Light-emitting auxiliary material and preparation method and application thereof

Abstract

The application provides a light-emitting auxiliary material and a preparation method and application thereof, and belongs to the field of organic electroluminescent materials, wherein the structural general formula of the light-emitting auxiliary material is chemical formula I; and the organic electroluminescent device using the light-emitting auxiliary material has excellent thermal stability, high light-emitting efficiency and long service life while keeping a low driving voltage.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of organic electroluminescence, and relates to a light-emitting auxiliary material and a preparation method and application thereof. BACKGROUND

[0002] An organic electroluminescence device (OLED) presents a multi-layer sandwiched structure, which specifically comprises electrode material film layers and organic functional materials sandwiched between different electrode film layers, including a hole injection layer, a hole transport layer, a light-emitting auxiliary layer, an electron blocking layer, a light-emitting layer, an electron buffer layer, a hole blocking layer, an electron transport layer, an electron injection layer, and the like.

[0003] The light-emitting auxiliary layer is arranged between the hole transport layer and the light-emitting layer, and can reduce the potential barrier between the hole transport layer and the light-emitting layer, reduce the driving voltage of the organic electroluminescence device, further increase the utilization rate of holes, and thus improve the light-emitting efficiency and service life of the device and reduce the driving voltage. However, there are few functional materials capable of forming a light-emitting auxiliary layer, and in particular, the morphology of the light-emitting auxiliary layer material in the device formed by evaporation is an amorphous disordered film, and the morphology of the thin film formed by evaporation affects the evaporation temperature and the service life and light-emitting efficiency of the OLED device. Therefore, it is particularly important to develop higher-performance organic functional materials to meet the requirements of panel manufacturing enterprises in mass production of organic electroluminescence displays. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a light-emitting auxiliary material and a preparation method and application thereof. The light-emitting auxiliary material according to the present application can be applied to an organic electroluminescence device, and can make the device have excellent thermal stability, high light-emitting efficiency and long service life while maintaining a low driving voltage.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0006] In one aspect, the present application provides a light-emitting auxiliary material, and the structure general formula of the light-emitting auxiliary material is chemical formula I:

[0007]

[0008] Ar1 and Ar2 are each independently selected from substituted or unsubstituted C6-C30 aryl, and the substituents in the substituted C6-C30 aryl are selected from deuterium, unsubstituted C1-C6 alkyl, C1-C6 alkyl fully or partially substituted by deuterium, or C6-C18 aryl.

[0009] The light-emitting auxiliary material of the present application connects benzofluorene and adamantane through a spiro ring, and further connects an aryl group triarylamine group side chain on one side of the fused ring of the fluorene. The light-emitting auxiliary material is applied to a device, so that the device has excellent thermal stability, high luminous efficiency and long service life while maintaining a low driving voltage.

[0010] Further preferably, Ar1and Ar2are each independently selected from a substituted or unsubstituted C6-C18aryl group, wherein the substituents are selected from deuterium, an unsubstituted C1-C6alkyl group, a C1-C6alkyl group fully or partially substituted with deuterium, or a C6-C12aryl group.

[0011] Still further preferably, Ar1, Ar2are each independently selected from any one of the following groups:

[0012]

[0013] wherein the position of * is the connecting site of the group;

[0014] R1-R9are each independently selected from hydrogen, deuterium, an unsubstituted C1-C6alkyl group, a C1-C6alkyl group fully or partially substituted with deuterium;

[0015] n1is each independently selected from 0, 1, 2, 3, 4, 5;

[0016] n2, n5are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;

[0017] n3, n8are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13;

[0018] n4, n6are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7;

[0019] n7, n9are each independently selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.

[0020] Further preferably, the light-emitting auxiliary material is selected from a compound having any one of the structures of Chemical Formula I-1 to Chemical Formula I-6:

[0021]

[0022] Ar1, Ar2are defined the same as in Formula I.

[0023] In the above technical solution, further preferably, the light-emitting auxiliary material is any one of the following compounds, but is not limited thereto:

[0024] .

[0025] The light-emitting auxiliary material of the present application can be prepared by a synthetic method known to those skilled in the art. Alternatively, the following preparation method is preferably used for the preparation.

[0026] The preparation method of the light-emitting auxiliary material of the present application comprises the following steps:

[0027] (1) reacting the raw material A with the raw material B to obtain an intermediate 1;

[0028] (2) reacting the intermediate 1 in the presence of methylsulfonic acid to obtain an intermediate 2;

[0029] (3) reacting the intermediate 2 with the raw material C to obtain the light-emitting auxiliary material of the formula I;

[0030] The reaction flow of the preparation method is as follows:

[0031] .

[0032] Preferably, the molar ratio of the raw material A to the raw material B in step (1) is 1.1-1.5:1, for example 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1.

[0033] Preferably, the reaction in step (1) is carried out in the presence of n-butyllithium, and the molar ratio of the n-butyllithium to the raw material B is 1.1-1.5:1 (for example 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1); the n-butyllithium is added into the reaction system at -78°C.

[0034] Preferably, the reaction in step (1) is carried out in an organic solvent selected from tetrahydrofuran.

[0035] Preferably, the temperature of the reaction in step (1) is room temperature (15-25°C), and the reaction time is 2-14h, for example 2h, 5h, 8h, 10h, 12h or 14h.

[0036] Preferably, the molar ratio of the intermediate 1 to the methylsulfonic acid in step (2) is 3-10:1, for example 3:1, 3.5:1, 4:1, 4.5:1, 5:1, 5.5:1, 6:1, 7:1, 8:1, 9:1 or 10:1.

[0037] Preferably, the reaction in step (2) is carried out in an organic solvent selected from toluene and tetrahydrofuran.

[0038] Preferably, the reaction in step (2) is carried out at room temperature (15-25℃) for 15-60 min, such as 15 min, 20 min, 30 min, 40 min, 50 min or 60 min.

[0039] Preferably, the molar ratio of the intermediate 2 to the raw material C in step (3) is 1: 1.0-1.3, such as 1:1.0, 1:1.1, 1:1.2 or 1:1.3.

[0040] Preferably, the reaction in step (3) is carried out in the presence of a basic substance, which is sodium tert-butoxide or potassium tert-butoxide, and the molar ratio of the basic substance to the raw material C is 2.0-4.0:1, such as 2.0:1, 2.5:1, 2.8:1, 3.0:1, 3.5:1, 3.8:1 or 4.0:1.

[0041] Preferably, the reaction in step (3) is carried out in the presence of a palladium catalyst selected from tris(dibenzylideneacetone)dipalladium, tetrakis(triphenylphosphine)palladium, palladium dichloride, [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium, palladium acetate or bis(triphenylphosphine)palladium dichloride; and the molar ratio of the palladium catalyst to the raw material C is 0.01-0.03:1, such as 0.01:1, 0.02:1 or 0.03:1.

[0042] Preferably, the reaction in step (3) is carried out in the presence of a phosphine ligand selected from tri-tert-butylphosphine, triethylphosphine, trimethylphosphine, triphenylphosphine, diphenylphosphine potassium or di-tert-butylchlorophosphine; and the molar ratio of the phosphine ligand to the raw material C is 0.02-0.15:1, such as 0.02:1, 0.05:1, 0.08:1, 0.10:1, 0.13:1 or 0.15:1.

[0043] Preferably, the reaction in step (3) is carried out at a temperature of 100-120℃, such as 100℃, 105℃, 110℃, 115℃ or 120℃, for 2-18 h, such as 2 h, 5 h, 8 h, 10 h, 12 h, 16 h or 18 h.

[0044] As a preferred technical solution, the preparation process of the luminescent auxiliary material is as follows:

[0045]

[0046] In the above formula, Ar1and Ar2are as defined in the above formula I.

[0047] In comparison with the complex raw materials not disclosed, the classic lithiation reaction, Buchwald-Hartwig coupling reaction will be adopted and applied to the present application.

[0048] Specific preparation method:

[0049] Step 1 specifically includes the following process:

[0050] At -78°C, the raw material A (1.1-1.5 eq) is added to the reaction bottle containing tetrahydrofuran, nitrogen is replaced for 3 times, stirring for 10-30 minutes, n-butyl lithium (1.1-1.5 eq) is slowly added to the reaction bottle, reaction for 2-4 h, then raw material B (1.0 eq) is dissolved in tetrahydrofuran and slowly dropped into the reaction bottle, after stirring uniformly, stop refrigeration, and continue to react for 2-14 h after warming to room temperature; the reaction is detected by thin layer chromatography, after the reaction is completed, water and dichloromethane are added for liquid separation and extraction, the organic phase is combined and concentrated, and the mixture solution of dichloromethane and petroleum ether (volume ratio of 1:2-1:10) is used for purification by column chromatography to obtain intermediate 1.

[0051] Step 2 specifically includes the following process:

[0052] In the reaction bottle, a mixture of toluene (3.0-10.0 eq) and THF (3.0-10.0 eq) is added, then intermediate 1 (1.0 eq) is added, stirring at room temperature until dissolution, then methyl sulfonic acid (3.0-10.0 eq) is added to the reaction bottle, reaction for 15-60 min; the reaction is detected by thin layer chromatography, after the reaction is completed, water and dichloromethane are added for liquid separation and extraction, the organic phase is combined and concentrated, and the mixture solution of dichloromethane and petroleum ether (volume ratio of 1:2-1:10) is used for purification by column chromatography to obtain intermediate 2.

[0053] Step 3 specifically includes the following process:

[0054] In the reaction bottle, intermediate 2 (1.0 eq), raw material C (1.0-1.3 eq), toluene and sodium tert-butoxide (2.0-4.0 eq) are added, under the condition of nitrogen, then tris(dibenzylideneacetone)dipalladium (0.01-0.03 eq) and tri-tert-butyl phosphine (0.02-0.15 eq) are added, the temperature is raised to 100-120°C, and the reaction is stirred for 2-18 h; the reaction is detected by thin layer chromatography, after determining that the reaction is completed, water and dichloromethane are extracted and separated, the organic phase is combined and concentrated, and the mixture solution of dichloromethane and petroleum ether (volume ratio of 1:4-1:10) is used for purification by column chromatography to obtain chemical formula I.

[0055] In another aspect, the present application provides a red organic light emitting device including a first electrode, a second electrode, and at least one organic layer disposed between the first electrode and the second electrode, the organic layer including the light emitting auxiliary material as described above.

[0056] Preferably, the organic layer includes a light emitting auxiliary layer including the light emitting auxiliary material as described above.

[0057] The organic layer of the red organic light emitting device of the present application can be formed as a single layer structure, but can also be formed as a multi-layer structure having two or more organic material layers. For example, the organic light emitting device of the present application can have a structure including a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting auxiliary layer, a light emitting layer, an electron transport layer, an electron injection layer, a hole blocking layer, etc. as the organic layer. However, the structure of the organic light emitting device is not limited thereto, and can include a smaller number of organic material layers or a larger number of organic layers.

[0058] Except for the compound of Chemical Formula I included in the light emitting auxiliary layer disclosed herein, there is no particular limitation on the material of other layers in the OLED device.

[0059] In another aspect, the present application provides an organic light emitting device including the organic electroluminescent device as described above.

[0060] The organic light emitting device of the present application includes, but is not limited to, a flat panel display, a computer monitor, a medical monitor, a television, a billboard, a lamp for interior or exterior illumination and / or signaling, a heads-up display, a fully or partially transparent display, a flexible display, a laser printer, a telephone, a cell phone, a photo album, a personal digital assistant (PDA), a wearable device, a notebook computer, a digital camera, a camcorder, a viewfinder, a micro display, a three-dimensional display, a virtual reality or augmented reality display, a vehicle, a video wall including a plurality of displays tiled together, a theater or venue screen, a phototherapy device, and a sign, etc.

[0061] The present application has the following advantageous effects over the prior art:

[0062] The compound of the present application is a benzo fluorene group and a 9-position fluorene group connected to an adamantane group as a core (benzo fluorene and adamantane are connected through a spiro ring), and a fluorene group fused with a phenyl group on one side is connected to a triarylamine group containing an aryl group. As a light emitting auxiliary layer material, it can make the device have excellent light emitting efficiency and long service life, while also maintaining a low driving voltage.

[0063] The benzofluorene structure itself has strong rigidity, and the fused ring system makes the overall structure have high thermal stability, which can maintain the integrity of the structure at high temperature. And the benzofluorene has a lower HOMO energy level, which is beneficial to the efficient injection and transmission of holes, can significantly improve the mobility of carriers, reduce charge recombination loss, and thus effectively improve the luminous efficiency of the device.

[0064] The benzofluorene is further connected with the adamantane group through a spiro ring to obtain a more unique rigid three-dimensional structure. The adamantane group is an electron-rich group, which can improve the electron density of the system, and thus improve the hole migration ability of the compound. And the adamantane group has a large steric hindrance, so it can reduce the intermolecular stacking effect, thereby improving the morphology of the compound when it is formed into a film, improving the evaporation temperature of the compound, and making it not easy to crack during high-temperature evaporation, having good thermal stability, and thus improving the service life of the device.

[0065] In addition, the triarylamine group with high transmission efficiency is connected to one side of the benzofluorene ring. The introduction of the triarylamine group increases the π-π conjugation effect in the molecule, making the π electron cloud distribution more uniform and the delocalization range wider, which helps to improve the fluorescence quantum efficiency. And the addition of the triarylamine group can also enhance the stability of the molecule, thereby prolonging the service life of the material device. BRIEF DESCRIPTION OF DRAWINGS

[0066] Figure 1 is the nuclear magnetic resonance hydrogen spectrum of compound 1 provided by the embodiment 1 of the present application. DETAILED DESCRIPTION

[0067] The technical solutions of the present application will be further described through specific embodiments. Those skilled in the art should understand that the embodiments are only to help understand the present application, and should not be regarded as specific limitations on the present application.

[0068] In addition, it should be noted that the numerical values given in the following embodiments are as accurate as possible, but those skilled in the art understand that due to unavoidable measurement errors and experimental operation problems, each number should be understood as an approximate number, not an absolutely accurate number.

[0069] Embodiment 1

[0070]

[0071] In a reaction bottle, raw material A-1 (1.0 eq, CAS No.: 2566427-85-96), raw material B-1 (1.2 eq, CAS No.: 500717-23-7), toluene and sodium tert-butoxide (3.0 eq) were added, and under the condition of nitrogen, tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butylphosphine (0.05 eq) were added, and the reaction was stirred at 120°C for 14 h. After the reaction was determined to be completed by thin layer chromatography, water and dichloromethane were added for extraction and separation, and the organic phase was combined and concentrated. Compound 1 was obtained by column chromatography using a mixture of dichloromethane and petroleum ether (volume ratio 1:4) (yield: 81.9%).

[0072] The obtained compound 1 was detected and analyzed, and the results were as follows:

[0073] HPLC purity: >99.8%.

[0074] Mass spectrometry: Waters XEVO TQD mass spectrometer, ESI source.

[0075] Test value MS (ESI, m / Z): [M+H] + =735.60.

[0076] Elemental analysis:

[0077] Calculated value: C, 91.39; H, 6.71; N, 1.90;

[0078] Test value: C, 91.11; H, 6.86; N, 2.04.

[0079] The nuclear magnetic resonance hydrogen spectrum of compound 1 is shown in Figure 1 .

[0080] Example 2

[0081]

[0082] Step 1 specifically includes the following process:

[0083] At -78°C, raw material A-23 (1.3 eq, CAS No.: 2142655-37-4) was added to a reaction bottle containing tetrahydrofuran, nitrogen was replaced for 3 times, stirred for 20 minutes, n-butyl lithium (1.3 eq) was slowly added to the reaction bottle, reacted for 2 h, raw material B-23 (1.0 eq, CAS No.: 98750-22-2) was dissolved in tetrahydrofuran and then slowly dropped into the reaction bottle, after stirring uniformly, the refrigeration was stopped, and the temperature was increased to room temperature for continuous reaction for 6 h; the reaction was detected by thin layer chromatography, after the reaction was completed, water and dichloromethane were added for liquid separation and extraction, the organic phases were combined and concentrated, a mixed solution of dichloromethane and petroleum ether (volume ratio 1:3) was used for column chromatography to obtain intermediate 1 (yield: 72.5%).

[0084] Step 2 specifically includes the following process:

[0085] Toluene (5.0 eq) and tetrahydrofuran (THF, 5.0 eq) were added to a reaction bottle, then intermediate 1 (1.0 eq) was added, stirred at room temperature until dissolved, then methyl sulfonic acid (5.0 eq) was added to the reaction bottle, reacted for 30 min; the reaction was detected by thin layer chromatography, after the reaction was completed, water and dichloromethane were added for liquid separation and extraction, the organic phases were combined and concentrated, a mixed solution of dichloromethane and petroleum ether (volume ratio 1:5) was used for column chromatography to obtain intermediate 2 (yield: 77.3%).

[0086] Step 3 specifically includes the following process:

[0087] Intermediate 2 (1.0 eq), raw material C-23 (1.1 eq, CAS No.: 32228-99-2), toluene and sodium tert-butoxide (3.0 eq) were added to a reaction bottle, under the condition of nitrogen, tris(dibenzylideneacetone)dipalladium (0.02 eq) and tri-tert-butyl phosphine (0.05 eq) were further added, the temperature was increased to 120°C and stirred for 12 h; the reaction was detected by thin layer chromatography, after the reaction was completed, water and dichloromethane were added for extraction and liquid separation, the organic phases were combined and concentrated, a mixed solution of dichloromethane and petroleum ether (volume ratio 1:5) was used for column chromatography to obtain compound 23 (yield: 81.8%).

[0088] The obtained compound 23 was detected and analyzed, and the results were as follows:

[0089] HPLC purity: >99.7%.

[0090] Mass spectrometry test: mass spectrometer of Waters XEVO TQD type, using ESI source.

[0091] Test value MS (ESI, m / Z): [M+H] += 579.52.

[0092] Elemental analysis:

[0093] Calculated: C, 91.15; H, 6.43; N, 2.42;

[0094] Test value: C, 90.88; H, 6.59; N, 2.57.

[0095] In addition, it should be noted that other compounds of the present application can be obtained by referring to the synthesis methods of the above-listed examples, and therefore will not be listed one by one here.

[0096] Device Example 1: Preparation of a red organic electroluminescent device

[0097] The structure of the prepared OLED device is: ITO anode / HIL / HTL / Prime / EML / HBL / ETL / EIL / cathode / CPL.

[0098] a. ITO anode: The ITO (indium tin oxide)-Ag-ITO (indium tin oxide) glass substrate with a coating thickness of 1500 angstroms was cleaned in distilled water for 3 times, ultrasonic washing for 40 min, and then repeatedly cleaned with distilled water for 3 times, ultrasonic washing for 20 min. After washing, methanol, acetone, and isopropanol were sequentially ultrasonic washed (5 min each time), dried, and then transferred to a plasma cleaning machine for washing for 5 min, and then sent to an evaporation machine. The substrate was used as an anode, and other functional layers were sequentially evaporated thereon.

[0099] b. HIL (hole injection layer): The hole injection layer materials HT and P-dopant were vacuum evaporated at an evaporation rate of 1 angstrom / s. The evaporation rate ratio of the HT and P-dopant was 97:3, and the thickness was 10 nm.

[0100] c. HTL (hole transport layer): 125 nm of HT as a hole transport layer was vacuum evaporated on the hole injection layer at an evaporation rate of 1.5 angstrom / s.

[0101] d. Prime (light-emitting auxiliary layer): 90 nm of the compound 1 provided in the above example as a light-emitting auxiliary layer was vacuum evaporated on the hole transport layer at an evaporation rate of 1.0 angstrom / s.

[0102] e. EML (emitting layer): Then, 40 nm of a host material (Host) and a doping material (Dopant) as an emitting layer were vacuum evaporated on the above light-emitting auxiliary layer at an evaporation rate of 1 angstrom / s, wherein the evaporation rate ratio of the Host and the Dopant was 97:3.

[0103] f、HBL (hole blocking layer): a 5 nm thick hole blocking layer HB was vacuum deposited at a deposition rate of 0.5 A / s.

[0104] g、ETL (electron transport layer): ET and Liq were vacuum deposited at a deposition rate of 1 A / s as an electron transport layer with a thickness of 30 nm, wherein the deposition rate ratio of ET and Liq was 50:50.

[0105] h、EIL (electron injection layer): a 1 nm thick Yb film layer was deposited at a deposition rate of 0.5 A / s to form an electron injection layer.

[0106] i、Cathode: magnesium and silver were deposited at a deposition rate ratio of 1:9 to obtain an OLED device.

[0107] j、CPL (light extraction layer): a 65 nm thick CPL was vacuum deposited on the cathode as a light extraction layer at a deposition rate of 1 A / s.

[0108] k、Subsequently, the substrate on which the deposition was completed was packaged. First, the cleaned cover plate was coated with UV glue using a gluing device, and then the coated cover plate was moved to the pressing section, the substrate on which the deposition was completed was placed on the end of the cover plate, and finally the substrate and the cover plate were bonded under the action of the bonding device, and the UV glue was simultaneously cured by light.

[0109] The structures of HT, P-dopant, Host, Dopant, HB, ET, and CPL used in the above device embodiment 1 are shown below:

[0110]

[0111] According to the method provided in the above device embodiment 1, the corresponding compounds in Table 1 were respectively selected to replace compound 1, the deposition of the light-emitting auxiliary layer was carried out, and the corresponding organic electroluminescent devices were prepared and were respectively recorded as device embodiments 2-25.

[0112] Device comparative examples 1-8:

[0113] This comparative example provides an organic electroluminescent device, and the only difference between the preparation method of the organic electroluminescent device and device embodiment 1 is that the organic electroluminescent device is deposited by using existing comparative compounds a-h instead of compound 1 in device embodiment 1 as a light-emitting auxiliary material. The chemical structural formulas of comparative compounds a-h are as follows:

[0114]

[0115] The driving voltage, luminous efficiency, and lifetime of the organic electroluminescent devices obtained in Examples 1-25 and Comparative Examples 1-8 were characterized at a brightness of 6000 nits. The test results are as follows.

[0116] As shown in Table 1.

[0117] Table 1

[0118]

[0119]

[0120] As can be seen from Table 1, compared with the organic electroluminescent devices prepared using the luminescent auxiliary materials provided by the present invention, the luminous efficiency and lifespan of the devices are effectively improved, while maintaining a lower driving voltage.

[0121]

[0122] Comparative compounds a and b, and compounds 63 and 86, are parallel comparative examples. The difference lies in the position of the fused ring of benzo[a]fluorene in comparative compounds a and b, which are at positions 1.2 and 2.3, respectively (for the definition of fused ring position: In addition, in compounds 63 and 86 of the present invention, the benzene ring is fused at the 3 and 4 positions of fluorene, resulting in a more compact structure and higher stability under high temperature conditions.

[0123]

[0124] Comparative examples c and d, and compounds 4 and 10, are parallel comparative examples. The difference lies in that the triarylamine N in comparative compounds c and d is attached to a benzene ring on the fluorene ring, while the triarylamine N in compounds 4 and 10 of this invention is attached to a benzo[a]fluorene group on the fused ring side, resulting in a benzo[a]fluorene core structure with greater rigidity. This effectively improves the thermal stability of the material, making it less prone to structural changes during high-temperature vapor deposition and thus extending the lifespan of the device. Furthermore, the introduction of the additional benzene ring creates a larger π-conjugated system. This extended conjugation effect helps reduce the band gap, thereby enabling longer wavelength (such as red light) emission. The expanded electron delocalization range increases the fluorescence quantum yield, effectively improving the luminescence efficiency of the material device.

[0125]

[0126] Comparative compound e and compound 16 are parallel examples, the difference between which is that in comparative compound e, a phen-9-phenylcarbazole group is connected in the side chain of the triarylamine group, while in compound 16 of the present application, a phen-9, 9-dimethylfluorene group is connected in the triarylamine group. Due to the steric hindrance effect of the methyl group, the intermolecular aggregation quenching is reduced, showing a higher fluorescence quantum yield, and thus having a higher light-emitting efficiency.

[0127]

[0128] Comparative compound f and compound 24 are parallel examples, the difference between which is that in compound 24 of the present application, no other non-hydrogen substituent is connected to the adamantane, while in comparative compound f, a substituent (phenyl) is connected to the adamantane in the mother nucleus. The introduction of the phenyl does not have the effect of extending the conjugated system, but rather increases the overall molecular weight, affecting the arrangement of the structure, and thus affecting the stability of the material.

[0129]

[0130] Comparative compound g and compound 3 are parallel examples, the difference between which is that in comparative compound g, a biphenyl group is connected between the triarylamine group and the benzofluorene group, while in compound 3 of the present application, the triarylamine group is directly connected to the benzofluorene group. The molecular structure is more compact, forming a more closely arranged structure, improving the thermal stability of the material, making the material less likely to crack under high-temperature evaporation, and thus enhancing the service life of the device.

[0131] The applicant states that the luminescent auxiliary material of the present application and the preparation method and application thereof are illustrated by the above examples, but the present application is not limited to the above examples, i.e. it does not mean that the present application must rely on the above examples to be implemented. It should be understood by those skilled in the art that any improvement on the present application, equivalent replacement of the selected materials, addition of auxiliary ingredients, selection of specific methods, etc. fall within the scope of protection and disclosure of the present application.

Claims

1. A luminescent auxiliary material, characterized in that, The luminescent auxiliary material is any one of the following compounds: 。 2. A red organic light-emitting device, characterized in that, The red organic light-emitting device includes a first electrode, a second electrode, and at least one organic layer disposed between the first electrode and the second electrode, wherein the organic layer contains the light-emitting auxiliary material as described in claim 1.

3. The red organic light-emitting device according to claim 2, characterized in that, The organic layer includes a light-emitting auxiliary layer, which comprises the light-emitting auxiliary material as described in claim 1.

4. The red organic light-emitting device according to claim 2, characterized in that, The organic layer further includes any one or a combination of at least two of the following: a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, an electron transport layer, an electron injection layer, or a hole blocking layer.

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