Perovskite / crystalline silicon solar cell recovery processing method and solar cell

Abstract

The invention discloses a perovskite / crystalline silicon solar cell recovery processing method and a solar cell, and the method comprises the steps: dissolving an electron transport layer, a perovskite layer and a hole transport layer of a laminated solar cell through a processing liquid A, a processing liquid B and a processing liquid C in sequence; and the performance of the crystalline silicon bottom battery is not damaged in the dissolving process, so that the crystalline silicon bottom battery with good performance is obtained, the recovered crystalline silicon bottom battery and different functional layer materials can be continuously used for preparing the laminated solar battery, and the production cost and the resource consumption are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell recycling, and in particular to a recycling method for a perovskite / crystalline silicon solar cell and a solar cell. Background Art

[0002] Perovskite / crystalline silicon tandem solar cells can convert light energy into electrical energy, with a maximum theoretical conversion efficiency of up to 43%, and are widely used in the field of photovoltaic power generation. Due to the inherent properties of perovskite materials, process mismatch, immature technology and other reasons, many poor perovskite top cells, i.e. low-efficiency secondary products, will appear in the preparation process of perovskite / crystalline silicon tandem solar cells. However, directly discarding secondary products will cause waste of resources and increase production costs. Summary of the invention

[0003] The purpose of the present invention is to design a recycling method for perovskite / crystalline silicon solar cells in order to solve the above problems.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions: The recycling method of perovskite / crystalline silicon solar cells comprises the following steps: (1) immersing the solar cell in a treatment solution A and performing ultrasonic cleaning at a first temperature, and after the electron transport layer of the solar cell is dissolved, obtaining a laminated solar cell to be treated and a solution containing the electron transport layer; (2) immersing the stacked solar cell to be treated in treatment solution B, and performing ultrasonic cleaning at a second temperature, and after the perovskite layer of the stacked solar cell is dissolved, obtaining a bottom cell to be treated and a solution containing the perovskite layer; (3) immersing the bottom cell to be treated in a treatment solution C, and performing ultrasonic cleaning at a third temperature, and after the hole transport layer of the treated bottom cell is dissolved, obtaining a crystalline silicon bottom cell to be cleaned and a solution containing the hole transport layer; (4) Drying and ultraviolet ozone cleaning the crystalline silicon bottom cell to be cleaned to obtain a crystalline silicon bottom cell.

[0005] The present invention also proposes a solar cell, which includes a crystalline silicon bottom cell, a hole transport layer, a perovskite absorption layer, an electron transport layer and a top electrode. The crystalline silicon bottom cell is obtained by the above-mentioned perovskite / crystalline silicon solar cell recycling method.

[0006] The beneficial effects of the present invention are: The recycling method of perovskite / crystalline silicon solar cells dissolves the electron transport layer, perovskite layer and hole transport layer of the stacked solar cell respectively by using treatment liquid A, treatment liquid B and treatment liquid C in sequence. The performance of the crystalline silicon bottom cell will not be damaged during the dissolution process, thereby obtaining a crystalline silicon bottom cell with good performance. The recycled crystalline silicon bottom cell and different functional layer materials can continue to be used in the preparation of the stacked solar cell, reducing production costs and resource consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a schematic flow chart of the recycling method of the perovskite / crystalline silicon solar cell of the present invention; Figure 2 The physical diagram of each stage of the recycling method of the perovskite / crystalline silicon solar cell of the present invention; Figure 3 It is a JV test curve diagram of the perovskite / crystalline silicon solar cell of Example 1 of the present invention and Comparative Example 1 and Comparative Example 2; Figure 4 A statistical diagram of material recovery rate of the recycling method of the perovskite / crystalline silicon solar cell of the present invention; In the figure: 1-crystalline silicon bottom cell, 2-hole transport layer, 3-perovskite layer, 4-electron transport layer, 5-top electrode. DETAILED DESCRIPTION

[0008] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0009] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0010] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0011] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0012] Furthermore, the terms “first”, “second”, etc. are merely used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0013] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" 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, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0014] Perovskite / crystalline silicon solar cells are composed of a crystalline silicon bottom cell 1, a perovskite top cell and a top electrode 5. The structure of the perovskite top cell is usually a hole transport layer 2, a perovskite layer 3, and an electron transport layer 4. The top electrode 5 is usually gold or silver. In the cost structure of perovskite / crystalline silicon stacked solar cells, the cost of the crystalline silicon bottom cell 1 and the precious metal electrode accounts for more than 80%, and the top perovskite cell accounts for less than 20% of the cost.

[0015] In the preparation process of perovskite / crystalline silicon tandem solar cells, due to the inherent properties of perovskite materials, process mismatch, immature technology and other reasons, a large number of defective perovskite top cells, that is, low-efficiency secondary products, are produced. However, directly discarding secondary products will cause waste of resources and increase production costs.

[0016] The present invention provides a method for recycling perovskite / crystalline silicon solar cells, wherein different functional layers in a stacked solar cell are selectively dissolved by different processing solutions to obtain a crystalline silicon bottom cell 1; and the dissolved solution is filtered, distilled, extracted, etc. to recover the precious metals and the functional layer materials. After the bottom cell is cleaned, a crystalline silicon bottom cell 1 with intact performance can be obtained, which can be directly used to re-prepare the stacked solar cell.

[0017] The specific implementation modes of the present invention are described in detail below in conjunction with the accompanying drawings.

[0018] like Figure 1-4 As shown, the recycling method of perovskite / crystalline silicon solar cells includes the following steps: (1) immersing the perovskite / crystalline silicon solar cell in a treatment solution A, performing ultrasonic cleaning at a first temperature, and after the electron transport layer 4 of the perovskite / crystalline silicon solar cell is dissolved, obtaining a laminated solar cell to be treated and a solution containing the electron transport layer 4; (2) immersing the stacked solar cell to be treated in treatment solution B, and performing ultrasonic cleaning at a second temperature, and after the perovskite layer 3 of the stacked solar cell is dissolved, obtaining a bottom cell to be treated and a solution containing the perovskite layer 3; (3) immersing the bottom cell to be treated in a treatment solution C, and performing ultrasonic cleaning at a third temperature, and after the hole transport layer 2 of the treated bottom cell is dissolved, a solution containing the crystalline silicon bottom cell 1 to be cleaned and the hole transport layer 2 is obtained; (4) The crystalline silicon bottom cell 1 to be cleaned is dried and cleaned by ultraviolet ozone to obtain a crystalline silicon bottom cell 1.

[0019] In one embodiment, the treatment liquid A in step (1) is one or more of chlorobenzene (CB), isopropyl alcohol (IPA), chloroform (CHCl3), xylene (DMB), acetonitrile (ACN), tetrahydrofuran (THF), ethyl acetate (EA), petroleum ether (PE), ether, and urea; The electron transport layer 4 is composed of at least one material selected from the group consisting of fullerene (C60, C70), fullerene derivatives ([6,6]-phenyl-C61-butyric acid methyl ester (PC61BM)), perylene diimide derivatives (PDI), naphthalene diimide derivatives (NDI), and hexaazatrinaphthalene derivatives (HATNA); The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 1-1.5 h, and the first temperature is 40-50 °C.

[0020] In this embodiment, ultrasonic cleaning is performed at the first temperature to accelerate the dissolution of the electron transport layer 4. After the battery transport layer is dissolved, the top electrode 5 will automatically fall off, thereby improving the recovery efficiency of the perovskite / crystalline silicon solar cell. After the crystalline silicon bottom battery 1 to be cleaned is dried, the crystalline silicon bottom battery 1 is then subjected to ultraviolet ozone cleaning. Ultraviolet ozone cleaning uses ultraviolet light and ozone to remove chemicals adsorbed on the surface of the crystalline silicon bottom battery 1 to be cleaned, thereby obtaining a crystalline silicon bottom battery 1 with good performance and a clean surface. Among them, the solution containing the electron transport layer 4 can recover the electron transport material by extraction, distillation, crystallization and other methods, and the top electrode 5 can directly remove organic impurities by high temperature.

[0021] In one embodiment, the treatment liquid B in step (2) is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), 1,2-pentanol (1,2-pentanediol), γ-vanadate lactone (GVL), and n-butyl acetate (BAC); The general structural formula of the perovskite layer 3 is ABX3, A is selected from at least one of CH3NH3+, CH(NH2)2+ or Cs+, B is selected from at least one of Pb+, Sn+ or Ge2+, and X is selected from at least one of Cl-, Br- or I-.

[0022] The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 1-1.5 h, and the second temperature is 50-60 °C.

[0023] In this embodiment, when the stacked solar cell to be processed is immersed in the processing liquid B, the perovskite layer and the residual processing liquid A will be selectively dissolved, and ultrasonic cleaning at the second temperature can shorten the dissolution time. When the perovskite layer 33 is completely dissolved, the bottom cell to be processed and the solution containing the perovskite material can be obtained, wherein the perovskite-containing solution can recover the perovskite material through solid lead reaction or ion exchange for lead-based perovskite.

[0024] In one embodiment, the treatment liquid C in step (3) is one or more of water (H2O), ethanol (EtOH), methanol (MeOH), toluene (TL), and acetone (AC); The hole transport layer 2 is composed of at least one material of 2,2',7,7'-tetrakis[n,n-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), and carbazole-based SAM-HTL (2PACz, MeO-2PACz, Me-4PACz); The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 30-60 min, and the third temperature is 40-50 °C.

[0025] In this embodiment, the bottom battery to be processed is immersed in the processing liquid C, the hole transport layer 2 is selectively dissolved, and the residual processing liquid B is also dissolved. Ultrasonic cleaning at the third temperature will accelerate the dissolution to obtain a crystalline silicon bottom battery 1 and a solution containing hole transport material. The solution containing hole transport material can recover the hole transport material by distillation, extraction, crystallization and other methods.

[0026] In one embodiment, the drying temperature in step (4) is 90-120° C., and the drying time is 10-20 min.

[0027] In one embodiment, the power of the ultraviolet ozone cleaning in step (4) is 1-1.2 kW and the time is 10-20 minutes.

[0028] In this embodiment, the drying treatment equipment can be implemented by an oven, a hot plate, a vacuum drying oven, a tube furnace, etc. The drying temperature range is 90-120 ° C, and the drying time range is 10-20 min; the power range of ultraviolet ozone cleaning is 1-1.2kW, and the time range is 10-20 min. The crystalline silicon bottom battery 1 is heated and dried to volatilize the residual organic solvent on the surface; the chemical adsorption on the surface of the crystalline silicon bottom battery 1 caused by chemical bonding during the ultrasonic cleaning process can be efficiently removed by ultraviolet ozone, and the wettability of the crystalline silicon bottom battery 1 will be significantly improved after ultraviolet ozone cleaning, which is conducive to the crystallization of the perovskite film on its surface.

[0029] The recycling method of the perovskite / crystalline silicon solar cell of the present invention dissolves the electron transport layer 4, the perovskite layer 3 and the hole transport layer 2 of the stacked solar cell in sequence through the treatment liquid A, the treatment liquid B and the treatment liquid C respectively. The performance of the crystalline silicon bottom cell 1 will not be damaged during the dissolution process, thereby obtaining a crystalline silicon bottom cell 1 with good performance. The recycled crystalline silicon bottom cell 1 and different functional layer materials can continue to be used in the preparation of the stacked solar cell, reducing production costs and resource consumption.

[0030] The present invention also proposes a solar cell, which includes a crystalline silicon bottom cell 1, a hole transport layer 2, a perovskite absorption layer, an electron transport layer 4 and a top electrode 5. The crystalline silicon bottom cell 1 is obtained by the above-mentioned perovskite / crystalline silicon solar cell recycling method.

[0031] In order to verify that the material recovery rate of the recycling method of the perovskite / crystalline silicon solar cell of the present invention is high and the obtained crystalline silicon bottom cell 1 has better performance, a plurality of embodiments and comparative examples are provided below to weigh the materials recovered by the method and to test the stacked solar cells.

[0032] Embodiment 1: This embodiment 1 provides a low-efficiency perovskite / crystalline silicon tandem solar cell caused by a bad perovskite top cell, wherein the structure is Ag / IWO / a-Si:H(p) / a-Si:H(i) / c-Si(n) / a-Si:H(i) / a-Si:H(n) / IWO / 2PACz / Cs0.05FA0.8MA0.15Pb(I0.755Br0.255)3 / C60 / Ag, and specifically comprises the following steps: (1) The perovskite / crystalline silicon tandem solar cell was immersed in a treatment solution A, the composition of which was 65% CB and 35% ACN, and ultrasonic cleaning was performed at a frequency of 100 kHz and a temperature of 45°C for 1 h; after the electron transport layer 4 material C60 was dissolved, the remaining tandem solar cell was removed from the solution; the solution was filtered to obtain Ag, and the electron transport material C60 was recovered by extractive distillation of the remaining solution.

[0033] (2) The remaining stacked solar cells were immersed in treatment solution B, which consisted of 80% DMF, 10% DMSO and 10% NMP, and ultrasonic cleaning was performed at a frequency of 100 kHz and a temperature of 50°C for 1 h. After the perovskite absorption layer material Cs0.05FA0.8MA0.15Pb(I0.755Br0.255)3 was dissolved, the crystalline silicon bottom cell 1 with the hole transport layer 2 was removed from the solution, and the perovskite material lead iodide in the solution was recovered.

[0034] (3) The crystalline silicon bottom cell 1 with the hole transport layer 2 is immersed in a treatment solution C composed of 70% EtOH and 30% AC, and ultrasonic cleaning is performed at a frequency of 80 kHz and a temperature of 45 °C for 30 min. After the hole transport material 2PACz is dissolved, the crystalline silicon bottom cell 1 with Ag / IWO / a-Si:H(p) / a-Si:H(i) / c-Si(n) / a-Si:H(i) / a-Si:H(n) / IWO is removed from the solution, and the remaining solution is subjected to extractive distillation to recover the hole transport material 2PACz.

[0035] (4) Place the crystalline silicon bottom cell 1 in a vacuum drying oven, set the temperature to 90 °C, and dry for 20 min; after drying, transfer the crystalline silicon bottom cell 1 to a UV ozone cleaning box, with a cleaning power of 1 kW and a time of 10 min.

[0036] (5) The recovered crystalline silicon bottom cell 1 and various functional layer materials are used to re-prepare a perovskite / crystalline silicon tandem solar cell having the same structure.

[0037] Comparative Example 1: This comparative example 1 provides a low-efficiency perovskite / crystalline silicon tandem solar cell caused by a defective perovskite top cell, which has the same Ag / IWO / a-Si:H(p) / a-Si:H(i) / c-Si(n) / a-Si:H(i) / a-Si:H(n) / IWO / 2PACz / Cs0.05FA0.8MA0.15Pb(I0.755Br0.255)3 / C60 / Ag structure as embodiment 1, and has not been processed by the recycling treatment method steps of the perovskite / crystalline silicon solar cell.

[0038] Comparative Example 2: This comparative example 2 provides a crystalline silicon bottom cell 1 that has not been recycled by the recycling process of the perovskite / crystalline silicon solar cell recycling method, and its structure is Ag / IWO / a-Si:H(p) / a-Si:H(i) / c-Si(n) / a-Si:H(i) / a-Si:H(n) / IWO. After the hole transport layer 2, the perovskite layer 3, the electron transport layer 4 are prepared and the top cell is deposited, a perovskite / crystalline silicon stacked solar cell with the same structure as Example 1 is formed.

[0039] The actual pictures of each stage of Example 1 are as follows Figure 2 As shown, Figure 2 The left side is a real picture of Example 1 before solution treatment, which clearly shows that the perovskite top cell has a bad performance during the preparation process due to surface contamination; Figure 2 The middle is a real picture of Example 1 after solution treatment, at which time there is no residue on the surface of the crystalline silicon bottom cell 1; Figure 2 The right side is a real picture of the re-prepared perovskite / crystalline silicon tandem solar cell in Example 1. Figure 2 The left side shows a significant improvement over the perovskite top cell.

[0040] like Figure 3 As shown, the JV curves and performance parameters of the stacked solar cells of Example 1, Comparative Example 1 and Comparative Example 2 were measured at 25°C and AM 1.5 G standard sunlight. The energy conversion efficiency of the low-efficiency perovskite / crystalline silicon solar cell that has not been recycled in Comparative Example 1 is only 16.6%, while the energy conversion efficiency of the perovskite / crystalline silicon stacked solar cell that is re-prepared using the crystalline silicon bottom cell 1 that has been recycled by the present method in Example 1 is 28.5%, and the energy conversion efficiency of the perovskite / crystalline silicon solar cell prepared by the crystalline silicon bottom cell 1 that has not been recycled is 28.7%; thus, the perovskite / crystalline silicon solar cell obtained by the present recycling method has no reduction in open circuit voltage (VOC), short circuit current density (JSC), fill factor (FF) and energy conversion efficiency (PCE) compared with the freshly manufactured perovskite / crystalline silicon solar cell, which proves the feasibility and effectiveness of the recycling method of the perovskite / crystalline silicon solar cell in the present invention.

[0041] like Figure 4 The figure shows the recycling rate obtained by the usage amount of each functional material and the recycled weight, which proves that this method can classify and recycle perovskite / crystalline silicon solar cells, thereby greatly reducing the waste of resources.

[0042] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for recycling perovskite / crystalline silicon solar cells, characterized in that: The recycling method of the perovskite / crystalline silicon solar cell comprises the following steps: (1) immersing the perovskite / crystalline silicon solar cell in a treatment solution A, performing ultrasonic cleaning at a first temperature, and after the electron transport layer of the perovskite / crystalline silicon solar cell is dissolved, obtaining a laminated solar cell to be treated and a solution containing the electron transport layer; (2) immersing the stacked solar cell to be treated in treatment solution B, and performing ultrasonic cleaning at a second temperature, and after the perovskite layer of the stacked solar cell is dissolved, obtaining a bottom cell to be treated and a solution containing the perovskite layer; (3) immersing the bottom cell to be treated in a treatment solution C, and performing ultrasonic cleaning at a third temperature, and after the hole transport layer of the treated bottom cell is dissolved, obtaining a crystalline silicon bottom cell to be cleaned and a solution containing the hole transport layer; (4) Drying and ultraviolet ozone cleaning the crystalline silicon bottom cell to be cleaned to obtain a crystalline silicon bottom cell.

2. The method for recycling perovskite / crystalline silicon solar cells according to claim 1, characterized in that: The treatment liquid A in step (1) is one or more of chlorobenzene (CB), isopropyl alcohol (IPA), chloroform (CHCl3), xylene (DMB), acetonitrile (ACN), tetrahydrofuran (THF), ethyl acetate (EA), petroleum ether (PE), ether, and urea; The electron transport layer is composed of at least one material selected from the group consisting of fullerene (C60, C70), fullerene derivatives ([6,6]-phenyl-C61-butyric acid methyl ester (PC61BM)), perylene diimide derivatives (PDI), naphthalene diimide derivatives (NDI), and hexaazatrinaphthalene derivatives (HATNA); The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 1-1.5 h, and the first temperature is 40-50 °C.

3. The method for recycling perovskite / crystalline silicon solar cells according to claim 1, characterized in that: The treatment liquid B in step (2) is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), 1,2-pentanol (1,2-pentanediol), γ-valerolactone (GVL), and n-butyl acetate (BAC); The general structural formula of the perovskite layer is ABX3, A is selected from at least one of CH3NH3+, CH(NH2)2+ or Cs+, B is selected from at least one of Pb+, Sn+ or Ge2+, and X is selected from at least one of Cl-, Br- or I-; The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 1-1.5 h, and the second temperature is 50-60 °C.

4. The method for recycling perovskite / crystalline silicon solar cells according to claim 1, characterized in that: The treatment liquid C in step (3) is one or more of water (H2O), ethanol (EtOH), methanol (MeOH), toluene (TL), and acetone (AC); The hole transport layer is composed of at least one material of 2,2',7,7'-tetrakis[n,n-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), polytriarylamine (PTAA), and carbazole-based SAM-HTL (2PACz, MeO-2PACz, Me-4PACz); The frequency of the ultrasonic cleaning is 40-100 kHz, the time is 30-60 min, and the third temperature is 40-50 °C.

5. The method for recycling perovskite / crystalline silicon solar cells according to claim 1, characterized in that: The drying temperature in step (4) is 90-120°C, and the drying time is 10-20 min.

6. The method for recycling perovskite / crystalline silicon solar cells according to claim 1, characterized in that: The power of the ultraviolet ozone cleaning in step (4) is 1-1.2 kW and the time is 10-20 min.

7. A solar cell, characterized in that: The solar cell comprises a crystalline silicon bottom cell, a hole transport layer, a perovskite absorption layer, an electron transport layer and a top electrode, and the crystalline silicon bottom cell is obtained by the recycling method of the perovskite / crystalline silicon solar cell according to any one of claims 1 to 6.

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