Aza-spiro-xanthene derivatives, electron transport material, light-emitting device, display device

Abstract

This application relates to an azaspiroxanthracene derivative having a structure as shown in molecular formula (Ⅰ): wherein Z1-Z8 are each independently an N atom, or a C atom connected to a substituent R1 or a hydrogen atom, and Z1-Z8 include at least one N atom and one C atom; X is O or S; A and B are aromatic groups. This application constructs an azaspiroxanthracene derivative based on azaspiroxanthracene. Because the azaspiroxanthracene derivative contains two sets of atoms in different planes, its spatial structure is very complex, making it difficult to crystallize and prone to π-π stacking. The overall regularity of the intermolecular arrangement is low, making it less prone to crystallization when applied to electron transport materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a light emitting diode. BACKGROUND

[0002] An organic electroluminescent device (OLED) is a device that emits light by applying a current or voltage to the major surfaces of two electrodes, holes are injected into an organic material layer, and electrons are injected into the organic layer. When the injected holes and electrons meet, an exciton is formed, the exciton falls to the ground state and emits light. Current organic electroluminescent devices generally include a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, and the like.

[0003] When the OLED device is running under applied voltage, Joule heat is generated, which can cause the organic material to crystallize, affecting the service life and efficiency of the device. The electron transport layer is formed of an electron transport material, which exhibits an electron-deficient system in the molecular structure and has a strong electron group, which makes the electron transport material have a certain polarity. Compared with the hole transport material, the electron transport material is more likely to crystallize, which can cause the electron transport material to have poor film forming ability during film forming due to crystallization, and even cause the material to block the hole, which is not conducive to the mass production of OLED devices. SUMMARY

[0004] The embodiments of the present application provide a kind of azaspiro xanthene derivative, electron transport material, light emitting device, display device, to solve the technical problem that electron transport material is easy to crystallize.

[0005] In the first aspect, the embodiments of the present application provide a kind of azaspiro xanthene derivative, which has a structure as shown in formula (I):

[0006]

[0007] Wherein, Z1-Z8 are each independently N atom, or C atom connected with substituent R1 Or hydrogen atom, and at least one N atom and one C atom are included in Z1-Z8;

[0008] X is O or S;

[0009] A, B is aromatic group.

[0010] In some embodiments of the present application, the substituent R1 It is one of substituted or unsubstituted hydrocarbon group, or it is one of substituted or unsubstituted heterocyclic group.

[0011] In some embodiments of the present application, the substituent R1is one of substituted or unsubstituted C1-C60alkyl, substituted or unsubstituted C3-C10cycloalkyl, substituted or unsubstituted C1-C10heterocycloalkyl, substituted or unsubstituted C3-C10cycloalkenyl, substituted or unsubstituted C1-C10heterocycloalkenyl, substituted or unsubstituted C6-C60aryl, substituted or unsubstituted C6-C60aryloxy, substituted or unsubstituted C6-C60arylthio, substituted or unsubstituted C1-C60heteroaryl, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0012] In some embodiments of the present application, at least one of the substituents R1has a structure as described in Formula (II), Formula (III), or Formula (IV):

[0013]

[0014]

[0015] wherein Y1-Y 11 , Y 13 -Y 15 are each independently a N atom, or a C atom to which a substituent R2or a hydrogen atom is attached, and Y1-Y 11 , Y 13 -Y 15 include at least two N atoms;

[0016] Y 12 is O, S, or a nitrogen atom to which a substituent R2or a hydrogen atom is attached;

[0017] * is a single electron, and * is bonded to a substituent or a hydrogen atom, or to other groups in the azaspiroxanthene derivative other than substituents R1.

[0018] In some embodiments of the present application, the substituent R2is one of -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazone, carboxylic acid or its salt, sulfonic acid or its salt, phosphoric acid or its salt, substituted or unsubstituted C3-C10cycloalkyl, substituted or unsubstituted C1-C10heterocycloalkyl, substituted or unsubstituted C3-C10cycloalkenyl, substituted or unsubstituted C1-C10heterocycloalkenyl, substituted or unsubstituted C6-C60aryl, substituted or unsubstituted C6-C60aryloxy, substituted or unsubstituted C6-C60arylthio, substituted or unsubstituted C1-C60heteroaryl, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0019] In some embodiments of the present application, the molecular formula (I) is one of the following chemical formulae:

[0020]

[0021] In some embodiments of the present application, the azaspiro xanthene derivative includes at least one of the following compounds:

[0022]

[0023]

[0024]

[0025] In some embodiments of the present application, the glass transition temperature of the azaspiro xanthene derivative is not less than 120℃; and / or,

[0026] The molecular weight of the azaspiro xanthene derivative is not higher than 1000.

[0027] In the second aspect, the embodiments of the present application provide an electron transport material, which includes the azaspiro xanthene derivative of any one of the embodiments of the first aspect.

[0028] In the third aspect, the embodiments of the present application provide a light emitting device, which includes the following layers arranged in a stack:

[0029] An anode;

[0030] A light emitting layer;

[0031] An electron transport layer, a material of the electron transport layer being the electron transport material of the second aspect;

[0032] A cathode.

[0033] In some embodiments of the present application, the light emitting device further includes at least one of a hole injection layer, a hole transport layer, and an electron injection layer.

[0034] In the fourth aspect, the embodiments of the present application provide a display device, which includes the light emitting device of the third aspect.

[0035] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art:

[0036] The nitrogen spiroxanthene derivative provided by the embodiment of the present application is constructed on the basis of the nitrogen spiroxanthene derivative, and due to the existence of two groups of atoms in different planes in the nitrogen spiroxanthene derivative, the spatial structure of the nitrogen spiroxanthene derivative is very complex, the nitrogen spiroxanthene derivative is not easy to crystallize, and the π-π stacking phenomenon is not easy to occur, the regularity of intermolecular arrangement is low as a whole, and when the nitrogen spiroxanthene derivative is applied to an electron transport material, the nitrogen spiroxanthene derivative is not easy to crystallize. BRIEF DESCRIPTION OF DRAWINGS

[0037] The drawings incorporated into the specification and constituting a part of the specification show the embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application.

[0038] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required to be used in the embodiment or prior art description will be briefly introduced as follows, and obviously, other drawings can also be obtained by those skilled in the art without creative labor under the premise of the drawings.

[0039] Figure 1 The structure schematic diagram of the light-emitting device provided by the embodiment of the present application is shown in the figure.

[0040] Figure 2 The flowchart of the preparation method of the upright light-emitting device provided by the embodiment of the present application is shown in the figure.

[0041] Figure 3 The flowchart of the preparation method of the inverted light-emitting device provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0043] Unless otherwise specifically indicated, the terms used in the present application should be understood as the meanings commonly used in the art. Therefore, unless otherwise defined, all the technical and scientific terms used in the present application have the same meanings as the general understanding of the skilled in the art to which the present application belongs. If there is a conflict, the present specification is preferred.

[0044] Unless otherwise specifically indicated, the various raw materials, reagents, instruments and equipment used in the present application can be purchased from the market or can be prepared by the existing method.

[0045] The electron transport material in the existing OLED device has a technical problem of easy crystallization.

[0046] The technical scheme provided by the embodiments of the present application is to solve the above technical problems, and the general idea is as follows:

[0047] In a first aspect, the embodiments of the present application provide a nitrogen spiroxanthene derivative, which has a structure as shown in formula (I):

[0048]

[0049] Z1-Z8 are each independently N atoms or C atoms connected with a substituent R1 or a hydrogen atom, and at least one of Z1-Z8 is an N atom and one is a C atom;

[0050] X is O or S;

[0051] A and B are aromatic groups.

[0052] It can be understood by those skilled in the art that both N atoms and C atoms in formula (I) are sp 2 hybridization, and the N atom does not need to be connected with other groups, while the C atom needs to be connected with another group to maintain stability. Those skilled in the art can select a suitable substituent R1 according to the general construction method of the electron transport material, and the substituent R1 described in the present application includes all available substituents.

[0053] The number of N atoms in Z1-Z8 can control the electronic energy level of the nitrogen spiroxanthene derivative, so that the LUMO energy level is suitable for electron transport material.

[0054] It is easy to understand that the C and N atoms in Z1-Z8 form a large π bond and are in the same plane. Since A and B are aromatic groups, it is easy to understand that A and B are also in the same plane, and Z1-Z8 and A, B are not in the same plane, which means that when the nitrogen spiroxanthene derivative described in the present application forms a continuous phase in macroscopic, due to its very complex microscopic spatial structure, it is not easy to crystallize, and it is not easy to occur π-π stacking phenomenon, and the overall regularity of intermolecular arrangement is low.

[0055] Those skilled in the art can understand that there can be multiple substituents R1 in the nitrogen spiroxanthene derivative, and the structures of the multiple substituents R1 can be the same or different.

[0056] The present application constructs aza-spiro-xanthene derivative on the basis of aza-spiro-xanthene. Due to the presence of two groups of atoms in different planes in the aza-spiro-xanthene derivative, the spatial structure of the aza-spiro-xanthene derivative is very complex, it is not easy to crystallize, and it is not easy to have π-π stacking phenomenon, the regularity of intermolecular arrangement is low as a whole, and it is not easy to crystallize when applied to electron transport material.

[0057] In some embodiments of the present application, the substituent R1 is one of a substituted or unsubstituted hydrocarbon group, or one of a substituted or unsubstituted heterocyclic group.

[0058] As can be understood by those skilled in the art, both the substituted or unsubstituted hydrocarbon group and the substituted or unsubstituted heterocyclic group are common groups in electron transport materials, and those skilled in the art can fine-tune the molecular structure of the aza-spiro-xanthene derivative by selecting different groups.

[0059] In some embodiments of the present application, the substituent R1 is one of a substituted or unsubstituted C1-C60 alkyl 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, or a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0060] As can be understood by those skilled in the art, the above-mentioned groups are common groups in electron transport materials, and many raw materials in the art contain the above-mentioned groups, which facilitate the preparation of the aza-spiro-xanthene derivative.

[0061] In some embodiments of the present application, at least one of the substituents R1 has a structure as described in Formula (II), Formula (III), or Formula (IV):

[0062]

[0063] wherein Y1-Y 11 , Y 13 -Y 15 each independently is an N atom, or a C atom connected with a substituent R2 or a hydrogen atom, and Y1-Y 11 , Y 13 -Y 15 comprises at least two N atoms.

[0064] Y 12O, S, or a nitrogen atom to which a substituent R2or a hydrogen atom is attached;

[0065] The * is a single electron, the * is bonded to a substituent or a hydrogen atom, or is bonded to other groups in the azaspiroxanthene derivative other than the substituent R1.

[0066] The present application further introduces at least one of a phenanthroline structure, a benzoxazole structure, and a triazine structure on the basis of the azaspiroxanthene structure, so as to adjust the LUMO energy level of the azaspiroxanthene derivative, reduce the injection barrier between the azaspiroxanthene derivative and a cathode, and increase the carrier injection capacity.

[0067] In addition, the OLED is a double-carrier injection device, and the recombination efficiency of the carriers affects the efficiency of the device. In order to realize effective recombination of the carriers in the light-emitting layer and prevent excitons from diffusing to the surrounding functional layers, it is required that the functional layer adjacent to the light-emitting layer has a relatively high T1 energy level. Therefore, the electron transport material needs to have a suitable T1 energy level, so as to effectively improve the efficiency of the device. The benzoxazole structure can adjust the T1 energy level of the azaspiroxanthene derivative, enhance the ability of blocking excitons, adjust the HOMO energy level to block holes, increase the exciton recombination probability, and improve the efficiency.

[0068] In some embodiments of the present application, the substituent R2is one of -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidine group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C3-C10cycloalkyl group, a substituted or unsubstituted C1-C10heterocycloalkyl group, a substituted or unsubstituted C3-C10cycloalkenyl group, a substituted or unsubstituted C1-C10heterocycloalkenyl group, a substituted or unsubstituted C6-C60aryl group, a substituted or unsubstituted C6-C60aryloxy group, a substituted or unsubstituted C6-C60arylthio group, a substituted or unsubstituted C1-C60heteroaryl group, a substituted or unsubstituted monovalent non-aromatic fused polycyclic group, and a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group.

[0069] The azaspiroxanthene derivative can contain a plurality of substituents R2, and different substituents R2may have the same structure or different structures.

[0070] The present application can fine-tune the energy level of the azaspiroxanthene derivative by selecting the above-mentioned groups.

[0071] In some embodiments of the present application, the molecular formula (I) is one of the following chemical formulae:

[0072]

[0073] In some embodiments of the present application, the aza-spiro-xanthene derivative includes at least one of the following compounds:

[0074]

[0075]

[0076]

[0077]

[0078] In some embodiments of the present application, the glass transition temperature of the aza-spiro-xanthene derivative is not lower than 120℃; and / or,

[0079] The molecular weight of the aza-spiro-xanthene derivative is not higher than 1000.

[0080] Since the molecular space configuration of the aza-spiro-xanthene derivative described in the present application is complex, it is not easy to form an ordered crystal structure, and therefore it will undergo glass transition and gradually liquefy in the heating phase change process.

[0081] 120℃ is a relatively high glass transition temperature in OLED materials, and a high glass transition temperature means that the aza-spiro-xanthene derivative has high stability during evaporation.

[0082] In order to make the aza-spiro-xanthene derivative have good evaporation property, its molecular weight is controlled to be within 1000.

[0083] In a second aspect, the embodiments of the present application provide an electron transport material, which includes the aza-spiro-xanthene derivative of any of the embodiments of the first aspect.

[0084] The electron transport material described in the present application can include one of the aza-spiro-xanthene derivatives, or any two or more of them, or other substances that can have a regulating effect.

[0085] Since the implementation of the electron transport material described in the present application is based on the aza-spiro-xanthene derivative described in the first aspect, the electron transport material described in the present application can have all the beneficial effects of the first aspect, which will not be repeated here.

[0086] In a third aspect, the embodiments of the present application provide a light-emitting device, which will be described with reference to Figure 1 , Figure 1 The structure of the light-emitting device described in the present application is shown, which includes the following layers arranged in layers:

[0087] an anode 07;

[0088] a light-emitting layer 04;

[0089] An electron transport layer 03, wherein the material of the electron transport layer 03 is the electron transport material described in the second aspect;

[0090] Cathode 01.

[0091] Since the implementation of the light-emitting device described in this application is based on the electron transport material described in the second aspect, the light-emitting device described in this application can have all the beneficial effects of the second aspect, which will not be repeated here.

[0092] Those skilled in the art will understand that the light-emitting device can be an upright device or an inverted device.

[0093] Those skilled in the art will understand that the light-emitting device can be a top-emitting device or a bottom-emitting device.

[0094] Those skilled in the art will understand that the materials of the anode 07 and the cathode 01 can be one or more of metals, carbon materials, and metal oxides. Metals can be, for example, one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, and Mg. Carbon materials can be, for example, one or more of graphite, carbon nanotubes, graphene, and carbon fibers. Metal oxides can be doped or undoped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, as well as composite electrodes with metal sandwiched between doped or undoped transparent metal oxides.

[0095] In some embodiments of this application, the light-emitting device further includes at least one of a hole injection layer 06, a hole transport layer 05, and an electron injection layer 02.

[0096] Those skilled in the art will understand that the material of the hole injection layer 06 is a material known in the art for use in hole injection layers 06. The material of the hole injection layer 06 may be selected from materials with hole injection capability, including but not limited to poly(3,4-ethylenedioxythiophene) (PEDOT), poly(3,4-ethylenedioxythiophene)-polystyrene sulfonic acid (PEDOT:PSS), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethylethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzphenanthrene (HATCN), copper polyester carbonate (CuPc), transition metal oxides, and transition metal chalcogenides, or one or more of these.

[0097] Those skilled in the art will understand that the material of the hole transport layer 05 can be selected from organic materials with hole transport capabilities, including but not limited to poly(9,9-dioctylfluorene-CO-N-(4-butylphenyl)diphenylamine) (TFB), polyvinylcarbazole (PVK), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (poly-TPD), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine) (PFB), 4,4',4”-tris(carbazole-9-yl)triphenylamine (TCATA), 4 The hole transport layer 05 may be selected from one or more of the following: 4'-di(9-carbazole)biphenyl (CBP), N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), doped graphene, undoped graphene, and C60. The hole transport layer 05 may also be selected from inorganic materials with hole transport capabilities, including but not limited to one or more of doped or undoped NiO, WO3, MoO3, and CuO.

[0098] Those skilled in the art will understand that the material of the light-emitting layer 04 can be selected from quantum dot light-emitting materials or organic light-emitting materials. However, this application is for OLED design, and the electron transport layer 03 described in this application has better interlayer compatibility with the organic light-emitting material of the OLED. The organic light-emitting material is an organic light-emitting material known in the art, and for example, it can be selected from, but is not limited to, diaromatic anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, blue-emitting TBPe fluorescent materials, green-emitting TTPA fluorescent materials, orange-emitting TBRb fluorescent materials, and red-emitting DBP fluorescent materials.

[0099] Those skilled in the art will understand that the material of the electron injection layer 02 can be selected from at least one of Li2O, LiF, and K2SiO3.

[0100] In addition, as part of the examples, this application also provides a method for fabricating the light-emitting device.

[0101] When the light-emitting device is a positively positioned device, i.e., a positively positioned light-emitting device, please refer to [reference needed]. Figure 2 , Figure 2 The fabrication process of the upright light-emitting device is shown. The fabrication method of the upright light-emitting device includes the following steps:

[0102] S11: Provides anode 07;

[0103] S12: Provide a light-emitting layer material, and use the light-emitting layer material to prepare a light-emitting layer 04 on the anode 07;

[0104] S13: Provide the electron transport material, and use the electron transport material to prepare an electron transport layer 03 on the light-emitting layer 04;

[0105] S14: Prepare cathode 01 on the electron transport layer 03.

[0106] When the light-emitting device is an inverted device, i.e., an inverted light-emitting device, please refer to... Figure 3 , Figure 3 The fabrication process of the inverted light-emitting device is shown. The fabrication method of the inverted light-emitting device includes the following steps:

[0107] S21: Provides cathode 01;

[0108] S22: Provide the electron transport material and use the electron transport material to prepare an electron transport layer 03 on the cathode 01;

[0109] S23: Provide a light-emitting layer material, and use the light-emitting layer material to prepare a light-emitting layer 04 on the electron transport layer 03;

[0110] S24: An anode 07 is prepared on the light-emitting layer 04.

[0111] In some embodiments of this application, step S111 is further included between step S11 and step S12: preparing a hole injection layer 06 on the anode 07.

[0112] In some embodiments of this application, step S112 is further included between step S11 and step S12: preparing a hole transport layer 05 on the anode 07.

[0113] In some embodiments of this application, step S113 is further included between step S111 and step S12: a hole transport layer 05 is prepared on the hole injection layer 06.

[0114] In some embodiments of this application, step S131 is further included between step S13 and step S14: an electron injection layer 02 is prepared on the electron transport layer 03.

[0115] In some embodiments of this application, step S211 is further included between step S21 and step S22: an electron injection layer O2 is prepared on the cathode O1.

[0116] In some embodiments of this application, step S221 is further included between step S22 and step S23: a hole transport layer 05 is prepared on the light-emitting layer 04.

[0117] In some embodiments of this application, step S222 is further included between step S22 and step S23: a hole injection layer 06 is prepared on the light-emitting layer 04.

[0118] In some embodiments of this application, step S223 is further included between step S221 and step S23: a hole injection layer 06 is prepared on the hole transport layer 05.

[0119] Fourthly, embodiments of this application provide a display device, which includes the light-emitting device described in the third aspect. Those skilled in the art will understand that the display device can be any display device that uses OLED, including but not limited to television screens, mobile phone screens, and iPad screens.

[0120] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0121] The structures of the compounds involved in the various embodiments and comparative examples are as follows:

[0122]

[0123]

[0124] Example 1

[0125] This embodiment provides a zazaspiroxanthracene derivative having a structure as shown in the following molecular formula:

[0126]

[0127] The azaspiroxanthracene derivatives described in this application are prepared via the following process:

[0128]

[0129] The specific preparation method for the above process is as follows:

[0130] 0.1 mol of fluorene-9-one was added to 200 mL of o-dichlorobenzene and stirred until completely dissolved. Then, 1 mol of methanesulfonic acid was added dropwise, and the mixture was stirred at room temperature for 1 h. Next, a solution of o-dichlorobenzene containing 0.5 mol of 2-iodopyridin-4-ol was added dropwise, and the mixture was kept at 35 °C for 2 h. The temperature was then increased to 150 °C, and the reaction was allowed to proceed for 24 h. After the reaction was confirmed to be complete, the reaction solution was concentrated and rotary evaporated, and then subjected to column chromatography to obtain intermediate 1-1 with a yield of 44%.

[0131] 0.048 mol of intermediate 1-1 was dissolved in 300 mL of 1,4-dioxane solvent and stirred under nitrogen purging. 0.096 mol of 1,10-phenanthroline-3-boric acid, 0.24 mol of potassium carbonate, and 0.96 mmol of tetra(triphenylphosphine)palladium were added sequentially. The mixture was heated to reflux and reacted. After 5 h, HPLC analysis showed that the reaction was basically complete. The reaction solution was evaporated to dryness under reduced pressure, and the residue was subjected to column chromatography to obtain compound 1 with a yield of 64%.

[0132] Example 2

[0133] This embodiment provides a zazaspiroxanthracene derivative having a structure as shown in the following molecular formula:

[0134]

[0135] Example 3

[0136] This embodiment provides a zazaspiroxanthracene derivative having a structure as shown in the following molecular formula:

[0137]

[0138] The azaspiroxanthracene derivatives described in this application are prepared via the following process:

[0139]

[0140] The specific preparation method for the above process is as follows:

[0141] 0.1 mol of intermediate 1-1 was dissolved in 590 mL of 1,4-dioxane solvent and stirred under nitrogen purging. Then, 0.1 mol of (3-(3a,7a-dihydrobenzoxazol-2-yl)phenyl)boronic acid, 0.25 mol of potassium carbonate, and 0.001 mol of tetra(triphenylphosphine)palladium were added sequentially. The mixture was heated to reflux and reacted. After 2.5 h, HPLC analysis showed that the reaction of the starting material was basically complete. The mixture was then completely concentrated under reduced pressure and obtained by column chromatography, yielding intermediate 3-1 in 52% yield.

[0142] 0.054 mol of intermediate 3-1 was added to 400 mL of anhydrous THF and stirred. Under nitrogen protection, the mixture was cooled to -78 °C. 24 mL (0.06 mol) of 2.5 mol / L n-butyllithium was added dropwise. The mixture was kept at -78 °C for 1 h and then heated to room temperature. After 5 h, the reaction of the starting material was detected as complete. 1 mol / L dilute hydrochloric acid aqueous solution was added dropwise to the reaction solution and stirred for 5 h. A solid precipitated out. The residue was filtered and subjected to column chromatography to obtain compound 3, with a yield of 64%.

[0143] Example 4

[0144] This embodiment provides a zazaspiroxanthracene derivative having a structure as shown in the following molecular formula:

[0145]

[0146] Example 5

[0147] This embodiment provides an OLED device, which is fabricated through the following steps:

[0148] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0149] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0150] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0151] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and GD are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of GD is 10%.

[0152] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0153] Sf: The azaspiroxanthracene derivative provided in Example 1 is deposited on the hole blocking layer to form an electron transport layer (ETL) with a thickness of 30 nm;

[0154] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0155] Example 6

[0156] The only difference between this embodiment and Example 5 is that the compound vapor-deposited in step Sf is from Example 2. Specifically:

[0157] This embodiment provides an OLED device, which is fabricated through the following steps:

[0158] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0159] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0160] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0161] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and Ir(ppy)3 are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of Ir(ppy)3 is 10%.

[0162] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0163] Sf: The azaspiroxanthracene derivative provided in Example 2 is deposited on the hole blocking layer to form an electron transport layer (ETL) with a thickness of 30 nm;

[0164] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0165] Example 7

[0166] The only difference between this embodiment and Example 5 is that the compound vapor-deposited in step Sf is from Example 3. Specifically:

[0167] This embodiment provides an OLED device, which is fabricated through the following steps:

[0168] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0169] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0170] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0171] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and Ir(ppy)3 are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of Ir(ppy)3 is 10%.

[0172] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0173] Sf: The azaspiroxanthracene derivative provided in Example 3 is deposited on the hole blocking layer to form an electron transport layer (ETL) with a thickness of 30 nm;

[0174] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0175] Example 8

[0176] The only difference between this embodiment and Example 5 is that the compound vapor-deposited in step Sf is from Example 4. Specifically:

[0177] This embodiment provides an OLED device, which is fabricated through the following steps:

[0178] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0179] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0180] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0181] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and Ir(ppy)3 are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of Ir(ppy)3 is 10%.

[0182] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0183] Sf: The azaspiroxanthracene derivative provided in Example 4 is deposited on the hole blocking layer to form an electron transport layer (ETL) with a thickness of 30 nm;

[0184] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0185] Comparative Example 1

[0186] The only difference between this comparative example and Example 5 is that the compounds vapor-deposited in step Sf are BCP and lithium 8-hydroxyquinoline. Specifically:

[0187] This embodiment provides an OLED device, which is fabricated through the following steps:

[0188] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0189] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0190] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0191] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and Ir(ppy)3 are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of Ir(ppy)3 is 10%.

[0192] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0193] Sf: Deposit compounds BCP and 8-hydroxyquinoline lithium on the hole blocking layer, so that the two raw materials are vaporized at the same rate to form an electron transport layer (ETL) with a thickness of 30 nm.

[0194] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0195] Comparative Example 2

[0196] The only difference between this comparative example and Example 5 is that the compound vapor-deposited in step Sf is compound X. Specifically:

[0197] This embodiment provides an OLED device, which is fabricated through the following steps:

[0198] Sa: On a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm thickness, compounds F4TCNQ and NPB are co-deposited at a vacuum of 1 × 10-5 Pa to form a hole injection layer (HIL) with a thickness of 10 nm.

[0199] Sb: The compound NPB is deposited on the hole injection layer to form a hole transport layer (HTL) with a thickness of 100 nm.

[0200] Sc: A 10 nm thick auxiliary transport layer (Prime) is formed by evaporating the compound CPB onto the hole transport layer.

[0201] Sd: 3,3'-bis(N-carbazolyl)-1,1'-biphenyl and Ir(ppy)3 are co-deposited on the auxiliary transport layer to form a light-emitting layer with a thickness of 20 nm, wherein the mass percentage of 3,3'-bis(N-carbazolyl)-1,1'-biphenyl in the light-emitting layer is 90% and the mass percentage of Ir(ppy)3 is 10%.

[0202] Se: TPBi compound is deposited on the light-emitting layer to form a hole blocking layer (HBL) with a thickness of 5 mm;

[0203] Sf: Compound X is deposited on the hole blocking layer to form an electron transport layer (ETL) with a thickness of 30 nm;

[0204] Sg: A 1 nm thick layer of metallic Yb is deposited on the electron transport layer, followed by a 13 nm thick Mg / Ag alloy metal cathode.

[0205] The structural formula of compound X is as follows:

[0206] Relevant experimental and effect data:

[0207] Regarding the electronic transport materials involved in the embodiments and comparative examples, this application conducted the following tests:

[0208] HOMO / LUMO energy levels were measured using AC3, CV, and UV spectroscopy.

[0209] Using Time-of-Flight (TOF) to test mobility, recombination can be obtained through simulation calculations.

[0210] The results are shown in the table below:

[0211] Compound HOMO level (eV) LOMO level (eV) λe (eV) Compound X 6.72 3.02 0.33 Example 1 6.72 3.25 0.25 Example 2 6.54 3.22 0.26 Example 3 6.50 3.15 0.30 Example 4 6.62 3.32 0.31

[0212] The above results demonstrate that the azaspiroxanthracene derivatives provided in Examples 1-4, compared to the comparative compounds, possess deeper HOMO and LUMO energy levels, theoretically enabling better electron transport and reducing the operating voltage of the device. The lower λe values ​​of Examples 1-4 indicate that they are less susceptible to structural changes due to electron influence during electron transport, thus exhibiting a smaller energy barrier and facilitating electron transport.

[0213] At 1000cd / m 2 At different brightness levels, the driving voltage, current efficiency, and lifetime of the OLED devices prepared in Device Examples 5-8 and Device Comparative Examples 1-2 were measured, and the results are shown in the table below:

[0214] Example Driving voltage Current efficiency Lifetime Comparative Example 1 100％ 100％ 100％ Comparative Example 2 98％ 103％ 102％ Example 1 95％ 113％ 110％ Example 2 94％ 107％ 115％ Example 3 97％ 110％ 113％ Example 4 94％ 104％ 107％

[0215] The above results show that the OLED devices in Examples 5-8 have significantly improved efficiency and reduced voltage to a certain extent compared with Comparative Examples 1-2, while also having a longer lifespan. This indicates that the electron transport material in Examples 5-8 itself has high mobility and stability.

[0216] This application also determined the glass transition temperature (Tg) of the azaspiroxanthracene derivatives provided in Examples 1-4 and compound X in Comparative Example 1. The measuring instrument was a DSC differential scanning calorimeter; the test atmosphere was nitrogen, the heating rate was 10 °C / min, and the temperature range was 50–300 °C.

[0217] This application also used a low-temperature phosphorescence spectrometer (T1 = 1240 / PL peak) to determine the triplet energy level (T1) of the azaspiroxanthracene derivatives provided in Examples 1-4 and compound X in Comparative Example 1.

[0218] The measured glass transition temperature (Tg) and triplet energy level (T1) are shown in the table below:

[0219] Compound Tg (°C) T1 (eV) Compound X 122 2.2 Example 1 138 2.42 Example 2 132 2.37 Example 3 129 2.51 Example 4 121 2.43

[0220] The results above demonstrate that the azaspiroxanthracene derivatives provided in Examples 1-4 have a higher glass transition temperature and better stability during vapor deposition compared to the comparative compounds; the triplet energy level is also higher, providing better blocking of exciton energy.

[0221] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0222] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, the terms "comprising," "including," etc., mean "including but not limited to." Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. For associations involving three or more related objects described using "and / or", it indicates that any one of the three related objects can exist alone, or at least two of them can exist simultaneously. For example, for A, and / or B, and / or C, it can mean that any one of A, B, and C exists alone, or any two of them exist simultaneously, or all three of them exist simultaneously. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can each be single or multiple.

[0223] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A light-emitting device, characterized in that, The light-emitting device comprises layers stacked together: anode; Emissive layer; An electron transport layer, wherein the material of the electron transport layer includes azaspiroxanthracene derivatives; cathode; The thickness of the electron transport layer is 30 nm; The azaspiroxanthracene derivative is selected from any of the following structural formulas:

2. The light-emitting device according to claim 1, characterized in that, The light-emitting device further includes at least one of a hole injection layer, a hole transport layer, and an electron injection layer.

3. A display device, characterized in that, The display device includes the light-emitting device as described in claim 1 or 2.

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