CN106222752A - A kind of method preparing organic crystal thin film - Google Patents

Abstract

The invention discloses a method for preparing an organic crystal thin film. Organic crystal raw materials and modifiers are dissolved in an organic solvent and stirred evenly, and then the mixed solution is dropped onto a substrate at 50-150 degrees Celsius to evaporate the solvent. The evaporation time is controlled. Within 3 minutes, then place the substrate in a closed petri dish, and incubate it at -30-50 degrees Celsius for 1-30 hours under the saturated vapor pressure of a good solvent, and the organic crystals grow along the two-dimensional direction , so as to obtain organic crystal thin films. The method includes the process of rapid precipitation of crystals when the high-temperature solvent evaporates, and the self-assembly process of organic molecular nanoparticles in a culture dish under saturated vapor pressure after being attracted by capillary phenomenon. The crystal growth is restricted in the direction perpendicular to the substrate, so two-dimensional organic crystal thin films can be obtained. The size of the organic crystal film changes with the culture time, the hydrophilicity and hydrophobicity of the substrate material and the culture temperature.

Description

A kind of method for preparing organic crystal film

technical field

The invention belongs to the field of optoelectronic information materials, and relates to an organic crystal, in particular to a method for preparing an organic crystal thin film.

Background technique

Nonlinear optical crystal materials can be used to convert laser frequency and extend the wavelength of laser; to modulate the intensity and phase of laser; to realize holographic storage of laser signal, self-pump phase conjugation to eliminate wavefront domain change, etc. Therefore, nonlinear optical crystal is an indispensable key material in high-tech and modern military technology. All developed countries put it in a priority position, and include it in their high-tech development plan as an important strategic measure, and attach great importance to it. and support.

In recent years, more and more researchers have begun to study organic crystals. Zheng Meiling and others have studied DAST organic nanocrystals and found that they have electromagnetic responsiveness, optical waveguide characteristics and nonlinear optical characteristics, and can be used as optoelectronic materials with good performance. They used dendrimers to prepare organic nanocrystals. Due to the effective adjustment of carbosiloxane dendrimers in the crystal growth process, they successfully obtained DAST nanocrystals, and also obtained a relatively easy way to control the shape and size of DAST nanocrystals. Methods. They designed and synthesized carbosiloxane dendrimers, studied the different size effects of dendrimers of different generations, and investigated the influence of dendrimers on the optical properties of organic materials. Nakanishi et al. reported a method to fix anisotropy and disperse organic crystals in a magnetic field. They dispersed anisotropic DAST crystals in naphthalene in a magnetic field, and tested the absorption spectrum of DAST crystals (the maximum value is 555nm), inferring that the SHG efficiency of anisotropic DAST crystals may be enhanced.

The preparation method of organic crystals is an important research topic in the field of crystal materials. In recent years, several different preparation methods have been developed successively: (1) Mechanical grinding method. Various series of crystals such as pure metals, alloys, intermetallic compounds and other compounds can be obtained by using this method, and it has the advantages of large output, low cost and simple process. However, due to impurity contamination and oxidation during the grinding process, it is difficult to obtain a clean crystal interface, which is not conducive to some basic research work. (2) Amorphous crystallization method. This method is characterized by simple process, low cost, large output, easy control of grain size change, clean and dense interface, and no microporosity in the sample. But its limitation is that it relies on the formation of amorphous solids. (3) Deposition method. A major goal of current crystal preparation is to obtain a large number of large-sized crystal samples with clean sample interfaces and no microporosity.

Contents of the invention

Aiming at the above-mentioned technical problems in the prior art, the present invention provides a method for preparing an organic crystal thin film. The method for preparing an organic crystal thin film should solve the problem that the organic crystal prepared by the method of the prior art has many defects and the size is variable. There are technical problems such as poor controllability and high cost.

The invention provides a method for preparing an organic crystal thin film. The organic crystal raw material and the modifier are dissolved in a first organic solvent and stirred evenly. The mass ratio of the organic crystal raw material and the modifier is 1:0.1-10 , and then add the mixed solution dropwise to the substrate at 50-150 degrees Celsius for evaporation, the evaporation time is controlled within 3 minutes, and then the substrate is placed in a container under the saturated vapor pressure of methanol, at a temperature of -30 to 50 degrees Celsius Under culture for 1 to 30 hours, an organic crystal film is obtained.

Further, after the substrate is placed in the container, the second organic solvent is dropped into the second organic solvent. The second organic solvent is a good solvent for the organic crystal. According to the principle of similar compatibility, according to the organic crystal Choose a second organic solvent with a different polarity. Under the vapor atmosphere of the solvent, the crystals on the substrate automatically and slowly self-assemble, thereby obtaining high-quality organic crystal thin films.

Further, the organic crystal raw material is dimethylaminostyryl picolinium salt, and the dimethylaminostyryl picolinium salt is 4-(4-dimethylaminostyryl ) methylpyridine p-toluenesulfonate (DAST), 4-(4-dimethylaminostyryl) methylpyridine 2,4,6-trimethylbenzenesulfonate (DSTMS), 4-(4- Dimethylaminostyryl)picoline naphthalene sulfonate (DSNS-1), 4-(4-dimethylaminostyryl)picoline p-vinylbenzenesulfonate (DSSS), 4-(4 -Dimethylaminostyryl)picoline 2,4-dimethylbenzenesulfonate, 4-(4-dimethylaminostyryl)picoline 2-naphthalenesulfonate (DSNS-2), 4-(4-dimethylaminostyryl)picoline 4-aminonaphthalenesulfonic acid (DSPAS), 4-(4-dimethylaminostyryl)picoline 4-aminonaphthalenesulfonic acid (DSNAS), 4-(4-dimethylaminostyryl)picoline 4-(4-dimethylaminophenyl)azomethylbenzenesulfonic acid (DSMO), or 4-(4-dimethylaminostyryl) Picoline p-chlorobenzenesulfonate (DASC).

Further, the first organic solvent is methanol, ethanol, chloroethanol, n-propanol, isopropanol, 1-butanol, isobutanol, 2-butanol, pentanol, isoamyl alcohol, glycerol , diacetone alcohol, acetone, butanone, cyclohexanone, methyl n-acetone, methyl isobutyl ketone, diisobutyl ketone, methyl isoamyl ketone, methyl ether, ethylene glycol propyl ether, ethylene glycol Butyl ether, ethylene glycol hexyl ether, hydroxyethyl ethyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol monobutyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, Ethylene glycol butyl ether, propylene glycol monopropyl ether, formic acid, acetic acid, methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, isobutyl acetate, n-butyl acetate, methylpentyl acetate, n-butyl propionate, amyl acetate, isobutyl isobutyrate, butyl glycol ether acetate, diethylene glycol ethyl ether acetate, 2-ethylhexyl formate, acrylonitrile, chloroform, di Any one or a combination of two or more of ethyl chloride, carbon disulfide, cyclohexane, benzene, toluene, xylene, pyridine, 2-nitropropane, or alkynes.

Further, the modifying agent is any one of alkyd resin, quaternary ammonium salt surfactant, anionic surfactant, or silicone surfactant.

Further, the quaternary ammonium salt surfactant is cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dodecyltrimethylammonium chloride, or dodecyltrimethylammonium chloride Any one or a mixture of two or more of alkyl dimethyl ammonium bromide.

Further, the anionic surfactant is selected from sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium fatty acid, alkyl polyoxyethylene ether, sodium carboxylate alkyl sulfonate, methylene bis-naphthalene sulfonic acid Sodium, or sodium oleoyl methyl taurate, any one or a mixture of two or more.

Further, the siloxane surfactant is any one of octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, or a dimethylsiloxane or a mixture of two or more .

Further, the prepared organic crystal has a length of 50-2000 μm, a width of 50-2000 μm, and a height of 0.02-5 μm.

Further, the second organic solvent is a low-boiling polar solvent, and the low-boiling polar solvent is selected from methanol, ethanol, dimethyl sulfoxide or propanol.

Furthermore, according to the different preparation conditions, linear, double/multi-branched, ring-shaped and thin-film crystals can be prepared respectively. The crystals exhibit single crystal properties under a polarizing microscope.

Further, the substrate is a hydrophilic heating substrate.

Further, low boiling point polar solvents such as methanol, ethanol, propanol, etc.

In the present invention, organic crystal raw materials and modifiers are dissolved in an organic solvent and stirred evenly, then the mixed solution is dripped onto a substrate at 50-150 degrees Celsius for evaporation, and then culture dishes are placed at different temperatures for cultivation. The cultivation process A small amount of organic solvent can be added dropwise, and organic crystal films of different sizes and shapes can be obtained according to the amount of modifier added, different incubation times, different heating times, and different incubation temperatures. We call it the method of surface-supported wet annealing to prepare organic crystal thin films. The substrate can be a hydrophilic substrate or a hydrophobic substrate, and a suitable substrate is selected according to the hydrophilicity of the organic crystal raw material. Generally, when the organic crystal raw material is a hydrophilic material, a hydrophilic substrate is selected; when the organic crystal raw material is a hydrophobic material, a hydrophobic substrate is selected.

The size distribution of organic crystals prepared by surface support wet annealing method can be controlled in the range of 1-1000 μm in length, 1-100 μm in width and 0.01-10 μm in height, and the size distribution of organic crystal films prepared by this method can be controlled in the range of 50- 2000μm, 50-2000μm in width, and 0.02-5μm in height, according to actual requirements, organic crystals of required size can be prepared.

The organic crystal thin film prepared by the method has low cost, good growth ability, complete lattice and activity. It can be applied to ultra-high-speed photoelectric signal modulation, bioluminescent microscopy, laser production, terahertz radiation source and detection and other application fields.

4-(4-methylaminostyryl)picoline p-toluenesulfonate (DAST) organic crystals belong to organic second-order nonlinear monoclinic crystals, due to the high fluorescent quantum dot efficiency, fast The advantages of photoresponse and high nonlinear coefficient have attracted widespread attention. Its second-order nonlinear coefficient at 1542 nm is 840 pm/V, and its electro-optic coefficient at 820 nm is 75 pm/V, which is more widely used than current The corresponding value of ZnTe is 1 to 2 orders of magnitude higher. Due to the low dielectric constant of DAST, it has longer coherence length and faster response characteristics. DAST has a special chemical structure and is one of the typical representatives of organic pyridinium salts. The carbon atom and nitrogen atom on the pyridine ring are bonded by sp ² hybrid orbitals, and each atom on the ring forms a conjugated system with a π orbital, and the lone pair of electrons on the nitrogen atom does not participate in conjugation. Therefore, pyridine forms a salt After that, the ring conjugated system is not destroyed. This type of molecule contains two large π bonds, one is a benzene ring and the other is a pyridine ring. The two large π bonds are conjugated through the carbon-carbon double bond in the middle, and the electronic charge can be delocalized from one end to the other. Thus, the second-order nonlinear susceptibility of DAST molecules increases. Pyridinium cation, as a positively charged group, is a strong electron-withdrawing group. The greater the acceptor strength, the greater the degree of intramolecular charge transfer, and the corresponding microscopic second-order polarizability will also be greater. The unique chemical structure of DAST shows strong application prospects in various technical fields, such as in the field of terahertz generation and emission. In 1992, XC Zhang, XF Ma, Y. Jin, "Terahertz Optical Rectification from a Nonlinear Organic Crystal", Applied Physics Let ters, 61(26), 3080-3082(1992) reported that DAST can emit THz waves through optical rectification . 2004, T. Taniuchi, S. Okada, H. Nakanishi, "Widely-tunable THz-wave Generation in 2-20THz Range from DASTCrystal by Non linear Difference Frequency Mixing", Electronics Letters, 40(1), 60-62 (2004) reported that tunable terahertz waves of 2-20 THz can be generated by OPO mixing in the range of 1300-1450 nm, the output energy is 82 nJ/pulse at 11.6 THz, the peak value is 10.3 W, and the output energy at 19 THz 110 nJ/pulse, 13.8 W peak. However, DAST crystals are only used to prepare small particles in the traditional reprecipitation method, and no DAST crystal film has been found so far, and the activity time of DAST particles is short. Under the irradiation of strong laser, the thermal damage is particularly severe. , cannot work for a long time. In the present invention, the surface-supported wet annealing method is used to prepare DAST organic crystal thin films. The crystal size distribution can be controlled within the range of 50-2000 μm, width 50-2000 μm, and height 0.02-5 μm. According to actual requirements, crystals of required sizes can be prepared film.

In the present invention, organic crystal raw materials and modifiers are dissolved in an organic solvent and stirred evenly, and then the mixed solution is dripped onto a substrate at 50-150 degrees Celsius according to the boiling point of the organic solution for evaporation, and the organic crystal grows along the ab crystal axis plane direction, The resulting organic crystal thin film. In this method, the precipitation of crystals is fast when the high-temperature solvent evaporates. In the petri dish under saturated vapor pressure, the self-assembly process of organic molecular nanoparticles after capillary attraction occurs, which is affected by the degree of hydrophilicity of the substrate material. , the growth of crystals in the direction perpendicular to the substrate is limited, resulting in the appearance of a two-dimensional organic crystal film, and the size and shape of the organic crystal film depends on the mass ratio of the modifier to the organic crystal, the incubation time, the hydrophilicity and hydrophobicity of the substrate material, and the culture. Changes in conditions such as temperature.

Compared with the prior art, the technical progress of the present invention is remarkable. A method for preparing organic crystal thin films by surface-supported wet annealing of the present invention has good size controllability, few defects, strong applicability, reduces the cost of organic crystal production, and broadens the range of optical properties of linear organic crystals and organic crystal thin films. application field of use.

Description of drawings

FIG. 1 is a schematic diagram of an optical microscope of the DAST organic crystal prepared in Example 1.

FIG. 2 is an optical microscope schematic diagram of the DAST organic crystal prepared in Example 2.

FIG. 3 is a schematic diagram of an optical microscope of the DAST organic crystal thin film prepared in Example 3. FIG.

FIG. 4 is an optical microscope schematic diagram of the DAST organic crystal thin film prepared in Example 4.

FIG. 5 is an optical microscope schematic diagram of the DAST organic crystal thin film prepared in Example 5.

FIG. 6 is an optical microscope schematic diagram of the DAST organic crystal film prepared in Example 6. FIG.

detailed description

The present invention will be described in further detail below in combination with specific embodiments.

Example 1

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take a drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, the cuvette was placed at room temperature, and methanol was not added dropwise to the cuvette, and incubated for 3 hours to obtain DAST particles.

In this method, due to the influence of the temperature and the material of the substrate, the crystals are agglomerated and arranged in two directions, and finally grow into a crystal thin film. The size and shape of the organic crystal film are changed according to the mass ratio of the modifier to the organic crystal, the temperature at which the substrate is heated, and the change of the hydrophilicity of the substrate. see picture 1.

Example 2

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them together into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take 1 drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in Acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, place the cuvette at room temperature, add 1 drop of methanol to the cuvette, and incubate for 3 hours to obtain the DAST organic crystal film.

The DAST crystals prepared by this method were not cultured, and were directly observed with a microscope after heating and resting for 30 minutes. The crystal thin film morphology is not too obvious, see Figure 2.

Example 3

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them together into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take 1 drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in Acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, place the cuvette at room temperature, add 2 drops of methanol to the cuvette, and incubate for 3 hours to obtain a DAST organic crystal film.

The DAST crystal film prepared by this method was cultured, and then observed with a microscope, it was found that the crystal size increased significantly, and the length and width were about 5-50 μm, as shown in FIG. 3 .

Example 4

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them together into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take 1 drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in Acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, put the cuvette into a -18°C refrigerator, add 2 drops of methanol to the cuvette, and incubate for 3 hours to obtain a DAST organic crystal film.

The DAST crystal film prepared by this method has a small size, and the size distribution is 500-300 μm. See Figure 4.

Example 5

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them together into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take 1 drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in Acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, put the cuvette into a -18°C refrigerator, add 2 drops of methanol to the cuvette, and incubate for 5 hours to obtain a DAST organic crystal film, as shown in Figure 5.

Example 6

Preparation of DAST organic crystal thin films.

Take 0.03 g of DAST crystal raw material and 0.01 g of cetyltrimethylammonium bromide, add them together into 5 ml of anhydrous methanol, and stir at 800 rpm/min for 1 hour. Take 0.1 ml of DAST-methanol at room temperature, add it to 10 ml of anhydrous methanol, stir at 1200 rpm/min for 20 minutes, take 1 drop of the above mixed solution and drop it on the hydrophilic substrate, which is first soaked in Acetone solution, then ultrasonically vibrated for 20 minutes, and then treated with a deep ultraviolet ozone cleaner for 1 hour. Finally, put the cuvette into a -18°C refrigerator, add 2 drops of methanol to the cuvette, and incubate for 7 hours to obtain a DAST organic crystal film, as shown in Figure 6.

From Examples 1, 2, and 3, it can be seen that the amount of methanol added has a great influence on the shape and size of the film, and the more methanol added, the better the shape of the film. From Examples 3 and 4, it can be seen that the importance of culture temperature is lower, the lower the culture temperature, the better the shape and the larger the size. From Examples 4, 5, and 6, it can be seen that the importance of culture time is longer, the longer the culture time, the larger the film size and the better the shape. The ratio of DAST crystal raw material to modifier is in the range of 1:1-20, and the shape and size of DAST organic crystal film are better.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (10)

1. A method for preparing organic crystal film, characterized in that: organic crystal raw material and modifier are dissolved in the first organic solvent, and stirred evenly, the mass ratio of described organic crystal raw material and modifier is 1:0.1 ~10, then drop the mixed solution onto the substrate at 50-150 degrees Celsius for evaporation, the evaporation time is controlled within 3 minutes, and then place the substrate in a container under the saturated vapor pressure of methanol, at -30-50 degrees Celsius Cultivate at a certain temperature for 1 to 30 hours to obtain an organic crystal film. 2. A kind of method for preparing organic crystal thin film according to claim 1, is characterized in that: drop into second kind of organic solvent after this substrate is placed in container, and described second kind of organic solvent is described As for the good solvent of the organic crystal, according to the principle of similar miscibility, a different second organic solvent is selected according to the polarity of the organic crystal. 3. A kind of method for preparing organic crystal thin film according to claim 1, is characterized in that: described organic crystal raw material is dimethylaminostyryl picolinium salt class material, and described dimethylaminostyrene The base picoline salts are 4-(4-dimethylaminostyryl)picoline p-toluenesulfonate, 4-(4-dimethylaminostyryl)picoline 2,4,6- Trimethylbenzenesulfonate, 4-(4-Dimethylaminostyryl)methylpyridinenaphthalenesulfonate, 4-(4-Dimethylaminostyryl)picoline p-vinylbenzenesulfonate , 4-(4-dimethylaminostyryl)picoline 2,4-dimethylbenzenesulfonate, 4-(4-dimethylaminostyryl)picoline 2-naphthalenesulfonate, 4-(4-Dimethylaminostyryl)methylpyridine p-anilinesulfonic acid, 4-(4-Dimethylaminostyryl)methylpyridine 4-aminonaphthalenesulfonic acid, 4-(4-di Methylaminostyryl)picoline 4-(4-dimethylaminophenyl)azomethylbenzenesulfonic acid, or 4-(4-dimethylaminostyryl)picoline p-chlorobenzenesulfonate . 4. a kind of method for preparing organic crystal film according to claim 1 is characterized in that: described first organic solvent is methyl alcohol, ethanol, chloroethanol, n-propanol, Virahol, 1-butanol, Isobutanol, 2-butanol, amyl alcohol, isoamyl alcohol, glycerol, diacetone alcohol, acetone, butanone, cyclohexanone, methyl n-acetone, methyl isobutyl ketone, diisobutyl ketone, Methyl isoamyl ketone, methyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, ethylene glycol hexyl ether, hydroxyethyl ethyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether, propylene glycol monobutyl ether, diethyl ether Glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, propylene glycol monopropyl ether, formic acid, acetic acid, methyl acetate, ethyl acetate, isopropyl acetate, n-acetic acid Propyl ester, isobutyl acetate, n-butyl acetate, methylpentyl acetate, n-butyl propionate, amyl acetate, isobutyl isobutyrate, butyl glycol ether acetate, diethylene glycol ethyl ether Any of acetate, 2-ethylhexyl formate, acrylonitrile, chloroform, dichloroethane, carbon disulfide, cyclohexane, benzene, toluene, xylene, pyridine, 2-nitropropane, or alkynes One or a combination of two or more. 5. A kind of method for preparing organic crystal film according to claim 1, is characterized in that: described modifying agent is alkyd resin class material, quaternary ammonium salt class surfactant, anionic surfactant or silicon oxide Any of the alkane surfactants. 6. A kind of method for preparing organic crystal film according to claim 5, is characterized in that: described quaternary ammonium salt surfactant is cetyltrimethylammonium bromide, cetyltrimethylammonium Ammonium chloride, dodecyl trimethyl ammonium chloride, or dodecyl dimethyl ammonium bromide any one or a mixture of two or more. 7. a kind of method for preparing organic crystal thin film according to claim 5 is characterized in that: described anion surfactant is selected from sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium fatty acid, alkyl polyoxygen Any one or a mixture of two or more of vinyl ether, sodium carboxylate, sodium alkyl sulfonate, sodium methylene bis-naphthalene sulfonate, or sodium oleoyl methyl taurate. 8. a kind of method for preparing organic crystal film according to claim 5 is characterized in that: described siloxane surfactant is octamethylcyclotetrasiloxane, hexamethylcyclotetrasiloxane, Or any one or a mixture of two or more of dimethyl siloxanes. 9. A method for preparing an organic crystal thin film according to claim 1, characterized in that: the length of the prepared organic crystal is 50-2000 μm, the width is 50-2000 μm, and the height is 0.02-5 μm. 10. A kind of method for preparing organic crystal thin film according to claim 2, is characterized in that: described second organic solvent is low boiling point polar solvent, and described low boiling point polar solvent is selected from methanol, ethanol, Dimethyl sulfoxide or propanol.