Conjugated polymer containing 1, 3-benzothiazole-2-amide structure, hole transport film and organic photovoltaic cell device

Abstract

The invention relates to a conjugated polymer containing a 1, 3-benzothiazole-2-amide structure, a hole transport type thin film and an organic photovoltaic cell device. According to the conjugated polymer, halogen atoms are introduced to benzene ring active sites of a 1, 3-benzothiazole-2-amide structure so as to adjust the energy level and the carrier mobility, and amide end groups are adjusted so as to adjust the morphology and solubility of the polymer. Compared with the prior art, the hole transport type polymer containing the 1, 3-benzothiazole-2-amide structure has good thermal stability, has good response to sunlight, and can be used as a donor phase in an active layer of an organic photovoltaic cell device.

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and in particular to a conjugated polymer containing a 1,3-benzothiazole-2-amide structure, a hole transport thin film, and an organic photovoltaic cell device. Background Technology

[0002] Solar cells, as a technology that can directly convert solar energy into electrical energy, are a key means to achieve carbon neutrality and have extremely broad development prospects. Among the many types of solar cells, organic solar cells (OSCs) have seen rapid development in recent years.

[0003] OSCs are manufactured using a low-temperature solution coating process, which effectively shortens the energy payback period. Initially, the photoelectric conversion efficiency (PCE) of OSCs improved slowly; only with continuous advancements in materials science and device manufacturing technologies has its photovoltaic performance significantly improved.

[0004] Currently, common polymer donor materials include PTB7-Th (a conjugated polymer material based on a thiophene / furan structure) and PBDB-T. Polymer donors possess many advantages, such as the ability to flexibly control their energy levels and optical band gaps through molecular design to match different acceptor materials and device structures; they also exhibit good solubility, facilitating processing using low-temperature solution coating techniques and helping to reduce production costs. However, the synthesis processes of most polymer donors are currently complex and costly, limiting their large-scale commercial application. Therefore, researchers are constantly striving to explore the principles and universal methods for improving and enhancing the performance of solar cells. To achieve these goals, the development of more novel conjugated polymer materials is crucial for advancing the performance of polymer solar cells.

[0005] CN118852591A discloses a hole-transporting polymer and its preparation and application. This hole-transporting polymer contains a 1,3-benzothiazole-2-carboxylic acid ester structure. Energy levels and film morphology are adjusted by introducing halogen atoms, and solubility is improved through polyalkyl branches. It is prepared using palladium-catalyzed Stille polymerization to form a semiconductor material with an efficient and economical route. However, the alkyl straight chains in the aforementioned conjugated polymer containing the benzothiazole structure interact only through van der Waals forces, which are weak and non-directional, hindering the formation of tighter π-π stacking and longer energy transport channels in donor / acceptor blends. Furthermore, the alkyl chain regulation methods involving transesterification in this scheme result in a complex synthetic route and high cost.

[0006] Therefore, a novel conjugated polymer containing a benzothiazole structure still needs to be developed and further used to prepare organic photovoltaic cell devices. Summary of the Invention

[0007] The purpose of this invention is to overcome the defects of the prior art and provide a conjugated polymer containing a 1,3-benzothiazole-2-amide structure, a hole transport thin film, and an organic photovoltaic cell device.

[0008] The objective of this invention can be achieved through the following technical solutions: This invention first provides a conjugated polymer containing a 1,3-benzothiazole-2-amide structure, having the following general structural formula: ; In the formula, n is the degree of aggregation, which is an integer from 3 to 5000, and a+b=100%; Ar is a conjugated structural unit selected from the following groups: thiophene and its derivatives, benzene and its derivatives, pyrrole and its derivatives, benzofuran and its derivatives, benzothiophene and its derivatives, benzodithiophene and its derivatives, benzothiadiazole and its derivatives; BTZA is a 1,3-benzothiazole-2-amide structural unit, and depending on the specific application, it can be selected from any of the following structures: or ; In the formula, X and Y are independently selected from H, F, Cl, Br, and I; R1, R2, R3, and R4 are independently selected from C1 to C2. 20 Straight-chain alkyl, branched alkyl, cyclic alkyl and their derivatives, wherein the cyclic alkyl is a monocyclic or polycyclic ring having 5 to 20 atoms.

[0009] Furthermore, unless otherwise specified, a and b are assumed to be 50% each.

[0010] Furthermore, X and Y are independently selected from H, F, or Cl.

[0011] Furthermore, in R1, R2, R3, and R4, the derived alkyl group is one or more of the -CH2- groups independently replaced by -O-, -S-, -C(=O)-, -C(=S)-, -C(=O)-O-, -OC(=O)-, -NRO-, -CF2-, or -NR. 0 -、-SiR 0 R 00 -、-CF 2 -、-CR 0 = CR 00 Alternatively, -C≡C- can be replaced by a molecular structure in which O or S atoms are not directly connected to each other; where R 0 R 00 Is it H or C? 1-12A straight-chain or branched alkyl group, wherein one or more H atoms are independently replaced by F, Cl, Br, I or CN, and wherein one or more CH2 or CH3 groups are independently replaced by cationic groups, anionic groups, aryl, heteroaryl, aryloxy or heteroaryloxy groups.

[0012] Furthermore, Ar is a structural unit of thiophene and its derivatives, benzene and its derivatives, pyrrole and its derivatives, benzofuran and its derivatives, benzothiophene and its derivatives, benzodithiophene and its derivatives, benzothiadiazole and its derivatives, other heterocyclic conjugated units and their derivatives, and extended conjugated systems.

[0013] Furthermore, the conjugate structural unit Ar is selected from any of the following structural formulas: , , , , , , , , , , , , , , , , , , , , , , , , , , , , or .

[0014] In the above general structural formula, R5 and R6 are independently H or C1~C. 20 Straight-chain alkyl, branched alkyl, cyclic alkyl and their derivative alkyl groups, wherein one or more -CH2- groups are independently replaced by -O-, -S-, -C (=O)-, -C (=S)-, -C(=O)-O-, -OC(=O)-, -NRO-, -CF2- or -C≡C- in such a way that the O or S atoms are not directly connected to each other, and / or one or more H atoms are independently replaced by F, Cl, Br, I or CN, and / or one or more CH2 or CH3 groups are independently replaced by cationic groups, anionic groups, aryl, heteroaryl, aryloxy or heteroaryloxy groups; X1 is selected from H, F, Cl, Br, I.

[0015] Furthermore, the conjugated polymer includes, but is not limited to, the following structural formulas: , , , , , , , , .

[0016] This invention also provides a method for preparing a conjugated polymer. When the 1,3-benzothiazole-2-amide structural unit has the following structural formula, the method for preparing the conjugated polymer includes the following steps: ; S1.1: Compound I was mixed with oxalyl chloride and subjected to a monosubstitution reaction; then triethylamine and compound II were added to the reaction solution and subjected to an acid-amine condensation reaction to obtain compound III; S1.2: Compound III is mixed with compound Me3Sn-Ar-SnMe3 and subjected to Stille polymerization under palladium catalyst to obtain a conjugated polymer containing a 1,3-benzothiazole-2-amide structure.

[0017] When the 1,3-benzothiazole-2-amide structural unit has the following structural formula, the method for preparing the conjugated polymer includes the following steps: ; S2.1: Compound III and compound IV are mixed and reacted under the catalysis of a palladium catalyst to obtain compound V; S2.2: Compound V was mixed with N-bromosuccinimide to undergo a substitution reaction, yielding compound VI; S2.3: Compound VI is mixed with compound Me3Sn-Ar-SnMe3 and subjected to Stille polymerization under palladium catalyst to obtain a conjugated polymer containing a 1,3-benzothiazole-2-amide structure.

[0018] The structural formulas of compounds I, II, III, IV, V, and VI are as follows: , , , , , .

[0019] Further, in step S1.1, the molar ratio of compound I, oxalyl chloride, and compound II is 1: (1.2-2.5): (1.2-2.5).

[0020] Further, in step S2.1, the molar ratio of compound III, compound IV and palladium catalyst is 1:(1.1-1.5):(0.01-0.05).

[0021] Further, in step S2.2, the molar ratio of compound V to N-bromosuccinimide is 1:(1.1-1.5).

[0022] Further, in step S1.2, the feeding ratio of the sum of the molar amounts of compound III, Me3Sn-Ar-SnMe3 to the molar amount of palladium catalyst is 2: (0.01-0.05).

[0023] Further, in step S2.3, the feeding ratio of the sum of the molar amounts of compound VI, Me3Sn-Ar-SnMe3 to the molar amount of palladium catalyst is 2: (0.01-0.05).

[0024] Furthermore, the Me3Sn-Ar-SnMe3 consists of two Me3Sn groups attached to two symmetrical active sites at the ends of the Ar groups.

[0025] The present invention also provides a hole transport type thin film, which is made of a conjugated polymer containing a 1,3-benzothiazole-2-amide structure.

[0026] Furthermore, the hole transport thin film is prepared by coating a conjugated polymer, which serves as an electron donor material, with an electron acceptor material at a mass ratio of 1:(1.0-1.2).

[0027] The present invention also provides an organic photovoltaic cell device, which includes any of the hole transport thin films described above.

[0028] Furthermore, the hole transport thin film serves as the active layer of an organic photovoltaic cell device.

[0029] Furthermore, the organic photovoltaic cell device comprises, from bottom to top, an ITO substrate, an anode interface layer, a hole transport thin film, a cathode interface layer, and an Ag electrode.

[0030] Furthermore, the composition of the anode interface layer is PEDOT:PSS.

[0031] Furthermore, the thickness of the hole transport thin film is 80-120 nm.

[0032] Furthermore, the thickness of the cathode interface layer is 15-25 nm.

[0033] Furthermore, the thickness of the Ag electrode is 80-120 nm.

[0034] Compared with the prior art, the present invention has the following technical advantages: (1) This invention provides a series of novel hole-transporting polymers containing a 1,3-benzothiazole-2-amide structure. The energy levels and carrier mobility can be adjusted by introducing halogen atoms at the active sites of the benzene ring, while the polymer morphology and solubility can be controlled by adjusting the amide end groups. The hole-transporting polymers containing a 1,3-benzothiazole-2-amide structure of this invention exhibit good thermal stability and a good response to sunlight, and can be used as donor phases in the active layer of organic photovoltaic cell devices.

[0035] (2) Compared with the existing 1,3-benzothiazole-2-carboxylic acid ester structure, the NH atom in the 1,3-benzothiazole-2-amide structure of the present invention has a significant positive charge, making it an excellent hydrogen bond donor, while C=O is a strong hydrogen bond acceptor. Strong and directional bonds can be formed between the two. Simultaneously, as a moderately strong electron-withdrawing group, the amide bond can moderately lower the highest occupied orbital (HOMO) energy level of the material without excessively affecting its lowest unfilled orbital (LUMO) energy level. This characteristic also allows it to have differentiated energy levels, better matching the energy requirements of different scenarios and improving energy conversion and transmission efficiency. In terms of synthesis, the present invention also reduces the alkyl chain control methods of transesterification, making its synthetic route simpler, which is beneficial for improving yield and purity, and reducing production costs.

[0036] (3) The novel hole-transporting polymer containing a 1,3-benzothiazole-2-amide structure of the present invention has a high absorption coefficient for sunlight. In practical applications, this copolymer can be uniformly coated on the surface of various substrates to form a thin film through drop-coating or spin-coating processes. In addition, the hole-transporting polymer provided by the present invention has good thermal stability and can be used as an electron donor material component for organic photovoltaic cell devices. Attached Figure Description

[0037] Figure 1 Compound 11 in Example 5 of this invention 1 H NMR spectrum.

[0038] Figure 2 The cyclic voltammetry curves are for polymers D1 to D6 in Examples 1-6 of this invention.

[0039] Figure 3 The images show the solution and film absorption spectra of polymers D1 to D6 of this invention.

[0040] Figure 4 This is a current-voltage curve of an organic solar cell device prepared using polymer D2 as an electron donor material according to the present invention. Detailed Implementation

[0041] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0042] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0043] Example 1: This embodiment provides a conjugated polymer (denoted as D1) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0044] 1) Synthesis of Compound 3: Compound 1 (CAS: 172377-05-8) (3.0 g, 11.15 mmol, 1.0 EQ) was added to a dried two-necked flask. The flask was evacuated and purged with nitrogen. Then, 50 mL of dichloromethane was added as a solvent, followed by dropwise addition of triethylamine (9.4 mL, 33.46 mmol, 3.0 EQ). The reaction mixture was placed in an ice bath, and Compound 2 (1.6 mL, 13.38 mmol, 1.2 EQ) was slowly added dropwise. After reacting for 30 minutes in the ice bath and nitrogen atmosphere, the ice bath was removed, and the reaction mixture was allowed to return to room temperature. The mixture was then stirred at 300 rpm for 3 hours. After the reaction was complete, 70 mL of water was added to a separatory funnel, followed by 70 mL of dichloromethane for extraction. The organic phase was collected. This process was repeated three times. The organic phase was dried using anhydrous magnesium sulfate, and after complete drying, the desiccant was removed by filtration. The organic solvent was removed using a rotary evaporator to obtain the crude product. The crude product was further purified by column chromatography to obtain a gray solid product, compound 3 (3.9 g, 91%).

[0045] 1H NMR (400 MHz, Chloroform-d) δ 9.39 (s, 1H), 8.70 (d, J = 6.8 Hz,1H), 7.40 (d, J = 7.5 Hz, 1H), 4.45 (q, J = 7.2 Hz, 2H), 1.45 (t, J = 7.1 Hz,3H).

[0046] 2) Synthesis of Compound 4: Compound 3 (3.9 g, 12.0 mmol, 1.0 EQ) and Lawson's reagent (2.3 g, 7.2 mmol, 0.6 EQ) were added together to a dried Schlenk flask. The flask was then evacuated and purged with nitrogen. 50 mL of toluene was added to the reaction mixture as a solvent, and the reaction system was heated to reflux and reacted under nitrogen protection for 8 hours. After the reaction was complete, the system was allowed to return to room temperature, and 100 mL of saturated brine was slowly added to the reaction mixture to quench the reaction. Then, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration. The organic solvent was removed using a rotary evaporator to obtain the crude product. Finally, the crude product was purified by column chromatography to obtain an orange-yellow solid product, namely compound 4 (3.0 g, 77%).

[0047] 1 H NMR (400 MHz, Chloroform-d) δ 10.94 (s, 1H), 9.27 (d, J = 6.8 Hz,1H), 7.47 (d, J = 7.4 Hz, 1H), 4.46 (q, J = 7.1 Hz, 2H), 1.46 (t, J = 7.1 Hz,3H).

[0048] 3) Synthesis of Compound 5: Compound 4 (3.0 g, 7.79 mmol, 1.0 EQ) was added to a two-necked flask. Then, 30 mL of methanol, 10 mL of tetrahydrofuran, and 50 mL of deionized water (H₂O) were added dropwise to form a homogeneous reaction mixture. Next, 20 mL of a 20% sodium hydroxide (NaOH) aqueous solution was slowly added dropwise to the reaction system. The reaction temperature was set at 50 °C and maintained at this condition for 2 hours. After the initial reaction was complete, the reaction system was placed in an ice bath to lower the temperature in preparation for the next step of the reaction. Subsequently, 40 mL of an aqueous solution containing potassium ferricyanide (11.7 g, 35.5 mmol, 5.0 EQ) was slowly added dropwise to the two-necked flask. The reaction temperature was again raised to 50 °C and the reaction was continued for 5 hours. After the reaction was complete, dilute hydrochloric acid was added dropwise to the reaction mixture to precipitate a crude solid product. Finally, the solid product was separated by vacuum filtration and transferred to a vacuum drying oven for drying. Finally, a bluish-green solid product, namely compound 5, was obtained.

[0049] 4) Synthesis of Compound 8: Compound 5 (2.0 g, 5.68 mmol, 1.0 EQ) was placed in a dried round-bottom flask, and the flask was evacuated and purged with nitrogen. Then, 20 mL of dichloromethane was added as a solvent, and the reaction mixture was placed in an ice bath. One drop of N,N-dimethylformamide was added dropwise. Compound 6 (0.58 mL, 6.82 mmol, 1.2 EQ) was added dropwise, and the reaction was continued in an ice bath for 2 hours. After the reaction was complete, the solvent and residual oxalyl chloride were removed from the reaction mixture using a rotary evaporator.

[0050] Next, 20 mL of dichloromethane and triethylamine (2.39 mL, 17.04 mmol, 3.0 EQ) were added to the reaction system in an ice bath environment, followed by dropwise addition of compound 7 (CAS No.: 143-16-8) (1.59 g, 6.82 mmol, 1.2 EQ). The reaction was then carried out at room temperature for 12 h. After the reaction was complete, the mixture was extracted three times with 70 mL of water and 70 mL of dichloromethane in a separatory funnel to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration after drying. The organic solvent was then removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow oily liquid, namely compound 8 (1.9 g, 52%).

[0051] 1H NMR (400 MHz, Chloroform-d) δ 7.56 (d, J = 8.2 Hz, 1H), 4.03 (dd,J=8.8,6.4Hz, 2H), 3.51 (dd, J = 9.0, 6.5 Hz, 2H), 1.41 – 1.29 (m, 16H), 0.90 –0.88 (m, 6H).

[0052] 5) Synthesis of Compound 10: Compound 8 (2.0 g, 3.85 mmol, 1.0 EQ), Compound 9 (3.16 g, 8.46 mmol, 2.2 EQ), and catalyst Pd(PPh3)4 (0.44 g, 0.38 mmol, 0.1 EQ) were added to a dried Schlenk reaction flask. The mixture was then purged to a nitrogen atmosphere, and 20 mL of toluene was added as a solvent. The reaction was carried out at 110 °C for 12 h. After the reaction was complete, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration. The organic solvent was then removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain an orange-yellow viscous liquid, namely Compound 10 (1.83 g, 90%).

[0053] 1 H NMR (400 MHz, Chloroform-d) δ 7.42 (dd, J = 3.7, 1.1 Hz, 1H), 7.31–7.23 (m, 2H), 7.10 (dd, J = 18.9, 5.1 Hz, 2H), 6.80 (ddd, J = 18.0, 5.1,3.7 Hz, 2H), 3.85 – 3.77 (m, 2H), 3.19 – 3.11 (m, 2H), 1.33 (q, J = 7.5 Hz,4H), 1.05 – 0.75 (m, 12H), 0.56 – 0.50 (m, 3H), 0.47 – 0.39 (m, 3H).

[0054] 6) Synthesis of Compound 11: Compound 10 (500 mg, 0.95 mmol, 1.0 EQ), NBS (370.79 mg, 2.08 mmol, 2.2 EQ), and 10 mL of THF were added to a dried two-necked flask at 0 °C. The reaction solution was reacted at room temperature for 12 h in the dark. After the reaction was completed, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration after drying. The organic solvent was removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow-green solid, which was compound 11 (345 mg, 53%).

[0055] 1 H NMR (400 MHz, Chloroform-d) δ 7.60 (d, J = 12.2 Hz, 1H), 7.49 (d,J = 4.0 Hz, 1H), 7.39 (d, J = 3.9 Hz, 1H), 7.16 (dd, J = 4.0, 0.9 Hz, 1H), 7.13 (d, J = 4.0 Hz, 1H), 4.25 – 4.16 (m, 2H), 3.59 – 3.50 (m, 2H), 1.80 –1.68 (m, 4H), 1.30 (d, J = 40.5 Hz, 12H), 0.95 – 0.79 (m, 6H).

[0056] 7) Synthesis of Polymer D1: The following operations were performed entirely in a glove box. Compound 11 (80 mg, 0.117 mmol), compound 12 (CAS No.: 1352642-37-5) (116.73 mg, 0.128 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask. Finally, 1.5 mL of o-xylene was added as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D1 (93 mg, 71%).

[0057] Example 2: This embodiment provides a conjugated polymer (denoted as D2) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0058] 1) Compound 3 was prepared according to the method of Example 1.

[0059] 2) Compound 4 was prepared according to the method of Example 1.

[0060] 3) Compound 5 was prepared according to the method of Example 1.

[0061] 4) Compound 8 was prepared according to the method of Example 1.

[0062] 5) Compound 10 was prepared according to the method of Example 1.

[0063] 6) Compound 11 was prepared according to the method of Example 1.

[0064] 7) Synthesis of Polymer D2: The following operations were performed entirely in a glove box. Compound 11 (80 mg, 0.117 mmol), compound 12 (CAS No.: 1514905-25-9) (113.31 mg, 0.120 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask, followed by 1.5 mL of o-xylene as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D2 (84 mg, 62%).

[0065] Example 3: This embodiment provides a conjugated polymer (denoted as D3) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0066] 1) Synthesis of Compound 3: Compound 1 (CAS No.: 3638-74-1) (2.5 g, 10.08 mmol, 1.0 EQ) was added to a dried two-necked flask. The flask was evacuated and purged with nitrogen. Then, 30 mL of dichloromethane was added as a solvent, followed by dropwise addition of triethylamine (4.3 mL, 30.24 mmol, 3.0 EQ). The reaction mixture was placed in an ice bath, and Compound 2 (1.4 mL, 12.10 mmol, 1.2 EQ) was slowly added dropwise. After reacting for 30 minutes in the ice bath and nitrogen atmosphere, the ice bath was removed, and the reaction mixture was allowed to return to room temperature. The mixture was then stirred at 300 rpm for 3 hours. After the reaction was complete, 70 mL of water was added to a separatory funnel, followed by 70 mL of dichloromethane for extraction. The organic phase was collected, and this process was repeated three times. The organic phase was dried using anhydrous magnesium sulfate, and the desiccant was removed by filtration after complete drying. The organic solvent was removed using a rotary evaporator to obtain the crude product. The crude product was further purified by column chromatography to obtain a gray solid product, namely compound 3 (2.9 g, 87%).

[0067] 1H NMR (400 MHz, Chloroform-d) δ 9.48 (s, 1H), 8.64 (d, J = 2.3 Hz, 1H), 7.44 (d, J = 8.5 Hz, 1H), 7.20 (dd, J = 8.6, 2.3 Hz, 1H), 4.45 (q, J =7.1 Hz, 2H), 1.45 (t, J = 7.2 Hz, 3H).

[0068] 2) Synthesis of Compound 4: Compound 3 (2.9 g, 8.76 mmol, 1.0 EQ) and Lawson's reagent (2.1 g, 5.3 mmol, 0.6 EQ) were added together to a dried Schlenk flask. The flask was then evacuated and purged with nitrogen. 50 mL of toluene was added to the reaction mixture as a solvent, and the reaction system was heated to reflux and reacted under nitrogen protection for 8 hours. After the reaction was complete, the system was allowed to return to room temperature, and 100 mL of saturated brine was slowly added to the reaction mixture to quench the reaction. Then, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration. The organic solvent was removed using a rotary evaporator to obtain the crude product. Finally, the crude product was purified by column chromatography to obtain an orange-yellow solid product, namely compound 4 (2.0 g, 65%).

[0069] 1 H NMR (400 MHz, Chloroform-d) δ 11.07 (s, 1H), 9.27 (d, J = 2.3 Hz,1H), 7.56 – 7.49 (m, 1H), 7.31 (dd, J = 8.6, 2.3 Hz, 1H), 4.46 (q, J = 7.2Hz, 2H), 1.46 (t, J = 7.1 Hz, 3H).

[0070] 3) Synthesis of Compound 5: Compound 4 (2.0 g, 5.73 mmol, 1.0 EQ) was added to a two-necked flask. Then, 30 mL of methanol, 10 mL of tetrahydrofuran, and 30 mL of deionized water (H₂O) were added dropwise to form a homogeneous reaction mixture. Next, 15 mL of a 20% sodium hydroxide (NaOH) aqueous solution was slowly added dropwise to the reaction system. The reaction temperature was set at 50 °C and the reaction was continued under these conditions for 2 hours. After the initial reaction was completed, the reaction system was placed in an ice bath to lower the temperature in preparation for the next step of the reaction. Subsequently, 40 mL of an aqueous solution containing potassium ferricyanide (9.4 g, 28.66 mmol, 5.0 EQ) was slowly added dropwise to the two-necked flask. The reaction temperature was again raised to 50 °C and the reaction was continued for 5 hours. After the reaction was completed, dilute hydrochloric acid was added dropwise to the reaction mixture to precipitate a crude solid product. Finally, the solid product was separated by vacuum filtration and transferred to a vacuum drying oven for drying. Finally, a bluish-green solid product, namely compound 5, was obtained.

[0071] 4) Synthesis of Compound 8: Compound 5 (2.0 g, 5.99 mmol, 1.0 EQ) was placed in a dried round-bottom flask, and the flask was evacuated and purged with nitrogen. Then, 20 mL of dichloromethane was added as a solvent, and the reaction system was placed in an ice bath. One drop of N,N-dimethylformamide was added dropwise. Compound 6 (0.56 mL, 7.18 mmol, 1.2 EQ) was added dropwise, and the reaction was continued in an ice bath for 2 hours. After the reaction was complete, the solvent and residual oxalyl chloride were removed from the reaction system using a rotary evaporator. Next, 20 mL of dichloromethane and triethylamine (2.52 mL, 17.97 mmol, 3.0 EQ) were added to the reaction system in an ice bath to adjust the pH to weakly alkaline, and Compound 7 (1.33 g, 7.18 mmol, 1.2 EQ) was added dropwise. Finally, the reaction was carried out at room temperature for 12 hours. After the reaction was complete, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration after drying. The organic solvent was then removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow oily liquid, namely compound 8 (1.68 g, 56%).

[0072] 1H NMR (400 MHz, Chloroform-d) δ 7.59 (d, J = 8.2 Hz, 1H), 7.45 (d, J= 8.2 Hz, 1H), 4.07 – 3.99 (m, 2H), 3.55 – 3.47 (m, 2H), 1.81 – 1.67 (m, 4H), 1.43 – 1.26 (m, 12H), 0.94 – 0.83 (m, 7H).

[0073] 5) Synthesis of Polymer D3: The following operations were performed entirely in a glove box. Compound 8 (80 mg, 0.159 mmol), compound 9 (CAS No.: 1352642-37-5) (130.39 mg, 0.159 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask. Finally, 1.5 mL of o-xylene was added as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D3 (102.75 mg, 68%).

[0074] Example 4: This embodiment provides a conjugated polymer (denoted as D4) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0075] 1) Compound 8 was prepared according to the method of Example 3.

[0076] 2) Synthesis of Polymer D4: The following operations were performed entirely in a glove box. Compound 8 (80 mg, 0.159 mmol), compound 9 (CAS No.: 1514905-25-9) (149.55 mg, 0.159 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask. Finally, 1.5 mL of o-xylene was added as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D4 (114.45 mg, 73%).

[0077] Example 5: This embodiment provides a conjugated polymer (denoted as D5) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0078] 1) Synthesis of Compound 3: Compound 1 (CAS No.: 1455435-87-6) (3.0 g, 10.56 mmol, 1.0 EQ) was added to a dried two-necked flask. The flask was evacuated and purged with nitrogen. Then, 50 mL of dichloromethane was added as a solvent, followed by dropwise addition of triethylamine (4.4 mL, 31.69 mmol, 3.0 EQ). The reaction mixture was placed in an ice bath, and Compound 2 (1.4 mL, 12.67 mmol, 1.2 EQ) was slowly added dropwise. After reacting for 30 minutes in the ice bath and nitrogen atmosphere, the ice bath was removed, and the reaction mixture was allowed to return to room temperature. The mixture was then stirred at 300 rpm for 3 hours. After the reaction was complete, 70 mL of water was added to a separatory funnel, followed by 70 mL of dichloromethane for extraction. The organic phase was collected. This process was repeated three times. The organic phase was dried using anhydrous magnesium sulfate, and after complete drying, the desiccant was removed by filtration. The organic solvent was removed using a rotary evaporator to obtain the crude product. The crude product was further purified by column chromatography to obtain a gray solid product, compound 3 (3.56 g, 91%).

[0079] 1H NMR (400 MHz, Chloroform-d) δ 9.42 (s, 1H), 8.55 (dd, J = 6.0, 2.5Hz, 1H), 4.46 (q, J = 7.1 Hz, 2H), 1.45 (t, J = 7.1 Hz, 3H).

[0080] 2) Synthesis of Compound 4: Compound 3 (3.56 g, 9.6 mmol, 1.0 EQ) and Lawson's reagent (2.3 g, 5.7 mmol, 0.6 EQ) were added together to a dried Schlenk flask. The flask was then evacuated and purged with nitrogen. 50 mL of toluene was added to the reaction mixture as a solvent, and the reaction system was heated to reflux and reacted under nitrogen protection for 8 hours. After the reaction was complete, the system was allowed to return to room temperature, and 100 mL of saturated brine was slowly added to the reaction mixture to quench the reaction. Then, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration. The organic solvent was removed using a rotary evaporator to obtain the crude product. Finally, the crude product was purified by column chromatography to obtain an orange-yellow solid product, namely compound 4 (2.56 g, 69%).

[0081] 1 H NMR (400 MHz, Chloroform-d) δ 10.98 (s, 1H), 9.16 (dd, J = 6.1,2.5 Hz, 1H), 4.46 (q, J = 7.1 Hz, 2H), 1.46 (t, J = 7.1 Hz, 3H).

[0082] 3) Synthesis of Compound 5: Compound 4 (2.56 g, 6.62 mmol, 1.0 EQ) was added to a two-necked flask. Then, 30 mL of methanol, 10 mL of tetrahydrofuran, and 50 mL of deionized water (H₂O) were added dropwise to form a homogeneous reaction mixture. Next, 20 mL of a 20% sodium hydroxide (NaOH) aqueous solution was slowly added dropwise to the reaction system. The reaction temperature was set at 50 °C and the reaction was continued under these conditions for 2 hours. After the initial reaction was complete, the reaction system was placed in an ice bath to lower the temperature in preparation for the next step of the reaction. Subsequently, 40 mL of an aqueous solution containing potassium ferricyanide (10.89 g, 33.1 mmol, 5.0 EQ) was slowly added dropwise to the two-necked flask. The reaction temperature was again raised to 50 °C and the reaction was continued for 5 hours. After the reaction was complete, dilute hydrochloric acid was added dropwise to the reaction mixture to precipitate a crude solid product. Finally, the solid product was separated by vacuum filtration and transferred to a vacuum drying oven for drying. Finally, a blue-green solid product, namely compound 5, was obtained.

[0083] 4) Synthesis of Compound 8: Compound 5 (2.0 g, 5.38 mmol, 1.0 EQ) was placed in a dried round-bottom flask, and the flask was evacuated and purged with nitrogen. Then, 20 mL of dichloromethane was added as a solvent, and the reaction mixture was placed in an ice bath. One drop of N,N-dimethylformamide was added dropwise. Compound 6 (0.50 mL, 6.45 mmol, 1.2 EQ) was added dropwise, and the reaction was continued in an ice bath for 2 hours. After the reaction was complete, the solvent and residual oxalyl chloride were removed from the reaction mixture using a rotary evaporator. Next, 20 mL of dichloromethane and triethylamine (2.27 mL, 16.14 mmol, 3.0 EQ) were added to the reaction mixture in an ice bath, and Compound 7 (1.20 g, 6.45 mmol, 1.2 EQ) was added dropwise. Finally, the reaction was allowed to proceed at room temperature for 12 h. After the reaction was complete, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration after drying. The organic solvent was then removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow oily liquid, namely compound 8 (1.3 g, 45%).

[0084] 1H NMR (400 MHz, Chloroform-d) δ 4.07 – 3.99 (m, 2H), 3.55 – 3.47 (m,2H), 1.73 (dp, J = 28.8, 7.6 Hz, 4H), 1.46 – 1.21 (m, 12H), 0.94 – 0.84 (m,6H).

[0085] 5) Synthesis of Compound 10: Compound 8 (2.0 g, 3.70 mmol, 1.0 EQ), Compound 9 (3.04 g, 8.15 mmol, 2.2 EQ), and catalyst Pd(PPh3)4 (0.43 g, 0.37 mmol, 0.1 EQ) were added to a dried Schlenk reaction flask. The mixture was then purged to a nitrogen atmosphere, and 20 mL of toluene was added as solvent. The reaction was carried out at 110 °C for 12 h. After the reaction was complete, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration. The organic solvent was then removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow fluorescent viscous liquid, namely Compound 10 (1.82 g, 90%).

[0086] 1 H NMR (400 MHz, Chloroformd) δ 7.94 (dd, J = 3.6, 1.6 Hz, 1H), 7.68 (dd, J = 3.8, 1.1 Hz, 1H), 7.56 (dt, J = 5.2, 1.3 Hz, 2H), 7.23 (dt, J = 5.5,2.9 Hz, 2H), 4.22 – 4.13 (m, 2H), 3.57 – 3.49 (m, 2H), 1.74 – 1.66 (m, 4H), 1.41 – 1.18 (m, 20H), 0.96 – 0.80 (m, 6H).

[0087] 6) Synthesis of Compound 11: Compound 10 (500 mg, 0.94 mmol, 1.0 EQ), NBS (367.35 mg, 2.06 mmol, 2.2 EQ), and 10 mL of THF were added to a dried two-necked flask at 0 °C. The reaction solution was reacted at room temperature for 12 h in the dark. After the reaction was completed, 70 mL of water and 70 mL of dichloromethane were added to a separatory funnel for three extractions to separate the lower organic phase. The organic phase was dried using anhydrous magnesium sulfate, and the drying agent was removed by filtration after drying. The organic solvent was removed again using a rotary evaporator. Finally, the crude product was purified by column chromatography to obtain a yellow-green solid, which was compound 11 (443 mg, 67%).

[0088] Compound 11 1 The H NMR spectrum is shown in Figure 1 .

[0089] 1 H NMR (400 MHz, Chloroform-d) δ 7.70 (dd, J = 4.1, 1.4 Hz, 1H), 7.42(d, J = 4.0 Hz, 1H), 7.22 – 7.15 (m, 2H), 4.28 – 4.10 (m, 2H), 3.58 – 3.50(m, 2H), 1.75 – 1.65 (m, 4H), 1.34 (d, J = 8.9 Hz, 6H), 1.25 (d, J = 7.1 Hz, 6H), 0.95 – 0.79 (m, 6H).

[0090] 7) Synthesis of Polymer D5: The following operations were performed entirely in a glove box. Compound 11 (80 mg, 0.114 mmol), compound 12 (CAS No.: 1352642-37-5) (105.87 mg, 117.04 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask, followed by 1.5 mL of o-xylene as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D5 (112.9 mg, 86%).

[0091] Example 6: This embodiment provides a conjugated polymer (denoted as D6) containing a 1,3-benzothiazole-2-amide structure, and its synthetic route is as follows: .

[0092] 1) Compound 11 was prepared according to the method of Example 5.

[0093] 2) Synthesis of Polymer D6: The following operations were performed entirely in a glove box. Compound 11 (80 mg, 0.117 mmol), compound 12 (CAS No.: 1514905-25-9) (112.87 mg, 0.120 mmol), and 6 mg of catalyst Pd(PPh3)4 were added to a dried two-necked flask, followed by 1.5 mL of o-xylene as a solvent. The mixture was stirred at 140 °C until a viscous colloid was formed. After the mixture returned to room temperature, the resulting polymer solution was completely dissolved in chlorobenzene, and then slowly added dropwise to 40 mL of methanol at a rate of 0.5 mL / min to precipitate. The precipitate was collected by filtration, and the resulting solid precipitate was the crude polymer product. Next, the collected crude polymer product was sequentially separated and purified using petroleum ether, dichloromethane, and chloroform as solvents using a Soxhlet extractor. The concentrated chloroform phase was collected and added dropwise to methanol, causing the polymer to precipitate again. Finally, the precipitate was collected by filtration and dried to obtain a black solid product, namely polymer D6 (107.7 mg, 81%).

[0094] Test example: Based on the successful preparation of the above-mentioned conjugated polymer containing the 1,3-benzothiazole-2-amide structure, this invention further utilizes the conjugated polymer containing the 1,3-benzothiazole-2-amide structure as an electron donor material in organic solar cell devices. The organic solar cell device structure of this invention is ITO / PEDOT4083 / Active Layer / PFN-Br / Ag, and the specific preparation method is as follows: First, the ITO substrate was subjected to dual ultrasonic cleaning with acetone and isopropanol to thoroughly remove surface impurities, followed by UV ozone treatment for 10 minutes. Next, a PEDOT:PSS aqueous solution (mass concentration) was uniformly spread on the ITO using spin coating, and dried at 150 °C for 15 minutes to form a dense anodic interface layer. The synthesized polymer donors D1-D6 and the commercially available acceptor Y6 (purchased from Suzhou Nakai) were precisely dissolved in chloroform at a mass ratio of 1:1 or 1:1.2, and an active layer approximately 100 nm thick was deposited on the PEDOT:PSS layer using spin coating. Subsequently, a 20 nm cathode interface layer was formed by spin-coating a solution of 3,3'-(1,3,8,10-tetraanthrone[2,1,9-DEF:6,5,10-D'E'F']diisoquinoline-2,9(1H,3H,8H,10H)-diyl)bis(N,N-dimethylpropane-1-amine oxide) (PNDINO). Finally, a 100 nm thick Ag electrode was deposited under high vacuum, completing the device structure. The effective working area of ​​the fabricated solar cell is 4 mm². 2 All of the above device fabrication processes were carried out in a glove box protected by a nitrogen atmosphere.

[0095] The testing process used an AM1.5 standard light source, with radiance precisely controlled at 1 kW / m². 2 With the Keithley 2400 digital source meter, the JV curve of the device can be accurately measured to comprehensively evaluate its open-circuit voltage (V). oc ), short-circuit current density (J sc Key parameters include fill factor (FF) and power conversion efficiency (PCE).

[0096] Figure 2 The cyclic voltammetry curves of polymers D1 to D6 in Examples 1-6 of this invention are shown. The HOMO and LUMO energy levels were calculated using the cyclic voltammetry method and the following formulas, and the results are summarized in Table 1.

[0097] HOMO level E HOMO (eV)=−(E ox onset -E 1 / 2 (Fc / Fc+ )+4.8); LUMO level E LUMO (eV)=−(E red onset -E 1 / 2 (Fc / Fc + )+4.8).

[0098] Table 1 Summary of energy levels of polymers D1~D6

[0099] In this invention, D3 and D4 are used as reference materials. Their electron-withdrawing units do not incorporate fluorine atoms and do not use thiophene as a π-bridge, resulting in weak molecular conjugation planarity. Although cyclic voltammetry tests show that they have deep HOMO and LUMO energy levels and wide energy level gaps, their molecular structures are difficult to form highly ordered stacking in the solid state, limiting charge transport efficiency and light absorption performance. Therefore, when used as a single donor in organic solar cells, the overall device performance is limited.

[0100] In contrast, D1 and D2, by introducing a single fluorine atom and constructing a thiophene π-bridge, achieved moderate energy level tuning. Their deeper HOMO energy level, when matched with common acceptor materials, is beneficial for obtaining a higher theoretical open-circuit voltage and enhancing the charge transfer driving force after exciton dissociation. This reduces the probability of charge being trapped by defect states or undergoing bimolecular recombination during transport, which is beneficial for improving the device fill factor and stability.

[0101] While D5 and D6 enhance molecular planarity and film ordering through the introduction of difluorine atoms and thiophene π-bridges, their excessively high LUMO energy levels result in a small LUMO energy difference with the mainstream acceptor, leading to insufficient driving force for electron transfer from the donor to the acceptor. This severely affects exciton dissociation and charge separation efficiency, becoming a key factor limiting device performance when used as a single donor. However, the material's wide bandgap, shallow HOMO energy level, and excellent film ordering suggest unique application potential in wide-bandgap subcells within ternary blend systems or tandem cells.

[0102] Figure 3The images show the solution and film absorption spectra of polymers D1-D6 of this invention. In the spectral characterization of the six materials, D1, D2, D5, and D6 all exhibited significant 0-0 vibrational peaks, with D5 and D6 showing particularly prominent peaks. This indicates that D5 and D6 possess higher molecular planarity and structural rigidity, which is beneficial for forming highly ordered self-assembled aggregates during film formation and effectively suppressing geometric relaxation and non-radiative vibrations in the excited state. In contrast, D3 and D4, due to the lack of thiophene as a π-bridge, have weaker molecular conjugation planarity and are prone to structural distortion, resulting in less prominent 0-0 peaks and a wide but unfocused spectral absorption range, which is detrimental to improving light absorption and charge transport performance. Furthermore, all materials exhibited a spectral redshift upon transitioning from solution to film, confirming a general enhancement of intermolecular π-π interactions in the solid state, providing a necessary physical basis for charge transport.

[0103] Figure 4 Table 2 shows the current-voltage curves of the organic solar cell device fabricated using polymer D2 as the electron donor material in Example 2 of this invention. Table 2 also shows the device performance parameters of the organic solar cell based on polymer D2 as the electron donor material and Y6 as the electron acceptor material.

[0104] Table 2 Summary of performance parameters of organic solar cells

[0105] Depend on Figure 4 As shown in Table 2, polymer D6 was selected as the acceptor material for the active layer according to the principle of material energy level matching in this invention, and the final efficiencies obtained by device testing were 14.45% and 14.92%, respectively.

[0106] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A conjugated polymer containing a 1,3-benzothiazole-2-amide structure, characterized in that, It has the following general structural formula: ； In the formula, n is the degree of aggregation, which is an integer from 3 to 5000, and a+b=100%; Ar is a conjugated structural unit selected from the following groups: thiophene and its derivatives, benzene and its derivatives, pyrrole and its derivatives, benzofuran and its derivatives, benzothiophene and its derivatives, benzodithiophene and its derivatives, benzothiadiazole and its derivatives; BTZA is a 1,3-benzothiazole-2-amide structural unit, selected from any of the following structures: or ; In the formula, X and Y are independently selected from H, F, Cl, Br, and I; R1, R2, R3, and R4 are independently selected from C1 to C2. 20 Straight-chain alkyl, branched alkyl, cyclic alkyl and their derivatives, wherein the cyclic alkyl is a monocyclic or polycyclic ring having 5 to 20 atoms.

2. The conjugated polymer containing a 1,3-benzothiazole-2-amide structure according to claim 1, characterized in that, In R1, R2, R3, and R4, the derived alkyl group is one or more of the -CH2- groups independently replaced by -O-, -S-, -C(=O)-, -C(=S)-, -C(=O)-O-, -OC(=O)-, -NRO-, -CF2-, or -NR. 0 -、-SiR 0 R 00 -、-CF 2 -、-CR 0 = CR 00 Alternatively, -C≡C- can be replaced by a molecular structure in which O or S atoms are not directly connected to each other; where R 0 R 00 Is it H or C? 1-12 A straight-chain or branched alkyl group, wherein one or more H atoms are independently replaced by F, Cl, Br, I or CN, and wherein one or more CH2 or CH3 groups are independently replaced by cationic groups, anionic groups, aryl, heteroaryl, aryloxy or heteroaryloxy groups.

3. The conjugated polymer containing a 1,3-benzothiazole-2-amide structure according to claim 1, characterized in that, The conjugate structural unit Ar is selected from any of the following structural formulas: , , , , , , , , , , , , , , , , , , , , , , , , , , , , or ; In the above general structural formula, R5 and R6 are independently H or C1~C. 20 Straight-chain alkyl, branched alkyl, cyclic alkyl and their derivative alkyl groups, wherein one or more -CH2- groups are independently replaced by -O-, -S-, -C (=O)-, -C (=S)-, -C(=O)-O-, -OC(=O)-, -NRO-, -CF2- or -C≡C- in such a way that the O or S atoms are not directly connected to each other, and / or one or more H atoms are independently replaced by F, Cl, Br, I or CN, and / or one or more CH2 or CH3 groups are independently replaced by cationic groups, anionic groups, aryl, heteroaryl, aryloxy or heteroaryloxy groups; X1 is selected from H, F, Cl, Br, I.

4. A method for preparing the conjugated polymer according to claim 1, characterized in that, When the 1,3-benzothiazole-2-amide structural unit has the following structural formula, the method for preparing the conjugated polymer includes the following steps: ； S1.1: Compound I was mixed with oxalyl chloride and subjected to a monosubstitution reaction; then triethylamine and compound II were added to the reaction solution and subjected to an acid-amine condensation reaction to obtain compound III; S1.2: Compound III is mixed with compound Me3Sn-Ar-SnMe3 and subjected to Stille polymerization under palladium catalyst to obtain a conjugated polymer containing a 1,3-benzothiazole-2-amide structure. When the 1,3-benzothiazole-2-amide structural unit has the following structural formula, the method for preparing the conjugated polymer includes the following steps: ； S2.1: Compound III and compound IV are mixed and reacted under the catalysis of a palladium catalyst to obtain compound V; S2.2: Compound V was mixed with N-bromosuccinimide to undergo a substitution reaction, yielding compound VI; S2.3: Compound VI is mixed with compound Me3Sn-Ar-SnMe3 and subjected to Stille polymerization under palladium catalyst to obtain a conjugated polymer containing a 1,3-benzothiazole-2-amide structure. The structural formulas of compounds I, II, III, IV, V, and VI are as follows: ， ， ， ， ， 。 5. The method for preparing the conjugated polymer according to claim 4, characterized in that, In step S1.1, the molar ratio of compound I, oxalyl chloride, and compound II is 1: (1.2-2.5): (1.2-2.5).

6. The method for preparing the conjugated polymer according to claim 4, characterized in that, In step S2.1, the molar ratio of compound III, compound IV and palladium catalyst is 1: (1.1-1.5): (0.01-0.05); In step S2.2, the molar ratio of compound V to N-bromosuccinimide is 1:(1.1-1.5).

7. The method for preparing the conjugated polymer according to claim 4, characterized in that, In step S1.2, the feeding ratio of the sum of the molar amounts of compound III, Me3Sn-Ar-SnMe3, and the molar amount of palladium catalyst is 2: (0.01-0.05). In step S2.3, the feeding ratio of the sum of the molar amounts of compound VI, Me3Sn-Ar-SnMe3 to the molar amount of palladium catalyst is 2: (0.01-0.05).

8. A hole transport type thin film, characterized in that, Made from the conjugated polymer containing a 1,3-benzothiazole-2-amide structure as described in any one of claims 1-3; The hole transport thin film is prepared by coating a conjugated polymer, which serves as an electron donor material, with an electron acceptor material at a mass ratio of 1:(1.0-1.2).

9. An organic photovoltaic cell device, characterized in that, Includes the hole transport type thin film as described in claim 8; The hole transport thin film serves as the active layer of the organic photovoltaic cell device.

10. The organic photovoltaic cell device according to claim 9, characterized in that, The organic photovoltaic cell device, from bottom to top, includes an ITO substrate, an anode interface layer, a hole transport thin film, a cathode interface layer, and an Ag electrode. The composition of the anode interface layer is PEDOT:PSS; The thickness of the hole transport thin film is 80-120 nm; The thickness of the cathode interface layer is 15-25 nm; The thickness of the Ag electrode is 80-120 nm.

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