阅读说明：本技术 一种d-a型氯化共轭聚合物及其制备方法和应用 (D-A type chlorinated conjugated polymer and preparation method and application thereof ) 是由 周逸辉 秦元成 倪彩玲 熊云奇 熊丽雯 张俊辉 肖文君 严浩东 艾禹川 于 2020-06-05 设计创作，主要内容包括：本发明提供了一种D-A型氯化共轭聚合物及其制备方法和应用,所述氯化共轭聚合物分子由不同重复单元所包含的噻吩单元数、给电子单体、吸电子单体和催化剂在有机溶剂体系中,惰性气体保护下,先进行避光反应,最后采用柱层析提纯,制备得到目标产物。本发明有较好的传输电子能力并且在可见光范围内具有较好的吸收,应用到有机太阳电池中的给体材料中,具有良好的光伏性能。(The invention provides a D-A type chlorinated conjugated polymer, a preparation method and application thereof, wherein the chlorinated conjugated polymer molecule is prepared by carrying out light-resistant reaction on thiophene unit number, electron-donating monomers, electron-withdrawing monomers and catalysts contained in different repeating units in an organic solvent system under the protection of inert gas, and finally purifying by adopting column chromatography to obtain a target product. The invention has better electron transmission capability and better absorption in the visible light range, is applied to donor materials in organic solar cells, and has good photovoltaic performance.)

1. A D-A type chlorinated conjugated polymer, characterized in that the structural formula of the polymer is formula I:

2. a preparation method of D-A type chlorinated conjugated polymer is characterized in that: the chlorinated polymer is prepared by respectively carrying out a light-shielding reaction on a compound with a structure shown in a formula II, an electron donor monomer and a catalyst in an organic solvent system under the protection of inert gas, and finally purifying by adopting column chromatography to obtain a target product shown in a formula I, wherein the structural formula of the formula II is as follows:

3. the process for preparing a chlorinated conjugated polymer of D-A type according to claim 2, characterized in that: the reaction temperature is 95-135 ℃, and the reaction time is 12-60 h.

4. The method for preparing the D-A type chlorinated conjugated polymer according to claim 2, wherein the compound of the structure shown in the formula II is prepared by the following method:

s1, 4, 7-dibromobenzo [ c ]][1,2,5]And (3) synthesis of thiadiazole: a benzene ring [ c ]][1,2,5]Thiadiazole (3.12g, 22.8mmol) was added to a dry three-necked round bottom flask, followed by the addition of hydrobromic acid (HBr) (60mL) to dissolve, and liquid bromine (Br) at 46% concentration was slowly added dropwise after all the material had dissolved₂) (2.94mL, 57mmol) and Br was added₂Then, the reaction system was heated to 127 ℃ and refluxed for 12 hours, cooled to room temperature after the reaction was completed, and then added with sodium hydrogen sulfite (NaHCO)₃) The excess bromine was removed in aqueous solution and chloroform (CHCl)₃) Extracting, collecting an organic layer, distilling the organic layer under reduced pressure to obtain a crude product, and purifying the crude product by silica gel column chromatography with a mobile phase of dichloromethane to obtain 2.45g of a target product;

s2, 4, 7-bis (4-hexylthiophen-2-yl) benzo [ c ] [1,2,5] thiadiazole: adding 4, 7-dibromobenzo [ C ] [1,2,5] thiadiazole (582mg, 2mmol), tributyl (4-hexyl-2-thienyl) stannane (2.26g, 5mmol) into a 25mL dry two-necked bottle, dissolving with dry and deoxygenated toluene (15mL), replacing air with nitrogen for three times, adding tris (2-methylphenyl) phosphine, copper oxide, and tris (dibenzylideneacetone) dipalladium into the system, replacing air with nitrogen again for three times, and heating to 115 ℃ for refluxing for 48 hours; after cooling, washing with an appropriate amount of dichloromethane, suction filtration, taking out the filtrate, then carrying out reduced pressure distillation, loading the material onto silica gel, and purifying by silica gel column chromatography using hexane/chloroform (6: 1) as the mobile phase to obtain 0.447g of a yellow solid;

s3, synthesis of compound II: to a tinfoil wrapped 50mL single neck bottle was added 4, 7-bis (4-hexylthiophen-2-yl) benzo [ c ] [1,2,5] thiadiazole (462mg, 0.995mmol), chloroform (20 mL); n-bromosuccinimide (NBS) (328mg, 1.58mmol) was added in portions at 0 deg.C, spotting was performed before each addition, and NBS addition was stopped until disubstituted product appeared on the silica gel plate. And carrying out reduced pressure distillation on the product to remove the solvent to obtain a crude product. Purification by column chromatography (15: 1 ratio between petroleum ether and dichloromethane) and drying of the pure product gave 0.365g of a yellow solid.

5. The process for preparing a chlorinated conjugated polymer of D-A type according to claim 2, characterized in that: the electron-donating monomer is (4, 8-bis (4-chloro-5- (2-ethylhexyl) thiophen-2-yl) benzo [1, 2-b: 4,5-b' ] dithiophene-2, 6-diyl) bis (trimethylstannane).

6. The process for preparing a chlorinated conjugated polymer of D-A type according to claim 2, characterized in that: the catalyst is tris (2-methylphenyl) phosphine, copper oxide and tris (dibenzylideneacetone) dipalladium.

7. The process for preparing a chlorinated conjugated polymer of D-A type according to claim 2, characterized in that: the organic solvent is toluene.

8. The process for preparing a chlorinated conjugated polymer of D-A type according to any one of claims 2 to 7, wherein: the molar ratio of the compound with the structure shown in the formula II to the electron-donating monomer is 1: 1-1.5.

9. The application of a D-A type chlorinated conjugated polymer is characterized in that: the D-A type chlorinated conjugated polymer prepared according to the claims 1-8 can be applied to organic solar cell devices.

10. Use of a chlorinated conjugated polymer of type D-a according to claim 9, characterized in that: the solar cell device is composed ofComprises a glass layer, an indium tin oxide conducting layer, a zinc oxide electron transmission layer, a D-A type chlorinated conjugated polymer and PC in sequence from bottom to top₇₁BM mixed active layer, molybdenum trioxide hole transport layer and silver electrode layer.

Technical Field

The invention relates to the technical field of solar cells, in particular to a D-A type chlorinated conjugated polymer and a preparation method and application thereof.

Background

Energy is an indispensable power in human development and progress so far, development and utilization of energy are a long-standing constant topic, with economic development and social progress, people pursue improvement of material life, more and more energy needs to be consumed, and application of a large amount of petrochemical energy causes irreversible damage to living environment of people, so that seeking of clean energy (such as solar energy, wind energy and the like) is urgent. The active material of the solar cell device occupies the market mainly and mainly comprises crystalline silicon and inorganic semiconductor materials. But the popularization is limited by the disadvantages of high cost, serious environmental pollution and the like. In recent years, it has been found that organic conjugated polymers have good optical, electrochemical and electrical properties, and that the polymers can be processed using solution processes such as spin coating, ink jet printing, screen printing, etc., and have excellent properties such as low cost, simple process, and device sinterability. Is expected to replace inorganic solar cells in the future, is popularized on a large scale and greatly relieves the shortage of energy.

Disclosure of Invention

In order to solve the technical problems, the invention provides a D-A type chlorinated conjugated polymer in a first aspect, wherein the structural formula of the chlorinated polymer is shown as formula I:

the invention provides a preparation method of a D-A conjugated chlorinated polymer, wherein the chlorinated polymer is prepared by a structure shown in a formula II, an electron donor monomer and a catalyst respectively in an organic solvent system under the protection of inert gas, a light-shielding reaction is firstly carried out, and finally, column chromatography purification is adopted to prepare a target product shown in a formula I, wherein the structural formula of the formula II is as follows:

wherein the reaction temperature is 95-135 ℃, and the reaction time is 12-60 h.

Wherein the compound with the structure shown in the formula II is prepared by the following method:

s1, 4, 7-dibromobenzo [ c ]][1,2,5]And (3) synthesis of thiadiazole: a benzene ring [ c ]][1,2,5]Thiadiazole (3.12g, 22.8mmol) was added to a dry three-necked round bottom flask, followed by the addition of hydrobromic acid (HBr) (60mL) to dissolve, and liquid bromine (Br) at 46% concentration was slowly added dropwise after all the material had dissolved₂) (2.94mL, 57mmol) and Br was added₂Then, the reaction system was heated to 127 ℃ and refluxed for 12 hours, cooled to room temperature after the reaction was completed, and then added with sodium hydrogen sulfite (NaHCO)₃) The excess bromine was removed in aqueous solution and chloroform (CHCl)₃) Extracting, collecting an organic layer, distilling the organic layer under reduced pressure to obtain a crude product, and purifying the crude product by silica gel column chromatography with a mobile phase of dichloromethane to obtain 2.45g of a target product;

s2, 4, 7-bis (4-hexylthiophen-2-yl) benzo [ c ] [1,2,5] thiadiazole: adding 4, 7-dibromobenzo [ C ] [1,2,5] thiadiazole (582mg, 2mmol), tributyl (4-hexyl-2-thienyl) stannane (2.26g, 5mmol) into a 25mL dry two-necked bottle, dissolving with dry and deoxygenated toluene (15mL), replacing air with nitrogen for three times, adding tris (2-methylphenyl) phosphine, copper oxide, and tris (dibenzylideneacetone) dipalladium into the system, replacing air with nitrogen again for three times, and heating to 115 ℃ for refluxing for 48 hours; after cooling, washing with an appropriate amount of dichloromethane, suction filtration, taking out the filtrate, then carrying out reduced pressure distillation, loading the material onto silica gel, and purifying by silica gel column chromatography using hexane/chloroform (6: 1) as the mobile phase to obtain 0.447g of a yellow solid;

s3, synthesis of compound II: to a tinfoil wrapped 50mL single neck bottle was added 4, 7-bis (4-hexylthiophen-2-yl) benzo [ c ] [1,2,5] thiadiazole (462mg, 0.995mmol), chloroform (20 mL); n-bromosuccinimide (NBS) (328mg, 1.58mmol) was added in portions at 0 ℃ and spotting was performed before each addition until a disubstituted product appeared on the silica gel plate, and the NBS addition was stopped and the product was distilled under reduced pressure to remove the solvent to give a crude product. Purification by column chromatography (15: 1 ratio between petroleum ether and dichloromethane) and drying of the pure product gave 0.365g of a yellow solid.

Wherein the electron-donating monomer is (4, 8-bis (4-chloro-5- (2-ethylhexyl) thiophen-2-yl) benzo [1, 2-b: 4,5-b' ] dithiophene-2, 6-diyl) bis (trimethylstannane).

Wherein the catalyst is tris (2-methylphenyl) phosphine, copper oxide and tris (dibenzylideneacetone) dipalladium serving as a catalyst. Wherein the organic solvent is toluene.

Wherein the molar ratio of the compound with the structure shown in the formula II to the electron-donating monomer is 1: 1-1.5.

Preferably, the molar ratio of the compound with the structure shown in the formula II to the electron-donating monomer is 1: 1-1.2.

The third aspect of the invention provides application of a D-A type chlorinated conjugated polymer, and the D-A type chlorinated conjugated polymer prepared by the method provided by the second aspect of the invention can be applied to an organic solar cell device, and the solar cell device sequentially comprises a glass layer, an indium tin oxide conducting layer, a zinc oxide electron transmission layer, a D-A type chlorinated conjugated polymer and PC (polycarbonate) from bottom to top₇₁BM mixed active layer, molybdenum trioxide hole transport layer and silver electrode layer.

The invention has the beneficial effects that:

the D-A type chlorinated conjugated polymer provided by the invention can be dissolved in common organic solvents such as dichloromethane, chloroform, tetrahydrofuran, toluene, chlorobenzene, dichlorobenzene and the like, and can be processed by adopting a solution processing mode (such as spin coating); has better absorption in the visible light range and proper energy level, and is suitable for being used as a donor material in an organic solar cell. The matching degree of the absorption spectrum of the solar cell material and the solar spectrum, the carrier mobility and the appropriate energy level are crucial to obtaining high device efficiency, and the benzothiadiazole adopted by the invention is used as an acceptor to form a donor-acceptor (D-A) conjugated structure with a chlorinated electron-donating group, so that the energy level can be effectively regulated and controlled, thereby obtaining a lower energy band gap, widening and enhancing the spectral absorption of the material, and being applied to constructing a high-efficiency organic solar cell material.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 shows the chlorinated conjugated polymer D-A in CHCl as provided in example 1 of the present invention₃Ultraviolet-visible absorption spectrum of (1);

FIG. 2 is a graph showing an ultraviolet-visible absorption spectrum of a D-A type chlorinated conjugated polymer in a film, provided in example 1 of the present invention;

FIG. 3 is a J-V curve diagram of a D-A type chlorinated conjugated polymer solar cell device provided in example 1 of the present invention;

fig. 4 is a schematic structural diagram of a D-a type chlorinated conjugated polymer solar cell device provided in embodiment 1 of the present invention.

Detailed Description

The following is a preferred embodiment of the present invention, and it should be noted that it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements are also considered to be within the scope of the present invention.

The invention provides a D-A type chlorinated conjugated polymer, the structural formula of which is shown in formula I as follows:

the D-A type chlorinated conjugated polymer provided in this example is prepared by the following method:

1mmol of the compound with the structure shown in the formula II and 1mmol (4, 8-bis (4-chloro-5- (2-ethylhexyl) thiophen-2-yl) benzo [1, 2-b: 4,5-b']Putting dithiophene-2, 6-diyl) bis (trimethylstannane) in a toluene solvent, adopting tris (dibenzylideneacetone) dipalladium as a catalyst, controlling the temperature to be 115 ℃ under the protection of inert gas, carrying out a light-shielding reaction for 48 hours, and carrying out column chromatography purification to obtain a target product shown in a formula I;¹H NMR(CDCl₃,500MHz,/ppm):8.31(s,1H),7.59(s,2H),741(s,2H),7.24(s,2H),7.09(s,1H),4.31(t,4H),2.89(t,2H),2.39(t,2H),1.72(m,10H),1.48(m,10H),1.27(m,110H).¹³C NMR(CDCl₃,125MHz,/ppm):159.1,155.2,147.2,143.9,131.1,128.7,128.3,117.1,86.2,68.4,42.5,38.3,36.5,35.1,34.3,32.8,30.3,28.5,27.4,25.6,24.1,15.3。

the synthetic route of the formula I is as follows:

the synthesized chlorinated polymer is applied to an organic solar cell device, and as shown in fig. 4, the solar cell device sequentially comprises a Glass (Glass) layer, an Indium Tin Oxide (ITO) conducting layer, a zinc oxide (ZnO) electronic transmission layer, a D-A conjugated polymer and a C from bottom to top₇₁Hybrid (D-A conjugated Polymer/PC₇₁BM), molybdenum trioxide (MoO)₃) A hole transport layer and a silver (Ag) electrode layer, wherein the structural formula of the D-A conjugated polymer is a compound shown in formula I, and the hole transport layer and the silver (Ag) electrode layer are prepared by the method provided in example 1.

The preparation method of the solar cell device is not particularly limited, and may be implemented by using a technical scheme for solar cell preparation well known to those skilled in the art, and in the embodiment of the present invention, the preparation method of the solar cell device preferably includes the following steps:

s1: firstly, sequentially cleaning and carrying out ultraviolet ozone treatment on glass with ITO sputtered on the surface to obtain a clean ITO glass layer;

s2: then, the ITO treated in step S1ZnO and D-A conjugated polymer/PC are sequentially spin-coated on the glass layer₇₁BM and then sequentially evaporating MoO₃And an Ag electrode, wherein a ZnO electron transmission layer and a D-A conjugated polymer/PC are sequentially formed on the ITO glass layer₇₁BM active layer, MoO₃And preparing the hole transport layer and the Ag electrode layer to obtain the solar cell device.