Schiff base metal complexes, organic phototransistors and methods of making the same

Abstract

The present application belongs to the technical field of organic photoelectric detection, and particularly relates to a Schiff base metal complex, which has the following structural formula: in the formula, M is a divalent metal ion, and R is an alkyl group. Compared with the prior art, the present application has excellent semiconductor characteristics without adding a dopant, has good solubility in an organic solvent, can be prepared into an organic photoelectric transistor active layer by using a low-cost liquid phase process, has excellent ultraviolet spectrum absorption characteristics, thereby improving photoelectric response performance of the transistor to an ultraviolet spectrum, has excellent thermal and chemical stability, and the alkyl chain has a hydrophobic property, so that the application of the present application to an organic photoelectric transistor can further improve the service life and stability of the device. Therefore, the present application provides a new type of semiconductor material for an organic photoelectric transistor.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of organic photoelectric detection, and particularly relates to a Schiff base metal complex, an organic photoelectric transistor and a preparation method thereof. BACKGROUND

[0002] At present, photoelectric detectors have been widely applied in the fields of image sensing, remote control, environmental monitoring, night monitoring, spectrum and medical equipment. Practical photoelectric detectors mainly adopt inorganic semiconductor materials, such as single crystal silicon, polycrystalline silicon or three-five semiconductor materials, which can realize wide-band detection from ultraviolet to infrared. However, the photoelectric detector based on inorganic semiconductor often needs a thick active layer to realize effective photoelectric response, and has the defects of high preparation cost and fragility, which limits its further popularization and application.

[0003] Compared with inorganic semiconductors, organic semiconductors have the advantages of modifiable structure, adjustable performance, large-scale preparation, low cost and flexibility. With the development of consumer electronics towards lightness, thinness, large area, flexibility and energy saving and environmental protection, the research on organic semiconductor materials and devices has become one of the frontiers in the field of semiconductors. Therefore, organic photoelectric detectors based on organic semiconductor materials have been widely valued at home and abroad, and have good application prospects in military defense, civil economy and life. Organic photoelectric detectors are mainly divided into three categories according to the device structure: organic photoconductor, organic photodiode and organic phototransistor. Compared with the former two, the organic phototransistor can integrate the functions of light detection and signal amplification, which is more conducive to circuit integration and has more practical value. Although certain progress has been made in this field, problems still exist, mainly in the difficulty of obtaining suitable organic semiconductor materials.

[0004] As an important class of organic semiconductor materials, organic metal complexes have the characteristics of simple synthesis and purification, low preparation cost, good chemical and thermal stability, and excellent semiconductor performance, and the physical, chemical, optical and electrical properties of the materials can be adjusted by changing the central metal and chemical functional groups to meet different practical needs. Therefore, it is a kind of organic semiconductor material with potential application value in organic photoelectric transistors. Therefore, it is of certain practical significance to design and develop suitable organic metal complexes to improve the performance of organic photoelectric transistor devices.

[0005] In view of the above, the present application aims to provide a Schiff base metal complex, an organic photoelectric transistor and a preparation method thereof, the Schiff base metal complex is low in price and has excellent semiconductor characteristics without adding a dopant; meanwhile, the Schiff base metal complex has good solubility in an organic solvent, and can be prepared into an active layer of an organic photoelectric transistor by using a low-cost liquid phase process; the Schiff base metal complex has excellent ultraviolet spectrum absorption characteristics and excellent thermal and chemical stability, and provides a new type of semiconductor material for an organic photoelectric transistor. SUMMARY

[0006] One of the purposes of the present application is to provide a Schiff base metal complex, which is low in price and has excellent semiconductor characteristics without adding a dopant; meanwhile, the Schiff base metal complex has good solubility in an organic solvent, and can be prepared into an active layer of an organic photoelectric transistor by using a low-cost liquid phase process; the Schiff base metal complex has excellent ultraviolet spectrum absorption characteristics and excellent thermal and chemical stability, and provides a new type of semiconductor material for an organic photoelectric transistor, in view of the above defects of the prior art.

[0007] To solve the above defects of the prior art, the technical scheme provided by the present application is:

[0008] A Schiff base metal complex has the following structural formula:

[0009]

[0010] In the formula, M is a divalent metal ion, and R is an alkyl group.

[0011] As an improvement of the Schiff base metal complex of the present application, the M is Co 2+ , Cu 2+ , Zn 2+ , Ni 2+ , Fe 2+ , Pt 2+ or Pd 2+ .

[0012] The alkyl group is -CH3, -C2H5, -C3H7 or -C4H9.

[0013] As an improvement of the Schiff base metal complex of the present application, the preparation method comprises the following steps:

[0014] Substituted o-phenylenediamine, a divalent metal salt, pyrrole-2-formaldehyde and an organic solvent are mixed and reacted to prepare the Schiff base metal complex; the divalent metal salt can be dissolved in the organic solvent, and the structural formula of the substituted o-phenylenediamine is

[0015]

[0016] As an improvement of the Schiff base metal complex of the present application, the molar ratio of the substituted o-phenylenediamine, the metal ion in the divalent metal salt and the pyrrole-2-carboxaldehyde is (1-2):(1-2):(2-4). The divalent metal salt is acetate or chloride containing Co, Cu, Zn, Ni, Fe, Pt or Pd.

[0017] As an improvement of the Schiff base metal complex of the present application, the organic solvent is methanol, ethanol, tetrahydrofuran, dichloromethane, chloroform, dimethylformamide or dimethyl sulfoxide; the temperature of the reaction is room temperature to 100 DEG C, and the reaction time is 2h to 24h. The preparation method of the above-mentioned Schiff base metal complex has simple process, is easy to mass production, and uses low-cost raw materials. The prepared Schiff base metal complex has excellent semiconductor characteristics and ultraviolet light absorption characteristics, and has good solubility in organic solvents. The organic photoelectric transistor active layer can be prepared by using low-cost liquid phase process, which can effectively improve the photoelectric response characteristics and stability of the device.

[0018] Compared with the prior art, the Schiff base metal complex of the present application has the advantages that: the Schiff base metal complex of the present application has excellent semiconductor characteristics without adding dopant; the Schiff base metal complex of the present application has good solubility in organic solvents, and can be prepared into an organic photoelectric transistor active layer by using low-cost liquid phase process; the Schiff base metal complex of the present application has excellent ultraviolet spectrum absorption characteristics, thereby improving the photoelectric response performance of the transistor to ultraviolet spectrum; the Schiff base metal complex of the present application has excellent thermal and chemical stability, and the alkyl chain has hydrophobic characteristics, which can further improve the service life and stability of the device when applied to the organic photoelectric transistor. Therefore, the Schiff base metal complex of the present application provides a new type of semiconductor material for the organic photoelectric transistor.

[0019] Another object of the present application is to provide an organic photoelectric transistor comprising a silicon substrate layer, a Schiff base metal complex active layer and a gold electrode arranged in sequence.

[0020] As an improvement of the organic photoelectric transistor of the present application, the thickness of the silicon substrate layer is 200-800μm; the silicon substrate layer comprises a silicon substrate layer and a silicon dioxide insulating layer, and the silicon dioxide insulating layer is in contact with the Schiff base metal complex active layer.

[0021] As an improvement of the organic photoelectric transistor of the present application, the thickness ratio of the silicon substrate layer and the silicon dioxide insulating layer is 1000:1-2500:1; the thickness of the Schiff base metal complex active layer is 20-100nm; and the thickness of the gold electrode is 60-150nm.

[0022] Compared with the prior art, since the novel Schiff base metal complex is used as the active layer in the application, the preparation cost is low, the chemical and thermal stability is good, and the semiconductor performance is superior, and since the Schiff base metal complex has excellent ultraviolet spectrum absorption characteristics, the photoelectric response performance of the transistor to the ultraviolet spectrum is improved; the alkyl chain of the Schiff base metal complex has a hydrophobic property, so that the organic photoelectric transistor has a long service life and good stability. In addition, the physical, chemical, optical and electrical properties of the material can be adjusted by changing the central metal and chemical functional group modification of the Schiff base metal complex to meet different actual needs, and the adjustable range is large and the application range is wide.

[0023] The application also aims to provide a preparation method of the organic photoelectric transistor, comprising the following preparation steps:

[0024] Firstly, the chlorobenzene solution of the Schiff base metal complex is spin-coated on the silicon substrate layer to obtain a silicon substrate layer loaded with a thin film of the Schiff base metal complex;

[0025] Secondly, the silicon substrate loaded with the thin film of the Schiff base metal complex is annealed to obtain an active layer of the Schiff base metal complex;

[0026] Thirdly, a gold electrode is vacuum evaporated on the active layer of the Schiff base metal complex by taking gold as the gold source to obtain the organic photoelectric transistor.

[0027] As an improvement of the preparation method of the organic photoelectric transistor, the concentration of the chlorobenzene solution of the Schiff base metal complex in the first step is 5-40 mg / mL;

[0028] The temperature of the annealing in the second step is 100-120 ℃, and the annealing time is 10-30 min; and the rate of the vacuum evaporation in the third step is The vacuum degree of the vacuum evaporation is ≥5×10 -6 mbar.

[0029] The method has simple steps and low cost, and can be used in a photoelectric detector on a large scale. BRIEF DESCRIPTION OF DRAWINGS

[0030] The application and the beneficial technical effects thereof will be described in detail below according to the drawings and specific embodiments.

[0031] Figure 1 The application provides a structural schematic diagram of the organic photoelectric transistor.

[0032] Figure 2 The thermogravimetric curve of the Schiff base metal complex obtained in Example 1.

[0033] Figure 3Thermogravimetric curve of the Schiff base metal complex obtained in Example 5.

[0034] Figure 4 Thermogravimetric curve of the Schiff base metal complex obtained in Example 7.

[0035] Figure 5 UV-Vis absorption spectrum of the Schiff base metal complex obtained in Example 1.

[0036] Figure 6 UV-Vis absorption spectrum of the Schiff base metal complex obtained in Example 5.

[0037] Figure 7 UV-Vis absorption spectrum of the Schiff base metal complex obtained in Example 7.

[0038] Figure 8 Atomic force microscope photograph of the active layer of the Schiff base metal complex obtained in Example 10.

[0039] Figure 9 Atomic force microscope photograph of the active layer of the Schiff base metal complex obtained in Example 14.

[0040] Figure 10 Atomic force microscope photograph of the active layer of the Schiff base metal complex obtained in Example 16.

[0041] Figure 11 Small angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 10.

[0042] Figure 12 Small angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 14.

[0043] Figure 13 Small angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 16.

[0044] Figure 14 Output characteristic curve of the organic photoelectric transistor prepared in Example 10.

[0045] Figure 15 Transfer characteristic curve of the organic photoelectric transistor prepared in Example 10 under bright-dark field.

[0046] Figure 16 Dynamic light response curve of the organic photoelectric transistor prepared in Example 10. DETAILED DESCRIPTION

[0047] For the purpose of promoting an understanding of the application, the application will be described in greater detail below with reference to the preferred embodiments. In order to facilitate the understanding of the application, a more comprehensive description of the application will be given below in conjunction with the specific embodiments. In the specific embodiments, the preferred embodiments of the application are given. However, the application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided for the purpose of making the disclosure of the application more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0049] To solve the problem of difficult to find suitable organic semiconductor material in the field of organic phototransistor, one embodiment of the application provides a Schiff base metal complex, having the following structural formula:

[0050]

[0051] In the formula, M is a divalent metal ion, and R is an alkyl group.

[0052] Specifically, M is Co 2+ , Cu 2+ , Zn 2+ , Ni 2+ , Fe 2+ , Pt 2+ or Pd 2+ ; and R is an alkyl group. The alkyl substituent on the periphery of the above-mentioned Schiff base metal complex helps to improve the solubility of the material in organic solvents, and is suitable for preparing an active layer of an organic phototransistor using a low-cost liquid phase process. In addition, the alkyl substituent also helps to improve the hydrophobicity of the material, thereby improving the lifetime and stability of the device.

[0053] Further, the alkyl group is -CH3, -C2H5, -C3H7 or -C4H9. It can be understood that the alkyl group is not limited to the above-mentioned substituents, but can also be an alkyl group with more than 4 carbon atoms, such as -C5H 11 , -C6H 13 , etc.

[0054] The above-mentioned Schiff base metal complex is low in price, has excellent semiconductor properties, and has excellent thermal and chemical stability, as well as excellent ultraviolet light absorption properties, which can effectively improve the photoelectric response properties and stability of the organic phototransistor.

[0055] The preparation method of the Schiff base metal complex of another embodiment comprises the following steps:

[0056] The substituted o-phenylenediamine, the divalent metal salt, the pyrrole-2-carboxaldehyde and the organic solvent are mixed to react to obtain the Schiff base metal complex, and the structural formula of the substituted o-phenylenediamine is

[0057]

[0058] The structural formula of the Schiff base metal complex is

[0059]

[0060] In the formula, M is a divalent metal ion; and R is an alkyl substituent.

[0061] Specifically, the divalent metal salt can be dissolved in the organic solvent. The divalent metal salt is Co 2+ , Cu 2+ , Zn 2+ , Ni 2+ , Fe 2+ , Pt 2+ or Pd 2+ . Further, the divalent metal salt is an acetate or a chloride.

[0062] Further, the molar ratio of the substituted o-phenylenediamine, the metal ion in the divalent metal salt and the pyrrole-2-carboxaldehyde is (1-2):(1-2):(2-4). In one embodiment, the molar ratio of the substituted o-phenylenediamine, the metal ion in the divalent metal salt and the pyrrole-2-carboxaldehyde is 1:1:2, 1:1.2:2.4, 1:1.3:2.4 or 1:1.5:3.

[0063] Preferably, the reaction temperature is room temperature to 100°C, and the reaction time is 2h-24h. In one embodiment, room temperature refers to 10°C-30°C. The reaction temperature is 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 80°C or 100°C. The reaction time is 2h, 3h, 5h, 10h, 12h, 15h or 20h.

[0064] Preferably, the organic solvent is methanol, ethanol, tetrahydrofuran, dichloromethane, chloroform, dimethylformamide or dimethyl sulfoxide.

[0065] Further, after the reaction, a purification step is included. Specifically, the purification step includes filtering, washing, column chromatography separation, concentration and recrystallization of the product after the reaction. In one embodiment, the organic solvent described above is used for washing. The column chromatography separation process can be adjusted according to the conventional means in the art, for example, the eluent used can be a mixture of ethanol and dichloromethane. The reagent used in the recrystallization process can be a mixture of ethanol and dichloromethane. It can be understood that the above only lists one commonly used processing parameter, and it can also be adjusted according to the actual situation. The product can be further purified through the above steps.

[0066] The preparation method of the Schiff base metal complex described above has simple process, is easy to mass production, and the raw materials used are low in price. The prepared Schiff base metal complex has excellent semiconductor properties and ultraviolet light absorption properties, and has good solubility in organic solvents. The organic photoelectric transistor active layer can be prepared by using a low-cost liquid phase process, which can effectively improve the photoelectric response properties and stability of the device.

[0067] Please refer to Figure 1 The application further provides an organic photoelectric transistor, which sequentially comprises a silicon substrate layer 1, a Schiff base metal complex active layer 2 and a gold electrode 3.

[0068] In the application, the thickness of the silicon substrate layer 1 is preferably 200-800 μm, more preferably 500-600 μm.

[0069] In the application, the silicon substrate layer 1 preferably comprises a silicon substrate layer 11 and a silicon dioxide insulating layer 12, and the silicon dioxide insulating layer 12 is in contact with the Schiff base metal complex active layer 2.

[0070] In the application, the thickness ratio of the silicon substrate layer 11 and the silicon dioxide insulating layer 12 is preferably 1000:1-2500:1, more preferably 1665:1-200:1.

[0071] The application does not have special limitations on the source of the silicon substrate layer 11, and commercially available products known to those skilled in the art can be selected.

[0072] In the application, the thickness of the Schiff base metal complex active layer 2 is preferably 20-100 nm, more preferably 40-80 nm, and most preferably 50-60 nm.

[0073] In the application, the thickness of the gold electrode 3 is preferably 60-150 nm, more preferably 80-120 nm, and most preferably 100 nm.

[0074] The application further provides a preparation method of the organic photoelectric transistor described above, which comprises the following steps:

[0075] 1) spin-coating a chlorobenzene solution of a Schiff base metal complex onto a silicon substrate layer 1 to obtain a silicon substrate layer 1 carrying a thin film of the Schiff base metal complex;

[0076] 2) annealing the above-mentioned silicon substrate layer 1 carrying a thin film of the Schiff base metal complex to obtain a Schiff base metal complex active layer 2;

[0077] 3) vacuum evaporation of a gold electrode 3 on the above-mentioned Schiff base metal complex active layer 2 to obtain an organic photoelectric transistor.

[0078] The present application spin-coats a chlorobenzene solution of a Schiff base metal complex onto a silicon substrate layer 1 to obtain a silicon substrate layer 1 carrying a thin film of the Schiff base metal complex. In the present application, preferably, the spin-coating is preceded by sequentially cleaning and vacuum drying the silicon substrate.

[0079] In the present application, the cleaning preferably comprises sequentially ultrasonic cleaning the silicon substrate in deionized water, ethanol, isopropanol and acetone.

[0080] In the present application, the silicon substrate layer 1 is ultrasonically cleaned in deionized water, ethanol, isopropanol and acetone for a time independently preferably of 10-20 min, more preferably of 12-18 min; the power of the ultrasonic independently preferably is 600-1500 W, more preferably 800-1200 W, and the frequency of the ultrasonic independently preferably is 50-150 kHz, more preferably 80-100 kHz.

[0081] In the present application, after each ultrasonic cleaning in deionized water, ethanol and isopropanol, preferably, air drying is included, and after ultrasonic cleaning in acetone, preferably, nitrogen blowing is included.

[0082] In the present application, the temperature of the vacuum drying preferably is 80-140°C, more preferably 100-120°C, and the time of the vacuum drying preferably is 8-24 h, more preferably 16-20 h.

[0083] In the present application, the vacuum degree of the vacuum drying is not particularly limited, and a vacuum degree known to those skilled in the art can be selected.

[0084] In the present application, the concentration of the chlorobenzene solution of the Schiff base metal complex preferably is 5-40 mg / mL, more preferably 10-30 mg / mL, and most preferably 20 mg / mL.

[0085] In the present application, the rate of the spin-coating preferably is 500-4000 rpm, more preferably 1000-2000 rpm.

[0086] In the present application, the time of the spin-coating preferably is 0.5-3 min, more preferably 1-2 min.

[0087] In the present application, the thickness of the spin coating is preferably 20-100 nm, more preferably 40-80 nm.

[0088] The method of the spin coating is not particularly limited in the present application, and any spin coating method known to those skilled in the art can be used.

[0089] The present application adopts a liquid phase spin coating process to prepare a Schiff base metal complex film of an organic photoelectric transistor, avoiding many drawbacks of the traditional vacuum evaporation film preparation method.

[0090] After obtaining the silicon substrate layer 1 loaded with the Schiff base metal complex film, the silicon substrate layer 1 is annealed in the present application to obtain a Schiff base metal complex active layer 2.

[0091] In the present application, the temperature of the annealing process is preferably 100℃, and the annealing time is preferably 10 min, and the heating rate is 5℃ / min.

[0092] In the present application, the rate of the vacuum evaporation is preferably more preferably

[0093] In the present application, the vacuum degree of the vacuum evaporation is preferably ≥5×10 -6 mbar, more preferably ≥1×10 -6 mbar.

[0094] In the present application, the purity of gold is preferably ≥99.999%.

[0095] In the present application, the vacuum evaporation is preferably carried out in a vacuum evaporation instrument.

[0096] In order to better understand the present application, the content of the present application will be further illustrated below in combination with examples, but the content of the present application is not limited to the following examples.

[0097] Example 1

[0098] The preparation process of the Schiff base metal complex of the present example is as follows:

[0099] 1) Put 0.98g (6.00mmol) of 3,6-diethyl-ortho-phenylenediamine, 0.78g (6.00mmol) of anhydrous nickel chloride, 1.14g (12.00mmol) of pyrrole-2-formaldehyde and 40mL of anhydrous ethanol into a 100mL flask, add a bottle plug, and stir at room temperature for 2h.

[0100] 2) Filter the reaction mixture obtained in step 1) above, wash the solid on the filter paper with 120mL of ethanol, and dry the solid on the filter paper in the air.

[0101] 3) The product of step 2) was purified by column chromatography, and a silica gel column was used, and a mixture of ethanol and dichloromethane (1 / 4 by volume) was used as an eluent, and the product solution was collected, and the solvent in the product solution was evaporated by using a rotary evaporator.

[0102] 4) The product of step 3) was further recrystallized in an ethanol / dichloromethane solvent system, and the final product obtained was a Schiff base metal complex, and the structure was as follows:

[0103]

[0104] Examples 2 to 9

[0105] The preparation process of the Schiff base metal complexes in Examples 2 to 9 was similar to that of the Schiff base metal complex in Example 1, and the difference was that the raw materials, the ratio, and the reaction temperature and time were different, and the specific parameters were shown in Table 1. Among them, the molar ratio represented the molar ratio of the substituted o-phenylenediamine, the divalent metal salt and the pyrrole-2-carboxaldehyde.

[0106] Table 1 Process parameters of the Schiff base metal complexes in Examples 2 to 9

[0107]

[0108] Example 10

[0109] The preparation process of the organic photoelectric transistor in this example was as follows:

[0110] 1) A silicon substrate (Si / SiO2) with an area of 2 cm x 2 cm was placed in deionized water containing a semiconductor cleaning agent, and ultrasonic cleaning was performed at room temperature for 15 min, and then taken out and dried. Then it was placed in anhydrous ethanol, and ultrasonic cleaning was performed at room temperature for 15 min, and then taken out and dried. Then it was placed in isopropanol, and ultrasonic cleaning was performed at room temperature for 15 min, and then taken out and dried. Then it was placed in acetone, and ultrasonic cleaning was performed at room temperature for 15 min, and then taken out and dried with N2. Finally, it was placed in a vacuum drying oven, and vacuum drying was performed at 120°C for 16 h, and then it was ready for use.

[0111] 2) 20 mg of the Schiff base metal complex in Example 1 was dissolved in 1 mL of chlorobenzene, and the solution was placed in a common ultrasonic water bath, and ultrasonic cleaning was performed for 30 min, and a 20 mg / mL chlorobenzene solution of the Schiff base metal complex was prepared, and then it was ready for use.

[0112] 3) 100 μL of the chlorobenzene solution of the Schiff base metal complex was taken by a pipette and dropped on the silicon substrate, and a spin coater was used to spin the solution into a film at 1000 rpm for 2 min. The substrate was placed on a heating stage and annealed at 100°C for 10 min to obtain a 50 nm thick active layer of the Schiff base metal complex.

[0113] 4) The silicon substrate with the active layer of the Schiff base metal complex was placed on a substrate stage of a vacuum evaporator (Mbraun MB200), and the vacuum degree of the chamber was controlled to be no less than 5 x 10 -6 mbar. Gold electrodes were evaporated on the insulating layer of the silicon substrate at a rate of 0.1 nm / s using high-purity gold (99.999%) as the gold source, and the thickness of the electrodes was controlled to be 100 nm to obtain an organic phototransistor.

[0114] Examples 11-18

[0115] The preparation process of the organic phototransistors of Examples 11-18 was similar to that of the organic phototransistor of Example 10, except that the materials of the active layers were different. The materials of the active layers of Examples 11-18 are shown in Table 2 below:

[0116] Table 2 Materials of the active layers of the organic phototransistors of Examples 11-18

[0117] Example Schiff base metal complexes Example 11 Example 2 Example 12 Example 3 Example 13 Example 4 Example 14 Example 5 Example 15 Example 6 Example 16 Example 7 Example 17 Example 8 Example 18 Example 9

[0118] The following is the test section:

[0119] Figure 2 Figure 1 is a thermogravimetric curve of the Schiff base metal complex obtained in Example 1. As can be seen from the figure, the decomposition temperature of the Schiff base metal complex is 325°C, and the thermal stability is good.

[0120] Figure 3 Figure 2 is a thermogravimetric curve of the Schiff base metal complex obtained in Example 5. As can be seen from the figure, the decomposition temperature of the Schiff base metal complex is 328°C, and the thermal stability is good.

[0121] Figure 4 Figure 3 is a thermogravimetric curve of the Schiff base metal complex obtained in Example 7. As can be seen from the figure, the decomposition temperature of the Schiff base metal complex is 346°C, and the thermal stability is good.

[0122] Figure 5 Figure 4 is an ultraviolet-visible absorption spectrum of the Schiff base metal complex obtained in Example 1. As can be seen from the figure, the Schiff base metal complex has good absorption in the ultraviolet-visible light region, especially in the ultraviolet region.

[0123] Figure 6 ​The UV-Vis absorption spectrum of the Schiff base metal complex obtained in Example 5 is shown in the figure. It can be seen from the figure that the Schiff base metal complex absorbs well in the UV-Vis light region, especially in the UV region.

[0124] Figure 7 The UV-Vis absorption spectrum of the Schiff base metal complex obtained in Example 7 is shown in the figure. It can be seen from the figure that the Schiff base metal complex absorbs well in the UV-Vis light region, especially in the UV region.

[0125] Figure 8 The atomic force microscope photo of the active layer of the Schiff base metal complex obtained in Example 10 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has a uniform and compact surface morphology.

[0126] Figure 9 The atomic force microscope photo of the active layer of the Schiff base metal complex obtained in Example 14 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has a uniform and compact surface morphology.

[0127] Figure 10 The atomic force microscope photo of the active layer of the Schiff base metal complex obtained in Example 16 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has a uniform and compact surface morphology.

[0128] Figure 11 The small-angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 10 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has good crystallinity and high crystallinity.

[0129] Figure 12 The small-angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 14 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has good crystallinity and high crystallinity.

[0130] Figure 13 The small-angle grazing incidence X-ray diffraction spectrum of the active layer of the Schiff base metal complex obtained in Example 16 is shown in the figure. It can be seen from the figure that the active layer of the Schiff base metal complex has good crystallinity and high crystallinity.

[0131] The transistor performance of the organic photoelectric transistor obtained in Example 10 is tested by using a Keithly 4200SCS semiconductor characteristic test system, the transistor channel length (L) is 50, 100, 150 or 200 μm, the channel width (W) is 100, 250, 500, 1000, 1500 or 3000 μm, and the test is normally carried out in an atmospheric environment.

[0132] The output characteristic curve of the organic photoelectric transistor prepared in Example 10 is shown in Figure 14As shown, the test results show that the transistor is a p-type transistor, and the hole mobility is 2.52 x 10 -2 cm 2 / Vs.

[0133] The device performance of the organic photoelectric transistors in Examples 11-18 is shown in Table 3:

[0134] Table 3 Carrier mobility of the organic photoelectric transistors in Examples 11-18

[0135]

[0136] The organic photoelectric transistors prepared in Example 10 were tested for light response characteristics using a ZOLIX Omni-λ200i light source system, and the light source used was 365 nm ultraviolet light with an illumination intensity of 25 μW / cm 2 , and the test was performed in a normal atmosphere, and the results are shown in Figure 15 and Figure 16 . The measured light response was 1.53 A / W, the bright-dark current ratio was 1299, and the response time was 106 ms.

[0137] The light response performance of the organic photoelectric transistors in Examples 11-18 is shown in Table 4:

[0138] Table 4 Light response performance of the organic photoelectric transistors in Examples 11-18

[0139]

[0140] As can be seen from the above experimental data, the Schiff base metal complex is used as the active layer material of the organic photoelectric transistor, and has low cost and good photoelectric response characteristics.

[0141] The technical features of the above-described embodiments can be combined in any manner, and to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described, however, as long as the combinations of the technical features do not contradict, they should be considered as the scope of the description.

[0142] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the patent of the present application should be subject to the appended claims.

Claims

1. A Schiff alkali metal complex, characterized in that, It has the following structural formula: ； In the formula, M is a divalent metal ion and R is an alkyl group; M is Co 2+ Cu 2+ Zn 2+ Ni 2+ Fe 2+ Pt 2+ or Pd 2+ ; The alkyl group is -CH3, -C2H5, -C3H7 or -C4H9.

2. The method for preparing Schiff alkali metal complexes according to claim 1, characterized in that, Includes the following steps: A Schiff base metal complex is prepared by reacting a substituted o-phenylenediamine, a divalent metal salt, pyrrole-2-carboxaldehyde, and an organic solvent; the divalent metal salt is soluble in the organic solvent, and the substituted o-phenylenediamine has the following structural formula: ； The molar ratio of the substituted o-phenylenediamine, the metal ion in the divalent metal salt, and the pyrrole-2-carboxaldehyde is (1~2):(1~2):(2~4); the divalent metal salt is an acetate or chloride containing Co, Cu, Zn, Ni, Fe, Pt, or Pd; The organic solvent is methanol, ethanol, tetrahydrofuran, dichloromethane, chloroform, dimethylformamide, or dimethyl sulfoxide; the reaction temperature is room temperature to 100°C, and the reaction time is 2 h to 24 h.

3. An organic phototransistor, characterized in that: It includes a silicon substrate layer, a Schiff base metal complex active layer as described in claim 1, and a gold electrode arranged sequentially.

4. The organic phototransistor according to claim 3, characterized in that: The thickness of the silicon substrate layer is 200~800μm; the silicon substrate layer includes a silicon substrate layer and a silicon dioxide insulating layer, and the silicon dioxide insulating layer is in contact with the Schiff alkali metal complex active layer.

5. The organic phototransistor according to claim 4, characterized in that: The thickness ratio of the silicon substrate layer to the silicon dioxide insulating layer is 1000:1 to 2500:1; the thickness of the Schiff alkali metal complex active layer is 20 to 100 nm; and the thickness of the gold electrode is 60 to 150 nm.

6. A method for fabricating an organic phototransistor according to any one of claims 3-5, characterized in that, The preparation steps include the following: The first step is to spin-coat a chlorobenzene solution of Schiff base metal complex onto a silicon substrate to obtain a silicon substrate carrying a Schiff base metal complex film. The second step is to anneal the silicon substrate containing the Schiff base metal complex film to obtain the Schiff base metal complex active layer. The third step involves vacuum evaporating a gold electrode onto the above-mentioned Schiff alkali metal complex active layer, using gold as the gold source, to obtain an organic phototransistor.

7. The method for fabricating an organic phototransistor according to claim 6, characterized in that: In the first step, the concentration of the chlorobenzene solution of the Schiff base metal complex is 5~40 mg / mL; In the second step, the annealing temperature is 100~120℃ and the annealing time is 10~30min; In the third step, the vacuum evaporation rate is 0.2~1 Å / s, and the vacuum degree of vacuum evaporation is ≥5×10⁻⁶. -6 mbar.

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