Self-assembled monomolecular material based on meta-position dicarbazole substituted structure and application of self-assembled monomolecular material

Abstract

The invention relates to the technical field of solar cells, in particular to a self-assembly monomolecular material based on a meta-position dicarbazole substitution structure and application of the self-assembly monomolecular material. In the monomolecular material, two carbazole derivatives are connected to two meta-positions of a phosphonic acid group; the meta-position disubstituted structure can restrain self-aggregation in the self-assembly process, a more compact and uniform film is formed, and high-quality growth of an upper-layer solar cell material is facilitated; due to the meta-position disubstituted structure, carbazole large rings on the two sides of a single molecule are exposed in a manner that the front surfaces face upwards, and large-area contact can be formed between the carbazole large rings and perovskite growing on the carbazole large rings; the side surface of a carbazole ring of the para-position monocarbazole substituted structure is upward, so that the contact area between the para-position monocarbazole substituted structure and an upper solar cell material is small; the disubstituted structure has larger dipole moment, energy level matching is better, conductivity is higher, and efficient extraction of holes can be promoted; and by tightly contacting with an upper-layer solar cell material, the defects of a buried interface can be passivated, non-radiative recombination is reduced, and the efficiency and the stability of the solar cell are improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of solar cells, and particularly relates to a self-assembled monomolecular material based on a meta-bis-carbazole substituted structure and application thereof. BACKGROUND

[0002] Metal halide perovskite solar cells (hereinafter referred to as perovskite solar cells) are a new solar cell technology, which uses metal halide perovskite as a light-absorbing layer material and can be produced on a large scale by a solution method. Compared with the already commercialized crystalline silicon solar cells, the perovskite solar cells have the advantages of high efficiency and low cost. The transverse perovskite solar cell is one of the perovskite solar cell structures, which is composed of a conductive glass substrate, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer, an electrode and the like from bottom to top.

[0003] In the transverse perovskite solar cell, the hole transport layer is crucial for efficient extraction of photo-generated holes and suppression of interface recombination. Traditional hole transport layer materials, such as polymer materials (such as PTAA) or metal oxide materials (such as NiO x ), still have problems such as parasitic absorption, mismatched energy levels, poor wettability, and many defects, which limit the improvement of the efficiency and stability of the transverse perovskite solar cell and hinder its commercialization.

[0004] In recent years, self-assembled monolayer (SAM) materials based on specific organic molecules are considered as a promising candidate for the hole transport layer due to their adjustable energy levels, ultra-thin thickness, strong hole extraction ability, and ability to passivate buried defects. The SAM molecule is mainly composed of an anchor group, a linking group and a terminal group, and can spontaneously form a monolayer on a conductive substrate or NiO x . The interface properties can be precisely controlled by changing the three parts of the SAM molecule. However, the current SAM materials applied in the transverse structure still have significant shortcomings: first, the SAM molecules are prone to self-aggregation on the substrate surface, resulting in uneven and poor dense monolayers, which affects the continuity of charge transport; second, the extraction rate of holes is still significantly lower than the extraction rate of electrons by the electron transport layer material, leading to unbalanced carrier extraction in the perovskite solar cell; third, the interface contact performance of some SAM materials with the upper perovskite layer is poor, which may introduce defect states and increase non-radiative recombination. These problems seriously restrict the full play of the performance of SAM in the transverse perovskite solar cell, and need to be improved. SUMMARY

[0005] In view of the above deficiencies of the prior art, the purpose of the present application is to provide a self-assembled monolayer material based on a meta-bis-carbazole substituted structure and its application as a hole transport layer in a solar cell, aiming to solve the problems of easy self-aggregation of the existing SAM, insufficient carrier extraction capability and poor contact with perovskite.

[0006] The self-assembled monolayer material based on a meta-bis-carbazole substituted structure provided by the present application has a chemical structure as shown in the following formula (I):

[0007]

[0008] In the formula, two carbazole derivatives are connected to the two meta positions of the phosphonic acid group, X is an N atom or a substituted C atom, Y1-Y 16 are independently selected from an N atom or a substituted C atom.

[0009] When X is a substituted C atom, the substituents can be H, B(OH)2, F, Cl, Br, I, CN, CHO, COOH, NH2, NH3 + , (CH2) n NH3 + (n has a value of 1-18), NO2, OH, SH, PO(OH)2, an alkyl group with a carbon atom number of 1-18, an alkoxy or alkylthio group with a carbon atom number of 1-18, or an aryl or substituted aryl group with a carbon atom number of 6-10, or a heteroaryl or substituted heteroaryl group with a carbon atom number of 4-8;

[0010] When Y1-Y 16 are independently selected from a substituted C atom, the substituents can be H, B(OH)2, F, Cl, Br, I, CN, CHO, COOH, NH2, NH3 + , (CH2) n NH3 + (n has a value of 1-18), NO2, OH, SH, PO(OH)2, an alkyl group with a carbon atom number of 1-18, an alkoxy or alkylthio group with a carbon atom number of 1-18, or an aryl or substituted aryl group with a carbon atom number of 6-10, or a heteroaryl or substituted heteroaryl group with a carbon atom number of 4-8;

[0011] Preferably, X is N or a C atom substituted with CH, F, Cl, Br, I, CH3, C(CH3)3, CN, CHO, COOH, NH2, NH3 + , (CH2)2NH3 + (CH2)2NH3 + , OH, OMe, SH, SMe, PO(OH)2;

[0012] Preferably, Y1-Y 16 is N or a C atom substituted by CH, F, Cl, Br, I, CH3, C(CH3)3, CN, CHO, COOH, NH2, NH3 + , (CH2)2NH3 + (CH2)2NH3 + , OH, OMe, SH, SMe, PO(OH)2;

[0013] More preferably, the self-assembled monolayer material based on the meta-bis-carbazole substituted structure is any one of compounds 1-40:

[0014]

[0015] The present application also provides a synthesis method of the compound shown in formula (I), and a synthesis route

[0016]

[0017] The specific steps of the synthesis are as follows:

[0018] Herein, X and Y1-Y 16 have the same meanings as those in the general formula (I).

[0019] (1) raw material 1 (1 equivalent) and raw material 2-1 (0.5-4 equivalents) are added, DMF is used as a solvent, fluorine atom is used as a leaving group, under the basic condition provided by Cs2CO3 (1-3 equivalents), in an inert gas atmosphere, through aromatic nucleophilic substitution reaction, to obtain intermediate 1-1;

[0020] (2) intermediate 1-1 (1 equivalent) and raw material 2-2 (0.5-4 equivalents) are added, DMF is used as a solvent, fluorine atom is used as a leaving group, under the basic condition provided by Cs2CO3 (1-3 equivalents), in an inert gas atmosphere, through aromatic nucleophilic substitution reaction, to obtain intermediate 1-2;

[0021] (3) intermediate 1-2 (1 equivalent), palladium acetate 3 (0.02-0.1 equivalent), 1,1-bis(diphenylphosphino)ferrocene (0.04-0.2 equivalent), potassium acetate (0.05-0.3 equivalent), triethylamine (0.8-4 equivalents) and 1,4-dioxane are added, refluxed in an inert gas atmosphere for 10-60 minutes, then diethyl phosphite (0.5-10 equivalents) is added dropwise, through palladium catalysis to obtain intermediate 2;

[0022] (4) intermediate 2 and dichloromethane are added, trimethylsilyl bromide is added dropwise, stirred at room temperature for 6-24 hours, then the reaction solution is rotary evaporated to dryness, and then methanol is added to continue the reaction for 0.5-24 hours to obtain the product.

[0023] It should be noted that when the raw material 2-2 and the raw material 2-1 are the same, the intermediate 1-2 can be directly obtained by one-step reaction of the raw material 1 and the raw material 2-1 by changing the ratio of the raw materials.

[0024] The self-assembled monolayer material based on the meta-bis-carbazole substituted structure can be applied as a hole transport layer material in a solar cell; the solar cell includes a perovskite solar cell and a laminated solar cell thereof. In the solar cell, the hole transport layer is the self-assembled monolayer material based on the meta-bis-carbazole substituted structure, which is prepared by a vacuum evaporation method, a molecular beam evaporation method, a solvent-dissolved dip coating method, a spin coating method, a rod coating method, or an inkjet printing method, and has a thickness of 1-100 nm, preferably 10-50 nm.

[0025] The application further provides a solar cell with a hole transport layer of a self-assembled monolayer material based on a meta-bis-carbazole substituted structure. The solar cell includes a perovskite solar cell and a laminated solar cell thereof.

[0026] The creativity and gain effect of the application are both from the special structure of meta-bis-carbazole substitution. The essential difference between the meta-bis-carbazole substituted structure and the para-single-carbazole substituted structure in the prior art (such as patent CN 117659083 A) is that:

[0027] (1) The special structure of meta-bis-carbazole substitution suppresses the self-aggregation phenomenon of the self-assembled monolayer material, thereby realizing more uniform self-assembly monolayer and promoting the more uniform growth of the upper solar cell material;

[0028] (2) The meta-bis-substituted structure exposes the carbazole macrocycle on both sides of a single molecule to the front, which can form a large-area contact with the perovskite grown above, and the contact effect is good; while the para-single-carbazole substituted structure exposes the carbazole ring to the side, which has a small contact area with the upper solar cell material and poor contact;

[0029] (3) The meta-bis-carbazole substituted structure has a larger dipole moment and stronger hole extraction and defect passivation capability.

[0030] These advantages cannot be realized by the para-single-carbazole substituted structure in the prior art.

[0031] Compared with the existing self-assembled monolayer material, the positive effect of the application mainly lies in:

[0032] The self-assembled monolayer material based on the meta-bis-carbazole substituted structure of the application can inhibit self-aggregation between molecules, has smaller colloidal average particle size in solution, and can form a more dense and uniform film in the self-assembly process, which is beneficial to the high-quality growth of the upper solar cell material. In addition, the bis-substituted structure has a larger dipole moment, improves the HOMO energy level and the degree of matching of the valence band of the upper solar cell material, stronger conductivity, promotes efficient extraction of holes, and has a more close contact with the upper solar cell material, passivates the buried interface defects, and reduces non-radiative recombination. Finally, the efficiency and stability of the solar cell are improved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Hydrogen nuclear magnetic spectrum of intermediate 20-Br synthesized for Example 1.

[0034] Figure 2 Hydrogen nuclear magnetic spectrum of intermediate 20-PE synthesized for Example 1.

[0035] Figure 3 Hydrogen nuclear magnetic spectrum of compound 20 synthesized for Example 1.

[0036] Figure 4 Mass spectrum of intermediate 1-Br synthesized for Example 2.

[0037] Figure 5 Mass spectrum of intermediate 1-PE synthesized for Example 2.

[0038] Figure 6 Mass spectrum of compound 1 synthesized for Example 2.

[0039] Figure 7 Mass spectrum of intermediate 23-Br synthesized for Example 3.

[0040] Figure 8 Mass spectrum of intermediate 23-PE synthesized for Example 2.

[0041] Figure 9 Mass spectrum of compound 23 synthesized for Example 2.

[0042] Figure 10 Structure schematic diagram of the trans-perovskite solar cell in Example 1 and Comparative Example 1.

[0043] Figure 11 Frontier molecular orbital distribution diagram and dipole moment of Example 1 compound 20 and Comparative Example comparative compound Me-PhpPACz.

[0044] Figure 12 Colloidal particle size distribution diagram of Example 1 compound 20 and Comparative Example comparative compound Me-PhpPACz.

[0045] Figure 13 Atomic force microscope topography of self-assembled monolayer thin film in Example 1 and Comparative Example 1.

[0046] Figure 14 Atomic force microscope topography of perovskite thin film in Example 1 and Comparative Example 1.

[0047] Figure 15 Scanning electron microscope images of perovskite thin film surface ((a) and (b)) and buried interface (c) and (d)) in Example 1 and Comparative Example 1.

[0048] Figure 16 X-ray diffraction pattern of perovskite thin film in Example 1 and Comparative Example 1.

[0049] Figure 17 Time-resolved fluorescence pattern of perovskite thin film in Example 1 and Comparative Example 1.

[0050] Figure 18 Device stability pattern of perovskite solar cell in Example 1 and Comparative Example 1 under maximum power point tracking for 1000 hours. DETAILED DESCRIPTION

[0051] The application will be further described below in conjunction with the drawings. Based on these embodiments, other embodiments obtained by those skilled in the art without creative work are within the protection scope of the application.

[0052] Example 1, synthesis and application test of compound 20.

[0053] (I) Synthesis of compound 20, the route is as follows:

[0054]

[0055] The specific steps of synthesis are as follows:

[0056] Step 1: Synthesis of intermediate 20-Br

[0057] Magnetic son, 1-bromo-3,5-difluorobenzene (1 g, 5.18 mmol, 1 eq), 3,6-dimethylcarbazole (2.02 g, 10.36 mmol, 2 eq), Cs2CO3(3.38 g, 10.36 mmol, 2 eq) were added into a 100 ml flask, vacuumed and purged with nitrogen for 3 times, then 50 mL super dry DMF was added, and the reaction was refluxed for 12 hours. After the reaction was completed, a large amount of distilled water was added to the reaction solution to precipitate the product, and then the product was filtered and washed with methanol for 3 times, and then vacuum dried to obtain the intermediate 20-Br as a white solid powder (2.48 g, 4.56 mmol, yield 88%).1 H NMR (400 MHz, CDC13) δ 7.91 - 7.87 (m, 4H), 7.79 (d, J = 1.9 Hz, 2H), 7.74 (s, 1H), 7.42 (d, J = 8.3 Hz, 4H), 7.26 - 7.22 (m, 4H), 2.54 (s, 12H).

[0058] Step 2: Synthesis of intermediate 20-PE

[0059] Magnetite, intermediate 20-Br (1 g, 1.84 mmol, 1 eq), Pd(OAc)2(0.0103 g, 0.046 mmol, 0.03 eq), dppf (0.06 eq), KOAc (0.0181 g, 0.184 mmol, 0.1 eq) were added into a 100 mL oven-dried flask, vacuumed and purged with nitrogen for 3 times, then TEA (0.2234 g, 0.307 mL, 2.21 mmol, 1.2 eq) and 50 mL 1,4-dioxane were added using a syringe, then the system was refluxed for 15 minutes, diethyl phosphite (0.254 g, 0.237 mL, 1.84 mmol, 1 eq) was added dropwise and the reaction was allowed to proceed for 24 hours. After the reaction was completed and cooled, the reaction solution was poured into a fritted funnel lined with THF-wetted celite and suction filtered. After the filtrate was rotary evaporated under reduced pressure, it was loaded onto a column for purification using column chromatography with DCM:EA = 20:1-10:1 as the eluent. The separated product was further purified by recrystallization with DCM and PE as the good and poor solvents, respectively. White crystals of intermediate 20-PE (0.829 g, 1.382 mmol, 75% yield) were obtained. 1 H NMR (400 MHz, CDC13) δ 7.91 - 7.87 (m, 4H), 7.79 (d, J = 1.9 Hz, 2H), 7.74 (s, 1H), 7.42 (d, J = 8.3 Hz, 4H), 7.26 - 7.22 (m, 4H), 2.54 (s, 12H).

[0060] Step 3: Synthesis of compound 20

[0061] The magnetic flux and intermediate 20-PE were added to a dried flask, and the mixture was evacuated and purged with nitrogen three times. 40 mL of ultra-dry DCM was added using a syringe, followed by the dropwise addition of Me3SiBr. The reaction mixture was allowed to react at room temperature for 12 hours. The reaction solution was then quickly transferred to a round-bottom flask and evaporated to dryness. 25 mL of MeOH was then added, and the mixture was stirred at room temperature for 6 hours. After further evaporation, the reaction solution was recrystallized using THF and AC as good and bad solvents, respectively, to obtain a white flocculent compound 20 (0.317 mg, 0.583 mmol, yield 70%). 1 H NMR (400MHz, DMSO) δ8.01(s,4H),7.89(d,J=14.6Hz,3H),7.45(d,J=8.4Hz,4H),7.28(d,J=8.4Hz,4H),2.49(s,12H).MS(ESI,m / z):544.19[M] + Calculated for C 34 H 29 N2O3P, found 544.39.

[0062] (II) Compound 20 was used to prepare inverse perovskite solar cells, and its performance was tested.

[0063] 1. The structure of a perovskite solar cell is specifically: indium tin oxide (ITO) / nickel oxide (NiO). x Self-assembled monolayer (compound 20) / Perovskite layer / Passivation layer / Electron transport layer / Hole blocking layer / Electrode. The perovskite layer is a 1.68 eV wide-bandgap perovskite Cs. 0.3 FA 0.6 DMA 0.1 Pb(I 0.87 Br 0.13 3. The passivation layer is made of ethylenediamine dihydroiodate (EDAI), and the electron transport layer is made of (6,6)-phenyl-C 61 methyl butyrate (PCBM), the hole-blocking layer is made of zirconium acetylacetonate (Zr(acac)4), and the electrodes are made of high-purity silver (>99.99%). The device structure is as follows: Figure 5 .

[0064] 2. The specific steps for fabricating perovskite solar cells are as follows:

[0065] (1) Spin-coating 10 mg / mL nano NiO onto a clean and dry ITO conductive glass at a speed of 3000 r / s. x The solution used was deionized water and isopropanol in a 3:1 ratio. Spin coating was performed for 30 seconds, followed by annealing at 100°C for 10 minutes to obtain coated NiO. x The base;

[0066] (2) spin 0.5 mg / mL compound 20 solution in ethanol at 5000 r / s for 30 s on the substrate coated with NiO x

[0067] (3) spin perovskite solution on the substrate coated with self-assembled monolayer, perovskite concentration is 1 M, solvent is DMF:DMSO = 4:1, spin speed is: first 2000 r for 15 s, then 4000 r for 45 s, at the 30th second, use nitrogen gun with pressure of 0.3 MPa to blow the substrate vertically from about 10 cm above the substrate for 20 s, remove the nitrogen gun after the film changes color, after the rotation stops, put the perovskite wet film on the hot stage to anneal at 100℃ for 20 minutes;

[0068] (4) spin 1 mg / mL EDAI solution in isopropanol:DMF = 150:1 at 5000 r / s on the perovskite film, then anneal at 65℃ for 10 minutes;

[0069] (5) after cooling, spin 23 mg / mL PCBM solution in chlorobenzene at 2500 r / s, then anneal at 70℃ for 10 minutes;

[0070] (6) after cooling, spin 2 mg / mL Zr(acac)4 solution in isopropanol at 4000 r / s;

[0071] (7) evaporate 100 nm silver electrode at a rate of 0.1 nm / s under a vacuum degree of 5×10 -4 Pa.

[0072] Solar cell performance characterization: the device structure of the trans- perovskite solar cell prepared by the above method is shown in Figure 10 , and the effective area is 0.0776 cm 2 . Test conditions: spectral distribution AM1.5G, light intensity 100 mW / cm 2 , SS-X100R solar simulator (Shengyan Electronics Technology (Shanghai) Co., Ltd.), J-V curve is measured by Keithly 2450 type digital source meter. The test results are shown in Table 1.

[0073] 3. Test of perovskite solar cell

[0074] ​​(1) Theoretical calculation: using density functional theory, the functional method is B3LYP, the basis set is 6-31G(d), and the quantum chemistry software Gaussian is used to optimize the geometric structure of compound 20 to obtain its electrostatic potential distribution, frontier molecular orbital distribution and dipole moment, and the results are as follows Figure 11 .

[0075] (2) Test of surface morphology of self-assembled monolayer:

[0076] Compound 20 was dissolved in DMF at a concentration of 5 mg / mL to prepare a solution, and the colloidal particle size distribution of the two compounds was tested using a nanoparticle size-Zeta potential analyzer (ZS90), and the results are as follows Figure 12 .

[0077] (3) Test of surface and buried interface morphology of perovskite film;

[0078] According to the above device preparation steps (1)-(3), the perovskite film sample was prepared, and the surface of the perovskite film was tested by scanning atomic force microscope and scanning electron microscope, and the results are as follows Figure 13 a, 14a. At the same time, the buried bottom interface of the perovskite film was tested by scanning electron microscope, and the results are as follows Figure 15 c.

[0079] Preparation method of perovskite film buried bottom interface sample: (1) A layer of UV curing glue is coated on the surface of the perovskite film sample, and the glass substrate is covered after uniform coating, and the overlapping part is about 1 / 3 to 1 / 2 of the perovskite film sample. Lightly press the glass substrate to squeeze out the excess air; (2) Put the glass and sample covered with glass under the UV lamp for 20-30s, then break the substrate with force, and get the perovskite film sample with the buried bottom interface facing up.

[0080] (4) Test of crystalline quality of perovskite film,

[0081] The perovskite film sample prepared above was tested by X-ray diffraction, and the results are as follows Figure 16 .

[0082] (5) Test of time-resolved fluorescence map of perovskite film,

[0083] The perovskite film sample prepared above was tested by time-resolved fluorescence map, and the excitation light source was a 512nm laser, and the results are as follows Figure 17 and Table 3.

[0084] (6) Stability test of trans-perovskite solar cell

[0085] According to ITO / NiO x / compound 20 / Cs 0.3 FA0.6 DMA 0.1 Pb(I 0.87 Br 0.13 )3 / PCBM / ALD-SnO2 / Ag Figure 18 .

[0086] (Three) Preparation and testing of perovskite-silicon tandem solar cells

[0087] 1. The structure of perovskite-silicon tandem solar cells, specifically: silicon cell / tunneling layer / self-assembled monolayer / perovskite layer / passivation layer / electron transport layer 1 / electron transport layer 2 / transparent electrode / anti-reflection layer / silver grid electrode. Among them, the silicon cell is purchased through a commercial channel, the tunneling layer uses a transparent conductive metal oxide, and the function is to connect the perovskite cell and the silicon cell; the self-assembled monolayer uses the compound 20 provided by the present application, the perovskite layer uses a wide-bandgap perovskite Cs 0.3 FA 0.6 DMA 0.1 Pb(I 0.87 Br 0.13 )3, the passivation layer uses ethylenediamine dihydroiodide (EDAI), the electron transport layer 1 uses fullerene C 60 , the electron transport layer 2 uses ALD-SnO2, the transparent electrode uses a transparent metal oxide, and the anti-reflection layer uses magnesium fluoride.

[0088] 2. Preparation of perovskite-silicon perovskite solar cells, the specific steps are:

[0089] (1) A transparent conductive metal oxide is deposited on a clean and dry silicon cell as a tunneling layer by vapor deposition;

[0090] (2) Prepare an assembled monolayer on the tunneling layer, the process is the same as the preparation of the transverse perovskite solar cell in this embodiment;

[0091] (3) Spin-coat a perovskite solution on the substrate coated with a self-assembled monolayer, the perovskite concentration is 1.5M, the solvent is DMF:DMSO=4:1, the spin-coating speed is: first 2000r 15s, then 4000r 45s, at the 10th second, 200uL chlorobenzene is added as an anti-solvent on the substrate to promote the nucleation and crystallization of the perovskite film, and after the rotation stops, the perovskite wet film is placed on a hot stage for annealing at 100℃ for 20 minutes;

[0092] (4) The passivation layer process is the same as the preparation of the transverse perovskite solar cell in this embodiment;

[0093] (5) Transfer to the evaporation chamber, evaporate 30 nm of C -4 at a rate of 0.2 nm / s at a vacuum of 5 x 10 Pa. 60 ;

[0094] (6) Transfer to the atomic layer deposition chamber, deposit 10 nm of -Sn02using atomic layer deposition technology at a vacuum of 5 x 10 -4 Pa, using tetra(dimethylamino)tin and water as the precursor source.

[0095] (7) Transfer to the magnetron sputtering chamber, deposit 20 nm of transparent conductive metal oxide using magnetron sputtering technology at a sputtering power of 80 W.

[0096] (8) Transfer to the evaporation chamber, evaporate 100 nm of a silver grid electrode at a rate of 0.2 nm / s at a vacuum of 5 x 10 -4 Pa.

[0097] The performance characterization method of the perovskite-crystalline silicon tandem solar cell is the same as that of the trans perovskite solar cell, except that the effective area of the perovskite-crystalline silicon tandem solar cell is 1.05 cm -2 . The test results are shown in Table 2.

[0098] Example 2, synthesis and application test of compound 1.

[0099] (I) Synthesis of compound 1, the route is as follows:

[0100]

[0101] The specific steps of synthesis are as follows:

[0102] Step 1: Synthesis of intermediate 1-Br

[0103] The synthesis steps of intermediate 1-Br are the same as those of intermediate 20-Br, except that the raw material 3,6-dimethylcarbazole is replaced by carbazole. 1 H NMR (400 MHz, CDC13) δ 8.18 - 8.12 (m, 4H), 7.87 (d, J = 1.9 Hz, 2H), 7.80 (t, J = 1.9 Hz, 1H), 7.55 (d, J = 8.2 Hz, 4H), 7.46 (ddd, J = 8.4, 7.0, 1.3 Hz, 4H), 7.37 - 7.30 (m, 4H).

[0104] Step 2: Synthesis of intermediate 1-PE

[0105] The synthesis steps of intermediate 1-PE are the same as those of 20-PE, except that the intermediate 20-Br in the raw material is replaced by 1-Br.​1 H NMR (400 MHz, CDC13) δ 8.20 - 8.08 (m, 6H), 8.02 (d, J = 2.0 Hz, 1H), 7.53 (dt, J = 8.3, 0.9 Hz, 4H), 7.46 (ddd, J = 8.3, 7.1, 1.2 Hz, 4H), 7.34 (ddd, J = 8.0, 7.1, 1.1 Hz, 4H), 4.38 - 4.19 (m, 4H), 1.42 (t, J = 7.1 Hz, 6H).

[0106] Step 3: synthesis of compound 1

[0107] The synthesis of compound 1 is the same as compound 20, except that the intermediate 20-PE is replaced by the intermediate 1-PE. 1 H NMR (400 MHz, DMSO) δ 8.29 (d, J = 7.9 Hz, 4H), 8.06 (s, 1H), 7.96 (dd, J = 13.3, 2.1 Hz, 2H), 7.63 - 7.54 (m, 4H), 7.54 - 7.44 (m, 4H), 7.38 - 7.26 (m, 4H), 1.05 (t, J = 7.0 Hz, 1H).

[0108] (II) Performance test of compound 1 for preparing trans-perovskite solar cells

[0109] The preparation and test method of trans-perovskite solar cells based on compound 1 are the same as those of compound 20, except that all the self-assembled monolayer materials are replaced by compound 1. The test results are shown in Table 1.

[0110] (III) Preparation and test of perovskite-crystalline silicon tandem solar cells

[0111] The performance characterization method of perovskite-crystalline silicon tandem solar cells is the same as that of Example 1, except that the self-assembled monolayer material is replaced by compound 1. The test results are shown in Table 2.

[0112] Example 3, synthesis and application test of compound 8.

[0113] (I) Synthesis of compound 1, the route is:

[0114]

[0115] The specific steps are:

[0116] Step 1: synthesis of intermediate 8-Br

[0117] The synthesis of intermediate 8-Br is the same as intermediate 20-Br, except that the starting material 3,6-dimethylcarbazole is replaced by 5H-pyrido[4,3-B]indole. Mass spectral data MS (ESI, m / z): 488.06 [M] + calculated for C 28 H 17 BrN4

[0118] Step 2: Synthesis of intermediate 8-PE

[0119] The synthesis of intermediate 8-PE is the same as 20-PE, except that intermediate 20-Br in the starting material is replaced by 8-Br. Mass spectral data MS (ESI, m / z): 546.18 [M] + calculated for C 32 H 27 N4O3P

[0120] Step 3: Synthesis of compound 8

[0121] The synthesis of compound 8 is the same as compound 20, except that intermediate 20-PE is replaced by intermediate 8-PE. Mass spectral data MS (ESI, m / z): 490.12 [M] + calculated for C 28 H 19 N4O3P.

[0122] (ii) Performance test of compound 8 for preparing trans-perovskite solar cells

[0123] The preparation and test method of trans-perovskite solar cells based on compound 8 is the same as compound 20, except that all the self-assembled monolayer materials are replaced by compound 8. The test results are shown in Table 1.

[0124] (iii) Preparation and test of perovskite-crystalline silicon tandem solar cells

[0125] The performance characterization method of perovskite-crystalline silicon tandem solar cells is the same as Example 1, except that the self-assembled monolayer material is replaced by compound 8. The test results are shown in Table 2.

[0126] Example 4, synthesis and application test of compound 23.

[0127] (i) Synthesis of compound 23, the route is:

[0128]

[0129] The specific steps for synthesis are:

[0130] Step 1: synthesis of intermediate 23-Br

[0131] The synthesis of intermediate 23-Br is the same as that of intermediate 20-Br, except that the raw material 3,6-dimethylcarbazole is replaced by 3,6-dimethoxycarbazole. 1 H NMR (400 MHz, CDC13) δ 7.77 (d, J = 1.8 Hz, 2H), 7.72 (s, 1H), 7.54 (d, J = 2.5 Hz, 4H), 7.45 (d, J = 8.9 Hz, 4H), 7.07 (dd, J = 8.9, 2.5 Hz, 4H), 3.95 (s, 13H);

[0132] Step 2: synthesis of intermediate 23-PE

[0133] The synthesis of intermediate 23-PE is the same as that of 20-PE, except that intermediate 20-Br in the raw material is replaced by 23-Br. 1 H NMR (400 MHz, CDC13) δ 8.03 (dd, J = 13.9, 2.1 Hz, 2H), 7.93 (s, 1H), 7.55 (d, J = 2.5 Hz, 4H), 7.42 (d, J = 8.9 Hz, 4H), 7.06 (dd, J = 8.9, 2.5 Hz, 4H), 4.26 (q, J = 7.2 Hz, 4H), 3.95 (d, J = 1.1 Hz, 12H), 1.40 (t, J = 7.1 Hz, 6H);

[0134] Step 3: synthesis of compound 23

[0135] The synthesis of compound 23 is the same as that of compound 20, except that intermediate 20-PE is replaced by intermediate 23-PE. 1 H NMR (400 MHz, DMSO) δ 7.84 (d, J = 11.9 Hz, 7H), 7.44 (d, J = 9.0 Hz, 4H), 7.05 (d, J = 8.9 Hz, 4H), 3.86 (t, J = 1.9 Hz, 12H).

[0136] (B) Performance test of compound 23 for preparing trans-perovskite solar cells

[0137] The preparation and test method of trans-perovskite solar cells based on compound 23 is the same as that of compound 20, except that all the self-assembled monolayer materials are replaced by compound 23. The test results are shown in Table 1.

[0138] (Three) Preparation and test of perovskite-crystalline silicon tandem solar cells

[0139] The perfoemance of the perovskite-silicon tandem solar cell was characterized in the same manner as in Example 1, except that the self-assembled monolayer material was replaced by compound 23. The test results are shown in Table 2.

[0140] Example 5, synthesis and application test of compound 26.

[0141] (I) Synthesis of compound 26, the route is as follows:

[0142]

[0143] The specific steps of synthesis are as follows:

[0144] Step 1: Synthesis of intermediate 26-Br

[0145] The synthesis steps of intermediate 26-Br are the same as those of intermediate 20-Br, except that the raw material 3,6-dimethylcarbazole is replaced by 3,6-dichlorocarbazole. The mass spectrum data MS (ESI, m / z): 625.91 [M] + calculated for C 30 H 15 BrCl4N2;

[0146] Step 2: Synthesis of intermediate 26-PE

[0147] The synthesis steps of intermediate 26-PE are the same as those of 20-PE, except that the intermediate 20-Br in the raw material is replaced by 26-Br. The mass spectrum data MS (ESI, m / z): 682.36 [M] + calculated for C 34 H 25 Cl4N2O3P;

[0148] Step 3: Synthesis of compound 26

[0149] The synthesis steps of compound 26 are the same as those of compound 20, except that the intermediate 20-PE is replaced by the intermediate 26-PE. The mass spectrum data MS (ESI, m / z): 490.12 [M] + calculated for C 28 H 19 N4O3P.

[0150] (II) Compound 26 is used for preparing a trans-perovskite solar cell, and the performance is tested

[0151] The preparation and test method of the trans-perovskite solar cell based on compound 26 are the same as those of compound 20, except that the self-assembled monolayer material is replaced by compound 26. The test results are shown in Table 1.

[0152] (Three) Preparation and testing of perovskite-crystalline silicon tandem solar cells

[0153] The perovskite-crystalline silicon tandem solar cell performance characterization method is the same as that of Example 1, except that the self-assembled monolayer material is replaced by compound 26. The test results are shown in Table 2.

[0154] Example 6, synthesis and application test of compound 37.

[0155] (I) Synthesis of compound 37, the route is as follows:

[0156]

[0157] The specific steps of synthesis are as follows:

[0158] Step 1: Synthesis of intermediate 37-Br

[0159] The synthesis steps of intermediate 37-Br are the same as those of intermediate 20-Br, except that the raw material 1-bromo-3,5-difluorobenzene is replaced by 4-bromo-2,6-difluorobenzonitrile. Mass spectral data MS (ESI, m / z): 567.13 [M] + calculated for C 35 H 26 BrN3;

[0160] Step 2: Synthesis of intermediate 37-PE

[0161] The synthesis steps of intermediate 37-PE are the same as those of 20-PE, except that intermediate 20-Br in the raw material is replaced by 37-Br. Mass spectral data MS (ESI, m / z): 625.25 [M] + calculated for C 39 H 36 N3O3P;

[0162] Step 3: Synthesis of compound 37

[0163] The synthesis steps of compound 37 are the same as those of compound 20, except that intermediate 20-PE is replaced by intermediate 37-PE. Mass spectral data MS (ESI, m / z): 490.12 [M] + calculated for C 28 H 19 N4O3P.

[0164] (II) Compound 37 is used to prepare a trans-perovskite solar cell, and the performance is tested

[0165] The preparation and testing method of the trans-perovskite solar cell based on compound 37 is the same as that of compound 20, except that the self-assembled monolayer material is replaced by compound 37. The test results are shown in Table 1.

[0166] (III) Preparation and testing of perovskite-crystalline silicon tandem solar cells

[0167] The performance characterization method of the perovskite-crystalline silicon tandem solar cell is the same as that of Example 1, except that the self-assembled monolayer material is replaced by compound 37. The test results are shown in Table 2.

[0168] Example 7, synthesis and application test of compound 40.

[0169] (I) Synthesis of compound 40, the route is as follows:

[0170]

[0171] The specific steps of synthesis are as follows:

[0172] Step 1: Synthesis of intermediate 40-Br

[0173] The synthesis steps of intermediate 40-Br are the same as those of intermediate 20-Br, except that the raw material 3,6-dimethylcarbazole is replaced by 3,6-dibromocarbazole. Mass spectrum data MS (ESI, m / z): 801.71 [M] + calculated for C 30 H 15 Br5N2;

[0174] Step 2: Synthesis of intermediate 40-PE

[0175] The synthesis steps of intermediate 40-PE are the same as those of 20-PE, except that the intermediate 20-Br in the raw material is replaced by 40-Br. Mass spectrum data MS (ESI, m / z): 1088.31 [M] + calculated for C 50 H 65 N2O 15 P5;

[0176] Step 3: Synthesis of compound 40

[0177] The synthesis steps of compound 1 are the same as those of compound 20, except that the intermediate 20-PE is replaced by the intermediate 40-PE. Mass spectrum data MS (ESI, m / z): 807.99 [M] + calculated for C 30 H 25 N2O 15 P5.

[0178] (II) Performance test of compound 40 for preparing trans-perovskite solar cells

[0179] The preparation and test method of trans-perovskite solar cells based on compound 40 is the same as that of compound 20, except that the self-assembled monolayer material is replaced by compound 40. The test results are shown in Table 1.

[0180] (III) Preparation and test of perovskite-crystalline silicon tandem solar cells

[0181] The performance characterization method of perovskite-crystalline silicon tandem solar cells is the same as that of Example 1, except that the self-assembled monolayer material is replaced by compound 40. The test results are shown in Table 2.

[0182] Comparative Example 1

[0183] The comparative compound is the compound Me-PhpPACz reported in the literature, and its chemical formula is as shown in formula (II)

[0184]

[0185] The preparation and test of trans-perovskite solar cells and perovskite-crystalline silicon tandem solar cells based on the comparative compound Me-PhpPACz are the same as those of Example 1, except that the self-assembled monolayer material is replaced by the comparative compound Me-PhpPACz, and the device structure is as shown in Figure 10 , and the test results are shown in Tables 1 and 2.

[0186] (1) Theoretical calculation, the method is the same as that of Example 1, except that the molecular structure is replaced by the comparative compound Me-PhpPACz, and the results are as shown in Figure 11 .

[0187] (2) Surface morphology test of self-assembled monolayer

[0188] The sample preparation and test method is the same as that of Example 1, except that the self-assembled monolayer material is replaced by the comparative compound Me-PhpPACz, and the results are as shown in Figure 12 .

[0189] (3) Surface and buried interface morphology test of perovskite thin film

[0190] The sample preparation and test method is the same as that of Example 1, except that the self-assembled monolayer material is replaced by the comparative compound Me-PhpPACz, and the results are as shown in Figure 13 b, 14b, 15d.

[0191] (4) Crystalline quality test of perovskite thin film

[0192] Sample preparation and testing methods were the same as Example 1, except that the self-assembled monolayer material was replaced by comparative compound Me-PhpPACz, and the results were as follows Figure 16 .

[0193] (5) Time-resolved fluorescence plot of perovskite thin film

[0194] Sample preparation and testing methods were the same as Example 1, except that the self-assembled monolayer material was replaced by comparative compound Me-PhpPACz, and the results were as follows Figure 17 and Table 3.

[0195] (6) Stability test of trans-perovskite solar cell

[0196] Sample preparation and testing methods were the same as Example 1, except that the self-assembled monolayer material was replaced by comparative compound Me-PhpPACz, and the results were as follows Figure 18 .

[0197] Table 1 Summary of performance parameters of trans-perovskite solar cells of Examples 1-7 and Comparative Example 1

[0198]

[0199] * Short circuit current is in milliampere per square centimeter.

[0200] Table 2 Summary of performance parameters of perovskite-silicon tandem solar cells of Examples 1-7 and Comparative Example 1

[0201]

[0202] * Short circuit current is in milliampere per square centimeter.

[0203] Table 2 Summary of performance parameters of best performing perovskite-silicon tandem solar cells of Examples 1 and Comparative Example 1

[0204] Table 2, Carrier lifetime of ITO / NiOx / SAM / PVK in Examples 1 and Comparative Example 1

[0205]

[0206] Results analysis

[0207] The following analyzes the data and charts in Examples 1-7 and Comparative Example 1 to illustrate the advantages of using the self-assembled monolayer material provided by the present application in solar cells.

[0208] As shown in Table 1, compared to Me-PhpPACz, the power conversion efficiency of inverted perovskite solar cells using the self-assembled monolayer materials compounds 20, 1, 8, 23, 26, 37, and 40 provided by this invention is significantly improved, increasing from 20.86% for Me-PhpPACz to 21.46-22.35%. The gain effect of the compounds provided by this invention in inverted perovskite solar cells is mainly reflected in the open-circuit voltage and short-circuit current.

[0209] As shown in Table 2, compared to Me-PhpPACz, the power conversion efficiency of perovskite-silicon tandem solar cells using the self-assembled monolayer materials compounds 20, 1, 8, 23, 26, 37, and 40 provided by this invention is significantly improved, increasing from 26.61% for Me-PhpPACz to 28.91-33.09%. The compounds provided by this invention are very effective in improving the open-circuit voltage, short-circuit current, and fill factor of perovskite-silicon tandem solar cells.

[0210] The self-assembled monolayer materials compounds 20, 1, 8, 23, 26, 37 and 40 provided by this invention are representative structures in the general structural formula provided by this invention. Therefore, the performance of these compounds well illustrates the gain effect of the general structural formula provided by this invention.

[0211] The following analysis, using compound 20 provided by this invention and the comparative compound Me-PhpPACz as examples, further illustrates the gain effect of the compounds provided by this invention:

[0212] Depend on Figure 11 As can be seen, compared to the comparative compound Me-PhpPACz, the compound 20 provided by this invention has a larger dipole moment and a shallower highest occupied molecular orbital (HOP) energy level. This is beneficial for achieving energy level alignment with the perovskite layer during self-assembly, thereby achieving better hole extraction functionality. Furthermore, the separation between the HOP and LOP of the compound 20 provided by this invention is more pronounced, indicating that the compound 20 provides better stability. In addition, thanks to the meta-biscarbazole substitution structure, the carbazole macrocycles on both sides of the compound 20 molecule are exposed upwards, meaning that the compound 20 provided by this invention can form better contact with the perovskite grown above it in the solar cell; while in the comparative compound Me-PhpPACz, only the methyl group and one carbazole ring are exposed upwards, meaning that the comparative compound 20 has poorer contact with the solar cell material above it.

[0213] Depend on Figure 12It can be seen that the colloidal particle size of the comparative compound Me-PhpPACz is generally around 400 nanometers; the compound 20 provided by this invention, in addition to colloidal particles with a size of around 500 nanometers, has a greater proportion of small colloidal particles with a size of around 1 nanometer. This indicates that the self-aggregation phenomenon between molecules is well suppressed due to the double meta-substitution structure of the compound 20 provided by this invention.

[0214] Depend on Figure 13 It can be seen that, compared with the comparative compound Me-PhpPACz (4.77 nm), the self-assembled monolayer film of compound 20 provided by the present invention has a smaller root mean square roughness (4.36 nm) and a more uniform distribution.

[0215] Depend on Figure 14 It can be seen that, compared with the comparative compound Me-PhpPACz (10.9 nm), the perovskite grown on the self-assembled monolayer film of compound 20 provided by the present invention has a smaller root mean square roughness (8.64 nm) and a more uniform distribution.

[0216] Depend on Figure 15 As shown in (a) and 11, compared to the comparative compound Me-PhpPACz, the perovskite grains grown on the self-assembled monolayer film of compound 20 provided by the present invention are larger and more uniform in size. The white, vertical flakes are PbI2, and the presence of excessive PbI2 will reduce the efficiency and stability of perovskite solar cells. PbI2 is more common in perovskites grown on the comparative compound Me-PhpPACz, but is almost undetectable in the perovskites grown on the compound 20 provided by the present invention. Figure 15 As shown in (c) and (d), the perovskite film grown on the self-assembled monolayer film of compound 20 provided by the present invention has fewer pores at the bottom, indicating good contact between the self-assembled layer and the perovskite layer. In contrast, the perovskite film grown on the self-assembled monolayer film of the comparative compound Me-PhpPACz shows a large number of pores at the bottom, indicating poor contact between the self-assembled layer and the perovskite layer. This will create a large number of non-radiative recombination channels, deteriorating the efficiency and stability of the solar cell. Figure 15 This indicates that, compared to the comparative compound Me-PhpPACz, the self-assembled monolayer film of compound 20 provided by the present invention regulates the crystal growth of perovskite by forming better contact with the bottom of the perovskite film.

[0217] Depend on Figure 16 As shown in (a) and 16(b), compared to the comparative compound Me-PhpPACz, the perovskite grown on the self-assembled monolayer film of compound 20 provided by the present invention exhibits stronger crystallinity. Figure 16(a) It can be known that the compound 20 provided by the present application also enhances the dominant orientation of the (100) crystal plane, which is beneficial to the enhancement of carrier transmission and extraction. Figure 16 (b) The surface information of the perovskite film is reacted, and it can be seen that, compared with the comparative compound Me-PhpPACz, the perovskite signal grown on the self-assembled monolayer film of the compound 20 provided by the present application is obviously stronger, and the PbI2 signal is weaker, which is consistent with the analysis result of Figure 15 .

[0218] It can be known from Figure 17 and Table 3 that the τ1 lifetime and τ2 lifetime of the perovskite grown on the comparative compound Me-PhpPACz are 21.48 and 117.05 ns, respectively, and the τ1 lifetime and τ2 lifetime of the perovskite grown on the compound 20 provided by the present application are 17.34 and 133.14 ns, respectively. The τ1 lifetime corresponds to carrier extraction, and the τ2 lifetime corresponds to non-radiative recombination. Compared with the comparative compound Me-PhpPACz, the perovskite grown on the compound 20 provided by the present application has obviously shorter τ1 lifetime and longer τ2 lifetime, which indicates that the compound 20 provided by the present application can accelerate the extraction of holes while inhibiting non-radiative recombination.

[0219] It can be known from Figure 18 that after 1000 hours of continuous operation at the maximum power point, the efficiency of the perovskite solar cell with the comparative compound Me-PhpPACz as the hole transport material decays to 88% of the initial value, while the efficiency of the perovskite solar cell with the compound 20 provided by the present application as the hole transport material still remains 95% of the initial value, which has higher stability.

[0220] In summary, the above test analysis shows that when the self-assembled monolayer material provided by the present application is used as a hole transport material, it can inhibit self-aggregation, has better hole extraction capability, has better contact with perovskite, promotes perovskite crystallization growth, reduces buried defect, and can significantly improve the efficiency and stability of the perovskite solar cell and the perovskite-silicon tandem solar cell.

Claims

1. A self-assembled monomolecular material based on a meta-biscarbazole-substituted structure, characterized in that, The chemical structure is shown in formula (Ⅰ): In the formula, the two carbazole derivatives are respectively attached to the two meta positions of the phosphonic acid group, X is an N atom or a substituted C atom, Y1-Y 16 They are derived independently from N atoms or substituted C atoms.

2. The self-assembled monomolecular material according to claim 1, characterized in that: When X is a substituted C atom, the substituents are H, B(OH)₂, F, Cl, Br, I, CN, CHO, COOH, NH₂, NH₃. + (CH2) n NH3 + , where n takes the value 1-18, NO2, OH, SH, PO(OH)2, alkyl with 1-18 carbon atoms, or alkoxy or alkylthio with 1-18 carbon atoms, or aryl or substituted aryl with 6-10 carbon atoms, or heteroaryl or substituted heteroaryl with 4-8 carbon atoms; When Y1-Y 16 When each substituent is taken independently from the substituted carbon atom, the substituents are H, B(OH)2, F, Cl, Br, I, CN, CHO, COOH, NH2, NH3. + (CH2) n NH3 + (n takes values ​​1-18), NO2, OH, SH, PO(OH)2, alkyl with 1-18 carbon atoms, or alkoxy or alkylthio with 1-18 carbon atoms, or aryl or substituted aryl with 6-10 carbon atoms, or heteroaryl or substituted heteroaryl with 4-8 carbon atoms.

3. The self-assembled monomolecular material according to claim 2, characterized in that: X is a C atom substituted by N or one of the following groups: CH, F, Cl, Br, I, CH3, C(CH3)3, CN, CHO, COOH, NH2, NH3 + (CH2)2NH3 + (CH2)2NH3 + ,OH,OMe,SH,SMe,PO(OH)2; Y1-Y 16 C atoms substituted by N or the following groups: CH, F, Cl, Br, I, CH3, C(CH3)3, CN, CHO, COOH, NH2, NH3 + (CH2)2NH3 + (CH2)2NH3 + ,OH,OMe,SH,SMe,PO(OH)2.

4. The self-assembled monomolecule material according to claim 1, characterized in that, It is any one of the following compounds 1-40:

5. The method for synthesizing self-assembled monomolecule materials based on meta-biscarbazole-substituted structures as described in any one of claims 1-4, characterized in that, The synthetic route is as follows: The specific steps of the synthesis are as follows: (1) Add 1 equivalent of raw material 1 and 0.5-4 equivalent of raw material 2-1, use DMF as solvent, fluorine atom as leaving group, under 1-3 equivalent of Cs2CO3 conditions, in an inert gas atmosphere, through aromatic nucleophilic substitution reaction to obtain intermediate 1-1; (2) Add 1 equivalent of intermediate 1-1 and 0.5-4 equivalent of raw material 2-2, use DMF as solvent and fluorine atom as leaving group, and in an inert gas atmosphere under the condition of 1-3 equivalent of Cs2CO3, through aromatic nucleophilic substitution reaction to obtain intermediate 1-2. (3) Add 1 equivalent of intermediate 1-2, 0.02-0.1 equivalent of palladium acetate 3, 0.04-0.2 equivalent of 1,1-bis(diphenylphosphine)ferrocene, 0.05-0.3 equivalent of potassium acetate, 0.8-4 equivalent of triethylamine and 1,4-dioxane, reflux in an inert gas atmosphere for 10-60 minutes, then add 0.5-10 equivalent of diethyl phosphonite dropwise, and obtain intermediate 2 through palladium catalysis. (4) Add intermediate 2 and dichloromethane, add trimethylbromosilane dropwise and stir at room temperature for 6-24 hours. Then, dry the reaction solution by rotary evaporation and add methanol to continue the reaction for 0.5-24 hours to obtain the product.

6. The application of the self-assembled monomolecule material based on the meta-biscarbazole substitution structure as described in any one of claims 1-4 as a hole transport layer material in solar cells; said solar cells include perovskite solar cells and their tandem solar cells.

7. In the application according to claim 6, the hole transport layer is prepared by vacuum evaporation, molecular beam evaporation, solvent-based dip coating, spin coating, rod coating or inkjet printing of a self-assembled monomolecular material based on meta-biscarbazole substitution structure, with a thickness of 1-100 nm.

8. A solar cell based on a self-assembled monomolecular material with a meta-dicarbazole-substituted structure as a hole transport layer, the solar cell comprising a perovskite solar cell and a tandem solar cell thereof.

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