Carbazole-based polymers and methods for their preparation, transistor memory and methods for their preparation

Abstract

The application discloses a kind of carbazole-based polymers and preparation method thereof, transistor memory and preparation method thereof.The structural general formula of carbazole-based polymer is as follows: Wherein, n is natural number in 1-100, R1 is selected from any one of hydrogen, phenyl and alkyl chain;R2 is selected from any one of hydrogen, linear alkyl chain with 1 to 8 carbon atoms, branched alkyl chain with 1 to 8 carbon atoms, cyclic alkyl chain with 1 to 8 carbon atoms and alkoxy with 1 to 8 carbon atoms;Any one selected from is selected from any one of the following formulae: The carbazole-based polymer molecule provided by the application has multiple active sites, has good expandability, can be expanded in multiple ways, provides an effective way to explore the relationship between the storage mechanism and the molecular structure of OFET memory;Meanwhile, the synthesis mode of carbazole-based polymer is simple, compared with COFs and MOFs, carbazole-based polymer material can be processed in large area solution, and production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of carbazole-based polymers and its preparation method, transistor memory and its preparation method, belong to organic storage and information technology field. BACKGROUND

[0002] Human society is rapidly stepping into the interconnection era, and the explosive growth of data is leading to a surge in demand for storage chips. Memory, as the home of data, is an indispensable element of information technology and artificial intelligence. This requires memory to have faster read and write speeds, smaller sizes, higher storage densities, and simpler manufacturing processes. It also has characteristics such as flexibility, portability, and other features. Emerging storage technologies include phase change PCM, ferroelectric RAM, magnetic RAM, memristor, and flash memory. Compared with inorganic storage materials, organic materials have many advantages such as low cost, solution processing, large-area preparation, and compatibility with flexible substrates.

[0003] Compared with traditional organic field effect transistors, organic field effect transistor memory adds a carrier trapping layer between the semiconductor layer and the gate. The carrier trapping layer can be divided into three types according to the trapping characteristics: ferroelectric, floating gate, and electret. Each type has its own advantages and disadvantages. Ferroelectric materials such as PZT, MXD6, or P(VDF / TrFE) have field effect transistor memory that is not affected by external conditions and can store data for a long time. However, it has a large leakage current, poor resistance, and poor polarization retention. Floating gate materials mainly include nanoparticles of Au, Ag, Cu, and organic materials, as well as two-dimensional materials. OFET memory has high storage density and can be processed on flexible substrates in large areas. However, it has high erase voltage, poor storage stability, complex processing technology, and device structure. Organic electret OFET memory can maintain a semi-permanent polarization state without an external electric field. However, it has high operating voltage, slow read and write speed, poor resistance, and unclear relationship between storage mechanism and molecular structure.

[0004] In the prior art, COFs (covalent organic framework materials) and MOFs (metal-organic framework materials) are commonly used as raw materials to prepare the carrier trapping layer. However, COFs and MOFs have poor expandability, complex synthesis methods, and cannot be processed in large areas.

[0005] Carbazole is an important nitrogen-containing aromatic heterocyclic compound. Carbazole-based polymers have received increasing attention due to their excellent stability and higher redox potential than other conductive polymers. Due to their high hole transport mobility and strong absorption in the UV spectral region, carbazole-based polymers exhibit good electrical and optical activity. These properties have expanded the applications of carbazole-based polymers, such as transistors, smart windows, light-emitting diodes, (bio)sensors, and photovoltaic devices.

[0006] Therefore, it is necessary to provide a carbazolyl polymer, a preparation method thereof, a transistor memory and a preparation method thereof to solve the above problems. SUMMARY

[0007] The present application aims to provide a carbazolyl polymer, a preparation method thereof, a transistor memory and a preparation method thereof to solve the problems of poor expandability of raw materials used in the carrier trapping layer in the prior art, and complex synthesis method and inability to realize large-area solution processing.

[0008] To achieve the above object, the present application provides a carbazolyl polymer, the structural general formula of which is:

[0009]

[0010] wherein n is a natural number in 1-100, R1 is selected from any one of hydrogen, phenyl and an alkyl chain with 1-8 carbon atoms;

[0011] R2 is selected from any one of hydrogen, a straight chain with 1-8 carbon atoms, a branched chain with 1-8 carbon atoms, a cyclic alkyl chain with 1-8 carbon atoms and an alkoxy group with 1-8 carbon atoms;

[0012] selected from any one of ;

[0013] selected from any one of .

[0014] To achieve the above object, the present application further provides a preparation method of a carbazolyl polymer, the preparation general formula of which is:

[0015]

[0016] wherein n is a natural number in 1-100, R1 is selected from any one of hydrogen, phenyl and an alkyl chain with 1-8 carbon atoms;

[0017] R2 is selected from any one of hydrogen, a straight chain with 1-8 carbon atoms, a branched chain with 1-8 carbon atoms, a cyclic alkyl chain with 1-8 carbon atoms and an alkoxy group with 1-8 carbon atoms;

[0018] selected from any one of ;

[0019] selected from any one of .

[0020] As a further improvement of the present application, the molar ratio of compound C to compound D is 1:1; the molar ratio of compound C1 to compound D1 is 1:1.

[0021] As a further improvement of the present application, the reaction temperature is 105℃, and the catalyst is any one or a combination of several of Lewis acid, triflic acid, boron trifluoride diethyl ether, p-toluene sulfonic acid monohydrate, and methyl sulfonic acid.

[0022] As a further improvement of the present application, it further comprises:

[0023]

[0024] As a further improvement of the present application, the molar ratio of magnesium, compound A and compound B is 3:2.5:1; the molar ratio of magnesium, compound A1 and compound B1 is 3:2.5:1.

[0025] To achieve the above object, the present application further provides an organic field effect transistor memory, sequentially comprising a source-drain electrode, an organic semiconductor layer, a charge storage layer, a gate insulating layer, a substrate and a gate electrode from top to bottom, and the material of the charge storage layer comprises the aforementioned carbazolyl polymer.

[0026] As a further improvement of the present application, the thickness of the charge storage layer is 10-30nm.

[0027] To achieve the above object, the present application further provides a preparation method of an organic field effect transistor memory, for preparing the aforementioned organic field effect transistor memory, comprising:

[0028] S1, using a substrate material as a substrate, and forming a gate electrode and a gate insulating layer on the substrate, and after cleaning and drying, using ultraviolet ozone treatment for 5-8min;

[0029] S2, dissolving the carbazolyl polymer material in a solvent and fully dissolving in the solvent, and then spin coating on the gate insulating layer and drying to prepare a charge storage layer;

[0030] S3, preparing an organic semiconductor layer on the charge storage layer by a thermal vacuum evaporation film forming method or a solution spin coating method, and then preparing a source-drain electrode on the organic semiconductor layer by a magnetron sputtering method, an inkjet printing method or a vacuum evaporation method.

[0031] As a further improvement of the present application, in S2, the solvent is chloroform, the concentration of the prepared carbazolyl polymer solution is 3-10mg / mL, the air humidity during spin coating is not more than 70%, and the drying temperature is 80℃.

[0032] The beneficial effects of this invention are: the carbazole-based polymer molecule of this invention has multiple active sites and good scalability, allowing for various extensions of the molecule, providing an effective way to explore the relationship between the storage mechanism and molecular structure of OFET memory; at the same time, the synthesis method of carbazole-based polymer is simple, and compared with COFs and MOFs raw materials, carbazole-based polymer materials can be processed in solution over a large area, reducing production costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the organic field-effect transistor memory in a preferred embodiment of the present invention.

[0034] Figure 2 This is the 1H NMR spectrum of the carbazole-based polymer prepared in Example 1.

[0035] Figure 3 This is the 1H NMR spectrum of the carbazole-based polymer prepared in Example 2.

[0036] Figure 4 This is the 1H NMR spectrum of the carbazole-based polymer prepared in Example 3.

[0037] Figure 5 The negative memory window characteristic curve is that of the organic field-effect transistor memory using the carbazole-based polymer in Example 1.

[0038] Figure 6 The negative memory window characteristic curve is that of the organic field-effect transistor memory using the carbazole-based polymer in Example 2.

[0039] Figure 7 The negative memory window characteristic curve is that of the organic field-effect transistor memory using the carbazole-based polymer in Example 3.

[0040] Figure 8 This is a graph showing the characteristics of 100 negative read / write / erase cycles of the organic field-effect transistor memory using the carbazole-based polymer in Example 1.

[0041] Figure 9 This is a graph showing the characteristics of 100 negative read / write / erase cycles of the organic field-effect transistor memory using the carbazole-based polymer in Example 2.

[0042] Figure 10 This is a graph showing the characteristics of 100 negative read / write / erase cycles of the organic field-effect transistor memory using the carbazole-based polymer in Example 3.

[0043] Figure 11 This is a 3000s retention time graph of the organic field-effect transistor memory using the carbazole-based polymer in Example 1.

[0044] Figure 12 This is a 3000s retention time graph of the organic field-effect transistor memory using the carbazole-based polymer in Example 2.

[0045] Figure 13 This is a 3000s retention time graph of the organic field-effect transistor memory using the carbazole-based polymer in Example 3. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0047] This invention provides a carbazole-based polymer, the general structural formula of which is:

[0048]

[0049] Where n is a natural number from 1 to 100, and R1 is selected from any one of hydrogen, phenyl and alkyl chains with 1 to 8 carbon atoms;

[0050] R2 is selected from any one of hydrogen, a straight chain having 1 to 8 carbon atoms, a branched chain having 1 to 8 carbon atoms, a cyclic alkyl chain having 1 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms;

[0051] Selected from Any one of them;

[0052] Selected from Any one of them.

[0053] This invention also provides a method for preparing a carbazole-based polymer, wherein the preparation formula is:

[0054]

[0055]

[0056] Where n is a natural number from 1 to 100, and R1 is selected from any one of hydrogen, phenyl and alkyl chains with 1 to 8 carbon atoms;

[0057] R2 is selected from any one of hydrogen, a straight chain having 1 to 8 carbon atoms, a branched chain having 1 to 8 carbon atoms, a cyclic alkyl chain having 1 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms;

[0058] Selected from Any one of them;

[0059] Selected from Any one of them.

[0060] Specifically, compound C is dissolved in an organic solvent at 105°C, and then a catalyst and compound D are added to react. After post-treatment, a carbazole-based polymer, namely compound E, is obtained. Alternatively, compound C1 is dissolved in an organic solvent at 105°C, and then a catalyst and compound D1 are added to react. After post-treatment, a carbazole-based polymer, namely compound E1, is obtained.

[0061] The molar ratio of compound C to compound D is 1:1; the molar ratio of compound C1 to compound D1 is 1:1. The reaction temperature is 105℃, and the catalyst is any one or a combination of several of Lewis acids, trifluoromethanesulfonic acid, boron trifluoride diethyl ether, p-toluenesulfonic acid monohydrate, and methanesulfonic acid.

[0062] In this embodiment, compounds C and D, C1 and D1 are directly used as existing products or purchased directly to reduce the length of the synthetic route. Of course, in other embodiments, compounds C and D, C1 and D1 can also be synthesized independently to reduce production costs, and no restrictions are imposed here.

[0063] The specific synthetic steps for compounds C and C1 are as follows:

[0064]

[0065] Specifically, compound B is synthesized into a Grignard reagent, and then the Grignard reagent is mixed with compound A and reacted to obtain compound C; or compound B1 is synthesized into a Grignard reagent, and then the Grignard reagent is mixed with compound A1 and reacted to obtain compound C1.

[0066] The specific steps are as follows: Compound B is reacted at 60°C for 7 hours to synthesize the Grignard reagent, and then the Grignard reagent is mixed with Compound A and reacted at 0°C for 24 hours to obtain Compound C; or Compound B1 is reacted at 60°C for 7 hours to synthesize the Grignard reagent, and then the Grignard reagent is mixed with Compound A1 and reacted at 90°C for 24 hours to obtain Compound C1.

[0067] The molar ratio of magnesium, compound A and compound B is 3:2.5:1; the molar ratio of magnesium, compound A1 and compound B1 is 3:2.5:1.

[0068] Please see Figure 1 As shown, the present invention also provides an organic field-effect transistor memory, which includes, from top to bottom, source and drain electrodes, an organic semiconductor layer, a charge storage layer, a gate insulating layer, a substrate, and a gate electrode, wherein the charge storage layer is made of carbazole-based polymer and the thickness of the charge storage layer is 10-30 nm.

[0069] Specifically, the source / drain electrodes and gate electrodes are made of metal, organic materials, or inorganic materials, with a thickness of 50-100 nm. Preferably, the source / drain electrodes and gate electrodes are made of copper. Of course, in other embodiments, the source / drain electrodes and gate electrodes can also be made of other materials, as long as they have conductive properties. No restrictions are imposed here.

[0070] The organic semiconductor layer is made of any one of pentanebenzene, tetrabenzene, copper phthalocyanine, copper phthalocyanine fluoride, red fluorene, triphenylene, or 3-hexylthiophene, and the thickness of the organic semiconductor layer is 30-50 nm.

[0071] The gate insulating layer is made of any one of silicon dioxide, aluminum oxide, zirconium oxide, polystyrene or polyvinylpyrrolidone, and has a thickness of 50 to 300 nm.

[0072] The substrate is made of any one of highly doped silicon wafers, glass sheets, or polyethylene terephthalate.

[0073] This invention also provides a method for fabricating an organic field-effect transistor memory, comprising the following steps:

[0074] S1. Using a substrate material as the substrate, a gate electrode and a gate insulating layer are formed on the substrate. After cleaning and drying, the substrate is treated with ultraviolet ozone for 5-8 minutes. The cleaning process includes sequential ultrasonic cleaning with acetone, ethanol, and ultrapure water.

[0075] S2. Dissolve the carbazole-based polymer material in a solvent and allow it to fully dissolve in the solvent. Then spin-coat the material onto the gate insulating layer and dry it to prepare the charge storage layer.

[0076] Specifically, the solvent is chloroform. After adding the carbazole polymer to the solvent, the carbazole polymer is heated or sonicated to fully dissolve the carbazole polymer in chloroform to obtain a carbazole polymer solution with a concentration of 3-10 mg / mL. The spin coating step is carried out in air, and the air humidity during spin coating is not greater than 70%. The drying temperature is 80℃.

[0077] S3. An organic semiconductor layer is prepared on the charge storage layer by thermal vacuum evaporation or solution spin coating, and then source and drain electrodes are prepared on the organic semiconductor layer by magnetron sputtering, inkjet printing or vacuum evaporation.

[0078] Specifically, the conditions for vacuum evaporation of organic semiconductor layers are: evaporation rate of... The vacuum level is controlled between 6×10⁻⁵ Pa and 6×10⁻⁴ Pa.

[0079] The conditions for vacuum evaporation of source and drain electrodes are: evaporation rate The vacuum level is controlled between 6×10⁻⁵ Pa and 6×10⁻⁴ Pa.

[0080] Example 1

[0081] The molecular formula of the carbazole-based polymer is:

[0082]

[0083] The synthetic route is as follows:

[0084]

[0085] The specific preparation method is as follows:

[0086] Before the experiment, all glassware was dried. Magnesium granules (1.74 g) and one iodine grain were added to a two-necked flask, sealed, and protected under a nitrogen atmosphere. Bromobenzene (7.5 mL) was added to 72 mL of tetrahydrofuran (THF), and after complete dissolution, 2 mL was slowly injected into the magnesium-iodine system. The mixture was heated until the grayish-brown color turned colorless. An ice-water bath was prepared during this process to prevent excessive temperature from causing bumping. The remaining solution was then added to the reaction flask and reacted at 60 °C for 3 h. In another apparatus, anthraquinone (3 g, 170 mL THF) was added and reacted at -10 °C for 20 min. The Grignard reagent prepared in the first apparatus was then injected into the reaction flask containing the anthraquinone solution. Both reactions were carried out under nitrogen protection and stirred at below 0 °C for 4 h until the reaction was complete.

[0087] After the reaction was completed, a suitable amount of saturated ammonium chloride aqueous solution was added to the reaction solution to quench the reaction. The mixture was then extracted multiple times with CH2Cl2, and the organic phase was collected. The organic phase was dried over anhydrous sodium sulfate, the desiccant was filtered off, and the solvent was removed by vacuum distillation. The crude product was separated by silica gel column chromatography to obtain a 45% pure product (100-200 mesh silica gel, eluent V). 石油醚 :V 二氯甲烷 =1:2), and then recrystallized from dichloromethane and petroleum ether to give a white flaky solid (2.32 g, 45%).

[0088] The white, flaky solid product was confirmed to be diphenylanthracene ditert-ol by proton NMR spectroscopy. The proton NMR data are as follows: 1 H NMR (400MHz, CDCl3) δ7.68 (dd, J = 3.39, J = 2.50Hz, 4H), 7.38 (dd, J = 3.35, 2.56Hz, 4H), 7.11-7.02 (m, 10H), 6.87 (s, 2H).

[0089] Prepare and dry a 10mL two-necked reaction flask and a spherical condenser beforehand. Weigh out diphenylanthracene ditert-tert-ol (0.623g, 1.8mmol) and carbazole (0.3g, 1.8mmol), and seal under nitrogen protection. Inject 4mL of 1,4-dioxane into a syringe and heat to 70°C, then inject 0.2mL of boron trifluoride diethyl ether into the syringe. Connect cooling water and raise the temperature to 105°C under reflux. Stop the reaction after 40 hours. Clean and dry a 500mL beaker and magnetic stir bar. Add 400mL of methanol to the beaker, turn on the stirrer, and add the reaction solution dropwise into the methanol, precipitating a large amount of powder. After standing, filter under vacuum. Collect the filter residue, dry it, and obtain the preliminary product.

[0090] A fat extractor and its matching condenser, along with a 500mL flat-bottomed single-necked flask, were pre-washed and dried. 300mL of acetone was added to the flask. The preliminary product was wrapped in filter paper and placed in the fat extractor. The apparatus was connected, and cooling water was introduced. The mixture was heated under reflux for 48 hours, after which the process was stopped. The remaining solid was then dried in a vacuum drying oven, yielding 280mg of carbazole-based polymer. The molecular weight of the carbazole-based polymer was Mn = 5202, and PDI = 1.23.

[0091] Please see Figure 2 As shown, the carbazole-based polymer was subjected to 1H NMR spectroscopy. The 1H NMR spectroscopy data are as follows: 1 H NMR (400MHz, DMSO-d6) δ11.03 (s, 11H), 7.65-6.79 (m, 253H).

[0092] Example 2

[0093] The molecular formula of the carbazole-based polymer is:

[0094]

[0095] The synthetic route is as follows:

[0096]

[0097] The specific preparation method is as follows:

[0098] Before the experiment, all glassware was dried. Magnesium granules (3.06 g, 0.127 mol) and one iodine grain were added to a two-necked flask, sealed, and protected under a nitrogen atmosphere. 1,4-Dibromobenzene (1 g, 0.042 mol) was added to 60 mL of tetrahydrofuran (THF). After complete dissolution, 5 mL was slowly injected into the magnesium-iodine system and heated until the blackish-purple color turned colorless. An ice-water bath was prepared to prevent excessive temperature and bumping. The remaining solution was then added to the reaction flask and reacted at 60 °C for 8 hours. After most of the magnesium granules had participated in the reaction, the Grignard reagent obtained from the reaction was injected into a reaction flask containing fluorenone (19.14 g, 0.106 mol, 30 mL THF) solution. The entire reaction system was carried out under nitrogen protection, with circulating cooling water connected, and reacted at 90 °C for 18 hours.

[0099] After the reaction was completed, an appropriate amount of saturated ammonium chloride was added to the cooled reaction solution for quenching. The mixture was extracted multiple times with CH2Cl2, and the organic phase was collected. The organic phase was dried over anhydrous sodium sulfate, the desiccant was filtered off, and the solvent was removed by vacuum distillation. The crude product was separated by silica gel column chromatography to obtain a 70% pure product (100-200 mesh silica gel, eluent V). 石油醚 :V 二氯甲烷 =1:3), and then recrystallized with dichloromethane and petroleum ether to obtain a white solid powder of terephthalic difluorene ditert-ol (4.5 g, 30%).

[0100] The white, flaky solid product was confirmed to be tert-butylbenzene difluorene ditert-ol by proton NMR spectroscopy. The proton NMR data are as follows: 1 H NMR (400MHz, DMSO-d6) δ7.81 (dt, J=7.6, 1.0Hz, 4H), 7.45 (d, J=8.4Hz, 4H), 7.36 (ddd, J=7.6, 6.7, 1.8Hz, 4H), 7.31–7.20 (m, 12H), 6.34 (s, 2H).

[0101] Prepare and dry a 10mL two-necked reaction flask and a spherical condenser beforehand. Weigh out 0.438g (1mmol) of terephthalene ditert-diol and 0.167g (1mmol) of carbazole, and seal under nitrogen protection. Inject 4mL of 1,4-dioxane into a syringe and heat to 70°C, then inject 0.5mL of methanesulfonic acid into the syringe. Connect cooling water and raise the temperature to 105°C under reflux. Stop the reaction after 24 hours. Clean and dry a 500mL beaker and magnetic stir bar. Add 400mL of methanol to the beaker, turn on the stirrer, and add the reaction solution dropwise into the methanol, precipitating a large amount of powder. After standing, filter under vacuum. Collect the filter residue, dry it, and obtain the preliminary product.

[0102] A fat extractor and its matching condenser were pre-washed and dried. A 500mL flat-bottomed single-necked flask was added to the flask with 300mL of acetone. The preliminary product was wrapped in filter paper and placed in the fat extractor. The apparatus was connected, and cooling water was introduced. The mixture was heated to reflux. After washing with acetone, the mixture was heated to reflux with 300mL of chloroform. The chloroform eluent was collected and subjected to vacuum distillation. The solid was then dried in a vacuum drying oven. 180mg of carbazole-based polymer was finally obtained, with a molecular weight of Mn = 4933 and PDI = 1.46.

[0103] Please see Figure 3 As shown, the carbazole-based polymer was subjected to 1H NMR spectroscopy. The 1H NMR spectroscopy data are as follows: 1 H NMR (400MHz, DMSO-d6) δ11.12(s,10H),8.01-7.82(m,26H),7.50-7.01(m,221H).

[0104] Example 3

[0105] The molecular formula of the carbazole-based polymer is:

[0106]

[0107] The synthetic route is as follows:

[0108]

[0109] The specific preparation method is as follows:

[0110] Before the experiment, all glassware was dried. Magnesium granules (0.31 g, 12.8 mmol) and iodine granules (2.54 mg, 0.02 mmol) were added to a two-necked flask, sealed, and protected under a nitrogen atmosphere. 1,4-Dibromobenzene (1 g, 4.2 mmol) was added to 50 mL of tetrahydrofuran (THF) and, after complete dissolution, the mixture was slowly injected into the magnesium-iodine system and heated until the brown color turned transparent. An ice-water bath was prepared to prevent excessive boiling. The remaining solution was then added to the reaction flask and reacted at 50 °C for 4 h. After most of the magnesium granules had participated in the reaction, the Grignard reagent obtained from the reaction was extracted and injected into a reaction flask containing a solution of benzophenone (2.33 g, 12.8 mmol). The entire reaction was carried out under nitrogen protection, with circulating cooling water connected, and the reaction was carried out at 90 °C for 12 h.

[0111] After the reaction was completed, an appropriate amount of ammonium chloride aqueous solution was added to the cooled reaction solution to continue the reaction. After the reaction was completed, the crude product was obtained by extraction, and the white product 1,4-phenylenebis(diphenylmethanol) (1.53 g, 82%) was obtained by column chromatography.

[0112] The white product was analyzed by proton NMR spectroscopy, confirming that the solid product was 1,4-phenylenebis(diphenylmethanol). The proton NMR data are as follows: 1 H NMR (400MHz, CDCl3) δ7.36 (dd, J = 2.3, 1.6Hz, 2H), 7.34-7.33 (m, 4H), 7.33-7.31 (m, 14H), 7.30-7.29 (m, 4H), 2.81 (s, 2H).

[0113] Prepare and dry a 10mL two-necked reaction flask and a spherical condenser beforehand. Weigh out 0.444g (1mmol) of p-1,4-phenylenebis(diphenylmethanol) and 0.167g (1mmol) of carbazole, and seal under nitrogen protection. Inject 4mL of 1,4-dioxane into a syringe and heat to 70°C, then inject 0.5mL of methanesulfonic acid into the syringe. Connect cooling water and raise the temperature to 105°C under reflux. Stop the reaction after 24 hours. Clean and dry a 500mL beaker and magnetic stir bar. Add 400mL of methanol to the beaker, turn on the stirrer, and add the reaction solution dropwise into the methanol, precipitating a large amount of powder. After standing, filter under vacuum. Collect the filter residue, dry it, and obtain the preliminary product.

[0114] A fat extractor and its matching condenser were pre-washed and dried, along with a 500mL flat-bottomed single-necked flask containing 300mL of acetone. The preliminary product was wrapped in filter paper and placed in the fat extractor. The apparatus was connected, and cooling water was introduced. The mixture was heated to reflux. After washing with acetone, the mixture was heated to reflux with 300mL of chloroform. The chloroform eluent was collected and subjected to vacuum distillation. The solid was then dried in a vacuum drying oven. 210mg of carbazole-based polymer was finally obtained, with a molecular weight of Mn = 4518 and PDI = 1.16.

[0115] Please see Figure 4 As shown, the carbazole-based polymer was subjected to 1H NMR spectroscopy. The 1H NMR spectroscopy data are as follows: 1 H NMR (400MHz, CDCl3) δ7.94(s,9H),7.24-7.21(m,95H),7.20-7.15(m,79),7.14-7.10(m,79H).

[0116] Example 4

[0117] Please see Figure 1As shown, the present invention provides an OFET memory structure, in which heavily doped silicon is used as the substrate and gate electrode; a 300 nm thick silicon dioxide layer is used as the gate insulating layer on the N-type heavily doped silicon; a carbazole-based polymer prepared in Example 1, Example 2, or Example 3 is used as the charge storage layer with a thickness of 20 nm; a 50 nm thick pentacene layer is then deposited on the charge storage layer as the organic semiconductor layer; finally, copper is deposited on the pentacene organic semiconductor layer as the source and drain electrodes.

[0118] During the experiment, the laboratory temperature was maintained at around 25°C and the humidity at 40%.

[0119] The fabrication method of OFET memory is as follows:

[0120] S1. Using a substrate material as the substrate, a gate electrode and a gate insulating layer are formed on the substrate. After cleaning and drying, the substrate is treated with ultraviolet ozone for 8 minutes. The cleaning process includes ultrasonic cleaning of the substrate with acetone, ethanol, and ultrapure water for 10 minutes in sequence, followed by blowing the surface of the substrate with high-purity nitrogen to ensure the substrate surface is clean, and then placing the substrate in an oven at 120°C to dry.

[0121] S2. Prepare a carbazole-based polymer material solution using chloroform as the solvent and a solution concentration of 3 mg / mL. Heat or sonicate the solution to ensure complete dissolution and allow it to stand for 24 hours to ensure uniform dispersion. Spin-coat the carbazole-based polymer solution onto the surface of the substrate with the grid insulating layer at a spin speed of 4000 rpm for 30 seconds. Anneal the spin-coated substrate in an oven at 80°C for 30 minutes to obtain the charge storage layer.

[0122] S3. An organic semiconductor layer is prepared by evaporating a pentabenzene layer on the surface of the charge storage layer using a vacuum evaporation device at a deposition rate of [missing information]. Vacuum degree 5×10 4 Below pa, the pentacene thickness is 30nm; subsequently, a mask is added to the organic semiconductor layer for multiple batches of processing in the same batch, and copper is vacuum-deposited as the source and drain electrodes, with a deposition rate of... Vacuum degree is 5×10 4 Below Pa, the electrode thickness is around 60 nm; the mask controls the channel width and length of a single group to be 1000 μm and 100 μm, respectively.

[0123] After the device was fabricated, its electrical properties were characterized using a Keysight 2636B semiconductor analyzer, and the characterized data were processed and plotted for analysis.

[0124] Please see Figure 5 , Figure 8 and Figure 11As shown, the memory device using the carbazole-based polymer prepared in Example 1 achieved hole storage of 54.3V under photoelectric control; after 100 negative read-write-erase cycles, the on / off ratio remained at 6 × 10⁻⁶. 2 After a sustaining time of 3000 s, the on / off ratio remained at 2 × 10⁻⁶. 3 .

[0125] Please see Figure 6 , Figure 9 and Figure 12 As shown, the memory device using the carbazole-based polymer prepared in Example 2 achieved hole storage of 39.5V under photoelectric control; after 100 negative read-write-erase cycles, the on / off ratio remained at 8 × 10⁻⁶. 3 After a sustaining time of 3000 s, the on / off ratio remained at 3 × 10⁻⁶. 3 .

[0126] Please see Figure 7 , Figure 10 and Figure 13 As shown, the carbazole-based polymer storage device prepared in Example 3 achieved hole storage of 40.5V under photoelectric control; after 100 negative read / write / erase cycles, the on / off ratio remained at 2×10⁻⁶. 3 After a sustaining time of 3000 s, the on / off ratio remained at 4 × 10⁻⁶. 4 .

[0127] This invention synthesizes a carbazole-based polymer material and applies the carbazole-based polymer as an electret thin film in an organic field-effect transistor (OFET) memory, serving as the charge trapping layer of the device. The carbazole-based polymer is prepared into a charge trapping layer thin film by spin-coating solution method. The OFET memory based on this charge trapping layer not only has a large storage window, but also good tolerance and stability. Moreover, the operation process is simple and low-cost, which is conducive to the promotion and production of future memory devices. At the same time, the large storage window also indicates that it has a good hole trapping ability.

[0128] In summary, the carbazole-based polymer molecule provided by this invention possesses multiple active sites and exhibits excellent scalability, allowing for various molecular extensions. This provides an effective approach to exploring the relationship between the storage mechanism and molecular structure of OFET (Organic Field-Effect Transistor) memories. Furthermore, the synthesis and processing of carbazole-based polymers are simple. Compared to COFs and MOFs, carbazole-based polymer materials can be processed in large-area solutions, reducing production costs. By using carbazole-based polymers as the organic charge storage layer of organic field-effect transistor memories, the memory's tolerance, storage density, and stability are improved. The fabrication method of the organic field-effect transistor memory of this invention is simple, reducing device fabrication costs and facilitating the further development, promotion, and production of future memory devices.

[0129] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An organic field-effect transistor memory, characterized in that: From top to bottom, it includes source and drain electrodes, an organic semiconductor layer, a charge storage layer, a gate insulating layer, a substrate, and a gate electrode. The charge storage layer is made of a carbazole-based polymer. The general structural formula of the carbazole-based polymer is: Where n is a natural number from 1 to 100, and R1 is selected from any one of hydrogen, phenyl and alkyl chains with 1 to 8 carbon atoms; R2 is selected from any one of hydrogen, a straight chain having 1 to 8 carbon atoms, a branched chain having 1 to 8 carbon atoms, a cyclic alkyl chain having 1 to 8 carbon atoms, and an alkoxy group having 1 to 8 carbon atoms; Selected from Any one of them; Selected from Any one of them.

2. The organic field-effect transistor memory according to claim 1, characterized in that: The thickness of the charge storage layer is 10–30 nm.

3. A method for fabricating an organic field-effect transistor memory, used to fabricate an organic field-effect transistor memory as described in any one of claims 1-2, characterized in that, include: S1. Using a substrate material as the substrate, a gate electrode and a gate insulating layer are formed on the substrate. After cleaning and drying, the substrate is treated with ultraviolet ozone for 5-8 minutes. S2. Dissolve the carbazole-based polymer material in a solvent and allow it to fully dissolve in the solvent. Then spin-coat the material onto the gate insulating layer and dry it to prepare a charge storage layer. S3. An organic semiconductor layer is prepared on the charge storage layer by thermal vacuum evaporation or solution spin coating, and then source and drain electrodes are prepared on the organic semiconductor layer by magnetron sputtering, inkjet printing or vacuum evaporation.

4. The method for fabricating an organic field-effect transistor memory according to claim 3, characterized in that: In S2, the solvent is chloroform, the concentration of the prepared carbazole-based polymer solution is 3-10 mg / mL, the air humidity during spin coating is not greater than 70%, and the drying temperature is 80℃.

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