Preparation method of high-intrinsic polarization red light emission organic single crystal material and application of high-intrinsic polarization red light emission organic single crystal material in electroluminescent device

Abstract

The invention discloses a preparation method of a high intrinsic polarization red light emission organic single crystal material and an application of the high intrinsic polarization red light emission organic single crystal material in an electroluminescent device, and the organic single crystal material is 2, 7-bis (4-methoxyphenyl)-9H-fluorene-9-ketone. Through molecular structure design and accumulation structure regulation and control, the organic single crystal electroluminescent device with high intrinsic polarization red light emission is prepared. Compared with the prior art, the intrinsic polarization ratio of the realized organic single crystal reaches up to 97, which is the best level in the field of intrinsic polarization luminescence of the organic single crystal at present; besides, according to the molecular and organic single crystal structure designed by the invention, intrinsic polarized light emission of a 610 nm red light wave band is successfully realized, and the blank that the light emitting wavelength does not exceed 600 nm in the field of organic single crystal electroluminescent devices is filled up.

Description

Technical Field

[0001] This invention belongs to the field of organic material preparation technology, specifically relating to a method for preparing a high intrinsic polarized red light emitting organic single crystal material and its application in electroluminescent devices. Background Technology

[0002] Polarized light is a type of optical signal with a regular electromagnetic oscillation direction. Besides wavelength, intensity, and phase, it can carry more information dimensions, thus exhibiting unique advantages and broad application prospects in high-bandwidth secure communication, 3D display, industrial visual inspection, and biomedical diagnostics. Compared to visible light of other wavelengths, polarized red light has lower photon energy, higher penetration, and lower scattering, making it more advantageous and promising for applications such as biological imaging, health monitoring, and secure communication. Acquiring polarized red light is a core step in related technological applications, but currently, it typically relies on superimposing a polarizer on front of a conventional red light source. Although this method is widely adopted, the added polarizing element introduces additional light absorption, weakening the brightness of the polarized red light source and resulting in high energy consumption and large device size. For example, currently commercially available polarizers often block more than half of the incident light during use, directly manifesting as a significant decrease in panel brightness and a significant increase in device power consumption in emerging applications such as polarized displays and health monitoring.

[0003] In contrast, organic semiconductor single crystals, with their long-range ordered molecular arrangement and asymmetric stacking characteristics, can achieve intrinsically linearly polarized emission without the need for external polarization elements. This characteristic not only effectively reduces optical losses and avoids wavelength dispersion caused by filtering, but also significantly reduces the size of polarized light sources, replacing traditional discrete devices and enabling ultra-high integration of polarized electroluminescent devices. Furthermore, the molecules constituting organic single crystals exhibit structural diversity, allowing for the modulation of photoelectric properties (such as emission color) and polarization characteristics, making them an ideal material system for realizing intrinsically polarized light sources.

[0004] Nevertheless, realizing organic single-crystal electroluminescent devices with high intrinsic polarization red light emission still faces significant challenges. The reasons are as follows: (1) For organic single-crystal electroluminescent devices, the molecular structure and stacking method of the emitting layer material determine its luminescence and polarization characteristics. Therefore, reasonable molecular structure design and stacking structure control become the core challenges in realizing high intrinsic polarization red light emission devices. (2) Currently reported, the intrinsic polarization ratio of organic single-crystal-based intrinsic polarization electroluminescent devices does not exceed 50, and the emission wavelength is mainly in the green and blue light bands before 580 nm. The fabrication of organic single-crystal electroluminescent devices with high intrinsic polarization red light emission faces challenges.

[0005] The above challenges have hindered the application of organic single-crystal intrinsically linearly polarized light-emitting devices in related fields. Summary of the Invention

[0006] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments.

[0007] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0008] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing organic single crystal materials with high intrinsic polarization red light emission.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a high intrinsic polarization red light emitting organic single crystal material, comprising, 2,7-bis(4-methoxyphenyl)-9H-fluorene-9-one was dissolved in a solvent to form a seed solution; Seed solution is dropped onto the surface of a hydrophilic substrate. The substrate and seed solution are placed in a glass culture dish containing n-butanol and then placed in a drying oven at 40°C. After the solution is completely evaporated, a flat, regular two-dimensional crystal material is obtained attached to the substrate, namely a high intrinsic polarized red light emitting organic single crystal material. The organic single-crystal material is 2,7-bis(4-methoxyphenyl)-9H-fluorene-9-one, and its chemical structural formula is: .

[0010] In a preferred embodiment of the preparation method described in this invention, the solvent includes m-xylene.

[0011] In a preferred embodiment of the preparation method described in this invention, the concentration of the seed solution is 1.5 mg / L.

[0012] In a preferred embodiment of the preparation method described in this invention, the ratio of the seed solution to n-butanol is 200 μL: 5 mL.

[0013] Another objective of this invention is to overcome the shortcomings of the prior art and provide a high intrinsic polarization red light emission organic single crystal material, wherein the organic single crystal has an intrinsic polarization ratio of 97.4, achieving intrinsic polarization light emission in the 610 nm red light band.

[0014] Another objective of this invention is to overcome the shortcomings of the prior art and provide an application of organic single-crystal materials in the fabrication of electroluminescent devices.

[0015] As a preferred embodiment of the application described in this invention, the method includes: epitaxially growing a BMeOPhFO single crystal on an ITO substrate using a solution method, followed by sequentially depositing functional layers in a high-vacuum evaporation system. First, 1,3,5-tris(3-pyridyl)benzene TmPyPB was deposited as an electron transport layer, with the deposition rate controlled at 0.8 Å / s; Subsequently, a calcium / silver composite cathode was deposited sequentially, wherein the calcium layer was deposited at a rate of 0.2 Å / s and the silver layer at a rate of 1 Å / s. The resulting device structure is ITO / BMeOPhFO single crystal / TmPyPB / Ca / Ag.

[0016] In a preferred embodiment of the application described in this invention, the electron transport layer has a thickness of 40 nm.

[0017] In a preferred embodiment of the application described in this invention, the calcium layer has a thickness of 20 nm and the silver layer has a thickness of 100 nm.

[0018] Beneficial effects of this invention: (1) This invention has achieved the fabrication of an organic single-crystal electroluminescent device with high intrinsic polarization red light emission through molecular structure design and stacking structure control. Compared with the prior art, the organic single crystal intrinsic polarization ratio achieved is as high as 97.4, which is the best level in the field of organic single crystal intrinsic polarization light emission. In addition, the molecular and organic single-crystal structure designed in this invention has successfully achieved intrinsic polarization light emission in the 610 nm red light band, filling the gap in the field of organic single-crystal electroluminescent devices with emission wavelengths not exceeding 600 nm.

[0019] (2) The high intrinsic polarization red light emission organic single crystal electroluminescent device realized by the present invention is expected to be applied in fields such as biological imaging, health monitoring and secure communication. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a chemical structure diagram of the BMeOPhFO organic small molecule single crystal in an embodiment of the present invention.

[0021] Figure 2 This is a graph showing the anisotropic transition dipole calculation results of organic molecules in an embodiment of the present invention.

[0022] Figure 3 This is a diagram showing the stacking structure of a highly intrinsically polarized red light organic single crystal in an embodiment of the present invention.

[0023] Figure 4This is a PL polarization spectrum and polarization ratio diagram of a highly intrinsically polarized red-emitting organic single crystal in an embodiment of the present invention.

[0024] Figure 5 This is a diagram showing the horizontal dipole orientation ratio of organic single crystals in an embodiment of the present invention.

[0025] Figure 6 This is a structural diagram of a high intrinsic polarization red light emitting organic single crystal electroluminescent device in an embodiment of the present invention.

[0026] Figure 7 This is a spectrum and color coordinate diagram of high intrinsic polarized red light emission organic single crystal electroluminescence in an embodiment of the present invention.

[0027] Figure 8 The BMeOPhFO molecule in the embodiments of the present invention 1 H and 13 C NMR image.

[0028] Figure 9 This is a synthetic route diagram of the BMeOPhFO compound in an embodiment of the present invention.

[0029] Figure 10 This is a single-crystal diffraction structure diagram of the BMeOPhFO organic small molecule in an embodiment of the present invention. Detailed Implementation

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0031] The specific sources of the raw materials used in the embodiments of this invention are as follows: Indium tin oxide (ITO) conductive glass substrate with resistivity <10 Ω was purchased from Zhuhai Kaiwei Optoelectronics Technology Co., Ltd. Polymethyl methacrylate (PMMA, model M0088) was purchased from TCI (Shanghai) Chemical Industry Development Co., Ltd. 1,3,5-Tris(3-pyridyl)benzene (TmPyPB, 99% purity), purchased from Sigma-Aldrich; Calcium (Ca, 99% purity) was purchased from Shanghai Bailingwei Chemical Technology Co., Ltd. Silver particles (Ag, purity 99.999%) were purchased from Zhongnuo New Materials Technology Co., Ltd. 2,7-Dibromofluorenone (≥98%, Shanghai Mairui Biochemical Technology Co., Ltd.), 4-methoxyphenylboronic acid (≥97%, Shanghai Bide Pharmaceutical Technology Co., Ltd.), and tetra-triphenylphosphine palladium (≥99%, Shanghai Mairui Biochemical Technology Co., Ltd.) are all commercially available products.

[0032] Example 1 (1) Synthesis of 2,7-bis(4-methoxyphenyl)-9H-fluorene-9-one (hereinafter referred to as BMeOPhFO) molecule Reactants and reagents are obtained through commercial procurement without any further processing.

[0033] The BMeOPhFO compound was synthesized in one step using the Suzuki coupling method; the product was purified by gel chromatography using petroleum ether and dichloromethane (3:1) as eluents.

[0034] For the specific synthetic method of BMeOPhFO compounds (see the synthetic route diagram), please refer to [link / diagram]. Figure 9 ): Using an electronic balance, 1.00 g of 2,7-dibromofluorenone yellow powder (338.00 g / mol, 2.96 mmol), 0.89 g of 4-methoxyphenylboronic acid powder (151.96 g / mol, 5.86 mmol), and 0.20 g of tetraphenylphosphine palladium powder (1155.56 g / mol, 0.17 mmol) were weighed into a round-bottom three-necked flask. 20 mL of toluene and 3 mL of a pre-prepared 2 mol% potassium carbonate aqueous solution were added. The mixture was refluxed under nitrogen at 85 °C for 48 h. After the reaction was completed, the temperature was lowered to room temperature. Then, dichloromethane and water were added to dilute the reaction solution. The mixture was extracted by separation in a separatory funnel, and the organic phase mixture was retained. The organic phase mixture was dried with anhydrous magnesium sulfate, and the organic solvent was removed by rotary evaporator to obtain the crude product. The crude product was purified by silica gel column chromatography using petroleum ether:dichloromethane = 3:1 as the eluent, and finally a white solid powder (0.87 g, 75%) was obtained.

[0035] BMeOPhFO molecules 1 H and 13 See the C NMR image. Figure 8 This indicates that the target product was successfully synthesized.

[0036] (2) The molecular skeleton of this compound exhibits a symmetrical donor-acceptor-donor (DAD) structure. Figure 1 The fluorenone unit at the molecular center acts as a strong electron acceptor, providing a rigid framework to maintain the overall planarity of the molecule and lowering the lowest unoccupied molecular orbital (LUMO) energy level, effectively reducing the optical band gap. Furthermore, the terminal methoxy-substituted benzene ring acts as an electron donor, raising the highest occupied molecular orbital (HOMO) energy level and further expanding the π-conjugated system. On the other hand, this DAD-type rod-shaped molecular structure endows BMeOPhFO with significant intramolecular charge transfer (ICT) properties, contributing to a redshift in the emission spectrum.

[0037] Furthermore, the DAD-type long rod-shaped molecular structure is advantageous for achieving high molecular anisotropy. Theoretical calculations show that the excited states of BMeOPhFO are located in the X, Y, and Z directions of the unit cell ( Figure 2 The light exhibits significant anisotropy, which is one of the necessary conditions for achieving highly intrinsically polarized light emission.

[0038] Example 2 (1) Preparation of BMeOPhFO single crystal material Solution-based growth process for organic small molecule single crystals: 200 μL of 1.5 mg / L BMeOPhFO / m-xylene solution was dropped onto the surface of a hydrophilic substrate (a glass substrate covered with an ITO conductive film, which was treated with oxygen plasma to modify its surface to be hydrophilic; the oxygen plasma bombardment power was 200 W and the time was 10 min). Place the substrate and seed solution in a glass culture dish containing 5 mL of n-butanol; The above-mentioned growth reagent combination was placed in a drying oven and kept at 40°C. The n-butanol evaporated in the sealed environment and acted as an anti-solvent to regulate the nucleation and crystal growth rate, promoting the stable growth of crystals at a steady and slow rate. After the solution completely evaporates, a flat, regular two-dimensional crystal, known as a BMeOPhFO single crystal, is obtained by adhering to the substrate. The selected area electron diffraction pattern of the single crystal using transmission electron microscopy is shown below. Figure 10 As can be seen, the discrete and clear diffraction points prove its single-crystal properties.

[0039] (2) Regulation of the stacking structure of organic crystals with high intrinsic polarization red light emission: BMeOPhFO molecules possess a typical long rod-shaped π-conjugated framework, exhibiting a highly ordered stacking pattern along the principal axis in single crystals. For example... Figure 3 As shown, this stacking not only maintains the tight π-π interactions between molecules, but also forms an anisotropic molecular arrangement in space, effectively amplifying the intrinsic anisotropic properties of the molecules. Therefore, organic crystals exhibit high intrinsic polarization emission characteristics on a macroscopic scale.

[0040] Molecular stacking structure regulation is also one of the necessary conditions for achieving highly intrinsically polarized red light emission. For the BMeOPhFO molecule, its excited-state transition dipoles are mainly distributed along the long axis of the molecule. It can be seen that the stacking direction of the BMeOPhFO molecules forms a 17° angle with the bottom surface, and the molecules are oriented almost parallel to each other along the unit cell in the crystal. b When axes are stacked in an ordered manner, the local dipole orientations superimpose at the crystal scale, thereby achieving high intrinsic polarization emission on a macroscopic scale.

[0041] At the same time, the π-π stacking in the direction perpendicular to the substrate is relatively strong, resulting in [the following effect] in the unit cell. c The radiation intensity along the axial direction is significantly reduced (aggregate quenching effect). This transmission effect of "molecular anisotropy - crystal orientation stacking - macroscopic polarization enhancement" is the fundamental reason why BMeOPhFO exhibits an ultra-high intrinsic polarization ratio.

[0042] (3) Angle-dependent photoluminescence (PL) test The test used a confocal micro-area Raman imaging system (WITec, alpha300 R) as the spectral acquisition platform, with a continuous laser at a wavelength of 405 nm as the excitation source. The polarization angle θ of the detection light was changed by manually rotating the half-wave plate (defined as θ = 0° at the crystal edge), and the PL emission spectra at different θ values ​​were recorded. The emission signal was collected by the objective lens (50×) and then acquired by the spectral detection module, with an integration time of 0.5 s, 30 integration iterations, and a step angle of 15°.

[0043] The polarization angle θ of the detected light was controlled by rotating the polarizer (θ = 0° is defined as the direction parallel to one side of the crystal, and the rotation is clockwise), and the results were obtained. Figure 4 The data shows that when θ is close to parallel to... b The PL strength reaches its maximum value in the axial direction; while it reaches its maximum value when θ is close to θ. c The PL intensity is lowest along the axial direction. Furthermore, the PL intensity of the 627 nm emission peak was systematically recorded within the range of θ = 0–360°, and a polar coordinate distribution plot was drawn. The results show that the emission of the BMeOPhFO single crystal exhibits significant anisotropy under different polarization angles, among which… b The axial direction is the strongly polarized emission direction.

[0044] Further analysis of molecular orientation ( Figure 5 It can be observed that BMeOPhFO single crystals have a high horizontal dipole orientation ratio (≈0.91), indicating that they have molecular dipole orientations that are highly parallel to the substrate. This highly horizontal dipole arrangement not only effectively improves the light extraction efficiency and suppresses light extraction loss due to total internal reflection, but also causes significant differences in radiative luminescence efficiency in different polarization directions, thus ensuring the high intrinsic polarization red light emission capability of BMeOPhFO organic single crystals.

[0045] In summary, BMeOPhFO single crystals exhibit excellent intrinsically polarized red light emission characteristics, with an intrinsic polarization ratio (PR) reaching a maximum of 97.4 (corresponding to a polarization degree DOP = 0.98), which is the highest value reported to date. This result fully demonstrates that the ordered stacking of molecules with long axis orientation significantly enhances the polarization characteristics of intrinsic red light emission, providing a solid material structure foundation for realizing high-performance polarized red light organic single crystal light-emitting devices.

[0046] Example 3 (1) Construction of high intrinsic polarization red light emission organic single crystal electroluminescent device BMeOPhFO single crystals were obtained by direct epitaxial growth on an ITO substrate using a solution method. Specifically, 200 μL of a 1.5 mg / L BMeOPhFO / m-xylene solution was dropped onto the surface of an ITO / glass hydrophilic substrate that had been treated with oxygen plasma. Place the substrate and seed solution in a glass culture dish containing 5 mL of n-butanol; The above-mentioned growth reagent combination was placed in a drying oven and kept at 40°C. The n-butanol evaporated in the sealed environment and acted as an anti-solvent to regulate the nucleation and crystal growth rate, promoting the stable growth of crystals at a steady and slow rate. After the solution is completely evaporated, a flat, regular two-dimensional BMeOPhFO single crystal can be obtained attached to an ITO / glass substrate; Subsequently, functional layers are deposited sequentially in a high-vacuum evaporation system: First, 1,3,5-tris(3-pyridyl)benzene (TmPyPB) was deposited as an electron transport layer with a thickness of approximately 40 nm, and the deposition rate was controlled at 0.8 Å / s. Subsequently, a calcium / silver composite cathode was deposited sequentially, with the calcium layer being approximately 20 nm thick at a deposition rate of 0.2 Å / s and the silver layer being approximately 100 nm thick at a deposition rate of 1 Å / s.

[0047] like Figure 6 As shown, the device structure consists of an ITO layer (1), a BMeOPhFO single crystal layer (2), a TmPyPB layer (3), a Ca layer (4), an Ag layer (5), and a polymethyl methacrylate layer (6) arranged from bottom to top. Indium tin oxide (ITO) in the device is used as a transparent conductive electrode, which plays the role of conductive anode and light emission in the device. Polymethyl methacrylate (PMMA) plays the role of covering the organic crystal around it, which can avoid short circuits caused by direct contact between the upper and lower electrodes, and can also prevent the vapor-deposited cathode from breaking at the edge of the organic single crystal due to the height difference.

[0048] The resulting device structure ( Figure 6 The composition is ITO (200 nm) / BMeOPhFO single crystal (420 nm) / TmPyPB (40 nm) / Ca (20 nm) / Ag (100 nm).

[0049] The calcium / silver composite cathode was prepared using a vacuum thermal evaporation process, under the following specific conditions: in a high-vacuum evaporation system (vacuum degree below 3 × 10⁻⁶). -4A composite cathode is formed by sequentially depositing a calcium layer and a silver layer (Pa). First, a calcium layer is deposited at a rate controlled at 0.2 Å / s with a thickness of 20 nm to ensure a continuous and dense electron injection interface. Subsequently, a silver layer was deposited under the same vacuum conditions at a deposition rate of approximately 1.0 Å / s, resulting in a thickness of approximately 100 nm. The deposition rate was monitored and calibrated in real time using a quartz crystal oscillator to ensure controllable film thickness and uniformity. The resulting Ca / Ag composite electrode forms a good ohmic contact with the underlying electron transport layer (TmPyPB), which is beneficial for achieving efficient electron injection and stable device performance.

[0050] (2) Electroluminescence test: Electroluminescence (EL) testing was performed on the BMeOPhFO single-crystal device. The system was an EL measurement platform consisting of a digital source meter (Keithley 2400) and a spectroradiometer (PhotoResearch PR655).

[0051] A voltage is applied via a Keithley 2400, while the PR655 can acquire the emission spectrum and corresponding color coordinates of the device under different bias voltages.

[0052] To further investigate the polarization characteristics of the emitted light, a confocal micro Raman spectroscopy system with the laser off (WITecalpha300 R) was used as the polarization EL measurement platform. The device was fixed on the sample stage, and a stable voltage was applied to the device using a Keithley 2400. By manually rotating the half-wave plate to precisely change the polarization angle θ of the emitted light, the spectral detection module of the WITec alpha300 R simultaneously acquired the EL spectral intensity at different polarization angles, obtaining the strongest and weakest polarization spectra, and calculating the polarization ratio accordingly.

[0053] The polarization ratio (PR) is the ratio of the luminous intensity in two polarization directions, defined as: Polarization Ratio(PR) = I max / I min .

[0054] In the electroluminescence test, the electroluminescence polarization PR value of the device was quantitatively calculated to be 62.7 (corresponding to a polarization degree of approximately 0.97). The main reason for the decrease in polarization ratio compared to photoluminescence is due to scattering from the amorphous functional layer thin film in the electroluminescent device.

[0055] For the spectrum and color coordinate diagram of high intrinsic polarized red light emission organic single crystal electroluminescence, please refer to [reference needed]. Figure 7The electroluminescence color coordinates of the device are (0.56, 0.39), close to the ideal red standard value, indicating that this organic single crystal achieves high intrinsic polarization red light emission under electrical injection. This provides a material and device foundation for the future application of high intrinsic polarization red light emission sources in polarization display and biological polarization imaging.

[0056] This invention designs and synthesizes a high intrinsic polarization red light emitting organic single crystal, and uses this organic single crystal to prepare an electroluminescent device as a high intrinsic polarization red light emission source. Its intrinsic polarization ratio is as high as 97.4, and the emission wavelength peak is located in the red light band of 610 nm. The organic molecule designed in this patent has the following structural characteristics: (1) It has a donor-acceptor-donor (DAD) chain molecular structure, which can effectively enhance the intramolecular charge transfer characteristics, reduce the material band gap, and realize red light emission. (2) The long rod-like structure of this molecule is conducive to enhancing the anisotropy of the molecule and realizing higher intrinsic polarization characteristics. (3) Based on this molecule, the organic single crystal has an angle of less than 20° between the long axis of the molecule and the substrate, and has a high horizontal dipole orientation, which is conducive to further enhancing the intrinsic polarization emission characteristics of the organic single crystal. In summary, this patented technical solution solves the challenge of achieving high intrinsic polarization red light emission in organic single crystal electroluminescent devices, and is expected to promote the application of organic single crystal electropolarized light emitting devices in the next generation of health monitoring and bioimaging.

[0057] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing a highly intrinsically polarized red-emitting organic single-crystal material, characterized in that: include, 2,7-bis(4-methoxyphenyl)-9H-fluorene-9-one was dissolved in a solvent to form a seed solution; Seed solution is dropped onto the surface of a hydrophilic substrate. The substrate and seed solution are placed in a glass culture dish containing n-butanol and then placed in a drying oven at 40°C. After the solution is completely evaporated, a flat, regular two-dimensional crystal material is obtained attached to the substrate, namely a high intrinsic polarized red light emitting organic single crystal material. The organic single-crystal material is 2,7-bis(4-methoxyphenyl)-9H-fluorene-9-one, and its chemical structural formula is: 。 2. The method for preparing organic single-crystal materials as described in claim 1, characterized in that: The solvent includes m-xylene.

3. The method for preparing organic single-crystal materials as described in claim 1 or 2, characterized in that: The concentration of the seed solution is 1.5 mg / L.

4. The method for preparing organic single-crystal materials as described in claim 3, characterized in that: The ratio of the seed solution to n-butanol is 200 μL: 5 mL.

5. The high intrinsic polarized red-emitting organic single-crystal material prepared by any one of claims 1 to 4, characterized in that: The organic single crystal has an intrinsic polarization ratio of 97.4, enabling intrinsically polarized light emission in the 610 nm red light band.

6. The application of the organic single-crystal material according to claim 5 in the preparation of electroluminescent devices.

7. The application as described in claim 6, characterized in that: include, BMeOPhFO single crystals were epitaxially grown on an ITO substrate using a solution method, followed by the sequential deposition of functional layers in a high-vacuum evaporation system. First, 1,3,5-tris(3-pyridyl)benzene TmPyPB was deposited as an electron transport layer, with the deposition rate controlled at 0.8 Å / s; Subsequently, a calcium / silver composite cathode was deposited sequentially, with the calcium layer evaporation rate being 0.2 Å / s and the silver layer evaporation rate being 1 Å / s. The resulting device structure is ITO / BMeOPhFO single crystal / TmPyPB / Ca / Ag.

8. The application as described in claim 7, characterized in that: The electron transport layer has a thickness of 40 nm.

9. The application as described in claim 7, characterized in that: The calcium layer has a thickness of 20 nm, and the silver layer has a thickness of 100 nm.

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