Luminescent material, luminescent device, display panel and display device

Abstract

The invention discloses a light-emitting material, a light-emitting device, a display panel and a display device, and the light-emitting material comprises a host material which comprises a first compound. According to the light-emitting material, the light-emitting material is applied to the light-emitting layer of a device, the ultrahigh color gamut is kept, meanwhile, high brightness and low power consumption can be achieved, the efficiency of the device is improved, and the service life of the device is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of display, and particularly relates to a luminescent material, a light-emitting device, a display panel and a display device. Background Art

[0002] With the development of OLEDs, the material structures used for green and red pixel dots can already achieve a theoretical luminous efficiency of 100%. However, the blue devices currently in use still employ fluorescent materials with a theoretical luminous efficiency of 25%. With the research on the third-generation luminescent material, thermally activated delayed fluorescence (TADF) material, blue devices with a theoretical luminous efficiency of 100% achieved through TADF technology have become the focus of attention. The blue hyperfluorescent OLED adopting this structure can effectively avoid the disadvantages of the material itself. It uses blue phosphorescent or TADF materials as sensitizers for separate terminal emitters. However, there is still a lack of in-depth research on hyperfluorescent OLEDs based on the above materials. For example, the achieved external quantum efficiency is still lower than that of TADF materials, and the reasons for the high quantum efficiency cannot be clearly explained, which affects the development and application of luminescent materials. Summary of the Invention

[0003] The purpose of the embodiments of the present invention is to provide a luminescent material, a light-emitting device, a display panel and a display device to solve the problem of low luminous efficiency of the device.

[0004] In a first aspect, the embodiments of the present invention provide a luminescent material, comprising:

[0005] A host material, the host material comprising a first compound, and the structural formula of the first compound is Structural Formula 1:

[0006]

[0007] Structural Formula 1

[0008] Ring Ar1 and Ring Ar2 are independently selected from C6-C60 carbocyclic groups and C5-C60 heterocyclic groups;

[0009] a1, a2, a3 and b1, b2 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a phenylsilyl group, a silyl group, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic fused polycyclic group, a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q1)(Q2)(Q3), -B(Q1)(Q2), -N(Q1)(Q2), -P(Q1)(Q2), -C(=O)(Q1), -S(=O)(Q1), -S(=O)2(Q1), -P(=O)(Q1)(Q2) and -P(=S)(Q1)(Q2);

[0010] Q1 to Q3 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazino group, a hydrazono group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic fused polycyclic group, a monovalent non-aromatic fused heteropolycyclic group, a biphenyl group and a terphenyl group;

[0011] At least one of a1, a2 and a3 is tetraphenylsilicon.

[0012] Optionally, the structural formula of the first compound is selected from structural formula BH1 to structural formula BH4, and structural formula BH1 to structural formula BH4 are selected from:

[0013]

[0014] Optionally, the luminescent material further comprises:

[0015] A sensitizer material, the sensitizer material comprising a second compound, and the structural formula of the second compound is structural formula 2:

[0016]

[0017] Structural formula 2

[0018] X1 is selected from alkyl, aryl, heterocycle, and X2 is selected from =C=O, -S(=O)2-.

[0019] Optionally, the structural formula of the second compound is selected from Structural formula S1 to Structural formula S4, and Structural formula S1 to Structural formula S4 are selected from:

[0020]

[0021] Optionally, the mass of the host material is 80%-95% of the total mass of the luminescent material, and the mass of the sensitizer material is 5%-20% of the total mass of the luminescent material.

[0022] Optionally, the luminescent material further includes:

[0023] A fluorescent doping material, and the mass of the fluorescent doping material is 0.4%-2% of the sum of the masses of the host material and the sensitizer material.

[0024] In a second aspect, an embodiment of the present invention provides a light-emitting device, including:

[0025] The luminescent material described in the above embodiment.

[0026] Optionally, the light-emitting device includes:

[0027] A light-emitting layer, and the light-emitting layer includes the luminescent material.

[0028] In a third aspect, an embodiment of the present invention provides a display panel, including:

[0029] The light-emitting device described in the above embodiment.

[0030] In a fourth aspect, an embodiment of the present invention provides a display device, including:

[0031] The display panel described in the above embodiment.

[0032] The luminescent material of the embodiment of the present invention includes a host material, the host material includes a first compound, the structural formula of the first compound is Structural formula 1, and by using the luminescent material of the present invention in the light-emitting layer of the device, while maintaining an ultra-high color gamut, high brightness, low power consumption can be achieved, the device efficiency can be improved, and the service life of the device can be extended. Description of the Drawings

[0033] Figure 1 It is a schematic structural diagram of a light-emitting device in an embodiment of the present invention;

[0034] Figure 2 It is the energy transfer mechanism of the luminescent material;

[0035] Figure 3 1H NMR spectrum of the prepared BH1 compound;

[0036] Figure 4 1H NMR spectrum of the prepared S4 compound. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally represents an "or" relationship between the associated objects before and after.

[0039] The luminescent material of the embodiment of the present invention includes:

[0040] A host material, the host material includes a first compound, and the structural formula of the first compound is Structural formula 1:

[0041]

[0042] Structural formula 1

[0043] Ring Ar1 and ring Ar2 are independently selected from C6-C60 carbocyclic groups and C5-C60 heterocyclic groups;

[0044] a1, a2, a3, and b1, b2 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a silylbenzene group, a silyl group, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic fused polycyclic group, a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q1)(Q2)(Q3), -B(Q1)(Q2), -N(Q1)(Q2), -P(Q1)(Q2), -C(=O)(Q1), -S(=O)(Q1), -S(=O)2(Q1), -P(=O)(Q1)(Q2), and -P(=S)(Q1)(Q2);

[0045] Q1 to Q3 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazino group, a hydrazono group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic fused polycyclic group, a monovalent non-aromatic fused heteropolycyclic group, a biphenyl group, and a terphenyl group;

[0046] At least one of a1, a2, and a3 is tetraphenylsilicon.

[0047] The luminescent material of the embodiment of the present invention includes: a host material, the host material includes a first compound, the structural formula of the first compound is Structural Formula 1. By using the luminescent material of the present invention in the light-emitting layer of a device, while maintaining an ultra-high color gamut, high brightness, low power consumption can be achieved, the device efficiency can be improved, and the service life of the device can be extended.

[0048] In some embodiments, the structural formula of the first compound can be selected from Structural Formula BH1 to Structural Formula BH4, and Structural Formula BH1 to Structural Formula BH4 are selected from:

[0049]

[0050] In an embodiment of the present invention, the luminescent material further comprises:

[0051] A sensitizer material, the sensitizer material comprising a second compound, the structural formula of the second compound being Structural Formula 2:

[0052]

[0053] Structural Formula 2

[0054] X1 is selected from an alkyl group, an aryl group, a heterocycle, and X2 is selected from =C=O, -S(=O)2-.

[0055] Optionally, the structural formula of the second compound may be selected from Structural Formula S1 to Structural Formula S4,

[0056] Structural Formula S1 to Structural Formula S4 are selected from:

[0057]

[0058] In an embodiment of the present invention, the mass of the host material is 80%-95% of the total mass of the luminescent material, and the mass of the sensitizer material is 5%-20% of the total mass of the luminescent material. For example, the mass of the host material is 90% of the total mass of the luminescent material, and the mass of the sensitizer material is 5% of the total mass of the luminescent material. The specific content can be selected according to the actual situation. The lower TADF transfer rate of the sensitizer reduces the exciton transfer competition for FRET, increases the transfer efficiency of FRET, and improves the device performance. The emission spectrum of the sensitizer and the absorption spectrum of the emitter do not need to have a large overlap, increasing the range of sensitizer selection; for the sensitizer dominated by FRET, the sensitizer itself hardly emits light, improving the color purity of the device.

[0059] In some embodiments of the present invention, the luminescent material may further comprise:

[0060] A fluorescent doping material, the mass of the fluorescent doping material being 0.4%-2% of the sum of the masses of the host material and the sensitizer material. For example, the mass of the fluorescent doping material is 0.8% of the sum of the masses of the host material and the sensitizer material. The specific content can be selected according to the actual situation.

[0061] The light-emitting device of the embodiment of the present invention comprises:

[0062] The luminescent material described in the above embodiment.

[0063] Applying the luminescent material in the light-emitting layer of the device can maintain an ultra-high color gamut, achieve high brightness, low power consumption, improve the device efficiency, and extend the service life of the device.

[0064] Optionally, the light-emitting device may include:

[0065] A light-emitting layer including the light-emitting material. Applying the light-emitting material in the light-emitting layer of the device can improve the device efficiency and extend the service life of the device.

[0066] In an embodiment of the present invention, the light-emitting device may further include:

[0067] A cathode, an anode, a hole injection layer, and an electron injection layer, which are stacked in the order of the cathode, the electron injection layer, the light-emitting layer, the hole injection layer, and the anode.

[0068] In an embodiment of the present invention, the light-emitting device may further include:

[0069] An electron transport layer, which may be disposed between the electron injection layer and the light-emitting layer.

[0070] In some other embodiments of the present invention, the light-emitting device may further include:

[0071] A hole transport layer, which may be disposed between the hole injection layer and the light-emitting layer.

[0072] In some embodiments of the present invention, the light-emitting device may further include:

[0073] An electron blocking layer, which may be disposed between the hole transport layer and the light-emitting layer.

[0074] In an embodiment of the present invention, the light-emitting device may further include:

[0075] A hole blocking layer, which may be disposed between the electron transport layer and the light-emitting layer.

[0076] Anode: The anode is an electrode material with a high work function. The electrodes of the top-emitting device can be Ag / ITO, Ag / IZO, Ag / SnO 2 , Ag / ZnO, Al / ITO, Al / IZO, Ag / ITO / Ag, etc. The thickness of the metal layer can be 80-100 nm, the thickness of the oxide layer can be 5-20 nm, and the average reflectivity reference value of the anode in the visible light region can be 85%-95%.

[0077] Hole injection layer (HIL): Its main function is to reduce the hole injection barrier and improve the hole injection efficiency. Hole injection materials such as HATCN, MnO 3 , CuPc, etc. can be selected, or p-type doping can be carried out in the hole transport material. For example, NPB:F4TCNQ, TAPC:MnO 3 , etc. The thickness of the hole injection layer can be 5 nm-20 nm, and the p-type doping concentration can be 0.5%-5%.

[0078] Hole transport layer: Its main function is to transport holes. This layer can be prepared by evaporation using carbazole-based materials with relatively high hole mobility. The thickness of the hole transport layer can be 10 - 100 nm.

[0079] Light-emitting layer: The light-emitting layer can include the host material, TADF sensitizer material, and fluorescent dopant material as shown above. The thickness of the light-emitting layer can be 30 - 60 nm, and the proportion relationship among the three can be: 80% - 95% of the host material, 5% - 20% of the phosphorescent sensitizer material, and the fluorescent dopant material can be 0.4% - 2% of the sum of the host material and the phosphorescent sensitizer material.

[0080] Hole blocking layer: Its main function is to transport electrons, block holes, and excitons generated in the light-emitting layer. The thickness of the hole blocking layer can be 1 - 10 nm.

[0081] Electron transport layer (ETL): Its main function is to transport electrons. A material with strong electron transport ability is doped with Liq, and the doping ratio is 10:1 - 1:1, and the thickness is 10 - 50 nm. The electron transport layer material can contain

[0082]

[0083] at least one of;

[0084] Liq is

[0085] Electron injection layer (EIL): Its main function is to inject electrons. The electron injection layer material can include materials such as Yb, Li, LiF, NaCl, CsF, Li 2 O, BaO, Liq, etc., or a combination of these materials, and the thickness can be 0.5 - 2 nm.

[0086] Cathode: The cathode material can be an electrode material with a low work function, such as Mg, Ag, Al, Al - Li, Ca, Mg:In, Mg:Ag, etc. For a top-emitting device, the thickness of this layer can be 10 - 20 nm. For example, it can be prepared using an alloy of Mg:Ag, and the adjustment ratio of Mg:Ag can be 3:7 - 1:9.

[0087] Cover layer (CPL): For a top-emitting device, a cathode cover layer can also be evaporated. Its main function is to improve the light extraction efficiency and protect the cathode. The thickness of this layer can be 50 - 100 nm, and the material of this layer can be a high refractive index material, and the refractive index at 530 nm should be greater than 1.9.

[0088] Encapsulation layer: It can be encapsulated with frame glue or with a thin film.

[0089] Such as Figure 1As shown, the structure of the light-emitting device may include:

[0090] A glass substrate 1, an anode 2, a hole injection layer 3, a hole transport layer 4, a light-emitting layer 5, a hole blocking layer 6, an electron transport layer 7, an electron injection layer 8, and a cathode 9 that are stacked.

[0091] The light-emitting layer may select the light-emitting material in the present invention. The sensitizer material of the light-emitting layer may be a low-performance TADF material, and the emitter may be a blue TADF material. Among them, the emission spectrum of the sensitizer and the absorption spectrum of the emitter do not need to mostly overlap. The FRET is fully utilized for exciton transfer, and the exciton accumulation is reduced to obtain a highly efficient deep blue superphosphorescent OLED. Through the TADF sensitizer material, the proportion of FRET in the device is increased, the device efficiency is improved, the selection range of materials is expanded, the manufacturing cost is reduced, the carrier transport region, the exciton recombination center, and the light-emitting center are effectively separated, making the device more stable. The multi-layer tandem device can further improve the device efficiency and lifespan, meeting the requirements of high dynamic range (HDR) for both static and dynamic scenes.

[0092] Preparation of the light-emitting device:

[0093] Before preparing the device, the ITO glass substrate is placed in oxygen plasma after being cleaned multiple times; then, the sample is transferred to a vacuum evaporation system, and all organic materials are deposited by vacuum evaporation. During the entire device preparation process, the organic materials are thermally deposited in a high vacuum environment of 5×10 -6 Torr at a rate. After depositing the organic layer, 1.5 nm of LiF and 200 nm of Al are thermally deposited on the organic film respectively, and the thermal deposition rates are 0.1 and

[0094] As Figure 2 shown, the superphosphorescent sensitization mechanism: Usually, the emissive layer (EML) of HF-OLEDs consists of a host material, a TADF sensitizer material, and a light-emitting material. Under the action of an electric field, carriers are injected through the electrodes and then transported to the EML by the carrier transport layer, forming singlet excitons and triplet excitons on the host material, and transferring energy to the TADF sensitizer through energy transfer (FRET) and Dexter energy transfer (DET) methods. The spin-orbit coupling of the TADF sensitizer is very strong, resulting in a considerable dipole strength for the donor triplet-acceptor singlet transition, thus enabling the FRET mechanism to occur for the triplet state. Since only a trace amount of the light-emitting material is doped, the FRET from the TADF sensitizer to the emitter is enhanced, the DET from the host and the sensitizer to the emitter is suppressed, and the situation where the emitter directly captures carriers and emits light is also suppressed. Therefore, the host and the sensitizer basically transfer to the singlet state of the light-emitting material through FRET, and the singlet state rapidly radiatively decays and emits light.

[0095] The present invention will be further described through some specific embodiments.

[0096] ITO: Indium Tin Oxide; EML: Emission Layer; CPL: Covering Layer

[0097] HIL: Hole Injection Layer; HTL: Hole Transport Layer;

[0098] EIL: Electron Injection Layer; ETL: Electron Transport Layer;

[0099] EBL: Electron Blocking Layer; HBL: Hole Blocking Layer.

[0100] The preparation method of the material includes:

[0101] Taking BH1 as an example of the host, the synthesis method is as follows:

[0102]

[0103] Synthesis process of BH1:

[0104] Dissolve (2-bromo-1,3-fluoro)benzene (6.0 g, 15 mmol) in 50 mL of NMP (N-methylpyrrolidone) under a nitrogen atmosphere, add dropwise an aqueous solution of K 2 CO 3 (10 mL, 35 mmol), stir at room temperature for 45 min, drop (1-hydroxy-4-alkyl)benzene (10 mL, 15 mmol) into the well-stirred solution, stir at room temperature for 2 h, extract the reaction mixture with ethyl acetate (EA) and distilled water, purify the crude product by column chromatography with an eluent of dichloromethane (MC): cyclohexane (Hex) with a volume ratio of 1:2, and recrystallize with toluene (Tol) / acetone (Ace) to obtain (5-bromo-1,3-phenyl)bis(oxy))di-p-toluene (8.0 g, 23 mmol);

[0105] Dissolve (5-bromo-1,3-phenyl)bis(oxy))di-p-toluene (8.0 g, 23 mmol) in 80 mL of tetrahydrofuran (THF) under a nitrogen atmosphere, cool to -78 °C, add dropwise 2.5 M n-BuLi (10 mL, 25 mmol), stir at the same temperature for 1 h, dissolve triphenylchlorosilane (7.6 g, 26 mmol) in tetrahydrofuran, add it at -78 °C, then stir at room temperature for 3 h, extract the reaction mixture with ethyl acetate (EA) and distilled water, and purify the crude product by recrystallization with dichloromethane (MC) / methanol (MeOH) to obtain 7.8 g of the solid compound (3,5-diphenoxyphenyl)triphenylsilane;

[0106] (3,5-Diphenoxyphenyl)triphenylsilane (5.0 g, 0.10 mmol) was dissolved in 50 mL of m-xylene under a nitrogen atmosphere, cooled to 0 °C, and 2.5 M n-BuLi (2.82 mL, 11.5 mmol) was added dropwise. The mixture was stirred at the same temperature for 1 h, boron tribromide (BBr3, 1.1 mL, 11.5 mmol) was added at -15 °C, and the mixture was stirred at room temperature for 1 h. N,N-Diisopropylethylamine (DIPEA, 3.4 mL, 19.2 mmol) was added at 0 °C, and the mixture was stirred at 130 °C overnight. After cooling to room temperature, the reaction mixture was extracted with EA and distilled water containing 1.58 g of sodium acetate. The crude product was purified by column chromatography using a dichloromethane (MC):cyclohexane (Hex) eluent in a volume ratio of 1:2 and recrystallized from toluene (Tol) / acetone (Ace) to obtain 1.8 g of the white solid of compound BH1.

[0107] The 1H NMR spectrum of BH1 is as follows:

[0108] 1 H NMR: δ 1.26 (18H, s), 7.02 - 7.36 (23H, 7.08 (dd, J = 8.0, 1.3 Hz), 7.10 (dd, J = 8.0, 0.4 Hz), 7.11 (d, J = 1.3 Hz), 7.17 (tt, J = 7.7, 1.4 Hz), 7.26 (dtd, J = 7.2, 1.4, 0.5 Hz), 7.29 (dddd, J = 7.7, 7.2, 1.7, 0.5 Hz), 7.29 (dd, J = 1.3, 0.4 Hz)).

[0109] Taking S4 as an example, the synthesis method is as follows:

[0110]

[0111] Synthesis process of S4:

[0112] Acridone (3.3 g, 15 mmol) was dissolved in 80 mL of sulfuric acid under a nitrogen atmosphere and heated to 65 °C. Then, benzypropanol (5 mL, 15 mmol) was added dropwise, and the mixture was stirred at the same temperature for 1 h. After cooling to room temperature, the reaction mixture was extracted with EA and distilled water containing 1.58 g of sodium bicarbonate. The crude product was purified by column chromatography using a dichloromethane (MC):cyclohexane (Hex) eluent with a volume ratio of 1:2, and recrystallized from toluene (Tol) / acetone (Ace) to obtain 1.1 g of a white solid compound. The white solid compound was added to tetrapropylammonium perruthenate (TPAP) and an N-methylmorpholine-N-oxide (NMO) solution with a mass concentration of 89%, and the mixture was stirred and reacted for 1 h. After cooling to room temperature, the mixture was extracted with EA and distilled water containing sodium bicarbonate, and then purified by column chromatography using a dichloromethane (MC):cyclohexane (Hex) eluent with a volume ratio of 1:2, and recrystallized from toluene (Tol) / acetone (Ace) to obtain Compound S4.

[0113] The 1H NMR spectrum of S4 is as follows:

[0114] 1 H NMR: δ 3.93 (3H, s), 7.12 (2H, ddd, J = 9.9, 1.5, 0.4 Hz), 7.40 (2H, ddd, J = 7.9, 7.5, 1.5 Hz), 7.48 - 7.75 (6H, 7.55 (ddd, J = 8.1, 7.1, 1.5 Hz), 7.67 (ddd, J = 9.9, 7.1, 1.7 Hz), 7.68 (ddd, J = 8.6, 7.5, 1.3 Hz)), 7.84 (2H, ddd, J = 8.6, 1.5, 0.5 Hz), 8.06 (2H, ddd, J = 8.1, 1.7, 0.4 Hz), 8.26 (2H, ddd, J = 7.9, 1.3, 0.5 Hz).

[0115] Comparative Example 1:

[0116] The layer structure of the device is:

[0117] ITO / Ag / ITO (150 nm) / HIL (10 nm) / HTL1 (30 nm) / EBL (5 nm) / EML (BH1:DMAC-TRZ:v-DABNA, 89%:10%:1%, 35 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (1:9, 15 nm) / CPL (80 nm).

[0118] Comparative Example 2:

[0119] The layer structure of the device is:

[0120] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:DMAC-TRZ, 90%:10%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0121] Comparative Example 3:

[0122] The stacked structure of the device is:

[0123] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:AZB-TRZ:v-DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0124] Comparative Example 4:

[0125] The stacked structure of the device is:

[0126] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:AZB-TRZ, 90%:10%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0127] Comparative Example 5:

[0128] The stacked structure of the device is:

[0129] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:S1, 90%:10%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0130] Comparative Example 6:

[0131] The stacked structure of the device is:

[0132] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:v-DABNA, 99%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0133] Comparative Example 7:

[0134] The stacked structure of the device is:

[0135] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH:S1:v-DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0136] Comparative Example 8:

[0137] The stacked structure of the device is:

[0138] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:BS:v-DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0139] BH is the comparative host material, and its chemical structural formula is

[0140] BS is the comparative sensitizer, and its chemical structural formula is

[0141] v-DABNA is a common blue light dopant material, and its chemical structural formula is

[0142] DMAC-TRZ is a high-performance blue light TADF material, and its chemical structural formula is

[0143] AZB-TRZ is a common blue light TADF material, and its chemical structural formula is

[0144] Example 1:

[0145] The stacked structure of the device is:

[0146] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH1:S1:v - DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0147] Example 2:

[0148] The stacked structure of the device is:

[0149] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH2:S1:v - DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0150] Example 3:

[0151] The stacked structure of the device is:

[0152] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH3:S1:v - DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0153] Example 4:

[0154] The stacked structure of the device is:

[0155] ITO / Ag / ITO(150 nm) / HIL(10 nm) / HTL1(30 nm) / EBL(5 nm) / EML(BH4:S1:v - DABNA, 89%:10%:1%, 35 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(1:9, 15 nm) / CPL(80 nm).

[0156] Example 5:

[0157] The stacked structure of the device is:

[0158] ITO / Ag / ITO (150 nm) / HIL (10 nm) / HTL1 (30 nm) / EBL (5 nm) / EML (BH1:S2:v - DABNA, 89%:10%:1%, 35 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (1:9, 15 nm) / CPL (80 nm).

[0159] Example 6:

[0160] The stacked structure of the device is:

[0161] ITO / Ag / ITO (150 nm) / HIL (10 nm) / HTL1 (30 nm) / EBL (5 nm) / EML (BH1:S3:v - DABNA, 89%:10%:1%, 35 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (1:9, 15 nm) / CPL (80 nm).

[0162] Example 7:

[0163] The stacked structure of the device is:

[0164] ITO / Ag / ITO (150 nm) / HIL (10 nm) / HTL1 (30 nm) / EBL (5 nm) / EML (BH1:S4:v - DABNA, 89%:10%:1%, 35 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (1:9, 15 nm) / CPL (80 nm).

[0165] Device testing:

[0166] Using an IVL test device to obtain the voltage, chromaticity coordinates, current efficiency (CE), and maximum external quantum efficiency (EQEmax) of the device at 15 mA / cm 2 .

[0167] Using a service life test device to obtain the time when the brightness of the organic light - emitting diode decays from the initial value to 95% (LT95) at 15 mA / cm 2 , with the unit of hours.

[0168] Testing the devices in the above - mentioned examples and comparative examples, the optoelectronic properties of the devices are specifically shown in Table 1.

[0169] Table 1 Optoelectronic properties of the devices

[0170]

[0171]

[0172] As can be seen from Table 1, according to Comparative Example 1 and Comparative Example 2, for TADF materials with better performance, they have relatively fast kISC and kr, resulting in a lower FRET rate, and they have no improvement effect on the device as a sensitizer. According to Comparative Example 5 and Example 1, for materials with poor TADF performance, when used alone as an emitter, the device efficiency is very low. However, as a sensitizer, due to its lower kISC and kr, the competition for FRET becomes weaker, and FRET becomes the main exciton transfer channel, significantly improving the efficiency of the sensitized device. According to Comparative Examples 1 to 4 and Example 1, the kISC and kr of AZB-TRZ are lower than those of DMAC-TRZ but higher than those of S1. Its performance is improved in the sensitized device, but not as much as that of Example 1, and there is a significant change in the color coordinates. It can be seen from Example 2 that silabenzene is better in the para position than in the meta position, which is more conducive to molecular stacking and has better performance. In Examples 3-4, although bis-silabenzene has a larger steric hindrance, it hinders the short-range vibration of the molecule, resulting in a decrease in performance and an increase in roll-off. In Examples 5-7, the sulfone group has a slightly improved performance compared to the carbonyl group, and the overall performance is basically the same. Comparing Comparative Example 7 with Example 1, the roll-off increases significantly and the performance decreases. Without silabenzene as a large steric hindrance group in the host, the molecules are prone to stacking effects. Comparing Comparative Example 8 with Example 1, the device performance is similar to that of AZB-TRZ. The relatively strong fluorescence performance of BS reduces the occurrence of FRET, thereby reducing the performance of the overall device. In addition, from the comparison of the comparative examples and examples, it can be seen that the FRET rate is the most important as a sensitizer. Reducing other rates and reducing competition can obtain a sensitized device with better performance, and can significantly improve the color coordinates, making the selection of sensitizers more extensive. Therefore, the device equipped with the luminescent material of the present invention has good efficiency and color coordinates, and the sensitizer material is easier to prepare.

[0173] The display panel of the embodiment of the present invention includes:

[0174] The light-emitting device described in the above embodiment. The display panel having the light-emitting device described in the above embodiment has high luminous efficiency and long service life.

[0175] The display device of the embodiment of the present invention includes:

[0176] The display panel described in the above embodiment. The display device having the display panel described in the above embodiment has high luminous efficiency and long service life.

[0177] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative rather than restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the spirit of the present invention and the scope protected by the claims, and all of them fall within the protection scope of the present invention.

Claims

1. A luminescent material, characterized in that: include: The main material includes a first compound, and the structural formula of the first compound is structural formula 1: Ring Ar1 and ring Ar2 are independently selected from a C6-C60 carbocyclic group and a C5-C60 heterocyclic group; a1, a2, a3 and b1, b2 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a silylphenyl group, a silane group, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a substituted or unsubstituted C1-C60 alkyl group, a substituted or unsubstituted C2-C60 alkenyl group, a substituted or unsubstituted C2-C60 alkynyl group, a substituted or unsubstituted C1-C60 alkoxy group, a substituted or unsubstituted C3-C10 cycloalkyl group, a substituted or unsubstituted C1-C10 heterocycloalkyl group, a substituted or unsubstituted C3-C10 cycloalkenyl group, a substituted or unsubstituted C1-C10 heterocycloalkenyl group, a substituted or unsubstituted a substituted C6-C60 aryl group, a substituted or unsubstituted C6-C60 aryloxy group, a substituted or unsubstituted C6-C60 arylthio group, a substituted or unsubstituted C1-C60 heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, -Si(Q1)(Q2)(Q3), -B(Q1)(Q2), -N(Q1)(Q2), -P(Q1)(Q2), -C(=O)(Q1), -S(=O)(Q1), -S(=O)2(Q1), -P(=O)(Q1)(Q2), and -P(=S)(Q1)(Q2); Q1 to Q3 are independently selected from hydrogen, fluorine, chlorine, bromine, iodine, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a C1-C60 alkyl group, a C2-C60 alkenyl group, a C2-C60 alkynyl group, a C1-C60 alkoxy group, a C3-C10 cycloalkyl group, a C1-C10 heterocycloalkyl group, a C3-C10 cycloalkenyl group, a C1-C10 heterocycloalkenyl group, a C6-C60 aryl group, a C1-C60 heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group; At least one of a1, a2 and a3 is tetraphenylsilicon.

2. The luminescent material according to claim 1, characterized in that The structural formula of the first compound is selected from structural formula BH1 to structural formula BH4, and structural formula BH1 to structural formula BH4 are selected from:

3. The luminescent material according to claim 1 or 2, characterized in that ,, also includes: A sensitizer material, wherein the sensitizer material includes a second compound, and the structural formula of the second compound is structural formula 2: X1 is selected from alkyl, aromatic, and heterocyclic rings, and X2 is selected from =C=O, -S(=O)2-.

4. The luminescent material according to claim 3, characterized in that The structural formula of the second compound is selected from Structural Formula S1 to Structural Formula S4, and Structural Formula S1 to Structural Formula S4 are selected from:

5. The luminescent material according to claim 3, characterized in that The mass of the host material is 80%-95% of the total mass of the luminescent material, and the mass of the sensitizer material is 5%-20% of the total mass of the luminescent material.

6. The luminescent material according to claim 5, characterized in that The luminescent material further comprises: The fluorescent doping material has a mass of 0.4% to 2% of the sum of the mass of the host material and the sensitizer material.

7. A light emitting device, characterized in that: include: The luminescent material according to any one of claims 1 to 6.

8. The light emitting device according to claim 7, characterized in that: The light emitting device comprises: A light-emitting layer comprises the light-emitting material.

9. A display panel, characterized in that: include: The light emitting device according to any one of claims 7 to 8.

10. A display device, characterized in that: include: The display panel as claimed in claim 9.

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