Pdi radical derivatives and graphene spin field effect transistors

Abstract

The present application relates to the technical field of molecular electronic devices, and particularly relates to a PDI free radical derivative and a graphene spin field effect transistor. The PDI free radical derivative comprises the following structural formula: wherein when R2 and R3 are (CH2) n NH2, R1 is, and R4 is H or, wherein n is 3, 4, 5 or 6; when R1 and R4 are (CH2) n NH2, R2 is, and R3 is H or, wherein n is 3, 4, 5 or 6. The PDI free radical derivative has stable free radicals, so that the PDI free radical derivative has unique conductivity, magnetic properties and nonlinear optical properties. The PDI free radical derivative is matched with a magnetic electrode and a graphene point electrode in the graphene spin field effect transistor, so that stable spin current is generated, the graphene spin field effect transistor has high stability, high reliability and excellent performance.

Description

Technical Field

[0001] This invention relates to the field of molecular electronic device technology, and more particularly to PDI radical derivatives and graphene spin field-effect transistors. Background Technology

[0002] With the rapid development of information technology, the demand for chip performance in today's society is increasing, further highlighting the importance of miniaturized components. However, the size of traditional electronic devices is approaching physical limits, necessitating the exploration of new mechanisms to further advance device miniaturization in semiconductor technology. Single-molecule electronic devices are advantageous for achieving device miniaturization. Currently, research on single-molecule electronic devices mainly focuses on spin analysis, and spin-based research primarily concentrates on single-molecule magnets based on magnetic metal complexes. However, the performance of single-molecule electronic devices obtained from these studies is unsatisfactory. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the related art. To this end, the present invention provides a PDI radical derivative, which has stable free radicals, giving it unique electrical conductivity, magnetic properties, and nonlinear optical properties. When combined with the magnetic electrodes and graphene point electrode pairs in a graphene spin field-effect transistor, it can generate a stable spin current, resulting in a graphene spin field-effect transistor with strong stability, high reliability, and excellent performance.

[0004] In one aspect of the present invention, a PDI radical derivative is provided, the PDI radical derivative comprising the following structural formula:

[0005]

[0006] Where R2 and R3 are (CH2) n When NH2 is present, R1 is R4 is H or , where n is 3, 4, 5 or 6;

[0007] When R1 and R4 are (CH2) n When NH2 is present, R2 is R3 is H or , where n is 3, 4, 5 or 6.

[0008] Furthermore, the PDI radical derivative comprises at least one of the structural formulas shown in formulas (1) to (4):

[0009] (1) (2) (3) and (4).

[0010] In another aspect of the present invention, a graphene spin field-effect transistor is provided, the graphene spin field-effect transistor comprising:

[0011] silicon substrate;

[0012] A gate dielectric layer disposed on one surface of the silicon substrate;

[0013] A gold electrode and a magnetic electrode are provided, wherein the gold electrode and the magnetic electrode are located on the side of the gate dielectric layer away from the silicon substrate, and the gold electrode and the magnetic electrode are disposed opposite to each other.

[0014] A graphene dot electrode pair is disposed on the surface of the gate dielectric layer away from the silicon substrate. One electrode of the graphene dot electrode pair is electrically connected to the gold electrode, and the other electrode of the graphene dot electrode pair is electrically connected to the magnetic electrode.

[0015] It also includes the PDI radical derivatives as described above, which are connected to two electrodes spaced apart from each other in the graphene point electrode pair.

[0016] Furthermore, the magnetic electrode comprises at least one of iron, cobalt, and nickel;

[0017] The gold electrode includes a chromium layer and a gold layer, wherein the chromium layer is disposed on the surface of the gate dielectric layer away from the silicon substrate, and the gold layer is disposed on the surface of the chromium layer away from the silicon substrate.

[0018] Furthermore, the graphene spin field-effect transistor also includes a protective layer disposed on the side of the graphene point electrode pair away from the silicon substrate, and covering the gold electrode, the magnetic electrode, and the graphene point electrode pair.

[0019] In another aspect of the present invention, the present invention provides a method for fabricating a graphene spin field-effect transistor as described above, the method comprising:

[0020] S1. A gate dielectric layer is formed on one surface of a silicon substrate;

[0021] S2. A gold electrode and a magnetic electrode are disposed on the side of the gate dielectric layer away from the silicon substrate, and the gold electrode and the magnetic electrode are disposed opposite to each other.

[0022] S3. A graphene dot electrode pair is disposed on the surface of the gate dielectric layer away from the silicon substrate, and one electrode of the graphene dot electrode pair is electrically connected to the gold electrode, and the other electrode of the graphene dot electrode pair is electrically connected to the magnetic electrode to obtain a silicon wafer containing a graphene dot electrode pair.

[0023] S4. Connect a PDI radical derivative between two electrodes spaced apart in the graphene point electrode pair to obtain the graphene spin field-effect transistor.

[0024] Furthermore, the method for preparing the PDI radical derivative includes:

[0025] 1,8-naphthalenediamine and 3-bromo-1,8-naphthalenediamine were dissolved in diethylene glycol dimethyl ether and reacted at 120-140°C under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide to obtain the first compound.

[0026] The first compound and 3-bromopropanol were dissolved in N,N-dimethylformamide and reacted at 110-130°C under the co-catalysis of potassium carbonate and potassium iodide to obtain the second compound.

[0027] The second compound and 2,5-tert-butyl-3-boron dihydroxyphenol were dissolved in toluene and reacted at 110-130°C under the co-catalysis of tetra(triphenylphosphine)palladium and sodium carbonate to obtain the third compound.

[0028] The third compound was dissolved in tetrahydrofuran and reacted at 80-100°C under the combined catalysis of cesium carbonate, palladium acetate and 1,1'-binaphthyl-2,2'-bisdiphenylphosphine to obtain the fourth compound;

[0029] The fourth compound was dissolved in diethyl ether and reacted at room temperature under the combined catalysis of potassium hexacyanidide and sodium hydroxide to obtain the PDI radical derivative.

[0030] Furthermore, the method for preparing the PDI radical derivative includes:

[0031] 3-Bromo-1,8-naphthalimide was dissolved in diethylene glycol dimethyl ether and reacted at 120-140°C under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide to obtain the fifth compound.

[0032] The fifth compound and 3-bromopropanol were dissolved in N,N-dimethylformamide and reacted at 110-130°C under the co-catalysis of potassium carbonate and potassium iodide to obtain the sixth compound.

[0033] The sixth compound and 2,5-tert-butyl-3-boron dihydroxyphenol were dissolved in toluene and reacted at 110-130°C under the co-catalysis of tetra(triphenylphosphine)palladium and sodium carbonate to obtain the seventh compound.

[0034] The seventh compound was dissolved in tetrahydrofuran and reacted at 80-100°C under the combined catalysis of cesium carbonate, palladium acetate and 1,1'-binaphthyl-2,2'-bisdiphenylphosphine to obtain the eighth compound.

[0035] The eighth compound was dissolved in diethyl ether and reacted at room temperature under the combined catalysis of potassium hexacyanidide and sodium hydroxide to obtain the PDI radical derivative.

[0036] Furthermore, the method for preparing the PDI radical derivative includes:

[0037] 5-(3-hydroxypropyl)-1H-benzisoquinoline-1,3(2H)-dione was dissolved in diethylene glycol dimethyl ether and reacted at 120-140°C under the co-catalysis of 2,5-dichloro-cyanobenzene and potassium tert-butoxide to obtain compound 9.

[0038] The ninth compound and 1,8-diazahexacyclic ring were dissolved in toluene, the mixture was cooled to 0°C and then dissolved in pyridine with triphenylphosphine and ammonia, and the reaction was carried out at room temperature to obtain the tenth compound.

[0039] The tenth compound was dissolved in tetrahydrofuran and reacted under the catalysis of potassium hydroxide to obtain the eleventh compound;

[0040] The eleventh compound was dissolved in diethyl ether and reacted at room temperature under the combined catalysis of potassium hexacyanidide and sodium hydroxide to obtain the PDI radical derivative.

[0041] Further, step S4 includes:

[0042] The silicon wafer containing the graphene point electrode pair was mixed with sufficient amounts of 1-(3-dimethylaminopropyl)-3-2-ethylcarbodiimide hydrochloride and PDI radical derivative to obtain a mixed system;

[0043] The mixture was placed in a nitrogen atmosphere, and anhydrous pyridine was injected into the mixture and then allowed to stand.

[0044] After cleaning and drying the silicon wafer containing the graphene point electrode pair, the graphene spin field-effect transistor is obtained.

[0045] And / or, the preparation method further includes:

[0046] A protective layer is provided on the side of the graphene point electrode pair away from the silicon substrate, so that the protective layer covers the gold electrode, the magnetic electrode and the graphene point electrode pair.

[0047] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects:

[0048] The PDI radical derivatives provided by this invention contain stable radicals, giving them unique electrical conductivity, magnetic properties, and nonlinear optical properties. The structure of the PDI radical derivatives of this invention is easy to control and the electronic spin state is stable, making them more suitable for single-molecule spin manipulation. When combined with the magnetic electrodes and graphene point electrode pairs in a graphene spin field-effect transistor, they can easily and precisely control spin electrons, thereby generating a stable spin current. By using a high-κ solid-state gate to regulate the single-molecule spin, single-molecule spin current transport and spin control can be achieved, resulting in graphene spin field-effect transistors with strong stability, high reliability, and excellent performance.

[0049] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of a graphene spin field-effect transistor provided by the present invention.

[0052] Figure 2 This is an I / V curve of a graphene spin field-effect transistor obtained in Embodiment 1 of the present invention.

[0053] Figure 3 This is another graphene spin field-effect transistor obtained in Embodiment 1 of the present invention, with an I / V curve.

[0054] Figure 4 This is another graphene spin field-effect transistor obtained in Embodiment 1 of the present invention, with an I / V curve.

[0055] Figure label:

[0056] 1. Graphene point electrode pair; 2. Gold electrode; 3. Magnetic electrode; 4. Silicon substrate; 5. Protective layer; 6. PDI radical derivative; 7. Gate dielectric layer. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but should not be used to limit the scope of this invention.

[0058] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0060] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0062] In one aspect of the present invention, a PDI radical derivative is provided, the PDI radical derivative comprising the following structural formula:

[0063]

[0064] Where R2 and R3 are (CH2) n When NH2 is present, R1 is R4 is H or Where n is 3, 4, 5, or 6; when R1 and R4 are (CH2) n When NH2 is present, R2 is R3 is H or , where n is 3, 4, 5 or 6.

[0065] It should be noted that free radicals refer to atoms, molecules, and ions containing unpaired electrons, also known as free radicals. Most free radicals formed from unpaired electrons have strong electrophilicity, high energy, and strong electron-electron repulsion, thus they are highly chemically reactive and readily undergo reactions such as hydrogen abstraction, oxidation, disproportionation, and dimerization.

[0066] The inventors unexpectedly discovered that, in terms of molecular materials, a single unpaired electron on a free radical molecule can serve as a basic unit for spin controllability. Through molecular design and external regulation, the number of free radicals can be effectively controlled, providing a basis for the precise control of spin electrons in graphene spin field-effect transistors.

[0067] The inventors unexpectedly discovered that PDI (perylenetetracarboxylic diimide, abbreviated as perylene diimide) molecules have a strong π-π conjugation effect, an electron affinity comparable to that of fullerenes, and strong electron-deficient properties, which enable its derivatives to gain electrons and generate stable free radicals, thus ensuring the generation of free radicals.

[0068] The PDI radical derivatives provided by this invention contain stable radicals, giving them unique electrical conductivity, magnetic properties, and nonlinear optical properties. The structure of the PDI radical derivatives of this invention is easy to control and the electronic spin state is stable, making them more suitable for single-molecule spin manipulation. When combined with the magnetic electrodes and graphene point electrode pairs in a graphene spin field-effect transistor, they can easily and precisely control spin electrons, thereby generating a stable spin current. By using a high-κ solid-state gate to regulate the single-molecule spin, single-molecule spin current transport and spin control can be achieved, resulting in graphene spin field-effect transistors with strong stability, high reliability, and excellent performance.

[0069] In some specific embodiments of the present invention, the PDI radical derivative includes at least one of the structural formulas shown in formulas (1) to (4):

[0070] (1) (2) (3) and (4).

[0071] In another aspect of the invention, a graphene spin field-effect transistor is provided, with reference to... Figure 1 The graphene spin field-effect transistor includes: a silicon substrate 4; a gate dielectric layer 7 disposed on one surface of the silicon substrate 4; a gold electrode 2 and a magnetic electrode 3 located on the side of the gate dielectric layer 7 away from the silicon substrate 4, and the gold electrode 2 and the magnetic electrode 3 are disposed opposite to each other; a graphene dot electrode pair 1 disposed on the surface of the gate dielectric layer 7 away from the silicon substrate 4, one electrode of the graphene dot electrode pair 1 being electrically connected to the gold electrode 2, and the other electrode of the graphene dot electrode pair 1 being electrically connected to the magnetic electrode 3; and a PDI radical derivative 6 as described above, the PDI radical derivative 6 being connected to the two electrodes of the graphene dot electrode pair 1 that are spaced apart.

[0072] Understandably, the gold electrode and magnetic electrode can be directly disposed on the surface of the gate dielectric layer, or they can be disposed on the surface of the graphene point electrode pair. The magnetic electrode is used to introduce spin current and filter spin states, thereby obtaining a fixed spin type.

[0073] In the graphene spin field-effect transistor of this invention, a PDI radical derivative with -NH2 at both ends is used as a bridging single molecule, which is connected to the graphene point electrode end with -COOH by forming an amide covalent bond. This constructs a graphene spin field-effect transistor based on PDI radical derivatives, providing technical support for studying molecular spin state modulation and spin transport at the single-molecule scale, and laying the foundation for the development of quantum information. In the graphene spin field-effect transistor, a stable spin current is input based on the combination of magnetic electrode structure and graphene point electrode pairs. Through external field modulation and precise injection of transport spin electrons, the spin state of a single electron and the spin coupling of multiple electrons can be manipulated, realizing single-molecule spin current transport and spin modulation.

[0074] In some embodiments of the present invention, the magnetic electrode comprises at least one of iron, cobalt, and nickel; the gold electrode comprises a chromium layer and a gold layer, the chromium layer being disposed on the surface of the gate dielectric layer away from the silicon substrate, and the gold layer being disposed on the surface of the chromium layer away from the silicon substrate.

[0075] In some embodiments of the present invention, reference is made to... Figure 1 The graphene spin field-effect transistor further includes a protective layer 5, which is disposed on the side of the graphene point electrode pair 1 away from the silicon substrate 4 and covers the gold electrode 2, the magnetic electrode 3, and the graphene point electrode pair 1. In some specific embodiments of the present invention, the protective layer is made of hexagonal boron nitride (h-BN), and the hexagonal boron nitride protective layer is used to encapsulate the graphene spin field-effect transistor to improve device stability.

[0076] In another aspect of the present invention, the present invention provides a method for fabricating a graphene spin field-effect transistor as described above, the method comprising:

[0077] S1. A gate dielectric layer is formed on one surface of a silicon substrate.

[0078] In some specific embodiments of the present invention, the specific steps of forming a gate dielectric layer on a surface of a silicon substrate include:

[0079] S11. On a pure silicon substrate with a surface covered by 300-400 nm silicon oxide, a gate is photolithographically etched, metal is deposited, and the resist is removed with acetone to obtain a film. The photolithographically etched gate is used for subsequent pin-down testing and photolithography calibration. The metal is deposited using a thermal evaporation method, first depositing 8-10 nm of chromium, then depositing 60-80 nm of gold.

[0080] S12. Continue photolithography on the substrate to obtain a bottom gate connected to the evaporated metal.

[0081] S13. An aluminum film is deposited on the bottom grid surface, and the adhesive is removed with acetone to obtain an alumina dielectric layer. The aluminum film is prepared by magnetron sputtering, and the film thickness is 30~40 nm. The alumina dielectric layer is obtained by natural oxidation of the aluminum film after acetone removal.

[0082] S14. A hafnium oxide film is deposited on the surface of the alumina dielectric layer to obtain the final solid-state gate dielectric layer. The hafnium oxide film is deposited by atomic beam deposition, and the film thickness is 3~10 nm.

[0083] In some specific embodiments of the present invention, before the gold electrode and the magnetic electrode are formed, a graphene layer is formed on the surface of the gate dielectric layer away from the silicon substrate. This step includes:

[0084] S15. Prepare single-layer graphene on copper foil using chemical vapor deposition.

[0085] S16. Spin-coat methyl methacrylate (950 PMMA) onto the single-layer graphene to obtain a PMMA-graphene-copper foil structure.

[0086] S17. Cut the PMMA-graphene-copper foil structure and dissolve the copper foil in FeCl3 solution. Soak the copper foil in hydrochloric acid solution, alkaline solution, and pure water, then transfer it to the surface of the gate dielectric layer obtained in step S1. Allow it to air dry and remove the adhesive. The adhesive removal can be done in two ways: (1) heat the silicon wafer after graphene transfer in acetone solution at 120°C for 8 minutes to remove the adhesive; (2) place the silicon wafer in a heating furnace and heat it at 400~500°C for 1~2 minutes to remove the adhesive.

[0087] S2. A gold electrode and a magnetic electrode are disposed on the side of the gate dielectric layer away from the silicon substrate, and the gold electrode and the magnetic electrode are disposed opposite to each other.

[0088] In some specific embodiments of the present invention, the specific steps of forming a gold electrode and a magnetic electrode on the side of the gate dielectric layer away from the silicon substrate include:

[0089] S21. A graphene strip is obtained by coating a graphene film layer with photoresist, photolithography of the strips, and oxygen plasma etching. After removing the photoresist with acetone, a graphene strip is obtained. The photolithography uses an ultraviolet lithography machine, and the resulting graphene strip is 200 μm long and 40 μm wide. The photolithographically obtained graphene strip is protected by photoresist, exposing the remaining graphene. Oxygen plasma etching is then used to remove the graphene outside the strip, resulting in a graphene strip protected only by an intermediate photoresist layer.

[0090] S22. A photoresist is coated onto the surface of the graphene strip, electrodes are photolithographically formed, and magnetic material is deposited on one electrode. After removing the photoresist with acetone, a silicon wafer containing magnetic electrodes is obtained. The magnetic material is deposited using magnetron sputtering with a thickness of 70 nm.

[0091] S23. A photoresist is applied to the silicon wafer containing the magnetic electrodes, and electrodes are photolithographically formed. Chromium and gold are then deposited on the other side by vapor deposition. After removing the photoresist, a graphene array electrode is obtained. Specifically, 8 nm of chromium is deposited first using thermal evaporation, followed by 80 nm of gold. The structure between the magnetic electrodes and the gold electrodes is called a graphene channel, which is used to construct graphene point electrodes.

[0092] S24. The conductivity of the obtained graphene array electrodes was tested at a voltage of 50 mV, and silicon wafers with conductivity in the range of 10 μA were selected for further experiments.

[0093] S3. A graphene dot electrode pair is disposed on the surface of the gate dielectric layer away from the silicon substrate, and one electrode of the graphene dot electrode pair is electrically connected to the gold electrode, and the other electrode of the graphene dot electrode pair is electrically connected to the magnetic electrode, thereby obtaining a silicon wafer containing a graphene dot electrode pair.

[0094] In some specific embodiments of the present invention, the specific operation steps for forming graphene point electrode pairs on the surface of the gate dielectric layer away from the silicon substrate include:

[0095] S31. The graphene array electrodes are etched and developed using an electron beam lithography machine to obtain graphene array electrodes with dashed lines between electrode pairs. The dashed lines etched by the electron beam lithography machine are located between each pair of magnetic electrodes and the gold electrode, with a total length of 60 μm, each dashed line segment being 150 nm long, and the interval between the dashed lines being 40 nm. The developing solution used is methyl isobutyl ketone (MIBK) diluted with isopropanol, with a MIBK:isopropanol ratio of 1:3, and the fixing solution is isopropanol.

[0096] S32. The graphene array electrode with the dashed line is etched with oxygen plasma, and then the current between the electrode pairs is tested using a probe station and a source meter. After repeating this process multiple times, graphene point electrode pairs are obtained, with a gap between the two electrodes of each graphene point electrode pair.

[0097] The source meter input voltage is 50 mV. When the current between every ten pairs of electrodes is measured to be on the order of a few μA, it can be considered that a graphene point electrode pair has been obtained.

[0098] S4. Connect a PDI radical derivative between two electrodes spaced apart in the graphene point electrode pair to obtain the graphene spin field-effect transistor.

[0099] In some embodiments of the present invention, step S4 includes: mixing the silicon wafer containing the graphene point electrode pair with sufficient amounts of 1-(3-dimethylaminopropyl)-3-2-ethylcarbodiimide hydrochloride and PDI radical derivative to obtain a mixed system; placing the mixed system in a nitrogen atmosphere, injecting anhydrous pyridine into the mixed system and allowing it to stand; and cleaning and drying the silicon wafer containing the graphene point electrode pair to obtain the graphene spin field-effect transistor.

[0100] In some specific embodiments of the present invention, step S4 includes:

[0101] S41. Place the silicon wafer containing the graphene point electrode pair in a two-necked flask, and add sufficient amounts of 1-(3-dimethylaminopropyl)-3-2-ethylcarbodiimide hydrochloride and PDI radical derivative to the flask.

[0102] In this process, both flasks and all experimental apparatus and materials must be kept in an anhydrous state to ensure that the -NH2 at both ends of the molecule can successfully form amide covalent bonds with the -COOH at the end of the graphene point electrode pair to bridge the molecule, thereby obtaining a graphene spin field-effect transistor. The sign of successful bridging is that the current changes with the gate voltage under constant bias, thus realizing the control of the device by the gate voltage.

[0103] In some specific embodiments of the present invention, 1-(3-dimethylaminopropyl)-3-2-ethylcarbodiimide hydrochloride is used as an activator at a concentration of 3 × 10⁻⁶. -3 mol / L.

[0104] S42. Seal the two-necked flasks and repeatedly introduce and extract nitrogen gas three times to ensure that the two-necked flasks are in a nitrogen atmosphere.

[0105] S43. Using a syringe and a long needle, draw 10 ml of anhydrous pyridine and inject it into the two-necked flask.

[0106] S44. Let the system obtained in step S43 stand for 48 hours, take out the silicon wafer, rinse it with acetone and ultrapure water and blow dry the surface to obtain a graphene spin field effect transistor.

[0107] Specifically, the distribution of spin electrons on the PDI radical derivative structure is controlled by a given gate voltage electric field. The coupling between spin electrons in the molecule and spin electrons at the electrode edge is controlled. The electrical characteristics of the device are monitored in real time, and the output conductance of the molecular device under different gate voltages is observed over time. Based on the Kondo effect and Zeeman effect, the differential conductance spectrum of the device is tested in a low temperature environment of 50mK-2K using a lock-in amplifier within a bias range of ±10 mV. The presence of free radical spin electrons in the device, the electronic spin state of the free radical molecule, and the control of free radical spin energy levels are determined by the Kondo characteristic signal.

[0108] In some embodiments of the present invention, the method for fabricating a graphene spin field-effect transistor further includes: providing a protective layer on the side of the graphene point electrode pair away from the silicon substrate, such that the protective layer covers the gold electrode, the magnetic electrode, and the graphene point electrode pair.

[0109] In some specific embodiments of the present invention, a 1-20 nm h-BN protective layer is deposited on the surface of the gold electrode, the magnetic electrode, and the graphene point electrode pair.

[0110] In some specific embodiments of the present invention, the preparation method of the PDI radical derivative includes: dissolving 1,8-naphthalenediamide and 3-bromo-1,8-naphthalenediamide in diethylene glycol dimethyl ether, and reacting them at 120-140°C under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide to obtain a first compound; dissolving the first compound and 3-bromopropanol in N,N-dimethylformamide, and reacting them at 110-130°C under the co-catalysis of potassium carbonate and potassium iodide to obtain a second compound; and reacting the second compound with 2,5-tert-butoxide... 3-Borondihydroxyphenol was dissolved in toluene and reacted at 110–130 °C under the co-catalysis of tetra(triphenylphosphine)palladium and sodium carbonate to obtain a third compound. The third compound was then dissolved in tetrahydrofuran and reacted at 80–100 °C under the co-catalysis of cesium carbonate, palladium acetate, and 1,1'-binaphthyl-2,2'-bisdiphenylphosphine to obtain a fourth compound. The fourth compound was then dissolved in diethyl ether and reacted at room temperature under the co-catalysis of potassium hexacyanoferrate and sodium hydroxide to obtain the PDI radical derivative. The specific synthetic process is shown below:

[0111] .

[0112] In some other specific embodiments of the present invention, the preparation method of the PDI radical derivative includes: dissolving 3-bromo-1,8-naphthalenediamide in diethylene glycol dimethyl ether, reacting it under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide at 120-140°C to obtain a fifth compound; dissolving the fifth compound and 3-bromopropanol in N,N-dimethylformamide, reacting it under the co-catalysis of potassium carbonate and potassium iodide at 110-130°C to obtain a sixth compound; and reacting the sixth compound with 2,5-tert-butyl-3- Boron dihydroxyphenol was dissolved in toluene and reacted at 110–130 °C under the co-catalysis of tetra(triphenylphosphine)palladium and sodium carbonate to obtain a seventh compound. The seventh compound was then dissolved in tetrahydrofuran and reacted at 80–100 °C under the co-catalysis of cesium carbonate, palladium acetate, and 1,1'-binaphthyl-2,2'-bisdiphenylphosphine to obtain an eighth compound. The eighth compound was then dissolved in diethyl ether and reacted at room temperature under the co-catalysis of potassium hexacyanoferrate and sodium hydroxide to obtain the PDI radical derivative. The specific synthetic process is shown below:

[0113] .

[0114] In some other specific embodiments of the present invention, the preparation method of the PDI radical derivative includes: dissolving 5-(3-hydroxypropyl)-1H-benzisoquinoline-1,3(2H)-dione in diethylene glycol dimethyl ether, reacting it at 120-140°C under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide to obtain a ninth compound; dissolving the ninth compound and 1,8-diazahexacyclic ring in toluene, cooling the mixture to 0°C, and then dissolving it in pyridine with triphenylphosphine and ammonia, reacting it at room temperature to obtain a tenth compound; dissolving the tenth compound in tetrahydrofuran, reacting it under the catalysis of potassium hydroxide to obtain an eleventh compound; dissolving the eleventh compound in diethyl ether, reacting it at room temperature under the co-catalysis of potassium hexacyanoferrate and sodium hydroxide to obtain the PDI radical derivative.

[0115] It should be noted that different amounts of 5-(3-hydroxypropyl)-1H-benzisoquinoline-1,3(2H)-dione result in different structural formulas for the ninth compound, and consequently, different structural formulas for the tenth to eleventh compounds and even the PDI radical derivatives. When the amount of 5-(3-hydroxypropyl)-1H-benzisoquinoline-1,3(2H)-dione is small, the synthesis process for the PDI radical derivative is as follows:

[0116] .

[0117] When a large amount of 5-(3-hydroxypropyl)-1H-benzisoquinoline-1,3(2H)-dione is used, the process for synthesizing PDI radical derivatives is as follows:

[0118]

[0119] The present invention will now be described in detail with reference to specific embodiments.

[0120] Example

[0121] Example 1

[0122] The preparation method of PDI radical derivatives includes the following steps:

[0123] 1 g (5.07 mmol) of 1,8-naphthalenediamide, 1.2 g (5.07 mmol) of 3-bromo-1,8-naphthalenediamide, 0.112 g (10%) of 2,5-dichlorocyanobenzene, and 0.112 g (10%) of potassium tert-butoxide were dissolved in 20 mL of diethylene glycol dimethyl ether. The mixture was heated to 130°C and stirred for 12 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 1 in 43% yield. ESI-TOF: C 24 H9BrN2O4, Mw=467.97. 1 H NMR (800 MHz, DMSO-d6) δ 8.57 (s,1H), 8.49 – 8.45 (m, 3H), 8.11 (dd, J = 8.5, 7.9 Hz, 2H), 8.06 (d, J = 8.4Hz, 1H).

[0124] 1 g (2.14 mmol) of compound 1 was dissolved in 15 ml of DMF with 0.301 g (2.2 mmol) of 3-bromopropanol, 0.036 g (10%) of potassium carbonate, and 0.042 g (10%) of potassium iodide. The mixture was heated to 120°C and stirred for 20 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 2 in 70% yield. ESI-TOF: C 32 H 25 BrN2O6, Mw=613.46. 1H NMR (800 MHz, DMSO-d6) δ 8.55 (dd, J = 8.6, 5.2 Hz, 2H), 8.49 (d, J= 8.6 Hz, 1H), 8.18 (s, 1H), 8.14 (d, J = 8.6 Hz, 1H), 8.10 (d, J = 8.6 Hz,1H), 8.05 (d, J = 8.6 Hz, 1H), 4.21 (d, J = 11.7 Hz, 1H), 3.58 (td, J = 5.8,1.9 Hz, 4H), 3.54 (q, J = 5.8 Hz, 4H), 1.70 (ttd, J = 8.3, 5.7, 0.7 Hz, 4H),1.58 (ttd, J = 8.4, 5.8, 0.8 Hz, 4H).

[0125] 1 g (1.6 mmol) of compound 2, 0.40 g (1.6 mmol) of 2,5-tert-butyl-3-boron dihydroxyphenol, 0.012 g (2%) of tetrakis(triphenylphosphine)palladium, and 0.036 g (10%) of sodium carbonate were dissolved in 20 mL of toluene. The mixture was heated to 120°C and stirred for 24 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 3 in 90% yield. ESI-TOF:C 46 H 46 N₂O₇, Mw=738.33. 1 H NMR (800 MHz, DMSO-d6) δ 8.56 (dd, J = 8.6, 7.9 Hz,1H), 8.47 (d, J = 8.6 Hz, 1H), 8.20 (s, 1H), 8.16 – 8.07 (m, 1H), 7.37 (s,1H), 6.84 (s, 1H), 4.21 (t, J = 5.9 Hz, 1H), 3.56 (dt, J = 28.2, 5.8 Hz, 4H), 1.70 (ttd, J = 8.3, 5.8, 0.7 Hz, 2H), 1.58 (ttd, J = 8.5, 5.9, 0.8 Hz, 2H),1.44 (s, 9H).

[0126] 1 g (1.4 mmol) of compound 3, 0.025 g (10%) of cesium carbonate, 0.036 g (4%) of palladium acetate, and 0.051 g (6%) of 1,1'-binaphthyl-2,2'-bis(diphenylphosphine) were dissolved in 10 mL of tetrahydrofuran. The mixture was heated to 90°C and stirred for 12 h. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 4 in 82% yield. ESI-TOF: C 46 H 48 N4O5, Mw=736.36. 1 H NMR (800 MHz, DMSO-d6) δ 8.56 (dd, J = 8.6, 7.9 Hz, 1H), 8.47 (d, J= 8.6 Hz, 1H), 8.20 (s, 1H), 8.16 – 8.07 (m, 1H), 7.37 (s, 1H), 6.84 (s, 1H), 3.54 (dt, J = 12.4, 6.2 Hz, 1H), 3.51 – 3.46 (m, 1H), 2.83 (tt, J = 6.5, 5.2Hz, 2H), 2.09 (t, J = 6.5 Hz, 2H), 1.71 – 1.65 (m, 2H), 1.58 (ttd, J = 7.8,5.2, 0.8 Hz, 2H), 1.44 (s, 9H).

[0127] Take 1 g (1.36 mmol) of compound 4, 0.078 g (10%) potassium hexacyanidide, and 0.012 g (20%) sodium hydroxide, dissolve them in 10 ml of diethyl ether, let stand at room temperature for 2 h, after the reaction is complete, extract the liquid phase mixture with dichloromethane and wash three times with saturated sodium chloride solution, take the organic phase and dry to obtain PDI radical derivative, yield 87%.

[0128] Three graphene spin field-effect transistors were fabricated using the PDI radical derivative of this embodiment. The performance test results of these three graphene spin field-effect transistors are as follows: Figures 2 to 4 As shown. It should be noted that, as... Figures 2 to 4 As shown, the performance test results of the three graphene spin field-effect transistors obtained in this embodiment are not exactly the same, but the difference is not significant.

[0129] Example 2

[0130] The preparation method of PDI radical derivatives includes the following steps:

[0131] 1.2 g (5.07 mmol) of 3-bromo-1,8-naphthalenedimide, 0.056 g (10%) of 2,5-dichlorocyanobenzene, and 0.055 g (10%) of potassium tert-butoxide were dissolved in 20 mL of diethylene glycol dimethyl ether. The mixture was heated to 130°C and stirred for 12 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 5 in 91% yield. ESI-TOF: C 24 H8Br2N2O4, Mw=548.15. 1 H NMR (800 MHz, DMSO-d6) δ 8.58 (s, 2H), 8.46 (d, J = 8.4 Hz, 2H), 8.07 (d, J = 8.4 Hz, 1H), 8.03 (d, J = 8.5 Hz, 1H).

[0132] 1 g (1.82 mmol) of compound 5 was dissolved in 15 ml of DMF with 0.265 g (1.90 mmol) of 3-bromopropanol, 0.032 g (10%) of potassium carbonate, and 0.038 g (10%) of potassium iodide. The mixture was heated to 120°C and stirred for 20 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 6 in 65% yield. ESI-TOF: C 32 H 24 Br2N2O6, Mw=692.36. 1 H NMR (800 MHz, DMSO-d6) δ 8.49 (d, J = 8.6 Hz, 1H), 8.18 (s, 1H), 8.07 (d, J = 8.6 Hz, 1H), 8.01 (d, J = 8.6 Hz, 1H), 4.21 (t, J = 5.9 Hz, 1H), 3.56 (dt, J = 26.5, 5.8 Hz, 4H), 1.70 (ttd, J = 8.3, 5.8, 0.7 Hz, 2H), 1.58 (ttd, J = 8.4, 5.8, 0.7 Hz, 2H).

[0133] 1 g (1.45 mmol) of compound 6, 0.36 g (1.45 mmol) of 2,5-tert-butyl-3-boron dihydroxyphenol, 0.012 g (2%) of tetrakis(triphenylphosphine)palladium, and 0.036 g (mmol) of sodium carbonate were dissolved in 20 mL of toluene. The mixture was heated to 120°C and stirred for 24 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 7 in 88% yield. ESI-TOF: C 60 H 66 N₂O₈, Mw=942.48. 1 H NMR (800 MHz, DMSO-d6) δ 8.49 (d, J = 8.6 Hz,1H), 8.05 (dd, J = 25.4, 8.6 Hz, 0H), 8.01 (s, 1H), 7.37 (s, 1H), 6.84 (s,1H), 3.58 (t, J = 5.8 Hz, 1H), 3.54 (q, J = 5.8 Hz, 1H), 1.70 (ttd, J = 8.4,5.8, 0.7 Hz, 1H), 1.58 (ttd, J = 8.4, 5.8, 0.7 Hz, 1H), 1.44 (s, 9H).

[0134] 1 g (1.06 mmol) of compound 7, 0.015 g (10%) of cesium carbonate, 0.031 g (4%) of palladium acetate, and 0.034 g (6%) of 1,1'-binaphthyl-2,2'-bis(diphenylphosphine) were dissolved in 10 mL of tetrahydrofuran. The mixture was heated to 90°C and stirred for 12 h. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 8 in 84% yield. ESI-TOF: C 60 H 68 N4O6, Mw=941.23. 1H NMR (800 MHz, DMSO-d6) δ 8.49 (d, J = 8.6 Hz, 1H), 8.05 (dd, J =25.4, 8.6 Hz, 1H), 8.01 (s, 1H), 7.37 (s, 2H), 6.84 (s, 1H), 3.54 (dt, J =12.4, 6.2 Hz, 1H), 3.51 – 3.47 (m, 1H), 2.83 (tt, J = 6.5, 5.2 Hz, 2H), 2.09(t, J = 6.5 Hz, 2H), 1.71 – 1.65 (m, 2H), 1.58 (ttd, J = 7.8, 5.2, 0.8 Hz,2H), 1.44 (s, 18H).

[0135] Take 1 g (1.05 mmol) of compound 8, 0.056 g (10%) potassium hexacyanidide, and 0.010 g (20%) sodium hydroxide, dissolve them in 10 ml of diethyl ether, let stand at room temperature for 2 h, after the reaction is complete, extract the liquid phase mixture with dichloromethane and wash three times with saturated sodium chloride solution, take the organic phase and dry to obtain PDI radical derivative, yield 89%.

[0136] Example 3

[0137] The preparation method of PDI radical derivatives includes the following steps:

[0138] 1.2 g (4.7 mmol) of 5-(3-hydroxypropyl)-1H-benzisicoquinoline-1,3(2H)-dione, 0.056 g (10%) of 2,5-dichlorocyanobenzene, and 0.055 g (10%) of potassium tert-butoxide were dissolved in 20 mL of diethylene glycol dimethyl ether. The mixture was heated to 130°C and stirred for 12 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 9 in 86% yield. ESI-TOF: C 30 H 22 N₂O₆, Mw=506.15. 1H NMR (800 MHz, DMSO-d6) δ 8.44 (d, J = 8.5 Hz, 2H), 8.12 (s, 2H), 8.07 (dd, J = 9.5, 8.4 Hz, 2H), 4.22 (d, J = 11.3 Hz, 1H), 3.53 (q, J = 5.8 Hz, 4H), 2.82 (t, J = 8.2 Hz, 4H), 1.82 (tt, J = 8.2, 5.9Hz, 4H).

[0139] 1 g (1.98 mmol) of compound 9 and 0.036 g (10%) of 1,8-diazacyclic compound were dissolved in 20 mL of toluene and cooled to 0 °C. Then, 0.057 g (3%) of triphenylphosphine and 0.033 g (4.78 mmol) of ammonia were dissolved in 15 mL of pyridine and reacted at room temperature. After the reaction was complete, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 10 in 70% yield. ESI-TOF:C 30 H 24 N4O4, Mw=504.18. 1 H NMR (800 MHz, DMSO-d6) δ 8.44 (d, J = 8.5 Hz, 1H),8.12 (s, 1H), 8.07 (dd, J = 9.5, 8.5 Hz, 1H), 2.88 (d, J = 15.2 Hz, 1H), 2.82– 2.77 (m, 2H), 1.88 – 1.82 (m, 3H), 1.80 (q, J = 6.4 Hz, 1H).

[0140] 1 g (1.98 mmol) of compound 10 was dissolved in 10 mL of tetrahydrofuran with 0.301 g (1.06 mmol) of 4-bromo-2,6-di-tert-butylphenol and 0.036 g (10%) potassium hydroxide, and refluxed. After the reaction was complete, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 11 in 34% yield. ESI-TOF: C 44 H 44 N4O5, Mw=708.33. 1H NMR (800 MHz, DMSO-d6) δ 8.46 (dd, J = 26.1, 8.5 Hz, 1H), 8.15 (s, 1H), 8.12 (s, 1H), 8.08 (dd, J = 8.5, 0.8 Hz, 1H), 7.78 (s, 1H), 7.19 (s, 1H), 2.88 (t, J = 7.6 Hz, 2H), 2.82 – 2.77 (m, 1H), 1.88 – 1.82 (m, 3H), 1.80 (q, J = 6.4 Hz, 1H), 1.41 (s, 9H).

[0141] Take 1 g (1.05 mmol) of compound 11, 0.056 g (10%) of potassium hexacyanidide, and 0.010 g (20%) of sodium hydroxide, dissolve them in 10 ml of diethyl ether, let stand at room temperature for 2 h, after the reaction is complete, extract the liquid phase mixture with dichloromethane and wash three times with saturated sodium chloride solution, take the organic phase and dry to obtain PDI radical derivative, yield 93%.

[0142] Example 4

[0143] The preparation method of PDI radical derivatives includes the following steps:

[0144] 1.2 g (5.07 mmol) of 5-(3-hydroxypropyl)-1H-benzisicoquinoline-1,3(2H)-dione, 0.056 g (10%) of 2,5-dichlorocyanobenzene, and 0.055 g (10%) of potassium tert-butoxide were dissolved in 20 mL of diethylene glycol dimethyl ether. The mixture was heated to 130°C and stirred for 12 hours. After the reaction, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 12 in 91% yield. ESI-TOF: C 30 H 22 N₂O₆, Mw=506.15. 1 H NMR (800 MHz, DMSO-d6) δ 8.44 (d, J = 8.5 Hz, 2H), 8.12 (s, 2H), 8.07 (dd, J = 9.5, 8.4 Hz, 2H), 4.22 (d, J = 11.3 Hz, 1H), 3.53 (q, J = 5.8 Hz, 4H), 2.82 (t, J = 8.2 Hz, 4H), 1.82 (tt, J = 8.2, 5.9Hz, 4H).

[0145] 1 g (1.98 mmol) of compound 12 and 0.036 g (10%) of 1,8-diazacyclic compound were dissolved in 20 mL of toluene and cooled to 0 °C. Then, 0.057 g (3%) of triphenylphosphine and 0.033 g (4.78 mmol) of ammonia monohydrate were dissolved in 15 mL of pyridine and reacted at room temperature. After the reaction was complete, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 13 in 70% yield. ESI-TOF:C 30 H 24 N4O4, Mw=504.18. 1 H NMR (800 MHz, DMSO-d6) δ 8.44 (d, J = 8.5 Hz, 1H),8.12 (s, 1H), 8.07 (dd, J = 9.5, 8.5 Hz, 1H), 2.88 (d, J = 15.2 Hz, 1H), 2.82– 2.77 (m, 2H), 1.88 – 1.82 (m, 3H), 1.80 (q, J = 6.4 Hz, 1H).

[0146] 1 g (1.98 mmol) of compound 13 was dissolved in 10 mL of tetrahydrofuran with 0.301 g (1.06 mmol) of 4-bromo-2,6-di-tert-butylphenol and 0.036 g (10%) potassium hydroxide, and refluxed. After the reaction was complete, the liquid phase mixture was extracted with dichloromethane and washed three times with saturated sodium chloride solution. The organic phase was dried and separated by column chromatography with ethyl acetate and petroleum ether to give compound 14 in 37% yield. ESI-TOF: C 58 H 64 N4O6, Mw=912.48. 1 H NMR (800 MHz, DMSO-d6) δ 8.46 (dd, J = 26.1, 8.5 Hz, 1H), 8.15 (s, 1H), 8.12 (s, 1H), 8.08 (dd, J = 8.5, 0.8 Hz, 1H), 7.78 (s, 1H), 7.19 (s, 1H), 2.88 (t, J = 7.6 Hz, 2H), 2.82 – 2.77 (m, 1H), 1.88 – 1.82 (m, 3H), 1.80 (q, J = 6.4 Hz, 1H), 1.41 (s, 9H).

[0147] Take 1 g (1.05 mmol) of compound 14, 0.056 g (10%) of potassium hexacyanidide, and 0.010 g (20%) of sodium hydroxide, dissolve them in 10 ml of diethyl ether, let stand at room temperature for 2 h, after the reaction is complete, extract the liquid phase mixture with dichloromethane and wash three times with saturated sodium chloride solution, take the organic phase and dry to obtain PDI radical derivative, yield 91%.

[0148] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PDI radical derivative, characterized in that, The structural formula of the PDI radical derivative is: R1 and R4 are (CH2) n NH2, R2 are R3 is H, where n is 3, 4, 5 or 6.

2. The PDI radical derivative according to claim 1, characterized in that, The PDI radical derivative has the structural formula shown in formula (1): （1）。 3. A graphene spin field-effect transistor, characterized in that, include: silicon substrate; A gate dielectric layer disposed on one surface of the silicon substrate; Graphene point electrode pairs, wherein the graphene point electrode pairs are disposed on the surface of the gate dielectric layer away from the silicon substrate. A gold electrode and a magnetic electrode are provided, wherein the gold electrode and the magnetic electrode are located on the side of the gate dielectric layer away from the silicon substrate, and the gold electrode and the magnetic electrode are disposed opposite to each other. One electrode of the graphene dot electrode pair is electrically connected to the gold electrode, and the other electrode of the graphene dot electrode pair is electrically connected to the magnetic electrode. It also includes the PDI radical derivative as described in claim 1 or 2, wherein the PDI radical derivative is connected to two electrodes spaced apart from each other in the graphene point electrode pair.

4. The graphene spin field-effect transistor according to claim 3, characterized in that, The magnetic electrode includes at least one of iron, cobalt, and nickel; The gold electrode includes a chromium layer and a gold layer, wherein the chromium layer is disposed on the surface of the gate dielectric layer away from the silicon substrate, and the gold layer is disposed on the surface of the chromium layer away from the silicon substrate.

5. The graphene spin field-effect transistor according to claim 4, characterized in that, Also includes: A protective layer is disposed on the side of the graphene point electrode pair away from the silicon substrate and covers the gold electrode, the magnetic electrode, and the graphene point electrode pair.

6. A method for fabricating a graphene spin field-effect transistor as described in claim 3, characterized in that, include: S1. A gate dielectric layer is formed on one surface of a silicon substrate; S2. A gold electrode and a magnetic electrode are disposed on the side of the gate dielectric layer away from the silicon substrate, and the gold electrode and the magnetic electrode are disposed opposite to each other. S3. A graphene dot electrode pair is disposed on the surface of the gate dielectric layer away from the silicon substrate, and one electrode of the graphene dot electrode pair is electrically connected to the gold electrode, and the other electrode of the graphene dot electrode pair is electrically connected to the magnetic electrode to obtain a silicon wafer containing a graphene dot electrode pair. S4. Connect a PDI radical derivative between two electrodes spaced apart in the graphene point electrode pair to obtain the graphene spin field-effect transistor.

7. The method for fabricating a graphene spin field-effect transistor according to claim 6, characterized in that, The preparation method of the PDI radical derivative includes: 1,8-naphthalenediamine and 3-bromo-1,8-naphthalenediamine were dissolved in diethylene glycol dimethyl ether and reacted at 120-140°C under the co-catalysis of 2,5-dichlorocyanobenzene and potassium tert-butoxide to obtain the first compound. The first compound and 3-bromopropanol were dissolved in N,N-dimethylformamide and reacted at 110-130°C under the co-catalysis of potassium carbonate and potassium iodide to obtain the second compound. The second compound and 2,5-tert-butyl-3-boron dihydroxyphenol were dissolved in toluene and reacted at 110-130°C under the co-catalysis of tetra(triphenylphosphine)palladium and sodium carbonate to obtain the third compound. The third compound was dissolved in tetrahydrofuran and reacted at 80-100°C under the combined catalysis of cesium carbonate, palladium acetate and 1,1'-binaphthyl-2,2'-bisdiphenylphosphine to obtain the fourth compound; The fourth compound was dissolved in diethyl ether and reacted at room temperature under the combined catalysis of potassium hexacyanidide and sodium hydroxide to obtain the PDI radical derivative.

8. The method for fabricating a graphene spin field-effect transistor according to any one of claims 6 to 7, characterized in that, Step S4 includes: The silicon wafer containing the graphene point electrode pair was mixed with sufficient amounts of 1-(3-dimethylaminopropyl)-3-2-ethylcarbodiimide hydrochloride and PDI radical derivative to obtain a mixed system; The mixture was placed in a nitrogen atmosphere, and anhydrous pyridine was injected into the mixture, which was then allowed to stand. After cleaning and drying the silicon wafer containing the graphene point electrode pair, the graphene spin field-effect transistor is obtained. And / or, the preparation method further includes: A protective layer is provided on the side of the graphene point electrode pair away from the silicon substrate, so that the protective layer covers the gold electrode, the magnetic electrode and the graphene point electrode pair.

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