Perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite solar cell and a preparation method thereof, and belongs to the technical field of perovskite solar cells. The preparation method comprises the following steps: adding 4-tert-butylpyridine and an iodine-rich nano metal organic framework material into a hole transport layer material to obtain a hole transport layer precursor solution; the hole transport layer precursor solution is coated on the surface of a base material to form a hole transport layer; the iodine-rich nano metal organic framework material comprises a metal organic framework and an iodine element introduced into the metal organic framework. The hole transport layer is prepared from a nano metal organic framework material containing an iodine element, and the iodine element in the nano metal organic framework can be coordinated with a dopant 4-tert-butylpyridine (tBP) through chemical bonding to form a tBP-metal organic framework-iodine element complex, so that the tBP is fixed, the transfer of the tBP to the perovskite active layer is prevented, and the hole transport layer is formed. And the damage of tBP to the perovskite active layer is reduced, so that the service life of the perovskite cell is prolonged.

Description

Technical Field

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

[0002] The dopant 4-tert-butylpyridine (tBP) added to the hole transport layer material will form tBP-PbI 2 The complexes corrode the perovskite film, induce the decomposition of the perovskite / Spiro interface, and affect the stability and service life of the perovskite solar cells. Summary of the invention

[0003] The main purpose of the present invention is to provide a perovskite solar cell and a preparation method thereof, so as to solve the technical problem that the dopant 4-tert-butylpyridine (tBP) easily damages the perovskite active layer of the perovskite solar cell.

[0004] To achieve the above object, the present invention provides a method for preparing a perovskite solar cell, comprising the following steps:

[0005] Adding 4-tert-butylpyridine and iodine-rich nano-metal organic framework material to the hole transport layer material to obtain a hole transport layer precursor solution;

[0006] The hole transport layer precursor solution is coated on the surface of the substrate to form a hole transport layer;

[0007] The iodine-rich nano metal organic framework material comprises a metal organic framework and an iodine element introduced into the metal organic framework.

[0008] In some embodiments of the present invention, the metal organic framework in the iodine-rich nano metal organic framework material includes UIO-66.

[0009] In some embodiments of the present invention, the iodine-rich nanometal organic framework material comprises the following structural formula:

[0010]

[0011] In some embodiments of the present invention, the iodine-rich nano-metal organic framework material and the 4-tert-butylpyridine form a complex, and the complex comprises the following structural formula:

[0012]

[0013] In some embodiments of the present invention, the mass ratio of 4-tert-butylpyridine to iodine-rich nano-metal organic framework material is (30:1) to (20:1);

[0014] And / or, the hole transport layer material includes 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD).

[0015] In some embodiments of the present invention, the surface of the substrate includes a perovskite active layer, and the hole transport layer is prepared on the surface of the perovskite active layer;

[0016] Alternatively, the method for preparing the perovskite solar cell further comprises the following steps:

[0017] A perovskite active layer is prepared on the surface of the hole transport layer.

[0018] In some embodiments of the present invention, the method for preparing the iodine-rich nano-metal organic framework material comprises the following steps:

[0019] Dispersing hexadecyltrimethylammonium bromide in isooctane and hexanol, heating and stirring to obtain solution A;

[0020] Similarly, dispersing hexadecyltrimethylammonium bromide into isooctane and hexanol, heating and stirring to obtain solution B;

[0021] Dispersing 2,5-diiodoterephthalic acid in water to obtain solution C;

[0022] ZrCl 4 Disperse in water to obtain solution D;

[0023] Adding the solution C to the solution A, heating and stirring to obtain emulsion A;

[0024] Adding the solution D into the solution B, heating and stirring to obtain emulsion B;

[0025] After the emulsion A and the emulsion B are stirred to be colorless and transparent, the emulsion A and the emulsion B are mixed, and the metal organic framework material UIO-66-2I nanoparticles are obtained through heating, cooling, centrifugation, washing and drying.

[0026] In some embodiments of the present invention, the addition ratio of hexadecyltrimethylammonium bromide and isooctane is (1.0-3.0) g / (20-60) ml;

[0027] and / or, the ratio of hexadecyltrimethylammonium bromide to hexanol is (1.0-3.0) g / (4-12) ml;

[0028] and / or, the ratio of 2,5-diiodoterephthalic acid to water is (5-15) mg / (50-150) μl;

[0029] And / or, the ZrCl 4The addition ratio of water is (5-15) mg / (50-150) μl;

[0030] and / or, after dispersing the hexadecyltrimethylammonium bromide in a mixed solution of isooctane and hexanol, further heating the solution at a temperature of 70° C. to 75° C.;

[0031] and / or, in the step of heating to obtain emulsion A, the heating temperature is 70° C. to 75° C.;

[0032] And / or, in the step of heating to obtain emulsion B, the heating temperature is 70° C. to 75° C.;

[0033] And / or, in the step of mixing the emulsion A and the emulsion B and heating them, the heating temperature is 70°C to 80°C.

[0034] The present invention also provides a perovskite solar cell prepared by the method for preparing a perovskite solar cell as described above.

[0035] In some embodiments of the present invention, the perovskite solar cell comprises, from bottom to top, a transparent conductive glass, an electron transport layer, a perovskite active layer, the hole transport layer and a back electrode.

[0036] Alternatively, the perovskite solar cell includes, from bottom to top, a transparent conductive glass, a hole transport layer, a perovskite active layer, an electron transport layer and a back electrode.

[0037] The beneficial effects that can be achieved by the present invention are:

[0038] The present invention prepares a hole transport layer using a metal organic framework material containing iodine. The iodine in the iodine-rich nano metal organic framework material can be coordinated with the dopant 4-tert-butylpyridine (tBP) through chemical bonding to form a tBP-metal organic framework-iodine complex, thereby fixing the tBP, reducing the risk of holes in the hole transport layer caused by the flow of tBP, preventing tBP from migrating to the perovskite active layer, reducing the damage of tBP to the perovskite active layer, and thus extending the service life of the perovskite battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0040] Figure 1 It is a schematic diagram of the process of a method for preparing a perovskite solar cell according to the present invention. DETAILED DESCRIPTION

[0041] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] The present invention provides a method for preparing a perovskite solar cell, referring to Figure 1 , including the following steps:

[0045] S10, adding 4-tert-butylpyridine (tBP) and iodine-rich nano-metal organic framework material to the hole transport layer material to obtain a hole transport layer precursor solution, wherein the iodine-rich nano-metal organic framework material includes a metal organic framework and iodine element;

[0046] S20, coating the hole transport layer precursor solution onto the surface of the substrate to form a hole transport layer.

[0047] In the present invention, the hole transport layer precursor solution contains iodine-rich nano-metal organic framework material, which includes a metal organic framework and iodine element. The iodine element in the iodine-rich nano-metal organic framework material can be coordinated with the dopant 4-tert-butylpyridine (tBP) through chemical bonding to form a tBP-metal organic framework-iodine element complex, thereby fixing tBP, reducing the risk of holes in the hole transport layer caused by the flow of tBP, preventing tBP from migrating to the perovskite active layer, reducing the damage of tBP to the perovskite active layer, and thus extending the service life of the perovskite battery.

[0048] The metal organic framework has porous properties and a large specific surface area, which is conducive to the rapid transfer and utilization of photogenerated charges, thereby effectively reducing the recombination of electrons and holes in the bulk phase of the photocatalytic material. The present invention also introduces iodine groups into the metal organic framework to obtain iodine-rich nano metal organic framework materials, and uses halogen bonds and tBP in the hole transport layer to chemically bond to form a tBP-metal organic framework-iodine element complex, anchoring tBP to prevent tBP from migrating to the perovskite active layer, thereby reducing the damage of tBP to the perovskite active layer, and prolonging the life of the perovskite solar cell on the basis of improving the photoelectric conversion efficiency of the perovskite solar cell.

[0049] In some embodiments, the metal organic framework in the iodine-rich nano metal organic framework material includes UIO-66, UIO-66 has zirconium ion (Zr) as the metal center, 1,4-phthalic acid as the organic ligand, and iodine element is introduced into UIO-66.

[0050] In some embodiments, the iodine-rich nanometal organic framework material comprises the following structural formula:

[0051] It can be expressed as UIO-66-2I.

[0052] In this embodiment, iodine-rich organic ligands and zirconium metal are coordinated to prepare iodine-rich UiO-66-2I nanoparticles. The iodine-rich UiO-66-2I nanoparticles are used to prepare a hole transport layer, and can be coordinated with the dopant 4-tert-butylpyridine (tBP) of the hole transport material to form a tBP-UiO-66-2I complex through chemical bonding, thereby fixing tBP and preventing tBP from migrating to the perovskite active layer, reducing the damage of tBP to the perovskite active layer, and extending the service life of the perovskite solar cell on the basis of improving the photoelectric conversion efficiency of the perovskite solar cell.

[0053] In this embodiment, the iodine-rich nano metal organic framework material UIO-66-2I and 4-tert-butylpyridine form a complex, and the complex can include the following structural formula:

[0054] The complex having the above structural formula can be represented by tBP-UiO-66-2I.

[0055] The iodine-rich nanometal-organic framework material UIO-66-2I uses halogen bonds and the nitrogen element in tBP to chemically bond to obtain the tBP-UiO-66-2I complex. The iodine element in this iodine-rich nanometal-organic framework material is relatively abundant and can bond to tBP in large quantities, thereby strengthening the anchoring effect on tBP and effectively preventing tBP from migrating into the perovskite active layer. On the basis of improving the perovskite solar cell, it extends the service life of the perovskite solar cell.

[0056] In some embodiments, the mass ratio of 4-tert-butylpyridine to iodine-rich nano-metal organic framework material in the hole transport layer precursor solution is (30:1) to (20:1). Within the above addition amount range, it is beneficial to reduce the migration of tBp to the perovskite active layer.

[0057] In some embodiments, the hole transport material, the dopant 4-tert-butylpyridine and the iodine-rich nano-metal organic framework material can be dispersed in a solvent to obtain a hole transport layer precursor solution.

[0058] In some embodiments, the solvent for dissolving the hole transport material, the dopant 4-tert-butylpyridine and the iodine-rich nanometal organic framework material comprises an organic solvent, and the organic solvent comprises at least one of chlorobenzene, ethanol and acetonitrile.

[0059] In some embodiments, the hole transport layer material includes 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), which is a common hole transport layer material and is usually used in combination with tBp. tBp is used to improve conductivity and ion mobility to improve the photoelectric conversion efficiency of perovskite solar cells. However, the mobility of tBp will cause some holes in the hole transport layer, and it is easy to migrate to the perovskite active layer to corrode the perovskite active layer. In addition, tBp will induce the rapid "de-doping" of the doped Spiro, which will reduce the overall conductivity of the hole transport layer, thereby affecting the photoelectric conversion efficiency of the perovskite solar cell. The present invention adds iodine-rich nano-metal organic framework materials to the hole transport layer precursor solution, which can effectively anchor tBp, thereby overcoming the disadvantages caused by the flow of tBp.

[0060] In some embodiments, adding 4-tert-butylpyridine and iodine-rich nano-metal organic framework material to the hole transport layer material to obtain a hole transport layer precursor solution includes the following steps: dissolving Spiro-OMeTAD in chlorobenzene, adding an acetonitrile solution of lithium bistrifluoromethanesulfonyl imide (Li-TFSI), an acetonitrile solution of cobalt (III) complex (FK209), triphenylbutylphosphine bromide (tBP) and UiO-66-2I nanoparticles to obtain a hole transport layer precursor solution.

[0061] In some embodiments, the hole transport layer precursor solution is coated onto the surface of the substrate by spin coating, the spin coating speed is 3500rpm~4500rpm, can be 4000rpm, the spin coating time is 25s~35s, can be 30s, and the spin coating acceleration is 1800rpm / s~2200rpm / s, can be 2000rpm / s.

[0062] The method for preparing the perovskite solar cell of the present invention may further include preparing a perovskite active layer.

[0063] In some embodiments, after the hole transport layer is completed, a perovskite active layer can be prepared on the surface of the hole transport layer, thereby preparing an inverted perovskite solar cell. In this embodiment, the substrate includes transparent conductive glass, and the hole transport layer can be directly prepared on the surface of the transparent conductive glass. In addition, in some embodiments, the substrate not only includes transparent conductive glass, but also includes an interface modification layer formed on the surface of the transparent conductive glass and the hole transport layer commonly used in the art, and the hole transport layer can be prepared on the surface of the interface modification layer. The iodine-rich nano-metal organic framework material in the hole transport layer can utilize its nano properties to be fully dispersed in the hole transport layer, and the iodine-rich nano-metal organic framework material can be chemically bonded with tBp by means of the introduced iodine element to form a complex, anchor tBp, and prevent tBp from migrating to the perovskite active layer to damage the perovskite active layer. In addition, the flow of tBp is also prevented to prevent the hole transport layer from appearing due to the flow of tBp.

[0064] In some embodiments, after the perovskite active layer is completed, a hole transport layer can be prepared on the surface of the perovskite active layer according to the preparation method of the present invention. At this time, the substrate includes the above-mentioned perovskite active layer, that is, the hole transport layer is prepared on the surface of the perovskite active layer of the substrate, and the prepared perovskite solar cell is a normal perovskite solar cell. In this embodiment, the substrate can also include some conventional functional layers in the art, for example, it can include transparent conductive glass, an electron transport layer prepared on the surface of the transparent conductive glass, a perovskite active layer prepared on the surface of the electron transport layer, and then the hole transport layer precursor solution is coated on the surface of the perovskite active layer to prepare the hole transport layer. The iodine-rich nano-metal organic framework material in the hole transport layer can utilize its nano properties to be fully dispersed in the hole transport layer, and the iodine-rich nano-metal organic framework material can chemically bond with the introduced iodine element and tBp to form a complex, anchor the tBp, and prevent tBp from migrating to the perovskite active layer to damage the perovskite active layer. In addition, it also blocks the flow of tBp and prevents the appearance of holes in the hole transport layer due to the flow of tBp.

[0065] In the present invention, the above-mentioned functions such as electron transport layer, interface modification layer, back electrode, etc. can be prepared by referring to the common technical means in the art.

[0066] The present invention also provides an iodine-rich nano-metal organic framework material and a preparation method thereof. The structural formula of the iodine-rich nano-metal organic framework material is as follows:

[0067]

[0068] The preparation method of the above iodine-rich nano metal organic framework material comprises the following steps:

[0069] Dispersing hexadecyltrimethylammonium bromide in isooctane and hexanol, heating and stirring to obtain solution A;

[0070] Similarly, dispersing hexadecyltrimethylammonium bromide into isooctane and hexanol, heating and stirring to obtain solution B;

[0071] Dispersing 2,5-diiodoterephthalic acid in water to obtain solution C;

[0072] ZrCl 4 Disperse in water to obtain solution D;

[0073] Adding the solution C to the solution A, heating and stirring to obtain emulsion A;

[0074] Adding the solution D into the solution B, heating and stirring to obtain emulsion B;

[0075] When both emulsion A and emulsion B are colorless and transparent, emulsion A and emulsion B are mixed, and the iodine-rich nano-metal organic framework material is obtained through heating, cooling, centrifugation, washing and drying. The iodine-rich nano-metal organic framework material of this embodiment can be represented by UIO-66-2I nanoparticles.

[0076] In this embodiment, an emulsion confinement method is used to prepare iodine-rich nano-metal organic framework materials, which can form a nanoscale emulsion. Confining metal ions and organic ligands in the nanoemulsion can control the growth size of the metal organic framework, thereby being able to synthesize iodine-rich nano-metal organic framework materials of uniform size, so that the iodine-rich nano-metal organic framework materials are uniformly dispersed in the hole transport layer precursor solution.

[0077] In some embodiments, the addition ratio of hexadecyltrimethylammonium bromide and isooctane is (1.0-3.0) g / (20-60) ml.

[0078] In some embodiments, the ratio of hexadecyltrimethylammonium bromide to hexanol is (1.0-3.0) g / (4-12) ml.

[0079] In some embodiments, hexadecyltrimethylammonium bromide is dispersed in isooctane and hexyl alcohol, and heated and stirred to obtain solution A and solution B, which can promote the dispersion of hexadecyltrimethylammonium bromide. In some embodiments, a rotor can be added to solution A for stirring and dispersion, the heating temperature can be 70°C to 75°C, and the heating and stirring time can be 0.5h to 1.5h.

[0080] In some embodiments, the addition ratio of 2,5-diiodoterephthalic acid and water is (5-15) mg / (50-150) μl.

[0081] In some embodiments, ZrCl 4 After being dispersed in water, solution D was obtained by ultrasonication.

[0082] In some embodiments, ZrCl 4 The addition ratio to water is (5-15) mg / (50-150) μl.

[0083] In some embodiments, emulsion A and emulsion B are colorless and transparent after stirring.

[0084] In some embodiments, after emulsion A and emulsion B are mixed, the temperature is heated to 70° C. to 80° C., and stirring can be performed to promote mixing and reaction of the reactants.

[0085] In some embodiments, the heating time is 2 h to 2.5 h.

[0086] In some embodiments, the centrifugal speed is 8000 rpm to 12000 rpm, and the product is collected under centrifugal conditions, and then the product is washed and dried to obtain the iodine-rich nano-metal organic framework material.

[0087] In some embodiments, the product can be washed with deionized water, DMF, and ethanol, respectively.

[0088] In some embodiments, the iodine-rich nano-metal organic framework material can be obtained by vacuum drying at 60°C.

[0089] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following specific embodiments are only used to explain the present invention, and are not used to limit the present invention.

[0090] Example 1

[0091] Preparation of iodine-rich nanometal organic framework materials:

[0092] The iodine-rich nanometal organic framework material UiO-66-2I nanoparticles were synthesized by emulsion confinement method, and the preparation steps are as follows:

[0093] Weigh 3.0 g of hexadecyltrimethylammonium bromide and disperse it in a 150 ml flask containing 60 ml of isooctane and 12 ml of hexanol, add a rotor, and stir and heat at 70 °C for 1 h to obtain solution A;

[0094] Weigh 3.0 g of hexadecyltrimethylammonium bromide and disperse it in a 150 ml flask containing 60 ml of isooctane and 12 ml of hexanol, add a rotor, and stir and heat at 70 °C for 1 h to obtain solution B;

[0095] 15 mg of 2,5-diiodoterephthalic acid and 150 uL of H 2 O mixed, and subjected to ultrasound for 15 min to obtain solution C;

[0096] 15 mg of ZrCl 4 and 150uL H 2 O mixed, and subjected to ultrasound for 15 min to obtain solution D;

[0097] Add solution C to solution A, continue heating and stirring to obtain emulsion A;

[0098] Add solution D to solution B, continue heating and stirring to obtain emulsion B;

[0099] Emulsion A was stirred until it became colorless and transparent, and emulsion B was stirred until it became colorless and transparent. Then, emulsion A and emulsion B were mixed, and heating and stirring were continued at 70°C for 2 hours. Then, the mixture was taken out and cooled. The product was collected by centrifugation at 12000 rpm. The product was washed with deionized water, DMF, and ethanol, respectively, and then dried under vacuum at 60°C to obtain iodine-rich nano-metal organic framework material UiO-66-2I nanoparticles.

[0100] The preparation method of perovskite solar cells is as follows:

[0101] Preparation of transparent conductive glass

[0102] Place 15 pieces of 2cm×2cm×1.1mm FTO glass on the glass holder, and then put them into a 400mL beaker. Add 250mL of detergent aqueous solution, deionized water, ethanol and IPA in sequence, and ultrasonically wash them at room temperature for 15 minutes each. Finally, take them out and use N 2 Blow dry with an air gun, then put it into the UVO cleaning machine and UVO clean it for 30 minutes.

[0103] Preparation of electron transport layer

[0104] Pipette 0.5mL of 15% Alfa SnO 2 The aqueous solution was added to 2.5 mL of deionized water and ultrasonically vibrated for 20 min to obtain an electron transport layer precursor solution. 150 uL of the electron transport layer precursor solution was spin-coated onto the surface of the transparent conductive glass at a spin coating speed of 3000 rpm, a spin coating time of 15 s, and a spin coating acceleration of 2000 rpm / s. The electron transport layer was then annealed on a hot plate at 150 °C for 45 min.

[0105] Preparation of perovskite active layer

[0106] FAPbI 3 The powder (1.8M) and MACl (0.63M) were dissolved in a mixed solvent of DMF and DMSO (DMF:MDMSO=4:1v / v) to prepare a perovskite active layer precursor solution. The perovskite solution was spin-coated on the surface of the electron transport layer at a spin-coating speed of 4000rpm, a spin-coating time of 50s, and a spin-coating acceleration of 2000rpm / s. At the 20th second of the spin-coating process, 1mL of chlorobenzene was added as an anti-solvent, and then the substrate was placed in a glove box and annealed at 150°C for 10min to obtain a perovskite active layer.

[0107] Preparation of hole transport layer

[0108] 140 mg of Spiro-OMeTAD was dissolved in 2 mL of chlorobenzene, and then 30 μl of 520 mg / mL lithium bistrifluoromethanesulfonyl imide (Li-TFSI) acetonitrile solution, 15 μl of 375 mg / mL cobalt (III) complex (FK209) acetonitrile solution, 50 μl of tBP (density 1.03 g / mL, mass 51.5 mg) and 2 mg of UiO-66-2I nanoparticles were added to obtain a hole transport layer precursor solution, and 100 μl of the hole transport layer precursor solution was spin coated on the surface of the perovskite active layer at a spin coating speed of 4000 rpm, a spin coating time of 30 s, and a spin coating acceleration of 2000 rpm / s to obtain a hole transport layer.

[0109] Preparation of back electrode

[0110] Au is deposited on the surface of the hole transport layer by magnetron sputtering or the like to obtain an Au back electrode, and the film thickness is 100 nm.

[0111] Control group 1

[0112] The control group 1 prepared a perovskite solar cell according to the preparation method of Example 1, but the difference is that when preparing the hole transport layer, the control group 1 did not add UiO-66-2I nanoparticles to the hole transport layer precursor solution.

[0113] Example 2

[0114] Example 2 A perovskite solar cell was prepared by referring to the preparation method of Example 1, but the difference is that the formula of the perovskite precursor solution in Example 2 is as follows: CsI:FAI:MAI:PbI 2 :PbBr 2 :MACl=0.04:0.80:0.05:0.95:0.03:0.20 are dissolved in a solution of DMF:DMSO=8:1 (v:v) and mixed to prepare the solution.

[0115] Control group 2

[0116] The control group 2 prepared a perovskite solar cell by referring to the preparation method of Example 2, but the difference is that when preparing the hole transport layer, the control group 2 did not add UiO-66-2I nanoparticles to the hole transport layer precursor solution.

[0117] Example 3

[0118] Example 3 A complete perovskite cell solar cell is prepared by referring to the preparation method of Example 1, but the difference is that Example 3 adopts a chemical bath method (CBD) to prepare the electron transport layer. The specific operation is as follows:

[0119] 2.5 g of urea (99%) was dissolved in 200 mL of deionized water, and then 50 μL of TGA and 2.5 mL of hydrochloric acid (37 wt%) were added. Ultrasonication was performed for 5 minutes to make the solution uniform, and then 0.55 g of SnCl was added. 2 ·2H 2 O was ultrasonically dissolved for 5 minutes, and then the UVO-treated substrate was immersed in a chemical bath solution and placed in an oven at 90 ° C for 5 hours. Then, it was taken out and ultrasonically cleaned with deionized water and IPA for 5 minutes, and then washed with N 2 Blow dry with an air gun and anneal on a hot plate at 180°C for 1 hour.

[0120] Control group 3

[0121] The control group 3 prepared a perovskite solar cell by referring to the preparation method of Example 3, but the difference is that when preparing the hole transport layer, the control group 3 did not add UiO-66-2I nanoparticles to the hole transport layer precursor solution.

[0122] Example 4

[0123] Example 4 A complete perovskite battery device was prepared by referring to the preparation method of Example 1, but the difference is that Example 4 uses the evaporation method to evaporate MoO with a thickness of 10 nm. 3 Layer and MoO 3 The surface of the layer was evaporated with a thickness of 90nm Ag as the back electrode.

[0124] Control group 4

[0125] The control group 4 prepared a perovskite solar cell by referring to the preparation method of Example 4, but the difference is that when preparing the hole transport layer, the control group 4 did not add UiO-66-2I nanoparticles to the hole transport layer precursor solution.

[0126] Example 5

[0127] Example 5 A perovskite solar cell was prepared by referring to the preparation method of Example 1, but the difference is that the added amount of UiO-66-2I nanoparticles in Example 5 is 2.5 mg.

[0128] Example 6

[0129] Example 6 The iodine-rich nanometal organic framework material UiO-66-2I nanoparticles were prepared by referring to the preparation method of Example 1, except that 3.0 g of hexadecyltrimethylammonium bromide was weighed and dispersed in a 150 ml flask containing 40 mL of isooctane and 12 mL of hexanol, a rotor was added, and the mixture was stirred and heated at 70 °C for 1 h to obtain solution A.

[0130] The UiO-66-2I nanoparticles prepared in Example 6 were used to prepare a perovskite solar cell according to the preparation method of the perovskite solar cell in Example 1.

[0131] Example 7

[0132] Example 7 The iodine-rich nano-metal organic framework material UiO-66-2I nanoparticles were prepared by referring to the preparation method of Example 1, except that 10 mg of 2,5-diiodoterephthalic acid and 150 uL of H 2 O and subjected to ultrasound for 15 min to obtain solution C.

[0133] The UiO-66-2I nanoparticles prepared in Example 7 were used to prepare a perovskite solar cell according to the preparation method of the perovskite solar cell in Example 1.

[0134] Example 8

[0135] Example 8 The iodine-rich nano-metal organic framework material UiO-66-2I nanoparticles were prepared by referring to the preparation method of Example 1, except that after emulsion A and emulsion B were mixed, they were heated and stirred at 80° C. for 2 h.

[0136] A perovskite solar cell was prepared by using the UiO-66-2I nanoparticles prepared in Example 8 and referring to the preparation method of the perovskite solar cell in Example 1.

[0137] Performance Testing

[0138] The photoelectric conversion efficiency (PCE%) of the perovskite solar cells prepared in the examples and comparative examples was determined, and the capacity retention rate (%) of the perovskite solar cells after being placed at room temperature and a humidity of 5-10% for 7 days was determined. The results are shown in Table 1.

[0139] Table 1

[0140]

[0141]

[0142] It can be seen from Table 1 that, in Examples 1 to 8, iodine-rich nano-metal organic framework material UiO-66-2I nanoparticles are added when preparing the hole transport layer. The UiO-66-2I nanoparticles can anchor the dopant tBp in the hole transport layer, prevent the hole transport layer from appearing due to the flow of tBp, and prevent the flow into the perovskite active layer to destroy the perovskite active layer, thereby ensuring the photoelectric conversion efficiency of the perovskite solar cell while extending the life of the perovskite solar cell. In the capacity retention experiment after 7 days of placement, the perovskite solar cells of Examples 1 to 8 all achieved a retention rate of more than 94%, and the retention rate of Example 1 even reached 98.97%.

[0143] Control groups 1 to 4 correspond to Examples 1 to 4, respectively, and no iodine-rich nano-metal organic framework material is added. The photoelectric conversion efficiency is slightly poor, and the retention rate after 7 days is greatly reduced, and the control group 4 is even only 83.24%.

[0144] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell, characterized in that: The following steps are involved: Adding 4-tert-butylpyridine and iodine-rich nano-metal organic framework material to the hole transport layer material to obtain a hole transport layer precursor solution; The hole transport layer precursor solution is coated on the surface of the substrate to form a hole transport layer; The iodine-rich nano metal organic framework material comprises a metal organic framework and an iodine element introduced into the metal organic framework.

2. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The metal organic framework in the iodine-rich nano metal organic framework material includes UIO-66.

3. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The iodine-rich nano metal organic framework material comprises the following structural formula:

4. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The iodine-rich nano metal organic framework material and the 4-tert-butylpyridine form a complex, and the complex comprises the following structural formula:

5. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The mass ratio of the 4-tert-butylpyridine to the iodine-rich nano-metal organic framework material is (30:1) to (20:1); And / or, the hole transport layer material includes 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD).

6. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The surface of the substrate includes a perovskite active layer, and the hole transport layer is prepared on the surface of the perovskite active layer; Alternatively, the method for preparing the perovskite solar cell further comprises the following steps: A perovskite active layer is prepared on the surface of the hole transport layer.

7. The method for preparing a perovskite solar cell according to claim 1, characterized in that: The preparation method of the iodine-rich nano metal organic framework material comprises the following steps: Dispersing hexadecyltrimethylammonium bromide in isooctane and hexanol, heating and stirring to obtain solution A; Similarly, dispersing hexadecyltrimethylammonium bromide into isooctane and hexanol, heating and stirring to obtain solution B; Dispersing 2,5-diiodoterephthalic acid in water to obtain solution C; Dispersing ZrCl4 in water to obtain solution D; Adding the solution C to the solution A, heating and stirring to obtain emulsion A; Adding the solution D into the solution B, heating and stirring to obtain emulsion B; After the emulsion A and the emulsion B are stirred to be colorless and transparent, the emulsion A and the emulsion B are mixed, and the iodine-rich nano-metal organic framework material is obtained through heating, cooling, centrifugation, washing and drying.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that: The addition ratio of hexadecyltrimethylammonium bromide and isooctane is (1.0-3.0) g / (20-60) ml; and / or, the ratio of hexadecyltrimethylammonium bromide to hexanol is (1.0-3.0) g / (4-12) ml; and / or, the ratio of 2,5-diiodoterephthalic acid to water is (5-15) mg / (50-150) μl; And / or, the addition ratio of ZrCl4 and water is (5-15) mg / (50-150) μl; and / or, after dispersing the hexadecyltrimethylammonium bromide in isooctane and hexanol, further heating the mixture at a temperature of 70° C. to 75° C.; and / or, in the step of heating to obtain emulsion A, the heating temperature is 70° C. to 75° C.; And / or, in the step of heating to obtain emulsion B, the heating temperature is 70° C. to 75° C.; And / or, in the step of mixing the emulsion A and the emulsion B and heating them, the heating temperature is 70°C to 80°C.

9. A perovskite solar cell prepared by the method for preparing a perovskite solar cell according to any one of claims 1 to 8.

10. The perovskite solar cell according to claim 9, characterized in that: The perovskite solar cell comprises, from bottom to top, a transparent conductive glass, an electron transport layer, a perovskite active layer, the hole transport layer and a back electrode. Alternatively, the perovskite solar cell includes, from bottom to top, a transparent conductive glass, a hole transport layer, a perovskite active layer, an electron transport layer and a back electrode.

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