Synthesis method of ultraviolet emission organic semiconductor, single crystal, and organic laser and organic electroluminescent device based on single crystal

Abstract

The invention discloses an ultraviolet emission organic semiconductor and a synthesis method thereof, an ultraviolet emission organic semiconductor single crystal and an organic electroluminescent device based on the ultraviolet emission organic semiconductor single crystal. A stilbene derivative molecule 5F-BBPS is designed and synthesized, a thin single crystal with uniform thickness and the size of more than 25 microns can be prepared by using a macro sublimation method, the crystal can realize laser emission under 360nm femtosecond laser pumping at a lower threshold (less than 4 mu J / cm < 2 >), the measured electron mobility of a field effect transistor made of the single crystal material is 1.03 E-4 cm < 2 > V <-1 > s <-1 >, and the electron mobility of the field effect transistor is 1.03 E-4 cm < 2 > V <-1 > s <-1 >. The organic light emitting diode made of the single crystal material can be lightened. The 5F-BBPS single crystal has a low laser threshold value, and can become a very competitive material in optional materials for realizing the continuous optical pumping organic laser.

Description

Technical Field

[0001] The invention relates to the technical field of organic lasers and organic electroluminescent devices, and in particular to the design and synthesis of a stilbene derivative molecule, the crystal of which has good optical properties and can realize ultraviolet low-threshold photolaser. Background Art

[0002] As an emerging organic laser, ultraviolet emitting organic semiconductors have shown broad application prospects in the fields of biomedicine, material processing, optical communications, etc. Its ultraviolet wavelength enables it to achieve more accurate medical imaging and treatment in the biomedical field, higher processing accuracy and resolution in the field of material processing, and has very important applications in the background light source of displays. With the continuous advancement of technology and the expansion of research fields, ultraviolet emitting organic semiconductors will be more widely used and promoted in the future, bringing new impetus and opportunities for the development of the field of optoelectronic devices. Distilbenes are a class of multifunctional materials with excellent performance: they can be used as luminescent materials in electroluminescent devices; they can be used as blue light additives to improve the luminous efficiency and stability of organic light-emitting diodes; they can be used in devices as electron transport layers. The present invention will describe its application in organic lasers and organic electroluminescent devices. Summary of the invention

[0003] The present invention relates to the technical field of biophotonics, and specifically, a stilbene derivative molecule is designed and synthesized, and its crystal has good optical properties. The purpose of the present invention is to prepare low-threshold organic photolasers, organic field effect transistors to measure mobility, and organic light-emitting diodes. Organic solid-state lasers have developed relatively maturely in recent years. Through the design of materials, many low-threshold organic solid-state lasers have also emerged. Compared with inorganic lasers, organic solid-state lasers are easy to prepare, low-cost, and suitable for a wider range of applications.

[0004] The invention discloses a method for synthesizing a stilbene derivative molecule, designs and synthesizes a (E)-1,2-bis(2',3',4',5',6'-pentafluoro-[1,1'-biphenyl]-4-yl)ethylene, namely 5F-BBPS, and specifically comprises the following steps:

[0005] Trans-4,4-dibromostilbene powder, palladium acetate powder, cesium carbonate powder, and tricyclohexylphosphine powder were loaded into a branch tube reactor tube, toluene was used as solvent, pentafluorobenzene was added, and the mixture was stirred at 100° C. overnight. The resulting suspension was filtered under negative pressure, and the solid product was repeatedly washed with ethanol and dichloromethane to obtain the final product 5F-BBPS powder.

[0006] The present invention designs and synthesizes a molecule 5F-BBPS, and uses a micro-sublimation method to obtain a thin single crystal with uniform thickness and a size of more than 25 μm. The crystal is pumped by a 360nm femtosecond laser at a low threshold (<4 μJ / cm 2 ) can realize laser emission, and the electron mobility of the field effect transistor made of this single crystal is 1.03E-4 (cm 2 V -1 s -1 ), and an organic light-emitting diode made from the single crystal can light it up.

[0007] It should be understood that the advantages of the present invention will be described in the following description, and the following detailed description is exemplary and explanatory. The purpose and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required in the description of the embodiments:

[0009] Figure 1 These are the specific steps for designing and synthesizing a 5F-BBPS according to the first embodiment of the present invention.

[0010] Figure 2 This is a brief step of growing 5F-BBPS single crystal using micro-space sublimation method and transferring it to Si / SiO2 / PMMA substrate in Example 2 of the present invention.

[0011] Figure 3 The morphology and luminescence photos of the 5F-BBPS single crystal of Example 3 of the present invention under a fluorescence microscope, as well as the absorption and emission spectra of the molecule in a dilute tetrachloromethane solution and the crystal.

[0012] Figure 4 This is the laser behavior of the 5F-BBPS single crystal of Example 4 of the present invention under 360nm femtosecond light.

[0013] Figure 5 It is a schematic diagram of the structure of an organic field effect transistor (OFET) device made from a 5F-BBPS single crystal according to the fifth embodiment of the present invention and a top view photograph of the actual device.

[0014] Figure 6 This is the transfer curve of the 5F-BBPS single crystal OFET device according to Example 6 of the present invention.

[0015] Figure 7 This is a schematic diagram of the structure of an organic light-emitting diode (OLED) device made of a 5F-BBPS single crystal according to Example 7 of the present invention and a top-down photograph of the actual device. DETAILED DESCRIPTION

[0016] The following will describe the implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly. It should be noted that as long as there is no conflict, the various features in the various embodiments of the present invention can be combined with each other, and the resulting technical solutions are all within the protection scope of the present invention.

[0017] Embodiment 1:

[0018] A method for synthesizing a stilbene derivative molecule is disclosed. A stilbene derivative (E)-1,2-bis(2',3',4',5',6'-pentafluoro-[1,1'-biphenyl]-4-yl)ethylene, namely 5F-BBPS, is designed and synthesized. The specific steps include:

[0019] Trans-4,4-dibromostilbene powder, palladium acetate powder, cesium carbonate powder, and tricyclohexylphosphine powder were loaded into a branch tube reactor tube, toluene was used as solvent, pentafluorobenzene was added, and the mixture was stirred at 100° C. overnight. The resulting suspension was filtered under negative pressure, and the solid product was repeatedly washed with ethanol and dichloromethane to obtain the final product 5F-BBPS powder.

[0020] For example, the molar ratio of each drug in the above steps is trans-4,4-dibromostilbene: pentafluorobenzene: palladium acetate: cesium carbonate: tricyclohexylphosphine = 1:2:0.1:0.6:0.2.

[0021] A stilbene derivative molecule 5F-BBPS is prepared according to the above synthesis method and has the structure:

[0022]

[0023] Embodiment 2:

[0024] Take 0.5 mg of 5F-BBPS powder and spread it evenly on a pre-cleaned ordinary glass cover slip, place it on a hot plate, add a 0.34 mm thick gasket, and then place a clean glass slide as the upper substrate directly on top, heat it to 280°C, stop heating after 1 minute, wait for the temperature to drop to room temperature and remove the upper substrate, you can see shiny 5F-BBPS crystals, most of which are observed under a microscope to grow vertically to the substrate surface. The upper substrate with 5F-BBPS single crystals is bonded to a Si / SiO2 sheet spin-coated with 20 nm thick PMMA, and the 5F-BBPS crystals can be transferred and laid flat on the PMMA surface.

[0025] Embodiment three:

[0026] The transferred 5F-BBPS crystal was observed under a fluorescence microscope. It was observed under a white field that it was well crystallized, with a flat surface and smooth and sharp edges. The fluorescence photo showed that the crystal had a good optical waveguide and optical confinement effect, and the edge emitted brighter blue light. From the absorption and emission spectra, it was found that the absorption peak wavelength of its dilute dichloromethane solution was at 317nm, and the emission peak wavelength was at 375nm and 393nm; the excitation peak of the solid single crystal was at 272nm and 360nm, and the emission peak was at 376nm, 396nm, 416nm and 436nm.

[0027] Embodiment 4:

[0028] Characterization of the laser behavior of the crystal: The transferred 5F-BBPS crystal was placed under a 360nm femtosecond laser to observe and collect its laser behavior. The left figure shows the change in the luminescence spectrum of the crystal as the pump energy increases. It can be seen that the luminescence half-peak width reaches 7μJ / cm 2 Then it decreases sharply with the increase of pump energy, showing obvious stimulated emission behavior. The inset is a photo of crystal luminescence above the threshold. The right picture shows the change of luminescence intensity with the increase of pump energy, showing an obvious S-shaped nonlinear relationship. The threshold of the laser at 395nm is 3.56μJ / cm 2 The threshold of the laser at 418nm is 3.63μJ / cm 2 .

[0029] Embodiment five:

[0030] The 5F-BBPS thin single crystal is transferred and laid flat on a Si / SiO2 substrate coated with 20nm thick polymethyl methacrylate (PMMA), and then a 100nm thick silver electrode is evaporated on the crystal after masking. The organic light-emitting field effect transistor device can be produced by removing the mask.

[0031] For example, a 5F-BBPS crystal laid on a PMMA / SiO2 / Si substrate was covered with a mask, and then placed in a vacuum metal evaporator to evaporate 100nm of silver. After the sample was removed, the mask was torn off to obtain an OFET device with a source-drain electrode as an Ag symmetrical electrode and a channel width of 25μm. The field effect was tested using a Keithley 4200SCS semiconductor electrical test system as follows: Figure 5 way to test.

[0032] Embodiment six:

[0033] Test of the migration curve of the OFET device: The electron migration signal of the device was tested with a source-drain voltage of 60V and a gate voltage range of 0-200V. The electron mobility was measured to be 1.03E-4cm when the source-drain voltage was 60V. 2 V -1 s-1 , and then the migration curve of the electronic signal is measured as shown in the figure.

[0034] Embodiment seven:

[0035] The 5F-BBPS thin single crystal was transferred and laid flat on a substrate with a metal anode and a hole injection layer evaporated thereon, and then an electron injection layer and a metal cathode were evaporated thereon after masking the crystal. The organic light-emitting diode device was obtained by removing the mask. The electrical tester Keithley 2400 was used to test the device as follows: Figure 7 The test is carried out in the following manner, wherein the metal anode and the metal cathode include Ag, Al, etc., the hole injection layer includes MoO3, etc., and the electron injection layer includes CsF, TPBi, etc.

Claims

1. A method for synthesizing a stilbene derivative molecule, characterized in that: A stilbene derivative (E)-1,2-bis(2',3',4',5',6'-pentafluoro-[1,1'-biphenyl]-4-yl)ethylene, namely 5F-BBPS, was designed and synthesized. The specific steps include: Trans-4,4-dibromostilbene powder, palladium acetate powder, cesium carbonate powder, and tricyclohexylphosphine powder were loaded into the branch reactor tube, and the gas was evacuated three times. Toluene was used as the solvent, pentafluorobenzene was added, and the mixture was stirred at 100° C. overnight. The resulting suspension was filtered under negative pressure, and the solid product was repeatedly washed with ethanol and dichloromethane to obtain the final product 5F-BBPS powder.

2. The synthesis method according to claim 1, characterized in that The reaction must be carried out under anhydrous and oxygen-free conditions.

3. The synthesis method according to claim 1, characterized in that The molar ratio of each drug in the step is trans-4,4-dibromostilbene: pentafluorobenzene: palladium acetate: cesium carbonate: tricyclohexylphosphine = 1:2:0.1:0.6:0.

2.

4. A stilbene derivative molecule 5F-BBPS, characterized in that: Prepared by the synthesis method according to claim 1, the structure is:

5. The stilbene derivative molecule according to claim 4, characterized in that: The absorption peak wavelength of its dilute dichloromethane solution is at 317nm, the luminescence peak wavelength is at 375nm and 393nm, and the fluorescence quantum yield is 0.66; the excitation peak of the solid single crystal is at 272nm and 360nm, the luminescence peak is at 376nm, 396nm, 416nm and 436nm, and the fluorescence quantum yield is 0.

75.

6. A single crystal of a stilbene derivative, characterized in that: The molecules described in claim 4 or 5 are subjected to a micro-sublimation method to obtain 5F-BBPS thin single crystals that grow vertically and flat on a substrate.

7. A stilbene derivative single crystal as claimed in claim 6, characterized in that: Under the excitation of a 360nm femtosecond laser, laser emission can be achieved at the edge of the crystal. The laser wavelength is 395nm and 418nm, and the threshold is less than 4μJ / cm 2 .

8. An organic field effect transistor device based on the stilbene derivative single crystal according to claim 6 or 7, characterized in that: The 5F-BBPS thin single crystal is transferred and laid flat on a Si / SiO2 substrate coated with 20nm thick polymethyl methacrylate (PMMA), and then a 100nm thick silver electrode is evaporated on the crystal after masking. The organic light-emitting field effect transistor device can be produced by removing the mask.

9. An organic light emitting diode device based on the stilbene derivative single crystal according to claim 6, characterized in that: The 5F-BBPS thin single crystal is transferred and laid flat on a substrate with a metal anode and a hole injection layer evaporated on it, and then an electron injection layer and a metal cathode are evaporated on the crystal after masking. The organic light-emitting diode device can be produced by removing the mask.

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