Organic conjugated compounds based on indoline derivatives, and methods of making and using the same

Abstract

The present application relates to the technical field of solar cells, and discloses a conjugated organic compound based on an indoline derivative and a preparation method and application thereof, and the compound structure is shown in the following formula, wherein Ar is a large planar conjugated aromatic group unit, X and Y are independently selected from a hydrogen atom, a fluorine atom or a chlorine atom, R1, R2 and R3 are independently selected from a hydrogen atom, a fluorine atom, a linear or branched alkyl or alkoxy group with a carbon atom number of 1-8. In the present application, indoline is used as an end group (D) to form a D-A-Ar-A-D type conjugated organic compound, and the structure can form a relatively close stack, is conducive to the charge transport between molecules, and improves the hole transport capacity of the molecule, and the intrinsic hole mobility is between 10 ‑3 ~10 ‑4 cm 2 V ‑1 s ‑1 , which is 10 times the intrinsic mobility of a Spiro-OMeTAD molecule, and lays a good practical foundation for a hole transport material with excellent transmission performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of solar cells, in particular to a kind of conjugated organic compound based on indoline derivative and its preparation method and application. BACKGROUND

[0002] Solar energy, as the most abundant green energy on earth, has important development and application value, and is an important part of new energy system. Developing a new generation of solar cell technology and improving the utilization efficiency of solar energy are important measures to achieve the "double carbon" goal. As a representative of the third generation of solar cells, perovskite solar cells (PVSCs) have made rapid progress in the past decade, with a photoelectric conversion efficiency (PCE) of 26.1% from 3.8%. Compared with traditional silicon-based solar cells, PVSCs have the characteristics of simple preparation process, low cost and high photoelectric conversion efficiency.

[0003] The traditional n-i-p type perovskite solar cell uses the organic small molecule material 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) as a hole transport layer. The spiro structure of Spiro-OMeTAD hinders the π-π stacking between molecules, resulting in a low hole mobility (~10 -5 cm 2 V -1 s -1 ) and conductivity (~10 -5 S cm -1 ), so it is necessary to add 4-tert-butylpyridine (tBP), lithium salt (such as LiTFSI), cobalt salt (such as KF209) and other dopants when used, and the prepared device needs to be oxidized.

[0004] CN115884648A discloses an organic silicon-doped hole transport layer and a perovskite solar cell preparation method. A certain amount of spiro-OMeTAD is dissolved in chlorobenzene together with Li-TFSI and heterocyclic organic silicon molecules to obtain a spiro-OMeTAD solution. The spiro-OMeTAD solution is spin-coated on the substrate, and after spin-coating is completed, the organic silicon-doped spiro-OMeTAD hole transport layer is obtained after drying. The present application innovatively uses heterocyclic organic silicon molecules instead of t BP as a hole dopant to inhibit the phase separation of spiro-OMeTAD and Li-TFSI, improve the quality of the spiro-OMeTAD hole transport layer, and further assemble stable and efficient n-i-p type perovskite solar cells.

[0005] CN115101677A discloses a carbon nanotube composite spiro-OMeTAD hole transport layer for optimizing carbon electrode interface conduction and a preparation method thereof, adopts multi-walled carbon nanotubes to replace the traditional dopant tBP and Li-TFSI for increasing the conductivity of spiro-OMeTAD, uniformly disperses the multi-walled carbon nanotubes into the undoped spiro-OMeTAD original solution, and forms a carbon nanotube-spiro-OMeTAD composite hole transport layer on the perovskite surface by a one-step spin coating method. The method adjusts the energy band structure of the solar cell, enhances the conductivity of the spiro-OMeTAD hole transport layer, improves the disadvantage of high hygroscopicity of the spiro-OMeTAD layer caused by the small molecule doping of Li-TFSI, and further helps the carbon electrode to contact the perovskite layer, so that the efficiency and stability of the carbon electrode solar cell containing the structure are significantly improved.

[0006] However, this P-type doping treatment increases the complexity of device preparation and affects the batch stability of device performance. More importantly, the introduction of the dopant reduces the stability of the perovskite solar cell. In addition, the synthesis route of Spiro-OMeTAD is complex, difficult to separate and purify, and therefore expensive (~$780g -1 from Sigma), which restricts the application of perovskite solar cells. SUMMARY

[0007] The present application aims at the problems of poor performance stability, low battery efficiency, complex synthesis route of Spiro-OMeTAD, and high cost of P-type doping treatment solar cell devices, and provides a kind of organic conjugated molecule based on indol derivative, which is used as a hole transport material to prepare a solar cell, and the photoelectric conversion efficiency of 22-24% can be obtained, which lays a good practical foundation for developing a new type of low-cost, simple structure, and excellent transport performance hole transport material.

[0008] To achieve the above object, the technical scheme adopted by the present application is:

[0009] An organic conjugated compound based on indol derivative has the general structure shown in the following formula (I):

[0010]

[0011] In the formula, Ar is a large planar conjugated aromatic group unit, X and Y are independently selected from hydrogen atom, fluorine atom or chlorine atom, R1, R2 and R3 are independently selected from hydrogen atom, fluorine atom, straight-chain or branched alkyl group with 1-8 carbon atoms, and straight-chain or branched alkoxy group with 1-8 carbon atoms.

[0012] In this invention, a π-conjugated aromatic group is used as the central unit (Ar), benzothiadiazole as the electron-withdrawing linking unit (A), and indoline as the terminal group (D), forming a DA-Ar-AD type conjugated organic compound. Compared with common aniline terminal groups (see structure b below), the indoline unit in this invention (see structure a below) exhibits better coplanarity. Density functional theory calculations show (see c below) that the dihedral angle between the two benzene rings in the diphenylamine structure is 13.5 degrees, and in the triphenylamine structure it is 27.1 degrees, while the atoms in the indoline unit are essentially in the same plane. Therefore, organic conjugated molecules with indoline derivatives as terminal groups are more likely to form a closer stack, which is beneficial for charge transport between molecules and improves the hole transport capability of the molecule.

[0013] The series of organic conjugated molecules provided by this invention exhibit good coplanarity, which facilitates the formation of tight molecular stacks and improves hole transport capability, with intrinsic hole mobility exceeding 10. -3 ~10 -4 cm 2 V -1 s -1 Between these values ​​is the Spiro-OMeTAD mobility (~10). -5 cm 2 V -1 s -1 This is more than 10 times that of other materials. Furthermore, these molecules lay a solid practical foundation for developing novel, low-cost, simple-structured hole transport materials with excellent transport performance.

[0014]

[0015] Preferably, the Ar structure is any one of those shown in (II)-(V):

[0016]

[0017] R4 is selected from any of the following structures:

[0018]

[0019] R8 is selected from any of the following structures:

[0020]

[0021] Wherein, R4' and R5 are independently selected from straight-chain or branched alkyl groups having 2-20 carbon atoms; R4” is a straight-chain or branched alkyl group, alkoxy group, or alkylthio group having 2-20 carbon atoms; X1 and X2 are independently selected from hydrogen atom, fluorine atom, or chlorine atom; R6, R7, and R8' are independently selected from straight-chain or branched alkyl groups having 6-20 carbon atoms; and Z is a carbon atom or silicon atom.

[0022] Preferably, X and Y are hydrogen atoms, and the structure without halogen atoms has relatively more excellent performance.

[0023] Preferably, R1, R2 and R3 are independently selected from any one of the following structures:

[0024]

[0025] wherein R1' is independently selected from linear or branched alkyl with carbon atom number 1-8, and n is any number from 2 to 6.

[0026] Further preferably, R1, R2 and R3 are independently selected from methoxy, hydrogen atom or fluorine atom.

[0027] Preferably, in the Ar structure, R4' is branched alkyl with carbon atom number 8-15, R5 is branched alkyl with carbon atom number 8-16; R4" is branched alkyl with carbon atom number 6-15, alkylthio; X1 is fluorine atom or chlorine atom, X2 is hydrogen atom or fluorine atom; R6, R7, R8' are independently selected from linear or branched alkyl with carbon atom number 8-12; Z is silicon atom.

[0028] Further preferably, in the Ar structure, R4' is branched alkyl with carbon atom number 8 or 12, R5 is branched alkyl with carbon atom number 12 or 16; R4" is branched alkyl with carbon atom number 8 or 12, alkylthio; X1 is fluorine atom or chlorine atom, X2 is hydrogen atom or fluorine atom; R6, R7, R8' are independently selected from linear or branched alkyl with carbon atom number 8-12; Z is silicon atom.

[0029] The present application also provides a preparation method of the organic conjugated compound based on indoline derivative, comprising the steps of:

[0030] Step 1, mixing raw materials comprising compound A and compound B in a solvent, refluxing under the action of a catalyst, and purifying to obtain compound C;

[0031] Step 2, mixing raw materials comprising compound C and compound D in a solvent, refluxing under the action of a catalyst, and purifying to obtain the organic conjugated compound;

[0032]

[0033] The reaction formula is as follows:

[0034]

[0035] The molar ratio of compound A to compound B is 1.2-1.8:1;

[0036] The molar ratio of compound C to compound D is 2.0-2.5:1.

[0037] The solvent in step 1 includes any one or more of toluene, tetrahydrofuran or dioxane.

[0038] The solvent in step 2 includes toluene and / or dimethylformamide;

[0039] The catalyst in step 1 includes a mixture of a palladium catalyst, a phosphine ligand and sodium tert-butoxide, in a molar ratio of 1:1.5-2.5:8-12; the catalyst is used in an amount of 5-15% of the reaction raw materials.

[0040] The catalyst in step 2 includes tetraphenylphosphine palladium or a mixture of a palladium catalyst and a phosphine ligand, and the catalyst is used in an amount of 1-8% of the reaction raw materials.

[0041] The reaction time in step 1 is 4-8h; and the reaction time in step 2 is 10-14h.

[0042] The purification refers to common purification methods such as column chromatography separation and recrystallization, so that the purity of the product is above 99.5%.

[0043] The application further provides application of the organic conjugated compound in preparation of a photoelectric functional device, and the photoelectric functional device is a perovskite solar cell.

[0044] The application further provides a perovskite solar cell, which comprises a substrate, a cathode, an electron transport layer, a perovskite layer, a hole transport layer and an anode, wherein the hole transport layer comprises the organic conjugated compound; the photoelectric conversion efficiency of the perovskite solar cell is above 22%, and the initial efficiency can still be maintained above 80% after 1000h of continuous illumination, and the stability is excellent.

[0045] Compared with the prior art, the application has the following beneficial effects:

[0046] The series of conjugated organic compounds with indolizine as an end group provided by the application have the advantage of high hole mobility, and the photoelectric device obtained under non-doped conditions can obtain a photoelectric conversion efficiency of 22-24%. Under the same experimental conditions, the photovoltaic efficiency of BDT-DPA-F molecules with diphenylamine as an end group and the same central structure is only 20.1%, which is much lower than that of the material of the application. The conjugated organic compounds in the application show higher short-circuit current and fill factor in perovskite cells, and have important significance for the development of subsequent new low-cost hole transport materials with excellent performance. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 is a structural schematic diagram of a perovskite solar cell in the examples.

[0048] Figure 2 is a structural formula of the hole transport material BDT-DPA-F of Comparative Example 1.

[0049] Figure 3 The current-voltage curves of the organic conjugated compounds used in Examples 1-3 in perovskite solar cells are shown.

[0050] Figure 4 The graph shows the hole mobility characterization data for Example 1 and Comparative Example 1.

[0051] Figure 5 The graphs show the stability test results for Example 1 and Comparative Example 1. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solutions of this invention, without departing from the spirit and scope of the invention, should be covered within the protection scope of this invention.

[0053] All raw materials used in the following specific implementation methods were purchased from Bid Pharmaceutical, reagents were purchased from Sinopharm Reagent, and other materials not specifically mentioned were purchased from the market.

[0054] Example 1

[0055] Synthesis of the conjugated organic compound Indo-1

[0056]

[0057] Compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol), and 50 mL of toluene were added to a two-necked flask. The mixture was refluxed for 6 h under nitrogen protection. After the reaction was complete, the mixture was filtered while hot. The filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain the crude product. Recrystallization was performed twice using methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to finally obtain red solid 3 (1.09 g).

[0058] In a two-necked flask, compound 3 (0.36 g, 1 mmol), compound 4 (0.47 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a purple-black solid Indo-1 (0.14 g).

[0059] Example 2: Synthesis of conjugated organic compound Indo-2

[0060]

[0061] In a two-necked flask, compound 1 (0.17 g, 1.12 mmol), compound 5 (0.73 g, 7.35 mmol), palladium acetate (0.02 g, 0.01 mmol), tri-tert-butylphosphine tetrafluoroborate (0.06 g, 0.02 mmol), sodium tert-butoxide (0.11 g, 1.17 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain a crude product. The crude product was recrystallized twice with methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a red solid 6 (0.14 g).

[0062] In a two-necked flask, compound 6 (0.14 g, 0.36 mmol), compound 4 (0.17 g, 0.18 mmol), tetrakis(triphenylphosphine)palladium (0.02 g, 0.01 mmol) and 15 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a purple-black solid Indo-2 (0.11 g).

[0063] Example 3: Synthesis of conjugated organic compound Indo-3

[0064]

[0065] In a two-necked flask, compound 1 (0.15 g, 1.01 mmol), compound 7 (0.5 g, 1.50 mmol), tris(dibenzylideneacetone)dipalladium (0.09 g, 0.10 mmol), Davephoxs 2-diphenylphosphino-2'-(N,N-dimethylamino)biphenyl (0.11 g, 0.20 mmol), sodium tert-butoxide (0.29 g, 2.02 mmol) and 20 mL of dioxane were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the resulting filtrate was filtered while hot, and then purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 8 (0.16 g).

[0066] In a two-necked flask, compound 8 (0.27 g, 0.68 mmol), compound 4 (0.29 g, 0.31 mmol), tetrakis(triphenylphosphine)palladium (0.03 g, 0.03 mmol) and 15 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate, and the resulting solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 3:2) to obtain a crude product. The crude product was recrystallized twice using acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain purple-black solid Indo-3 (0.15 g).

[0067] Example 4: Synthesis of conjugated organic compound Indo-4

[0068]

[0069] In a two-necked flask, compound 9 (1 g, 6.70 mmol), compound 2 (2.94 g, 10.05 mmol), palladium acetate (0.15 g, 0.67 mmol), tri-tert-butylphosphine tetrafluoroborate (0.39 g, 1.3 mmol), sodium tert-butoxide (0.64 g, 6.70 mmol) and 50 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the resulting filtrate was filtered while hot, and then purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 10 (1.10 g).

[0070] In a two-necked flask, compound 10 (0.36 g, 1 mmol), compound 4 (0.47 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen atmosphere, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic layer was separated, and concentrated. The obtained solid was precipitated by dropwise addition of methanol, and column chromatography (eluent: petroleum ether: dichloromethane = 1:1) was performed to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain Indo-4 (0.20 g) as a purple solid.

[0071] Example 5: Synthesis of conjugated organic compound Indo-5

[0072]

[0073] In a two-necked flask, compound 11 (0.33 g, 2.0 mmol), compound 2 (0.88 g, 3.0 mmol), palladium acetate (0.18 g, 0.20 mmol), tri-tert-butylphosphine tetrafluoroborate (0.10 g, 0.4 mmol), sodium tert-butoxide (0.21 g, 2.0 mmol) and 50 mL of toluene were added under nitrogen atmosphere, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and column chromatography (eluent: petroleum ether: dichloromethane = 4:1) was performed to obtain a crude product. The crude product was recrystallized twice with methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain 12 (0.38 g) as a red solid.

[0074] In a two-necked flask, compound 12 (0.38 g, 1 mmol), compound 4 (0.48 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen atmosphere, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic layer was separated, and concentrated. The obtained solid was precipitated by dropwise addition of methanol, and column chromatography (eluent: petroleum ether: dichloromethane = 1:1) was performed to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain Indo-5 (0.32 g) as a blue-purple solid.

[0075] Example 6: Synthesis of conjugated organic compound Indo-6

[0076]

[0077] In a two-necked flask, compound 13 (1.01 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added, and the reaction was carried out under reflux for 6 h under nitrogen atmosphere. After the reaction was completed, the reaction mixture was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 14 (1.10 g).

[0078] In a two-necked flask, compound 14 (0.36 g, 1 mmol), compound 4 (0.61 g, 0.5 mmol), palladium tetra-triphenylphosphine (0.05 g, 0.05 mmol) and 20 mL of toluene were added, and the reaction was carried out under reflux for 12 h under nitrogen atmosphere. After the reaction was completed, the reaction mixture was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic layer was separated, and concentrated. The obtained solid was recrystallized twice using acetone: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain purple solid Indo-6 (0.36 g).

[0079] Example 7: Synthesis of conjugated organic compound Indo-7

[0080]

[0081] In a two-necked flask, compound 15 (0.38 g, 2.0 mmol), compound 2 (0.88 g, 3.0 mmol), palladium acetate (0.18 g, 0.20 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.10 g, 0.4 mmol), sodium tert-butoxide (0.21 g, 2.0 mmol) and 50 mL of toluene were added, and the reaction was carried out under reflux for 6 h under nitrogen atmosphere. After the reaction was completed, the reaction mixture was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 16 (0.40 g).

[0082] In a two-necked flask, compound 16 (0.40 g, 1 mmol), compound 4 (0.48 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain blue-purple solid Indo-5 (0.37 g).

[0083] Example 8: Synthesis of conjugated organic compound Indo-8

[0084]

[0085] In a two-necked flask, compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether:dichloromethane = 4:1) to obtain a crude product. The crude product was recrystallized twice with methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 3 (1.09 g).

[0086] In a two-necked flask, compound 3 (0.36 g, 1 mmol), compound 17 (0.52 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether:dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain purple solid Indo-8 (0.42 g).

[0087] Example 9: Synthesis of conjugated organic compound Indo-9

[0088]

[0089] Compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol), and 50 mL of toluene were added to a two-necked flask. The mixture was refluxed for 6 h under nitrogen protection. After the reaction was complete, the mixture was filtered while hot. The filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain the crude product. Recrystallization was performed twice using methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to finally obtain red solid 3 (1.09 g).

[0090] Compound 3 (0.36 g, 1 mmol), compound 18 (0.39 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol), and 20 mL of toluene were added to a two-necked flask. The mixture was refluxed for 12 h under nitrogen protection. After the reaction was complete, the mixture was poured into a saturated potassium fluoride aqueous solution and stirred overnight. The liquid was separated, the organic phase was concentrated, and precipitated by adding methanol. The resulting solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain the crude product. Recrystallization was performed twice using acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to finally obtain the purple solid Indo-9 (0.28 g).

[0091] Example 10: Synthesis of the conjugated organic compound Indo-10

[0092]

[0093] Compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol), and 50 mL of toluene were added to a two-necked flask. The mixture was refluxed for 6 h under nitrogen protection. After the reaction was complete, the mixture was filtered while hot. The filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain the crude product. Recrystallization was performed twice using methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to finally obtain red solid 3 (1.09 g).

[0094] In a two-necked flask, compound 3 (0.36 g, 1 mmol), compound 19 (0.49 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a black solid Indo-10 (0.39 g).

[0095] Example 11: Synthesis of conjugated organic compound Indo-11

[0096]

[0097] In a two-necked flask, compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether:dichloromethane = 4:1) to obtain a crude product. The crude product was recrystallized twice with methanol:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a red solid 3 (1.09 g).

[0098] In a two-necked flask, compound 3 (0.36 g, 1 mmol), compound 20 (0.36 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain a purple solid Indo-11 (0.35 g).

[0099] Example 12: Synthesis of conjugated organic compound Indo-12

[0100]

[0101] In a two-necked flask, compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 3 (1.09 g).

[0102] In a two-necked flask, compound 3 (0.36 g, 1 mmol), compound 21 (0.37 g, 0.5 mmol), palladium tetra-triphenylphosphine (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution, and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate, and the obtained solid was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain a crude product. The crude product was recrystallized twice using acetone: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain black solid Indo-12 (0.45 g).

[0103] Example 13: Synthesis of conjugated organic compound Indo-13

[0104]

[0105] In a two-necked flask, compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1) to obtain a crude product. The crude product was recrystallized twice using methanol: dichloromethane (volume ratio, 1:4) as a mixed solvent to obtain red solid 3 (1.09 g).

[0106] In two flasks, compound 3 (0.36 g, 1 mmol), compound 22 (0.52 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to settle. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain the crude product. The product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as the mixed solvent to obtain purple-black solid Indo-13 (0.25 g).

[0107] Example 14: Synthesis of conjugated organic compound Indo-14

[0108]

[0109] In two flasks, compound 1 (0.96 g, 6.56 mmol), compound 2 (3.86 g, 13.13 mmol), palladium acetate (0.14 g, 0.65 mmol), tri-tert-butylphosphine tetrafluoroborate (0.38 g, 1.3 mmol), sodium tert-butoxide (0.63 g, 6.56 mmol) and 50 mL of toluene were added under nitrogen protection, and refluxed for 6 h. After the reaction was completed, the reaction was filtered while hot, and the obtained filtrate was purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain the crude product. The product was recrystallized twice with methanol:dichloromethane (volume ratio, 1:4) as the mixed solvent to obtain red solid 3 (1.09 g).

[0110] In two flasks, compound 3 (0.36 g, 1 mmol), compound 24 (0.67 g, 0.5 mmol), tetrakis(triphenylphosphine)palladium (0.05 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to settle. The obtained solid was purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1) to obtain the crude product. The product was recrystallized twice with acetone:dichloromethane (volume ratio, 1:4) as the mixed solvent to obtain black solid Indo-14 (0.27 g).

[0111] The conjugated organic compound prepared in the above examples was used as a hole transport layer to prepare a perovskite solar cell, and the photoelectric performance of the device was measured. The device structure was indium tin oxide conductive glass / tin dioxide / perovskite / hole transport layer / molybdenum trioxide / silver, as shown in Figure 1

[0112] Comparative Example 1​

[0113] Preparation of perovskite solar cell with compound BDT-DPA-F as hole transport layer

[0114]

[0115] In a two-necked flask, compound 1 (0.45 g, 2.0 mmol), compound 2 (0.88 g, 3.0 mmol), palladium acetate (0.04 g, 0.20 mmol), tri-tert-butylphosphonium tetrafluoroborate (0.11 g, 0.4 mmol), sodium tert-butoxide (0.28 g, 3.0 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 6 h. After the reaction was completed, the mixture was filtered while hot, and the obtained filtrate was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 3: 1). After recrystallization twice with methanol:dichloromethane (volume ratio, 1:4) as mixed solvents, red solid 3 (0.44 g) was obtained.

[0116] In a two-necked flask, compound 3 (0.36 g, 0.81 mmol), compound 4 (0.36 g, 0.36 mmol), tetrakis(triphenylphosphine)palladium (0.02 g, 0.05 mmol) and 20 mL of toluene were added under nitrogen protection, and the reaction was refluxed for 12 h. After the reaction was completed, the reaction was poured into saturated aqueous potassium fluoride solution and stirred overnight. The organic phase was separated and concentrated, and then dropped into methanol to precipitate. After the obtained solid was separated and purified by column chromatography (eluent: petroleum ether:dichloromethane = 1:1), the crude product was obtained. After recrystallization twice with acetone:dichloromethane (volume ratio, 1:4) as mixed solvents, purple-black solid BDT-DPA-F (0.31 g) was obtained.

[0117] 20 mg of compound BDT-DPA-F (the structure of which is shown in Figure 2A 15 mg of the organic conjugated compound Indo-1 prepared in Example 1 was dissolved in 1 mL of chlorobenzene and heated with stirring at 50 °C for 6 h. A Sn02nanodispersion was spin-coated on a cleaned ITO glass substrate at 6500 rpm / s for 10 s and annealed at 150 °C for 10 min. A PbI2solution (1.5 M in DMF:DMSO = 9:1) was spin-coated on the Sn02film at 1500 rpm / s and annealed at 70 °C for 1 min. Then a FAI solution (90 mg / mL) was dynamically spin-coated on the PbI2film at 1800 rpm / s and annealed at 150 °C for 15 min in an environment with a relative humidity of 40%. A PEAI solution (5 mg / mL) was spin-coated on the prepared perovskite film at 5000 rpm / s, followed by spin-coating of a BDT-DPA-F chlorobenzene solution at 3000 rpm / s for 30 s. After spin-coating, 10 nm thick Mo03and 80 nm thick Ag electrodes were evaporated, respectively, to complete the device fabrication.

[0118] The tested photovoltaic device performance: under white light 1.5G (100 mW cm -2 ) irradiation, open-circuit voltage (V oc ) = 1.10 V, short-circuit current (J sc ) = 24.1 mA cm -2 , fill factor (FF) = 76.2%, and power conversion efficiency (PCE) = 20.1%.

[0119] Application Example 1:

[0120] Preparation of a perovskite solar cell with conjugated organic compound Indo-1 as a hole transport layer

[0121] A 15 mg of the organic conjugated compound Indo-1 prepared in Example 1 was dissolved in 1 mL of chlorobenzene and heated with stirring at 50 °C for 6 h. A Sn02nanodispersion was spin-coated on a cleaned ITO glass substrate at 6500 rpm / s for 10 s and annealed at 150 °C for 10 min. A PbI2solution (1.5 M in DMF:DMSO = 9:1) was spin-coated on the Sn02film at 1500 rpm / s and annealed at 70 °C for 1 min. Then a FAI solution (90 mg / mL) was dynamically spin-coated on the PbI2film at 1800 rpm / s and annealed at 150 °C for 15 min in an environment with a relative humidity of 40%. A PEAI solution (5 mg / mL) was spin-coated on the prepared perovskite film at 5000 rpm / s, followed by spin-coating of a BDT-DPA-F chlorobenzene solution at 3000 rpm / s for 30 s. After spin-coating, 10 nm thick Mo03and 80 nm thick Ag electrodes were evaporated, respectively, to complete the device fabrication.

[0122] The tested photovoltaic device performance: under white light 1.5G (100 mW cm -2 ) irradiation, open-circuit voltage (V oc ) = 1.16 V, short-circuit current (J sc ) = 25.5 mA cm -2 , fill factor (FF) = 80.2%, and power conversion efficiency (PCE) = 23.6%.

[0123] Application Example 2:

[0124] Preparation of a perovskite solar cell with conjugated organic compound Indo-2 as a hole transport layer

[0125] 15 mg of the organic conjugated compound Indo-2 was dissolved in 1 mL of chlorobenzene and heated and stirred at 50 °C for 6 h. Perovskite solar cells with Indo-2 as the hole transport layer were prepared according to the procedure described in Comparative Example 1. Photovoltaic device performance: 1.5 G (100 mW cm⁻¹) under white light. -2 Under illumination, the open-circuit voltage (V) oc =1.13V, short-circuit current (J) sc )=24.8mA cm -2 The fill factor (FF) is 78.6% and the power conversion efficiency (PCE) is 22.0%.

[0126] Application Example 3:

[0127] Fabrication of perovskite solar cells using the conjugated organic compound Indo-3 as a hole transport layer

[0128] 15 mg of the organic conjugated compound Indo-3 was dissolved in 1 mL of chlorobenzene and heated and stirred at 50 °C for 6 h. Perovskite solar cells with Indo-3 as the hole transport layer were prepared according to the procedure described in Comparative Example 1.

[0129] Photovoltaic device performance: 1.5G (100mW cm⁻¹) in white light -2 Under illumination, the open-circuit voltage (V) oc = 1.11V, short-circuit current (J) sc )=25.1mA cm -2 The fill factor (FF) is 79.3% and the power conversion efficiency (PCE) is 22.1%.

[0130] Application Example 4:

[0131] Fabrication of perovskite solar cells using the conjugated organic compound Indo-4 as a hole transport layer

[0132] 18 mg of the organic conjugated compound Indo-4 was dissolved in 1 mL of chlorobenzene and heated and stirred at 50 °C for 6 h. A perovskite solar cell with Indo-4 as the hole transport layer was prepared according to the procedure described in Comparative Example 1.

[0133] Photovoltaic device performance: 1.5G (100mW cm⁻¹) in white light -2 Under illumination, the open-circuit voltage (V) oc =1.14V, short-circuit current (J) sc )=24.8mA cm -2 The fill factor (FF) is 78.5%, and the photoelectric conversion efficiency (PCE) is 22.1%.

[0134] Application Example 5:

[0135] Preparation of perovskite solar cell with conjugated organic compound Indo-5 as hole transport layer

[0136] Dissolve 12 mg of conjugated organic compound Indo-5 in 1 mL of chlorobenzene, heat and stir at 50℃ for 6 h. Prepare perovskite solar cell with Indo-5 as hole transport layer according to the procedure described in Comparative Example 1.

[0137] Photovoltaic device performance: under white light 1.5G (100 mW cm -2 ) irradiation, open circuit voltage (V oc ) = 1.16 V, short circuit current (J sc ) = 25.1 mA cm -2 , fill factor (FF) = 80.5%, power conversion efficiency (PCE) = 23.2%.

[0138] Application Example 6:

[0139] Preparation of perovskite solar cell with conjugated organic compound Indo-6 as hole transport layer

[0140] Dissolve 25 mg of conjugated organic compound Indo-6 in 1 mL of chlorobenzene, heat and stir at 50℃ for 6 h. Prepare perovskite solar cell with Indo-6 as hole transport layer according to the procedure described in Comparative Example 1.

[0141] Photovoltaic device performance: under white light 1.5G (100 mW cm -2 ) irradiation, open circuit voltage (V oc ) = 1.15 V, short circuit current (J sc ) = 24.5 mA cm -2 , fill factor (FF) = 78.5%, power conversion efficiency (PCE) = 22.0%.

[0142] Application Example 7:

[0143] Preparation of perovskite solar cell with conjugated organic compound Indo-7 as hole transport layer

[0144] Prepare a solution of Indo-10 with a concentration of 10 mg / mL in chlorobenzene, heat and stir at 50℃ for 6 h. Prepare perovskite solar cell with Indo-7 as hole transport layer according to the procedure described in Comparative Example 1.

[0145] Device photovoltaic performance: under white light 1.5G (100 mW cm -2 ) irradiation, open circuit voltage (V oc ) = 1.12 V, short circuit current (J sc ) = 25.0 mA cm -2, fill factor (FF) = 80.5%, photoelectric conversion efficiency (PCE) = 22.4%.

[0146] Application Example 8:

[0147] Preparation of perovskite solar cell with conjugated organic compound Indo-8 as hole transport layer

[0148] Indo-8 solution with a concentration of 10 mg / mL was prepared with chlorobenzene and heated and stirred at 50°C for 6 h. Perovskite solar cell with Indo-8 as hole transport layer was prepared according to the procedure described in Comparative Example 1.

[0149] Device photovoltaic performance: under white light 1.5G (100 mW cm -2 ) irradiation, open-circuit voltage (V oc ) = 1.13 V, short-circuit current (J sc ) = 25.3 mA cm -2 , fill factor (FF) = 81.5%, photoelectric conversion efficiency (PCE) = 23.1%.

[0150] Application Example 9:

[0151] Preparation of perovskite solar cell with conjugated organic compound Indo-9 as hole transport layer

[0152] Indo-9 solution with a concentration of 10 mg / mL was prepared with chlorobenzene and heated and stirred at 50°C for 6 h. Perovskite solar cell with Indo-9 as hole transport layer was prepared according to the procedure described in Comparative Example 1.

[0153] Device photovoltaic performance: under white light 1.5G (100 mW cm -2 ) irradiation, open-circuit voltage (V oc ) = 1.14 V, short-circuit current (J sc ) = 25.2 mA cm -2 , fill factor (FF) = 80.1%, photoelectric conversion efficiency (PCE) = 22.9%.

[0154] Application Example 10:

[0155] Preparation of perovskite solar cell with conjugated organic compound Indo-10 as hole transport layer

[0156] Indo-10 solution with a concentration of 12 mg / mL was prepared with chlorobenzene and heated and stirred at 50°C for 6 h. Perovskite solar cell with Indo-10 as hole transport layer was prepared according to the procedure described in Comparative Example 1.

[0157] Device photovoltaic performance: under white light 1.5G (100 mW cm -2Under illumination, the open-circuit voltage (V) oc =1.15V, short-circuit current (J) sc )=25.1mA cm -2 The fill factor (FF) is 80.1%, and the photoelectric conversion efficiency (PCE) is 23.1%.

[0158] Application Example 11:

[0159] Fabrication of perovskite solar cells using the conjugated organic compound Indo-11 as a hole transport layer

[0160] A 14 mg / mL Indo-11 solution was prepared using chlorobenzene and heated and stirred at 50 °C for 6 h. A perovskite solar cell with Indo-11 as the hole transport layer was then prepared according to the procedure described in Comparative Example 1.

[0161] Device photovoltaic performance: 1.5G (100mW cm⁻¹) in white light -2 Under illumination, the open-circuit voltage (V) oc = 1.12V, short-circuit current (J) sc )=24.9mA cm -2 The fill factor (FF) is 80.3% and the photoelectric conversion efficiency (PCE) is 22.4%.

[0162] Application Example 12:

[0163] Fabrication of perovskite solar cells using the conjugated organic compound Indo-12 as a hole transport layer

[0164] A 9 mg / mL Indo-12 solution was prepared using chlorobenzene and heated and stirred at 50 °C for 6 h. A perovskite solar cell with Indo-12 as the hole transport layer was then fabricated following the procedure described in Comparative Example 1.

[0165] Device photovoltaic performance: 1.5G (100mW cm⁻¹) in white light -2 Under illumination, the open-circuit voltage (V) oc = 1.13V, short-circuit current (J) sc )=25.1mA cm -2 The fill factor (FF) is 79.6% and the power conversion efficiency (PCE) is 22.6%.

[0166] Application Example 13:

[0167] Fabrication of perovskite solar cells using the conjugated organic compound Indo-13 as a hole transport layer

[0168] Indo-13 solution with a concentration of 15 mg / mL was prepared using chlorobenzene as solvent, heated and stirred at 50℃ for 6 h. Perovskite solar cells with Indo-13 as hole transport layer were prepared according to the procedure described in Comparative Example 1.

[0169] Device photovoltaic performance: under white light 1.5G (100 mW cm -2 ) irradiation, open circuit voltage (V oc ) = 1.14 V, short circuit current (J sc ) = 24.6 mA cm -2 , fill factor (FF) = 80.2%, photoelectric conversion efficiency (PCE) = 22.5%.

[0170] Application Example 14:

[0171] Preparation of perovskite solar cells with conjugated organic compound Indo-14 as hole transport layer

[0172] Indo-14 solution with a concentration of 10 mg / mL was prepared using chlorobenzene as solvent, heated and stirred at 50℃ for 6 h. Perovskite solar cells with Indo-14 as hole transport layer were prepared according to the procedure described in Comparative Example 1.

[0173] Device photovoltaic performance: under white light 1.5G (100 mW cm -2 ) irradiation, open circuit voltage (V oc ) = 1.12 V, short circuit current (J sc ) = 25.3 mA cm -2 , fill factor (FF) = 80.5%, photoelectric conversion efficiency (PCE) = 22.8%.

[0174] The photovoltaic device performance of the solar cells prepared by the organic conjugated compounds in the examples and comparative examples is summarized in Table 1. The current-voltage curves of the perovskite solar cells prepared by the compounds Indo-1, Indo-2 and Indo-3 in Application Examples 1-3 are shown in Figure 3 .

[0175] Table 1 Performance of solar cells prepared by organic conjugated compounds in examples and comparative examples

[0176]

[0177] As can be seen from Table 1, BDT-DPA-F in Comparative Example 1 has a similar structure to the organic conjugated compounds of the present application, and the central structure is the same, but it is a diphenylamine end group. Its photoelectric conversion efficiency is only 20.1%, while the indolizine end group organic conjugated compounds in Examples 1-14 prepared by the same preparation method have a photoelectric conversion efficiency of more than 22%, which is obviously different.

[0178] In addition, from the structural point of view, the indoline end group has good universality for different conjugated center groups, and there are three substitution sites on the indoline group, which has potential for subsequent development. For example, introducing a fluorine atom with stronger electronegativity can enhance the passivation ability of the molecule to the uncoordinated lead ion in the perovskite crystal, which can be used as a subsequent preferred scheme.

[0179] From Figure 4 It can be seen that the hole mobility of Example 1 is 2.59 x 10 -3 cm 2 V -1 s -1 , higher than Comparative Example 1, and much higher than Spiro-OMeTAD, further proving the superiority of the technology of the present application. From Figure 5 It can be seen that the stability of the device of Example 1 is much better than that of Spiro-OMeTAD, and can still maintain 80% of the initial efficiency under 1000h of continuous light, which helps to promote the commercial application of perovskite solar cells.

Claims

1. A class of organic conjugated compounds based on indoline derivatives, characterized in that, Its general structural formula is shown in equation (I) below: Wherein, X and Y are independently selected from hydrogen atoms, fluorine atoms, or chlorine atoms; R1, R2, and R3 are independently selected from hydrogen atoms, fluorine atoms, straight-chain or branched alkyl groups having 1-8 carbon atoms, or straight-chain or branched alkoxy groups having 1-8 carbon atoms; the Ar structure is any one of those shown in (II)-(V): R4 is selected from any of the following structures: R8 is selected from any of the following structures: Wherein, R4' is a branched alkyl group with 8-15 carbon atoms, R5 is a branched alkyl group with 8-16 carbon atoms; R4” is a branched alkyl group with 6-15 carbon atoms or an alkylthio group with 6-15 carbon atoms; X1 is a fluorine atom or a chlorine atom, X2 is a hydrogen atom or a fluorine atom; R6, R7, and R8' are independently selected from straight-chain or branched alkyl groups with 8-12 carbon atoms; Z is a carbon atom or a silicon atom.

2. The organic conjugated compound based on indoline derivatives according to claim 1, characterized in that, X and Y are hydrogen atoms.

3. The organic conjugated compound based on indoline derivatives according to claim 1, characterized in that, R1, R2, and R3 are independently selected from any of the following structures: R1' is independently selected from straight-chain or branched alkyl groups having 1-8 carbon atoms.

4. The method for preparing the organic conjugated compound based on indoline derivatives according to any one of claims 1-3, characterized in that, Including the following steps: Step 1: Mix the raw materials containing compound A and compound B in a solvent, reflux them under the action of a catalyst, and then purify them to obtain compound C; Step 2: Mix the raw materials containing compound C and compound D in a solvent, reflux the reaction under the action of a catalyst, and then purify to obtain the organic conjugated compound; 5. The method for preparing organic conjugated compounds based on indoline derivatives according to claim 4, characterized in that, The molar ratio of compound A to compound B is 1.2-1.8:1; the molar ratio of compound C to compound D is 2.0-2.5:

1.

6. The method for preparing organic conjugated compounds based on indoline derivatives according to claim 4, characterized in that, The solvent in step 1 is any one or more of toluene, tetrahydrofuran, or dioxane; And / or, the solvent in step 2 is toluene and / or dimethylformamide; And / or, in step 1, the catalyst is a mixture of palladium catalyst, phosphine ligand and sodium tert-butoxide, with a molar ratio of 1:1.5-2.5:8-12; the amount of catalyst used is 5-15% of the reactants. And / or, in step 2, the catalyst is tetratetraphenylphosphine palladium or a mixture of palladium catalyst and phosphine ligand, and the amount of catalyst used is 1-8% of the reactants; And / or, the reaction time for step 1 is 4-8 hours; And / or, the reaction time for step 2 is 10-14 hours.

7. The application of the indoline derivative-based organic conjugated compound according to any one of claims 1-3 in the preparation of optoelectronic functional devices, characterized in that, The optoelectronic device is a perovskite solar cell.

8. A perovskite solar cell, comprising a substrate, a cathode, an electron transport layer, a perovskite layer, a hole transport layer, and an anode, characterized in that, The hole transport layer comprises the organic conjugated compound based on an indoline derivative as described in any one of claims 1-3; the photoelectric conversion efficiency of the perovskite solar cell is above 22%.

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