Conjugated block copolymers with a two-layer acceptor conformation and applications thereof

Abstract

A kind of conjugated block copolymer with double-layer acceptor conformation and its application, the structure general formula of the copolymer is as follows: the structure induces the torsion of donor-acceptor main chain, changes the stacking form between molecules, forms J-type aggregation solid state dominated by slip stacking, enhances the stress dissipation capacity of thin film, and the double-layer conformation can also form intramolecular end group π-π stacking, which helps to improve the photovoltaic performance.The invention successfully applies double-layer acceptor strategy to single-component system, providing a new idea for developing high-efficiency, high-stability wearable organic solar cells.

Description

Technical Field

[0001] This invention belongs to the field of organic optoelectronic materials and devices, specifically relating to a class of conjugated block copolymers with a bilayer acceptor conformation and their application in single-component organic solar cells. Background Technology

[0002] Organic solar cells (OSCs) have shown broad application prospects due to their advantages such as light weight, flexibility, and solution-processability. The efficiency of OSCs based on bulk heterojunction (BHJ) structures has exceeded 21%, but the kinetically metastable morphology formed by the blending of donors and acceptors in their active layer is prone to phase separation under heat or light, resulting in poor long-term device stability, which has become a core bottleneck for commercialization.

[0003] To overcome this problem, single-component organic solar cells (SC-OSCs) have emerged. Among them, conjugated block copolymers (CBCs), which connect donor and acceptor segments to the same molecular chain via covalent bonds, can significantly improve morphological stability. However, existing CBCs face a core photophysics challenge: the covalently locked DA structure results in weak chain mobility and easy stacking into brittle thin films, which does not meet the requirements of flexible electronics and other applications. Furthermore, the intrinsically rigid molecular framework and the lack of an effective mechanical deformation energy dissipation mechanism make it difficult to balance the photoelectric performance and mechanical flexibility of SC-OSCs.

[0004] Researchers have made various attempts to address the issue of mechanical flexibility. For example, Professor Shao Ming's research group (D. Zhang, et al. “Twisted” Terpolymer Donor Enabling High-PerformanceIntrinsically Stretchable Organic Solar Cells. Angewandte Chemie International Edition 2025, e202509160) introduced Th-BO units into PM6 to construct a twisted ternary donor. By moderately twisting the main chain to increase the amorphous region and improve stretchability, while retaining conjugation to ensure efficient transport, they ultimately achieved an efficiency of 18.3% and a crack strain of 23.8%. The stretchable device reached 14.2% and maintained 80% of its performance at 31% strain, providing a key molecular design paradigm for wearable OPVs.

[0005] Recently, Professor Yan He's research group (Yu, H., et al. A polymer acceptor with double-decker configuration enhances molecular packing for high-performance all-polymer solar cells. Journal 2024, 8, 2304-2324) reported a polymer acceptor PffBQx-T with a double-decker configuration constructed through a core-core polymerization method. This double-core-core connected polymer acceptor inherently possesses an authentic twisted conformation, intramolecular π-π stacking, and weak interchain interactions, generally exhibiting a tendency for J aggregation rather than forming brittle H aggregation. Introducing it into a single-component system allows for precise control of the degree of twist in the single component without disrupting conjugation, increasing the amorphous region, and improving the film's stretchability and mechanical toughness, achieving a balance between photoelectric conversion efficiency (PCE) and flexibility.

[0006] In summary, developing a class of CBC materials that can both utilize the stacking advantages of bilayer acceptor configurations and covalently link them with donor blocks to regulate the twisted conformation of molecular chains is of great significance for overcoming the performance bottleneck of SC-OSC. Summary of the Invention

[0007] The present invention aims to provide a class of conjugated block copolymers with a bilayer acceptor conformation. By introducing a bilayer acceptor conformation and modifying the stacking form, the stress dissipation ability of the thin film is enhanced, which solves the problems of poor mechanical properties of existing SC-OSC, which cannot meet the requirements of organic photovoltaic stretching, wearables and other applications, and the commercialization is limited by this.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A class of conjugated block copolymers with a bilayer acceptor conformation comprising an electron donor block and an electron acceptor block, wherein the electron donor block and the electron acceptor block are covalently linked, and the electron acceptor block has a bilayer conformation formed by a nucleus-nucleus polymerization process.

[0010] First, in the bilayer conformation of the CBC, the donor and acceptor blocks exhibit a non-coplanar twisted conformation with a dihedral angle greater than 15° (preferably 16-23°), enhancing stress dissipation and improving flexibility. Second, in the bilayer conformation of the electron acceptor blocks, intramolecular π-π stacking is formed between the terminal groups of adjacent acceptor monomer units, which is beneficial for improving photovoltaic performance. The copolymer is represented by the following general formula:

[0011]

[0012] Ar1 can be any of the following groups:

[0013]

[0014] Ar2 can be any of the following groups:

[0015]

[0016] Ar3 can be any of the following groups:

[0017]

[0018] Ar4 can be any of the following groups:

[0019]

[0020] Ar5 can be any of the following groups:

[0021]

[0022] X1 is an oxygen, sulfur, or selenium atom; X2 is a hydrogen or halogen atom; R, R1, R2, R3, R4, R5, and R6 are hydrogen, halogen, or C1-C atoms. 30 Alkyl, C1-C 10 The alkoxy, haloalkyl, heteroalkyl, aralkyl, aryl, ester, and cyano groups.

[0023] As a preferred embodiment, the electron donor block is PM6 (poly[bis(2-ethylhexyl)-thieno[3,4-b]thiophene-π-carboxylic acid ester-alternating-thiophene]), with the following structural formula:

[0024]

[0025] The electron acceptor block is a polymer acceptor PffBQx-T or PffBQx-TT based on a quinoxaline unit, and the structural formula of its monomer BQx-4F is as follows:

[0026]

[0027] The structural diagram of the conjugated block copolymer PM6-b-PffBQx-T is shown below:

[0028]

[0029] The structural diagram of the conjugated block copolymer PM6-b-PffBQx-TT is shown below:

[0030]

[0031] Furthermore, the conjugated block copolymer is PM6-b-PffBQx-T or PM6-b-PffBQx-TT.

[0032] The present invention also protects a single-component organic solar cell made from this type of material, characterized in that the active layer of the single-component organic solar cell contains the conjugated block copolymer described in any of the above technical solutions.

[0033] The structure of the single-component organic solar cell is an anode / hole transport layer / active layer / electron transport layer / cathode, wherein the active layer is composed solely of the conjugated block copolymer, or is composed of the conjugated block copolymer and a linear conjugated block copolymer (preferably PM6-b-PYIT polymerized via an end-to-end group approach).

[0034] The structural diagram of the conjugated block copolymer PM6-b-PYIT is shown below.

[0035]

[0036] Furthermore, the present invention also protects an intrinsically stretchable organic solar cell, characterized in that the active layer of the intrinsically stretchable organic solar cell contains the conjugated block copolymer described in any of the above-mentioned technical solutions.

[0037] Compared with the prior art, this invention is the first to apply the bilayer acceptor conformation to a single-component conjugated block copolymer system, achieving unexpected technical effects:

[0038] (1) Excellent mechanical flexibility: Compared with linear CBC, the twisted bilayer conformation of the present invention makes the film aggregation form tend to be J-aggregate solid, which has better tensile properties. The crack initiation strain (COS) of PM6-b-PffBQx-T based on the present invention is increased to 21.80%. The intrinsically stretchable device prepared can still maintain more than 80% initial efficiency at 42.91% tensile strain, while the traditional device drops to 80% initial efficiency at 22.04% tensile strain.

[0039] (2) Significantly improved single-component device efficiency: The photoelectric conversion efficiency of the single-component device based on PM6-b-PffBQx-T of this invention reaches 15.20%, which is higher than the level of CBC-based single-component organic solar cells in the prior art and significantly better than the prior art (B. Li. et al. Enhanced Intramolecular Hole Transfer in Block Copolymer Enables >15% and Operational Stable Single-Material–Organic Solar Cells Advanced. Materials. 2024, 2408988). Attached Figure Description

[0040] Figure 1 The present invention provides a comparison of the molecular structures and DFT-simulated dihedral angles of linear conjugated block copolymers (PM6-b-PYIT) and bilayer conjugated block copolymers (PM6-b-PffBQx-T, PM6-b-PffBQx-TT). (a) shows schematic diagrams of the linear and bilayer conjugated structures; (b) shows the DFT calculation results of the torsion angles between the donor and acceptor units and the linker units.

[0041] Figure 2 The UV-Vis absorption spectrum and energy level diagram of the material of this invention are shown below. (a) is the UV-Vis absorption spectrum in chloroform solution; (b) is the UV-Vis absorption spectrum in thin film state; and (c) is the energy level diagram of the material used in this invention.

[0042] Figure 3 The temperature dependence test results of the materials of this invention are as follows: (a)-(c) temperature-dependent UV-Vis absorption curves of PM6-b-PYIT, PM6-b-PffBQx-T, and PM6-b-PffBQx-TT in chlorobenzene solution; (d) change in relative aggregation intensity.

[0043] Figure 4 The device structure and photoelectric performance characterization of a single-component organic solar cell based on the material of this invention are shown in the figure. (a) is a schematic diagram of the device structure (ITO / PEDOT:PSS / active layer / PNDIT-F3N / Ag); (b) is the steady-state photoluminescence (PL) spectrum; (c) is the time-resolved photoluminescence (TRPL) spectrum; and (d) is the photogenerated current density and effective voltage (J / L). ph -V eff (e) is a curve showing the relationship between the current density and voltage (JV) of a single-component device; (f) is a bar chart showing the hole and electron mobility; (c) is a curve showing the current density-voltage (JV) characteristic of a single-component device.

[0044] Figure 5The stability and thermal performance of devices based on the materials of this invention are characterized. Among them, (a)-(c) are the temperature-varying UV-Vis absorption spectra of the thin film; (d) is the glass transition temperature (Tg) measured by temperature-varying UV-Vis absorption spectroscopy; (e) is the thermal stability test result after 1000 hours at 85°C under a nitrogen atmosphere.

[0045] Figure 6 Mechanical properties characterization of intrinsically stretchable organic solar cells (is-OSCs) based on the materials of this invention. (a) shows the dihedral angle between the donor and acceptor blocks (DFT simulation); (b) shows the cosine initiation strain (COS) obtained by the water film method (FOW); (c)-(d) show the JV curves of PM6-b-PYIT and PM6-b-PffBQx-T based is-OSCs under different tensile strains; (e) shows the PCE variation with tensile strain; (f) shows photographs of the devices under tensile conditions; and (g)-(h) show optical microscope images of the thin films (PM6-b-PYIT and PM6-b-PffBQx-T) under 50% tensile strain. Detailed Implementation

[0046] The technical solution of the present invention will be further described in detail below through specific embodiments, and explained in conjunction with the accompanying drawings. It should be understood that these embodiments are only for illustrating the present invention, and do not constitute any limitation on the scope of protection of the present invention.

[0047] Example 1: Synthesis of PM6-b-PffBQx-T, a conjugated block copolymer with a bilayer acceptor conformation

[0048] (1) Synthesis of receptor monomer BQx-4F:

[0049]

[0050]

[0051]

[0052] (1-1) Synthesis of Compound 2: 300 mg of Compound 1 (0.229 mmol) was dissolved in 20 mL of anhydrous tetrahydrofuran. 156 mg of lithium aluminum hydride (4.2 mmol) was added to the solution at 0 °C. After cooling to room temperature, the solution was refluxed overnight. After stirring for 18 h, the reaction was quenched with water. The mixture was extracted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to obtain a brown crude oil. This product did not require further purification and was directly dissolved in 20 mL of anhydrous chloroform. 104.1 mg of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ, 0.459 mmol) was added to the solution, followed by 5 mL of 1 mol / L hydrochloric acid solution. The reaction mixture was stirred for 12 h. The crude product was purified by rapid column chromatography to obtain 103.1 mg of a green solid, which was Compound 2, with a yield of 35%.

[0053] (1-2) Synthesis of Compound 4: 103.1 mg of Compound 2 (0.0805 mmol) and 60.79 mg of Compound 3 (0.201 mmol) were dissolved in 20 mL of toluene, and 3 mL of glacial acetic acid was added to the resulting solution. After stirring for 6 h, the reaction mixture was extracted with dichloromethane and dried over anhydrous sodium sulfate. The crude product was purified by rapid column chromatography to give 89.7 mg of green solid, designated as Compound 4, with a yield of 87%.

[0054] (1-3) Synthesis of Compound 5: Vilsmeier's reagent was prepared by adding 2.4 mL of phosphorus oxychloride to 3 mL of anhydrous N,N-dimethylformamide at 0 °C. After stirring for 30 min, the reagent was added dropwise to 10 mL of 1,2-dichloroethane solution containing 89.7 mg (0.0580 mmol) of Compound 4 at the same temperature. The mixture was then cooled to room temperature and heated at 85 °C for 12 h. The reaction solution was washed with water, extracted with dichloromethane, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by rapid column chromatography to give 82.6 mg of red solid, which was Compound 5, with a yield of 89%.

[0055] (1-4) Synthesis of BQx-4F: 82.6 mg (0.0515 mmol) of compound 5 was dissolved in 10 mL of toluene, and acetic anhydride (0.1 mL), boron trifluoride diethyl ether complex (0.3 mL), and IC-2F (29.65 mg, 0.128 mmol) were added sequentially. The reaction tube was transferred to a microwave reactor and reacted at 60 °C for 1 h. The mixture was purified by rapid column chromatography and then recrystallized in methanol to give 79 mg of BQx-4F, with a yield of 76%.

[0056] (2) Synthesis of PM6 donor prepolymer:

[0057] Under argon protection, 3 mL of toluene was added to a polymerization tube containing BDT-2F (37.06 mg, 0.0394 mmol), BDD-2Br (30.60 mg, 0.0394 mmol), and Pd(PPh3)4 (5.01 mg). The reaction system was stirred and refluxed at 110 °C for 2 h to obtain PM6 prepolymer. The crude product was used directly in the next reaction without purification.

[0058] (3) Synthesis of PffBQx-T receptor prepolymer (C2C polymerization):

[0059] Under an argon atmosphere, 2 mL of toluene was added to a polymerization tube containing 2,5-bis(trimethyltinyl)thiophene (12.13 mg, 0.0296 mmol), BQx-4F (60 mg, 0.0296 mmol), Pd2(dba)3 (2.03 mg, 0.0022 mmol), and P(o-tolyl)3 (2.07 mg, 0.0089 mmol). The reaction mixture was stirred and refluxed at 110 °C for 10 h to obtain the PffBQx-T prepolymer. The crude product was used directly in the next reaction without purification.

[0060] (4) Block copolymerization:

[0061] The pre-prepared PM6 prepolymer was then added to the reaction system of the PffBQx-T prepolymer using a syringe. The new reaction system was vigorously stirred at 110 °C for 72 h. The mixture was then poured into 150 mL of methanol and filtered. The dried precipitate was purified by Soxhlet extraction with methanol, acetone, and n-hexane, respectively, for 5 h with each solvent. Finally, the product was extracted with chloroform. The chloroform-extracted solution was concentrated in warm chloroform and then purified by passing it through a pre-prepared 80-100 mesh wet silica gel column using chloroform as the eluent. The collected chloroform solution was concentrated and precipitated in methanol to obtain the dark black solid product PM6-b-PffBQx-T.

[0062] Structural characterization: such as Figure 1 As shown in (a), the PM6-b-PffBQx-T synthesized in this invention has a significantly different molecular conformation from the linear control PM6-b-PYIT. Figure 1 (b) The DFT calculation results show that the average torsion angle of PM6-b-PffBQx-T is 22.8°, while that of PM6-b-PYIT is only 10.9°, proving that the present invention has successfully constructed a twisted molecular skeleton.

[0063] Example 2: Synthesis of PM6-b-PffBQx-TT, a conjugated block copolymer with a bilayer acceptor conformation

[0064] Referring to Example 1, the difference lies in step (3): 2,5-bis(trimethyltin)thiophene is replaced with an equimolar amount of thiophene[3,2-b]thiophene-2,5-bis(trimethyltin) (12.13 mg, 0.0296 mmol), while the remaining steps are exactly the same, ultimately yielding the target product PM6-b-PffBQx-TT. Its average torsion angle calculated by DFT is 16.6° ( Figure 1 (c)).

[0065] Comparative Example 1: Synthesis of the conventional linear CBC material PM6-b-PYIT

[0066] Following previously reported methods, PM6-b-PYIT was prepared using a traditional end-group linked polymerization method as a comparative material. Its molecular conformation is nearly coplanar. Figure 1 (c), with a twist angle of 10.9°.

[0067] Example 3: Optical and Electrochemical Performance Testing

[0068] The CBC materials from Examples 1, 2 and Comparative Example 1 were dissolved in chloroform (10 mg / mL) and spin-coated into films, and then subjected to UV-Vis absorption spectroscopy and cyclic voltammetry tests.

[0069] like Figure 2 As shown in (a), the absorption peak positions of the three materials in chloroform solution are similar: PM6-b-PYIT at 798 nm, PM6-b-PffBQx-T at 782 nm, and PM6-b-PffBQx-TT at 784 nm. Figure 2 As shown in (b), in the thin film state, the absorption peaks of PM6-b-PffBQx-T and PM6-b-PffBQx-TT are red-shifted to 803 nm and 804 nm, respectively, a redshift of approximately 20 nm, while PM6-b-PYIT is only red-shifted to 808 nm, a redshift of 10 nm. This indicates that bilayer conformation materials are more prone to forming slip-stacking J-type aggregates, which, compared to H-type aggregates in linear materials, can reduce the crystalline region and thus effectively enhance the stress dissipation capability of the thin film.

[0070] Figure 2 The energy level diagram in (c) shows that the LUMO / HOMO energy levels of PM6-b-PYIT, PM6-b-PffBQx-T, and PM6-b-PffBQx-TT are -3.59 / -5.58 eV, -3.61 / -5.62 eV, and -3.61 / -5.60 eV, respectively, and the differences in energy levels among the three are negligible.

[0071] Example 4: Aggregation behavior research further validates aggregation behavior through temperature-dependent tests, such as... Figure 3 The results of temperature-dependent UV-Vis absorption spectroscopy of solutions (a)-(d) show that the absorption peak intensity of bilayer molecules decreases more significantly, which is consistent with the structural characteristics of J aggregates being more sensitive to temperature.

[0072] Example 5: Fabrication and Performance of Single-Component Organic Solar Cells

[0073] Device structure: such as Figure 4 As shown in (a), the device structure is ITO / PEDOT:PSS / active layer / PNDIT-F3N / Ag. Specific preparation steps: The patterned ITO glass substrate was sequentially ultrasonically cleaned with detergent, deionized water, acetone, and isopropanol for 30 minutes each, dried, and then subjected to UV-ozone treatment for 15 minutes. PEDOT:PSS (Al 4083) was spin-coated at 5000 rpm for 30 seconds, followed by annealing at 150°C for 15 minutes to obtain a hole transport layer approximately 30 nm thick. The CBC materials from Examples 1, 2, and Comparative Example 1 were dissolved in chloroform (10 mg / mL, containing 0.5% CN additive), and spin-coated at 2000 rpm to obtain an active layer approximately 120 nm thick, followed by annealing at 100°C for 5 minutes. Then, PNDIT-F3N (10 mg / mL in methanol) was spin-coated at 3000 rpm for 30 seconds to obtain an electron transport layer approximately 10 nm thick. Finally, a 100 nm Ag electrode was deposited by vapor deposition.

[0074] Photoelectric properties: such as Figure 4 As shown in the PL spectrum in (b), PM6-b-PffBQx-T exhibits the lowest fluorescence intensity and the highest quenching efficiency at 660 nm. Figure 4 (c) TRPL shows that the exciton lifetime of PM6-b-PffBQx-T is only 0.268 ns, which is shorter than that of PM6-b-PYIT (0.315 ns), indicating that the exciton dissociation is the fastest. Figure 4 (d) J ph -V eff The exciton dissociation probability (η) is obtained by curve calculation. diss ): PM6-b-PffBQx-T was 91.2%, PM6-b-PffBQx-TT was 89.6%, and PM6-b-PYIT was 87.3%. Figure 4 (e) SCLC mobility tests showed that the hole / electron mobility of PM6-b-PffBQx-T was 3.59 × 10⁻ 4 / 2.94×10⁻ 4 cm²V⁻¹s⁻¹, PM6-b-PYIT is 3.98×10⁻ 4 / 3.19×10⁻ 4 cm²V⁻¹s⁻¹, PM6-b-PffBQx-TT is 3.13×10⁻4 / 2.52×10⁻ 4 cm²V⁻¹s⁻¹.

[0075] JV characteristics: such as Figure 4 As shown in (f), the device based on PM6-b-PffBQx-T has the following parameters: Voc = 0.921 V, Jsc = 23.66 mA / cm², FF = 69.57%, and PCE = 15.20%; based on PM6-b-PYIT, PCE = 14.90%; and based on PM6-b-PffBQx-TT, PCE = 14.35%.

[0076] Example 6: Thermal stability test

[0077] like Figure 5 (a)-(c), Glass transition temperature T was measured by temperature-dependent UV-Vis absorption spectroscopy of thin films. g . , Figure 5 (d) Displaying PM6-b-PYIT T g =136 ℃, T of PM6-b-PffBQx-T g =128 ℃, T of PM6-b-PffBQx-TT g =117℃. The device was annealed at 85℃ in a nitrogen atmosphere for 1000 hours, as... Figure 5 As shown in (e), all CBC-based devices retain more than 90% of their initial efficiency, while the traditional BHJ device (PM6:L8-BO) retains only 70%, demonstrating that the material of this invention has excellent thermal stability.

[0078] Example 8: Fabrication and Mechanical Properties of Intrinsically Stretchable Devices

[0079] Molecular conformation and orientation: Figure 6 (a) DFT simulations show that the donor-acceptor dihedral angles of the bilayer CBC structure (PM6-b-PffBQx-T is 11.2° and PM6-b-PffBQx-TT is 37.9°) are significantly greater than those of the linear PM6-b-PYIT (9.8°), indicating better molecular flexibility.

[0080] Tensile properties: Figure 6 The water film method (FOW) test showed that the crack initiation strain (COS) of PM6-b-PffBQx-T was 21.80%, and that of PM6-b-PffBQx-TT was 23.78%, both of which were better than the 16.35% of PM6-b-PYIT.

[0081] Device tensile testing: Fabrication of intrinsically stretchable devices (structure as above, but using a flexible stretchable substrate with an active layer thickness of approximately 200 nm). Figure 6(c)-(d) are the JV curves under different tensile strains. Figure 6 (e) shows the PCE retention rate as a function of strain. The device based on PM6-b-PffBQx-T retains more than 80% of its initial efficiency at a strain of 42.91% (initial PCE = 11.42%, PCE = 9.14% at 42.91% strain), while the PCE of the PM6-b-PYIT device drops to 80% of the initial PCE at a tensile strain of 22.04% (initial PCE = 11.27%, PCE = 9.02% at 22.04% strain). Figure 6 (f) is a photograph of the device under tension. Figure 6 Optical microscopy images (g)-(h) show that, when stretched to 50% strain, the PM6-b-PffBQx-T film exhibits significantly fewer cracks than the PM6-b-PYIT film. These results demonstrate the immense application potential of the material of this invention in the field of wearable photovoltaics.

[0082] Although the invention has been described in conjunction with preferred embodiments, the invention is not limited to the above embodiments, and it should be understood that the appended claims summarize the scope of the invention. Guided by the inventive concept, those skilled in the art should recognize that any modifications made to the embodiments of the invention will be covered by the spirit and scope of the claims.

Claims

1. A class of conjugated block copolymers having a bilayer acceptor conformation, characterized in that, The conjugated block copolymer comprises an electron donor block and an electron acceptor block, wherein the electron donor block and the electron acceptor block are covalently linked, and the electron acceptor block has a bilayer conformation formed by nucleo-nucleopolymerization; the copolymer is represented by the following general formula: Ar1 is selected from any of the following groups: Ar2 is selected from any of the following groups: Ar3 is selected from any of the following groups: Ar4 is selected from any of the following groups: Ar5 is selected from any of the following groups: X1 is an oxygen, sulfur, or selenium atom; X2 is a hydrogen or halogen atom; R, R1, R2, R3, R4, R5, and R6 are each independently selected from hydrogen, halogen, or C1-C atoms. 30 Alkyl, C1-C 10 The alkoxy, haloalkyl, heteroalkyl, aralkyl, aryl, ester or cyano groups.

2. The conjugated block copolymer according to claim 1, characterized in that, The electron donor block and the electron acceptor block are in a non-coplanar twisted conformation with a dihedral angle greater than 15°, preferably 16-23°.

3. The conjugated block copolymer according to claim 1, characterized in that, In the electron acceptor block with a bilayer conformation, intramolecular π-π stacking is formed between the terminal groups of adjacent acceptor monomer units.

4. The conjugated block copolymer according to claim 1, characterized in that, The electron donor block is PM6, and its structural formula is: The electron acceptor block is a polymer acceptor PffBQx-T or PffBQx-TT based on a quinoxaline unit, and the structural formula of its monomer BQx-4F is as follows: 。 5. The conjugated block copolymer according to claim 4, characterized in that, The conjugated block copolymer is PM6-b-PffBQx-T, and its structural formula is: Or it could be PM6-b-PffBQx-TT, with the following structural formula: 。 6. A method for preparing the conjugated block copolymer according to any one of claims 1-5, characterized in that, This includes synthesizing an electron donor prepolymer and an electron acceptor prepolymer with a bilayer conformation separately via Stille condensation reaction, and then mixing the two for block copolymerization.

7. The preparation method according to claim 6, characterized in that, In the synthesis step of the electron acceptor prepolymer, a conjugated bridging unit substituted with bis(trimethyltin) is used to polymerize with the acceptor monomer BQx-4F. The conjugated bridging unit is preferably 2,5-bis(trimethyltin)thiophene or thieno[3,2-b]thiophene-2,5-bis(trimethyltin).

8. A single-component organic solar cell, comprising an anode, a cathode, and an active layer located between the anode and the cathode, characterized in that, The active layer comprises the conjugated block copolymer according to any one of claims 1-5.

9. The single-component organic solar cell according to claim 8, characterized in that, The active layer further comprises a linear conjugated block copolymer, wherein the donor-acceptor backbone of the linear conjugated block copolymer is in a coplanar conformation; preferably, the linear conjugated block copolymer is PM6-b-PYIT prepared by end-to-end polymerization, and its structural formula is: 。 10. An intrinsically stretchable organic solar cell, characterized in that, Its active layer comprises the conjugated block copolymer as described in any one of claims 1-5.

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