A highly crystalline small molecule donor material containing multiple non-covalent interactions, and a preparation method and application thereof

Abstract

The application provides a high-crystallinity small-molecule donor material containing multiple non-covalent bonds and a preparation method and application thereof, and relates to the technical field of semiconductor materials. The application takes difluoro-substituted benzene or dialkoxy-substituted benzene and 2,3-dihydrothieno[3,4-B][1,4]dioxin (EDOT) as a core structure, and obtains the high-crystallinity small-molecule donor material through organic synthesis. The high-crystallinity small-molecule donor material has a simple structure, is applied to a ternary organic solar cell device as a third component, can obviously improve the performance of the device, and realizes photoelectric conversion efficiency far exceeding that of an original binary organic solar cell. The results of the embodiments show that the high-crystallinity small-molecule donor material is applied to the ternary organic solar cell device, the incorporation proportion is regulated, the photoelectric conversion efficiency of 19.3% can be realized, and the ideal photoelectric conversion efficiency can still be maintained in a large incorporation proportion interval (0-50%).

Description

Technical Field

[0001] This invention relates to the field of semiconductor materials technology, and in particular to a highly crystalline small molecule donor material containing multiple non-covalent bond interactions, its preparation method, and its applications. Background Technology

[0002] Organic solar cells possess advantages such as lightweight, low cost, solution-processability, and the ability to fabricate flexible electronic devices, making them highly promising for applications in building-mounted photovoltaic power generation, flexible wearable devices, and the Internet of Things (IoT). Thanks to the development of novel donor-acceptor materials and advancements in device engineering, the energy conversion efficiency of organic solar cells has now exceeded 19%. As a key factor influencing the photoelectric performance of the active layer material, the regulation of its crystallinity has been a crucial direction for optimizing its performance.

[0003] In recent years, active layer systems based on polymer donor materials and small-molecule non-fullerene acceptor materials have shown excellent performance, with binary organic solar cells based on this system achieving power conversion efficiencies exceeding 18%. However, their low open-circuit voltage and short-circuit current density remain key limitations to further performance improvements. Introducing a third component into the binary active layer system to optimize energy level structure, construct complementary absorption spectra, and control the active layer morphology—a ternary cell design strategy—has become a reliable means to address this issue and improve the performance of organic solar cells. Currently, most third components are small-molecule non-fullerene acceptors; however, small-molecule acceptors have complex structures, cumbersome synthesis routes, and high costs. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a highly crystalline small molecule donor material containing multiple non-covalent interactions, its preparation method, and its application. The highly crystalline small molecule donor material containing multiple non-covalent interactions provided by this invention has a simple structure. When used as a third component in ternary organic solar cell devices, it can significantly improve device performance, giving it excellent photoelectric conversion efficiency.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a highly crystalline small molecule donor material with multiple non-covalent interactions, having the structure shown in Formula I:

[0007]

[0008] In formula I, R is -C2H5 or -C6H 13 ,

[0009] R1 is -F,

[0010] This invention provides a method for preparing highly crystalline small molecule donor materials containing multiple non-covalent bond interactions as described in the above technical solutions, comprising the following steps:

[0011] Tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane, compound 1, tetratriphenylphosphine palladium and organic solvent were mixed and subjected to Stille coupling reaction to obtain compound 2;

[0012] Compound 2, N,N-dimethylformamide, phosphorus oxychloride and an organic solvent were mixed and subjected to a Vilsmeier-Haack reaction to obtain compound 3;

[0013] The compound 3, tannin-like compounds, organic bases and organic solvents were mixed and subjected to a Knoevenagel condensation reaction to obtain the highly crystalline small molecule donor material containing multiple non-covalent bond interactions.

[0014] Compound 1, Compound 2, Compound 3, and the ratannin-like compounds sequentially have the structures shown in Formulas II to V:

[0015]

[0016] Preferably, the molar equivalent ratio of the tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane to compound 1 is 2.5:1; and the molar equivalent ratio of the tetratriphenylphosphine palladium to compound 1 is 5 to 10:100.

[0017] Preferably, the Stille coupling reaction is carried out at a temperature of 90–120°C for 12–24 hours; the Stille coupling reaction is carried out in a nitrogen atmosphere.

[0018] Preferably, the molar equivalent ratio of compound 2 to N,N-dimethylformamide is 1:10, and the molar equivalent ratio of compound 2 to phosphorus oxychloride is 1:10.

[0019] Preferably, the Vilsmeier-Haack reaction is carried out at a temperature of 95°C for a time of 10–18 hours.

[0020] Preferably, the molar equivalent ratio of compound 3 to raffinine is 1:5; the organic base includes piperidine and / or pyridine, and the molar equivalent ratio of the organic base to compound 3 is 10-15:100.

[0021] Preferably, the Knoevenagel condensation reaction is carried out at a temperature of 65°C for 12–24 hours.

[0022] This invention provides the application of highly crystalline small molecule donor materials containing multiple non-covalent bond interactions as described in the above technical solutions or the highly crystalline small molecule donor materials containing multiple non-covalent bond interactions prepared by the above technical solutions in solar cells.

[0023] This invention provides a ternary solar cell, comprising a photoactive layer. The photoactive layer is made of a donor, an acceptor, and a third component. The third component comprises a highly crystalline small molecule donor material with multiple non-covalent interactions as described in the above technical solutions, or a highly crystalline small molecule donor material with multiple non-covalent interactions prepared by the preparation method described in the above technical solutions.

[0024] This invention provides a highly crystalline small-molecule donor material with multiple non-covalent bond interactions, having the structure shown in Formula I. The invention uses difluoro-substituted benzene or dialkoxy-substituted benzene and 2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin (EDOT) as the core structure, and obtains the highly crystalline small-molecule donor material through organic synthesis. The highly crystalline small-molecule donor material provided by this invention has a simple structure. When used as a third component in ternary organic solar cell devices, it can significantly improve device performance, achieving a photoelectric conversion efficiency far exceeding that of traditional binary organic solar cells. Example results show that applying the highly crystalline small-molecule donor material provided by this invention to ternary organic solar cell devices, by controlling the doping ratio, can achieve a photoelectric conversion efficiency of 19.3%, and can maintain an ideal photoelectric conversion efficiency even within a large doping ratio range (0-50%).

[0025] This invention provides a method for preparing highly crystalline small molecule donor materials containing multiple non-covalent bond interactions as described in the above technical solutions. The preparation method provided by this invention is simple, efficient, reproducible, low-cost, universal, and easy to scale up for production. Attached Figure Description

[0026] Figure 1 The 1H NMR spectrum of the highly crystalline small molecule donor material X1 in Example 1 is shown below.

[0027] Figure 2 The UV-Vis absorption spectrum (a), cyclic voltammetry curve (b), thermogravimetric analysis curve (c), and X-ray diffraction pattern (d) of the highly crystalline small molecule donor material X1 in Example 1 are shown.

[0028] Figure 3 The JV curve (a) and external quantum efficiency diagram (b) of the three-element device (donor materials are PM6 and X1, and acceptor material is L8-BO) in Example 2 are shown.

[0029] Figure 4The JV curve (a) and external quantum efficiency diagram (b) of the three-element device (donor materials are PM6 and X1, and acceptor material is BTP-4Cl) in Example 2 are shown.

[0030] Figure 5 The JV curves of the three components in Example 2 are shown. Figure 5 In Figure (a), the JV curve of the three-element device (donor materials are D18 and X1, and acceptor material is N3) in Example 2 is shown. Figure 5 (b) shows the JV curves of a ternary device with unequal amounts of X1 (donor materials are PM6 and X1, and acceptor material is L8-BO). Detailed Implementation

[0031] This invention provides a highly crystalline small molecule donor material with multiple non-covalent interactions, having the structure shown in Formula I:

[0032]

[0033] In formula I, R is -C2H5 or -C6H 13 ,

[0034] R1 is -F,

[0035] In this invention, -C2H5 is an ethyl group, and -C6H... 13 The R is hexyl; the R is preferably -C2H5.

[0036] In this invention, R1 is preferably...

[0037] This invention uses difluorosubstituted benzene or dialkoxysubstituted benzene and 2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin (EDOT) as the core structure. There are non-covalent bonds between the oxygen atom on the dialkoxybenzene and the sulfur atom on the EDOT unit, and between the oxygen atom on the EDOT unit and the hydrogen atom on the dialkoxybenzene unit. The effect of multiple non-covalent bonds strengthens the coplanarity of the molecular structure, thereby enhancing the crystallinity of the material. The enhanced crystallinity is beneficial to improving the carrier mobility of the active layer of organic solar cells, thereby ultimately improving the various performance characteristics of the battery device.

[0038] This invention provides a method for preparing highly crystalline small molecule donor materials containing multiple non-covalent bond interactions as described in the above technical solutions, comprising the following steps:

[0039] Tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane, compound 1, tetratriphenylphosphine palladium and organic solvent were mixed and subjected to Stille coupling reaction to obtain compound 2;

[0040] Compound 2, N,N-dimethylformamide, phosphorus oxychloride and an organic solvent were mixed and subjected to a Vilsmeier-Haack reaction to obtain compound 3;

[0041] The compound 3, tannin-like compounds, organic bases and organic solvents were mixed and subjected to a Knoevenagel condensation reaction to obtain the highly crystalline small molecule donor material containing multiple non-covalent bond interactions.

[0042] Compound 1, Compound 2, Compound 3, and the ratannin-like compounds sequentially have the structures shown in Formulas II to V:

[0043]

[0044] In this invention, unless otherwise specified, all raw materials involved are commercially available products well known to those skilled in the art or prepared using preparation methods well known to those skilled in the art.

[0045] In this invention, tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane, compound 1, tetrakis(triphenylphosphine)palladium, and an organic solvent (denoted as the first organic solvent) are mixed and subjected to a Stille coupling reaction to obtain compound 2.

[0046] In this invention, compound 1 has the structure shown in Formula II, where R1 in Formula II is consistent with R1 in Formula I. In this invention, the molar equivalent ratio of tributyl(2,3-dihydrothieno[3,4-B]-[1,4]dioxin-5-yl)stanane to compound 1 is preferably 2.5:1. In this invention, tetraphenylphosphine palladium is used as a catalyst, and the molar equivalent ratio of tetraphenylphosphine palladium to compound 1 is preferably 5–10:100. In this invention, the first organic solvent is preferably toluene, and the toluene is preferably anhydrous and oxygen-free toluene; this invention does not have particular requirements on the amount of toluene used, as long as the reaction proceeds smoothly.

[0047] The present invention does not have any particular requirements for the method of mixing the tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane, compound 1, tetratriphenylphosphine palladium and organic solvent; any mixing method known to those skilled in the art can be used.

[0048] In this invention, the temperature of the Stille coupling reaction is preferably 90-120°C, more preferably 110°C, and the time is preferably 12-24 h, more preferably 18 h; the Stille coupling reaction is preferably carried out in a nitrogen atmosphere.

[0049] After the Stille coupling reaction is completed, the present invention preferably performs post-treatment on the obtained reaction solution. The preferred post-treatment method is as follows: washing the reaction solution with saturated brine, extracting with dichloromethane, drying and rotary evaporating the obtained organic phase sequentially to obtain a concentrate; and performing column chromatography on the concentrate to obtain compound 2. In the present invention, the extraction is preferably performed three times, and the organic phases are combined. In the present invention, the drying reagent is preferably anhydrous sodium sulfate, which is filtered after drying, and the filtrate is collected. The solvent is removed by rotary evaporation. In the present invention, the column chromatography preferably uses a silica gel column, and the eluent is preferably petroleum ether and dichloromethane, with a preferred volume ratio of 3:1.

[0050] In this invention, compound 2 has the structure shown in Formula III, where R1 in the structure shown in Formula III is consistent with R1 in the structure shown in Formula II.

[0051] After obtaining compound 2, the present invention mixes compound 2, N,N-dimethylformamide (DMF), phosphorus oxychloride and an organic solvent (denoted as the second organic solvent) and carries out a Vilsmeier-Haack reaction to obtain compound 3.

[0052] In this invention, the molar equivalent ratio of compound 2 to N,N-dimethylformamide is preferably 1:10, and the molar equivalent ratio of compound 2 to phosphorus oxychloride is preferably 1:10. In this invention, the second organic solvent is preferably 1,2-dichloroethane. This invention does not have specific requirements on the amount of 1,2-dichloroethane used, as long as the reaction proceeds smoothly.

[0053] In this invention, the temperature of the Vilsmeier-Haack reaction is preferably 95°C, and the time is preferably 10 to 18 hours, more preferably 12 hours. The temperature of the Vilsmeier-Haack reaction is preferably achieved by an oil bath.

[0054] In this invention, N,N-dimethylformamide is added to a 1,2-dichloroethane solution of compound 2 cooled in an ice-water bath under a nitrogen atmosphere. Then, phosphorus oxychloride is slowly added dropwise to the resulting solution. After that, the resulting mixed solution is transferred to an oil bath at 95°C for the Vilsmeier-Haack reaction.

[0055] After the Vilsmeier-Haack reaction is completed, the present invention preferably quenches the reaction with a saturated sodium acetate solution, and then performs post-treatment on the resulting reaction solution. The preferred post-treatment method is: extracting the resulting reaction solution with dichloromethane, drying and rotary evaporating the resulting organic phase sequentially to obtain a concentrate; and performing column chromatography on the concentrate to obtain compound 3. In the present invention, the extraction is preferably performed three times, and the organic phases are combined. In the present invention, the drying reagent is preferably anhydrous sodium sulfate. The solvent is removed by rotary evaporation. In the present invention, the column chromatography preferably uses a silica gel column, and the eluent is preferably petroleum ether and dichloromethane, with a preferred volume ratio of 3:1.

[0056] In this invention, compound 3 has the structure shown in Formula IV, where R1 in the structure shown in Formula IV is consistent with R1 in the structure shown in Formula III.

[0057] After obtaining compound 3, the present invention mixes compound 3, tannin-like compounds, organic bases and organic solvents (denoted as the third organic solvent) and carries out a Knoevenagel condensation reaction to obtain the highly crystalline small molecule donor material containing multiple non-covalent bond interactions.

[0058] In this invention, the raffinine compound has the structure shown in Formula V, where R in Formula V is consistent with R in Formula I. In this invention, the molar equivalent ratio of compound 3 to the raffinine compound is preferably 1:5; the organic base preferably includes piperidine and / or pyridine, and the molar equivalent ratio of the organic base to compound 3 is preferably 10-15:100, wherein the organic base provides an alkaline reaction environment. In this invention, the third organic solvent is preferably chloroform; the amount of chloroform used is not particularly important, as long as the reaction proceeds smoothly.

[0059] In this invention, compound 3 is preferably dissolved in an organic solvent, and razotanine and piperidine are added sequentially to the resulting solution under stirring conditions.

[0060] In this invention, the temperature of the Knoevenagel condensation reaction is preferably 65°C, and the time is preferably 12-24 h, more preferably 18 h; the Knoevenagel condensation reaction is preferably carried out under stirring conditions.

[0061] After the Knoevenagel condensation reaction is completed, the present invention preferably washes the resulting reaction solution with saturated brine, then extracts it with dichloromethane, and successively dries and rotary evaporates the resulting organic phase to obtain a concentrate; the concentrate is then subjected to column chromatography to obtain the highly crystalline small molecule donor material containing multiple non-covalent bonds (structure shown in Formula I). ​​In the present invention, the extraction is preferably performed three times, and the organic phases are combined. In the present invention, the drying reagent is preferably anhydrous sodium sulfate. The present invention removes the organic solvent by rotary evaporation. In the present invention, the column chromatography preferably uses a silica gel column, and the eluent is preferably petroleum ether and dichloromethane, with the volume ratio of petroleum ether to dichloromethane preferably being 2:1.

[0062] The reaction formulas involved in preparing the highly crystalline small molecule donor material containing multiple non-covalent interactions according to the present invention are as follows:

[0063]

[0064] This invention provides the application of highly crystalline small molecule donor materials with multiple non-covalent bonds as described in the above technical solutions, or highly crystalline small molecule donor materials with multiple non-covalent bonds prepared by the above preparation methods, in solar cells. Applying these highly crystalline small molecule donor materials with multiple non-covalent bonds to ternary organic solar cells can significantly improve device performance, achieving photoelectric conversion efficiency far exceeding that of traditional binary organic solar cells.

[0065] This invention provides a ternary solar cell, comprising a photoactive layer. The photoactive layer is made of a donor, an acceptor, and a third component. The third component comprises a highly crystalline small molecule donor material with multiple non-covalent interactions as described in the above technical solutions, or a highly crystalline small molecule donor material with multiple non-covalent interactions prepared by the preparation method described in the above technical solutions.

[0066] In this invention, the donor is preferably PM6, and the acceptor is preferably BTP-BO4Cl or L8-BO; alternatively, the donor is preferably D18, and the acceptor is preferably N3. The structural formulas of PM6, BTP-BO4Cl, and L8-BO are as follows:

[0067]

[0068] In this invention, the ratio of the sum of the masses of the donor and the third component to the mass of the acceptor is preferably 1:1.2, and the mass of the third component is preferably 0-50% of the sum of the masses of the donor and the third component, and the mass of the third component is not zero; more preferably, the mass of the third component is 10-30% of the sum of the masses of the donor and the third component. This invention does not impose any special requirements on the preparation method of the photoactive layer; methods well known to those skilled in the art can be used. This invention does not impose any special requirements on the composition of other structural layers of the ternary solar cell or the construction method of the ternary solar cell; corresponding technical solutions well known to those skilled in the art can be used.

[0069] Currently, the photoelectric conversion efficiencies (PCEs) of single-junction organic solar cell devices using PM6 and L8-BO as photoactive layers, PM6 and BTP-BO-4Cl as photoactive layers, and D18 and N3 as photoactive layers are generally around 18%, 17%, and 18%, respectively. However, after introducing the aforementioned highly crystalline small-molecule donor material with multiple non-covalent bonds as a third component, the PCEs of ternary organic solar cell devices reach 19.3%, 18.0%, and 19.14%, respectively, achieving world-leading levels in this field. Furthermore, the aforementioned highly crystalline small-molecule donor material with multiple non-covalent bonds can maintain ideal PCEs across a wide doping ratio range (0–50%), demonstrating its potential application value in organic solar cells.

[0070] To further illustrate the present invention, the highly crystalline small molecule donor materials with multiple non-covalent bond interactions provided by the present invention, their preparation methods, and applications are described in detail below with reference to examples, but these should not be construed as limiting the scope of protection of the present invention.

[0071] Example 1

[0072] The synthesis method of the highly crystalline small molecule donor material X1 is shown below:

[0073]

[0074] The specific synthesis steps are as follows:

[0075] Tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane (1.8 g, 4.18 mmol, 2.5 eq) and compound 1 (1.2 g, 1.67 mmol, 1 eq) were added to a two-necked reaction flask. Tetraphenylphosphine palladium (96.50 mg, 0.0835 mmol, 0.05 eq) was used as a catalyst, and anhydrous and oxygen-free toluene was used as a solvent. The reaction was carried out at 110 °C for 18 h under nitrogen protection. After the reaction was completed, the mixture was washed with saturated brine, extracted three times with dichloromethane, and the organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation. The mixture was then purified by silica gel column chromatography (petroleum ether: dichloromethane = 3:1) to give compound 2 as a pale yellow solid with a yield of approximately 76.9%.

[0076] (2) Under a nitrogen atmosphere, DMF (0.78 g, 10.7 mmol, 10 eq) was added to a 1,2-dichloroethane solution of compound 2 (0.9 g, 1.07 mmol, 1 eq) cooled in an ice-water bath. Then, phosphorus oxychloride (1.64 g, 10.7 mmol, 10 eq) was slowly added dropwise to the above solution. After the addition was complete, the solution was transferred to an oil bath at 95 °C and the reaction continued for 12 h. After the reaction was completed, the reaction solution cooled to room temperature was added to a saturated sodium acetate solution and stirred to quench the reaction. When the organic phase turned orange-yellow, it was transferred to a separatory funnel and extracted three times with dichloromethane. The organic phases were combined, dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation. The solution was then separated and purified by silica gel column chromatography (petroleum ether: dichloromethane = 3:1) to obtain compound 3 as a pale yellow solid with a yield of approximately 95.1%.

[0077] (3) Compound 3 (0.5 g, 0.56 mmol, 1 eq) was dissolved in a two-necked reaction flask using chloroform as the solvent. 2-Ethylrhotanine (0.45 g, 2.80 mmol, 5 eq) was added to the reaction system with stirring, followed by piperidine (0.5 mL). The reaction was continued for 18 h with heating and stirring at 65 °C. After the reaction was complete, the mixture was washed with saturated brine and extracted three times with dichloromethane. The combined organic phases were dried over anhydrous sodium sulfate, filtered, and the solvent was removed by rotary evaporation. The mixture was then purified by silica gel column chromatography (petroleum ether: dichloromethane = 2:1) to obtain the small molecule donor material X1 as a pale yellow solid with a yield of approximately 87.8%. 1 1H NMR (400MHz, CDCl3): δ 7.99 (s, 2H), 7.89 (s, 2H), 4.41 (s, 8H), 4.19 (d, J = 7.0Hz, 4H), 4.04 (d, J = 4.7Hz, 4H), 2.05–1.97 (m, 2H), 1.67–1.56 (m, 8H), 1.39–1.10 (m, 46H), 0.84 (d, J = 6.1Hz, 12H); its 1H NMR spectrum is as follows: Figure 1As shown. By Figure 1 It can be determined that the structure of the small molecule donor material X1 is correct.

[0078] Figure 2 The UV-Vis absorption spectrum (a), cyclic voltammetry curve (b), thermogravimetric analysis curve (c), and X-ray diffraction pattern (d) of the highly crystalline small molecule donor material X1 prepared in Example 1 are shown. Figure 2 As can be seen, the absorption spectrum of X1 solution (chloroform solution) is distributed between 450 and 630 nm, with the highest absorption peak at 579 nm. However, the absorption of the X1 film (spin-coated from a 10 mg / mL X1 chloroform solution) shows a significant red shift, with the maximum absorption peak at 611 nm. Comparison with the absorption spectra of PM6:L8-BO in the literature indicates that the ternary active layer can achieve complementary absorption spectra. Cyclic voltammetry calculations show that X1's highest unoccupied orbital (HOMO) is -5.67 eV, while its lowest occupied orbital (LUMO) is -3.83 eV; the lower HOMO level is beneficial for obtaining a higher open-circuit voltage. Thermogravimetric analysis shows that X1 has excellent thermal stability, with a decomposition temperature exceeding 350 °C. Finally, XRD results show that X1 exhibits high and sharp crystallization peaks, indicating that the material has very strong crystallinity.

[0079] Example 2

[0080] Organic solar cell devices using highly crystalline small molecule donor X1 as the third component of the donor material:

[0081] The donor material used in the battery device is PM6, and the acceptor materials are BTP-BO4Cl and L8-BO.

[0082] When the donor material is PM6 and the acceptor material is L8-BO, the specific preparation and performance test results are as follows:

[0083] (1) After cleaning and drying the ITO glass substrate, the device was treated with a UV cleaner for 15 minutes and then set aside. A VOC2O4 aqueous solution for the hole transport layer was spin-coated onto the ITO substrate at 4000 rpm. After annealing at 200°C for 15 minutes, a UVO treatment was performed for 15 minutes to form a uniform thin film. After annealing, the sample was transferred to a nitrogen glove box, and the prepared active layer solution was spin-coated onto the hole transport layer at 3000 rpm for 30 seconds, resulting in an active layer thickness of approximately 90 nm. The active layer was annealed at 80°C for 5 minutes, followed by spin-coating of the electron transport layer solution PNDIT-F3N-Br at 3500 rpm. Finally, a 100 nm Ag electrode was deposited. The active layer solution was divided into a control group and an experimental group. The active layer solution of the control group was a chloroform solution of PM6 and L8-BO, in which the mass ratio of PM6 to L8-BO was 1:1.2 and the total concentration of PM6 and L8-BO was 15 mg / mL. The experimental group replaced 10% (denoted as X1(10%)), 20% (denoted as X1(20%)), 30% (denoted as X1(30%)), and 50% (denoted as X1(50%)) of the mass of PM6 in the control group with X1.

[0084] Under optimal device conditions (test area 0.0289 cm²), 2 The parameters were measured and are shown in Tables 1 and 2.

[0085] Table 1. Performance characteristics of solar cells (donor material: PM6, acceptor material: L8-BO)

[0086] index Voc(V) J sc (mA cm -2 )]]> <![CDATA[J cal (mA cm -2 )]]> FF (%) PCE (%) Area (cm2) Comparison 0.885 26.23 24.91 78.57 18.25 0.0289 X1(10％) 0.893 26.54 25.17 81.54 19.34 0.0289

[0087] In Table 1, Voc represents the open-circuit voltage; J represents the open-circuit voltage. sc Short-circuit current density; J cal : Correction current (obtained by external quantum efficiency EQE test, which is a correction of the value); FF: Fill factor; PCE: Power conversion efficiency; Area: Effective operating area of ​​the device.

[0088] Currently, the photoelectric conversion efficiency of single-junction organic solar cell devices with PM6 and L8-BO as photoactive layers is generally 18%. However, after introducing X1 (10%) as the third component, the photoelectric conversion efficiency of ternary organic solar cell devices is 19.3%, which has reached the world's leading level in this field, proving that this material has potential application value in organic solar cells. Figure 3 The images show the JV curve (a) and external quantum efficiency plot (b) of the ternary device (donor materials PM6 and X1, acceptor material L8-BO) in Example 2. Figure 3As can be seen, after introducing X1 as the third component, the device parameters are comprehensively improved compared to the PM6:L8-BO binary device, and the efficiency is broken through to 19.34%. The EQE current correction also confirms the reliability of the short-circuit current density.

[0089] Table 2 shows the performance of solar cells with varying X1 content (donor material: PM6, acceptor material: L8-BO):

[0090] Table 2. Performance of solar cells with varying X1 content.

[0091] index Voc(V) <![CDATA[J sc (mA cm -2 )]]> FF (%) PCE (%) <![CDATA[Area(cm 2 )]]> X1(10％) 0.893 26.54 81.54 19.34 0.0289 X1(20％) 0.896 26.24 79.39 18.68 0.0289 X1(30％) 0.905 24.73 79.82 17.86 0.0289 X1(50％) 0.913 23.01 76.83 16.15 0.0289

[0092] When PM6 is the donor material and BTP-BO4Cl is the acceptor material, the specific preparation and performance test results are as follows:

[0093] (1) After cleaning and drying the ITO glass substrate, the device was treated with a UV cleaner for 15 minutes and then set aside. A VOC2O4 aqueous solution for the hole transport layer was spin-coated onto the ITO substrate at 4000 rpm. After annealing at 200°C for 15 minutes, a UVO treatment was performed for 15 minutes to form a uniform thin film. After annealing, the sample was transferred to a nitrogen glove box, and the prepared active layer solution was spin-coated onto the hole transport layer at 3500 rpm for 30 seconds, resulting in an active layer thickness of approximately 90 nm. The active layer was annealed at 80°C for 5 minutes, followed by spin-coating of the electron transport layer solution PNDIT-F3N-Br at 3500 rpm. Finally, a 100 nm Ag electrode was deposited. The active layer solution was divided into a control group and an experimental group. The control group was a chlorobenzene solution of PM6 and BTP-BO4Cl, where PM6:BTP-BO4Cl (mass ratio) = 1:1.2 and the total concentration of PM6 and BTP-BO4Cl was 15 mg / mL. The experimental group replaced 10% of the mass of PM6 in the control group with X1 (denoted as X1(10%)).

[0094] (2) Under optimal device conditions (test area 0.04 cm²) 2 The parameters were measured and are shown in Table 3.

[0095] Table 3. Performance characteristics of solar cells (donor material: PM6, acceptor material: BTP-BO4Cl)

[0096] index Voc(V) <![CDATA[Jsc(mA cm -2 )]]> FF (%) PCE (%) <![CDATA[Area(cm 2 )]]> Comparison 0.841 27.48 73.60 17.01 0.04 X1(10％) 0.857 27.65 75.87 17.98 0.04

[0097] Currently, the photoelectric conversion efficiency (PCE) of single-junction organic solar cell devices using PM6 and BTP-BO-4Cl as photoactive layers is around 17%. However, after introducing X1 as a third component, the PCE of ternary organic solar cell devices reaches 18.0%, achieving a world-leading level in this field. This invention uses the PM6:BTP-BO4Cl system for universality testing. Figure 4 The JV curve (a) and external quantum efficiency diagram (b) of the ternary device (donor materials PM6 and X1, acceptor material BTP-4Cl) in Example 2 show that the device efficiency is also significantly improved, approaching 18%.

[0098] When the donor material is D18 and the acceptor material is N3, the specific preparation and performance test results are as follows:

[0099] (1) After cleaning and drying the ITO glass substrate, the device was treated with a UV cleaner for 15 minutes and then set aside. A VOC2O4 aqueous solution for the hole transport layer was spin-coated onto the ITO substrate at 4000 rpm. After annealing at 200°C for 15 minutes, a UVO treatment was performed for 15 minutes to form a uniform thin film. After annealing, the sample was transferred to a nitrogen glove box, and a prepared active layer solution was spin-coated onto the hole transport layer at 2200 rpm for 30 seconds, resulting in an active layer thickness of approximately 95 nm. The active layer was annealed at 80°C for 5 minutes, followed by spin-coating of the electron transport layer solution PNDIT-F3N-Br at 3500 rpm. Finally, a 100 nm Ag electrode was deposited. The active layer solution was divided into a control group and an experimental group. The active layer solution of the control group was a chloroform solution of D18 and N3, where the mass ratio of D18 to N3 was 1:1.2 and the total concentration of D18 and N3 was 10 mg / mL. The experimental group replaced 10% of the mass of D18 in the control group with X1 (denoted as X1(10%)).

[0100] (2) Under optimal device conditions (test area is 0.0289 cm²) 2 The parameters of the instrument were measured and are shown in Table 4.

[0101] Table 4. Performance characteristics of solar cells (donor material: D18, acceptor material: N3)

[0102] index Voc(V) <![CDATA[Jsc(mA cm -2 )]]> FF (%) PCE (%) <![CDATA[Area(cm 2 )]]> Comparison 0.833 27.43 79.79 18.24 0.0289 X1(10％) 0.840 28.22 80.76 19.14 0.0289

[0103] Currently, the photoelectric conversion efficiency (PCE) of single-junction organic solar cell devices using D18 and N3 as photoactive layers is around 18%. However, after introducing X1 as a third component, the PCE of ternary organic solar cell devices reaches 19.14%, achieving a world-leading level in this field. This invention uses the D18:N3 system for universality testing. Figure 5In Figure (a), the JV curve of the ternary device (donor materials are D18 and X1, and acceptor material is N3) in Example 2 can be seen. It can be seen that the device efficiency is significantly improved, indicating that X1, a strongly crystalline small molecule donor, has a significant effect on improving the device efficiency of the current high-efficiency active layer system.

[0104] Furthermore, even when the amount of the third component increased from 10% to 50%, the ternary device still maintained a good photoelectric conversion efficiency, demonstrating the potential application value of this material in organic solar cells. Figure 5 (b) shows the JV curves of the ternary device (donor materials are PM6 and X1, and acceptor material is L8-BO) with unequal amounts of X1 introduced in Example 2.

[0105] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A highly crystalline small molecule donor material containing multiple non-covalent interactions, having the structure shown in Formula I: Formula I, In Equation I, R is , R1 is .

2. The method for preparing the highly crystalline small molecule donor material containing multiple non-covalent bond interactions as described in claim 1, characterized in that, Includes the following steps: Tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane, compound 1, tetratriphenylphosphine palladium and organic solvent were mixed and subjected to Stille coupling reaction to obtain compound 2; Compound 2, N,N-dimethylformamide, phosphorus oxychloride and an organic solvent were mixed and subjected to a Vilsmeier-Haack reaction to obtain compound 3; The compound 3, tannin-like compounds, organic bases and organic solvents were mixed and subjected to a Knoevenagel condensation reaction to obtain the highly crystalline small molecule donor material containing multiple non-covalent bond interactions. Compound 1, compound 2, compound 3, and the ratannin-like compound have the structures shown in formulas II to V, respectively: Formula II, Formula III, Formula IV, Formula V.

3. The preparation method according to claim 2, characterized in that, The molar equivalent ratio of the tributyl(2,3-dihydrothiopheno[3,4-B]-[1,4]dioxin-5-yl)stanane to compound 1 is 2.5:1; the molar equivalent ratio of the tetratriphenylphosphine palladium to compound 1 is 5~10:

100.

4. The preparation method according to claim 2 or 3, characterized in that, The Stille coupling reaction is carried out at a temperature of 90~120℃ for 12~24h; the Stille coupling reaction is carried out in a nitrogen atmosphere.

5. The preparation method according to claim 2, characterized in that, The molar equivalent ratio of compound 2 to N,N-dimethylformamide is 1:10, and the molar equivalent ratio of compound 2 to phosphorus oxychloride is 1:

10.

6. The preparation method according to claim 2 or 5, characterized in that, The Vilsmeier-Haack reaction was carried out at a temperature of 95°C for 10–18 hours.

7. The preparation method according to claim 2, characterized in that, The molar equivalent ratio of compound 3 to razotanine is 1:5; the organic base is selected from piperidine and / or pyridine, and the molar equivalent ratio of the organic base to compound 3 is 10~15:

100.

8. The preparation method according to claim 2 or 7, characterized in that, The Knoevenagel condensation reaction was carried out at a temperature of 65°C for 12–24 hours.

9. The application of the highly crystalline small molecule donor material containing multiple non-covalent bond interactions as described in claim 1 or the highly crystalline small molecule donor material containing multiple non-covalent bond interactions prepared by the preparation method described in any one of claims 2 to 8 in solar cells.

10. A ternary solar cell, comprising a photoactive layer, wherein the material of the photoactive layer comprises a donor, an acceptor, and a third component, characterized in that, The third component includes the highly crystalline small molecule donor material with multiple non-covalent bond interactions as described in claim 1, or the highly crystalline small molecule donor material with multiple non-covalent bond interactions prepared by the preparation method described in any one of claims 2 to 8.

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