An organic electroluminescent device

Abstract

The present invention relates to an organic electroluminescent device, which comprises an anode, a cathode, a light-emitting layer and an organic functional layer disposed between the anode and the cathode; the organic functional layer includes a first electron transport layer and a second electron transport layer; the first electron transport layer contains any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3; the second electron transport layer contains the compound represented by Formula II-1 and / or Formula II-2. The organic electroluminescent device provided by the present invention can significantly improve the carrier transport efficiency in the device, reduce the energy level barrier, preferably reduce the problem of carrier accumulation at the interface between material layers, and improve the performance of the device while maintaining a relatively low voltage.

Description

Technical Field

[0001] The present invention relates to the technical field of organic electroluminescence, and particularly to an organic electroluminescent device. Background Art

[0002] The research on high-efficiency organic light-emitting diodes (OLEDs) began in the 1960s. In order to improve the device efficiency, the devices are often prepared by using a double-host structure in the light-emitting layer. Although the light-emitting efficiency is improved to a certain extent, the use of evaporation sources is increased at the same time, and the preparation is slightly difficult, which limits the commercial development of OLEDs.

[0003] In an OLED device, it is known that hole transport is generally faster than electron transport, and the recombination region in the light-emitting layer will be biased towards the ET layer direction, resulting in adverse consequences such as reduced device efficiency; although increasing the thickness of the hole transport layer slows down the hole transport to the cathode, it increases the voltage of the device. At the same time, the energy level barriers between different material layers cause a large amount of positive and negative carriers to accumulate at their respective interfaces, all of which result in reduced device efficiency.

[0004] In recent years, industry insiders have continuously tried and explored to improve the device efficiency and stability. Among them, there are many ways to seek new materials to improve the device performance, and a large number of novel materials have been developed for electron transport. Although it has a certain improvement on the device performance, there is still a large amount of carrier accumulation at the interface, and there are also problems such as high device voltage and short life.

[0005] Therefore, there is an urgent need in this field to develop an organic electroluminescent device with both high performance and low voltage. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, one of the purposes of the present invention is to provide an organic electroluminescent device. The organic electroluminescent device can significantly improve the carrier transport efficiency in the device, reduce the energy level barrier, and preferably reduce the problem of carrier accumulation at the interfaces between material layers, so that while the device has a lower voltage, its performance is also improved to a certain extent.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] The present invention provides an organic electroluminescent device, which includes an anode, a cathode, and a light-emitting layer and an organic functional layer disposed between the anode and the cathode;

[0009] The organic functional layer includes a first electron transport layer and a second electron transport layer;

[0010] The first electron transport layer contains any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3;

[0011]

[0012] The second electron transport layer contains any one or at least two combinations of the compounds represented by Formula II-1 and / or Formula II-2;

[0013]

[0014] Ring C represents a five- or six-membered aromatic or heteroaromatic ring fused to a benzene ring;

[0015] Each of the said Ar1 and Ar2 is independently selected from C1-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkyl, C1-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkoxy, C3-C 30 (such as C4, C6, C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 , etc.) cycloalkyl, C2-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkenyl, C2-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkynyl, halogen, cyano, substituted or unsubstituted C6-C 40 (such as C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 , C30 , C 32 , C 34 , C 36 , C 38 , etc.) aryl, substituted or unsubstituted C3-C 30 (such as C4, C6, C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 , etc.) heteroaryl;

[0016] The R is selected from hydrogen, C1-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkyl, C1-C 18 (such as C2, C4, C6, C8, C 10 , C 12 , C 14 , C 16 , etc.) alkoxy, C3-C 30 (such as C4, C6, C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 , etc.) cycloalkyl, halogen, cyano, substituted or unsubstituted C6-C 40 (such as C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 , C 30 , C 32 , C 34 , C 36 , C 38 , etc.) aryl, substituted or unsubstituted C3-C 30 (such as C4, C6, C8, C 10 , C12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 etc.) any one of heteroaryl groups;

[0017] When the above groups have substituents, the substituents are each independently selected from halogen, C1-C 10 (such as C2, C4, C6, C8, etc.) alkyl groups, C3-C 10 (such as C4, C5, C6, C7, C8, C9, C 10 etc.) cycloalkyl groups, C2-C 10 (such as C3, C4, C5, C6, C7, C8, C9, C 10 etc.) alkenyl groups, C1-C6 (such as C2, C3, C4, C5, etc.) alkoxy or thioalkoxy groups, cyano group, nitro group, amino group, carboxyl group, carbonyl group, ester group, C6-C 30 (such as C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 etc.) monocyclic aromatic hydrocarbon or polycyclic aromatic hydrocarbon groups, C3-C 30 (such as C8, C 10 , C 12 , C 14 , C 16 , C 18 , C 20 , C 22 , C 24 , C 26 , C 28 etc.) monocyclic heteroaromatic hydrocarbon or polycyclic heteroaromatic hydrocarbon groups. Preferably, the substituents are each independently selected from halogen, cyano group, methyl group, methoxy group, phenyl group, biphenyl group, naphthyl group, phenanthryl group or anthracenyl group. When the expression method of "substituted or unsubstituted" is involved in the present invention, the substituents all have the above selection range and will not be elaborated one by one.

[0018] In the present invention, the expression of chemical elements includes the concept of isotopes with the same chemical properties. For example, the expression of "hydrogen" also includes the concepts of "deuterium" and "tritium" with the same chemical properties.

[0019] In the present invention, the heteroatoms of the heteroaryl group generally refer to those selected from N, O, and S.

[0020] The present invention provides a novel organic electroluminescent device provided with two electron transport layers, and specific electron transport materials are selected respectively. First, the two electron transport materials have the same core group, which effectively reduces the interface difference between the two layers. Second, compared with the traditional device structure, the design of the second electron transport layer can not only make electrons better injected from the electrode into the organic layer, but also make electrons better transferred in the direction of the light-emitting layer.

[0021] Through the cooperation of appropriate materials and device structures, the present invention can not only facilitate the injection of cathode electrons into the light-emitting layer more easily, significantly improve the carrier transport efficiency in the device, and increase the light-emitting efficiency of the device, but also reduce the energy level barrier, preferably reduce the problem of carrier accumulation at the interfaces between material layers, and make the voltage of the device lower.

[0022] Preferably, R is selected from hydrogen, fluorine, chlorine, bromine, cyano, methyl, ethyl, n-propyl, isopropyl, n-butyl, n-hexyl, n-octyl, isopropyl, isobutyl, tert-butyl, isobutyl, tert-butyl, phenyl, biphenyl, terphenyl, naphthyl, anthracenyl, phenanthryl, indenyl, fluorenyl and its derivatives, fluoranthenyl, triphenylenyl, pyrenyl, perylenyl, group, pyridyl, pyrimidinyl, triazinyl, furyl, thienyl, pyrrolyl, benzofuryl, benzothienyl, isobenzofuryl, indolyl, dibenzofuryl, dibenzothienyl, carbazolyl and its derivatives.

[0023] Preferably, ring C represents a benzene ring, naphthalene ring, pyridine ring, furan ring, benzofuran ring, thiophene ring or benzothiophene ring fused with a benzene ring.

[0024] Preferably, each of Ar1 and Ar2 is independently selected from any one of the following substituted or unsubstituted groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthryl, benzophenanthryl, pyrenyl, chrysenyl, perylenyl, fluoranthenyl, tetraphenyl, pentaphenyl, benzopyrenyl, biphenyl, azobenzene, terphenyl, triphenyl, tetraphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indeno[1,2-b]fluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indolocarbazolyl, pyridyl, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthimidazolyl, phenanthrimidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthraoxazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthracenyl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperylene, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazolyl, phenanthroline, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl.

[0025] When the above groups have substituents, the substituents are selected from halogen, cyano, methyl, methoxy, phenyl, biphenyl, naphthyl, phenanthryl or anthracenyl.

[0026] Preferably, the first electron transport layer contains any one or at least two combinations of the following compounds:

[0027]

[0028] Preferably, the second electron transport layer contains any one or at least two combinations of the following compounds:

[0029]

[0030] Preferably, the first electron transport layer and the second electron transport layer are located between the cathode and the light-emitting layer, and their positional relationship is: the first electron transport layer is far from the cathode, and the second electron transport layer is close to the cathode. The first electron transport layer is far from the cathode, and the second electron transport layer is close to the cathode.

[0031] Preferably, the first electron transport layer contains a first host material and a first alkali metal compound. The first host material includes any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3, and preferably any one of the compounds represented by A1 to A12.

[0032] In a preferred technical solution of the present invention, the first electron transport layer is in a dual-material doping form, that is, an alkali metal compound is doped on the basis of the host material. This form is beneficial to further improving the light-emitting efficiency of the device and reducing the voltage.

[0033] Preferably, the first alkali metal compound includes any one or at least two combinations of Liq, LiF, CaO, Al2O3, and preferably Liq.

[0034] Preferably, the molar ratio m of the first alkali metal compound to the first host material is 10% to 100%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, etc., and preferably 67% to 100%.

[0035] The present invention preferably dopes 10% to 100% of an alkali metal compound in the first electron transport layer, especially 67% to 100%. Within this range, the device has higher light-emitting efficiency and lower voltage. Excessive doping amount will cause metal ions to enter the light-emitting layer and damage the light emission. Too low doping amount is not conducive to electron transport, and both will cause the device performance to decline.

[0036] Preferably, the second electron transport layer contains a second host material and a second alkali metal compound. The second host material includes any one or at least two combinations of the compounds represented by Formula II-1 and / or Formula II-2, and preferably any one of the compounds represented by B1 to B13.

[0037] In a preferred technical solution of the present invention, the second electron transport layer is in a dual-material doping form, that is, an alkali metal compound is doped on the basis of the host material. This form is beneficial to further improving the light-emitting efficiency of the device and reducing the voltage.

[0038] Preferably, the second alkali metal compound includes any one or at least two combinations of Liq, LiF, CaO, and Al2O3, preferably Liq.

[0039] Preferably, the molar ratio n of the second alkali metal compound to the second host material is 10% to 150%, such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 110%, 120%, 130%, 140%, etc., and more preferably 120% to 150%.

[0040] Preferably, 10% to 150% of an alkali metal compound, especially 120% to 150%, is doped in the second electron transport layer. Within this range, the device has higher luminous efficiency and lower voltage. Excessive or too low doping amount will lead to a decline in device performance.

[0041] When the first electron transport layer and / or the second electron transport layer meet the above preferred doping ratio, the luminous efficiency of the device is higher than 10 cd / A, and the driving voltage is not higher than 4.7 V.

[0042] Preferably, n - m ≥ 50%, such as 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, etc.

[0043] Preferably, n - m ≥ 50%, and m is 67% to 100%, and n is 120% to 150%.

[0044] Preferably, the thickness relationship between the first electron transport layer and the second electron transport layer is: 1 nm ≤ the first electron transport layer ≤ the second electron transport layer ≤ 30 nm.

[0045] Preferably, the thickness of the first electron transport layer is 10 to 13 nm, such as 10.5 nm, 11 nm, 11.5 nm, 12 nm, 12.5 nm, etc.

[0046] The present invention further preferably has the thickness of the first electron transport layer being 10 to 13 nm. Within this range, the device has higher luminous efficiency and lower voltage.

[0047] Preferably, the thickness of the second electron transport layer is 18 to 20 nm, such as 18.5 nm, 19 nm, 19.5 nm, etc.

[0048] The present invention further preferably has the thickness of the second electron transport layer being 18 to 20 nm. Within this range, the device has higher luminous efficiency and lower voltage.

[0049] Preferably, the organic functional layer further includes any one or at least two combinations of a hole transport layer, a hole injection layer, an electron injection layer, an electron blocking layer, or a hole blocking layer, preferably any one or at least two combinations of a hole transport layer, a hole injection layer, or an electron injection layer, and preferably a hole transport layer.

[0050] In the present invention, the first electron transport material and the second electron transport material used can be synthesized by methods in the prior art. Exemplary specific synthesis routes of Compound A1, A2 and Compounds B1, B4, B13 are given, and other compounds can be prepared by replacing reaction raw materials on the basis of this route;

[0051] Synthesis of Compound A1:

[0052]

[0053] Synthesis of Compound A2:

[0054]

[0055] Synthesis of Compound B1:

[0056]

[0057] Synthesis of Compound B4:

[0058]

[0059] Synthesis of Compound B13:

[0060]

[0061] Among them, B2Pin2 is bis(pinacolato)diboron, Pd(dppf)Cl2 is dichloride [1,1'-bis(diphenylphosphino)ferrocene] palladium, Pd(OAc)2 is palladium acetate, Sphos is 2-bis(cyclohexylphosphino)-2',6'-dimethoxybiphenyl, KOAc is potassium acetate, and Pd2(dba)3 is tris(dibenzylideneacetone)dipalladium.

[0062] In the organic electroluminescent device of the present invention, it is prepared by vacuum evaporation, and other methods can also be used, not limited to vacuum deposition. Only the device prepared by vacuum deposition is used for illustration in the present invention. The substrate is cleaned, post-baked, pre-treated, put into the cavity, and the hole transport layer, the light-emitting layer, the first electron transport layer, the second electron transport layer, and the cathode are successively vacuum deposited.

[0063] The substrate can be a rigid substrate or a flexible substrate. The rigid substrate includes a glass substrate, a Si substrate, etc. The flexible substrate includes a polyvinyl alcohol (PVA) film, a polyimide (PD) film, a polyester (PET) film, etc. The substrate of the present invention is preferably a rigid glass substrate.

[0064] For the anode, a conductive compound, alloy, metal with a relatively large work function, and a mixture of such materials can be preferably used. Inorganic materials can be used, including metal oxides such as indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), tin oxide (SnO), etc., or metals with a relatively high work function such as gold, silver, copper, aluminum, or a laminate formed by alternating metals with metals or non-metals, etc. The anode of the present invention is preferably ITO.

[0065] The material of the hole transport region can be selected from, but not limited to, phthalocyanine derivatives such as CuPc, conductive polymers, or polymers containing conductive dopants such as poly(phenylene vinylene), polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), polyaniline / poly(4-styrenesulfonate) (Pani / PSS), aromatic amine derivatives (such as the compounds shown as HT-1 to HT-34 below), or any combination thereof.

[0066]

[0067]

[0068]

[0069] In one aspect of the present invention, the light-emitting layer adopts the technology of fluorescent electroluminescence. The fluorescent host material of the light-emitting layer can be selected from, but not limited to, one or more combinations of BFH-1 to BFH-4 listed below.

[0070] The fluorescent dopant of the light-emitting layer is selected as BFD-1:

[0071]

[0072] In one aspect of the present invention, the light-emitting layer can also adopt the technology of phosphorescent electroluminescence. The host material of the light-emitting layer is selected from, but not limited to, one or more combinations of GPH-1 to GPH-4.

[0073]

[0074] The phosphorescent dopant of the light-emitting layer is selected as GPD-1:

[0075]

[0076] In the present invention, preferably, the first electron transport layer is in the form of a dual-material doping, and the host material is selected from any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3;

[0077] Preferably, the guest material of the first electron transport layer is the alkali metal compound Liq:

[0078]

[0079] In the present invention, the second electron transport layer is in the form of a dual-material doping, and the host material is selected from the compounds represented by Formula II-1 and / or Formula II-2:

[0080] Preferably, the guest material of the second electron transport layer is the alkali metal compound Liq:

[0081]

[0082] Compared with the prior art, the present invention has the following beneficial effects:

[0083] The present invention provides a novel organic electroluminescent device, which is provided with two electron transport layers, and specific electron transport materials are selected respectively. Through the cooperation of appropriate materials and device structures, it can not only promote the easier injection of cathode electrons into the light-emitting layer, significantly improve the carrier transport efficiency in the device, improve the light-emitting efficiency of the device, but also reduce the energy level barrier, and preferably reduce the problem of carrier accumulation at the interfaces between material layers, so that the voltage of the device is lower, the highest light-emitting efficiency can reach 11.03 cd / A, and the lowest driving voltage can be as low as 4.18 V. Description of the Drawings

[0084] Figure 1 is a schematic structural diagram of the organic electroluminescent device provided in Embodiment 1 of the present invention;

[0085] Wherein, 1 - anode, 2 - hole transport layer, 3 - light-emitting layer, 4 - first electron transport layer, 5 - second electron transport layer, 6 - cathode. Detailed Embodiments

[0086] To facilitate the understanding of the present invention, the following examples are listed. Those skilled in the art should understand that the examples are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0087] Preparation Example 1

[0088] Synthesis of Compound A1:

[0089]

[0090] The specific steps are as follows:

[0091] Preparation of Compound 1-1

[0092]

[0093] Add 60 g of Compound 1 into a single-necked flask, add 1200 mL of ethanol, stir at room temperature, add 51 g of m-chlorobenzaldehyde, react for about 2 h, continue to add 105 g of iodobenzene diacetate, a yellowish-brown solid precipitates, and stop the reaction. After filtration, about 60 g of yellowish-brown solid is obtained.

[0094] Preparation of Compound 1-2

[0095]

[0096] Add 40 g (1.0 eq) of Compound 1-1, 18.63 g of phenylboronic acid, 52.7 g of potassium carbonate and 2.79 g of Pd(dppf)2Cl2 into a three-necked flask, then add 400 mL of solvent tetrahydrofuran and 70 mL of water, heat to 80 °C, react for 5 h, then wash with ethanol and dry to obtain 40 g of Compound 1-2.

[0097] Preparation of Compound 1-3

[0098]

[0099] Add 20 g of Compound 1-2, 21.4 g of binaphthyl glycolate, 16.5 g of potassium acetate and 0.37 g of Pd(OAc)2, 1.2 g of Sphos into a three-necked flask, then add 200 mL of solvent dioxane, heat to 120 °C, react for 5 h and then filter to obtain 20 g of gray solid 1-3.

[0100] Preparation of Final Product A1

[0101]

[0102] Add 15 g of Compound 1-3, 13 g of 2-(3-bromophenyl)-4,6-diphenyl-1,3,5-triazine, 13.89 g of potassium carbonate, 150 mL of toluene, 20 mL of ethanol, 20 mL of water and 1.0 g of Pd(PPh3)4 into a single-necked flask, react for 4 h, and a white solid precipitates. After drying, 12 g of Compound A1 is obtained.

[0103] Characterization Results:

[0104] The M / S test value of A1 is: 629.2

[0105] The measured thermodynamic properties of A1: Tg: 116.9 °C; Tm: 251.76 °C; Td(1%): 426.7 °C.

[0106] Preparation Example 2

[0107] Synthesis of Compound A2:

[0108] The specific steps are the same as those in Preparation Example 1, except that m-chlorobenzaldehyde in the first step is changed to an equimolar amount of p-chlorobenzaldehyde.

[0109] Characterization results:

[0110] The M / S test value of A2 is: 629.2

[0111] The measured thermodynamic property of A2: Tm: 296.61 °C.

[0112] Preparation Example 3

[0113] Synthesis of Compound B1:

[0114]

[0115] The specific steps are as follows:

[0116] Preparation of Compound 3-1

[0117]

[0118] Add 15.0 g of Compound 2 and 6.9 g of phenylboronic acid to a three-necked flask, then dissolve 19.8 g of potassium carbonate in 200 mL of water and add it, add 1.0 L of tetrahydrofuran, and then add 0.35 g of [1,1'-bis(diphenylphosphino)ferrocene] dichloropalladium. React at 90 °C overnight, filter and dry to obtain about 14.7 g of crude product. (The crude product is directly used in the next step)

[0119] Preparation of Compound 3-2

[0120]

[0121] Add 14.7 g of Compound 3-1, 15.7 g of bis(pinacolato)diboron, 12.1 g of potassium acetate, 0.19 g of palladium acetate, 0.7 g of 2-(dicyclohexylphosphino)-2',6'-dimethoxybiphenyl (S-phos), and 300 mL of dioxane to a single-necked flask. React to obtain 17.2 g of Compound 3-2. (Yield: 93.00%)

[0122] Preparation of Compound B1

[0123]

[0124] 17.2 g of Compound 3-2 and 14.7 g of Compound 3 were added to a single-necked flask. Then, 15.9 g of potassium carbonate dissolved in water was added to the single-necked flask, along with 50 mL of ethanol and 250 mL of toluene. Subsequently, 0.44 g of tetrakis(triphenylphosphine)palladium was added. After the reaction, filtration yielded 10 g of a white solid. (Yield: 41.67%)

[0125] Characterization results:

[0126] The M / S test value of B1 was: 625.2

[0127] The measured thermodynamic properties of B1 were: Tg: 130.0 °C; Tm: 295.0 °C; Td(1%): 470.0 °C.

[0128] Preparation Example 4

[0129] Synthesis of Compound B4:

[0130]

[0131] The specific steps were the same as those in Preparation Example 3, except that Compound 3 was replaced with an equimolar amount of Compound 4.

[0132] Characterization results:

[0133] The M / S test value of B4 was: 626.2

[0134] The measured thermodynamic properties of B4 were: Tg: 173.13 °C; Tm: 345.93 °C; Td(1%): 449.4 °C.

[0135] Preparation Example 5

[0136] Synthesis of Compound B13:

[0137]

[0138] The specific steps were the same as those in Preparation Example 3, except that Compound 3 was replaced with an equimolar amount of Compound 5.

[0139] Characterization results:

[0140] The M / S test value of B13 was: 643.3

[0141] The measured thermodynamic properties of B13 were: Tg: 133.9 °C; Tm: 304.72 °C; Td(1%): 440.3 °C.

[0142] Example 1

[0143] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0144] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above anode layer film as the hole transport layer of the device at a deposition rate of 0.1 nm / s and a total deposition film thickness of 80 nm;

[0145] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the deposition rate of the host material is 0.1 nm / s, the deposition rate of the dye is 0.005 nm / s, and the total deposition film thickness is 20 nm.

[0146] Vacuum deposit the first electron transport layer material A1:10% Liq of the device on the light-emitting layer. The deposition rate of A1 is 0.1 nm / s and the total deposition film thickness is 10 nm;

[0147] Vacuum deposit the second electron transport layer material B1:10% Liq of the device on the first electron transport layer. The deposition rate of B1 is 0.1 nm / s and the total deposition film thickness is 20 nm;

[0148] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0149] Device structure:

[0150] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:10%Liq(10) / B1:10%Liq(20) / Mg:Ag(150), the numbers in parentheses represent the thickness in nm, and the percentages represent the molar doping ratio. For example, "BFH-1:5%BFD-1" means the molar ratio of BFD-1 to BFH-1 is 5%, "A1:10%Liq" means the molar ratio of Liq to A1 is 10%, and the same applies hereinafter and will not be elaborated one by one.

[0151] For the device structure of Example 1, see Figure 1 , which includes an anode 1, a hole transport layer 2, a light-emitting layer 3, a first electron transport layer 4, a second electron transport layer 5, and a cathode 6.

[0152] Example 2

[0153] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0154] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above anode layer film as the hole transport layer of the device, with a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0155] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total deposited film thickness is 20 nm.

[0156] Vacuum deposit the first electron transport layer material A1:10% Liq of the device on the light-emitting layer, with an A1 deposition rate of 0.1 nm / s and a total deposited film thickness of 10 nm;

[0157] Vacuum deposit the second electron transport layer material B1:30% Liq of the device on the first electron transport layer, with a B1 deposition rate of 0.1 nm / s and a total deposited film thickness of 20 nm;

[0158] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0159] Device structure:

[0160] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:10%Liq(10) / B1:30%Liq(20) / Mg:Ag(150), the numbers in parentheses represent the thickness, with the unit of nm.

[0161] Example 3

[0162] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0163] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3Pa, HT-1 was vacuum-evaporated on the above-mentioned anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s, and the total evaporation film thickness was 80 nm;

[0164] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the evaporation rate of the host material was 0.1 nm / s, the evaporation rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm.

[0165] The first electron transport layer material A1:10% Liq of the device was vacuum-evaporated on the light-emitting layer. The evaporation rate of A1 was 0.1 nm / s, and the total evaporation film thickness was 10 nm;

[0166] The second electron transport layer material B1:60% Liq of the device was vacuum-evaporated on the first electron transport layer. The evaporation rate of B1 was 0.1 nm / s, and the total evaporation film thickness was 20 nm;

[0167] A Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0168] Device structure:

[0169] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:10%Liq(10) / B1:60%Liq(20) / Mg:Ag(150), the values in parentheses represent the thickness, with the unit of nm.

[0170] Example 4

[0171] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0172] The glass substrate with the anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, HT-1 was vacuum-evaporated on the above-mentioned anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s, and the total evaporation film thickness was 80 nm;

[0173] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the evaporation rate of the host material was 0.1 nm / s, the evaporation rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm.

[0174] Above the light-emitting layer, the first electron transport layer material A1 of the device is vacuum-evaporated: 33% Liq, the evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm;

[0175] Above the first electron transport layer, the second electron transport layer material B1 of the device is vacuum-evaporated: 100% Liq, the evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm;

[0176] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0177] Device structure:

[0178] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:33%Liq(10) / B1:100%Liq(20) / Mg:Ag(150)

[0179] Example 5

[0180] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0181] The glass substrate with the anode is placed in a vacuum chamber, and the vacuum is pumped to 1×10 -5 ~9×10 -3 Pa, and HT-1 is vacuum-evaporated on the above anode layer film as the hole transport layer of the device, the evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm;

[0182] Above the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, and the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0183] Above the light-emitting layer, the first electron transport layer material A1 of the device is vacuum-evaporated: 50% Liq, the evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm;

[0184] Above the first electron transport layer, the second electron transport layer material B1 of the device is vacuum-evaporated: 100% Liq, the evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm;

[0185] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0186] Device structure:

[0187] ITO / HT-1(80) / BFH-1: 5%BFD-1(20) / A1: 50%Liq(10) / B1: 100%Liq(20) / Mg:Ag(150)

[0188] Example 6

[0189] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0190] The above-mentioned glass substrate with an anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, and HT-1 was vacuum-evaporated on the above-mentioned anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0191] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer included the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material was 0.1 nm / s, the rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm.

[0192] The first electron transport layer material A1: 50%Liq of the device was vacuum-evaporated on the light-emitting layer. The evaporation rate of A1 was 0.1 nm / s and the total evaporation film thickness was 10 nm;

[0193] The second electron transport layer material B1: 120%Liq of the device was vacuum-evaporated on the first electron transport layer. The evaporation rate of B1 was 0.1 nm / s and the total evaporation film thickness was 20 nm;

[0194] A Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0195] Device structure:

[0196] ITO / HT-1(80) / BFH-1: 5%BFD-1(20) / A1: 50%Liq(10) / B1: 120%Liq(20) / Mg:Ag(150)

[0197] Example 7

[0198] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0199] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device, with a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0200] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total deposited film thickness is 20 nm.

[0201] Vacuum deposit the first electron transport layer material A1:50% Liq of the device on the light-emitting layer, with an A1 deposition rate of 0.1 nm / s and a total deposited film thickness of 10 nm;

[0202] Vacuum deposit the second electron transport layer material B1:150% Liq of the device on the first electron transport layer, with a B1 deposition rate of 0.1 nm / s and a total deposited film thickness of 20 nm;

[0203] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0204] Device structure:

[0205] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:50% Liq(10) / B1:150% Liq(20) / Mg:Ag(150)

[0206] Example 8

[0207] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0208] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device, with a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0209] Above the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0210] Above the light-emitting layer, the first electron transport layer material A1: 67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm;

[0211] Above the first electron transport layer, the second electron transport layer material B1: 120% Liq of the device is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm;

[0212] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0213] Device structure:

[0214] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(10) / B1:120%Liq(20) / Mg:Ag(150)

[0215] Example 9

[0216] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone: ethanol, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface;

[0217] Place the glass substrate with the anode above in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum-evaporate HT-1 as the hole transport layer of the device on the above anode layer film. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm;

[0218] Above the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0219] Above the light-emitting layer, the first electron transport layer material A1: 67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm;

[0220] Above the first electron transport layer, the second electron transport layer material of the device, B1: 150% Liq, is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm.

[0221] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0222] Device structure:

[0223] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(10) / B1:150%Liq(20) / Mg:Ag(150)

[0224] Example 10

[0225] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone and ethanol, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam.

[0226] Place the above-mentioned glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa. On the above-mentioned anode layer film, HT-1 is vacuum-evaporated as the hole transport layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm.

[0227] Above the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0228] Above the light-emitting layer, the first electron transport layer material of the device, A1: 100% Liq, is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm.

[0229] Above the first electron transport layer, the second electron transport layer material of the device, B1: 150% Liq, is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm.

[0230] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0231] Device structure:

[0232] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:100%Liq(10) / B1:150%Liq(20) / Mg:Ag(150)

[0233] Example 11

[0234] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0235] The above glass substrate with the anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, and HT-1 was vacuum-evaporated on the above anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0236] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer included the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material was 0.1 nm / s, the rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm.

[0237] The first electron transport layer material A1:100%Liq of the device was vacuum-evaporated on the light-emitting layer. The evaporation rate of A1 was 0.1 nm / s and the total evaporation film thickness was 1 nm;

[0238] The second electron transport layer material B1:150%Liq of the device was vacuum-evaporated on the first electron transport layer. The evaporation rate of B1 was 0.1 nm / s and the total evaporation film thickness was 20 nm;

[0239] A Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0240] Device structure:

[0241] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:100%Liq(1) / B1:150%Liq(20) / Mg:Ag(150)

[0242] Example 12

[0243] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0244] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device, with a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0245] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total deposited film thickness is 20 nm.

[0246] Vacuum deposit the first electron transport layer material A1:100% Liq of the device on the light-emitting layer, with an A1 deposition rate of 0.1 nm / s and a total deposited film thickness of 5 nm;

[0247] Vacuum deposit the second electron transport layer material B1:150% Liq of the device on the first electron transport layer, with a B1 deposition rate of 0.1 nm / s and a total deposited film thickness of 20 nm;

[0248] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0249] Device structure:

[0250] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:100% Liq(5) / B1:150% Liq(20) / Mg:Ag(150)

[0251] Example 13

[0252] Ultrasonically treat the glass plate coated with the ITO transparent conductive layer in a commercial cleaning agent, rinse it in deionized water, ultrasonically remove oil in an acetone:ethanol mixed solvent, bake it in a clean environment until all moisture is completely removed, clean it with ultraviolet light and ozone, and bombard the surface with a low-energy cation beam;

[0253] Place the above-mentioned glass substrate with an anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device, with a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0254] The light-emitting layer of the device is vacuum-evaporated on top of the hole-transporting layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0255] On top of the light-emitting layer, the first electron-transporting layer material A1:67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 13 nm.

[0256] On top of the first electron-transporting layer, the second electron-transporting layer material B1:150% Liq of the device is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm.

[0257] On the electron-transporting layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0258] Device structure:

[0259] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67% Liq(13) / B1:150% Liq(20) / Mg:Ag(150)

[0260] Example 14

[0261] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam.

[0262] The glass substrate with the anode is placed in a vacuum chamber, and the vacuum is pumped to 1×10 -5 ~9×10 -3 Pa. On the above anode layer film, HT-1 is vacuum-evaporated as the hole-transporting layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm.

[0263] The light-emitting layer of the device is vacuum-evaporated on top of the hole-transporting layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0264] On top of the light-emitting layer, the first electron-transporting layer material A1:67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 15 nm.

[0265] On top of the first electron transport layer, the second electron transport layer material B1:150% Liq of the device is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm.

[0266] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0267] Device structure:

[0268] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67% Liq(15) / B1:150% Liq(20) / Mg:Ag(150)

[0269] Example 15

[0270] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment until all moisture is removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam.

[0271] Place the above glass substrate with the anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum-evaporate HT-1 on the above anode layer film as the hole transport layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm.

[0272] On top of the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0273] On top of the light-emitting layer, the first electron transport layer material A1:67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 18 nm.

[0274] On top of the first electron transport layer, the second electron transport layer material B1:150% Liq of the device is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 20 nm.

[0275] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0276] Device structure:

[0277] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(18) / B1:150%Liq(20) / Mg:Ag(150)

[0278] Example 16

[0279] The glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0280] The above glass substrate with an anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, and HT-1 was vacuum-evaporated on the above anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0281] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer included a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material was 0.1 nm / s, the rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm.

[0282] The first electron transport layer material A1:67%Liq of the device was vacuum-evaporated on the light-emitting layer. The evaporation rate of A1 was 0.1 nm / s and the total evaporation film thickness was 10 nm;

[0283] The second electron transport layer material B1:150%Liq of the device was vacuum-evaporated on the first electron transport layer. The evaporation rate of B1 was 0.1 nm / s and the total evaporation film thickness was 13 nm;

[0284] A Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0285] Device structure:

[0286] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(10) / B1:150%Liq(13) / Mg:Ag(150)

[0287] Example 17

[0288] The glass plate coated with an ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with a low-energy cation beam;

[0289] Place the above-mentioned glass substrate with an anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa. Vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device at a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0290] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the deposition rate of the host material is 0.1 nm / s, the deposition rate of the dye is 0.005 nm / s, and the total deposited film thickness is 20 nm.

[0291] Vacuum deposit the first electron transport layer material A1:67% Liq of the device on the light-emitting layer. The deposition rate of A1 is 0.1 nm / s and the total deposited film thickness is 10 nm;

[0292] Vacuum deposit the second electron transport layer material B1:150% Liq of the device on the first electron transport layer. The deposition rate of B1 is 0.1 nm / s and the total deposited film thickness is 15 nm;

[0293] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0294] Device structure:

[0295] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67% Liq(10) / B1:150% Liq(15) / Mg:Ag(150)

[0296] Example 18

[0297] Ultrasonically treat the glass plate coated with the ITO transparent conductive layer in a commercial cleaning agent, rinse it in deionized water, ultrasonically remove oil in an acetone:ethanol mixed solvent, bake it in a clean environment until all moisture is completely removed, clean it with ultraviolet light and ozone, and bombard the surface with a low-energy cation beam;

[0298] Place the above-mentioned glass substrate with an anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa. Vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device at a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0299] The light-emitting layer of the device is vacuum-evaporated on top of the hole transport layer. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0300] On top of the light-emitting layer, the first electron transport layer material A1: 67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm.

[0301] On top of the first electron transport layer, the second electron transport layer material B1: 150% Liq of the device is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 18 nm.

[0302] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0303] Device structure:

[0304] ITO / HT-1(80) / BFH-1: 5% BFD-1(20) / A1: 67% Liq(10) / B1: 150% Liq(18) / Mg:Ag(150)

[0305] Example 19

[0306] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam.

[0307] Place the glass substrate with the anode described above in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum-evaporate HT-1 on the above anode layer film as the hole transport layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm.

[0308] The light-emitting layer of the device is vacuum-evaporated on top of the hole transport layer. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0309] On top of the light-emitting layer, the first electron transport layer material A1: 67% Liq of the device is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm.

[0310] Above the first electron transport layer, the second electron transport layer material of the device, B1: 150% Liq, is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 25 nm.

[0311] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0312] Device structure:

[0313] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(10) / B1:150%Liq(25) / Mg:Ag(150)

[0314] Example 20

[0315] The glass plate coated with the ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in a mixed solvent of acetone:ethanol, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface.

[0316] Place the above glass substrate with the anode in a vacuum chamber, evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum-evaporate HT-1 on the above anode layer film as the hole transport layer of the device. The evaporation rate is 0.1 nm / s, and the total evaporation film thickness is 80 nm.

[0317] Above the hole transport layer, the light-emitting layer of the device is vacuum-evaporated. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the rate of the host material is 0.1 nm / s, the rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0318] Above the light-emitting layer, the first electron transport layer material of the device, A1: 67% Liq, is vacuum-evaporated. The evaporation rate of A1 is 0.1 nm / s, and the total evaporation film thickness is 10 nm.

[0319] Above the first electron transport layer, the second electron transport layer material of the device, B1: 150% Liq, is vacuum-evaporated. The evaporation rate of B1 is 0.1 nm / s, and the total evaporation film thickness is 30 nm.

[0320] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated as the cathode of the device.

[0321] Device structure:

[0322] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:67%Liq(10) / B1:150%Liq(30) / Mg:Ag(150)

[0323] Examples 21 to 25

[0324] The differences between Examples 21 to 25 and Example 1 are only in the electron transport material, the doping amount of the alkali metal compound, and the thickness of the electron transport layer. See Table 1 for details.

[0325] Comparative Example 1

[0326] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and bombarded with a low-energy cation beam on the surface;

[0327] The above glass substrate with the anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, and HT-1 was vacuum-evaporated on the above anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0328] The light-emitting layer of the device was vacuum-evaporated on the hole transport layer. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the evaporation rate of the host material is 0.1 nm / s, and the evaporation rate of the dye is 0.005 nm / s, and the total evaporation film thickness is 20 nm.

[0329] The electron transport layer material ET-2:Liq of the device was vacuum-evaporated on the light-emitting layer. The evaporation rates of ET-2 and Liq are 0.1 nm / s and 0.15 nm / s respectively, and the total evaporation film thickness is 30 nm;

[0330] A Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0331]

[0332] Device structure:

[0333] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / ET-2:150%Liq(30) / Mg:Ag(150)

[0334] Comparative Example 2

[0335] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0336] Place the above-mentioned glass substrate with an anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10 -3 Pa, and vacuum deposit HT-1 on the above-mentioned anode layer film as the hole transport layer of the device at a deposition rate of 0.1 nm / s and a total deposited film thickness of 80 nm;

[0337] Vacuum deposit the light-emitting layer of the device on the hole transport layer. The light-emitting layer includes a host material BFH-1 and a dye BFD-1. Using the method of co-evaporation from multiple sources, the deposition rate of the host material is 0.1 nm / s, the deposition rate of the dye is 0.005 nm / s, and the total deposited film thickness is 20 nm.

[0338] Vacuum deposit the material ET-1:Liq of the first electron transport layer of the device on the light-emitting layer. The deposition rates of both ET-1 and Liq are 0.1 nm / s, and the total deposited film thickness is 10 nm;

[0339] Vacuum deposit the material ET-2:Liq of the second electron transport layer of the device on the first electron transport layer. The deposition rates of ET-2 and Liq are 0.1 nm / s and 0.15 nm / s respectively, and the total deposited film thickness is 20 nm;

[0340] Vacuum deposit a Mg / Ag layer with a thickness of 150 nm on the electron transport layer (ETL) as the cathode of the device.

[0341]

[0342] Device structure:

[0343] ITO / HT-1(80) / BFH-1:5%BFD-1(20) / ET-1:100%Liq(10) / ET-2:150%Liq(20) / Mg:Ag(150)

[0344] Comparative Example 3

[0345] The glass plate coated with an ITO transparent conductive layer is ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture is completely removed, cleaned with ultraviolet light and ozone, and the surface is bombarded with a low-energy cation beam;

[0346] Place the above-mentioned glass substrate with an anode in a vacuum chamber and evacuate to 1×10 -5 ~9×10-3 At a pressure of Pa, HT-1 was vacuum-evaporated on the above-mentioned anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0347] On top of the hole transport layer, the light-emitting layer of the device was vacuum-evaporated. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the evaporation rate of the host material was 0.1 nm / s, the evaporation rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm;

[0348] On top of the light-emitting layer, the electron transport layer material B1:150% Liq of the device was vacuum-evaporated. The evaporation rate of B1 was 0.1 nm / s, the evaporation rate of Liq was 0.15 nm / s, and the total evaporation film thickness was 30 nm;

[0349] On the electron transport layer (ETL), a Mg / Ag layer with a thickness of 150 nm was vacuum-evaporated as the cathode of the device.

[0350] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / B1:150% Liq(30) / Mg:Ag(150)

[0351] Comparative Example 4

[0352] The glass plate coated with the ITO transparent conductive layer was ultrasonically treated in a commercial cleaning agent, rinsed in deionized water, ultrasonically degreased in an acetone:ethanol mixed solvent, baked in a clean environment until all moisture was completely removed, cleaned with ultraviolet light and ozone, and the surface was bombarded with low-energy cation beams;

[0353] The above-mentioned glass substrate with the anode was placed in a vacuum chamber, and the vacuum was pumped to 1×10 -5 ~9×10 -3 Pa, HT-1 was vacuum-evaporated on the above-mentioned anode layer film as the hole transport layer of the device at an evaporation rate of 0.1 nm / s and a total evaporation film thickness of 80 nm;

[0354] On top of the hole transport layer, the light-emitting layer of the device was vacuum-evaporated. The light-emitting layer includes the host material BFH-1 and the dye BFD-1. Using the method of co-evaporation from multiple sources, the evaporation rate of the host material was 0.1 nm / s, the evaporation rate of the dye was 0.005 nm / s, and the total evaporation film thickness was 20 nm;

[0355] On top of the light-emitting layer, the electron transport layer material A1:150% Liq of the device was vacuum-evaporated. The evaporation rate of A1 was 0.1 nm / s, the evaporation rate of Liq was 0.15 nm / s, and the total evaporation film thickness was 30 nm;

[0356] A Mg / Ag layer with a thickness of 150 nm is vacuum-evaporated on the electron transport layer (ETL) as the cathode of the device.

[0357] Device structure: ITO / HT-1(80) / BFH-1:5%BFD-1(20) / A1:150%Liq(30) / Mg:Ag(150)

[0358] Comparative Example 5

[0359] The difference from Example 7 is that compound A1 is replaced by compound ET-1.

[0360] Comparative Example 6

[0361] The difference from Example 7 is that compound B1 is replaced by compound ET-1.

[0362] Device testing method:

[0363] The following performance determinations are carried out on the organic electroluminescent devices prepared by the above process:

[0364] At the same brightness, the driving voltage and current efficiency of the organic electroluminescent devices prepared in the examples and comparative examples are measured using a PR 750 type optical radiometer and an ST-86LA type luminance meter (Beijing Normal University Optoelectronic Instrument Factory) of Photo Research Corporation and a Keithley 4200 test system. Specifically, the voltage is increased at a rate of 0.1 V per second, and the voltage when the brightness of the organic electroluminescent device reaches 1000 cd / m 2 is measured as the driving voltage, and the current density at this time is also measured; the ratio of brightness to current density is the current efficiency.

[0365] The test results are shown in Table 1.

[0366] Table 1

[0367]

[0368]

[0369] As can be seen from Table 1, the organic electroluminescent device provided by the present invention has a high luminous efficiency and a low driving voltage. The highest luminous efficiency can reach 11.03 cd / A, and the lowest driving voltage can be as low as 4.18 V.

[0370] Comparative Example 1 only contains one electron transport layer, and the electron transport material is ET-2. Compared with Example 7 with the same thickness and Liq doping amount, the driving voltage of Comparative Example 1 increases and the current efficiency decreases;

[0371] Comparative Example 2 contains two electron transport layers, but ET-1 and ET-2 are used as electron transport materials respectively. Compared with Example 10 having the same thickness and doping amount, the driving voltage increases and the current efficiency decreases;

[0372] Although electron transport materials A1 and B1 of the present invention are also used in Comparative Example 3 and Comparative Example 4, they only contain one electron transport layer. Compared with Example 7 having the same thickness and doping amount, the driving voltage increases and the current efficiency decreases;

[0373] The differences between Comparative Example 5 and Comparative Example 6 and Example 7 are only that A1 and B1 are replaced by ET-1 respectively. The results show that compared with Example 7, the driving voltage increases and the current efficiency decreases for both of them.

[0374] The comparison results of the above examples and comparative examples show that when the doping amount and thickness are the same or similar, setting two electron transport layers and selecting specific materials will all contribute to the final effect to a certain extent.

[0375] Lacking any one of the conditions will increase the voltage of the device and reduce the efficiency.

[0376] Comparing Examples 9, 11 to 15, it can be seen that when the thickness of the first electron transport layer is 10 - 13 nm (Examples 9 and 13), the voltage can be further reduced and the lifespan can be increased;

[0377] Comparing Examples 9, 16 to 20, it can be seen that when the thickness of the second electron transport layer is 18 - 20 nm (Examples 9 and 18), the voltage can be further reduced and the lifespan can be increased;

[0378] Comparing Examples 7, 9 to 10, it can be seen that when the molar ratio of Liq in the first electron transport layer is 67% - 100% (Examples 9 and 10), the voltage can be further reduced and the lifespan can be increased;

[0379] Comparing Examples 5 to 7, it can be seen that when the molar ratio of Liq in the second electron transport layer is 120 - 150% (Examples 6 and 7), the voltage can be further reduced and the lifespan can be increased;

[0380] When the thickness of the first electron transport layer is 10 - 13 nm and the molar ratio of Liq is 67% - 100%, and the thickness of the second electron transport layer is 18 - 20 nm and the molar ratio of Liq is 120 - 150%, the device performance is optimal.

[0381] The applicant declares that the detailed preparation process and product structure of the present invention are illustrated by the above embodiments, but the present invention is not limited to the above detailed preparation process and product structure, that is, it does not mean that the present invention must rely on the above detailed preparation process and product structure to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and disclosure scope of the present invention.

Claims

1. An organic electroluminescent device, characterized in that, The organic electroluminescent device includes an anode, a cathode, and a light-emitting layer and an organic functional layer disposed between the anode and the cathode; The organic functional layer includes a first electron transport layer and a second electron transport layer; The first electron transport layer contains any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2, or Formula I-3; The second electron transport layer contains any one or at least two combinations of the compounds represented by Formula II-1 and / or Formula II-2; Ring C represents a five- or six-membered aromatic or heteroaromatic ring fused to a benzene ring; Ar1 and Ar2 are each independently selected from C1-C 18 alkyl, C1-C 18 alkoxy, C3-C 30 cycloalkyl, C2-C 18 alkenyl, C2-C 18 alkynyl, halogen, cyano, substituted or unsubstituted C6-C 40 aryl, substituted or unsubstituted C3-C 30 any one of heteroaryl; R is selected from hydrogen, C1-C 18 alkyl, C1-C 18 alkoxy, C3-C 30 cycloalkyl, halogen, cyano, substituted or unsubstituted C6-C 40 aryl, substituted or unsubstituted C3-C 30 heteroaryl; When any of the substituted or unsubstituted C6-C 40 aryl, substituted or unsubstituted C3-C 30 heteroaryl has a substituent, the substituents are each independently selected from halogen, C1-C 10 alkyl, C3-C 10 cycloalkyl, C2-C 10 alkenyl, C1-C6 alkoxy or thioalkoxy group, cyano, nitro, amino, carboxyl, carbonyl, ester group, C6-C 30 monocyclic aromatic hydrocarbon or polycyclic aromatic hydrocarbon group, C3-C 30 any one of monocyclic heteroaromatic hydrocarbon or polycyclic heteroaromatic hydrocarbon groups.

2. The organic electroluminescent device according to claim 1, wherein Ring C represents a benzene ring, a naphthalene ring, a pyridine ring, a furan ring, a benzofuran ring, a thiophene ring, or a benzothiophene ring fused to a benzene ring.

3. The organic electroluminescent device according to claim 1, characterized in that, Ar1 and Ar2 are each independently selected from any one of the following substituted or unsubstituted groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, phenyl, naphthyl, anthracenyl, benzanthracenyl, phenanthryl, benzophenanthryl, pyrenyl, chrysenyl, perylenyl, fluoranthenyl, tetraphenyl, pentaphenyl, benzopyrenyl, biphenyl, azobenzene, terphenyl, triphenyl, tetraphenyl, fluorenyl, spirobifluorenyl, dihydrophenanthryl, dihydropyrenyl, tetrahydropyrenyl, cis- or trans-indeno[1,2-b]fluorene, trimeric indene, isomeric trimeric indene, spirotrimeric indene, spiroisomeric trimeric indene, furyl, benzofuryl, isobenzofuryl, dibenzofuryl, thienyl, benzothienyl, isobenzothienyl, dibenzothienyl, pyrrolyl, isoindolyl, carbazolyl, indolocarbazolyl, pyridyl, quinolinyl, isoquinolinyl, acridinyl, phenanthridinyl, benzo[5,6]quinolinyl, benzo[6,7]quinolinyl, benzo[7,8]quinolinyl, phenothiazinyl, phenazinyl, pyrazolyl, indazolyl, imidazolyl, benzimidazolyl, naphthimidazolyl, phenanthrimidazolyl, pyridinimidazolyl, pyrazinimidazolyl, quinoxalinimidazolyl, oxazolyl, benzoxazolyl, naphthoxazolyl, anthraoxazolyl, phenanthroxazolyl, 1,2-thiazolyl, 1,3-thiazolyl, benzothiazolyl, pyridazinyl, benzopyridazinyl, pyrimidinyl, benzopyrimidinyl, quinoxalinyl, 1,5-diazaanthracenyl, 2,7-diazapyrenyl, 2,3-diazapyrenyl, 1,6-diazapyrenyl, 1,8-diazapyrenyl, 4,5-diazapyrenyl, 4,5,9,10-tetraazaperylenyl, pyrazinyl, phenazinyl, phenothiazinyl, naphthyridinyl, azacarbazolyl, benzocarbazolyl, phenanthroline, 1,2,3-triazolyl, 1,2,4-triazolyl, benzotriazolyl, 1,2,3-oxadiazolyl, 1,2,4-oxadiazolyl, 1,2,5-oxadiazolyl, 1,2,3-thiadiazolyl, 1,2,4-thiadiazolyl, 1,2,5-thiadiazolyl, 1,3,4-thiadiazolyl, 1,3,5-triazinyl, 1,2,4-triazinyl, 1,2,3-triazinyl, tetrazolyl, 1,2,4,5-tetrazinyl, 1,2,3,4-tetrazinyl, 1,2,3,5-tetrazinyl, purinyl, pteridinyl, indolizinyl, benzothiadiazolyl.

4. The organic electroluminescent device according to claim 1, wherein The first electron transport layer contains any one or at least two combinations of the following compounds:

5. The organic electroluminescent device according to claim 1, characterized in that, The second electron transport layer contains any one or at least two combinations of the following compounds:

6. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The first electron transport layer and the second electron transport layer are located between the cathode and the light-emitting layer, and their positional relationship is: the first electron transport layer is away from the cathode, and the second electron transport layer is close to the cathode.

7. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The first electron transport layer contains a first host material and a first alkali metal compound, and the first host material includes any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3.

8. The organic electroluminescent device according to claim 7, characterized in that, The first alkali metal compound includes any one or at least two combinations of Liq, LiF, CaO, Al2O3.

9. The organic electroluminescent device according to claim 7, wherein The first alkali metal compound includes Liq.

10. The organic electroluminescent device according to claim 7, wherein The molar ratio m of the first alkali metal compound to the first host material is 10% to 100%.

11. The organic electroluminescent device according to claim 10, characterized in that, The molar ratio m of the first alkali metal compound to the first host material is 67% to 100%.

12. The organic electroluminescent device according to claim 1, wherein The second electron transport layer contains a second host material and a second alkali metal compound, and the second host material includes any one or at least two combinations of the compounds represented by Formula II-1 and / or Formula II-2.

13. The organic electroluminescent device according to claim 12, characterized in that, The second alkali metal compound includes any one or at least two combinations of Liq, LiF, CaO, Al2O3.

14. The organic electroluminescent device according to claim 12, characterized in that, The second alkali metal compound includes Liq.

15. The organic electroluminescent device according to claim 12, wherein The molar ratio n of the second alkali metal compound to the second host material is 10% to 150%.

16. The organic electroluminescent device according to claim 15, characterized in that, The molar ratio n of the second alkali metal compound to the second host material is 120% to 150%.

17. The organic electroluminescent device according to claim 15, characterized in that, The first electron transport layer contains a first host material and a first alkali metal compound, and the first host material includes any one or at least two combinations of the compounds represented by Formula I-1, Formula I-2 or Formula I-3; the molar ratio m of the first alkali metal compound to the first host material is 10% to 100%, and n - m ≥ 50%.

18. The organic electroluminescent device according to claim 17, wherein, n - m ≥ 50%, m is 67% to 100%, and n is 120% to 150%.

19. The organic electroluminescent device according to any one of claims 1 to 5, wherein The thickness relationship between the first electron transport layer and the second electron transport layer is: 1 nm ≤ the first electron transport layer ≤ the second electron transport layer ≤ 30 nm.

20. The organic electroluminescent device according to claim 19, wherein The thickness of the first electron transport layer is 10 - 13 nm.

21. The organic electroluminescent device according to claim 19, characterized in that, The thickness of the second electron transport layer is 18 - 20 nm.

22. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The organic functional layer further includes any one or at least two combinations of a hole transport layer, a hole injection layer, an electron injection layer, an electron blocking layer or a hole blocking layer.

23. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The organic functional layer further includes any one or at least two combinations of a hole transport layer, a hole injection layer or an electron injection layer.

24. The organic electroluminescent device according to any one of claims 1 to 5, characterized in that, The organic functional layer further includes a hole transport layer.

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