Oligomeric condensed ring electron acceptor material as well as preparation method and application thereof
By synthesizing oligomeric fused-ring electron acceptor materials with specific structures and optimizing molecular stacking and charge transport, the efficiency and stability problems of existing materials in organic solar cells have been solved, achieving high-efficiency photoelectric conversion and thermal stability.
Patent Information
- Application Number
- CN202511714598.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-10
AI Technical Summary
Existing oligomeric fused-ring electron acceptor materials have limitations in terms of molecular stacking and charge transport, which affect the efficiency and stability of organic solar cells.
By employing oligomeric fused-ring electron acceptor materials with specific structures and their preparation methods, and through the reaction synthesis between compounds, the molecular configuration and stacking mode are optimized to form pseudo-para-type molecules, thereby improving charge transport efficiency and thermal stability.
It improves the photoelectric conversion efficiency and thermal stability of organic solar cells, optimizes the thin film morphology, fills the absorption defects of donor and acceptor materials, and improves spectral utilization.
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Figure CN121494872A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solar cell technology, and in particular to an oligomeric fused-ring electron acceptor material, its preparation method and application, specifically an oligomeric fused-ring electron acceptor material, its preparation method and its application in organic solar cells. Background Technology
[0002] Organic solar cells (OSCs) are an emerging photovoltaic technology whose active layer consists of a hybrid of electron donors and electron acceptors. The electron donors and acceptors exhibit excellent energy level matching and complementary absorption. The development of electron acceptors reflects the arduous and challenging journey of OSCs, and the advancement of novel acceptor materials has greatly propelled progress in the field of organic solar cells.
[0003] In 2015, Zhan Xiaowei's team developed a series of novel acceptor materials (ITICs) represented by acceptor-donor-acceptor (ADA) types (Adv. Mater. 2015, 27, 1170-1174), and proposed the groundbreaking concept of "fused-ring electron acceptors (FREAs)". In 2019, Zou Yingping's team (Joule 2019, 3, 1140-1151) developed a new generation of FREAs represented by Y6, further improving the photoelectric conversion efficiency (PCE) of state-of-the-art OSCs to over 19%. However, recent studies have shown that small molecule materials often exhibit a rapid diffusion trend, leading to morphological aging under thermal stress; polymer acceptor materials suffer from poor batch reproducibility due to the polydispersity of molecular weight. Based on these problems, Professor Zou Yingping of Central South University (Chem, 2020, 6, 2147-2161) first proposed a novel acceptor material called "quasi-polymer," which is the origin of the oligomeric fused-ring electron acceptor concept.
[0004] Currently, oligomeric fused-ring electron acceptors, using Y-series electron acceptors as monomers, have been rapidly developed due to the presence of multiple potential oligomerization linkage sites on this unit, such as end-group units, the N-site on the pyrrole ring, shoulder side chains, and the central fused-ring core. The photoelectric conversion efficiency of organic photovoltaic devices based on these acceptors has also rapidly exceeded 20%. Based on the current development of these acceptor materials, they can be classified into directly linked, rigid-unit linked, flexible-unit linked, and directly fused oligomers. However, all of these types of oligomers affect the "end-to-end" stacking of the molecule, limiting the formation of an effective three-dimensional interpenetrating network structure and hindering efficient charge transport. Summary of the Invention
[0005] To overcome the aforementioned problems in the prior art, one object of the present invention is to provide an oligomeric fused-ring electron acceptor material. Another object of the present invention is to provide a method for preparing the oligomeric fused-ring electron acceptor material. A third object of the present invention is to provide the application of the described oligomeric fused-ring electron acceptor material in the fabrication of organic solar cells.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides an oligomeric fused-ring electron acceptor material, with the following structural formula: , Where n is 0-4; the specific structure of R is: ; R1 is a five-membered heterocyclic or six-membered aromatic ring compound; R2 and R3 are independently selected from alkyl chains or alkyl aromatics; R4, R5, R6, and R7 are independently selected from hydrogen, halogens, or methoxy groups; R8 is one of S and Se.
[0007] In the aforementioned oligomeric fused-ring electron acceptor material, the R1 structure is specifically one of the following structures: .
[0008] Preferably, the specific structure of R1 is one of the following structures: .
[0009] Preferably, the specific structure of R1 is one of the following structures: .
[0010] In the aforementioned oligomeric fused-ring electron acceptor material, the R2 structure is specifically one of the following structures: .
[0011] Preferably, the specific structure of R2 is one of the following structures: , , .
[0012] Preferably, the specific structure of R2 is as follows: .
[0013] In the aforementioned oligomeric fused-ring electron acceptor material, the R3 structure specifically comprises one of the following structures: .
[0014] Secondly, the present invention provides a method for preparing oligomeric fused-ring electron acceptor materials as described above, comprising the following steps: S1, compound 1, and aromatic heterocyclic derivative react to give compound 2; S2. Compound 2 from step S1 reacts with a brominating reagent to obtain compound 3; S3, compound 4, and ninhydrin derivative react to give compound 5; S4. The compound 5 described in step S3 reacts with the tin-modified five-membered heterocyclic derivative to obtain compound 6; S5, compound 6 described in step S4 and compound 3 described in step S2 react to obtain the oligomeric fused ring electron acceptor material.
[0015] The above preparation method, in step S1, describes compound 1 with the following structural formula: ; The aromatic heterocyclic derivative described in step S1 has the following structural formula: or ; Compound 2 described in step S1 has the following structural formula: or ; The brominating reagent mentioned in step S2 is N-bromosuccinimide or liquid bromine; The compound 3 described in step S2 has the following structural formula: or , Where X1 is one of S, O, and Se, X2 and Y1 are independently selected from N or H, and Y is S, N, or H; Compound 4 described in step S3 has the following structural formula: ; The indanedione derivative mentioned in step S3 is and The combination Compound 5 described in step S3 has the following structural formula: ; The tin-modified five-membered heterocyclic derivative described in step S4 has the following structural formula: , Compound 6 described in step S4 has the following structural formula: .
[0016] In the preparation method described above, in step S1, a catalyst is also used in the reaction.
[0017] In the above preparation method, in step S1, the molar ratio of compound 1, aromatic heterocyclic derivative and catalyst is 1:2.1-2.8:0.03-0.05; the concentration of the reaction solution of compound 1 is 0.15-0.34 mol / L.
[0018] In the above preparation method, in step S2, the molar ratio of compound 2 to the brominating reagent is 1:10-15; the concentration of the reaction solution of compound 2 is 0.1-0.3 mol / L.
[0019] In the above preparation method, in step S3, the... and The molar ratio is 1:1.
[0020] In the above preparation method, in step S3, the molar ratio of compound 4 to the indanedione derivative is 1:2.4-5; the concentration of the reaction solution of compound 4 is 0.05-0.1 mol / L.
[0021] In the preparation method described above, step S4, the reaction also uses a catalyst and a catalyst ligand.
[0022] Preferably, in step S4, the molar ratio of compound 5, tin-modified five-membered heterocyclic derivative, catalyst, and catalyst ligand is 1:1.2-2.5:1.2-2.5; and the concentration of the reaction solution of compound 5 is 0.05-0.1 mol / L.
[0023] Thirdly, the present invention provides an application of an oligomeric fused-ring electron acceptor material as described above in the fabrication of organic solar cells.
[0024] In the above applications, the structure of the organic solar cell includes a transparent conductive substrate, a hole transport layer material, an active layer, an electron transport layer material, and a metal electrode.
[0025] The specific steps for fabricating the organic solar cell described above are as follows: Step A: After cleaning the substrate, transfer it to an inert gas glove box; Step B involves spin-coating a hole transport layer solution, followed by annealing to obtain a substrate / hole transport layer base. Step C: Spin-coat the active layer solution onto the substrate / hole transport layer substrate described in step B, and then anneal the solution to form the active layer, thus obtaining the substrate / hole transport layer / active layer substrate. Step D: Spin-coating an electron transport material solution onto the substrate / hole transport layer / active layer substrate described in step C, followed by annealing to form an electron transport layer, thus obtaining the substrate / hole transport layer / active layer / electron transport layer substrate. Step E: A 100 nm thick metal electrode is formed by vacuum deposition, and the effective active layer area is controlled to be 4 mm using a mask. 2 .
[0026] Preferably, the concentration of the hole transport layer solution in step B is 0.2-0.5 mg / mL; the spin coating speed is 2500-3500 rpm and the time is 25-30 s; the annealing temperature is 90-100℃ and the time is 5-10 min.
[0027] Preferably, in step C, the spin coating of the active layer solution is performed at a speed of 2500-3000 rpm for 25-30 seconds; the annealing treatment is performed at a temperature of 80-100℃ for 8-10 minutes.
[0028] Preferably, the concentration of the electron transport material solution in step D is 1.0-1.2 mg / mL, the spin coating speed is 3500 rpm, and the time is 25-35 s; the annealing temperature is 90-100℃, and the time is 5-15 min.
[0029] The beneficial effects of this invention are: (1) The oligomeric fused ring electron acceptor material provided by the present invention has a pseudo-para configuration. The pseudo-para configuration can optimize the molecular stacking mode and has better "end-to-end" stacking, which helps to optimize the thin film morphology, improve the charge transport efficiency of the device, and thus improve the performance of organic solar cells.
[0030] (2) The oligomeric fused ring electron acceptor material provided by the present invention is an oligomeric molecule. Oligomeric molecules have a higher glass transition temperature, which is beneficial to improving the thermal stability of organic solar cells.
[0031] (3) The oligomeric fused ring electron acceptor material provided by the present invention has a high absorption coefficient in the range of 650-850 nm, which can fill the absorption defects of existing donor and acceptor materials, improve the utilization rate of the spectrum, and help improve the short-circuit current of solar cells, thereby improving the photoelectric conversion efficiency of organic solar cells. Attached Figure Description
[0032] Figure 1 These are schematic diagrams of the organic solar cells prepared in Examples 1-4 and Comparative Examples 2-4 of the present invention; Figure 2 This is the normalized absorption spectrum (light intensity 100 mW / cm²) of the oligomeric fused-ring electron acceptor material prepared in Example 1 of this invention and PM6 as the active layer material. 2 ); Figure 3This is a JV curve (illuminance 100 mW / cm²) of the oligomeric fused-ring electron acceptor material prepared in Example 1 of this invention for use in polymer-based organic solar cells. 2 ); Figure 4 This is a transmission electron microscope image of the morphology of the active layer of a polymer-based organic solar cell formed using the oligomeric fused ring electron acceptor material prepared in Example 1 of this invention as an acceptor. Detailed Implementation
[0033] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
[0034] Terminology and Declarations of this Invention: 1. Articles “a,” “a kind,” and “the”: These include plural objects unless otherwise explicitly specified as a single (kind) object.
[0035] 2. Numerical Range: Unless otherwise expressly indicated, all ranges or ratios disclosed in this invention shall be understood to include any and all subranges or subratios contained herein. For example, a stated range or ratio of 1 to 30 shall be considered to be included between a minimum value of 1 and a maximum value of 30, and includes any subranges or subratios, integers, decimals, or subranges or subratios consisting of integers or decimals, including the endpoints.
[0036] 3. Unless otherwise specified, all methods described herein are conventional methods, and all raw materials described herein are available from publicly available commercial sources unless otherwise specified.
[0037] Example 1 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0038] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0039] The specific synthesis steps include: (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (1.7 g, 6.87 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (869.8 mg, yield 85%). 1 H NMR (600 MHz, CDCl3) δ 7.31 (dd, J = 5.0, 1.0 Hz, 2H), 7.09 – 7.06 (m, 2H), 7.05 (dd, J =3.4, 1.1 Hz, 2H), 6.67 (dd, J = 7.8, 1.5 Hz, 2H), 6.58 (d, J = 1.4 Hz, 2H), 6.51 (d, J = 7.8 Hz, 2H), 3.66 (ddd, J = 13.5, 8.9, 4.8 Hz, 2H), 2.93 – 2.87 (m, 2H), 2.84 – 2.78 (m, 4H).
[0040] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, yield 92.8%). 1 H NMR (600 MHz, CDCl3) δ = 7.02 (d, J =3.7, 2H), 6.79(d, J =3.8, 2H), 6.67 (dd, J =7.8, 1.8, 2H), 6.48 (dd, J=9.5, 4.7, 4H), 3.67 –3.56 (m, 2H), 2.94 – 2.85 (m, 2H), 2.85 – 2.76 (m, 4H).
[0041] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound 4 (981.3 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as eluent to give compound 5 (381.9 mg, yield 29%). 1 H NMR (400 MHz, CDCl3) δ 9.12 (d, J = 9.4 Hz, 2H), 8.61 – 8.42 (m, 2H), 7.97 (d, J = 1.8 Hz, 1H), 7.81 (dd, J = 8.4, 1.9 Hz, 1H), 7.63 (t, J = 7.5 Hz, 1H), 4.69 (d, J =7.4 Hz, 4H), 3.17 (t, J = 7.8 Hz, 4H), 2.04 (s, 2H), 1.81 (dd, J = 15.0, 8.0Hz, 4H), 1.7 – 0.7 (m, 114H).
[0042] (iv) Under nitrogen protection, compound 5 (46 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound 6.
[0043] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound 6 (2.2 eq, 460.9 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M1, which is the oligomeric fused-ring electron acceptor material (129.1 mg, yield 32%). 1 H NMR (600 MHz, CDCl3) δ 9.06 (s, 4H), 8.63 (d, J = 8.0 Hz,2H), 8.47 (s, 2H), 8.01 (s, 2H), 7.87 (d, J = 8.0 Hz, 2H), 7.61 (t, J = 7.1Hz, 2H), 7.49 (d, J = 3.6 Hz, 2H), 7.26 (d, J = 3.4 Hz, 4H), 7.02 (d, J =12.7 Hz, 2H), 6.76 (d, J = 7.6 Hz, 2H), 6.67 – 6.51 (m, 4H), 4.72 (s, 8H),3.78 (dd, J = 17.8, 11.1 Hz, 2H), 3.42 (d, J = 4.9 Hz, 2H), 3.14 (s, 8H), 2.92 (s, 4H), 2.19 – 2.05 (m, 4H), 2.0-0.75 (m, 236H).
[0044] Example 2 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0045] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0046] (i) In a dry flask, trimethyl(sphen-2-yl)stanane (2.02 g, 6.87 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous and oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound ph-Se as a white solid (1068.2 mg, yield 83%).
[0047] (ii) In a dry flask, compound ph-Se (936 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound ph-Se-Br as a white solid (1165.3 mg, yield 93.4%).
[0048] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound 4 (981.3 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as eluent to give compound 5 (381.9 mg, yield 29%).
[0049] (iv) Under nitrogen protection, compound 5 (46 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound 6.
[0050] (v) In a dry flask, compound ph-Se-Br (62.4 mg, 0.1 mmol), compound 6 (2.2 eq, 460.9 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M2, which is the oligomeric fused-ring electron acceptor material (128 mg, yield 31%).
[0051] Example 3 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0052] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0053] (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (1.7 g, 6.87 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (869.8 mg, yield 85%).
[0054] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, yield 92.8%).
[0055] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound Y-C2C4 (739.1 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as the eluent to obtain compound Y-C2C4-Br (354.6 mg, yield 33%).
[0056] (iv) Under nitrogen protection, compound Y-C2C4-Br (37.3 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 42 mg of compound Y-C2C4-Sn.
[0057] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound Y-C2C4-Sn (2.2 eq, 393 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M3, which is the oligomeric fused-ring electron acceptor material (110.9 mg, yield 33%).
[0058] Example 4 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0059] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0060] (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (1.7 g, 6.87 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (869.8 mg, yield 85%).
[0061] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, yield 92.8%).
[0062] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound Y-C2 (920.7 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as the eluent to obtain compound Y-C2-Br (389.4 mg, yield 31%).
[0063] (iv) Under nitrogen protection, compound Y-C2-Br (43.6 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound Y-C2-Sn.
[0064] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound Y-C2-Sn (2.2 eq, mg, 0.22 mmol), and catalyst tetrakis(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M4, which is the oligomeric fused-ring electron acceptor material (131.4 mg, yield 34%).
[0065] Example 5 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0066] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0067] The specific synthesis steps include: (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (1.48 g, 6 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (18 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (706.1 mg, 69%).
[0068] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, 92.8%).
[0069] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound 4 (981.3 mg, 0.72 mmol) were added to a mixed solvent of chloroform (100 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as eluent to obtain compound 5 (381.9 mg, 29%).
[0070] (iv) Under nitrogen protection, compound 5 (46 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound 6.
[0071] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound 6 (2.2 eq, 460.9 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M1, which is the oligomeric fused-ring electron acceptor material (129.1 mg, 32%).
[0072] Comparative Example 1 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0073] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0074] The specific synthesis steps include: (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (2.04 g, 8.25 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (429.8 mg, yield 42%).
[0075] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, yield 92.8%).
[0076] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and compound 4 (981.3 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as eluent to give compound 5 (381.9 mg, yield 29%).
[0077] (iv) Under nitrogen protection, compound 5 (46 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound 6.
[0078] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound 6 (2.2 eq, 460.9 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-M1, which is the oligomeric fused-ring electron acceptor material (129.1 mg, yield 32%).
[0079] Comparative Example 2 An oligomeric fused-ring electron acceptor material, with the following structural formula: .
[0080] A method for preparing oligomeric fused-ring electron acceptor materials, the synthetic route is shown below: .
[0081] The specific synthesis steps are as follows: (i) In a dry flask, trimethyl(thiophen-2-yl)stanane (1.7 g, 6.87 mmol), compound 1 (1 g, 2.75 mmol), and catalyst tetra(triphenylphosphine)palladium (95.33 mg) were dissolved in anhydrous, oxygen-free toluene (15 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 2 as a white solid (869.8 mg, yield 85%).
[0082] (ii) In a dry flask, compound 2 (744.2 mg, 2 mmol) was dissolved in anhydrous tetrahydrofuran solution, and N-bromosuccinimide (3.56 g, 20 mmol) was added in portions. The mixture was reacted overnight at 0 °C in the dark with stirring. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 3:1) to give compound 3 as a white solid (980 mg, yield 92.8%).
[0083] (iii) INCN-Br (489.5 mg, 1.8 mmol), INCN-2F (414.1 mg, 1.8 mmol), and YF (972.2 mg, 0.72 mmol) were added to a mixed solvent of chloroform (10 mL) and pyridine (4 mL) and reacted overnight in an oil bath at 65°C. After removing the residual solvent by rotary evaporation under low pressure (<300 mbar), the product was purified by silica gel column chromatography using dichloromethane:petroleum ether (volume ratio 2:1) as eluent to obtain compound YF-Br (326.9 mg, yield 25%).
[0084] (iv) Under nitrogen protection, compound YF-Br (45.4 mg, 0.025 mmol), 2,5-bis(tributyltinyl)thiophene (8 eq, 0.20 mmol), tris(dibenzylacetone)dipalladium (1 mg), and tris(o-methylphenyl)phosphine (2 mg) were dissolved in toluene (15 mL). After stirring at 70 °C for 1.5 h, the reaction mixture was cooled to room temperature and then poured into methanol. The precipitate was collected by filtration and recrystallized from ethanol to give 40 mg of compound YF-Sn.
[0085] (v) In a dry flask, compound 3 (52.8 mg, 0.1 mmol), compound YF-Sn (2.2 eq, 464.3 mg, 0.22 mmol), and catalyst tetra(triphenylphosphine)palladium (7.63 mg) were dissolved in anhydrous toluene solution (10 mL). The mixture was stirred at 110°C for 24 h under argon protection. The mixture was then cooled to room temperature, poured into water, and extracted with chloroform. The organic layer was dried over anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation, and the resulting mixture was purified by silica gel chromatography (dichloromethane to petroleum ether volume ratio 2:1) to give a deep blue solid Z-MF, which is the oligomeric fused-ring electron acceptor material (84.2 mg, yield 21%).
[0086] Comparative Example 3 J. Mater. Chem. A, 2024, 12, 31581-31588 (ApA type quasi-macromolecular acceptors with molecular conjugation length control strategy for high-performance organic solar cells), page 3, QM-1T, QM-2T and QM-3T molecules in Fig. 1(a).
[0087] Comparative Example 4 Adv. Energy Mater. 2024, 2404567 (Dimeric Acceptors Using DifferentCentral Linkers to Manipulate Electronic and Morphological Properties), page 2, DY-2FBT, DY-pB, DY-Th, DY-BT, DY-mB and DY-EDOT molecules in Figure 1.
[0088] Performance test This invention uses the oligomeric fused ring electron acceptor materials prepared in Examples 1-4 and Comparative Examples 2-4 as active layer materials to prepare organic solar cells.
[0089] Organic solar cell structure such as Figure 1 As shown, it includes a transparent conductive substrate, a hole transport layer material, an active layer, an electron transport layer material, and a metal electrode. The specific fabrication steps are as follows: (1) Before fabrication, the indium tin oxide conductive glass (ITO) substrate was ultrasonically cleaned for 20 minutes in sequence with detergent, deionized water, acetone and isopropanol.
[0090] (2) The ITO substrate was cleaned with ultraviolet ozone for 15-25 minutes and then transferred to an N2 gas glove box with oxygen content <10ppm and water content <10ppm.
[0091] (3) Then, 2PACz solution (0.5 mg / mL) was spin-coated onto the ITO substrate at a speed of 3000 rpm for 30 s, and annealed at 100 °C for 10 min to obtain the ITO / 2PACz substrate.
[0092] (4) The mass ratio of donor material (PM6) to oligomeric fused ring electron acceptor material in the active layer solution is 1:1.2. The donor / acceptor material is dissolved in chloroform to obtain a solution with a concentration of 16 mg / mL. 5% of the acceptor mass of 3,6-bis(thiophene-2-yl)pyridazine is used as a solid additive. The solution is spin-coated at 3000 rpm for 30 s to obtain a 100 nm thick active layer film. Then, it is annealed at 80 °C for 10 min to obtain the ITO / 2PACz / PM6: oligomeric fused ring electron acceptor material substrate.
[0093] (5) Spin-coating PDINN electron transport material onto ITO / 2PACz / PM6: oligomeric fused ring electron acceptor material substrate. A 1.0 mg / mL PDINN methanol solution was spin-coated onto the active layer at 3500 rpm for 30 s to obtain ITO / 2PACz / PM6: oligomeric fused ring electron acceptor material / PDINN substrate.
[0094] (6) The final 100nm thick metal electrode is deposited onto the electron transport layer by vacuum evaporation to form the metal electrode. The effective active layer area is controlled to be 4mm using a mask. 2 .
[0095] In step (3), the molecular formula of 2PACz is: .
[0096] In step (4), the molecular formula of PM6 is: .
[0097] In step (4), the oligomeric fused ring electron acceptor material is Z-M1, Z-M2, Z-M3, Z-M4, Z-MF, QM-1T, QM-2T, QM-3T, DY-2FBT, DY-pB, DY-Th, DY-BT, DY-mB and DY-EDOT.
[0098] In step (5), the molecular formula of PDINN is: .
[0099] In step (6), the metal is Ag, Au, Cu, Al, or other materials.
[0100] The organic solar cells prepared in Examples 1-4 and Comparative Examples 2-4 were tested, and the cell structures are as follows: Figure 1 As shown in Table 1. Figure 2 , Figure 3 As shown, where, Figure 2 This is the normalized absorption spectrum of the oligomeric fused-ring electron acceptor material prepared in Example 1 of this invention and PM6 as the active layer material. BTP-eC9 is a commonly used electron acceptor in organic solar cells. Currently, the most advanced binary organic solar cells are based on BTP-eC9 as the acceptor material, and its molecular formula is: .
[0101] Depend on Figure 2 It is known that the absorption spectrum of Z-M1 is complementary to that of PM6 and BTP-eC9, which can effectively enhance the light utilization rate of 650-800nm and improve the short-circuit current of the battery.
[0102] Figure 3 This is a JV curve (light intensity 100 mW / cm²) of the oligomeric fused-ring electron acceptor material prepared in Example 1 of this invention applied to a polymer-based organic solar cell. 2 ).Depend on Figure 3It can be seen that the binary polymer-based organic solar cell based on PM6:Z-M1 as the active layer achieved a photoelectric conversion efficiency of 19.02%, which is one of the highest efficiencies of binary organic solar cells based on oligomers.
[0103] Figure 4 This is a morphology diagram of the active layer formed by the oligomeric fused-ring electron acceptor material prepared in Example 1 of this invention and PM6. Figure 4 It can be seen that Z-MI and PM6 form a continuous interpenetrating network with alternating light and dark phases, which is beneficial to exciton dissociation and charge transport, thereby improving battery performance.
[0104] Table 1 summarizes the efficiency statistics of the materials prepared in Examples 1-4 and Comparative Examples 2-4 applied to polymer-based organic solar cells. As shown in Table 1, the binary organic solar cell with Z-M1 as the active layer material in Example 1 of this invention has the highest efficiency of 19.02%. The organic solar cell with pseudo-para-type oligomeric fused-ring electron acceptor material as the active layer material prepared in this embodiment of the invention has a higher efficiency than the solar cell with traditional oligomeric fused-ring electron acceptor material as the active layer material in the comparative examples. This is due to the favorable "end-to-end" stacking, which can form a continuous interpenetrating network morphology, thereby promoting exciton dissociation. The cell based on Z-MF in Comparative Example 2 has a slightly lower efficiency because its N-position is linked with a polyfluoroalkyl chain, which reduces its solubility and affects the film-forming properties of the material, resulting in a slightly lower device efficiency.
[0105] Table 1. Statistical table of photovoltaic performance of binary organic solar cells with different active layer materials.
[0106] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its scope and protection, and such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.
Claims
1. An oligomeric fused-ring electron acceptor material, characterized in that, The structure is as follows: ， Where n is 0-4; the specific structure of R is: ； R1 is a five-membered heterocyclic or six-membered aromatic ring compound; R2 and R3 are independently selected from alkyl chains or alkyl aromatics; R4, R5, R6, and R7 are independently selected from hydrogen, halogens, or methoxy groups; R8 is one of S and Se.
2. The oligomeric fused-ring electron acceptor material according to claim 1, characterized in that, The specific structure of R1 is one of the following structures: 。 3. The oligomeric fused-ring electron acceptor material according to claim 1, characterized in that, The specific structure of R2 is one of the following structures: 。 4. The oligomeric fused-ring electron acceptor material according to claim 1, characterized in that, The specific structure of R3 is one of the following structures: 。 5. A method for preparing an oligomeric fused-ring electron acceptor material according to any one of claims 1-4, characterized in that, Includes the following steps: S1, compound 1, and aromatic heterocyclic derivative react to give compound 2; S2. Compound 2 from step S1 reacts with a brominating reagent to obtain compound 3; S3, compound 4, and ninhydrin derivative react to give compound 5; S4. The compound 5 described in step S3 reacts with the tin-modified five-membered heterocyclic derivative to obtain compound 6; S5, Compound 6 described in step S4 and Compound 3 described in step S2 react to obtain the oligomeric fused ring electron acceptor material; Compound 1 described in step S1 has the following structural formula: ; Compound 4 described in step S3 has the following structural formula: .
6. The preparation method according to claim 5, characterized in that, The aromatic heterocyclic derivative described in step S1 has the following structural formula: or , Compound 2 described in step S1 has the following structural formula: or , The compound 3 described in step S2 has the following structural formula: or , Where X1 is one of S, O, and Se, X2 and Y1 are independently selected from N or H, and Y is S, N, or H; The indanedione derivative mentioned in step S3 is and The combination; Compound 5 described in step S3 has the following structural formula: ； The tin-modified five-membered heterocyclic derivative described in step S4 has the following structural formula: ; Compound 6 described in step S4 has the following structural formula: .
7. The preparation method according to claim 6, characterized in that, In step S1, a catalyst is also used; in step S1, the molar ratio of compound 1, aromatic heterocyclic derivative and catalyst is 1:2.1-2.8:0.03-0.05; the concentration of the reaction solution of compound 1 is 0.15-0.34 mol / L. In step S2, the molar ratio of compound 2 to the brominating reagent is 1:10-15; the concentration of the reaction solution of compound 2 is 0.1-0.3 mol / L.
8. The preparation method according to claim 6, characterized in that, The aforementioned and The molar ratio is 1:1; In step S3, the molar ratio of compound 4 to the indanedione derivative is 1:2.4-5; the concentration of the reaction solution of compound 4 is 0.05-0.1 mol / L. In step S4, a catalyst and a catalyst ligand are also used; In step S4, the molar ratio of compound 5, tin-modified five-membered heterocyclic derivative, catalyst, and catalyst ligand is 1:1.2-2.5:1.2-2.5; the concentration of the reaction solution of compound 5 is 0.05-0.1 mol / L.
9. The application of an oligomeric fused-ring electron acceptor material according to any one of claims 1-4 or an oligomeric fused-ring electron acceptor material prepared by the preparation method according to any one of claims 5-8 in the preparation of organic solar cells.
10. The application according to claim 9, characterized in that, The specific steps for preparing the organic solar cell are as follows: Step A: After cleaning the substrate, transfer it to an inert gas glove box; Step B: Deposit hole transport layer solution by spin coating, followed by annealing treatment to obtain substrate / hole transport layer substrate; Step C: Spin-coat the active layer solution onto the substrate / hole transport layer substrate described in step B, and then anneal it to form an active layer, thus obtaining the substrate / hole transport layer / active layer substrate. Step D: Spin-coat an electron transport material solution onto the substrate / hole transport layer / active layer substrate described in step C, and then anneal it to form an electron transport layer, thus obtaining the substrate / hole transport layer / active layer / electron transport layer substrate. Step E: Form a metal electrode by vacuum deposition and control the effective active layer area using a mask.