Method and device for preparing solar cell electrode and heterojunction solar cell

Abstract

The invention provides a method and device for preparing a solar cell electrode and a heterojunction solar cell. The device comprises a micro-flow probe electrode and a micro-flow field device, the micro-flow field device is provided with a circular electroplating liquid pumping-in channel, the outer side of the circular electroplating liquid pumping-in channel is further provided with a circular electroplating liquid pumping-out channel which is coaxial with the circular electroplating liquid pumping-in channel, and the circular electroplating liquid pumping-out channel is arranged on the micro-flow field device; the bottom end of the circular electroplating liquid pumping-in channel is communicated with the bottom end of the circular electroplating liquid pumping-out channel; a micro-flow probe electrode coaxial with the circular electroplating liquid pumping channel is arranged in the circular electroplating liquid pumping channel; the top end of the micro-flow probe electrode is connected with the positive electrode of the power supply, and the bottom end of the micro-flow probe electrode penetrates through the bottom end of the circular electroplating liquid pumping channel. The solar cell electrode prepared by the device has a high aspect ratio, the steps of mask blocking, mask removing and the like are omitted, the production cost can be effectively reduced, the shading area can be reduced, and the photoelectric conversion efficiency of a solar cell can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method and device for preparing solar cell electrodes and a heterojunction solar cell. Background Art

[0002] The metallization of solar cells affects the cost and conversion efficiency of the cells, and ultimately it is related to the choice of cell path. Cell metallization is one of the important links in the production of solar cells. The methods of cell metallization include: preparing metallized electrodes on the front and back of solar cells through contact and non-contact technologies, so that a tight and efficient ohmic contact is formed between the electrodes and the cells to conduct the photogenerated carriers. Copper electroplating technology is a non-contact metallization technology. The biggest advantage of copper electroplating technology is that it replaces all metal silver paste with copper, fundamentally solving the problem of high material cost. At the same time, copper electroplating can achieve double-sided metallization at the same time, improving production efficiency. However, copper electroplating metallization technology still has many shortcomings.

[0003] At present, the existing copper electroplating process needs to be combined with a graphic process, using a mask as a barrier to constrain the morphology of the electroplated copper metal electrode to form a conductive metal electrode area and a non-conductive light-receiving area. The mask needs to be removed later, and the preparation process is relatively complicated and the material cost is high. In addition, in order to increase the aspect ratio of the metal grid line, the thickness of the mask needs to be increased accordingly, and the mask cost is even higher.

[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a method and device for preparing solar cell electrodes and a heterojunction solar cell. The solar cell electrodes are prepared by using a device for preparing solar cell electrodes, eliminating steps such as mask blocking and mask removal, greatly simplifying the preparation process, and being able to effectively reduce the mask material cost and the preparation cost; based on the local electrodeposition technology of the device for preparing solar cell electrodes, the prepared solar cell electrodes have a higher aspect ratio, that is, based on the local electrodeposition technology of the device for preparing solar cell electrodes, solar cell electrodes with a higher aspect ratio can be prepared without a thick mask, thereby further reducing the mask material cost and the preparation cost, and can also effectively reduce the shading area and improve the photoelectric conversion efficiency of the solar cell.

[0006] To achieve the above objectives, this application adopts the following technical solutions: A device for preparing solar cell electrodes, comprising a microfluidic probe electrode and a microfluidic field device; the microfluidic field device is provided with a circular electroplating liquid pumping channel, the outer side of the circular electroplating liquid pumping channel is also provided with a coaxial annular electroplating liquid pumping channel, and the annular electroplating liquid pumping channel is provided on the microfluidic field device; The bottom end of the circular electroplating liquid pumping channel is connected to the bottom end of the annular electroplating liquid pumping channel; The circular electroplating liquid pumping channel is provided with the microfluidic probe electrode coaxial therewith; the top end of the microfluidic probe electrode is connected to the positive pole of the power supply, and the bottom end of the microfluidic probe electrode penetrates the bottom end of the circular electroplating liquid pumping channel; the bottom end of the circular electroplating liquid pumping channel is located above the bottom end of the microfluidic probe electrode.

[0007] In some embodiments, the tip diameter of the microfluidic probe electrode is less than 5 μm.

[0008] In some embodiments, the diameter of the bottom end of the circular electroplating solution pumping channel is 10-15 μm; and / or The inner diameter of the bottom end of the annular electroplating liquid pumping channel is 20-25 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel is 50-55 μm.

[0009] The present application also provides a method for preparing a solar cell electrode, comprising: Using the above-mentioned device for preparing solar cell electrodes, a plating seed layer is prepared on a solar cell sheet; A copper-plated electrode layer is prepared on the plating seed layer by using the above-mentioned device for preparing solar cell electrodes.

[0010] In some embodiments, the thickness of the plating seed layer is 350-450 nm, and the width of the plating seed layer is 13-17 μm; and / or The copper-plated electrode layer has a thickness of 8 to 12 μm and a width of 13 to 17 μm.

[0011] In some embodiments, the method for preparing the plating seed layer / the copper plating electrode layer comprises: Immersing the solar cell sheet and the bottom end of the device for preparing the solar cell electrode in ultrapure water; placing the device for preparing the solar cell electrode above the solar cell sheet; The top of the microfluidic probe electrode is connected to the positive electrode of the power supply, the solar cell is connected to the negative electrode of the power supply, and the power supply is turned on; A nickel plating solution or a copper plating solution is pumped into the top of the circular electroplating solution pumping channel. The nickel plating solution or the copper plating solution flows in from the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and is then pumped out from the top of the annular electroplating solution pumping channel.

[0012] In some embodiments, the method for preparing the plating seed layer satisfies at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 18~22mA; (2) 1.8X10 -4 ~2.2X10 -4 The nickel plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 3.5×10 μL / s. The nickel plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 3.5×10 -4 ~4.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s; and / or The method for preparing the copper-plated electrode layer meets at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 28~32mA; (2) 3.5X10 -4 ~4.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 μL / s. The copper plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s.

[0013] In some of the embodiments, the method further comprises: preparing a plated electrode protection layer on the copper plated electrode layer.

[0014] In some embodiments, the method satisfies at least one of the following characteristics: (1) The distance between the bottom end of the microfluidic probe electrode and the battery cell is 45-55 μm; the distance between the bottom end of the microfluidic field device and the battery cell is 50-65 μm; (2) The distance between the bottom of the microfluidic probe electrode and the battery cell is denoted as H, and the distance between the bottom of the microfluidic device and the battery cell is denoted as H'; wherein H and H' satisfy: H'-H = 5-10 μm; (3) When preparing the plating seed layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm; (4) When preparing the copper-plated electrode layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm; (5) Arrangement of the microfluidic probe electrode array; (6) When preparing the plating seed layer, the moving speed of the microfluidic probe electrode is 5.5-6.5 mm / s; (7) When preparing the copper-plated electrode layer, the moving speed of the microfluidic probe electrode is 0.7-0.9 mm / s; (8) The plated electrode protective layer is a chemically plated tin layer, and the thickness of the plated electrode protective layer is 80-120 nm; (9) The tip diameter of the microfluidic probe electrode is 2-3.5 μm; (10) After preparing the plating seed layer and before preparing the copper plating electrode layer, the method further comprises: cleaning the device for preparing the solar cell electrode; the cleaning method comprises: -4 ~6.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 μL / s. The copper plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s.

[0015] The present application also provides a heterojunction solar cell, including a solar cell electrode; The solar cell electrode is prepared by the above method.

[0016] In the technical solution of the present application, a device for preparing solar cell electrodes is used to prepare solar cell electrodes, which omits steps such as mask blocking and mask removal, greatly simplifies the preparation process, and can effectively reduce the mask material cost and preparation cost; based on the local electrodeposition technology of the device for preparing solar cell electrodes, the prepared solar cell electrodes have a higher aspect ratio, that is, based on the local electrodeposition technology of the device for preparing solar cell electrodes, solar cell electrodes with a higher aspect ratio can be prepared without a thick mask, thereby further reducing the mask material cost and preparation cost, and can also effectively reduce the shading area and improve the photoelectric conversion efficiency of solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts 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. Figure 1 A cross-sectional view of a device for preparing a solar cell electrode for the present application; Figure 2 A top view of a device for preparing solar cell electrodes for this application; Figure 3 A schematic diagram of the array operation of the device for preparing solar cell electrodes for this application; Figure 4 A schematic diagram of the plating of a device for preparing solar cell electrodes in this application.

[0018] Numbers in the figure: 1, microfluidic probe electrode; 2, microfluidic field device; 21, circular electroplating solution pumping channel; 22, circular electroplating solution pumping channel. DETAILED DESCRIPTION

[0019] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0020] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can 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. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0021] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0022] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0023] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and 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 merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0024] The present application provides a method and device for preparing solar cell electrodes, and a heterojunction solar cell. The solar cell electrodes are prepared by using the device for preparing solar cell electrodes, eliminating steps such as mask blocking and mask removal, greatly simplifying the preparation process, and being able to effectively reduce the mask material cost and the preparation cost. Based on the local electrodeposition technology of the device for preparing solar cell electrodes, the prepared solar cell electrodes have a higher aspect ratio, that is, based on the local electrodeposition technology of the device for preparing solar cell electrodes, solar cell electrodes with a higher aspect ratio can be prepared without a thick mask, thereby further reducing the mask material cost and the preparation cost, and can also effectively reduce the shading area and improve the conversion efficiency of the solar cell.

[0025] The embodiment of the present application aims to provide a device for preparing a solar cell electrode, comprising a microfluidic probe electrode and a microfluidic field device; the microfluidic field device is provided with a circular electroplating liquid pumping channel, and a circular electroplating liquid pumping channel coaxial with the circular electroplating liquid pumping channel is also provided on the outer side of the circular electroplating liquid pumping channel, and the circular electroplating liquid pumping channel is provided on the microfluidic field device; The bottom end of the circular electroplating liquid pumping channel is connected to the bottom end of the annular electroplating liquid pumping channel; The circular electroplating liquid pumping channel is provided with the microfluidic probe electrode coaxial therewith; the top end of the microfluidic probe electrode is connected to the positive pole of the power supply, and the bottom end of the microfluidic probe electrode penetrates the bottom end of the circular electroplating liquid pumping channel; the bottom end of the circular electroplating liquid pumping channel is located above the bottom end of the microfluidic probe electrode.

[0026] In an embodiment of the present application, the diameter of the circular electroplating solution pumping channel can be 8-50μm, the inner diameter of the annular electroplating solution pumping channel can be 10~80μm, the outer diameter of the annular electroplating solution pumping channel can be 40~120μm, and the diameter of the microfluidic probe electrode can be 2-7μm. The microfluidic probe electrode can be a needle-shaped structure, a tubular structure or a rod-shaped structure; the structure of the microfluidic field device can be set according to actual needs, and it is only necessary to ensure that the microfluidic probe electrode, the circular electroplating solution pumping channel and the annular electroplating solution pumping channel can be set inside the microfluidic field device. The shape of the circular electroplating solution pumping channel and the annular electroplating solution pumping channel can be set according to actual needs. The size of the microfluidic probe electrode and the microfluidic field device can be set according to actual needs, and it is sufficient to prepare a solar cell electrode with a high aspect ratio. In addition, the microfluidic probe electrode is coaxial with the circular electroplating solution pumping channel and the annular electroplating solution pumping out channel, so a connector is provided between the microfluidic probe electrode and the microfluidic field device to fix the microfluidic probe electrode at a specific position of the microfluidic field device, and the arrangement of the connector is preferably such that it does not affect the pumping in and out of the electroplating solution on the microfluidic field device. It should also be noted that, although the bottom end of the circular electroplating solution pumping in channel is connected to the bottom end of the annular electroplating solution pumping out channel, the top end of the circular electroplating solution pumping in channel and the top end of the annular electroplating solution pumping out channel may be connected or may not be connected to each other, and it can be arranged according to actual needs.

[0027] In the embodiment of the present application, the working process of the device for preparing the solar cell electrode is as follows: immersing the solar cell sheet in ultrapure water; then immersing the bottom end of the device for preparing the solar cell electrode in ultrapure water, so that the device for preparing the solar cell electrode is located above the solar cell sheet; The top of the microfluidic probe electrode is connected to the positive pole of the power supply, and the solar cell is connected to the negative pole of the power supply, and the power is turned on; the plating solution is pumped into the top of the circular plating solution pumping channel, and the plating solution flows in from the top of the circular plating solution pumping channel, flows through the bottom of the circular plating solution pumping channel, and then pumped out from the top of the annular plating solution pumping channel to form a solar cell electrode with a high aspect ratio. By rationally arranging a sufficient number of devices for preparing solar cell electrodes, a patterned metal electrode area can be quickly prepared. It can save steps such as mask blocking and mask removal, greatly simplifying the preparation process.

[0028] In the embodiments of the present application, a solar cell electrode is prepared by using a device for preparing solar cell electrodes, which eliminates steps such as mask blocking and mask removal, greatly simplifies the preparation process, and can effectively reduce the mask material cost and the preparation cost; based on the local electrodeposition technology of the device for preparing solar cell electrodes, the prepared solar cell electrode has a higher aspect ratio, that is, based on the local electrodeposition technology of the device for preparing solar cell electrodes, solar cell electrodes with a higher aspect ratio can be prepared without a thick mask, thereby further reducing the mask material cost and the preparation cost, and can also effectively reduce the shading area, thereby improving the photoelectric conversion efficiency of the solar cell.

[0029] In an optional embodiment, the tip diameter of the microfluidic probe electrode is less than 5 μm (eg, 1 μm, 2 μm, 3 μm, 4 μm).

[0030] In the embodiment of the present application, the diameter of the microfluidic probe electrode is slightly larger than the needle tip diameter of the microfluidic probe electrode, and the diameter of the microfluidic probe electrode can be 2-7 μm. The shape and size of the microfluidic probe electrode are optimized so that the prepared solar cell electrode has a higher aspect ratio, and the electrode deposition quality can be improved, thereby improving the photoelectric conversion efficiency of the solar cell.

[0031] In an optional embodiment, the diameter of the bottom end of the circular electroplating liquid pumping channel is 10-15 μm (for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm); and / or The inner diameter of the bottom end of the annular electroplating liquid pumping channel is 20~25μm (for example, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm), and the outer diameter of the bottom end of the annular electroplating liquid pumping channel is 50~55μm (for example, 50μm, 51μm, 52μm, 53μm, 54μm, 55μm).

[0032] In the embodiments of the present application, the size of the microfluidic device is optimized so that the prepared solar cell electrode has a higher aspect ratio, while the electrode deposition quality can be improved, thereby improving the photoelectric conversion efficiency of the solar cell.

[0033] The present application also provides a method for preparing a solar cell electrode, comprising: Using the above-mentioned device for preparing solar cell electrodes, a plating seed layer is prepared on a solar cell sheet; A copper-plated electrode layer is prepared on the plating seed layer by using the above-mentioned device for preparing solar cell electrodes.

[0034] In the embodiment of the present application, the preparation of a patterned electroplating mask is eliminated, which greatly simplifies the preparation process, thereby further reducing the mask material cost and the preparation cost; by using local electrodeposition technology, electroplated electrodes with a high aspect ratio can be prepared without a thick mask, thereby effectively reducing the shading area and improving the battery's photoelectric conversion efficiency.

[0035] In an optional embodiment, the thickness of the plating seed layer is 350-450 nm (e.g., 350 nm, 370 nm, 390 nm, 410 nm, 430 nm, 450 nm), and the width of the plating seed layer is 13-17 μm (e.g., 13 μm, 14 μm, 15 μm, 16 μm, 17 μm); and / or The copper plated electrode layer has a thickness of 8 to 12 μm (eg, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm), and a width of 13 to 17 μm (eg, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm).

[0036] In the embodiment of the present application, the thickness of the plating seed layer and the thickness of the copper plating electrode layer are optimized, which can improve the contact effect and adhesion between the solar cell electrode and the functional layer, thereby improving the photoelectric conversion efficiency of the cell.

[0037] In an optional embodiment, the method for preparing the plating seed layer / the copper plating electrode layer includes: Immersing the solar cell sheet and the bottom end of the device for preparing the solar cell electrode in ultrapure water; placing the device for preparing the solar cell electrode above the solar cell sheet; The top of the microfluidic probe electrode is connected to the positive electrode of the power supply, the solar cell is connected to the negative electrode of the power supply, and the power supply is turned on; A nickel plating solution or a copper plating solution is pumped into the top of the circular electroplating solution pumping channel. The nickel plating solution or the copper plating solution flows in from the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and is then pumped out from the top of the annular electroplating solution pumping channel.

[0038] In the embodiment of the present application, the preparation of a patterned electroplating mask is eliminated, which greatly simplifies the preparation process, thereby further reducing the mask material cost and the preparation cost; by using local electrodeposition technology, electroplated electrodes with a high aspect ratio can be prepared without a thick mask, thereby effectively reducing the shading area and improving the battery's photoelectric conversion efficiency.

[0039] In an optional embodiment, the method for preparing the plating seed layer satisfies at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 18-22 mA (e.g., 18 mA, 19 mA, 20 mA, 21 mA, 22 mA); (2) 1.8X10 -4 ~2.2X10 -4 μL / s (e.g., 1.8X10 -4 μL / s、1.9X10 -4 μL / s, 2.0X10 -4 μL / s, 2.1X10 -4 μL / s、2.2X10 -4 The nickel plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 3.5×10 -4 ~4.5X10 -4 μL / s (e.g., 3.5X10 -4 μL / s、3.7X10 -4 μL / s、3.9X10 -4 μL / s、4.1X10 -4 μL / s、4.3X10 -4 μL / s、4.5X10 -4 μL / s) from the top of the annular electroplating solution pumping channel; and / or The method for preparing the copper-plated electrode layer meets at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 28-32 mA (e.g., 28 mA, 29 mA, 30 mA, 31 mA, 32 mA); (2) 3.5X10 -4 ~4.5X10 -4 μL / s (e.g., 3.5X10 -4 μL / s、3.7X10 -4 μL / s、3.9X10 -4 μL / s、4.1X10 -4 μL / s、4.3X10 -4 μL / s、4.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 μL / s (e.g., 7.5X10 -4 μL / s、7.7X10 -4 μL / s、7.9X10 -4 μL / s、8.1X10 -4 μL / s、8.3X10-4 μL / s、8.5X10 -4 μL / s) is pumped out from the top of the annular electroplating solution pumping channel.

[0040] In the embodiments of the present application, the process parameters of the local electrodeposition of the solar cell electrode are optimized so that the prepared solar cell electrode has a higher aspect ratio, thereby effectively reducing the shading area, which is beneficial to the deposition of the electrode, improving the electrode deposition quality, and improving the photoelectric conversion efficiency of the cell.

[0041] In an optional embodiment, the method further comprises: preparing a plated electrode protective layer on the copper plated electrode layer. Providing the plated electrode protective layer can improve the corrosion resistance and mechanical stability of the electrode.

[0042] In an optional embodiment, the method satisfies at least one of the following characteristics: (1) The spacing between the bottom end of the microfluidic probe electrode and the battery cell is 45-55 μm (for example, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, 51 μm, 52 μm, 53 μm, 54 μm, 55 μm); the spacing between the bottom end of the microfluidic field device and the battery cell is 50-65 μm (for example, 50 μm, 51 μm, 52 μm, 53 μm, 54 μm, 55 μm, 56 μm, 57 μm, 58 μm, 59 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm); (2) The distance between the bottom end of the microfluidic probe electrode and the battery cell is denoted as H, and the distance between the bottom end of the microfluidic field device and the battery cell is denoted as H'; wherein H and H' satisfy: H'-H=5~10μm (for example, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm); (3) When preparing the plating seed layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm (for example, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm); (4) When preparing the copper-plated electrode layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm (for example, 0.8 cm, 0.9 cm, 1.0 cm, 1.1 cm, 1.2 cm); (5) Arrangement of the microfluidic probe electrode array; (6) When preparing the plating seed layer, the moving speed of the microfluidic probe electrode is 5.5-6.5 mm / s (for example, 5.5 mm / s, 5.7 mm / s, 5.9 mm / s, 6.1 mm / s, 6.3 mm / s, 6.5 mm / s); (7) When preparing the copper-plated electrode layer, the moving speed of the microfluidic probe electrode is 0.7-0.9 mm / s (for example, 0.7 mm / s, 0.75 mm / s, 0.8 mm / s, 0.85 mm / s, 0.9 mm / s); (8) The plated electrode protective layer is a chemically plated tin layer, and the thickness of the plated electrode protective layer is 80 to 120 nm (for example, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm); (9) The tip diameter of the microfluidic probe electrode is 2 to 3.5 μm (e.g., 2 μm, 2.5 μm, 3 μm, 3.5 μm); (10) After preparing the plating seed layer and before preparing the copper plating electrode layer, the method further comprises: cleaning the device for preparing the solar cell electrode; the cleaning method comprises: -4 ~6.5X10 -4 μL / s (e.g., 5.5X10 -4 μL / s、5.7X10 -4 μL / s、5.9X10 -4 μL / s、6.1X10 -4 μL / s、6.3X10 -4 μL / s、6.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 μL / s (e.g., 7.5X10 -4 μL / s、7.7X10 -4 μL / s、7.9X10 -4 μL / s、8.1X10 -4 μL / s、8.3X10 -4 μL / s、8.5X10 -4 μL / s) is pumped out from the top of the annular electroplating solution pumping channel.

[0043] In the embodiments of the present application, the process parameters of the local electrodeposition of the solar cell electrode are further optimized so that the prepared solar cell electrode has a higher aspect ratio, which is beneficial to the deposition of the electrode and improves the quality of electrode deposition, thereby effectively reducing the shading area and improving the photoelectric conversion efficiency of the cell.

[0044] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0045] Example 1 A device for preparing solar cell electrodes, such as Figure 1 , Figure 2 As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 10 μm, the inner diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 20 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 50 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, the microfluidic probe electrode 1 is needle-shaped, and the needle tip diameter of the microfluidic probe electrode 1 is 3.5 μm.

[0046] A method for preparing a heterojunction solar cell comprises the following steps: ① Heterojunction (HJT) cell (size 210mmX105mm) after passivation but before electrode preparation.

[0047] ② Prepare the plating seed layer by using the above-mentioned device for preparing solar cell electrodes like Figure 3 As shown, a microfluidic probe electrode array device is used to prepare a plating seed layer, and the current of each microfluidic probe electrode 1 is controlled to be 18 mA. The electroplating solution used for the plating seed layer is Watts nickel plating solution, and the pump flow rate is 1.8X10 -4 μL / s, the pump flow rate is 3.5X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom 2 of the microfluidic field device and the battery cell is 50μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 5.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0048] ③ Prepare the plated electrode layer by using the above-mentioned device for preparing solar cell electrodes The microchannel was cleaned by pumping in and out the copper plating solution at a flow rate of 5.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 28 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 0.7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water. Specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared copper-plated electrode layer has a thickness of 8μm and a width of 13μm. The plating process of step ② and step ③ is as follows Figure 4 shown.

[0049] ④Preparation of plated electrode protective layer The cleaned battery cell is plated with an 80nm chemical tin layer on the surface of the copper electrode using a general chain chemical plating equipment as a protective layer for the plated electrode.

[0050] Example 2 The heterojunction solar cell of Example 2 is prepared by referring to the preparation method of Example 1, except that the device in Example 2 is: a device for preparing a solar cell electrode, such as Figure 1 , Figure 2As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top end of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom end of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 10 μm, the inner diameter of the bottom end of the circular electroplating liquid pumping channel 22 is 20 μm, and the outer diameter of the bottom end of the circular electroplating liquid pumping channel 22 is 50 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, and the microfluidic probe electrode 1 is cylindrical.

[0051] Example 3 The heterojunction solar cell of Example 3 is prepared by referring to the preparation method of Example 1, except that the device in Example 3 is: a device for preparing a solar cell electrode, such as Figure 1 , Figure 2 As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 15 μm, the inner diameter of the bottom end of the circular electroplating liquid pumping channel 22 is 25 μm, and the outer diameter of the bottom end of the circular electroplating liquid pumping channel 22 is 55 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, the microfluidic probe electrode 1 is needle-shaped, and the needle tip diameter of the microfluidic probe electrode 1 is 3.5 μm.

[0052] Example 4 The heterojunction solar cell of Example 4 is prepared by referring to the preparation method of Example 1, except that the device in Example 4 is: a device for preparing a solar cell electrode, such as Figure 1 , Figure 2As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 9 μm, the inner diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 18 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 48 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, the microfluidic probe electrode 1 is needle-shaped, and the needle tip diameter of the microfluidic probe electrode 1 is 3.5 μm.

[0053] Example 5 The heterojunction solar cell of Example 5 is prepared by referring to the preparation method of Example 1, except that the device in Example 5 is: a device for preparing a solar cell electrode, such as Figure 1 , Figure 2 As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 20 μm, the inner diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 30 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 60 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, the microfluidic probe electrode 1 is needle-shaped, and the needle tip diameter of the microfluidic probe electrode 1 is 3.5 μm.

[0054] Example 6 A device for preparing solar cell electrodes, such as Figure 1 , Figure 2As shown, it includes a microfluidic probe electrode 1 and a microfluidic field device 2; the microfluidic field device 2 is provided with a circular electroplating liquid pumping channel 21, and the outer side of the circular electroplating liquid pumping channel 21 is also provided with a coaxial annular electroplating liquid pumping channel 22, and the annular electroplating liquid pumping channel 22 is provided on the microfluidic field device 2; The bottom end of the circular electroplating liquid pumping channel 21 is connected to the bottom end of the annular electroplating liquid pumping channel 22; The circular electroplating liquid pumping channel 21 is provided with the microfluidic probe electrode 1 coaxial therewith; the top of the microfluidic probe electrode 1 is connected to the positive pole of the power supply, and the bottom of the microfluidic probe electrode 1 penetrates the circular electroplating liquid pumping channel 21; wherein, the diameter of the bottom end of the circular electroplating liquid pumping channel 21 is 10 μm, the inner diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 20 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel 22 is 50 μm; the diameter of the microfluidic probe electrode 1 is 7 μm, the microfluidic probe electrode 1 is needle-shaped, and the needle tip diameter of the microfluidic probe electrode 1 is 3.5 μm.

[0055] A method for preparing a heterojunction solar cell comprises the following steps: ① Heterojunction (HJT) cell (size 210mmX105mm) after passivation but before electrode preparation.

[0056] ② Prepare the plating seed layer by using the above-mentioned device for preparing solar cell electrodes like Figure 3 As shown, a microfluidic probe electrode array device is used to prepare a plating seed layer. The current of each microfluidic probe electrode 1 is controlled to be 22 mA. The electroplating solution used for the plating seed layer is Watts nickel plating solution, and the pump flow rate is 2.2X10 -4 μL / s, the pump flow rate is 4.5X10 -4 μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 55μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 65μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=10μm. The moving speed of the microfluidic probe array is 6.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 1.2cm. The prepared nickel plating seed layer has a thickness of 450nm and a width of 17μm.

[0057] ③ Prepare the plated electrode layer by using the above-mentioned device for preparing solar cell electrodes The copper plating solution was used to clean the microchannel by pumping in and out, with a pumping flow rate of 6.5X10 -4μL / s, the pumping rate is 8.5X10 -4 μL / s. After washing for 10 s, a 32 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 4.5X10 -4 μL / s, the pumping rate is 8.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 55μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 65μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=10μm. The moving speed of the microfluidic probe array is 0.9mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water. Specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 1.2cm. The copper-plated electrode layer is prepared with a thickness of 12μm and a width of 17μm.

[0058] ④Preparation of plated electrode protective layer The cleaned battery cell is plated with a 120nm chemical tin layer on the surface of the copper electrode using a general chain chemical plating equipment as a protective layer for the plated electrode.

[0059] Example 7 The heterojunction solar cell of Example 7 was prepared by referring to the preparation method of Example 1, except that, in Example 7: the prepared nickel-plated seed layer had a thickness of 320 nm and a width of 12 μm; the prepared copper-plated electrode layer had a thickness of 7 μm and a width of 12 μm.

[0060] Example 8 The heterojunction solar cell of Example 8 was prepared by referring to the preparation method of Example 1, except that, in Example 8: the prepared nickel-plated seed layer had a thickness of 470 nm and a width of 18 μm; the prepared copper-plated electrode layer had a thickness of 13 μm and a width of 18 μm.

[0061] Example 9 The heterojunction solar cell of Example 9 was prepared by referring to the preparation method of Example 1, except that step ② in Example 9 is: a plating seed layer is prepared by using a microfluidic probe electrode array device, the current of each microfluidic probe electrode 1 is controlled to be 16 mA, the plating solution used for plating the seed layer is a Watts nickel plating solution, and the pumping flow rate is 1.6×10 -4 μL / s, the pump flow rate is 3.0X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 5.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0062] Step ③ in Example 9 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 20 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.0X10 -4 μL / s, the pumping rate is 6.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 0.7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The thickness of the prepared copper-plated electrode layer is 8μm and the width is 13μm.

[0063] Example 10 The heterojunction solar cell of Example 10 was prepared by referring to the preparation method of Example 1, except that step ② in Example 10 was as follows: a plating seed layer was prepared using a microfluidic probe electrode array device, the current of each microfluidic probe electrode 1 was controlled to be 25 mA, the plating solution used for the plating seed layer was a Watts nickel plating solution, and the pumping flow rate was 2.5×10 -4 μL / s, the pump flow rate is 5.0X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 5.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0064] Step ③ in Example 10 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5×10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 35 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 5X10 -4 μL / s, the pumping rate is 9X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 0.7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The thickness of the prepared copper-plated electrode layer is 8μm and the width is 13μm.

[0065] Embodiment 11 The heterojunction solar cell of Example 11 was prepared by referring to the preparation method of Example 1, except that step ② in Example 11 was as follows: a plating seed layer was prepared by using a microfluidic probe electrode array device, the current of each microfluidic probe electrode 1 was controlled to be 18 mA, the plating solution used for plating the seed layer was a Watts nickel plating solution, and the pumping flow rate was 1.8×10 -4 μL / s, the pump flow rate is 3.5X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 40μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 43μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=3μm. The moving speed of the microfluidic probe array is 5.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0066] Step ③ in Example 11 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5×10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 28 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 40μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 43μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=3μm. The moving speed of the microfluidic probe array is 0.7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The copper-plated electrode layer is prepared with a thickness of 8μm and a width of 13μm.

[0067] Example 12 The heterojunction solar cell of Example 12 was prepared by referring to the preparation method of Example 1, except that step ② in Example 12 was: a plating seed layer was prepared by using a microfluidic probe electrode array device, the current of each probe electrode 1 was controlled to be 18 mA, the plating solution used for plating the seed layer was a Watts nickel plating solution, and the pumping flow rate was 1.8×10 -4 μL / s, the pump flow rate is 3.5X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 57μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 69μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=12μm. The moving speed of the microfluidic probe array is 5.5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0068] Step ③ in Example 12 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5×10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 28 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 57μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 69μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=12μm. The moving speed of the microfluidic probe array is 0.7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The thickness of the prepared copper-plated electrode layer is 8μm and the width is 13μm.

[0069] Example 13 The heterojunction solar cell of Example 13 was prepared by referring to the preparation method of Example 1, except that step ② in Example 13 was as follows: a plating seed layer was prepared by using a microfluidic probe electrode array device, the current of each microfluidic probe electrode 1 was controlled to be 18 mA, the plating solution used for the plating seed layer was a Watts nickel plating solution, and the pumping flow rate was 1.8×10 -4 μL / s, the pump flow rate is 3.5X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 5mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0070] Step ③ in Example 13 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5×10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 28 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 0.6mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The thickness of the prepared copper-plated electrode layer is 8μm and the width is 13μm.

[0071] Embodiment 14 The heterojunction solar cell of Example 14 was prepared by referring to the preparation method of Example 1, except that step ② in Example 14 was as follows: a plating seed layer was prepared using a microfluidic probe electrode array device, the current of each microfluidic probe electrode 1 was controlled to be 18 mA, the plating solution used for the plating seed layer was a Watts nickel plating solution, and the pumping flow rate was 1.8×10 -4 μL / s, the pump flow rate is 3.5X10 -4μL / s, the distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 7mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water, specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The prepared nickel plating seed layer has a thickness of 350nm and a width of 13μm.

[0072] Step ③ in Example 14 is: use copper plating solution to clean the microchannel by pumping in and out, and the pumping flow rate is 5.5×10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. After washing for 10 s, a 28 mA current was applied to each microfluidic probe electrode 1. At this time, the pump flow rate was adjusted to 3.5X10 -4 μL / s, the pumping rate is 7.5X10 -4 μL / s. The distance between the microfluidic probe electrode 1 and the battery cell is 45μm, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is 50μm; the distance between the bottom end of the microfluidic probe electrode 1 and the battery cell is recorded as H, and the distance between the bottom end of the microfluidic field device 2 and the battery cell is recorded as H'; wherein, H and H' satisfy: H'-H=5μm. The moving speed of the microfluidic probe array is 1mm / s; during electroplating, the surface of the battery cell is immersed under the surface of ultrapure water. Specifically, the distance between the top surface of the battery cell and the surface of ultrapure water is 0.8cm. The thickness of the prepared copper-plated electrode layer is 8μm and the width is 13μm.

[0073] Comparative Example 1 A method for preparing a heterojunction solar cell comprises the following steps: ① Heterojunction (HJT) cell (size 210mmX105mm) after passivation but before electrode preparation.

[0074] ② Use the existing copper electroplating process, use the mask as a barrier, and combine it with a graphic process to prepare solar cell electrodes.

[0075] The heterojunction solar cells prepared in the above examples and comparative examples were tested, and the test results are shown in Table 1 below: Table 1 Heterojunction solar cell performance data

[0076] Referring to the data of the above-mentioned Examples 1-2, it can be seen that optimizing the shape and size of the microfluidic probe electrode 1 enables the prepared solar cell electrode to have a higher aspect ratio, which is beneficial to the deposition of the electrode, improves the electrode deposition quality, and thus improves the photoelectric conversion efficiency of the solar cell.

[0077] Referring to the data of the above-mentioned Examples 1 and 3-5, it can be seen that optimizing the size of the microfluidic device 2 allows the prepared solar cell electrode to have a higher aspect ratio, which is beneficial to the deposition of the electrode, improves the electrode deposition quality, and thus improves the photoelectric conversion efficiency of the solar cell.

[0078] According to the data of the above-mentioned Example 1 and Examples 6-8, optimizing the thickness of the plating seed layer and the thickness of the copper plating electrode layer can improve the contact effect and adhesion between the solar cell electrode and the functional layer, thereby improving the cell photoelectric conversion efficiency.

[0079] Referring to the data of the above-mentioned Example 1 and Examples 9-10, it can be seen that optimizing the flow rate of the copper plating solution and the nickel plating solution is beneficial to the deposition of the electrode and can improve the electrode deposition quality, thereby effectively reducing the shading area and improving the photoelectric conversion efficiency of the battery.

[0080] Referring to the data of the above-mentioned Examples 1 and 11-12, it can be seen that optimizing the relevant parameters of the device for preparing solar cell electrodes and its parameters such as the use distance is beneficial to the deposition of the electrode and can improve the quality of electrode deposition, thereby effectively reducing the shading area and improving the photoelectric conversion efficiency of the cell.

[0081] Referring to the data of the above-mentioned embodiment 1 and embodiments 13-14, it can be known that optimizing the moving speed of the microfluidic probe electrode 1 is beneficial to the deposition of the electrode and can improve the electrode deposition quality, thereby effectively reducing the shading area and improving the photoelectric conversion efficiency of the battery.

[0082] To summarize, the present application adopts a device for preparing solar cell electrodes to prepare solar cell electrodes, eliminating steps such as mask blocking and mask removal, greatly simplifying the preparation process, and being able to effectively reduce the mask material cost and the preparation cost; based on the local electrodeposition technology of the device for preparing solar cell electrodes, the prepared solar cell electrodes have a higher aspect ratio, that is, based on the local electrodeposition technology of the device for preparing solar cell electrodes, solar cell electrodes with a higher aspect ratio can be prepared without a thick mask, thereby further reducing the mask material cost and the preparation cost, and can also effectively reduce the shading area and improve the photoelectric conversion efficiency of solar cells.

[0083] The present application may also provide a heterojunction solar cell, including a solar cell electrode; the solar cell electrode is prepared by the above method.

[0084] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0085] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0086] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A device for preparing a solar cell electrode, characterized in that: It comprises a microfluidic probe electrode and a microfluidic field device; the microfluidic field device is provided with a circular electroplating liquid pumping channel, the outer side of the circular electroplating liquid pumping channel is also provided with a coaxial annular electroplating liquid pumping channel, and the annular electroplating liquid pumping channel is provided on the microfluidic field device; The bottom end of the circular electroplating liquid pumping channel is connected to the bottom end of the annular electroplating liquid pumping channel; The circular electroplating liquid pumping channel is provided with the microfluidic probe electrode coaxial therewith; the top end of the microfluidic probe electrode is connected to the positive pole of the power supply, and the bottom end of the microfluidic probe electrode penetrates the bottom end of the circular electroplating liquid pumping channel; the bottom end of the circular electroplating liquid pumping channel is located above the bottom end of the microfluidic probe electrode.

2. The device for preparing a solar cell electrode according to claim 1, characterized in that: The tip diameter of the microfluidic probe electrode is less than 5 μm.

3. The device for preparing a solar cell electrode according to any one of claims 1 to 2, characterized in that: The diameter of the bottom end of the circular electroplating liquid pumping channel is 10-15 μm; and / or The inner diameter of the bottom end of the annular electroplating liquid pumping channel is 20-25 μm, and the outer diameter of the bottom end of the annular electroplating liquid pumping channel is 50-55 μm.

4. A method for preparing a solar cell electrode, characterized in that: include: Preparing a plating seed layer on a solar cell by using the device for preparing a solar cell electrode according to any one of claims 1 to 3; A copper-plated electrode layer is prepared on the plating seed layer by using the device for preparing a solar cell electrode according to any one of claims 1 to 3.

5. The method according to claim 4, characterized in that The thickness of the plating seed layer is 350-450 nm, and the width of the plating seed layer is 13-17 μm; and / or The copper-plated electrode layer has a thickness of 8 to 12 μm and a width of 13 to 17 μm.

6. The method according to claim 4, characterized in that The preparation method of the plating seed layer / the copper plating electrode layer comprises: Immersing the solar cell sheet and the bottom end of the device for preparing the solar cell electrode in ultrapure water; placing the device for preparing the solar cell electrode above the solar cell sheet; The top of the microfluidic probe electrode is connected to the positive electrode of the power supply, the solar cell is connected to the negative electrode of the power supply, and the power supply is turned on; A nickel plating solution or a copper plating solution is pumped into the top of the circular electroplating solution pumping channel. The nickel plating solution or the copper plating solution flows in from the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and is then pumped out from the top of the annular electroplating solution pumping channel.

7. The method according to claim 6, characterized in that The method for preparing the plating seed layer satisfies at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 18~22mA; (2) 1.8X10 -4 ~2.2X10 -4 The nickel plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 3.5×10 μL / s. The nickel plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 3.5×10 -4 ~4.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s; and / or The method for preparing the copper-plated electrode layer meets at least one of the following characteristics: (1) The current of the microfluidic probe electrode is 28~32mA; (2) 3.5X10 -4 ~4.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 μL / s. The copper plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s.

8. The method according to claim 4, characterized in that Also includes: A plated electrode protection layer is prepared on the copper plated electrode layer.

9. The method according to any one of claims 4 to 8, characterized in that: The method satisfies at least one of the following characteristics: (1) The distance between the bottom end of the microfluidic probe electrode and the battery cell is 45-55 μm; the distance between the bottom end of the microfluidic field device and the battery cell is 50-65 μm; (2) The distance between the bottom of the microfluidic probe electrode and the battery cell is denoted as H, and the distance between the bottom of the microfluidic device and the battery cell is denoted as H'; wherein H and H' satisfy: H'-H = 5-10 μm; (3) When preparing the plating seed layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm; (4) When preparing the copper-plated electrode layer, the solar cell is immersed in ultrapure water, and the distance between the top surface of the solar cell and the surface of the ultrapure water is 0.8-1.2 cm; (5) Arrangement of the microfluidic probe electrode array; (6) When preparing the plating seed layer, the moving speed of the microfluidic probe electrode is 5.5-6.5 mm / s; (7) When preparing the copper-plated electrode layer, the moving speed of the microfluidic probe electrode is 0.7-0.9 mm / s; (8) The plated electrode protective layer is a chemically plated tin layer, and the thickness of the plated electrode protective layer is 80-120 nm; (9) The tip diameter of the microfluidic probe electrode is 2-3.5 μm; (10) After preparing the plating seed layer and before preparing the copper plating electrode layer, the method further comprises: cleaning the device for preparing the solar cell electrode; the cleaning method comprises: -4 ~6.5X10 -4 The copper plating solution is pumped into the top of the circular electroplating solution pumping channel at a flow rate of 7.5×10 μL / s. The copper plating solution flows into the top of the circular electroplating solution pumping channel, flows through the bottom of the circular electroplating solution pumping channel, and then flows into the bottom of the circular electroplating solution pumping channel at a flow rate of 7.5×10 -4 ~8.5X10 -4 The electroplating liquid is pumped out from the top of the annular electroplating liquid pumping channel at a flow rate of μL / s.

10. A heterojunction solar cell, characterized in that: including solar cell electrodes; The solar cell electrode is prepared by the method according to any one of claims 4 to 8.

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