Method for preparing flexible perovskite solar cell substrate through screen printing and flexible perovskite solar cell

Abstract

The invention discloses a method for preparing a flexible perovskite solar cell substrate through screen printing and a flexible perovskite solar cell. The preparation method of the flexible substrate comprises the following steps: providing a high-molecular polymer precursor solution; placing a high-temperature-resistant silk screen plate above a glass substrate, transferring the high-molecular polymer precursor solution to one end of the high-temperature-resistant silk screen plate, applying pressure to the precursor solution on the silk screen plate through a scraper, moving towards the other end of the silk screen plate, extruding the precursor solution to the glass substrate from meshes by the scraper, and drying to obtain the high-molecular polymer precursor. Forming a high-molecular polymer wet film, and then annealing the high-molecular polymer wet film to obtain the flexible substrate. The flexible perovskite solar cell substrate prepared through silk-screen printing has few defects, so that each layer above the substrate can generate fewer non-radiative recombination centers, and the photoelectric conversion efficiency of a device is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials and devices, and in particular relates to a method for preparing a flexible perovskite solar cell substrate by screen printing and a flexible perovskite solar cell. Background Art

[0002] Organic-inorganic hybrid perovskite solar cells are the fastest-growing photovoltaic technology to date, with a world-certified efficiency of 25.8%, and have the potential to replace traditional silicon solar cells. Flexible perovskite solar cells have developed rapidly in recent years due to their excellent optoelectronic properties, light weight, low cost, and high production feasibility. Compared with rigid silicon-based solar cells, flexible perovskites show their unique commercial value and can be widely used in various industries such as wearable electronics, smart vehicles, medical testing, and building integration.

[0003] However, the flexible substrates currently used to prepare flexible perovskite devices are mostly commercially available products, which have certain defects. Many holes can be seen under a 5000x optical microscope. This defect causes non-radiative recombination centers to form in the layers above the substrate (transparent conductive layer, electron transport layer, perovskite layer, hole transport layer, and metal electrode), thereby affecting the photovoltaic performance of the flexible device. Therefore, it is particularly important to develop a method for preparing a high-quality flexible substrate. Summary of the invention

[0004] In view of the above shortcomings, the object of the present invention is to provide a method for preparing a flexible perovskite solar cell substrate by screen printing and a flexible perovskite solar cell. The flexible substrate prepared by screen printing in the present invention is of high quality and has few defects, thereby reducing the generation of non-radiative recombination centers in the layers above the substrate and improving the photovoltaic performance of the flexible perovskite solar cell.

[0005] To achieve the above object, the present invention is implemented through the following technical solutions:

[0006] A method for preparing a flexible perovskite solar cell substrate by screen printing, comprising the following steps:

[0007] S1. Providing a polymer precursor solution;

[0008] S2. Place a high temperature resistant silk screen plate above a glass substrate, transfer the polymer precursor solution to one end of the high temperature resistant silk screen plate, apply pressure to the precursor solution on the silk screen plate with a scraper, and move toward the other end of the silk screen plate at the same time. The precursor solution is squeezed from the mesh holes onto the glass substrate by the scraper to form a polymer wet film, and then the polymer wet film is annealed to obtain a flexible substrate.

[0009] Preferably, the high molecular polymer includes at least one of polyethylene terephthalate, polyamic acid, and polyethylene naphthalate.

[0010] Preferably, the pressure applied by the screen printing is 0.08±0.02 mPa, and the printing speed is 0.2-1.0 m / s.

[0011] Preferably, the annealing temperature is 80-220° C., and the annealing time is 0.5-2 h.

[0012] Preferably, during the screen printing process, the scraper is always in line contact with the glass substrate.

[0013] Preferably, the mesh number of the silk screen screen is 100-500 meshes, and the screen pattern area is 14 mm×20 mm.

[0014] The present invention also provides a flexible substrate prepared by the above preparation method.

[0015] On the other hand, the present invention also provides a flexible perovskite solar cell, comprising a flexible substrate prepared by the above-mentioned preparation method, a transparent electrode layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer, a modification layer and a metal electrode layer arranged in sequence on the flexible substrate, or a transparent electrode layer, a hole transport layer, a perovskite light absorption layer, an electron transport layer, a modification layer and a metal electrode layer arranged in sequence on the flexible substrate.

[0016] Preferably, the perovskite light absorbing layer is prepared by screen printing technology.

[0017] Preferably, the material of the perovskite light-absorbing layer includes an inorganic halide AX2 and an organic halide, wherein A=Pb or Sn, X=Cl, Br or I, and the organic halide is at least one of MAI and FAI.

[0018] The beneficial effects of the present invention are:

[0019] The flexible perovskite solar cell substrate prepared by screen printing in the present invention has very few defects, and each layer above the substrate can produce fewer non-radiative recombination centers, thereby solving the problem that the photovoltaic performance of flexible devices is reduced due to a large number of defects in commercially available flexible substrates.

[0020] The flexible perovskite solar cell made from the flexible substrate prepared by the present invention has a high energy conversion efficiency, overcomes the problems of current rigid perovskite solar cells being heavy, large in size, and inconvenient to carry, and meets the needs of the emerging flexible electronics market. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the drawings of the embodiment are briefly introduced below.

[0022] Figure 1 It is a schematic diagram of the structure of a flexible perovskite solar cell provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0024] The embodiment of the present invention provides a method for preparing a flexible perovskite solar cell substrate by screen printing, comprising the following steps:

[0025] S1. Providing a polymer precursor solution;

[0026] S2. Place a high temperature resistant screen plate above the glass substrate, transfer the polymer precursor solution to one end of the high temperature resistant screen plate, apply a pressure of 0.08±0.02mPa to the precursor solution on the screen plate through a scraper, and move toward the other end of the screen plate at a speed of 0.2-1.0m / s. The precursor solution is squeezed from the mesh to the glass substrate by the scraper to form a polymer wet film, and then the polymer wet film is annealed at a temperature of 80-220°C for 0.5-2h to obtain a flexible substrate. During the screen printing process, the scraper is always in line contact with the glass substrate.

[0027] The high molecular polymer of the present invention is any high molecular material that can form a flexible film. In one embodiment, the high molecular polymer includes but is not limited to polyethylene terephthalate, polyamic acid and polyethylene naphthalate.

[0028] The crystallization temperature affects the crystallization rate and film forming cycle, and thus affects the defect density of the flexible substrate. In a preferred embodiment, when the polymer is polyethylene terephthalate (PET), it can be PET pellets, waste PET sheets, etc., and the crystallization temperature (annealing temperature) is 110-140°C; when the polymer is polyamic acid, the annealing temperature is 80-100°C; when the polymer is polyethylene naphthalate (PEN), the annealing temperature is 121-220°C.

[0029] In one embodiment, the mesh size of the silk screen is 100-500 meshes, and the pattern area of ​​the screen is 14 mm×20 mm.

[0030] On the other hand, the present invention also provides a flexible perovskite solar cell, comprising a flexible substrate prepared by the above-mentioned preparation method, and a transparent electrode layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer, a modification layer and a metal electrode layer arranged on the flexible substrate in sequence.

[0031] In one embodiment, the perovskite light absorbing layer is prepared by screen printing technology.

[0032] In one embodiment, the material of the perovskite light-absorbing layer includes an inorganic halide AX2 and an organic halide, wherein A=Pb or Sn, X=Cl, Br or I, and the organic halide is at least one of MAI and FAI.

[0033] The present invention will be further described below by means of specific examples.

[0034] Example 1

[0035] A method for preparing a flexible perovskite solar cell substrate by screen printing, comprising the following steps:

[0036] S1. Melting the PET pellets at 250-255° C. to obtain a PET melt;

[0037] S2. Place a high temperature resistant screen plate on the glass substrate, the screen plate has a mesh size of 100 and a pattern area of ​​14 mm×20 mm; transfer the PET melt to one end of the high temperature resistant screen plate, apply a pressure of 0.08±0.02 mPa to the PET melt on the screen plate through a scraper, and move toward the other end of the screen plate at a speed of 0.2-1.0 m / s. The PET melt is squeezed from the mesh holes by the scraper onto the glass substrate to form a wet polymer film, and then the wet polymer film is annealed at 140°C for 2h to form a PET film, which is peeled off from the glass substrate to obtain a screen-printed PET flexible substrate. During the printing process, the scraper is always in line contact with the glass substrate.

[0038] Example 2

[0039] A method for preparing a flexible perovskite solar cell substrate by screen printing, comprising the following steps:

[0040] S1. Dissolve pyromellitic anhydride and p-phenylenediamine in dimethylacetamide solvent in a nitrogen atmosphere, stir for 30 to 50 minutes at -20 to -5°C for low-temperature polycondensation, and obtain a soluble polyamic acid solution with a certain viscosity. Put the obtained polyamic acid solution into a vacuum device to remove bubbles in the solution, and obtain the polyamic acid ink required for screen printing;

[0041] S2. Place a high temperature resistant screen plate on the glass substrate, the screen mesh number is 500 mesh, and the pattern area is 14mm×20mm; transfer the polyamic acid ink to one end of the high temperature resistant screen plate, apply a pressure of 0.08±0.02mPa to the polyamic acid ink on the screen plate through a scraper, and move toward the other end of the screen plate at a speed of 0.2-1.0m / s. The polyamic acid ink is squeezed from the mesh to the glass substrate by the scraper. After standing for 5 minutes, the polymer wet film is annealed at 100℃ for 1.5h to form a thin film, and the film is peeled off from the glass substrate with an ordinary scraper, and then embedded in a metal frame to clamp to prevent the film from shrinking and deforming due to heat during high temperature imidization, and then high temperature imidization is carried out in a high temperature blast oven at 200-450℃ for 10-60min to obtain a PI film, which is a screen-printed PI flexible substrate. During the printing process, the scraper is always in line contact with the glass substrate.

[0042] Example 3

[0043] A method for preparing a flexible perovskite solar cell substrate by screen printing, comprising the following steps:

[0044] S1. Melting the PEN pellets at 265-270° C. to obtain a PEN melt;

[0045] S2. Place a high temperature resistant screen plate on the glass substrate, the screen has a mesh size of 300 and a pattern area of ​​14 mm × 20 mm; transfer the PEN melt to one end of the high temperature resistant screen plate, apply a pressure of 0.08 ± 0.02 mPa to the PEN melt on the screen plate through a scraper, and move toward the other end of the screen plate at a speed of 0.2 to 1.0 m / s. The PEN melt is squeezed from the mesh to the glass substrate by the scraper. After standing for 3 minutes, the polymer wet film is annealed at 220 ° C for 2 hours to form a PEN film, which is peeled off from the glass substrate to obtain a screen-printed PEN flexible substrate. During the printing process, the scraper is always in line contact with the glass substrate.

[0046] Example 4

[0047] like Figure 1 As shown, this embodiment provides a flexible perovskite solar cell, wherein the layers are a flexible substrate layer, a transparent electrode layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer, a modification layer and a metal electrode layer. The preparation method thereof is as follows:

[0048] Transparent conductive substrate: The PET flexible substrate prepared in Example 1 is selected as the substrate layer, and the ITO material is spin-coated on the PET flexible substrate to form an ITO transparent conductive electrode layer.

[0049] Electron transport layer: The SnO2 solution is spin-coated on the ITO transparent conductive electrode layer at 3000 rpm for 30 seconds. After the spin coating, the solution is gradient annealed at 80-110°C for 1.5 hours to form a SnO2 electron transport layer.

[0050] Perovskite layer:

[0051] Weigh 259.5 mg of lead iodide, 76.1 mg of iodomethane, and 14.5 mg of iodine methyl ether, dissolve the three in 1 mL of methylamine acetate (MAAc) solvent, stir the mixture at 60±10°C for 12 hours in a glove box filled with inert gas, and then let it stand for 1-2 hours in a 10-15°C environment to prepare a perovskite precursor solution. Place the wire mesh above the electron transport layer, use a pipette to transfer the prepared perovskite precursor solution to one end of the wire mesh, apply a pressure of 0.1 mPa to the perovskite precursor solution of the wire mesh by a scraper, and move toward the other end of the wire mesh at a speed of 0.4 m / s. The perovskite precursor solution is squeezed from the mesh by the scraper onto a flexible substrate with an electron transport material. After standing for 1-2 minutes, the perovskite wet film is annealed at 100°C for 5 minutes to obtain a dense and uniform perovskite film. The scraper is always in line contact with the screen mesh and the flexible substrate. The screen mesh number is 400 meshes.

[0052] Hole transport layer:

[0053] Weigh 73.2 mg of Spiro-OMeTAD and dissolve it in 1 mL of chlorobenzene; dissolve 520 mg of lithium bis(trifluoromethanesulfonyl)imide in 1 mL of acetonitrile solution to prepare a lithium salt solution; add 28.8 μL of TBP solution to the Spiro-OMeTAD solution, and then add 17.6 μL of lithium salt solution, stir the mixed solution at room temperature for 2 hours to obtain a Spiro-OMeTAD mixed solution. Spin-coat the Spiro-OMeTAD mixed solution on the screen-printed perovskite layer at 3000 rpm for 30 seconds, and then oxidize it in a dry oxidation tank for 20 hours to form a hole transport layer.

[0054] Modified layer and metal electrode

[0055] A 22nm modified layer of MoO3 and a 200nm metal Ag electrode were sequentially vacuum-evaporated on the hole transport layer to obtain a flexible perovskite solar cell.

[0056] Example 5

[0057] A flexible perovskite solar cell is basically the same as Example 4, except that the flexible substrate is the PI flexible substrate prepared in Example 2.

[0058] Example 6

[0059] A flexible perovskite solar cell is basically the same as Example 4, except that the flexible substrate is the PEN flexible substrate prepared in Example 3.

[0060] Comparative Example 1

[0061] The preparation method of the flexible perovskite solar cell in this comparative example is basically the same as that in Example 4, except that the flexible substrate is a commercially available polyethylene naphthalate (PEN) flexible substrate.

[0062] Under standard test conditions (AM1.5G illumination), the energy conversion efficiency of the flexible perovskite solar cells prepared in Examples 4 to 6 and Comparative Example 1 was tested, and the results are shown in Table 1 below.

[0063] Table 1 Energy conversion efficiency of perovskite solar cells prepared in Examples 4 to 6 and Comparative Example 1

[0064] project Efficiency Example 4 18.2％ Example 5 21.6％ Example 6 20.5％ Comparative Example 1 15.54％

[0065] It can be seen from Table 1 that the flexible perovskite solar cell prepared by the present invention has a high energy conversion efficiency. The energy conversion efficiency of Example 6 is significantly better than that of Comparative Example 1. This is attributed to the preparation of a high-quality, low-defect flexible substrate by screen printing, which enables each layer above the substrate (transparent conductive layer, electron transport layer, perovskite layer, hole transport layer and metal electrode) to produce fewer non-radiative recombination centers, thereby improving device performance.

[0066] It should be noted that the above embodiments all belong to the same inventive concept, and the description of each embodiment has its own focus. For matters that are not described in detail in some embodiments, reference may be made to the description in other embodiments.

[0067] The above-mentioned embodiments only express the 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, which 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 method for preparing a flexible perovskite solar cell substrate by screen printing, characterized in that: The following steps are involved: S1. Providing a polymer precursor solution; S2. Place a high temperature resistant silk screen plate above a glass substrate, transfer the polymer precursor solution to one end of the high temperature resistant silk screen plate, apply pressure to the precursor solution on the silk screen plate with a scraper, and move toward the other end of the silk screen plate at the same time. The precursor solution is squeezed from the mesh holes onto the glass substrate by the scraper to form a polymer wet film, and then the polymer wet film is annealed to obtain a flexible substrate.

2. The method for preparing a flexible perovskite solar cell substrate by screen printing according to claim 1, characterized in that: The high molecular polymer includes at least one of polyethylene terephthalate, polyamic acid, and polyethylene naphthalate.

3. The method for preparing a flexible perovskite solar cell substrate by screen printing according to claim 1, characterized in that: The pressure applied by the screen printing is 0.08±0.02 mPa, and the printing speed is 0.2-1.0 m / s.

4. The method for preparing a flexible perovskite solar cell substrate by screen printing according to claim 1, characterized in that: The annealing temperature is 80-220° C., and the annealing time is 0.5-2 hours.

5. The method for preparing a flexible perovskite solar cell substrate by screen printing according to claim 1, characterized in that: During the screen printing process, the scraper is always in line contact with the glass substrate.

6. The method for preparing a flexible perovskite solar cell substrate by screen printing according to claim 1, characterized in that: The mesh number of the silk screen mesh plate is 100 to 500 meshes.

7. A flexible substrate prepared by the method according to any one of claims 1 to 6.

8. A flexible perovskite solar cell, characterized in that: It comprises the flexible substrate as claimed in claim 7, and a transparent electrode layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer, a modification layer and a metal electrode layer are sequentially arranged on the flexible substrate.

9. The flexible perovskite solar cell according to claim 8, characterized in that: The perovskite light-absorbing layer is prepared by screen printing technology.

10. The flexible perovskite solar cell according to claim 8, characterized in that: The material of the perovskite light-absorbing layer includes an inorganic halide AX2 and an organic halide, wherein A=Pb or Sn, X=Cl, Br or I, and the organic halide is at least one of MAI and FAI.

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