A pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, its synthesis method, and its application in OLED device fabrication.

Abstract

This invention discloses a pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, its synthesis method, and its application in OLED device fabrication. The pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material disclosed in this invention possesses a highly conjugated planar structure and high rigidity, showing significant potential for solid-state light emission. Through a donor-π bridge-acceptor design strategy, the overlap between HOMO and LUMO orbitals is increased, thereby improving the photoinduced quantum yield. Furthermore, by matching strong donor and acceptor units, the electron cloud is localized on the HOMO and LUMO orbitals, effectively improving the triplet exciton utilization rate, providing a new approach for practical blue OLED applications.

Description

Technical Field

[0001] This invention belongs to the field of organic semiconductor materials technology, and relates to the design and synthesis of pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material molecules, as well as the preparation method and application of OLED devices based thereon. Specifically, it relates to a pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, its synthesis method and its application in preparing OLED devices. Background Technology

[0002] Organic light-emitting diodes (OLEDs) play an indispensable role in flexible display technology, smart wearable devices, and everyday lighting. Since the advent of the first low-voltage driven organic electroluminescent device, organic electroluminescent materials have undergone rapid upgrades, from initial fluorescent materials to phosphorescent materials with high exciton utilization, and then to thermally activated delayed fluorescence materials made of pure organic molecules, greatly improving the performance of electroluminescent devices. Currently, research on red and green light-emitting devices is relatively mature, while the development of blue light-emitting host materials is progressing slowly. Therefore, developing novel blue light-emitting host materials is particularly important.

[0003] Common blue OLED devices consist of an anode, an electron injection layer, an electron transport layer, a light-emitting molecular layer, a hole transport layer, a hole injection layer, and a cathode. The light-emitting molecular layer, as the core of the blue OLED device, plays a crucial role. Existing light-emitting molecular structures are primarily designed using a donor-conjugated bridge-donor strategy, with common nitrogen-containing acceptor materials including cyanopyridine, dicyandiamide, pyrimidine, triazine, quinoxaline, and their derivatives.

[0004] The limited variety of usable acceptor materials currently available hinders the achievement of optimal matching with donors to achieve high quantum yields. This presents a significant challenge to the design of novel, high-efficiency blue OLEDs. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the present invention aims to provide a pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, its synthesis method and its application in OLED device preparation, thereby solving the problem of the scarcity of existing organic blue light-emitting diode materials.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] This invention discloses a pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, comprising TM-1 and TM-2, with the structural formulas shown below:

[0008]

[0009] This invention also discloses a method for synthesizing the above-mentioned pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, comprising the following steps:

[0010] 1) Under an inert atmosphere, 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline and 3,6-di-tert-butylcarbazole / di(4-tert-butylphenyl)amine, along with the catalyst, are dissolved in an organic solvent and stirred thoroughly until homogeneous.

[0011] 2) Tris(dibenzylacetone)palladium Pd2(dba)3 and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenylXPhos were added to the mixed system and reacted at 80-120℃-100℃. The crude product was purified by silica gel column chromatography to obtain pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material.

[0012] When 3,6-di-tert-butylcarbazole is selected as the reactant in step 1), TM-1 is prepared.

[0013] When di(4-tert-butylphenyl)amine is selected as the reactant in step 1), TM-2 is prepared.

[0014] Preferably, the molar ratio of 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline and 3,6-di-tert-butylcarbazole / di(4-tert-butylphenyl)amine is 1:1.

[0015] Preferably, the catalyst is Cs2CO3, and the molar ratio of Cs2CO3 to 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline is 2:1.

[0016] Preferably, the organic solvent is toluene.

[0017] Preferably, the silica gel column chromatography purification uses a mobile phase of petroleum ether: dichloromethane = 1:2 for elution.

[0018] This invention also discloses the application of the above-mentioned pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material in the preparation of OLED light-emitting devices.

[0019] The present invention also discloses an OLED light-emitting device made of the above-mentioned pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material, wherein the pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material is used to prepare an organic semiconductor light-emitting layer located between the electron transport layer and the hole transport layer.

[0020] Preferably, the OLED light-emitting device includes:

[0021] (a) A matrix material;

[0022] (b) A cathode;

[0023] (b) An electron injection layer near the cathode;

[0024] (c) An electron transport layer close to the electron injection layer;

[0025] (d) An anode;

[0026] (e) A hole injection layer near the anode;

[0027] (f) A hole transport layer close to the hole injection layer;

[0028] (g) An organic semiconductor light-emitting layer sandwiched between an electron transport layer and a hole transport layer, the light-emitting layer containing an organic semiconductor compound.

[0029] Preferably, the thickness of the organic semiconductor light-emitting layer is 10–100 nm.

[0030] Preferably, the substrate material is glass, metal foil, or polymer film.

[0031] Preferably, the cathode material is a metal such as gold, silver, aluminum, or iron, with a thickness of 10-50 nm.

[0032] Preferably, the electron injection layer material is lithium fluoride, cesium fluoride, or rubidium fluoride, with a thickness of 1-10 nm.

[0033] Preferably, the electron transport layer material is 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) with a thickness of 10-100 nm.

[0034] Preferably, the anode material is indium tin oxide (ITO) with a thickness of 10-50 nm.

[0035] Preferably, the hole injection layer material is molybdenum trioxide with a thickness of 1-10 nm.

[0036] Preferably, the hole transport layer material is N,N'-diphenyl-N,N'-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) and tris(4-carbazolyl-9-ylphenyl)amine (TCTA), with a thickness of 1-10 nm.

[0037] Preferably, the OLED light-emitting device exhibits blue emission at a voltage of 9V.

[0038] More preferably, the above-mentioned method for fabricating the OLED light-emitting device includes the following steps:

[0039] 1) Clean the ITO glass substrate sequentially using an ultrasonic cleaner, passing it through detergent, ethanol, acetone, and pure water for 5 minutes each, repeating this process 3 times. Then dry it in an infrared oven, and finally treat the ITO glass substrate with ultraviolet ozone.

[0040] 2) Place the ITO glass in the vacuum coating apparatus and set the vacuum coating parameters as follows: evaporation rate is... The vapor deposition pressure is 1E-6 to 1E-5 mbar, and the vapor deposition temperature is 80 to 200℃. The gas pressure inside the vacuum coating device is reduced. When the gas pressure inside the device is less than 5.0 mbar, the molecular pump is turned on. When the gas pressure reaches the vapor deposition pressure, the thin film is vapor deposited. The following materials are vapor deposited: molybdenum trioxide, N,N'-diphenyl-N,N'-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB), tris(4-carbazolyl-9-ylphenyl)amine (TCTA), organic light-emitting layer material, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, lithium fluoride, and aluminum.

[0041] 3) Package the fabricated device.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material disclosed in this invention possesses a ternary fused-ring molecular structure, resulting in a highly conjugated planar structure and high rigidity, demonstrating significant application potential in solid-state light emission. Through a donor-π-bridge-acceptor design strategy, the overlap between HOMO and LUMO orbitals is increased, thereby improving the photoinduced quantum yield. Furthermore, by matching strong donor and acceptor units, the electron cloud is localized on the HOMO and LUMO orbitals, enhancing triplet exciton utilization and providing a new approach for practical blue OLED applications.

[0044] The OLED device based on the above-mentioned pyrroloquinoxaline organic nitrogen-containing semiconductor material has the following advantages:

[0045] (1) The electroluminescence spectra of the TM-1 and TM-2 devices at 9V have maximum emission peaks of 456nm and 470nm, respectively, with CIE coordinates of (0.159, 0.131) and (0.164, 0.217), respectively, showing blue emission;

[0046] (2) The turn-on voltage and maximum luminous intensity of the TM-1 and TM-2 devices are 7.82V and 1718cd / m², respectively. 2 and 4.24V / 2633cd / m 2 ;

[0047] (3) Maximum external quantum efficiency (EQE) of TM-1 and TM-2 devices max The current efficiency is 0.73% and 1.08%; maximum current efficiency CE maxThe values ​​are 0.81 cd / A and 1.63 cd / A; the maximum power efficiency PE is... max The values ​​are 0.25 lm / W and 1.11 lm / W, respectively.

[0048] (4) The TM-1 device exhibited an efficiency roll-off of 2.7% and 12.3%, while the TM-2 device exhibited an efficiency roll-off of 6.5% and 23.1%. Attached Figure Description

[0049] Figure 1 The UV and fluorescence spectra of TM-1 and TM-2 molecules are shown.

[0050] Figure 2 Thermogravimetric diagrams of TM-1 and TM-2 molecules;

[0051] Figure 3 Cyclic voltammograms for TM-1 and TM-2 molecules;

[0052] Figure 4 Fluorescence lifetime plots for TM-1 and TM-2;

[0053] Figure 5 The diagram shows the device's energy levels and structure.

[0054] Figure 6 The device's EQE efficiency curve (EL spectrum) is shown.

[0055] Figure 7 This is a PE-L-CE curve of the device. Detailed Implementation

[0056] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0057] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0058] The present invention will now be described in further detail with reference to the accompanying drawings:

[0059] Example 1: Synthesis and structural characterization of TM-1 and TM-2

[0060] Synthesis and structural characterization of TM-1:

[0061] Under nitrogen protection, 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline 3 (161.0 mg, 0.5 mmol), 3,6-di-tert-butylcarbazole (0.5 mmol, 1.1 equiv.), and Cs₂CO₃ (325.8 mg, 1.0 mmol, 2 equiv.) were dissolved in toluene (10 mL) and magnetically stirred. Then, Pd₂(dba)₃ (14 mg, 0.015 mmol, 0.03 equiv.) and XPos (28.6 mg, 0.06 mmol, 0.12 equiv.) were added to the mixture, and the reaction was carried out at 100 °C under TLC monitoring. After the reaction was complete, the reaction was quenched with ice-salt water, extracted with dichloromethane, and the organic phases were combined. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. Purification was achieved by silica gel column chromatography (petroleum ether:dichloromethane = 1:2) to obtain product TM-1. The structural formula is as follows:

[0062]

[0063] The corresponding physicochemical identification data are shown below:

[0064] Pale yellow (242mg, 92% yield), 1H NMR (400MHz, CDCl3) δ: 8.26 (d, J = 8.2Hz, 2H), 8.18 (s, 2H), 8.10 (d, J = 7.8Hz, 1H), 8.06 (s, 1H), 7.93 (d, J = 8. 0Hz,1H),7.77(d,J=8.2Hz,2H),7.59~7.47(m,6H),7.15(d,J=3.7Hz,1H),7.01~6.95(m,1H),1.50(s,18H); 13 C NMR(100MHz, CDCl3)δ:153.5,143.1,139.7,139.0,136.8,136.1,130.2,130.1,127.7,127.1,126.6,1 25.4,125.2,123.7,123.5,116.3,114.9,114.2,113.7,109.3,108.7,34.7,32.0.HRMS-ESI:m / z[M+H] + Theory: [C] 37 H 36 BrN3] + :522.2909, Experiment:522 2897.

[0065] Synthesis and structural characterization of TM-2:

[0066] Under nitrogen protection, 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline 3 (161.0 mg, 0.5 mmol), di(4-tert-butylphenyl)amine (0.5 mmol, 1.1 equiv.), and Cs₂CO₃ (325.8 mg, 1.0 mmol, 2 equiv.) were dissolved in toluene (10 mL) and magnetically stirred. Then, Pd₂(dba)₃ (14 mg, 0.015 mmol, 0.03 equiv.) and XPos (28.6 mg, 0.06 mmol, 0.12 equiv.) were added to the mixture, and the reaction was carried out at 100 °C under TLC monitoring. After the reaction was complete, the reaction was quenched with ice-salt water, extracted with dichloromethane, and the organic phases were combined. The organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated to obtain the crude product. Purification was achieved by silica gel column chromatography (petroleum ether:dichloromethane = 1:2) to obtain product TM-2. The structural formula is as follows:

[0067]

[0068] The corresponding physicochemical identification data are shown below:

[0069] TM-2, bright yellow (210mg, 80% yield), 1H NMR (400MHz, CDCl3) δ: 8.03 (d, J=

[0070] 7.7Hz,1H),7.98(d,J=1.3Hz,1H),7.88(t,J=9.1Hz,3H),7.54~7.39(m,2H),7.31(d,J=8.6Hz,4H),7 .18(d,J=8.6Hz,2H),7.11(d,J=8.6Hz,4H),7.07(d,J=3.7Hz,1H),6.92~6.86(m,1H),1.34(s,18H); 13 C NMR (100MHz, CDCl3) δ: 154.0, 149.9, 146.4, 144.6, 130.0, 129.5, 129.0, 128.4, 127.1, 126. 2,125.4,125.3,124.6,121.7,114.5,113.9,113.6,108.7,34.4,31.5.HRMS-ESI:m / z[M+H] + Theory: [C] 37 H 38 BrN3] + :524.3066, Experiment:524.3058.

[0071] The solution-state UV-Vis and fluorescence emission spectra of TM-1 and TM-2 are as follows: Figure 1 As shown, the maximum absorption wavelength λ of compounds TM-1 and TM-2 in dichloromethane max The absorption wavelengths at 349 nm and 379 nm are due to intramolecular charge transfer, while the absorptions at 294 nm and 297 nm are due to π-π* transitions. The maximum absorption wavelength λ is due to the stronger electron-donating ability of diphenylamine and the stronger conjugation of the TM-2 molecule. max Compared to TM-1, it shifts 30 nm into the low-energy absorption region. Fluorescence emission spectra show that TM-1 and TM-2 exhibit maximum fluorescence emission wavelengths of 470 nm and 513 nm in dichloromethane, respectively, with only one broad emission peak, attributed to emission generated by charge transfer.

[0072] Thermogravimetric diagrams of TM-1 and TM-2 are as follows Figure 2 As shown, under a nitrogen atmosphere, in the range of room temperature to 800℃, at a heating rate of 10℃ / min, both TM-1 and TM-2 exhibited excellent thermal stability, with corresponding decomposition temperatures Td (the temperature corresponding to 5% weight loss) of 385℃ and 358℃, respectively. This indicates that these two compounds can meet the conditions for preparing OLEDs.

[0073] The cyclic voltammetry curves of TM-1 and TM-2 are as follows: Figure 3 As shown, a three-electrode system was used, with a platinum electrode as the counter electrode, a silver / silver chloride electrode as the reference electrode, a platinum-ITO glass plate as the working electrode, ferrocene as the internal standard, and tetrabutylammonium hexafluorophosphate (Bu4NPF6) as the electrolyte. The onset oxidation peak positions of TM-1 and TM-2 were 0.81 eV and 1.0 eV, respectively, with HOMO energies of -5.34 eV and -5.15 eV, and LUMO energies of -2.28 eV and -2.25 eV, respectively.

[0074] The fluorescence lifetimes of TM-1 and TM-2 are as follows: Figure 4 As shown, the fluorescence lifetimes of TM-1 and TM-2 are 2.16 ns and 5.82 ns, respectively.

[0075] Example 2: Fabrication of blue OLED device structure A

[0076] The specific steps for creating a blue OLED device using ITO / MoO3 (3nm) / NPB (40nm) / TCTA (10nm) / TM-1 (20nm) / TPBi (40nm) / LiF (1nm) / Al are as follows:

[0077] 1) Clean the ITO glass sequentially using an ultrasonic cleaner, passing it through detergent, ethanol, acetone, and pure water for 5 minutes each, repeating this process 3 times. Then dry it in an infrared oven.

[0078] 2) Place the ITO glass substrate in an ultraviolet ozone generator for 20 minutes to further remove organic matter adhering to the ITO glass substrate and improve the work function of the ITO surface.

[0079] 3) Place the ITO glass in the vacuum coating apparatus and set the vacuum coating parameters as follows: evaporation rate is... The vapor deposition pressure is 1E-6 to 1E-5 mbar, and the vapor deposition temperature is 80 to 200℃. The gas pressure inside the vacuum coating device is reduced. When the gas pressure inside the device is less than 5.0 mbar, the molecular pump is turned on. When the gas pressure reaches the vapor deposition pressure, the thin film is vapor deposited. The following materials are vapor deposited respectively: molybdenum trioxide (3nm), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) (40nm), tris(4-carbazolyl-9-ylphenyl)amine (TCTA) (10nm), organic light-emitting layer material TM-1 (20nm), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (40nm), lithium fluoride (1nm) and aluminum.

[0080] 4) After the vapor deposition is completed, remove the device and, in a glove box with a water and oxygen content of less than 1 ppm, use a prefabricated fixture to bond a glass cover plate coated with UV-curable adhesive to the device substrate. After shielding the organic layer, irradiate it under UV light for 3 minutes to cure. After UV exposure, a barrier is formed that isolates the device from the atmospheric environment. This barrier effectively prevents water and oxygen in the air from entering the device and avoids reactions with them.

[0081] 5) In the current-voltage-brightness characteristic test, a test system consisting of a Keithley 2400 power meter and a Topcon SR-UL1R spectroradiometer was used to collect relevant data (voltage, current, brightness, and spectrum) of the OLED devices. The external quantum efficiency (EQE) of all devices was calculated from the current density, brightness, and spectral data obtained from the above tests. No packaging was performed on any of the devices before testing. All tests were conducted at room temperature in a dark room.

[0082] Example 3: Fabrication of a blue OLED device (Device Structure B)

[0083] The specific steps for developing a blue OLED device using ITO / MoO3 (3nm) / NPB (40nm) / TCTA (10nm) / TM-2 (20nm) / TPBi (40nm) / LiF (1nm) / Al are as follows:

[0084] 1) Clean the ITO glass sequentially using an ultrasonic cleaner, passing it through detergent, ethanol, acetone, and pure water for 5 minutes each, repeating this process 3 times. Then dry it in an infrared oven.

[0085] 2) Place the ITO glass substrate in an ultraviolet ozone generator for 20 minutes to further remove organic matter adhering to the ITO glass substrate and improve the work function of the ITO surface.

[0086] 3) Place the ITO glass in the vacuum coating apparatus and set the vacuum coating parameters as follows: evaporation rate is... The vapor deposition pressure is 1E-6 to 1E-5 mbar, and the vapor deposition temperature is 80 to 200℃. The gas pressure inside the vacuum coating device is reduced. When the gas pressure inside the device is less than 5.0 mbar, the molecular pump is turned on. When the gas pressure reaches the vapor deposition pressure, the thin film is vapor deposited. The following materials are vapor deposited respectively: molybdenum trioxide (3nm), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1′-biphenyl-4,4′-diamine (NPB) (40nm), tris(4-carbazolyl-9-ylphenyl)amine (TCTA) (10nm), organic light-emitting layer material TM-2 (20nm), 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (40nm), lithium fluoride (1nm), and aluminum.

[0087] 4) After the vapor deposition is completed, remove the device and, in a glove box with a water and oxygen content of less than 1 ppm, use a prefabricated fixture to bond a glass cover plate coated with UV-curable adhesive to the device substrate. After shielding the organic layer, irradiate it under UV light for 3 minutes to cure. After UV exposure, a barrier is formed that isolates the device from the atmospheric environment. This barrier effectively prevents water and oxygen in the air from entering the device and avoids reactions with them.

[0088] 5) In the current-voltage-brightness characteristic test, a test system consisting of a Keithley 2400 power meter and a Topcon SR-UL1R spectroradiometer was used to collect relevant data (voltage, current, brightness, and spectrum) of the OLED devices. The external quantum efficiency (EQE) of all devices was calculated from the current density, brightness, and spectral data obtained from the above tests. No packaging was performed on any of the devices before testing. All tests were conducted at room temperature in a dark room.

[0089] Depend on Figure 6 , Figure 7 As shown, the device in Example 3 requires a lower turn-on voltage and has a higher luminous efficiency than the device in Comparative Example 2, indicating that the pyrroloquinoxaline organic nitrogen-containing semiconductor material TM-2 is more suitable for use in high-efficiency blue OLED devices than TM-1.

[0090] The electroluminescence performance parameters of blue OLED device structure A and device structure B are shown in Table 1:

[0091] Table 1. Device Performance Characterization

[0092]

[0093] a: At a brightness of 1 cd / m 2 Test data at time, b: Data in order: maximum value, at a brightness of 100 cd / m² 2 Test data at a brightness of 1000 cd / m² 2 Test data at that time.

[0094] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention. The above content is only for illustrating the technical concept of the present invention and cannot be used to limit the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in the present invention fall within the scope of protection of the claims of the present invention.

Claims

1. The application of a pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material in the fabrication of OLED light-emitting devices, characterized in that, The pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material is TM-1 or TM-2, and the structural formulas are shown below: 。 2. The application according to claim 1, characterized in that, The pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material is prepared according to the following method: 1) Under an inert atmosphere, dissolve 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline and 3,6-di-tert-butylcarbazole, or 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline and di(4-tert-butylphenyl)amine, and the catalyst in an organic solvent and stir thoroughly until homogeneous; 2) Add tris(dibenzylacetone)dipalladium Pd2(dba)3 and 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl XPhos to the mixed system, and heat at 80-120 °C. o The crude product was purified by silica gel column chromatography after reaction at C to obtain pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material; When 3,6-di-tert-butylcarbazole is selected as the reactant in step 1), TM-1 is prepared. When di(4-tert-butylphenyl)amine is selected as the reactant in step 1), TM-2 is prepared.

3. The application according to claim 2, characterized in that, The molar ratio of 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline to 3,6-di-tert-butylcarbazole is 1:1; or the molar ratio of 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline to 3,6-di-tert-butylcarbazole to di(4-tert-butylphenyl)amine is 1:

1.

4. The application according to claim 2, characterized in that, The catalyst used is Cs2CO3, and the molar ratio of Cs2CO3 to 4-(4'-bromophenyl)pyrrolo[1,2-α]quinoxaline is 2:

1.

5. The application according to claim 2, characterized in that, Toluene is used as the organic solvent.

6. The application according to claim 2, characterized in that, Purification by silica gel column chromatography was performed using a mobile phase of petroleum ether: dichloromethane = 1:

2.

7. An OLED light-emitting device, characterized in that, It includes an electron transport layer and a hole transport layer, and an organic semiconductor light-emitting layer is disposed between the electron transport layer and the hole transport layer. The organic semiconductor light-emitting layer is made of pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material. The pyrroloquinoxaline organic nitrogen-containing semiconductor light-emitting layer material is TM-1 or TM-2, with the following structural formulas: ； At 9V, the OLED light-emitting device exhibits blue emission.

8. The OLED light-emitting device as described in claim 7, characterized in that, The thickness of the organic semiconductor light-emitting layer is 10~100 nm.

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