to the dissociated ions. Under the continuous action of the external electric field, the formed positive and negative ions can accelerate along a predetermined direction and finally linearly impact the surface of the substrate. The etching process can be carried out continuously or interrupted at any time, so as to achieve etching with a precise depth. The etching effect of negatively charged fluoride ions on the substrate can be strengthened, the etching depth is more precisely controllable, and precise patterning etching can be carried out. Side etching and penetration etching are greatly reduced. The etching process is free of metal ion pollution, has a high cleanliness, and can effectively improve the photoelectric conversion efficiency of the solar cell.

[0063] It should be noted that the terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. The orientation terms "inner" and "outer" refer to the inside and outside relative to the contour of each component itself. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "on other devices or structures" will be positioned "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the relative spatial descriptions used here.

[0064] It should be noted that the terms "first", "second", etc. in the description, claims and the above-mentioned drawings of this application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of this application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0065] It should also be noted that the "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in connection with that embodiment being included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the description does not necessarily refer to the same embodiment. Furthermore, when describing a specific feature, structure or characteristic in connection with any one embodiment, it is intended that the implementation of such feature, structure or characteristic in combination with other embodiments also falls within the scope of this application.

[0066] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0067] It should also be noted that the above are only the preferred embodiments of this application, and do not limit the patent protection scope of this application. Any equivalent structural or equivalent process transformation made using the content of the description and drawings of this application, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of this application.

Claims

1. An etching method for a solar cell, characterized in that, Comprising: Using a laser to dissociate positive and negative ions in the gas to be dissociated, obtaining dissociated ions; Etching the substrate through the etching action of the dissociated ions.

2. The etching method of a solar cell according to claim 1, wherein The laser includes an ultrashort pulse width laser, and the wavelength range of the ultrashort pulse width laser is 355 nm to 1064 nm; The ultrashort pulse width laser includes one or more of picosecond laser and femtosecond laser.

3. The etching method of a solar cell according to claim 1, characterized in that, The gas to be dissociated includes one or more of sulfur hexafluoride, nitrogen trifluoride, trifluoromethane, and tetrafluoromethane.

4. The etching method of the solar cell according to claim 1, wherein During the dissociation process of the gas to be dissociated: the gas to be dissociated is placed in a closed chamber, and the laser irradiates the closed chamber to dissociate positive and negative ions in the gas to be dissociated, obtaining dissociated ions.

5. The etching method of the solar cell according to claim 1, characterized in that, During the process of etching the substrate: an external electric field is applied to the dissociated ions, and the external electric field prompts the dissociated ions to impact the substrate along a predetermined direction and etch the substrate.

6. An etching system for a solar cell, characterized in that, Comprising: A closed chamber for placing the gas to be dissociated and the substrate; A laser for emitting a laser, the laser dissociating positive and negative ions in the gas to be dissociated in the closed chamber, obtaining dissociated ions; the dissociated ions impact the substrate along a predetermined direction and etch the substrate.

7. The etching system for a solar cell according to claim 6, wherein Further comprising a scanning galvanometer; the scanning galvanometer is used to irradiate the laser emitted by the laser to a predetermined position.

8. The etching system for a solar cell according to any one of claims 6-7, characterized in that, Further comprising an electric field generator, and the electric field generator is used to apply an external electric field to the dissociated ions.

9. The etching system for a solar cell according to claim 8, wherein Further comprising a focusing mirror, and the focusing mirror is used to focus the laser emitted by the laser.

10. The etching system for a solar cell according to claim 9, characterized in that, Further comprising a reflecting mirror; the reflecting mirror is used to reflect the laser emitted by the laser to a predetermined position.

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