Polymer and application thereof in organic electronic device

Abstract

The invention relates to the field of organic photovoltaic materials, in particular to a polymer and application thereof in organic electronic devices. The polymer material provided by the invention is simple in structure and easy to synthesize, and shows excellent photoelectric properties when being applied to an organic solar photoactive layer as a donor material.

Description

Technical Field

[0001] The invention relates to the technical field of organic photovoltaic materials, and in particular to a polymer and application thereof in organic electronic devices. Background Art

[0002] Organic photovoltaic cells have attracted much attention due to their outstanding advantages such as light weight, flexibility, translucency and large-area processing and preparation by solution method. Organic photovoltaic cells adopt a "sandwich" structure. The molecular design based on active layer materials (including donors and acceptors) and interface layer materials has promoted a significant improvement in the overall performance of the device, achieving a single-cell device with a photoelectric conversion efficiency of more than 20%, showing its huge application potential.

[0003] At present, the commonly used high-efficiency polymer donor materials for the active layer of organic photovoltaic cells are selected from PM6 (Joule, 2019, 3, 1140.) or D18 (Science Bulletin, 2020, 65, 272). PM6 and D18 have the advantages of optical absorption and energy levels matching high-efficiency non-fullerene acceptor materials, high charge mobility, etc., but their complex structures and lengthy synthesis routes lead to high synthesis costs, which is not conducive to promoting the mass production of organic solar cells.

[0004] In order to meet the large-scale production of organic photovoltaic cells, it is necessary to develop high-performance, low-cost and easy-to-synthesize polymer donor materials. Based on this, CN108948327A discloses a quinoxaline conjugated polymer, which is obtained by copolymerizing quinoxaline groups containing alkoxy and F-substituted with thiophene to obtain a medium-bandgap conjugated polymer donor material, which achieves a photoelectric conversion efficiency of over 10% when combined with the acceptor material IDIC. This type of polymer has a simple structure and a short synthesis path. CN114195988A discloses a carboxyl-substituted benzodithiophene conjugated polymer, which achieves a photoelectric conversion efficiency of over 16% by copolymerizing carboxyl-substituted benzodithiophene groups with thiophene and combining them with the non-fullerene acceptor material Y6.

[0005] However, there are only a limited number of polymer materials that are simple in structure, easy to synthesize and have high performance. On the other hand, the photoelectric conversion efficiency of their devices still needs to be further improved. Therefore, the development of polymer donor materials that are simple in structure, easy to synthesize and have high performance is still a key technical issue that must be solved for the industrial development of organic solar cells. Summary of the invention

[0006] Based on this, the present invention develops a new type of polymer material, which has a simple structure and is easy to synthesize. When the material is used as a donor material in the photoactive layer of an organic photovoltaic cell, it exhibits excellent photoelectric properties.

[0007] The technical solution of the present invention is:

[0008] A polymer having a structure as shown in general formula (I):

[0009]

[0010] in:

[0011] Each occurrence of Y1 and Y2 is independently selected from O, S or Se;

[0012] Each occurrence of Z1 and Z2 is independently selected from O, S or Se;

[0013] Each occurrence of R1, R2, and R3 is independently selected from an alkyl group having 1 to 30 carbon atoms;

[0014] R2---The dashed line in R2 is selected from none or a single bond;

[0015] x, y are the molar percentages of the repeating unit and 0 <x≤1,0≤y<1,x+y=1。

[0016] Accordingly, the present invention also provides a mixture, which comprises the polymer as described above and at least another organic functional material; the another organic functional material is selected from a photoactive layer donor material or a photoactive layer acceptor material.

[0017] Accordingly, the present invention also provides a composition, which comprises the polymer as described above or the mixture as described above and at least one organic solvent.

[0018] Correspondingly, the present invention also provides an organic electronic device, comprising a cathode, an anode and at least one functional layer located between the cathode and the anode, characterized in that: the at least one functional layer comprises the polymer as described above or the mixture as described above or is prepared from the composition as described above.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] The polymer of the present invention has a simple structure and is easy to synthesize. The introduction of can, on the one hand, regulate the molecular spatial structure of the polymer through the action of non-covalent bonds, and utilize the action of non-covalent bonds to improve the planarity and stacking effect of the polymer, thereby optimizing the molecular morphology of the blended film formed with the receptor; on the other hand, the introduction of alkoxy can regulate the energy level and solubility of the polymer, thereby achieving more favorable charge dissociation and transmission when blended with the receptor material. Through multi-party coordination and optimization, when it is used as a donor material in the photoactive layer of organic photovoltaic cells, a photoelectric conversion efficiency of over 17.8% is achieved, showing excellent device performance and great prospects for industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of an organic photovoltaic cell in an embodiment of the device of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and effect of the present invention clearer and more specific, the present invention is further described in detail below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] The terms "and / or", "or / and", and "and / or" used in this article include any one of two or more related listed items, and also include any and all combinations of related listed items, and the arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or", "or / and", and "and / or", it should be understood that in this application, the technical solution undoubtedly includes technical solutions that are all connected by "logical and", and undoubtedly includes technical solutions that are all connected by "logical or". For example, "A and / or B" includes three parallel solutions of A, B and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, the technical solution that is all connected by "logical OR"), and also includes any and all combinations of A, B, C, and D, that is, the combination of any two or any three of A, B, C, and D, and also includes the combination of four of A, B, C, and D (that is, the technical solution that is all connected by "logical AND").

[0024] In the present invention, organic photovoltaic device, organic solar cell, OPV and OSC have the same meaning and can be interchangeable.

[0025] In the present invention, photoactive layer and active layer have the same meaning and can be interchanged.

[0026] In the present invention, when a group contains multiple substituents with the same symbol, the substituents may be the same or different from each other. The six Rs on the benzene ring may be the same as or different from each other.

[0027] In the present invention, "alkyl" can represent a straight chain, branched chain or cyclic alkyl group. The alkyl group containing m carbon atoms means that the alkyl group contains m carbon atoms, and the alkyl group can be a straight chain alkyl group, a branched chain alkyl group, a cyclic alkyl group or a combination thereof. The number of carbon atoms in a straight chain alkyl group can be 1 to 30, 1 to 20, 1 to 16, 1 to 10, or 1 to 6. The number of carbon atoms in a branched chain alkyl group can be 3 to 30, 3 to 20, 3 to 16, 3 to 10, or 3 to 6. The number of carbon atoms in a cyclic alkyl group can be 3 to 30, 3 to 20, 3 to 16, 3 to 10, or 3 to 6. Non-limiting examples of straight chain alkyl groups include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, -C 10 H 21 , -C 11 H 23 , -C 12 H 25 , -C 13 H 27 , -C 14 H 29 , -C 15 H 31 , -C 16 H 33 Non-limiting examples of branched alkyl groups include isopropyl, branched alkyl groups containing 4 C atoms, branched alkyl groups containing 5 C atoms, branched alkyl groups containing 6 C atoms, branched alkyl groups containing 7 C atoms, branched alkyl groups containing 8 C atoms, branched alkyl groups containing 9 C atoms, branched alkyl groups containing 10 C atoms, branched alkyl groups containing 11 C atoms, branched alkyl groups containing 12 C atoms, branched alkyl groups containing 13 C atoms, branched alkyl groups containing 14 C atoms, branched alkyl groups containing 15 C atoms, and branched alkyl groups containing 16 C atoms. Non-limiting examples of cyclic alkyl groups include: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclic alkyl groups containing 7 C atoms, cyclic alkyl groups containing 8 C atoms, cyclic alkyl groups containing 9 C atoms, cyclic alkyl groups containing 10 C atoms, cyclic alkyl groups containing 11 C atoms, cyclic alkyl groups containing 12 C atoms, cyclic alkyl groups containing 13 C atoms, cyclic alkyl groups containing 14 C atoms, cyclic alkyl groups containing 15 C atoms, and cyclic alkyl groups containing 16 C atoms.

[0028] In the present invention, one or more groups "independently selected from" means that when one or more groups appear simultaneously and in multiple places in a compound, they are all independently selected and may be the same or different.

[0029] In the process of describing the structural elements of the present invention, the words "include" or "comprises" and the like used in the present invention mean that the devices or materials appearing before the word include the devices or materials listed after the word and their equivalents, but do not exclude other devices or materials.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "between layers", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the organic solar cell device is conventionally placed when in use, or are the orientations or positional relationships conventionally understood by those skilled in the art. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0031] The "combinations thereof", "any combinations thereof", "any combinations thereof", "combinations" and the like used in the present invention include all suitable combinations of any two, any three or more items in the listed groups.

[0032] In the present invention, “further”, “furthermore”, “particularly”, etc. are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present invention.

[0033] In the present invention, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel solutions of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0034] In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0035] The first aspect of the present invention provides a polymer having a structure as shown in the general formula (I):

[0036]

[0037] in:

[0038] Each occurrence of Y1 and Y2 is independently selected from O, S or Se;

[0039] Each occurrence of Z1 and Z2 is independently selected from O, S or Se;

[0040] Each occurrence of R1, R2, and R3 is independently selected from an alkyl group having 1 to 30 carbon atoms;

[0041] R2---The dashed line in R2 is selected from none or a single bond;

[0042] x, y are the molar percentages of the repeating unit and 0 <x≤1,0≤y<1,x+y=1。

[0043] In one embodiment, when the dashed line in R2---R2 is selected from none, the Selected from When the dotted line in R2---R2 is selected from a single bond, Selected from

[0044] Preferably, the polymer has a structure as shown in general formula (II-1) or (II-2):

[0045]

[0046] Each occurrence of R2 in the general formula (II-1) is independently selected from an alkyl group having 1 to 20 carbon atoms.

[0047] In a specific embodiment, each occurrence of Y1 and Y2 is selected from S.

[0048] In one embodiment, each occurrence of R1 and R3 is independently selected from an alkyl group having 1-20 carbon atoms; further, each occurrence of R1 and R3 is independently selected from a straight-chain alkyl group having 1-20 carbon atoms, or a branched-chain alkyl group having 3-20 carbon atoms.

[0049] In a preferred embodiment, each occurrence of R1 and R3 is independently selected from the following structures:

[0050] *-C6H 13 、*-C8H 17 、*-C 12 H 25 *-C2H5, *-*-C4H9;

[0051] Wherein: * indicates the connection site.

[0052] In a specific embodiment, R1 and R3 are selected from the same group.

[0053] In one embodiment, each occurrence of Z1 and Z2 is independently selected from S or S e .

[0054] In one embodiment, each occurrence of R2 is independently selected from alkyl groups having 1 to 20 carbon atoms; further, each occurrence of R2 is independently selected from straight-chain alkyl groups having 1 to 20 carbon atoms, or branched-chain alkyl groups having 3 to 20 carbon atoms; further still, each occurrence of R2 is independently selected from straight-chain alkyl groups having 1 to 15 carbon atoms, or branched-chain alkyl groups having 3 to 15 carbon atoms.

[0055] In one embodiment, each occurrence of *-O-R2 is independently selected from the following groups:

[0056] *-O- *-O-C4H9, *-O-C5H 11 , *-O-C6H 13 , *-O-C8H 17 , .

[0058] Specifically, the polymer according to the present invention is preferably, but not limited to, the following structure:

[0059]

[0060]

[0061]

[0062] In one embodiment, for the polymer according to the present invention, 0 < x ≤ 0.5; further, 0 < x ≤ 0.2; still further, 0.1 ≤ x ≤ 0.2.

[0063] In a specific embodiment, for the polymer according to the present invention, in the polymers (P1)-(P20), x is selected from 0.2 and y is selected from 0.8.

[0064] In another specific embodiment, for the polymer according to the present invention, in the polymers (P1)-(P20), x is selected from 0.1 and y is selected from 0.9.

[0065] The present invention further relates to a mixture, which comprises the polymer as described above and at least one other organic functional material. Preferably, the other organic functional material is selected from an active layer donor material or an active layer acceptor material.

[0066] In a preferred embodiment, the other organic functional material is selected from an active layer acceptor material.

[0067] Further, the active layer acceptor material is selected from one or more of small molecule non-fullerene acceptor materials, polymer non-fullerene acceptor materials or fullerene acceptor materials.

[0068] In a specific embodiment, the photoactive layer acceptor material is preferably selected from Y6, L8-BO, H2, N3, BTP-eC9, M3, IT-4F, PC 61 BM ([6,6]-phenyl C61 butyric acid methyl ester), PC 71 One, two or three or more of BM ([6,6]-phenyl C71 butyric acid methyl ester), indene-containing fullerene, etc., but not limited thereto.

[0069] Furthermore, the present invention also relates to a composition, which comprises the polymer or mixture as described above, and at least one organic solvent.

[0070] Preferably, the organic solvent can be selected from one of dichloromethane, chloroform, chlorobenzene, chloroform, o-dichlorobenzene, tetrahydrofuran, anisole, 2,4-dimethylanisole, 1-methylnaphthalene, morpholine, toluene, o-xylene, m-xylene, p-xylene, 1,4-dioxane, acetone, methyl ethyl ketone, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane, ethyl acetate, n-butyl acetate, N,N-dimethylformamide, dimethylacetamide, dimethyl sulfoxide 1,5-dimethyltetrahydrofuran, acetophenone, tetralin, 2-methylthiophene, 3-methylthiophene, decahydronaphthalene, indane, methyl benzoate, ethyl benzoate, and mesitylene, or a mixture of two or more thereof.

[0071] Preferably, the organic solvent is selected from chlorobenzene, toluene, o-xylene, or chloroform, but is not limited thereto.

[0072] In one embodiment, the composition may further include additives for adjusting viscosity, adjusting film-forming properties, improving adhesion, etc. The additives may be selected from, but not limited to, 1,8-diiodooctane (DIO), diphenyl ether (DPE), anthracene, 1,4-diiodobenzene (DIB), 1,3-dibromo-5-chlorobenzene (DBCl), 3,5-dichlorobromobenzene (DCBB), 1-chloronaphthalene (1-CN), 1,3,5-tribromobenzene (TBB), etc., but are not limited thereto.

[0073] It should be noted that the present application also relates to the use of the composition as a coating or printing ink in the preparation of an organic solar cell. In one embodiment, the composition is used to prepare an organic solar cell by a printing or coating preparation method. The printing or coating preparation method can be, but is not limited to, inkjet printing, gravure printing, spray printing, letterpress printing, screen printing, dip coating, spin coating, doctor blade coating, roller printing, twist roller printing, lithography, flexographic printing, rotary printing, spray coating, brush coating, pad printing, slit extrusion coating, etc. The preferred ones are slit coating, spin coating and inkjet printing.

[0074] The present invention also provides an organic electronic device, comprising a cathode, an anode and at least one functional layer located between the cathode and the anode, characterized in that the at least one functional layer comprises the polymer as described above or the mixture as described above or is prepared from the composition as described above.

[0075] Preferably, the organic electronic device is selected from organic photovoltaic cells.

[0076] Specifically, the present invention further relates to an organic photovoltaic cell, which comprises a cathode, an anode and a photoactive layer located between the cathode and the anode, wherein the photoactive layer comprises the polymer or mixture as described above, or is prepared from the composition as described above.

[0077] Furthermore, the photoactive layer comprises a photoactive layer donor material and a photoactive layer acceptor material, and the photoactive layer donor material is selected from the polymers described above.

[0078] Furthermore, the photoactive layer acceptor material is selected from one or more of small molecule non-fullerene acceptor materials, polymer non-fullerene acceptor materials or fullerene acceptor materials. Specifically, the photoactive layer acceptor material is preferably selected from Y6, L8-BO, H2, N3, BTP-eC9, M3, IT-4F, PC 61 BM ([6,6]-phenyl C61 butyric acid methyl ester), PC 71 One, two or three or more of BM ([6,6]-phenyl C71 butyric acid methyl ester), indene-containing fullerene, etc., but not limited thereto.

[0079] In one embodiment, the mass ratio of the photoactive layer donor material to the photoactive layer acceptor material is 0.8:1.8 to 1.8:0.8; preferably, the mass ratio is 1:1 to 1:1.8; more preferably, the mass ratio is 1:1 to 1:1.5; more preferably, the mass ratio is 1:1 to 1:1.2.

[0080] Further, the photoactive layer can be formed by dissolving the active layer donor and acceptor materials in an organic solvent and then coating the resulting solution by methods such as spin coating, dip coating, screen printing, gravure printing, spraying, doctor blade, slit coating and inkjet printing, but not limited thereto.

[0081] The materials used to prepare the electrodes (cathode and anode) can be selected from metals, such as vanadium (V), chromium (Cr), zinc (Zn), silver (Ag), aluminum (Al), platinum (Pt), tungsten (W), copper (Cu), molybdenum (Mo), gold (Au), nickel (Ni), palladium (Pd), or alloys of the above metals; conductive nanomaterials, such as metal nanowires, nanoparticle slurries, graphene, carbon nanotubes, etc.; metal oxides, such as zinc oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), etc.; combinations of metals and oxides, such as ZnO:Al or SnO2:Sb, etc.; and conductive polymers, such as PEDOT:PSS, polypyrrole and polyaniline, etc.; or materials with a multilayer structure, such as LiF / Al, LiO2 / Al, LiF / Fe, MoO3 / Al, Al:Li, Al:BaF2 and Al:BaF2:Ba, etc., but are not limited thereto.

[0082] In one embodiment, the organic photovoltaic cell further comprises a cathode buffer layer, wherein the cathode buffer layer is located between the cathode and the active layer.

[0083] Preferably, the cathode buffer layer material can be selected from metal complexes, metal oxides, metal salts, etc. with low work function, such as metal complexes of 8-hydroxyquinoline, complexes containing Alq3, metal complexes containing Liq, LiF, Ca, titanium oxide (TiO x ), zinc oxide (ZnO), cesium carbonate (Cs2CO3), etc.; it can also be a polymer material, such as PFN-Br or PFN or PDINN or PDINO or PNDIT-F3N-Br or PNDIT-F3N, etc., but not limited to this.

[0084] In one embodiment, the organic photovoltaic cell further comprises an anode buffer layer, wherein the anode buffer layer is located between the anode and the active layer.

[0085] Preferably, the anode buffer layer material is selected from PEDOT:PSS, molybdenum oxide (MoO x ), vanadium oxide (V2O5), nickel oxide (NiO), tungsten oxide (WO x , preferably, x is selected from 2 or 3), small molecule self-assembly materials such as 2PACz, MeO-2PACz, etc., but not limited thereto.

[0086] It should be noted that, in order to improve the performance of the organic photovoltaic cell device, the functional layer may further include other functional layers, including but not limited to a charge blocking layer and a charge transport layer.

[0087] Furthermore, the organic solar cell further comprises a substrate. In one embodiment, the substrate is disposed on one side of the anode and on a different side from the active layer. In another embodiment, the substrate is disposed on one side of the cathode and on a different side from the active layer.

[0088] In one embodiment, as a substrate, a substrate having excellent transparency, surface smoothness, ease of operation and water resistance can be used. Specifically, a glass substrate, a thin film glass substrate or a transparent plastic substrate can be used. The plastic substrate may include a film in a single or multilayer form, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetheretherketone (PEEK) and polyimide (PI), polyparaxylene (Parylene), etc., but is not limited thereto, and a substrate commonly used for organic solar cells may also be used.

[0089] In a specific embodiment, the organic photovoltaic cell sequentially stacks an anode, an anode buffer layer, a photoactive layer, a cathode buffer layer and a cathode from bottom to top, and the photoactive layer comprises the polymer or mixture as described above, or is prepared from the above composition.

[0090] The present invention further relates to the application of the organic photovoltaic cell in various devices, including, but not limited to, automobiles and building integrated photovoltaics (BIPV), electronic price tags, indoor photovoltaics, the Internet of Things, smart agriculture, etc. Specific embodiments

[0092] The present invention will be described below in conjunction with preferred embodiments, but the present invention is not limited to the following embodiments. It should be understood that the attached claims summarize the scope of the present invention. Under the guidance of the concept of the present invention, those skilled in the art should be aware that certain changes made to the various embodiments of the present invention will be covered by the spirit and scope of the claims of the present invention.

[0093] The polymer and organic electronic device of the present invention are exemplified herein, but the present invention is not limited to the following embodiments.

[0094] Synthesis of monomer M-1:

[0095]

[0096] Accurately weigh compound 1-1 (7.7 g, 10.0 mmol) and dissolve it in ultra-dry THF (210 mL). Replace nitrogen three times, add n-BuLi (2.0 M, 11 mL, 22 mmol) dropwise at -70 ° C, keep warm and stir for 2 hours, then add trimethyltin chloride (1.43 g, 12.0 mmol) dropwise at -70 ° C, keep warm and stir for 1 hour, return to room temperature naturally and stir overnight. After the reaction is completed, pour the reaction solution into potassium fluoride aqueous solution to quench and extract with dichloromethane. Dry the combined organic phase with anhydrous MgSO4, remove the excess solvent by vacuum distillation, and then recrystallize from isopropanol to obtain about 7.32 g of compound M-1, with a yield of 77.8%. MS: 940.67.

[0097] Synthesis of monomer M-2:

[0098]

[0099] Accurately weigh compound 2-1 (1.07 g, 1.6 mmol) and dissolve it in ultra-dry THF (25 mL). Replace nitrogen three times, add n-BuLi (2.0 M, 1.6 mL, 3.2 mmol) dropwise at -70 ° C, keep warm and stir for 2 hours, then add trimethyltin chloride (0.64 g, 3.2 mmol) dropwise at -70 ° C, keep warm and stir for 1 hour, naturally return to room temperature and stir overnight. After the reaction is completed, pour the reaction solution into potassium fluoride aqueous solution to quench and extract with dichloromethane. Dry the combined organic phase with anhydrous MgSO4, remove the excess solvent by vacuum distillation, and then recrystallize from isopropanol to obtain about 1.15 g of compound M-2, with a yield of 86.7%. MS: 828.58.

[0100] Synthesis of monomer M-3:

[0101]

[0102] Accurately weigh compound 3-1 (0.86 g, 5.0 mmol) and dissolve it in ultra-dry DCM (25 mL). Add NBS (1.87 g, 10.5 mmol) in batches at -5 °C and stir for 1 h. After the reaction is completed, pour the reaction solution into an aqueous sodium sulfite solution to quench and extract with dichloromethane. Dry the combined organic phase with anhydrous MgSO4, remove the excess solvent by vacuum distillation, and perform column chromatography on silica gel. The eluent is PE:DCM=30:1 (volume ratio). About 1.38 g of compound M-3 is obtained, with a yield of 83.6%. MS: 329.68.

[0103] Synthesis Example 1: Synthesis of polymer (P1)

[0104]

[0105] The monomers M-1 (940.7 mg, 1.0 mmol), 4-1 (60.4 mg, 0.2 mmol), and 4-2 (193.5 mg, 0.8 mmol) were accurately weighed and added to a 100 mL thick-walled pressure tube, and 40 mL of ultra-dry toluene was added. After nitrogen blowing for 5 min, tetrakistriphenylphosphine palladium (57.8 mg, 0.05 mmol) was added, and nitrogen blowing was continued for 10 min. After reacting at 110 ° C for 36 h, heating was stopped. The reaction solution was cooled to room temperature, added dropwise to methanol, solids were precipitated, and filtered. The filter cake was washed with methanol, n-hexane, and chloroform in a Soxhlet extractor. The last washing solution was concentrated and added dropwise to methanol to precipitate solids. After the filter cake was filtered and vacuum dried, about 592.1 mg of polymer (P1) was obtained, with a yield of 83.7%. Mn: 28.4 KDa, PDI: 2.26.

[0106] Synthesis Example 2: Synthesis of polymer (P3)

[0107]

[0108] The synthesis of polymer (P3) was based on the synthesis of polymer (P1), except that compound 4-1 was replaced by compound 4-5, and about 509.5 mg of polymer (P3) was obtained with a yield of 70.4%. Mn: 30.6 KDa, PDI: 2.15.

[0109] Synthesis Example 3: Synthesis of polymer (P10)

[0110]

[0111] The monomers M-2 (828.4 mg, 1.0 mmol), M-3 (66.0 mg, 0.2 mmol), and 4-2 (193.5 mg, 0.8 mmol) were accurately weighed and added to a 100 mL thick-walled pressure tube, and 40 mL of ultra-dry toluene was added. After nitrogen blowing for 5 min, tetrakistriphenylphosphine palladium (57.8 mg, 0.05 mmol) was added, and nitrogen blowing was continued for 10 min. After reacting at 110 ° C for 36 h, heating was stopped. The reaction solution was cooled to room temperature, added dropwise to methanol, solids were precipitated, and filtered. The filter cake was washed with methanol, n-hexane, and chloroform in a Soxhlet extractor. The last washing solution was concentrated and added dropwise to methanol to precipitate solids. After the filter cake was filtered and vacuum dried, about 493.7 mg of polymer (P10) was obtained, with a yield of 82.2%. Mn: 24.4 KDa, PDI: 2.43.

[0112] Synthesis Example 4: Synthesis of Conjugated Compound (P13)

[0113]

[0114] The monomers M-1 (940.7 mg, 1.0 mmol), 7-1 (34.9 mg, 0.1 mmol), and 4-2 (217.7 mg, 0.9 mmol) were accurately weighed and added to a 100 mL thick-walled pressure-resistant tube, and 40 mL of ultra-dry toluene was added. After nitrogen blowing for 5 min, tetrakistriphenylphosphine palladium (57.8 mg, 0.05 mmol) was added, and nitrogen blowing was continued for 10 min. After reacting at 110 ° C for 36 h, heating was stopped. The reaction solution was cooled to room temperature, added dropwise to methanol, solids were precipitated, and filtered. The filter cake was washed with methanol, n-hexane, and chloroform in a Soxhlet extractor in turn. The last washing solution was concentrated and added dropwise to methanol to precipitate solids. After the filter cake was filtered and vacuum dried, about 549.8 mg of polymer (P13) was obtained, with a yield of 77.9%. Mn: 27.6 KDa, PDI: 2.64.

[0115] Synthesis Example 5: Synthesis of polymer (P17)

[0116]

[0117] The synthesis of polymer (P17) was based on the synthesis of polymer (P13), except that compound 7-1 was changed to 8-1, and about 586.7 mg of polymer (P17) was obtained with a yield of 83.6%. Mn: 32.8 KDa, PDI: 2.52.

[0118] Organic Photovoltaic Cell (OPV) Device Preparation and Characterization

[0119] This example illustrates the preparation, implementation and characterization of the OPV device provided by the present invention, but the present invention is not limited to the following examples.

[0120] like Figure 1 As shown, the OPV device structure is as follows: indium tin oxide ITO / anode buffer layer / active layer / PDINN / Ag.

[0121] Device Example 1:

[0122] 1) ITO substrate cleaning:

[0123] The ITO conductive glass was cleaned with detergent, rinsed, and then ultrasonically cleaned with deionized water, acetone, and isopropanol for 15 minutes, then blown dry with nitrogen and treated in a plasma cleaner for 5 minutes to further clean the surface and improve wettability.

[0124] 2) Anode buffer layer preparation

[0125] PEDOT:PSS(Clevios TMP VP Al 4083) was evenly spin-coated on ITO at a spin-coating speed of 4000 rpm for 30 s, and dried at 150° C. for 15 min to obtain an anode buffer layer.

[0126] 3) Preparation of photoactive layer

[0127] In a glove box (inert gas atmosphere), the photoactive layer material solvent is evenly spin-coated on the anode buffer layer at a rotation speed of 1800-4000 rpm to obtain a photoactive layer with a total thickness of about 100 nm.

[0128] The active layer material preparation method is as follows: dissolving the donor material and the acceptor material in toluene to a total concentration of 17.6 mg / mL, and adding 0.7% by volume of 1-chloronaphthalene as an additive to the solvent;

[0129] Among them, the donor material in the photoactive layer material is selected from polymer (P1), the acceptor material is selected from L8-BO, and the mass ratio of the donor material polymer (P1) to the acceptor material L8-BO is 1:1.2.

[0130]

[0131] 4) Preparation of cathode buffer layer

[0132] After thermal annealing on a hot plate at 100°C for 10 minutes, the cathode buffer layer material PDINN (PDINN was dissolved in methanol to prepare a solution with a concentration of 1 mg / mL) was evenly spin-coated on the active layer at a spin coating speed of 3000 rpm and a spin time of 30 seconds to obtain a cathode buffer layer.

[0133] 5) Cathode layer preparation

[0134] In high vacuum (1×10 -6 Ag was evaporated onto the cathode buffer layer at 400 mbar to form a cathode layer with a thickness of about 100 nm.

[0135] 6) Packaging

[0136] The devices were encapsulated with UV-curable resin in a nitrogen glove box.

[0137] Device Example 2:

[0138] The preparation method of device example 2 refers to the preparation method of device example 1, except that the selection of donor material in the photoactive layer is different. Specifically, the donor material polymer (P1) in device example 1 is replaced by polymer (P3).

[0139] Device Example 3:

[0140] The preparation method of device example 3 refers to the preparation method of device example 1, except that the selection of donor material in the photoactive layer is different. Specifically, the donor material polymer (P1) in device example 1 is replaced by polymer (P10).

[0141] Device Example 4:

[0142] The preparation method of device example 4 refers to the preparation method of device example 1, except that the selection of donor material in the photoactive layer is different. Specifically, the donor material polymer (P1) in device example 1 is replaced by polymer (P13).

[0143] Device Example 5:

[0144] The preparation method of device example 5 refers to the preparation method of device example 1, except that the selection of donor material in the photoactive layer is different. Specifically, the donor material polymer (P1) in device example 1 is replaced by polymer (P17).

[0145] Device comparison example:

[0146] The preparation method of the device comparative example refers to the preparation method of the device example 1, except that the selection of the donor material in the photoactive layer is different. Specifically, the donor material polymer (P1) in the device example 1 is replaced by polymer (Ref).

[0147]

[0148] The prepared organic photovoltaic cell device was subjected to a performance test. Under the irradiation of standard light from a solar simulator (AM 1.5G), the cell current-voltage curve was tested and the photoelectric conversion efficiency was calculated, as shown in Table 1.

[0149] Table 1

[0150] Device Embodiment Photoactive layer donor material Photoelectric conversion efficiency (%) Device Example 1 Polymer (P1) 17.77 Device Example 2 Polymer (P3) 17.92 Device Example 3 Polymer (P10) 17.56 Device Example 4 Polymer (P13) 17.06 Device Example 5 Polymer (P17) 17.34 Device Comparison Example Polymer (Ref) 15.41

[0151] It can be seen from the data in Table 1 that when the polymer described in the present invention is used as a donor material in an organic solar cell device, the photoelectric conversion efficiency of the device is greatly improved compared with the device comparison example. The reason is that the polymer described in the present invention introduces The unit, on the one hand, can adjust the molecular spatial structure of the polymer through the action of non-covalent bonds, and utilize the action of non-covalent bonds to improve the planarity and stacking effect of the polymer, thereby optimizing the molecular morphology of the blended film formed between it and the receptor; on the other hand, the introduction of alkoxy groups can adjust the energy level and solubility of the polymer, thereby enhancing its charge transfer ability when used as an electron donor material, thereby improving the photoelectric performance of the device.

[0152] Furthermore, the polymer according to the present invention has good solubility in a non-halogen solvent (toluene) and exhibits excellent photoelectric conversion efficiency, which is more conducive to industrial preparation.

[0153] The preferred embodiments of the present application are described in detail above, but the present application is not limited to the specific details in the above embodiments. Within the technical concept of the present application, a variety of simple modifications can be made to the technical solution of the present application, and these simple modifications all belong to the protection scope of the present application.

Claims

1. A polymer, characterized in that: The polymer has a structure as shown in general formula (I): in: Each occurrence of Y1 and Y2 is independently selected from O, S or Se; Each occurrence of Z1 and Z2 is independently selected from O, S or Se; Each occurrence of R1, R2, and R3 is independently selected from an alkyl group having 1 to 30 carbon atoms; R2---The dashed line in R2 is selected from none or a single bond; x, y are the molar percentages of the repeating units, and 0 <x≤1,0≤y<1,x+y=1。 2. The polymer according to claim 1, characterized in that: The polymer is selected from the structure shown in (II-1) or (II-2): Wherein, each occurrence of R2 in the general formula (II-1) is independently selected from an alkyl group having 1 to 20 carbon atoms.

3. The polymer according to claim 1 or 2, characterized in that: Each occurrence of R1 and R3 is independently selected from a straight chain alkyl group having 1 to 20 carbon atoms, or a branched chain alkyl group having 3 to 20 carbon atoms.

4. The polymer according to claim 3, characterized in that: Each occurrence of R1 and R3 is independently selected from any of the following structures: <h2 style=";text-align:left;direction:ltr">*-C6H13*-C8H17、*-C12H25<h2 style=";text-align:left;direction:ltr"> *-C2H5*-*-C4H9 Wherein, "*" indicates the connection site.

5. The polymer according to claim 2, characterized in that: In the general formula (II-1), each occurrence of *-O-R2 is selected from any of the following groups: *-ZERO- *-O-C4H9*-O-C5H11*-O-C6H13*-O-C8H17 。 6. The polymer according to claim 1, characterized in that: The polymer is selected from any of the following structural formulas:

7. The polymer according to claim 1, 2 or 6, characterized in that: The 0.1≤x≤0.

2.

8. A mixture, characterized in that: The mixture comprises the polymer according to any one of claims 1 to 7, and at least another organic functional material.

9. A composition, characterized in that: The composition comprises the polymer according to any one of claims 1 to 7 or the mixture according to claim 8, and at least one organic solvent.

10. An organic electronic device comprising a cathode, an anode and at least one functional layer located between the cathode and the anode, characterized in that: The at least one functional layer comprises the polymer according to any one of claims 1 to 7 or the mixture according to claim 8 or is prepared from the composition according to claim 9.

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