Conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole and preparation method and application thereof

Abstract

The application discloses a conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole and a preparation method and application thereof. The conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole has a conjugated main chain and a side chain group, wherein the non-centrosymmetric benzodithiazole structure and other copolymer units D are contained in the conjugated main chain, and the side chain group is an alkyl chain R. The conjugated main chain structure of the polymer makes the polymer exhibit semiconductor characteristics and have rich photoelectric properties; meanwhile, the group R makes the polymer be able to be dissolved in an organic solvent, and the polymer is suitable for being prepared into a photoelectric device by using a printing processing method or the like. The conjugated polymer containing non-centrosymmetric benzodithiazole can be applied in photoelectric devices as a photovoltaic active layer and the like, significantly improves short-circuit current density and a fill factor of the device, and has a good application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of conjugated polymers and polymer optoelectronic materials, and particularly relates to a conjugated polymer optoelectronic material containing a non-centrosymmetric benzodithiazole and a preparation method and application thereof. BACKGROUND

[0002] Due to the gradual depletion of fossil energy, more efficient use of clean and renewable energy such as solar energy, wind energy, geothermal energy, and tidal energy has become a very important issue in the 21st century. Solar cells play a crucial role in the exploration of new energy sources. Compared with inorganic photovoltaic materials such as silicon and perovskite, organic materials have obvious advantages in terms of light weight and low cost in solvent processing. More importantly, organic semiconductors are more likely to achieve flexibility and roll-to-roll processability for solar cells through solvent processing, which will greatly improve production efficiency. In addition, through rational material design and device fabrication, specific waveband photon capture can be achieved, which has broad application prospects in the field of building and environmental engineering.

[0003] Organic solar cells (OSCs) show great promise in smart cities and indoor applications due to their advantages in manufacturing lightweight and flexible, semi-transparent photovoltaic panels through economical and efficient printing methods. Over the past two decades, the power conversion efficiency (PCE) of OSCs has rapidly increased, with major contributions coming from the innovation of light-active layer donor and acceptor materials, device optimization, and interface engineering. Among them, donor and acceptor materials jointly control the photophysical processes of light absorption, exciton dissociation, and carrier transport, thus playing a crucial role in the performance of OSCs. The improvement of PCE is inseparable from the increasing understanding of the structure-property relationship of active layer materials. From a chemical perspective, the molecular structure of donor and acceptor materials determines the basic characteristics of organic solar cells, such as absorption spectrum, molecular energy level, and charge mobility, which further determine the photoelectric conversion efficiency of organic solar cells. Therefore, designing donor and acceptor molecules to improve the efficiency of organic solar cells is currently a research focus in this field.

[0004] The donor polymer molecules of organic solar cells are generally co-polymerized from electron-rich units (D units) and electron-deficient units (A units), mainly composed of conjugated main chain, side chain and substituent group. The D-A co-polymer structure has the effect of optimizing the energy level, which is beneficial to improve the open-circuit voltage (VOC) of the device without changing the absorption. In the synthesis design of D-A co-polymer, many factors must be considered. From the perspective of molecular engineering, selecting appropriate conjugated repeat units determines the energy level and band gap; selecting appropriate side chains largely determines the solubility in processing solvents; the conjugated main chain and side chain have significant influence on the aggregation of the active layer and intermolecular interaction. From the perspective of polymer engineering, it is necessary to carefully balance the molecular weight, dispersity, solubility in processing solvents and viscosity of the obtained solution. For specific molecular design, generally, the star molecule PM6 is selected as the basis for modification, and the main modification strategies include electron-deficient unit design, side chain engineering, substituent modification, ternary copolymer design, etc.

[0005] For D-A co-polymer donor polymers, polymer materials containing a central symmetrical benzodithiazole electron-deficient unit have been widely used. The rigidity, high planarity and large π conjugated extension of benzodithiazole can reduce the steric hindrance between adjacent rings, thereby improving the coplanarity of the molecule and the tighter interchain packing in the solid film. In addition, due to the strong electron-deficiency of thiazole, the thiazole-containing heterocycle has good frontier molecular orbital distribution, which is beneficial to effective intramolecular charge transfer, thereby obtaining good energy level distribution. When the polymer material containing a central symmetrical benzodithiazole electron-deficient unit is applied to an organic solar cell photovoltaic device, a high open-circuit voltage and a low energy loss (ELOSS) can be obtained, but it has a relatively low short-circuit current density (JSC) and a fill factor (FF), so that the final cell device PCE is low, which limits its application range.

[0006] In view of the above, it is necessary to develop a new technical scheme to solve the defects and deficiencies in the prior art. SUMMARY

[0007] The present application aims at providing a conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole, a preparation method and application thereof, in view of the shortcomings of the prior art. Compared with centrosymmetric benzodithiazole, the non-centrosymmetric benzodithiazole with an asymmetric structure makes the molecule have a larger dipole moment, which not only enhances the intermolecular interaction and pi-pi stacking, but also optimizes the micro-morphology of the active layer, and can significantly improve the short-circuit current density and fill factor of the organic solar cell. Therefore, it can be predicted that the conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole will have good photoelectric performance, good absorption of sunlight, adjustable lowest unoccupied molecular orbital energy level (LUMO) and highest occupied molecular orbital energy level (HOMO), excellent rigidity and high planarity, large conjugated extension, good intermolecular interaction, and can be applied to the preparation of a polymer solar cell active layer, and is a kind of material with commercial application prospect. However, as a kind of promising photoelectric material, the conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole has not been reported in this field so far. The present application first synthesizes a new non-centrosymmetric benzodithiazole unit and its polymer and successfully applies it in the field of photoelectric materials, and the obtained material has good photoelectric performance when applied in photoelectric devices.

[0008] One object of the present application is to provide a conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole, which has the following structure:

[0009]

[0010] wherein,

[0011] n is selected from natural numbers of 1-10000;

[0012] x is selected from 0.05-0.95;

[0013] y is selected from 0.05-0.95;

[0014] and x+y=1;

[0015] D is an electron-donating unit;

[0016] R is a cosolvent group.

[0017] Further, the D is selected from one or more of the following structures:

[0018]

[0019] Further, the D has The substituent is not shown; specifically, the substituent can be, but is not limited to, various solubilizing alkyl groups or alkyl derivatives; for example, alkyl groups in which one or more hydrogen atoms are replaced with other groups, such as hydroxyalkyl, carboxyalkyl, aminoalkyl, cyanoalkyl, and the like; the alkyl group can be, but is not limited to, a straight chain, branched chain, or cyclic chain.

[0020] Further, R is selected from a C1-C40 alkyl group or alkyl derivative, or a C1-C40 alkoxy group or alkoxy derivative;

[0021] Further, one or more carbon atoms in the alkyl derivative or alkoxy derivative are replaced with one or more functional groups selected from oxygen atoms, alkenyl groups, alkynyl groups, aryl groups, ester groups, nitrile groups, amine groups, quaternary ammonium salt groups, amine oxide groups, pyridine oxide groups, quaternary phosphonium salt groups, phosphate groups, phosphate ester groups, sulfonate groups, carboxyl groups, and hydroxyl groups, and / or one or more hydrogen atoms in the alkyl derivative or alkoxy derivative are replaced with one or more functional groups selected from fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms;

[0022] Another object of the present application is to provide a method for preparing the conjugated polymer optoelectronic material containing a non-centrosymmetric benzodithiazole described above, which is shown in the following flowchart:

[0023]

[0024] S1, iodization of m-phenylenediamine (compound 1) to obtain 4,6-diiodobenzene-1,3-diamine (compound 2);

[0025] S2, ring closure reaction of the compound 2 to obtain a non-centrosymmetric benzodithiazole (compound 3);

[0026] S3, bromination of the compound 3 with liquid bromine to obtain a dibromo non-centrosymmetric benzodithiazole (compound 4);

[0027] S4, coupling reaction of the compound 4 with a thienyl tributyltin with a solubilizing side chain R to obtain compound 5 (a coupling thienyl derivative containing a non-centrosymmetric benzodithiazole);

[0028] S5, NBS bromination of the compound 5 to obtain compound 6 (a dibromo coupling thienyl derivative target monomer containing a non-centrosymmetric benzodithiazole);

[0029] S6, mixing of the compound 6 with a bistrimethyltin functionalized electron donor, and adding a palladium catalyst to perform a Stille reaction to obtain compound 7 (a conjugated polymer optoelectronic material containing a non-centrosymmetric benzodithiazole).

[0030] Further, in step S1, the iodination reaction introduces iodine substituent to compound 1 by potassium iodide;

[0031] Further, in step S1, the molar ratio of compound 1 to potassium iodide in the iodination reaction is 1:0.5-2;

[0032] Further, in step S2, the molar ratio of compound 2, potassium sulfide and ammonium acetate in the reaction is 1:3-6:5-12; the reaction temperature is 110-140℃.

[0033] Further, in step S1, the 4,6-diiodobenzene-1,3-diamine is obtained by reacting p-phenylenediamine in solution under the action of potassium iodide and with hydrogen peroxide as catalyst.

[0034] Further, in step S2, the non-centrosymmetric benzodithiazole is obtained by heating 4,6-diiodobenzene-1,3-diamine in solution under the action of ammonium acetate and cuprous iodide under inert gas protection.

[0035] Further, in step S3, the dibrominated non-centrosymmetric benzodithiazole is obtained by adding liquid bromine to the non-centrosymmetric benzodithiazole under alkaline conditions and heating.

[0036] Another object of the present application is to disclose the application of the above-mentioned conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole.

[0037] As a preferred technical solution, the conjugated polymer photoelectric material containing non-centrosymmetric benzodithiazole is dissolved in an organic solvent, and a polymer film is processed by spin coating, printing, roll-to-roll or inkjet printing solution, which is applied in photovoltaic, light-emitting or field effect transistor photoelectric devices as a carrier transport layer, light-emitting layer or photovoltaic active layer.

[0038] As a preferred technical solution, the photovoltaic device is composed of a substrate, a cathode, a cathode interface layer, a light absorbing layer, an anode interface layer, an anode, or is composed of a substrate, an anode, an anode interface layer, a light absorbing layer, a cathode interface layer, a cathode in turn.

[0039] As a preferred technical solution, the anode material is preferably aluminum, silver, gold.

[0040] As a preferred technical solution, the anode interface layer is an organic conjugated polymer or an inorganic semiconductor.

[0041] As a preferred technical solution, the cathode is at least one of metal, metal oxide, doped tin dioxide, zinc oxide, indium gallium zinc oxide or graphene and its derivatives; the substrate is at least one of glass, flexible material, metal, alloy or stainless steel film.

[0042] In the organic / polymer solar cell device (ITO cathode / electron transport layer / light active layer / hole transport layer / metal anode, or ITO anode / hole transport layer / light active layer / electron transport layer / metal cathode), the application method of the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole: the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole is dissolved in toluene, chloroform, chlorobenzene, xylene and other organic solvents in a certain proportion as a donor material with other acceptor materials, is spin-coated on an ITO electrode to prepare a photovoltaic active layer, and is processed by a solvent, an additive, a solvent vapor treatment, thermal annealing and the like to form a morphology structure favorable to carrier separation, transmission and collection, so that a high-efficiency polymer solar cell is realized. The polymer not only has a large conjugated plane, but also ensures good carrier mobility; and the electron-deficient unit of thiazole makes the molecule have stronger electron-withdrawing ability, so that the polymer has lower HOMO and LUMO energy levels; and a copolymer with a suitable conjugated unit can obtain a wider absorption spectrum; the newly developed conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole can be used as a polymer donor, and a high-efficiency all-polymer solar cell device can be realized.

[0043] The application has the following beneficial effects:

[0044] 1. The conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole of the application is composed of benzene and two thiazole units, has a large conjugated plane structure, can reduce the steric hindrance between adjacent rings, thereby improving the coplanarity of the molecule and the closer interchain packing in a solid film and ensuring good carrier mobility. This property not only improves the fill factor of the solar cell of the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole, but also enables the preparation of a thick photovoltaic active layer, so that the effective absorption and utilization of sunlight are realized.

[0045] 2. Compared with traditional organic / polymer materials, the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole of the application is composed of two electron-deficient units of thiazole, has stronger electron-deficient ability, and makes the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole have lower HOMO and LUMO energy levels, so that the application of the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole as a donor in a polymer solar cell is beneficial to obtaining a higher open-circuit voltage.

[0046] 3. Compared with a symmetric structure, the non-centrally symmetric benzodithiazole of the conjugated polymer photoelectric material containing non-centrally symmetric benzodithiazole has a larger dipole moment, which not only enhances the intermolecular interaction and pi-pi stacking, but also optimizes the micro-morphology of the active layer, so that the short-circuit current density and the fill factor of the organic solar cell can be significantly improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 (A) is the structural formula of the target intermediate compound 3 synthesized in Example 1;

[0048] Figure 1 (B) is the structural formula of the target intermediate compound a2 synthesized in the comparative example.

[0049] Figure 2 The nuclear magnetic resonance spectrum (1H NMR) of the target intermediate compound 3 synthesized in Example 1 is as follows: 1

[0050] Figure 3 The nuclear magnetic resonance spectrum (1H NMR) of the target intermediate compound a2 synthesized in the comparative example is as follows: 1 DETAILED DESCRIPTION

[0051] The present application will be further described in detail below in conjunction with the accompanying drawings and Example 1, but the embodiments and protection of the present application are not limited thereto. It should be noted that if the following processes are not specifically described in detail, they can be implemented or understood by those skilled in the art according to the prior art.

[0052] The practice of the present application can employ conventional techniques of organic chemistry within the relevant art. In the following Example 1, efforts have been made to ensure accuracy with respect to numbers (amounts, temperature, reaction times, etc.) but some experimental error and deviations are inevitable in experimental matters. The temperatures used in the following Example 1 are expressed in °C, and the pressure is atmospheric or close to atmospheric. The solvents used are all of analytical or chromatographic purity, and all reactions are carried out in an inert gas atmosphere. Unless otherwise indicated, all reagents are obtained through commercial channels.

[0053] The Stille reaction of the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole is as follows:

[0054]

[0055] Example 1

[0056] A conjugated polymer optoelectronic material Cis-BBTz containing non-centrosymmetric benzodithiazole has the following structural formula:

[0057]

[0058] The synthetic route thereof is as follows:

[0059]

[0060] S1, synthesis of compound 2

[0061] ​​To 350 mL of methanol, 12 mL of concentrated sulfuric acid was added, and 16.2 g of compound 1, 49.8 g of potassium iodide, and 20.4 g of hydrogen peroxide were added to the above mixture solution, and the reaction was allowed to proceed at room temperature for 2 h. After the reaction was completed, the reaction solution was poured into water, suction filtered, and recrystallized using dichloromethane: petroleum ether (10:1, v / v) to obtain 8 g of gray needle-shaped solid, which was compound 2, at a yield of 15%.

[0062] S2, Synthesis of compound 3

[0063] To 250 mL of DMSO, 1.78 g of compound 2, 3.26 g of potassium sulfide, 4.57 g of ammonium acetate, and 0.38 g of cuprous iodide were added, 10 mL of water was added, and the mixture was heated to 130°C under an argon atmosphere. After the reaction was allowed to proceed for 24 h, the mixture was suction filtered and washed with dichloromethane. The resulting filtrate was transferred to a separatory funnel, and water was added. The organic phase was extracted with dichloromethane, washed with brine, dried, and concentrated under vacuum. The resulting residue was purified using a silica gel column to obtain 0.2 g of yellow solid, which was compound 3, at a yield of 20%.

[0064] S3, Synthesis of compound 4

[0065] To 50 mL of DMF, 2 g of compound 3 and 1.44 g of K2CO3 were added, and 8 mL of liquid bromine was added, and the mixture was heated to 120°C. After the reaction was allowed to proceed for 3 h, the reaction solution was poured into a saturated sodium bisulfite solution to quench the reaction, and suction filtered. The resulting 2.3 g of brown powder was dried to obtain compound 4 at a yield of 63%.

[0066] S4, Synthesis of compound 5

[0067] To 20 mL of CF, 0.4 g of compound 5 was added, and 0.2 g of NBS was added in portions in the dark, and the reaction was allowed to proceed at room temperature for 3 h. After the reaction was completed, the reaction solution was poured into water to quench the reaction, extracted with dichloromethane, dried, and concentrated to obtain 0.3 g of orange-yellow solid, which was compound 6, at a yield of 61%.

[0068] S5, Synthesis of compound 6

[0069] To 20 mL of CF, 0.4 g of compound 5 was added, and 0.2 g of NBS was added in portions in the dark, and the reaction was allowed to proceed at room temperature for 3 h. After the reaction was completed, the reaction solution was poured into water to quench the reaction, extracted with dichloromethane, dried, and concentrated to obtain 0.3 g of orange-yellow solid, which was compound 6, at a yield of 61%.

[0070] S6, Synthesis of compound 8

[0071] A mixture of 103 mg of compound 6, 59.5 mg of 5,5-bistrimethyltin-2,2'-bithiophene, and 4.5 mg of tris(dibenzylideneacetone)dipalladium was dissolved in a mixture of 10 mL of toluene and 5 mL of tetrahydrofuran. The reaction was refluxed under argon for 20 h, and after cooling to room temperature, the reaction solution was dropped into 300 mL of methanol to precipitate, and the solid was filtered. After Soxhlet extraction with acetone, methanol, n-hexane, and dichloromethane for 24 h, respectively, the polymer was finally washed down with chloroform, precipitated in methanol, filtered, and dried in vacuum. 130 mg of polymer, i.e., solid BT-Cis-BBTz, was obtained, with a yield of 80%.

[0072] Example 2

[0073] A conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole, BT-Cis-BBTz, has the following structural formula:

[0074]

[0075] The preparation method of Example 2 is the same as that of Example 1, except that step S6 is modified as follows:

[0076] A mixture of 103 mg of compound 6, 59.5 mg of 5,5-bistrimethyltin-2,2'-bithiophene, and 4.5 mg of tris(dibenzylideneacetone)dipalladium was dissolved in a mixture of 10 mL of toluene and 5 mL of tetrahydrofuran. The reaction was refluxed under argon for 20 h, and after cooling to room temperature, the reaction solution was dropped into 300 mL of methanol to precipitate, and the solid was filtered. After Soxhlet extraction with acetone, methanol, n-hexane, and dichloromethane for 24 h, respectively, the polymer was finally washed down with chloroform, precipitated in methanol, filtered, and dried in vacuum. 130 mg of polymer, i.e., solid BT-Cis-BBTz, was obtained, with a yield of 80%.

[0077] Example 3

[0078] A conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole, FT-Cis-BBTz, has the following structural formula:

[0079]

[0080] The preparation method of Example 3 is the same as that of Example 1, except that step S6 is modified as follows:

[0081] A mixture of 103 mg of compound 6, 54.0 mg of 3,4-difluoro-2,5-bistri- methyltin thiophene, 4.5 mg of tris(dibenzylideneacetone)dipalladium was dissolved in a mixed solvent of 10 mL of toluene and 5 mL of tetrahydrofuran. After refluxing under argon protection for 20 h, the reaction solution was dropped into 300 mL of methanol for precipitation, and a solid was obtained by filtration. After extraction with acetone, methanol, n-hexane, and dichloromethane for 24 h in a Soxhlet extractor, the polymer was finally washed down with chloroform, precipitated in methanol, filtered, and dried in vacuum. 120 mg of polymer, i.e., solid FT-Cis-BBTz, was obtained at a yield of 78%.

[0082] Example 4

[0083] A conjugated polymer optoelectronic material containing a non-centrosymmetric benzodithiazole, DFT-Cis-BBTz, has the following structural formula:

[0084]

[0085] The preparation method of Example 4 is the same as that of Example 1, except that step S6 is modified as follows:

[0086] A mixture of 103 mg of compound 6, 54.0 mg of 3,4-difluoro-2,5-bistri- methyltin thiophene, 4.5 mg of tris(dibenzylideneacetone)dipalladium was dissolved in a mixed solvent of 10 mL of toluene and 5 mL of tetrahydrofuran. After refluxing under argon protection for 20 h, the reaction solution was dropped into 300 mL of methanol for precipitation, and a solid was obtained by filtration. After extraction with acetone, methanol, n-hexane, and dichloromethane for 24 h in a Soxhlet extractor, the polymer was finally washed down with chloroform, precipitated in methanol, filtered, and dried in vacuum. 120 mg of polymer, i.e., solid FT-Cis-BBTz, was obtained at a yield of 78%.

[0087] Comparative Example

[0088] A polymer optoelectronic material containing a centrosymmetric benzodithiazole, BBTz, has the following structural formula:

[0089]

[0090] The synthetic route thereof is as follows:

[0091]

[0092] (1) Synthesis of compound a2

[0093] Dissolve 10 g of compound a1 (2,5-diamino-1,4-benzenedithiol dihydrochloride), 24.3 g of triethyl orthoformate, 6.5 g of pyridine, and 1.24 g of ytterbium triflate in 250 mL of DMA, and heat to 55°C under an argon atmosphere. After 3 h of reaction, pour into water, and suction filter. Dry to obtain 5.3 g of yellow powder, which is compound a2 (centrosymmetric benzo dithiazole), at a yield of 67%.

[0094] (2) Synthesis of compound a3

[0095] Dissolve 2 g of compound a2 and 1.44 g of K2CO3 in 50 mL of DMF, add 8 mL of liquid bromine, and heat to 120°C. After 3 h of reaction, pour the reaction solution into saturated sodium bisulfite solution to quench, and suction filter. Dry to obtain 2.3 g of brown powder compound a3 (dibromo centrosymmetric benzo dithiazole), at a yield of 63%.

[0096] (3) Synthesis of compound a4

[0097] Dissolve 2 g of compound a3 and 9.26 g of 2-(4-(2-butyl octyl) thiophene) trimethyl tin in degassed toluene, add 0.33 g of tetrakis triphenyl phosphine palladium, and heat to 150°C. After 24 h of reaction, perform rotary evaporation under reduced pressure to remove toluene, and purify using a silica gel column to obtain 0.8 g of orange yellow solid compound a4 (centrosymmetric benzo dithiazole coupled thiophene derivative), at a yield of 20%.

[0098] (4) Synthesis of compound a5

[0099] Dissolve 0.4 g of compound a4 in 20 mL of CF, and add 0.2 g of NBS in batches in a dark environment, and react at room temperature for 3 h. After completion of the reaction, pour the reaction solution into water to quench, extract with dichloromethane, dry and concentrate to obtain 0.3 g of orange yellow solid compound a5 (dibromo centrosymmetric benzo dithiazole coupled thiophene derivative monomer), at a yield of 61%.

[0100] (5) Synthesis of compound a6

[0101] 103 mg of compound a5, 105 mg of compound 6, 4.5 mg of tris(dibenzylacetone)dipalladium (Pd2(dba)3), and 9.0 mg of tris(o-methylphenyl)phosphine (P(o-Tol)3) were dissolved in a mixed solvent of 10 mL toluene and 5 mL tetrahydrofuran. The reaction mixture was refluxed for 20 h under argon protection. After cooling to room temperature, the reaction solution was added dropwise to 300 mL of methanol to precipitate the solid, which was then filtered to obtain a blood-red solid. The solid was extracted with acetone, methanol, n-hexane, and dichloromethane for 24 h each in a Soxhlet extractor. Finally, the polymer was washed with chloroform, precipitated in methanol, filtered, and dried under vacuum to obtain 103 mg of dark red compound a6, i.e., the solid polymer BBTz, with a yield of 75%.

[0102] Figure 1 (A) is the structural formula of target intermediate compound 3 synthesized in Example 1;

[0103] Figure 1 (B) is the structural formula of the target intermediate compound a2 synthesized in the comparative example.

[0104] Figure 2 The nuclear magnetic resonance spectrum of the target intermediate compound 3 synthesized in Example 1 ( 1 H NMR);

[0105] Figure 3 The nuclear magnetic resonance spectrum of the target intermediate compound a2 synthesized for comparison ( 1 H NMR).

[0106] Test case

[0107] Taking Cis-BBTz synthesized in Example 1 and BBTz synthesized in the comparative example as examples, they were blended with acceptors, and then the current-voltage curves were tested to illustrate their application as donors in polymer solar cell devices.

[0108] The specific fabrication process of polymer solar cell devices is as follows:

[0109] The sheet resistance of ITO conductive glass is approximately 20 Ω / cm. 2 The glass blocks are pre-cut into 15mm × 15mm squares. They are then ultrasonically cleaned sequentially with acetone, a micron-level semiconductor-specific detergent, deionized water, and isopropanol. After nitrogen purging, they are placed in a constant-temperature oven for later use. A 20nm thick cathode interface layer, PEDOT, is spin-coated onto the ITO, followed by spin-coating of the active layer material, Cis-BBTz / PY-IT or BBTz / PY-IT, with a thickness of approximately 100nm. Finally, an Ag electrode is deposited as the anode, completing the device fabrication.

[0110] All preparation processes were carried out in a glove box under a nitrogen atmosphere, with PY-IT serving as the electron acceptor. The structural formula of PY-IT is as follows:

[0111]

[0112] The polymer solar cell device comprises, from bottom to top, an ITO cathode (20nm), a cathode interface layer PEDOT (20nm), an active layer (100nm), and an anode Ag (100nm).

[0113] The current-voltage characteristics of the aforementioned polymer solar cell device were measured.

[0114] The test results are shown in Table 1.

[0115] Table 1: Performance parameters of polymer solar cell devices

[0116]

[0117] As shown in Table 1, the solar cell based on the Cis-BBTz conjugated polymer optoelectronic material of non-centrosymmetric benzodithiazole achieved better short-circuit current and fill factor than the polymer BBTz of centrosymmetric benzodithiazole. This confirms that the larger dipole moment of the non-centrosymmetric structure can enhance intermolecular interactions and π-π stacking, optimize the microstructure of the active layer, and thus achieve higher battery energy conversion efficiency.

[0118] The above-described embodiment 1 of the present invention is merely an example to clearly illustrate the present invention, and is not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole, characterized in that, The conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole has the following structure: in, n is a natural number selected from 1 to 10000; x is selected from 0.05-0.95; y is selected from 0.05-0.95; And x + y = 1; D stands for electron-donating unit; R is a solubilizing group.

2. The conjugated polymer optoelectronic material containing non-centrosymmetric benzodiazidine according to claim 1, characterized in that, The D is selected from one or more of the following structures: 。 3. The conjugated polymer optoelectronic material containing non-centrosymmetric benzodiazidine according to claim 1, characterized in that, The R is selected from C1-C40 alkyl or alkyl derivatives, or C1-C40 alkoxy or alkoxy derivatives; One or more carbon atoms on the alkyl or alkoxy derivative may be replaced by one or more functional groups selected from oxygen, alkenyl, alkynyl, aryl, ester, nitrile, amino, quaternary ammonium salt, quaternary phosphate salt, phosphate, phosphate ester, sulfonate, carboxyl, and hydroxyl. and / or One or more hydrogen atoms on the alkyl or alkoxy derivative may be replaced by one or more functional groups selected from fluorine, chlorine, bromine, and iodine atoms.

4. A method for preparing the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole as described in any one of claims 1-3, characterized in that, The preparation method of the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole includes the following steps: S1. The iodination reaction of p-m-phenylenediamine yields 4,6-diiodophenyl-1,3-diamine. S2. The 4,6-diiodophenyl-1,3-diamine is subjected to a ring-closing reaction to obtain a non-centrosymmetric benzodithiazole; S3. The non-centrosymmetric benzodithiazole is subjected to a bromination reaction with liquid bromine to obtain dibromo-non-centrosymmetric benzodithiazole; S4. The dibromo-non-centrosymmetric benzodithiazole is coupled with thiophene tributyltin with a solubilizing side chain R to obtain a coupled thiophene derivative containing non-centrosymmetric benzodithiazole. S5. The coupling thiophene derivative containing non-centrosymmetric benzodithiazole is subjected to NBS bromination reaction to obtain a dibrominated coupling thiophene derivative target monomer containing non-centrosymmetric benzodithiazole. S6. The target monomer of the dibromo-containing non-centrosymmetric benzodithiazole-coupled thiophene derivative is mixed with a bis(trimethyltin)-functionalized electron donor, and a palladium catalyst is added to carry out a Stille reaction to obtain a conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole. In step S2, the non-centrosymmetric benzodithiazole is obtained by heating a solution under inert gas protection, using 4,6-diiodophenyl-1,3-diamine as a raw material, in the presence of ammonium acetate and cuprous iodide.

5. The method for preparing the conjugated polymer optoelectronic material containing non-centrosymmetric benzodiazylazole as described in claim 4, characterized in that, In step S1, the molar ratio of m-phenylenediamine and potassium iodide in the iodination reaction is 1:0.5-2.

6. The method for preparing the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole as described in claim 4, characterized in that, In step S2, the molar ratio of 4,6-diiodophenyl-1,3-diamine, potassium sulfide, and ammonium acetate in the reaction is 1:3-6:5-12, and the reaction temperature is 110-140℃.

7. The method for preparing the conjugated polymer optoelectronic material containing non-centrosymmetric benzodiazylazole as described in claim 4, characterized in that, In step S1, the 4,6-diiodophenyl-1,3-diamine is obtained by reacting p-m-phenylenediamine as a raw material in solution with potassium iodide and hydrogen peroxide as a catalyst.

8. The method for preparing the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole as described in claim 4, characterized in that, In step S3, the dibromo-asymmetric benzodithiazole is obtained by adding liquid bromine to a non-symmetric benzodithiazole under alkaline conditions and heating the reaction.

9. The application of the conjugated polymer optoelectronic material containing non-centrosymmetric benzodithiazole as described in any one of claims 1-3 in optoelectronic devices.

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