Perovskite solar cell and preparation method and application thereof

Abstract

The application belongs to the technical field of solar cells, and discloses a perovskite solar cell, a preparation method and application thereof. The perovskite solar cell comprises, from bottom to top, a flexible conductive substrate, a hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer and a metal electrode layer. The perovskite active layer comprises APbX3. A comprises at least one of formamidinium ion, methylamine ion, cesium ion and potassium ion. X comprises at least one of chloride ion, bromide ion and iodide ion. The passivation layer comprises 2-ethyl-2-phenyl malonic acid diethyl ester. The solar cell has excellent photoelectric conversion efficiency and long-term stability, and can be used to prepare photovoltaic modules and electronic devices. In addition, the preparation method is simple and easy to implement, does not require complex equipment and processes, can effectively control the thickness of each layer, is used to prepare large-area high-performance perovskite solar cells, and meets the needs of industrial production.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a perovskite solar cell, its preparation method, and its application. Background Technology

[0002] Perovskite solar cells have attracted widespread attention due to their advantages such as tunable bandgap, high absorption coefficient, and ultra-high carrier mobility. However, the interface contact between the hole transport layer / perovskite and the perovskite / electron transport layer has a crucial impact on the performance of perovskite solar cells. Poor interface contact can lead to the following problems: (1) increased probability of charge recombination, resulting in ineffective separation and transport of photogenerated carriers, reducing the photoelectric conversion efficiency of the device; (2) charge accumulation and uneven charge transport at the interface can lead to hysteresis in the current-voltage curve; (3) accelerated device aging and shortened device lifespan. Currently, although existing organic halide perovskites can be used as the bottom cell of organic perovskite tandem cells in combination with other solar cell materials with different bandgap to cover a wider spectral range, the interface compatibility of organic halide perovskites with other solar cell materials is poor, resulting in problems such as uneven charge transport, charge accumulation, and charge recombination, which seriously affect the charge transport efficiency, device stability, and lifespan.

[0003] Meanwhile, large-area perovskite solar cells are typically fabricated in air, where halide ions are readily oxidized and volatilized by O2, creating defects on the perovskite film surface. These defects accumulate on the perovskite film surface, forming recombination centers that reduce the lifetime of photogenerated carriers and device efficiency. Furthermore, they readily absorb moisture from the environment, triggering phase transitions or chemical degradation of the perovskite, severely impacting device lifespan.

[0004] Furthermore, in existing perovskite solar cells, highly hygroscopic dopants are typically used to improve the conductivity of the hole transport material. For example, lithium salts (LiTFSI) and cobalt salts are commonly used as dopants in the hole transport material Spiro-OMeTAD. However, while these dopants improve efficiency, they can lead to performance degradation in humid environments, and even cause internal short circuits or damage, affecting the long-term operational stability of the device. Therefore, there is an urgent need to develop a perovskite solar cell that can improve interfacial compatibility, promote efficient charge transport, and possess high efficiency, stability, and excellent photoelectric conversion efficiency. This is of great significance for promoting the application and development of perovskite solar cells in a wider range of fields. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a perovskite solar cell, its preparation method, and its application.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a perovskite solar cell, characterized in that the perovskite solar cell comprises, from bottom to top, a flexible conductive substrate, a hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, and a metal electrode layer; the perovskite active layer comprises APbX3; the A comprises at least one of formamidinium ions, methylamine ions, cesium ions, and potassium ions; the X comprises at least one of chloride ions, bromide ions, and iodide ions; and the passivation layer comprises diethyl 2-ethyl-2-phenylmalonate.

[0007] The perovskite solar cell of the present invention introduces a special 2-ethyl-2-phenylmalonate diethyl passivation layer between the perovskite active layer and the electron transport layer. The carbonyl O in the 2-ethyl-2-phenylmalonate diethyl passivation layer interacts with uncoordinated Pb. 2+ The strong interactions between ions have two main effects. Firstly, they coat the surface of the perovskite film, reducing the number of surface defects and effectively lowering the charge recombination rate. Secondly, they adjust the energy level arrangement between the perovskite active layer and the charge transport layer, improving the interfacial energy level matching and carrier transport rate. This allows electrons to transport more smoothly from the perovskite active layer to the charge transport layer, significantly reducing the recombination rate between carriers (electrons and holes). This helps to effectively collect more photogenerated charges and improve the photoelectric conversion efficiency of the battery. Furthermore, the diethyl 2-ethyl-2-phenylmalonate passivation layer of this invention can also prevent the perovskite film from being corroded by environmental factors such as moisture and oxygen, enhancing the environmental tolerance of the perovskite solar cell and improving its long-term stability.

[0008] In a preferred embodiment of the perovskite solar cell of the present invention, the thickness of the passivation layer is 1 nm-10 nm.

[0009] Preferably, the thickness of the hole transport layer is any one or a range between 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, and 10nm.

[0010] In a preferred embodiment of the perovskite solar cell of the present invention, the hole transport layer comprises cuprous iodide (CuI), cuprous thiocyanate (CuSCN), and nickel oxide (NiO). x At least one of the following: polytriarylamine (PTAA), poly(3,4-ethylenedioxythiophene-polystyrene sulfonate) (PEDOT:PSS), and poly(3-hexylthiophene) (P3HT).

[0011] Preferably, the hole transport layer comprises poly(3,4-ethylenedioxythiophene-polystyrene sulfonate).

[0012] In a preferred embodiment of the perovskite solar cell of the present invention, the thickness of the hole transport layer is 10nm-80nm.

[0013] Preferably, the thickness of the hole transport layer is any one or a range between 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, and 80nm.

[0014] In a preferred embodiment of the perovskite solar cell of the present invention, the thickness of the perovskite active layer is 400nm-800nm.

[0015] Preferably, the thickness of the perovskite active layer is any one of 400nm, 500nm, 600nm, 700nm, 800nm, or a range between two of them.

[0016] In a preferred embodiment of the perovskite solar cell of the present invention, the electron transport layer is made of fullerene derivatives and phenanthroline derivatives; the mass ratio of the fullerene derivatives to the phenanthroline derivatives is (8-10):1.

[0017] Preferably, the mass ratio of the fullerene derivative to the phenanthroline derivative is 9:1.

[0018] The electron transport layer of this invention uses phenanthroline derivatives with large conjugated systems and unique electronic properties, in conjunction with fullerene derivatives with excellent electron accepting and transporting capabilities, to form complementary electron transport channels, improve electron transport efficiency, improve the interfacial contact between the electron transport layer and the perovskite layer, reduce interfacial resistance, and further improve battery performance.

[0019] Preferably, the phenanthroline derivative is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; and the fullerene derivative is methyl (6,6)-phenyl-C61-butyrate and / or methyl (6,6)-phenyl-C71-butyrate.

[0020] In a preferred embodiment of the perovskite solar cell of the present invention, the thickness of the electron transport layer is 20nm-80nm.

[0021] Preferably, the thickness of the electron transport layer is any one or a range between two of 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, and 80nm.

[0022] In a preferred embodiment of the perovskite solar cell of the present invention, the material of the metal electrode layer is any one of gold (Au), silver (Ag), and aluminum (Al).

[0023] In a preferred embodiment of the perovskite solar cell of the present invention, the thickness of the metal electrode layer is 70nm-100nm.

[0024] Preferably, the thickness of the metal electrode layer is any one of 70nm, 80nm, 90nm, 100nm, or a range between two of them.

[0025] Secondly, the present invention provides a method for preparing the perovskite solar cell, wherein the passivation layer is prepared by applying a 2-ethyl-2-phenylmalonate solution to the surface of the perovskite active layer using a slot coating method, followed by annealing.

[0026] In a preferred embodiment of the preparation method of the perovskite solar cell of the present invention, the concentration of diethyl 2-ethyl-2-phenylmalonate is 2 mg / mL-14 mg / mL.

[0027] Preferably, the concentration of the diethyl 2-ethyl-2-phenylmalonate is 8 mg / mL to 12 mg / mL.

[0028] More preferably, the concentration of the diethyl 2-ethyl-2-phenylmalonate is any one of 8 mg / mL, 9 mg / mL, 10 mg / mL, 11 mg / mL, 12 mg / mL, or a range between two of them.

[0029] Preferably, the solvent for the diethyl 2-ethyl-2-phenylmalonate includes at least one of anhydrous ethanol, diethyl ether, ethyl acetate, chlorobenzene, and isopropanol.

[0030] Preferably, the slit coating head moving speed is 10 mm / s-20 mm / s; the slit coating ink injection speed is 0.1 mL / min-10 mL / min; the annealing temperature is 50℃-100℃; and the annealing time is 10 min-20 min.

[0031] In a preferred embodiment of the perovskite solar cell fabrication method of the present invention, the hole transport layer is formed by coating the flexible conductive substrate with hole transport layer material using a slot coating method, followed by annealing.

[0032] Preferably, the concentration of the hole transport layer material is 5 mg / mL to 15 mg / mL.

[0033] Preferably, the solvent of the hole transport layer material includes at least one of deionized water, anhydrous ethanol, chlorobenzene, isopropanol, acetonitrile, and anisole.

[0034] Preferably, the coating is performed using a slot coating method; the moving speed of the coating head in the slot coating is 10 mm / s-20 mm / s; and the ink injection speed in the slot coating is 0.1 mL / min-10 mL / min.

[0035] Preferably, the annealing temperature is 100℃-200℃; the annealing time is 10min-20min.

[0036] In a preferred embodiment of the method for preparing the perovskite solar cell of the present invention, the perovskite active layer is prepared by applying a perovskite precursor solution to the surface of the hole transport layer using a slot coating method, followed by annealing.

[0037] Preferably, the concentration of the perovskite precursor solution is 0.1 mol / L to 2 mol / L.

[0038] Preferably, the solvent of the perovskite precursor solution includes at least one of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), and γ-butyrolactone.

[0039] Preferably, the moving speed of the slit coating head is 10 mm / s-20 mm / s; the ink injection speed of the slit coating is 0.1 mL / min-10 mL / min.

[0040] Preferably, the annealing temperature is 100℃-200℃; the annealing time is 10min-20min.

[0041] In a preferred embodiment of the method for preparing the perovskite solar cell of the present invention, the electron transport layer is prepared by coating the passivation layer surface with an electron transport layer material using a slot coating method, followed by annealing.

[0042] Preferably, the concentration of the electron transport layer material is 10 mg / mL to 30 mg / mL.

[0043] Preferably, the solvent of the electron transport layer material includes at least one of anhydrous ethanol, anhydrous diethyl ether, chlorobenzene, isopropanol, anisole, and ethyl acetate.

[0044] Preferably, the moving speed of the slit coating head is 10 mm / s-20 mm / s; the ink injection speed of the slit coating is 0.1 mL / min-10 mL / min.

[0045] Preferably, the annealing temperature is 100℃-200℃; the annealing time is 10min-20min.

[0046] In a preferred embodiment of the method for preparing the perovskite solar cell of the present invention, the metal electrode layer is prepared by vapor deposition.

[0047] The perovskite solar cell fabrication method of this invention employs a slot coating technique to uniformly deposit the hole transport layer, perovskite active layer, passivation layer, and electron transport layer onto a substrate. This ensures high precision and uniformity of the perovskite thin film in the solar cell, reduces surface defects, and improves the compatibility between interfaces. Furthermore, the fabrication method of this invention is simple and easy to implement, requiring no complex equipment or processes, and can effectively control the thickness of each layer. It can be used to fabricate large-area, high-performance perovskite solar cells, meeting the needs of industrial production.

[0048] Thirdly, the present invention provides the application of the perovskite solar cell in photovoltaic modules and electronic devices.

[0049] The perovskite solar cells of this invention have excellent photoelectric conversion efficiency and long-term stability, and can be used in the manufacture of photovoltaic modules and electronic devices, such as photovoltaic modules installed on rooftops, ground or building surfaces to convert sunlight into electrical energy and provide clean energy for homes, businesses and the power grid; they can also be used to manufacture portable chargers, smartwatches, drones and other electronic devices, achieving longer battery life and a wider range of applications.

[0050] Compared with the prior art, the beneficial effects of the present invention are as follows: First, the perovskite solar cell of the present invention forms a 2-ethyl-2-phenylmalonate diethyl passivation layer on the perovskite thin film, through which the carbonyl O in the 2-ethyl-2-phenylmalonate diethyl passivating agent reacts with the uncoordinated Pb 2+ Ion interactions reduce surface defects in the perovskite film, while simultaneously improving interfacial energy level matching and carrier transport rate between the perovskite and charge transport layers, reducing carrier recombination, and enhancing the perovskite solar cell's resistance to environmental damage. Secondly, the perovskite solar cell of this invention exhibits excellent photoelectric conversion efficiency and long-term stability. Furthermore, the fabrication method of this invention uses slit coating to uniformly deposit the hole transport layer, perovskite active layer, passivation layer, and electron transport layer on the substrate, ensuring high precision and uniformity of the perovskite film in the solar cell, reducing surface defects, and enabling the fabrication of large-area perovskite solar cells to meet the needs of industrial production. Detailed Implementation

[0051] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0052] The following description, in conjunction with specific embodiments, illustrates the practical effects of the present invention.

[0053] Unless otherwise specified, the test methods used in the following examples and comparative examples are conventional methods; the materials, reagents, equipment, etc. used are commercially available unless otherwise specified.

[0054] The structural formula of diethyl 2-ethyl-2-phenylmalonate used in the following examples and comparative examples is shown below: . Example 1: Fabrication of perovskite solar cells (1) The indium tin oxide (ITO) flexible conductive substrate was ultrasonically cleaned in acetone, anhydrous ethanol and deionized water for 30 min each, and then dried with a nitrogen gun to obtain a clean ITO flexible conductive substrate.

[0055] (2) A PEDOT:PSS solution with a concentration of 10 mg / mL was prepared by dispersing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) (purchased from Heraeus, Germany, model 4083) in deionized water. The solution was then slit-coated onto an ITO flexible conductive substrate. The coating head moved at a speed of 15 mm / s and the ink injection speed was 0.6 mL / min. After coating, the substrate was annealed at 120 °C for 15 min to obtain a hole transport layer of 30 nm.

[0056] (3) Methylamine iodide (MAI) and lead iodide (PbI2) were dissolved in a mixed solvent (DMF and DMSO volume ratio of 4:1) at a molar ratio of 1:1 and stirred until completely dissolved to obtain a 1.5 mol / L MAPbI3 perovskite precursor solution. The prepared MAPbI3 perovskite precursor solution was slit-coated onto the hole transport layer prepared above. The coating head moving speed was 15 mm / s and the ink injection speed was 0.6 mL / min. After coating, annealing was performed at a temperature of 120 °C for 15 min to obtain a 400 nm perovskite active layer.

[0057] (4) Dissolve 2-ethyl-2-phenylmalonate diethyl ester in anhydrous ethanol and stir until completely dissolved to obtain a passivating agent solution with a concentration of 10 mg / mL. Slit-coat the passivating agent solution onto the perovskite film with a coating head moving at a speed of 15 mm / s and an ink injection speed of 0.6 mL / min. After coating, annealing is performed at a temperature of 80 °C for 15 min to obtain a passivation layer of 5 nm. The anhydrous ethanol is an analytical grade reagent.

[0058] (5) Methyl (6,6)-phenyl C61-butyrate (PC61BM) and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) were dissolved in chlorobenzene at a mass ratio of 9:1 to prepare an electron transport material solution with a total solute mass concentration of 20 mg / mL. The electron transport layer solution was slit-coated onto the 2-ethyl-2-phenylmalonate diethyl passivation layer. The coating head moving speed was 15 mm / s and the ink injection speed was 0.6 mL / min. After coating, annealing was performed at a temperature of 120 °C for 15 min to obtain an electron transport layer with a diameter of 40 nm.

[0059] (6) A 100 nm Ag electrode layer is deposited on the electron transport layer prepared above to obtain a pin-type MAPbI3 perovskite solar cell.

[0060] Comparative Example 1: Fabrication of Perovskite Solar Cells The only difference between the preparation method of the perovskite solar cell described in this comparative example and that in Example 1 is that the passivation layer in step (4) is not prepared, and the electron transport layer solution is directly applied to the perovskite active layer through a slit.

[0061] Test Example: Performance Testing of Perovskite Solar Cells The performance of the perovskite solar cells prepared in the above embodiments and comparative examples was tested.

[0062] Test method: Under conditions of 25℃ and standard atmospheric pressure, the AM1.5G standard spectrum was provided using a Class AAA solar simulator, with light intensity calibrated to 100mW / cm². 2 During the test, an effective area of ​​0.1 cm² was used. 2 A metal mask was used to cover the light-receiving area of ​​the battery. JV scanning was performed using a Keithley 2400 source meter with a starting voltage of -0.1V and a stopping voltage of 1.2V. The reverse and forward scan curves were recorded to evaluate the hysteresis effect.

[0063] Table 1: Performance of perovskite solar cells prepared in the examples and comparative examples Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A perovskite solar cell, characterized in that, The perovskite solar cell comprises, from bottom to top, a flexible conductive substrate, a hole transport layer, a perovskite active layer, a passivation layer, an electron transport layer, and a metal electrode layer; the perovskite active layer comprises APbX3; A comprises at least one of formamidinium ion, methylamine ion, cesium ion, and potassium ion; X comprises at least one of chloride ion, bromide ion, and iodide ion; the passivation layer comprises diethyl 2-ethyl-2-phenylmalonate.

2. The perovskite solar cell as described in claim 1, characterized in that, The thickness of the passivation layer is 1nm-10nm.

3. The perovskite solar cell according to claim 1, characterized in that, The hole transport layer includes at least one of cuprous iodide, cuprous thiocyanate, nickel oxide, polytriarylamine, poly(3,4-ethylenedioxythiophene-polystyrene sulfonate), and poly(3-hexylthiophene).

4. The perovskite solar cell according to claim 1, characterized in that, The electron transport layer comprises a fullerene derivative and a phenanthroline derivative; the mass ratio of the fullerene derivative to the phenanthroline derivative is (8-10):

1.

5. The perovskite solar cell as described in claim 4, characterized in that, The phenanthroline derivative is 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; the fullerene derivative is methyl (6,6)-phenyl-C61-butyrate and / or methyl (6,6)-phenyl-C71-butyrate.

6. A method for preparing a perovskite solar cell according to any one of claims 1-5, characterized in that, The passivation layer is formed by applying a 2-ethyl-2-phenylmalonate solution to the surface of the perovskite active layer using a slot coating method, followed by annealing.

7. The method for preparing a perovskite solar cell as described in claim 6, characterized in that, The concentration of the 2-ethyl-2-phenylmalonate diethyl ester solution is 2 mg / mL to 14 mg / mL.

8. The method for preparing a perovskite solar cell as described in claim 7, characterized in that, The concentration of the 2-ethyl-2-phenylmalonate diethyl ester solution is 8 mg / mL to 12 mg / mL.

9. The method for preparing a perovskite solar cell as described in claim 6, characterized in that, The slit coating head moving speed is 10 mm / s-20 mm / s; the slit coating ink injection speed is 0.1 mL / min-10 mL / min; the annealing temperature is 50℃-100℃; and the annealing time is 10 min-20 min.

10. The application of the perovskite solar cell according to any one of claims 1-5 in photovoltaic modules and electronic devices.

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