A low-dimensional perovskite solar cell based on aminobutyric acid and preparation method thereof

Abstract

The present invention discloses a low-dimensional perovskite solar cell based on aminobutyric acid and a preparation method thereof, which belongs to the technical field of optoelectronic materials, and solves the technical problem that the organic macromolecules most used in the prior art are butylamine salts and benzylamine salts, and the resulting solar cells have low efficiency and stability. The preparation method disclosed by the present invention can prepare a perovskite active layer in the air, and the solvent used is a low-toxic organic solvent, which conforms to the concept of green chemistry. The grains of the two-dimensional perovskite film prepared by using the aminobutyric acid hydroiodide obtained after acidification grow in a direction perpendicular to the substrate, the grains are large, and the defects are few, so that a low-dimensional perovskite solar cell with excellent performance, high efficiency and stability can be realized, which greatly promotes the commercialization process of perovskite solar cells.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials, and in particular relates to a low-dimensional perovskite solar cell based on aminobutyric acid and a preparation method thereof. Background Art

[0002] With the rapid development of society, the environmental problems and energy shortages caused by traditional fossil energy sources are receiving more and more attention. It is urgent to expand environmentally friendly and renewable energy. Among them, solar energy has attracted widespread attention for its unique advantages of abundant reserves, green and clean, and renewable. In recent years, the photoelectric conversion efficiency of perovskite solar cells has increased from 3.8% to 25.7% in just a few years. This growth rate is unprecedented in the photovoltaic field. Perovskite materials themselves have the advantages of strong light absorption, high carrier mobility, long carrier diffusion distance, and adjustable band gap, making perovskite materials expected to become the most ideal solar cell materials, and even achieve an energy conversion efficiency of 33%. At the same time, perovskite solar cells can be prepared by a simple low-temperature solution method, and bendable and flexible devices can be made on flexible substrates. Compared with other photovoltaic technologies, the production process of perovskite solar cells is simple, the cost is low, and the theoretical application range is wider.

[0003] However, the most efficient perovskite solar cells are mainly three-dimensional structures, but they are very sensitive to water, oxygen, light, etc. in the environment and have poor stability, which greatly limits the practical application and commercialization of perovskite solar cells. To this end, by adding large organic amine groups or organic molecules such as aromatic amines to the perovskite structure, a stable two-dimensional or low-dimensional structure can be formed, which has good hydrophobicity and environmental stability, while reducing the internal self-doping effect and ion migration phenomenon. Therefore, both in theoretical research and practical application, the development prospects of two-dimensional or low-dimensional structure solar cells are very broad.

[0004] Now people use organic amine molecules to partially replace methylamine cations, forming a layered quantum well structure, which improves the charge transfer efficiency while ensuring the stability of the perovskite structure, and greatly improves the photoelectric conversion efficiency of the device. The most commonly used organic macromolecules in the existing technology are butylamine salts and benzylamine salts, which have relatively simple functional groups. It is necessary to find more suitable organic macromolecules to improve the efficiency and stability of solar cells. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art mentioned above, the object of the present invention is to provide a low-dimensional perovskite solar cell based on aminobutyric acid and a preparation method thereof, so as to solve the technical problem that the solar cells prepared by the organic macromolecules most commonly used in the prior art, such as butylamine salts and benzylamine salts, have low efficiency and stability.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention discloses a method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid, comprising the following steps:

[0008] S1: Lead iodide, iodomethylamine, and 4-aminobutyric acid hydroiodide are dissolved in methylamine acetate solution, and then chloromethylamine is added and stirred to obtain a perovskite precursor solution;

[0009] S2: Coating a hole transport material on a conductive glass to obtain a conductive glass having a hole transport layer; coating a perovskite precursor solution on the surface of the conductive glass having the hole transport layer, followed by heat treatment to obtain a pretreated substrate; coating an electron transport layer on the surface of the pretreated substrate, and then coating a modification layer and a metal electrode on the surface of the electron transport layer to obtain a low-dimensional perovskite solar cell based on aminobutyric acid.

[0010] Furthermore, in S1, the conductive glass is ITO conductive glass; the methylamine acetate solution is prepared by mixing acetic acid and methylamine in a molar ratio of 1:1.5 and stirring the mixture in an ice bath for 2h to 6h; the preparation method of the 4-aminobutyric acid hydroiodide is as follows: 4-aminobutyric acid and hydroiodic acid are mixed, stirred in an ice bath for 2h to 6h, and 4-aminobutyric acid hydroiodide is obtained after rotary evaporation, wherein the molar ratio of 4-aminobutyric acid to hydroiodic acid is 1:1.

[0011] Furthermore, in S1, according to the stoichiometric ratio, the ratio of lead iodide, methylamine iodide and 4-aminobutyric acid hydroiodide is n:(n-1):2, wherein n is a natural number greater than 1; and the dosage ratio of the methylamine acetate solution and methylamine chloride is (1-2) mL:(10-20) mg.

[0012] Furthermore, in S1, the stirring is carried out at 30°C to 120°C for 2h to 6h; and the concentration of the perovskite precursor solution is 200mg / mL to 300mg / mL.

[0013] Further, in S2, the coating method of the hole transport material is spin coating deposition, the hole transport material is PEDOT:PSS, and the process parameters of the spin coating deposition are: spin coating at 5000rad / min to 6000rad / min for 50s to 60s;

[0014] In S2, after coating the hole transport material on the conductive glass, annealing is performed to obtain a conductive glass with hole transport properties; the annealing temperature is 120° C. to 150° C., and the annealing time is 30 minutes.

[0015] Furthermore, in S2, the coating method of the perovskite precursor solution is spin coating deposition, the heat treatment method is annealing, the annealing temperature is 100° C. to 120° C., and the annealing time is 4 min to 6 min.

[0016] Further, in S2, the electron transport layer is PCBM; the specific steps of coating the electron transport layer on the surface of the pretreated substrate are: dissolving PCBM in chlorobenzene, stirring at 50°C to 60°C to obtain a spin coating liquid, and spin coating the spin coating liquid on the surface of the pretreated substrate; the mass concentration of the PCBM in chlorobenzene is 16mg / mL to 18mg / mL;

[0017] In S2, the process parameters of the spin coating are: spin coating at a rotation speed of 1000-1200 rad / min for 50s-60s.

[0018] Furthermore, in S2, the modification layer is LiF, and the metal electrode is Al; the thickness of the LiF is 1 nm to 1.5 nm, and the thickness of the Al is 100 nm to 150 nm.

[0019] The present invention also discloses a low-dimensional perovskite solar cell based on aminobutyric acid prepared by the above preparation method.

[0020] Furthermore, the energy conversion efficiency of the low-dimensional perovskite solar cell based on aminobutyric acid is 14.74%, the open circuit voltage is 0.95V, and the short circuit current is 20.53mA / cm 2 , the filling factor is 75.93%.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention discloses a method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid, wherein lead iodide, methylamine iodide and 4-aminobutyric acid hydroiodide are used as a perovskite precursor solution. Since aminobutyric acid has a double functional group, namely an ammonium group and a carboxyl group, it can react with Pb 2+ and I - The interaction can regulate the microstrain in the lattice, enhance the connection between perovskites, thereby improving stability and facilitating the growth of large grains. In addition, the carboxyl group in aminobutyric acid can modify the surface of the electron transport layer, thereby providing a more complete coverage of the perovskite. The grains of the prepared two-dimensional perovskite film grow in a direction perpendicular to the substrate, with larger grains and fewer defects, and can achieve high-performance, efficient and stable low-dimensional perovskite solar cells; the solvent used in this method is a low-toxic organic solvent, which is in line with the concept of green chemistry, with simple steps and easy industrial production.

[0023] The present invention also discloses a low-dimensional perovskite solar cell based on aminobutyric acid prepared by the above-mentioned preparation method. Since the two ends of aminobutyric acid hydroiodide contain an ammonium group and a carboxyl group respectively, compared with organic macromolecules with a single functional group, a more efficient and stable perovskite solar cell can be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the structure of a low-dimensional perovskite solar cell based on aminobutyric acid prepared by the present invention;

[0025] Figure 2 The JV characteristic curve of the low-dimensional perovskite solar cell based on aminobutyric acid prepared by the present invention; DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0027] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0028] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions).

[0029] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0030] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0031] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only intended to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art may make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0032] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0033] Example 1

[0034] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0035] Step 1: Place 90 mL of methylamine in a round-bottom flask in an ice-water bath, and slowly drop 27.6 mL of acetic acid thereinto. After 2 hours of ice-water bath, evaporate at 55°C until no liquid drops, and prepare methylamine acetate solution for use; Place 1 g of aminobutyric acid in a round-bottom flask in an ice-water bath, add hydroiodic acid (HI) thereto in a molar ratio of 1:1, after 2 hours of ice-water bath, evaporate at 55°C until no liquid drops, then wash the evaporated solid with ether, and vacuum dry at 40°C to obtain 4-aminobutyric acid hydroiodide; According to the structural formula (C4H9NO2)2(CH3NH3)4Pb5I 16 Weigh 182.88 mg of lead iodide, 50.46 mg of iodomethylamine, 36.66 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 60 ° C for 6 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 270 mg / mL;

[0036] Step 2: Clean the ITO conductive glass in the following order: ethanol, detergent, ultrapure water, and acetone. Ultrasonic treatment was performed for 15 minutes in ethanol, dried with nitrogen, and dried in a 120°C oven for 30 minutes. The cleaned ITO conductive glass was treated under UV ozone for 15 minutes. 45uL of hole transport material PEDOT:PSS was dropped on the surface of the treated ITO conductive glass, and a spin coater was used to spin-coat the glass at a speed of 5000rad / min for 50s. The ITO coated with PEDOT:PSS was annealed at 150°C for 30 minutes. The ITO transparent conductive glass with hole transport was placed on a heated spin coater for preheating for 5 minutes, and then 90μL of perovskite precursor solution was dropped on the surface, and the film was spin-coated and then annealed. , forming a perovskite film to obtain a pretreated substrate; the spin coating of the perovskite precursor solution is at a rotation speed of 4000 rad / min, the spin coating is performed for 20 seconds, and the solution is annealed at 100°C in air for 5 minutes; then 18 mg of PCBM is weighed and completely dissolved in 1 ml of chlorobenzene solvent, stirred overnight at 60°C and then allowed to stand for 2 hours, and a PCBM electron transport layer is spin coated on the surface of the pretreated substrate, the spin coating of the PCBM is performed at a speed of 1000 rad / min for 60 seconds, and then at a speed of 2000 rad / min for 2 seconds to form an electron transport layer; then a 1 nm LiF layer is evaporated on the surface of the electron transport layer by vacuum evaporation technology, and then a 100 nm metal electrode Al is evaporated to obtain a low-dimensional perovskite solar cell based on aminobutyric acid.

[0037] Example 2

[0038] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0039] Step 1: Place 90 mL of methylamine in an ice-water bath in a round-bottom flask, and slowly drop 27.6 mL of glacial acetic acid thereinto. After 6 hours of ice-water bath, evaporate at 55°C until no liquid drops, and prepare methylamine acetate solution for use; Place 1 g of aminobutyric acid in an ice-water bath in a round-bottom flask, add HI thereto in a molar ratio of 1:1, and after 6 hours of ice-water bath, evaporate at 55°C until no liquid drops, then wash the evaporated solid with ether, and dry in vacuum at 40°C to obtain 4-aminobutyric acid hydroiodide; According to the structural formula (C4H9NO2)2(CH3NH3)2Pb3I 10 Weigh 172.64 mg of lead iodide, 39.69 mg of iodomethylamine, 57.67 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 120 ° C for 2 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 270 mg / mL;

[0040] Step 2: Clean the ITO conductive glass in the following order: ethanol, detergent, ultrapure water, and acetone. Ultrasonic treatment was performed for 15 minutes in ethanol, dried with nitrogen, and dried in a 120°C oven for 30 minutes. The cleaned ITO conductive glass was treated under UV ozone for 15 minutes. 45uL of hole transport material PEDOT:PSS was dropped on the treated surface of the ITO conductive glass, and a spin coater was used to spin-coat the glass at a speed of 6000rad / min for 60s. The ITO coated with PEDOT:PSS was annealed at 120°C for 30 minutes. The ITO transparent conductive glass with hole transport was placed on a heated spin coater for preheating for 5 minutes, and then 90μL of perovskite precursor solution was dropped on the surface, and the film was spin-coated and then annealed. , forming a perovskite film to obtain a pretreated substrate; the spin coating of the perovskite precursor solution is at a rotation speed of 4000 rad / min, the spin coating is 20 seconds, and the solution is annealed at 120°C in air for 6 minutes; then 16 mg of PCBM is weighed and completely dissolved in 1 ml of chlorobenzene solvent, stirred overnight at 50°C and then allowed to stand for 2 hours, and a PCBM electron transport layer is spin coated on the surface of the pretreated substrate, the spin coating of the PCBM is performed at a speed of 1200 rad / min for 50 seconds, and then at a speed of 2000 rad / min for 2 seconds to form an electron transport layer; then a 1.5 nm LiF layer is evaporated on the surface of the electron transport layer by vacuum evaporation technology, and then a 150 nm metal electrode Al is evaporated to obtain a low-dimensional perovskite solar cell based on aminobutyric acid.

[0041] Example 3

[0042] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0043] Different from Example 1, according to the structural formula (C4H9NO2)2(CH3NH3)3Pb4I 13 Weigh 178.90 mg of lead iodide, 46.28 mg of iodomethylamine, 44.82 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 60 ° C for 6 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 270 mg / mL; the rest of the process and parameters are the same as in Example 1, and finally a low-dimensional perovskite solar cell based on aminobutyric acid is obtained.

[0044] Example 4

[0045] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0046] Different from Example 1, according to the structural formula (C4H9NO2)2(CH3NH3)5Pb6I 19Weigh 185.64 mg of lead iodide, 53.36 mg of iodomethylamine, 31.01 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 60 ° C for 6 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 270 mg / mL; the rest of the process and parameters are the same as in Example 1, and finally a low-dimensional perovskite solar cell based on aminobutyric acid is obtained.

[0047] Example 5

[0048] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0049] Different from Example 1, according to the structural formula (C4H9NO2)2(CH3NH3)4Pb5I 16 Weigh 135.47 mg of lead iodide, 37.38 mg of iodomethylamine, 27.15 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 60 ° C for 6 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 200 mg / mL; the rest of the process and parameters are the same as in Example 1, and finally a low-dimensional perovskite solar cell based on aminobutyric acid is obtained.

[0050] Example 6

[0051] A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid comprises the following steps:

[0052] Different from Example 1, according to the structural formula (C4H9NO2)2(CH3NH3)4Pb5I 16 Weigh 203.20 mg of lead iodide, 56.67 mg of iodomethylamine, 40.73 mg of 4-aminobutyric acid hydroiodide and 20 mg of additive chloromethylamine, dissolve in 1 mL of methylamine acetate solution, stir at 60 ° C for 6 h until completely dissolved, and obtain a perovskite precursor solution with a concentration of 300 mg / mL; the rest of the process and parameters are the same as in Example 1, and finally a low-dimensional perovskite solar cell based on aminobutyric acid is obtained.

[0053] Figure 1 The figure shows a schematic diagram of the structure of a low-dimensional perovskite solar cell based on aminobutyric acid prepared by the present invention. The low-dimensional perovskite solar cell based on aminobutyric acid prepared by the present invention comprises, from top to bottom, a metal electrode layer (Al), a modification layer (LiF), an electron transport layer (PCBM), a titanium ore precursor solution, a hole transport layer (PEDOT:PSS), and an ITO transparent conductive glass; Figure 2The JV characteristic curve of the low-dimensional perovskite solar cell based on aminobutyric acid prepared by the present invention is shown. It can be seen from the figure that the open circuit voltage is 0.95V and the short circuit current is 20.53mA / cm 2 .

[0054] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid, characterized in that: The following steps are involved: S1: Lead iodide, iodomethylamine, and 4-aminobutyric acid hydroiodide are dissolved in methylamine acetate solution, and then chloromethylamine is added and stirred to obtain a perovskite precursor solution; S2: coating a hole transport material on the conductive glass to obtain a conductive glass having a hole transport layer; A perovskite precursor solution is coated on a conductive glass surface having a hole transport layer, followed by heat treatment to obtain a pretreated substrate; An electron transport layer is coated on the surface of a pretreated substrate, and then a modification layer and a metal electrode are coated on the surface of the electron transport layer to obtain a low-dimensional perovskite solar cell based on aminobutyric acid; In S1, according to the stoichiometric ratio, the ratio of lead iodide, methylamine iodide and 4-aminobutyric acid hydroiodide is n:(n-1):2, wherein n is a natural number greater than 1; and the dosage ratio of the methylamine acetate solution and methylamine chloride is (1-2) mL:(10-20) mg.

2. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S1, the conductive glass is ITO conductive glass; the methylamine acetate solution is prepared by mixing acetic acid and methylamine in a molar ratio of 1:1.5 and stirring the mixture in an ice bath for 2h to 6h; the preparation method of the 4-aminobutyric acid hydroiodide is as follows: 4-aminobutyric acid and hydroiodic acid are mixed, stirred in an ice bath for 2h to 6h, and 4-aminobutyric acid hydroiodide is obtained after rotary evaporation, wherein the molar ratio of 4-aminobutyric acid to hydroiodic acid is 1:

1.

3. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S1, the stirring is carried out at 30° C. to 120° C. for 2 h to 6 h; and the concentration of the perovskite precursor solution is 200 mg / mL to 300 mg / mL.

4. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S2, the coating method of the hole transport material is spin coating deposition, the hole transport material is PEDOT:PSS, and the process parameters of the spin coating deposition are: spin coating at 5000rad / min~6000rad / min for 50s~60s; In S2, after coating the hole transport material on the conductive glass, annealing is performed to obtain a conductive glass with hole transport properties; the annealing temperature is 120° C. to 150° C., and the annealing time is 30 minutes.

5. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S2, the method of coating the perovskite precursor solution is spin coating deposition, the method of heat treatment is annealing, the annealing temperature is 100° C. to 120° C., and the annealing time is 4 min to 6 min.

6. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S2, the electron transport layer is PCBM; the specific steps of coating the electron transport layer on the surface of the pretreated substrate are: dissolving PCBM in chlorobenzene, stirring at 50°C to 60°C to obtain a spin coating liquid, and spin coating the spin coating liquid on the surface of the pretreated substrate; the mass concentration of the PCBM in chlorobenzene is 16mg / mL to 18mg / mL; In S2, the process parameters of the spin coating are: spin coating at a rotation speed of 1000-1200 rad / min for 50s-60s.

7. The method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to claim 1, characterized in that: In S2, the modification layer is LiF, and the metal electrode is Al; the thickness of the LiF is 1 nm to 1.5 nm, and the thickness of the Al is 100 nm to 150 nm.

8. A low-dimensional perovskite solar cell based on aminobutyric acid prepared by the method for preparing a low-dimensional perovskite solar cell based on aminobutyric acid according to any one of claims 1 to 7.

9. A low-dimensional perovskite solar cell based on aminobutyric acid according to claim 8, characterized in that: The low-dimensional perovskite solar cell based on GABA has an energy conversion efficiency of 14.74%, an open circuit voltage of 0.95 V, and a short circuit current of 20.53 mA / cm 2 , the filling factor is 75.93%.

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