Organic micro-nano crystals with longitudinally stacked heterostructures and their preparation and application

Abstract

The present invention discloses an organic micro-nano crystal with a longitudinally stacked heterostructure and its preparation and application. The core of the preparation method lies in finely controlling the ratio between the core layer material and the shell layer material, and on this basis constructing a semi-wrapped core / shell structure with obvious grooves. Furthermore, when the core layer material is further added to the structure, the core layer material will grow directionally at the groove, and the superposition site in the vertical direction is controllable, forming vertically stacked organic micro-nano crystals in the groove to obtain organic micro-nano crystals with a longitudinally stacked heterostructure. The organic micro-nano crystals with a longitudinally stacked heterostructure provided by the present invention can be applied to fields such as optoelectronics and catalysis, and can also be applied to optical logic gates, and photonic barcodes are constructed based on anisotropic optical properties, which has broad application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of organic micro-nano materials, and in particular to organic micro-nano crystals with a longitudinally stacked heterogeneous structure and preparation and application thereof. Background Art

[0002] Organic micro- and nanocrystalline materials inherit many of the advantages of bulk single crystal materials, such as low defects, high stability, and regular morphology. They have become the most ideal and active structural units for the development of next-generation highly integrated, high-performance electronic and photonic devices. They are also the key to building ultra-efficient photodetection and novel nanoscale optoelectronic devices. The ability to precisely synthesize organic low-dimensional multi-level micro- and nanocrystalline structures with high spatial and angular precision is crucial to meeting the growing practical needs of nanoscience and nanotechnology. The realization of organic integrated optoelectronic circuits requires organic low-dimensional crystalline heterostructures with specific geometric features to obtain photonic properties that cannot be achieved with a single structure, thereby meeting the growing demand for multifunctionality and miniaturization in high-performance organic photonic components.

[0003] Currently, some common methods for preparing organic low-dimensional hierarchical crystalline heterostructures include top-down micromanipulation techniques, programmable laser beam scanning techniques, chemical / physical vapor deposition techniques, as well as bottom-up multi-level self-assembly techniques, doping techniques, step-by-step seeding and growth techniques, and photochromic techniques. For example, when preparing organic low-dimensional crystalline heterostructures with specific geometric features, a probe can be manipulated under a microscope to apply specific external force patterns to different crystals, causing the crystals to respond mechanically, thereby obtaining organic low-dimensional crystalline heterostructures with distinct shared interfaces. Another example is multi-level self-assembly techniques that precisely control the strength of multiple non-covalent interactions to control the nucleation order of molecular crystal structures, allowing molecules with stronger non-covalent interactions to preferentially nucleate and crystallize in solution. Subsequently, molecules with weaker non-covalent interactions grow epitaxially on the surface of the already crystallized crystals based on lattice matching and surface-interface energy balance, ultimately forming a complex structure with multiple hierarchical units.

[0004] However, it is a challenge to precisely and controllably stack organic nanowires in the vertical direction while ensuring the integrity of the single crystallinity of the crystal. For example, in the commonly used top-down micromanipulation method, the external stress brought by the probe often causes disturbances in the low-ductility, high-crystallinity crystal structure, thereby reducing the single crystallinity integrity of the prepared crystal. At the same time, due to the simple physical contact, this method also leads to increased structural instability and a significant increase in optical loss. In addition, in the process of preparing multi-level heterostructures using solution self-assembly, the epitaxial growth sites in the random nucleation process are difficult to control, and the stacking direction is mainly limited to the horizontal direction, which greatly limits the utilization of vertical space and is not conducive to the development of spatial integration and three-dimensional optoelectronic information processing and communication technology. Summary of the Invention

[0005] In order to solve the technical problems that the existing technology is difficult to achieve vertical stacking of organic low-dimensional crystalline structures, difficult to prepare organic crystalline heterogeneous micro / nanostructures with specific epitaxial growth sites, difficult to manipulate the lattice mismatch of different material combinations during the nucleation process, difficult to capture metastable substructures of organic low-dimensional crystalline heterogeneous structures, and difficult to accurately control the size of different regions in organic low-dimensional crystalline heterogeneous structures, the purpose of the present invention is to provide an organic micro-nano crystal with a longitudinally stacked heterogeneous structure and its preparation and application, which can obtain organic low-dimensional crystalline heterogeneous micro / nanostructures with clear epitaxial growth sites in the vertical direction. At the same time, the method can also achieve precise control of the relative sizes between different materials in the heterogeneous structure.

[0006] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0007] A first aspect of the present invention provides a method for preparing organic micro-nano crystals having a longitudinally stacked heterostructure, comprising the following steps:

[0008] (1) dissolving the acceptor molecule A and the donor molecule B in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material; dissolving the acceptor molecule A and the donor molecule C in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material; or

[0009] The acceptor molecule A and the donor molecule B are dissolved in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material; the acceptor molecule D and the donor molecule B are dissolved in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material;

[0010] (2) mixing the organic micro-nano crystal stock solution of the core layer material in good organic solvent and a poor organic solvent to obtain an organic micro-nano crystal stock solution of the core layer material; mixing the organic micro-nano crystal stock solution of the shell layer material in good organic solvent and a poor organic solvent to obtain an organic micro-nano crystal stock solution of the shell material;

[0011] (3) dripping the organic micro-nano crystal stock solution of the core layer material described in step (2) onto the substrate, and obtaining organic micro-nano crystals of the core layer material after crystallization; dripping the organic micro-nano crystal stock solution of the shell layer material described in step (2) onto the organic micro-nano crystals of the core layer material, and obtaining organic micro-nano crystals having a semi-encapsulated core / shell structure after crystallization;

[0012] (4) adding the organic micro-nano crystal stock solution of the core layer material described in step (2) onto the organic micro-nano crystal with the semi-encapsulated core / shell structure described in step (3), and obtaining the organic micro-nano crystal with a longitudinally stacked heterogeneous structure after the solvent is completely evaporated.

[0013] This invention aims to propose a method for preparing organic low-dimensional crystalline materials by precisely stacking them in the vertical direction. By regulating the molar ratio of the core-to-shell material in the core / shell structure and cleverly exploiting the fact that low-concentration shell material cannot completely encapsulate the core material, this method constructs a semi-encapsulated core / shell crystalline heterostructure with grooves in the vertical direction due to the incomplete shell coverage. Subsequently, the core material is added to this structure, and the core material preferentially undergoes epitaxial growth in the grooves, thus achieving the directional stacking of micro- / nanocrystals in the vertical direction.

[0014] Furthermore, in step (1), the acceptor molecules (referring to acceptor molecules A and acceptor molecules D) are electron-deficient acceptor molecules, and the donor molecules (referring to donor molecules B and donor molecules C) are electron-rich polycyclic and heterocyclic aromatic semiconductor donor molecules.

[0015] Furthermore, the acceptor molecule and the donor molecule are dissolved in a good organic solvent and subjected to ultrasonic treatment to obtain a stock solution of a one-dimensional rod-shaped organic charge transfer cocrystal.

[0016] Furthermore, in step (1), the receptor molecule A and the receptor molecule D are independently selected from tetrafluoroterephthalonitrile (TFP), 2,4,6-trimethylbenzene-1,3,5-tricarboxylic acid nitrile (TBT), benzene-1,2,4,5-tetracarbonitrile (TCNB), 7,7,8,8-tetracyanoquinodimethane (TCNQ) or phthalic anhydride (Pa).

[0017] Furthermore, the structural formula of the receptor molecule is as follows:

[0018]

[0019] Furthermore, in step (1), the donor molecule B and the donor molecule C are independently selected from anthracene (An), pyrene (Py), benzo[c]phenanthrene (BHT), triphenylene (TP), perylene (Per), dithienopyrrole (HDP), benzodithiophene (BDP), tetrathiophene (BBTT), carbazole (CZ) or acridine (AD).

[0020] Furthermore, in step (1), the structural formula of the donor molecule is as follows:

[0021]

[0022] Furthermore, in step (1), the molar ratio of the acceptor molecule A to the donor molecule B is (1-5):1, the molar ratio of the acceptor molecule A to the donor molecule C is (1-5):1, and the molar ratio of the acceptor molecule D to the donor molecule B is (1-5):1.

[0023] Furthermore, in step (1), the concentration of the acceptor molecule A in the good organic solvent stock solution of the core layer material's organic micro-nano crystals is 2-20 mmol / L; the concentration of the donor molecule B in the good organic solvent stock solution of the core layer material's organic micro-nano crystals is 2-20 mmol / L.

[0024] Furthermore, in step (1), the concentration of the acceptor molecule A in the good organic solvent stock solution of the organic micro-nano crystals of the shell material is 2 to 20 mmol / L; the concentration of the donor molecule C in the good organic solvent stock solution of the organic micro-nano crystals of the shell material is 2 to 20 mmol / L.

[0025] Furthermore, in step (1), the concentration of the acceptor molecule D in the good organic solvent stock solution of the organic micro-nano crystals of the shell material is 2-20 mmol / L; the concentration of the donor molecule B in the good organic solvent stock solution of the organic micro-nano crystals of the shell material is 2-20 mmol / L.

[0026] Furthermore, in step (1), the good organic solvent is selected from one of dichloromethane (DCM), chloroform, acetonitrile, acetone, tetrahydrofuran, chlorobenzene and toluene.

[0027] Furthermore, in step (2), the poor organic solvent is selected from one of methanol, ethanol, isopropanol, n-hexane and cyclohexane.

[0028] Furthermore, in step (2), the volume ratio of the organic micro-nano crystal good organic solvent stock solution and the poor organic solvent of the core layer material is 1:(1-5); the volume ratio of the organic micro-nano crystal good organic solvent stock solution and the poor organic solvent of the shell layer material is 1:(1-5).

[0029] Furthermore, in step (3), the volume ratio of the organic micro-nano crystal stock solution of the core layer material to the organic micro-nano crystal stock solution of the shell layer material is 1:(1-19).

[0030] In a specific embodiment, in step (3), the crystallization time of the organic micro-nano crystals of the core layer material and the organic micro-nano crystals with a semi-enclosed core / shell structure can both be 30 to 300 seconds.

[0031] Furthermore, in step (3), after the organic micro-nano crystal stock solution of the core layer material described in step (2) is dripped onto the substrate, the organic micro-nano crystal stock solution of the shell layer material described in step (2) is dripped onto the organic micro-nano crystals of the core layer material before the solvent is completely evaporated.

[0032] Furthermore, in step (3), after the organic micro-nano crystal stock solution of the shell layer material described in step (2) is added dropwise onto the organic micro-nano crystal of the core layer material, the solvent is completely evaporated to obtain complete organic micro-nano crystals with a semi-encapsulated core / shell structure.

[0033] Furthermore, in step (4), the organic micro-nano crystal stock solution of the core layer material described in step (2) is added dropwise onto the organic micro-nano crystals with a semi-wrapped core / shell structure from which the solvent has not been completely evaporated.

[0034] Furthermore, in step (4), the volume ratio of the organic micro-nano crystal stock solution of the core layer material to the organic micro-nano crystal stock solution of the core layer material described in step (3) is 1:(1-4).

[0035] Furthermore, in step (4), the amount of the organic micro-nano crystal stock solution of the core layer material added can be 100 to 2000 μL.

[0036] Furthermore, because the organic micro-nano crystal good organic solvent stock solution described in step (1) is based on the same acceptor molecule or donor molecule, the present invention fully utilizes the characteristic that the molecular orientation and lattice of the same material on the same plane are completely consistent, so that after the organic micro-nano crystal stock solution of the core layer material is added dropwise to the organic micro-nano crystal with a semi-encapsulated core / shell structure in step (4), a significant effect of lattice matching of up to 100% is achieved during the vertical stacking process.

[0037] Furthermore, each step in the preparation method of the present invention is carried out at room temperature.

[0038] The second aspect of the present invention provides an organic micro-nano crystal having a longitudinally stacked heterostructure prepared by the preparation method described in the first aspect.

[0039] The third aspect of the present invention provides applications of the organic micro-nano crystals with a longitudinally stacked heterostructure described in the second aspect in the optoelectronics and catalysis fields, including solar cells, transistors, electronic devices, optical instruments, etc.

[0040] The organic micro-nano crystals with longitudinally stacked heterostructures described in the second aspect can also be applied to optical logic gates to construct photonic barcodes based on anisotropic optical properties.

[0041] Beneficial effects of the present invention:

[0042] 1. The present invention cleverly constructs a metastable semi-encapsulated core / shell structure through organic charge transfer eutectic crystal engineering technology, and adopts a solution method to realize a simple and rapid preparation method for vertically stacking organic micro-nanocrystals. The present invention fully utilizes the unique structural advantages of semi-encapsulated core / shell crystals to provide preferential nucleation sites for the subsequent vertical stacking of organic micro-nanocrystals, thus opening up a new path for the precise construction of organic low-dimensional multi-level heterogeneous structures.

[0043] 2. The present invention can precisely control the size of the grooves in the semi-encapsulated core / shell structure, achieving precise control of the relative sizes of the structural dimensions within the stacked layers. It can be precisely controlled at the macroscale (>1000μm), mesoscale (1μm-1000μm), and microscale (<1μm).

[0044] 3. The present invention fully utilizes the multi-channel characteristics of the organic crystal stacked heterostructure and realizes a photon barcode function simply and quickly based on the close correlation between the excitation position and the photon transport behavior. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 These are characterization results of the organic micro-nano crystals with a semi-encapsulated core / shell structure prepared in Example 1 and Example 2; wherein, a is a fluorescence microscope image of Example 1, b is an ultraviolet light excitation image of Example 1, c is a green light excitation image of Example 1, d is a scanning electron microscope image of Example 2, and e is a microscopic spectrum analysis diagram of Example 1.

[0046] Figure 2 Graph showing the precise control of the relative length of stacked heterostructures in longitudinally stacked heterostructures; wherein, a to h are fluorescence microscope images of the organic micro-nano crystals of Examples 3 to 9 and Comparative Example 1, and i is a graph showing the relationship between the ratio of core layer and shell layer materials and the relative length between layers.

[0047] Figure 3 These are characterization results of the organic micro-nanocrystals with longitudinally stacked heterostructures prepared in Examples 3 and 5; wherein, a is a fluorescence microscope image of Example 3, b is an ultraviolet light excitation image of Example 3, c is a green light excitation image of Example 3, d is a bright field microscope image of Example 3, and e and f are microscopic spectrum analysis diagrams of Example 5.

[0048] Figure 4 TEM images and SAED images of the organic micro-nano crystals with longitudinally stacked heterostructures prepared in Example 3; wherein, a is a TEM image, b is a SAED image of the TDP eutectic, and c is a SAED image of the core / shell structure.

[0049] Figure 5These are the fluorescence microscope images and spatially resolved PL spectra of the organic micro-nano crystals with longitudinally stacked heterostructures prepared in Example 8; wherein, a is a fluorescence microscope image of an organic micro-nano crystal with a single longitudinally stacked heterostructure excited by a 380nm focused laser beam at two typical positions (In 1), b is a fluorescence microscope image of an organic micro-nano crystal with a single longitudinally stacked heterostructure excited by a 380nm focused laser beam at two typical positions (In 2), c is the spatially resolved PL spectrum of the four output channels corresponding to a, and d is the spatially resolved PL spectrum of the four output channels corresponding to b.

[0050] Figure 6 This is a description of the encoding rules of the photon barcode and the barcode of the organic micro-nano crystal with a longitudinally stacked heterostructure prepared in Example 8. DETAILED DESCRIPTION

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0052] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0053] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are all commercially available unless otherwise specified.

[0054] Example 1

[0055] A method for preparing organic micro-nano crystals with a semi-encapsulated core / shell structure comprises the following steps:

[0056] (1) Dissolve 0.02 mmol (3.6 mg) of TCNB and 0.02 mmol (7.2 mg) of HDP in 10 mL of dichloromethane (DCM) to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material (TDP stock solution); dissolve 0.15 mmol (26.7 mg) of TCNB and 0.15 mmol (34.2 mg) of BHT in 10 mL of DCM to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material (THT stock solution).

[0057] (2) The TDP stock solution described in step (1) was mixed with 10 mL of ethanol (EtOH) to obtain an organic micro-nano crystal stock solution (TDP stock solution) of the core layer material; the THT stock solution described in step (1) was mixed with 10 mL of EtOH to obtain an organic micro-nano crystal stock solution (THT stock solution) of the shell layer material.

[0058] (3) 200 μL of the TDP stock solution described in step (2) was added dropwise onto the glass substrate, and a TDP eutectic was obtained after crystallization for 60 s. 1800 μL of the THT stock solution described in step (2) was added dropwise onto the TDP eutectic, and after the solvent was completely evaporated, an organic micro-nano crystal with a semi-encapsulated core / shell structure was obtained.

[0059] Example 2

[0060] A method for preparing organic micro-nano crystals with a semi-encapsulated core / shell structure comprises the following steps:

[0061] (1) Dissolve 0.02 mmol (3.6 mg) of TCNB and 0.02 mmol (7.2 mg) of HDP in 10 mL of dichloromethane (DCM) to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material (TDP stock solution); dissolve 0.15 mmol (26.7 mg) of TCNB and 0.15 mmol (34.2 mg) of BHT in 10 mL of DCM to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material (THT stock solution).

[0062] (2) The TDP stock solution described in step (1) was mixed with 10 mL of ethanol (EtOH) to obtain an organic micro-nano crystal stock solution (TDP stock solution) of the core layer material; the THT stock solution described in step (1) was mixed with 10 mL of EtOH to obtain an organic micro-nano crystal stock solution (THT stock solution) of the shell layer material.

[0063] (3) 200 μL of the TDP stock solution described in step (2) was added dropwise onto the glass substrate, and a TDP eutectic was obtained after crystallization for 60 s. 3000 μL of the THT stock solution described in step (2) was added dropwise onto the TDP eutectic, and after the solvent was completely evaporated, an organic micro-nano crystal with a semi-encapsulated core / shell structure was obtained.

[0064] The organic micro-nano crystals with semi-encapsulated core / shell structure prepared in Example 1 and Example 2 were characterized. The characterization results are shown in FIG. Figure 1 First, its morphology was directly observed by fluorescence microscopy, as shown in Figure 1As shown in Figure a, a unique organic semi-encapsulated heterostructure can be clearly observed from the substrate surface, in which the green-emitting THT eutectic partially covers the red-emitting TDP eutectic surface, and the bright areas at both ends are THT eutectics. The image is obtained using ultraviolet light (λ = 330 ~ 380nm) excitation, as shown in Figure 3. Figure 1 As shown in Figure b, the luminescence characteristics of organic micro-nanocrystals with a semi-encapsulated core / shell structure are further revealed. Region 1 is the THT eutectic, and region 2 is the exposed TDP eutectic not covered by the THT eutectic. The image is excited by green light of a specific wavelength (λ = 500-550nm), which enhances the visibility of the red fluorescent area, as shown in Figure 4. Figure 1 As shown in c. Scanning electron microscopy provides high-resolution surface morphology information. Figure 1 In the image d, we can clearly see the presence of significant groove features on the surface of the organic micro-nano crystal. Microscopic spectroscopy was used to further explore the structural properties of the material, such as Figure 1 Based on these test results, it is confirmed that the core layer material of the semi-encapsulated structure is composed of red-emitting TDP eutectic, while the shell is composed of green-emitting THT eutectic. Due to the incompleteness of the encapsulation process, significant groove features exist on the surface of the structure.

[0065] Example 3

[0066] A method for preparing organic micro-nano crystals with a longitudinally stacked heterostructure comprises the following steps:

[0067] (1) Dissolve 0.02 mmol (3.6 mg) of TCNB and 0.02 mmol (7.2 mg) of HDP in 10 mL of dichloromethane (DCM) to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material (TDP stock solution); dissolve 0.15 mmol (26.7 mg) of TCNB and 0.15 mmol (34.2 mg) of BHT in 10 mL of DCM to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material (THT stock solution).

[0068] (2) The TDP stock solution described in step (1) was mixed with 10 mL of ethanol (EtOH) to obtain an organic micro-nano crystal stock solution (TDP stock solution) of the core layer material; the THT stock solution described in step (1) was mixed with 10 mL of EtOH to obtain an organic micro-nano crystal stock solution (THT stock solution) of the shell layer material.

[0069] (3) 200 μL of the TDP stock solution described in step (2) was added dropwise onto the glass substrate, and a TDP eutectic was obtained after crystallization for 60 s. 3000 μL of the THT stock solution described in step (2) was added dropwise onto the TDP eutectic (the volume ratio of the TDP stock solution to the THT stock solution was 1:15), and crystallization was performed for 120 s (the solvent was not completely evaporated) to obtain an organic micro-nano crystal with a semi-encapsulated core / shell structure.

[0070] (4) 350 μL of the TDP stock solution described in step (2) is added dropwise onto the organic micro-nano crystals having a semi-encapsulated core / shell structure described in step (3), and after the solvent is completely evaporated, an organic micro-nano crystal having a longitudinally stacked heterogeneous structure is obtained.

[0071] Figure 2 The figure is a result of precise control of the relative length of stacked heterostructures in a longitudinally stacked heterostructure; wherein ah is the fluorescence microscope image of the organic micro-nano crystals of Examples 3 to 9 and Comparative Example 1, and i is the relationship between the ratio of the core layer and the shell layer materials and the relative length between the layers. Figure 2 As shown in b, the length of the stacked heterostructure of the organic micro-nano crystal with longitudinal stacked heterostructure prepared in Example 3 accounts for 21.7% of the length of the organic micro-nano crystal.

[0072] Example 4

[0073] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 2600 μL (the volume ratio of TDP stock solution to THT stock solution is 1:13); in step (4), the amount of TDP stock solution added is 400 μL. Figure 2 As shown in middle c, the length of the stacked heterostructure accounts for 27.8% of the length of the organic micro-nano crystal.

[0074] Example 5

[0075] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 2200 μL (the volume ratio of TDP stock solution to THT stock solution is 1:11); in step (4), the amount of TDP stock solution added is 450 μL. Figure 2 As shown in middle d, the length of the stacked heterostructure accounts for 33.3% of the length of the organic micro-nano crystal.

[0076] The organic micro-nano crystals with longitudinally stacked heterostructures prepared in Example 3 and Example 5 were characterized. The characterization results are shown in FIG. Figure 3 and Figure 4As shown, vertically stacked organic heterostructures were observed from the substrate. Figure 3 (a), image under ultraviolet light excitation ( Figure 3 Middle b), image under green light excitation ( Figure 3 Middle c), bright field microscopic image ( Figure 3 Middle d), scanning electron microscope image ( Figure 3 e and f) to explore its surface microstructure in depth, supplemented by transmission electron microscopy (TEM) images and selected electron diffraction (SAED) technology images ( Figure 4 ) for detailed crystallographic analysis. Figure 3 and Figure 4 All test results confirm that these organic micro-nanocrystals are precisely stacked on vertical grooves in a directionally integrated manner, showing a high degree of structural order and integration characteristics.

[0077] Example 6

[0078] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 1800 μL (the volume ratio of TDP stock solution to THT stock solution is 1:9); in step (4), the amount of TDP stock solution added is 500 μL. Figure 2 As shown in middle e, the length of the stacked heterostructure accounts for 40.0% of the length of the organic micro-nano crystal.

[0079] Example 7

[0080] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 1400 μL (the volume ratio of TDP stock solution to THT stock solution is 1:7); in step (4), the amount of TDP stock solution added is 550 μL. Figure 2 As shown in middle f, the length of the stacked heterostructure accounts for 48.2% of the length of the organic micro-nano crystal.

[0081] Example 8

[0082] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 1000 μL (the volume ratio of TDP stock solution to THT stock solution is 1:5); in step (4), the amount of TDP stock solution added is 600 μL. Figure 2 As shown in middle g, the length of the stacked heterostructure accounts for 58.3% of the length of the organic micro-nano crystal.

[0083] Example 9

[0084] A method for preparing organic micro-nano crystals with a longitudinally stacked heterogeneous structure is basically the same as the preparation method of Example 1, except that: in step (3), the amount of THT stock solution added is 600 μL (the volume ratio of TDP stock solution to THT stock solution is 1:3); in step (4), the amount of TDP stock solution added is 650 μL. Figure 2 As shown in (h), the length of the stacked heterostructure accounts for 78.9% of the length of the organic micro-nano crystal.

[0085] Comparative Example 1

[0086] A method for preparing organic micro-nano crystals with a fully encapsulated core / shell structure comprises the following steps:

[0087] (1) Dissolve 0.02 mmol (3.6 mg) of TCNB and 0.02 mmol (7.2 mg) of HDP in 10 mL of dichloromethane (DCM) to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material (TDP stock solution); dissolve 0.15 mmol (26.7 mg) of TCNB and 0.15 mmol (34.2 mg) of BHT in 10 mL of DCM to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material (THT stock solution).

[0088] (2) The TDP stock solution described in step (1) was mixed with 10 mL of ethanol (EtOH) to obtain an organic micro-nano crystal stock solution (TDP stock solution) of the core layer material; the THT stock solution described in step (1) was mixed with 10 mL of EtOH to obtain an organic micro-nano crystal stock solution (THT stock solution) of the shell layer material.

[0089] (3) 200 μL of the TDP stock solution described in step (2) was added dropwise onto the glass substrate, and a TDP eutectic was obtained after crystallization for 60 seconds. 4000 μL of the THT stock solution described in step (2) was added dropwise onto the TDP eutectic, and after the solvent was completely evaporated, an organic micro-nano crystal with a fully encapsulated core / shell structure was obtained, as shown in FIG. Figure 2 As shown in a.

[0090] Application Examples

[0091] A continuous laser 380 nm laser spot (diameter 2-4 μm) was selected to focus on different parts of the organic micro-nano crystal with longitudinally stacked heterostructure prepared in Example 8, and the photon emission spectra of the four output channels were collected respectively ( Figure 5). Based on the significantly different emission and polarization signals, a multi-channel information encoding function is realized. The output channels (O1-O4) on the left side of the horizontal coordinate correspond to the input mode In 1, and the four output channels (O1'-O4') on the right side correspond to the input mode In2; the vertical axis represents the wavelength and intensity of the photoluminescence spectrum, as well as the angle and intensity of the polarization. Then, the emission and polarization excitation position-dependent waveguides of different output channels are collected as photon barcodes. The optical parameters of these vertical axes represent two types of logical values, namely 0 and 1. Specifically, the same wavelength of the output channel and the excitation position is defined as 1, otherwise it is defined as 0; if the photoluminescence spectrum (PL spectrum) intensity of the output signal is greater than half of the PL spectrum intensity of the excitation position, the output signal is considered to be 1, otherwise it is defined as 0. In addition, the polarization output signal >90° relative to the structural direction is defined as 1, otherwise it is considered to be 0. For polarization intensity, when the lowest intensity is less than (greater than) 50% of the highest intensity, the output signal can be defined as 1 (0). Therefore, by summarizing the output signals of multiple output channels in the superposition heterostructure, photonic barcode ( Figure 6 ).

[0092] The present invention provides an innovative method for precisely stacking organic micro- and nanocrystals in the vertical direction. The core of this method lies in finely controlling the ratio between the core and shell materials, thereby constructing a semi-enclosed core / shell structure with distinct grooves. Furthermore, as core material is added to this structure, it grows directionally in the grooves, and the vertical stacking sites are controllable, forming vertically stacked organic micro- and nanocrystals in the grooves. By replacing the cocrystal based on the same donor or acceptor molecule, organic low-dimensional crystalline heterostructures with precise vertical stacking can be obtained.

[0093] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing organic micro-nano crystals with a longitudinally stacked heterostructure, characterized in that: The following steps are involved: (1) dissolving the acceptor molecule A and the donor molecule B in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material; dissolving the acceptor molecule A and the donor molecule C in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material; or The acceptor molecule A and the donor molecule B are dissolved in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the core layer material; the acceptor molecule D and the donor molecule B are dissolved in a good organic solvent to obtain a good organic solvent stock solution of organic micro-nano crystals of the shell layer material; (2) mixing the organic micro-nano crystal stock solution of the core layer material in good organic solvent and a poor organic solvent to obtain an organic micro-nano crystal stock solution of the core layer material; mixing the organic micro-nano crystal stock solution of the shell layer material in good organic solvent and a poor organic solvent to obtain an organic micro-nano crystal stock solution of the shell material; (3) dripping the organic micro-nano crystal stock solution of the core layer material described in step (2) onto the substrate, and obtaining organic micro-nano crystals of the core layer material after crystallization; dripping the organic micro-nano crystal stock solution of the shell layer material described in step (2) onto the organic micro-nano crystals of the core layer material, and obtaining organic micro-nano crystals having a semi-encapsulated core / shell structure after crystallization; (4) adding the organic micro-nano crystal stock solution of the core layer material described in step (2) onto the organic micro-nano crystal with the semi-encapsulated core / shell structure described in step (3), and obtaining the organic micro-nano crystal with a longitudinally stacked heterogeneous structure after the solvent is completely evaporated.

2. The preparation method according to claim 1, characterized in that In step (1), the acceptor molecule A and the acceptor molecule D are independently selected from tetrafluoroterephthalonitrile, 2,4,6-trimethylbenzene-1,3,5-tricarboxylic acid nitrile, benzene-1,2,4,5-tetracarbonitrile, 7,7,8,8-tetracyanobenzoquinodimethane or phthalic anhydride; the donor molecule B and the donor molecule C are independently selected from anthracene, pyrene, benzo[c]phenanthrene, triphenylene, perylene, dithienopyrrole, benzodithiophene, tetrathiophene, carbazole or acridine.

3. The preparation method according to claim 1, characterized in that In step (1), the molar ratio of the acceptor molecule A to the donor molecule B is (1-5):1, the molar ratio of the acceptor molecule A to the donor molecule C is (1-5):1, and the molar ratio of the acceptor molecule D to the donor molecule B is (1-5):

1.

4. The preparation method according to claim 1, characterized in that In step (1), the concentration of the acceptor molecule A in the organic micro-nano crystal good organic solvent stock solution of the core layer material is 2 to 20 mmol / L; the concentration of the donor molecule B in the organic micro-nano crystal good organic solvent stock solution of the core layer material is 2 to 20 mmol / L; the concentration of the acceptor molecule A in the organic micro-nano crystal good organic solvent stock solution of the shell layer material is 2 to 20 mmol / L; the concentration of the donor molecule C in the organic micro-nano crystal good organic solvent stock solution of the shell layer material is 2 to 20 mmol / L.

5. The preparation method according to claim 1, characterized in that In step (1), the good organic solvent is selected from one of dichloromethane, chloroform, acetonitrile, acetone, tetrahydrofuran, chlorobenzene and toluene; in step (2), the poor organic solvent is selected from one of methanol, ethanol, isopropanol, n-hexane and cyclohexane.

6. The preparation method according to claim 1, characterized in that In step (2), the volume ratio of the organic micro-nano crystal good organic solvent stock solution and the poor organic solvent of the core layer material is 1:(1-5); the volume ratio of the organic micro-nano crystal good organic solvent stock solution and the poor organic solvent of the shell layer material is 1:(1-5).

7. The preparation method according to claim 1, characterized in that In step (3), the volume ratio of the organic micro-nano crystal stock solution of the core layer material to the organic micro-nano crystal stock solution of the shell layer material is 1:(1-19).

8. The preparation method according to claim 1, characterized in that In step (4), the volume ratio of the organic micro-nano crystal stock solution of the core layer material to the organic micro-nano crystal stock solution of the core layer material described in step (3) is 1:(1-4).

9. Organic micro-nano crystals with a longitudinally stacked heterostructure obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the organic micro-nano crystals with vertically stacked heterostructures according to claim 9 in the fields of optoelectronics and catalysis.

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