Polymers containing bisiminoaromatic annelated benzodifuranes, methods of making and using the same

Abstract

This invention discloses a polymer containing a bis-imino aromatic ring and benzo[i]difuran, its preparation method, and its applications. The polymer has the structure shown in formula (I) or the structure shown in formula (II). The polymer containing a bis-imino aromatic ring and benzo[i]difuran of this invention can be applied in the field of solar cells. Experiments have shown that the polymer provided by this invention, as an active layer component of a photoelectric conversion device, can significantly improve the photoelectric conversion efficiency, reaching up to 19.37% or higher. Formula (I) Formula (II).

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a polymer containing a bisimino aromatic ring and benzodifuran, its preparation method, and its application. Background Technology

[0002] With fossil fuels gradually depleting and environmental pollution becoming increasingly serious, solar energy, as an inexhaustible clean energy source, plays a particularly important role in the current energy structure. How to efficiently convert solar energy into electricity is one of the major challenges facing the 21st century. In recent years, numerous research teams both domestically and internationally have increasingly focused on conjugated semiconductor polymers. Among these, the photovoltaic effect is a particularly important characteristic, bringing new hope for the development of organic photovoltaic (OPV) devices. Through unremitting efforts, scientists have developed various solution processing technologies, such as rotational molding, dip coating, and inkjet printing, for the fabrication of organic solar cells. Compared with the evaporation technology commonly used in manufacturing inorganic thin-film devices, solution processing technology is lower in cost and easier to scale up for mass production. Furthermore, organic photovoltaic devices have significant advantages such as light weight, low cost, and the ability to be fabricated into flexible, large-area devices, thus becoming a research hotspot in the field of solar cells. Therefore, organic solar cells have enormous commercial application potential.

[0003] Despite the numerous advantages exhibited by organic photovoltaic (OLED) devices, several unresolved issues remain. Compared to monocrystalline silicon and inorganic hybrid solar cells, their energy conversion efficiency needs further improvement. This is primarily attributed to factors such as the mismatch between the cell's spectral response range and the solar ground radiation spectrum, low carrier mobility, and low carrier collection efficiency of the electrodes. The photoactive layer is the most crucial component of organic solar cells, and improvements to photoactive layer materials, especially the structural design of conjugated polymer materials, have become a key focus of research in this field.

[0004] Most high-performance polymer donor materials are based on donor-acceptor (DA) alternating copolymer structures. Among the various donor moieties, benzodithiophene (BDT) possesses a rigid, symmetrical, large π-conjugated plane, enabling high carrier mobility. Furthermore, its side chains are easily modified, offering diverse options for finely controlling the physicochemical properties of the material; therefore, most donor moieties are predominantly BDT-based. Similarly, most acceptor moieties containing electron-withdrawing groups are also predominantly BDT-based, such as dithienoquinoxaline (DTQx), dithienobenzothiadiazole (DTBT), and benzodithiophene dione (BDD). The DTQx and DTBT units, with their large planar conjugated structure and strong electron-withdrawing ability, promote the formation of ordered molecular stacks with high hole mobility and low HOMO energy levels in their corresponding DA copolymers, resulting in high open-circuit voltage and high short-circuit current density OPVs. These advantages indicate that polymer donor materials based on bis-imino aromatic fused-ring acceptor moieties have broad prospects for constructing high-performance OPVs.

[0005] Compared to BDT, benzodifuran (BDF) exhibits the following advantages: (1) According to the Pauling electronegativity scale, oxygen (≈3.5) has a higher electronegativity than sulfur (≈2.5), which can effectively reduce the highest occupied molecular orbital energy level of the molecule, which is beneficial to the improvement of the open-circuit voltage of the device; (2) The covalent radius of the oxygen atom (1.52 Å) is smaller than that of the sulfur atom (1.80 Å). Therefore, the molecular packing of BDF-based materials is more compact and the crystallinity is higher, which is conducive to the transport of charge carriers; (3) Furan-based materials usually exhibit higher solubility, which is beneficial to the solution processing of the device; (4) Most importantly, the basic unit of BDF, furan, is renewable and biodegradable, which can significantly reduce the cost of raw materials. Recently, researchers have developed polymer donor materials containing BDF donor fragments, and their devices have shown excellent photovoltaic performance. However, no BDF-containing structures have been developed in the acceptor fragment. Therefore, the development of BDF acceptor moieties containing bisimino aromatic fused rings is of great significance for the diversity of polymer donor materials and the improvement of the photoelectric conversion efficiency of solar cells. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a polymer containing a bisimino aromatic ring and benzodifuran, its preparation method and application. The polymer provided by the present invention, when used as the active layer of a solar cell, results in a solar cell with high energy conversion efficiency and has a wide range of raw material sources.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0008] A polymer containing a bis-imino aromatic ring benzo[a]difuran, wherein the polymer containing the bis-imino aromatic ring benzo[a]difuran is a polymer having the structure shown in formula (I) or a polymer having the structure shown in formula (II): Equation (Ⅰ), Among them, R 1-1 and R 1-2 Independently selected from one of the following groups: oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine. R 2-1 R 2-2 R 3-1 and R 3-2 Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups. Ar1 is selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar2 is selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. n is an integer between 5 and 10000; (Formula II) Among them, R 4-1 R 4-2 R 4-1 'and R 4-2 'Independently selected from one of the following groups: oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine.' R 5-1 R 5-2 R 6-1 R 6-2 R 5-1 '、R 5-2 '、R 6-1 'and R 6-2 'Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups,' Ar4 and Ar6 are independently selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar5 and Ar5' are independently selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. Both x and y are integers between 5 and 10000.

[0009] The polymers containing the above-mentioned bisimino aromatic ring and benzodifuran, preferably, in formula (I): The R 1-1 The R group is oxygen, sulfur, selenium, or amine. 1-2 It can be oxygen, sulfur, selenium, or amine. The R 2-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 2-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 3-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 3-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. In Ar1, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

[0010] The polymers containing bisimino aromatic rings and benzodifurans mentioned above, preferably, in (Formula II): The R 4-1 The R group is oxygen, sulfur, selenium, or amine. 4-2 The R group is oxygen, sulfur, selenium, or amine. 4-1'is oxygen, sulfur, selenium or amine group, said R 4-2 'For oxygen, sulfur, selenium or amine groups, The R 5-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. In Ar4 and Ar6, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

[0011] More preferably, in the above-mentioned polymer containing a bisimino aromatic ring and benzodifuran, formula (I) is: The R 2-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 2-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 3-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 3-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; In Ar1, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: alkyl-substituted C6-C30 aryl, unsubstituted C6-C30 aryl, alkyl-substituted C6-C60 arylalkyl, unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

[0012] More preferably, in the above-mentioned polymer containing a bisimino aromatic ring and benzodifuran, in formula II: The R 5-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 5-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 6-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 6-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 5-1'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 5-2 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 6-1 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 6-2 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' In Ar4 and Ar6, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: alkyl-substituted C6-C30 aryl, unsubstituted C6-C30 aryl, alkyl-substituted C6-C60 arylalkyl, unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

[0013] The polymers containing bisimino aromatic rings and benzodifurans described above are further preferably wherein, in formula (I), Ar1 is selected from the following structures: , Wherein, R is one of hydrogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester sulfone, fluoroalkyl, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings; X is a group oxalic element. Y represents a group of carbon elements.

[0014] The polymers containing bisimino aromatic rings and benzodifurans described above are further preferably wherein, in formula (II), Ar4 and Ar6 are selected from the following structures: , Wherein, R is one of hydrogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester sulfone, fluoroalkyl, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings; X is a group oxalic element. Y represents a group of carbon elements.

[0015] The aforementioned polymer containing a bisimino aromatic ring and benzodifuran is further preferred. In formula (Ⅰ), Ar1 is , Among them, R A-1 R A-2 The alkyl group is independently selected from hydrogen and C1 to C30 alkyl groups, more preferably from hydrogen and C8 to C15 alkyl groups; The Ar2 is selected from the following structures: , , Wherein, R1 and R2 are independently selected from one of the following: hydrogen, halogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester, sulfone, fluoroalkyl, fluoroheterocyclic, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings.

[0016] Z can be oxygen, sulfur, selenium, or an amino group.

[0017] Ar3 is one of the following: alkyl-substituted C6-C30 aryl groups (C1-C20), alkyl-substituted C6-C60 arylalkyl groups (C1-C30), heterocyclic groups, monocyclic arylene groups, bicyclic arylene groups, arylene groups containing three rings, monocyclic heteroarylene groups, bicyclic heteroarylene groups, and heteroarylene groups containing three rings.

[0018] The aforementioned polymer containing a bisimino aromatic ring and benzodifuran is further preferred.

[0019] In formula (II), Ar4 and Ar6 are independently selected from... ,

[0020] Wherein, the R A-1 R A-2 The alkyl group is independently selected from hydrogen and C1 to C30 alkyl groups, more preferably from hydrogen and C8 to C15 alkyl groups;

[0021] Ar5 and Ar5' are independently selected from the following structures: , , Wherein, R1 and R2 are independently selected from one of the following: hydrogen, halogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester, sulfone, fluoroalkyl, fluoroheterocyclic, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings. Z can be oxygen, sulfur, selenium, or an amino group.

[0022] Ar3 is one of the following: alkyl-substituted C6-C30 aryl groups (C1-C20), alkyl-substituted C6-C60 arylalkyl groups (C1-C30), heterocyclic groups, monocyclic arylene groups, bicyclic arylene groups, arylene groups containing three rings, monocyclic heteroarylene groups, bicyclic heteroarylene groups, and heteroarylene groups containing three rings.

[0023] The polymers containing the above-mentioned bisimino aromatic ring and benzodifuran, preferably, in Ar1, the R A-1 R A-2 The individual compounds are selected independently from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-butylhexyl, 3-butylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-butyloctyl.

[0024] The polymers containing the above-mentioned bisimino aromatic ring and benzodifuran, preferably, in Ar4 and Ar6, the R A-1 R A-2 The individual compounds are selected independently from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-butylhexyl, 3-butylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-butyloctyl.

[0025] The polymers containing bisimino aromatic rings and benzodifurans described above preferably have a number-average molecular weight of 1,000 Da to 1,000,000 Da, more preferably 3,000 Da to 500,000 Da, and even more preferably 20,000 Da to 200,000 Da. It should be understood that the molecular weight can be varied to optimize polymer properties; for example, a lower molecular weight can ensure solubility, while a higher molecular weight can ensure good film-forming properties.

[0026] The polymers containing bisimino aromatic rings and benzodifurans described above, preferably, have a x:y ratio of 0.05–0.95:0.95–0.05, more preferably 0.2:0.8, in the polymer shown in formula (II); the number-average molecular weight of the polymer shown in formula (II) is from 1,000 Da to 1,000,000 Da, preferably from 3,000 Da to 500,000 Da, and even more preferably from 20,000 Da to 200,000 Da. It should be understood that the molecular weight can be changed to optimize polymer properties; for example, a lower molecular weight can ensure solubility, while a higher molecular weight can ensure good film-forming properties.

[0027] As a general technical concept, the present invention also provides a method for preparing the above-mentioned polymer containing a double imino aromatic ring and benzodifuran, wherein a polymer having the structure of formula (I) is obtained by polymerizing a monomer with the structure of formula (III) with formula (IV); Formula (III) Equation (Ⅳ) Wherein, V is a borate group, borate ester group, zinc halide group, or trialkyltin group, and W is I, Br, or Cl. R 1-1 and R 1-2 Independently selected from one of the following groups: oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine; R 2-1 R 2-2 R 3-1 and R 3-2Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups. Ar1 is selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar2 is selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. n is an integer between 5 and 10000.

[0028] This invention does not impose special requirements on the copolymerization method. Those skilled in the art can choose a suitable preparation method according to actual needs. For example, if a polycondensation reaction is carried out between a dimagnesium haloaromatic compound and an aromatic dihalide, the polymerization reaction is as reported by McCulough and Lowe. The typical McCullough method of Tao [Enhanced electrical conductivity inregioselectively synthesized poly] (3alkylthiophenes). Chem. Commun. 1992,70].

[0029] In the McCulough process, tetrahydrofuran and toluene are commonly used solvents, and sometimes a mixture of tetrahydrofuran and toluene can be used. Some catalysts containing Pd or Ni, such as [1,3-bis(diphenylphosphine)propane]dichloronickel(II) and tetra(triphenylphosphine)palladium(O), can be used as catalysts for this reaction, with a molar ratio of catalyst to reactants of 10%-0.1%. The reaction is typically carried out at approximately 10°C to the solvent reflux temperature. Depending on the reactivity of the reactants, the polymerization reaction can proceed from 10 minutes to 72 hours. The dimagnesium halide used in this reaction can be obtained from, for example, Loewe... Similar to the Grignard substitution reaction method reported by McCulough [Regioregular, Head-to-Tail Coupled Poly(3-alkylthiophenes)] Made Easy by the GRIM Method: Investigation of the Reaction and the Origin of Regioselectivity. [Macromolecules, 2001, 34, 4324-4333], or prepared by reaction between an aromatic dihalide and magnesium. In some embodiments, the aromatic dihalide and dimagnesium haloaromatics used in the "McCullough process" of the polymer of the present invention are aromatic dibromides and dimagnesium bromides.

[0030] If a polycondensation reaction occurs between a zinc haloaromatic compound and an aromatic dihalide, the polymerization reaction is a typical “Rieke process” as reported by Chen and Rieke. [Conductivity. Synth. Met, 1993, 60, 175]. In this method, tetrahydrofuran is typically used as a solvent, and [1,2-bis(diphenylphosphino)ethane]nickel(II) dichloride can be used as a catalyst for the reaction, with a molar ratio of catalyst to reactant of 10% to 0.1%. The reaction is typically carried out at about 10°C to the reflux temperature of the solvent. Depending on the reactivity of the reactants, polymerization can proceed from 10 minutes to 72 hours. In a preferred embodiment, the aromatic dihalides and zinc haloalkenes used in the "Rieke process" of the polymer of the present invention are aromatic dibromides and zinc chloroaromatics.

[0031] If a polycondensation reaction occurs between an aromatic diboronic acid compound or an aromatic diboronic ester compound and an aromatic dihalide, the polymerization reaction is a typical “Suzuki reaction” as reported by Miyaura and Suzuki [Palladium-Catalyzed Cross-Coupling Reactions of...]. [Organoboron Compounds. ChemRev. 1995, 95, 2457-2483]. In this method, solvents include, but are not limited to, many types of solvents such as tetrahydrofuran and toluene. Some catalysts containing Pd, such as tetra(triphenylphosphine)palladium(O), can be used as catalysts for this reaction, and the molar ratio between catalyst and starting material is 10%-0.1%. The reaction is generally carried out at about 10°C to the solvent reflux temperature. Depending on the reactivity of the reactants, the polymerization reaction can proceed from 10 minutes to 72 hours. In some embodiments, the aromatic dihalides used in the "Suzuki reaction" of the polymer used in some embodiments of the present invention are aromatic diiodides, aromatic dihalides, or aromatic dichlorides.

[0032] If a polycondensation reaction occurs between a trialkyltin-substituted aromatic compound and an aromatic dihalide, the polymerization reaction is a typical “Stille reaction” as reported by John K. Stille and Luping Yu [The Palladium-Catalyzed Cross-Coupling Reactions of Organotin]. [Reagents with Organic Electrophiles [New Synthetic Methods (58)]. Angew. Chem. Int. Ed. 1986, 25, 508-524; Stille Polycondensation for Synthesis of Functional Materials. 2011, 111, 1493-1528], in which the solvent includes, but is not limited to, many types of solvents such as tetrahydrofuran, N,N-dimethylformamide, toluene, and chlorobenzene, and sometimes mixed solvents such as a mixture of tetrahydrofuran and toluene, or a mixture of toluene and N,N-dimethylformamide, but not limited to a mixture of these two mixed solvents. Some Pd-containing catalysts such as tetra(triphenylphosphine)palladium(O), palladium chloride, palladium acetate, and / or bis(dibenzylacetone)palladium(O) can be used as catalysts for this reaction, and the molar ratio between the catalyst and the starting material is 10%-0.1%. The reaction is usually carried out between 10-200°C. The polymerization time is from 10 minutes to 72 hours. In some embodiments, the aromatic dihalides used in the "Stille reaction" of the polymer used in some embodiments of the present invention are aromatic diiodides, aromatic dihalides, or aromatic dichlorides and bis(trimethyltin) aromatics. The present invention does not have special requirements regarding the source of the raw materials; those skilled in the art can select a suitable preparation process based on existing disclosed methods.

[0033] As a general technical concept, the present invention also provides a method for preparing the above-mentioned polymer containing bisimino aromatic ring benzodifuran, wherein monomers of formula (V), formula (VI), formula (VII) and formula (VIII) are mixed and randomly copolymerized to obtain a random copolymer having the structure of formula (II). Formula (V), Formula (VI), Formula (VII), Formula (VIII), Wherein, V is a borate group, borate ester group, zinc halide group or trialkyltin, and W is I, Br or Cl; R 4-1 R 4-2 R4-1 '、and R 4-2 'Independently selected from one of oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine groups;' R 5-1 R 5-2 R 6-1 R 6-2 R 5-1 '、R 5-2 '、R 6-1 'and R 6-2 'Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups,' Ar4 and Ar6 are independently selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar5 and Ar5' are independently selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings.

[0034] x and y are integers between 5 and 10000.

[0035] In this invention, monomers of formula (V), formula (VI), formula (VII), and formula (VIII) are randomly copolymerized to obtain a polymer having the structure of formula (II); wherein, in the substituent V of the monomer, the borate group is preferably 1,3,2-dioxaborane-2-yl, 4,4,5,5-tetramethyl-1,2,3-dioxacyclopentaborane-2-yl, or 5,5-dimethyl-1,3,2-dioxaborane-2-yl, the magnesium halide group is preferably magnesium chloride, magnesium bromide, or magnesium iodide, the zinc halide group is preferably zinc chloride or zinc bromide, and the trialkyltin group is preferably trimethyltin, triethyltin, or tributyltin; other substituents are defined in the same way as the groups in the aforementioned polymer.

[0036] This invention does not impose any special requirements on the copolymerization method. Those skilled in the art can choose a suitable preparation method according to actual needs. If a condensation reaction is carried out between a dimagnesium halide aromatic compound and an aromatic dihalide, the polymerization reaction is the typical “McCullough” method reported by McCulough and Lowe [Enhanced electrical conductivity in regioselectively synthesized poly (3alkylthiophenes). Chem. Commun. 1992, 70]. In the McCulough method, tetrahydrofuran and toluene are commonly used solvents, and sometimes a mixture of tetrahydrofuran and toluene can also be used. Some catalysts containing Pd or Ni, such as [1,3-bis(diphenylphosphine)propane]dichloronickel(II) and tetra(triphenylphosphine)palladium(O), can be used as catalysts for this reaction, and the molar ratio between the catalyst and the reactants is 10%-0.1%. The reaction is usually carried out at about 10°C to the solvent reflux temperature. Depending on the reactivity of the reactants, the polymerization reaction can proceed from 10 minutes to 72 hours. The dimagnesium halide used in this reaction can be prepared by the Grignard substitution reaction reported by Loewe and McCulough [Regioregular, Head-to-Tail Coupled Poly(3-alkylthiophenes) Made Easy by the GRIM Method: Investigation of the Reaction and the Origin of Regioselectivity. Macromolecules, 2001, 34, 4324-4333], or by a reaction between an aromatic dihalide and magnesium. In some embodiments, the aromatic dihalide and dimagnesium halide used in the “McCullough process” of the polymer of the present invention are aromatic dibromides and dimagnesium bromides.

[0037] If a polycondensation reaction is carried out between a zinc haloaryne compound and an aromatic dihalide, the polymerization reaction is a typical “Rieke process” as reported by Chen and Rieke [Polyalkylthiophenes with the smallest bandgap and the highest intrinsic conductivity. Synth. Met, 1993, 60, 175]. In this method, tetrahydrofuran is typically used as a solvent, and nickel(II) dichloride [1,2-bis(diphenylphosphino)ethane] can be used as a catalyst for the reaction with a molar ratio of catalyst to reactants of 10% to 0.1%. The reaction is typically carried out at about 10°C to the reflux temperature of the solvent. Depending on the reactivity of the reactants, the polymerization can proceed from 10 minutes to 72 hours. In a preferred embodiment, the aromatic dihalide and the zinc haloaryne used in the “Rieke process” of the polymer of the present invention are aromatic dibromides and zinc chloroaromatics.

[0038] If a polycondensation reaction is carried out between an aromatic diboronic acid compound or an aromatic diboronic ester compound and an aromatic dihalide, the polymerization reaction is a typical “Suzuki reaction” as reported by Miyaura and Suzuki [Palladium-Catalyzed Cross-Coupling Reactions of Organoboron Compounds. ChemRev. 1995, 95, 2457-2483]. In this method, solvents include, but are not limited to, many types of solvents such as tetrahydrofuran and toluene, and some catalysts containing Pd, such as tetra(triphenylphosphine)palladium(O), can be used as catalysts for the reaction, with a molar ratio between catalyst and starting material of 10%-0.1%. The reaction is typically carried out at about 10°C to the solvent reflux temperature. Depending on the reactivity of the reactants, the polymerization reaction can proceed from 10 minutes to 72 hours. In some embodiments, the aromatic dihalide used in the polymer “Suzuki reaction” used in some embodiments of the present invention is an aromatic diiodide, an aromatic dihalide, or an aromatic dichloride.

[0039] If a polycondensation reaction is carried out between a trialkyltin aromatic compound and an aromatic dihalide, the polymerization reaction is a typical “Stille reaction” as reported by John K. Stille and Luping Yu [The Palladium-Catalyzed Cross-Coupling Reactions of Organotin Reagents with Organic Electrophiles [New Synthetic Methods (58)]. Angew. Chem. Int. Ed. 1986, 25, 508-524; Stille Polycondensation for Synthesis of Functional Materials. 2011, 111, 1493-1528]. In this method, the solvents include, but are not limited to, many types of solvents such as tetrahydrofuran, N,N-dimethylformamide, toluene, and chlorobenzene. Sometimes mixed solvents such as a mixture of tetrahydrofuran and toluene, or a mixture of toluene and N,N-dimethylformamide, can also be used, but are not limited to a mixture of these two mixed solvents. Some Pd-containing catalysts, such as tetra(triphenylphosphine)palladium(O), palladium chloride, palladium acetate, and / or bis(dibenzylacetone)palladium(O), can be used as catalysts for this reaction, with a molar ratio of catalyst to reactants of 10%-0.1%. The reaction is typically carried out between 10-200°C. The polymerization time ranges from 10 minutes to 72 hours. In some embodiments, the aromatic dihalides used in the "Stille reaction" of the polymer used in some embodiments of the present invention are aromatic diiodides, aromatic dihalides, or aromatic dichlorides and bis(trimethyltin) aromatics. The present invention does not have special requirements regarding the source of the reactants; those skilled in the art can select a suitable preparation process based on existing disclosed methods.

[0040] Unless otherwise indicated, the present invention is not limited to specific raw materials, reagents or reaction conditions, but can be varied. As used herein, the term "alkyl" refers to branched or unbranched saturated alkyl groups that typically, but not necessarily, contain 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-octyl, isooctyl, decyl, etc., and cycloalkyl groups such as cyclopentyl, cyclohexyl, etc.

[0041] The term "arylene" has its usual meaning. As used herein, the term "heteroarylene" refers to an aromatic ring with five or six atoms containing one or more "heteratoms" (i.e., atoms other than carbon, such as nitrogen, oxygen, sulfur, silicon, selenium, and phosphorus). The term "N-containing heteroarylene" as used herein refers to a heteroarylene in which one or more "heteratoms" as defined above are nitrogen. "Fused" rings share the same bonds, and "linked" rings are connected by single bonds.

[0042] In terms such as "substituted arylene" and "substituted heteroarylene," the term "substituted" refers to the portion in which at least one hydrogen atom bonded to a carbon or heteroatom is replaced by one or more non-hydrogen substituents, including but not limited to alkyl or aryl groups and functional groups such as halogen, hydroxyl, alkylthio, alkoxy, aryloxy, alkyl carbonyl, acyloxy, nitro, nitrile, etc.

[0043] In this invention, the number of carbons in the substituted Cx to Cy groups does not include the number of carbons on the substituents.

[0044] As a general technical concept, the present invention also provides the application of the above-mentioned polymer containing a bisimino aromatic ring and benzodifuran or the polymer containing a bisimino aromatic ring and benzodifuran prepared by the above-mentioned preparation method in the field of solar cells.

[0045] In applications, the present invention also provides a semiconductor composition comprising a polymer having formula (I) or a polymer having a structure of formula (II) as described in the present invention; wherein the composition further comprises a dopant, said dopant being typically a compound selected such that when an excitation source including light or voltage is applied to the composition, charge transfer and / or energy transfer occurs between the dopant and the polymer. For example, the dopant may be a fullerene, such as C60 or C70, or some substituted fullerene derivatives, such as PCBM ([6,6]-phenyl C61 butyrate) and indene-containing fullerenes. Polymers according to some embodiments of the present invention are particularly suitable for use as photovoltaic materials in photovoltaic devices such as photodetector devices, solar cell devices, etc.

[0046] In application, the present invention also provides a photoelectric conversion device, wherein the active layer material in the photoelectric conversion device is a polymer having formula (I) or a polymer having formula (II) as described in the present invention.

[0047] This invention provides a polymer having formula (I) or a polymer having formula (II). The polymer provided by this invention, when used as the active layer of a photoelectric conversion device, can improve the photoelectric conversion efficiency of the device. Experimental results show that the polymer provided by this invention, when used as the active layer of a photoelectric conversion device, can achieve an energy conversion efficiency of up to 19.37% or higher.

[0048] In this invention, n represents the number of repeating units in the polymer, and x and y represent the number of repeating units in the polymer.

[0049] Compared with the prior art, the advantages of the present invention are as follows: The polymer containing a bis-imino aromatic ring and benzodifuran provided by this invention is a polymer with the structure of formula (I) or formula (II). Experiments have shown that the polymer provided by this invention, as an active layer component of a photoelectric conversion device, can achieve a high photoelectric conversion efficiency of over 19.37%. The key difference between this invention and the prior art is that the sulfur atom of thiophene in the acceptor part of this structure—dithienylquinoxaline—is precisely replaced by an oxygen atom, synthesizing difuranoquinoxaline. The polymer donor material PBQx-2 obtained by the ternary random copolymerization of difuranoquinoxaline derivatives, benzodifuran derivatives, and dithienylquinoxaline derivatives is blended with the polymer acceptor material PY-DT to prepare an all-polymer solar cell device. Its photoelectric conversion efficiency is higher than that of all benzodifuran derivative-based all-polymer solar cell devices and higher than that of all binary all-polymer solar cell devices. Due to the substitution of oxygen atoms, the highest occupied molecular orbital energy level of these polymer materials is effectively reduced, resulting in an increase in the open-circuit voltage of their devices. Simultaneously, because the covalent radius of oxygen atoms is smaller than that of sulfur atoms, the molecules of these materials are more densely packed, exhibiting higher crystallinity and improving carrier transport performance. These two improvements lead to an overall increase in the device's open-circuit voltage, short-circuit current density, and fill factor, significantly enhancing photoelectric conversion efficiency. Attached Figure Description

[0050] Figure 1 The UV-Vis absorption spectra of the polymer PBQx-2 containing a bisimino aromatic ring and benzodifuran in Example 1 of this invention are shown in chloroform solution and film.

[0051] Figure 2 This is a cyclic voltammetry curve of the solid membrane of polymer PBQx-2 containing a bisimino aromatic ring and benzodifuran in Example 1 of the present invention.

[0052] Figure 3 This is a JV curve of the photovoltaic device prepared by the polymer PBQx-2 containing a bisimino aromatic ring and benzodifuran in Example 1 of the present invention. Detailed Implementation

[0053] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention. All materials and instruments used in the following embodiments are commercially available.

[0054] Example 1

[0055] A polymer of the present invention containing a bisimino aromatic ring and benzodifuran is a polymer having the structure shown in formula (II): Formula (II), Among them, R 4-1 R 4-2R 4-1 'and R 4-2 'All are sulfur,' R 5-1 R 5-2 R 5-1 'and R 5-2 'All are , R 6-1 R 6-2 R 6-1 'and R 6-2 'All are hydrogen,' Ar4 and Ar6 are both , Both Ar5 and Ar5' are vinyl groups. x is 0.2n, y is 0.8n, and x∶y is 1∶4.

[0056] The number-average molecular weight of the polymer shown in formula (II) is 196.29 kDa.

[0057] In this embodiment, the specific structure of equation (II) is as follows:

[0058] A method for preparing a polymer containing a bisimino aromatic ring and benzodifuran according to this embodiment includes the following steps:

[0059] (1) Synthesis of intermediate 2

[0060] 5,8-Dibromo-6,7-difluoroquinoxaline (500 mg, 1.54 mmol), bis(triphenylphosphine)palladium dichloride (82.2 mg, 1.03 mmol), cuprous iodide (54 mg, 1.08 mmol), and triphenylphosphine (202.4 mg, 0.77 mmol) were added to a round-bottom flask, and the air in the system was replaced three times with argon. 4-(2-Butyloctyl)-2-ethynylthiophene (1280 mg, 4.63 mmol), triethylamine (5 mL), and tetrahydrofuran (10 mL) were added to the system, and the reaction was carried out overnight under reflux at 66 °C. The organic phase was extracted with dichloromethane, washed with water to remove impurities, dried with anhydrous sodium sulfate, filtered and concentrated; petroleum ether:dichloromethane (v:v = 5:1) was used as the eluent, and the crude product was eluted by silica gel column chromatography; finally, 320 mg of intermediate 2 was obtained, with a yield of 29.0%.

[0061] The structural confirmation data is as follows: 1H NMR (400 MHz, CDCl3) δ 8.98 (s, 2H), 7.31 (s, 2H), 6.99 (s, 2H), 2.54 (d, J = 6.8 Hz, 4H), 1.62-1.58 (m, 2H), 1.31-1.23 (m, 32H), 0.91-0.86(m, 12H).

[0062] (2) Synthesis of intermediate 3

[0063] o-Dichlorobenzene (6 mL) and N,N-dimethylacetamide (3 mL) were injected into a round-bottom flask containing intermediate 2 (120 mg, 0.17 mmol), potassium acetate (494.1 mg, 5.03 mmol), and tetrabutylammonium bromide (10 mg, 0.03 mmol). After stirring at 120 °C for 72 hours, the organic phase was extracted with dichloromethane, washed with water to remove impurities, dried over anhydrous sodium sulfate, filtered, and concentrated. Using pure petroleum ether as the eluent, the crude product was eluted through a silica gel column to give 90 mg of intermediate 3, with a yield of 75.4%.

[0064] The structural confirmation data is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.88 (s, 2H), 7.63 (s, 2H), 7.44 (s, 2H), 6.96 (s, 2H), 2.60 (d, J = 6.8 Hz, 4H), 1.76-1.69 (m, 2H), 1.31-1.27 (m,32H), 0.92-0.87 (m,12H).

[0065] MALDI-TOF MS (m / z): calcd for C 44 H 58 N2O2S2: 710.39; Found: 710.56.

[0066] (3) Synthesis of intermediate M1

[0067] At 0 °C, intermediate 3 (90 mg, 0.13 mmol) was added to a round-bottom flask, followed by 10 mL of dichloromethane. While stirring, NBS (N-bromosuccinimide) (45.1 mg, 0.25 mmol) was added. After reacting for 3 hours, the solvent was evaporated, and the crude product was eluted with a silica gel column using petroleum ether:dichloromethane (v:v = 1:1.5) as the eluent to give 82 mg of intermediate M1, with a yield of 74.6%.

[0068] The structural confirmation data is as follows: 1 H NMR (400 MHz, CDCl3) δ 8.73 (s, 2H), 7.37 (s, 2H), 7.16 (s, 2H), 2.50 (s, 4H), 1.83-1.71 (m, 2H), 1.27-1.36 (m, 32H), 0.86-0.94 (m, 12H).

[0069] MALDI-TOF MS (m / z): calcd for C 44 H 56 Br2N2O2S2: 868.21; Found: 868.34.

[0070] (4) Synthesis of polymer PBQx-2

[0071] Under an inert atmosphere, compounds M1 (5.36 mg, 0.0062 mmol), M2 (22.23 mg, 0.0247 mmol), M3 (30.00 mg, 0.0308 mmol), Pd2(dba)3 (0.50 mg), P(o-tol)3 (1.00 mg), and 0.5 mL of toluene were added to a round-bottom flask. After stirring at 110 °C for approximately 72 hours, the mixture was poured into 30 mL of methanol to settle. The precipitate was filtered and dried under vacuum to obtain 33.00 mg of brick-red solid, which was the target polymer PBQx-2, with a yield of 77%.

[0072] Molecular weight by GPC (chloroform, 25℃): Mn = 156.29 kDa, PDI =4.42.

[0073] By changing the amounts of monomers M1 and M2 according to the above preparation method, a series of polymers with different contents of M1 and M2 were obtained.

[0074] The polymer donor material prepared in Example 1 was physically characterized, and its solar cell device was fabricated and its performance tested. The specific tests are as follows: 1 H NMR spectra were measured using a Bruker AVANCE 400 instrument, UV-Vis absorption spectra were measured using a Perkin-Elmer Cary 60 UV-Vis-NIR spectrometer, and time-of-flight mass spectrometry was measured using a Bruker Aupoflex Ⅲ MALDI-TOF mass spectrometer.

[0075] The organic solar cell prepared based on the polymer prepared in Example 1 as the active layer adopts a forward structure, which is ITO / PEDOT:PSS / active layer / PNDIT-F3N / Ag, including a conductive glass electrode, indium tin oxide (ITO), PEDOT:PSS, PNDIT-F3N and a silver electrode. The active layer material is the polymer donor material prepared in Example 1 of this invention and the PY-DT non-fullerene polymer acceptor material, and their blending weight ratio is 1:1.2.

[0076] Photophysical, electrochemical and solar cell device performance of polymer PBQx-2

[0077] The UV-Vis absorption spectra of polymer PBQx-2 in chloroform solution and thin film are as follows: Figure 1 As shown, Figure 1 The UV-Vis absorption spectra of the polymer PBQx-2 prepared in this embodiment in chloroform solution and film are shown in Table 1; detailed statistics are presented in Table 1.

[0078] Table 1 Optical absorption data of polymer PBQx-2

[0079] The maximum absorption position of polymer PBQx-2 in solution is 566 nm, and the initial absorption position is 599 nm. When polymer PBQx-2 is spin-coated into a film, its maximum absorption and initial absorption are 561 nm and 635 nm, respectively. From the initial absorption position of the polymer film, according to the formula... The obtained polymer PBQx-2 has an optical bandgap of 1.95 eV. The performance data of the solar cell device based on polymer PBQx-2 are summarized in Table 2.

[0080] The cyclic voltammetry curves of the solid film of polymer PBQx-2 are as follows: Figure 2 As shown, Figure 2 The figure shows the cyclic voltammetry curves of the solid film of polymer PBQx-2, calibrated with ferrocene. The HOMO energy level of the material is calculated to be -5.54 eV from the figure, and the LUMO energy level of the material is calculated to be -3.64 eV from the reduction peak.

[0081] The polymer PBQx-2 and PY-DT were mixed at a ratio of 1:1.2 (w / w, 15 mg / mL), with 150 wt% 2-MN added. Using chloroform as the solvent, the JV curve of the photovoltaic device is shown below. Figure 3 As shown. Under these conditions, the short-circuit current density of the device is 25.88 mA / cm². 2 The open-circuit voltage is 0.957 V, the fill factor is 78.20%, and the energy conversion efficiency is 19.37%.

[0082] Table 2 Performance data of solar cell devices using polymer PBQx-2

[0083] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the spirit and technical essence of the present invention. Therefore, any simple modifications, equivalent substitutions, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall still fall within the protection scope of the technical solutions of the present invention.

Claims

1. A polymer containing a bis-imino aromatic ring and benzodifuran, characterized in that, The polymer containing a bisimino aromatic ring and benzodifuran is a polymer having the structure shown in formula (I) or a polymer having the structure shown in formula (II): Equation (Ⅰ), wherein R 1-1 and R 1-2 are independently selected from one of oxygen, sulfur, selenium, amine, carbonyl, sulfone, sulfoxide, vinyl, and imine, R 2-1 , R 2-2 , R 3-1 and R 3-2 are independently selected from one of hydrogen, fluorine, chlorine, bromine, iodine, sulfone group, sulfoxide group, ester group, carbonyl group, trifluoromethyl group, acetylenic group and C1-C30 alkyl group, Ar1 is selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar2 is selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. n is an integer between 5 and 10000; Formula (II), wherein R 4-1 , R 4-2 , R 4-1 , and R 4-2 are independently selected from one of oxygen, sulfur, selenium, amine, carbonyl, sulfone, sulfoxide, vinyl, and imine, R 5-1 R 5-2 R 6-1 R 6-2 R 5-1 '、R 5-2 '、R 6-1 'and R 6-2 'Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups,' Ar4 and Ar6 are independently selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar5 and Ar5' are independently selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. Both x and y are integers between 5 and 10000.

2. The polymer containing a bis-imino aromatic ring and benzodifuran according to claim 1, characterized in that, In the formula (Ⅰ): The R 1-1 The R group is oxygen, sulfur, selenium, or amine. 1-2 It can be oxygen, sulfur, selenium, or amine. The R 2-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 2-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 3-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 3-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. In Ar1, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene. Alternatively, in equation (II): The R 4-1 The R group is oxygen, sulfur, selenium, or amine. 4-2 The R group is oxygen, sulfur, selenium, or amine. 4-1 'is oxygen, sulfur, selenium or amine group, said R 4-2 'For oxygen, sulfur, selenium or amine groups, The R 5-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 5-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-1 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. The R 6-2 It is one of the following: hydrogen, fluorine, chlorine, bromine, iodine, C1-C5 sulfone group, C1-C5 sulfoxide group, C2-C6 ester group, C1-C5 carbonyl group, trifluoromethyl group, C2-C5 alkynyl group, and C5-C20 alkyl group. In Ar4 and Ar6, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

3. The polymer containing a bisimino aromatic ring and benzodifuran according to claim 2, characterized in that, In the formula (Ⅰ): The R 2-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 2-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 3-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; The R 3-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl; In Ar1, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: alkyl-substituted C6-C30 aryl, unsubstituted C6-C30 aryl, alkyl-substituted C6-C60 arylalkyl, unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene. Alternatively, in equation (II): The R 5-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 5-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 6-1 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 6-2 It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl. The R 5-1 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 5-2 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 6-1 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' The R 6-2 'It can be hydrogen, chlorine, bromine, iodine, methyl sulfone, ethyl sulfone, dimethyl sulfone, methyl formate, ethyl formate, methyl carbonyl, ethyl carbonyl, trifluoromethyl, ethynyl, propynyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-ethylhexyl, 3-ethylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-hexyloctyl.' In Ar4 and Ar6, the substituent in the substituted vinylene, substituted ethynylene, substituted monocyclic arylene, substituted bicyclic arylene, substituted tricyclic arylene, substituted monocyclic heteroarylene, substituted bicyclic heteroarylene, and substituted tricyclic heteroarylene is one of the following: alkyl-substituted C6-C30 aryl, unsubstituted C6-C30 aryl, alkyl-substituted C6-C60 arylalkyl, unsubstituted C6-C60 arylalkyl, C1-C20 alkyl, C1-C20 alkoxy, ester sulfone, fluoroalkyl, vinylene, ethynylene, monocyclic arylene, bicyclic arylene, tricyclic arylene, monocyclic heteroarylene, bicyclic heteroarylene, and tricyclic heteroarylene.

4. The polymer containing a bis-imino aromatic ring and benzodifuran according to claim 3, characterized in that, In formula (Ⅰ), Ar1 is selected from the following structures: ， Wherein, R is one of hydrogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester sulfone, fluoroalkyl, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings; X is a group oxalic element. Y represents a group of carbon elements; In formula (II), Ar4 and Ar6 are selected from the following structures: ， Wherein, R is one of hydrogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester sulfone, fluoroalkyl, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings; X is a group oxalic element. Y represents a group of carbon elements.

5. The polymer containing a bis-imino aromatic ring and benzodifuran according to any one of claims 1 to 4, characterized in that, In formula (Ⅰ), Ar1 is , Among them, R A-1 R A-2 Independently selected from hydrogen and alkyl groups from C1 to C30; The Ar2 is selected from the following structures: ， ， Wherein, R1 and R2 are independently selected from one of the following: hydrogen, halogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester, sulfone, fluoroalkyl, fluoroheterocyclic, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings. Z can be oxygen, sulfur, selenium, or an amino group. Ar3 is one of the following: alkyl-substituted C6-C30 aryl, alkyl-substituted C6-C60 arylalkyl, heterocyclic, monocyclic arylene, bicyclic arylene, arylene containing three rings, monocyclic heteroarylene, bicyclic heteroarylene, and heteroarylene containing three rings. In formula (II), Ar4 and Ar6 are independently selected from... , Wherein, the R A-1 R A-2 Independently selected from hydrogen and alkyl groups from C1 to C30; Ar5 and Ar5' are independently selected from the following structures: ， ， Wherein, R1 and R2 are independently selected from one of the following: hydrogen, halogen, C1-C20 alkyl, C1-C20 alkoxy, C1-C20 alkyl-substituted C6-C30 aryl, C1-C30 alkyl-substituted C6-C60 arylalkyl, ester, sulfone, fluoroalkyl, fluoroheterocyclic, vinylidene, ethynylidene, monocyclic arylide, bicyclic arylide, arylide containing three rings, monocyclic heteroarylide, bicyclic heteroarylide, and heteroarylide containing three rings. Z can be oxygen, sulfur, selenium, or an amino group. Ar3 is one of the following: alkyl-substituted C6-C30 aryl groups (C1-C20), alkyl-substituted C6-C60 arylalkyl groups (C1-C30), heterocyclic groups, monocyclic arylene groups, bicyclic arylene groups, arylene groups containing three rings, monocyclic heteroarylene groups, bicyclic heteroarylene groups, and heteroarylene groups containing three rings.

6. The polymer containing a bisimino aromatic ring and benzodifuran according to claim 5, characterized in that, In Ar1, the R A-1 R A-2 The individual components are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-butylhexyl, 3-butylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-butyloctyl; In Ar4 and Ar6, the R A-1 R A-2 The individual compounds are selected independently from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylbutyl, n-heptyl, 2-ethylpentyl, n-octyl, 2-butylhexyl, 3-butylhexyl, 3-propylhexyl, 2-propylhexyl, n-nonyl, 2-ethylheptyl, or 2-butyloctyl.

7. The polymer containing a bis-imino aromatic ring and benzodifuran according to any one of claims 1 to 4, characterized in that, The number-average molecular weight of the polymer shown in formula (I) is from 1,000 Da to 1,000,000 Da; the x:y ratio of the polymer shown in formula (II) is 0.05 to 0.95: 0.95 to 0.05, and the number-average molecular weight of the polymer shown in formula (II) is from 1,000 Da to 1,000,000 Da.

8. A method for preparing a polymer containing a bis-imino aromatic ring and benzodifuran as described in any one of claims 1 to 7, characterized in that, By polymerizing the monomer with the structure of formula (III) with that of formula (IV), a polymer with the structure of formula (I) is obtained; Formula (III) Equation (Ⅳ) Wherein, V is a borate group, borate ester group, zinc halide group, or trialkyltin group, and W is I, Br, or Cl. R 1-1 and R 1-2 Independently selected from one of the following groups: oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine; R 2-1 R 2-2 R 3-1 and R 3-2 Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups. Ar1 is selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar2 is selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. n is an integer between 5 and 10000.

9. A method for preparing a polymer containing a bis-imino aromatic ring and benzodifuran as described in any one of claims 1 to 7, characterized in that, Random copolymerization of monomers with structure (V), structure (VI), structure (VII), and structure (VIII) yields a random copolymer with structure (II). Formula (V), Equation (VI), Formula (VII), Formula (VIII), Wherein, V is a borate group, borate ester group, zinc halide group or trialkyltin, and W is I, Br or Cl; R 4-1 R 4-2 R 4-1 '、and R 4-2 'Independently selected from one of oxygen, sulfur, selenium, amino, carbonyl, sulfone, sulfoxide, vinyl, and imine groups;' R 5-1 R 5-2 R 6-1 R 6-2 R 5-1 '、R 5-2 '、R 6-1 'and R 6-2 'Independently selected from hydrogen, fluorine, chlorine, bromine, iodine, sulfone, sulfoxide, ester, carbonyl, trifluoromethyl, alkynyl, and C1-C30 alkyl groups,' Ar4 and Ar6 are independently selected from one of the following: unsubstituted or substituted vinylene, unsubstituted or substituted ethynylene, unsubstituted or substituted monocyclic arylene, unsubstituted or substituted bicyclic arylene, unsubstituted or substituted tricyclic arylene, unsubstituted or substituted monocyclic heteroarylene, unsubstituted or substituted bicyclic heteroarylene, and unsubstituted or substituted tricyclic heteroarylene. Ar5 and Ar5' are independently selected from one of the following: oxalic elements, nitrogenous elements, dialkyl-substituted vinyl groups, and aromatic fused rings. x and y are integers between 5 and 10000.

10. The application of a polymer containing a bisimino aromatic ring benzodifuran as described in any one of claims 1 to 7, or a polymer containing a bisimino aromatic ring benzodifuran prepared by the preparation method described in claims 8 or 9, in the field of solar cells.

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