Dimer non-fullerene acceptor molecule based on pyrone-ring lock structure, preparation and application of dimer non-fullerene acceptor molecule as acceptor photovoltaic material

Abstract

The invention relates to a dimer non-fullerene acceptor molecule based on a pyrone-ring lock structure, preparation of the dimer non-fullerene acceptor molecule and application of the dimer non-fullerene acceptor molecule as an acceptor photovoltaic material, and belongs to the technical field of organic solar cell materials. An A-D-A '-D-A type dimer non-fullerene acceptor molecule is designed and synthesized based on a pyrone structure, A is an electron withdrawing unit, D is an electron donating unit, and A' is an electron withdrawing unit based on the pyrone structure. The dimer molecule has a structural general formula I shown in the specification. Wherein EG is selected from conjugated groups with electron withdrawing capability, Ar is selected from conjugated groups with electron donating capability, and X is selected from hydrogen atoms or halogen. The dimer acceptor molecule shows a small dihedral angle, which is beneficial to accumulation between molecules, so that the material has high carrier mobility. The dimer acceptor molecule with the pyrone structure shows obviously improved stability under illumination and attack of a nucleophilic reagent, and the organic solar cell device shows good photoelectric conversion efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of organic solar cell materials, relates to the preparation of photovoltaic materials, and in particular to a dimer non-fullerene receptor molecule based on a pyrone-ring-locked structure, and its preparation and application as a receptor photovoltaic material. Background Art

[0002] In recent years, organic solar cells (OSCs) have attracted widespread attention. Compared with inorganic solar cells, solar cells have the following advantages: solution processability, light weight, good flexibility, and can also be mass-produced using low-cost solution roll-to-roll spraying and printing technologies. At present, thanks to the coordinated development of new material design and device processes, the photoelectric conversion efficiency (PCE) of OSCs based on acceptor-donor-acceptor (ADA) type non-fullerene acceptors (NFA) has exceeded 20%, which is comparable to commercial silicon-based solar cells, showing its great application prospects. However, the stability of OSCs has always been a difficult problem in this field.

[0003] In common ADA-type NFAs, such as the ITIC series, Y series, and non-condensed ring series, they all have a common structural feature, namely, two exocyclic ethylene bridges formed by Knoevenagel condensation at the junction of the D and A units. The strong push-pull electron effect caused by this structural design makes this exocyclic ethylene bridge highly reactive. This ethylene bridge is not only attacked by interfacial layer nucleophiles, but is also susceptible to photooxidation in an oxygen environment or six-electron electrocyclic reactions in an inert atmosphere, all of which can cause NFAs to degrade during device operation. Therefore, how to improve the intrinsic chemical and photochemical stability of NFAs at the molecular level remains a major challenge in this field. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention solves the technical problem that the organic solar cell receptor material in the prior art is prone to degradation under light and nucleophilic reagent environments. By introducing the pyrone-ring lock structure, the resulting dimer receptor photovoltaic material has technical advantages such as high light stability and chemical stability, and the organic solar cell device based on the receptor material exhibits high light and thermal stability.

[0005] According to a first aspect of the present invention, there is provided an AD-A'-DA type dimer non-fullerene acceptor molecule based on a pyrone-ring lock structure, wherein the AD-A'-DA type dimer non-fullerene acceptor molecule has a structural formula as shown in Formula I: wherein A is an electron-withdrawing unit, D is an electron-donating unit, and A' is an electron-withdrawing unit based on a pyrone structure;

[0006]

[0007] in:

[0008] EG is selected from a conjugated group having electron-withdrawing ability;

[0009] Ar is selected from an electron-rich conjugated aromatic structure;

[0010] X is selected from a hydrogen atom or a halogen.

[0011] Preferably, EG is selected from one of the following structures:

[0012]

[0013] Wherein Y is any one of a hydrogen atom or a halogen, and the dotted line is the connection position between EG and Ar.

[0014] Preferably, Ar is selected from one of the following structures:

[0015]

[0016] Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any one of the alkoxy groups; R2 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any one of the alkoxy groups; the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

[0017] According to another aspect of the present invention, a method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure is provided, comprising the following steps:

[0018] (1) Compound 1 and 2,6-dimethyl-4H-pyrone are dissolved in acetic anhydride and reacted under heating conditions; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and the reaction solution is purified to obtain Compound 2;

[0019]

[0020] Wherein X is any one of a hydrogen atom or a halogen;

[0021] (2) Under the protection of nitrogen or inert gas, compound 2, compound 3 and piperidine are dissolved in an organic solvent A, and reacted at 70-140° C.; the organic solvent A is chloroform, toluene or xylene; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and purified to obtain compound 4;

[0022]

[0023] (3) Under the protection of nitrogen or inert gas, dissolving compound 4, compound 5, ether solution of boron trifluoride and acetic anhydride in organic solvent B, wherein organic solvent B is dry chloroform, toluene or xylene; reacting at 0-60° C.; after sufficient reaction, extracting the reaction solution, removing the solvent, and purifying to obtain AD-A'-DA type dimer non-fullerene receptor based on pyrone structure of formula I;

[0024]

[0025] Wherein Y is any one of a hydrogen atom or a halogen.

[0026] Preferably, Ar in the compound 3 and compound 4 is selected from one of the following structures:

[0027]

[0028] Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any of the alkoxy groups of 30 Alkyl, C1-C 30 Any one of the alkoxy groups; the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

[0029] Preferably, in the step (1), the molar ratio of compound 1 to 2,6-dimethyl-4H-pyrone is 1:(1-4); the concentration of compound 1 in acetic anhydride is 8 mg / mL to 12 mg / mL; and the reaction time is 8-24 h.

[0030] Preferably, in the step (2), the molar ratio of compound 2 to compound 3 is 1:(2-4); the concentration of compound 2 in organic solvent A is 1 mg / mL to 25 mg / mL; and the reaction time is 12-24 h.

[0031] Preferably, in the step (3), the molar ratio of compound 4, compound 5, boron trifluoride and acetic anhydride is 1:(2.1-3):(0.05-1):(0.05-1); the concentration of compound 4 in organic solvent B is 0.01 mg / mL to 6 mg / mL; and the reaction time is 0.5 to 12 h.

[0032] According to another aspect of the present invention, there is provided the use of the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring-lock structure in the preparation of photovoltaic receptor materials.

[0033] According to another aspect of the present invention, there is provided the use of the AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone-ring-locked structure in the preparation of an organic solar cell binary device or an organic solar cell ternary device.

[0034] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0035] (1) The electron-withdrawing unit (compound 2) based on the pyrone structure prepared by the present invention has strong planarity, and its crystals have a relatively compact and regular stacking, which is conducive to the formation of good π-π stacking in the receptor molecule.

[0036] (2) The AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone structure prepared by the present invention has excellent thermal stability, good energy level, and a wide and strong absorption spectrum, making the dimerized material feasible as a photovoltaic acceptor material and providing a choice for future oligomer materials as active layer materials for binary and ternary devices.

[0037] (3) The AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone structure prepared by the present invention has strong molecular planarity and can form effective π-π stacking in organic solar cell devices, which is beneficial to the transport of carriers.

[0038] (4) The AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone structure prepared by the present invention has good intrinsic stability and exhibits significantly improved stability under strong light irradiation and nucleophilic reagent environments, which is beneficial to improving the stability of organic solar cell devices.

[0039] (5) The organic solar cell device constructed by the AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone structure prepared by the present invention has excellent external quantum efficiency and considerable photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The schematic diagram is a synthetic route of the preparation method of ITBIC-F of the present invention.

[0041] Figure 2 The schematic diagram is a synthetic route of the preparation method of TBTBIC-F of the present invention.

[0042] Figure 3 It is the hydrogen spectrum of compound ITBIC-F of the present invention.

[0043] Figure 4 It is the hydrogen spectrum of the compound TBTBIC-F of the present invention.

[0044] Figure 5 It is the UV-visible absorption spectrum of the dimer receptor of the pyrone-ring-lock structure of the present invention.

[0045] Figure 6 The molecular structure diagram (top view and side view) of the pyrone-ring-locked dimer receptor of the present invention is optimized by DFT.

[0046] Figure 7 Schematic diagram of the stability improvement of the pyrone-ring-locked dimer receptor under light and nucleophilic environment. a) is under light environment, b) is under nucleophilic environment.

[0047] Figure 8 The current-voltage curve of the organic solar cell made of the pyrone-ring-locked dimer acceptor material and PM6 provided in the example.

[0048] Fig. 9 The external quantum efficiency curve of the organic solar cell made of the pyrone-ring-locked dimer acceptor material and PM6 provided in the example. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] In the first aspect, the present invention provides an AD-A'-DA type dimer non-fullerene receptor molecule based on a pyrone structure, wherein A is an electron-withdrawing unit, D is an electron-donating unit, and A' is an electron-withdrawing unit based on a pyrone structure. The AD-A'-DA type dimer non-fullerene receptor molecule has a structural formula as shown in Formula I:

[0051]

[0052] in:

[0053] EG is selected from a conjugated group having electron-withdrawing ability;

[0054] Ar is selected from an electron-rich conjugated aromatic structure;

[0055] X is selected from a hydrogen atom or a halogen.

[0056] In some embodiments, EG is selected from one of the following structures:

[0057]

[0058] Wherein Y is any one of a hydrogen atom or a halogen, and the dotted line is the connection position between EG and Ar.

[0059] In some embodiments, Ar is selected from one of the following structures:

[0060]

[0061] Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any of the alkoxy groups of 30 Alkyl, C1-C 30 Any one of the alkoxy groups, the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

[0062] In a second aspect, the present invention provides a method for synthesizing and preparing a pyrone-structured AD-A'-DA type dimer non-fullerene receptor molecule, comprising the following steps:

[0063] (1) Compound 1 and 2,6-dimethyl-4H-pyrone are dissolved in acetic anhydride and reacted under heating conditions; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and the reaction solution is purified to obtain Compound 2;

[0064]

[0065] Wherein X is any one of a hydrogen atom or a halogen;

[0066] (2) Under the protection of nitrogen or inert gas, compound 2, compound 3 and piperidine are dissolved in an organic solvent A, and reacted at 70-140° C.; the organic solvent A is chloroform, toluene or xylene; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and purified to obtain compound 4;

[0067]

[0068] (3) Under the protection of nitrogen or inert gas, dissolving compound 4, compound 5, ether solution of boron trifluoride and acetic anhydride in organic solvent B, wherein organic solvent B is dry chloroform, toluene or xylene; reacting at 0-60° C.; after sufficient reaction, extracting the reaction solution, removing the solvent, and purifying to obtain AD-A'-DA type dimer non-fullerene receptor based on pyrone structure of formula I;

[0069]

[0070] Wherein Y is any one of a hydrogen atom or a halogen.

[0071] Preferably, Ar in the compound 3 and compound 4 is selected from one of the following structures:

[0072]

[0073] Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any of the alkoxy groups of 30 Alkyl, C1-C 30 Any one of the alkoxy groups, the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

[0074] Preferably, in the step (1), the molar ratio of compound 1 to 2,6-dimethyl-4H-pyrone is 1:1 to 1:4; the concentration of compound 1 in acetic anhydride is 8 mg / mL to 12 mg / mL; and the reaction time is 8-24 h.

[0075] Preferably, in the step (2), the molar ratio of compound 2 to compound 3 is 1:2 to 1:4; the concentration of compound 2 in organic solvent A is 1 mg / mL to 25 mg / mL; and the reaction time is 12-24 h.

[0076] Preferably, in the step (3), the molar ratio of compound 4, compound 5, boron trifluoride and acetic anhydride is 1:(2.1-3):(0.05-1):(0.05-1); the concentration of compound 4 in organic solvent B is 0.01 mg / mL to 6 mg / mL; and the reaction time is 0.5 to 12 h.

[0077] In a third aspect, the present invention also provides a method for testing the stability of an organic solar cell receptor material. The specific testing method is:

[0078] The absorption change intensity of the AD-A'-DA type dimer non-fullerene receptor molecules based on the pyrone structure and the control receptor materials under light and nucleophilic reagent environment was tested by UV-visible absorption spectroscopy to reflect the stability of each receptor material.

[0079] In a fourth aspect, the present invention also provides an organic solar cell device based on the organic solar cell. The organic solar cell comprises an active layer of electron donor and electron acceptor materials, wherein the acceptor material is the AD-A'-DA type dimer non-fullerene acceptor molecule material with the pyrone structure.

[0080] In one embodiment of the present invention, the receptor material used as a control is IT-4F.

[0081] The structure of IT-4F is as follows:

[0082]

[0083] In one embodiment of the present invention, the donor material is PM6.

[0084] The structure of PM6 is shown below:

[0085]

[0086] Example 1: Preparation of pyrone-ring-locked dimer receptor ITBIC-F

[0087] The specific synthetic route is as attached. Figure 1 As shown, the specific steps are as follows:

[0088] (1) Synthesis of Compound 2:

[0089] Compound 1 (300 mg, 1.3 mmol) and 2,6-dimethyl-4H-pyran-4-one (458 mg, 3.7 mmol) were dissolved in acetic anhydride (40 mL) and refluxed at 130 ° C overnight. The reaction progress was monitored by thin layer chromatography. After sufficient reaction, the reaction solution was extracted with water and dichloromethane, then dried over anhydrous sodium sulfate, and the solvent was removed under vacuum. The residue was purified by silica gel chromatography using dichloromethane as the eluent to obtain a crude product. The crude product was purified by recrystallization with dichloromethane petroleum ether, and then compound 2 was obtained as an orange solid (337 mg, 77%) by ether reprecipitation. 1 H NMR (600MHz, CDCl3): δ (ppm) 8.32 (broad, 1.7H, ArH), 7.53 (t, J = 7.8Hz, 1H, ArH), 6.59 (broad, 0.7H, ArH), 2.53 (s, 6H, Ar-CH3). 13 C NMR (151MHz, CDCl3) δ185.92,166.08,162.26,154.27,152.56,149.41,136.67,13 3.90,115.53,115.05,113.87,113.73,112.01,111.89,109.90,65.60,20.67.HRMS m / z:[M+H] + Theoretical value C 19 H 10 F2N2O2,337.0710, measured value:337.0794.

[0090] (2) Synthesis of compound 4-1:

[0091] Under N2 protection, compound 2 (80 mg, 0.24 mmol) and compound 3-1 (511 mg, 0.48 mmol) were dissolved in 20 mL of dry chloroform. The mixture was heated to 70 ° C, and then 0.1 mL of piperidine was added dropwise. The solution was stirred at 70 ° C overnight, and the reaction progress was monitored by thin layer chromatography. After sufficient reaction, the reaction solution was extracted with water and dichloromethane, then dried over anhydrous sodium sulfate, and the solvent was removed in vacuo. Dichloromethane: petroleum ether: ethyl acetate = 4:1:0.05 was used as the eluent, and compound 4-1 was purified by silica gel chromatography to obtain a black solid (180 mg, 30%). 1 H NMR (600MHz, CDCl3): δ (ppm) 9.89 (s, 1H, Ar-CHO), 8.33 (dd, J = 9.6, 6.6Hz, 1H, = CH-) ,7.94(s,2H,ArH),7.68(d,J=15.6Hz,2H,=CH-),7.60(d,J=11.4Hz,4H,ArH),7.53( m,3H,ArH),7.15(m,32H,ArH),6.66(d,J=15.0Hz,2H,=CH-),2.58(m,16H,-CH2-),1 .61(m,16H,-CH2-),1.34(m,16H,-CH2-),1.29(m,32H,-CH2-),0.87(m,24H,-CH3).

[0092] (3) Synthesis of ITBIC-F:

[0093] Under N2 protection, compound 4-1 (140 mg, 0.057 mmol) and compound 5 (28 mg, 0.12 mmol) were dissolved in 15 mL of dry toluene. The mixture was heated to 60 ° C, and 0.1 mL of acetic anhydride and 0.1 mL of boron trifluoride ether solution (48% BF3) were added dropwise. After heating for 30 minutes, the reaction solution was extracted with water and dichloromethane, then dried over anhydrous sodium sulfate, and the solvent was removed in vacuo. With dichloromethane: petroleum ether = 2:1 as the eluent, it was purified by silica gel chromatography and recrystallized from dichloromethane / methanol to obtain ITBIC-F as a black solid (145 mg, 88%). 1H NMR (400MHz, CDCl3): δ (ppm) 8.85 (s, 2H, = CH-), 8.53 (dd, J = 9.6, 6.4Hz, 2H, ArH), 8.34 (dd, J = 9.6, 6.4Hz, 1H, ArH), 8.23 ​​(s, 2H, ArH), 7.67 (m, 6H, = CH- + ArH ),7.56(m,5H,ArH),7.18(m,32H,ArH),6.67(d,J=15.6Hz,2H,=CH-),2.58(m ,16H,-CH2-),1.61(m,16H,-CH2-),1.32(m,48H,-CH2-),0.87(m,24H,-CH3). 13 C NMR (151MHz, CDCl3) δ186.08,185.93,160.32,158.43,155.90,154.71,154.54,148.13,147.71,147.18,1 46.90,143.77,143.52,142.64,142.58,142.44,139.38,139.26,139.15,138.58,138.21,136.27,135.65 ,131.71,128.98,128.93,128.02,124.92,121.55,118.74,117.81,117.56,114.45,114.35,111.36,69.6 9,63.34,63.16,35.75,31.84,31.83,31.42,31.40,29.33,29.32,22.73,14.23.MS(MALDI-TOF)m / z:[M+H] + Theoretical value C 183 H 158 F6N6O4S8,2875.00,measured value:2875.39. Figure 3 The hydrogen spectrum of the product prepared in this example is shown in FIG.

[0094] Example 2: Preparation of pyrone-ring-locked dimer receptor TBTBIC-F

[0095] The specific synthetic route is as attached. Figure 2 As shown, the specific steps are as follows:

[0096] (1) Synthesis of compound 4-2:

[0097] Under N2 protection, compound 2 (17 mg, 0.05 mmol) and compound 3-2 (100 mg, 0.10 mmol) were dissolved in 20 mL of dry chloroform. The mixture was heated to 70 ° C, and then 0.05 mL of piperidine was added dropwise. The solution was stirred at 70 ° C overnight, and the reaction progress was monitored by thin layer chromatography. After sufficient reaction, the reaction solution was extracted with water and dichloromethane, then dried over anhydrous sodium sulfate, and the solvent was removed in vacuo. Dichloromethane: petroleum ether: ethyl acetate = 4:1:0.05 was used as the eluent, and the compound 4-2 was purified by silica gel chromatography to obtain a black solid (35 mg, 30%). 1 H NMR (600MHz, CDCl3): δ (ppm) 10.05 (s, 2H, Ar-CHO), 8.35 (dd, J = 9.0, 6.6Hz, 1H, ArH), 7.83 (d ,J=15.0Hz,2H,=CH-),7.54(m,5H,ArH),7.25(m,4H,ArH),6.71(d,J=15.0Hz,2H,=CH-),4.0 4(m,8H,-OCH2-),2.98(m,4H,Ar-CH2-),2.82(m,4H,Ar-CH2-),1.93(m,4H,-CH-),1.73(m,8 H,-CH2-),1.57(m,8H,-CH2-),1.49(m,8H,-CH2-),1.28(m,120H,-CH2-),0.86(m,36H,CH3).

[0098] (3) Synthesis of TBTBIC-F:

[0099] Under N2 protection, compound 4-2 (90 mg, 0.039 mmol) and compound 5 (28 mg, 0.12 mmol) were dissolved in 15 mL of dry toluene. The mixture was heated to 60 ° C, and 0.1 mL of acetic anhydride and 0.1 mL of ether solution of boron trifluoride (48% BF3) were added dropwise. After heating for 30 minutes, the reaction solution was extracted with water and dichloromethane, dried over anhydrous sodium sulfate, and the solvent was removed in vacuo. With dichloromethane: petroleum ether = 2:1 as the eluent, TBTBIC-F was purified by silica gel chromatography and recrystallized from dichloromethane / methanol to obtain TBTBIC-F as a black solid (105 mg, 99%). 11H NMR (600 MHz, CDCl3): δ (ppm) 9.04 (s, 2H, =CH-), 8.55 (dd, J = 10.2, 6.6 Hz, 2H, ArH), 8.35 (dd, J = 9.6, 6.6 Hz, 1H, ArH), 7.83 (d, J = 15.0 Hz, 2H, =CH-), 7.69 (s, 2H, ArH), 7.66 (t, J = 7.8 Hz, 2H, ArH), 7.60 (s, 2H, ArH), 7.54 (t, J = 7.8 Hz, 1H, ArH), 7.37 (s, 2H, ArH), 7.28 (s, 2H, ArH), 6.72 (d, J = 15.6 Hz, 2H, =CH-), 4.11 (d, J = 4.8 Hz, 8H, -OCH2-), 3.01 (t, J = 7.8 Hz, 4H, Ar-CH2-), 2.84 (t, J = 7.8 Hz, 4H, Ar-CH2-), 2.06 (m, 2H, -CH-), 1.96 (m, 2H, -CH-), 1.74 (m, 8H, -CH2-), 1.60 (m, 16H, -CH2-), 1.33 (m, 120H, -CH2-), 0.86 (m, 36H, -CH3). 13 13C NMR (151 MHz, CDCl3) δ 186.04, 185.62, 161.73, 160.82, 159.53, 155.21, 151.31, 150.30, 148.04, 142.08, 136.53, 135.24, 135.07, 134.83, 132.78, 130.55, 129.97, 129.26, 124.92, 122.54, 120.37, 116.92, 115.85, 115.07, 115.00, 114.94, 114.76, 112.61, 112.38, 112.26, 111.10, 77.37, 72.77, 72.42, 68.90, 64.07, 38.48, 38.43, 32.31, 32.10, 32.09, 32.04, 31.89, 31.87, 31.65, 31.36, 30.45, 30.31, 30.27, 29.96, 29.92, 29.86, 29.82, 29.77, 29.73, 29.64, 29.55, 29.54, 29.41, 29.13, 27.25, 27.21, 27.16, 27.15, 22.86, 22.83, 14.27, 14.26, 14.25, 14.24. MS (MALDI-TOF) m / z: [M+H] + Theoretical value C 171 H 222F6N6O8S4, 2731.60, measured value: 2732.05. Figure 4 The hydrogen spectrum of the product prepared in this example is shown in FIG.

[0100] Example 3: UV-Vis absorption spectra of ITBIC-F and TBTBIC-F

[0101] The UV-visible absorption spectra of ITBIC-F and TBTBIC-F are shown in the attached figure. Figure 5 As shown. The absorption peaks of ITBIC-F and TBTBIC-F in chloroform solution are located at 697nm and 651nm, respectively. The absorption peaks of ITBIC-F and TBTBIC-F films are located at 716nm and 718nm, respectively. The absorption spectra of ITBIC-F and TBTBIC-F films are red-shifted relative to their absorption spectra in chloroform solution, indicating that there is a strong intermolecular interaction between ITBIC-F and TBTBIC-F films.

[0102] Example 4: Theoretical simulation calculation of ITBIC-F and TBTBIC-F

[0103] We used density functional theory (DFT) to perform theoretical simulation calculations on the molecular conformations of ITBIC-F and TBTBIC-F. During the calculation process, all alkyl chains were simplified to methyl groups, and then the B3LYP / 6-31G** algorithm was used for simulation calculations. The simulation calculation results are shown in the attached figure. Figure 6 As shown, in the top view, ITBIC-F and TBTBIC-F present the same V-shaped geometry; in the side view, both ITBIC-F and TBTBIC-F show strong planarity, which is conducive to the formation of strong π-π stacking between molecules and promotes carrier transport.

[0104] Example 5: Intrinsic stability test of ITBIC-F and TBTBIC-F

[0105] We investigated the chemical and photochemical stabilities of ITBIC-F and TBTBIC-F by monitoring the changes in their UV-visible absorption spectra upon external stimuli and used the star receptor IT-4F as a control compound for comparison.

[0106] Light stability test: Take 10 -3 mmol ITBIC-F (2.9 mg) was dissolved in 1.00 mL tetrahydrofuran to obtain solution A, and 50 μL of solution A was taken and diluted to 5.00 mL to obtain 10 -5 mol / L ITBIC-F tetrahydrofuran solution. Then take 10 -3 mmol TBTBIC-F (2.7 mg) and IT-4F (1.5 mg) were used to obtain 10-5 mol / L tetrahydrofuran solution of TBTBIC-F and IT-4F. The above solution was heated to 200 mW cm -2 The absorption intensity changes under xenon lamp irradiation are shown in the attached figure. Figure 7 After 40 min of illumination, the IT-4F solution retained less than 1% of the initial absorption intensity, while the IT-BIC-F and TBTBIC-F solutions retained 89% and 99% of the initial absorption intensity, respectively.

[0107] Chemical stability test: Take 4.95mL 10 -5 mol / L tetrahydrofuran solution of ITBIC-F, TBTBIC-F and IT-4F, to which 50 μL 10 -1 mol / L ethanolamine tetrahydrofuran solution, and tested the UV-visible absorption spectra before, after and 1 hour after addition. The test results are shown in the attached Figure 7 As shown in b). For IT-4F solution, its absorption intensity dropped sharply after adding ethanolamine. After stirring for 1 hour, the absorption intensity of ITBIC-F and TBTBIC-F solutions only dropped to 36% and 55% of the initial value, respectively, and did not change much compared with the beginning of adding ethanolamine, while the absorption of IT-4F solution almost disappeared.

[0108] These results indicate that the photostability and chemical stability of the pyrone-ring-locked dimer receptors ITBIC-F and TBTBIC-F are significantly improved.

[0109] Example 6: Preparation of organic solar cells based on ITBIC-F and TBTBIC-F

[0110] The solar cell device is prepared using the ITO / PEDOT:PSS / active layer (PM6:ITBIC-F / TBTBIC-F) / PNDIT-F3N-Br / Ag structure, and the preparation process is as follows:

[0111] The prefabricated ITO-coated glass substrates were cleaned in an ultrasonic bath with methylbenzene, deionized water, acetone, and isopropanol for 15 minutes, respectively. After drying with high-purity nitrogen, all ITO substrates were cleaned in a UV-ozone cleaning system for 15 minutes. Then all the cleaned ITO glasses were placed in a UV-ozone cleaner and irradiated with a UV-ozone lamp for 15 minutes to obtain UV-ozone treated ITO anodes. Subsequently, a layer of PEDOT:PSS was spin-coated at 4000 rpm on the pre-cleaned ITO-coated glass with a PEDOT:PSS aqueous solution, annealed at 150°C for 15 minutes, and then the active layer was spin-coated in a glove box. The active layer was composed of 16 mg / mL PM6:ITBIC-F or PM6:TBTBIC-F in chloroform, where the mass ratios of PM6:ITBIC-F and PM6:TBTBIC-F were 1:1 and 1:1.2, respectively. The active layer solution was spin coated at 3500 rpm for 30 seconds and then annealed at 100 °C for 10 minutes. Preferably, the thickness of the optimal active layer is 110 nm. -1 The PNDIT-F3N-Br solution was spin coated at 4000 rpm for 30 seconds to deposit the PNDIT-F3N-Br layer. -6 The top silver electrode was obtained by thermal evaporation onto the cathode interface layer under vacuum conditions of 100 mbar. The typical active area of ​​the device studied is 5 mm 2 The devices based on PM6:ITBIC-F and PM6:TBTBIC-F achieved photoelectric conversion efficiencies of 13.03% and 10.01%, respectively. Their current density-voltage curves are shown in the attached figure. Figure 8 The external quantum efficiency spectra of organic solar cells based on ITBIC-F and TBTBIC-F are shown in the attached figure. Fig. 9 Both devices have good photoresponse in the full range of 300-900nm. The external quantum efficiency spectrum integrated current density of the ITBIC-F-based and TBTBIC-F-based devices is 19.99mAcm -2 and 17.87mAcm -2 , which is in good agreement with the value of the current density-voltage curve.

[0112] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A pyrone-ring-locked structure-based AD-A'-DA type dimer non-fullerene receptor molecule, characterized in that: The AD-A'-DA type dimer non-fullerene receptor molecular structure is shown in Formula I: wherein A is an electron-withdrawing unit, D is an electron-donating unit, and A' is an electron-withdrawing unit based on a pyrone structure; in: EG is selected from a conjugated group having electron-withdrawing ability; Ar is selected from an electron-rich conjugated aromatic structure; X is selected from a hydrogen atom or a halogen.

2. The AD-A'-DA type dimer non-fullerene receptor molecule based on pyrone-ring lock structure according to claim 1, characterized in that: EG is selected from one of the following structures: Wherein Y is any one of a hydrogen atom or a halogen, and the dotted line is the connection position between EG and Ar.

3. The AD-A'-DA type dimer non-fullerene receptor molecule based on pyrone-ring lock structure according to claim 1, characterized in that: Ar is selected from one of the following structures: Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any one of the alkoxy groups; R2 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any one of the alkoxy groups; the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

4. The method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Compound 1 and 2,6-dimethyl-4H-pyrone are dissolved in acetic anhydride and reacted under heating conditions; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and the reaction solution is purified to obtain Compound 2; Wherein X is any one of a hydrogen atom or a halogen; (2) Under the protection of nitrogen or inert gas, compound 2, compound 3 and piperidine are dissolved in an organic solvent A, and reacted at 70-140° C.; the organic solvent A is chloroform, toluene or xylene; after sufficient reaction, the reaction solution is extracted, the solvent is removed, and purified to obtain compound 4; (3) Under the protection of nitrogen or inert gas, dissolving compound 4, compound 5, ether solution of boron trifluoride and acetic anhydride in organic solvent B, wherein organic solvent B is dry chloroform, toluene or xylene; reacting at 0-60° C.; after sufficient reaction, extracting the reaction solution, removing the solvent, and purifying to obtain AD-A'-DA type dimer non-fullerene receptor based on pyrone structure of formula I; Wherein Y is any one of a hydrogen atom or a halogen.

5. The method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure according to claim 4, characterized in that: In the compound 3 and compound 4, Ar is selected from one of the following structures: Where R1 is a hydrogen atom, C1-C 30 Alkyl, C1-C 30 Any of the alkoxy groups of 30 Alkyl, C1-C 30 Any one of the alkoxy groups; the dotted line is the connection position between Ar and the electron-withdrawing units at both ends.

6. The method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure according to claim 4, characterized in that: In the step (1), the molar ratio of compound 1 to 2,6-dimethyl-4H-pyrone is 1:(1-4); the concentration of compound 1 in acetic anhydride is 8 mg / mL to 12 mg / mL; and the reaction time is 8-24 h.

7. The method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure according to claim 4, characterized in that: In the step (2), the molar ratio of compound 2 to compound 3 is 1:(2-4); the concentration of compound 2 in organic solvent A is 1 mg / mL to 25 mg / mL; and the reaction time is 12-24 h.

8. The method for synthesizing the AD-A'-DA type dimer non-fullerene receptor molecule based on the pyrone-ring lock structure according to claim 4, characterized in that: In the step (3), the molar ratio of compound 4, compound 5, boron trifluoride and acetic anhydride is 1:(2.1-3):(0.05-1):(0.05-1); the concentration of compound 4 in organic solvent B is 0.01 mg / mL to 6 mg / mL; and the reaction time is 0.5 to 12 h.

9. Use of the AD-A'-DA type dimer non-fullerene acceptor molecule based on pyrone-ring-locked structure according to any one of claims 1 to 3 in the preparation of photovoltaic acceptor materials.

10. Use of the AD-A'-DA type dimer non-fullerene acceptor molecule based on the pyrone-ring-locked structure according to any one of claims 1 to 3 in the preparation of an organic solar cell binary device or an organic solar cell ternary device.

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