Organic compound, light emitting device and display device

Abstract

Disclosed are an organic compound, a light-emitting device and a display device, which relate to the field of display technology and are used to improve the luminous efficiency of the light-emitting device. The light-emitting device includes a first electrode, a second electrode, and at least two light-emitting units stacked between the first electrode and the second electrode, and a group of connecting layers are arranged between any two adjacent light-emitting units. The first light-emitting unit includes a first electron transport layer and a first light-emitting layer, and the first electron transport layer is a binary doping structure including a host material and a guest material. The light-emitting device provided by the present disclosure makes the first electron transport layer a binary doping structure, and the first electron transport layer has the characteristics of two doping materials, thereby changing the characteristics such as the electron mobility of the first electron transport layer, making the electron transport performance of the first electron transport layer more stable, and the electron transport efficiency higher, which helps to inject electrons into the first light-emitting layer to recombine carriers in the first light-emitting layer, thereby improving the luminous efficiency of the light-emitting device.

Description

Technical Field

[0001] The present disclosure relates to the field of display technology, and in particular to an organic compound, a light-emitting device and a display apparatus. Background Art

[0002] Organic Light Emitting Diode (OLED) is a new generation of display technology that has developed rapidly in recent years. It has the advantages of self-luminescence, fast response, high luminous efficiency and brightness, ultra-thinness, wide viewing angle, wide operating temperature range, simple production process, low power consumption and flexibility. It is widely used in many fields such as flat panel displays, flexible displays, automotive displays and solid-state lighting.

[0003] With the continuous development of OLED technology, people gradually found that if a single-layer OLED device wants to achieve high brightness, it will cause a surge in heat due to excessive driving current, thereby reducing the performance and working life of the device. Therefore, achieving high luminous brightness and efficiency at a lower current density while increasing the working life of the device is a key factor in realizing the industrialization of OLED. Summary of the invention

[0004] An object of the present disclosure is to provide an organic compound, a light-emitting device and a display apparatus for improving the light-emitting efficiency of the light-emitting device.

[0005] In order to achieve the above objectives, the present disclosure provides the following technical solutions:

[0006] On the one hand, a light-emitting device is provided. The light-emitting device comprises: a first electrode, a second electrode, at least two light-emitting units stacked between the first electrode and the second electrode, and a group of connecting layers are arranged between any two adjacent light-emitting units. Wherein, a group of connecting layers is arranged between each two adjacent light-emitting units; the connecting layer comprises an N-type charge generation layer and a P-type charge generation layer arranged in a stacked manner; wherein the at least two light-emitting units comprise a first light-emitting unit; the first light-emitting unit comprises a first electron transport layer and a first light-emitting layer arranged in a stacked manner; the first electron transport layer is a binary doping structure comprising a host material and a guest material.

[0007] In some embodiments, the host material in the first electron transport layer is a triazine compound.

[0008] In some embodiments, the dipole moment of the host material of the first electron transport layer is 0.5 Debye to 2.0 Debye.

[0009] In some embodiments, the mobility of the host material of the first electron transport layer is: 5.0×10 -6 Vs / cm 2 ~5.0×10-4 Vs / cm 2 .

[0010] In some embodiments, the host material of the first electron transport layer has a structure of formula (I):

[0011]

[0012] Wherein, Ar1, Ar2, Ar3 are each independently selected from hydrogen atoms, deuterium atoms, substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aromatic groups, or capable of combining with adjacent groups to form a substituted or unsubstituted benzene ring;

[0013] Ar3 has the structure of formula (II):

[0014]

[0015] Wherein, R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups; R1 and R2 can be connected to each other to form a saturated or unsaturated cyclic compound.

[0016] In some embodiments, the guest material of the first electron transport layer is a compound containing a phosphorus oxygen group.

[0017] In some embodiments, the dipole moment of the guest material of the first electron transport layer is 4.0 Debye to 6.0 Debye.

[0018] In some embodiments, the guest material mobility of the first electron transport layer is 5.0×10 -7 Vs / cm 2 ~5.0×10 -5 Vs / cm 2 .

[0019] In some embodiments, the guest material of the first electron transport layer has a structure of formula (III):

[0020]

[0021] Wherein, X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24A cyclopentane, a strong electron-withdrawing group of CN or CF3 as a substituent; X3, X4 are independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups; L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20 A type of heteroaryl group.

[0022] In some embodiments, the guest material of the first electron transport layer has any one of the following formulas 1 to 15:

[0023]

[0024]

[0025] In some embodiments, the N-type charge generation layer is a dual-doped structure including a host material and a guest material.

[0026] In some embodiments, the host material of the N-type charge generation layer and the guest material of the first electron transport layer include the same general material.

[0027] In some embodiments, the N-type charge generation layer includes lithium ions or a compound containing an alkali metal.

[0028] In some embodiments, the doping concentration of the lithium ions or the alkali metal-containing compound in the N-type charge generation layer is 0.5% to 2%.

[0029] In some embodiments, the P-type charge generation layer includes: an organic compound containing at least two cyano groups.

[0030] In some embodiments, the doping concentration of the organic compound containing at least two cyano groups in the P-type charge generation layer is 3% to 8%.

[0031] In some embodiments, the lowest excited triplet energy level of the first electron transport layer is higher than the lowest excited triplet energy level of the first light emitting layer.

[0032] In some embodiments, the first electrode is an anode, and the second electrode is a cathode; the at least two light-emitting units also include a second light-emitting unit; the second light-emitting unit is closer to the cathode than the first light-emitting unit; wherein the second light-emitting unit includes a second electron transport layer and a second light-emitting layer stacked in layers; the second electron transport layer is a binary doping structure comprising a host material and a guest material.

[0033] In some embodiments, the dipole moment of the host material of the second electron transport layer is 0.15 Debye to 2.0 Debye.

[0034] In some embodiments, the guest material of the second electron transport layer is an alkali metal or alkaline earth metal compound.

[0035] In some embodiments, the total thickness of the first light emitting unit is 90 nm to 150 nm; and / or the total thickness of the second light emitting unit is 90 nm to 150 nm.

[0036] In some embodiments, the first light-emitting layer and the second light-emitting layer both include: a red light-emitting portion, a green light-emitting portion and a blue light-emitting portion; wherein the red light-emitting portion, the green light-emitting portion and the blue light-emitting portion are arranged at intervals; the red light-emitting portion, the green light-emitting portion and the blue light-emitting portion are all binary doping structures comprising a host material and a guest material; wherein the host material of the red light-emitting portion, the host material of the green light-emitting portion and the host material of the blue light-emitting portion are the same; and / or the guest material of the red light-emitting portion, the guest material of the green light-emitting portion and the guest material of the blue light-emitting layer are the same.

[0037] In some embodiments, the thickness of the red light-emitting portion is 30nm to 50nm; the thickness of the green light-emitting portion is 30nm to 50nm; and the thickness of the blue light-emitting portion is 10nm to 20nm.

[0038] In some embodiments, the first light-emitting unit further includes: a first electron blocking layer, located on a side of the first light-emitting layer away from the first electron transport layer; a first hole transport layer, located on a side of the first electron blocking layer away from the first light-emitting layer; and a first hole injection layer, located on a side of the first hole transport layer away from the first electron blocking layer; the second light-emitting unit further includes: a hole blocking layer, located between the second light-emitting layer and the second electron transport layer; an electron injection layer, located on a side of the second electron transport layer away from the second light-emitting layer; a second hole transport layer, located on a side of the second light-emitting layer away from the second electron transport layer; and a second hole injection layer, located on a side of the second hole transport layer away from the second light-emitting layer.

[0039] In some embodiments, the material of the second hole transport layer is the same as the host material of the P-type charge generation layer.

[0040] In another aspect, a display device is provided, wherein the display device comprises the light emitting device described in any one of the above embodiments.

[0041] In another aspect, an organic compound is provided. The structural formula of the organic compound is shown in the following formula (I):

[0042]

[0043] Wherein, Ar1, Ar2, Ar3 are each independently selected from hydrogen atoms, deuterium atoms, substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aromatic groups, or capable of combining with adjacent groups to form a substituted or unsubstituted benzene ring;

[0044] Ar3 has the structure of formula (II):

[0045]

[0046] Wherein, R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups;

[0047] R1 and R2 can be linked to each other to form a saturated or unsaturated cyclic compound.

[0048] In another aspect, an organic compound is provided. The structural formula of the organic compound is shown in the following formula (III):

[0049]

[0050] Wherein, X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24 One of a cyclopentane, and a strong electron withdrawing group whose substituent is CN or CF3;

[0051] X3, X4 are independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups;

[0052] L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20 A type of heteroaryl group.

[0053] In some embodiments, the organic compound is selected from any one of the following formulas 1 to 15:

[0054]

[0055] The light emitting device provided by the present disclosure has the following beneficial effects:

[0056] The light-emitting device provided by the present disclosure includes at least two light-emitting units, and the at least two light-emitting units are connected in series through a connecting layer, so that the luminous efficiency of the light-emitting device can be improved and the service life of the light-emitting device can be extended. The luminous efficiency can be increased exponentially with the increase in the number of light-emitting units. Under the same brightness, the service life of the stacked light-emitting device increases exponentially; and by making the first electron transport layer a binary doping structure including a host material and a guest material, the first electron transport layer has the characteristics of two doping materials at the same time, thereby changing the characteristics of the first electron transport layer such as the electron mobility, making the electron transport performance of the first electron transport layer more stable and the electron transport efficiency higher, which helps to inject electrons into the first light-emitting layer to recombine carriers in the first light-emitting layer, thereby improving the luminous efficiency of the light-emitting device.

[0057] The beneficial effects that can be achieved by the display device provided by the present disclosure are the same as the beneficial effects that can be achieved by the light-emitting device provided by the above technical solution, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0059] Figure 1 is a structural diagram of a light emitting device according to some embodiments;

[0060] Figure 2 is a structural diagram of a first electron transport layer of a light-emitting device according to some embodiments;

[0061] Figure 3 is a schematic diagram of electron movement between multiple layers of a light emitting device according to some embodiments;

[0062] Figure 4 is a structural diagram of another light emitting device according to some embodiments;

[0063] Figure 5 Graphs showing current density and luminous efficiency characteristics of light-emitting devices of some embodiments of the present disclosure and light-emitting devices of comparative examples, respectively;

[0064] Figure 6 Graphs showing time and brightness of light-emitting devices of some embodiments of the present disclosure and light-emitting devices of comparative examples are shown respectively. DETAILED DESCRIPTION

[0065] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present disclosure.

[0066] Unless the context requires otherwise, throughout the specification and claims, the term "comprise" and other forms thereof, such as the third person singular form "comprises" and the present participle form "comprising", are to be interpreted as open, inclusive, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that specific features, structures, materials or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0067] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

[0068] When describing some embodiments, the expressions "coupled" and "connected" and their derivatives may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also refer to two or more components that are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0069] Exemplary embodiments are described herein with reference to cross-sectional views and / or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are conceivable. Therefore, the exemplary embodiments should not be interpreted as being limited to the shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device, and are not intended to limit the scope of the exemplary embodiments.

[0070] See also Figure 1 The embodiment of the present disclosure provides a light-emitting device 100, which includes a first electrode 10, a second electrode 20, and at least two light-emitting units 30, and a group of connecting layers 40 are arranged between any two adjacent light-emitting units 30.

[0071] The first electrode 10 has conductivity. For example, the first electrode 10 may include one selected from silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), Ca-LiF alloy, Al-LiF alloy, molybdenum (Mo), titanium (Ti), indium (In), tin (Sn) and zinc (Zn), or a mixture of two or more thereof.

[0072] The first electrode 10 may be a transmissive electrode, a transflective electrode, or a reflective electrode. When the first electrode 10 is a transmissive electrode, the first electrode 10 may be formed using a transparent metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), and / or indium tin zinc oxide (ITZO). When the first electrode 10 is a transflective electrode or a reflective electrode, the first electrode 10 may include silver (Ag), magnesium (Mg), copper (Cu), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), Ca-LiF alloy, Al-LiF alloy, molybdenum (Mo), titanium (Ti), a composite thereof, or a mixture thereof (e.g., a mixture of Ag and Mg).

[0073] In addition, the first electrode 10 may be formed as a single layer or a multilayer. When the first electrode 10 includes a multilayer structure, the multilayer structure may include a reflective layer or a transflective layer formed using the above materials and a transmissive conductive layer formed using indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) and / or indium tin zinc oxide (ITZO). For example, the first electrode 10 may be a three-layer structure of ITO / Ag / ITO.

[0074] The second electrode 20 may be formed as a single layer or multiple layers. Each layer constituting the second electrode 20 may be formed of a metal, an inorganic material, a mixture of metals, a mixture of metals and an inorganic material, and a mixture thereof. When each layer constituting the second electrode 20 is formed of a mixture of a metal and an inorganic material, the mixing ratio of the metal and the inorganic material may be 10:1 to 1:10; when each layer constituting the second electrode 20 is formed of a mixture of two metals, the mixing ratio of the two metals in each layer may be 10:1 to 1:10. Exemplarily, the metal constituting the second electrode 20 may be silver (Ag), magnesium (Mg), ytterbium (Yb), lithium (Li) or calcium (Ca); the inorganic material constituting the second electrode 20 may be lithium oxide (Li2O), calcium oxide (CaO), lithium fluoride (LiF) or magnesium fluoride (MgF2), etc.

[0075] The at least two light emitting units 30 are stacked between the first electrode 10 and the second electrode 20 .

[0076] For some examples, see Figure 1 There are two light emitting units 30, and a group of connecting layers 40 is disposed between the two light emitting units 30. Those skilled in the art can understand that, in other examples, there can be three or more light emitting units 30.

[0077] The two light emitting units 30 include a first light emitting unit 31 and a second light emitting unit 32. The first light emitting unit 31 is close to the first electrode 10, and the second light emitting unit 32 is close to the second electrode 20.

[0078] A set of connection layers 40 includes an N-type charge generation layer 41 and a P-type charge generation layer 42 which are stacked.

[0079] The first light emitting unit 31 includes a first electron transport layer 311 and a first light emitting layer 312 which are stacked.

[0080] For example, see Figure 2 The first electron transport layer 311 is a dual-doped structure including a host material 3111 and a guest material 3112 .

[0081] The above-mentioned "first electron transport layer" is a layer that receives electrons and transports them to the first light-emitting layer 312. As an electron transport material, it is a material that can well receive electrons and transfer them to the light-emitting layer, and is suitable for materials with high electron mobility.

[0082] "Dual doping structure" means that two doping materials are doped into the main material. The method used for doping the impurity material can be ion implantation or diffusion. The first electron transport layer 311 is a dual doping structure in which two doping materials are doped into the main material. The first electron transport layer 311 has the characteristics of the two doping materials, thereby changing the characteristics of the electron transport layer such as electron mobility.

[0083] The light-emitting device 100 provided by some of the above embodiments of the present disclosure includes at least two light-emitting units 30, and at least two light-emitting units 30 are connected in series through a connecting layer, so that the luminous efficiency of the light-emitting device 100 can be improved and the service life of the light-emitting device 100 can be extended. The luminous efficiency can increase exponentially with the increase in the number of light-emitting units. Under the same brightness, the service life of the stacked light-emitting device increases exponentially; and by making the first electron transport layer 311 a binary doping structure including a main material 3111 and a guest material 3112, the first electron transport layer has the characteristics of two doping materials at the same time, thereby changing the characteristics of the first electron transport layer such as the electron mobility, so that the electron transport performance of the first electron transport layer 311 is more stable and the electron transport efficiency is higher, which helps to inject electrons into the first light-emitting layer 312 to recombine carriers in the first light-emitting layer 312, thereby improving the luminous efficiency of the light-emitting device 100.

[0084] In some embodiments, please refer to Figure 1 When the first electrode 10 is an anode and the second electrode 20 is a cathode, the first light-emitting unit 31 is close to the anode, and the second light-emitting unit 32 is closer to the cathode than the first light-emitting unit 31 .

[0085] In this embodiment, the first light-emitting unit 31 is close to the anode, which injects holes into the first light-emitting unit 31, and then emits light by combining with the electrons transmitted to the first light-emitting layer 312 via the first electron transport layer 311. The second light-emitting unit 32 is closer to the cathode, which is used to inject electrons into the second light-emitting unit 32.

[0086] In some embodiments, please refer to Figure 1 , the first light emitting unit 31 is in direct contact with the N-type charge generation layer 41 , and the second light emitting unit 32 is not in direct contact with the N-type charge generation layer 41 .

[0087] Those skilled in the art can understand that the first light-emitting unit 31 is in direct contact with the N-type charge generation layer 41, and the N-type charge generation layer 41 provides electrons to the first electron transport layer 311 of the first light-emitting unit 31, and the first electron transport layer 311 transfers electrons to the first light-emitting layer 312, which then recombines with holes from the first electrode 10 to emit light. The second light-emitting unit 32 is not in direct contact with the N-type charge generation layer 41, and the P-type charge generation layer 42 in direct contact with the second light-emitting unit 32 provides holes to the second light-emitting unit 32, which then recombines with electrons from the second electrode 20 to emit light.

[0088] In this embodiment, when the first electron transport layer 311 is a binary doped structure including a main material 3111 and a guest material 3112, the first electron transport layer has the characteristics of two doping materials at the same time, thereby changing the electron mobility and other characteristics of the first electron transport layer, making the electron transport performance of the first electron transport layer 311 more stable, improving the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312, and the balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminous efficiency of the light-emitting device 100.

[0089] In some embodiments, the host material 3111 in the first electron transport layer 311 of the first light-emitting unit 31 is a triazine compound.

[0090] As a typical strong electron-withdrawing group, the compounds with triazine group as the central structure have higher electron mobility and lower energy level.

[0091] In the present embodiment, since the main material 3111 in the first electron transport layer 311 is a triazine compound, the triazine compound has a higher electron mobility, and thus the electron mobility of the first electron transport layer 311 is increased, and the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311 are improved, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312, and the balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminous efficiency of the light-emitting device 100; moreover, the higher electron mobility can also enable the light-emitting device 100 to have a lower driving voltage, thereby reducing the power consumption of the light-emitting device 100.

[0092] In some embodiments, the dipole moment of the host material 3111 of the first electron transport layer 311 is 0.5 Debye to 2.0 Debye.

[0093] It should be noted that the dipole moment can be used to determine the spatial configuration of a molecule. The dipole moment indicates the size of polarity. The larger the bond dipole moment, the greater the polarity of the bond; the larger the dipole moment of the molecule, the greater the polarity of the molecule. The main material 3111 has a higher dipole moment, which increases the polarity of the material and the triplet energy level of the molecule, which can block excitons and reduce the quenching of effective excitons in the transport layer. When the main material 3111 is used as the electron transport material of the first electron transport layer 311 of the first light-emitting unit 31, it has the advantages of high carrier mobility, improved device luminous efficiency and service life, and reduced operating voltage of the light-emitting device 100.

[0094] In some embodiments, the mobility of the host material 3111 of the first electron transport layer 311 is: 5.0×10 -6 Vs / cm 2 ~5.0×10 -4 Vs / cm 2 .

[0095] In this embodiment, the main material 3111 of the first electron transport layer 311 has a higher electron mobility, thereby increasing the electron mobility of the first electron transport layer 311, improving the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, allowing electrons to move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312, and the balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminous efficiency of the light-emitting device 100; moreover, the higher electron mobility can also enable the light-emitting device 100 to have a lower driving voltage, thereby reducing the power consumption of the light-emitting device 100.

[0096] In some embodiments, the main material 3111 of the first electron transport layer 311 has a structural formula as shown in the following formula (I):

[0097]

[0098] In formula (I), Ar1, Ar2, and Ar3 are each independently selected from a hydrogen atom, a deuterium atom, a substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aryl groups may be combined with an adjacent group to form a substituted or unsubstituted benzene ring.

[0099] Wherein, Ar3 has the structure of formula (II):

[0100]

[0101] In formula (II), R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups.

[0102] R1 and R2 can be linked to each other to form a saturated or unsaturated cyclic compound.

[0103] It should be noted that the above-mentioned "substituted or unsubstituted" refers to an unsubstituted group or a group substituted with at least one substituent, wherein the at least one substituent is selected from the group consisting of a deuterium atom, a halogen atom, a cyano group, a nitro group, an amino group, a silyl group, an oxy group (or referred to as "oxy-containing group"), a thiol group, a sulfinyl group, a sulfonyl group, a carbonyl group, a boron group, a phosphine oxide group, a phosphine sulfide group, an alkyl group, an alkenyl group, an alkoxy group, a hydrocarbon ring group, an aryl group, and a heterocyclic group. In addition, each of the exemplary substituents may be substituted or unsubstituted. For example, a biphenyl group may be interpreted as an aryl group or a phenyl group substituted with a phenyl group.

[0104] In the above “forming a substituted or unsubstituted benzene ring through bonding with an adjacent group”, the “adjacent group” may refer to a substituent that replaces an atom directly bonded to an atom substituted with a corresponding substituent, another substituent that replaces an atom substituted with a corresponding substituent, or a substituent that is spatially located closest to the corresponding substituent. For example, in 1,2-dimethylbenzene, two methyl groups may be interpreted as “adjacent groups” to each other, and in 1,1-diethylcyclopentane, two ethyl groups may be interpreted as “adjacent groups” to each other.

[0105] In this embodiment, the compound with a structural formula as shown in formula (I) has a core structure of a triazine group. The triazine group is a typical strong electron-withdrawing group. The compound with the triazine group as the central structure has a higher electron mobility and a lower energy level. When it is applied to the light-emitting device 100 as the main material 3111 of the first electron transport layer 311, the electron mobility of the first electron transport layer 311 is increased, and the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311 are improved, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312. The balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminous efficiency of the light-emitting device 100.

[0106] In some embodiments, the guest material 3112 of the first electron transport layer 311 is a compound containing a phosphorus oxygen group.

[0107] In the present embodiment, the compound containing phosphorus oxide has a higher triplet energy level. When the compound containing phosphorus oxide is used as the guest material 3112 of the first electron transport layer 311, the compound containing phosphorus oxide can increase the electron injection ability, thereby improving the electron mobility of the first electron transport layer 311, and improving the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312. The balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminescence efficiency of the light-emitting device 100.

[0108] In some embodiments, the guest material 3112 of the first electron transport layer 311 has a dipole moment of 4.0 Debye to 6.0 Debye.

[0109] It should be noted that the dipole moment can be used to determine the spatial configuration of a molecule. The dipole moment indicates the size of polarity. The larger the bond dipole moment, the greater the polarity of the bond; the larger the dipole moment of the molecule, the greater the polarity of the molecule. The guest material 3112 has a higher dipole moment, which increases the polarity of the material and the triplet energy level of the molecule, which can block excitons and reduce the quenching of effective excitons in the transport layer. When the guest material 3112 is used as the electron transport material of the first electron transport layer 311 of the first light-emitting unit 31, it has the advantages of high carrier mobility, improved device luminous efficiency and service life, and reduced operating voltage of the light-emitting device 100.

[0110] In some embodiments, the guest material 3112 of the first electron transport layer 311 has a structure of formula (III):

[0111]

[0112] In formula (III), X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24 One of a cyclopentane, and a strong electron withdrawing group whose substituent is CN or CF3;

[0113] X3, X4 are independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups;

[0114] L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20A type of heteroaryl group.

[0115] In these embodiments, the guest material 3112 of the first electron transport layer 311 is composed of a compound containing a phosphorus oxide group. Since the compound containing a phosphorus oxide group has a higher triplet energy level, when the compound containing a phosphorus oxide group is used as the guest material 3112 of the first electron transport layer 311, the compound containing a phosphorus oxide group can increase the electron injection capability, thereby improving the electron mobility of the first electron transport layer 311.

[0116] In some embodiments, the guest material 3112 of the first electron transport layer 311 has any one of the following formulas 1 to 15:

[0117]

[0118]

[0119] The compounds represented by the above chemical formula are all compounds containing phosphorus oxide. Since the compounds containing phosphorus oxide have a higher triplet energy level, when the compounds containing phosphorus oxide are used as the guest material 3112 of the first electron transport layer 311, the compounds containing phosphorus oxide can increase the electron injection ability, thereby improving the electron mobility of the first electron transport layer 311, and improving the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312. The balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminescence efficiency of the light-emitting device 100.

[0120] In some embodiments, the N-type charge generation layer 41 is a dual-doped structure including a host material and a guest material.

[0121] Those skilled in the art will appreciate that the N-type charge generation layer 41 provides electrons to the first electron transport layer 311 of the first light emitting unit 31 , and the first electron transport layer 311 provides electrons to the first light emitting layer 312 adjacent to the first electrode 10 .

[0122] In this embodiment, by making the N-type charge generation layer 41 a dual-doped structure including a main material and a guest material, the injection barrier from the N-type charge generation layer 41 to the first electron transport layer 311 can be reduced, and the accumulation of electrons at the interface between the N-type charge generation layer 41 and the first electron transport layer 311 can be effectively avoided, thereby improving the life of the light-emitting device 100.

[0123] In some embodiments, the host material of the N-type charge generation layer 41 and the guest material 3112 of the first electron transport layer 311 include the same general material.

[0124] See also Figure 3 , electrons are injected from the N-type charge generation layer 41 into the first electron transport layer 311 .

[0125] When the host material of the N-type charge generation layer 41 and the guest material 3112 of the first electron transport layer 311 include the same general material, the electron injection barrier from the N-type charge generation layer 41 to the first electron transport layer 311 is relatively reduced, and the electron flow is smoother.

[0126] In this embodiment, since the host material of the N-type charge generation layer 41 and the guest material 3112 of the first electron transport layer 311 include the same general material, a homojunction is formed between the first electron transport layer 311 and the N-type charge generation layer 41 including the guest material 3112 of the first electron transport layer 311. Since the number of heterojunction interfaces is reduced, the possibility of charge trapping at the interface between the heterojunctions is minimized, thereby reducing the driving voltage of the light-emitting device 100 and reducing power consumption; moreover, the injection barrier of electrons from the N-type charge generation layer 41 to the first electron transport layer 311 is relatively reduced, making it easier for electrons to be transferred to the first light-emitting layer 312, and then to recombine with holes from the first electrode 10 to emit light, and the continuity of the energy level arrangement in the N-type charge generation layer 41 can be increased, and the position of the electrons that can be accepted is increased, thereby effectively avoiding the accumulation of electrons at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, thereby improving the life of the organic electroluminescent device.

[0127] In some embodiments, the N-type charge generation layer 41 includes lithium ions or a compound containing an alkali metal. For example, the alkali metal may be calcium (Ca), magnesium (Mg), ytterbium (Yb), etc. The doping concentration of the lithium ions or the compound containing an alkali metal in the N-type charge generation layer 41 may be 0.5% to 2%.

[0128] Exemplarily, the N-type charge generation layer 41 may further include a material selected from lithium quinolate (LiQ), lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), rubidium fluoride (RbF), cesium fluoride (CsF), francium fluoride (FrF), beryllium fluoride (BeF2), magnesium fluoride (MgF2), calcium fluoride (CaF2), strontium fluoride (SrF2), barium fluoride (BaF2) and radium fluoride (RaF2). The present disclosure does not limit this.

[0129] In this embodiment, the electron injection characteristics of the N-type charge generation layer 41 can be improved by doping the N-type charge generation layer 41 with the alkali metal-containing compound. For example, when the alkali metal-containing compound is used as a dopant for the N-type charge generation layer 41, the alkali metal reacts with the N matrix to form an energy gap state, and the electrons generated from the P-type charge generation layer 42 are easily injected into the N-type charge generation layer 41 through the energy gap state, thereby being more conducive to the injection of electrons from the N-type charge generation layer 41 into the first electron transport layer 311.

[0130] Those skilled in the art may understand that, in some embodiments, the P-type charge generation layer 42 is used to generate holes and electrons, inject the generated holes into the second light emitting unit 32 , and inject the generated electrons into the N-type charge generation layer 41 .

[0131] In some embodiments, the P-type charge generation layer 42 includes: an organic compound containing at least two cyano groups, and the doping concentration of the organic compound containing at least two cyano groups in the P-type charge generation layer 42 is 3% to 8%.

[0132] In this embodiment, the organic compound containing at least two cyano groups has a higher lowest unoccupied molecular orbital (LUMO) energy level and a larger energy band gap. Therefore, the electrons generated by the P-type charge generation layer 42 quickly move to the N-type charge generation layer 41, thereby reducing the driving voltage of the light-emitting device 100.

[0133] In some embodiments, the lowest excited triplet energy level of the first electron transport layer 311 is higher than the lowest excited triplet energy level of the first light emitting layer 312 .

[0134] Those skilled in the art can understand that when the material of the first light-emitting layer 312 is a fluorescent material, during the light-emitting process of the light-emitting device 100, the fluorescent material will produce 25% singlet excitons and 75% triplet excitons under current excitation, among which the singlet exciton radiation can be deactivated to ground state excitons to emit fluorescence.

[0135] Since the lowest excited triplet energy level of the first electron transport layer 311 is higher than the lowest excited triplet energy level of the first light emitting layer 312 , excitons can be blocked to prevent excitons from leaking from the first light emitting layer 312 to the first electron transport layer 311 , thereby improving the luminous efficiency of the light emitting device 100 .

[0136] In some embodiments, please refer to Figure 1 , the first electrode 10 is an anode, and the second electrode 20 is a cathode 20. The second light emitting unit 32 is closer to the cathode than the first light emitting unit 31.

[0137] The second light-emitting unit 32 includes a stacked second light-emitting layer 321 and a second electron transport layer 322. The second electron transport layer 322 is a binary doping structure including a host material and a guest material.

[0138] The "binary doping structure" refers to two doping materials doped in the main material. The method used for doping the impurity material can be ion implantation or diffusion. The second electron transport layer 322 is a binary doping structure in which two doping materials are doped in the main material, thereby changing the electron mobility and other characteristics of the electron transport layer.

[0139] In the present embodiment, by making the second electron transport layer 322 a binary doped structure including a main material and a guest material, the electron mobility of the second electron transport layer 322 is increased, and the electron injection characteristics at the interface between the P-type charge generation layer 42 and the second electron transport layer 322 are improved, so that electrons can move smoothly from the P-type charge generation layer 42 to the second light-emitting layer 321. Due to the balanced and stable charges in the second light-emitting layer 321, the formation rate of excitons formed by recombination between electrons and holes is increased, thereby improving the luminous efficiency of the light-emitting device 100.

[0140] In some embodiments, the dipole moment of the host material of the second electron transport layer 322 is 0.15 Debye to 2.0 Debye.

[0141] It should be noted that the dipole moment can be used to determine the spatial configuration of a molecule. The dipole moment indicates the size of polarity. The larger the bond dipole moment, the greater the polarity of the bond; the larger the dipole moment of the molecule, the greater the polarity of the molecule. The main material of the second electron transport layer 322 has a higher dipole moment, which increases the polarity of the material and the triplet energy level of the molecule, which can block excitons and reduce the quenching of effective excitons in the transport layer; when the second electron transport layer 322 of the light-emitting device 100 includes a main material with a larger molecular dipole moment, it has the advantages of high carrier mobility, improved device luminous efficiency and service life, and reduced operating voltage of the light-emitting device 100.

[0142] In some embodiments, the guest material of the second electron transport layer 322 is an alkali metal or alkaline earth metal compound. For example, the alkali metal may be lithium (Li), sodium (Na), potassium (K), cesium (Cs), etc., and the alkaline earth metal may be magnesium (Mg), strontium (Sr), barium (Ba), radium (Ra), etc.

[0143] In this embodiment, the electron transport performance of the second light emitting unit 32 can be improved by doping the second electron transport layer 322 with a compound containing an alkali metal or an alkaline earth metal.

[0144] In some embodiments, the total thickness of the first light emitting unit 31 is 90 nm to 150 nm, for example, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, etc.

[0145] In some embodiments, the total thickness of the second light emitting unit 32 is 90 nm to 150 nm, for example, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, etc.

[0146] In some embodiments, please refer to Figure 1 The first light-emitting layer 312 and the second light-emitting layer 322 each include a red light-emitting portion 301, a green light-emitting portion 302, and a blue light-emitting portion 303. The red light-emitting portion 301, the green light-emitting portion 302, and the blue light-emitting portion 303 of the first light-emitting layer 312 are all formed on one side of the first electrode 10 close to the first electron transport layer 311 and are spaced apart.

[0147] In some embodiments, the red light-emitting portion 301 , the green light-emitting portion 302 , and the blue light-emitting portion 303 are all dual-doped structures including a host material and a guest material.

[0148] In some examples, the host material of the red light-emitting portion 301, the host material of the green light-emitting portion 302, and the host material of the blue light-emitting portion 303 are the same.

[0149] In some examples, the guest material of the red light-emitting portion 301, the guest material of the green light-emitting portion 302, and the guest material of the blue light-emitting portion 303 are the same.

[0150] It is understood that the red light emitting portion 301, the green light emitting portion 302, and the blue light emitting portion 303 respectively include hosts of different dopants. The dopants may be added to the hosts at a ratio of about 1 wt% to about 30 wt%.

[0151] The red light-emitting portion 301 may be a phosphorescent light-emitting material layer including a host such as CBP and a dopant selected from a group including bis(1-phenylisoquinoline)iridium acetylacetonate (PIQIr(acac)), bis(1-phenylquinoline)iridium acetylacetonate (PIQIr(acac)) and platinum octaethylporphyrin (PtOEP).

[0152] The green light emitting portion 302 may be a phosphorescent light emitting material layer including a host such as CBP and an iridium group (eg, dp2Ir(acac), op2Ir(acac)) dopant.

[0153] The blue light emitting portion 303 may be a phosphorescent light emitting material layer including a dopant selected from the group consisting of anthracene and its derivatives, pyrene and its derivatives, and perylene and its derivatives doped with a fluorescent dopant.

[0154] In some examples, the thickness of the red light emitting portion 301 is 30nm to 50nm, such as 30nm, 40nm, 50nm, etc. The thickness of the green light emitting portion 302 is 30nm to 50nm, such as 30nm, 40nm, 50nm, etc. The thickness of the blue light emitting portion 303 is 10nm to 20nm, such as 10nm, 15nm, 20nm, etc.

[0155] In some embodiments, please refer to Figure 4 The first light emitting unit 31 further includes: a first electron blocking layer 313 , a first hole transport layer 314 and a first hole injection layer 315 .

[0156] Among them, the first electron blocking layer 313 is located on the side of the first light-emitting layer 312 away from the first electron transport layer 311; the first hole transport layer 314 is located on the side of the first electron blocking layer 313 away from the first light-emitting layer; the first hole injection layer 315 is located on the side of the first hole transport layer away from the first electron blocking layer 312.

[0157] The first hole injection layer 315 may improve interface characteristics between the first electrode 10 and the first hole transport layer 314 .

[0158] In some embodiments, please refer to Figure 4 The second light emitting unit 32 further includes: a hole blocking layer 323 , an electron injection layer 324 , a second hole transport layer 325 and a second hole injection layer 326 .

[0159] Among them, the hole blocking layer 323 is located between the second light-emitting layer and the second electron transport layer; the electron injection layer 324 is located on the side of the second electron transport layer away from the second light-emitting layer; the second hole transport layer 325 is located on the side of the second light-emitting layer away from the second electron transport layer; the second hole injection layer 326 is located on the side of the second hole transport layer away from the second light-emitting layer.

[0160] In some embodiments, the material of the second hole transport layer 325 is the same as the host material of the P-type charge generation layer 42 .

[0161] In this embodiment, the material of the second hole transport layer 325 is the same as the matrix material of the P-type charge generation layer 42, which can reduce the potential barrier between the P-type charge generation layer 42 and the second hole transport layer 325 and effectively realize the injection of holes from the P-type charge generation layer 42 to the second hole transport layer 325.

[0162] The electronic luminescence characteristics of the light emitting device 100 in the above embodiment of the present disclosure and the comparative example in which the first electron transport layer is a single component material are as follows: Figure 5-6 The following table shows the relevant test data of the light emitting device 100 in the above embodiment of the present disclosure and the comparative example:

[0163] Current density (mA / cm2) Voltage (V) Efficiency (cd / A) Lifespan (T95) Comparative Example 15 7.6 100％ 100％ Example 15 6.4 103％ 150％

[0164] The above results show that any light-emitting device 100 in the above embodiments of the present disclosure, that is, a light-emitting device 100 in which at least the first electron transport layer 311 is a dual-doped structure including a host material and a guest material, exhibits the advantages of low driving voltage, high luminous efficiency and long service life compared with the comparative example in which the first electron transport layer is a single-component material.

[0165] The present disclosure also provides a display device, which includes any one of the light-emitting devices 100 described above.

[0166] The display device may be any device that displays either moving (e.g., video) or fixed (e.g., still images) and whether text or images. More specifically, it is contemplated that the embodiments may be implemented in or associated with a variety of electronic devices, such as (but not limited to) mobile phones, wireless devices, personal digital assistants (PDAs), handheld or portable computers, global positioning system (GPS) receivers / navigators, cameras, moving picture experts group 4 (MP4) video players, video cameras, game consoles, watches, clocks, calculators, television monitors, computer monitors, automotive displays (e.g., odometer displays, etc.), navigators, cockpit controls and / or displays, displays of camera views (e.g., displays of rear-view cameras in vehicles), electronic photographs, electronic billboards or signs, projectors, architectural structures, packaging, and aesthetic structures (e.g., displays of images of a piece of jewelry), etc.

[0167] The display device provided by some embodiments of the present disclosure includes a light-emitting device 100 provided by the above technical solution, including at least two light-emitting units 30, and at least two light-emitting units 30 are connected in series through a connecting layer, so as to improve the luminous efficiency of the light-emitting device 100 and extend the service life of the light-emitting device 100. The luminous efficiency can increase exponentially with the increase in the number of light-emitting units. Under the same brightness, the service life of the stacked light-emitting device increases exponentially; and by making the first electron transport layer 311 a binary doping structure including a main material 3111 and a guest material 3112, the first electron transport layer has the characteristics of two doping materials at the same time, thereby changing the characteristics of the first electron transport layer such as the electron mobility, so that the electron transport performance of the first electron transport layer 311 is more stable and the electron transport efficiency is higher, which helps to inject electrons into the first light-emitting layer 312 to recombine carriers in the first light-emitting layer 312, thereby improving the luminous efficiency of the light-emitting device 100.

[0168] The present disclosure also provides a compound, the structural formula of the compound is shown in the following formula (I):

[0169]

[0170] Wherein, Ar1, Ar2, Ar3 are each independently selected from hydrogen atoms, deuterium atoms, substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aromatic groups, or capable of combining with adjacent groups to form a substituted or unsubstituted benzene ring;

[0171] Ar3 has the structure of formula (II):

[0172]

[0173] Wherein, R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups;

[0174] R1 and R2 can be linked to each other to form a saturated or unsaturated cyclic compound.

[0175] In this embodiment, the compound with a structural formula as shown in formula (I) has a core structure of a triazine group. The triazine group is a typical strong electron-withdrawing group. The compound with the triazine group as the central structure has a higher electron mobility and a lower energy level. When it is applied to the light-emitting device 100 as the main material 3111 of the first electron transport layer 311, the electron mobility of the first electron transport layer 311 is increased, and the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311 are improved, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312. The balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminous efficiency of the light-emitting device 100.

[0176] The present disclosure also provides a compound, the structural formula of the compound is shown in the following formula (III):

[0177]

[0178] Wherein, X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24 One of a cyclopentane, and a strong electron withdrawing group whose substituent is CN or CF3;

[0179] X3, X4 are each independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups;

[0180] L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20 A type of heteroaryl group.

[0181] In this embodiment, the compound with a structural formula as shown in formula (III) contains a phosphorus oxygen group. The compound containing a phosphorus oxygen group has a higher triplet energy level. When the compound containing a phosphorus oxygen group is used as the guest material 3112 of the first electron transport layer 311, the compound containing a phosphorus oxygen group can increase the electron injection capability, thereby improving the electron mobility of the first electron transport layer 311.

[0182] In some embodiments, the organic compound is selected from any one of the following Formulas 1 to 15:

[0183]

[0184]

[0185] The compounds represented by the above chemical formula are all compounds containing phosphorus oxide. Since the compounds containing phosphorus oxide have a higher triplet energy level, when the compounds containing phosphorus oxide are used as the guest material 3112 of the first electron transport layer 311, the compounds containing phosphorus oxide can increase the electron injection ability, thereby improving the electron mobility of the first electron transport layer 311, and improving the electron injection characteristics at the interface between the N-type charge generation layer 41 and the first electron transport layer 311, so that electrons can move smoothly from the N-type charge generation layer 41 to the first light-emitting layer 312. The balanced and stable charges in the first light-emitting layer 312 increase the formation rate of excitons formed by recombination between electrons and holes, thereby improving the luminescence efficiency of the light-emitting device 100.

[0186] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A light emitting device, characterized in that: include: a first electrode; a second electrode; At least two light-emitting units are stacked between the first electrode and the second electrode; as well as, at least one set of connected layers; A group of the connecting layers is arranged between each two adjacent light-emitting units; the connecting layers include an N-type charge generation layer and a P-type charge generation layer arranged in a stacked manner; Wherein, the at least two light-emitting units include a first light-emitting unit; The first light-emitting unit comprises a first electron transport layer and a first light-emitting layer which are stacked; the first electron transport layer is a binary doping structure comprising a host material and a guest material; The host material of the first electron transport layer has a structure of formula (I): Wherein, Ar1, Ar2, Ar3 are each independently selected from hydrogen atoms, deuterium atoms, substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aromatic groups, or capable of combining with adjacent groups to form a substituted or unsubstituted benzene ring; Ar3 has the structure of formula (II): Wherein, R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups; R1 and R2 can be connected to each other to form a saturated or unsaturated cyclic compound; The guest material of the first electron transport layer has a structure of formula (III): Wherein, X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24 One of a cyclopentane, and a strong electron withdrawing group whose substituent is CN or CF3; X3, X4 are each independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups; L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20 A type of heteroaryl group.

2. The light emitting device according to claim 1, characterized in that: The main material in the first electron transport layer is a triazine compound.

3. The light emitting device according to claim 1, characterized in that: The dipole moment of the host material of the first electron transport layer is 0.5 Debye to 2.0 Debye.

4. The light emitting device according to claim 1, characterized in that: The mobility of the main material of the first electron transport layer is: 5.0×10 -6 Vs / cm 2 ~5.0×10 -4 Vs / cm 2 。 5. The light emitting device according to claim 1, characterized in that: The guest material of the first electron transport layer is a compound containing a phosphorus oxygen group.

6. The light emitting device according to claim 1, characterized in that: The dipole moment of the guest material of the first electron transport layer is 4.0 Debye to 6.0 Debye.

7. The light emitting device according to claim 1, characterized in that: The guest material mobility of the first electron transport layer is 5.0×10 -7 Vs / cm 2 ~5.0×10 -5 Vs / cm 2 .

8. The light emitting device according to claim 1, characterized in that: The guest material of the first electron transport layer has any one of the following formulas 1 to 15:

9. The light emitting device according to any one of claims 1 to 8, characterized in that: The N-type charge generation layer is a dual-doping structure including a host material and a guest material.

10. The light emitting device according to claim 9, characterized in that: The host material of the N-type charge generation layer and the guest material of the first electron transport layer include materials of the same general formula.

11. The light emitting device according to any one of claims 1 to 8, characterized in that: The N-type charge generation layer includes lithium ions or a compound containing an alkali metal.

12. The light emitting device according to claim 11, characterized in that: The doping concentration of the lithium ion or the alkali metal-containing compound in the N-type charge generation layer is 0.5% to 2%.

13. The light emitting device according to any one of claims 1 to 8, characterized in that: The P-type charge generation layer includes an organic compound containing at least two cyano groups.

14. The light emitting device according to claim 13, characterized in that: The doping concentration of the organic compound containing at least two cyano groups in the P-type charge generation layer is 3% to 8%.

15. The light emitting device according to any one of claims 1 to 8, characterized in that: The lowest excited triplet energy level of the first electron transport layer is higher than the lowest excited triplet energy level of the first light emitting layer.

16. The light emitting device according to any one of claims 1 to 8, characterized in that: The first electrode is an anode, and the second electrode is a cathode; The at least two light-emitting units further include a second light-emitting unit; the second light-emitting unit is closer to the cathode than the first light-emitting unit; The second light-emitting unit includes a second electron transport layer and a second light-emitting layer which are stacked; The second electron transport layer is a binary doping structure including a host material and a guest material.

17. The light emitting device according to claim 16, characterized in that: The dipole moment of the host material of the second electron transport layer is 0.15 Debye to 2.0 Debye.

18. The light emitting device according to claim 16, characterized in that: The guest material of the second electron transport layer is an alkali metal or alkaline earth metal compound.

19. The light emitting device according to claim 16, characterized in that: The total thickness of the first light-emitting unit is 90nm to 150nm; and / or, The total thickness of the second light-emitting unit is 90 nm to 150 nm.

20. The light emitting device according to claim 19, characterized in that: The first light-emitting layer and the second light-emitting layer each include: a red light-emitting portion, a green light-emitting portion and a blue light-emitting portion; wherein the red light-emitting portion, the green light-emitting portion and the blue light-emitting portion are arranged at intervals; The red light-emitting portion, the green light-emitting portion and the blue light-emitting portion are all dual-doped structures including a host material and a guest material; Wherein, the main material of the red light-emitting portion, the main material of the green light-emitting portion and the main material of the blue light-emitting portion are the same; and / or, The guest material of the red light-emitting portion, the guest material of the green light-emitting portion, and the guest material of the blue light-emitting portion are the same.

21. The light emitting device according to claim 20, characterized in that: The thickness of the red light-emitting portion is 30nm to 50nm; the thickness of the green light-emitting portion is 30nm to 50nm; and the thickness of the blue light-emitting portion is 10nm to 20nm.

22. The light emitting device according to claim 16, characterized in that: The first light emitting unit further comprises: A first electron blocking layer is located on a side of the first light-emitting layer away from the first electron transport layer; A first hole transport layer is located on a side of the first electron blocking layer away from the first light-emitting layer; and A first hole injection layer, located on a side of the first hole transport layer away from the first electron blocking layer; The second light emitting unit further comprises: a hole blocking layer, located between the second light-emitting layer and the second electron transport layer; an electron injection layer, located on a side of the second electron transport layer away from the second light-emitting layer; A second hole transport layer is located on a side of the second light-emitting layer away from the second electron transport layer; and The second hole injection layer is located on a side of the second hole transport layer away from the second light-emitting layer.

23. The light emitting device according to claim 22, characterized in that: The material of the second hole transport layer is the same as the host material of the P-type charge generation layer.

24. A display device, characterized in that: include: A light emitting device as claimed in any one of claims 1 to 23.

25. An organic compound, characterized in that The structural formula of the organic compound is shown in the following formula (I): Wherein, Ar1, Ar2, Ar3 are each independently selected from hydrogen atoms, deuterium atoms, substituted or unsubstituted C1 to C 40 Alkyl, and substituted or unsubstituted C6~C 60 One of the aromatic groups, or capable of combining with adjacent groups to form a substituted or unsubstituted benzene ring; Ar3 has the structure of formula (II): Wherein, R1 to R6 are independently selected from hydrogen atom, C1 to C6 alkyl, amino, arylamino, substituted or unsubstituted C6 to C 30 Aryl, and substituted or unsubstituted C3~C 20 One of the oxygen-containing heteroaryl groups; R1 and R2 can be linked to each other to form a saturated or unsaturated cyclic compound.

26. An organic compound, characterized in that The structural formula of the organic compound is shown in the following formula (III): Wherein, X1 and X2 are each independently selected from substituted or unsubstituted C6 to C 20 Aryl, C5~C 20 Heteroaryl, substituted or unsubstituted C 12 ~C 24 One of a cyclopentane, and a strong electron withdrawing group whose substituent is CN or CF3; X3, X4 are each independently selected from C1 to C 12 Alkyl, substituted or unsubstituted C6~C 20 Aryl, and substituted or unsubstituted C5~C 20 One of the heteroaryl groups; L1 is selected from: a single bond or a C1-C5 alkyl group, a C6-C 20 Aryl, and substituted or unsubstituted C5~C 20 A type of heteroaryl group.

27. The organic compound according to claim 26, characterized in that The organic compound is selected from any one of the following formulas 1 to 15:

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