Material for light-emitting layer, organic electroluminescent display device, and display panel

Abstract

At least one embodiment of the present disclosure provides a material for a light-emitting layer. The material for the light-emitting layer comprises: a carrier transport material, an energy transfer material, and a light-emitting material, wherein the light-emitting material comprises a platinum complex, and the energy transfer material comprises a rare earth complex. A trace amount of rare earth complex is added into the material for the light-emitting layer, and rare earth complex molecules can store excess carriers, so that the excess carriers can be transferred to the molecules of the light-emitting material by means of intermolecular hopping under the action of the continuously increased external electric field, and carriers around the molecules of the light-emitting material can be balanced, reducing the intensification of a triplet-triplet annihilation (TTA) process and a triplet-polaron quenching (TPQ) process, and reducing the internal Joule heat.

Description

Material for light-emitting layer, organic electroluminescent display device and display panel TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate to a material for a light-emitting layer, an organic electroluminescent display device, and a display panel. BACKGROUND

[0002] There is an increasing demand for organic light-emitting diode display panels for life scenes and usage frequency, which requires high performance in display efficiency, service life, color gamut, viewing angle, and the like.

[0003] According to the spin quantum statistics theory, in an organic light-emitting diode display panel, 25% of singlet excitons and 75% of triplet excitons are included in excitons generated by the recombination of electrons injected from a cathode and holes injected from an anode. Generally, a fluorescent material can only utilize singlet excitons, which leads to a theoretical internal quantum efficiency (IQE) of 25% of the finally formed organic light-emitting diode display panel. A phosphorescent material containing a heavy metal can simultaneously trap singlet excitons and triplet excitons, so that the organic light-emitting diode display panel can not only make the theoretical IQE reach 100%, but also make the voltage small and the spectrum stable. However, in a blue phosphorescent device, the high energy of triplet excitons easily leads to the decomposition of the phosphorescent material, and the long lifetime of the triplet exciton on the order of microseconds easily leads to triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA), thereby leading to a short service life and serious efficiency roll-off of the organic light-emitting diode display panel. Therefore, the performance of the current blue PhOLEDs needs to be improved.

[0004] SUMMARY

[0005] At least one embodiment of the present disclosure provides a material for a light-emitting layer, an organic electroluminescent display device, and a display panel. Embodiments of the present disclosure introduce a trace amount of rare earth complexes, such as thulium (III) complexes, or dysprosium (III) complexes, or cerium (III) complexes, into a light-emitting layer of a blue phosphorescent organic light-emitting diode, so as to regulate the carrier distribution and energy transfer rate of the light-emitting layer, and thereby improve the working efficiency and service life of the blue phosphorescent organic light-emitting diode display device, so as to solve the technical problems of short service life and serious efficiency roll-off under high brightness of the blue phosphorescent organic light-emitting diode display device.

[0006] At least one embodiment of the present disclosure provides a material for a light-emitting layer, the material for a light-emitting layer comprising: a carrier transport material, an energy transfer material, and a light-emitting material, wherein the light-emitting material comprises a platinum complex, and the energy transfer material comprises a rare earth complex.

[0007] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the rare earth complex includes at least one of a thulium complex, a dysprosium complex, and a cerium complex.

[0008] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure general formula of the rare earth complex includes at least one of R1 to R4 are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a substituted or unsubstituted C1-C 60 alkyl group, a substituted or unsubstituted C2-C 60 alkenyl group, a substituted or unsubstituted C2-C 60 alkynyl group, a substituted or unsubstituted C1-C 60 alkoxy group, a substituted or unsubstituted C3-C 10 cycloalkyl group, a substituted or unsubstituted C1-C 10 heterocycloalkyl group, a substituted or unsubstituted C3-C 10 cycloalkenyl group, a substituted or unsubstituted C1-C 10 heterocycloalkenyl group, a substituted or unsubstituted C6-C 60 aryl group, a substituted or unsubstituted C6-C 60 aryloxy group, a substituted or unsubstituted C6-C 60 arylthio group, a substituted or unsubstituted C1-C 60 heteroaryl group, a substituted or unsubstituted C1-C 60 heteroaryloxy group, a substituted or unsubstituted C1-C 60 heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic fused polycyclic group, a substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, a substituted or unsubstituted C5-C 60 carbocyclic group, a substituted or unsubstituted C1-C 60 heterocyclic group, -Si(Q’)(Q”)(Q”’), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=O)(Q’), -S(=O)(Q’), -S(=O)2(Q’), -P(=O)(Q’)(Q”), and -P(=S)(Q’)(Q”), wherein Q’, Q”, Q”’ are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a substituted or unsubstituted C1-C 60 alkyl group, a C2-C 60 alkenyl group, a C2-C 60 alkynyl group, a C1-C 60 alkoxy group, a C3-C 10 cycloalkyl group, a C1-C 10 heterocycloalkyl group, a C3-C 10 cycloalkenyl group, a C1-C10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

[0009] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure formula of the rare earth complex comprises at least one of: For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure formula of the rare earth complex comprises at least one of:

[0010] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure formula of the rare earth complex comprises at least one of: X is selected from I -1 , Br -1 , Cl -1 , NO3 -1 , CH3COO -1 , CCl3COO -1 , CF3COO -1 , ClO4 -1 , BF4 -1 , BPh4 -1 , N3 -1 , at least one of substituted or unsubstituted pyrazole anion, p-toluic acid, p-toluene sulfonate, o-nitrophenol oxygen, p-nitrophenol oxygen, m-nitrophenol oxygen, 2,4-dinitrophenol oxygen, 3,5-nitrophenol oxygen, 2,4,6-trinitrophenol oxygen, 3,5-dichlorophenol oxygen, 3,5-difluorophenol oxygen, 3,5-di-trifluoromethylphenol oxygen anion, trifluoromethanesulfonate, tetrafluoroborate, and hexafluorophosphate; R5, R6, R7, and R8are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazine, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C60 heteroaryl, substituted or unsubstituted C1-C 60 Heteroaryl groups, substituted or unsubstituted C1-C 60 The following groups are selected: heteroaryl thiols, substituted or unsubstituted monovalent non-aromatic fused polycyclic groups, substituted or unsubstituted monovalent non-aromatic fused heterocyclic groups, -Si(Q')(Q”)(Q”'), -B(Q')(Q”), -N(Q')(Q”), -P(Q')(Q”), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q”), and -P(=S)(Q')(Q”), wherein Q', Q”, and Q”' are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amido, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 10 cycloalkyl, C1-C 10 Heterocyclic alkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocyclic alkenyl, C6-C 60 Aryl, C1-C 60 Heteroaryl, monovalent non-aromatic fused polycyclic groups, monovalent non-aromatic fused heterocyclic groups, biphenyl and terphenyl.

[0011] For example, in the material of the light-emitting layer provided in at least one embodiment of this disclosure, the structural formula of the rare earth complex includes: At least one of them.

[0012] For example, in the material of the light-emitting layer provided in at least one embodiment of this disclosure, the general structural formula of the platinum complex includes A1 to A4 are each independently selected from substituted or unsubstituted C5-C. 60 Carbocyclic groups and substituted or unsubstituted C1-C 60 Heterocyclic groups, and at least one of A1 to A4 contains a carbene group directly attached to Pt; X1 to X 10 Each is independently C or N; L1 to L3 are each independently selected from single bonds, -O-, -S-, -C(R')(R”)-, -C(R')=, =C(R')-, -C(R')=C(R”)-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R”)-, -P(=O)(R')-)- and -Ge(R')(R”)-; R9 to R 12each of R, R', R" is independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q')(Q")(Q'"), -B(Q')(Q"), -N(Q')(Q"), -P(Q')(Q"), -C(=0)(Q'), -S(=0)(Q'), -S(=0)2(Q'), -P(=0)(Q')(Q"), and -P(=S)(Q')(Q"); each of k1 to k4 is independently selected from an integer from 0 to 10; each of Q', Q", Q'" is independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazono, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

[0013] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure formula of the platinum complex is For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure formula of the platinum complex is at least one of the group consisting of

[0014] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the carrier transport material comprises a combination of a hole transport type material and an electron transport type material.

[0015] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structure general formula of the hole transport type material is: A5to A8are independently selected from the group consisting of substituted or unsubstituted C5-C 60 carbocyclic groups and substituted or unsubstituted C1-C 60 heterocyclic groups; L4is selected from a single bond, -O-, -S-, -C(R’)(R”)-, -C(R’)=, =C(R’)-, -C(R’)=C(R”)-, -C(=O)-, -C(=S)-, -C≡C-, -B(R’)-, -N(R’)-, -P(R’)-, -Si(R’)(R”)-, -P(=O)(R’)- and -Ge(R’)(R”)-; R 13 to R 17 , R’, R” are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60heteroarylsulfinyl, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q')(Q")(Q'"), -B(Q')(Q"), -N(Q')(Q"), -P(Q')(Q"), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q"), and -P(=S)(Q')(Q"); each of k5 to k9 is independently selected from an integer of 0 to 10; each of Q', Q", Q'" is independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazono, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

[0016] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the structural formula of the hole-transporting material includes at least one of:

[0017] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the structural formula of the electron-transporting material is: A 10 to A 12 are independently selected from substituted or unsubstituted C5-C 60 carbocyclic group and substituted or unsubstituted C1-C 60 heterocyclic group; each of Z1 to Z3 is independently CH or N; each of L6 to L8 is independently selected from a single bond, -O-, -S-, -C(R')(R")-, -C(R')=, =C(R')-, -C(R')=C(R")-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R")-, -P(=O)(R')-, and -Ge(R')(R")-; each of R 18 to R 20 ​each of R', R" is independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q')(Q")(Q'"), -B(Q')(Q"), -N(Q')(Q"), -P(Q')(Q"), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q"), and -P(=S)(Q')(Q"); each of K7, K8, and K9 is independently selected from an integer from 0 to 10; each of Q', Q", Q'" is independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazono, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

[0018] For example, in the material of the light-emitting layer provided in at least one embodiment of the present disclosure, the structural formula of the electron transport type material comprises: at least one of the following.

[0019] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the carrier transport material comprises a bipolar material.

[0020] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the bipolar material comprises a donor moiety and an acceptor moiety, the donor moiety comprises carbazole, and the acceptor moiety comprises at least one of phosphine oxide, cyano, pyridine, carboline, triazole, and phenylimidazole.

[0021] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the bipolar material has a structural formula comprising: at least one of the following.

[0022] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the energy of the lowest triplet excited state of the carrier transport material is greater than the energy of the lowest triplet excited state of the energy transfer material, and the energy of the lowest triplet excited state of the energy transfer material is greater than the energy of the lowest triplet excited state of the light-emitting material.

[0023] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the mass percentage of the carrier transport material is 80% to 95%, the mass percentage of the energy transfer material is 0.1% to 1%, and the mass percentage of the light-emitting material is 5% to 20%.

[0024] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the energy transfer material has a spectral overlap range with the absorption spectrum of the light-emitting material, and after normalization, the area of the spectral overlap range is greater than or equal to 50% of the area of the absorption spectrum of the light-emitting material.

[0025] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the energy of the highest triplet excited state of the energy transfer material is greater than the energy of the highest triplet excited state of the carrier transport material, and the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is less than or equal to 0.2 eV.

[0026] For example, in the material of the light-emitting layer provided in at least one of the embodiments of the present disclosure, the difference between the energy of the lowest triplet excited state of the carrier transport material and the energy of the lowest triplet excited state of the energy transfer material is greater than or equal to 0.3 eV.

[0027] The organic electroluminescent display device provided by at least one embodiment of the present disclosure comprises a first electrode, a hole transport layer, a hole injection layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a second electrode which are sequentially stacked, wherein the light-emitting layer is formed by using the material of the light-emitting layer according to any one of the above embodiments.

[0028] For example, in the organic electroluminescent display device provided by at least one embodiment of the present disclosure, the material of the light-emitting layer is a blue phosphorescent light-emitting material.

[0029] The display panel provided by at least one embodiment of the present disclosure comprises the organic electroluminescent display device according to any one of the above embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only related to some embodiments of the present disclosure, but not limit the present disclosure.

[0031] FIG. 1 is a schematic diagram of a cross-sectional structure of an organic electroluminescent display device provided by at least one embodiment of the present disclosure;

[0032] FIG. 2 is a schematic diagram of different light-emitting intensities caused by different insertion positions of an intercalation device provided by an embodiment of the present disclosure;

[0033] FIG. 3 is a schematic diagram of different current efficiencies caused by different current densities of a top emission device provided by an embodiment of the present disclosure;

[0034] FIG. 4 is a block diagram of a display panel provided by at least one embodiment of the present disclosure;

[0035] FIG. 5 is a schematic diagram of a cross-sectional structure of a display panel provided by at least one embodiment of the present disclosure;

[0036] FIG. 6 is a schematic diagram of a circuit structure of a pixel driving circuit included in the display panel shown in FIG. 5;

[0037] FIG. 7 is a schematic diagram of white light color deviation of a display panel provided by at least one embodiment of the present disclosure; and

[0038] FIG. 8 is a schematic diagram of white light brightness decay of a display panel provided by at least one embodiment of the present disclosure. DETAILED DESCRIPTION

[0039] In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present disclosure.

[0040] Unless otherwise defined, technical terms or scientific terms used in the present disclosure shall have the ordinary meaning of the terms to a person of ordinary skill in the art to which the present disclosure belongs. The terms "first", "second" and similar terms used in the present disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects before the terms encompass the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms "connect" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms "upper", "lower", "left", "right" and the like are only used to indicate relative positional relationships, and when the absolute positions of the described objects are changed, the relative positional relationships may also be changed accordingly.

[0041] Generally, the light-emitting layer of an organic light-emitting diode display device is composed of a host material and a guest light-emitting material. Under the action of an electric field, carriers are injected through an electrode and transported to the light-emitting layer by a carrier transport layer. The host material captures the carriers and transports them to the guest light-emitting material by energy transfer, and the guest light-emitting material emits light by radiative recombination of the carriers. Energy transfer or Dexter energy transfer makes the guest light emitting material emit light, or the guest light emitting material directly captures carriers to emit light. However, the different migration rates of carriers in various layer structures can cause some holes or electrons to remain in the recombination region, which can cause the problem of relatively narrow exciton recombination region and unbalanced carrier distribution, further causing the exacerbation of triplet-triplet annihilation (TTA) and triplet-polaron quenching (TPQ) processes, thus increasing the internal Joule heat of the organic light emitting diode display device, and deteriorating the display efficiency and the lifetime of the organic light emitting diode display device. The inventors of the present disclosure notice that a trace amount of rare earth complex can be added to the material of the light emitting layer of the organic light emitting diode device, and the rare earth complex molecules can store excess carriers, which can be transferred to the light emitting material molecules by intermolecular hopping under the action of an increasing external electric field, so that the carriers around the light emitting material molecules can be balanced. On the other hand, the appropriate triplet energy of the rare earth complex can play the role of energy ladder, thus promoting the energy transfer from the host material to the guest light emitting material, to facilitate the exciton radiative decay. In addition, the trace amount of doping will not change the overall exciton density in the light emitting layer and the position of the recombination region, nor will it reduce other performances of the organic light emitting diode display device. Therefore, by adding a trace amount of rare earth complex as a sensitizer to the material of the light emitting layer, and using the material of the light emitting layer to form the light emitting layer of the organic light emitting diode, a high-efficiency and stable organic light emitting diode can be obtained, and the efficiency roll-off of the organic light emitting diode under high brightness can be effectively alleviated.

[0042] At least one embodiment of the present disclosure provides a material of a light emitting layer, which comprises a carrier transport material, an energy transfer material and a light emitting material, and the light emitting material comprises a platinum complex, and the energy transfer material comprises a rare earth complex. By adding a trace amount of rare earth complex to the material of the light emitting layer, and the rare earth complex molecules can store excess carriers, which can be transferred to the molecules of the light emitting material by intermolecular hopping under the action of an increasing external electric field, so that the carriers around the molecules of the light emitting material can be balanced, thus reducing the exacerbation of triplet-triplet annihilation (TTA) and triplet-polaron quenching (TPQ) processes and reducing the internal Joule heat. For example, the appropriate triplet energy of the rare earth complex can play the role of energy ladder, thus facilitating the exciton radiative decay.

[0043] For example, when a trace amount of rare earth complex is used as a sensitizer as part of the material of the light emitting layer, and the material of the light emitting layer is used to form a light emitting layer and used in a blue organic light emitting diode, a high-efficiency and stable blue organic light emitting diode can be obtained, and when the blue organic light emitting diode is used in a display panel, the display efficiency roll-off problem of the display panel under high brightness can be effectively alleviated.

[0044] For example, in one embodiment of the present disclosure, the rare earth complex included in the energy transfer material can be thulium (III) complex and dysprosium (III) complex with f-f transition of electron transition, and cerium (III) complex with d-f transition of electron transition.

[0045] For example, in one example, introducing trace amounts of thulium (III) complex, or dysprosium (III) complex, or cerium (III) complex into the light-emitting layer of the blue phosphor organic light-emitting diode can regulate the carrier distribution and energy transfer rate of the light-emitting layer, and thus can improve the display efficiency and service life of the finally formed display device, thereby solving the technical problems of short service life and serious efficiency roll-off under high brightness of the blue organic light-emitting diode display device.

[0046] For example, the carrier transport material of the organic light-emitting diode emitting blue light needs to meet the following conditions: the carrier transport material has higher energy than the triplet excited state energy of the light-emitting material to prevent energy backflow. The energy transfer E T ≈2.8eV. The matching of the carrier transport material with the HOMO level and LUMO level of the carrier transport layer / barrier layer and the light-emitting layer can reduce the injection barrier of the carrier and reduce the lighting voltage and operating voltage of the finally formed display panel. The carrier transport material has good carrier transport capacity, so that the density of holes and the density of electrons in the light-emitting layer are more balanced, and the carrier recombination region is wider, thereby forming good thermal stability.

[0047] For example, in one example, the structural formula of the rare earth complex includes at least one of The above structural formula is the structural formula of thulium (III) complex, dysprosium (III) complex and cerium (III) complex, respectively. The specific structure is described below.

[0048] For example, in one example, the structural formula of the rare earth complex includes at least one of R1 to R4 are each independently selected from hydrogen, deuterium, F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazine, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, substituted or unsubstituted C5-C 60 carbocyclic group, substituted or unsubstituted C1-C 60 heterocyclic group, -Si(Q')(Q")(Q")', -B(Q')(Q"), -N(Q')(Q"), -P(Q')(Q"), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q") and -P(=S)(Q')(Q"), wherein Q', Q", Q'" are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazone, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, at least one of monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl and terphenyl.

[0049] For example, in one example, the structural formula of the rare earth complex includes: At least one of the above structural formulae of the thulium (III) complex and dysprosium (III) complex can be used as an energy transfer material to form a display panel with good display effect.

[0050] For example, in one example, the structural formula of the rare earth complex includes: X is selected from I -1 , Br -1 , Cl -1 , NO3-1 CH3COO -1 CCl3COO -1 CF3COO -1 ClO4 -1 BF4 -1 BPh4 -1 N3 -1 at least one of substituted or unsubstituted pyrazolate, p-toluene carboxylate, p-toluene sulfonate, o-nitrophenolate, p-nitrophenolate, m-nitrophenolate, 2,4-dinitrophenolate, 3,5-dinitrophenolate, 2,4,6-trinitrophenolate, 3,5-dichlorophenolate, 3,5-difluorophenolate, 3,5-di-trifluoromethylphenolate, triflate, tetrafluoroborate, and hexafluorophosphate; R5, R6, R7, and R8are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidine, hydrazine, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 aralkyl, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroaralkyl, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q’)(Q”)(Q”’), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=O)(Q’), -S(=O)(Q’), -S(=O)2(Q’), -P(=O)(Q’)(Q”), and -P(=S)(Q’)(Q”), wherein Q’, Q”, Q”’ are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidine, hydrazine, hydrazone, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C6-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

[0051] For example, in one example, the structure formula of the rare earth complex includes:

[0052] at least one of the following:

[0053] For example, in one example, the structure general formula of the platinum complex includes A1to A4are each independently selected from the group consisting of substituted or unsubstituted C5-C 60 carbocyclic group and substituted or unsubstituted C1-C 60 heterocyclic group, and at least one of A1to A4contains a carbene group directly connected to Pt; X1to X 10 are each independently C or N; L1to L3are each independently selected from the group consisting of a single bond, -O-, -S-, -C(R’)(R”)-, -C(R’)=, =C(R’)-, -C(R’)=C(R”)-, -C(=O)-, -C(=S)-, -C≡C-, -B(R’)-, -N(R’)-, -P(R’)-, -Si(R’)(R”)-, -P(=O)(R’)-)- and -Ge(R’)(R”)-; R9to R 12 , R’, R” are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60substituted or unsubstituted C6-C 60 substituted or unsubstituted C1-C 60 substituted or unsubstituted C1-C 60 substituted or unsubstituted C1-C 60 substituted or unsubstituted C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl and terphenyl.

[0054] For example, in one embodiment of the present disclosure, the structural formula of the platinum complex is at least one of Note that the structural formula of the platinum complex provided by the embodiments of the present disclosure is not limited to this, and can also be any other platinum complex that meets the requirements, and the embodiments of the present disclosure are not limited to this.

[0055] For example, in one example, the carrier transport material includes a combination of hole transport type material and electron transport type material, and there are electrons and holes in the carrier transport material, so that there are enough electrons and holes to realize light emission by recombination.

[0056] For example, in one example, the structural formula of the hole transport type material is:

[0057] A5 to A8 are independently selected from substituted or unsubstituted C5-C 60 carbocyclic group and substituted or unsubstituted C1-C60 Heterocyclic groups; L4 is selected from single bonds, -O-, -S-, -C(R')(R”)-, -C(R')=, =C(R')-, -C(R'=C(R”)-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R”)-, -P(=O)(R')- and -Ge(R')(R”)-; R 13 To R 17 R' and R" are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amido, hydrazine, hydrazone, substituted or unsubstituted C1-C. 60 Alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 Alkyne, substituted or unsubstituted C1-C 60 Alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 Heterocyclic alkyl, substituted or unsubstituted C3-C 10 Cycloalkenyl, substituted or unsubstituted C1-C 10 Heterocyclic alkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 Arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 Heteroaryl groups, substituted or unsubstituted C1-C 60 The following groups are selected independently: heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic groups, substituted or unsubstituted monovalent non-aromatic fused heterocyclic groups, -Si(Q')(Q”)(Q”'), -B(Q')(Q”), -N(Q')(Q”), -P(Q')(Q”), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q”), and -P(=S)(Q')(Q”); k5 to k9 are each independently selected from integers from 0 to 10; Q', Q”, Q”' are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amido, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 10 cycloalkyl, C1-C 10 Heterocyclic alkyl, C3-C 10cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl, of course, embodiments of the present disclosure are not limited thereto, the structural formula of the hole-transporting material can also be other structural formulas.

[0058] For example, in one example, the structural formula of the hole-transporting material includes at least one of:

[0059]

[0060] For example, in one embodiment of the present disclosure, the structural formula of the electron-transporting material is: A 10 to A 12 is independently selected from substituted or unsubstituted C5-C 60 carbocyclic group and substituted or unsubstituted C1-C 60 heterocyclic group; Z1 to Z3 are each independently CH or N; L6 to L8 are each independently selected from a single bond, -O-, -S-, -C(R’)(R”)-, -C(R’)=, =C(R’)-, -C(R’)=C(R”)-, -C(=O)-, -C(=S)-, -C≡C-, -B(R’)-, -N(R’)-, -P(R’)-, -Si(R’)(R”)-, -P(=O)(R’)-, and -Ge(R’)(R”)-; R 18 to R 20 , R’, R” are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 ​heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q')(Q")(Q'"), -B(Q')(Q"), -N(Q')(Q"), -P(Q')(Q"), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q") and -P(=S)(Q')(Q"); K7, K8 and K9 are each independently selected from an integer from 0 to 10; Q', Q", Q'" are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazone, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl and terphenyl.

[0061] For example, in one example, the structural formula of the electron transport type material includes:

[0062] at least one of the following.

[0063] For example, in one example, the carrier transport material includes a bipolar material. The bipolar material is a semiconductor material with both n-type and p-type conductive properties, and electrons or holes can move freely in the bipolar material. The bipolar material can better meet the requirements of different conductive properties of the semiconductor device, thereby improving the display effect of the display panel.

[0064] For example, in one example, the bipolar material includes an electron-donating portion and an electron-accepting portion, the electron-donating portion includes carbazole, and the electron-accepting portion includes at least one of phosphine oxide, cyano, pyridine, carboline, triazole and phenylimidazole. The electron-donating portion of the bipolar material can be combined with a group having electron-accepting properties in the mixed material, and the electron-accepting portion of the bipolar material can be combined with a group having electron-donating properties in the mixed material.

[0065] For example, in one example, the structural formula of the ambipolar material comprises:

[0066] at least one of the following.

[0067] For example, in one example, the energy of the lowest triplet excited state of the carrier transport material is greater than the energy of the lowest triplet excited state of the energy transfer material, the energy of the lowest triplet excited state of the energy transfer material is greater than the energy of the lowest triplet excited state of the light emitting material, i.e. the energy of the lowest triplet excited state of the carrier transport material, the energy of the lowest triplet excited state of the energy transfer material, and the energy of the lowest triplet excited state of the light emitting material decrease in turn, which can form a gradual trend to make the uniformity of the emitted light better.

[0068] For example, in the material of the light emitting layer, the mass percentage content of the carrier transport material is 80% to 95%, the mass percentage content of the energy transfer material is 0.1% to 1%, and the mass percentage content of the light emitting material is 5% to 20%, the above combination range of the material of the light emitting layer can make the display panel have good display effect when it is used in the display panel, and the manufacturing cost of the material of the light emitting layer is relatively low.

[0069] For example, in another example, the mass percentage content of the carrier transport material is 85% to 90%, the mass percentage content of the energy transfer material is 0.3% to 0.7%, and the mass percentage content of the light emitting material is 10% to 15%.

[0070] For example, in another example, the mass percentage content of the carrier transport material is 87%, the mass percentage content of the energy transfer material is 0.5%, and the mass percentage content of the light emitting material is 12.5%.

[0071] For example, in another example, the mass percentage content of the carrier transport material is 88%, the mass percentage content of the energy transfer material is 0.5%, and the mass percentage content of the light emitting material is 11.5%.

[0072] For example, when the material of the light emitting layer provided by the embodiment of the present disclosure is used to form an organic light emitting diode display device, the thickness of the light emitting layer is 10 to 100 nm.

[0073] For example, in one example, the electroluminescent spectrum of the energy transfer material and the absorption spectrum of the light emitting material have a spectral overlap range, and after normalization, the area of the spectral overlap range is greater than or equal to 50% of the area of the absorption spectrum of the light emitting material, which can make the purity of the emitted light higher.

[0074] For example, in one example, the energy of the highest triplet excited state of the energy transfer material is greater than the energy of the highest triplet excited state of the carrier transport material, and the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is less than or equal to 0.2 eV. Setting the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material to be less than or equal to 0.2 eV can result in a higher efficiency of light emission of the finally formed device.

[0075] For example, when the difference between the energy of the highest triplet excited state of the carrier transport material and the energy of the highest triplet excited state of the energy transfer material is greater than 0.2 eV, the energy transfer efficiency can be low, which can affect the light emission efficiency of the finally formed light emitting device.

[0076] For example, in one example, the difference between the energy of the lowest triplet excited state of the carrier transport material and the energy of the lowest triplet excited state of the energy transfer material is greater than or equal to 0.3 eV. For example, in one example, the energy of the lowest triplet excited state of the carrier transport material is 0.8 eV, and the energy of the lowest triplet excited state of the energy transfer material is 0.5 eV. In another example, the energy of the lowest triplet excited state of the carrier transport material is 1.2 eV, and the energy of the lowest triplet excited state of the energy transfer material is 0.8 eV. In yet another example, the energy of the lowest triplet excited state of the carrier transport material is 1.8 eV, and the energy of the lowest triplet excited state of the energy transfer material is 1.2 eV.

[0077] The present disclosure at least one embodiment further provides an organic electroluminescent display device. For example, FIG. 1 is a schematic diagram of a cross-sectional structure of an organic electroluminescent display device according to at least one embodiment of the present disclosure. As shown in FIG. 1, the organic electroluminescent display device 100 includes a first electrode 101, a hole transport layer 102, a hole injection layer 103, an electron blocking layer 104, a light emitting layer 105, a hole blocking layer 106, an electron transport layer 107, an electron injection layer 108, and a second electrode 109, which are sequentially stacked. The light emitting layer 105 is formed using the material of the light emitting layer in any of the above embodiments, i.e., the material of the light emitting layer includes a carrier transport material, an energy transfer material, and a light emitting material, and the light emitting material includes a platinum complex and the energy transfer material includes a rare earth complex. When the organic electroluminescent display device is used in a display panel, the display efficiency of the display panel and the service life of the display panel can be improved.

[0078] For example, in one example, the material of the light emitting layer in the organic electroluminescent display device is a blue phosphorescent light emitting material, i.e., the organic electroluminescent display device is a blue phosphorescent light emitting device.

[0079] For example, in the structure shown in FIG. 1, the first electrode 101 is formed of an electrode material with a high work function, and the first electrode 101 can serve as an anode of an organic electroluminescent display device. The material of the first electrode 101 in a bottom-emitting device can be indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), or zinc oxide (ZnO), and the thickness of the first electrode 101 is 80-200 nm. The material of the second electrode 109 in a top-emitting device can be Ag / ITO, Ag / IZO, Ag / SnO2, Ag / ZnO, Al / ITO, or Al / IZO, i.e., the second electrode 109 is a bilayer structure formed of a metal layer and a metal oxide layer, wherein the thickness of the metal layer is 10-100 nm and the thickness of the oxide layer is 5-20 nm.

[0080] For example, the material of the hole injection layer 102 can be a hole injection material such as MnO3 and CuPc, or the hole injection layer 102 can also be obtained by p-type doping of a hole transport material, e.g., the material of the hole injection layer is NPB:F4TCNQ, TAPC:MnO3, etc., and the concentration of p-type doping is 0.5%-10% in terms of mass percentage. The thickness of the hole injection layer 102 is 5-20 nm.

[0081] For example, the main function of the hole transport layer 103 is to transport holes. The material of the hole transport layer 103 can be selected from a carbazole-based material with a high hole mobility, and the hole transport layer 103 can be formed by evaporation. For example, in one example of the present disclosure, the thickness of the hole transport layer 103 is 80-140 nm.

[0082] For example, the material of the electron blocking layer 104 has an energy of the lowest triplet excited state (T1) that is higher than the energy of the lowest triplet excited state (T1) of the transition metal complex material in the light-emitting layer 105, and the difference is greater than or equal to 0.2 eV. The material of the electron blocking layer 104 has a HOMO energy level that is deeper than the HOMO energy level of the host material in the light-emitting layer 105, and the difference is less than or equal to 0.2 eV. For example, in one example of the present disclosure, the thickness of the electron blocking layer 104 is 1-100 nm.

[0083] For example, the energy of the lowest triplet excited state (T1) of the hole blocking layer 106 is greater than the energy of the lowest triplet excited state (T1) of the material of the transition metal complex in the light emitting layer 105, and the difference between the energy of the lowest triplet excited state (T1) of the hole blocking layer 106 and the energy of the lowest triplet excited state (T1) of the material of the transition metal complex in the light emitting layer 105 is less than or equal to 0.2 eV. The LUMO level of the material of the hole blocking layer 106 is shallower than the LUMO level of the carrier transporting material in the light emitting layer 105, and the difference between the LUMO level of the material of the hole blocking layer 106 and the LUMO level of the carrier transporting material in the light emitting layer 105 is less than or equal to 0.2 eV. For example, in one example of the present disclosure, the thickness of the hole blocking layer 106 is 1-30 nm.

[0084] For example, the material of the electron transporting layer 107 is Liq doped in a material with strong electron transporting capability, and the doping ratio of Liq is 10:1-1:1 in terms of mass percentage, and the thickness of the electron transporting layer 107 is 10-70 nm.

[0085] For example, the material of the electron injecting layer 108 can include Yb, Li, LiF, NaCl, CsF, Li2O, BaO, Liq, and the like, or a combination of the above materials. For example, the thickness of the electron injecting layer 108 is 0.5-2 nm.

[0086] For example, in the structure shown in FIG. 1, the second electrode 109 can serve as the cathode of the organic electroluminescent display device. For example, the material of the second electrode 109 is a low work function electrode material. For example, the low work function electrode material includes Mg, Ag, Al, Al / Li, Ca, Mg / In, Mg / Ag, and the like. When the organic electroluminescent display device is a bottom emission device, the thickness of the second electrode 109 is 80-100 nm. When the organic electroluminescent display device is a top emission device, the thickness of the second electrode 109 is 10-20 nm. When the material of the second electrode 109 is an alloy formed by Mg and Ag, the molar ratio of the metals Mg and Ag is 3:7-1:9.

[0087] For example, in another example, when the organic electroluminescent display device further includes a light extraction layer disposed between the light emitting layer 105 and the second electrode 109, the refractive index of the light extraction layer is greater than 1.8, and the thickness is 50-100 nm. The second electrode 109 can cover the light extraction layer.

[0088] For example, before fabricating the organic electroluminescent display device, the glass substrate was repeatedly cleaned and then placed in oxygen plasma. Next, the sample was transferred to a vacuum evaporation system, where each layer structure formed using organic materials was fabricated using a vacuum evaporation deposition process. Throughout the entire fabrication process of the organic electroluminescent display device, the organic material was deposited at a density of 5 × 10⁻⁶. -6 Torr in a high vacuum environment The electrode layer is also formed by thermal deposition. For example, in one example, when the electron injection layer 108 is formed of Yb metal and the second electrode 109 is formed of Mg metal, the thermal deposition rate of the electron injection layer 108 and the second electrode 109 is both... When the second electrode 109 is formed using Ag metal, the thermal deposition rate of the second electrode 109 is:

[0089] For example, in one example, the structure of intercalation device 1 is: ITO / HIL (10nm) / HTL (100nm) / EBL (5nm) / EML (46% P-4:46% N-4:8% Pt-1, x nm) / IL (TBRB, 0.6nm) / EML (46% P-4:46% N-4:8% Pt-1, x nm) / HBL (5nm) / ETL (35nm) / EIL (1nm) / Mg:Ag (100nm), where ITO represents the first electrode 101, HIL (10nm) represents a hole injection layer with a thickness of 10nm, HTL (100nm) represents a hole transport layer with a thickness of 100nm, EBL (5nm) represents an electron blocking layer with a thickness of 5nm, and EIL (46% P-4:46% N-4:8% Pt-1, x nm) / IL (TBRB, 0.6nm) / EML (46% P-4:46% N-4:8% Pt-1, x nm) / HIL ... (nm) represents the first light-emitting layer with a thickness of x nm, formed by a combination of a platinum complex with a mass percentage of 8% and a carrier transport material with a mass percentage of 92%. IL(TBRB,0.6nm) represents the insertion layer with a thickness of 0.6 nm. EML(46%P-4:46%N-4:8%Pt-1,Lx nm) represents the second light-emitting layer with a thickness of Lx nm, formed by a combination of a platinum complex with a mass percentage of 8%, a rare earth complex with a mass percentage of 46%, and a carrier transport material with a mass percentage of 46%, where L is the total length of the second light-emitting layer. HBL(5nm) represents a hole blocking layer with a thickness of 5 nm. ETL(35nm) represents an electron transport layer with a thickness of 35 nm. EIL(1nm) represents an electron injection layer with a thickness of 1 nm. Mg:Ag(100nm) represents the second electrode 109 with a thickness of 100 nm.

[0090] For example, in one example, the structure of the intercalation device 2 is: ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, x nm) / IL (TBRB, 0.6 nm) / EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, L-x nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (100 nm), wherein ITO represents the first electrode 101, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, x nm) represents a first light-emitting layer with a thickness of x nm formed by a material of a light-emitting layer formed by a combination of a mass percentage content of 7.5% of a platinum complex, a mass percentage content of 0.5% of an erbium complex, and a mass percentage content of 92% of a carrier transport material, IL (TBRB, 0.6 nm) represents an intercalation layer with a thickness of 0.6 nm, EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, L-x nm) represents a second light-emitting layer with a thickness of L-x nm formed by a material of a light-emitting layer formed by a combination of a mass percentage content of 7.5% of a platinum complex, a mass percentage content of 0.5% of an erbium complex, a mass percentage content of 46% of a rare earth complex, and a mass percentage content of 46% of a carrier transport material, and L is the total length of the second light-emitting layer, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, and Mg:Ag (100 nm) represents a second electrode 109 with a thickness of 100 nm.

[0091] For example, in one example, the structure of the intercalation device 3 is: ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.5% Dy-1:8% Pt-1, x nm) / IL (TBRB, 0.6 nm) / EML (46% P-4:46% N-4:0.5% Dy-1:7.5% Pt-1, L-x nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (100 nm), wherein ITO represents the first electrode 101, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:0.5% Dy-1:7.5% Pt-1, x nm) represents a first light-emitting layer with a thickness of x nm formed by a material of a light-emitting layer formed by a combination of a platinum complex with a mass percentage of 7.5%, a dysprosium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, IL (TBRB, 0.6 nm) represents an intercalation layer with a thickness of 0.6 nm, EML (46% P-4:46% N-4:0.5% Dy-1:7.5% Pt-1, L-x nm) represents a second light-emitting layer with a thickness of L-x nm formed by a material of a light-emitting layer formed by a combination of a platinum complex with a mass percentage of 7.5%, a dysprosium complex with a mass percentage of 0.5%, a rare earth complex with a mass percentage of 46%, and a carrier transport material with a mass percentage of 46%, and L is the total length of the second light-emitting layer, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, and Mg:Ag (100 nm) represents a second electrode 109 with a thickness of 100 nm.

[0092] For example, in one example, the structure of the intercalation device 4 is: ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46%P-4:46%N-4:0.5%Ce-1:7.5%Pt-1, x nm) / IL (TBRB, 0.6 nm) / EML (46%P-4:46%N-4:0.5%Ce-1:7.5%Pt-1, L-x nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (100 nm), wherein ITO represents the first electrode 101, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46%P-4:46%N-4:0.5%Ce-1:7.5%Pt-1, x nm) represents a first light-emitting layer with a thickness of x nm formed by a material of a light-emitting layer formed by a combination of a platinum complex with a mass percentage of 7.5%, a cerium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, IL (TBRB, 0.6 nm) represents an intercalation layer with a thickness of 0.6 nm, EML (46%P-4:46%N-4:0.5%Ce-1:7.5%Pt-1, L-x nm) represents a second light-emitting layer with a thickness of L-x nm formed by a material of a light-emitting layer formed by a combination of a platinum complex with a mass percentage of 7.5%, a cerium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, and L is the total length of the second light-emitting layer, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, and Mg:Ag (100 nm) represents a second electrode 109 with a thickness of 100 nm.

[0093] wherein the above x is respectively 0.06L, 0.33L, 0.6L, 0.86L. The main role of the above intercalation layer IL is to study the position of the light-emitting center in the light-emitting layer.

[0094] For example, FIG. 2 is a schematic diagram of different light-emitting intensities caused by different intercalation positions of the intercalation device provided by the embodiments of the present disclosure, as shown in FIG. 2, the abscissa represents the position of the intercalation layer, and the ordinate represents the light-emitting intensity of different intercalation devices. For example, starting from the side close to the electron blocking layer, 0.06L represents a length of 0.06 times L away from the electron blocking layer, and L is the total length of the light-emitting layer.

[0095] For example, as shown in FIG. 2, the distribution of excitons in the light-emitting layer of the intercalation device 1 is obviously uneven, mainly concentrated on one side of the hole-blocking layer, which will result in low light-emitting efficiency and short service life of the intercalation device 1. The distribution of excitons in the light-emitting layer of the intercalation device 2 is more balanced, which will help to improve the light-emitting efficiency of the intercalation device 2 and prolong the service life of the intercalation device 2. The distribution of excitons in the light-emitting layer of the intercalation device 3 is more balanced, which will help to improve the light-emitting efficiency of the intercalation device 3 and prolong the service life of the intercalation device 3. The distribution of excitons in the light-emitting layer of the intercalation device 4 is more balanced, which will help to improve the light-emitting efficiency of the intercalation device 4 and prolong the service life of the intercalation device 4.

[0096] For example, in one example, the structure of the top-emitting device 1 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:8% Pt-1, 30 nm) represents a first light-emitting layer with a thickness of 30 nm formed by a material formed by combining a mass percentage content of 8% of a platinum complex and a mass percentage content of 92% of a carrier transport material, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents a second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0097] For example, in one example, the structure of the top emission device 2 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.5% Tm-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, 30 nm) represents a light-emitting layer formed of a material of a light-emitting layer formed of a combination of a platinum complex with a mass percentage of 7.5%, a thulium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, with a thickness of 30 nm, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0098] For example, in one example, the structure of the top emission device 3 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.5% Dy-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:0.5% Tm-1:7.5% Pt-1, 30 nm) represents a light-emitting layer formed of a material of a light-emitting layer formed of a combination of a platinum complex with a mass percentage of 7.5%, a thulium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, with a thickness of 30 nm, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0099] For example, in one example, the structure of the top-emitting device 4 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46%P-4:46%N-4:0.5%Dy-1:8%Ce-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46%P-4:46%N-4:0.5%Dy-1:7.5%Ce-1, 30 nm) represents a light-emitting layer with a thickness of 30 nm formed by a material of a light-emitting layer formed by a combination of a cerium complex with a mass percentage of 7.5%, a dysprosium complex with a mass percentage of 0.5%, and a carrier transport material with a mass percentage of 92%, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents the light extraction layer with a thickness of 65 nm.

[0100] For example, FIG. 3 is a schematic diagram of different current efficiencies caused by different current densities of the top-emitting device provided by the embodiments of the present disclosure. Table 1 is obtained in combination with FIG. 3.

[0101] Table 1: Performance test parameters of the top-emitting device 1 to the top-emitting device 4 provided by the embodiments of the present disclosure

[0102] For example, in Table 1, J refers to the current density, λ EL refers to the peak, FWHM refers to the full width at half maximum, V on refers to the voltage when the device brightness is 1 cd m -2 , LT 95 refers to the lifetime when the device brightness decays to 95% under the condition of 15 mA cm -2 .

[0103] In combination with FIG. 3 and Table 1, it can be seen that the incorporation of a small amount of rare earth complex can significantly improve the photoelectric performance of the blue phosphor organic light-emitting diode device.

[0104] For example, when the carrier transport material of the above top-emitting device is changed, the following top-emitting device is obtained.

[0105] For example, in one example, the layer stack of the top emission device 5 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-6:46% N-6:0.5% Ce-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer layer stack, HIL (10 nm) represents a hole injection layer having a thickness of 10 nm, HTL (100 nm) represents a hole transport layer having a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer having a thickness of 5 nm, EML (46% P-6:46% N-6:0.5% Ce-1:7.5% Pt-1, 30 nm) represents an emissive layer having a thickness of 30 nm formed of a material of an emissive layer formed of a combination of a cerium complex having a mass percentage content of 0.5%, a platinum complex having a mass percentage content of 7.5%, and a carrier transport material having a mass percentage content of 92%, HBL (5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL (35 nm) represents an electron transport layer having a thickness of 35 nm, EIL (1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL (65 nm) represents the light outcoupling layer having a thickness of 65 nm.

[0106] For example, in one example, the layer stack of the top emission device 6 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-1 :46% N-1 :0.5% Ce-1 :8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer layer stack, HIL (10 nm) represents a hole injection layer having a thickness of 10 nm, HTL (100 nm) represents a hole transport layer having a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer having a thickness of 5 nm, EML (46% P-6:46% N-6:0.5% Ce-1 :7.5% Pt-1, 30 nm) represents an emission layer having a thickness of 30 nm formed of a material of an emission layer formed of a combination of a cerium complex having a mass percentage content of 0.5%, a platinum complex having a mass percentage content of 7.5%, and a carrier transport material having a mass percentage content of 92%, HBL (5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL (35 nm) represents an electron transport layer having a thickness of 35 nm, EIL (1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer having a thickness of 65 nm.

[0107] For example, in one example, the layer stack of the top emission device 7 is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (92% BP-1:0.5% Ce-1:7.5% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stack structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (92% BP-1:0.5% Ce-1:7.5% Pt-1, 30 nm) represents a light-emitting layer with a thickness of 30 nm formed by a material of a light-emitting layer formed by a combination of a mass percentage of 0.5% of a cerium complex, a mass percentage of 7.5% of a platinum complex, and a mass percentage of 92% of a carrier transport material, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0108] By comparing the top emission devices 5-7, the following Table 2 can be obtained.

[0109] Table 2: Performance test parameters of the top emission device 5 to the top emission device 7 provided by the embodiments of the present disclosure

[0110] For example, taking the top emission device as an example, when the mass percentage of the energy transfer material in the material of the light-emitting layer is greater than 1% or less than 0.1%, the problems of poor display effect and short service life will occur.

[0111] For example, in Comparative Example 1, the structure of the top-emission device is ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.05% Tm-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer having a thickness of 10 nm, HTL (100 nm) represents a hole transport layer having a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer having a thickness of 5 nm, EML (46% P-4:46% N-4:0.05% Tm-1:8% Pt-1, 30 nm) represents a first light-emitting layer having a thickness of 30 nm formed of a material of a light-emitting layer formed of a combination of a thulium complex having a mass percentage content of 0.05%, a platinum complex having a mass percentage content of 8%, and a carrier transport material having a mass percentage content of 92%, HBL (5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL (35 nm) represents an electron transport layer having a thickness of 35 nm, EIL (1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer having a thickness of 65 nm.

[0112] For example, in Comparative Example 2, the structure of the top-emission device is ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:0.05% Dy-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer having a thickness of 10 nm, HTL (100 nm) represents a hole transport layer having a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer having a thickness of 5 nm, EML (46% P-4:46% N-4:0.05% Dy-1:8% Pt-1, 30 nm) represents a first light-emitting layer having a thickness of 30 nm formed of a material of a light-emitting layer formed of a combination of 0.05% by mass of dysprosium complex, 8% by mass of platinum complex, and 92% by mass of a carrier transport material, HBL (5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL (35 nm) represents an electron transport layer having a thickness of 35 nm, EIL (1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer having a thickness of 65 nm.

[0113] For example, in Comparative Example 3, the structure of the top emission device is: ITO / Ag / ITO / HIL(10 nm) / HTL(100 nm) / EBL(5 nm) / EML(46% P-4:46% N-4:0.05% Ce-1:8% Pt-1, 30 nm) / HBL(5 nm) / ETL(35 nm) / EIL(1 nm) / Mg:Ag(15 nm) / CPL(65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL(10 nm) represents a hole injection layer having a thickness of 10 nm, HTL(100 nm) represents a hole transport layer having a thickness of 100 nm, EBL(5 nm) represents an electron blocking layer having a thickness of 5 nm, EML(46% P-4:46% N-4:0.05% Ce-1:8% Pt-1, 30 nm) represents a first light-emitting layer having a thickness of 30 nm formed of a material of a light-emitting layer formed of a combination of a cerium complex having a mass percentage content of 0.05%, a platinum complex having a mass percentage content of 8%, and a carrier transport material having a mass percentage content of 92%, HBL(5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL(35 nm) represents an electron transport layer having a thickness of 35 nm, EIL(1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag(15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL(65 nm) represents a light extraction layer having a thickness of 65 nm.

[0114] For example, in Comparative Example Four, the structure of the top-emitting device is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:2% Tm-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer having a thickness of 10 nm, HTL (100 nm) represents a hole transport layer having a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer having a thickness of 5 nm, EML (46% P-4:46% N-4:2% Tm-1:8% Pt-1, 30 nm) represents a first light-emitting layer having a thickness of 30 nm formed of a material of a light-emitting layer formed of a combination of a thulium complex having a mass percentage content of 2%, a platinum complex having a mass percentage content of 8%, and a carrier transport material having a mass percentage content of 92%, HBL (5 nm) represents a hole blocking layer having a thickness of 5 nm, ETL (35 nm) represents an electron transport layer having a thickness of 35 nm, EIL (1 nm) represents an electron injection layer having a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 having a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer having a thickness of 65 nm.

[0115] For example, in Comparative Example Five, the structure of the top emission device is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:2% Dy-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:2% Dy-1:8% Pt-1, 30 nm) represents a first light-emitting layer with a thickness of 30 nm formed of a material of a light-emitting layer formed of a combination of a dysprosium complex with a mass percentage content of 2%, a platinum complex with a mass percentage content of 8%, and a carrier transport material with a mass percentage content of 92%, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0116] For example, in Comparative Example Six, the structure of the top emission device is: ITO / Ag / ITO / HIL (10 nm) / HTL (100 nm) / EBL (5 nm) / EML (46% P-4:46% N-4:2% Ce-1:8% Pt-1, 30 nm) / HBL (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL (100 nm) represents a hole transport layer with a thickness of 100 nm, EBL (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML (46% P-4:46% N-4:2% Ce-1:8% Pt-1, 30 nm) represents a first light-emitting layer with a thickness of 30 nm formed by a material of a light-emitting layer combined by a cerium complex with a mass percentage of 2%, a platinum complex with a mass percentage of 8%, and a carrier transport material with a mass percentage of 92%, HBL (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0117] For example, the top emission devices in Comparative Examples One to Six are tested to obtain Table Three as follows.

[0118] Table Three: Performance test parameters of the top emission devices in Comparative Examples One to Six

[0119] For example, by comparing Table One and Table Three, it can be concluded that when the mass percentage of the energy transfer material added in the material of the light-emitting layer is less than 0.1% or more than 1%, the service life of the blue phosphor organic light-emitting diode device is reduced, and the on-state voltage of the blue light-emitting device is increased, thereby reducing the photoelectric performance of the blue phosphor organic light-emitting diode device, so it is necessary to limit the mass percentage of the energy transfer material in the material of the light-emitting layer to 0.1% to 1%.

[0120] For example, in one example, the blue phosphor tandem device is more conducive to increasing device stability and improving EQE, and when applied to a display panel, the relative area of the blue light pixel can be reduced to meet the photoelectric performance index and increase the PPI. The tandem structure blue OLED further comprises a charge generation layer between the first light-emitting layer and the second light-emitting layer.

[0121] For example, in one example, the tandem structure of blue OLEDs: ITO / Ag / ITO / HIL (10 nm) / HTL1 (30 nm) / EBL1 (5 nm) / EML1 (20 nm) / HBL1 (5 nm) / NCGL (15 nm) / PCGL (10 nm) / HTL2 (30 nm) / EBL2 (5 nm) EML2 (20 nm) / HBL2 (5 nm) / ETL (35 nm) / EIL (1 nm) / Mg:Ag (15 nm) / CPL (65 nm), wherein ITO / Ag / ITO represents the first electrode 101 having a three-layer stacked structure, HIL (10 nm) represents a hole injection layer with a thickness of 10 nm, HTL1 (30 nm) represents a hole transport layer with a thickness of 30 nm, EBL1 (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML1 (20 nm) represents a first light-emitting layer with a thickness of 20 nm, HBL1 (5 nm) represents a hole blocking layer with a thickness of 5 nm, NCGL (15 nm) represents an N-type charge generation layer with a thickness of 15 nm, PCGL (10 nm) represents a P-type charge generation layer with a thickness of 10 nm, HTL2 (30 nm) represents a hole transport layer with a thickness of 30 nm, EBL2 (5 nm) represents an electron blocking layer with a thickness of 5 nm, EML2 (20 nm) represents a light-emitting layer with a thickness of 20 nm, HBL2 (5 nm) represents a hole blocking layer with a thickness of 5 nm, ETL (35 nm) represents an electron transport layer with a thickness of 35 nm, EIL (1 nm) represents an electron injection layer with a thickness of 1 nm, Mg:Ag (15 nm) represents the second electrode 109 with a thickness of 15 nm, and CPL (65 nm) represents a light extraction layer with a thickness of 65 nm.

[0122] EML1 and EML2: 40% P-4: 60% N-4: 0.5% Ce-1: 8% Pt-1.

[0123] The following Table 4 was obtained by testing the tandem structure of blue OLEDs.

[0124] Table 4: Performance test parameters of the tandem structure of blue OLEDs

[0125] For example, the carrier transport material can be a bipolar host material in addition to being a combination of hole transport type material and electron transport type material. The electron donating portion of the bipolar host material is mainly based on carbazole, and the electron withdrawing portion is mainly based on phosphinyl, cyano, pyridine, carboline, triazole, phenylimidazole, etc. Specific examples of bipolar materials can be found in the relevant description in the foregoing.

[0126] For example, in the embodiments of the present disclosure, the energy of the highest triplet excited state of the energy transfer material is greater than the energy of the highest triplet excited state of the carrier transport material, and the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is less than or equal to 0.2 eV, for example, in the embodiments shown in top emitting device 1 to top emitting device 4 shown in Table 1, the energy of the highest triplet excited state of the energy transfer material is 2.5 eV, the energy of the highest triplet excited state of the carrier transport material is 2.6 eV, that is, the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is equal to 0.1 eV.

[0127] For example, in Comparative Examples 7 to 9, the energy of the highest triplet excited state of the energy transfer material is 2.3 eV, the energy of the highest triplet excited state of the carrier transport material is 2.6 eV, that is, the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is equal to 0.3 eV, so that the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is greater than 0.2 eV, and the top emitting devices shown in Comparative Examples 7 to 9 will cause the efficiency of energy transfer to be reduced.

[0128] For example, the top emitting devices in Comparative Examples 7 to 9 are tested to obtain the following Table 5.

[0129] Table 5: Performance test parameters of the top emitting devices in Comparative Examples 7 to 9

[0130] For example, by comparing Table 1 and Table 5, it can be concluded that when the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is greater than 0.2 eV, the service life of the blue phosphor organic light-emitting diode device will be reduced, and the on-state voltage of the blue light-emitting device will be increased, thereby reducing the photoelectric performance of the blue phosphor organic light-emitting diode device, so it is necessary to set the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material to be less than or equal to 0.2 eV.

[0131] The at least one embodiment of the present disclosure also provides a display panel, for example, FIG. 4 is a block diagram of a display panel provided by at least one embodiment of the present disclosure, as shown in FIG. 4, the display panel comprises the organic electroluminescent display device of any one of the above. For example, using a blue organic light-emitting diode device for a display panel can reduce the power consumption of the display panel, and when the brightness of the display panel is higher, the color saturation of the display panel is higher.

[0132] In another aspect, the display panel includes the organic electroluminescent display device provided by any of the above embodiments and a pixel driving circuit configured to drive the organic electroluminescent display device to emit light.

[0133] For example, FIG. 5 is a schematic diagram of a cross-sectional structure of a display panel according to at least one embodiment of the present disclosure. As shown in FIG. 5, the display panel includes a substrate BS; a plurality of thin film transistors TFT on the substrate BS, each of the thin film transistors TFT including an active layer ACT; a gate insulating layer GI on a side of the active layer ACT away from the substrate BS. A gate G and a first capacitor electrode Ce1 (both are part of a first gate metal layer) are on a side of the gate insulating layer GI away from the substrate BS. An insulating layer IN is on a side of the gate G and the first capacitor electrode Ce1 away from the gate insulating layer GI, and a second capacitor electrode Ce2 (part of a second gate metal layer) is on a side of the insulating layer IN away from the gate insulating layer GI. An interlayer dielectric layer ILD is on a side of the second capacitor electrode Ce2 away from the gate insulating layer GI. A source S and a drain D (part of a first source-drain metal layer) are on a side of the interlayer dielectric layer ILD away from the gate insulating layer GI. A passivation layer PVX is on a side of the source S and the drain D away from the interlayer dielectric layer ILD. A first planarization layer PLN1 is on a side of the passivation layer PVX away from the interlayer dielectric layer ILD. A relay electrode RE (part of a second SD metal layer) is on a side of the first planarization layer PLN1 away from the passivation layer PVX. A second planarization layer PLN2 is on a side of the relay electrode RE (part of the second SD metal layer) away from the first planarization layer PLN1. A pixel definition layer PDL is configured to define sub-pixel openings and is on a side of the second planarization layer PLN2 away from the substrate BS. An organic electroluminescent display device LE is disposed in each of the openings corresponding to the sub-pixels. The organic electroluminescent display device LE includes an anode AD on the substrate BS, a hole injection layer HIL on a side of the anode AD away from the substrate BS; a hole transport layer HTL on a side of the hole injection layer HIL away from the substrate BS; an emission layer EL on a side of the hole transport layer HTL away from the substrate BS; an electron transport layer ETL on a side of the emission layer EL away from the substrate BS; an electron injection layer EIL on a side of the electron transport layer ETL away from the substrate BS; and a cathode CD on a side of the electron injection layer EIL away from the substrate BS.

[0134] For example, as shown in FIG. 5, the display panel further has an encapsulation layer EN disposed in the display region of the display panel, the encapsulation layer EN is used for encapsulating the light emitting element LE, and the encapsulation layer EN is located on the side of the cathode layer CD away from the substrate base plate BS. In some embodiments, the encapsulation layer EN includes a first inorganic encapsulation sub-layer CVD1 located on the side of the cathode layer CD away from the substrate base plate BS, an organic encapsulation sub-layer IJP located on the side of the first inorganic encapsulation sub-layer CVD1 away from the substrate base plate BS, and a second inorganic encapsulation sub-layer CVD2 located on the side of the organic encapsulation sub-layer IJP away from the substrate base plate BS.

[0135] For example, in some embodiments, the display panel further includes a touch structure TS. In some embodiments, the touch structure TS includes a buffer layer BUF, a first touch electrode layer TE1, a touch insulation layer TI, a second touch electrode layer TE2, and an overcoat layer OC. The buffer layer BUF is located on the side of the encapsulation layer EN away from the substrate base plate BS. The first touch electrode layer TE1 is located on the side of the buffer layer BUF away from the encapsulation layer EN. The touch insulation layer TI is located on the side of the first touch electrode layer TE1 away from the buffer layer BUF. The second touch electrode layer TE2 is located on the side of the touch insulation layer TI away from the buffer layer BUF. The overcoat layer OC is located on the side of the second touch electrode layer TE2 away from the touch insulation layer TI.

[0136] For example, FIG. 6 is a schematic diagram of a circuit structure of a pixel driving circuit included in the display panel shown in FIG. 5. As shown in FIG. 6, in some embodiments, each pixel driving circuit includes: a driving transistor Td; a storage capacitor Cst including a first capacitor electrode Ce1 and a second capacitor electrode Ce2. A first transistor T1 has a gate connected to a corresponding reset control signal line rstN in a current stage (or current row) of a plurality of reset control signal lines, a first electrode connected to a corresponding first reset signal line Vint1N in a current stage (or current row) of a plurality of first reset signal lines, and a second electrode connected to the first capacitor electrode Ce1 of the storage capacitor Cst and the gate of the driving transistor Td. A second transistor T2 has a gate connected to a corresponding gate line GL of a plurality of gate lines, a first electrode connected to a corresponding data line DL of a plurality of data lines, and a second electrode connected to a first electrode of the driving transistor Td. A third transistor T3 has a gate connected to a corresponding gate line, a first electrode connected to the first capacitor electrode Ce1 of the storage capacitor Cst and the gate of the driving transistor Td, and a second electrode connected to a second electrode of the driving transistor Td. A fourth transistor T4 has a gate connected to a corresponding emission control signal line of a plurality of emission control signal lines, a first electrode connected to a corresponding voltage supply line of a plurality of voltage supply lines Vdd, and a second electrode connected to the first electrode of the driving transistor Td and the second electrode of the second transistor T2. A fifth transistor T5 has a gate connected to a corresponding emission control signal line, a first electrode connected to the second electrode of the driving transistor Td and the third transistor T3, and a second electrode connected to an anode of a light emitting element LE. A sixth transistor T6 has a gate connected to a corresponding reset control signal line rst(N+1) in a next adjacent stage (or next adjacent row) of a plurality of reset control signal lines, a first electrode connected to a corresponding second reset signal line Vint2N in a current stage (or current row) of a plurality of second reset signal lines, and a second electrode connected to the second electrode of the fifth transistor and the anode of the light emitting element LE. The second capacitor electrode Ce2 is connected to a corresponding voltage supply line and the first electrode of the fourth transistor T4.

[0137] For example, the test method for performance of the display panel of the embodiments of the present disclosure is as follows: the final luminance of the display panel is set to 800 cd m -2 . Wherein the number of subpixels of the display panel: 1370250 for red, 2740500 for green, and 1370250 for blue; the opening area: 190.00 μm 2 for red, 242.50 μm 2 for green, and 212.50 μm 2The reference color coordinates of the display panel are set as follows: red (0.679, 0.321), green (0.260, 0.706), and blue (0.130, 0.041), and the performance of Table 6 is obtained.

[0138] Table 6: Test data of performance of display panel of embodiments of the present disclosure

[0139] As can be seen from Table 6 above, the display panel has excellent photoelectric performance and low power consumption.

[0140] FIG. 7 is a schematic diagram of white light color deviation of a display panel according to at least one embodiment of the present disclosure, and FIG. 8 is a schematic diagram of white light brightness decay of a display panel according to at least one embodiment of the present disclosure. The abscissa of FIGS. 7 and 8 represents an angle, for example, 0° is perpendicular to the light-emitting surface of the display panel, and 30 degrees represents an angle of 30° between the light-emitting angle of the display panel and the plane of the display panel.

[0141] At least one embodiment of the present disclosure provides a light-emitting layer material, an organic electroluminescent display device, and a display panel. In the light-emitting layer of a blue phosphor organic light-emitting diode, a trace amount of a thulium (III) complex, a dysprosium (III) complex, or a cerium (III) complex is introduced, which can regulate the carrier distribution and energy transfer rate of the light-emitting layer, thereby improving the display efficiency and service life of the display panel, and thus solving the problems of short service life and serious efficiency roll-off under high brightness of the organic light-emitting diode display device.

[0142] The following points need to be explained:

[0143] (1) The drawings of the embodiments of the present disclosure only involve the structures involved in the embodiments of the present disclosure, and other structures can be referred to the general design.

[0144] (2) For the sake of clarity, the thickness of a layer or region is exaggerated or reduced in the drawings used to describe the embodiments of the present disclosure, that is, these drawings are not drawn according to the actual proportions.

[0145] (3) In the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0146] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure should be subject to the protection scope of the claims.

Claims

1. A material for a light-emitting layer, comprising: A carrier transport material, an energy transfer material, and a light emitting material, wherein the light emitting material comprises a platinum complex, and the energy transfer material comprises a rare earth complex.

2. The material of the light-emitting layer according to claim 1, wherein, The rare earth complex comprises at least one of a thulium complex, a dysprosium complex, and a cerium complex.

3. The material of the light-emitting layer according to claim 2, wherein, The general structure of the rare earth complex comprises at least one of R1to R4are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 aralkyl, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, substituted or unsubstituted C5-C 60 carbocyclic group, substituted or unsubstituted C1-C 60 heterocyclic group, -Si(Q’)(Q”)(Q”’), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=O)(Q’), -S(=O)(Q’), -S(=O)2(Q’), -P(=O)(Q’)(Q”), and -P(=S)(Q’)(Q”), wherein Q’, Q”, Q”’ are each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazone, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, at least one of monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

4. The material of the light-emitting layer according to claim 3, wherein The structural formula of the rare earth complex includes: at least one of the following.

5. The material of the light-emitting layer according to claim 2, wherein, The general structure of the rare earth complex includes: X is selected from the group consisting of I -1 , Br -1 , Cl -1 , NO3 -1 , CH3COO -1 , CCl3COO -1 , CF3COO -1 , ClO4 -1 , BF4 -1 , BPh4 -1 , N3 -1 , at least one of a substituted or unsubstituted pyrazolate, p-toluene carboxylate, p-toluene sulfonate, o-nitrophenolate, p-nitrophenolate, m-nitrophenolate, 2,4-dinitrophenolate, 3,5-dinitrophenolate, 2,4,6-trinitrophenolate, 3,5-dichlorophenolate, 3,5-difluorophenolate, 3,5-di-trifluoromethylphenolate, triflate, tetrafluoroborate, and hexafluorophosphate. R5, R6, R7, and R8 are each independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amidine, hydrazine, hydrazone, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q’)(Q”)(Q”’), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=0)(Q’), -S(=0)(Q’), -S(=0)2(Q’), -P(=0)(Q’)(Q”), and -P(=S)(Q’)(Q”), wherein Q’, Q”, Q”’ are each independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amino, amidine, hydrazine, hydrazone, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycloalkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

6. The material of the light-emitting layer according to claim 5, wherein The structural formula of the rare earth complex includes: at least one of the following.

7. The material of the light-emitting layer according to any one of claims 1 to 6, wherein The structural formula of the platinum complex includes A1to A4are each independently selected from substituted or unsubstituted C5-C 60 carbocyclic groups and substituted or unsubstituted C1-C 60 heterocyclic groups, and at least one of A1to A4contains a carbene group directly attached to Pt; X1to X 10 each independently C or N; L1 to L3 are each independently selected from a single bond, -O-, -S-, -C(R')(R")-, -C(R')=, =C(R')-, -C(R')=C(R")-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R")-, -P(=O)(R')-, and -Ge(R')(R")-; R9to R 12 each independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroarylthio, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q’)(Q”)(Q’”), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=O)(Q’), -S(=O)(Q’), -S(=O)2(Q’), -P(=O)(Q’)(Q”), and -P(=S)(Q’)(Q”). k1 to k4 are each independently selected from an integer from 0 to 10; Q', Q", and Q"' are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amido, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 10 cycloalkyl, C1-C 10 Heterocyclic alkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocyclic alkenyl, C6-C 60 Aryl, C1-C 60 Heteroaryl, monovalent non-aromatic fused polycyclic groups, monovalent non-aromatic fused heterocyclic groups, biphenyl and terphenyl.

8. The material of the light-emitting layer according to claim 7, wherein The platinum complex has a structural formula of at least one of the following:

9. The material of the light-emitting layer according to any one of claims 1 to 8, wherein The carrier transport material comprises a combination of a hole transport type material and an electron transport type material.

10. The material of the light-emitting layer according to claim 9, wherein, The structural general formula of the hole transport type material is: A5to A8are independently selected from substituted or unsubstituted C5-C 60 carbocyclic groups and substituted or unsubstituted C1-C 60 heterocyclic groups; L4 is selected from a single bond, -O-, -S-, -C(R')(R")-, -C(R')=, =C(R')-, -C(R')=C(R")-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R")-, -P(=O)(R')-, and -Ge(R')(R")-; R 13 to R 17 , each R', R" is independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C generation 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 Arylthio, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 Heteroaryl groups, substituted or unsubstituted C1-C 60 Heteroaryl thiols, substituted or unsubstituted monovalent non-aromatic fused polycyclic groups, substituted or unsubstituted monovalent non-aromatic fused heterocyclic groups, -Si(Q')(Q”)(Q”'), -B(Q')(Q”), -N(Q')(Q”), -P(Q')(Q”), -C(=O)(Q'), -S(=O)(Q'), -S(=O)2(Q'), -P(=O)(Q')(Q”) and -P(=S)(Q')(Q”); k5 to k9 are each independently selected from an integer from 0 to 10; Q', Q", and Q"' are each independently selected from hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amino, amido, hydrazine, hydrazone, C1-C 60 Alkyl, C2-C 60 alkenyl, C2-C 60 Alkyne group, C1-C 60 Alkoxy, C3-C 10 cycloalkyl, C1-C 10 Heterocyclic alkyl, C3-C 10 Cycloalkenyl, C1-C 10 Heterocyclic alkenyl, C6-C 60 Aryl, C1-C 60 Heteroaryl, monovalent non-aromatic fused polycyclic groups, monovalent non-aromatic fused heterocyclic groups, biphenyl and terphenyl.

11. The material of the light-emitting layer according to claim 10, wherein, The structural formula of the hole transport type material includes: at least one of the following.

12. The material of the light-emitting layer according to any one of claims 9 to 11, wherein The structural general formula of the electron transport type material is: A 10 to A 12 is independently selected from substituted or unsubstituted C5-C 60 carbocyclic groups and substituted or unsubstituted C1-C 60 heterocyclic groups; Z1 to Z3 are each independently CH or N; L6 to L8 are each independently selected from a single bond, -O-, -S-, -C(R')(R")-, -C(R')=, =C(R')-, -C(R')=C(R")-, -C(=O)-, -C(=S)-, -C≡C-, -B(R')-, -N(R')-, -P(R')-, -Si(R')(R")-, -P(=O)(R')-, and -Ge(R')(R")-; R 18 to R 20 , each R’, R” is independently selected from the group consisting of hydrogen, deuterium, -F, -Cl, -Br, -I, hydroxyl, cyano, nitro, amidino, hydrazino, hydrazono, substituted or unsubstituted C1-C 60 alkyl, substituted or unsubstituted C2-C 60 alkenyl, substituted or unsubstituted C2-C 60 alkynyl, substituted or unsubstituted C1-C 60 alkoxy, substituted or unsubstituted C3-C 10 cycloalkyl, substituted or unsubstituted C1-C 10 heterocycloalkyl, substituted or unsubstituted C3-C 10 cycloalkenyl, substituted or unsubstituted C1-C 10 heterocycloalkenyl, substituted or unsubstituted C6-C 60 aryl, substituted or unsubstituted C6-C 60 aryloxy, substituted or unsubstituted C6-C 60 aralkyl, substituted or unsubstituted C1-C 60 heteroaryl, substituted or unsubstituted C1-C 60 heteroaryloxy, substituted or unsubstituted C1-C 60 heteroaralkyl, substituted or unsubstituted monovalent non-aromatic fused polycyclic group, substituted or unsubstituted monovalent non-aromatic fused heteropolycyclic group, -Si(Q’)(Q”)(Q’”), -B(Q’)(Q”), -N(Q’)(Q”), -P(Q’)(Q”), -C(=O)(Q’), -S(=O)(Q’), -S(=O)2(Q’), -P(=O)(Q’)(Q”), and -P(=S)(Q’)(Q”). k 10 to k 12 each independently is an integer selected from 0 to 10; Q', Q", Q"' are each independently selected from the group consisting of hydrogen, deuterium, -F, -CI, -Br, -I, hydroxyl, cyano, nitro, amino, amidino, hydrazino, hydrazono, C1-C 60 alkyl, C2-C 60 alkenyl, C2-C 60 alkynyl, C1-C 60 alkoxy, C3-C 10 cycloalkyl, C1-C 10 heterocycloalkyl, C3-C 10 cycloalkenyl, C1-C 10 heterocycle alkenyl, C6-C 60 aryl, C1-C 60 heteroaryl, monovalent non-aromatic fused polycyclic group, monovalent non-aromatic fused heteropolycyclic group, biphenyl, and terphenyl.

13. The material of the light-emitting layer according to claim 12, wherein, The structural formula of the electron transport type material includes: at least one of the following.

14. The material of the light-emitting layer according to any one of claims 1 to 8, wherein The carrier transport material comprises a bipolar material.

15. The material of the light-emitting layer according to claim 14, wherein, The bipolar material comprises a donating moiety and an accepting moiety, the donating moiety comprises carbazole, and the accepting moiety comprises at least one of phosphine oxide, cyano, pyridine, carboline, triazole, and phenylimidazole.

16. The material of the light-emitting layer according to claim 14, wherein, The structural formula of the bipolar material includes: at least one of the following:

17. The material of the light-emitting layer according to any one of claims 1 to 16, wherein The energy of the lowest triplet excited state of the carrier transport material is greater than the energy of the lowest triplet excited state of the energy transfer material, and the energy of the lowest triplet excited state of the energy transfer material is greater than the energy of the lowest triplet excited state of the light emitting material.

18. The material of the light-emitting layer according to claim 17, wherein, The mass percentage of the carrier transport material is 80% to 95%, the mass percentage of the energy transfer material is 0.1% to 1%, and the mass percentage of the light emitting material is 5% to 20%.

19. The material of the light-emitting layer according to claim 17, wherein, The electroluminescent spectrum of the energy transfer material and the absorption spectrum of the light emitting material have a spectral overlap range, and after normalization, the area of the spectral overlap range is greater than or equal to 50% of the area of the absorption spectrum of the light emitting material.

20. The material of the light-emitting layer according to any one of claims 17 to 19, wherein, The energy of the highest triplet excited state of the energy transfer material is greater than the energy of the highest triplet excited state of the carrier transport material, and the difference between the energy of the highest triplet excited state of the energy transfer material and the energy of the highest triplet excited state of the carrier transport material is less than or equal to 0.2 eV.

21. The material of the light-emitting layer according to claim 20, wherein, The difference between the energy of the lowest triplet excited state of the carrier transport material and the energy of the lowest triplet excited state of the energy transfer material is greater than or equal to 0.3 eV.

22. An organic electroluminescent display device comprising a first electrode, a hole transport layer, a hole injection layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer and a second electrode which are sequentially stacked, wherein, The light-emitting layer is formed using the material of the light-emitting layer according to any one of claims 1 to 21.

23. The organic electroluminescent display device according to claim 22, wherein The material of the light-emitting layer is a blue phosphorescent light-emitting material.

24. A display panel comprising the organic electroluminescent display device according to claim 22 or 23.

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