A method and product for improving the stability of perovskite photovoltaic films

Abstract

The present invention provides a method and product for improving the stability of a perovskite photovoltaic film, belonging to the field of perovskite film materials. The method comprises: S1, in an oxygen-free and water-free environment, immediately and evenly adhering the entire tape to the surface of the perovskite film's light-absorbing layer after exposing the adhesive surface of the tape; S2, maintaining the oxygen-free and water-free environment, applying pressure to the tape, causing the tape to adhere to the surface of the perovskite film's light-absorbing layer under pressure for a set period of time until the adhesive surface of the tape and the perovskite film's light-absorbing layer undergo a material exchange, wherein the adhesive surface of the tape comprises an organic silicone pressure-sensitive adhesive material having a viscosity of 1000 to 5000 MPa·s; S3, then slowly tearing the tape from the surface of the perovskite film in the same direction. The present invention also provides a perovskite photovoltaic film provided by the above method. The method of the present invention can effectively improve the stability of perovskite film materials, is simple in process, low in cost, and is economical and environmentally friendly.

Description

Technical Field

[0001] The present invention belongs to the field of perovskite thin film materials, and more specifically, relates to a method and product for improving the stability of perovskite photovoltaic thin films. Background Art

[0002] Organic-inorganic hybrid perovskite materials boast strong light absorption, high mobility, long carrier lifetime, tunable band gap, simple and inexpensive preparation, and versatile processing methods. They were selected by Science as one of the top ten scientific breakthroughs of 2013. These advantages have led to their remarkable performance in the photovoltaic field. In less than a decade, the efficiency of perovskite solar cells has leapt from 3.8% to 25.2%, reaching a level competitive with traditional photovoltaics. The emergence of perovskite solar cells addresses the shortcomings of current thin-film solar cells in terms of photoelectric conversion efficiency, preparation process, and production cost, significantly promoting the development of thin-film photovoltaic technology. In addition to their outstanding performance in the photovoltaic field, perovskite materials also have broad applications in other areas of optoelectronics. For example, in recent years, perovskite materials have been applied to the manufacture of light detection and light-emitting devices (light-emitting diodes, lasers, light-emitting field-effect transistors), photodetectors, and single-crystal devices.

[0003] While perovskite materials have garnered significant attention in optoelectronics and have become a research hotspot, all perovskite materials experience varying degrees of decomposition, particularly when exposed to high humidity, high temperature, strong light, and oxygen-rich conditions. This degradation is particularly severe in high humidity conditions, presenting a significant challenge in the practical application of perovskite materials in photovoltaic solar cells. Therefore, improving the stability of perovskite films has significant scientific and social value for promoting the industrialization of perovskite materials in optoelectronics.

[0004] At present, the methods to overcome this problem are mainly from the aspects of additives, element doping, interface passivation or surface coating, which can improve the stability of perovskite materials to a certain extent. The Chinese patent with publication number CN112071982A introduces hydrophobic carboxylic acid functional groups into formamidine perovskite to inhibit the occurrence of moisture-induced phase change, thereby improving the stability of α-phase formamidine perovskite. The Chinese patent application with publication number CN108232014A provides a perovskite film doped with an ion stabilizer and a preparation method thereof. By doping the ion stabilizer R1-R-R2 in the perovskite film, a doped perovskite solar cell is prepared, the performance of the cell is improved, and the stability of the solar cell is improved. The Chinese patent application with publication number CN111435709A combines the two means of element regulation and additive defect passivation to achieve the preparation of highly stable perovskite solar cells. Chinese patent application publication number CN108899425A provides a method for doping a perovskite light-absorbing layer with tetrabutylammonium ions, which improves the thermal and wet stability of the perovskite material, thereby producing a highly stable perovskite solar cell. Chinese patent application publication number CN111435709A also discloses a method for treating the perovskite film surface with hydrogen sulfide gas, which promotes the formation of a lead sulfide layer on the surface of the perovskite film, inhibiting the degradation of the perovskite, thereby improving the performance of the perovskite film material and prolonging its stability.

[0005] However, the above method has the problem of complex preparation process. Therefore, it is necessary to develop a simple method to improve the stability of perovskite photovoltaic films. Summary of the Invention

[0006] In response to the defects of the existing technology, the purpose of the present invention is to provide a method and product for improving the stability of perovskite photovoltaic films. By sticking tape on the surface of the perovskite film, its hydrophobicity and stability are improved. This method is simple to operate, economical and environmentally friendly, and is suitable for improving the stability of all multi-component mixed perovskite film materials. It has important scientific significance and social value for promoting the industrialization of perovskite solar cells.

[0007] To achieve the above object, the present invention provides a method for improving the stability of perovskite photovoltaic thin films, which comprises the following steps:

[0008] S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer.

[0009] S2: Maintain an oxygen-free and water-free environment, apply pressure to the tape, and stick the tape to the surface of the perovskite film light-absorbing layer under pressure for a set time until the adhesive surface of the tape and the perovskite film light-absorbing layer exchange substances.

[0010] The adhesive surface of the tape has a silicone pressure-sensitive adhesive material, and the viscosity of the adhesive surface is 1000 to 5000 mPa·s.

[0011] S3: Then, slowly tear off the tape on the surface of the perovskite film along the same direction.

[0012] In the above invention, the viscosity of the adhesive surface is 1000 mPa·s to 5000 mPa·s. Such a viscosity is appropriate, which can ensure the pasting effect and is easy to paste and tear.

[0013] Furthermore, the perovskite film composition is a perovskite compound with an ABX3 structure, wherein A is mainly a methylamino group CH3NH 3+ or carbamimidyl CH(NH2) 2+ , B is a lead ion, and X is a halogen anion I-.

[0014] Furthermore, A is a monovalent inorganic cation K + , Rb + or Cs + At least one of, B is a stannous ion, X is a halogen anion Cl - or Br - .

[0015] Furthermore, X is a monovalent anion thiocyanate or acetate ion.

[0016] Furthermore, the tape is one or more of high temperature tape, 3M tape, transparent tape, etc.

[0017] Furthermore, in step S2, pressure is applied to the tape at a temperature of 10°C to 150°C.

[0018] Furthermore, in step S2, a pressure of 0N to 50N is applied to the tape at a temperature of 10°C to 150°C.

[0019] Furthermore, in step S2, at a temperature of 10° C. to 150° C., a pressure of 0 N to 50 N is applied to the tape so that the tape is adhered to the surface of the perovskite film light-absorbing layer under pressure for 1 min to 30 min.

[0020] Furthermore, in step S2, a pressure of 10N to 40N is applied to the tape at a temperature of 20°C to 80°C, causing the tape to adhere to the surface of the perovskite film's light-absorbing layer while under pressure for 5 to 20 minutes. The thickness of the adhesive surface of the tape does not exceed 0.2mm. The combined effect of these preferred temperature, pressure, and time factors effectively removes dangling ionic bonds on the perovskite film's surface while also introducing new elements.

[0021] According to the second aspect of the present invention, a perovskite photovoltaic film prepared according to the above method is also provided.

[0022] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0023] The present invention provides a method for improving the stability of perovskite photovoltaic films based on tape tearing, which can remove the surface of the perovskite film, such as Pb 2+ and I - Ionic dangling bonds are formed. At the same time, special elements on the tape surface, such as Si, can enter the surface and grain boundaries of the perovskite material, improving the hydrophobicity of the perovskite film material and inhibiting the degradation of the perovskite material, thereby effectively improving the stability of the perovskite film material, ensuring the high performance and stability of the perovskite solar cell, and extending its service life. The method provided by the present invention has a simple preparation process, low cost, economical and environmentally friendly, and high repeatability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a comparison diagram of the static water contact angles on the surface of the perovskite thin film material in Example 1 of the present invention and Comparative Example 1.

[0025] Figure 2 This is a comparison chart of the XPS spectra of the perovskite thin film material and high-temperature tape in Example 1 of the present invention and Comparative Example 1.

[0026] Figure 3 This is a comparison chart of the efficiency spectra of the complete devices of Example 1 and Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] The present invention provides a method for improving the stability of perovskite photovoltaic films based on tape tearing, which specifically includes the following steps:

[0029] S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer.

[0030] S2: Maintain an oxygen-free and water-free environment, apply 0N to 50N pressure to the tape at a temperature of 10℃ to 150℃, and stick the tape to the surface of the perovskite film light-absorbing layer under pressure for 1min to 30min until material exchange occurs between the sticky surface of the tape and the perovskite film light-absorbing layer.

[0031] The adhesive surface of the tape has a silicone pressure-sensitive adhesive material or an acrylic oil pressure-sensitive adhesive, and the viscosity of the adhesive surface is 1000 to 5000 mPa·s. The tape is one or more of high-temperature tape, 3M tape, transparent tape, etc., and the thickness of the adhesive surface of the tape does not exceed 0.2 mm.

[0032] The perovskite film composition is a perovskite compound with ABX3 structure, in which A is mainly methylamine CH3NH3 + , carbamimidyl CH(NH2)2 + , monovalent inorganic cation K + , Rb + or Cs + At least one of, B is a lead ion, a stannous ion, X is a halogen anion I - 、Cl - or Br - , or X is a monovalent anion thiocyanate or acetate ion

[0033] S3: Then, slowly tear off the tape on the surface of the perovskite film along the same direction.

[0034] In order to further illustrate the method of the present invention, the following is a specific embodiment

[0035] Implementation Case 1

[0036] In this example, the perovskite thin film prepared by the method of the present invention was assembled into a perovskite cell and the cell performance was tested. The perovskite solar cell structure includes: a conductive substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer and an electrode layer.

[0037] S1: Deposit TiO2, an electron transport material, onto a dry, clean FTO conductive glass substrate. Subsequently, within a glove box, spin-coat a perovskite precursor solution onto the electron transport material layer, anneal, and cool naturally to room temperature. This results in a structured FTO / c-TiO2 / m-TiO2 / CH3NH3PbI3 substrate with a perovskite thin film on the surface.

[0038] S2: In an oxygen- and water-free environment, apply high-temperature tape evenly to the surface of the prepared perovskite film (FTO / c-TiO2 / m-TiO2 / CH3NH3PbI3) substrate. Apply a uniform external pressure of 10 N to the tape surface for 5 minutes at 30°C. Then, slowly remove the tape from the perovskite film along the same axis. The material structure of the perovskite film treated with high-temperature tape is designated as FTO / c-TiO2 / m-TiO2 / T-CH3NH3PbI3 substrate.

[0039] S3: Prepare spiro-OMeTAD on the FTO / c-TiO2 / m-TiO2 / T-CH3NH3PbI3 substrate after the surface of the above-mentioned perovskite film has been treated with high-temperature tape. After oxidation for 8 hours, a gold electrode is evaporated on the Spiro-OMeTAD film using a metal evaporation coating apparatus to complete a high-stability perovskite solar cell with the structure of FTO / c-TiO2 / m-TiO2 / T-CH3NH3PbI3 / spiro-OMeTAD / Au.

[0040] Comparative Case 1

[0041] In this example, conventional perovskite thin films that had not been treated by the method of the present invention were assembled into perovskite cells for performance testing. The perovskite solar cell structure includes a conductive substrate, an electron transport layer, a perovskite light absorption layer, a hole transport layer, and an electrode layer.

[0042] S1: Deposit TiO2, an electron transport material, onto a dry, clean FTO conductive glass substrate. Subsequently, in a glove box, spin-coat a perovskite precursor solution onto the electron transport material layer, anneal, and cool naturally to room temperature. This creates an FTO / c-TiO2 / m-TiO2 / CH3NH3PbI3 substrate with a perovskite film on its surface.

[0043] S2: Prepare spiro-OMeTAD on the above-mentioned perovskite film FTO / c-TiO2 / m-TiO2 / CH3NH3PbI3 substrate. After oxidation for 8 hours, use a metal evaporation coating device to evaporate gold electrodes on the Spiro-OMeTAD film to complete a complete perovskite solar cell with the following structure: FTO / c-TiO2 / m-TiO2 / T-CH3NH3PbI3 / spiro-OMeTAD / Au.

[0044] Figure 1 The static water contact angles of the perovskite film materials in Example 1 and Comparative Example 1 are shown in the figure. The figure clearly shows that the static water contact angle of the perovskite film FTO / c-TiO2 / m-TiO2 / T-CH3NH3PbI3 substrate treated with high-temperature tape is 115°, indicating hydrophobicity. Under the same conditions, the static water contact angle of the perovskite film FTO / c-TiO2 / m-TiO2 / CH3NH3PbI3 substrate not treated with high-temperature tape is 28°, indicating hydrophilicity.

[0045] Figure 2The following is a comparison of the XPS spectra of the perovskite film and high-temperature tape used in Case 1 and Comparative Case 1. As can be seen, after the high-temperature tape treatment, a new element, Si, appears on the surface of the CH3NH3PbI3 perovskite film. This is due to the unique Si element on the tape surface incorporating into the perovskite surface and grain boundaries, thereby increasing the hydrophobicity of the perovskite film and inhibiting its degradation.

[0046] Figure 3 To compare the efficiency spectra of the complete devices of Case 1 and Comparative Case 1, the surface treatment of the perovskite thin film material with tape did not affect its photoelectric conversion efficiency.

[0047] Implementation Case 2

[0048] S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer.

[0049] S2: Maintaining an oxygen-free and water-free environment at a temperature of 10°C, apply 50 N of pressure to the tape, adhering the tape to the surface of the perovskite film light-absorbing layer while under pressure for 30 minutes, until a material exchange occurs between the adhesive surface of the tape and the perovskite film light-absorbing layer. The adhesive surface of the tape comprises a silicone pressure-sensitive adhesive or an acrylic oil-based pressure-sensitive adhesive with a viscosity of 1000 to 2000 mPa·s. The tape is 3M tape, and the thickness of the adhesive surface of the tape does not exceed 0.2 mm.

[0050] The perovskite film composition is a perovskite compound with an ABX3 structure, where A is a carboxamidine group CH(NH2)2 + , B is lead ion, X is halogen anion Cl - .

[0051] S3: Then, slowly tear off the tape on the surface of the perovskite film along the same direction.

[0052] Implementation Case 3

[0053] S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer.

[0054] S2: Maintain an oxygen-free and water-free environment at a temperature of 150°C. Apply 0N (no pressure) to the tape, so that the tape is adhered to the surface of the perovskite film light-absorbing layer without pressure. Continue for 1 minute until material exchange occurs between the sticky surface of the tape and the perovskite film light-absorbing layer.

[0055] The adhesive surface of the tape has an organic silicon pressure-sensitive adhesive material or an acrylic oil pressure-sensitive adhesive, and the viscosity of the adhesive surface is 2000-3000 mPa·s. The tape is a transparent tape, and the thickness of the adhesive surface of the tape does not exceed 0.2 mm.

[0056] The perovskite film composition is a perovskite compound with an ABX3 structure, where A is a monovalent inorganic cation Cs + , B is lead ion, X is halogen anion Br - .

[0057] S3: Then, slowly tear off the tape on the surface of the perovskite film along the same direction.

[0058] Implementation Case 4

[0059] S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer.

[0060] S2: Maintain an oxygen-free and water-free environment, apply 25N pressure to the tape at a temperature of 90°C, and stick the tape to the surface of the perovskite film light-absorbing layer under pressure for 15 minutes until the adhesive surface of the tape and the perovskite film light-absorbing layer undergo material exchange. The adhesive surface of the tape has a silicone pressure-sensitive adhesive material or an acrylic oil-based pressure-sensitive adhesive, and the viscosity of the adhesive surface is 3000 to 5000 mPa·s. The tape is a high-temperature tape, and the thickness of the adhesive surface of the tape does not exceed 0.1 mm. The perovskite film component is a perovskite compound with an ABX3 structure, where A is FA + and Cs + , B is Sn 2+ , X is a monovalent anion I - .

[0061] S3: Then, slowly tear off the tape on the surface of the perovskite film along the same direction.

[0062] The present invention closely combines the adhesive tape with the surface of the perovskite film, and the adhesiveness of the adhesive tape can remove the surface of the perovskite film, such as Pb 2+ and I -Ionic hanging bonds promote the stability of the perovskite surface structure. At the same time, special elements on the tape surface, such as Si, can enter the surface and grain boundaries of the perovskite material, improve the hydrophobicity of the perovskite film material, inhibit the degradation of the perovskite material, and thus further effectively improve the stability of the perovskite film material. The present invention provides a method for improving the stability of perovskite photovoltaic films based on tape tearing, which can ensure the high performance stability of perovskite solar cells and extend their service life. The method is simple to operate, economical and environmentally friendly, and can be widely used to improve the stability of all MAPbI3, FAPbI3 and CsPbBr3 and their multi-component mixed perovskite film materials. It has important scientific significance and social value for promoting the industrialization of perovskite materials in the field of optoelectronics technology, such as perovskite solar cells, photodetectors, light-emitting devices, etc.

[0063] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for improving the stability of perovskite photovoltaic thin films, characterized in that: It includes the following steps: S1: In an oxygen-free and water-free environment, expose the sticky side of the tape and immediately and evenly stick it on the surface of the perovskite film light-absorbing layer. S2: Maintain an oxygen-free and water-free environment, apply pressure to the tape, and stick the tape to the surface of the perovskite film light-absorbing layer under pressure for a set time until the adhesive surface of the tape and the perovskite film light-absorbing layer exchange substances. The adhesive surface of the tape has a silicone pressure-sensitive adhesive material, and the viscosity of the adhesive surface is 1000 to 5000 mPa·s. In step S2, a pressure of 10N to 40N is applied to the tape at a temperature of 20°C to 80°C, so that the tape is adhered to the surface of the perovskite film light absorption layer under pressure for 5 minutes to 20 minutes. The thickness of the adhesive surface of the tape does not exceed 0.2mm. S3: Then, the tape on the surface of the perovskite film is slowly torn off along the same direction. The adhesiveness of the tape can remove the ionic dangling bonds on the surface of the perovskite film, and introduce the new element Si into the surface and grain boundaries of the perovskite material, thereby improving the hydrophobicity of the perovskite film material and inhibiting the degradation of the perovskite material, thereby effectively improving the stability of the perovskite film material.

2. The method for improving the stability of a perovskite photovoltaic film according to claim 1, wherein: The perovskite film composition is a perovskite compound with ABX3 structure, in which A is mainly methylamine CH3NH3 + or carbamimidyl CH(NH2)2 + , B is lead ion, X is halogen anion I - .

3. The method for improving the stability of a perovskite photovoltaic film according to claim 1, wherein: The perovskite film composition is a perovskite compound with ABX3 structure, where A is a monovalent inorganic cation K + , Rb + or Cs + At least one of, B is a stannous ion, X is a halogen anion Cl - or Br - .

4. The method for improving the stability of a perovskite photovoltaic film according to claim 1, wherein: The perovskite film composition is a perovskite compound with ABX3 structure, where A is a monovalent inorganic cation K + , Rb + or Cs + At least one of the following, B is a stannous ion, and X is a monovalent anion thiocyanate or acetate ion.

5. A method for improving the stability of a perovskite photovoltaic film according to any one of claims 2 to 4, characterized in that: The adhesive tape is one or more of high temperature adhesive tape, 3M adhesive tape and transparent adhesive tape.

6. A perovskite photovoltaic film prepared by the method for improving the stability of a perovskite photovoltaic film according to any one of claims 1 to 5, wherein: The new element Si enters the surface and grain boundaries of the perovskite material to improve the hydrophobicity of the perovskite thin film material.

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