Organic electroluminescent device and display device

Abstract

The present disclosure relates to an organic electroluminescence device and a display device. The organic electroluminescence device comprises a first electrode, a second electrode facing the first electrode, and a sandwich layer between the first electrode and the second electrode and comprising a light-emitting layer, the sandwich layer comprising a hole transport layer between the first electrode and the light-emitting layer, and a light-emitting auxiliary layer between the hole transport layer and the light-emitting layer, wherein the light-emitting auxiliary layer comprises a hole transport material with a segment of triplet spin density distribution and an alkyl part substituted by D. The present disclosure reduces molecular vibration by introducing deuterium on the segment of triplet spin density aggregation, thereby improving the stability of the material, thereby facilitating the improvement of the device life. In addition, the introduction of deuterated alkyl in the light-emitting auxiliary layer material reduces the voltage to a certain extent, and the introduction of alkyl also protects the original active site, reduces the degree of molecular aggregation, and also improves the device life to a certain extent.

Description

Technical Field

[0001] This disclosure belongs to the field of organic electroluminescent device technology, and specifically relates to an organic electroluminescent device and a display device. Background Technology

[0002] In recent years, organic light-emitting diodes (OLEDs) have gradually attracted more attention as a new type of flat panel display. Due to their characteristics such as active light emission, high brightness, high resolution, wide viewing angle, fast response speed, low power consumption, and flexibility, they have become a popular mainstream display product in the market.

[0003] As products continue to evolve, customers demand increasingly higher resolution and lower power consumption. This necessitates the development of high-efficiency, low-voltage, and long-life devices. Summary of the Invention

[0004] Organic light-emitting diode (OLED) display devices typically include an anode, a cathode, and one or more layers selected from hole injection layers, hole transport layers, electron blocking layers, light-emitting layers (including host and guest doped layers), hole blocking layers, electron transport layers, and electron injection layers. A light-emitting auxiliary layer (sometimes called an electron blocking layer or prime layer) is usually added between the hole transport layer and the light-emitting layer, thus forming a multilayer hole transport layer together with the hole transport layer to improve device lifetime and efficiency. The light-emitting auxiliary layer mainly assists the hole transport layer, reducing the potential barrier between the hole transport layer and the light-emitting layer, lowering the driving voltage of the OLED, further increasing hole utilization, and thus improving the device's luminous efficiency and lifetime.

[0005] Phosphorescent organic light-emitting diode (OLED) displays utilize triplet excitons for light emission. However, the long lifetime of triplet excitons significantly increases the likelihood of exciton accumulation, leading to severe triplet-triplet quenching (TTA) and triplet-polaron quenching (TPQ) processes, which are highly detrimental to maintaining device stability. Two T1 excitons can form Tn or Sn excitons, both of which have high energies and are prone to degrading the emissive layer material. Furthermore, since the exciton recombination region is close to the hole transport side, both the emissive region and the hole transport region near the emissive region require improved material stability to enhance device lifetime.

[0006] The inventors discovered that some hydrogen atoms in OLED materials have low bond energies with their connected parts. Furthermore, the presence of triplet excitons inevitably leads to the localization of triplet spin density within fixed segments of the material structure, causing localized energy concentration and resulting in material decomposition. Deuterium, an isotope of hydrogen, possesses an additional neutron, which can suppress molecular vibrations, reduce bond lengths, and increase bond energies, thereby significantly improving device lifetime.

[0007] The inventors also discovered that for open-shell systems, the alpha and beta electron density distributions are different, and spin density can be used to examine the distribution of unpaired electrons in three-dimensional space (spin density = alpha electron density - beta electron density). In the triplet spin density distribution region, energy accumulation easily leads to material decomposition. Therefore, by substituting hydrogen (H) with dihydrogen (D) in this region, vibrations are suppressed, and bond dissociation energy is further increased, thereby improving device lifetime.

[0008] In some embodiments, this disclosure addresses the problem of material decomposition caused by localized concentration of triplet exciton energy in the luminescent auxiliary layer material. By introducing deuterium into segments with concentrated triplet spin density, molecular vibrations are reduced, thereby improving the material's stability. In some embodiments, this disclosure introduces deuterated alkyl groups into the active sites of the luminescent auxiliary layer material, combined with a luminescent layer compound having deuterated alkyl substitution. The introduction of alkyl groups can reduce material conjugation, decrease molecular packing, and narrow the spectrum, thereby lowering the evaporation temperature. The use of deuterated alkyl groups improves efficiency and stability. This disclosure, by combining the luminescent layer and the luminescent auxiliary layer, enables the device to maintain high efficiency while exhibiting a long overall lifetime.

[0009] Therefore, this disclosure provides an organic electroluminescent device with low driving voltage, high luminous efficiency and improved lifetime.

[0010] One aspect of this disclosure provides an organic electroluminescent device, comprising:

[0011] First electrode,

[0012] The second electrode facing the first electrode, and

[0013] An interlayer comprising a light-emitting layer is provided between the first electrode and the second electrode.

[0014] The interlayer includes: a hole transport layer between the first electrode and the light-emitting layer, and a light-emitting auxiliary layer between the hole transport layer and the light-emitting layer.

[0015] The light-emitting auxiliary layer includes segments with triplet spin density distribution and hole transport materials in which all H in the alkyl portion is replaced by D.

[0016] In organic electroluminescent devices, the light-emitting auxiliary layer (i.e., the electron-blocking layer, or prime layer) can be fabricated using hole transport materials. Hole transport materials are materials with good hole transport properties, such as aromatic amines, dimethylfluorene, or carbazoles, but are not limited to these. For example, hole transport materials can be 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-bis(9-carbazolyl)biphenyl (CBP), 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (PCzPA), etc., but are not limited to these.

[0017] In some embodiments, the hole transport material of the light-emitting auxiliary layer comprises a compound of formula I:

[0018]

[0019] in,

[0020] One of Ar1 to Ar4 is The other three of Ar1 to Ar4 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, and at least one is not H.

[0021] One of Ar5 to Ar8 is The other three of Ar5 to Ar8 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, and at least one is not H.

[0022] L1 and L2 are each independently selected from single bonds, substituted or unsubstituted alkylene groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkylene groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkylene groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted arylalkylene groups having 7-30 carbon atoms, substituted or unsubstituted alkeneoxy groups having 1-20 carbon atoms, and substituted or unsubstituted... aryleneoxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted arylene groups having 6-30 carbon atoms, substituted or unsubstituted heteroarylene groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylenesilyl groups having 6-20 carbon atoms, substituted or unsubstituted imino groups having 0-20 carbon atoms, and combinations thereof;

[0023] At least one of R1 to R4 is selected from the following groups: The remaining elements are each independently selected from hydrogen, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aryloxy groups having 6-30 carbon atoms, and substituted or unsubstituted... Alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0024] R7, R8, and R9 represent one or more substituents, each of which independently represents a substituent selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aralkyl groups having 6-30 carbon atoms. Oxygen, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms;

[0025] X and Y are each independently a direct bond, CR5, CR5R6, NR6, O or S, provided that X and Y are not both direct bonds at the same time;

[0026] R5 and R6 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, and substituted or unsubstituted... Alkenyl groups having 2-20 carbon atoms, aryl groups having 6-30 carbon atoms (substituted or unsubstituted), heteroaryl groups having 3-30 carbon atoms (substituted or unsubstituted), alkylsilyl groups having 3-20 carbon atoms (substituted or unsubstituted), arylsilyl groups having 6-20 carbon atoms (substituted or unsubstituted), and amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms (substituted or unsubstituted).

[0027] In Formula I, all H atoms in the triplet spin density distribution segment and the alkyl moiety are replaced by D atoms.

[0028] "All H atoms in the triplet spin density distribution segment and the alkyl moiety are replaced by D atoms" means that in Formula I, all H atoms in the triplet spin density distribution segment are replaced by D atoms, and when an alkyl moiety is also present in Formula I, all H atoms in the alkyl moiety are replaced by D atoms. The alkyl moiety may or may not be present in Formula I.

[0029] In some embodiments, L1 and L2 in Formula I are direct bonds.

[0030] In some embodiments, in formula I, Ar1 to Ar8, except for Of the remaining six, one is a fully deuterated alkyl group with 1-10 carbon atoms (especially fully deuterated alkyl groups with 1-4 carbon atoms, such as fully deuterated methyl and fully deuterated ethyl), and the rest are each independently selected from hydrogen and deuterium.

[0031] In some embodiments, in Formula I, one of X and Y is a direct bond, and the other is O or S.

[0032] In some embodiments, one or two of R1 to R4 are selected from the following groups: The remainder are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof.

[0033] In some embodiments, R7, R8, and R9 represent one or more substituents, each of which independently represents a substituent selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and combinations thereof.

[0034] In some embodiments, one or both of R1 to R4 are selected from

[0035] The rest are selected from phenyl, biphenyl, and pentadeuterated phenyl.

[0036] In some embodiments, the compound of formula I is selected from the structure shown in formula I-1:

[0037]

[0038] in,

[0039] One of Ar1 to Ar4 is The other three of Ar1 to Ar4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and at least one is not H;

[0040] One of Ar5 to Ar8 is The other three of Ar5 to Ar8 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and at least one is not H;

[0041] The definitions of R1 to R4 are as described above;

[0042] X is either O or S.

[0043] In some embodiments, the compound of formula I is selected from, but is not limited to, the following structures:

[0044]

[0045]

[0046] Regardless of any particular theory, in compounds of Formula I, alkyl groups are weak electron-donating groups, which can improve the mobility of the compound, enhance the density of the film after deposition, and improve stability, thereby increasing the lifetime of electroluminescent devices. Furthermore, deuteration of the alkyl group further increases the bond dissociation energy of the material, improving material stability and device lifetime. Simultaneously, the CD vibration is weaker than the CH vibration, reducing energy loss due to vibrational relaxation and improving efficiency to some extent.

[0047] There are no particular limitations on the methods for calculating the triplet spin density distribution of materials; any feasible method in the field can be used. For example, calculations can be performed using DFT (density functional theory) at the PBE0 / 6-31G(d,p) level. The calculated wavefunction can be imported into Multiwfn software, and the electron distribution at the isovalue of 0.01 can be selected to obtain the triplet spin density distribution of the compound.

[0048] The triplet spin density distribution of some compounds is shown in Table 1 below:

[0049] Table 1

[0050]

[0051]

[0052] "All H atoms in the triplet spin density distribution segment are replaced by D atoms" means that in the triplet spin density distribution of a compound, the H atoms in the electron cloud distribution segment should be replaced by deuterium. For example, if the triplet spin density distribution of compounds 1-13 is located in the phenanthrene segment, then "all H atoms in the triplet spin density distribution segment are replaced by D atoms" means that the H atoms in the phenanthrene segment should be replaced by D atoms.

[0053] In the organic electroluminescent device according to the present invention, the light-emitting layer material can be any suitable material. For example, the light-emitting layer material can be a red light-emitting host material and a red light-emitting dopant, a green light-emitting host material and a green light-emitting dopant, or a blue light-emitting host material and a blue light-emitting dopant. The light-emitting host material of the light-emitting layer can contain one material or a mixture of two or more materials. For example, the light-emitting host material can be a combination of an electron-type compound and a hole-type compound.

[0054] For example, the blue luminescent host material can be selected from anthracene derivatives, such as 9,10-di-(2-naphthyl)anthracene (AND) and 2-methyl-9,10-di-2-naphthylanthracene (MADN). The blue light dopant can be pyrene derivatives, fluorene derivatives, perylene derivatives, styrylamine derivatives, metal complexes, etc., such as N1,N6-bis([1,1'-biphenyl]-2-yl)-N1,N6-bis([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 2,5,8,11-tetra-tert-butylperylene (TBPe), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAVBi), 4,4'-bis[4-(di-p-tolylamino)styryl]biphenyl (DPAVBi), bis(4,6-difluorophenylpyridine-C2,N)pyridinecarboxyiridium (FIrpic), etc.

[0055] For example, the green light-emitting host material can be selected from coumarin dyes, quinacrine copper derivatives, polycyclic aromatic hydrocarbons, diamine anthracene derivatives, carbazole derivatives, triazine derivatives, etc., such as DMQA, BA-NPB, Alq3, etc., and the green light dopant can be metal complexes, such as Ir(ppy)3, Ir(ppy)2(acac), etc.

[0056] For example, the red emitting host material can be selected from DCM series materials, such as DCM, DCJTB, DCJTI, etc., and the red light dopant can be a metal complex, such as Ir(piq)2(acac), PtOEP, Ir(btp)2(acac), etc.

[0057] In some embodiments, the organic electroluminescent device according to the present invention is a green organic electroluminescent device.

[0058] In some embodiments, the dopant included in the light-emitting layer comprises a structure represented by Formula II:

[0059]

[0060] Where * indicates that it is connected to metal M at this location, and metal M is Ir or Pt;

[0061] A1 and A2 are each independently selected from aryl groups having 5-24 ring carbon atoms, or heteroaryl groups having 5-24 ring atoms;

[0062] Y4 is C, Y1 is N, and Y2 and Y3 are each independently selected from C and N;

[0063] R 10 and R 11 Each of the substituents independently represents one or two substituents, each of which is independently selected from hydrogen, alkyl groups having 1-20 carbon atoms whose hydrogens are all replaced by deuterium, or an R group adjacent to A1 and A2. 10And an R 11 They are linked together to form alkylene groups with 1-4 carbon atoms, in which all hydrogen atoms are replaced by deuterium.

[0064] In some embodiments, the dopant contained in the light-emitting layer is selected from compounds represented by Formula II-1:

[0065]

[0066] Where M is Ir or Pt;

[0067] R 101 R 112 and R 121 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms (e.g., alkyl groups with 1-4 carbon atoms, such as methyl and ethyl) whose hydrogen atoms are all replaced by deuterium;

[0068] R 102 and R 111 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms (e.g., alkyl groups with 1-4 carbon atoms, such as methyl, ethyl) whose hydrogen atoms are all replaced by deuterium; or R 102 and R 111 They connect together to form alkylene groups with 1-4 carbon atoms, where all hydrogen atoms are replaced by deuterium;

[0069] R 131 and R 132 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms (e.g., alkyl groups with 1-4 carbon atoms, such as methyl, ethyl) whose hydrogen atoms are all replaced by deuterium; or R 131 and R 132 Together with the benzene rings they are connected to form Where X2 is O or S, X3 is C or N, and R 141 Selected from hydrogen and alkyl groups having 1-10 carbon atoms (e.g., alkyl groups with 1-4 carbon atoms, such as methyl and ethyl) whose hydrogen atoms are all replaced by deuterium.

[0070] Among them, R 101 R 112 R 121 and R 141 At least one of them is not hydrogen.

[0071] In some embodiments, the dopant contained in the light-emitting layer is selected from, but not limited to, the following compounds:

[0072]

[0073] Not limited to any theory, in dopants including those with the formula II structure, the introduction of alkyl groups onto the ligands can reduce the conjugation of the material, decrease molecular stacking, and narrow the spectrum to lower the evaporation temperature; the use of D-substituted alkyl groups can improve efficiency and stability.

[0074] There are no particular limitations on the thickness of the auxiliary light-emitting layer and the light-emitting layer; they can be determined through routine experiments. Generally, the thickness of the auxiliary light-emitting layer can be 5 nm to 50 nm, and the thickness of the light-emitting layer can be 20 nm to 100 nm.

[0075] In addition to the materials mentioned above, the light-emitting layer and the light-emitting auxiliary layer may also include other materials, such as non-deuterated compounds, as needed.

[0076] In addition to the hole transport layer, the light-emitting layer, and the light-emitting auxiliary layer, the interlayer may also include one or more of the following: an electron injection layer, a hole injection layer, and a hole blocking layer, but is not limited thereto.

[0077] Organic electroluminescent devices can have the structure of conventional organic electroluminescent devices without particular limitations. For example, an organic electroluminescent device can have a structure of anode / hole injection layer / hole transport layer / light-emitting auxiliary layer (or electron blocking layer) / light-emitting layer / hole blocking layer / electron transport layer / electron injection layer / cathode, but is not limited to this.

[0078] Figure 1 An organic electroluminescent device according to one embodiment of the present disclosure is shown. As shown, it includes 1: a substrate, 2: a first electrode (anode), 3: a hole injection layer, 4: a hole transport layer, 5: a light-emitting auxiliary layer (electron blocking layer), 6: a light-emitting layer (which may include a host material and a guest dopant material), 7: a hole blocking layer, 8: an electron transport layer, 9: an electron injection layer, and 10: a second electrode (cathode) stacked in sequence.

[0079] In some embodiments, the first electrode can be a transparent oxide ITO, IZO, or a composite electrode formed of ITO / Ag / ITO, Ag / IZO, CNT / ITO, CNT / IZO, etc.; the second electrode can be a silver-magnesium composite electrode or an Al electrode, but is not limited thereto. In some embodiments, the anode is ITO glass and the cathode is an Ag:Mg composite electrode.

[0080] The organic electroluminescent device according to this disclosure also includes a substrate 1 disposed on the side of the first electrode 2 away from the second electrode 10. The substrate 1 can be a transparent rigid or flexible material, such as glass, polyimide, etc., which can realize rigid substrate display and flexible display.

[0081] Therefore, in the organic electroluminescent device according to this disclosure, the interlayer may further include a hole injection layer disposed between the first electrode 2 and the hole transport layer; it may also include a hole blocking layer, an electron transport layer and an electron injection layer disposed sequentially on the side of the light-emitting layer away from the light-emitting auxiliary layer between the light-emitting layer and the second electrode 10.

[0082] The hole injection layer can be made of inorganic oxides, such as molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, manganese oxide, etc., or it can be a p-type dopant of a strong electron-withdrawing system or a dopant of a hole transport material, such as hexacyanohexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-p-quinone dimethylane (F4TCNQ), 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane, etc. The thickness of the hole injection layer can be 5 nm to 30 nm.

[0083] Hole transport layers can be prepared using hole transport materials. Examples of hole transport materials include aromatic amines and dimethylfluorene or carbazole materials with hole transport properties, such as 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-bis(9-carbazolyl)biphenyl (CBP), 9-phenyl-3-[4-(10-phenyl-9-anthrayl)phenyl]-9H-carbazole (PCzPA), etc., but not limited to these. The thickness of the hole transport layer can be 300nm to 100nm.

[0084] The materials for hole-blocking layers and electron transport layers are generally aromatic heterocyclic compounds, such as imidazole derivatives like benzimidazole derivatives, imidazopyridine derivatives, and benzimidazolephenanthridine derivatives; pyrimidine derivatives; triazine derivatives; and compounds containing nitrogen-containing six-membered ring structures, such as quinoline derivatives, isoquinoline derivatives, and phenanthreneroline derivatives. These also include compounds with phosphine oxide substituents on the heterocycle, such as 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3- Examples of suitable electron transport layers include bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), phenanthroline (BPhen), (BCP), and 4,4'-bis(5-methylbenzoxazol-2-yl)stilbene (BzOs), but not limited to these. The hole-blocking layer can be 5 nm to 100 nm thick. The electron transport layer can be 20 nm to 100 nm thick.

[0085] The thickness of the electron injection layer can range from 1 nm to 10 nm. The electron injection layer material can generally be an alkali metal fluoride or a metal, such as LiF, Yb, Mg, Ca, etc., but is not limited to these.

[0086] In some implementations, F4TCNQ (as a P-type dopant) and m-MTDATA (as the host material for the hole injection layer) are selected as the hole injection layer material, m-MTDATA as the hole transport layer material, TPBi as the hole blocking layer material, and BCP (as the host material) and Liq (as the guest material) as the electron transport layer material.

[0087] The organic electroluminescent device disclosed herein may also include a capping layer (sometimes also called a light extraction layer, CPL), an encapsulation layer, etc., disposed on the side of the cathode away from the anode.

[0088] The specific structures and fabrication methods of the cathode, anode, electron blocking layer, electron transport layer, electron injection layer, light-emitting layer, hole injection layer, hole transport layer, hole blocking layer, capping layer, and encapsulation layer of the organic electroluminescent device disclosed herein can employ any suitable structure and fabrication method without particular limitation. This disclosure does not involve improvements to these components, and therefore these components are not described in detail to avoid obscuring the main technical concept of this disclosure.

[0089] This disclosure also provides a display device including an organic electroluminescent device according to this disclosure.

[0090] In some embodiments, the display device may include a plurality of organic electroluminescent devices, at least one of which is an organic electroluminescent device according to the present disclosure. For example, the organic electroluminescent device in the display device may be a blue, green, or red organic electroluminescent device, but is not limited thereto.

[0091] The display device disclosed herein can be any product or component with display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, navigator, in-vehicle display, smartwatch, or smart bracelet. Other essential components of this display device are readily understood by those skilled in the art and will not be described in detail here, nor should they be construed as limiting the invention.

[0092] In this disclosure, the description method “each independent” should be interpreted broadly. It can mean that the specific options expressed by the same symbol in different groups do not affect each other, or that the specific options expressed by the same symbol in the same group do not affect each other.

[0093] In this disclosure, a non-positional substituent refers to a substituent connected by a single bond extending from the center of the ring system, which means that the substituent can be attached to any possible position in the ring system.

[0094] In the structure of this disclosure, "*" indicates a connection at that location.

[0095] In this disclosure, when a group is defined as a "single bond", it means that the groups on both sides of the group are directly connected together.

[0096] In this disclosure, when a certain group is defined as "directly disconnected", it means that the group does not exist and the groups on both sides of the group are not connected together at that position.

[0097] In this disclosure, unless otherwise specifically defined, "hybrid" means that a functional group includes at least one heteroatom selected from B, N, O, S, Se, Si, P, etc.

[0098] In this disclosure, "alkyl" can include straight-chain or branched alkyl groups. Unless otherwise specified, an alkyl group can have 1 to 20 carbon atoms, or 1 to 10 carbon atoms. In this disclosure, numerical ranges such as "1 to 10" refer to integers within a given range; for example, "1 to 10 carbon atoms" means an alkyl group that may contain 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. An alkyl group can also be a lower alkyl group having 1 to 6 carbon atoms. Furthermore, an alkyl group can be substituted or unsubstituted. An unsubstituted alkyl group can be a "saturated alkyl group" without any double or triple bonds. Optionally, the alkyl group is selected from alkyl groups having 1 to 6 carbon atoms, including but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl.

[0099] In this disclosure, "alkenyl" can include straight-chain or branched alkenyl groups containing at least one carbon-carbon double bond. Unless otherwise specified, an alkenyl group can have 2 to 10 carbon atoms, and in this disclosure, numerical ranges such as "2 to 10" refer to integers within a given range; for example, "2 to 10 carbon atoms" means an alkenyl group that may contain 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. An alkenyl group can also be a lower alkenyl group having 2 to 6 carbon atoms. Furthermore, an alkenyl group can be substituted or unsubstituted. Optionally, the alkenyl group is selected from alkenyl groups having 2 to 6 carbon atoms, including but not limited to vinyl, 1-propenyl, 2-propenyl, butenyl, pentenyl, hexenyl, etc.

[0100] In this disclosure, cycloalkyl refers to a group derived from a saturated cyclic carbon chain structure. Unless otherwise specified, cycloalkyl can have 3 to 10 carbon atoms, and in this disclosure, numerical ranges such as "3 to 10" refer to integers within a given range; for example, "3 to 10 carbon atoms" means a cycloalkyl group that may contain 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. Cycloalkyl can be substituted or unsubstituted. Optionally, specific examples of cycloalkyl include, but are not limited to, cyclopentyl, cyclohexyl, etc.

[0101] In this disclosure, aryl refers to any optional functional group or substituent derived from an aromatic carbon ring. An aryl group can be a monocyclic aryl (e.g., phenyl) or a polycyclic aryl; in other words, an aryl group can be a monocyclic aryl, a fused-ring aryl, two or more monocyclic aryl groups conjugated by carbon-carbon bonds, a monocyclic aryl and a fused-ring aryl group conjugated by carbon-carbon bonds, or two or more fused-ring aryl groups conjugated by carbon-carbon bonds. That is, unless otherwise stated, two or more aromatic groups conjugated by carbon-carbon bonds can also be considered as aryl groups in this disclosure. Fused-ring aryl groups may include, for example, bicyclic fused aryl (e.g., naphthyl), tricyclic fused aryl (e.g., phenanthrene, fluorene, anthracene), etc. The aryl group does not contain heteroatoms such as B, N, O, S, P, Se, and Si. For example, in this disclosure, biphenyl, terphenyl, etc., are aryl groups. Examples of aryl groups may include, but are not limited to, phenyl, naphthyl, fluorenyl, anthracene, phenanthryl, biphenyl, terphenyl, tetraphenyl, pentaphenyl, benzo[9,10]phenanthryl, pyrene, benzofluoranthracene, etc. The term "aryl" in this disclosure may contain 6-30 carbon atoms. In some instances, the number of carbon atoms in the aryl group may be 6-25; in others, it may be 6-18; and in still others, it may be 6-13. For example, in this disclosure, the number of carbon atoms in the aryl group may be 6, 10, 12, 13, 14, 15, 18, 20, 24, 25, or 30. Of course, other numbers of carbon atoms are also possible, which will not be listed here. In this disclosure, biphenyl can be understood as a phenyl-substituted aryl group or an unsubstituted aryl group.

[0102] In this disclosure, a heteroaryl group refers to a monovalent aromatic ring containing at least one, for example, 1, 2, 3, 4, or 5 heteroatoms, wherein the heteroatoms can be at least one selected from B, O, N, P, Si, Se, and S. The heteroaryl group can be a monocyclic heteroaryl or a polycyclic heteroaryl; in other words, a heteroaryl group can be a single aromatic ring system or a system of multiple aromatic rings connected by conjugation, and any aromatic ring system can be an aromatic monocyclic or an aromatic fused ring. For example, heteroaryl groups can include thiophene, furanyl, pyrrole, imidazolyl, thiazolyl, oxazolyl, oxadiazolyl, triazolyl, pyridyl, bipyridyl, pyrimidinyl, triazinyl, acridinel, pyridazinyl, pyrazinyl, quinolinyl, quinazolinyl, quinoxazinyl, phenoxazinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, isoquinolinyl, indolyl, carbazole, benzoxazolyl, benzimidazolyl, benzo[] Thiazolyl, benzotriazolyl, benzocarbazole, benzothiophene, dibenzothiophene, thienobenzothiophene, benzofuranyl, phenanthrolinel, isoxazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, silanyl, dibenzofuranyl, and N-arylcarbazole (such as N-phenylcarbazole), N-heteroarylcarbazole (such as N-pyridylcarbazole), N-alkylcarbazole (such as N-methylcarbazole), etc., but not limited to these. Among them, thiophene, furanyl, phenanthroline, etc. are heteroaryl groups of the single aromatic ring type, while N-arylcarbazole and N-heteroarylcarbazole are heteroaryl groups of the polycyclic system type connected by conjugation. Unless otherwise specified, the "heteroaryl" in this application may contain 5-30 ring atoms. In some instances, the number of ring atoms in the heteroaryl may be 5-23, and in other instances, it may be 5-19. For example, the number of ring atoms may be 5, 6, 7, 10, 11, 12, 13, 18, 19, 20, 21, 22, 23, 25, or 30. Of course, the number of ring atoms may also be other numbers, which will not be listed here. In this disclosure, the substituted heteroaryl may be one or more hydrogen atoms of the heteroaryl being replaced by groups such as deuterium atoms, halogen groups, cyano groups, aryl groups, heteroaryl groups, alkyl groups, cycloalkyl groups, etc. Specific examples of aryl-substituted heteroaryl include, but are not limited to, phenyl-substituted dibenzofuranyl, phenyl-substituted dibenzothiophenyl, N-phenylcarbazoyl, etc. It should be understood that the number of carbon atoms in a substituted heteroaryl group refers to the total number of carbon atoms in the heteroaryl group and the substituents on it.

[0103] In this disclosure, the heterocyclic group is a monovalent non-aromatic ring containing at least one, for example, 1, 2, 3, 4, or 5 heteroatoms, which can be at least one selected from B, O, N, P, Si, Se, and S. The heterocyclic group can be monocyclic or polycyclic. For example, heterocyclic groups may include, but are not limited to, dihydropyridinyl, piperidinyl, tetrahydrothiopheneyl, sulfur-oxidized tetrahydrothiopheneyl, 4-piperidinoneyl, pyrrolyl, 2-pyrrolidoneyl, pyrrolinyl, tetrahydrofuranyl, bis-tetrahydrofuranyl, tetrahydropyranyl, bis-tetrahydropyranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, decahydroquinolinyl, octahydroisoquinolinyl, azacyclic octacyclic tetracarbamatel, phenanthridine, acridine, pyrimidinyl, imidazoalkyl, imidazolinyl, pyrazolyl, piperazinyl, indololinyl, isoindololinyl, quininecycloyl, morpholinyl, oxazolyl, etc.

[0104] In this disclosure, "heteroalkyl" means a group formed by at least one heteroatom contained in the chain of the aforementioned alkyl group.

[0105] In this disclosure, "aryl group" refers to a group formed by replacing the alkyl group with the aryl group.

[0106] In this disclosure, "alkoxy" refers to a group formed by attaching an oxygen atom to the end of the aforementioned alkyl group.

[0107] In this disclosure, "aryloxy group" refers to a group formed by attaching an oxygen atom to the end of the aforementioned aryl group.

[0108] In this disclosure, "alkylsilyl" refers to a group formed by replacing a silyl group (-SiH3) with 1 to 3 of the aforementioned alkyl groups.

[0109] In this disclosure, "arylsilyl" refers to a group formed by substituting a silyl group (-SiH3) with 1 to 3 of the above-mentioned aryl groups.

[0110] In this disclosure, "acyl" refers to an RC (=O)- group, wherein R is selected from the above-mentioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0111] In this disclosure, "ester group" refers to RC(=O)-O- or ROC(=O)-O- group, wherein R is selected from the above-mentioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0112] In this disclosure, "sulfinyl" refers to an RS(=O)- group, wherein R is selected from the above-mentioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0113] In this disclosure, "sulfonyl" refers to an RS(=O)2- group, wherein R is selected from the above-mentioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0114] In this disclosure, "phosphinyl" refers to an R2P- group, wherein each R is independently selected from hydrogen, and the aforementioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0115] In this disclosure, "amino" refers to an R2P- group, wherein each R is independently selected from hydrogen, and the aforementioned alkyl, cycloalkyl, heteroalkyl, aralkyl, aryl, and heteroaryl groups.

[0116] In this disclosure, "alkylene", "cycloalkylene", "heteroalkylene", "heterocyclic", "aramylene", "alkoxy", "aramoxy", "alkenyl", "aryl", "heteroaryl", "alkoxysilyl", "arylsilyl", and "imino" refer to the divalent groups formed by the loss of one hydrogen atom from the aforementioned alkyl, cycloalkyl, heteroalkyl, heterocyclic, aralkyl, alkoxy, aryloxy, alkenyl, aryl, heteroaryl, alkoxysilyl, arylsilyl, and amino groups.

[0117] In this disclosure, the halogen group may include fluorine, iodine, bromine, chlorine, etc.

[0118] In this disclosure, "ring" includes rings of cycloalkyl, aryl, heteroaryl, heterocyclic, etc., as defined above.

[0119] In this disclosure, the substituted alkyl, alkylene, alkenyl, cycloalkyl, alkoxy, aryl, arylene, heteroaryl, heteroarylene, heterocyclic, etc., can be groups in which one or more hydrogen atoms are replaced by groups such as deuterium, halogen groups, cyano, nitro, amino, hydroxyl, C6-C12 aryl, 5-12 heteroaryl, C1-C6 alkyl, C1-C6 alkoxy, C3-C6 cycloalkyl, etc.

[0120] In this disclosure, the word “including” or variations thereof, such as “comprising,” “containing,” or “having,” will be understood to include the stated elements, integers, or steps, or combinations thereof, but does not preclude the addition of other elements, integers, or steps, or combinations thereof.

[0121] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While those methods and materials similar to or equivalent to those described herein may be used in the practice or testing of this invention, suitable methods and materials are described below. In case of conflict, this specification (including definitions) shall prevail. Furthermore, the materials, methods, and examples described are illustrative only and not intended to be limiting.

[0122] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0123] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0124] In this disclosure, unless otherwise stated, "multiple" means two or more.

[0125] Beneficial effects

[0126] This disclosure addresses the problem of light-emitting auxiliary layer materials being susceptible to decomposition due to localized concentrations of triplet exciton energy. By introducing deuterium into segments with concentrated triplet spin density, molecular vibrations are reduced, thereby improving material stability and ultimately extending device lifetime. Furthermore, this disclosure reduces material conjugation and molecular stacking by introducing deuterated alkyl groups into the active sites of the light-emitting auxiliary layer material, in conjunction with light-emitting layer compounds substituted with deuterated alkyl groups. This reduces material conjugation, decreases molecular stacking, and narrows the spectral density, thus lowering the evaporation temperature. The use of D-substituted alkyl groups further improves efficiency and stability. Therefore, this disclosure, through the combination of a light-emitting layer and a light-emitting auxiliary layer, enables the device to maintain high efficiency while achieving an overall long lifetime. Attached image description:

[0127] Figure 1 This diagram shows a structural schematic of an organic electroluminescent device according to an embodiment of the present disclosure.

[0128] Reference numerals: 1: Substrate; 2: First electrode; 3: Hole injection layer; 4: Hole transport layer; 5: Electron blocking layer; 6: Light emitting layer; 7: Hole blocking layer; 8: Electron transport layer; 9: Electron injection layer; 10: Second electrode. Detailed Implementation

[0129] To objectively evaluate the technical effects of the embodiments of this disclosure, the technical solutions provided by this disclosure will be described in detail and by way of examples below. These embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of exemplary embodiments to those skilled in the art. The features, structures, or characteristics described in these exemplary embodiments can be combined in any suitable manner in one or more embodiments, thereby enabling implementation in various forms, and therefore should not be construed as limited to the examples set forth herein. Obviously, the described embodiments are merely some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided by this disclosure are within the scope of protection of this disclosure.

[0130] Example

[0131] The following provides the fabrication process of organic electroluminescent devices according to some exemplary embodiments of this disclosure, as well as the results of testing and comparison of the performance of the fabricated organic electroluminescent devices.

[0132] A top-emitting device was prepared by vacuum evaporation, and the effect of the organic electroluminescent device that meets the requirements of the light-emitting auxiliary layer and the light-emitting layer according to this disclosure was tested.

[0133] Organic electroluminescent devices include an anode, a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer (including host and guest doping), a hole blocking layer, an electron transport layer, an electron injection layer, and a cathode.

[0134] The materials used in the following embodiments and comparative examples are summarized in Table 2 below:

[0135] Table 2

[0136]

[0137]

[0138]

[0139] Comparative Example

[0140] The simplified representation of the component structure of an organic electroluminescent device is: ITO / m-MTDATA:F4TCNQ 3%.

[0141] 10nm / m-MTDATA 100nm / Compound A 45nm / GH:GD 10% 40nm / TPBI 5nm / BCP:Liq 1:1

[0142] 30nm / Yb 1nm / Mg:Ag 13nm / CPL 80nm

[0143] Organic electroluminescent devices are fabricated as follows.

[0144] In 1×10 -5 A thin film was deposited on a glass substrate containing indium tin oxide (ITO) with an anode of 100 nm using a vacuum evaporation method at a vacuum level of Pa.

[0145] First, F4TCNQ (as a P-type dopant) and m-MTDATA (as the host material for the hole injection layer) are co-deposited on the substrate to form a hole injection layer (HIL) with a thickness of 10 nm. In the hole injection layer, the concentration of m-MTDATA is 97% and the concentration of F4TCNQ is 3% by weight.

[0146] The compound m-MTDATA (as a hole transport layer material) is then deposited onto the HIL with a thickness of 100 nm to function as a hole transport layer (HTL).

[0147] Compound A (as a light-emitting auxiliary layer material) with a thickness of 10 nm was deposited on the hole transport layer to function as a light-emitting auxiliary layer (Prime).

[0148] GH material (compounds B and C premixed together in a 4:6 ratio) and GD material (compound D) were co-deposited on the prime layer to a thickness of 20 nm as the emissive layer (EML). The concentration of GH material in the emissive layer was 90% and the concentration of GD material was 10%, based on weight.

[0149] A 5nm thick TPBi layer was deposited on the light-emitting layer as a hole blocking layer (HBL).

[0150] BCP (as the host material of the electron transport layer) and Liq (as the guest material of the electron transport layer) are co-deposited on the HBL, and the two materials are vaporized at the same rate to form an electron transport layer (ETL) with a film thickness of 30 μm to perform its function.

[0151] A 1 nm thick layer of metallic Yb (as an electron injection layer material) and a 13 nm thick metallic cathode Mg:Ag were deposited on the ETL.

[0152] Compound E is deposited on the cathode to form an 80 nm light extraction layer (CPL).

[0153] Examples 1-6

[0154] Except for replacing the light-emitting auxiliary layer material and GD material as shown in Table 3, everything else is the same as the comparative example.

[0155] The light-emitting auxiliary layer materials and light-emitting layer materials used in the examples and comparative examples, as well as the performance of the prepared organic electroluminescent devices, are shown in Table 3:

[0156] Table 3

[0157] Example Light-emitting auxiliary layer material GD materials Voltage efficiency Lifespan (LT95) Example 1 Compounds 1-6 Compound D 97％ 103％ 118％ Example 2 Compounds 1-9 Compound D 95％ 101％ 127％ Example 3 Compounds 1-12 Compound D 95％ 102％ 134％ Example 4 Compounds 1-6 Compound 2-1 98％ 108％ 120％ Example 5 Compounds 1-9 Compounds 2-6 96％ 112％ 132％ Example 6 Compounds 1-12 Compounds 2-6 94％ 110％ 140％ Comparative Example Compound A Compound D 100％ 100％ 100％

[0158] Comparing Examples 1-3 with the comparative examples, it is evident that deuteration of the light-emitting auxiliary layer material plays a crucial role in improving device lifetime. Furthermore, the introduction of deuterated alkyl groups into the light-emitting auxiliary layer material reduces voltage to some extent. Additionally, the introduction of alkyl groups protects the original active sites, reduces molecular aggregation, and further enhances device lifetime.

[0159] Furthermore, a comparison of Examples 1-3 with Examples 4-5 shows that introducing alkyl groups into the dopant of the light-emitting layer can reduce the conjugation of the material, reduce molecular stacking, and narrow the spectrum to lower the evaporation temperature. The deuterated alkyl group can further improve the device lifetime.

[0160] Although this disclosure has been described above, the content described is merely an embodiment adopted to facilitate understanding of this disclosure and is not intended to limit this disclosure. Any person skilled in the art may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed herein, but the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.

Claims

1. An organic electroluminescent device, comprising: First electrode, The second electrode facing the first electrode, and An interlayer comprising a light-emitting layer is provided between the first electrode and the second electrode. The interlayer includes: a hole transport layer between the first electrode and the light-emitting layer, and a light-emitting auxiliary layer between the hole transport layer and the light-emitting layer. The hole transport material of the light-emitting auxiliary layer includes a compound of formula I: （I） in, One of Ar1 to Ar4 is The other three of Ar1 to Ar4 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, and at least one is not H. One of Ar5 to Ar8 is The other three of Ar5 to Ar8 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, substituted or unsubstituted cycloalkyl group having 3 to 20 cyclic carbon atoms, substituted or unsubstituted heteroalkyl group having 1 to 20 carbon atoms, and at least one is not H. L1 and L2 are each independently selected from single bonds, substituted or unsubstituted alkylene groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkylene groups having 3-20 cyclic carbon atoms, substituted or unsubstituted heteroalkylene groups having 1-20 carbon atoms, substituted or unsubstituted heterocyclic groups having 3-20 cyclic atoms, substituted or unsubstituted arylalkylene groups having 7-30 carbon atoms, substituted or unsubstituted alkeneoxy groups having 1-20 carbon atoms, and substituted or unsubstituted... aryleneoxy groups having 6-30 carbon atoms, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted arylene groups having 6-30 carbon atoms, substituted or unsubstituted heteroarylene groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylenesilyl groups having 6-20 carbon atoms, substituted or unsubstituted imino groups having 0-20 carbon atoms, and combinations thereof; At least one of R1 to R4 is selected from the following groups: , , The remaining elements are each independently selected from hydrogen, deuterium, halogens, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, and substituted or unsubstituted... Alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; R7, R8, and R9 represent one or more substituents, each of which independently represents a substituent selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, and substituted or unsubstituted aralkyl groups having 6-30 carbon atoms. Oxygen, substituted or unsubstituted alkenyl groups having 2-20 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, substituted or unsubstituted heteroaryl groups having 3-30 carbon atoms, substituted or unsubstituted alkylsilyl groups having 3-20 carbon atoms, substituted or unsubstituted arylsilyl groups having 6-20 carbon atoms, substituted or unsubstituted amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms; X and Y are each independently a direct bond, CR5, CR5R6, NR6, O or S, provided that X and Y are not both direct bonds at the same time; R5 and R6 are each independently selected from hydrogen, deuterium, halogen, substituted or unsubstituted alkyl groups having 1-20 carbon atoms, substituted or unsubstituted cycloalkyl groups having 3-20 ring carbon atoms, substituted or unsubstituted heteroalkyl groups having 1-20 carbon atoms, substituted or unsubstituted aralkyl groups having 7-30 carbon atoms, substituted or unsubstituted alkoxy groups having 1-20 carbon atoms, substituted or unsubstituted aroxy groups having 6-30 carbon atoms, and substituted or unsubstituted... Alkenyl groups having 2-20 carbon atoms, aryl groups having 6-30 carbon atoms (substituted or unsubstituted), heteroaryl groups having 3-30 carbon atoms (substituted or unsubstituted), alkylsilyl groups having 3-20 carbon atoms (substituted or unsubstituted), arylsilyl groups having 6-20 carbon atoms (substituted or unsubstituted), and amino, acyl, carboxyl, ester, cyano, isocyano, mercapto, sulfinyl, sulfonyl, phosphinyl, and combinations thereof having 0-20 carbon atoms (substituted or unsubstituted). In Formula I, all H atoms in the triplet spin density distribution segment and the alkyl moiety are replaced by D atoms.

2. The organic electroluminescent device according to claim 1, wherein, In Equation I, L1 and L2 are direct bonds.

3. The organic electroluminescent device according to claim 1, wherein, In Formula I, Ar1 to Ar8, except for and Of the remaining six, one is a fully deuterated alkyl group with 1-10 carbon atoms, and the others are each independently selected from hydrogen and deuterium.

4. The organic electroluminescent device according to claim 1, wherein, One of X and Y is a direct bond, and the other is O or S.

5. The organic electroluminescent device according to claim 1, wherein, One or two of R1 to R4 are selected from the following groups: , , The remainder are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1-10 carbon atoms, substituted or unsubstituted aryl groups having 6-30 carbon atoms, and combinations thereof; R7, R8, and R9 represent one or more substituents, each of which independently represents a substituent selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and combinations thereof.

6. The organic electroluminescent device according to claim 1, wherein, One or two of R1 to R4 are selected from , , , The rest are selected from phenyl, biphenyl, and pentadeuterated phenyl.

7. The organic electroluminescent device according to any one of claims 1-6, wherein, Compounds of Formula I are selected from those with the structures shown in Formula I-1 below: （I-1） in, One of Ar1 to Ar4 is The other three of Ar1 to Ar4 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and at least one is not H; One of Ar5 to Ar8 is The other three of Ar5 to Ar8 are each independently selected from hydrogen, deuterium, substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms, and at least one is not H; R1 to R4 are as defined in the referenced claims; X is either O or S.

8. The organic electroluminescent device according to claim 1, wherein, Compounds of Formula I are selected from the following structures:

9. The organic electroluminescent device of claim 1, wherein, The dopant contained in the light-emitting layer includes the structure represented by Formula II: (II) in , * indicates that it is connected to metal M at this location, and metal M is Ir or Pt; A1 and A2 are each independently selected from aryl groups having 5-24 ring carbon atoms, or heteroaryl groups having 5-24 ring atoms; Y4 is C, Y1 is N, and Y2 and Y3 are each independently selected from C and N; R 10 and R 11 Each of the substituents independently represents one or two substituents, each independently selected from hydrogen, alkyl groups having 1-20 carbon atoms whose hydrogen atoms are all replaced by deuterium, or... A1 and A2 are adjacent R 10 And an R 11 They are linked together to form alkylene groups with 1-4 carbon atoms, in which all hydrogen atoms are replaced by deuterium.

10. The organic electroluminescent device of claim 1, wherein, The dopant contained in the light-emitting layer is selected from compounds represented by Formula II-1: (II-1) Where M is Ir or Pt; R 101 R 112 and R 121 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms whose hydrogen is completely replaced by deuterium; R 102 and R 111 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms whose hydrogen atoms are all replaced by deuterium; or R 102 and R 111 They connect together to form alkylene groups with 1-4 carbon atoms, where all hydrogen atoms are replaced by deuterium; R 131 and R 132 Each is independently selected from hydrogen and alkyl groups having 1-10 carbon atoms whose hydrogen atoms are all replaced by deuterium; or R 131 and R 132 Together with the benzene rings they are connected to form Where X2 is O or S, X3 is C or N, and R 141 Selected from hydrogen and alkyl groups having 1-10 carbon atoms, in which all hydrogen atoms are replaced by deuterium. Among them, R 101 R 112 R 121 and R 141 At least one of them is not hydrogen.

11. The organic electroluminescent device according to claim 1, wherein, The dopant contained in the light-emitting layer is selected from the following compounds:

12. A display device comprising an organic electroluminescent device according to any one of claims 1-11.

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