Photosensitive molecular junction with photoelectric response rectification function and preparation method and application thereof

Abstract

The present invention discloses a photosensitive molecular junction with a photoelectric response rectification function, and a preparation method and application thereof, which belong to the technical field of molecular electronics. The preparation method of the photosensitive molecular junction with a photoelectric response rectification function of the present invention comprises the following steps: preparing a gold substrate electrode layer by vacuum evaporation; performing molecular film self-assembly on the surface of the gold substrate electrode layer to obtain the photosensitive molecular junction with a photoelectric response rectification function. Since the rhodium acetate dimer and the organic ligand selected in the present invention can easily form a stable complex [Rh2(μ‑O2CCR3)4L2], the present invention utilizes this characteristic and realizes the precise preparation of a supramolecular structure containing a photosensitive element on the gold substrate electrode layer through a step-by-step construction strategy. The present invention designs a photosensitive self-assembled molecular junction, which has a high sensitivity to ultraviolet light photoelectric response and can achieve a variety of rectification performances.

Description

Technical Field

[0001] The invention relates to the technical field of molecular electronics, in particular to a photosensitive molecular junction with a photoelectric response rectification function and a preparation method and application thereof. Background Art

[0002] With the rapid development of microelectronics technology, the trend of miniaturization and diversification of devices is becoming increasingly obvious. The challenge of constantly pursuing smaller sizes based on silicon-based microelectronic devices has opened up a new path for molecular electronics. The current transmission capacity of molecular electronic devices is closely related to their chemical structure. By adjusting the chemical composition of supramolecules, the electron transport properties of molecular junctions can be changed to achieve diversified device functions. Due to the wide variety of molecules, countless different combinations can be formed, and their structures are highly adjustable, which lays the foundation for the development of molecular electronic devices with specific functions. By integrating single molecules or composite molecules into circuits, a variety of molecular electronic components such as molecular wires and molecular switches can be created. Molecular rectifiers, as key components in the field of molecular electronic devices, enable electrons to choose a preferred direction for transmission. At present, there are few studies on molecular rectifiers that can achieve the photoelectric effect. Such devices can convert optical signals into electrical signals, thereby regulating the rectification effect. Therefore, in-depth exploration of the application of molecular electronics in the field of photoelectric rectifiers has a far-reaching impact on the development of the next generation of high-performance microelectronic devices. Summary of the invention

[0003] The purpose of the present invention is to provide a photosensitive molecular junction with a photoelectric response rectification function and a preparation method and application thereof to solve the above-mentioned problems in the background technology. Since the rhodium acetate dimer selected by the present invention can easily form a stable complex [Rh2(μ-O2CCR3)4L2] with an organic ligand, the present invention utilizes this characteristic and realizes the precise preparation of a supramolecular structure containing a photosensitive element on a gold substrate electrode layer through a step-by-step construction strategy. The present invention designs a photosensitive self-assembled molecular junction, which has a highly sensitive photoelectric response capability to ultraviolet light and can achieve a variety of rectification performances.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] One of the technical solutions of the present invention is to provide a photosensitive molecular junction with a photoelectric response rectification function, wherein the photosensitive molecular junction has a structure shown in the following formula (I):

[0006]

[0007] Formula (I);

[0008] Wherein, X of -CX3 is H, F or CH3, Y of -CY3 is H, F or CH3, and X and Y are not H, F or CH3 at the same time;

[0009] The photosensitive molecular junction comprises a gold substrate electrode layer and a self-assembled molecular film layer, wherein the self-assembled molecular film layer is located on the gold substrate electrode layer.

[0010] The present invention uses two identical rhodium acetate dimer complex structures as subunits (the first two rhodium acetate dimer complex structures are one subunit, and the last two rhodium acetate dimer complex structures are another subunit). Due to the asymmetry between the two subunits, the charge transfer is asymmetric, so the photosensitive molecular junction prepared by the present invention exhibits rectification characteristics.

[0011] Preferably, R1 and R2 are pyridyl bidentate organic ligands; R3 and R4 are photosensitive molecules;

[0012] The self-assembled molecular film layer is composed of 4-mercaptopyridine, rhodium acetate dimer complex [Rh2(O2CCR3)4], R1, rhodium acetate dimer complex [Rh2(O2CCR3)4], R2, rhodium acetate dimer complex [Rh2(O2CCR3)4], R3, rhodium acetate dimer complex [Rh2(O2CCR3)4] and R4 from bottom to top on the surface of the gold substrate electrode layer.

[0013] More preferably, the pyridyl bidentate organic ligand is pyridylethane, pyridylethylene, pyrazine, pyridylporphyrin or pyridylanthracene; and the photosensitive molecule is pyridylanthracene or pyridylporphyrin.

[0014] The second technical solution of the present invention is to provide a method for preparing the above-mentioned photosensitive molecular junction with photoelectric response rectification function, comprising the following steps:

[0015] The gold substrate electrode layer was prepared by vacuum evaporation;

[0016] The molecular film layer is self-assembled on the surface of the gold substrate electrode layer to obtain the photosensitive molecular junction with the photoelectric response rectification function.

[0017] Preferably, the vacuum evaporation method is as follows: fix the substrate on the evaporation base of a high vacuum resistance evaporation coating machine, set the evaporation rate to 3Å / s, and -6 The gold substrate electrode layer is obtained by evaporating the gold substrate electrode layer at a temperature of 10 to 300 nm.

[0018] Preferably, the molecular film layer self-assembles as follows: the gold substrate electrode layer is immersed in the following immersion solutions in sequence: 4-mercaptopyridine immersion solution, rhodium acetate dimer complex immersion solution, pyridine bidentate organic ligand immersion solution, rhodium acetate dimer complex immersion solution, pyridine bidentate organic ligand immersion solution, rhodium acetate dimer complex immersion solution, photosensitive molecule immersion solution, rhodium acetate dimer complex immersion solution and photosensitive molecule immersion solution.

[0019] The reason why the present invention needs to cycle the soaking process of the rhodium acetate dimer complex soaking solution and the pyridyl bidentate organic ligand soaking solution twice after soaking in the 4-mercaptopyridine soaking solution is that, after actual research, the present invention found that when only soaked once, the rectification change of the product under the switch light is not large (Comparative Example 2), while the product prepared according to the preparation process designed in accordance with the present invention can greatly improve the rectification change.

[0020] More preferably, the concentration of 4-mercaptopyridine in the 4-mercaptopyridine soaking solution is 0.01-5 mmol / L; the concentration of rhodium acetate dimer complex in the rhodium acetate dimer complex soaking solution is 0.01-5 mmol / L; the concentration of pyridyl bidentate organic ligand in the pyridyl bidentate organic ligand soaking solution is 0.01-5 mmol / L; the concentration of photosensitive molecule in the photosensitive molecule soaking solution is 0.01-5 mmol / L;

[0021] When the soaking liquid is a 4-mercaptopyridine soaking liquid, a pyridyl bidentate organic ligand soaking liquid and a photosensitive molecule soaking liquid, the soaking temperature is 10-30°C and the time is 0.02-1h; when the soaking liquid is a rhodium acetate dimer complex soaking liquid, the soaking temperature is <0°C.

[0022] Preferably, the solvent in the soaking liquid is ethanol.

[0023] The third technical solution of the present invention is to provide a molecular rectifier, using the self-assembled molecular film layer of the photosensitive molecular junction with the photoelectric response rectification function as the molecular layer of the molecular rectifier.

[0024] Preferably, the molecular rectifier is prepared by using the above-mentioned photosensitive molecular junction with photoelectric response rectification function and conductive atomic force probe as raw materials, using the gold substrate electrode layers of the conductive atomic force probe and the photosensitive molecular junction as metal electrodes respectively, and using the self-assembled molecular film layer of the photosensitive molecular junction as the middle molecular layer to form a metal / molecule / metal junction.

[0025] The fourth technical solution of the present invention is to provide an application of the above-mentioned photosensitive molecular junction with photoelectric response rectification function or the above-mentioned molecular rectifier in the field of molecular photoelectric rectification.

[0026] In the present invention, taking into account the axial coordination characteristics of the molecule, a strongly Lewis-acidic rhodium acetate dimer, a pyridine-based bidentate organic ligand and a photosensitive molecule are selected as reactants, and ethanol is used as a medium. By adjusting parameters such as the solution molar concentration and the reaction duration, a molecular film is formed on a gold substrate using a hierarchical self-assembly technique, thereby obtaining a metal-molecule junction with an adjustable chemical structure.

[0027] The beneficial technical effects of the present invention are as follows:

[0028] Since the rhodium acetate dimer selected in the present invention can easily form a stable complex [Rh2(μ-O2CCR3)4L2] with an organic ligand, the present invention utilizes this property and realizes the precise preparation of a supramolecular structure containing a photosensitive element on a gold substrate electrode layer through a step-by-step construction strategy. The present invention designs a photosensitive self-assembled molecular junction, which has a highly sensitive photoelectric response capability to ultraviolet light and can achieve a variety of rectification performances.

[0029] The present invention successfully integrates photosensitive molecules into the main chain of oligomers based on rhodium acetate dimer and pyridine, and forms a photosensitivity supramolecular structure on a gold electrode through a step-by-step construction technique. Experimental data show that the synthesized photosensitive molecular junction exhibits excellent photoelectric rectification performance; specifically, under the action of a bias voltage of ±1V, the rectification ratio of the product is about 3.1:1 under the condition of no ultraviolet irradiation, and under 365nm ultraviolet irradiation, the product rectification ratio is significantly increased to 7.1:1, and this rectification effect can be stably switched within 10 cycles. The research results show that the supramolecular with a special chemical structure designed by the present invention exhibits a light-responsive rectification effect and has the potential to be applied to molecular photodiodes.

[0030] The present invention connects a rectifying molecular junction with a conductive atomic force microscope probe to construct a metal / molecule / metal junction, and then studies its photoelectric rectification properties. The molecular junction designed by the present invention has photoelectric response and rectification functions. Before being applied in the field of molecular photoelectric rectification, the molecular junction needs to be combined with a conductive atomic force microscope probe to construct a metal / molecule / metal junction.

[0031] The preparation method of the invention is simple and has a short production cycle, and can grow a self-assembled molecular film with high stability, thus having good application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 The differential voltammetric curves of the photosensitive molecular junction and the oligomers therein in Example 1. Among them, (a) is the differential voltammetric curve of the photosensitive molecular junction, (b) is the differential voltammetric curve of rhodium acetate dimer and pyrazine oligomer, and (c) is the differential voltammetric curve of rhodium trifluoroacetate dimer and pyridyl anthracene oligomer.

[0034] Figure 2 The characteristic curves of the current (I)-voltage (V) mean values ​​of the photosensitive molecular junction in Example 1 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 20 mW / cm 2 Ultraviolet light irradiation.

[0035] Figure 3 The current (I)-voltage (V) characteristic curves of the photosensitive molecular junction in Example 1 with and without ultraviolet irradiation. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0036] Figure 4 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 1 with and without ultraviolet irradiation are shown in Figure 1. (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0037] Figure 5 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 2 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0038] Figure 6 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 3 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0039] Figure 7 The following are the test results of the cycle performance of the product of Example 1. DETAILED DESCRIPTION

[0040] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0041] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0042] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0043] The words “include,” “including,” “have,” “contain,” etc. used in the present invention are open-ended terms, meaning including but not limited to.

[0044] The "room temperature" in the present invention is 10-30°C unless otherwise specified.

[0045] The preparation method of the gold substrate electrode layer used in the following embodiments and comparative examples of the present invention is as follows: a newly cut mica sheet is fixed on the evaporation base of a high vacuum resistance evaporation coating machine, the evaporation rate is set to 3Å / s, and the temperature is 2.25×10 -6 The gold substrate electrode layer was obtained by evaporation at 0.0547°C to a thickness of 150 nm.

[0046] All raw materials used in the following examples and comparative examples of the present invention are commercially available products.

[0047] Example 1

[0048] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0049] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene is a photosensitive molecule, and pyrazine and pyridyl ethane are pyridyl bidentate organic ligands.

[0050] At room temperature, the gold substrate electrode was immersed in a 0.5 mmol / L 4-mercaptopyridine ethanol solution for 1 h to prepare 4-mercaptopyridine SAMs. The SAMs were transferred into a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10°C for 1h; then soaked in a 1 mmol / L pyrazine ethanol solution at room temperature for 15min, a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution at -10°C for 10min, a 1 mmol / L pyridylethane ethanol solution at room temperature for 10min, a 1 mmol / L rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 10min, a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10min, a 1 mmol / L rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 10min, and a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10min to obtain the target product, a photosensitive molecular junction. After each soaking, rinse with ethanol and blow dry with N2.

[0051] The structure of the self-assembled molecular film layer on the photosensitive molecular junction of this embodiment was characterized using Chenhua electrochemical workstation CH1760E. The test results are shown in Figure 1 shown.

[0052] Figure 1 The differential voltammetric curves of the photosensitive molecular junction and the oligomers therein in Example 1. Among them, (a) is the differential voltammetric curve of the photosensitive molecular junction, (b) is the differential voltammetric curve of rhodium acetate dimer and pyrazine oligomer, and (c) is the differential voltammetric curve of rhodium trifluoroacetate dimer and pyridyl anthracene oligomer.

[0053] Depend on Figure 1 It can be seen that the peak position of the photosensitive molecular junction is between the rhodium acetate dimer and the pyrazine oligomer ( Figure 1 (b)) and rhodium trifluoroacetate dimer and pyridyl anthracene oligomer ( Figure 1 The area between (c) in the figure proves that the self-assembled molecular film was successfully grown on the gold substrate surface in the expected manner.

[0054] Example 2 (Compared with Example 1, only the soaking time is modified)

[0055] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0056] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene is a photosensitive molecule, and pyrazine and pyridyl ethane are pyridyl bidentate organic ligands.

[0057] At room temperature, the gold substrate electrode was immersed in a 0.5 mmol / L 4-mercaptopyridine ethanol solution for 2 h to prepare 4-mercaptopyridine SAMs. The SAMs were transferred to a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10°C for 2h; then, they were soaked in a 1 mmol / L pyrazine ethanol solution at room temperature for 30min, in a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution at -10°C for 20min, in a 1 mmol / L pyridylethane ethanol solution at room temperature for 20min, in a 1 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 20min, in a 1 mmol / L pyridylanthracene ethanol solution at room temperature for 20min, in a 1 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 20min, and in a 1 mmol / L pyridylanthracene ethanol solution at room temperature for 10min. min, and the target product, the photosensitive molecular junction, was obtained. After each immersion, it was necessary to rinse with ethanol and blow dry with N2.

[0058] Example 3 (Compared with Example 1, only the concentration of the soaking liquid is modified)

[0059] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0060] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene is a photosensitive molecule, and pyrazine and pyridyl ethane are pyridyl bidentate organic ligands.

[0061] At room temperature, the gold substrate electrode was immersed in 1 mmol / L 4-mercaptopyridine ethanol solution for 1 h to prepare 4-mercaptopyridine SAMs. The SAMs were transferred to a 2 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10°C for 1 hour; then soaked in a 2 mmol / L pyrazine ethanol solution at room temperature for 15 minutes, in a 2 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution at -10°C for 10 minutes, in a 2 mmol / L pyridylethane ethanol solution at room temperature for 10 minutes, in a 2 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 10 minutes, in a 2 mmol / L pyridylanthracene ethanol solution at room temperature for 10 minutes, in a 2 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 10 minutes, and in a 2 mmol / L pyridylanthracene ethanol solution at room temperature for 10 minutes to obtain the target product, a photosensitive molecular junction. After each soaking, rinse with ethanol and blow dry with N2.

[0062] Example 4 (only the pyrazine in Example 1 is modified to pyridyl anthracene)

[0063] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0064] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene is a photosensitive molecule, and pyridyl anthracene and pyridyl ethane are pyridyl bidentate organic ligands.

[0065] At room temperature, the gold substrate electrode was immersed in a 0.5 mmol / L 4-mercaptopyridine ethanol solution for 1 h to prepare 4-mercaptopyridine SAMs. The SAMs were transferred to a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10°C for 1 h; then, they were sequentially soaked in a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 15 min, in a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution at -10°C for 10 min, in a 1 mmol / L pyridyl ethane ethanol solution at room temperature for 10 min, in a 1 mmol / L rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] ethanol solution at -10°C for 10 min, in a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10 min, and in a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10 min. min, and the target product, the photosensitive molecular junction, was obtained. After each immersion, it was necessary to rinse with ethanol and blow dry with N2.

[0066] The photosensitive molecular junctions in Examples 1-4 have the structure shown in the following formula (I):

[0067]

[0068] Formula (I).

[0069] Comparative Example 1

[0070] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0071] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene (R3) is a photosensitive molecule, and pyrazine (R1) and pyridyl ethane (R2) are pyridyl bidentate organic ligands.

[0072] At room temperature, the gold substrate electrode was placed in a 0.5 mmol / L 4-mercaptopyridine ethanol solution and soaked for 1 hour to prepare 4-mercaptopyridine SAMs. The SAMs were transferred to a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10℃ for 1 hour; then soaked in a 1 mmol / L pyrazine ethanol solution at room temperature for 15 minutes, a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution at -10℃ for 10 minutes, a 1 mmol / L pyridylethane ethanol solution at room temperature for 10 minutes, a 1 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10℃ for 10 minutes, and a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10 minutes to obtain the target product photosensitive molecular junction. After each soaking, it is necessary to rinse with ethanol and blow dry with N2.

[0073] The photosensitive molecular junction in Comparative Example 1 has a structure shown in the following formula (II):

[0074]

[0075] Formula (II).

[0076] Comparative Example 2

[0077] The only difference from Example 1 is that the rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] is replaced by an equal concentration of rhodium acetate dimer [Rh2(O2CCH3)4].

[0078] The photosensitive molecular junction in Comparative Example 2 has a structure shown in the following formula (III):

[0079]

[0080] Formula (III).

[0081] Comparative Example 3

[0082] A method for preparing a photosensitive molecular junction with a photoelectric response rectification function, the steps are as follows:

[0083] Rhodium acetate dimer [Rh2(O2CCH3)4] and rhodium trifluoroacetate dimer [Rh2(O2CCF3)4] are Lewis acids, pyridyl anthracene (R2) is a photosensitizing molecule, and pyridyl ethane (R1) is a pyridyl bidentate organic ligand.

[0084] At room temperature, the gold substrate electrode was placed in a 0.5 mmol / L 4-mercaptopyridine ethanol solution and soaked for 1 hour to prepare 4-mercaptopyridine SAMs. The SAMs were transferred to a 1 mmol / L rhodium acetate dimer [Rh2(O2CCH3)4] ethanol solution and soaked at -10℃ for 1 hour; then soaked in a 1 mmol / L pyridylethane ethanol solution at room temperature for 10 minutes, soaked in a 1 mmol / L trifluoroacetate rhodium dimer [Rh2(O2CCF3)4] ethanol solution at -10℃ for 10 minutes, and soaked in a 1 mmol / L pyridyl anthracene ethanol solution at room temperature for 10 minutes to obtain the target product photosensitive molecular junction. After each soaking, it is necessary to rinse with ethanol and blow dry with N2.

[0085] The photosensitive molecular junction in Comparative Example 3 has a structure shown in the following formula (IV):

[0086]

[0087] Formula (IV).

[0088] Effect verification

[0089] According to the synthesis technology designed by the present invention, a photosensitive molecular junction with photoelectric response and rectification function was successfully manufactured, and its performance was tested by a Bruker Multimode 8 atomic force microscope. The test process includes: contacting the prepared photosensitive molecular junction with a conductive atomic force probe to form a metal / molecule / metal junction, then applying a bias voltage, and measuring the current flowing through the sample through a current amplifier, and testing the characteristic curves of current (I) and voltage (V) with and without ultraviolet light (365nm) irradiation. The relevant data are recorded in Figure 2-6 middle.

[0090] Figure 2 The characteristic curves of the current (I)-voltage (V) mean values ​​of the photosensitive molecular junction in Example 1 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 20 mW / cm 2 Ultraviolet light irradiation.

[0091] Figure 3 The current (I)-voltage (V) characteristic curves of the photosensitive molecular junction in Example 1 with and without ultraviolet irradiation. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0092] Figure 4 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 1 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm2 Ultraviolet light irradiation.

[0093] Figure 5 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 2 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0094] Figure 6 The characteristic curves of the current (I)-voltage (V) average values ​​of the photosensitive molecular junction in comparative example 3 with and without ultraviolet irradiation are compared. Among them, (a) is without ultraviolet irradiation, and (b) is 6 mW / cm 2 Ultraviolet light irradiation.

[0095] Depend on Figure 2-3 It can be seen that under UV irradiation of different optical powers, the rectification ratio of Example 1 is significantly improved to about 7.1: 1, while under no UV irradiation, the rectification ratio is about 3: 1. These observed molecular junction properties indicate that it has great application potential in the field of photosensitive molecular electronic devices.

[0096] Depend on Figure 4 It can be seen that the rectification ratio of Comparative Example 1 is only slightly increased from 2.4:1 without ultraviolet light irradiation to 2.8:1 with ultraviolet light irradiation, and the change in rectification ratio is small, which is not enough to serve as a rectifying molecular junction with photoelectric response function.

[0097] Depend on Figure 5 It can be seen that the rectification ratio of Comparative Example 2 is less than 2 under the irradiation of ultraviolet light and without the irradiation of ultraviolet light, which is not enough to serve as a rectifying molecular junction with photoelectric response function.

[0098] Depend on Figure 6 It can be seen that under the asymmetric metal skeleton of comparative example 3, the molecular junction formed by bridging the pyridine-based bidentate organic ligand and the photosensitive molecule is shorter than that in example 1. In the presence or absence of ultraviolet light, the rectification ratio is less than 3, which is insufficient to serve as a rectifying molecular junction with photoelectric response function.

[0099] The product of Example 1 was subjected to a 10-cycle cycle performance test; the specific test method is: continuous switching lamp current (I) voltage (V) characteristic curve cycle test is performed using a Bruker Multimode 8 atomic force microscope, and the rectification ratio is calculated each time the lamp is switched on and off. The test results are shown in FIG. Figure 7 shown.

[0100] Figure 7 The following are the test results of the cycle performance of the product of Example 1.

[0101] Depend on Figure 7It can be seen that the rectifying effect of the product prepared by the present invention can be stably switched within 10 cycles.

[0102] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A photosensitive molecular junction with photoelectric response rectification function, characterized in that: The photosensitive molecular junction has a structure shown in the following formula (I): Formula (I); Wherein, X of -CX3 is H, F or CH3, Y of -CY3 is H, F or CH3, and X and Y are not H, F or CH3 at the same time; The photosensitive molecular junction comprises a gold substrate electrode layer and a self-assembled molecular film layer, wherein the self-assembled molecular film layer is located on the gold substrate electrode layer; The R1 and R2 are pyridyl bidentate organic ligands; R3 and R4 are photosensitive molecules.

2. The photosensitive molecular junction with photoelectric response rectification function according to claim 1, characterized in that: The pyridyl bidentate organic ligand is pyridylethane, pyridylethylene, pyrazine, pyridylporphyrin or pyridylanthracene; and the photosensitive molecule is pyridylanthracene or pyridylporphyrin.

3. A method for preparing a photosensitive molecular junction having a photoelectric response rectification function according to any one of claims 1 to 2, characterized in that: The following steps are involved: The gold substrate electrode layer was prepared by vacuum evaporation; The molecular film layer is self-assembled on the surface of the gold substrate electrode layer to obtain the photosensitive molecular junction with the photoelectric response rectification function.

4. The preparation method according to claim 3, characterized in that: The vacuum evaporation method is as follows: the substrate is fixed on the evaporation base of the high vacuum resistance evaporation coating machine, the evaporation rate is set to 3Å / s, and the -6 The gold substrate electrode layer is obtained by evaporating the gold substrate electrode layer at a temperature of 10 to 300 nm.

5. A molecular rectifier, characterized in that: The self-assembled molecular film layer of the photosensitive molecular junction with photoelectric response rectification function as described in any one of claims 1 to 2 is used as the molecular layer of the molecular rectifier.

6. Use of the photosensitive molecular junction with photoelectric response rectification function as claimed in any one of claims 1 to 2 or the molecular rectifier as claimed in claim 5 in the field of molecular photoelectric rectification.

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