Preparation method of inverted perovskite solar cell

Abstract

The invention relates to the technical field of perovskite solar cells, and discloses a preparation method of an inverted perovskite solar cell. The preparation method comprises the following steps: pretreating a substrate, and sequentially preparing a perovskite light absorption layer, an electron transport layer, a hole blocking layer and a metal electrode layer on the surface of the substrate to obtain the inverted perovskite solar cell, wherein the substrate is soaked in the treating agent; the solvent of the treating agent is water, and the solute is selected from at least one of phosphonic acid derivatives, sulfonic acid derivatives, phosphoric acid derivatives, carboxyl compounds, alkali metal hydroxides, ammonia gas and hydrogen peroxide. A precursor of the perovskite light absorption layer comprises self-assembly molecules. According to the preparation method of the inverted perovskite solar cell provided by the invention, the wettability of the substrate to the perovskite precursor can be effectively improved, and a perovskite nucleation crystallization template is formed, so that the inverted perovskite solar cell which does not have a pre-deposited hole transport layer and has excellent photovoltaic performance is obtained.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cells, and particularly relates to a preparation method of an inverted perovskite solar cell. Background Art

[0002] In recent years, inverted structure (p-i-n) perovskite solar cells have received extensive attention due to their excellent optoelectronic properties and stability. Currently, most high-performance inverted perovskite solar cells use self-assembled organic molecules for the hole transport layer, such as [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid and their derivatives, etc. These commonly used self-assembled molecules have poor wettability to the perovskite precursor, and it is difficult to prepare a dense perovskite film with full coverage on them, leaving many holes at the interface, resulting in serious non-radiative recombination centers.

[0003] It has been reported that self-assembled molecules are directly added to the perovskite precursor and co-deposited on a transparent conductive oxide substrate to directly form a perovskite hole-selective contact on the substrate. This process avoids the substrate non-wettability caused by pre-depositing self-assembled molecules, thereby improving the quality of the perovskite film. However, the binding between the self-assembled molecule and the transparent conductive oxide is weak, and due to the surface morphology change and different deposition conditions of the transparent conductive oxide, it is difficult to form a continuous and directionally arranged hole-selective contact by co-depositing the perovskite self-assembled molecule in one step, damaging the optoelectronic conversion efficiency and stability of the device, especially reducing the performance of the module prepared on a large area. Summary of the Invention

[0004] The present invention aims to at least solve one of the above technical problems existing in the prior art. For this reason, one of the purposes of the present invention is to provide a preparation method of an inverted perovskite solar cell; the second purpose of the present invention is to provide an inverted perovskite solar cell; the third purpose of the present invention is to provide an inverted perovskite solar module.

[0005] In order to achieve the above purposes, the technical solutions adopted by the present invention are as follows:

[0006] The first aspect of the present invention provides a preparation method of an inverted perovskite solar cell, including the following steps:

[0007] Substrate pretreatment, directly preparing a perovskite light-absorbing layer, an electron transport layer, a hole blocking layer and a metal electrode layer on the surface of the substrate in sequence to obtain the inverted perovskite solar cell;

[0008] Among them, the substrate pretreatment includes soaking the substrate in a treatment agent; the solvent of the treatment agent is water, and the solute is selected from at least one of phosphonic acid derivatives, sulfonic acid derivatives, phosphoric acid derivatives, carboxyl compounds, alkali metal hydroxides, ammonia, and hydrogen peroxide;

[0009] The precursor of the perovskite light-absorbing layer includes self-assembled molecules.

[0010] In some embodiments of the present invention, the substrate includes transparent conductive glass.

[0011] In some embodiments of the present invention, the light transmittance of the substrate is greater than 90%.

[0012] In some embodiments of the present invention, the resistance of the substrate is 10 - 25 Ω.

[0013] In some specific embodiments of the present invention, the substrate is selected from one of indium-doped tin oxide conductive glass (ITO) and fluorine-doped tin oxide conductive glass (FTO).

[0014] In some embodiments of the present invention, the substrate pretreatment includes substrate cleaning, treatment agent soaking, and ultraviolet ozone treatment performed in sequence.

[0015] In the present invention, soaking the substrate in the treatment agent can simultaneously achieve the wettability treatment and templating treatment of the substrate, thereby inducing ordered crystallization.

[0016] In some embodiments of the present invention, the substrate cleaning includes ultrasonically cleaning the substrate with deionized water, ethanol, and isopropanol in sequence.

[0017] In some embodiments of the present invention, the phosphonic acid derivative is selected from at least one of aminomethylphosphonic acid, aminoethylphosphonic acid, aminopropylphosphonic acid, and aminobutylphosphonic acid.

[0018] In some embodiments of the present invention, the sulfonic acid derivative is selected from at least one of aminomethanesulfonic acid, aminoethanesulfonic acid, aminopropanesulfonic acid, and aminobutanesulfonic acid.

[0019] In some embodiments of the present invention, the phosphoric acid derivative is selected from at least one of hypophosphorous acid, phenylethylphosphoric acid, and phenylethylphosphoric acid derivatives.

[0020] In some embodiments of the present invention, the carboxyl compound is selected from at least one of glycine, glutamic acid, butyric acid, benzoic acid, phenylacetic acid, phenylacetic acid derivatives, iminodiacetic acid, and nitrilotriacetic acid.

[0021] In some embodiments of the present invention, the alkali metal hydroxide includes sodium hydroxide and potassium hydroxide.

[0022] In some embodiments of the present invention, the concentration of the treatment agent is 0.05 - 15 mg / mL.

[0023] In some specific embodiments of the present invention, the concentration of the treatment agent is 0.1 - 10 mg / mL.

[0024] In some embodiments of the present invention, the temperature of the soaking is 20 - 80 °C.

[0025] In some specific embodiments of the present invention, the temperature of the soaking is 50 - 80 °C.

[0026] In some embodiments of the present invention, the time of the soaking is 5 - 60 min.

[0027] In some specific embodiments of the present invention, the time of the soaking is 10 - 30 min.

[0028] In some embodiments of the present invention, after the soaking, there is also a step of annealing.

[0029] In some embodiments of the present invention, the temperature of the annealing is 100 - 120 °C.

[0030] In some specific embodiments of the present invention, the temperature of the annealing is 105 - 115 °C.

[0031] In some embodiments of the present invention, the time of the annealing is 5 - 60 min.

[0032] In some specific embodiments of the present invention, the time of the annealing is 5 - 15 min.

[0033] In some embodiments of the present invention, the time of the ultraviolet ozone treatment is 5 - 10 min.

[0034] In some embodiments of the present invention, the self-assembled molecule is selected from at least one of [2-(9H-carbazol-9-yl)ethyl]phosphonic acid, (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid, [4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphoric acid and its derivatives.

[0035] In some embodiments of the present invention, the precursor of the perovskite light-absorbing layer further includes Cs 1-x- y FA x MA y PbI 3 , where 0.8 ≤ x ≤ 1 and 0 ≤ y ≤ 0.2. (Cs is cesium, FA is formamidine, MA is methylamine, Pb is lead, and I is iodine)

[0036] In the present invention, Cs doped with self-assembled molecules 1-x-y FA x MA y PbI 3 (0.8 ≤ x ≤ 1, 0 ≤ y ≤ 0.2) is used as a precursor of the perovskite light-absorbing layer and is directly deposited on a substrate to directly form a perovskite hole-selective contact on the substrate.

[0037] In some specific embodiments of the present invention, the material of the perovskite light-absorbing layer includes 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid and Cs 0.05 MA 0.1 FA 0.85 PbI 3 .

[0038] In some embodiments of the present invention, the material of the electron transport layer includes [6,6]-phenyl C61 butyric acid methyl ester or fullerene C 60 .

[0039] In some embodiments of the present invention, the material of the hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0040] In some embodiments of the present invention, the material of the metal electrode layer includes at least one of Cu and Ag.

[0041] In some embodiments of the present invention, the thickness of the perovskite light-absorbing layer is 400 - 1200 nm.

[0042] In some embodiments of the present invention, the thickness of the electron transport layer is 10 - 60 nm.

[0043] In some embodiments of the present invention, the thickness of the metal electrode layer is 40 - 200 nm.

[0044] In some embodiments of the present invention, the methods for preparing the perovskite light-absorbing layer, the electron transport layer, and the hole blocking layer include spin coating or blade coating.

[0045] In some embodiments of the present invention, the preparation of the perovskite light-absorbing layer specifically includes the following steps:

[0046] 1) Prepare a perovskite layer precursor solution: Add FAI, PbI 2 , MAI, and CsI in an equimolar ratio to an organic solvent, and then add a self-assembled molecule, and heat and stir at 50 - 70 °C for 1 - 2 h to obtain the perovskite layer precursor solution;

[0047] 2) Spin coat the perovskite layer precursor solution on a substrate and anneal to form a perovskite light-absorbing layer.

[0048] In some embodiments of the present invention, the concentration of the perovskite layer precursor solution is 1-3 mol / mL.

[0049] In some embodiments of the present invention, the organic solvent is selected from at least one of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0050] In some embodiments of the present invention, the concentration of the self-assembled molecules in the perovskite layer precursor solution is 0.5-5 mg / mL.

[0051] In some specific embodiments of the present invention, the specific operation of spin-coating the perovskite layer precursor solution is as follows: first spin-coat at a speed of 500-1000 rpm for 10-15 s, and then spin-coat at a speed of 4000-5000 rpm for 30-40 s.

[0052] In some embodiments of the present invention, 15-20 s before the end of spin-coating the perovskite layer precursor solution, there is also a step of dropping anisole at the center of the substrate.

[0053] In some embodiments of the present invention, the annealing temperature of the perovskite light-absorbing layer is 90-110 °C, and the time is 20-40 min.

[0054] In some embodiments of the present invention, the preparation of the electron transport layer specifically includes the following steps:

[0055] Spin-coat a passivator on the perovskite light-absorbing layer, anneal to form a passivator layer, dissolve the electron transport layer material in chlorobenzene, and then spin-coat it on the surface of the passivator layer to form an electron transport layer.

[0056] In some embodiments of the present invention, the passivator is prepared by a method including the following steps: dissolving phenethylamine iodide and methylammonium iodide in a mixed solution of isopropanol and N,N-dimethylformamide.

[0057] In some embodiments of the present invention, in the passivator, the concentration of phenethylamine iodide is 1-3 mg / mL; the concentration of methylammonium iodide is 1-2 mg / mL; the volume ratio of isopropanol to N,N-dimethylformamide is (190-210):1.

[0058] In some embodiments of the present invention, the spin-coating speed of the passivator layer is 3000-5000 rpm, and the time is 20-40 s.

[0059] In some embodiments of the present invention, the annealing temperature of the passivator layer is 90-110 °C, and the time is 5-10 min.

[0060] In some embodiments of the present invention, the solid-liquid ratio of the electron transport layer material to chlorobenzene is (15-25) mg: 1 mL.

[0061] In some embodiments of the present invention, the spin coating speed of the electron transport layer is 300-2000 rpm, and the time is 20-40 s.

[0062] In some embodiments of the present invention, the preparation of the hole blocking layer specifically includes the following steps:

[0063] Dissolve the hole blocking layer material in isopropanol and spin coat it on the surface of the electron transport layer to form a hole blocking layer.

[0064] In some embodiments of the present invention, the solid-liquid ratio of the hole blocking layer material to isopropanol is (0.3-3) mg: 1 mL.

[0065] In some embodiments of the present invention, the spin coating speed of the hole blocking layer is 4000-6000 rpm, and the time is 20-40 s.

[0066] In some embodiments of the present invention, the method for preparing the metal electrode layer includes evaporation coating.

[0067] In some embodiments of the present invention, the vacuum degree of the evaporation coating is less than 3×10 -4 Pa.

[0068] In some embodiments of the present invention, the evaporation rate of the evaporation coating is

[0069] The second aspect of the present invention provides an inverted perovskite solar cell, which is prepared by using the preparation method described in the first aspect of the present invention.

[0070] In some embodiments of the present invention, the energy conversion efficiency of the inverted perovskite solar cell is 21.5%-25%.

[0071] The third aspect of the present invention provides an inverted perovskite solar module, which includes the inverted perovskite solar cell described in the second aspect of the present invention.

[0072] In some embodiments of the present invention, the inverted perovskite solar module includes an inverted perovskite / silicon tandem cell, a series-connected inverted perovskite cell.

[0073] Compared with the prior art, the beneficial effects of the present invention are:

[0074] 1) The preparation method of the inverted perovskite solar cell provided by the present invention can effectively improve the wettability of the substrate to the perovskite precursor by soaking the substrate in an aqueous solution of substances such as phosphonic acid derivatives and carboxyl compounds, and form a template for perovskite nucleation and crystallization, thereby inducing the formation of a continuous hole-selective contact interface of perovskite and self-assembled molecules on its surface, improving the interface contact and reducing the non-radiative recombination centers at the interface, facilitating the transport and extraction of hole carriers, and realizing the controllable preparation of high-performance hole-free inverted perovskite solar cells;

[0075] 2) The preparation method of the inverted perovskite solar cell provided by the present invention significantly improves the photovoltaic performance and stability of the inverted perovskite solar cell after the substrate is treated with wetting treatment agents such as sodium hydroxide aqueous solution, amino acid aqueous solution and / or hydrogen peroxide aqueous solution. In particular, for the device treated with hydrogen peroxide aqueous solution, its photoelectric conversion efficiency can reach 23.95%, and the aqueous solution treatment of the transparent conductive oxide substrate meets the requirements of green environmental protection production, removes the step of pre-depositing the self-assembled molecular layer, reduces the process flow, and lowers the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] Figure 1 It is a schematic structural diagram of the inverted perovskite solar cell in the embodiment, wherein 1 - substrate, 2 - perovskite light-absorbing layer, 3 - electron transport layer, 4 - hole blocking layer, 5 - silver electrode layer;

[0077] Figure 2 It is an operation schematic diagram of the substrate soaking pretreatment in the embodiment;

[0078] Figure 3 It is a statistical chart of the energy conversion efficiency of the inverted perovskite solar cells in Examples 1 - 6 and Comparative Example 1;

[0079] Figure 4 It is the J-V curve of the inverted perovskite solar cells in Example 4 and Comparative Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0080] The content of the present invention will be further described in detail below through specific embodiments. The raw materials, reagents or devices used in the embodiments and comparative examples can be obtained from conventional commercial channels or can be obtained by existing technical methods without special instructions. Unless otherwise specified, the test or measurement methods are all conventional methods in the art.

[0081] 1. The perovskite layer precursor solution used in the following examples and comparative examples was prepared by the following steps:

[0082] Dissolve FAI, PbI 2, MAI and CsI were added to a mixed solution of N,N-dimethylformamide and dimethyl sulfoxide in an equimolar ratio (4:1, v / v) to obtain a precursor solution with a concentration of 1.5 mol / mL; 3.6 mg of 4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphoric acid was added as a self-assembled molecule to the precursor solution, and after heating and stirring at 60 °C for 1 h, it was filtered to obtain a perovskite layer precursor solution, which was used for the preparation of the perovskite light-absorbing layer.

[0083] 2. The passivator used in the following examples and comparative examples was prepared by the following steps:

[0084] Phenethylamine iodide and methylammonium iodide were dissolved in a mixed solvent of isopropanol and N,N-dimethylformamide (200:1, v / v) to obtain a passivator with a concentration of 2 mg / mL of phenethylamine iodide and 1 mg / mL of methylammonium iodide.

[0085] 3. The [6,6]-phenyl-C61 butyric acid methyl ester solution used in the following examples and comparative examples was prepared by the following steps:

[0086] [6,6]-Phenyl-C61 butyric acid methyl ester was dissolved in chlorobenzene to obtain a [6,6]-phenyl-C61 butyric acid methyl ester solution with a concentration of 20 mg / mL, which was used for the preparation of the electron transport layer.

[0087] 4. The 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution used in the following examples and comparative examples was prepared by the following steps:

[0088] 2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline was dissolved in isopropanol to obtain a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution with a concentration of 1 mg / mL, which was used for the preparation of the hole blocking layer.

[0089] Figure 1 is a schematic structural diagram of the inverted perovskite solar cell in the example. It can be seen that the inverted perovskite solar cell prepared in the example includes, from bottom to top, 1 - a substrate, 2 - a perovskite light-absorbing layer, 3 - an electron transport layer, 4 - a hole blocking layer, and 5 - a silver electrode layer. Figure 1 It can be seen that the immersion pretreatment of the substrate in the example includes the steps of immersing the substrate in a treatment agent and taking it out for annealing treatment.

[0090] Figure 2 is a schematic operation diagram of the immersion pretreatment of the substrate in the example. It can be seen that the immersion pretreatment of the substrate in the example includes the steps of immersing the substrate in a treatment agent and taking it out for annealing treatment. Figure 2 It can be seen that the immersion pretreatment of the substrate in the example includes the steps of immersing the substrate in a treatment agent and taking it out for annealing treatment.

[0091] The following will refer to Figure 1 and Figure 2 to describe the preparation process of the inverted perovskite solar cell in the example:

[0092] Example 1

[0093] In this example, an inverted perovskite solar cell is prepared as follows:

[0094] S1. Substrate pretreatment:

[0095] The ITO conductive glass is successively placed in deionized water, ethanol, and isopropanol for ultrasonic cleaning. Each solvent is cleaned twice, 30 min each time. After cleaning, it is dried with nitrogen and reserved. The ITO conductive glass is immersed in a 0.1 mg / mL sodium hydroxide aqueous solution at a temperature of 60 °C for 30 min, taken out and annealed at 110 °C for 10 min; the ITO conductive glass cooled to room temperature is treated with ultraviolet ozone for 5 min to obtain the pretreated ITO conductive glass, which is transferred to a nitrogen glove box;

[0096] S2. Preparation of perovskite light-absorbing layer:

[0097] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is first gradually increased from 500 rpm to 1000 rpm and spin-coated for 10 s, then gradually increased to 5000 rpm and spin-coated for 35 s. 15 s before the end of spin-coating, 200 μL of anisole is dropped onto the center of the ITO conductive glass. The prepared perovskite thin film is immediately transferred to a hot plate, annealed at 100 °C for 30 min, and then taken out with tweezers to form a perovskite light-absorbing layer;

[0098] S3. Preparation of electron transport layer:

[0099] After the perovskite light-absorbing layer is cooled to room temperature, take 45 μL of the passivator and drop it onto the center of the perovskite light-absorbing layer, spin-coat it at a rotation speed of 4000 rpm for 30 s, and immediately transfer it to a hot plate after spin-coating. After annealing at 100 °C for 5 min, take it out with tweezers to form a passivator layer; after cooling, drop 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution on the surface, and the rotation speed is gradually increased from 300 rpm to 1500 rpm and spin-coated for 30 s to form an electron transport layer;

[0100] S4. Preparation of hole blocking layer:

[0101] Take 35 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, spin-coat it at a rotation speed of 5000 rpm for 30 s to form a hole blocking layer;

[0102] S5. Preparation of metal electrode layer:

[0103] Through a thermal evaporation instrument in a vacuum chamber (<3×10 -4 Pa), on the surface of the hole blocking layer at Deposit 20 nm of silver at a high rate, and then Deposit 80 nm of silver at a rate to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0104] Example 2

[0105] Prepare an inverted perovskite solar cell in the following steps:

[0106] S1. Substrate pretreatment:

[0107] Place the ITO conductive glass in deionized water, ethanol, and isopropanol successively for ultrasonic cleaning, with each solvent being cleaned twice for 30 min each time. After cleaning, dry it with nitrogen and set aside. Immerse the ITO conductive glass in a 0.1 mg / mL glycine aqueous solution at 60 °C for 10 min, take it out and anneal it at 110 °C for 10 min. Ultraviolet ozone treat the ITO conductive glass cooled to room temperature for 5 min to obtain the pretreated ITO conductive glass, and transfer it to a nitrogen glove box;

[0108] S2. Prepare the perovskite light-absorbing layer:

[0109] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is first gradually increased from 500 rpm to 1000 rpm for 10 s, then gradually increased to 5000 rpm for 35 s. 15 s before the end of spin-coating, drop 200 μL of anisole onto the center of the ITO conductive glass. Immediately transfer the prepared perovskite thin film to a hot plate, anneal it at 100 °C for 30 min, and then pick it out with tweezers to form the perovskite light-absorbing layer;

[0110] S3. Prepare the electron transport layer:

[0111] After the perovskite light-absorbing layer is cooled to room temperature, take 45 μL of the passivating agent and drop it onto the center of the perovskite light-absorbing layer, spin-coat it at 4000 rpm for 30 s, and immediately transfer it to a hot plate after spin-coating. Anneal it at 100 °C for 5 min and then pick it out with tweezers to form the passivating agent layer; after cooling, drop 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution on the surface, and gradually increase the rotation speed from 300 rpm to 1500 rpm and spin-coat for 30 s to form the electron transport layer;

[0112] S4. Prepare the hole blocking layer:

[0113] Take 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, spin-coat it at 5000 rpm for 30 s to form the hole blocking layer;

[0114] S5. Prepare the metal electrode layer:

[0115] Using a thermal evaporation coater in a vacuum chamber (<3×10 -4 Pa), silver is evaporated on the surface of the hole blocking layer at a rate to deposit 20 nm of silver, and then at a rate to deposit 80 nm of silver, obtaining a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0116] Example 3

[0117] In this example, an inverted perovskite solar cell is prepared, and the steps are as follows:

[0118] S1. Substrate pretreatment:

[0119] The ITO conductive glass is successively placed in deionized water, ethanol, and isopropanol for ultrasonic cleaning, with each solvent being cleaned twice for 30 min each time. After cleaning, it is dried with nitrogen and set aside; the ITO conductive glass is immersed in an aqueous solution of iminodiacetic acid at 0.1 mg / mL, at a temperature of 60 °C for 10 min, taken out and annealed at 110 °C for 10 min; the ITO conductive glass cooled to room temperature is treated with ultraviolet ozone for 5 min to obtain the pretreated ITO conductive glass, which is transferred to a nitrogen glove box;

[0120] S2. Preparation of the perovskite light-absorbing layer:

[0121] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is first gradually increased from 500 rpm to 1000 rpm for 10 s of spin-coating, and then gradually increased to 5000 rpm for 35 s of spin-coating. 15 s before the end of spin-coating, 200 μL of anisole is dropped onto the center of the ITO conductive glass. The prepared perovskite thin film is immediately transferred to a hot plate, annealed at 100 °C for 30 min, and then taken out with tweezers to form the perovskite light-absorbing layer;

[0122] S3. Preparation of the electron transport layer:

[0123] After the perovskite light-absorbing layer is cooled to room temperature, 45 μL of the passivating agent is dropped onto the center of the perovskite light-absorbing layer and spin-coated at a rotation speed of 4000 rpm for 30 s. After spin-coating, it is immediately transferred to a hot plate, annealed at 100 °C for 5 min, and then taken out with tweezers to form the passivating agent layer; after cooling, 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution is dropped onto the surface, and the rotation speed is gradually increased from 300 rpm to 1500 rpm for 30 s of spin-coating to form the electron transport layer;

[0124] S4. Preparation of the hole blocking layer:

[0125] Take 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, then spin-coat it at 5000 rpm for 30 s to form a hole-blocking layer;

[0126] S5. Prepare the metal electrode layer:

[0127] In a vacuum chamber (<3×10 -4 Pa) using a thermal evaporation instrument, evaporate 20 nm of silver on the surface of the hole-blocking layer at a rate, and then evaporate 80 nm of silver at a rate to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0128] Example 4

[0129] In this example, an inverted perovskite solar cell is prepared, and the steps are as follows:

[0130] S1. Substrate pretreatment:

[0131] Place the ITO conductive glass in deionized water, ethanol, and isopropanol in sequence for ultrasonic cleaning, with each solvent being cleaned twice for 30 min each time. After cleaning, dry it with nitrogen and set aside; Immerse the ITO conductive glass in a 0.1 mg / mL nitrilotriacetic acid aqueous solution at 60 °C for 10 min, take it out and anneal it at 110 °C for 10 min; Subject the ITO conductive glass cooled to room temperature to ultraviolet ozone treatment for 5 min to obtain the pretreated ITO conductive glass, and transfer it to a nitrogen glove box;

[0132] S2. Prepare the perovskite light-absorbing layer:

[0133] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is first gradually increased from 500 rpm to 1000 rpm and spin-coated for 10 s, then gradually increased to 5000 rpm and spin-coated for 35 s. 15 s before the end of spin-coating, drop 200 μL of anisole onto the center of the ITO conductive glass. Immediately transfer the prepared perovskite thin film to a hot plate, anneal it at 100 °C for 30 min, and then pick it out with tweezers to form the perovskite light-absorbing layer;

[0134] S3. Prepare the electron transport layer:

[0135] After the perovskite light-absorbing layer is cooled to room temperature, 45 μL of the passivating agent is dropped onto the center of the perovskite light-absorbing layer and spin-coated at 4000 rpm for 30 s. Immediately after the spin-coating is completed, it is transferred to a hot plate, annealed at 100 °C for 5 min, and then picked out with tweezers to form a passivating agent layer. After cooling, 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution is dropped onto the surface, and the rotation speed is gradually increased from 300 rpm to 1500 rpm, and spin-coated for 30 s to form an electron transport layer;

[0136] S4. Preparation of hole blocking layer:

[0137] 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution is dropped onto the center of the electron transport layer and spin-coated at 5000 rpm for 30 s to form a hole blocking layer;

[0138] S5. Preparation of metal electrode layer:

[0139] In a vacuum chamber (<3×10 -4 Pa), 20 nm of silver is evaporated onto the surface of the hole blocking layer at a rate, and then 80 nm of silver is evaporated at a rate to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0140] Example 5

[0141] In this example, an inverted perovskite solar cell is prepared, and the steps are as follows:

[0142] S1. Substrate pretreatment:

[0143] The ITO conductive glass is successively placed in deionized water, ethanol, and isopropanol for ultrasonic cleaning, and each solvent is cleaned twice, 30 min each time. After cleaning, it is dried with nitrogen and reserved. The ITO conductive glass is immersed in a 1.76 mg / mL hydrogen peroxide aqueous solution at a temperature of 60 °C for 30 min, taken out and annealed at 110 °C for 10 min. The ITO conductive glass cooled to room temperature is treated with ultraviolet ozone for 5 min to obtain the pretreated ITO conductive glass, which is transferred to a nitrogen glove box;

[0144] S2. Preparation of perovskite light-absorbing layer:

[0145] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is gradually increased from 500 rpm to 1000 rpm first, spin-coat for 10 s, then gradually increased to 5000 rpm and spin-coat for 35 s. 15 s before the end of spin-coating, 200 μL of anisole is dropped onto the center of the ITO conductive glass. The prepared perovskite thin film is immediately transferred to a hot plate, annealed at 100 °C for 30 min, and then picked out with tweezers to form the perovskite light-absorbing layer;

[0146] S3. Prepare the electron transport layer:

[0147] After the perovskite light-absorbing layer is cooled to room temperature, take 45 μL of the passivator and drop it onto the center of the perovskite light-absorbing layer, spin-coat at 4000 rpm for 30 s. Immediately after the spin-coating is completed, transfer it to a hot plate, anneal at 100 °C for 5 min, and then pick out with tweezers to form the passivator layer; After cooling, 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution is dropped onto the surface, and the rotation speed is gradually increased from 300 rpm to 1500 rpm, spin-coat for 30 s to form the electron transport layer;

[0148] S4. Prepare the hole blocking layer:

[0149] Take 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, spin-coat at 5000 rpm for 30 s to form the hole blocking layer;

[0150] S5. Prepare the metal electrode layer:

[0151] Through a thermal evaporation instrument in a vacuum chamber (<3×10 -4 Pa), evaporate 20 nm of silver on the surface of the hole blocking layer at a rate, and then evaporate 80 nm of silver at a rate to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0152] Example 6

[0153] This example prepares an inverted perovskite solar cell, and the steps are as follows:

[0154] S1. Substrate pretreatment:

[0155] The ITO conductive glass was successively placed in deionized water, ethanol, and isopropanol for ultrasonic cleaning, with each solvent being cleaned twice for 30 minutes each time. After cleaning, it was dried with nitrogen and reserved; the ITO conductive glass was immersed in ammonia water at 9.02 mg / mL at a temperature of 60 °C for 30 minutes, taken out and annealed at 110 °C for 10 minutes; the ITO conductive glass cooled to room temperature was treated with ultraviolet ozone for 5 minutes to obtain the pretreated ITO conductive glass, which was then transferred to a nitrogen glove box;

[0156] S2. Preparation of perovskite light-absorbing layer:

[0157] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed was first gradually increased from 500 rpm to 1000 rpm for 10 s, then gradually increased to 5000 rpm for 35 s. 15 s before the end of spin-coating, 200 μL of anisole was dropped onto the center of the ITO conductive glass. The prepared perovskite thin film was immediately transferred to a hot plate, annealed at 100 °C for 30 minutes, and then taken out with tweezers to form a perovskite light-absorbing layer;

[0158] S3. Preparation of electron transport layer:

[0159] After the perovskite light-absorbing layer cooled to room temperature, 45 μL of the passivating agent was dropped onto the center of the perovskite light-absorbing layer and spin-coated at 4000 rpm for 30 s. After spin-coating, it was immediately transferred to a hot plate, annealed at 100 °C for 5 minutes, and then taken out with tweezers to form a passivating agent layer; after cooling, 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution was dropped onto the surface, and the rotation speed was gradually increased from 300 rpm to 1500 rpm and spin-coated for 30 s to form an electron transport layer;

[0160] S4. Preparation of hole blocking layer:

[0161] Take 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, and spin-coat it at 5000 rpm for 30 s to form a hole blocking layer;

[0162] S5. Preparation of metal electrode layer:

[0163] Through a thermal evaporation instrument in a vacuum chamber (<3×10 -4 Pa), silver was evaporated on the surface of the hole blocking layer at a rate of 20 nm, and then silver was evaporated at a rate of 80 nm to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell was prepared.

[0164] Comparative Example 1

[0165] This comparative example prepares an inverted perovskite solar cell, and the steps are as follows:

[0166] S1. Substrate pretreatment:

[0167] The ITO conductive glass is successively placed in deionized water, ethanol, and isopropanol for ultrasonic cleaning, each solvent is cleaned twice, 30 minutes each time. After cleaning, it is dried with nitrogen and then treated with ultraviolet ozone for 5 minutes to obtain the pretreated ITO conductive glass, which is transferred to a nitrogen glove box;

[0168] S2. Preparation of the perovskite light-absorbing layer:

[0169] Take 45 μL of the perovskite layer precursor solution and spin-coat it on the pretreated ITO conductive glass. The rotation speed is first gradually increased from 500 rpm to 1000 rpm, spin-coated for 10 s, and then gradually increased to 5000 rpm, spin-coated for 35 s. 15 s before the end of spin-coating, 200 μL of anisole is dropped onto the center of the ITO conductive glass. The prepared perovskite film is immediately transferred to a hot plate, annealed at 100 °C for 30 minutes, and then picked out with tweezers to form the perovskite light-absorbing layer;

[0170] S3. Preparation of the electron transport layer:

[0171] After the perovskite light-absorbing layer is cooled to room temperature, take 45 μL of the passivator and drop it onto the center of the perovskite light-absorbing layer, spin-coat at a rotation speed of 4000 rpm for 30 s. After spin-coating, it is immediately transferred to a hot plate, annealed at 100 °C for 5 minutes, and then picked out with tweezers to form the passivator layer; after cooling, 25 μL of [6,6]-phenyl C61 butyric acid methyl ester solution is dropped onto the surface, and the rotation speed is gradually increased from 300 rpm to 1500 rpm, spin-coated for 30 s to form the electron transport layer;

[0172] S4. Preparation of the hole blocking layer:

[0173] Take 40 μL of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline solution and drop it onto the center of the electron transport layer, spin-coat at a rotation speed of 5000 rpm for 30 s to form the hole blocking layer;

[0174] S5. Preparation of the metal electrode layer:

[0175] Through a thermal evaporation instrument in a vacuum chamber (<3×10 -4 Pa), 20 nm of silver is evaporated on the surface of the hole blocking layer at a rate, and then 80 nm of silver is evaporated at a rate to obtain a silver electrode layer with a final thickness of 100 nm, and the inverted perovskite solar cell is prepared.

[0176] Performance testing

[0177] The inverted perovskite solar cells prepared in Examples 1-6 and Comparative Example 1 were tested under AM 1.5G sunlight with an illumination intensity of 100 mW / cm 2 During the test, a 0.06 cm 2 mask was used to cover the 2 cm × 2 cm sized inverted perovskite solar cell as the effective area in the test curve. A bias voltage of -0.2 V - 1.3 V was applied across the solar cell by a 2400 source meter, and the test was carried out at a scanning speed of 10 mV / s.

[0178] Table 1 Photovoltaic performance parameters of the inverted perovskite solar cells in Examples 1-6 and Comparative Example 1

[0179] <![CDATA[Short-circuit current (mA / cm 2 )]]> Open-circuit voltage (V) Fill factor (%) Energy conversion efficiency (%) Comparative Example 1 24.84 1.07 76.5 20.56 Example 1 25.43 1.07 79.6 21.76 Example 2 25.19 1.12 77.7 22.10 Example 3 25.29 1.11 81.4 22.90 Example 4 25.41 1.12 82.1 23.57 Example 5 25.75 1.14 81.2 23.95 Example 6 25.15 1.14 82.3 23.32

[0180] Table 1 shows the photovoltaic performance parameters of the inverted perovskite solar cells in Examples 1-6 and Comparative Example 1. Figure 3 Figure 1 is a statistical chart of the energy conversion efficiency of the inverted perovskite solar cells in Examples 1-6 and Comparative Example 1. Figure 4 Figure 2 is the J-V curve of the inverted perovskite solar cells in Example 4 and Comparative Example 1. From Table 1, Figure 3 and Figure 4 it can be seen that the energy conversion efficiencies of the inverted perovskite solar cells in Examples 1-6 are 21.76%, 22.10%, 22.90%, 23.57%, 23.95% and 23.32% respectively. Compared with Comparative Example 1 (20.56%), the energy conversion efficiencies of the inverted perovskite solar cells have been improved to varying degrees, indicating that the ITO conductive glass substrates were treated with aqueous sodium hydroxide solution, aqueous glycine solution, aqueous iminodiacetic acid solution, aqueous nitrilotriacetic acid solution, aqueous hydrogen peroxide solution and aqueous ammonia for wettability and templating treatment in Examples 1-6, which can make the self-assembled molecule-doped perovskite form a continuous and dense hole-selective contact interface on the substrate, optimize the crystallization quality of the perovskite, reduce the defect states in the perovskite light-absorbing layer, reduce the non-radiative recombination, promote the efficient transport and extraction of holes, and thus obtain an inverted perovskite solar cell without a pre-deposited hole transport layer and with excellent photovoltaic performance.

Claims

1. A method for preparing an inverted perovskite solar cell, characterized in that: The following steps are involved: Substrate pretreatment, directly preparing a perovskite light absorbing layer, an electron transport layer, a hole blocking layer and a metal electrode layer in sequence on the substrate surface to obtain the inverted perovskite solar cell; Wherein, the substrate pretreatment comprises immersing the substrate in a treatment agent; the solvent of the treatment agent is water, and the solute is selected from at least one of phosphonic acid derivatives, sulfonic acid derivatives, phosphoric acid derivatives, carboxyl compounds, alkali metal hydroxides, ammonia, and hydrogen peroxide; The precursor of the perovskite light-absorbing layer includes self-assembling molecules.

2. The preparation method according to claim 1, characterized in that: The substrate includes transparent conductive glass.

3. The preparation method according to claim 1, characterized in that: The phosphonic acid derivative is selected from at least one of aminomethylphosphonic acid, aminoethylphosphonic acid, aminopropylphosphonic acid and aminobutylphosphonic acid; And / or, the sulfonic acid derivative is at least one selected from aminomethanesulfonic acid, aminoethanesulfonic acid, aminopropanesulfonic acid, and aminobutanesulfonic acid; And / or, the phosphoric acid derivative is selected from at least one of hypophosphorous acid, phenethyl phosphoric acid, and phenethyl phosphoric acid derivatives; And / or, the carboxyl compound is selected from at least one of glycine, glutamic acid, butyric acid, benzoic acid, phenylacetic acid, phenylacetic acid diffractor, iminodiacetic acid, and nitrilotriacetic acid.

4. The preparation method according to claim 1, characterized in that: The concentration of the treatment agent is 0.05-15 mg / mL; And / or, the soaking temperature is 20-80°C; And / or, the soaking time is 5-60 min.

5. The preparation method according to claim 1, characterized in that: The self-assembling molecules are selected from at least one of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, [4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl]phosphonic acid and their derivatives.

6. The preparation method according to claim 1, characterized in that: The precursor of the perovskite light absorbing layer also includes Cs 1-x-y FA x MA y PbI3, where 0.8≤x≤1, 0≤y≤0.2; And / or, the material of the electron transport layer is selected from [6,6]-phenyl C61 butyric acid methyl ester or fullerene C 60 ; And / or, the material of the hole blocking layer includes 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline; And / or, the material of the metal electrode layer includes at least one of Cu and Ag.

7. The preparation method according to claim 1, characterized in that: The thickness of the perovskite light absorbing layer is 400-1200nm; And / or, the thickness of the electron transport layer is 10-60 nm; And / or, the thickness of the metal electrode layer is 40-200 nm.

8. The preparation method according to claim 1, characterized in that: The method of preparing the perovskite light absorbing layer, the electron transport layer and the hole blocking layer comprises spin coating or scraping coating; And / or, the method for preparing the metal electrode layer includes evaporation.

9. An inverted perovskite solar cell, characterized in that: The method comprises preparing the product by the preparation method according to any one of claims 1 to 8.

10. An inverted perovskite solar module, characterized in that: Includes the inverted perovskite solar cell as described in claim 9.

Images