A perovskite solar cell and its fabrication method

Abstract

This invention relates to the field of new energy materials technology, and particularly to a perovskite solar cell and its preparation method. The preparation method includes: A) coating an electron transport layer slurry onto a conductive substrate and heating to form an electron transport layer; coating an insulating layer slurry onto the electron transport layer and heating to form an insulating layer; coating a protective material onto the insulating layer and curing to obtain a protective film; coating a carbon slurry onto the protective film, heating to form a carbon electrode and causing the protective film to evaporate, obtaining a blank device; and specifying the raw materials for preparing the electron transport layer slurry, insulating layer slurry, and carbon slurry; B) dropping a perovskite precursor solution onto the carbon electrode of the blank device, and after the perovskite precursor solution has fully penetrated into the carbon electrode, insulating layer, and electron transport layer, annealing to obtain a perovskite-containing device; C) covering with a backplate, connecting wires, and applying sealant to obtain a mesoporous perovskite solar cell. This method effectively prevents short circuits and exhibits superior electrochemical performance.

Description

Technical Field

[0001] This invention relates to the field of new energy materials technology, and in particular to a perovskite solar cell and its preparation method. Background Technology

[0002] Perovskite solar cells possess advantages such as high theoretical conversion efficiency and low cost, making them a potential next-generation solar cell alternative to silicon-based solar cells. Mesoporous perovskite solar cells offer significant advantages in increasing the contact area between perovskite and the charge transport layers (electron transport layer and hole transport layer), enhancing carrier separation, and improving the cell's photoelectric conversion efficiency. Their fabrication method involves first preparing a slurry of nanoscale electron transport materials, hole transport materials, and insulating layers, which is then coated onto a conductive substrate. The solvent is removed to form a porous structure. Next, a perovskite precursor solution is infiltrated into the porous structure, and perovskite crystallization is induced through methods such as heating and evaporation, thus producing a mesoporous perovskite solar cell.

[0003] The key to the fabrication of mesoporous perovskite solar cells lies in the preparation of high-performance pastes. Perovskite solar cell pastes generally use terpineol as a solvent, and ethyl cellulose and lauric acid as thickeners and surfactants, respectively, and are prepared through processes such as mixing and rotary evaporation (see Nano Lett. 2014, 14, 2, 1000-1004, patent CN202210806436.4, etc.). A representative mesoporous perovskite solar cell technology is the three-layer mesoporous carbon electrode mesoporous perovskite solar cell (see reference J. Phys. Chem. Lett. 2014, 5, 17, 2927-2934). This method involves sequentially coating an electron transport layer paste, an insulating layer paste, and a carbon paste onto FTO glass. The paste is then heated and calcined to remove terpineol and induce the decomposition and volatilization of ethyl cellulose to create pores, forming a perovskite-free "blank device." A perovskite precursor solution is then dropped onto the blank device, penetrating into the porous structure. Finally, perovskite crystallization is induced through heating and evaporation, thus fabricating the perovskite solar cell. This method eliminates the need for a hole transport layer, significantly reducing costs. Furthermore, the carbon electrode does not chemically react with the perovskite, improving the cell's stability.

[0004] However, in the fabrication of three-layer mesoporous carbon electrode perovskite solar cells, the problem of short circuits in blank devices is frequently encountered. After the carbon paste is coated onto the insulating layer paste, due to the strong solubility and permeability of terpineol in the paste, the carbon paste often penetrates through the insulating layer and comes into contact with the electron transport layer, leading to short circuits and leakage. The decrease in the leakage resistance of the battery device greatly increases leakage loss, causing a precipitous drop in the device's photoelectric conversion efficiency. In previous production practices, the method mostly adopted was to cool and age the device coated with the insulating layer before applying the carbon paste to alleviate the corrosion of the insulating layer by the carbon paste, but this could not completely avoid the problem of carbon electrode penetration into the insulating layer and short circuits. For the production of large-area cells, this short circuit problem has a particularly serious impact. Therefore, it is urgent to develop a process that can effectively prevent carbon paste from corroding the insulating layer, prevent the carbon electrode from contacting the electron transport layer, and prevent short circuits. Summary of the Invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide a perovskite solar cell and a method for preparing the same, which can effectively prevent the short circuit problem of the three-layer mesoporous carbon electrode perovskite solar cell and the resulting perovskite solar cell has better electrochemical performance.

[0006] This invention provides a method for preparing a perovskite solar cell, comprising the following steps:

[0007] A) An electron transport layer paste is coated onto a conductive substrate and heated and annealed to form an electron transport layer; an insulating layer paste is coated onto the electron transport layer and dried to form an insulating layer; a protective material is then coated onto the insulating layer and cured to obtain a protective film; a carbon paste is then coated onto the protective film and heated and annealed to form a carbon electrode and allow the protective film to evaporate, resulting in a blank device without perovskite.

[0008] The raw materials for preparing the electron transport layer slurry consist of terpineol, dispersant, thickener, ethanol, and electron transport material; the raw materials for preparing the insulating layer slurry consist of terpineol, dispersant, thickener, ethanol, and insulating material; the raw materials for preparing the carbon slurry consist of terpineol, dispersant, thickener, ethanol, and carbon material.

[0009] B) The perovskite precursor solution is dropped onto the carbon electrode of the blank device. After the perovskite precursor solution has fully penetrated into the carbon electrode, the insulating layer and the electron transport layer, the device is annealed to obtain a perovskite-containing device.

[0010] C) Add a backplate to the bottom electrode of the device obtained in step B), connect the wires, and apply sealant to obtain a mesoporous perovskite solar cell.

[0011] Preferably, the protective material is selected from at least one of petrolatum, paraffin, stearic acid, and oleic acid.

[0012] Preferably, the dispersant is selected from at least one of acetylacetone, lauric acid, and acetic acid; the volume of the dispersant is 1% to 10% of the volume of terpineol.

[0013] The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; the ratio of the thickener to the terpineol is 50-250 mg: 1 mL;

[0014] The volume of the ethanol is 1 to 3 times that of terpineol.

[0015] Preferably, the electron transport material includes TiO2, SnO2, or ZnO;

[0016] The electron transport material is nanoparticles with a particle size of 10–100 nm;

[0017] In the preparation of the electron transport layer slurry, the ratio of electron transport material to terpineol is 50-200 mg: 1 mL.

[0018] Preferably, the method for preparing the electron transport layer slurry includes the following steps:

[0019] Terpineol, dispersant, thickener, ethanol and electron transport material are mixed, and the ethanol is removed by rotary evaporation to obtain an electron transport layer slurry;

[0020] The rotary evaporation process uses a rotation speed of 15–60 rpm, a gas pressure of 15–50 mbar, a heating temperature of 45–60°C, and a time of 4–12 h.

[0021] Preferably, the insulating layer material includes ZrO2, Al2O3, or SiO2;

[0022] The insulating layer material is nanoparticles with a particle size of 10-100 nm;

[0023] In the raw materials for preparing the insulating layer slurry, the ratio of the insulating layer material to the terpineol is 150-450 mg: 1 mL.

[0024] The method for preparing the insulating layer slurry includes the following steps:

[0025] Terpineol, dispersant, thickener, ethanol and insulating material are mixed, and the ethanol is removed by rotary evaporation to obtain insulating slurry;

[0026] The rotary evaporation process uses a rotation speed of 15–60 rpm, a gas pressure of 15–50 mbar, a heating temperature of 45–60°C, and a time of 4–12 h.

[0027] Preferably, the carbon material is selected from graphite and conductive carbon black;

[0028] The ratio of the carbon material to the terpineol is 150-450 mg: 1 mL;

[0029] The method for preparing the carbon slurry includes the following steps:

[0030] Terpineol, dispersant, thickener, ethanol and carbon materials are mixed, and the ethanol is removed by rotary evaporation to obtain carbon slurry;

[0031] The rotary evaporation process uses a rotation speed of 15–60 rpm, a gas pressure of 15–50 mbar, a heating temperature of 45–60°C, and a time of 4–12 h.

[0032] Preferably, the coating thickness of the electron transport layer slurry is 0.5–2 μm;

[0033] The coating thickness of the insulating layer slurry is 1–3 μm;

[0034] The thickness of the protective film is 0.1–10 μm;

[0035] The coating thickness of the carbon slurry is 10–50 μm.

[0036] Preferably, in step B), the solvent in the perovskite precursor solution includes at least one of dimethylformamide and dimethyl sulfoxide; the solute is ABX3; wherein A is at least one of methylamine ion, formamidinium ion, and cesium ion, and B is Pb 2+ and Sn 2+ At least one of them, X is I - ,Br - and Cl - At least one of them;

[0037] The concentration of the perovskite precursor solution is 1.0–1.5 mol / L;

[0038] The perovskite precursor solution was added to the blank device at a rate of 2–4 μL / cm². 2 ;

[0039] The annealing temperature is 60–120°C, and the time is 4–24 hours.

[0040] The present invention also provides a perovskite solar cell prepared by the preparation method described above.

[0041] This invention employs a sacrificial protective film method, temporarily introducing a protective film between the insulating layer and the carbon electrode. During the coating process, the protective film prevents the carbon slurry from penetrating the insulating layer, thus preventing short circuits. During subsequent heating and drying, the protective film evaporates without hindering the penetration of the perovskite precursor solution into the device. This invention effectively prevents short circuits in three-layer mesoporous carbon electrode perovskite solar cells, resulting in perovskite solar cells with superior electrochemical performance. This is of great significance for improving device yield and producing large-area cells. Attached Figure Description

[0042] Figure 1 This is a comparison diagram of the coating method for perovskite solar cells and the present invention;

[0043] Figure 2 The IV test curves are those of the mesoporous perovskite solar cells obtained in Examples 1-3 and the comparative examples of the present invention. Detailed Implementation

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0045] This invention provides a method for preparing a perovskite solar cell, comprising the following steps:

[0046] A) An electron transport layer paste is coated onto a conductive substrate and heated and annealed to form an electron transport layer; an insulating layer paste is coated onto the electron transport layer and dried to form an insulating layer; a protective material is then coated onto the insulating layer and cured to obtain a protective film; a carbon paste is then coated onto the protective film and heated and annealed to form a carbon electrode and allow the protective film to evaporate, resulting in a blank device without perovskite.

[0047] The raw materials for preparing the electron transport layer slurry consist of terpineol, dispersant, thickener, ethanol, and electron transport material; the raw materials for preparing the insulating layer slurry consist of terpineol, dispersant, thickener, ethanol, and insulating material; the raw materials for preparing the carbon slurry consist of terpineol, dispersant, thickener, ethanol, and carbon material.

[0048] B) The perovskite precursor solution is dropped onto the carbon electrode of the blank device. After the perovskite precursor solution has fully penetrated into the carbon electrode, the insulating layer and the electron transport layer, the device is annealed to obtain a perovskite-containing device.

[0049] C) Add a backplate to the bottom electrode of the device obtained in step B), connect the wires, and apply sealant to obtain a mesoporous perovskite solar cell.

[0050] In step A):

[0051] An electron transport layer paste is coated onto a conductive substrate and heated and annealed to form an electron transport layer; an insulating layer paste is coated onto the electron transport layer and dried to form an insulating layer; a protective material is then coated onto the insulating layer and cured to obtain a protective film; a carbon paste is then coated onto the protective film and heated and annealed to form a carbon electrode and allow the protective film to evaporate, resulting in a blank device without perovskite.

[0052] The raw materials for preparing the electron transport layer slurry consist of terpineol, dispersant, thickener, ethanol, and electron transport material; the raw materials for preparing the insulating layer slurry consist of terpineol, dispersant, thickener, ethanol, and insulating material; and the raw materials for preparing the carbon slurry consist of terpineol, dispersant, thickener, ethanol, and carbon material.

[0053] Regarding conductive substrates:

[0054] The conductive substrate includes FTO glass, ITO glass, or other any transparent conductive substrate, preferably FTO glass. The film thickness of the conductive substrate is 200–500 nm, preferably 350 nm.

[0055] Regarding the electron transport layer:

[0056] The electron transport material includes TiO2, SnO2, ZnO, or other arbitrary n-type semiconductor materials.

[0057] The electron transport material is nanoparticles with a particle size of 10–100 nm; preferably, the particle size is 30–50 nm.

[0058] The ratio of the electron transport material to the terpineol is 50-200 mg: 1 mL, for example, 100 mg: 1 mL.

[0059] The dispersant is selected from at least one of acetylacetone, lauric acid and acetic acid; specifically, it is acetylacetone, lauric acid and acetic acid in a volume ratio of 1:1:2; the volume of the dispersant is 1% to 10% of the volume of terpineol, preferably 4%.

[0060] The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; specifically, it is ethyl cellulose and polyethylene glycol; the average molecular weight of the thickener is 5000 to 20000, preferably 10000; the ratio of the thickener to the terpineol is 50 to 250 mg: 1 mL, for example 150 mg: 1 mL.

[0061] The volume of ethanol is 1 to 3 times that of terpineol, preferably 2 times.

[0062] The preparation method of the electron transport layer slurry includes the following steps:

[0063] Terpineol, dispersant, thickener, ethanol and electron transport material are mixed, and the ethanol is removed by rotary evaporation to obtain electron transport layer slurry.

[0064] The mixing is at least one of mechanical stirring, ball milling, sand milling, ultrasonic mixing, and high-shear emulsification; the mixing time is ≥12h.

[0065] The rotary evaporation process uses a rotation speed of 15–60 rpm, preferably 30 rpm; a gas pressure of 15–50 mbar, preferably 20 mbar; a heating temperature of 45–60°C, preferably 50°C; and a heating time of 4–12 h, preferably 6 h.

[0066] The coating thickness of the electron transport layer paste is 0.5–2 μm, preferably 0.8 μm.

[0067] The coating method is slot coating, bar coating, screen printing, or any other paste coating method.

[0068] The temperature for the heating annealing to form the electron transport layer is 400–600°C, preferably 500°C; the time is 15–60 min, preferably 40 min.

[0069] Regarding the insulation layer:

[0070] The insulating layer material includes ZrO2, Al2O3, SiO2, or other arbitrary insulating materials.

[0071] The insulating layer material is nanoparticles with a particle size of 10-100 nm; preferably, the particle size is 30-50 nm.

[0072] The ratio of the insulating layer material to the terpineol is 150-450 mg: 1 mL, for example, 250 mg: 1 mL.

[0073] The dispersant is selected from at least one of acetylacetone, lauric acid and acetic acid; specifically, it is acetylacetone, lauric acid and acetic acid in a volume ratio of 1:1:2; the volume of the dispersant is 1% to 10% of the volume of terpineol, preferably 4%.

[0074] The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; specifically, it is ethyl cellulose and polyethylene glycol; the average molecular weight of the thickener is 5000 to 20000, preferably 10000; the ratio of the thickener to the terpineol is 50 to 250 mg: 1 mL, for example 150 mg: 1 mL.

[0075] The volume of ethanol is 1 to 3 times that of terpineol, preferably 2 times.

[0076] The method for preparing the insulating layer slurry includes the following steps:

[0077] Terpineol, dispersant, thickener, ethanol and insulating material are mixed, and the ethanol is removed by rotary evaporation to obtain insulating slurry.

[0078] The mixing is at least one of mechanical stirring, ball milling, sand milling, ultrasonic mixing, and high-shear emulsification; the mixing time is ≥12h.

[0079] The rotary evaporation process uses a rotation speed of 15–60 rpm, preferably 30 rpm; a gas pressure of 15–50 mbar, preferably 20 mbar; a heating temperature of 45–60°C, preferably 50°C; and a heating time of 4–12 h, preferably 6 h.

[0080] The coating thickness of the insulating slurry is 1–3 μm, preferably 1.5 μm.

[0081] The coating method is slot coating, bar coating, screen printing, or any other paste coating method.

[0082] The temperature at which the insulating layer is formed by heating is 400–600°C, preferably 500°C; and the time is 15–60 min, preferably 40 min.

[0083] Regarding the protective film:

[0084] The protective material is selected from organic compounds that are solid at room temperature and volatile above 300°C; such as at least one of petrolatum, paraffin, stearic acid and oleic acid; the petrolatum can be white petrolatum; preferably, white petrolatum and stearic acid are used in a mass ratio of 1:1; or paraffin and oleic acid are used in a mass ratio of 1:1.

[0085] The coating method is slot coating, bar coating, screen printing, or any other paste coating method.

[0086] The thickness of the protective film is 0.1 to 10 μm, preferably 1 μm.

[0087] Regarding carbon electrodes:

[0088] The carbon material is selected from graphite and conductive carbon black; preferably, graphite with a particle size of 5-10 μm (preferably 7 μm) and conductive carbon black with a particle size of 30-50 nm (preferably 30 nm) are used in a mass ratio of 4:1.

[0089] The ratio of the carbon material to the terpineol is 150-450 mg: 1 mL, for example, 250 mg: 1 mL.

[0090] The dispersant is selected from at least one of acetylacetone, lauric acid and acetic acid; specifically, it is acetylacetone, lauric acid and acetic acid in a volume ratio of 1:1:2; the volume of the dispersant is 1% to 10% of the volume of terpineol, preferably 4%.

[0091] The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; specifically, it is ethyl cellulose and polyethylene glycol; the average molecular weight of the thickener is 5000 to 20000, preferably 10000; the ratio of the thickener to the terpineol is 50 to 250 mg: 1 mL, for example 150 mg: 1 mL.

[0092] The volume of ethanol is 1 to 3 times that of terpineol, preferably 2 times.

[0093] The method for preparing the carbon slurry includes the following steps:

[0094] Terpineol, dispersant, thickener, ethanol, and carbon materials are mixed, and the ethanol is removed by rotary evaporation to obtain a carbon slurry.

[0095] The mixing is at least one of mechanical stirring, ball milling, sand milling, ultrasonic mixing, and high-shear emulsification; the mixing time is ≥12h.

[0096] The rotary evaporation process uses a rotation speed of 15–60 rpm, preferably 30 rpm; a gas pressure of 15–50 mbar, preferably 20 mbar; a heating temperature of 45–60°C, preferably 50°C; and a heating time of 4–12 h, preferably 6 h.

[0097] The coating thickness of the carbon slurry is 10–50 μm, preferably 25 μm.

[0098] The coating method is slot coating, bar coating, screen printing, or any other paste coating method.

[0099] The temperature at which the insulating layer is formed by heating is 400–600°C, preferably 500°C; and the time is 15–60 min, preferably 40 min.

[0100] In step B):

[0101] The perovskite precursor solution was dropped onto the carbon electrode of the blank device. After the perovskite precursor solution had fully penetrated into the carbon electrode, the insulating layer and the electron transport layer, the device was annealed to obtain a perovskite-containing device.

[0102] The perovskite precursor solution contains at least one solvent selected from dimethylformamide (DMF) and dimethyl sulfoxide (DMSO); the solute is ABX3 (where A is at least one selected from methylamine (MA) ion, formamidinium (FA) ion, and cesium (Cs) ion, and B is Pb). 2+ and Sn 2+ At least one of them, X is I - ,Br - and Cl - At least one of them), such as MA 0.4 FA 0.6 PbI3. In some embodiments, the solvent comprises DMF and DMSO in a volume ratio of 4:1.

[0103] The concentration of the perovskite precursor solution is 1.0–1.5 mol / L, preferably 1.2 mol / L.

[0104] The perovskite precursor solution was added to the blank device at a rate of 2–4 μL / cm². 2 Preferably 3 μL / cm 2 .

[0105] The annealing temperature is 60–120°C, and the time is 4–24 h; preferably, when the annealing temperature is 60°C / 80°C / 100°C / 120°C, the corresponding times are 24 h / 16 h / 8 h / 4 h, respectively. The annealing is used to remove the solvent from the perovskite precursor solution and precipitate the perovskite.

[0106] In step C):

[0107] A backplate is added to the bottom electrode of the device obtained in step B), wires are connected, and sealant is applied to obtain a mesoporous perovskite solar cell.

[0108] The back panel can be made of glass, plexiglass, or other non-breathable materials.

[0109] The present invention does not impose any special restrictions on the method of connecting the wires; any method of connecting the wires that is well known to those skilled in the art can be used.

[0110] The sealant can be a commercially available sealant, with common components being epoxy resin or ethylene-vinyl acetate copolymer.

[0111] Figure 1 This is a comparison diagram of the coating methods for this invention and traditional perovskite solar cells. From... Figure 1As can be seen, the traditional coating process involves coating carbon electrode paste onto the ZrO2 insulating layer. This can lead to the carbon paste dissolving and penetrating the ZrO2 insulating layer, resulting in short circuits and reduced efficiency. The core of the method used in this invention is that a protective layer is pre-coated on the surface of the ZrO2 insulating layer. The carbon electrode cannot dissolve or corrode the ZrO2 insulating layer during coating, thus preventing short circuits and improving device efficiency.

[0112] Beneficial effects:

[0113] 1) This invention can effectively prevent battery short circuits: Because there is a protective film between the insulating layer and the carbon slurry, the carbon slurry cannot completely corrode the protective film before drying, thus preventing the carbon slurry from penetrating the insulating layer and contacting the electron transport layer, and preventing the device from short-circuiting.

[0114] 2) The process is simple, the equipment cost is low, and the production process is mild, low-risk, and easy to operate.

[0115] 3) Low cost: The main raw materials used, such as petrolatum, paraffin, and stearic acid, are all common and inexpensive chemical raw materials, eliminating the need for expensive raw materials or equipment, thus reducing costs.

[0116] 4) High device performance: The device obtained by this invention does not experience internal short circuits, reducing leakage current loss and thus ensuring the photoelectric conversion efficiency of the solar cell.

[0117] 5) Facilitates large-area production: Large-area perovskite solar cells are more sensitive to short-circuit problems. This invention significantly reduces the risk of internal short circuits in the cell, which is beneficial for manufacturing large-area perovskite solar cells.

[0118] The present invention does not impose any special restrictions on the source of the raw materials used above, and they can be commercially available.

[0119] To further illustrate the present invention, the following detailed description of a perovskite solar cell and its preparation method provided by the present invention is provided in conjunction with embodiments, but it should not be construed as limiting the scope of protection of the present invention.

[0120] Example 1

[0121] 1) Preparation of electron transport layer slurry:

[0122] The electron transport layer slurry was obtained by sequentially emulsifying the following materials: 20 mL of terpineol, 40 mL of ethanol, 0.2 mL of acetylacetone, 0.4 mL of acetylacetone, 0.2 mL of lauric acid, 2 g of ethyl cellulose (average molecular weight 10000) and 1 g of polyethylene glycol (average molecular weight 10000), and 2 g of TiO2 with a particle size of 30–50 nm. The mixture was then subjected to high-shear emulsification for 1 h (6000 rpm), ball milling for 24 h (300 rpm), ultrasonication for 1 h, and rotary evaporation at 45 °C for 6 h (20 mbar).

[0123] 2) Preparation of insulating layer paste:

[0124] The insulating slurry was prepared by using 20 mL of terpineol, 40 mL of ethanol, 0.2 mL of acetylacetone, 0.4 mL of acetylacetone, 0.2 mL of lauric acid, 2 g of ethyl cellulose (average molecular weight 10000) and 1 g of polyethylene glycol (average molecular weight 10000), and 5 g of ZrO2 with a particle size of 30-50 nm. The mixture was then subjected to high-shear emulsification for 1 h (6000 rpm), ball milling for 24 h (300 rpm), ultrasonication for 1 h, and rotary evaporation at 45 °C for 6 h (20 mbar) to remove the ethanol.

[0125] 3) Preparation of carbon slurry:

[0126] A carbon slurry was prepared by sequentially emulsifying the following materials: 20 mL of terpineol, 40 mL of ethanol, 0.2 mL of acetylacetone, 0.4 mL of acetic acid, 0.2 mL of lauric acid, 2 g of ethyl cellulose (average molecular weight 10000) and 1 g of polyethylene glycol (average molecular weight 10000), 4 g of graphite with a particle size of 7 μm and 1 g of conductive carbon black with a particle size of 30 nm, under high shear emulsification for 1 h (6000 rpm), ball milling for 24 h (300 rpm), ultrasonication for 1 h, and rotary evaporation at 45 °C for 6 h (20 mbar).

[0127] 4) An electron transport layer paste is coated onto a conductive substrate to a thickness of 0.8 μm, and heated at 500 °C for 40 min to form an electron transport layer. An insulating layer paste is coated onto the electron transport layer to a thickness of 1500 nm (1.5 μm), and heated at 500 °C for 40 min to form an insulating layer. A protective material (white petrolatum and stearic acid in a mass ratio of 1:1) is then coated onto the insulating layer and cured to obtain a protective film with a thickness of 1 μm. A carbon paste is then coated onto the protective film to a thickness of 40 μm, and heated at 400 °C for 40 min to form a carbon electrode and allow the protective film to evaporate, resulting in a blank device without perovskite.

[0128] 5) Prepare the perovskite precursor solution (solvents include DMF and DMSO, volume ratio 4:1; solute is MA). 0.4 FA 0.6 PbI3 (1.2 mol / L) was added dropwise to the bottom electrode of the blank device (dropping volume: 3 μL / cm). 2 After the perovskite precursor solution has fully penetrated into the carbon electrode, insulating layer and electron transport layer, it is annealed at 80°C for 16 hours to obtain a perovskite-containing device.

[0129] 6) Add a backplate to the bottom electrode of the device obtained in step 5), connect the wires, and apply sealant to obtain a mesoporous perovskite solar cell.

[0130] Example 2

[0131] The difference from Example 1 is as follows:

[0132] In step 4): the thickness of the protective film is 5 μm.

[0133] All other steps are the same as in Example 1, resulting in a mesoporous perovskite solar cell.

[0134] Example 3

[0135] The difference from Example 1 is as follows:

[0136] In step 4): the protective materials are paraffin and oleic acid in a mass ratio of 1:1.

[0137] All other steps are the same as in Example 1, resulting in a mesoporous perovskite solar cell.

[0138] Comparative Example

[0139] The difference from Example 1 is as follows:

[0140] In step 4): No protective film is set, and the carbon paste is directly applied to the insulating layer.

[0141] All other steps are the same as in Example 1, resulting in a mesoporous perovskite solar cell.

[0142] Figure 2 The IV test curves are shown for the mesoporous perovskite solar cells obtained in Examples 1-3 and the comparative example of this invention. The IV test used a steady-state solar light source, with a test scan range of 1V to 0V, employing reverse scanning at a scan rate of 50mV / s. Figure 2 It can be seen that the voltage and current in the three embodiments are significantly higher than those in the comparative example.

[0143] The electrical performance of the mesoporous perovskite solar cells obtained in Examples 1-3 and the comparative example of the present invention was tested, and the results are shown in Table 1. The test conditions were the same as described above. Figure 2 .

[0144] Table 1. Electrical performance test results of mesoporous perovskite solar cells obtained in Examples 1-3 and the comparative examples.

[0145]

[0146]

[0147] As shown in Table 1, after adopting the coating method of the present invention with added protective layer, the leakage resistance of the device increased by about two orders of magnitude, suppressing the leakage loss of the device, thereby improving the voltage and current of the device, and ultimately improving the photoelectric conversion efficiency of the device by about 5 to 9 percentage points. It can be seen that the voltage, current and conversion efficiency of the embodiment are all higher than those of the comparative example.

[0148] The descriptions of the above embodiments are merely illustrative of the methods and core ideas of the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a perovskite solar cell, comprising the following steps: A) The electron transport layer paste is coated onto a conductive substrate and then heated and annealed to form an electron transport layer; An insulating slurry is applied to the electron transport layer and dried to form an insulating layer. A protective material is then applied to the insulating layer and cured to obtain a protective film. A carbon slurry is then applied to the protective film and heated and annealed to form a carbon electrode and allow the protective film to evaporate, resulting in a blank device without perovskite. The raw materials for preparing the electron transport layer slurry consist of terpineol, dispersant, thickener, ethanol, and electron transport material; the raw materials for preparing the insulating layer slurry consist of terpineol, dispersant, thickener, ethanol, and insulating material; the raw materials for preparing the carbon slurry consist of terpineol, dispersant, thickener, ethanol, and carbon material. B) The perovskite precursor solution is dropped onto the carbon electrode of the blank device. After the perovskite precursor solution has fully penetrated into the carbon electrode, insulating layer and electron transport layer, it is annealed to obtain a perovskite-containing device. C) Add a backplate to the bottom electrode of the device obtained in step B), connect the wires, and apply sealant to obtain a mesoporous perovskite solar cell.

2. The preparation method according to claim 1, characterized in that, The protective material is selected from at least one of petrolatum, paraffin, stearic acid, and oleic acid.

3. The preparation method according to claim 1, characterized in that, The raw materials for preparing the electron transport layer slurry include: The dispersant is selected from at least one of acetylacetone, lauric acid, and acetic acid; the volume of the dispersant is 1% to 10% of the volume of terpineol. The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; the ratio of the thickener to the terpineol is 50~250 mg: 1 mL; The volume of the ethanol is 1 to 3 times that of terpineol; The raw materials for preparing the insulating layer slurry include: The dispersant is selected from at least one of acetylacetone, lauric acid, and acetic acid; the volume of the dispersant is 1% to 10% of the volume of terpineol. The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; the ratio of the thickener to the terpineol is 50~250 mg: 1 mL; The volume of the ethanol is 1 to 3 times that of terpineol; The raw materials for preparing the carbon slurry include: The dispersant is selected from at least one of acetylacetone, lauric acid, and acetic acid; the volume of the dispersant is 1% to 10% of the volume of terpineol. The thickener is selected from at least one of ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and polyethylene glycol; the ratio of the thickener to the terpineol is 50~250 mg: 1 mL; The volume of the ethanol is 1 to 3 times that of terpineol.

4. The preparation method according to claim 1, characterized in that, The electron transport material includes TiO2, SnO2, or ZnO; The electron transport material is nanoparticles with a particle size of 10~100 nm; In the raw materials for preparing the electron transport layer slurry, the ratio of electron transport material to terpineol is 50~200mg:1mL.

5. The preparation method according to claim 1, characterized in that, The preparation method of the electron transport layer slurry includes the following steps: Terpineol, dispersant, thickener, ethanol and electron transport material are mixed, and the ethanol is removed by rotary evaporation to obtain an electron transport layer slurry; The rotary evaporation process uses a rotation speed of 15-60 rpm, a gas pressure of 15-50 mbar, a heating temperature of 45-60℃, and a time of 4-12 h.

6. The preparation method according to claim 1, characterized in that, The insulating layer material includes ZrO2, Al2O3, or SiO2; The insulating layer material is nanoparticles with a particle size of 10~100 nm; In the raw materials for preparing the insulating layer slurry, the ratio of the insulating layer material to the terpineol is 150~450 mg:1 mL; The method for preparing the insulating layer slurry includes the following steps: Terpineol, dispersant, thickener, ethanol and insulating material are mixed, and the ethanol is removed by rotary evaporation to obtain insulating slurry; The rotary evaporation process uses a rotation speed of 15-60 rpm, a gas pressure of 15-50 mbar, a heating temperature of 45-60℃, and a time of 4-12 h.

7. The preparation method according to claim 1, characterized in that, The carbon material is selected from graphite and conductive carbon black; The ratio of the carbon material to the terpineol is 150~450mg:1mL; The method for preparing the carbon slurry includes the following steps: Terpineol, dispersant, thickener, ethanol and carbon materials are mixed, and the ethanol is removed by rotary evaporation to obtain carbon slurry; The rotary evaporation process uses a rotation speed of 15-60 rpm, a gas pressure of 15-50 mbar, a heating temperature of 45-60℃, and a time of 4-12 h.

8. The preparation method according to claim 1, characterized in that, The coating thickness of the electron transport layer slurry is 0.5~2μm; The coating thickness of the insulating layer slurry is 1~3μm; The thickness of the protective film is 0.1~10 μm; The coating thickness of the carbon slurry is 10~50μm.

9. The preparation method according to claim 1, characterized in that, In step B), the solvent in the perovskite precursor solution includes at least one of dimethylformamide and dimethyl sulfoxide; the solute is ABX3; wherein A is at least one of methylamine ion, formamidinium ion, and cesium ion, and B is Pb. 2+ and Sn 2+ At least one of them, X is I - ,Br - and Cl - At least one of them; The concentration of the perovskite precursor solution is 1.0~1.5 mol / L; The perovskite precursor solution was added to the blank device at a rate of 2-4 μL / cm². 2 ; The annealing temperature is 60~120℃, and the time is 4~24h.

10. A perovskite solar cell prepared by the preparation method according to any one of claims 1 to 9.

Images