A non-fullerene acceptor with spatial confinement crystallization characteristics and a preparation method and application thereof

Abstract

This invention discloses a non-fullerene acceptor with vertically confined crystallization (VSC) characteristics, its preparation method, and its applications, comprising asymmetric oligoethylene glycol side chains (OEG). The non-fullerene acceptor (AT-β2O) of this invention exhibits high acceptor crystallinity and can be used to construct active layers with good vertical phase separation (enrichment of the acceptor phase near the cathode interface). Single-junction OSCs fabricated based on the VSC-equipped non-fullerene acceptor demonstrate excellent film thickness independence within the active layer thickness range of 100 nm to 400 nm. These advantages pave the way for the fabrication of high-efficiency, large-area devices. Furthermore, the VSC-equipped non-fullerene acceptor enhances device operational stability through strong interactions with other acceptor molecules. Moreover, the VSC-equipped non-fullerene acceptor exhibits good compatibility with different active layer systems, solvents, processing methods, and post-processing techniques, thus demonstrating excellent versatility.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic materials, specifically relating to the application of non-fullerene acceptors with spatially confined crystallization properties in solar cells. Background Technology

[0002] Organic solar cells (OSCs) are a promising solar energy technology. Researchers have made significant efforts in device engineering, modification of photovoltaic material molecular structures, and optimization of active layer morphology, resulting in a photoelectric conversion efficiency (PCE) exceeding 19% for OSCs. However, high-efficiency OSCs are typically achieved with active layer thicknesses around 100 nm, which makes it difficult to produce uniform and defect-free films in high-throughput industrial fabrication. Therefore, using thicker active layers exceeding several hundred nanometers can significantly expand the printing process window, which is crucial for meeting the requirements of large-scale manufacturing. However, increasing the active layer thickness usually leads to a decrease in PCE. Therefore, developing efficient "thick-film" OSCs is essential to meet the requirements of high-throughput roll-to-roll manufacturing. Summary of the Invention

[0003] To address the aforementioned issues, the present invention aims to provide a non-fullerene acceptor with spatially confined crystallization properties and its preparation method, overcoming the limitation of existing non-fullerene acceptors in achieving high performance in thick films, laying the foundation for their large-area preparation, and promoting the industrialization of organic solar cells.

[0004] To achieve the above-mentioned technical objectives, the present invention provides the following technical solution: a non-fullerene acceptor with spatially confined crystallization properties, containing ethylene glycol groups, preferably having asymmetric oligomeric ethylene glycol chains; its chemical structural formula is one of the following:

[0005]

[0006] Among them, X1, X2, X3, and X4 are independently selected from one of O, S, Se, and Te; D1 to D4 are independently selected from H, CH3, OCH3, F, Cl, Br, CF3, CN, and C. a H 2a+1 One of them, where a is 1 to 20;

[0007] End bases A1 and A2 are independently selected from one of the following structural formulas:

[0008]

[0009] B1 and B2 are independently selected from or B3 to B8 are independently selected from H, CH3, OCH3, F, Cl, Br, CF3, CN, and C.b H 2b+1 One of them, where b is 1 to 20;

[0010] R1 is -C n H 2n+1 , where n is 1 to 20; R2 is -(CH2CH2O). m CH3 or -C n H 2n+1 Where m is 1–10, n is 1–20; R3 is -(CH2CH2O). m CH3 or -C n H 2n+1 Where m is 1–10, n is 1–20; R4 is hydrogen, -(CH2CH2O) m CH3 or -C n H 2n+1 Where m is 1–10, n is 1–20; R5 is hydrogen, -(CH2CH2O) m CH3 or -C n H 2n+1 , where m is 1 to 10 and n is 1 to 20;

[0011] In Equations 1, 4, 5, and 6, R2 and R3 are different; in Equation 2, R2, R3, and R4 are not completely the same; in Equation 3, R2, R3, R4, and R5 are not completely the same.

[0012] In the above technical solution, R1 is -C n H 2n+1 Where n is 3 to 10; R2 is -(CH2CH2O). m CH3 or -C n H 2n+1 Where m is 1–5, n is 5–15; R3 is -(CH2CH2O). m CH3 or -C n H 2n+1 Where m is 1–5 and n is 5–15; R4 is hydrogen or -C n H 2n+1 Where n is 3 to 15; R5 is hydrogen or -C n H 2n+1 , where n is 3 to 15.

[0013] This invention discloses a method for preparing a spatially confined crystallizing non-fullerene acceptor, comprising the following steps: reacting a DA'D type conjugated core with an electron-withdrawing terminal group to obtain a spatially confined crystallizing non-fullerene acceptor. Preferably, the reaction is carried out under nitrogen protection, in a solvent, and in the presence of a catalyst, for a reaction time of 10–30 hours and a temperature of 50–80°C; the molar ratio of the DA'D type conjugated core to the electron-withdrawing terminal group is 1:(1–10), preferably 1:(2–6). The solvent is chloroform, dichloromethane, toluene, etc.; the catalyst is an organic small molecule catalyst, such as pyridine.

[0014] In the above technical solution, the chemical structural formula of the DA'D type conjugated nucleus is one of the following structural formulas:

[0015]

[0016] The electron-withdrawing terminal group can be independently selected from one of the following compounds:

[0017]

[0018] In the above structural formulas, the selection of substituents (X1, X2, X3, X4, B1 to B8, R1, R2, R3, R4, R5) is the same as the selection of substituents in formulas 1 to 6 above.

[0019] This invention discloses the application of the above-mentioned non-fullerene acceptor with spatially confined crystallization in the preparation of organic solar cells or active layers of organic solar cells.

[0020] This invention discloses the application of the aforementioned non-fullerene acceptor with spatially confined crystallization properties in improving the efficiency of ultra-thick active layer solar cells. Generally, the thickness of the ultra-thick active layer is greater than 100 nm, further greater than 150 nm, further greater than 200 nm, and even further greater than 250 nm.

[0021] In this invention, a non-fullerene acceptor with spatially confined crystallization having an ethylene glycol group means that the structural formula of the non-fullerene acceptor with spatially confined crystallization has one substituent as an ethylene glycol group, denoted by R1, R2, R3, R4, and R5. The ethylene glycol group can be a monoethylene glycol group, such as -(CH2CH2O)CH3, or an oligomeric ethylene glycol group, such as -(CH2CH2O). m CH3, m is 2–10. In the chemical structure of a non-fullerene acceptor with spatially confined crystallization, there may be one or more ethylene glycol groups. -C n H 2n+1 It represents branched-chain alkanes or straight-chain alkanes, and n is preferably 3 to 18, and more preferably 5 to 15.

[0022] The spatially confined crystallization non-fullerene acceptor of the present invention comprises an asymmetric oligoethylene glycol (OEG) chain. Its high crystallinity can induce additional crystal nucleation and promote molecular assembly, contributing to an increase in crystal nucleation sites. These nucleation sites can, in turn, stimulate molecular assembly through molecular interactions between acceptors. Therefore, the acceptor of the present invention enhances crystallinity and optimizes vertical phase separation within the active layer. As an example, based on the spatially confined crystallization acceptor of the present invention as the guest and D18-Cl:N3 as the host component, the PCE based on D18-Cl:N3:AT-β2O (100 nm) reached 20.24%, the open-circuit voltage was 0.892 V, and the fill factor was 80.34%. When the film thickness was 130 nm, the PCE of OSCs reached a record 20.82% (certified as 20.43%). Furthermore, when the film thickness is further increased to 250 nm and 400 nm, the device still maintains efficiencies as high as 19.15% and 17.93%, respectively, indicating that the addition of the spatially confined crystal acceptor significantly improves the film thickness independence. This invention also utilizes this spatially confined crystal acceptor to fabricate large-area components; the PCE of the device based on D18-Cl:N3:AT-β2O (250 nm) is as high as 18.36% (certified as 18.04%).

[0023] This invention discloses the application of the aforementioned spatially confined crystallization non-fullerene acceptor in the fabrication of organic solar cells. Specifically, the spatially confined non-fullerene acceptor of this invention is used as a guest to prepare the active layer of organic solar cells, especially the active layer of thick-film organic solar cells, which can obtain high-performance small-area devices and large-area modules. When the spatially confined crystallization non-fullerene acceptor disclosed in this invention is blended with the host active layer, a more stable microstructure and morphology can be obtained, and the resulting device has better operational stability.

[0024] This invention discloses an active layer material for organic solar cells, comprising the aforementioned spatially confined crystalline non-fullerene acceptor; further comprising a Y-series acceptor and a donor material. The aforementioned spatially confined crystalline non-fullerene acceptor serves as the guest material, while the Y-series acceptor and donor material serve as the host material, constituting the active layer for solar cells. The donor material is a conjugated polymer or a conjugated small organic molecule. The Y-series acceptor is 2,2'-(((12,13-bis(3-ethylheptyl)-3,9-bisundecyl-12,13-dihydro-[1,2,5]thiadiazo[3,4-e]thieno[2”,3”:4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-bis(5,6-difluoro-3-(dicyano) (methylene)indene-1-one)(N3), 2,2'-(((12,13-bis(2-ethylhexyl)-3,9-bisundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2”,3”:4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylene)indene-1-one)(Y6), 2,2'-(((12,13-bis(2-butyloctyl)-3,9-bisnonyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2”,3”:4,5]thieno[3,2-b]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylene)indene-1-one)(Y6), 2,2'-(((12,13-bis(2-butyloctyl)-3,9-bisnonyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno ... Diazolo[3,4-e]thieno[2”,3”:4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-bis(5,6-dichloro-3-(dicyanomethylene)indone)(BTP-eC9), 2,2'-(((12,13-bis(2-ethylhexyl)-3,9-bis(2-butyloctyl)-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2”,3”:4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2 [L8-BO] thieno[3,2-b]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylene)indole-1-one), 2,2'-(((12,13-bis(2-decyldodecyl)-3,9-bisundecyl-12,13-dihydro-[1,2,5]thiadiazo[3,4-e]thieno[2”,3”:4',5']thieno[2',3':4,5]pyrrolo[3,2-g]thieno[2',3':4,5]thieno[3,2-b]indole-2,10-bis(5,6-difluoro-3-(dicyanomethylene)indole-1-one) (DTY6), etc.;The donor material is poly[[4,8-bis(5-(2-ethylhexyl)-4-chlorothiophene-2-yl)benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][5,8-bis(4-(2-butyloctyl)thiophene-2-yl)dithiophene[3',2':3,4;2”,3”:5,6]benzo[1,2-c][1,2,5]thiadiazolediyl]](D18-Cl), poly[(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluorothiophene-2-yl)-benzo][1,2-b:4,5-b']dithiophene))-alt -(5,5-(1',30-bis-2-thiophene-50,7'-bis(2-ethylhexyl)benzo[1',2'-c:4',50-c']dithiophene-4,8-dione)(PM6), poly[[4,8-bis(5-(2-ethylhexyl)-4-fluorothiophene-2-yl)benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][5,8-bis(4-(2-butyloctyl)thiophene-2-yl)dithiophene[3',2':3,4;2”,3”:5,6]benzo[1,2-c][1,2,5]thiadiazolediyl]](D18), etc.;

[0025] This invention discloses an organic solar cell, comprising an active layer, a hole transport layer, an electron transport layer, and an electrode; the active layer comprises the aforementioned non-fullerene acceptor with spatially confined crystallization properties.

[0026] This invention discloses a method for preparing the above-mentioned organic solar cell, comprising the following steps: sequentially preparing a hole transport layer, an active layer, an electron transport layer, and an electrode on a conductive substrate to obtain an organic solar cell; wherein the active layer comprises the above-mentioned non-fullerene acceptor with spatially confined crystallization properties.

[0027] In this invention, when preparing the active layer, a conjugated polymer is used as the donor material, and Y-series conjugated small molecules (such as N3, L8-BO, BTP-eC9, and the star molecule Y6) and the aforementioned non-fullerenes with spatially confined crystallization properties are used as acceptor components. A mixed solution containing the donor and acceptor materials and the spatially confined crystallization properties of the non-fullerene acceptor is prepared using different processing solvents. The active layer film is then prepared using conventional solution processing methods, such as spin coating or blade coating. In the aforementioned mixed solution, the processing solvent is chloroform (CF), diphenyl ether (DPE), toluene (TL), p-xylene (PX), or o-xylene (OX); the concentration of the donor material is 5–20 mg / mL; and the mass fraction of the aforementioned non-fullerenes with spatially confined crystallization properties in the donor material is 0–50%, preferably 10–40%, and more preferably 15–30%. The inventiveness of this invention lies in using the aforementioned non-fullerene acceptor with spatially confined crystallization properties as the third component, and existing light-emitting layer materials (composed of existing donor and acceptor materials) as the main body, to achieve an active layer with film thickness independence. Furthermore, the non-fullerene acceptor with spatially confined crystallization properties has good compatibility with different active layer systems, processing solvents, processing methods, and post-processing techniques.

[0028] In the organic solar cell of this invention, the electron transport layer, hole transport layer, and electrodes are existing products, and the specific preparation methods for each layer are also conventional techniques. For example, the hole transport layer material is PEDOT:PSS, and the electron transport layer material is C. 60 / BCP, with silver electrodes, and an active layer thickness of 100–400 nm, particularly 200–400 nm. The inventiveness of this invention lies in disclosing a novel material as a non-fullerene acceptor possessing spatially confined crystallization properties, enabling the achievement of record-breaking high-performance batteries, while maintaining high PCE and other performance characteristics even in thick-film applications.

[0029] The beneficial effects of this invention:

[0030] 1. This invention creatively introduces asymmetric oligoethylene glycol chains into non-fullerene receptors to obtain non-fullerene receptors with spatially confined crystallization properties. Compared with existing high-efficiency non-fullerene receptors, it can regulate the molecular assembly process of other receptors, induce other receptors to preferentially form face-on orientation, and enhance long-range ordered molecular stacking (higher crystallinity).

[0031] 2. The non-fullerene acceptor with spatially confined crystallization properties disclosed in this invention, when incorporated into the host as a guest component, can regulate acceptor nucleation and molecular assembly, thereby improving the crystallinity of the active layer and optimizing vertical phase separation. This enables the preparation of high-performance OSCs in thick film conditions, solving the problem of thin film pinholes caused by low film thickness in the fabrication of large-area devices. This lays the foundation for the fabrication of large-area devices and has considerable application potential in the printing of large-area devices.

[0032] 3. When the non-fullerene acceptor with spatially confined crystallization properties disclosed in this invention is blended with the host donor-acceptor material, a more stable microstructure and morphology can be obtained, and the resulting device has better working stability.

[0033] 4. The non-fullerene acceptor with spatially confined crystallization properties disclosed in this invention, when added as a guest molecule to different active layer systems (with different solvents, post-processing techniques, and processing methods), can simultaneously improve photoelectric properties and film thickness independence. These results indicate that the non-fullerene acceptor with spatially confined crystallization properties is versatile and compatible with different active layers, solvents, processing methods, and post-processing techniques. Attached Figure Description

[0034] Figure 1 The hydrogen nuclear magnetic resonance spectrum of AT-β2O in Example X;

[0035] Figure 2 The carbon NMR spectrum of AT-β2O in Example X;

[0036] Figure 3 The matrix-assisted laser desorption / ionization time-of-flight mass spectrometry of AT-β2O in Example X;

[0037] Figure 4 The thermogravimetric curve of AT-β2O in Example X;

[0038] Figure 5 The cyclic voltammetry curve of AT-β2O in Example X;

[0039] Figure 6 The scattering curves of N3, AT-β2O and N3:AT-β2O along the directions a, IP and b, OOP in Example 1; c, the pole figure extracted by (010) diffraction of the corresponding thin film.

[0040] Figure 7 In Example 2, at AM 1.5G 100mW cm -2 JV curves of devices with different thicknesses of D18-Cl:N3 and D18-Cl:N3:AT-β2O based on chloroform / diphenyl ether processing;

[0041] Figure 8 The images show cross-sectional SEM images and corresponding EDS spectra of D18-Cl:N3 (400 nm) and D18-Cl:N3:AT-β2O (400 nm) processed by chloroform / diphenyl ether deposited on ITO in Example 2.

[0042] Figure 9 The molecular structures of PM6, Y6, BTP-eC9, D18, L8-BO and DTY6 in Example 3 are shown.

[0043] Figure 10 In Example 3, at AM 1.5G 100mW cm -2 JV curves of devices with different thicknesses of PM6:Y6 and PM6:Y6:AT-β2O based on chloroform processing under irradiation;

[0044] Figure 11 In Example 4, at AM 1.5G 100mW cm -2 JV curves of PM6:BTP-eC9 and PM6:BTP-eC9:AT-β2O devices with different thicknesses processed in chloroform under irradiation;

[0045] Figure 12 In Example 5, at AM 1.5G 100mW cm -2 JV curves of devices with different thicknesses of PM6:L8-BO and PM6:L8-BO:AT-β2O based on chloroform processing under irradiation;

[0046] Figure 13 In Example 6, at AM 1.5G 100mW cm -2 JV curves of devices based on PM6:L8-BO and PM6:L8-BO:AT-β2O with different thicknesses processed with toluene under irradiation;

[0047] Figure 14 In Example 7, at AM 1.5G 100mW cm -2 JV curves of devices based on different thicknesses of p-xylene-processed D18:L8-BO and D18:L8-BO:AT-β2O under irradiation;

[0048] Figure 15 In Example 8, at AM 1.5G 100mW cm -2 JV curves of devices based on PM6:DTY6 and PM6:DTY6:AT-β2O with different thicknesses processed with o-xylene under irradiation;

[0049] Figure 16In Example 9, at AM 1.5G 100mW cm -2 JV curves of OSC modules based on chloroform / diphenyl ether processed D18-Cl:N3 and D18-Cl:N3:AT-β2O films (250 nm) under irradiation;

[0050] Figure 17 This is an LBIC image of the large-area component in Example 9;

[0051] Figure 18 The molecular formula of the comparative material BT-β2O in the comparative examples is shown below;

[0052] Figure 19 In the comparative example, at AM 1.5G 100mW cm -2 JV curves of devices with different thicknesses of D18-Cl:N3:AT-β2O and D18-Cl:N3:BT-β2O processed with chloroform / diphenyl ether under irradiation. Detailed Implementation

[0053] Currently, most OSCs employ a bulk heterojunction (BHJ) structure, where electron donors (D) and electron acceptors (A) are mixed to form a bicontinuous interpenetrating D / A network. Photogenerated excitons initially diffuse through the D / A phase to the D / A interface, and then, driven by the energy difference between the donor and acceptor materials, dissociate into charge carriers, overcoming the exciton binding energy. Therefore, the exciton diffusion length (L...) D The exciton density at the DA interface has a significant impact on device performance because it determines the exciton density reaching the DA interface. However, in organic semiconductors, L... D The size of the small molecule acceptor (typically ~10-30 nm) is much shorter than that of the pure phase domains, and this difference leads to severe charge recombination. Furthermore, in the thicker active layer, the crystallization of the upper small molecule acceptor (SMA) depends only weakly on the substrate-induced force, thus forming a less crystallinity SMA phase. The resulting high-energy disorder hinders exciton transitions and suppresses... Exciton diffusion further reduces L D On the other hand, more dissociated carriers are generated at the bottom of the active layer (because the incident light is illuminating the transparent electrode side), which causes electrons in a forward thick-film device to travel a much longer distance to the top electrode (cathode) than holes to travel a much longer distance to the anode.

[0054] To address this issue, this invention introduces a vertical spatially confined crystallization (VSC) strategy based on functional acceptors; this VSC strategy can coordinate and regulate the crystallization and vertical phase separation of SMAs. The designed acceptor AT-β2O with spatially confined crystallization properties has an asymmetric molecular configuration with a hydrophilic oligoethylene glycol (OEG) chain at the β position of the thiophene unit. This design allows AT-β2O to regulate the crystallization sequence of components in the BHJ active layer by interacting with the secondary bonds of the acceptor material and modulating the solubility of the active layer material, thereby achieving spatially confined crystallization of the acceptor material. This precise regulation of crystallization kinetics results in better crystallinity and good vertical phase separation in the active layer (with an acceptor-rich phase near the cathode interface), thereby reducing energy disorder and enhancing exciton diffusion. Using this effective regulation strategy, single-junction OSCs achieved a record PCE of 20.82% (certified efficiency 20.43%). In particular, the active layer of this OSC exhibits thickness independence; when the film thickness increases to 250 nm and 400 nm, its PCE remains at 19.15% (certified 18.81%) and 17.93%, respectively. Based on this high-performance thick active layer, a pinhole-free large-area (15.03 cm²) film was also fabricated. 2 The component achieved a record PCE of 18.36% (certified at 18.04%). Notably, the VSC strategy significantly improved the device's operational stability at 100mW cm⁻¹. -2 Under white light emitting diode (LED) illumination, OSCs retained 83% of their initial PCE after aging at the maximum power point (MPP). Similar experimental results were observed in parallel experiments with different active layers, solvents, processing methods, and post-treatments, demonstrating the universality of the proposed spatially confined crystallization acceptor.

[0055] The structural formula of the non-fullerene acceptor material (AT-β2O) with vertically confined spatial crystallization is as follows:

[0056]

[0057] The preparation process of AT-β2O is illustrated above, and the specific preparation method is as follows:

[0058] Sodium metal (3.36 g, 0.15 mol) was added to diethylene glycol monomethyl ether (52.64 g, 0.44 mol) and heated at 100 °C for more than 6 hours. After naturally cooling to room temperature, copper oxide (7.0 g, 88 mmol) and potassium iodide (0.66 g, 4 mmol) were added. Under nitrogen protection, 3-bromothiophene[3,2-B]thiophene (8.06 g, 36 mmol) was added dropwise to the reaction system and stirred overnight at 110 °C. Petroleum ether / ethyl acetate (volume ratio 5:1) was used as the eluent, and the solution was separated by silica gel column chromatography to obtain a pale yellow liquid 3-[2-(2-methoxyethoxy)]ethoxythiophene[3,2-b]thiophene.

[0059] Under nitrogen protection, a tetrahydrofuran solution (50 mL) of 3-[2-(2-methoxyethoxy)]ethoxythiopheno[3,2-b]thiophene (5 g, 19 mmol) was cooled to -98 °C with liquid nitrogen, followed by the dropwise addition of n-butyllithium solution (9.3 mL, 23.5 mmol). After reacting for 2 h, tributyltin chloride (8.2 g, 24.7 mmol) was added and the reaction was allowed to proceed overnight at room temperature. The reaction was quenched with water to obtain a brownish-yellow liquid, 3-[2-(2-methoxyethoxy)]ethoxythiopheno[3,2-b]thiophene tributyltin.

[0060] Under nitrogen protection, 4,7-dibromo-5,6-dinitrobenzo[c][1,2,5]thiadiazole (4.65 g, 12 mmol), 3-[2-(2-methoxyethoxy)]ethoxythieno[3,2-b]thiophene tributyltin (10.6 g, 19 mmol), 3-undecylthieno[3,2-b]thiophene (7.07 g, 12 mmol), and Pd(PPh3)Cl2 (0.62 g, 0.88 mmol) were dissolved in anhydrous toluene (50 mL) and stirred overnight at 110 °C. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. Separation was performed by silica gel column chromatography, using petroleum ether / ethyl acetate (volume ratio 3:1) as eluent, to obtain a red solid 4-[6-(2-methoxyethoxy)ethoxythieno[3,2-b]thieno-2-yl]-5,6-dinitro-7-(6-undecyl)thieno[3,2-b]thieno-2-ylbenzo[c][1,2,5]thiadiazole;

[0061] Under nitrogen protection, 4-[6-(2-methoxyethoxy)ethoxythienro[3,2-b]thien-2-yl]-5,6-dinitro-7-(6-undecyl)thienro[3,2-b]thien-2-ylbenzo[c][1,2,5]thiadiazole (2.83 g, 4 mmol) and triphenylphosphine (9.38 g, 36 mmol) were dissolved in o-dichlorobenzene (10 mL) and heated at 180 °C. After heating for 4 hours and naturally cooling to room temperature, the mixture was added dropwise to anhydrous methanol (200 mL) to obtain a red solid 3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno-2,2-g]thieno[2,3':4,5]thieno[3,2-b]indole;

[0062] Under nitrogen protection, 3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno-2,2-g]thieno[2,3':4,5]thieno[3,2-b]indole (2.83 g, 4 mmol), isooctane (12.68 g, 65 mmol), cesium carbonate (11.9 g, 37 mmol), and potassium iodide (12.12 g, 73 mmol) were dissolved in DMF (120 mL) and heated overnight at 110 °C. The reaction mixture was then allowed to cool naturally to room temperature and concentrated under reduced pressure. Separation was performed by silica gel column chromatography, using petroleum ether / ethyl acetate (5:1 v / v) as eluent, to obtain a red oily liquid 12,13-bis(2-ethylhexyl)-3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno[3',3':4,5]pyrrolo[3,2-g]thieno[4,3':4,5]thieno[3,2-b]indole;

[0063] Under nitrogen protection, phosphorus oxychloride (2.99 g, 20 mmol) was added dropwise to DMF (2.14 g, 30 mmol), and the mixture was stirred at 0 °C for 2 h. 12,13-bis(2-ethylhexyl)-3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno[3',3':4,5]pyrrolo[3,2-g]thieno[4,3':4,5]thieno[3,2-b]indole (1 g, 1 mmol) was dissolved in chloroform (20 mL) and added to the reaction system. The mixture was heated at 75 °C overnight. The reaction mixture was cooled to room temperature and then concentrated under reduced pressure. Separation was performed by silica gel column chromatography, using petroleum ether / ethyl acetate (5:1 v / v) as eluent, to obtain a red oily liquid 12,13-bis(2-ethylhexyl)-3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno[3',3':4,5]pyrrolo[3,2-g]thieno[20',3':4,5]thieno[3,2-b]indole-2,10-dicarboxaldehyde;

[0064] Under nitrogen protection, 12,13-bis(2-ethylhexyl)-3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl-12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2',3':4',5']thieno[3',3':4,5]pyrrolo[3,2-g]thieno[20',3':4,5]thieno[3,2-b]indole-2,10-dicarboxaldehyde (0.6 g, 0.6 mmol) and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malonitrile (0.42 g, 1.8 mmol) were dissolved in chloroform (10 mL), pyridine (1 mL) was added, and the mixture was stirred overnight at 65 °C. After naturally cooling to room temperature, the mixture was poured into methanol and filtered. The residue was purified by silica gel column chromatography using dichloromethane as the eluent to give a blue-black solid 2,2'-(2Z,2'Z)-[(12,13-bis(2-ethylhexyl)]-3-[2-(2-methoxyethoxy)ethoxy]-9-undecyl 12,13-dihydro-[1,2,5]thiadiazole[3,4-e]thieno[2”,3”:4',5']thieno[3',3':4,5]pyrrolo[3',3':4,5]thieno[4,5]thieno[3,2-b]indole)bis(methylene alkyl))(5-difluoro-3-oxo-2-dihydro-1H-indene) (yield 75%) 1H NMR(600MHz, CDCl3)δ9.32(s,1H),9.12(s,1H),8.54–8.47(m,2H),7.73–7.65(m,2 H),4.97(s,2H),4.78(m,4H),4.07(t,2H),3.82(t,2H),3.65(t,2H),3.42(s,3H), 3.21(t,2H),2.11(m,2H),1.87(m,2H),1.50(m,2H),1.37(m,2H),1.26–1.25(m,12 H),1.20–1.19(m,4H),1.06–1.04(m,12H),0.87–0.85(t,3H),0.78–0.66(m,12H). 13 C NMR (150MHz, CDCl3) δ186.58,186.12,162.04,158.51,153.83,147.46,147.34,145.20,137.82,137. 53,137.16,135.84,135.20,134.37,133.56,133.26,131.83,130.41,128.33,120.06,117.67,114.65 ,113.80,113.03,112.24,73.04,71.95,70.79,69.39,68.81,67.37,59.08,55.67,40.47,31.91,31.21,29.82,29.65,29.62,29.51,29.45,29.34,27.79,27.62,23.23,22.83,22.69,14.12,13.77,10.20.

[0065] The raw materials used in this invention are all existing products, and the specific preparation operations and testing methods are conventional methods in the field. Unless otherwise specified, the thickness of the hole transport layer is 35 nm.

[0066] Example 1

[0067] An active layer material for organic solar cells includes the aforementioned non-fullerene acceptor, other Y-series acceptors, and donor materials. Taking N3 and AT-β2O acceptors and D18-Cl donors as examples:

[0068] (1) The indium tin oxide (ITO) conductive glass sheet was ultrasonically cleaned with ethanol, acetone and isopropanol in sequence. After drying, a PEDOT:PSS layer was spin-coated at 6000 rpm as a hole transport layer (35 nm). Then it was heated and dried at 150℃ for 15 min and transferred to an N2 glove box for later use.

[0069] (2) Prepare the active layer solution by adding N3, D18-Cl, AT-β2O or N3, D18-Cl to chloroform / diphenyl ether. The specific preparation process is as follows: the ratio of D18-Cl:N3:AT-β2O is 1:1.4:0, 1:1.3:0.1, 1:1.2:0.2 and 1:1.1:0.3 (w / w, CF / DPE (volume ratio 96:4%), and the concentration of the donor is 5 mg / mL. -1 Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer (no post-treatment required) to prepare the active layer.

[0070] The self-assembly process of AT-β2O molecules was analyzed using grazing incidence wide-angle X-ray scattering (GIWAXS). Figure 6 When a small amount of AT-β2O is mixed with N3, the diffraction signal of N3 becomes stronger in both the IP (100) and OOP (010) directions, indicating a significant increase in the orderliness of N3 along the side chains and π-π stacking directions. This suggests that AT-β2O molecules can also regulate the assembly of N3 molecules in the mixture. As shown in Tables 1-3, the ratio of face-on orientation to edge-on orientation (A... z / A xy The increase in ) and the increase in crystal coherence lengths (CCLs) (along the IP(100) and OOP(010) directions) confirm that AT-β2O induces N3 to preferentially form a face-on orientation, resulting in higher crystallinity.

[0071] Table 1 Figure 6 face-on (A) of the middle membrane z ) and edge-on(A xy The ratio of orientation

[0072] film <![CDATA[A z (%)]]> <![CDATA[A xy (%)]]> <![CDATA[A z / A xy ]]> N3 71.46 28.54 2.50 AT-β2O 75.49 24.51 3.08 N3:AT-β2O 80.81 19.19 4.21

[0073] Table 2 Figure 6 Positions of in-plane (100) diffraction peaks and corresponding CCL values ​​of different thin films

[0074]

[0075] Table 3 Figure 6 Positions of out-of-plane (010) diffraction peaks and corresponding CCL values ​​of different thin films

[0076]

[0077] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP(5nm) / Ag(100nm) electrode.

[0078] The effective area of ​​the device is 6.28 mm². 2 At AM 1.5G 100mW cm -2 The performance of the above-mentioned organic solar cells was tested under different irradiation conditions, and the corresponding performance parameters were obtained, as shown in Table 4.

[0079] Table 4. Photovoltaic performance parameters of OSCs based on different ratios of D18-Cl:N3:AT-β2O

[0080]

[0081] This embodiment uses ITO / PEDOT:PSS / active layer / C 60 OSCs were fabricated using a forward structure of / BCP / Ag. Devices based on D18-Cl:N3:AT-β2O (1:1.2:0.2 w / w / w) exhibited the highest PCE. The PCE of the D18-Cl:N3 (100 nm) based OSC was 18.11%, consistent with previous reports. In contrast, the PCE of the D18-Cl:N3:AT-β2O (1:1.2:0.2) active layer was 20.24% (certified efficiency 19.99%), with an improved FF of 80.34% and an open-circuit voltage (V... oc The voltage is 0.892V.

[0082] After further altering the active layer thickness, OSCs based on D18-Cl:N3:AT-β2O (1:1.2:0.2, 130 nm) achieved a record PCE of 20.82% (certified efficiency of 20.43%), which is the highest reported value for OSCs based on a thin (~100 nm) active layer.

[0083] Example 2

[0084] An active layer material for organic solar cells includes the aforementioned non-fullerene acceptor, other Y-series acceptors, and donor materials. Taking N3 and AT-β2O acceptors and D18-Cl donor materials as examples:

[0085] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0086] (2) Add N3, D18-Cl, and AT-β2O or N3 and D18-Cl to chloroform / diphenyl ether to prepare the active layer solution. The specific preparation process is as follows: the ratio of D18-Cl:N3:AT-β2O is 1:1.2:0.2 (w / w, CF / DPE (volume ratio 96:4%)). The concentration of the donor is 5, 10, and 15 mg / mL when preparing active layers of different thicknesses. -1Then, the active layer solution was spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100 (Example 1), 250 and 400 nm (no post-treatment);

[0087] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP(5nm) / Ag(100nm) electrode.

[0088] The effective area of ​​the device is 6.28 mm². 2 At AM 1.5G 100mW cm -2 The performance of the above-mentioned organic solar cells was tested under irradiation conditions, and the current-voltage curves were obtained, as shown below. Figure 7 As shown in Table 5, the corresponding battery performance parameters are obtained.

[0089] Table 5. Photovoltaic performance parameters of OSCs with different film thicknesses for D18-Cl:N3 and D18-Cl:N3:AT-β2O

[0090]

[0091] c For the efficiency of SIMIT certification in Shanghai, China.

[0092] Vertical phase separation in a 400 nm thick film was investigated using cross-sectional scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Figure 8 It was observed that an F-rich layer, representing N3 and AT-β2O, appeared at the top of the D18-Cl:N3:AT-β2O (400 nm) film, while Cl-rich layers, representing D18-Cl, were distributed in the middle and bottom. The results indicate a gradient distribution of the vertical components, with the top being a acceptor-rich phase and the middle and bottom being donor-rich phases. The D18-Cl:N3 (400 nm) film exhibited a more uniform phase distribution in the vertical direction. This suggests that AT-β2O helps optimize vertical phase separation within the thick film active layer.

[0093] Figure 7 Table 5 shows the JV curves and photovoltaic parameters of D18-Cl:N3 and D18-Cl:N3:AT-β2O at different thicknesses. When the active layer thickness of D18-Cl:N3 was increased to 250 nm and 400 nm, the fill factor and PCE significantly decreased. In contrast, after adding a spatially confined crystallization acceptor, the active layer of D18-Cl:N3:AT-β2O exhibited film thickness independence; the device with an active layer thickness of 250 nm achieved an efficiency of 19.15% (certified efficiency 18.81%) and a short-circuit current density (J / L). scIncreased to 28.56 mA cm -2 V oc The voltage drop was slightly reduced (0.869V), and the field factor (FF) also decreased slightly (76.43%). When the active layer thickness was further increased to 400 nm, the PCE remained at 17.93%, significantly higher than the 12.45% of the device without AT-β2O. These results indicate that spatially confined crystallized non-fullerene acceptors can improve the film thickness independence of the active layer. These results demonstrate that the proposed VSC strategy is advantageous for large-scale production of OSCs using high-throughput roll-to-roll technology.

[0094] Example 3

[0095] An organic solar cell has an active layer material comprising the aforementioned non-fullerene acceptor, other Y-series acceptors (Y6), and a donor material (PM6). The fabrication method of the organic solar cell is as follows:

[0096] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0097] (2) Then, an active layer film was prepared on the hole transport layer by spin. The specific preparation process of the active layer solution is as follows: the ratio of PM6:Y6:AT-β2O(CF) is 1:1.2:0 and 1:1:0.2 (w / w), the additive is 0.5% CN, and the concentration of the donor is 7.27, 11.5, and 15 mg / mL when preparing active layers of different thicknesses. -1 Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100, 250, and 400 nm (the active layer does not require any post-treatment).

[0098] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0099] Figure 9 The molecular structures of PM6, Y6, BTP-eC9, D18, L8-BO, and DTY6 were determined. The performance of the above organic solar cells was tested at AM 1.5G 100mW cm⁻¹. -2 Measurements were taken under irradiation conditions to obtain current-voltage curves, such as... Figure 10 As shown in Table 6, the corresponding battery performance parameters were obtained. When the thickness was further increased to 400 nm, the ternary device also exhibited a better PCE than the binary device. It can be seen that spatially confined crystallized non-fullerene acceptors play a particularly prominent role in the fabrication of thick-film devices.

[0100] Table 6. Photovoltaic performance parameters of OSCs with different film thicknesses for PM6:Y6 and PM6:Y6:AT-β2O

[0101]

[0102]

[0103] Example 4

[0104] An organic solar cell, wherein the active layer material comprises the aforementioned non-fullerene acceptor, other Y-series acceptor (BTP-eC9), and donor material (PM6), and the preparation method is as follows:

[0105] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0106] (2) Then, an active layer film was prepared on the hole transport layer by spin coating. The specific preparation process of the active layer solution is as follows: the ratio of PM6:BTP-eC9:AT-β2O (processed with chloroform / diphenyl ether) is 1:1.15:0 and 1:1.05:0.1 (w / w), and the additive is 0.5% DIO. The concentration of the donor is 7, 11, and 15.3 mg / mL when preparing active layers of different thicknesses. -1 Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100, 250 and 400 nm (without post-treatment);

[0107] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0108] The performance of the above organic solar cells was tested at AM 1.5G 100mW cm⁻¹ -2 Measurements were taken under irradiation conditions to obtain current-voltage curves, such as... Figure 11 As shown in Table 7, the corresponding battery performance parameters are obtained.

[0109] Table 7. Photovoltaic performance of OSCs with different film thicknesses for PM6:BTP-eC9 and PM6:BTP-eC9:AT-β2O

[0110]

[0111] Example 5

[0112] An organic solar cell, wherein the active layer material comprises the aforementioned non-fullerene acceptor, other Y-series acceptors (L8-BO), and a donor material (PM6), is prepared by the following method:

[0113] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0114] (2) Then, an active layer film was prepared on the hole transport layer by spin coating. The specific preparation process of the active layer solution is as follows: the ratio of PM6:L8-BO:AT-β2O(CF) is 1:1.2:0 and 1:1.1:0.1 (w / w), and the additive is 0.25% DIO. The concentration of the donor is 7, 11, and 15 mg / mL when preparing active layers of different thicknesses. -1 Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100, 250 and 400 nm (no post-treatment required);

[0115] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0116] The performance of the different organic solar cells mentioned above was tested at AM 1.5G 100mW cm⁻¹ -2 Measurements under irradiation conditions, such as Figure 12 As shown in Table 8, the corresponding battery performance parameters were obtained. The results indicate that spatially confined crystallization of non-fullerene acceptors provides great potential for the preparation of highly efficient ternary thick-film OSCs.

[0117] Table 8. Photovoltaic performance parameters of OSCs with different film thicknesses for PM6:L8-BO and PM6:L8-BO:AT-β2O

[0118]

[0119] Example 6

[0120] An organic solar cell, wherein the active layer material comprises the aforementioned non-fullerene acceptor, other Y-series acceptors (L8-BO), and a donor material (PM6), is prepared by the following method:

[0121] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0122] (2) Then, an active layer film was prepared on the hole transport layer by spin coating. The specific preparation process of different active layer solutions is as follows: the ratio of PM6:L8-BO:AT-β2O (TL) is 1:1.2:0 and 1:1.1:0.1 (w / w), the additive is 0.25% DIO, and the concentration of the donor is 8-16 mg / mL when preparing active layers of different thicknesses. -1 Then, the active layer solution is spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100, 250 and 400 nm (the active layer does not require any post-treatment).

[0123] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0124] The performance of the different organic solar cells mentioned above was tested at AM 1.5G 100mW cm⁻¹ -2 Measurements were taken under irradiation conditions to obtain current-voltage curves, such as... Figure 13 As shown, the corresponding battery performance parameters are obtained, as shown in Table 9. The higher FF indicates that the addition of spatially confined, non-fullerene acceptors is crucial for maintaining high photovoltaic performance in thick-film devices.

[0125] Table 9. Performance of OSCs with different film thicknesses for PM6:L8-BO(TL) and PM6:L8-BO:AT-β2O(TL)

[0126]

[0127] Example 7

[0128] An organic solar cell, wherein the active layer material comprises the aforementioned non-fullerene acceptor, other Y-series acceptors (L8-BO), and a donor material (D18), is prepared by the following method:

[0129] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0130] (2) Then, an active layer film was prepared on the hole transport layer by spin coating. The specific preparation process of different active layer solutions is as follows: the ratio of D18:L8-BO:AT-β2O(PX) is 1:1.2:0 and 1:1:0.2 (w / w), and the concentration of the donor is 8, 12.25, and 16.5 mg / mL when preparing active layers of different thicknesses. -1Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of 100, 250, and 400 nm (the active layer does not require any post-treatment).

[0131] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0132] The performance of the different organic solar cells mentioned above was tested at AM 1.5G 100mW cm⁻¹ -2 Measurements were taken under irradiation conditions to obtain current-voltage curves, such as... Figure 14 As shown in Table 10, the corresponding battery performance parameters are obtained.

[0133] Table 10 Performance of OSCs with different film thicknesses for D18:L8-BO(PX) and D18:L8-BO:AT-β2O(PX)

[0134]

[0135]

[0136] At a film thickness of approximately 100 nm, the PCE of a ternary battery is 17.68%, while that of a binary battery with a similar film thickness is 16.22%. For both binary and ternary devices, as the active layer thickness increases from 100 nm to 400 nm, the maximum PCE of the binary device decreases from 16.22% to 10.78%, while the maximum PCE of the ternary device only decreases from 17.68% to 16.02%. Ternary devices are less sensitive to the thickness of the photoactive layer than binary devices, which is key to maintaining a high device PCE even with a thicker photoactive layer.

[0137] Example 8

[0138] An organic solar cell, wherein the active layer material comprises the aforementioned non-fullerene acceptor, other Y-series acceptors (DTY6), and a donor material (PM6), and the preparation method is as follows:

[0139] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0140] (2) Then, an active layer film was prepared on the hole transport layer by spin coating. The specific preparation process of different active layer solutions is as follows: the ratio of PM6:DTY6:AT-β2O(OX) is 1:1.2:0 and 1:1:0.2 (w / w), the additive is 0.5% CN, and the concentration of the donor is 8.2, 12.3, and 16.4 mg / mL when preparing active layers of different thicknesses. -1 Then, the active layer solution is spin-coated onto the PEDOT:PSS layer to obtain active layers with thicknesses of ~100, 250 and 400 nm (the active layer does not require any post-treatment);

[0141] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP (5nm) / Ag (100nm) electrodes. The effective area of ​​the device is 6.28mm². 2 .

[0142] The performance of the different organic solar cells mentioned above was tested at AM 1.5G 100mW cm⁻¹ -2 Measurements were taken under irradiation conditions to obtain current-voltage curves, such as... Figure 15 As shown in Table 11, the corresponding battery performance parameters are obtained.

[0143] Table 11 Performance of OSCs with different film thicknesses of PM6:DTY6(OX) and PM6:DTY6:AT-β2O(OX)

[0144]

[0145]

[0146] Compared with binary OSCs, the PM6:DTY6:AT-β2O(OX) ternary device improves efficiency by 1.18%, 3.07%, and 4.65% at active layer thicknesses of 100 nm, 250 nm, and 400 nm, respectively.

[0147] This invention applies the acceptor to OSCs treated with different solvents (the chemical structures of the relevant photovoltaic materials are as follows). Figure 9As shown in the figure, the universality of spatially confined crystallization acceptors was tested. When non-fullerene acceptors with spatially confined crystallization properties were added, the PCE of all OSCs containing AT-β2O (halogenated solvents (CF) or non-halogenated solvents (toluene (TL), p-xylene (PX), and o-xylene (OX)) was significantly higher than that of devices without AT-β2O, and the film thickness dependence was weaker. OSCs with different solvent systems and active layer materials were prepared by various processing methods, such as spin coating and blade coating for D18-Cl:N3, solvent annealing for PM6:BTP-eC9 system, and thermal annealing for other active layers. These results collectively indicate that the proposed VSC strategy is universal and compatible with different active layers, solvents, processing methods, and post-processing techniques.

[0148] Example 9

[0149] (1) The structure of large-area components is similar to that of small-area devices. (For example, in a size of 5×5cm...) 2 An OSC module with eight series-connected sub-cells was fabricated on an ITO glass substrate, with an opening area of ​​15.64 cm². 2 The series interconnection of the components is achieved by lines P1, P2, and P3 (P1, P2, and P3 are cut using a GH-LS300 laser cutting system). First, P1 is etched onto the ITO using a laser; P1 has a width of 30 μm.

[0150] (2) Then PEDOT:PSS was deposited, active layer was scraped, C60 and BCP were deposited; before silver deposition, P2 line was cut with a width of about 140 μm.

[0151] (3) In 1×10 -6 A 100 nm thick Ag electrode was thermally evaporated under a pressure of mbar to form the P3 (80 μm) line. Simultaneously, the edges were cleaned using a laser; the distances between P1 and P2, and between P2 and P3, were 25 μm.

[0152] Testing the above large-area (PEDOT:PSS (35nm) / active layer (250nm) / C 60 (10nm) / BCP(5nm) / Ag(100nm), the effective area of ​​the module is 15.03cm². 2 The performance of organic solar cells was analyzed, and the JV curve was obtained, as shown below. Figure 16 As shown, the corresponding battery performance parameters were obtained from the curves, as shown in Table 12. Table 12 Photovoltaic performance parameters of OSC modules based on chloroform-processed D18-Cl:N3 and D18-Cl:N3:AT-β2O

[0153]

[0154]

[0155] a SIMIT certification efficiency in Shanghai, China.

[0156] A high-quality, thick active layer can suppress the formation of pinholes in the film, which is beneficial for the rapid and large-scale production of efficient OSCs. A 5×5cm film was prepared using a scraping method. 2 The active layer of the device was constructed using the D18-Cl:N3:AT-β2O (1:1.2:0.2, 250nm) cell. The 100nm active layer without spatially confined crystallization acceptor exhibited randomly distributed pinholes. In contrast, the thick (~250nm) active layer, regardless of the presence or absence of the spatially confined crystallization acceptor AT-β2O, exhibited a pinhole-free morphology. Next, a module consisting of eight sub-cells connected in series was fabricated using the thick active layer under atmospheric conditions. Table 12 shows that the PCE of the device based on D18-Cl:N3:AT-β2O (1:1.2:0.2, 250nm) was 18.36% (certified as 18.04%), significantly higher than the PCE of the device based on D18-Cl:N3 (250nm) (10.26%). The significant difference in efficiency is mainly attributed to the different FF values ​​(56.63% for the D18-Cl:N3 (250nm) module and 77.24% for the D18-Cl:N3:AT-β2O (250nm) module). The beam-induced current (LBIC) imaging generated by the 632nm laser scanning device shows that the photocurrent of the D18-Cl:N3:AT-β2O (250nm) component is stronger and more uniformly distributed than that of the D18-Cl:N3 (250nm) component. Figure 17 Currently, 18.36% have an effective area >10cm². 2 The highest efficiency of the OSC component far exceeds that of previous research reports, which proves that the acceptor with spatially confined crystallization properties in this invention can effectively improve the efficiency of the OSC component.

[0157] Comparative Examples

[0158] Figure 18 The molecular formula of the comparative material BT-β2O in the comparative examples is shown below.

[0159] An example of an active layer material for organic solar cells, using N3:BT-β2O as the acceptor material and D18-Cl as the donor material:

[0160] (1) Prepare an indium tin oxide (ITO) hole transport layer as in Example 1, and use an N2 glove box for later use;

[0161] (2) N3, D18-C, and BT-β2O were added to chloroform / diphenyl ether to prepare the active layer solution. The specific preparation process is as follows: the ratio of D18-Cl:N3:AT-β2O and D18-Cl:N3:BT-β2O is 1:1.2:0.2 (w / w), CF / DPE (volume ratio 96:4%), and the concentration of the donor is 5, 10, and 15 mg / mL. -1 Subsequently, the active layer solution was spin-coated onto the PEDOT:PSS layer (without any post-treatment) to prepare active layers of different thicknesses.

[0162] (3) Finally, in 1×10 -6 Under mbar vacuum evaporation conditions, C is sequentially deposited on the active layer. 60 (10nm) / BCP(5nm) / Ag(100nm) electrode.

[0163] The effective area of ​​the device is 6.28 mm². 2 .

[0164] The performance of the different organic solar cells mentioned above was tested at AM 1.5G 100mW cm⁻¹ -2 The corresponding battery performance parameters were obtained by measuring under irradiation conditions, as shown in Table 13. Figure 19 .

[0165] Table 13 Photovoltaic performance parameters of OSCs based on D18-Cl:N3:AT-β2O and D18-Cl:N3:BT-β2O with different thicknesses

[0166]

[0167] As shown in Table 13, the active layer D18-Cl:N3:BT-β2O ternary device developed based on the symmetric OEG-substituted comparative material BT-β2O has a PCE of 19.27% ​​when the active layer thickness is 100 nm, which is lower than the efficiency (20.24%) of the D18-Cl:N3:AT-β2O ternary device. When the film thickness reaches 400 nm, the efficiency based on D18-Cl:N3:BT-β2O is only 15.87%, while the device based on D18-Cl:N3:AT-β2O maintains a high efficiency of 17.93%. This trend indicates that asymmetric OEG-substituted non-fullerene acceptors are crucial for maintaining high photovoltaic performance in thick-film devices.

[0168] Studies have shown that the addition of the spatially confined crystallization-possessing non-fullerene acceptor AT-β2O to the host (D18-Cl:N3 system) of this invention enables the regulation of N3 assembly behavior through its molecular interactions with N3. The regulation of N3 nucleation and molecular assembly by AT-β2O enhances and maintains the crystallinity of the N3:AT-β2O film. Simultaneously, the addition of AT-β2O optimizes vertical phase separation in the thick-film active layer, thereby contributing to more balanced charge transport and significantly improving the energy conversion efficiency of the thick-film device. Furthermore, the universality of this spatially confined crystallization-possessing acceptor has been demonstrated in different active layer systems, processing solvents, preparation processes, and post-processing techniques.

[0169] The non-fullerene acceptor with spatially confined crystallization characteristics disclosed in this invention is added as a guest molecule to the main component, which solves the problems of pinholes caused by low film thickness in large-area modules and low performance of thick film devices. Ultimately, high-performance and high-stability large-area device modules are obtained, which promotes the industrialization of organic solar cells.

Claims

1. A non-fullerene receptor with spatially confined crystallization, characterized in that, The non-fullerene acceptor with spatially confined crystallization has the following chemical structural formula: 。 2. The application of the spatially confined crystallization non-fullerene acceptor as described in claim 1 in the preparation of organic solar cells or the active layer of organic solar cells.

3. The method for preparing a non-fullerene acceptor with spatially confined crystallization as described in claim 1, characterized in that, The reaction involves the following steps: reacting a DA'D-type conjugated core with an electron-withdrawing end group to obtain a non-fullerene acceptor with spatially confined crystallization; the reaction is illustrated below: 。 4. The application of the non-fullerene acceptor with spatially confined crystallization properties as described in claim 1 in improving the efficiency of ultra-thick active layer solar cells.

5. An active layer material for organic solar cells, characterized in that, Including the non-fullerene acceptor with spatially confined crystallization properties as described in claim 1.

6. The active layer material for organic solar cells according to claim 5, characterized in that, It also includes Y-series receptors and donor materials.

7. An organic solar cell, comprising an active layer, an electron transport layer, a hole transport layer, and electrodes, characterized in that, The active layer includes the non-fullerene acceptor with spatially confined crystallization properties as described in claim 1.

8. A method for fabricating an organic solar cell, comprising the following steps: sequentially fabricating a hole transport layer, an active layer, an electron transport layer, and an electrode on a conductive substrate to obtain an organic solar cell; characterized in that, The active layer includes the non-fullerene acceptor with spatially confined crystallization properties as described in claim 1.

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