Carbazole derivative monomolecular layer, preparation method of carbazole derivative monomolecular layer, transistor memory and preparation method of transistor memory

Abstract

The invention discloses a carbazole derivative monomolecular layer and a preparation method thereof, and a transistor memory and a preparation method thereof, and relates to the technical field of organic storage and information, and the carbazole derivative monomolecular layer comprises a source and drain electrode, a semiconductor layer, the carbazole derivative monomolecular layer, a gate insulating layer, a substrate and a gate electrode which are arranged in sequence. The carbazole derivative monomolecular layer is prepared and applied to the organic field effect transistor memory to serve as a charge trapping layer of a device, the operation process is simple, the cost is low, the preparation period is shortened while the preparation difficulty of the transistor memory is reduced, and the production efficiency is improved. And the storage performance and the stability of the transistor memory are improved.

Description

Technical Field

[0001] The present application relates to the field of organic storage and information technology, and in particular to a carbazole derivative monomolecular layer and a preparation method thereof, a transistor memory and a preparation method thereof. Background Art

[0002] As human society rapidly enters the era of the Internet, data is growing explosively, and the demand for memory chips is surging. As the home of data, memory is an indispensable element of information technology and artificial intelligence. This requires memory to have faster read and write speeds, smaller size, higher storage density, and simpler manufacturing processes. It also has the characteristics of flexibility, lightness, and portability. Emerging storage technologies mainly 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] In recent years, a large number of theoretical and experimental results have shown that the transport of carriers in OFETs only occurs within a single molecular layer near the interface between the semiconductor layer and the dielectric layer. Compared with traditional transistors, single-layer thin-film field-effect transistors have many unique advantages, such as visible transmission channels, lower contact resistance, higher flexibility and transparency, etc. These results show that single-layer thin-film transistors are not only conducive to characterizing the relationship between the structure and performance of organic semiconductor materials, but also provide a feasible research idea for building the next generation of high-performance organic electronic products.

[0004] However, there are still few processes for constructing monolayer thin film devices, mainly self-assembly (SAM), Langmuir-Blodgett (LB), physical vapor deposition (PVD) and other coating technologies. These processes themselves have certain defects, resulting in problems such as harsh preparation environment, long preparation cycle, poor tolerance and stability of organic field effect transistor memory, and low storage density. Summary of the invention

[0005] In view of the deficiencies of the above-mentioned related technologies, the present application provides a monolayer of carbazole derivatives and a preparation method thereof, a transistor memory and a preparation method thereof. The present application prepares a monolayer of carbazole derivatives and applies the monolayer of carbazole derivatives to an organic field effect transistor memory, which acts as a charge trapping layer of the device. The operation process is simple and the cost is low, which reduces the difficulty of preparing the transistor memory and shortens the preparation cycle, thereby improving the storage performance and stability of the transistor memory.

[0006] In the first aspect, the present application provides a monolayer of carbazole derivatives using the following technical solution: A monomolecular layer of a carbazole derivative comprises any one of the following structural formulas: , and ; Wherein, n is a natural number between 1 and 100, and m is a natural number between 1 and 100; It is a fluorenyl derivative; It is a benzene derivative; Selected from and Any of the following: Selected from , and Any one of .

[0007] Preferably, is a fluorenyl derivative selected from , and Any one of; wherein R is an alkyl chain or a halogen atom.

[0008] Preferably, A benzene derivative selected from and Any one of; wherein R1 is an alkyl chain.

[0009] Preferably, the specific structural formula of the monomolecular layer of the carbazole derivative is one of the following formulae: , , and .

[0010] In the second aspect, the present application provides a method for preparing a monolayer of a carbazole derivative using the following technical solution: A method for preparing a monomolecular layer of a carbazole derivative comprises the following steps: reacting a carbazole derivative with 3-chloroalkylalkyldialkoxysilane to obtain an intermediate product, and condensing the intermediate product with a hydroxylated modified substrate to obtain the monomolecular layer of the carbazole derivative.

[0011] Preferably, the molar ratio of the carbazole derivative to the 3-chloroalkylalkyldialkoxysilane is 1:2-10.

[0012] Preferably, the molar ratio of the carbazole derivative to the 3-chloroalkylalkyldialkoxysilane is 1:2.

[0013] Preferably, the molar ratio of the carbazole derivative to the 3-chloroalkylalkyldialkoxysilane is 1:3.

[0014] Preferably, the molar ratio of the carbazole derivative to the 3-chloroalkylalkyldialkoxysilane is 1:10.

[0015] Preferably, the hydroxylation-modified substrate is prepared by the following steps: mixing sulfuric acid and hydrogen peroxide to prepare a mixed solution, and immersing the silicon wafer in the mixed solution.

[0016] Preferably, in the mixed solution, the molar ratio of sulfuric acid to hydrogen peroxide is 2.8-3.2:1.

[0017] Preferably, in the mixed solution, the molar ratio of sulfuric acid to hydrogen peroxide is 3:1.

[0018] Preferably, the general structural formula of the carbazole derivative includes the following formula: , and One of them.

[0019] Preferably, the specific structural formula of the monomolecular layer of the carbazole derivative is one of the following formulae: , , and .

[0020] Preferably, the specific structural formula of the intermediate product is one of the following: , , and .

[0021] In a third aspect, the present application provides an organic field effect transistor memory using the following technical solution: An organic field effect transistor memory comprises a source-drain electrode, a semiconductor layer, a monomolecular layer such as a carbazole derivative, a gate insulating layer, a substrate and a gate electrode which are arranged in sequence.

[0022] Preferably, the source-drain electrode and the gate electrode are made of metal, organic material or inorganic material.

[0023] Preferably, the source / drain electrodes and the gate electrode are made of one or more of highly doped silicon, gold, silver, copper and aluminum.

[0024] Preferably, the material of the semiconductor layer is one or more of pentacene, tetracene, copper phthalocyanine, fluorinated copper phthalocyanine, rubrene, triacene and 3-hexylthiophene.

[0025] Preferably, the gate insulating layer is made of one or more of silicon dioxide, aluminum oxide, zirconium oxide, polystyrene and polyvinyl pyrrolidone.

[0026] Preferably, the gate insulating layer has a thickness of 50-300 nm.

[0027] Preferably, the substrate is one or more of a highly doped silicon wafer, a glass wafer and a polyethylene terephthalate wafer.

[0028] Preferably, the thickness of the monomolecular layer of the carbazole derivative is 1-10 nm.

[0029] In a fourth aspect, the present application provides a method for preparing an organic field effect transistor memory using the following technical solution: A method for preparing an organic field effect transistor memory comprises the following steps: forming a gate electrode and a gate insulating layer on a substrate, and drying after ultrasonic cleaning, placing the substrate in a mixed solution, heating the substrate at 88-92°C for 0.8-1.5h, washing and drying the mixed solution to obtain a hydroxylated modified substrate; mixing a carbazole derivative, a catalyst, tetrahydrofuran and 3-chloroalkylalkyldialkoxysilane, reacting the mixed solution at 78-82°C for 60-80h, and obtaining an intermediate product; placing the hydroxylated modified substrate in a solution of the intermediate product, reacting the mixed solution at 65-75°C for 10-14h, washing and drying the mixed solution to obtain a substrate having a monomolecular layer of the carbazole derivative formed thereon; preparing an organic semiconductor layer on the monomolecular layer of the carbazole derivative, and preparing a source-drain electrode on the semiconductor layer.

[0030] Preferably, the method comprises the following steps: forming a gate electrode and a gate insulating layer on a substrate, and drying and then placing the mixture in a mixed solution after ultrasonic cleaning, heating at 90°C for 1h, washing and drying to obtain a hydroxylated modified substrate; mixing a carbazole derivative, a catalyst, tetrahydrofuran and 3-chloroalkylalkyldialkoxysilane, and reacting the mixture at 80°C for 72h to obtain an intermediate product; placing the hydroxylated modified substrate in a solution of the intermediate product, reacting the mixture at 70°C for 12h, washing and drying the mixture to obtain a substrate having a monomolecular layer of the carbazole derivative formed thereon; preparing a semiconductor layer on the monomolecular layer of the carbazole derivative, and preparing a source-drain electrode on the organic semiconductor layer.

[0031] Preferably, in the solution of the intermediate product, the concentration of the intermediate product is 2-5 mg / mL.

[0032] Preferably, in the solution of the intermediate product, the concentration of the intermediate product is 3 mg / mL.

[0033] Preferably, the semiconductor layer is a pentacene layer.

[0034] Preferably, the pentacene layer has a thickness of 20-50 nm.

[0035] Preferably, the pentacene layer has a thickness of 30 nm.

[0036] Preferably, the pentacene layer is obtained by vacuum evaporation, the evaporation rate is 1Å / s, and the vacuum degree is controlled at 6×10 -5 -6×10 -4 Pa.

[0037] Preferably, the source-drain electrodes are copper electrodes.

[0038] Preferably, the thickness of the source-drain electrode is 50-100 nm.

[0039] Preferably, the copper electrode is obtained by vacuum evaporation, the evaporation rate is 0.5Å / s, and the vacuum degree is controlled at 6×10 -5 -6×10 -4 Pa.

[0040] In summary, the present application includes at least one of the following beneficial technical effects: 1. The monomolecular layer of the carbazole derivative of the present application is used as a charge trapping layer. On the one hand, it realizes 16.2-32.49V electron storage and improves the storage density. On the other hand, the water contact angle reaches 77.67-82.4°, which improves the hydrophobicity of the charge trapping layer and thus improves the stability of the prepared organic field effect transistor storage tube; 2. The organic field effect transistor using a monolayer of carbazole derivatives as a charge trapping layer in this application has a switching ratio of 2.01×10 3 -7.76×10 3 , improving the tolerance and storage performance of organic field effect transistor storage tubes; 3. The monolayer of the carbazole derivative of the present application is formed by a solution method, which has a simple preparation process, low cost, controllable thickness and high substrate recognition; 4. The organic field effect transistor storage tube device of the present application has high tolerance, storage density and stability, and at the same time has a simple structure and low cost, which is conducive to commercial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1It is a schematic diagram of the structure of the organic field effect transistor memory of the present application.

[0042] Figure 2 This is a diagram showing the change in the water contact angle on the substrate surface during the preparation of the organic field effect transistor memory in Example 1 of the present application.

[0043] Figure 3 This is a diagram showing the change in the water contact angle on the substrate surface during the preparation of the organic field effect transistor memory in Example 2 of the present application.

[0044] Figure 4 This is a diagram showing the change in the water contact angle on the substrate surface during the preparation of the organic field effect transistor memory in Example 3 of the present application.

[0045] Figure 5 This is a diagram showing the change in the water contact angle on the substrate surface during the preparation of the organic field effect transistor memory in Example 4 of the present application.

[0046] Figure 6 This is an X-ray photoelectron spectrum of the organic field effect transistor memory of Example 1 of the present application.

[0047] Figure 7 This is an X-ray photoelectron spectrum of the organic field effect transistor memory of Example 2 of the present application.

[0048] Figure 8 This is the X-ray photoelectron spectrum of the organic field effect transistor memory of Example 3 of the present application.

[0049] Fig. 9 This is the X-ray photoelectron spectrum of the organic field effect transistor memory of Example 4 of the present application.

[0050] Fig.10 This is a forward storage window diagram of the organic field effect transistor memory of Example 1 of the present application.

[0051] Fig.11 This is a forward storage window diagram of the organic field effect transistor memory of Example 2 of the present application.

[0052] Fig.12 This is a forward storage window diagram of the organic field effect transistor memory of Example 3 of the present application.

[0053] Fig.13 This is a forward storage window diagram of the organic field effect transistor memory of Example 4 of the present application.

[0054] Fig.14 This is a forward maintenance time diagram of the organic field effect transistor memory of Example 1 of the present application.

[0055] Fig.15This is a forward maintenance time diagram of the organic field effect transistor memory of Example 2 of the present application.

[0056] Fig.16 This is a forward maintenance time diagram of the organic field effect transistor memory of Example 3 of the present application.

[0057] Fig.17 This is a forward maintenance time diagram of the organic field effect transistor memory of Example 4 of the present application. DETAILED DESCRIPTION

[0058] The present application is further described in detail below in conjunction with examples. The following examples are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. In the following examples, if specific conditions are not specified, they are carried out according to normal conditions or conditions recommended by the manufacturer. The methods used are conventional methods known in the art unless otherwise specified, and the consumables and reagents used are commercially available unless otherwise specified. Unless otherwise specified, the professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the recorded content may also be applied to the present invention.

[0059] The raw materials used in the examples and comparative examples can all be obtained from commercial sources. Figure 1 As shown, the gate electrode and the source-drain electrode are both copper, the semiconductor layer is a pentacene layer, the single molecular layer is a carbazole derivative single molecular layer, the gate insulating layer is silicon dioxide, and the substrate is heavily doped silicon.

[0060] Example 1 Embodiment 1 of the present application provides an organic field effect transistor memory, and the preparation steps thereof are as follows: (1) Before the experiment, all glassware used were dried in advance. 0.026 mmol of the compound of formula A1 was added to a three-necked flask equipped with a spherical condenser and protected by nitrogen. The carbazole derivative (dicarbazole metaphenyl), 50 mL of ultra-dry tetrahydrofuran (THF) and 0.06 mmol of anhydrous potassium carbonate as a catalyst were added, and magnetic stirring was turned on. Then the oil bath was heated to 70°C and continued to heat and stir for 1 hour. 3 mL of 3-chloropropylmethyldimethoxysilane (excess) was added dropwise at a rate of 5 seconds / drop. After the addition was completed, the oil bath was heated to 80°C and heated and stirred for 72 hours. After the reaction was completed, the anhydrous potassium carbonate was removed by filtration using a G4 sand core, and the filtrate was then dried to remove tetrahydrofuran and 3-chloropropylmethyldimethoxysilane to obtain the compound of formula B1. intermediate product.

[0061] (2) Prepare a mixed solution of 42 mL of concentrated sulfuric acid and 18 mL of hydrogen peroxide in a beaker for later use, form a gate electrode and a gate insulating layer on the substrate, and sequentially perform three-step ultrasonic cleaning treatments with acetone, ethanol, and ultrapure water, and then dry and soak in the mixed solution in the beaker, heat at 90°C for 1 h, and then sequentially perform pure water rinsing, ethanol rinsing, and nitrogen blow-drying operations to obtain a hydroxylated modified substrate.

[0062] (3) The intermediate product of formula B1 was dissolved in toluene as a solvent to prepare an intermediate product solution with a concentration of 3 mg / mL.

[0063] (4) The hydroxylated modified substrate was immersed in the intermediate product solution, heated at 70°C for 12 hours, and after the reaction was completed, it was taken out and ultrasonically cleaned with chloroform, acetone, and ethanol for 10 minutes respectively, and dried with nitrogen to obtain a shaped product as shown in Formula C1 The substrate is a monolayer of a carbazole derivative.

[0064] (5) The monolayer of carbazole derivative was deposited on the surface of the vacuum evaporation equipment at a rate of 1 Å / s and a vacuum degree of 6×10 -5 -6×10 -4 Pa, a pentacene layer with a thickness of 30 nm was evaporated as a semiconductor layer; then the substrate with the pentacene layer was taken out and a mask was added to perform multiple batches of treatments. The evaporation rate was 0.5 Å / s and the vacuum degree was controlled at 6×10 -5 -6×10 -4 Under the condition of Pa, copper electrodes with a thickness of 60nm were evaporated as source and drain electrodes, and the mask template controlled the channel width and length of a single group to be 1000μm and 100μm respectively, to obtain an organic field effect transistor memory.

[0065] Example 2 Embodiment 2 of the present application provides an organic field effect transistor memory. The difference between Embodiment 2 and Embodiment 1 is that: 0.025 mmol of formula A2 is used. The carbazole derivative (ternary carbazole meta-phenyl) of formula A1 was replaced with 0.026 mmol of the carbazole derivative (divalent carbazole meta-phenyl) of formula A1 and 0.08 mmol of anhydrous potassium carbonate was added as a catalyst to prepare a compound of formula B2 The intermediate product of formula B2 is used to replace the intermediate product of formula B1 to obtain a shaped product of formula C2 The substrate is a monolayer of a carbazole derivative.

[0066] Example 3 Embodiment 3 of the present application provides an organic field effect transistor memory. The difference between Embodiment 3 and Embodiment 1 is that: 0.05 mmol of formula A3 is used. The carbazole derivative of formula A1 is replaced by 0.026 mmol of carbazole derivative (dicarbazole meta-benzoate) to prepare formula B3 The intermediate product of formula B3 is used to replace the intermediate product of formula B1 to obtain a shaped product of formula C3 The substrate is a monolayer of a carbazole derivative.

[0067] Example 4 Embodiment 4 of the present application provides an organic field effect transistor memory. The difference between Embodiment 4 and Embodiment 1 is that: 0.05 mmol of formula A4 is used. The carbazole derivative of formula A1 is replaced by 0.026 mmol of carbazole derivative (dicarbazole meta-benzoate) to prepare formula B4 The intermediate product of formula B4 is used to replace the intermediate product of formula B1 to obtain a shaped product of formula C4 The substrate is a monolayer of a carbazole derivative.

[0068] Test and Inspection (1) During the preparation of the organic field effect transistor memory of Examples 1-4, the water contact angle of the substrate that was ultrasonically cleaned in three steps of acetone, ethanol, and ultrapure water was tested; the water contact angle of the hydroxylated modified substrate was tested; and the water contact angle of the substrate formed with a monolayer of carbazole derivatives was tested. The above results were arranged from left to right to obtain a graph showing the change of the water contact angle of the substrate surface, as shown in FIG. Figure 2-5 shown.

[0069] (2) Determine the X-ray photoelectron spectrum of the organic field effect transistor memory of Examples 1-4, such as Figure 6-9 shown.

[0070] (3) Determine the forward storage window diagram of the organic field effect transistor memory of Examples 1-4, as shown in FIG. Figure 10-13 shown.

[0071] (4) The forward holding time diagram of the organic field effect transistor memory of Examples 1-4 is measured, as shown in FIG. Figure 14-17 shown.

[0072] Results Analysis The following combination Figure 1-17 The experimental results provided are used to explain this application in detail.

[0073] Reference Figure 2-5It can be seen that the hydrophobicity of the substrate surface of the organic field effect transistor memory in Examples 1-4 first decreases and then decreases during the preparation process. After a monolayer of carbazole derivatives is formed on the substrate surface, the hydrophobicity reaches the maximum. In the order of Examples 1-4, after a monolayer of carbazole derivatives is formed on the substrate surface, the water contact angles are increased to 82.4°, 79.82°, 77.67° and 79.69°, respectively, which improves the hydrophobicity of the charge trapping layer in the organic field effect transistor memory, thereby improving the stability of the prepared organic field effect transistor memory.

[0074] Reference Figure 6-9 It can be seen that N elements appear on the substrate surfaces of the organic field effect transistor memories of Examples 1-4, which originally had no N elements, indicating that a monomolecular film of carbazole derivatives is successfully grafted onto the substrate surface.

[0075] Reference Figure 10-13 It can be seen that the organic field effect transistor memory of Examples 1-4 realizes 32.49V, 28.06V, 26.18V and 16.2V electronic storage in turn under the control of photoelectricity, thereby improving the storage density of the organic field effect transistor memory. Figure 2-5 It can be seen that the water contact angle of the organic field effect transistor memory of Example 1 is the largest and the storage density is the largest, indicating that using binary carbazole meta-benzoate as a carbazole derivative to make an organic field effect transistor memory is beneficial to improving both the stability and storage performance of the organic field effect transistor memory.

[0076] Reference Figure 14-17 It can be seen that the switching ratios of the organic field effect transistor memories of Examples 1 to 4 are respectively maintained at 5.75×10 3 ,7.76×10 3 , 2.88×10 3 and 2.01×103, having good tolerance and storage performance, especially the organic field effect transistor memory of Example 1 and Example 2, the switching ratio is maintained at 5×10 3 The above indicates that using binary carbazole meta-phenyl lattice or ternary carbazole meta-phenyl lattice as carbazole derivatives to prepare organic field effect transistor memory is beneficial to improving the tolerance and storage performance of the organic field effect transistor memory.

[0077] In summary, the monolayer of carbazole derivatives and the preparation method thereof provided in the present application have controllable thickness, high substrate recognition, and use toluene solvent, which is low in price, and adopts a solution method for film formation, which has a simple process and low cost. By using the monolayer of carbazole derivatives as the organic charge storage layer of the organic field effect transistor memory, the tolerance, storage density and stability of the memory are improved. The preparation method of the organic field effect transistor memory of the present application is simple, which reduces the device preparation cost, and is conducive to the further development, promotion and production of future memory devices.

[0078] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A monolayer of a carbazole derivative, characterized in that: Including any one of the following structural formulas: 、 and Any of the following; Wherein, n is a natural number from 1 to 100, and m is a natural number from 1 to 100; It is a fluorenyl derivative; It is a benzene derivative; Selected from and Any of the following; Selected from 、 and Any one of .

2. A method for preparing a monolayer of a carbazole derivative according to claim 1, characterized in that: The method comprises the following steps: reacting a carbazole derivative with 3-chloroalkylalkyldialkoxysilane to obtain an intermediate product, and condensing the intermediate product with a hydroxylated modified substrate to obtain a monomolecular layer of the carbazole derivative.

3. The method for preparing a monolayer of a carbazole derivative according to claim 2, wherein: The molar ratio of the carbazole derivative to the 3-chloroalkylalkyldialkoxysilane is 1:2-10.

4. The method for preparing a monolayer of a carbazole derivative according to claim 2, wherein: The hydroxylation modified substrate is prepared by the following steps: mixing sulfuric acid and hydrogen peroxide to prepare a mixed solution, and immersing the substrate in the mixed solution.

5. The method for preparing a monolayer of a carbazole derivative according to claim 4, wherein: In the mixed solution, the molar ratio of sulfuric acid to hydrogen peroxide is 2.8-3.2:

1.

6. The method for preparing a monolayer of a carbazole derivative according to claim 2, wherein: The general structural formula of the carbazole derivatives includes the following: 、 and One of them.

7. An organic field-effect transistor memory, characterized in that: The invention comprises a source-drain electrode, a semiconductor layer, a carbazole derivative monomolecular layer as claimed in claim 1, a gate insulating layer, a substrate and a gate electrode which are arranged in sequence.

8. The organic field effect transistor memory according to claim 7, wherein: The thickness of the monomolecular layer of the carbazole derivative is 1-10 nm.

9. A method for preparing an organic field effect transistor memory according to claim 7, characterized in that: The method comprises the following steps: forming a gate electrode and a gate insulating layer on a substrate, performing ultrasonic cleaning and drying, then placing the substrate in a mixed solution, heating the mixed solution at 88-92°C for 0.8-1.5h, washing, and drying to obtain a hydroxylated modified substrate; mixing a carbazole derivative, a catalyst, tetrahydrofuran, and 3-chloroalkylalkyldialkoxysilane, reacting the mixed solution at 78-82°C for 60-80h to obtain an intermediate product; placing the hydroxylated modified substrate in a solution of the intermediate product, reacting the mixed solution at 65-75°C for 10-14h, washing, and drying to obtain a substrate formed with a monomolecular layer of the carbazole derivative; preparing an organic semiconductor layer on the monomolecular layer of the carbazole derivative, and preparing a source-drain electrode on the organic semiconductor layer.

10. The method for preparing an organic field effect transistor memory according to claim 9, wherein: In the solution of the intermediate product, the concentration of the intermediate product is 2-5 mg / mL.

Images