Organic light emitting diode, display device including same, and compound

Abstract

The invention relates to an organic light emitting diode and a display device including the same. The invention also relates to a compound which can be used in an organic light emitting diode.

Description

Technical Field

[0001] The present invention relates to an organic light emitting diode and a device comprising the same. The present invention also relates to a compound that can be used in the organic light emitting diode. Background Art

[0002] Organic semiconductor devices, such as organic light-emitting diodes (OLEDs), are self-luminous devices that offer wide viewing angles, excellent contrast, fast response, high brightness, excellent operating voltage characteristics, and excellent color reproducibility. A typical OLED comprises an anode, a hole transport layer (HTL), an emissive layer (EML), an electron transport layer (ETL), and a cathode, stacked sequentially on a substrate. The HTL, EML, and ETL are thin films formed from organic compounds.

[0003] When voltage is applied to the anode and cathode, holes injected from the anode move to the EML via the HTL, and electrons injected from the cathode move to the EML via the ETL. Holes and electrons recombine in the EML to produce excitons. When the excitons drop from an excited state to a ground state, light is emitted. The injection and flow of holes and electrons must be balanced to ensure that OLEDs with this structure have excellent efficiency and / or a long lifetime.

[0004] The performance of the organic light emitting diode may be affected by the characteristics of the organic semiconductor layer, among which the characteristics of the organic material of the organic semiconductor layer may be affected.

[0005] In particular, there is a need to develop an organic semiconductor layer that can improve electron mobility and simultaneously improve electrochemical stability, so that organic semiconductor devices such as organic light emitting diodes can be applied to large-scale flat panel displays.

[0006] Therefore, an object of the present invention is to provide an organic light emitting diode and a compound for preparing the same that overcomes the disadvantages of the prior art, in particular to provide a compound that is used in an organic light emitting diode comprising the same to help improve its performance, especially efficiency. Summary of the Invention

[0007] The object is achieved by an organic light emitting diode comprising an opaque substrate, an anode, a cathode, a light emitting layer and an electron transport layer stack;

[0008] in

[0009] - the electron transport layer stack is arranged between the light emitting layer and the cathode;

[0010] - the electron transport layer stack optionally comprises a first electron transport layer;

[0011] - the electron transport layer stack comprises a second electron transport layer;

[0012] - the second electron transport layer is arranged between the light-emitting layer and the cathode;

[0013] - The second electron transport layer comprises a compound of formula (II)

[0014] (Ar 2 ) m -(Z k -G) n (II)

[0015] -n is 2 or greater;

[0016] -m is 1 or 2;

[0017] -k is 0, 1, or 2;

[0018] -Ar 2 independently selected from substituted or unsubstituted C2 to C 42 Heteroaryl and substituted or unsubstituted C6 to C 60 aryl;

[0019] - Among them, if Ar 2 is substituted, then one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy;

[0020] -Ar 2 Each C6 to C 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen;

[0021] -Z is independently selected from substituted or unsubstituted C6 to C 30 Aryl and substituted or unsubstituted C2 to C 42 heteroaryl;

[0022] - wherein, if Z is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy;

[0023] - Each C6 to C on Z 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen;

[0024] -G comprises at least one 6-membered heteroaromatic ring, wherein the 6-membered heteroaromatic ring comprises one N atom;

[0025] - G is selected so that the dipole moment of the compound G-phenyl is ≥ 1D and ≤ 7D; and

[0026] - The first electron transport layer and the second electron transport layer do not contain electrical dopants.

[0027] The object is also achieved by a display device comprising the organic light emitting diode according to the invention.

[0028] The object is also achieved by a compound of formula (IV)

[0029]

[0030] in

[0031] R a independently selected from substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C3 to C 18 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D, phenyl and C1 to C12 alkyl;

[0032] Z is independently selected from a single bond and C6 to C 24 aromatic subunits;

[0033] G is independently selected from (IVa-1) to (IVa-3)

[0034]

[0035] For IVa-1, p is an integer from 0 to 4;

[0036] For IVa-2 and IVa-3, p is an integer from 0 to 6; and

[0037] R S Independently selected from D, C1 to C 12 Aryl, C1 to C 12 Alkyl and pyridyl, wherein each C1 to C 12 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

[0038] Second electron transport layer

[0039] The organic light emitting diode according to the present invention must include a second electron transport layer. The second electron transport layer does not contain an electrical dopant, such as an n-type dopant, especially a redox n-type dopant.

[0040] In this context, the term "free" does not exclude impurities. Impurities do not have a technical effect on the purpose achieved by the invention. Impurities are not intentionally added to the layer during processing.

[0041] The term "free of" compounds means that such compounds are not intentionally added to the layer during processing.

[0042] Electrical dopants, in particular n-type dopants, are understood to be compounds which, when embedded in an electron-transporting matrix, improve the electronic properties of the resulting organic material, in particular with regard to electron injection and / or electron conductivity, compared to the pure matrix under the same physical conditions.

[0043] In the context of the present invention, "embedded in the electron transport matrix" means homogeneously mixed with the electron transport matrix.

[0044] The electrical dopants referred to herein are especially selected from elemental metals, metal salts, metal complexes and organic groups.

[0045] In one embodiment, the electrical dopant is selected from alkali metal salts and alkali metal complexes; preferably selected from lithium salts and lithium organic complexes; more preferably selected from lithium halides and lithium organic chelates; even more preferably selected from lithium fluoride, lithium quinolate, lithium borate, lithium phenoxide, lithium pyridinolate or selected from lithium complexes with Schiff base ligands; most preferably,

[0046] - The lithium complex has the formula II, III or IV:

[0047]

[0048] in

[0049] A1 to A6 are identical or independently selected from CH, CR, N, O;

[0050] R are identical or independently selected from hydrogen, halogen, alkyl or aryl or heteroaryl having 1 to 20 carbon atoms; more preferably A1 to A6 are CH,

[0051] - the organic ligand based on the borate anion is tetrakis(1H-pyrazol-1-yl)borate anion,

[0052] -phenolate anion is 2-(pyridin-2-yl)phenolate anion, 2-(diphenylphosphoryl)phenolate anion, imidazophenolate anion, 2-(pyridin-2-yl)phenolate anion or 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenolate anion,

[0053] -pyridinol anion is 2-(diphenylphosphoryl)pyridin-3-ol anion,

[0054] -The lithium Schiff base has structure 100, 101, 102 or 103:

[0055]

[0056] According to one embodiment of the present invention, the electron transport layer of the present invention does not contain a lithium organic complex, or does not contain 8-hydroxyquinolate lithium (=LiQ).

[0057] According to one embodiment of the present invention, the electron transport layer does not contain metal, and the metal is preferably selected from alkali metals, alkaline earth metals, rare earth metals, and metals of the first transition period Ti, V, Cr and Mn, in particular selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sm, Eu, Tm, Yb; more preferably selected from Li, Na, K, Rb, Cs, Mg and Yb, even more preferably selected from Li, Na, Cs and Yb, most preferably selected from Li, Na and Yb.

[0058] The most practical criterion for the strength of an n-type dopant is its redox potential. There is no particular limitation on how negative the redox potential can be.

[0059] The reduction potential of electron transport substrates commonly used in organic semiconductors, when measured by cyclic voltammetry against a ferrocene / ferrocene cation reference redox couple, is generally in the range of about -0.8 V to about -3.1 V. For n-type dopants that can effectively n-type-dope such substrates, the practically applicable redox potential range is slightly wider, from about -0.5 V to about -3.3 V.

[0060] The measurement of redox potential is actually carried out on the corresponding redox couple consisting of the reduced form and the oxidized form of the same compound.

[0061] When the n-type dopant is an electrically neutral metal complex and / or an electrically neutral organic group, the measurement of its redox potential is actually carried out on a redox couple formed by the following substances:

[0062] (i) an electrically neutral metal complex and a cationic group thereof formed by abstracting an electron from the electrically neutral metal complex, or

[0063] (ii) an electrically neutral organic group and a cation thereof formed by abstracting an electron from the electrically neutral organic group.

[0064] Preferably, if the measurement is performed by cyclic voltammetry against a ferrocene / ferrocenium reference redox couple, then for the corresponding redox couple consisting of:

[0065] (i) an electrically neutral metal complex and a cationic group thereof formed by abstracting an electron from the electrically neutral metal complex, or

[0066] (ii) an electrically neutral organic group and a cation thereof formed by abstracting an electron from the electrically neutral organic group,

[0067] The redox potential of the electrically neutral metal complex and / or the redox potential of the electrically neutral organic group may have a value more negative than -0.5 V, preferably more negative than -1.2 V, more preferably more negative than -1.7 V, even more preferably more negative than -2.1 V, most preferably more negative than -2.5 V.

[0068] In a preferred embodiment, the redox potential of the n-type dopant is between about 0.5 V more positive and about 0.5 V more negative than the reduction potential of the selected electron transport matrix.

[0069] Suitable electrically neutral metal complexes as n-type dopants may be, for example, strongly reducing complexes of certain transition metals in a low oxidation state. Particularly strong n-type dopants may be selected, for example, from Cr(II), Mo(II) and / or W(II) guanidinium complexes, such as W2(hpp)4, as described in more detail in WO 2005 / 086251.

[0070] The electrically neutral organic group suitable as an n-type dopant can be, for example, an organic group generated from its stable dimer, oligomer or polymer by supplying additional energy, as described in more detail in EP 1837 926B1, WO 2007 / 107306 or WO 2007 / 107356. Elemental metal should be understood to be a metal in a pure metal state, a metal alloy state, or a free atom or metal cluster state. It should be understood that the metal deposited from a metallic phase, for example, from a pure bulk metal by vacuum thermal evaporation evaporates in its elemental form. It should be further understood that if the evaporated elemental metal is deposited together with a covalent matrix, the metal atoms and / or metal clusters are embedded in the covalent matrix. In other words, it should be understood that any metal-doped covalent material prepared by vacuum thermal evaporation contains a metal that is at least partially in its elemental form.

[0071] For consumer electronics applications, only metals containing stable nuclides or nuclides with very long half-lives for radioactive decay may be applicable. As an acceptable level of nuclear stability, the nuclear stability of natural potassium may be employed.

[0072] In one embodiment, the electrical dopant may be selected from an electropositive metal selected from alkali metals, alkaline earth metals, rare earth metals, and first transition period metals Ti, V, Cr, and Mn. Preferably, the n-type dopant may be selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sm, Eu, Tm, and Yb; more preferably, selected from Li, Na, K, Rb, Cs, Mg, and Yb; even more preferably, selected from Li, Na, Cs, and Yb; and most preferably, selected from Li, Na, and Yb.

[0073] The second electron transport layer can be arranged between the first electron transport layer and the electron injection layer. The second electron transport layer can be arranged in direct contact with the first electron transport layer. The second electron transport layer can be arranged in a "contact sandwich" between the first electron transport layer and the electron injection layer.

[0074] The second electron transport layer may have a thickness of <100 nm, optionally between 10 nm and 90 nm, optionally between 10 nm and 60 nm, optionally between 10 nm and 50 nm.

[0075] Compound of formula (II)

[0076] The second electron transport layer comprises a compound of formula (II)

[0077] (Ar 2 ) m -(Z k -G) n (II).

[0078] The second electron transport layer may be composed of a compound of formula (II). The second electron transport layer may include a compound of formula (II) and one or more other compounds, or may be composed of a compound of formula (II) and one or more other compounds, such as compound (III) as defined herein, provided that none of the other compounds is an electrical dopant. The second electron transport layer may include more than one compound of formula (II). The electron transport layer may be composed of a mixture of a compound of formula (II) and compound (III). Exemplary other electron transport matrix compounds that may be contained are disclosed below.

[0079] In the compounds of formula (II), the group "Z" is a group connected (if present, ie in the case of k>1) to the group Ar 2 and the spacer portion of G. For the group (Z k -G), each of the groups may independently contain a spacer group Z or may not independently contain a spacer group Z.

[0080] In formula (II), n is 2 or greater. In formula (II), n may be 2 to 4. In formula (II), n may be 2.

[0081] In formula (II), m is independently 1 or 2. In formula (II), m may be 1.

[0082] In formula (II), k is independently 0, 1 or 2. In formula (II), k may be independently 1 or 2.

[0083] Ar 2 Can be independently selected from: substituted or unsubstituted C2 to C 39 Heteroaryl and substituted or unsubstituted C6 to C 54 Aryl, optionally substituted or unsubstituted C2 to C 36 Heteroaryl and substituted or unsubstituted C6 to C 48 Aryl, optionally substituted or unsubstituted C3 to C 30 Heteroaryl and substituted or unsubstituted C6 to C 42 aryl, and optionally substituted or unsubstituted C3 to C 28 Heteroaryl and substituted or unsubstituted C6 to C 30 Aryl.

[0084] Ar 2 Can be independently selected from: substituted or unsubstituted C2 to C39 N-containing heteroaryl and substituted or unsubstituted C6 to C 54 Aryl, optionally substituted or unsubstituted C2 to C 36 N-containing heteroaryl and substituted or unsubstituted C6 to C 48 Aryl, optionally substituted or unsubstituted C3 to C 30 N-containing heteroaryl and substituted or unsubstituted C6 to C 42 aryl, and optionally substituted or unsubstituted C3 to C 28 N-containing heteroaryl and substituted or unsubstituted C6 to C 30 In this regard, each N-containing heteroaryl group may contain one or more N atoms as the only heteroatom(s).

[0085] Ar 2 It may contain at least two fused 5-membered rings or 6-membered rings.

[0086] Ar 2 They may be independently selected from: pyridyl, triazinyl, pyrimidinyl, pyrazinyl, quinoxalinyl; quinazolinyl, benzoquinazolinyl, benzimidazolyl, quinolinyl, benzoquinolinyl, benzoacridinyl, dibenzoacridinyl, fluoranthenyl, anthracenyl, naphthyl, terphenylidene, phenanthrolinyl and dinaphthofuranyl, and said groups may be substituted or unsubstituted.

[0087] If the respective groups are substituted, one or more substituents may be independently selected from: D, C6 to C 24 Aryl, C3 to C 21 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 Heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, wherein Ar 2 Each C6 to C 24 Aryl substituents and Ar 2 Each C3 to C 21 Heteroaryl substituents may be substituted with D, C1 to C4 alkyl or halogen.

[0088] If the respective groups are substituted, the substituent(s) may be independently selected from:

[0089]

[0090] wherein each substituent is at a * with Ar 2 combination.

[0091] Ar 2 It may be a substituted pyrazinyl, wherein one or more substituents may be independently selected from: D, C6 to C 24 Aryl, C3 to C 21 Heteroaryl and C1 to C6 alkyl, wherein Ar 2 Each C6 to C 24 Aryl substituents and Ar 2 Each C3 to C 21 Heteroaryl substituents may be substituted with D, C1 to C4 alkyl or halogen.

[0092] Ar 2 It may be a substituted pyrazinyl, wherein one or more substituents may be independently selected from: C6 to C 24 Aryl and C3 to C 21 Heteroaryl, wherein Ar 2 Each C6 to C 24 Aryl substituents and Ar 2 Each C3 to C 21 Heteroaryl substituents may be substituted with D, C1 to C4 alkyl or halogen.

[0093] Ar 2 It may be a substituted pyrazinyl, wherein one or more substituents may be independently selected from: C6 to C 24 Aryl and C3 to C 21 Heteroaryl.

[0094] Ar including all substituents 2 Can be independently selected from the following structures

[0095]

[0096] Two of them (Z k -G) are respectively connected with the corresponding Ar 2 combination.

[0097] Ar including all substituents 2 Can be independently selected from the following structures

[0098]

[0099] Two of them (Zk -G) are respectively connected with the corresponding Ar 2 combination.

[0100] Z can be independently selected from: substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C2 to C 21 Heteroaryl. Z can be independently selected from: substituted or unsubstituted C6 to C 18 Aryl and substituted or unsubstituted C2 to C 15 Heteroaryl. Z can be independently selected from: substituted or unsubstituted C6 to C 12 Aryl and substituted or unsubstituted C2 to C 11 If each of the groups is substituted, one or more substituents are independently selected from: D, C1 to C 12 Alkyl and phenyl.

[0101] Z can be independently selected from the following structures

[0102]

[0103] Each of the structures may be unsubstituted or substituted with one or more substituents selected from the group consisting of: D, C1 to C 12 Alkyl and phenyl.

[0104] Z can be independently selected from the following groups

[0105]

[0106] Where Z is respectively at * and Ar 2 Combined with G.

[0107] Z can be independently selected from the following groups

[0108]

[0109] Where Z is respectively at * and Ar 2 Combined with G.

[0110] G comprises at least one 6-membered heteroaromatic ring, wherein the 6-membered heteroaromatic ring comprises one N atom. The 6-membered heteroaromatic ring comprising one N atom may be: unsubstituted pyridine (G is pyridine), substituted pyridine (G comprises one or more other groups in addition to the pyridine ring, wherein the one or more other groups are each bound to the pyridine ring via a single bond), or may be part of a ring system of two or more fused rings, preferably part of a ring system of two or more fused (hetero)aromatic rings, most preferably part of a ring system of two fused (hetero)aromatic rings, for example, quinoline.

[0111] G may be selected from substituted or unsubstituted C5 to C6 containing at least one 6-membered heteroaromatic ring 42 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. G can be selected from substituted or unsubstituted C5 to C 35 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. G can be selected from substituted or unsubstituted C5 to C 29 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. G can be selected from substituted or unsubstituted C5 to C 23 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. G can be selected from substituted or unsubstituted C5 to C 17 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. G can be selected from substituted or unsubstituted C5 to C 15 Heteroaryl, wherein the 6-membered heteroaromatic ring contains one N atom. If each G is substituted, one or more substituents are independently selected from: D, phenyl, naphthyl, C1 to C 12 Alkyl and pyridyl.

[0112] G can be selected from

[0113]

[0114] Each of the structures may be unsubstituted or substituted by one or more substituents independently selected from the group consisting of D, phenyl, naphthyl, C1 to C 12 Alkyl and pyridyl.

[0115] G including all substituents can be selected from the following groups

[0116]

[0117]

[0118] Each G is combined with Z at *.

[0119] G including all substituents can be

[0120]

[0121] Where G combines with Z at *.

[0122] G is selected such that the dipole moment of the G-phenyl group of the compound is ≥ 1D and ≤ 7D.

[0123] G is selected so that the dipole moment calculated by the TURBOMOLE V6.5 program package using the hybrid functional B3LYP and Gaussian 6-31G* basis set of the compound G-phenyl is ≥1D and ≤7D. The unit of dipole moment "Debye (Debye)" is abbreviated as symbol "D". The inventors have found that if the compound of formula (II) includes two groups with specific polarity, i.e., groups with specific dipole moments within the above range or the following range, it is advantageous. It is also found that the following situation is still advantageous: the compound of formula (II) includes such polar groups in the structure of the compound of formula (II) with the geometric shape of the first polar group and the second polar group so that the total dipole moment of the compound of formula (II) is low, for example, when the compound is a symmetrical molecule comprising the same first polar group and the second polar group, the dipole moment can be 0 Debye. Therefore, the compound of formula (II) cannot be characterized by reference to the total dipole moment of the compound. Therefore, instead, reference is made to a simulation compound comprising a polar group "G" and a non-polar group "phenyl". In this regard, the dipole moment of a compound containing N atoms It is given by:

[0124]

[0125] where q i and Is the partial charge and position of atom i in the molecule. Dipole moment is determined by semi-empirical molecular orbital method. As implemented in program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135Karlsruhe, Germany), hybrid functional B3LYP and 6-31G* basis set are used to optimize the geometry of the molecular structure in the gas phase. If more than one conformation is feasible, the conformation with the lowest total energy is selected to determine the bond length of the molecule. In this respect, the whole G part includes all possible substituents that can be included.

[0126] G can be independently selected such that the dipole moment of compound G-phenyl is >1D, optionally ≥1.2D, and optionally ≥1.5D. G can be selected such that the dipole moment of compound G-phenyl is ≤7D, optionally ≤6D, optionally ≤5D, optionally ≤4D, optionally ≤3.6D. If more than one conformer of compound G-phenyl is possible, the average of the dipole moments of the conformers of G-phenyl is selected to be within this range. Conformational isomerism is a form of stereoisomerism in which isomers can be converted into each other only by rotation of a formally single bond.

[0127] By selecting G so that the dipole moment of the compound G-phenyl is within the above range, electron injection from an adjacent different electron injection layer (EIL) can be improved, and the voltage of the OLED device can be reduced and the cd / A efficiency of the OLED device can be increased.

[0128] The exemplary compound "G-phenyl" is listed in Table 1 below, wherein the moieties in the corresponding compounds are

[0129]

[0130] Instructions "G- Phenyl ” in the “phenyl” part.

[0131] Table 1:

[0132]

[0133]

[0134]

[0135]

[0136] The compound of formula (II) may have the following structure (IIa)

[0137]

[0138] Two R's a Can be different or the same. a The two Zs can be selected to be the same or different. The two Zs can be selected to be the same.

[0139] The two Gs can be different or the same. The two Gs can be the same.

[0140] R a Independently selected from: substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C3 to C 21 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D, phenyl and C1 to C 12 alkyl.

[0141] R a Can be independently selected from: substituted or unsubstituted C6 to C 18 Aryl and substituted or unsubstituted C3 to C 17 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D and C1 to C 12 alkyl.

[0142] R a Can be independently selected from: substituted or unsubstituted C6 to C 12 Aryl and substituted or unsubstituted C5 to C 11 Heteroaryl, where R a is substituted, then the one or more substituents are independently selected from the group consisting of: D, phenyl, and C1 to C4 alkyl.

[0143] R a Can be independently selected from

[0144]

[0145] wherein each group is at a *

[0146]

[0147] Z is independently selected from a single bond and C6 to C 24 Arylene. Z can be independently selected from a single bond and C6 to C 18 Arylene. Z can be independently selected from a single bond and C6 to C 12 Arylene. Z can be independently selected from a single bond and C6 to C 10 Aromatic subunit.

[0148] Z can be independently selected from

[0149]

[0150] Z can be independently selected from

[0151]

[0152] Where Z is at * and

[0153]

[0154] Combined with *G.

[0155] G is independently selected from (IIa-1) to (IIa-3)

[0156]

[0157] According to the present invention, in the formula showing the following combination,

[0158]

[0159] Group R S Binding can be to any suitable binding position, ie, to any carbon atom not bound to Z.

[0160] In the shown R SIn cases where the bonds span more than one ring, for example

[0161]

[0162] Group R S Binding may be to any suitable binding position on each ring across which the bond spans, ie, to any carbon atom not bound to Z.

[0163] Z may be bound to the ortho, meta or para position of the N atom of the pyridine ring in formula IIa-1, and the remaining positions may each have or not have a substituent R s .

[0164] Z may be bound to the ortho or meta position of the N atom of the pyridine ring in formula IIa-2, or to the carbon atom of any ring condensed with the pyridine ring, and the remaining positions may each have or not have a substituent R s .

[0165] Z may be combined at the meta or para position relative to the N atom of the pyridine ring in formula IIa-3, or at the carbon atom of any ring condensed with the pyridine ring, and the remaining positions may each have or not have a substituent R s .

[0166] R S Independently selected from D, C1 to C 12 Aryl, C1 to C 12 Alkyl and pyridyl, wherein each of the C1 to C 12 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

[0167] R S Can be independently selected from D, C1 to C 10 aryl, C1 to C4 alkyl and pyridyl, wherein each of the C1 to C 10 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

[0168] R S Can be independently selected from D, phenyl, naphthyl, C1 to C 12 Alkyl and pyridyl.

[0169] R S and may be independently selected from D, phenyl, naphthyl, C1 to C4 alkyl, and pyridyl.

[0170] R s Can be independently selected from

[0171] *CH3

[0172] wherein each R sCombine with Z at *.

[0173] For IIa-1, p is an integer from 0 to 4. For IIa-1, p may be an integer from 0 to 2. For IIa-1, p may be an integer from 0 to 1.

[0174] For IIa-2 and IIa-3, p is an integer from 0 to 6. For IIa-2 and IIa-3, p may be an integer from 0 to 4. For IIa-2 and IIa-3, p may be an integer from 0 to 2. For IIa-2 and IIa-3, p may be an integer from 0 to 1.

[0175] The compound of formula (II) can be selected from B-1 to B-44

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182] The compound of formula (II) can be selected from B-1 to B-4

[0183]

[0184] Compound (III)

[0185] The second electron transport layer can also include compound (III), wherein compound (III) includes 8 to 13 aromatic or heteroaromatic rings, optionally 8 to 11 aromatic or heteroaromatic rings, optionally 9 to 11 aromatic or heteroaromatic rings, optionally 9 aromatic or heteroaromatic rings, wherein one or more of the aromatic or heteroaromatic rings can be replaced by C1 to C4 alkyl.In this respect, aromatic ring, correspondingly heteroaromatic ring is a single aromatic ring, for example 6 yuan of aromatic rings such as phenyl, 6 yuan of heteroaromatic rings such as pyridyl, 5 yuan of heteroaromatic rings such as pyrrolyl etc.In the system of condensed (hetero) aromatic rings, each ring is considered to be a single ring in this respect.For example, naphthalene includes two aromatic rings.

[0186] Compound (III) may comprise at least one heteroaromatic ring, optionally 1 to 5 heteroaromatic rings, optionally 1 to 4 heteroaromatic rings, optionally 1 to 3 heteroaromatic rings, optionally 1 or 2 heteroaromatic rings.

[0187] The aromatic or heteroaromatic ring of compound (III) may be a 6-membered ring.

[0188] The heteroaromatic rings of compound (III) may be N-containing heteroaromatic rings, optionally all heteroaromatic rings are N-containing heteroaromatic rings, optionally all heteroaromatic rings contain N as the only type of heteroatom.

[0189] Compound (III) may contain at least one 6-membered heteroaromatic ring containing 1 to 3 N atoms in each heteroaromatic ring, and compound (III) optionally contains 1 to 3 6-membered heteroaromatic rings containing 1 to 3 N atoms in each heteroaromatic ring.

[0190] The at least one 6-membered heteroaromatic ring contained in compound (III) may be azine, triazine, diazine or pyrazine.

[0191] If compound (III) contains two or more heteroaromatic rings, the heteroaromatic rings may be separated from one another by at least one aromatic ring containing no heteroatoms.

[0192] In one embodiment, the heteroatom in the heteroaromatic ring of compound (III) is bonded to the molecular structure of compound (III) via at least one double bond.

[0193] The molecular dipole moment of compound (III) was calculated using the hybrid functional B3LYP and Gaussian6-31G* basis set using the TURBOMOLE V6.5 program package. The molecular dipole moment can be ≥0D and ≤4D; or ≥0.1D and ≤3.9D; or ≥0.2D and ≤3.7D; or ≥0.3D and ≤3.5D.

[0194] By selecting compound (III) according to these embodiments, the electron mobility of the second electron transport layer can be further improved, the voltage of the OLED device can be reduced, and the cd / A efficiency of the OLED device can be increased.

[0195] In one embodiment, compound (III) is not a compound of formula (II). The compound of formula (III) may be selected from compounds C-1 to C-6 in Table 2 below.

[0196] Table 2:

[0197]

[0198]

[0199] In the case where the second electron transport layer comprises both the compound of formula (II) and compound (III), the weight ratio of formula (II) to compound (III) can be 1:99 to 99:1, or 10:90 to 60:40, or 20:80 to 50:50, or 25:75 to 40:60, or about 30:70.

[0200] In one embodiment, the LUMO energy level of the compound of formula (III) is calculated by the TURBOMOLE V6.5 program package using the hybrid functional B3LYP and the Gaussian6-31G* basis set, with the vacuum level as the absolute scale, and is in the range of -2.00 eV to -1.70 eV, preferably -1.95 eV to -1.80 eV.

[0201] In one embodiment, compound (III) comprises a nitrogen-containing six-membered ring.

[0202] In another embodiment, compound (III) comprises two nitrogen-containing six-membered rings.

[0203] In one embodiment, the compound of formula (I) is not the compound of formula (II). In another embodiment, the compound of formula (II) is not compound (III). In another embodiment, the compound of formula (I) is not compound (III). In another embodiment of the present invention, all three compounds, i.e., the compound of formula (I), the compound of formula (II), and compound (III) are different from each other because they have different molecular structural formulas.

[0204] First electron transport layer

[0205] The organic electron transport layer stack optionally includes a first electron transport layer, that is, it may include a first electron transport layer or may not include a first electron transport layer. In the case where the organic electron transport layer stack does not include a first electron transport layer, the stack may consist solely of a second electron transport layer. The first electron transport layer may be referred to as a hole blocking layer, auxiliary electron transport layer, or α-ETL.

[0206] The first electron transport layer may be disposed between the second electron transport layer and the light emitting layer. The first electron transport layer may be disposed between the second electron transport layer and the light emitting layer and directly contact the second electron transport layer and the light emitting layer.

[0207] The first electron transport layer may comprise a compound of formula (I)

[0208] (Ar 1 -A c ) a -X b (I)

[0209] -a is 1 or 2;

[0210] -b is 1 or 2;

[0211] -c is 0 or 1;

[0212] -Ar 1 independently selected from substituted or unsubstituted C6 to C 60 Aryl or substituted or unsubstituted C2 to C 42 heteroaryl;

[0213] - Among them, if Ar 1 is substituted, then one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy;

[0214] -Ar 1 Each C6 to C 12 Aryl substituents and Ar 1 Each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen;

[0215] -A is independently selected from substituted or unsubstituted C6 to C 30 aryl;

[0216] - wherein, if A is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy;

[0217] - Each C6 to C on A 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen;

[0218] -X is independently selected from substituted or unsubstituted C2 to C 42 Heteroaryl and substituted or unsubstituted C6 to C 60 aryl;

[0219] -wherein, if X is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy;

[0220] - where each C6 to C on X 12 The aryl substituent and each C3 to C 11The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; and

[0221] - The dipole moment of the compound of formula (I) is ≥0D and ≤4D.

[0222] The first electron transport layer may be composed of a compound of formula (I). Alternatively, the first electron transport layer may be composed of a mixture of a compound of formula (I) and one or more other compounds. The first electron transport layer may contain more than one compound of formula (I). In particular, the first electron transport layer may be composed of a mixture of a compound of formula (I) and other compounds known in the art as electron transport matrix compounds. Exemplary other electron transport matrix compounds that may be contained are disclosed below. Preferably, the first electron transport layer does not contain an electrical dopant, such as an n-type dopant, especially a redox n-type dopant.

[0223] In this context, the term "free" does not exclude impurities. Impurities do not have a technical effect on the purpose achieved by the invention. Impurities are not intentionally added to the layer during processing.

[0224] The term "free of" compounds means that such compounds are not intentionally added to the layer during processing.

[0225] In the compounds of formula (I), the group "A" is linked (if present, ie in the case of c>1) to the group Ar 1 and the spacer moiety of X. In the case where the compound of formula (I) contains more than one group (Ar 1 -A c ), the group may independently contain a spacer A or may not independently contain a spacer A.

[0226] In the compounds of formula (I), a and b are independently 1 or 2. Alternatively, a and b may both be 1.

[0227] In the compounds of formula (I), c is independently 0 or 1.

[0228] Ar 1 Independently selected from C6 to C 60 Aryl or C2 to C 42 Heteroaryl, or C6 to C 54 Aryl or C2 to C 39 Heteroaryl, or C6 to C 48 Aryl or C2 to C 36 Heteroaryl, or C6 to C 42 Aryl or C2 to C 36 Heteroaryl, or C6 to C 36 Aryl or C2 to C 30 Heteroaryl, or C6 to C 30 Aryl or C2 to C24 Heteroaryl.

[0229] Ar 1 Can be independently C6 to C 54 Aryl, optionally C6 to C 48 Aryl, optionally C6 to C 42 Aryl, optionally C6 to C 36 Aryl, optionally C6 to C 30 Aryl, optionally C6 to C 24 Aryl.

[0230] Ar 1 Can be independently C2 to C 42 Heteroaryl, optionally C2 to C 40 Heteroaryl, optionally C2 to C 36 Heteroaryl, optionally C2 to C 30 Heteroaryl, optionally C2 to C 24 Heteroaryl.

[0231] In one embodiment, Ar 1 Different from X.

[0232] Ar 1 The system may comprise two or more fused aromatic rings, preferably three or more fused aromatic rings.

[0233] Ar 1 Can contain at least one sp 3- Hybridized carbon atoms.

[0234] Ar 1 May contain at least one carbon-carbon sp not incorporated into the aromatic ring structure 2 In one embodiment, wherein Ar 1 Independently selected from unsubstituted C2 to C 42 Heteroaryl, the heteroatom is bonded to Ar by a single bond 1 in the molecular structure.

[0235] Ar 1 may be independently selected from: phenyl, naphthyl, anthracenyl, fluoranthenyl, xanthene, spiro-xanthene, fluorenyl, spiro-fluorenyl, triphenylsilyl, tetraphenylsilyl, dibenzofuranyl, di-dibenzofuranyl, pyrimidinyl, pyrazinyl, aryl-alkenyl or a group having formula (Ia)

[0236]

[0237] in

[0238] - the asterisk symbol "*" indicates the binding position of the group of formula (Ia) to A; and

[0239] -R 1 to R 5 Independently selected from H, C6 to C 12 Aryl and C3 to C 10 heteroaryl or C4 to C5 heteroaryl.

[0240] Ar 1 May be independently selected from: phenyl, anthracenyl, fluorenyl or a group having formula (Ia)

[0241]

[0242] where R 1 to R 5 Independently selected from: H and phenyl.

[0243] Ar 1 It may be a group of formula (Ia)

[0244]

[0245] And R 1 to R 5 At least two of them are not H.

[0246] In the group of formula (Ia), R 1 to R 5 At least two of the R groups other than H may be in adjacent positions to each other. 1 to R 5 At least one of the radicals other than H may be in an ortho position to the * position. In this respect, if two radicals are respectively bonded to adjacent carbon atoms of the benzene ring in formula (Ia), the two radicals are in an ortho position to each other.

[0247] Ar 1 Can be independently selected from one of the following groups

[0248]

[0249] The asterisk symbol "*" represents the binding position for binding to A.

[0250] In Ar 1 Where substituted, each substituent may be independently selected from the group consisting of phenyl, naphthyl, biphenyl, pyridyl, methylpyridyl, dimethylpyridyl, dibenzofuranyl, dibenzothiophenyl and benzothiophenyl.

[0251] A can be independently selected from: substituted or unsubstituted C6 to C 30 Aryl, or C6 to C 24 Aryl, or C6 to C 18 Aryl.

[0252] A may be independently selected from the group consisting of a phenylene group, a naphthalene group, a biphenylene group, and a terphenylene group, each of which may be substituted or unsubstituted.

[0253] A can be independently selected from one or a combination of the following groups,

[0254]

[0255] Among them, it is used with Ar 1 The binding position of X can be freely selected, preferably

[0256]

[0257] The asterisk symbol "*" indicates the binding position.

[0258] In the case where A is substituted, each substituent on A may be independently selected from phenyl and C1 to C4 alkyl.

[0259] X can be independently selected from: C2 to C 39 Heteroaryl and C6 to C 54 Aryl, optionally C2 to C 36 Heteroaryl and C6 to C 48 Aryl, optionally C3 to C 30 Heteroaryl and C6 to C 42 Aryl, optionally C3 to C 27 Heteroaryl and C6 to C 36 Aryl, optionally C3 to C 24 Heteroaryl and C6 to C 30 Aryl, and optionally C3 to C 21 Heteroaryl and C6 to C 24 Aryl, wherein the individual groups mentioned may be substituted or unsubstituted.

[0260] X can be independently selected from: C2 to C 39 Containing N heteroaryl, C2 to C 39 Containing O heteroaryl and C6 to C 54 Aryl, optionally C2 to C 36 Containing N heteroaryl, C2 to C 36 Containing O heteroaryl and C6 to C 48 Aryl, optionally C3 to C 30 Containing N heteroaryl, C3 to C 30 Containing O heteroaryl and C6 to C 42 Aryl, optionally C3 to C 27 Containing N heteroaryl, C3 to C 27 Containing O heteroaryl and C6 to C 36 Aryl, optionally C3 to C 24 Containing N heteroaryl, C3 to C 24Containing O heteroaryl and C6 to C 30 Aryl, and optionally C3 to C 21 Containing N heteroaryl, C3 to C 21 Containing O heteroaryl and C6 to C 24 Aryl, wherein the individual groups mentioned may be substituted or unsubstituted.

[0261] X can be independently selected from: C2 to C 39 Containing N heteroaryl and C6 to C 54 Aryl, optionally C2 to C 36 Containing N heteroaryl and C6 to C 48 Aryl, optionally C3 to C 30 Containing N heteroaryl and C6 to C 42 Aryl, optionally C3 to C 27 Containing N heteroaryl and C6 to C 36 Aryl, optionally C3 to C 24 Containing N heteroaryl and C6 to C 30 Aryl, and optionally C3 to C 21 Containing N heteroaryl and C6 to C 24 Aryl, wherein each of the groups may be substituted or unsubstituted. In this regard, each N-containing heteroaryl group may contain one or more N atoms as the only heteroatom(s).

[0262] X may be independently selected from the group consisting of triazinyl, pyrimidinyl, pyrazinyl, quinazolinyl, benzoquinazolinyl, benzimidazolyl, quinolinyl, benzoquinolinyl, benzoacridinyl, dibenzoacridinyl, fluoranthenyl, anthracenyl, naphthyl, terphenylidene, phenanthrolinyl and dinaphthofuranyl, each of which may be substituted or unsubstituted.

[0263] X may be independently selected from the group consisting of triazinyl, pyrimidinyl, pyrazinyl, quinazolinyl, benzoquinazolinyl, benzoacridinyl, dibenzoacridinyl, fluoranthenyl, anthracenyl, naphthyl, terphenylidene, phenanthrolinyl and dinaphthofuranyl, each of which may be substituted or unsubstituted.

[0264] X may be independently selected from the group consisting of triazinyl, pyrimidinyl, pyrazinyl, quinazolinyl, benzoquinazolinyl, benzoacridinyl, dibenzoacridinyl, and fluoranthenyl, and these groups may be substituted or unsubstituted.

[0265] X can be independently selected from one of the following groups

[0266]

[0267] The asterisk symbol "*" represents the binding position of the group to A, and each of the groups may be substituted or unsubstituted.

[0268] In the case where X is substituted, each substituent on X may be independently selected from: phenyl, naphthyl, and biphenyl. In the case where X is substituted, each substituent on X may be independently selected from: phenyl and biphenyl.

[0269] In the case where X is substituted, each substituted X group (including all substituents) may be

[0270]

[0271] The asterisk symbol "*" represents the binding position of the group to A.

[0272] The compound of formula (I) may not contain a P=O moiety. The compound of formula (I) may not contain a P(=O)aryl2. The compound of formula (I) may not contain a P(=O)alkyl2. The compound of formula (I) may not contain a P(=O)Ph2. The compound of formula (I) may not contain a P(=O)(CH3)2. The compound of formula (I) may not contain R'P(=O)R", wherein R' and R" are linked to each other to form a ring, i.e., it does not contain a cyclo-phosphine oxide. The compound of formula (I) may not contain R'P(=O)R", wherein R' and R" are linked to each other to form a 7-membered ring.

[0273] The compound of formula (I) may not contain two P=O moieties. The compound of formula (I) may not contain two P(=O)aryl2. The compound of formula (I) may not contain two P(=O)alkyl2. The compound of formula (I) may not contain two P(=O)Ph2. The compound of formula (I) may not contain two P(=O)(CH3)2. The compound of formula (I) may not contain CN.

[0274] One or more of the following formulae may be excluded from the scope of compounds of formula (I)

[0275]

[0276]

[0277] The compound of formula (I) can comprise 6 to 14 aromatic or heteroaromatic rings, optionally 7 to 13 aromatic or heteroaromatic rings, optionally 7 to 12 aromatic or heteroaromatic rings, optionally 9 to 11 aromatic or heteroaromatic rings.In this respect, aromatic ring, correspondingly heteroaromatic ring are single aromatic rings, for example 6 yuan of aromatic rings such as phenyl, 6 yuan of heteroaromatic rings such as pyridyl, 5 yuan of heteroaromatic rings such as pyrrolyl etc.In the system of condensed (hetero) aromatic ring, each ring is considered to single ring in this respect.For example, naphthalene comprises two aromatic rings.

[0278] The molecular dipole moment is calculated by TURBOMOLE V6.5 program package using hybrid functional B3LYP and Gaussian 6-31G* basis set, and the molecular dipole moment of the compound of formula (I) can be ≥0D and ≤4D; or ≥0D and ≤3.5D; or ≥0D and ≤3.0D; or ≥0D and ≤2.5D; or ≥0D and ≤2.0D. In this regard, the dipole moment of a molecule containing N atoms is It is given by:

[0279]

[0280] where q i and is the partial charge and position of atom i in the molecule. The dipole moment is determined by the semi-empirical molecular orbital method. As implemented in the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany), the geometry of the molecular structure is optimized in the gas phase using the hybrid functional B3LYP with the 6-31G* basis set. If more than one conformation is feasible, the conformation with the lowest total energy is selected to determine the bond length of the molecule.

[0281] In one embodiment, the LUMO energy level of the compound of formula (I) is calculated by the TURBOMOLE V6.5 program package using the hybrid functional B3LYP and Gaussian6-31G* basis set, taking the vacuum level as an absolute scale of zero, and is in the range of -1.90 eV to -1.60 eV, preferably -1.87 eV to -1.65 eV, preferably -1.85 eV to -1.65 eV.

[0282] The compound of formula (I) may be selected from compounds A-1 to A-29 in Table 3 below.

[0283] Table 3:

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291] In one embodiment, the LUMO energy level of the compound of formula (I) is calculated by the TURBOMOLE V6.5 program package using the hybrid functional B3LYP and the Gaussian6-31G* basis set, with the vacuum level as the absolute scale of zero, in the range of -1.90 eV to -1.60 eV, preferably -1.85 eV to -1.65 eV.

[0292] The first electron transport layer may be arranged between the light-emitting layer and the second electron transport layer. The first electron transport layer may be arranged in direct contact with the light-emitting layer. The first electron transport layer may be arranged in a "contact sandwich" manner between the light-emitting layer and the second electron transport layer.

[0293] The first electron transport layer may have a thickness of <50 nm, optionally between 1 nm and 30 nm, optionally between 1 nm and 10 nm, optionally between 1 nm and 5 nm.

[0294] organic light-emitting diodes

[0295] The organic light-emitting diode may further include an electron injection layer, wherein the electron injection layer is disposed between the electron layer stack and the cathode. The electron injection layer may be in direct contact with the electron transport layer stack. The electron injection layer may be in direct contact with the second electron transport layer. The electron injection layer may be in direct contact with the cathode. The electron injection layer may be sandwiched between the second electron transport layer and the cathode in a contacting manner.

[0296] The electron injection layer may not contain the compound of formula (I). The electron injection layer may not contain the compound of formula (II). The electron injection layer may not contain the compound of formula (III). The electron injection layer may not contain any one of the compounds of formula (I) and formula (II). The electron injection layer may not contain any one of the compounds of formula (I), formula (II) and formula (III).

[0297] The electron injection layer may include a first electron injection sublayer and a second electron injection sublayer, wherein the first electron injection sublayer and the second electron injection sublayer are in direct contact with each other.

[0298] The first electron injection sublayer may be in direct contact with the electron transport layer, and the first electron injection sublayer may comprise a metal salt or a metal complex, preferably a lithium salt or a lithium organic complex; more preferably a compound selected from lithium halides and lithium organic chelates; even more preferably selected from lithium fluoride, lithium quinoline, lithium borate, lithium phenoxide, lithium pyridinolate or a lithium complex with a Schiff base ligand; most preferably,

[0299] - The lithium complex has the formula II, III or IV:

[0300]

[0301] in

[0302] A1 to A6 are identical or independently selected from CH, CR, N, O;

[0303] R are identical or independently selected from hydrogen, halogen, alkyl or aryl or heteroaryl having 1 to 20 carbon atoms; more preferably A1 to A6 are CH,

[0304] - the organic ligand based on the borate anion is tetrakis(1H-pyrazol-1-yl)borate anion,

[0305] -phenolate anion is 2-(pyridin-2-yl)phenolate anion, 2-(diphenylphosphoryl)phenolate anion, imidazophenolate anion, 2-(pyridin-2-yl)phenolate anion or 2-(1-phenyl-1H-benzo[d]imidazol-2-yl)phenolate anion,

[0306] -pyridinol anion is 2-(diphenylphosphoryl)pyridin-3-ol anion,

[0307] -The lithium Schiff base has structure 100, 101, 102 or 103:

[0308]

[0309] Preferably, the first electron injection sublayer comprises 8-hydroxyquinolate lithium (=LiQ).

[0310] The second electron injection sublayer comprises a metal, which is preferably selected from alkali metals, alkaline earth metals and rare earth metals, preferably the metal can be selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Sm, Eu, Tm, Yb; more preferably selected from Li, Na, K, Rb, Cs, Mg and Yb, even more preferably selected from Li, Na, Cs and Yb, most preferably selected from Li, Na and Yb, most preferably Yb.

[0311] The second electron injection sublayer may be in direct contact with the cathode.

[0312] The organic light-emitting diode may further include an n-type charge generation layer, wherein the n-type charge generation layer is disposed between the electron transport layer stack and the cathode. The n-type charge generation layer may be in direct contact with the electron transport layer stack. The n-type charge generation layer may be in direct contact with the second electron transport layer. The n-type charge generation layer may be in direct contact with the cathode. The n-type charge generation layer may be sandwiched between the second electron transport layer and the cathode in a contacting manner.

[0313] The organic light emitting diode may not include an electron injection layer.

[0314] The organic light emitting diode may not include an n-type charge generation layer.

[0315] Other layers

[0316] According to the present invention, in addition to the layers mentioned above, the organic light emitting diode may include other layers. Exemplary embodiments of each layer are described below:

[0317] base

[0318] The substrate can be any substrate commonly used to manufacture electronic devices such as organic light-emitting diodes. If light is emitted through the substrate, the substrate should be a transparent or translucent material, such as a glass substrate or a transparent plastic substrate. If light is emitted through the top surface, the substrate can be transparent or opaque, such as a glass substrate, plastic substrate, metal substrate, or silicon substrate.

[0319] Anode electrode

[0320] The first electrode or the second electrode included in the organic electronic device of the present invention can be an anode electrode. The anode electrode can be formed by depositing or sputtering a material for forming the anode electrode. The material for forming the anode electrode can be a high work function material, thereby facilitating hole injection. The anode material can also be selected from a low work function material (i.e., aluminum). The anode electrode can be a transparent or reflective electrode. Transparent conductive oxides such as indium tin oxide (ITO), indium zinc oxide (IZO), tin dioxide (SnO2), aluminum zinc oxide (AlZnO) and zinc oxide (ZnO) can be used to form the anode electrode. Metals, typically silver (Ag), gold (Au), or metal alloys can also be used to form the anode electrode.

[0321] hole injection layer

[0322] A hole injection layer (HIL) can be formed on the anode electrode by vacuum deposition, spin coating, printing, casting, slot die coating, Langmuir-Blodgett (LB) deposition, etc. When vacuum deposition is used to form the HIL, the deposition conditions may vary depending on the compound used to form the HIL and the desired structure and thermal properties of the HIL. However, in general, the vacuum deposition conditions may include a deposition temperature of 100° C. to 500° C., a temperature of 100° C. to 500° C., and a temperature of 100° C. to 500° C. -8 Support up to 10 -3 Torr pressure (1 Torr equals 133.322 Pa) and a deposition rate of 0.1 nm / sec to 10 nm / sec.

[0323] When the HIL is formed by spin coating or printing, the coating conditions may vary depending on the compound used to form the HIL and the desired structure and thermal properties of the HIL. For example, the coating conditions may include a coating speed of about 2000 rpm to about 5000 rpm and a heat treatment temperature of about 80° C. to about 200° C. After coating, heat treatment is performed to remove the solvent.

[0324] The HIL can be formed from any compound commonly used to form a HIL. Examples of the compound that can be used to form the HIL include phthalocyanine compounds such as copper phthalocyanine (CuPc), 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA), TDATA, 2T-NATA, polyaniline / dodecylbenzenesulfonic acid (Pani / DBSA), poly(3,4-ethylidenedioxythiophene) / poly(4-styrenesulfonate) (PEDOT / PSS), polyaniline / camphorsulfonic acid (Pani / CSA), and polyaniline / poly(4-styrenesulfonate) (PANI / PSS).

[0325] The HIL may include or consist of a p-type dopant, and the p-type dopant may be selected from tetrafluoro-tetracyanoquinodimethane (F4TCNQ), 2,2'-(perfluoronaphthalene-2,6-diylidene)dimalononitrile, or 2,2',2"-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile), but is not limited thereto. The HIL may be selected from a hole-transporting host compound doped with a p-type dopant. A typical example of a known doped hole-transporting material is copper phthalocyanine (CuPc), which has a HOMO energy level of approximately -5.2e V, doped with tetrafluoro-tetracyanoquinodimethane (F4TCNQ), whose LUMO energy level is approximately -5.2 eV; zinc phthalocyanine (ZnPc) doped with F4TCNQ (HOMO = -5.2 eV); α-NPD (N,N'-bis(naphthalene-1-yl)-N,N'-bis(phenyl)-benzidine) doped with F4TCNQ; and α-NPD doped with 2,2'-(perfluoronaphthalene-2,6-diylidene)dimalononitrile. The concentration of the p-type dopant can be selected from 1 wt% to 20 wt%, more preferably from 3 wt% to 10 wt%.

[0326] The thickness of the HIL may be within a range of about 1 nm to about 100 nm, for example, about 1 nm to about 25 nm. When the thickness of the HIL is within this range, the HIL may have excellent hole injection characteristics without a substantial loss in driving voltage.

[0327] hole transport layer

[0328] A hole transport layer (HTL) can be formed on the HIL by vacuum deposition, spin coating, slot die coating, printing, casting, Langmuir-Blodgett (LB) deposition, or the like. When the HTL is formed by vacuum deposition or spin coating, the deposition and coating conditions can be similar to those for forming the HIL. However, the vacuum or solution deposition conditions may vary depending on the compound used to form the HTL.

[0329] The HTL can be formed from any compound commonly used to form an HTL. Suitable compounds are disclosed in, for example, Yasuhiko Shirota and Hiroshi Kageyama, Chem. Rev. 2007, 107, 953-1010, and are incorporated herein by reference. Examples of compounds that can be used to form the HTL are: carbazole derivatives, such as N-phenylcarbazole or polyvinylcarbazole; benzidine derivatives, such as N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine (TPD) or N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine (α-NPD); and triphenylamine compounds, such as 4,4',4"-tris(N-carbazolyl)triphenylamine (TCTA). Among these compounds, TCTA is capable of transporting holes and inhibiting the diffusion of excitons into the EML.

[0330] The thickness of the HTL may be in the range of about 5 nm to about 250 nm, preferably about 10 nm to about 200 nm, further preferably about 20 nm to about 190 nm, further preferably about 40 nm to about 180 nm, further preferably about 60 nm to about 170 nm, further preferably about 80 nm to about 160 nm, further preferably about 100 nm to about 160 nm, further preferably about 120 nm to about 140 nm. The preferred thickness of the HTL may be 170 nm to 200 nm.

[0331] When the thickness of the HTL is within this range, the HTL may have excellent hole transport characteristics without a substantial loss in driving voltage.

[0332] electron blocking layer

[0333] The function of the electron blocking layer (EBL) is to prevent electrons from being transferred from the light-emitting layer to the hole transport layer, thereby confining the electrons to the light-emitting layer. As a result, efficiency, operating voltage and / or life are improved. Typically, the electron blocking layer comprises a triarylamine compound. The LUMO energy level of the triarylamine compound may be closer to the vacuum energy level than the LUMO energy level of the hole transport layer. Compared with the HOMO energy level of the hole transport layer, the electron blocking layer may have a HOMO energy level that is further away from the vacuum energy level. The thickness of the electron blocking layer may be selected between 2 nm and 20 nm.

[0334] If the electron blocking layer has a high triplet energy level, it may also be described as a triplet control layer.

[0335] If a phosphorescent green or blue emitting layer is used, the function of the triplet control layer is to reduce triplet quenching. This allows for a higher luminous efficiency from the phosphorescent emitting layer. The triplet control layer is selected from triarylamine compounds having a triplet energy level higher than that of the phosphorescent emitter in the adjacent emitting layer. Suitable compounds for triplet control layers, in particular triarylamine compounds, are described in EP 2 722 908 A1.

[0336] Emitting Layer (EML)

[0337] The light-emitting layer in the organic light-emitting diode according to the present invention may be a blue light-emitting layer or a green light-emitting layer.

[0338] The EML can be formed on the HTL by vacuum deposition, spin coating, slot die coating, printing, casting, LB deposition, or the like. When vacuum deposition or spin coating is used to form the EML, the deposition and coating conditions can be similar to those for forming the HIL. However, the deposition and coating conditions may vary depending on the compound used to form the EML.

[0339] The light-emitting layer may not contain the compound of formula (II) or (I).

[0340] The light-emitting layer (EML) can be formed from a combination of a host and an emitter dopant. Examples of hosts include Alq3, 4,4'-N,N'-dicarbazole-biphenyl (CBP), poly(n-vinylcarbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4',4"-tris(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI), 3-tert-butyl-9,10-di-2-naphthylanthracene (TBADN), distyrylarene (DSA), and zinc bis(2-(2-hydroxyphenyl)benzothiazole acid) (Zn(BTZ)2).

[0341] The emitter dopant may be a phosphorescent or fluorescent emitter. Phosphorescent emitters and emitters emitting via a thermally activated delayed fluorescence (TADF) mechanism may be preferred due to their higher efficiency. The emitter may be a small molecule or a polymer.

[0342] Examples of red emitter dopants are, but are not limited to, PtOEP, Ir(piq)3, and Btp2Ir(acac). These compounds are phosphorescent emitters, however, fluorescent red emitter dopants may also be used.

[0343] Examples of phosphorescent green emitter dopants are Ir(ppy)3 (ppy=phenylpyridine), Ir(ppy)2(acac), Ir(mpyp)3.

[0344] Examples of phosphorescent blue emitter dopants are: F2Irpic, (F2ppy)2Ir(tmd) and Ir(dfppz)3; and terfluorene. Examples of fluorescent blue emitter dopants are 4,4'-bis(4-diphenylaminophenyl)biphenyl (DPAVBi), 2,5,8,11-tetra-tert-butylperylene (TBPe).

[0345] The amount of the luminophore dopant can be in a range of about 0.01 parts by weight to about 50 parts by weight based on 100 parts by weight of the host. Alternatively, the luminescent layer can be composed of a luminescent polymer. The EML can have a thickness of about 10 nm to about 100 nm, for example, about 20 nm to about 60 nm. When the EML thickness is within this range, the EML can have excellent luminescence without a substantial loss in driving voltage.

[0346] Hole blocking layer (HBL)

[0347] A hole-blocking layer (HBL) can be formed on the EML by vacuum deposition, spin coating, slot die coating, printing, casting, LB deposition, or the like to prevent holes from diffusing into the ETL. When the EML contains a phosphorescent dopant, the HBL can also have a triplet exciton-blocking function. The hole-blocking layer can be a first electron transport layer comprising or consisting of a compound of formula (I), as described above.

[0348] HBL may also be called auxiliary ETL or a-ETL.

[0349] When vacuum deposition or spin coating is used to form the HBL, the deposition and coating conditions may be similar to those used to form the HIL. However, the deposition and coating conditions may vary depending on the compound used to form the HBL. Any compound commonly used to form the HBL may be used. Examples of compounds used to form the HBL include Oxadiazole derivatives, triazole derivatives and phenanthroline derivatives.

[0350] The thickness of the HBL may be in the range of about 5 nm to about 100 nm, for example, about 10 nm to about 30 nm. When the thickness of the HBL is within this range, the HBL may have excellent hole-blocking properties without a substantial loss in driving voltage.

[0351] The hole blocking layer may also be described as an a-ETL or auxiliary ETL.

[0352] According to one embodiment, the hole-blocking layer is arranged between the at least one light-emitting layer and the second electron-transporting layer comprising the compound of formula (II).

[0353] HBL may not contain the compound of formula (II). HBL may not contain the compound (III). HBL may not contain the compound of formula (II) and not contain the compound (III).

[0354] In one embodiment, the OLED according to the invention does not comprise a first electron transport layer. In one embodiment, the OLED according to the invention does not comprise a hole blocking layer (HBL).

[0355] In one embodiment, the OLED according to the present invention does not comprise a first electron transport layer and the triplet energy level T1 of the compound of formula (II) is in the range of 2.45 eV to 3.00 eV, preferably between 2.47 eV and 3.00 eV, more preferably between 2.60 eV and 3.00 eV, more preferably between 2.65 eV and 2.99 eV.

[0356] In one embodiment, the OLED according to the present invention does not comprise a first electron transport layer and the triplet energy level T1 of the compound of formula (IV) is in the range of 2.45 eV to 3.00 eV, preferably between 2.47 eV and 3.00 eV, more preferably between 2.60 eV and 3.00 eV, more preferably between 2.65 eV and 2.99 eV.

[0357] Electron Transport Layer (ETL)

[0358] The OLED according to the invention comprises one or more electron transport layers (ETL).According to the invention, at least one electron transport layer is an inventive electron transport layer as described above comprising a compound of formula (II).

[0359] According to various embodiments, the OLED may comprise an electron transport layer or an electron transport layer stack comprising at least a first electron transport layer and at least a second electron transport layer.

[0360] The electron transport layer may be a second electron transport layer.

[0361] By properly adjusting the energy levels of specific layers of the ETL, the injection and transport of electrons can be controlled, and holes can be effectively blocked, thereby enabling the OLED to have a long lifespan.

[0362] In addition to comprising the compound of formula (II), the electron transport layer may also comprise other ETM materials known in the art. Similarly, the electron transport layer may comprise a compound of formula (II) as the sole electron transport matrix material. In the case where the organic electronic device of the present invention comprises more than one electron transport layer, the compound of formula (II) may be contained only in one electron transport layer, may be contained in more than one electron transport layer, or may be contained in all electron transport layers. There is no particular restriction on other compounds suitable for ETM. In one embodiment, the electron transport matrix compound consists of covalently bound atoms. Preferably, the electron transport matrix compound comprises a conjugated system of at least 6, more preferably at least 10 delocalized electrons. In one embodiment, the conjugated system of delocalized electrons may be contained in an aromatic or heteroaromatic structure, as disclosed in, for example, document EP 1 970 371 A1 or WO 2013 / 079217 A1.

[0363] According to the present invention, the electron transport layer is free of electrical dopants, such as n-type dopants, in particular redox n-type dopants. In this context, the term "free" does not exclude impurities. Impurities have no technical effect on the objectives achieved by the present invention. Impurities are not intentionally added to the layer during processing.

[0364] The term "free of" compounds means that such compounds are not intentionally added to the layer during processing.

[0365] The electron transport layer may comprise compound (III).

[0366] Electron injection layer (EIL)

[0367] An EIL may be formed on the electron transport layer stack. The EIL may facilitate electron injection from the cathode into the electron transport layer stack. The EIL is preferably formed directly on the electron transport layer stack, preferably directly on the second electron transport layer, and preferably in direct contact with the second electron transport layer. Examples of materials for forming the EIL or included in the EIL include 8-hydroxyquinoline lithium (LiQ), LiF, NaCl, CsF, Li2O, BaO, Ca, Ba, Yb, and Mg known in the art. Although the deposition and coating conditions for forming the EIL are similar to those for forming the HIL, the deposition and coating conditions may vary depending on the material used to form the EIL. The EIL may include an organic matrix material doped with an n-type dopant. The matrix material may be selected from materials commonly used as matrix materials for electron transport layers.

[0368] The EIL may be composed of a plurality of separate EIL sublayers. In the case where the EIL is composed of a plurality of separate EIL sublayers, the number of sublayers is preferably 2. Each EIL sublayer may include a different material for forming the EIL.

[0369] The thickness of the EIL may be within a range of about 0.1 nm to about 10 nm, for example, about 0.5 nm to about 9 nm. When the thickness of the EIL is within this range, the EIL may have satisfactory electron injection properties without a substantial loss in driving voltage.

[0370] The electron transport stack of the present invention is not part of the electron injection layer.

[0371] The electron injection layer may be in direct contact with the electron transport layer.

[0372] The electron injection layer may be in direct contact with the second electron transport layer.

[0373] cathode electrode

[0374] If an EIL is present, a cathode electrode is formed on the EIL, preferably directly on the EIL, preferably in direct contact with the EIL. In the sense of the present invention, the cathode and the EIL can be regarded as a functional part capable of injecting electrons into the electron transport layer stack. The cathode electrode can be formed of a metal, an alloy, a conductive compound, or a mixture thereof. The cathode electrode can have a low work function. For example, the cathode electrode can be formed of lithium (Li), magnesium (Mg), aluminum (Al), aluminum (Al)-lithium (Li), calcium (Ca), barium (Ba), ytterbium (Yb), magnesium (Mg)-indium (In), magnesium (Mg)-silver (Ag), etc. Alternatively, the cathode electrode can be formed of a transparent conductive oxide such as ITO or IZO.

[0375] The thickness of the cathode electrode may be in the range of about 5 nm to about 1000 nm, for example, in the range of about 10 nm to about 100 nm. When the thickness of the cathode electrode is in the range of about 5 nm to about 50 nm, the cathode electrode may be transparent or translucent even if it is formed of a metal or a metal alloy. A transparent or translucent cathode may promote cathode luminescence.

[0376] It is understood that the cathode electrode and the electron injection layer are not part of the electron transport layer stack.

[0377] Charge Generation Layer (CGL)

[0378] The charge generation layer (CGL) may include a p-type charge generation layer (p-CGL) and an n-type charge generation layer (n-CGL). An intermediate layer may be disposed between the p-CGL and the n-CGL.

[0379] Typically, the charge generation layer is a pn junction connecting an n-type charge generation layer (electron generation layer) and a hole generation layer. The n-side of the pn junction generates electrons and injects them into the adjacent layer in the direction of the anode. Similarly, the p-side of the pn junction generates holes and injects them into the adjacent layer in the direction of the cathode.

[0380] Charge generation layers are used in tandem and stacked devices, such as tandem or stacked OLEDs, which contain two or more light-emitting layers between two electrodes. In a tandem or stacked OLED containing two light-emitting layers, the n-type charge generation layer provides electrons to the first light-emitting layer positioned near the anode, while the hole generation layer provides holes to the second light-emitting layer positioned between the first light-emitting layer and the cathode.

[0381] The host material suitable for the hole generation layer can be a material conventionally used as a hole injection and / or hole transport host material. In addition, the p-type dopant used in the hole generation layer can be a conventional material. For example, the p-type dopant can be one selected from the following: tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), a derivative of tetracyanoquinodimethane, a radialene derivative, iodine, FeCl3, FeF3, and SbCl5. In addition, the host can be one selected from the following: N,N'-di(naphthalene-1-yl)-N,N-diphenyl-benzidine (NPB), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1-biphenyl-4,4'-diamine (TPD), and N,N',N'-tetaraphthyl-benzidine (TNB). The p-type charge generation layer can be composed of CNHAT.

[0382] The n-type charge generation layer can be a layer comprising a compound of formula (I). The n-type charge generation layer can be a layer of a pure n-type dopant such as a metal, or can be composed of an organic matrix material doped with an n-type dopant. In one embodiment, the n-type dopant can be an alkali metal, an alkali metal compound, an alkaline earth metal, an alkaline earth metal compound, a transition metal, a transition metal compound, or a rare earth metal. In another embodiment, the metal can be one selected from the following: Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, La, Ce, Sm, Eu, Tb, Dy, and Yb. More specifically, the n-type dopant can be one selected from the following: Li, Cs, K, Rb, Mg, Na, Ca, Sr, Eu, and Yb. The matrix material suitable for the electron generation layer can be a material conventionally used as a matrix material for an electron injection or electron transport layer. The matrix material can be, for example, one selected from the following: a triazine compound, a hydroxyquinoline derivative such as tris(8-hydroxyquinoline)aluminum, a benzoxazole derivative, and a silacyclopentane derivative.

[0383] The CGL may be free of the compound of formula (I).

[0384] The CGL may not contain the compound of formula (II).

[0385] The CGL may not contain the compound of formula (III).

[0386] The CGL may be free of the compound of formula (I) and free of the compound of formula (II).

[0387] The CGL may contain no compound of formula (I) and no compound of formula (II) and no compound (III).

[0388] The hole generation layer may be disposed in direct contact with the n-type charge generation layer.

[0389] According to one aspect of the present invention, the electron transport layer is arranged between the first and second light emitting layers.

[0390] The CGL may be in direct contact with the second electron transport layer.

[0391] The n-CGL may be in direct contact with the second electron transport layer.

[0392] According to one aspect of the present invention, the electron transport layer comprising the compound of formula (II) is disposed between the first and second light emitting layers, and the electron transport layer comprising the compound of formula (II) is disposed between the second light emitting layer and the cathode.

[0393] According to one aspect of the present invention, an organic light-emitting diode (OLED) is provided, comprising: a substrate; an anode electrode formed on the substrate; a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer comprising a compound of formula (II), and a cathode electrode.

[0394] According to another aspect of the present invention, an OLED is provided, comprising: a substrate; an anode electrode formed on the substrate; a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer comprising a compound of formula (II), and a cathode electrode.

[0395] According to another aspect of the present invention, an OLED is provided, comprising: a substrate; an anode electrode formed on the substrate; a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, a first electron transport layer comprising a compound of formula (I), a second electron transport layer comprising a compound of formula (II), an electron injection layer, and a cathode electrode.

[0396] According to various embodiments of the present invention, an OLED layer may be provided that is disposed between the above-mentioned layers, on the substrate, or on the top electrode.

[0397] According to one aspect, an OLED may comprise the following layer structure: a substrate is arranged adjacent to an anode electrode, the anode electrode is arranged adjacent to a first hole injection layer, the first hole injection layer is arranged adjacent to a first hole transport layer, the first hole transport layer is arranged adjacent to a first electron blocking layer, the first electron blocking layer is arranged adjacent to a first light-emitting layer, the first light-emitting layer is arranged adjacent to the first electron transport layer, the first electron transport layer is arranged adjacent to an n-type charge generation layer, the n-type charge generation layer is arranged adjacent to the hole generation layer, the hole generation layer is arranged adjacent to a second hole transport layer, the second hole transport layer is arranged adjacent to a second electron blocking layer, the second electron blocking layer is arranged adjacent to a second light-emitting layer, and an optional electron transport layer and / or an optional injection layer are arranged between the second light-emitting layer and the cathode electrode.

[0398] For example, according to Figure 2 The OLED can be formed by the following process: an anode (120), a hole injection layer (130), a hole transport layer (140), an electron blocking layer (145), a light-emitting layer (150), a hole blocking layer (155), an electron transport layer (160), an electron injection layer (180) and a cathode electrode (190) are sequentially formed on a substrate (110).

[0399] According to another aspect of the present invention, an electronic device is provided, comprising at least one organic light-emitting device according to any embodiment described herein. Preferably, the electronic device comprises an organic light-emitting diode according to one of the embodiments described herein. More preferably, the electronic device is a display device or a lighting device, most preferably a display device.

[0400] In one embodiment, the organic light emitting diode according to the present invention further includes a layer including a radialene compound and / or a quinodimethane compound.

[0401] In one embodiment, the radialene compound and / or quinodimethane compound can be substituted with one or more halogen atoms and / or one or more electron withdrawing groups. The electron withdrawing group can be selected from a nitrile group, a haloalkyl group, or a perhaloalkyl group, or a perfluoroalkyl group. Other examples of electron withdrawing groups can be acyl, sulfonyl or phosphoryl groups.

[0402] Alternatively, the acyl group, sulfonyl group and / or phosphoryl group may contain halogenated and / or perhalogenated hydrocarbon groups. In one embodiment, the perhalogenated hydrocarbon group may be a perfluoroalkyl group. Examples of perfluoroalkyl groups may be perfluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorophenyl, perfluorotolyl; Examples of sulfonyl groups containing halogenated hydrocarbon groups may be trifluoromethylsulfonyl, pentafluoroethylsulfonyl, pentafluorophenylsulfonyl, heptafluoropropylsulfonyl, nonafluorobutylsulfonyl, etc.

[0403] In one embodiment, the radialene and / or quinodimethane compound may be included in the hole injection layer, the hole transport layer, and / or the hole generation layer.

[0404] In one embodiment, the radialene compound may have formula (XX) and / or the quinodimethane compound may have formula (XXIa) or (XXIb):

[0405]

[0406] where (as an exception to the above description) R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R 11 、R 12 、R 15 、R 16 、R 20 、R 21 are independently selected from the above electron withdrawing groups and R 9 、R 10 、R 13 、R 14 、R 17 、R 18 、R 19 、R 22 、R 23 and R 24 Independently selected from: H, halogen and the above-mentioned electron withdrawing groups.

[0407] Method for preparing an organic electronic device

[0408] According to another aspect, the present invention relates to a process for producing an organic electronic device according to the invention, wherein said process comprises the step of depositing a compound of formula (II) according to the invention on a solid support.

[0409] Methods for deposition may include:

[0410] -Deposition via vacuum thermal evaporation;

[0411] - deposition via solution processing, preferably said processing being selected from spin coating, printing, casting; and / or

[0412] -Slot die coating.

[0413] Display device

[0414] According to a further aspect, the present invention relates to a display device comprising an organic light-emitting diode according to the invention, preferably comprising at least two organic light-emitting diodes according to the invention.

[0415] Compound of formula (IV)

[0416] According to another aspect, the present invention relates to a compound of formula (IV)

[0417]

[0418] Two R's a Can be different or the same. a The two Zs can be selected to be the same or different. The two Zs can be selected to be the same.

[0419] The two Gs can be different or the same. The two Gs can be the same.

[0420] R a Independently selected from: substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C3 to C 18 Heteroaryl, wherein if R is substituted, one or more substituents are independently selected from: D, phenyl and C1 to C 12 alkyl.

[0421] R a Can be independently selected from: substituted or unsubstituted C6 to C 18 Aryl and substituted or unsubstituted C3 to C 17 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D and C1 to C 12 alkyl.

[0422] R a Can be independently selected from: substituted or unsubstituted C6 to C 12 Aryl and substituted or unsubstituted C5 to C 11 Heteroaryl, where R a is substituted, then the one or more substituents are independently selected from the group consisting of: D, phenyl, and C1 to C4 alkyl.

[0423] R a Can be independently selected from

[0424]

[0425] wherein each group is at a *

[0426] combination.

[0427] Z is independently selected from a single bond and C6 to C 24 Arylene. Z can be independently selected from a single bond and C6 to C 18 Arylene. Z can be independently selected from a single bond and C6 to C 12 Arylene. Z can be independently selected from a single bond and C6 to C 10 Aromatic subunit.

[0428] Z can be independently selected from

[0429]

[0430] Z can be independently selected from

[0431]

[0432] Where Z is at * and

[0433]

[0434] Combined with *G.

[0435] G is independently selected from (IVa-1) to (IVa-3)

[0436]

[0437] According to the present invention, in the formula showing the following combination,

[0438] Group R S Binding can be to any suitable binding position, ie, to any carbon atom not bound to Z.

[0439] In the shown R S In the case where the bond spans more than one ring

[0440]

[0441] Group R S Binding may be to any suitable binding position on each ring across which the bond spans, ie, to any carbon atom not bound to Z.

[0442] Z may be bound to the ortho, meta or para position of the N atom of the pyridine ring in formula IIa-1, and the remaining positions may each have or not have a substituent R s .

[0443] Z may be bound to the ortho or meta position of the N atom of the pyridine ring in formula IIa-2, or to the carbon atom of any ring condensed with the pyridine ring, and the remaining positions may each have or not have a substituent R s .

[0444] Z may be combined at the meta or para position relative to the N atom of the pyridine ring in formula IIa-3, or at the carbon atom of any ring condensed with the pyridine ring, and the remaining positions may each have or not have a substituent R s .

[0445] R S Independently selected from D, C1 to C 12 Aryl, C1 to C 12 Alkyl and pyridyl, wherein each of the C1 to C 12 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

[0446] R S Can be independently selected from D, C1 to C 10 aryl, C1 to C4 alkyl and pyridyl, wherein each of the C1 to C 10 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

[0447] R S Can be independently selected from D, phenyl, naphthyl, C1 to C 12 Alkyl and pyridyl.

[0448] R S and may be independently selected from D, phenyl, naphthyl, C1 to C4 alkyl, and pyridyl.

[0449] R s Can be independently selected from

[0450] *CH3

[0451] wherein each R s Combine with Z at *.

[0452] For IVa-1, p is an integer from 0 to 4. For IVa-1, p may be an integer from 0 to 2. For IVa-1, p may be an integer from 0 to 1.

[0453] For IVa-2 and IVa-3, p is an integer from 0 to 6. For IVa-2 and IVa-3, p may be an integer from 0 to 4. For IVa-2 and IVa-3, p may be an integer from 0 to 2. For IVa-2 and IVa-3, p may be an integer from 0 to 1.

[0454] The compound of formula (IV) can be selected from B-1 to B-44

[0455]

[0456]

[0457]

[0458]

[0459]

[0460]

[0461]

[0462] The compound of formula (IV) can be selected from B-1 to B-4

[0463]

[0464] General Definition

[0465] If not explicitly mentioned otherwise, various moieties of the compounds described herein, in particular compounds of formula (I) and (II) and compound (III), may be substituted by one or more D (deuterium) and / or C1 to C4 alkyl groups.

[0466] In this specification, when no definition is provided otherwise, an "alkyl group" may refer to an aliphatic hydrocarbon group. An alkyl group may refer to a "saturated alkyl group" without any double or triple bonds. The term "alkyl" as used herein should encompass straight-chain, branched, and cyclic alkyl groups. For example, a C3-alkyl group may be selected from n-propyl and isopropyl. Similarly, a C4-alkyl group includes n-butyl, sec-butyl, and tert-butyl. Similarly, a C6-alkyl group includes n-hexyl and cyclohexyl.

[0467] If not explicitly mentioned otherwise, the asterisk symbol "*" as used herein indicates the binding position where the correspondingly labeled moiety is bonded to another moiety.

[0468] C n The subscript number n in relates to the total number of carbon atoms in the corresponding alkyl, arylene, heteroarylene or aryl group.

[0469] As used herein, the term "aryl" or "arylidene" should encompass: phenyl (C6-aryl); fused aromatic hydrocarbons, such as naphthalene, anthracene, phenanthrene, tetracene, etc. Also encompassed are biphenyl and oligophenyls or polyphenyls, such as terphenyl, phenyl-substituted biphenyl, phenyl-substituted terphenyls (such as tetraphenylphenyl groups), etc. "arylidene", correspondingly "heteroarylidene" refers to a group connected to two other parts. In this specification, the term "aryl group" or "arylidene group" may refer to a group comprising at least one hydrocarbon aromatic portion, and all elements of the hydrocarbon aromatic portion may have a p-orbital forming conjugation, such as a phenyl group, a naphthyl group, an anthracene group, a phenanthrene group, a pyrenyl group, a fluorenyl group, etc. Also included are spiro compounds, in which two aromatic moieties are connected to each other by a spiro atom, such as 9,9'-spirodi[9H-fluorene] base. Aryl or arylene groups can include monocyclic or fused-ring polycyclic (ie, linkages that share adjacent pairs of carbon atoms) functional groups.

[0470] As used herein, the term "heteroaryl" refers to an aryl group in which at least one carbon atom is replaced by a heteroatom. The term "heteroaryl" may refer to an aromatic heterocycle having at least one heteroatom, and all elements of the hydrocarbon heteroaromatic portion may have a p-orbital forming a conjugation. The heteroatom may be selected from N, O, S, B, Si, P, Se, preferably selected from N, O and S. The heteroarylidene ring may contain at least 1 to 3 heteroatoms. Preferably, the heteroarylidene ring may contain at least 1 to 3 heteroatoms independently selected from N, S and / or O. As in the case of "aryl" / "arylidene", the term "heteroaryl" includes, for example, spiro compounds in which two aromatic moieties are connected to each other, such as spiro[fluorene-9,9'-xanthene]. Other exemplary heteroaryl groups are diazines, triazines, dibenzofurans, dibenzothiophenes, acridines, benzoacridines and dibenzoacridines.

[0471] As used herein, the term "alkenyl" refers to a group containing a carbon-carbon double bond -CR 1 =CR 2 R 3 .

[0472] As used herein, the term "perhalogenated" refers to a hydrocarbyl group in which all of the hydrogen atoms of the hydrocarbyl group are replaced by halogen (F, Cl, Br, I) atoms.

[0473] As used herein, the term "alkoxy" refers to a structural fragment of the formula -OR, wherein R is a hydrocarbon group, preferably an alkyl group or a cycloalkyl group.

[0474] As used herein, the term "thioalkyl" refers to a structural fragment of the formula -SR, wherein R is a hydrocarbon group, preferably an alkyl group or a cycloalkyl group.

[0475] C n-heteroaryl refers only to the number of carbon atoms and does not include the number of heteroatoms. In this context, it is clear that a C3 heteroarylidene group is an aromatic compound containing three carbon atoms such as pyrazole, imidazole, Azoles, thiazoles, etc.

[0476] As used herein, the term "heteroaryl" shall include pyridine, quinoline, benzoquinoline, quinazoline, benzoquinazoline, pyrimidine, pyrazine, triazine, benzimidazole, benzothiazole, benzo[4,5]thieno[3,2-d]pyrimidine, carbazole, xanthene, phenanthroline, Azine, benzoacridine, dibenzoacridine, etc.

[0477] In this specification, the term single bond refers to a direct bond.

[0478] As used herein, the term "fluorinated" refers to a hydrocarbon group in which at least one hydrogen atom contained in the hydrocarbon group is replaced by a fluorine atom. A fluorinated group in which all of its hydrogen atoms are replaced by fluorine atoms is called a perfluorinated group and is specifically denoted by the term "fluorinated".

[0479] According to the present invention, a group is "substituted" by another group if one of the hydrogen atoms contained in the group is replaced by another group, wherein the other group is a substituent.

[0480] According to the present invention, as an illustrative example, any group A is used in the formula showing the following combination

[0481]

[0482] Group A may be attached to any suitable attachment position. In cases where the bond of A is shown to span more than one ring

[0483]

[0484] The group A may be attached to any suitable attachment position on each ring across which the bond spans.

[0485] According to the present invention, the expression "between" with respect to a layer being between two other layers does not exclude the presence of further layers that may be arranged between the layer and one of the two other layers. According to the present invention, the expression "in direct contact" with respect to two layers being in direct contact with one another means that no further layers are arranged between the two layers. A layer deposited on top of another layer is considered to be in direct contact with that layer.

[0486] The term "contact sandwiched" refers to an arrangement of three layers whereby the middle layer is in direct contact with two adjacent layers.

[0487] With regard to the electron transport layer stacks of the invention, the compounds mentioned in the experimental part are most preferred.

[0488] A lighting device is any device used for illumination, irradiation, signal transmission, or projection. They are categorized accordingly as lighting, irradiation, signal transmission, and projection devices. A lighting device typically consists of the following elements: a source of optical radiation; a device that transmits the radiation flux into space in the desired direction; and an enclosure that connects the components into a single device and protects the radiation source and optical transmission system from environmental damage and influences.

[0489] According to another aspect, the organic electroluminescent device according to the invention comprises two or three or more light-emitting layers. OLEDs comprising more than one light-emitting layer are also described as tandem OLEDs or stacked OLEDs.

[0490] Organic electroluminescent devices (OLEDs) can be bottom- or top-emitting devices. Organic electroluminescent devices (OLEDs) can emit light through a transparent anode or through a transparent cathode.

[0491] Another aspect relates to an apparatus comprising at least one organic electroluminescent device (OLED).

[0492] Devices comprising organic light emitting diodes are, for example, displays or lighting panels.

[0493] In this disclosure, the following defined terms shall apply with these definitions unless a different definition is given in the claims or elsewhere in this specification.

[0494] In the context of this specification, the term "different" or "other than" in relation to a host material means that the host material differs in its structural formula.

[0495] The terms "OLED" and "organic light emitting diode" are used concurrently and have the same meaning. The term "organic electroluminescent device" as used herein may include organic light emitting diodes as well as organic light emitting transistors (OLETs).

[0496] As used herein, "weight percent," "wt%," "percent by weight," "% wt," and variations thereof refer to a composition, component, substance, or agent expressed as the weight of the component, substance, or agent of the corresponding electron transport layer divided by the total weight of its corresponding electron transport layer, multiplied by 100. It is understood that the amount of the total weight percentage of all components, substances, and agents of the corresponding electron transport layer and electron injection layer is selected so that it does not exceed 100 wt%.

[0497] As used herein, "volume percent," "volume %," "percent by volume," "% volume," and variations thereof refer to expressing a composition, component, substance, or agent as the volume of the component, substance, or agent of the corresponding electron transport layer divided by the total volume of its corresponding electron transport layer, multiplied by 100. It is understood that the amount of the total volume percentage of all components, substances, and agents of the cathode layer is selected such that it does not exceed 100 volume percent.

[0498] Whether or not explicitly stated, it is assumed herein that all numerical values ​​are modified by the term "about". As used herein, the term "about" refers to the amount of variation that can occur. Whether or not modified by the term "about", the claims include equivalents to the stated amounts.

[0499] It must be noted that, as used in this specification and the claims, the singular forms "a," "an," "the," and "said" include plural referents unless the content clearly dictates otherwise.

[0500] The terms "does not contain", "does not include", and "does not include" do not exclude impurities. Impurities have no technical impact on the purpose achieved by the present invention.

[0501] In the context of this specification, the term "substantially non-luminescent" or "non-luminescent" means that the contribution of a compound or layer to the visible light emission spectrum from a device is less than 10%, preferably less than 5%, relative to the visible light emission spectrum. The visible light emission spectrum is the light emission spectrum having a wavelength of about ≥380 nm to about ≤780 nm.

[0502] Preferably, the organic semiconductor layer comprising the compound of formula (II) is substantially non-emissive or non-emissive.

[0503] The working voltage, also called U, is 10 mA / cm2. 2 ) is measured in volts (V).

[0504] Candela / ampere efficiency, also known as cd / A efficiency or Ceff, is measured at 10 mA / cm². 2 ) is measured in candela per ampere.

[0505] External quantum efficiency, also known as EQE, is measured in percent (%).

[0506] Color space is described by the coordinates CIE-x and CIE-y (International Commission on Illumination, 1931). CIE-y is particularly important for blue light. A smaller CIE-y value indicates a deeper blue. Efficiency values ​​are compared at the same CIE-y value.

[0507] The highest occupied molecular orbital (also called HOMO) and the lowest unoccupied molecular orbital (also called LUMO) are measured in electron volts (eV).

[0508] The terms "OLED," "organic light emitting diode," "organic light emitting device," "organic optoelectronic device," and "organic light emitting diode" are used concurrently and have the same meaning.

[0509] The terms "lifetime" and "service life" are used interchangeably and have the same meaning.

[0510] The anode and cathode may be described as anode electrode / cathode electrode or anode / cathode or anode electrode layer / cathode electrode layer.

[0511] Room temperature, also known as ambient temperature, is 23°C.

[0512] Hereinafter, the embodiments will be described in more detail with reference to the examples. However, the present invention is not limited to the following examples. Reference will now be made in detail to the exemplary aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0513] The components described above and claimed and used according to the invention in the described embodiments do not have any special exceptions with regard to their size, shape, material selection and technical concept, so that selection criteria known from the relevant art can be applied without restriction.

[0514] Further details, features, and advantages of the objects of the present invention are disclosed in the dependent claims and in the following description of the various drawings, which show, by way of example, preferred embodiments according to the present invention. However, no embodiment necessarily represents the full scope of the invention, and reference is made to the claims and this text for interpretation of the scope of the invention. It should be understood that both the foregoing general description and the following detailed description are merely exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

[0515] Figure 1 is a schematic cross-sectional view of an organic electronic device according to an exemplary embodiment of the present invention;

[0516] Figure 2 is a schematic cross-sectional view of an organic light emitting diode (OLED) according to an exemplary embodiment of the present invention;

[0517] Figure 3 is a schematic cross-sectional view of an OLED according to an exemplary embodiment of the present invention.

[0518] Figure 4 is a schematic cross-sectional view of an OLED including a charge generation layer and two light-emitting layers according to an exemplary embodiment of the present invention.

[0519] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the following drawings.

[0520] Herein, when a first element is referred to as being formed or arranged “on” or “over” a second element, the first element may be arranged directly on the second element, or one or more other elements may be disposed therebetween. When a first element is referred to as being arranged “directly on” or “directly over” a second element, no other elements are disposed therebetween.

[0521] Figure 1 FIG1 is a schematic cross-sectional view of an organic electronic device 100 according to an exemplary embodiment of the present invention. Organic electronic device 100 includes a substrate 110, an anode 120, an emitting layer (EML) 125, and a second electron transport layer 160 including a compound of formula (II). Second electron transport layer 160 including a compound of formula (II) is formed on EML 125. A cathode 190 is disposed on electron transport layer 160 including a compound of formula (II).

[0522] Figure 2 1 is a schematic cross-sectional view of an organic light-emitting diode (OLED) 100 according to an exemplary embodiment of the present invention. OLED 100 includes a substrate 110, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an emission layer (EML) 150, and a second electron transport layer (ETL) 160. Second electron transport layer (ETL) 160 is formed on EML 150. Electron injection layer (EIL) 180 is disposed on second electron transport layer (ETL) 160. Cathode 190 is disposed directly on electron injection layer (EIL) 180.

[0523] Figure 3 is a schematic cross-sectional view of an OLED 100 according to another exemplary embodiment of the present invention. Figure 3 and Figure 2 The difference is that Figure 3 The OLED 100 includes an electron blocking layer (EBL) 145 and a first electron transport layer 155 .

[0524] Reference Figure 3 OLED 100 includes a substrate 110, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, an emission layer (EML) 150, a first electron transport layer 155, a second electron transport layer 160 including a compound of formula (II), an electron injection layer (EIL) 180 and a cathode 190.

[0525] Figure 4 is a schematic cross-sectional view of an OLED 100 according to another exemplary embodiment of the present invention. Figure 4 and Figure 3 The difference is that Figure 4 The OLED 100 further includes a charge generation layer (CGL) and a second light emitting layer (151).

[0526] Reference Figure 4 OLED 100 includes a substrate 110, an anode 120, a first hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first electron blocking layer (EBL) 145, a first light-emitting layer (EML) 150, a first electron transport layer (HBL) 155, a second electron transport layer 160 including a compound of formula (II), an n-type charge generation layer (n-type CGL) 185, a hole generation layer (p-type charge generation layer; p-type GCL) 135, a second hole transport layer (HTL) 141, a second electron blocking layer (EBL) 146, a second light-emitting layer (EML) 151, a hole blocking layer (HBL) 156, an additional electron transport layer 161, a second electron injection layer (EIL) 181 and a cathode 190.

[0527] Despite Figure 1 、 Figure 2 、 Figure 3 and Figure 4 Although not shown in the figure, a sealing layer may be further formed on the cathode electrode 190 to seal the OLED 100. In addition, various other modifications may be made thereto.

[0528] Hereinafter, embodiments will be described in detail with reference to the following examples. However, the present invention is not limited to the following examples.

[0529] Experimental part

[0530] Melting point

[0531] The melting point (mp) was determined as the peak temperature of the DSC curve according to the above-mentioned TGA-DSC measurement or a separate DSC measurement (Mettler Toledo DSC822e, the sample was heated from room temperature to complete melting at a heating rate of 10 K / min under a pure nitrogen flow. A sample amount of 4 to 6 mg was placed in a 40 μL Mettler Toledo aluminum pan with a lid and a hole of <1 mm was punched in the lid).

[0532] Glass transition temperature

[0533] The glass transition temperature (Tg) was measured as described in DIN EN ISO 11357, published in March 2010, in a Mettler Toledo DSC 822e differential scanning calorimeter under nitrogen and using a heating rate of 10 K / min.

[0534] Standard starting temperature

[0535] Standard starting temperature (T RO ) is determined by loading 100 mg of compound into a VTE source. As a VTE source, a point source of organic material provided by Kurt J. Lesker Company (www.Lesker.com) or CreaPhys GmbH (http: / / www.creaphys.com) can be used. -5 The VTE source was heated at a constant rate of 15 K / min under a pressure of 100 mbar, and the temperature inside the source was measured with a thermocouple. The evaporation of the compound was detected with a QCM detector, which detected the deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal was The VTE source is measured in units of . To determine the standard onset temperature, the deposition rate is plotted against the VTE source temperature. The standard onset is the temperature at which significant deposition occurs on the QCM detector. To obtain accurate results, the VTE source is heated and cooled three times, and only the results from the second and third runs are used to determine the standard onset temperature.

[0536] To effectively control the evaporation rate of organic compounds, the standard starting temperature may be in the range of 200 to 255°C. If the standard starting temperature is below 200°C, evaporation may be too rapid, making it difficult to control. If the standard starting temperature is above 255°C, the evaporation rate may be too slow, which may result in a low cycle time and the organic compounds in the VTE source may decompose due to prolonged exposure to high temperatures.

[0537] The standard onset temperature is an indirect measure of the volatility of a compound. The higher the standard onset temperature, the lower the volatility of the compound.

[0538] Reduction potential

[0539] The reduction potential is determined at room temperature using a constant potential device Metrohm PGSTAT30 and software Metrohm Autolab GPES by cyclic voltammetry. The redox potential given under a specific compound is measured as follows: in a dry 0.1M THF solution of the experimental substance degassed with argon, under an argon atmosphere, a 0.1M tetrabutylammonium hexafluorophosphate supporting electrolyte is used between platinum working electrodes, and an Ag / AgCl pseudo-standard electrode (Metrohm silver rod electrode) consisting of a silver wire covered with silver chloride and directly immersed in the measurement solution is measured at a scan rate of 100mV / s. The first run is completed within the widest range of potentials set on the working electrode, and the range is then appropriately adjusted in subsequent runs. The last three runs are completed by adding ferrocene (0.1M concentration) as a standard. The average potential corresponding to the cathode and anode peaks of the studied compound is calculated after subtracting the average potential for standard Fc + The values ​​reported above were obtained by averaging the cathodic and anodic potentials observed for the α / Fc redox couple. All investigated compounds, as well as the reported comparative compounds, showed clear reversible electrochemical behavior.

[0540] dipole moment

[0541] Dipole moment of a molecule containing N atoms It is given by:

[0542]

[0543] where q i and is the partial charge and position of atom i in the molecule.

[0544] The dipole moment was determined by the semiempirical molecular orbital method.

[0545] The geometry of the molecular structure was optimized in the gas phase using the hybrid functional B3LYP and 6-31G* basis set as implemented in the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). If more than one conformation was feasible, the conformation with the lowest total energy was selected to determine the bond lengths of the molecule.

[0546] Calculated HOMO, LUMO, S1 (singlet) and T1 (triplet) energy levels

[0547] HOMO, LUMO, S1 and T1 were calculated using the program packages ORCA V5.0.3 (Max Planck Institute für Kohlenforschung, Kaiser Wilhelm Platz 1, 45470, Muelheim / Ruhr, Germany) and WEASEL 1.9.2 (FAccTs GmbH, Rolandstrasse 67, 50677 Calculations were performed using the hybrid functional B3LYP and 6-31G* basis sets using optimized geometries obtained using the B3LYP and 6-31G* basis sets. All calculations were performed in the gas phase. If more than one conformation was feasible, the one with the lowest total energy was selected.

[0548] Table 4:

[0549] Material Tg / ℃ Tm / ℃ Standard starting temperature / ℃ B-1 109 295 234 B-4 86 272 226

[0550] Table 5

[0551]

[0552]

[0553]

[0554]

[0555]

[0556]

[0557]

[0558]

[0559]

[0560]

[0561]

[0562]

[0563]

[0564] Synthesis process Synthesis of compound B-1

[0565]

[0566] Under Ar atmosphere, 15 g (49.8 mmol, 1 eq) of 2,5-dichloro-3,6-diphenylpyrazine [CAS 74134-61-5] was mixed with 33.6 g (119.5 mmol, 2.4 eq) of 3-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine [CAS 929203-04-3], 42.3 g (200 mmol, 4 eq) of K3PO4 and 1.2 g (2 mmol, 0.04 eq) of SPhosPd(crotyl)Cl [CAS1798781-99-3] in a 1% argon atmosphere. The reaction mixture was stirred for 18 hours at 45°C in an alkane:water (4:1) mixture. The crude product was recrystallized twice from chlorobenzene for purification. A total of 15.9 g (yield 59%) of product was obtained.

[0567] HPLC 99.8%, ESI-MS m / z 539 [M+H].

[0568] Further purification was achieved by high vacuum sublimation.

[0569] Synthesis of compound B-4

[0570]

[0571] Under Ar atmosphere, 20 g (66.4 mmol, 1 eq) of 2,5-dichloro-3,6-diphenylpyrazine [CAS 74134-61-5] was reacted with 21.5 g (76.4 mmol, 1.15 eq) of 3-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyridine [CAS 939430-30-5], 18.4 g (132.8 mmol, 2 eq) of K2CO3 and 1.9 g (1.6 mmol, 0.025 eq) of Pd(PPh3)4 [CAS14221-01-3] in a mixture of toluene:THF:water (1:1:1) at 65°C for 4 days. After dissolution in aqueous solution, the crude product was purified by filtration using dichloromethane. The obtained solution was filtered through a pad of Celite®. Hexane was added to the obtained solution, the solid was filtered out and recrystallized from toluene. The obtained solid was chromatographed on silica gel using dichloromethane and a dichloromethane:ethyl acetate mixture. After collecting the fractions, 5.3 g (yield 19%) of the product was obtained.

[0572] HPLC 99.9%, ESI-MS m / z 539 [M+H].

[0573] Further purification was achieved by high vacuum sublimation.

[0574] General process for manufacturing top-emitting OLEDs

[0575] The devices were fabricated as follows: a 10nm hole-injection layer of HT-1 doped with D-1 (host to dopant ratio of 92:8 vol%) was deposited on a glass substrate with a silver anode, followed by the deposition of an undoped hole-transport layer of HT-1. A 5nm electron-blocking layer of HT-2 was deposited on the HTL. Subsequently, a blue fluorescent light-emitting layer of the emitter host H09 (Sun Fine Chemicals) doped with BD200 (Sun Fine Chemicals) (97:3 vol%) was deposited. A layer made of ET-1 was deposited on the light-emitting layer as a hole-blocking layer. An electron-transport layer was then deposited on the HBL. Subsequently, a first electron-injection layer made of LiQ was deposited for type A OLED devices, or a first electron-injection layer made of Li-doped ET-2 for type B devices. A second electron-injection layer of Yb was then deposited on the ETL for both type A and type B OLED devices, followed by a cathode composed of a silver-magnesium alloy with a volume ratio of 90:10. Finally, a capping layer made of HT-3 is deposited on top of the cathode. All depositions are performed by vacuum thermal evaporation.

[0576] Table 6: List of compounds used

[0577]

[0578]

[0579] Structure of ET-3 (Comparative Compound 1):

[0580]

[0581] Structure of ET-4 (Comparative Compound 2):

[0582]

[0583] Structure of ET-5 (Comparative Compound 3)

[0584]

[0585] Table 7 exemplarily describes an A-type OLED device with LiQ EIL1.

[0586] Table 7:

[0587]

[0588]

[0589] Table 8a and Table 8b show the device performance of the A-type OLED device.

[0590] Table 8a:

[0591] ETL Relative V[%] Relative CEff / CIEy [%] ET-3 100 100 B-1 102 114 B-1:C-3(3:7) 105 124 B-4 103 129 B-4:C-3(3:7) 102 128

[0592] Table 8b:

[0593] ETL Relative V[%] Relative CEff / CIEy [%] Relative life LT97[%] Relative voltage rise [%] ET-5 100 100 100 100 B-1 48 148 523 7 B-4 50 163 155 55

[0594] Table 9 exemplarily describes a B-type OLED device with ET-2:Li EIL1.

[0595] Table 9:

[0596]

[0597]

[0598] Table 10 shows the device performance of the B-type OLED device.

[0599] Table 10:

[0600] ETL Relative V[%] Relative CEff / CIEy [%] ET-3 100 100 ET-4:C-3(3:7) 112 100 B-1 104 103 B-1:C-3(3:7) 99 111 B-4 105 116 B-4:C-3(3:7) 99 114

[0601] Technical effects of the present invention

[0602] OLED devices comprising compounds of the present invention, such as exemplary compounds E1, E20, and E28, show improved current efficiency at comparable operating voltages.

[0603] The features disclosed in the foregoing description and the dependent claims can, both individually and in any combination thereof, serve as material for realizing the aspects of the disclosure set out in the independent claims in their various forms.

Claims

1. An organic light-emitting diode, comprising an opaque substrate, an anode, a cathode, a light-emitting layer, and an electron transport layer stack; in - the electron transport layer stack is arranged between the light emitting layer and the cathode; - the electron transport layer stack optionally comprises a first electron transport layer; - the electron transport layer stack comprises a second electron transport layer; - the second electron transport layer is arranged between the light-emitting layer and the cathode; - The second electron transport layer comprises a compound of formula (II) (The 2 ) m -(Z k -G) n (II) -n is 2 or greater; -m is 1 or 2; -k is 0, 1, or 2; -Ar 2 independently selected from substituted or unsubstituted C2 to C 42 Heteroaryl and substituted or unsubstituted C6 to C 60 aryl; - Among them, if Ar 2 is substituted, then one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; -Ar 2 Each C6 to C 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; -Z is independently selected from substituted or unsubstituted C6 to C 30 Aryl and substituted or unsubstituted C2 to C 42 heteroaryl; - wherein, if Z is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; - Each C6 to C on Z 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; -G comprises at least one 6-membered heteroaromatic ring, wherein the 6-membered heteroaromatic ring comprises one N atom; - G is selected so that the dipole moment of the compound G-phenyl is ≥ 1D and ≤ 7D; and - The first electron transport layer and the second electron transport layer do not contain electrical dopants.

2. The organic light emitting diode according to claim 1, wherein -Ar 2 Independently selected from: pyridyl, triazinyl, pyrimidinyl, pyrazinyl, quinoxalinyl; quinazolinyl, benzoquinazolinyl, benzimidazolyl, quinolinyl, benzoquinolinyl, benzoacridinyl, dibenzoacridinyl, fluoranthenyl, anthracenyl, naphthyl, terphenylidene, phenanthrolinyl and dinaphthofuranyl, each of which may be substituted or unsubstituted; - If each group is substituted, one or more substituents are independently selected from: D, C6 to C 24 Aryl, C3 to C 21 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; and -Ar 2 Each C6 to C 24 Aryl substituents and Ar 2 Each C3 to C 21 Heteroaryl substituents may be substituted with D, C1 to C4 alkyl or halogen.

3. The organic light emitting diode according to claim 1 or 2, wherein Z is independently selected from the following groups Each structure may be unsubstituted or substituted with one or more substituents selected from the group consisting of: D, C1 to C 12 Alkyl and phenyl.

4. An organic light emitting diode according to any one of the preceding claims, wherein -G is selected from and - Each structure may be unsubstituted or substituted with one or more substituents independently selected from the group consisting of D, phenyl, naphthyl, C1 to C 12 Alkyl and pyridyl.

5. The organic light-emitting diode according to any one of the preceding claims, wherein the compound of formula (II) has the following structure (IIa) in R a independently selected from substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C3 to C 21 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D, phenyl and C1 to C 12 alkyl; Z is independently selected from a single bond and C6 to C 24 aromatic subunits; G is independently selected from (IIa-1) to (IIa-3) For IIa-1, p is an integer from 0 to 4; For IIa-2 and IIa-3, p is an integer from 0 to 6; and R S Independently selected from D, C1 to C 12 Aryl, C1 to C 12 Alkyl and pyridyl, wherein each C1 to C 12 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

6. The organic light emitting diode according to any one of the preceding claims, wherein the compound of formula (II) is selected from the following structures B-1 to B-44 7. An organic light-emitting diode according to any one of the preceding claims, wherein the first electron transport layer comprises a compound of formula (I) (Ar 1 -A c ) a -X b (I) -a is 1 or 2; -b is 1 or 2; -c is 0 or 1; -Ar 1 independently selected from substituted or unsubstituted C6 to C 60 Aryl or substituted or unsubstituted C2 to C 42 heteroaryl; -in, If Ar 1 is substituted, then one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; -Ar 1 Each C6 to C 12 Aryl substituents and Ar 1 Each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; -A is independently selected from substituted or unsubstituted C6 to C 30 aryl; - wherein, if A is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; - Each C6 to C on A 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; -X is independently selected from substituted or unsubstituted C2 to C 42 Heteroaryl and substituted or unsubstituted C6 to C 60 aryl; -wherein, if X is substituted, one or more substituents are independently selected from: D, C6 to C 12 Aryl, C3 to C 11 heteroaryl and C1 to C6 alkyl, D, C1 to C6 alkoxy, C3 to C6 branched alkyl, C3 to C6 cyclic alkyl, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, halogen, CN or PY (R 10 )2, wherein Y is selected from O, S or Se, preferably O, and R 10 Independently selected from C6 to C 12 Aryl, C3 to C 12 heteroaryl, C1 to C6 alkyl, C1 to C6 alkoxy, partially or perfluorinated C1 to C6 alkyl, partially or perfluorinated C1 to C6 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy; - where each C6 to C on X 12 The aryl substituent and each C3 to C 11 The heteroaryl substituent may be substituted with D, C1 to C4 alkyl, or halogen; - The dipole moment of the compound of formula (I) is ≥0D and ≤4D.

8. The organic light emitting diode according to claim 7, wherein Ar 1 are independently selected from: phenyl, naphthyl, anthracenyl, fluoranthenyl, xanthenyl, spiro-xanthenyl, fluorenyl, spiro-fluorenyl, triphenylsilyl, tetraphenylsilyl or a group having formula (Ia), in -Ar having the formula (Ia) 1 Combine with A at *1; -R 1 to R 5 Independently selected from: H, substituted or unsubstituted C6 to C 12 Aryl and substituted or unsubstituted C4 to C 10 heteroaryl; - wherein one or more substituents, if present, are independently selected from D, C1 to C4 alkyl or halogen. 9 . The organic light emitting diode according to claim 7 , wherein A is selected from the group consisting of a phenylene group, a naphthalene group, a biphenylene group, and a terphenylene group, and the groups may be substituted or unsubstituted.

10. The organic light emitting diode according to any one of claims 7 to 9, wherein X is independently selected from the group consisting of triazinyl, pyrimidinyl, pyrazinyl, quinazolinyl, benzoquinazolinyl, benzimidazolyl, quinolinyl, benzoquinolinyl, benzoacridinyl, dibenzoacridinyl, fluoranthenyl, anthracenyl, naphthyl, terphenylidene, phenanthrolinyl and dinaphthofuranyl, and each of these groups may be substituted or unsubstituted. 11 . The organic light-emitting diode according to claim 1 , wherein the second electron transport layer further comprises compound (III), wherein the compound (III) comprises 8 to 13 aromatic or heteroaromatic rings. 12 . The organic light emitting diode according to claim 11 , wherein the compound (III) comprises two or more heteroaromatic rings, and the heteroaromatic rings are separated from each other by at least one aromatic ring not containing a heteroatom. 13 . The organic light emitting diode according to claim 1 , wherein the organic light emitting diode further comprises an electron injection layer, and the electron injection layer is arranged between the second electron transport layer and the cathode.

14. A device comprising an organic light emitting diode according to any one of the preceding claims, wherein the device is a display device or a lighting device.

15. A compound of formula (IV) in R a independently selected from substituted or unsubstituted C6 to C 24 Aryl and substituted or unsubstituted C3 to C 18 Heteroaryl, where R a is substituted, then one or more substituents are independently selected from: D, phenyl and C1 to C 12 alkyl; Z is independently selected from a single bond and C6 to C 24 aromatic subunits; G is independently selected from (IVa-1) to (IVa-3) For IVa-1, p is an integer from 0 to 4; For IVa-2 and IVa-3, p is an integer from 0 to 6; and R S Independently selected from D, C1 to C 12 Aryl, C1 to C 12 Alkyl and pyridyl, among which Each C1 to C 12 The aryl and pyridyl groups may be unsubstituted or substituted with one or more D and C1 to C4 alkyl groups.

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