Crystalline silicon solar cell, preparation method and application thereof, and laminated cell

Abstract

The invention relates to a crystalline silicon solar cell, a preparation method and application thereof, and a laminated cell. According to the crystalline silicon solar cell, a passivation layer is arranged on the crystalline silicon solar cell, the passivation layer contains a passivation material, and the passivation material is at least one of 3-aminopropyl trimethoxy silane, (3-aminopropyl) triethoxy silane, (3-mercaptopropyl) trimethoxy silane and methyl triethoxy silane. According to the crystalline silicon solar cell, 3-aminopropyltrimethoxysilane and the like are used as passivation materials to passivate the surface of polycrystalline silicon, and particularly, secondary passivation is carried out on a cutting surface formed after the crystalline silicon solar cell is cut, so that the conversion efficiency of the crystalline silicon solar cell can be effectively improved; and the fill factor FF and the open-circuit voltage Voc of the crystalline silicon solar cell are also improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a crystalline silicon solar cell and a preparation method and application thereof, and a laminated cell. Background Art

[0002] With the continuous development of crystalline silicon solar cell technology, the thickness of silicon wafers has been continuously reduced, and the surface passivation of cells has become particularly important for improving the conversion efficiency of solar cells. Surface passivation technology is one of the most effective means to improve the conversion efficiency of crystalline silicon cells, but silicon wafer cutting destroys this passivation layer. In the use of crystalline silicon, due to size matching and series connection problems, it is sometimes necessary to laser cut the entire piece of crystalline silicon. New unpassivated edges will appear during the cutting process, causing edge recombination, which will lead to reduced efficiency of solar cells. Small-sized cells have a larger perimeter-to-area ratio, and edge recombination is more obvious, which will also cause open circuit voltage V oc Therefore, it is necessary to perform secondary passivation on the edge of the cut crystalline silicon.

[0003] At present, the most commonly used surface passivation methods for crystalline silicon cells are plasma enhanced chemical vapor deposition, hydrogenated amorphous silicon, thermal oxidation, atomic layer deposition, and stacked passivation. Plasma enhanced chemical vapor deposition (PECVD) technology is used to prepare silicon nitride films and has been widely used in industrial production, but it is not very effective for highly doped P + The surface passivation effect is not as good as other technologies, which limits its application scope; the hydrogenated amorphous silicon method (a-Si:H) adopts plasma enhanced chemical vapor deposition (PECVD) technology, which has low preparation temperature and excellent passivation effect, but a-Si:H has poor thermal stability. The high temperature in the subsequent process of solar cells will cause fatal damage to the hydrogenated amorphous silicon film, making its passivation effect ineffective; thermal oxidation SiO2 technology has excellent passivation effect, but the high temperature of 1100℃ required for its passivation process reduces the body lifetime of carriers in the silicon wafer, making its effect on improving the conversion efficiency of solar cells limited. At the same time, it requires high equipment requirements, which increases its production cost; atomic layer deposition aluminum oxide technology (ALD), aluminum oxide film has high dielectric constant, good thermal stability, low preparation temperature, and P + Silicon and N + Silicon has excellent passivation effect, but the preparation process is not mature enough and needs further research; the stacking passivation method deposits thin films of different materials in sequence on the surface of crystalline silicon solar cells, which can effectively passivate the battery in body and surface, reduce the surface recombination rate, significantly increase the open circuit voltage and short circuit current of the battery, and improve the battery conversion efficiency, but the stacking passivation process is more complicated and more expensive, and its passivation effect is closely related to the film parameters.

[0004] Therefore, it is necessary to study a method with simple process, significant effect and low cost to perform secondary passivation on the edge of the cut crystalline silicon. Summary of the invention

[0005] Based on this, it is necessary to provide a crystalline silicon solar cell and its preparation method and application, and a laminated cell to address the problems of poor effect, complex process, and high cost of the existing secondary passivation method for the cut surface of crystalline silicon cells.

[0006] A crystalline silicon solar cell is provided with a passivation layer, the passivation layer contains a passivation material, and the passivation material is at least one of 3-aminopropyltrimethoxysilane, (3-aminopropyl)triethoxysilane, (3-mercaptopropyl)trimethoxysilane and methyltriethoxysilane.

[0007] In one of the embodiments, the crystalline silicon solar cell comprises a first electrode, a back surface field layer, a polysilicon layer, a front surface field layer, the passivation layer, and a second electrode stacked in sequence; the passivation layer is also arranged on the side surface of the crystalline silicon solar cell.

[0008] In one of the embodiments, the back surface field layer is a boron-doped emitter electrode layer, and the front surface field layer is a phosphorus-doped polysilicon layer.

[0009] In one of the embodiments, the crystalline silicon solar cell has at least one cutting surface, and the passivation layer is disposed on the cutting surface of the crystalline silicon solar cell.

[0010] The above-mentioned crystalline silicon solar cell uses 3-aminopropyltrimethoxysilane as a passivation material to passivate the surface of polycrystalline silicon, especially performing secondary passivation on the cut surface formed after the crystalline silicon solar cell is cut, which can effectively improve the conversion efficiency of the crystalline silicon solar cell, the fill factor FF and the open circuit voltage of the crystalline silicon solar cell V oc They have also been improved.

[0011] In one embodiment, the thickness of the passivation layer is 1 nm to 1 μm.

[0012] The present invention also provides a method for preparing the crystalline silicon solar cell, comprising the following steps: coating: coating the passivation material on the surface of polycrystalline silicon and / or the surface of the front surface field layer and / or the surface of the back surface field layer; heating to obtain.

[0013] In one of the embodiments, the method for preparing the crystalline silicon solar cell comprises the following steps: cutting: cutting the crystalline silicon cell piece a into a plurality of crystalline silicon cell pieces b; coating: coating the passivation material on the cut surface of the crystalline silicon cell piece b; and heating.

[0014] In one embodiment, the crystalline silicon cell a is a topcon crystalline silicon cell or a HJT crystalline silicon cell.

[0015] In one of the embodiments, the crystalline silicon cell a is a topcon crystalline silicon cell.

[0016] In one embodiment, the heating temperature is 50-120°C.

[0017] In one embodiment, the heating temperature is 60-100°C.

[0018] In one embodiment, the heating time is 3 to 20 minutes.

[0019] In one embodiment, the heating time is 5 to 15 minutes.

[0020] In one of the embodiments, the method for preparing a crystalline silicon solar cell further includes a pretreatment step after the cutting step and before the coating step; the specific method of the pretreatment is: after polishing the cut surface to be smooth, washing it with ethanol having a concentration of 99.5~99.9%.

[0021] In one of the embodiments, after the heating step, a lamination step is further included; the lamination conditions are: vacuum degree 10~90kPa, temperature 100~150°C.

[0022] In one embodiment, the lamination time is 300-450s.

[0023] In one embodiment, the lamination pressure is 10~90kPa.

[0024] The method for preparing the crystalline silicon solar cell of the present invention uses 3-aminopropyltrimethoxysilane or the like as a passivation material to perform secondary passivation on the cut edges of the crystalline silicon solar cell, and then laminates the crystalline silicon solar cell, thereby further improving the conversion efficiency of the crystalline silicon solar cell.

[0025] The present invention also provides a stacked cell, comprising the crystalline silicon solar cell as described above.

[0026] In one of the embodiments, the tandem cell is a crystalline silicon-perovskite tandem cell, including at least one perovskite sub-cell and at least one crystalline silicon sub-cell; the crystalline silicon sub-cell includes the crystalline silicon solar cell as described above.

[0027] The present invention also provides an application of the crystalline silicon solar cell in preparing a power generation device and / or an energy storage device and / or an electrical device.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The crystalline silicon solar cell and its preparation method and application, and the laminated cell of the present invention use 3-aminopropyltrimethoxysilane as a passivation material to passivate the surface of polycrystalline silicon, especially perform secondary passivation on the cut surface formed after the crystalline silicon solar cell is cut, which can effectively improve the conversion efficiency of the crystalline silicon solar cell, the fill factor FF and the open circuit voltage of the crystalline silicon solar cell V oc At the same time, the edges of the crystalline silicon solar cells after cutting are passivated again using 3-aminopropyltrimethoxysilane as a passivation material, and the crystalline silicon solar cells are laminated, which further improves the conversion efficiency of the crystalline silicon solar cells. The preparation method of the present invention uses a passivation material that adapts to mild manufacturing conditions and can form a film without vacuum and long-term high-temperature heating, effectively preventing the crystalline silicon substrate from having defects due to long high-temperature time, and preventing the compound from strengthening, thereby reducing the minority carrier life and affecting the battery performance. The preparation method greatly shortens the process flow, is simple to operate and low in cost, and is suitable for application in large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of a crystalline silicon solar cell having a passivation layer disposed on the side surface and / or the cut surface in the present invention;

[0031] Figure 2 It is a schematic diagram of a crystalline silicon solar cell provided with a passivation layer in the present invention. DETAILED DESCRIPTION

[0032] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] The reagents used in the following examples, unless otherwise specified, are all commercially available; the methods used in the following examples, unless otherwise specified, are all achievable by conventional methods.

[0035] Example 1

[0036] Preparation of crystalline silicon cells.

[0037] The preparation method comprises the following steps:

[0038] (1) Cutting: Cut the large crystalline silicon cell (crystalline silicon cell a, JA Topcon 199cm×182cm) into small cells of the required area (crystalline silicon cell b, area 14cm 2 ), use sandpaper to grind the cut surface until it is smooth.

[0039] (2) Pretreatment: Rinse the cut surface with 99.8% ethanol to obtain the crystalline silicon cell to be passivated.

[0040] (3) Passivation: Coating: Use a clean medical cotton swab to dip into 3-aminopropyltrimethoxysilane (liquid, CAS No. 13822-56-5, purchased from McLean), and apply it to the cut surface of the above-mentioned crystalline silicon cell to be passivated (note that 3-aminopropyltrimethoxysilane cannot be applied to the surface of the cell); Heating: Place on a heating table at 100°C and heat for 5 minutes; Cool for 5 minutes to obtain the passivated crystalline silicon cell.

[0041] (4) Welding: Weld the galvanized copper strip electrodes onto the above passivated crystalline silicon cell.

[0042] (5) Lamination: Cut out the edge of the crystalline silicon and the bottom glass of 2 cm, and then cut out 2 sheets of POE film and 2 sheets of PET plastic film of the same size as the bottom glass; stack and fix in the order of bottom glass, POE film, passivated crystalline silicon cell, POE film, PET plastic film (frosted side down), PET (smooth side down, to be torn off after lamination); put into the laminator and laminate.

[0043] The lamination conditions are as follows: temperature of 110°C; vacuum degree of 60kPa (the pressure applied on the surface of the crystalline silicon cell is 40kPa), maintained for 50s; vacuum degree of 30kPa (the pressure applied on the surface of the crystalline silicon cell is 70kPa), maintained for 50s; vacuum degree of 10kPa (the pressure applied on the surface of the crystalline silicon cell is 90kPa), lamination for 350s.

[0044] Example 2

[0045] Preparation of crystalline silicon cells.

[0046] The preparation method is basically the same as that of Example 1, except that in step (3) passivation, 3-aminopropyltrimethoxysilane is applied to the cut surface and then placed on a heating table at 60° C. and heated for 10 min.

[0047] Example 3

[0048] Preparation of crystalline silicon cells.

[0049] The preparation method is basically the same as that of Example 1, except that in step (3) passivation, 3-aminopropyltrimethoxysilane is applied to the cut surface and then placed on a heating table at 60° C. and heated for 15 minutes.

[0050] Experimental Example 1

[0051] A solar simulator (Newport Oriel ORIEL-SOI3A) was used to test the cells at different stages in Examples 1 to 3, namely the crystalline silicon cells to be passivated (before passivation), the crystalline silicon cells after passivation, and the crystalline silicon cells after lamination. The test results are shown in Tables 1 to 3. The efficiency of the silicon cells after passivation is improved compared to that before passivation, and it will be improved again after lamination. Because the test results show that the crystalline silicon cell prepared in Example 1 has better performance, the crystalline silicon cell prepared according to the method of Example 1 is used in subsequent tests.

[0052]

[0053]

[0054]

[0055] Experimental Example 2

[0056] (1) According to the method of Example 1, four crystalline silicon cells to be passivated (before passivation) were first obtained, and two of them were connected in series to obtain a first group of two crystalline silicon cells in series and a second group of two crystalline silicon cells in series, which were tested using a solar simulator (Newport Oriel ORIEL-SOI3A).

[0057] (2) The four crystalline silicon cells to be passivated are passivated according to the method of Example 1, and a solar simulator (Newport Oriel ORIEL-SOI3A) is used to detect the performance of the first and second groups of two crystalline silicon cells in series after passivation.

[0058] (3) The above two groups of crystalline silicon cells are connected in series to obtain four crystalline silicon cells connected in series, and are tested using a solar simulator (Newport Oriel ORIEL-SOI3A).

[0059] (4) The four series-connected crystalline silicon cells were laminated according to the method of Example 1 and tested using a solar simulator (Newport Oriel ORIEL-SOI3A).

[0060] The test results are shown in Tables 4 to 6. The efficiency of the silicon wafers after passivation is improved compared to before passivation, and the efficiency is improved again after lamination.

[0061]

[0062]

[0063]

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A crystalline silicon solar cell, characterized in that: A passivation layer is arranged on the crystalline silicon solar cell, and the passivation layer contains a passivation material, and the passivation material is at least one of 3-aminopropyltrimethoxysilane, (3-aminopropyl)triethoxysilane, (3-mercaptopropyl)trimethoxysilane, and methyltriethoxysilane.

2. The crystalline silicon solar cell according to claim 1, characterized in that: It comprises a first electrode, a back surface field layer, a polysilicon layer, a front surface field layer, the passivation layer and a second electrode which are stacked in sequence; the passivation layer is also arranged on the side surface of the crystalline silicon solar cell.

3. The crystalline silicon solar cell according to any one of claims 1 or 2, characterized in that: The crystalline silicon solar cell has at least one cutting surface, and the passivation layer is arranged on the cutting surface of the crystalline silicon solar cell.

4. The method for preparing a crystalline silicon solar cell according to any one of claims 1 to 3, characterized in that: The steps include: Coating: coating the passivation material on the surface of polysilicon and / or the surface of the front surface field layer and / or the surface of the back surface field layer; Heat and serve.

5. The method for preparing a crystalline silicon solar cell according to claim 4, characterized in that: The steps include: Cutting: cutting the crystalline silicon cell a into several crystalline silicon cell b; Coating: coating the passivation material on the cut surface of the crystalline silicon cell b; Heat and serve.

6. The method for preparing a crystalline silicon solar cell according to any one of claims 4 or 5, characterized in that: The heating temperature is 50-120°C.

7. The method for preparing a crystalline silicon solar cell according to claim 6, characterized in that: The heating temperature is 60-100°C.

8. The method for preparing a crystalline silicon solar cell according to any one of claims 4 or 5, characterized in that: The heating time is 3 to 20 minutes.

9. A laminated battery, characterized in that: Comprising the crystalline silicon solar cell as described in any one of claims 1 to 3.

10. Use of the crystalline silicon solar cell according to any one of claims 1 to 3 in the preparation of a power generation device and / or an energy storage device and / or an electrical device.

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