阅读说明：本技术 一种基于苯并呋喃酮的芳杂环型共轭聚合物及其制备方法和应用、有机场效应晶体管 (Aromatic heterocyclic conjugated polymer based on benzofuranone, preparation method and application thereof, and organic field effect transistor ) 是由 张海昌 邓志峰 李锐 戴志诚 王成 崔帅玮 石昕 梁东旭 于 2021-01-08 设计创作，主要内容包括：本发明属于有机半导体材料技术领域,特别涉及一种基于苯并呋喃酮的芳杂环型共轭聚合物及其制备方法和应用、有机场效应晶体管。本发明提供的基于苯并呋喃酮的芳杂环型共轭聚合物中含有3,6-双(4-溴)苯并[2,1-b:3,4-b’]二呋喃-2,7-二酮活性基团,能与(4,4,9,9-四辛基-4,9-二氢-s-二癸烯[1,2-b:5,6-b’]二噻吩-2,7-二取代)双(四甲基锡)构造出平面性良好的聚合物,有利于提供较高的空穴迁移率,从而提高基于苯并呋喃酮的芳杂环型共轭聚合物在形成半导体薄膜时的分子间自组装和有序排列性能,有利于得到更好的分子晶体,提高电荷传输性能。(The invention belongs to the technical field of organic semiconductor materials, and particularly relates to an aromatic heterocyclic conjugated polymer based on benzofuranone, a preparation method and application thereof, and an organic field effect transistor. The aromatic heterocyclic conjugated polymer based on the benzofuranone contains 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-diketone active groups, can construct a polymer with good planarity with (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin), and is favorable for providing higher hole mobility, so that the intermolecular self-assembly and ordered arrangement performance of the aromatic heterocyclic conjugated polymer based on the benzofuranone when a semiconductor film is formed is improved, better molecular crystals are obtained, and the charge transport performance is improved.)

1. A benzofuranone based aromatic heterocyclic conjugated polymer having the structure of formula I:

2. the process for the preparation of conjugated polymers of the heteroaromatic type based on benzofuranones according to claim 1, characterized by the following steps:

mixing 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione, (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) with a mixed organic solvent, and carrying out first anhydrous oxygen-free treatment to obtain a precursor solution;

and mixing the precursor solution with palladium tetratriphenylphosphine, and sequentially carrying out second anhydrous anaerobic treatment and Stille coupling reaction to obtain the benzofuranone-based aromatic heterocyclic conjugated polymer.

3. The method according to claim 2, wherein the molar ratio of 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione to (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) is 1: (1.0-1.2).

4. The production method according to claim 2, wherein the mixed organic solvent comprises toluene and N, N-dimethylformamide; the volume ratio of the toluene to the N, N-dimethylformamide is (2.5-3.5): 1.

5. the method according to claim 2 or 3, wherein the total concentration of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione and (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) in the precursor solution is 0.030 to 0.035 g/L.

6. The method according to claim 2, wherein the molar ratio of 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione to palladium tetrakistriphenylphosphine is 1: (0.015 to 0.025).

7. The method of claim 2, wherein the first and second anaerobic anhydrous treatments are independently sonication, and wherein the sonication is performed under a protective atmosphere.

8. The preparation method according to claim 2, wherein the temperature of the Stille coupling reaction is 88-92 ℃ and the time is 23-26 h.

9. Use of the benzofuranone-based aromatic heterocyclic conjugated polymer according to claim 1 or the benzofuranone-based aromatic heterocyclic conjugated polymer prepared by the preparation method according to any one of claims 2 to 8 as a semiconductor material in an electronic device.

10. An organic field effect transistor comprising an organic semiconductor layer, an electrode and a gate insulating layer, wherein the organic semiconductor layer is the benzofuranone-based aromatic heterocyclic conjugated polymer according to claim 1 or the benzofuranone-based aromatic heterocyclic conjugated polymer prepared by the preparation method according to any one of claims 2 to 8.

Technical Field

The invention belongs to the technical field of organic semiconductor materials, and particularly relates to an aromatic heterocyclic conjugated polymer based on benzofuranone, a preparation method and application thereof, and an organic field effect transistor.

Background

The organic semiconductor material has the advantages of easy structure design and cutting, various types, strong performance controllability, simple preparation process, low manufacturing cost, easy large-area application, application to flexible electronic devices and the like, and has excellent application prospect in the fields of Organic Field Effect Transistors (OFETs) and the like.

The traditional organic field effect transistor material (OFET) is mostly constructed by adopting receptor structural units such as pyrrolo-pyrrole-Dione (DPP), and the construction units are single.

Disclosure of Invention

In view of the above, the present invention provides an aromatic heterocyclic conjugated polymer based on benzofuranone, which has excellent molecular planarity, ordered stacking between molecules, tight connection between phase states, good pi-pi stacking and overlapping, and high carrier mobility, and can significantly improve the performance of electronic devices and meet the use requirements of organic field effect transistors on organic semiconductor materials.

In order to achieve the purpose of the invention, the invention provides the following technical scheme:

the invention provides an aromatic heterocyclic conjugated polymer based on benzofuranone, which has a structure shown in formula I:

the invention also provides a preparation method of the aromatic heterocyclic conjugated polymer based on the benzofuranone in the technical scheme, which comprises the following steps:

mixing 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione, (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) with a mixed organic solvent, and carrying out first anhydrous oxygen-free treatment to obtain a precursor solution;

and mixing the precursor solution with palladium tetratriphenylphosphine, and sequentially carrying out second anhydrous anaerobic treatment and Stille coupling reaction to obtain the benzofuranone-based aromatic heterocyclic conjugated polymer.

Preferably, the molar ratio of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione to (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) is 1: (1.0-1.2).

Preferably, the mixed organic solvent comprises toluene and N, N-dimethylformamide; the volume ratio of the toluene to the N, N-dimethylformamide is (2.5-3.5): 1.

preferably, the total concentration of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione and (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) in the precursor solution is 0.030-0.035 g/L.

Preferably, the molar ratio of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione to palladium tetratriphenylphosphine is 1: (0.015 to 0.025).

Preferably, the first anhydrous anaerobic treatment and the second anhydrous anaerobic treatment are independently ultrasonic treatment, and the ultrasonic treatment is carried out under the condition of protective atmosphere.

Preferably, the temperature of the Stille coupling reaction is 88-92 ℃, and the time is 23-26 h.

The invention also provides the application of the aromatic heterocyclic conjugated polymer based on benzofuranone or the aromatic heterocyclic conjugated polymer based on benzofuranone prepared by the preparation method in the technical scheme as a semiconductor material in an electronic device.

The invention also provides an organic field effect transistor which comprises an organic semiconductor layer, an electrode and a gate insulating layer, wherein the organic semiconductor layer is the aromatic heterocyclic conjugated polymer based on the benzofuranone in the technical scheme or the aromatic heterocyclic conjugated polymer based on the benzofuranone prepared by the preparation method in the technical scheme.

The invention provides an aromatic heterocyclic conjugated polymer based on benzofuranone, which has a structure shown in formula I:

the aromatic heterocyclic conjugated polymer based on the benzofuranone contains 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-diketone active groups, can construct a polymer with good coplanarity with (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin), is favorable for enhancing the interaction between molecules and reducing the space between molecules, and is favorable for providing higher hole mobility, so that the molecular order arrangement performance of the planar polymer based on the benzofuranone during the formation of a semiconductor film is improved, and the molecular planarity is favorably obtained, The polymer film with better connection between the stacking order and the phase state among molecules improves the charge transmission performance. In addition, the aromatic heterocyclic conjugated polymer based on benzofuranone provided by the invention also has excellent pi-pi conjugated system and strong donor-acceptor exchange performance, excellent intermolecular and intramolecular charge transfer characteristics, and excellent thermal stability and solubility.

The test results of the examples show that the aromatic heterocyclic conjugated polymer based on benzofuranone provided by the invention is used as a semiconductor layer, an n-type doped silicon wafer subjected to surface treatment by octadecyl trichlorosilane is used as a grid electrode (the surface of the n-type doped silicon wafer contains 300nm thick silicon dioxide as an insulating layer), gold is used as a source electrode and a drain electrode, and the hole mobility of the organic field effect transistor prepared by adopting a solution drop film method is 0.85cm²V^-1·s^-1On-off ratio I_on/I_offIs 10⁶And excellent p-type organic field effect transistor device characteristics are shown.

Drawings

FIG. 1 is a chart of an infrared spectrum of a benzofuranone-based conjugated aromatic heterocyclic polymer obtained in example 1;

FIG. 2 is a graph showing the molecular weights and molecular weight distributions of the benzofuranone-based heteroaromatic conjugated polymer obtained in example 1;

FIG. 3 is a DSC of the benzofuranone based conjugated polymers of heteroaromatic type obtained in example 1;

FIG. 4 is a TGA profile of a benzofuranone based conjugated aromatic heterocyclic polymer obtained in example 1;

fig. 5 is an output characteristic curve of the organic field effect transistor prepared in application example 1;

fig. 6 is a transfer transmission characteristic curve after annealing of the organic field effect transistor prepared in application example 1.

Detailed Description

The invention provides an aromatic heterocyclic conjugated polymer based on benzofuranone, which has a structure shown in formula I:

the invention is directed to-C in said formula I₈H₁₇Any octyl group may be used without particular limitation.

In the present invention, the chemical name of the benzofuranone-based aromatic heterocyclic conjugated polymer is: poly 3- (4- (7-methyl-4, 4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5,6-b '] dithiophene-2, 7-disubstituted) phenyl-6- (p-tolyl) -benzo [2,1-b:3,4-b' ] difuran-2, 7-dione).

In the present invention, the color of the benzofuranone-based aromatic heterocyclic conjugated polymer is greenish black. In an embodiment of the invention, the weight average molecular weight of the benzofuranone based conjugated polymer is 65.1kDa, the molecular weight distribution PDI is 4.285, and the thermal decomposition temperature corresponding to 5% mass loss is 393 ℃. In the present invention, n in the formula I is based on the condition that the weight average molecular weight of the benzofuranone-based aromatic heterocyclic conjugated polymer is 65.1kDa and the molecular weight distribution PDI is 4.285.

The invention also provides a preparation method of the aromatic heterocyclic conjugated polymer based on the benzofuranone in the technical scheme, which comprises the following steps:

mixing 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione, (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) with a mixed organic solvent, and carrying out first anhydrous oxygen-free treatment to obtain a precursor solution;

and mixing the precursor solution with palladium tetratriphenylphosphine, and sequentially carrying out second anhydrous anaerobic treatment and Stille coupling reaction to obtain the benzofuranone-based aromatic heterocyclic conjugated polymer.

In the present invention, unless otherwise specified, each component in the preparation method is a commercially available product well known to those skilled in the art.

The method comprises the steps of mixing 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-diketone, (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) and a mixed organic solvent, and carrying out first anhydrous and oxygen-free treatment to obtain a precursor solution.

The source of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione is not particularly limited in the present invention, and the compound can be prepared by a method well known to those skilled in the art. In the present invention, the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione is preferably prepared by the method described in "Zhang, k., Tieke, b.low-baseband benzodifuranone-based polymers, macromolecules,2011,44, 4596-.

In the present invention, the (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) is preferably a commercially available product; in the embodiment of the invention, the (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecene [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) is purchased from Shenzhen Ruizhen photoelectric materials science and technology Limited.

In the present invention, the molar ratio of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione to (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) is preferably 1: (1.0 to 1.2), more preferably 1: (1.03-1.15), and more preferably 1: (1.05-1.10).

In the present invention, the mixed organic solvent preferably includes toluene and N, N-dimethylformamide; the volume ratio of the toluene to the N, N-dimethylformamide is preferably (2.5-3.5): 1, more preferably (2.7 to 3.3): 1, and more preferably (2.9 to 3.2): 1, most preferably 3: 1.

in the present invention, the total concentration of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b '] difuran-2, 7-dione and (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin) in the precursor solution is preferably 0.030 to 0.035g/L, more preferably 0.030 to 0.034g/L, and still more preferably 0.030 to 0.032 g/L.

In the present invention, the first anhydrous anaerobic treatment is preferably an ultrasonic treatment. The present invention does not specifically limit the frequency of the ultrasound in the ultrasonic treatment, and a frequency known to those skilled in the art may be used. In the present invention, the ultrasonic treatment is preferably performed under a protective atmosphere. In the present invention, the shielding gas providing the protective atmosphere is preferably nitrogen. The flow rate of the shielding gas in the first anhydrous anaerobic treatment is not particularly limited, and the first anhydrous anaerobic treatment is performed on the basis of being capable of exhausting gas fully to form an anhydrous anaerobic condition, such as 10 sccm. In the present invention, the time of the first anhydrous anaerobic treatment is preferably 10 min. The method removes oxygen and moisture existing in the precursor solution through first anhydrous anaerobic treatment.

After a precursor solution is obtained, the precursor solution is mixed with palladium tetratriphenylphosphine, and second anhydrous anaerobic treatment and Stille coupling reaction are sequentially carried out to obtain the aromatic heterocyclic conjugated polymer based on benzofuranone.

In the present invention, the molar ratio of the 3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione to palladium tetrakistriphenylphosphine is preferably 1: (0.015 to 0.025), more preferably 1: (0.017-0.023), preferably 1: (0.019-0.022). In the present invention, the mixing of the precursor solution and the tetrakistriphenylphosphine palladium is preferably performed by adding the tetrakistriphenylphosphine palladium to the precursor solution. In the invention, the mixing of the precursor solution and the palladium tetratriphenylphosphine is preferably carried out in the presence of a protective gas; the protective gas is preferably nitrogen.

In the present invention, the second anhydrous anaerobic treatment is preferably an ultrasonic treatment. The present invention does not specifically limit the frequency of the ultrasound in the ultrasonic treatment, and a frequency known to those skilled in the art may be used. In the present invention, the ultrasonic treatment is preferably performed under a protective atmosphere. In the present invention, the shielding gas providing the protective atmosphere is preferably nitrogen. The flow rate of the shielding gas in the second anhydrous anaerobic treatment is not particularly limited, and the second anhydrous anaerobic treatment is performed on the basis that the shielding gas can be fully exhausted to form an anhydrous anaerobic condition, specifically 10 sccm. In the present invention, the time of the second anhydrous anaerobic treatment is preferably 10 min. According to the invention, oxygen and moisture existing in a mixed system formed by mixing the precursor solution and the palladium tetratriphenylphosphine are removed through second anhydrous oxygen-free treatment.

In the invention, the temperature of the Stille coupling reaction is preferably 88-92 ℃, more preferably 89-91 ℃, and most preferably 90 ℃; the time is preferably 23 to 26 hours, more preferably 23.5 to 25.5 hours, and most preferably 24 hours. In the present invention, the Stille coupling reaction is preferably performed under the condition of solvent reflux; the solvent reflux rate is not particularly limited in the invention, so that the temperature stability of the Stille coupling reaction can be ensured.

After the Stille coupling reaction, the obtained coupling product is preferably cooled and then purified to obtain the aromatic heterocyclic conjugated polymer based on the benzofuranone.

In the present invention, the temperature reduction is preferably natural temperature reduction to room temperature.

In the present invention, the purification treatment preferably comprises the steps of:

and sequentially diluting and extracting the coupling product, and sequentially drying, carrying out solid-liquid separation, solvent removal treatment and Soxhlet extraction treatment on the obtained organic phase to obtain the aromatic heterocyclic conjugated polymer of the benzofuranone.

In the present invention, the diluent used in the dilution is preferably dichloromethane. In the invention, the volume ratio of the diluent to the coupling product is preferably (4-7): 1, more preferably (5-6): 1.

in the present invention, the extraction preferably includes a first extraction and a second extraction performed in this order. In the present invention, the extractant of the first extraction is preferably a NaCl solution; the concentration of the NaCl solution is not particularly limited in the invention, and the NaCl concentration known to those skilled in the art can be adopted; in the embodiment of the present invention, the NaCl solution preferably has a concentration of 20% by mass. In the present invention, the number of times of the first extraction is preferably 2 times. In the invention, the volume ratio of the extracting agent to the coupling product in the single extraction in the first extraction is preferably (2-3): 1, more preferably (2.2 to 2.8): 1. the invention selects the organic phase after the first extraction as a continuous processing object.

In the present invention, the extractant of the second extraction is preferably water, more preferably distilled water. In the invention, the volume ratio of the extracting agent to the coupling product in the second extraction is preferably (2-3): 1, more preferably (2.2 to 2.8): 1.

the organic phase after the first extraction is selected as a continuous processing object, and the obtained organic phase is subjected to drying, solid-liquid separation, solvent removal and Soxhlet extraction in turn to obtain the aromatic heterocyclic conjugated polymer of the benzofuranone. In the present invention, the drying agent used for the drying is preferably anhydrous magnesium sulfate. The present invention is not particularly limited to the specific drying process, and the organic phase may be dried by using a solid drying agent known to those skilled in the art. The invention removes the water in the organic phase obtained by the second extraction through drying.

In the present invention, the solid-liquid separation is preferably filtration; the filtration is not particularly limited in the present invention, and filtration known to those skilled in the art may be employed.

The solvent removal treatment in the present invention is not particularly limited, and is carried out by a rotary evaporation method, for example, so as to remove the solvent. In the present invention, the apparatus used in the rotary evaporation method is preferably a rotary evaporator. The present invention is not particularly limited to the specific operation of the rotary evaporation method, and the solvent can be removed. After the solvent is removed, the invention obtains the crude aromatic heterocyclic conjugated polymer.

In the invention, the soxhlet extraction treatment is preferably to sequentially extract the aromatic heterocyclic type conjugated polymer crude product by using methanol, n-hexane and tetrahydrofuran, dissolve the obtained first extract in chloroform and then spin-dry, dissolve the obtained spin-dried product in dichloromethane, mix the obtained spin-dried product dichloromethane solution with methanol, perform precipitation treatment, and perform solid-liquid separation to obtain the aromatic heterocyclic type conjugated polymer product based on benzofuranone. The amount of methanol, n-hexane, tetrahydrofuran, chloroform and dichloromethane in the Soxhlet extraction treatment is not particularly limited in the present invention, and may be those known to those skilled in the art. The invention removes unreacted raw materials and oligomers by sequentially adopting methanol, normal hexane and tetrahydrofuran for extraction.

The invention has no special limitation on the process parameters in the column chromatography separation treatment, and the process parameters of the column chromatography separation treatment which are well known by the technical personnel in the field can be adopted.

In the invention, the preparation method of the aromatic heterocyclic conjugated polymer based on benzofuranone has the principle shown in formula II:

the invention also provides the application of the aromatic heterocyclic conjugated polymer based on benzofuranone or the aromatic heterocyclic conjugated polymer based on benzofuranone prepared by the preparation method in the technical scheme as a semiconductor material in an electronic device.

The invention also provides an organic field effect transistor which comprises an organic semiconductor layer, an electrode and a gate insulating layer, wherein the organic semiconductor layer is the aromatic heterocyclic conjugated polymer based on the benzofuranone in the technical scheme or the aromatic heterocyclic conjugated polymer based on the benzofuranone prepared by the preparation method in the technical scheme.

In the present invention, the organic field effect transistor is preferably a bottom gate bottom contact field effect transistor.

The method for manufacturing the organic field effect transistor is not particularly limited, and the method for manufacturing the organic field effect transistor known by the person skilled in the art can be adopted.

In the present invention, the method for manufacturing the organic field effect transistor preferably includes the steps of:

providing a wafer substrate; the wafer substrate comprises a Si layer and SiO attached to one side of the Si layer₂A layer;

sequentially carrying out piranha etching solution etching, deionized water washing and acetone washing on the wafer substrate, placing the wafer substrate in a toluene solution of octadecyl trichlorosilane, and carrying out surface treatment to obtain a primary substrate;

spraying gold on SiO of the primary substrate by adopting a mask method₂Forming a gold source electrode and a gold drain electrode on one surface of the layer to obtain a secondary substrate;

and coating the aromatic heterocyclic conjugated polymer based on benzofuranone on the surface of the gold source electrode and the surface of the gold drain electrode of the secondary substrate by adopting a film dropping method, and sequentially standing and removing the solvent to obtain the organic field effect transistor.

The present invention provides a wafer substrate; the wafer substrate comprises a Si layer and SiO attached to one side of the Si layer₂And (3) a layer.

In the present invention, the wafer substrate is preferably n-type doped Si (n)⁺⁺) A wafer. In the present invention, the SiO₂The thickness of the layer is preferably 300 nm. In an embodiment of the invention, the wafer substrate is purchased from Silicon Quest International. In the present invention, the Si layer serves as a gate electrode, SiO₂The layer serves as a dielectric layer.

After the wafer substrate is obtained, the wafer substrate is sequentially subjected to piranha etching solution etching, deionized water washing and acetone washing, and then placed in a toluene solution of octadecyl trichlorosilane for surface treatment to obtain a primary substrate.

In the invention, the volume ratio of sulfuric acid to hydrogen peroxide in the piranha etching solution is preferably 3: 1; the concentration of the sulfuric acid in the piranha etching solution is not particularly limited, and the sulfuric acid concentration known to those skilled in the art can be adopted. The present invention has no special limitation on the piranha etching solution, the deionized water washing and the acetone washing, and the present invention adopts the process known to those skilled in the art. In the present invention, the octadecyl trichlorosilane content in the toluene solution of octadecyl trichlorosilane is preferably 5% by mass. In the present invention, the surface treatment is preferably performed under a protective gas condition; the shielding gas is preferably argon. In the present invention, the time for the surface treatment is preferably 18 hours.

After the primary substrate is obtained, the method of spraying gold on the SiO of the primary substrate by adopting a mask₂And forming a gold source electrode and a gold drain electrode on one surface of the layer to obtain the secondary substrate.

The method for spraying gold on the mask is not particularly limited, and the method for spraying gold on the mask, which is well known to those skilled in the art, can be adopted. In the present invention, the thickness of the gold source electrode and the gold drain electrode is independently preferably 30 nm. In the present invention, the conductive trenches on the secondary substrate preferably have a length of 1000 μm and a width of 30 μm.

After the secondary substrate is obtained, the invention adopts a film dropping method, coats the surfaces of a gold source electrode and a gold drain electrode of the secondary substrate with the aromatic heterocyclic conjugated polymer based on benzofuranone in the technical scheme, and sequentially carries out standing and solvent removal to obtain the organic field effect transistor.

The coating amount of the aromatic heterocyclic conjugated polymer based on benzofuranone on the surface of the secondary substrate is not particularly limited in the invention, and the aromatic heterocyclic conjugated polymer on the surface of the secondary substrate can be coated by adopting the coating amount well known to a person skilled in the art. In the present invention, the benzofuranone-based aromatic heterocyclic conjugated polymer is preferably provided in the form of a chloroform solution of the benzofuranone-based aromatic heterocyclic conjugated polymer; the concentration of the benzofuranone-based aromatic heterocyclic conjugated polymer in the chloroform solution of the benzofuranone-based aromatic heterocyclic conjugated polymer is preferably 5 mg/mL. In the present invention, the coating is preferably performed by a dropping film method; the film dropping method preferably comprises the following steps: the chloroform solution of the benzofuranone-based aromatic heterocyclic conjugated polymer was pipetted between the source and drain under argon atmosphere, and then covered with a watch glass to evaporate the chloroform. In the invention, the action of covering the surface dish is to make the solution volatilization speed slower, thus being beneficial to the aromatic heterocyclic conjugated polymer based on the benzofuranone to have enough time for arrangement, promoting the ordered arrangement among molecules of the large aromatic ring conjugated polymer based on the benzofuranone and leading the large aromatic ring conjugated polymer based on the benzofuranone to form more ordered accumulation; good ordered packing facilitates the transfer of charge carriers between individual molecules in a thin film formed from a conjugated polymer of the heteroaromatic type based on benzofuranones.

In the invention, the temperature of the standing is preferably room temperature, and specifically, 18-30 ℃; the time is preferably 0.5 h. In the present invention, the standing is preferably performed under a protective atmosphere; the gas providing the protective atmosphere is preferably argon.

In the present invention, the solvent is preferably removed by constant temperature evaporation; the constant temperature evaporation temperature is preferably 50 ℃, and the time is preferably 5 min. In the present invention, the solvent removal is preferably carried out under a protective atmosphere; the gas providing the protective atmosphere is preferably argon.

In order to further illustrate the present invention, the following examples are provided to describe in detail a benzofuranone-based aromatic heterocyclic conjugated polymer, a preparation method and applications thereof, and an organic field effect transistor, but they should not be construed as limiting the scope of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

And (3) reagent sources:

3, 6-bis (4-bromo) benzo [2,1-b:3,4-b' ] difuran-2, 7-dione: prepared according to the literature "Zhang, K., Tieke, B.Low-base benzodifuranone-based polymers, macromolecules,2011,44,4596-,

(4,4,9, 9-tetraoctyl-4, 9-dihydro-s-dideceno [1,2-b:5, 6-b' ] dithiophene-2, 7-disubstituted) bis (tetramethyltin): purchased from Shenzhen Rui Xun photoelectric materials science and technology Limited,

palladium tetratriphenylphosphine: purchased from sahn chemical technology (shanghai) ltd;

preparation of benzofuranone-based conjugated polymers of the heteroaromatic type:

74.7mg (0.15mmol)3, 6-bis (4-bromo) benzo [2,1-b:3,4-b']Difuran-2, 7-dione, 156mg (0.15mmol) (4,4,9, 9-tetraoctyl-4, 9-dihydro-s-didecen [1,2-b:5, 6-b']Mixing dithiophene-2, 7-disubstituted) bis (tetramethyltin) and 8mL of solvent, wherein the volume ratio of the solvent to the solvent is 3: 1 is mixed, and the mixed system is N with the flow rate of 10sccm₂Performing first anhydrous anaerobic treatment for 10min under the ultrasonic condition to obtain a precursor solution;

in N₂Under these conditions, 3.5mg (0.003mmol) of palladium tetratriphenylphosphine was added to the precursor solution at room temperature under a flow rate of 10sccm of N₂Carrying out second anhydrous anaerobic treatment for 5min under the ultrasonic condition, reacting for 24h at 90 ℃ for Stille coupling reaction, and naturally cooling the obtained coupled product to room temperature after the reaction is finished;

adding 50mL of dichloromethane into the obtained coupling product for dilution to obtain a green solution, sequentially extracting the green solution by adopting 100mL of a NaCl solution with the mass percentage concentration of 20%, 100mL of a NaCl solution with the mass concentration of 20% and distilled water, then drying an organic phase obtained after extraction by adopting anhydrous magnesium sulfate, filtering and evaporating the solvent to obtain a crude heteroaromatic conjugated polymer; and purifying the aromatic heterocyclic type conjugated polymer crude product by a Soxhlet extraction method to obtain the aromatic heterocyclic type conjugated polymer based on benzofuranone.

The resulting benzofuranone-based heteroaromatic conjugated polymers were subjected to the following tests:

1. the structure of the obtained benzofuranone-based aromatic heterocyclic conjugated polymer is analyzed by adopting an AC-500(500MHz) nuclear magnetic resonance spectrometer of BRUKER company, wherein Tetramethylsilane (TMS) is used as an internal standard, and a deuterated solvent is deuterated chloroform (CDCl)₃) And the chemical shift data thereof are delta ppm, namely 7.67-7.96(d,6H),7.63-7.72(d,2H),7.25-7.45(m,8H),1.80-2.08(br,8H),1.00-1.30(br,48H) and 0.72-0.82(m,12H), thereby confirming that the invention successfully synthesizes the aromatic heterocyclic conjugated polymer based on benzofuranone.

2. The obtained aromatic heterocyclic conjugated polymer based on benzofuranone was subjected to infrared analysis using Thermo Fisher Nicolet 6700 Fourier transform infrared spectrometer, and the test results are shown in FIG. 1. As can be seen from FIG. 1, 1590cm^-1And 1527cm^-1Is a benzene ring boneExtension vibration peak of frame, 1750cm^-1Strong stretching vibration peak at 2920cm of C ═ O carbonyl^-1And 2850cm^-1And 1430cm^-1And 1376cm^-1And 700cm^-1Is located at the vibration peak of the long chain of the alkyl, 1130cm^-1The vibration peak is-C-O, which proves that the invention synthesizes the aromatic heterocyclic conjugated polymer based on benzofuranone.

3. The obtained benzofuranone-based aromatic heterocyclic conjugated polymer was subjected to molecular weight measurement using EcoSEC GPC (HLC-8320GPC), and the measurement was performed in a chloroform solution at 45 ℃ and the measurement results are shown in FIG. 2. As can be seen from FIG. 2, the number average molecular weight (Mn) of the benzofuranone-based aromatic heterocyclic conjugated polymer obtained in this example was 15.2kDa, the weight average molecular weight (Mn) was 65.1kDa, and the molecular weight distribution PDI was 4.28.

4. Differential Scanning Calorimetry (DSC) was performed on the obtained benzofuranone-based conjugated polymers by cyclic heating and cooling processes using a Netzsch DSC (204F1) instrument at a temperature change rate of 10 deg.C/min and a nitrogen gas blowing rate of 20mL/min, and the results are shown in FIG. 3.

As can be seen from FIG. 3, the benzofuranone-based aromatic heterocyclic conjugated polymer obtained in this example has no significant melting temperature at 300 ℃, a small endothermic peak at 102 ℃ during heating, and a small exothermic peak at 92 ℃ during cooling, which are related to the movement and rearrangement of alkyl side chains on the polymer backbone.

5. And (3) thermogravimetric analysis detection: the detection is carried out by using a Netzsch TGA (209F1) thermogravimetric analyzer, and the detection chart is shown in figure 4.

As can be seen from FIG. 4, the aromatic heterocyclic conjugated polymer based on benzofuranone obtained in this example showed no weight loss by heat before 300 ℃ and 5% weight loss at 393 ℃, indicating that the aromatic heterocyclic conjugated polymer based on benzofuranone provided has higher thermal stability.

As can be seen from FIGS. 3 and 4, the benzofuranone-based aromatic heterocyclic conjugated polymer provided by the present invention has good processability and thermal stability.

Application example 1

A wafer substrate: from Silicon Quest International, N-type doped Si (n)⁺⁺) A wafer having 300nm SiO attached to its surface₂A layer;

preparing an organic field effect transistor by adopting a bottom-gate bottom-contact field effect transistor structure:

selected n-type doped Si (n)⁺⁺) A wafer as a substrate, wherein the silicon layer is used as a gate electrode, SiO₂The layer is used as a dielectric layer; sequentially etching Si wafer substrate with piranha etching solution (H)₂SO₄And H₂O₂Is 3: 1) etching, washing with deionized water, washing with acetone, soaking in 5 wt.% toluene solution of octadecyl trichlorosilane under the protection of argon at room temperature, and soaking for 18 h; forming a gold source electrode and a gold drain electrode on the silicon chip by a mask gold spraying method, wherein the width of the gold source electrode and the width of the gold drain electrode are both 30nm, the length of the conductive groove is 1000 mu m, and the width of the conductive groove is 30 mu m; then, under the protection of argon, dropwise coating 3-4 drops of 5mg/mL chloroform solution of aromatic heterocyclic conjugated polymer based on benzofuranone on the surface of the substrate of the treated gold electrode at one time; covering with a culture dish, standing at room temperature for 0.5h, and heating to 50 deg.C for 5min to remove solvent to obtain the final product.

Carrying out an output characteristic test and a transfer characteristic test on the obtained organic field effect transistor, wherein the test charts are shown in fig. 5-6, and fig. 5 is an output characteristic curve of the organic field effect transistor; fig. 6 is a transfer transmission characteristic curve after annealing of the organic field effect transistor.

As can be seen from FIGS. 5 to 6, the benzofuranone-based aromatic heterocyclic conjugated polymer shows p-type device characteristics and hole mobility of 0.85cm²V^-1s^-1On-off ratio I_on/I_offIs 10⁶. High hole mobility is generated, which can be attributed to the advantages that the aromatic heterocyclic conjugated polymer based on benzofuranone has a large pi-conjugated system, a donor-acceptor system with a molecular main chain structure, good arrangement among molecules and good pi-orbit overlapping, so that the polymer has excellent aggregation among molecules, and pi-pi bonding is tight, and furtherThe transfer speed of carriers (namely holes) between polymer molecules and in the polymer molecules is improved, so that the polymer film is promoted to show good carrier migration performance. The aromatic heterocyclic conjugated polymer based on benzofuranone provided by the invention can have potential and developable application in an organic field effect transistor, and meets the use requirement of the organic field effect transistor on organic semiconductor materials.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.