Dimeric acceptor material and preparation method and application thereof

Abstract

The application provides a kind of dimer type acceptor material and its preparation method and application. Among them, the structure general formula of the dimer type acceptor material is (I), which is constructed with rigid unit with π conjugated structure as bridging unit. The acceptor material has a higher glass transition temperature and a lower diffusion coefficient. The material is used in optoelectronic functional devices, which can stabilize the thin film morphology of the active layer, and finally effectively improve the stability of the device, for example, as the active layer acceptor material of organic solar cell, which can promote the commercialization of organic solar cell.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic optoelectronic materials, and particularly relates to a kind of dimer acceptor materials, a preparation method thereof, and application thereof in preparing optoelectronic functional devices such as organic solar cells. BACKGROUND

[0002] With the increasing seriousness of environmental pollution, energy crisis and other problems, finding and developing renewable energy has become an important issue for the development of human society. Among many renewable energy sources (such as solar energy, wind energy, tidal energy, geothermal energy, etc.), solar energy has received widespread attention from the industry and academia due to its advantages such as no pollution, wide source, and inexhaustible use, and has made great progress.

[0003] Organic solar cells (OSCs) are currently a popular third-generation photovoltaic technology, which has attracted widespread attention due to its advantages such as wide source of active layer, light weight, strong processability, and simple manufacturing process (roll-to-roll, printing, spin coating, spraying, etc.). The power conversion efficiency (PCE) of organic solar cells has exceeded 20%, and they have a broad application prospect. However, the stability problem is currently a bottleneck for commercial application.

[0004] Dimer acceptor materials have become a strong competitor for small molecule and polymer acceptors due to their advantages such as clear structure, good batch repeatability, good film-forming property, low diffusion coefficient, and excellent stability. However, most of the current dimer materials use thiophene, ethylene, acetylene, thiophene-ethylene-thiophene, and thiophene-alkyl chain-thiophene structures as bridging units, and their glass transition temperatures are all below 150℃. The low glass transition temperature, high diffusion coefficient, and easy over-aggregation of molecules under thermal stress are not conducive to the morphology stability of the active layer and the long service life of the device. SUMMARY

[0005] The purpose of the present application is to provide a kind of dimer acceptor material and its preparation method and application, which has a high glass transition temperature and can improve the stability of optoelectronic functional devices. The above purpose can be achieved by the following technical solutions:

[0006] The dimer acceptor material provided by the present application has a general structure (I):

[0007]

[0008] Wherein, in (I), Ar1 and Ar2 both represent rigid units with π conjugated structure; X and Y are same or different hydrogen atom, F, Cl or Br; Z is hydrogen atom, F, Cl or Br.

[0009] Optionally, the Ar1 structural formula is one of (II):

[0010]

[0011] Wherein, in (II), R1 and R2 are linear or branched alkyl with carbon atom number of 10-25; R3 is linear or branched alkyl with carbon atom number of 6-10; R4 is methyl, trifluoromethyl or methoxy; X is hydrogen atom, F, Cl or Br.

[0012] Optionally, the Ar2 structural formula is one of (III):

[0013]

[0014] Wherein, in (III), R is linear alkyl.

[0015] Optionally, the glass transition temperature of the acceptor material is ≥180℃.

[0016] Optionally, the synthesis reaction equation of the acceptor material is (IV):

[0017]

[0018] The application provides a preparation method of a kind of dimer type acceptor material, and the preparation method comprises the following steps:

[0019] (1) dialdehyde substituted Ar1 Compound (a) is dissolved with Br substituted indene ketone compound (b) according to the molar ratio 1:0.8-1.2 in organic solvent, and acetic anhydride and boron trifluoride ether are added and reacted for 30-90 minutes, after the reaction is finished, the organic solvent is spun dry, and column chromatography is separated to obtain single side precursor compound (c);

[0020] (2) the single side precursor compound (c) prepared in step (1) is dissolved with bistrimethyltin substituted Ar2 compound (d) according to the molar ratio 2-2.5:1 in organic solvent, and catalyst, ligand and cuprous iodide are added, under inert gas atmosphere, 100-150℃ is reacted for 12-36 hours, after the reaction is finished, the organic solvent is spun dry, and column chromatography is separated to obtain dialdehyde precursor compound (e);

[0021] (3) the dialdehyde precursor compound (e) prepared in step (2) is dissolved in an organic solvent at a molar ratio of 1:2-4 with an indenone compound (f), acetic anhydride and boron trifluoride ether are added, and the reaction is carried out for 30-600 minutes; after the reaction is completed, the organic solvent is spin-dried, and column chromatography is used to separate to obtain the dimer-type acceptor material (g).

[0022] Optionally, the organic solvent is chloroform, toluene, chlorobenzene or tetrahydrofuran; the catalyst is Pd(PPh3)4, Pd2(dba)3 or Pd(PPh3)2Cl2; and the ligand is P(o-tol)3 or P(t-Bu)3.

[0023] The dimer-type acceptor material provided by the application is used in the preparation of a photoelectric functional device.

[0024] Optionally, the photoelectric functional device is an organic solar cell, wherein the dimer-type acceptor material is used as an active layer acceptor material to prepare a photoactive layer of the organic solar cell by mixing with a donor material.

[0025] Optionally, the photoactive layer has a thickness of 80-120 nm.

[0026] Compared with the prior art, the dimer-type acceptor material provided by the application has the advantages that: the dimer-type acceptor material is constructed by using a rigid conjugated group as a bridging unit, and has a high glass transition temperature and a low diffusion coefficient. The material is used in a photoelectric functional device to improve the stability of the device.

[0027] In a preferred embodiment, the dimer-type acceptor material constructed by the application is selected to have a weak electron-withdrawing quinoxaline unit as a central core, and a bridging unit of a large planar rigid structure, i.e., indacenodithiophene, so that the LUMO energy level of the material is raised, and the glass transition temperature is increased. The material is used in a photoelectric functional device, such as an active layer of a solar cell, to obtain high open-circuit voltage and high stability of the OSCs. Due to the introduction of the large planar conjugated unit, the glass transition temperature of the protected molecule is greatly improved (not less than 180℃), and the kinetic process of molecular diffusion is reduced. The material is used as an active layer acceptor material of an organic solar cell, so that a stable active layer morphology is formed, and the stability of the device is effectively improved, which is of great significance for the commercial application of the organic solar cell. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 is a schematic diagram of the layer structure of an organic solar cell device according to an embodiment of the application.

[0029] Figure 2 is a chemical structural formula of a donor material PM6 in an active layer of an organic solar cell device according to an embodiment of the application.

[0030] Figure 3 is a chemical structural formula of an electron transport layer material PDINN in an organic solar cell device according to an embodiment of the present application.

[0031] Figure 4 is a chemical structural formula of a hole transport layer material 2PACz in an organic solar cell device according to an embodiment of the present application.

[0032] Figure 5 is a structural general formula of a dimeric acceptor material provided by the present application.

[0033] Figure 6 is a chemical reaction line chart in preparation of a dimeric acceptor material according to an embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative work, fall within the protection scope of the present application.

[0035] The present application provides a kind of dimeric acceptor material, which is combined by one bridging unit and two small molecule acceptors, and its structural general formula is shown as (I):

[0036]

[0037] In (I), Ar1 and Ar2 both represent rigid unit with π conjugated structure; X and Y are same or different hydrogen atom, F, Cl or Br; Z is hydrogen atom, F, Cl or Br.

[0038] Further, the structural formula of Ar1 is one of (II):

[0039]

[0040] In (II), R1 and R2 are linear or branched alkyl with carbon number of 10-25; R3 is linear or branched alkyl with carbon number of 6-10; R4 is methyl, trifluoromethyl or methoxy; X is hydrogen atom, F, Cl or Br.

[0041] Further, the structural formula of Ar2 is one of (III):

[0042]

[0043] wherein, in (III), R is a linear alkyl group.

[0044] The preparation method of the dimeric acceptor material provided by the application is prepared by using dialdehyde-substituted Ar1 compound (a), Br-substituted indenone compound (b), bistrimethyltin-substituted Ar2 compound (d) and indenone compound (f) as reactants through three reactions. The organic solvent used in the reaction process can be chloroform, toluene, chlorobenzene or tetrahydrofuran.

[0045] Reference Figure 6 as shown, comprising the following steps:

[0046] (1) The dialdehyde-substituted Ar1 compound (a) and the Br-substituted indenone compound (b) are dissolved in an organic solvent at a molar ratio of 1:0.8-1.2, and acetic anhydride and boron trifluoride ether are added and reacted for 30-90 minutes. After the reaction is completed, the organic solvent is spun dry, and column chromatography is used to separate the single-sided precursor compound (c).

[0047] (2) The single-sided precursor compound (c) prepared in step (1) is dissolved in an organic solvent at a molar ratio of 2-2.5:1 with the bistrimethyltin-substituted Ar2 compound (d), and a catalyst, a ligand and cuprous iodide are added, and reacted at 100-150°C for 12-36 hours under an inert gas atmosphere. After the reaction is completed, the organic solvent is spun dry, and column chromatography is used to separate the dialdehyde precursor compound (e). The catalyst can be Pd(PPh3)4, Pd2(dba)3 or Pd(PPh3)2Cl2. The ligand can be P(o-tol)3 or P(t-Bu)3.

[0048] (3) The dialdehyde precursor compound (e) prepared in step (2) is dissolved in an organic solvent at a molar ratio of 1:2-4 with the indenone compound (f), and acetic anhydride and boron trifluoride ether are added and reacted for 30-600 minutes. After the reaction is completed, the organic solvent is spun dry, and column chromatography is used to separate the dimeric acceptor material (g).

[0049] The application further provides a use of the dimeric acceptor material in the preparation of a photoelectric functional device. For example, in an organic solar cell device. Figure 1 The structure of an organic solar cell device in an embodiment of the application is schematically shown. As shown in Figure 1 The layer structure of the organic solar cell device includes a substrate layer 1, a hole transport layer 2, an active layer 3, an electron transport layer 4 and an electrode 5. The substrate layer 1 can be an ITO substrate. The hole transport layer 2 can be PEDOT:PSS, 2PACz (structural formula as shown in Figure 4) or ZnO with a thickness of 20-40 nm. The active layer 3 can be a donor material PM6 (structural formula as Figure 2 ) and any one of the dimeric acceptor materials of the present application with a thickness of 80-120 nm. The electron transport layer 4 can be MoO3 or PDINN (structural formula as Figure 3 ) with a thickness of 5-10 nm. The electrode 5 can be an Al or Ag electrode with a thickness of 80-100 nm. By using the dimeric acceptor materials of the present application to prepare the active layer in the organic solar cell, high open voltage and high stability of the OSCs can be obtained.

[0050] The technical solutions of the present application are described in more detail below in combination with specific examples:

[0051] Example 1: Synthesis of dimeric acceptor material DQ1

[0052]

[0053] First step, add dialdehyde end group precursor SMA1 (400 mg, 0.34 mmol), 5-bromo cyano indanone (96 mg, 0.35 mmol) and 50 mL of tetrahydrofuran in a reaction bottle, under argon protection, drop 0.5 mL of acetic anhydride and 0.5 mL of boron trifluoride ether at room temperature, react for 35 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. The obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain 253 mg of single side precursor compound, with a yield of 54%.

[0054] Second step, add single side precursor compound (205 mg, 0.15 mmol), bridging unit B1 (70 mg, 0.07 mmol), Pd(PPh3)4 (12 mg, 0.01 mmol), and 45 mL of toluene in a two-necked flask, and reflux under argon protection for 24 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, spin dry the solvent to obtain the crude product. The obtained crude product is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 3:1) to obtain 130 mg of dimeric acceptor material dialdehyde end group precursor compound, with a yield of 59%.

[0055] Third step, add dimeric acceptor material dialdehyde end group precursor compound (130 mg, 0.04 mmol), difluorodicyanoindanone (21 mg, 0.09 mmol) and 22 mL of toluene in a reaction bottle, under argon protection, drop 0.2 mL of acetic anhydride and 0.3 mL of boron trifluoride ether at room temperature, react for 90 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. The obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 2:1) to obtain dimeric acceptor material DQ1 (131 mg, yield 89%).

[0056] Example 2: Synthesis of dimeric acceptor material DQ2

[0057]

[0058] First step, add dialdehyde end group precursor SMA2 (400 mg, 0.35 mmol), 5- bromocyanoinandanone (96 mg, 0.35 mmol) and 50 mL of toluene in a reaction bottle, under argon protection, drop 0.5 mL of acetic anhydride and 0.5 mL of boron trifluoride ether at room temperature, react for 35 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. The obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain single side precursor compound 253 mg, yield 55%.

[0059] Second step, add single side precursor compound (206 mg, 0.16 mmol), bridging unit B1 (70 mg, 0.07 mmol), Pd(PPh3)4(16 mg, 0.01 mmol), and 45 mL of toluene in a two-necked flask, under argon protection, reflux for 24 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, spin dry the solvent to obtain the crude product. The obtained crude product is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 3:1) to obtain dimeric acceptor material dialdehyde end group precursor compound 125 mg, yield 56%.

[0060] Third step, add dimeric acceptor material dialdehyde end group precursor compound (130 mg, 0.04 mmol), difluorodicyanoindanone (21 mg, 0.09 mmol) and 22 mL of toluene in a reaction bottle, under argon protection, drop 0.2 mL of acetic anhydride and 0.3 mL of boron trifluoride ether at room temperature, react for 90 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. The obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 2:1) to obtain dimeric acceptor material DQ1 (131 mg, yield 89%).

[0061] Example 3: Synthesis of dimeric acceptor material DQ3

[0062]

[0063] First step, in a reaction flask was added dialdehyde end group precursor SMA3 (500 mg, 0.38 mmol), 5-bromo cyanoinindanone (123 mg, 0.45 mmol) and 50 mL chloroform, under argon protection, 0.5 mL acetic anhydride and 0.5 mL boron trifluoride etherate was added dropwise at room temperature, the reaction was carried out for 35 min. After the reaction was completed, the solvent was rotary evaporated, the crude product was precipitated in methanol, the obtained solid was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4: 1), 350 mg of single side precursor compound was obtained, the yield was 60%.

[0064] Second step, in a two-necked flask was added single side precursor compound (307 mg, 0.20 mmol), bridging unit B1 (104 mg, 0.10 mmol), Pd(PPh3)2Cl2 (7 mg, 0.01 mmol), and 35 mL toluene, the reaction was carried out under reflux for 24 h under argon protection. After the reaction was completed, the reaction solution was extracted with dichloromethane, dried with anhydrous sodium sulfate, and the solvent was rotary evaporated to obtain the crude product. The obtained crude product was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 3: 1), 219 mg of dialdehyde end group precursor compound of dimeric acceptor material was obtained, the yield was 61%.

[0065] Third step, in a reaction flask was added dialdehyde end group precursor compound of dimeric acceptor material (200 mg, 0.06 mmol), 2-(2-chloro-6-oxo-5,6-dihydro-4H-cyclopenta[b]thiophene-4-ylidene)malononitrile (21 mg, 0.09 mmol) and 12 mL toluene, under argon protection, 0.3 mL acetic anhydride and 0.3 mL boron trifluoride etherate was added dropwise at room temperature, the reaction was carried out for 65 min. After the reaction was completed, the solvent was rotary evaporated, the crude product was precipitated in methanol, the obtained solid was separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 2: 1), 210 mg of dimeric acceptor material DQ3 was obtained, the yield was 93%.

[0066] Example 4: Synthesis of dimeric acceptor material DQ4

[0067]

[0068] First step, in a reaction flask, add dialdehyde end group precursor SMA4 (300 mg, 0.24 mmol), 5-bromo-1,3-indanedione (59 mg, 0.26 mmol) and 50 mL of tetrahydrofuran, under argon protection, drop 0.3 mL of acetic anhydride and 0.3 mL of boron trifluoride etherate at room temperature, react for 30 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol, and the obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain 196 mg of single precursor compound, yield 56%.

[0069] Second step, in a two-necked flask, add single precursor compound (190 mg, 0.13 mmol), bridging unit B1 (62 mg, 0.06 mmol), Pd(PPh3)4(19 mg, 0.01 mmol), and 45 mL of toluene, under argon protection, reflux for 24 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, spin dry the solvent to obtain the crude product. After the obtained crude product is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 3:1), 142 mg of dimeric acceptor material dialdehyde end group precursor compound is obtained, yield 72%.

[0070] Third step, in a reaction flask, add dimeric acceptor material dialdehyde end group precursor compound (140 mg, 0.04 mmol), 5,6-dichloro-1,3-indanedione (19 mg, 0.09 mmol) and 12 mL of toluene, under argon protection, drop 0.2 mL of acetic anhydride and 0.4 mL of boron trifluoride etherate at room temperature, react for 180 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol, and the obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 2:1) to obtain dimeric acceptor material DQ4 (149 mg, yield 95%).

[0071] Example 5: Synthesis of dimeric acceptor material DQ5

[0072]

[0073] First step, in a reaction flask, add dialdehyde end group precursor SMA5 (453 mg, 0.27 mmol), 6-bromo cyanoinindanone (76 mg, 0.28 mmol) and 40 mL of chloroform, under argon protection, drop 0.3 mL of acetic anhydride and 0.5 mL of boron trifluoride etherate at room temperature, react for 35 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol, and the obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 4:1) to obtain 340 mg of single precursor compound, yield 68%.

[0074] Second step, in two flasks, add the unilaterally precursor compound (335 mg, 0.18 mmol), bridging unit B1 (83 mg, 0.08 mmol), Pd2(dba)3(9 mg, 0.01 mmol), P(o-tol)3(20 mg, 0.05 mmol), CuI (9 mg, 0.05 mmol) and 45 mL of toluene, reflux the reaction under argon protection for 18 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, and spin dry the solvent to obtain the crude product. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 3:1) of the obtained crude product, 276 mg of the dimeric acceptor material dialdehyde end group precursor compound is obtained, with a yield of 82%.

[0075] Third step, in a reaction flask, add the dimeric acceptor material dialdehyde end group precursor compound (164 mg, 0.04 mmol), diiodo dicyano indenone (45 mg, 0.10 mmol) and 16 mL of toluene, under argon protection, add 0.5 mL of acetic anhydride and 1.0 mL of boron trifluoride ether dropwise at room temperature, and react for 45 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 2:1) of the obtained solid, 180 mg of the dimeric acceptor material DQ5 is obtained, with a yield of 91%.

[0076] Example 6: Synthesis of dimeric acceptor material DQ6

[0077]

[0078] First step, in a reaction flask, add the dialdehyde end group precursor SMA6 (462 mg, 0.30 mmol), 5-bromo cyanoinde ketone (87 mg, 0.32 mmol) and 43 mL of chloroform, under argon protection, add 0.4 mL of acetic anhydride and 0.3 mL of boron trifluoride ether dropwise at room temperature, and react for 40 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 4:1) of the obtained solid, 325 mg of the unilaterally precursor compound is obtained, with a yield of 60%.

[0079] Second step, in two flasks, add the unilaterally precursor compound (323 mg, 0.18 mmol), bridging unit B2 (99 mg, 0.08 mmol), Pd2(dba)3(8 mg, 0.01 mmol), P(o-tol)3(15 mg, 0.05 mmol) and 45 mL of toluene, reflux the reaction under argon protection for 18 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, and spin dry the solvent to obtain the crude product. After column chromatography separation and purification of the obtained crude product (eluent: petroleum ether:dichloromethane = 3:1), 268 mg of the dimeric acceptor material dialdehyde end group precursor compound is obtained, with a yield of 75%.

[0080] Third step, in a reaction flask, add the dimeric acceptor material dialdehyde end group precursor compound (260 mg, 0.06 mmol), difluorobiscyanoinde-none (28 mg, 0.11 mmol) and 22 mL of toluene, under argon protection, add 0.6 mL of acetic anhydride and 1.0 mL of boron trifluoride ether dropwise at room temperature, and react for 75 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification of the obtained solid (eluent: petroleum ether:dichloromethane = 2:1), 268 mg of the dimeric acceptor material DQ6 is obtained, with a yield of 94%.

[0081] Example 7: Synthesis of dimeric acceptor material DQ7

[0082]

[0083] First step, in a reaction flask, add the dialdehyde end group precursor SMA7 (527 mg, 0.31 mmol), 5-bromocyanoinde-none (87 mg, 0.32 mmol) and 40 mL of chloroform, under argon protection, add 0.4 mL of acetic anhydride and 0.5 mL of boron trifluoride ether dropwise at room temperature, and react for 45 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification of the obtained solid (eluent: petroleum ether:dichloromethane = 4:1), 280 mg of the unilaterally precursor compound is obtained, with a yield of 48%.

[0084] Second step, in two flasks, add the unilaterally precursor compound (250 mg, 0.13 mmol), bridging unit B1 (60 mg, 0.06 mmol), Pd2(dba)3(6 mg, 0.01 mmol), P(o-tol)3(12 mg, 0.04 mmol) and 30 mL of toluene, reflux the reaction under argon protection for 18 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry with anhydrous sodium sulfate, and spin dry the solvent to obtain the crude product. After column chromatography separation and purification of the obtained crude product (eluent: petroleum ether:dichloromethane = 3:1), 186 mg of dimeric acceptor material dialdehyde end group precursor compound is obtained, with a yield of 74%.

[0085] Third step, in a reaction flask, add the dimeric acceptor material dialdehyde end group precursor compound (170 mg, 0.04 mmol), 5,6-dichloro-1,3-indandione (24 mg, 0.11 mmol) and 18 mL of toluene, under argon protection, add 0.7 mL of acetic anhydride and 1.4 mL of boron trifluoride ether dropwise at room temperature, and react for 75 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification of the obtained solid (eluent: petroleum ether:chloroform = 4:1), 176 mg of dimeric acceptor material DQ7 is obtained, with a yield of 95%.

[0086] Example 8: Synthesis of dimeric acceptor material DQ8

[0087]

[0088] First step, in a reaction flask, add the dialdehyde end group precursor SMA8 (500 mg, 0.34 mmol), 5-bromo cyanoinandione (98 mg, 0.36 mmol) and 50 mL of chloroform, under argon protection, add 0.4 mL of acetic anhydride and 0.6 mL of boron trifluoride ether dropwise at room temperature, and react for 35 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After column chromatography separation and purification of the obtained solid (eluent: petroleum ether:dichloromethane = 5:1), 320 mg of unilaterally precursor compound is obtained, with a yield of 55%.

[0089] Second step, add monomer precursor compound (224 mg, 0.13 mmol), bridging unit B3 (67 mg, 0.05 mmol), Pd2(dba)3(4 mg, 0.01 mmol), P(o-tol)3(7 mg, 0.03 mmol) and 40 mL of toluene in two flasks, reflux the reaction under argon protection for 18 h. After the reaction is completed, the reaction solution is extracted with dichloromethane, dried over anhydrous sodium sulfate, and the solvent is evaporated to obtain the crude product. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 3:1), 170 mg of dimeric acceptor material dialdehyde end group precursor compound is obtained, with a yield of 78%.

[0090] Third step, add dimeric acceptor material dialdehyde end group precursor compound (150 mg, 0.03 mmol), difluorobiscyanoindeketone (25 mg, 0.12 mmol) and 25 mL of toluene in a reaction flask, and add 0.7 mL of acetic anhydride and 1.3 mL of boron trifluoride ether dropwise at room temperature under argon protection, and react for 60 min. After the reaction is completed, the solvent is evaporated, and the crude product is settled in methanol. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 2:3) of the obtained solid, dimeric acceptor material DQ8 (152 mg, yield 92%) is obtained.

[0091] Example 9: Synthesis of dimeric acceptor material DQ9

[0092]

[0093] First step, add dialdehyde end group precursor SMA8 (589 mg, 0.40 mmol), 2-(2-bromo-6-oxo-5,6-dihydro-4H-cyclopenta[b]thiophene-4-ylidene)malononitrile (112 mg, 0.40 mmol) and 50 mL of toluene in a reaction flask, and add 0.6 mL of acetic anhydride and 0.7 mL of boron trifluoride ether dropwise at room temperature under argon protection, and react for 50 min. After the reaction is completed, the solvent is evaporated, and the crude product is settled in methanol. After column chromatography separation and purification (eluent: petroleum ether:dichloromethane = 5:1) of the obtained solid, monomer precursor compound 424 mg is obtained, with a yield of 61%.

[0094] Second step, in two flasks, add the monomeric precursor compound (260 mg, 0.15 mmol), bridging unit B3 (81 mg, 0.06 mmol), Pd2(dba)3(9 mg, 0.01 mmol), P(o-tol)3(18 mg, 0.06 mmol) and 40 mL of toluene, reflux the reaction under argon protection for 21 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry over anhydrous sodium sulfate, and spin dry the solvent to obtain the crude product. After the obtained crude product is separated and purified by column chromatography (eluent: petroleum ether: chloroform = 4: 1), 180 mg of the dialdehyde end group precursor compound of the dimeric acceptor material is obtained, with a yield of 69%.

[0095] Third step, in a reaction flask, add the dialdehyde end group precursor compound of the dimeric acceptor material (130 mg, 0.03 mmol), difluorobiscyanoinde (21 mg, 0.09 mmol) and 25 mL of toluene, and drop 0.7 mL of acetic anhydride and 1.3 mL of boron trifluoride etherate at room temperature under argon protection, and react for 60 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After the obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 2:3), the dimeric acceptor material DQ9 (126 mg, yield 88%) is obtained.

[0096] Example 10: Synthesis of the dimeric acceptor material DQ10

[0097]

[0098] First step, in a reaction flask, add the dialdehyde end group precursor SMA9 (630 mg, 0.36 mmol), 5-bromocyanoinde (98 mg, 0.36 mmol) and 50 mL of toluene, and drop 0.4 mL of acetic anhydride and 0.5 mL of boron trifluoride etherate at room temperature under argon protection, and react for 50 min. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. After the obtained solid is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 5:1), the monomeric precursor compound 410 mg is obtained, with a yield of 57%.

[0099] Second step, in two flasks, add the monomeric precursor compound (220 mg, 0.11 mmol), bridging unit B4 (47 mg, 0.05 mmol), Pd(PPh3)2Cl2(8 mg, 0.01 mmol) and 25 mL of toluene, reflux the reaction under argon protection for 28 h. After the reaction is completed, extract the reaction solution with dichloromethane, dry over anhydrous sodium sulfate, and spin dry the solvent to obtain the crude product. After the obtained crude product is separated and purified by column chromatography (eluent: petroleum ether: dichloromethane = 1:1), 180 mg of the dialdehyde end group precursor compound of the dimeric acceptor material is obtained, with a yield of 87%.

[0100] The third step, in a reaction bottle, add dimeric acceptor material dialdehyde end group precursor compound (164 mg, 0.04 mmol), 5,6-dichloro-1,3-indandione (23 mg, 0.10 mmol) and 18 mL of toluene, under the protection of argon, drop 0.5 mL of acetic anhydride and 1.0 mL of boron trifluoride ether, react for 75 min at room temperature. After the reaction is completed, spin dry the solvent, and the crude product is settled in methanol. The obtained solid is separated and purified by column chromatography (eluent: petroleum ether: chloroform = 3:1) to obtain dimeric acceptor material DQ10 (173 mg, yield 97%).

[0101] Example 11: Test of glass transition temperature of dimeric acceptor material

[0102] The glass transition temperature of the dimeric acceptor material obtained in Examples 1-10 was tested, and the specific process was as follows:

[0103] The solution (chloroform solution of DQ1-DQ10, solution concentration = 10 mg / mL) was prepared into a thin film on a quartz glass substrate by spin coating. The glass transition temperature of DQ1-DQ10 was obtained by measuring the red shift deviation of the temperature-dependent UV-Vis absorption spectrum, as shown in Table 1 below.

[0104] Table 1 Glass transition temperature of DQ1-DQ10

[0105] Material Glass transition temperature (°C) DQ1 189 DQ2 207 DQ3 196 DQ4 189 DQ5 180 DQ6 201 DQ7 199 DQ8 212 DQ9 205 DQ10 182

[0106] As can be seen from Table 1, the glass transition temperature of the dimeric acceptor material DQ1-DQ10 prepared in the above examples is improved, and is not less than 180°C.

[0107] Example 12: Device preparation of organic solar cell based on dimeric acceptor material

[0108] The dimeric acceptor material obtained in Examples 1-10 was used as the active layer acceptor material to prepare an organic solar cell device, and the specific preparation process was as follows:

[0109] The active layer solution (donor material and acceptor material in the same proportion, such as PM6:DQ1 = 1:1, solution concentration = 14 mg / mL) was prepared into a photoactive layer on a PEDOT:PSS modified ITO glass substrate by spin coating. The active layer was subjected to heat annealing treatment (100°C / 10 min), and then a layer of PDINN (concentration: 1.0 mg mL -1 of methanol solution) was spin coated, and finally Ag was evaporated to prepare a cathode.

[0110] Photovoltaic device performance: under white light 1.5G (100 mW cm-2 ) under irradiation, device performance and T 90 (keeping initial efficiency 90% for time) lifetime is shown in Table 2 below, wherein, V oc represents open circuit voltage, J sc represents short circuit current, FF represents fill factor, and PCE represents photoelectric conversion efficiency.

[0111] Table 2 Photovoltaic device performance

[0112] Active layer V oc (V) J sc (V)]]> FF (%) PCE (%) T 90 (h)]]> PM6:DQ1 1.06 21.20 72 16.18 1300 PM6:DQ2 1.02 22.31 71 16.16 1696 PM6:DQ3 1.04 22.15 73 16.82 2040 PM6:DQ4 1.08 20.12 70 15.21 1308 PM6:DQ5 0.99 21.98 72 15.66 1726 PM6:DQ6 1.02 22.03 71 15.95 1496 PM6:DQ7 1.08 21.99 72 17.10 2108 PM6:DQ8 1.10 21.86 71 17.07 1820 PM6:DQ9 1.09 22.01 69 16.55 1592 PM6:DQ10 1.11 22.98 72 18.36 1600

[0113] As can be seen from the above table, the organic solar cell device prepared by using the dimer-type acceptor material prepared in the above examples as the active layer acceptor material has an open circuit voltage ≥ 0.99 V, T 90 up to 1300 h, especially more than 2000 h, and a photoelectric conversion efficiency > 15%.

[0114] The description of the application is given for the purpose of illustration and description, and is not intended to be exhaustive or to limit the application to the precise form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments were chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A class of dimeric acceptor materials characterized in that, The structural general formula of the acceptor material is (I)： In (I), X and Y are the same or different hydrogen atoms, F, Cl or Br; Z is a hydrogen atom, F, Cl or Br. The Ar1 structural formula is one of (II): In (II), R1 and R2 are linear or branched alkyl groups with 10-25 carbon atoms; R3 is a linear or branched alkyl group with 6-10 carbon atoms; R4 is a methyl group, a trifluoromethyl group or a methoxy group; X is a hydrogen atom, F, Cl or Br. The Ar2 structural formula is one of (III): In (III), R is a linear alkyl group.

2. The class of dimeric acceptor materials according to claim 1, characterized in that The glass transition temperature of the acceptor material is ≥180°C.

3. A method for producing a kind of dimeric acceptor material according to claim 1, characterized by, The synthesis reaction equation of the acceptor material is (IV): In (g), the reagent is the structural general formula (I) in claim 1.

4. The production method according to claim 3, characterized by, The preparation method comprises the following steps: (1) Dissolve the dialdehyde-substituted Ar1 compound (a) and the Br-substituted indenone compound (b) in an organic solvent at a molar ratio of 1:0.8-1.2, add acetic anhydride and boron trifluoride ether, and react for 30-90 minutes. After the reaction is completed, spin dry the organic solvent, and separate the single-side precursor compound (c) by column chromatography; (2) Dissolve the single-side precursor compound (c) prepared in step (1) and the bistrimethyltin-substituted Ar2 compound (d) in an organic solvent at a molar ratio of 2-2.5:1, add a catalyst, a ligand and cuprous iodide, and react at 100-150°C for 12-36 hours under an inert gas atmosphere. After the reaction is completed, spin dry the organic solvent, and separate the dialdehyde precursor compound (e) by column chromatography; (3) Dissolve the dialdehyde precursor compound (e) prepared in step (2) and the indenone compound (f) in an organic solvent at a molar ratio of 1:2-4, add acetic anhydride and boron trifluoride ether, and react for 30-600 minutes. After the reaction is completed, spin dry the organic solvent, and separate the dimer-type acceptor material (g) by column chromatography.

5. The preparation method according to claim 4, wherein the organic solvent is chloroform, toluene, chlorobenzene or tetrahydrofuran; the catalyst is Pd(PPh3)4, Pd2(dba)3 or Pd(PPh3)2Cl2; the ligand is P(o-tol)3 or P(t-Bu)3.

6. Use of a dimer-type acceptor material according to any one of claims 1-2 in the preparation of a photoelectric functional device. The photoelectric functional device is an organic solar cell, wherein the dimer-type acceptor material is used as an active layer acceptor material to prepare a photoactive layer of the organic solar cell by mixing with a donor material.

7. Use according to claim 6, characterized in that, The thickness of the photoactive layer is 80-120 nm.

8. Use according to claim 7, characterized in that, ​

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