Patent Application
20240397812
The present invention relates to an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least a first emission layer, and a hole injection layer that comprises a metal complex.
Organic electronic devices, such as organic light-emitting diodes OLEDs, which are self-emitting devices, have a wide viewing angle, excellent contrast, quick response, high brightness, excellent operating voltage characteristics, and color reproduction. A typical OLED comprises an anode layer, a hole injection layer HIL, a hole transport layer HTL, an emission layer EML, an electron transport layer ETL, and a cathode layer, which are sequentially stacked on a substrate. In this regard, the HIL, the HTL, the EML, and the ETL are thin films formed from organic compounds.
When a voltage is applied to the anode and the cathode, holes injected from the anode move to the EML, via the HIL and HTL, and electrons injected from the cathode move to the EML, via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted. The injection and flow of holes and electrons should be balanced, so that an OLED having the above-described structure has low operating voltage, excellent efficiency and/or a long lifetime.
Performance of an organic light emitting diode may be affected by characteristics of the hole injection layer, and among them, may be affected by characteristics of the hole transport compound and the metal complexes which are contained in the hole injection layer.
WO 2009/050115 A1 refers to organometallic latent catalyst compounds, which are suitable as catalysts in polyaddition or polycondensation reactions which are catalysed by a Lewis acid type catalyst, in particular for the crosslinking of a blocked or unblocked isocyanate or isothiocyanate component with a polyol or polythiol to form a polyurethane (PU).
WO 2021/048044 A1 refers to an to an electronic component comprising a cerium IV complex, a doped semi-conductor matrix material comprising the cerium IV complex and at least one electron donor, the use of the cerium IV complex, especially as an organic semi-conductor, as a dopant in organic semiconductor matrix materials and as a charge injector in a charge injection layer, and new cerium IV complexes.
US 2011/031876 A1 refers to an organic light emitting diode (OLED) display device is provided. The OLED display device according to an embodiment of this document may comprise a substrate and a number of unit pixels placed over the substrate. Each of the unit pixels comprises emission layers each interposed between first electrodes and a second electrode. The unit pixel further comprises three subpixels emitting respective pieces of light of red, green, and blue. Each of two or less of the three subpixels may comprise a translucent reflection layer.
Photoelectron Spectrophotometer in air. Surface Analyzer. Model AC-3″, 11 Jun. 2012 (2012 Jun. 11), pages 1-6, XP055029420, Retrieved from the Internet: URL: http://www.rkiinstruments.com/pdf/AC3.pdf [retrieved on 2012 Jun. 11].
There remains a need to improve performance of organic electronic devices by providing hole injection layers with improved performance, in particular to achieve improved operating voltage, voltage stability over time and/or lifetime through improving the characteristics of the hole injection layer and the organic electronic device.
Further there remains a need to provide hole injection layers which enable injection into adjacent layers comprising compounds with a HOMO level further away from vacuum level.
It is a further objective to provide a hole injection layer comprising compounds which can be deposited through vacuum thermal evaporation under conditions suitable for mass production.
It is a further objective to provide metal complexes with improved thermal properties, in particular improved thermal stability and/or rate onset temperature.
An aspect of the present invention provides an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
Another aspect of the present invention provides an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
Another aspect of the present invention provides an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
It should be noted that throughout the application and the claims any An, Arn, Rn, Tn etc. always refer to the same moieties, unless otherwise noted.
Ancillary ligands are defined as those ligands that provide the appropriate steric and electronic environment around the central element but remain innocent in any transformation that the compound undergoes. In contrast, reactive ligands are those groups that undergo changes.
In the present specification, when a definition is not otherwise provided, “substituted” refers to at least one substituted with D, C6 aryl, C3 to C9 heteroaryl, C1 to C6 alkyl, 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 C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy, COR3, COOR3, halogen, F or CN.
In the present specification, when a definition is not otherwise provided, a substituted aryl group with at least 6 C-ring atoms can be substituted with 1, 2, 3, 4 or 5 substituents. For example a substituted C6 aryl group may have 1, 2, 3, 4 or 5 phenyl substituents.
However, in the present specification “aryl substituted” refers to a substitution with one or more aryl groups, which themselves may be substituted with one or more aryl and/or heteroaryl groups.
Correspondingly, in the present specification “heteroaryl substituted” refers to a substitution with one or more heteroaryl groups, which themselves may be substituted with one or more aryl and/or heteroaryl groups.
In the present specification, when a definition is not otherwise provided, a substituted heteroaryl group with at least 2 C-ring atoms can be substituted with one or more substituents. For example a substituted C2 heteroaryl group may have 1 or 2 substituents.
In the present specification, when a definition is not otherwise provided, an “alkyl group” refers to a saturated aliphatic hydrocarbyl group. The alkyl group may be a C1 to C6 alkyl group. More specifically, the alkyl group may be a C1 to C4 alkyl group or a C1 to C3 alkyl group. For example, a C1 to C4 alkyl group includes 1 to 4 carbons in alkyl chain, and may be selected from methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and tert-butyl.
Specific examples of the alkyl group may be a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a branched pentyl group, a hexyl group.
The term “cycloalkyl” refers to saturated hydrocarbyl groups derived from a cycloalkane by formal abstraction of one hydrogen atom from a ring atom comprised in the corresponding cycloalkane. Examples of the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methyl cyclohexyl group, an adamantly group and the like.
The term “hetero” is understood the way that at least one carbon atom, in a structure which may be formed by covalently bound carbon atoms, is replaced by another polyvalent atom. Preferably, the heteroatoms are selected from B, Si, N, P, O, S; more preferably from N, P, O, S.
Preferred examples of the hole transport compounds, which can be covalent hole transport compounds, are organic compounds, consisting substantially from covalently bound C, H, O, N, S, which may optionally comprise also covalently bound B, P or Si. In one embodiment, the hole transport compounds, which can be a covalent compound, is free of metal atoms and majority of its skeletal atoms may be selected from C, O, S, N. Alternatively, the covalent compound is free of metal atoms and majority of its skeletal atoms may be selected from C and N.
In the present specification, “aryl group” and “aromatic rings” refers to a hydrocarbyl group which can be created by formal abstraction of one hydrogen atom from an aromatic ring in the corresponding aromatic hydrocarbon. Aromatic hydrocarbon refers to a hydrocarbon which contains at least one aromatic ring or aromatic ring system. Aromatic ring or aromatic ring system refers to a planar ring or ring system of covalently bound carbon atoms, wherein the planar ring or ring system comprises a conjugated system of delocalized electrons fulfilling Hückel's rule. Examples of aryl groups include monocyclic groups like phenyl or tolyl, polycyclic groups which comprise more aromatic rings linked by single bonds, like biphenyl, and polycyclic groups comprising fused rings, like naphthyl or fluorenyl.
Analogously, under “heteroaryl” and “heteroaromatic”, it is especially where suitable understood a group derived by formal abstraction of one ring hydrogen from a heterocyclic aromatic ring in a compound comprising at least one such ring.
The term “non-heterocycle” is understood to mean a ring or ring-system comprising no hetero-atom as a ring member.
The term “heterocycle” is understood to mean that the heterocycle comprises at least one ring comprising one or more hetero-atoms. A heterocycle comprising more than one ring means that all rings comprising a hetero-atom or at least one ring comprising a hetero atom and at least one ring comprising C-atoms only and no hetero atom.
Under heterocycloalkyl, it is especially where suitable understood a group derived by formal abstraction of one ring hydrogen from a saturated cycloalkyl ring in a compound comprising at least one such ring.
The term “fused aryl rings” or “condensed aryl rings” is understood the way that two aryl rings are considered fused or condensed when they share at least two common sp2-hybridized carbon atoms.
The term “fused ring system” is understood to mean a ring system wherein two or more rings share at least two atoms.
The term “5-, 6- or 7-member ring” is understood to mean a ring comprising 5, 6 or 7 atoms. The atoms may be selected from C and one or more hetero-atoms.
In the present specification, the single bond refers to a direct bond.
In the present specification, when a definition is not otherwise provided, “substituted” refers to one substituted with a H, deuterium, C1 to C12 alkyl, unsubstituted C6 to C18 aryl, and unsubstituted C3 to C18 heteroaryl.
In the present specification, when a substituent is not named, the substituent can be a H.
In the context of the present invention, “different” means that the compounds do not have an identical chemical structure.
The term “free of”, “does not contain”, “does not comprise” does not exclude impurities which may be present in the compounds prior to deposition. Impurities have no technical effect with respect to the object achieved by the present invention.
The term “contacting sandwiched” refers to an arrangement of three layers whereby the layer in the middle is in direct contact with the two adjacent layers.
The terms “light-absorbing layer” and “light absorption layer” are used synonymously.
The terms “light-emitting layer”, “light emission layer” and “emission layer” are used synonymously.
The terms “OLED”, “organic light-emitting diode” and “organic light-emitting device” are used synonymously.
The terms anode, anode layer and anode electrode are used synonymously.
The term “at least two anode sub-layers” is understood to mean two or more anode sub-layers, for example two or three anode sub-layers. The terms cathode, cathode layer and cathode electrode are used synonymously.
The term “hole injection layer” is understood to mean a layer which improves charge injection from the anode layer into further layers in the organic electronic device or from further layers of the organic electronic device into the anode.
The term “hole transport layer” is understood to mean a layer which transports holes between the hole injection layer and further layers arranged between the hole injection layer and the cathode layer.
The operating voltage U is measured in Volt.
In the context of the present specification the term “essentially non-emissive” or “non-emissive” means that the contribution of the matrix compound of formula (IIIa) or formula (IIIb), metal complex and/or layer, such as hole injection layer, to the visible emission spectrum from an organic electronic device, such as OLED or display device, is less than 10%, preferably less than 5% relative to the visible emission spectrum. The visible emission spectrum is an emission spectrum with a wavelength of about ≥380 nm to about ≤780 nm.
In the specification, hole characteristics refer to an ability to donate an electron to form a hole when an electric field is applied and that a hole formed in the anode may be easily injected into the emission layer and transported in the emission layer due to conductive characteristics according to a highest occupied molecular orbital (HOMO) level.
In addition, electron characteristics refer to an ability to accept an electron when an electric field is applied and that electrons formed in the cathode may be easily injected into the emission layer and transported in the emission layer due to conductive characteristics according to a lowest unoccupied molecular orbital (LUMO) level.
The term “LUMO level” is understood to mean the lowest unoccupied molecular orbital and is determined in eV (electron volt).
The term “LUMO level further away from vacuum level” is understood to mean that the absolute value of the LUMO level is higher than the absolute value of the LUMO level of the reference compound.
The term “HOMO level” is understood to mean the highest occupied molecular orbital and is determined in eV (electron volt).
The term “HOMO level further away from vacuum level” is understood to mean that the absolute value of the HOMO level is higher than the absolute value of the HOMO level of the reference compound. For example, the term “further away from vacuum level than the HOMO level of N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine is understood to mean that the absolute value of the HOMO level of the matrix compound of the hole injection layer is higher than the HOMO level of N2,N2,N2′,N2′,N7,N7,N7,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine.
The term “absolute value” is understood to mean the value without the “-” symbol. According to one embodiment of the present invention, the HOMO level of the matrix compound of the hole injection layer may be calculated by quantum mechanical methods.
The work function of the first metal is measured in eV (electron volt). Tabulated values of work functions can be found for example in CRC Handbook of Chemistry and Physics version 2008, p. 12-114. Further, tabulated values of work functions can be found for example at https://en.wikipedia.org/wiki/Work_function#cite_note-12.
For example, the metals Ag, Mg, Al, Cr, Pt, Au, Pd, Ni, Nd, and Ir are metals having a work function in the range of ≥4 and ≤6 eV.
According to one embodiment of the present invention, the work function of the first metal of the first anode sub-layer is determined by measuring the photoelectric effect by means of ultraviolet photoelectron spectroscopy in vacuum.
Surprisingly, it was found that the organic electronic device according to the invention solves the problem underlying the present invention by enabling organic electronic devices, such as organic light-emitting diodes, in various aspects superior over the organic electronic devices known in the art, in particular with respect to operating voltage, voltage stability over time and/or lifetime.
Additionally, it was found that the problem underlying the present invention can be solved by providing compounds which may be suitable for deposition through vacuum thermal evaporation under conditions suitable for mass production. In particular, the thermal stability and/or rate onset temperature of the metal complex and the matrix compound of the present invention may be in a range suitable for mass production.
An aspect of the present invention provides an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
According to one embodiment the organic electronic device comprises a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
According to one embodiment the organic electronic device comprises an organic electronic device comprising a substrate, an anode layer, a cathode layer, at least one first emission layer, and a hole injection layer, wherein
M4⊕(L⊖)4(AL)n (I),
According to one embodiment, “n” is an integer selected from 0, 1 or 2, preferably 2, further preferred 1 and in addition preferred 0.
According to one embodiment, the first metal of the first anode sub-layer may have a work function in the range of ≥4.2 and ≤6 eV. The first metal may be selected from a metal or a metal alloy.
According to one embodiment, wherein the first metal of the first anode sub-layer may be selected from the group comprising Ag, Mg, Al, Cr, Pt, Au, Pd, Ni, Nd, Ir, preferably Ag, Au or Al, and more preferred Ag.
The first anode sub-layer may have a thickness in the range of 5 to 200 nm, alternatively 8 to 180 nm, alternatively 8 to 150 nm, alternatively 100 to 150 nm.
The first anode sub-layer may formed by depositing the first metal via vacuum thermal evaporation.
It is to be understood that the first anode layer is not part of the substrate.
According to one embodiment, the transparent conductive oxide may be selected from the group comprising indium tin oxide (ITO) or indium zinc oxide (IZO), more preferred indium tin oxide (ITO), preferably ITO or IZO.
The first anode sub-layer may have a thickness in the range of 3 to 200 nm, alternatively 3 to 180 nm, alternatively 3 to 150 nm, alternatively 3 to 20 nm.
The second anode sub-layer may be formed by sputtering of the transparent conductive oxide.
According to one embodiment the anode layer of the organic electronic device may comprises at least three anode sub-layers of a first anode sub-layer, a second anode sub-layer and third anode sub-layer. According to one embodiment the anode layer of the organic electronic device may comprises in addition to the first and second anode sub-layers a third anode sub-layer, wherein the third anode sub-layer comprises a transparent conductive oxide, wherein the third anode sub-layer may be arranged between the substrate and the first anode sub-layer.
The third anode sub-layer may have a thickness in the range of 3 to 200 nm, alternatively 3 to 180 nm, alternatively 3 to 150 nm, alternatively 3 to 20 nm.
The third anode sub-layer may be formed by sputtering of the transparent conductive oxide.
It is to be understood that the third anode layer is not part of the substrate.
According to one embodiment, the anode layer may comprise a first anode sub-layer comprising or consisting of Ag or Au, a second anode-sub-layer comprising or consisting of ITO or IZO and optionally a third anode sub-layer comprising or consisting of ITO or IZO. Preferably the first anode sub-layer may comprises or consists of Ag, the second anode-sublayer may comprises or consists of ITO and the third anode sub-layer may comprises or consists of ITO. Preferably, the transparent conductive oxide in the second and third anode sub-layer may be selected the same.
According to one embodiment, the anode layer may comprise a first anode sub-layer comprising Ag or Au having a thickness of 100 to 150 nm, a second anode-sub-layer comprising ITO or IZO having a thickness of 3 to 20 nm and a third anode sub-layer comprising ITO or IZO having a thickness of 3 to 20 nm.
The metal complex and the metal complex according to formula (I) are non-emissive. In the context of the present specification the term “essentially non-emissive” or “non-emissive” means that the contribution of the metal complex according to formula (I) to the visible emission spectrum from an organic electronic device, such as OLED or display device, is less than 10%, preferably less than 5% relative to the visible emission spectrum. The visible emission spectrum is an emission spectrum with a wavelength of about ≥380 nm to about ≤780 nm.
According to one embodiment of the present invention, the valency of M of the metal complex according to formula (I) is 4.
According to one embodiment, wherein the metal is selected from Ce or Hf.
According to one embodiment, wherein the metal complex of formula (I) may have a molecular weight Mw of ≥287 g/mol and ≤2000 g/mol, preferably a molecular weight Mw of ≥400 g/mol and ≤1500 g/mol, further preferred a molecular weight Mw of ≥580 g/mol and ≤1500 g/mol, in addition preferred a molecular weight Mw of ≥580 g/mol and ≤1400 g/mol.
According to one embodiment, wherein AL is selected from the group comprising H2O, C2 to C40 mono- or multi-dentate ethers and C2 to C40 thioethers, C2 to C40 amines, C2 to C40 phosphine, C2 to C20 alkyl nitrile or C2 to C40 aryl nitrile, or a compound according to Formula (II);
wherein
According to one embodiment, wherein the ligand L in compound of formula (I) comprises per ligand L at least 14 covalently bound atoms and may be selected from a group comprising:
According to one embodiment, wherein the ligand L and the ligand L of formula I may be selected from G1 to G76:
According to one embodiment, L of formula (I) is selected from (G1) to (G18), preferably from (G2) to (G10).
According to one embodiment, wherein the metal complex and the metal complex of formula I of the hole injection are selected from the following formulas (Ia) to (Id):
According to one embodiment, wherein A1 and A2 may be selected different.
The negative charge in compounds of formulas (I), (Ia) to (Id), may be delocalised partially or fully over the N(SO2)2 group, NSO2 group or CO2 group or CO group and optionally also over the A1 and A2 groups.
According to one embodiment, wherein
According to one embodiment of the present invention, the substituents on A1 and A2 are independently selected from halogen, with F especially preferred, C1 to C3 perhalogenated, especially perfluorinated alkyl or alkoxy, or —(O)l—CmH2m—CnHaln2n+1 with l=0 or 1, especially 0, m=1 or 2, especially 1 and n=1 to 3, especially n=1 or 2 and Hal=halogen, especially F.
According to one embodiment of the present invention, at least one of A1 and A2 is substituted alkyl and the substituents of the alkyl moiety are fluorine with the number nF (of fluorine substituents) and nH (of hydrogens) follow the equation: nF>nH+2.
According to one embodiment of the present invention, at least one of A1 and A2 is selected from perfluorinated C1 to C6 alkyl and/or phenyl substituted with F or CF3.
According to one embodiment of the present invention, at least one of A1 and A2 is selected from perfluorinated alkyl or aryl.
According to one embodiment of the present invention, the sum of A1 and A2 comprise ≥3 carbon atoms and ≤25 carbon atoms, or ≥4 carbon atoms and ≤24 carbon atoms, or ≥5 carbon atoms and ≤18 carbon atoms.
According to one embodiment of the present invention, at least one of A1 and A2 is substituted C3 to C6 alkyl.
According to one embodiment of the present invention, at least one of A1 and A2 is substituted C3 to C6 linear or cyclic alkyl.
According to one embodiment of the present invention, compound of formula (I) is free of alkoxy, COR1 and/or COOR1 groups.
According to one embodiment of the present invention, A2 is aryl or heteroaryl, whereby the substituents of the aryl and/or heteroaryl moiety are selected from hydrogen, halogen, F, CN or trifluoro methyl.
According to one embodiment of the present invention A2 is phenyl or six-membered heteroaryl, which is substituted with 1 to 5 F atoms.
According to one embodiment of the present invention, A1 is substituted or unsubstituted C1 to C6 alkyl or substituted phenyl and A2 is substituted C3 to C6 alkyl; alternatively, A1 is substituted or unsubstituted C1 to C4 alkyl or substituted phenyl and A2 is substituted C3 to C4 alkyl or substituted phenyl.
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia) to (Id), wherein at least one of A1 and A2 may comprises a substituent, wherein at least one of the substituents of A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; preferably at least one of A1 and A2 may comprises at least two substituents, wherein the substituents on A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; and further preferred A1 and A2 comprise at least one substituent independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5, or CN; and in addition preferred A1 and A2 may comprise at least two substituents independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5 or CN;
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia), (Ib), (Ic), (Id), wherein M is selected from Ce(IV), Zr(IV) or Hf(IV), preferably M is Ce(IV) or Hf(IV); A1, A2 and A3 may be independently selected from substituted or unsubstituted C1 to C12 alkyl, substituted or unsubstituted C6 to C12 aryl, substituted or unsubstituted C3 to C12 heteroaryl; wherein at least one of A1, A2 and A3 may comprises a substituent, wherein at least one of the substituents of A1, A2 and A3 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; preferably at least one of A1, A2 and A3 may comprises at least two substituents, wherein the substituents on A1, A2 and A3 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; and further preferred A1, A2 and A3 comprise at least one substituent independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5, or CN; and in addition preferred A1, A2 and A3 may comprise at least two substituents independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5 or CN.
The sum of A1, A2 and A3 may comprise ≥3 carbon atoms and ≤25 carbon atoms.
According to one embodiment, wherein the sum of A1 and A2 may comprise ≥3 carbon atoms and ≤25 carbon atoms.
According to one embodiment, wherein A3 is selected from H or D, preferably H.
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia) to (Id), wherein A3 is selected from H or D, preferably H and at least one of A1 and A2 may comprises a substituent, wherein at least one of the substituents of A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; preferably at least one of A1 and A2 may comprises at least two substituents, wherein the substituents on A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; and further preferred A1 and A2 comprise at least one substituent independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5, or CN; and in addition preferred A1 and A2 may comprise at least two substituents independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5 or CN;
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia), (Ib), (Ic), (Id), wherein M is selected from Ce(IV), Zr(IV) or Hf(IV), preferably M is Ce(IV) or Hf(IV); A3 is selected from H or D, preferably H and A1 and A2 may be independently selected from substituted or unsubstituted C1 to C12 alkyl, substituted or unsubstituted C6 to C12 aryl, substituted or unsubstituted C3 to C12 heteroaryl; wherein at least one of A1 and A2 may comprises a substituent, wherein at least one of the substituents of A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; preferably at least one of A1 and A2 may comprises at least two substituents, wherein the substituents on A1 and A2 may be independently selected from C3 to C9 heteroaryl, C1 to C6 alkoxy, C3 to C6 branched alkoxy, C3 to C6 cyclic alkoxy, partially or perfluorinated C1 to C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkoxy, COR1, COOR1, halogen, F or CN; and further preferred A1 and A2 comprise at least one substituent independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5, or CN; and in addition preferred A1 and A2 may comprise at least two substituents independently selected from halogen, F, CF3, C2F5, C3F7, C4F9, OCF3, OC2F5 or CN.
According to one embodiment, wherein the metal complex and the metal complex of formula I are free of alkoxy, COR1 and/or COOR1 groups, wherein R1 is selected from C6 aryl, C3 to C9 heteroaryl, C1 to C6 alkyl, 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 C16 alkyl, partially or perfluorinated C1 to C16 alkoxy, partially or perdeuterated C1 to C6 alkyl, partially or perdeuterated C1 to C6 alkoxy.
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia) to (Id), wherein A1, A2 and/or A3 are selected from the following Formulas D1 to D71:
wherein the “*” denotes the binding position.
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia) to (Id), wherein one A1, A2 or A3 is selected from the above formulae D1 to D34 and/or D38 to D71; preferably D3 to D34 and/or D39 to D71.
According to one embodiment, wherein the metal complex of the hole injection layer may be selected from the following formulas (Ia) to (Id), wherein A1 is selected from formula D1 to D34 and/or D38 to D71, A2 is selected from substituted or unsubstituted C1 to C12 alkyl, and A3 is selected from H, D, F, CN, C1 to C4 alkyl, partially or perfluorinated C1 to C4 alkyl.
According to one embodiment, wherein the metal complex and the metal complex of formula I are selected from E1 to E28:
wherein M is selected from Ce(IV), Zr(IV) or Hf(IV), preferably M is Ce(IV) or Hf(IV). Preferably, the metal complex and the metal complex of formula I are selected from E2 to E17.
According to an embodiment, the metal complex of formula I is selected from formulae H1 to H14:
According to one embodiment, the metal complex of formula I is selected from H1 to H3, H11, H12, H13 and/or H14.
According to one embodiment, the metal complex of formula I is selected from H1 to H3, H7, H10, H12, H13 and/or H14.
According to one embodiment the hole injection layer may further comprises a matrix compound, preferably the matrix compound is a covalent matrix compound.
According to one embodiment the hole transport layer may further comprises a matrix compound, preferably the matrix compound is a covalent matrix compound.
According to one embodiment the hole transport layer comprises a matrix compound and the hole injection layer comprises a matrix compound.
According to one embodiment the hole transport layer comprises a matrix compound and the hole injection layer comprises a matrix compound, wherein the matrix compound in the hole injection layer and hole transport layer are selected the same.
According to one embodiment the covalent matrix compound of the hole injection layer and/or hole transport layer may be selected from at least one organic compound. The covalent matrix may consists substantially from covalently bound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
According to one embodiment of the organic electronic device, the hole injection layer and/or hole transport layer further comprises a matrix compound, wherein the matrix compound of the hole injection layer and/or hole transport layer may be selected from organic compounds consisting substantially from covalently bound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
Organometallic compounds comprising covalent bonds carbon-metal, metal complexes comprising organic ligands and metal salts of organic acids are further examples of organic compounds that may serve as covalent matrix compounds of the hole injection layer and/or hole transport layer.
In one embodiment, the covalent matrix compound lacks metal atoms and majority of its skeletal atoms may be selected from C, O, S, N. Alternatively, the covalent matrix compound lacks metal atoms and majority of its skeletal atoms may be selected from C and N.
According to one embodiment, the covalent matrix compound of the hole injection layer and/or hole transport layer may have a molecular weight Mw of ≥400 and ≤2000 g/mol, preferably a molecular weight Mw of ≥450 and ≤1500 g/mol, further preferred a molecular weight Mw of ≥500 and ≤1000 g/mol, in addition preferred a molecular weight Mw of ≥550 and ≤900 g/mol, also preferred a molecular weight Mw of ≥600 and ≤800 g/mol.
In one embodiment, the HOMO level of the covalent matrix compound may be more negative than the HOMO level of N2,N2,N2′,N2′,N7,N7,N7,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine (CAS 207739-72-8) when determined under the same conditions.
In one embodiment, the HOMO level of the covalent matrix compound, when calculated using TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase, may be more negative than −4.27 eV, preferably more negative than −4.3 eV, alternatively more negative than −4.5 eV, alternatively more negative than −4.6 eV, alternatively more negative than −4.65 eV.
In one embodiment, the HOMO level of the covalent matrix compound may be more negative than the HOMO level of N2,N2,N2′,N2′,N7,N7,N7,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine (CAS 207739-72-8) and more positive than the HOMO level of N-([1,1′-biphenyl]-4-yl)-N-(2-(9,9-diphenyl-9H-fluoren-4-yl)phenyl)-9,9-dimethyl-9H-fluoren-2-amine when determined under the same conditions.
In one embodiment of the present invention, the covalent matrix compound may be free of alkoxy groups.
Preferably, the covalent matrix compound comprises at least one arylamine moiety, alternatively a diarylamine moiety, alternatively a triarylamine moiety.
Preferably, the matrix compound of the hole injection layer and/or hole transport layer is free of metals and/or ionic bonds.
According to another aspect of the present invention, the at least one matrix compound, also referred to as “substantially covalent matrix compound”, of the hole injection layer and/or hole transport layer may comprises at least one arylamine compound, diarylamine compound, triarylamine compound, a compound of formula (IIIa) or a compound of formula (IIIb):
According to an embodiment of the organic electronic device, wherein the matrix compound of the hole injection layer and/or hole transport layer comprises a compound of formula (IIIa) or formula (IIIb):
Preferably, the substituents of Ar1, Ar2, Ar3, Ar4 and Ar5 are selected the same or different from the group comprising H, straight-chain alkyl having 1 to 6 carbon atoms, branched alkyl having 1 to 6 carbon atoms, cyclic alkyl having 3 to 6 carbon atoms, alkenyl or alkynyl groups having 2 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, C6 to C18 aryl, C3 to C18 heteroaryl, a fused ring system comprising 2 to 4 unsubstituted 5- to 7-member rings and the rings are selected from the group comprising unsaturated 5- to 7-member ring of a heterocycle, 5- to 6-member of an aromatic heterocycle, unsaturated 5- to 7-member ring of a non-heterocycle, and 6-member ring of an aromatic non-heterocycle; more preferred the substituents are selected the same or different from the group consisting of H, straight-chain alkyl having 1 to 4 carbon atoms, branched alkyl having 1 to 4 carbon atoms, cyclic alkyl having 3 to 4 carbon atoms and/or phenyl.
Thereby, the compound of formula (IIIa) or (IIIb) may have a rate onset temperature suitable for mass production.
According to an embodiment of the organic electronic device, wherein the matrix compound of the hole injection layer and/or hole transport layer comprises a compound of formula (IIIa) or formula (IIIb):
According to an embodiment of the organic electronic device, wherein the matrix compound of the hole injection layer and/or hole transport layer comprises a compound of formula (IIIa) or formula (IIIb):
Thereby, the compound of formula (IIIa) or (IIIb) may have a rate onset temperature suitable for mass production.
According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from a single bond, phenylene, biphenylene or terphenylene. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene, biphenylene or terphenylene and one of T1, T2, T3, T4 and T5 are a single bond. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene or biphenylene and one of T1, T2, T3, T4 and T5 are a single bond. According to an embodiment wherein T1, T2, T3, T4 and T5 may be independently selected from phenylene or biphenylene and two of T1, T2, T3, T4 and T5 are a single bond.
According to an embodiment wherein T1, T2 and T3 may be independently selected from phenylene and one of T1, T2 and T3 are a single bond. According to an embodiment wherein T1, T2 and T3 may be independently selected from phenylene and two of T1, T2 and T3 are a single bond.
According to an embodiment wherein T6 may be phenylene, biphenylene, terphenylene. According to an embodiment wherein T6 may be phenylene. According to an embodiment wherein T6 may be biphenylene. According to an embodiment wherein T6 may be terphenylene.
According to an embodiment wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from K1 to K16:
According to an embodiment, wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from K1 to K15; alternatively selected from K1 to K10 and K13 to K15.
According to an embodiment, wherein Ar1, Ar2, Ar3, Ar4 and Ar5 may be independently selected from the group consisting of K1, K2, K5, K7, K9, K10, K13 to K16.
The rate onset temperature may be in a range particularly suited to mass production, when Ar1, Ar2, Ar3, Ar4 and Ar5 are selected in this range.
The “matrix compound of formula (IIIa) or formula (IIIb)” may be also referred to as “hole transport compound”.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings and at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings and at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings, and at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems comprising heteroaromatic rings and optional at least ≥1 to ≤3 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle, and additional preferred wherein the aromatic fused ring systems comprising heteroaromatic rings are unsubstituted and optional at least ≥1 to ≤3 unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems, which comprises substituted or unsubstituted heteroaromatic rings.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 7-member ring of a heterocycle.
According to one embodiment substituted or unsubstituted aromatic fused ring systems of the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the substituted or unsubstituted aromatic fused ring systems of the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems, and wherein the aromatic fused ring system comprises substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems, which comprises substituted or unsubstituted heteroaromatic rings, and wherein the aromatic fused ring system comprises substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems, and wherein the aromatic fused ring system comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least ≥1 to ≤6 substituted or unsubstituted aromatic fused ring systems, preferably ≥2 to ≤5 substituted or unsubstituted aromatic fused ring systems, and further preferred 3 or 4 substituted or unsubstituted aromatic fused ring systems, which comprises substituted or unsubstituted heteroaromatic rings, and wherein the aromatic fused ring system comprises at least ≥1 to ≤3 or 2 substituted or unsubstituted unsaturated 5- to 7-member ring of a heterocycle.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises:
It should be noted here that the wording “aromatic fused ring system” may include at least one aromatic ring and at least one substituted or unsubstituted unsaturated 5- to 7-member ring. It should be noted here that the substituted or unsubstituted unsaturated 5- to 7-member ring may not be an aromatic ring.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least at least ≥1 to ≤6, preferably ≥2 to ≤5, or further preferred 3 or 4 of the substituted or unsubstituted aromatic fused ring systems with:
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least at least ≥1 to ≤6, preferably ≥2 to ≤5, or further preferred 3 or 4 of the substituted or unsubstituted aromatic fused ring systems with:
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises:
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises a hetero-atom, which may be selected from the group comprising O, S, N, B or P, preferably the hetero-atom may be selected from the group comprising O, S or N.
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may comprises at least at least ≥1 to ≤6, preferably ≥2 to ≤5, or further preferred 3 or 4 of the substituted or unsubstituted aromatic fused ring systems with:
According to one embodiment the matrix compound of formula (IIIa) or formula (IIIb) may be free of hetero-atoms which are not part of an aromatic ring and/or part of an unsaturated 7-member-ring, preferably the hole transport compound or the hole transport compound according to formula (I) may be free on N-atoms except N-atoms which are part of an aromatic ring or are part of an unsaturated 7-member-ring.
According to one embodiment, the hole transport compound comprises at least one naphthyl group, carbazole group, dibenzofurane group, dibenzothiophene group and/or substituted fluorenyl group, wherein the substituents are independently selected from methyl, phenyl or fluorenyl.
According to an embodiment of the electronic device, wherein the matrix compound of formula (IIIa) or formula (IIIb) are selected from F1 to F18:
The matrix compound of the hole injection layer and/or hole transport layer may be free of HTM014, HTM081, HTM163, HTM222, EL-301, HTM226, HTM355, HTM133, HTM334, HTM604 and EL-22T. The abbreviations denote the manufacturers' names, for example, of Merck or Lumtec.
The hole injection layer (HIL) may be formed on the anode layer by vacuum deposition, spin coating, printing, casting, slot-die coating, Langmuir-Blodgett (LB) deposition, or the like. When the HIL is formed using vacuum deposition, the deposition conditions may vary according to the hole transport compound that is used to form the HIL, and the desired structure and thermal properties of the HIL. In general, however, conditions for vacuum deposition may include a deposition temperature of 100° C. to 350° C., a pressure of 10−8 to 10−3 Torr (1 Torr equals 133.322 Pa), and a deposition rate of 0.1 to 10 nm/sec.
When the HIL is formed using spin coating or printing, coating conditions may vary according to the hole transport compound that is 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 thermal treatment temperature of about 80° C. to about 200° C. Thermal treatment removes a solvent after the coating is performed.
The HIL may be formed of a metal complex or a metal complex of formula (I) or formulae (Ia) to (Id) and optionally of any compound of formulae (IIIa) or (IIIb).
The thickness of the HIL may be in the range from about 1 nm to about 15 nm, and for example, from about 2 nm to about 15 nm, alternatively about 2 nm to about 12 nm.
When the thickness of the HIL is within this range, the HIL may have excellent hole injecting characteristics, without a substantial penalty in driving voltage.
According to one embodiment of the present invention, the hole injection layer may comprise:
Preferably, the hole injection layer is free of ionic liquids, metal phthalocyanine, CuPc, HAT-CN, Pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile, F4TCNQ, metal fluoride and/or metal oxides, wherein the metal in the metal oxide is selected from Re and/or Mo. Thereby, the hole injection layer can be deposited under conditions suitable for mass production.
According to an embodiment of the organic electronic device, wherein the hole injection layer is non-emissive.
It is to be understood that the hole injection layer is not part of the anode layer.
In accordance with the invention, the organic electronic device may comprise, besides the layers already mentioned above, further layers. Exemplary embodiments of respective layers are described in the following:
The substrate may be any substrate that is commonly used in manufacturing of, electronic devices, such as organic light-emitting diodes. If light is to be emitted through the substrate, the substrate shall be a transparent or semitransparent material, for example a glass substrate or a transparent plastic substrate. If light is to be emitted through the top surface, the substrate may be both a transparent as well as a non-transparent material, for example a glass substrate, a plastic substrate, a metal substrate, a silicon substrate or a transistor backplane. Preferably, the substrate is a silicon substrate or transistor backplane.
According to one embodiment of the organic electronic device, wherein the organic electronic device further comprises a hole transport layer, wherein the hole transport layer is arranged between the hole injection layer and the at least one emission layer.
The hole transport layer may comprises a matrix compound, preferably a covalent matrix compound. According to one embodiment the covalent matrix compound of the hole transport layer may be selected from at least one organic compound.
According to one embodiment the matrix compound in the hole injection layer and hole transport layer are selected the same.
The covalent matrix may consists substantially from covalently bound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
According to one embodiment of the organic electronic device, the hole transport layer comprises a matrix compound, wherein the matrix compound of the hole transport layer may be selected from organic compounds consisting substantially from covalently bound C, H, O, N, S, which optionally comprise in addition covalently bound B, P, As and/or Se.
According to one embodiment, the covalent matrix compound of the hole transport layer may have a molecular weight Mw of ≥400 and ≤2000 g/mol, preferably a molecular weight Mw of ≥450 and ≤1500 g/mol, further preferred a molecular weight Mw of ≥500 and ≤1000 g/mol, in addition preferred a molecular weight Mw of ≥550 and ≤900 g/mol, also preferred a molecular weight Mw of ≥600 and ≤800 g/mol.
Preferably, the matrix compound of the hole injection layer and the matrix compound of the hole transport layer are selected the same.
According to one embodiment of the organic electronic device, wherein the hole transport layer of the organic electronic device comprises a matrix compound according to formulae (IIIa) or (IIIb), preferably the matrix compound in the hole injection layer and hole transport layer are selected the same.
The hole transport layer may be free of HTM014, HTM081, HTM163, HTM222, EL-301, HTM226, HTM355, HTM133, HTM334, HTM604 and EL-22T. The abbreviations denote the manufacturers' names, for example, of Merck or Lumtec.
The hole transport layer (HTL) may 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 conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for the vacuum or solution deposition may vary, according to the hole transport compound that is used to form the HTL.
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 about 20 nm to about 190 nm, further about 40 nm to about 180 nm, further about 60 nm to about 170 nm, further about 80 nm to about 200 nm, further about 100 nm to about 180 nm, further about 110 nm to about 140 nm.
When the thickness of the HTL is within this range, the HTL may have excellent hole transporting characteristics, without a substantial penalty in driving voltage.
The function of an electron blocking layer (EBL) is to prevent electrons from being transferred from an emission layer to the hole transport layer and thereby confine electrons to the emission layer. Thereby, efficiency, operating voltage and/or lifetime may be improved. Typically, the electron blocking layer comprises a triarylamine compound.
If the electron blocking layer has a high triplet level, it may also be described as triplet control layer.
The function of the triplet control layer is to reduce quenching of triplets if a phosphorescent green or blue emission layer is used. Thereby, higher efficiency of light emission from a phosphorescent emission layer can be achieved. The triplet control layer may be selected from triarylamine compounds with a triplet level above the triplet level of the phosphorescent emitter in the adjacent emission layer.
The thickness of the electron blocking layer may be selected between 2 and 20 nm.
The at least one first emission layer (EML), also referred to as first emission layer may be formed on the HTL or EBL by vacuum deposition, spin coating, slot-die coating, printing, casting, LB deposition, or the like. When the EML is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for deposition and coating may vary, according to the compound that is used to form the EML.
According to the present invention it is preferred that the organic electronic device comprises one emission layer that is named “first emission layer”. However the organic electronic device optionally comprises two emission layers, wherein the first layer is named first emission layer and second layer is named second emission layer.
It may be provided that the at least one emission layer also referred to as first emission layer is free of the matrix compound of the hole injection layer.
It may be provided that the at least one emission layer does not comprise the compound of Formulae (IIIa) or (IIIb).
The at least one emission layer (EML) may be formed of a combination of a host and an emitter dopant. Example of the host are Alq3, 4,4′-N,N′-dicarbazole-biphenyl (HTC-10), poly(n-vinyl carbazole) (PVK), 9,10-di(naphthalene-2-yl)anthracene (ADN), 4,4′,4″-tris(carbazol-9-yl)-triphenylamine (TCTA), 1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI), 3-tert-butyl-9,10-di-2-naphthylanthracenee (TBADN), distyrylarylene (DSA) and bis(2-(2-hydroxyphenyl)benzo-thiazolate)zinc (Zn(BTZ)2).
The emitter dopant may be a phosphorescent or fluorescent emitter. Phosphorescent emitters and emitters which emit light 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.
Examples of red emitter dopants are PtOEP, Ir(piq)3, and Btp2Ir(acac), but are not limited thereto. These compounds are phosphorescent emitters, however, fluorescent red emitter dopants could also be used.
Examples of phosphorescent green emitter dopants are Ir(ppy)3 (ppy=phenylpyridine), Ir(ppy)2(acac), Ir(mpyp)3.
Examples of phosphorescent blue emitter dopants are F2Irpic, (F2ppy)2Ir(tmd) and Ir(dfppz)3 and ter-fluorene. 4,4′-bis(4-diphenyl amiostyryl)biphenyl (DPAVBi), 2,5,8,11-tetra-tert-butyl perylene (TBPe) are examples of fluorescent blue emitter dopants.
The amount of the emitter dopant may be in the range from about 0.01 to about 50 parts by weight, based on 100 parts by weight of the host. Alternatively, the at least one emission layer may consist of a light-emitting polymer. The EML may have a thickness of about 10 nm to about 100 nm, for example, from about 20 nm to about 60 nm. When the thickness of the EML is within this range, the EML may have excellent light emission, without a substantial penalty in driving voltage.
A hole blocking layer (HBL) may be formed on the EML, by using vacuum deposition, spin coating, slot-die coating, printing, casting, LB deposition, or the like, in order to prevent the diffusion of holes into the ETL. When the EML comprises a phosphorescent emitter dopant, the HBL may have also a triplet exciton blocking function.
The HBL may also be named auxiliary ETL or a-ETL.
When the HBL is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the HIL. However, the conditions for deposition and coating may vary, according to the compound that is used to form the HBL. Any compound that is commonly used to form a HBL may be used. Examples of compounds for forming the HBL include oxadiazole derivatives, triazole derivatives, phenanthroline derivatives and triazine derivatives.
The HBL may have a thickness in the range from about 5 nm to about 100 nm, for example, from 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 penalty in driving voltage.
The organic electronic device according to the present invention may further comprise an electron transport layer (ETL).
According to another embodiment of the present invention, the electron transport layer may further comprise an azine compound, preferably a triazine compound.
In one embodiment, the electron transport layer may further comprise a dopant selected from an alkali organic complex, preferably LiQ
The thickness of the ETL may be in the range from about 15 nm to about 50 nm, for example, in the range from about 20 nm to about 40 nm. When the thickness of the EIL is within this range, the ETL may have satisfactory electron-injecting properties, without a substantial penalty in driving voltage.
According to another embodiment of the present invention, the organic electronic device may further comprise a hole blocking layer and an electron transport layer, wherein the hole blocking layer and the electron transport layer comprise an azine compound. Preferably, the azine compound is a triazine compound.
An optional EIL, which may facilitates injection of electrons from the cathode, may be formed on the ETL, preferably directly on the electron transport layer. Examples of materials for forming the EIL include lithium 8-hydroxyquinolinolate (LiQ), LiF, NaCl, CsF, Li2O, BaO, Ca, Ba, Yb, Mg which are known in the art. Deposition and coating conditions for forming the EIL are similar to those for formation of the HIL, although the deposition and coating conditions may vary, according to the material that is used to form the EIL.
The thickness of the EIL may be in the range from about 0.1 nm to about 10 nm, for example, in the range from about 0.5 nm to about 9 nm. When the thickness of the EIL is within this range, the EIL may have satisfactory electron-injecting properties, without a substantial penalty in driving voltage.
The cathode layer is formed on the ETL or optional EIL. The cathode layer may be formed of a metal, an alloy, an electrically conductive compound, or a mixture thereof. The cathode layer may have a low work function. For example, the cathode layer may 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), or the like. Alternatively, the cathode layer may be formed of a transparent conductive oxide, such as ITO or IZO.
The thickness of the cathode layer may be in the range from about 5 nm to about 1000 nm, for example, in the range from about 10 nm to about 100 nm. When the thickness of the cathode layer is in the range from about 5 nm to about 50 nm, the cathode layer may be transparent or semitransparent even if formed from a metal or metal alloy.
It is to be understood that the cathode layer is not part of an electron injection layer or the electron transport layer.
According to one embodiment of the organic electronic device, wherein the hole injection layer may comprise a first hole injection sub-layer comprising the metal complex of formula (I) and a second hole injection sub-layer comprising a matrix compound, wherein the first hole injection sub-layer is arranged closer to the anode layer and the second hole injection sub-layer is arranged closer to the at least one emission layer; preferably the matrix compound consists of a covalent matrix compound.
According to one embodiment of the organic electronic device, wherein the hole injection layer may comprise a first hole injection sub-layer comprising the metal complex of formula (I) and a second hole injection sub-layer comprising a matrix compound, wherein the first hole injection sub-layer is arranged closer to the anode layer comprising a first anode sub-layer and a second anode sub-layer and the second hole injection sub-layer is arranged closer to the at least one emission layer; preferably the matrix compound consists of a covalent matrix compound.
According to one embodiment of the organic electronic device, wherein the hole injection layer may comprise a first hole injection sub-layer comprising the metal complex of formula (I) and a second hole injection sub-layer comprising a matrix compound comprising of at least one arylamine compound, diarylamine compound, triarylamine compound and/or compound of formulae (IIIa) or (IIIb), wherein the first hole injection sub-layer is arranged closer to the anode layer and the second hole injection sub-layer is arranged closer to the at least one emission layer.
According to one embodiment of the organic electronic device, wherein the hole injection layer may comprise a first hole injection sub-layer comprising the metal complex of formula (I) and a second hole injection sub-layer comprising the matrix compound comprising of at least one arylamine compound, diarylamine compound, triarylamine compound and/or compound of formulae (IIIa) or (IIIb), wherein the first hole injection sub-layer is arranged closer to the anode layer comprising a first anode sub-layer and a second anode sub-layer and the second hole injection sub-layer is arranged closer to the at least one emission layer.
According to one embodiment of the organic electronic device, the hole injection layer may comprise a first hole injection sub-layer consisting essentially of the metal complex of formula (I) or formulae (Ia) to (Id) and a second hole injection sub-layer comprising a matrix compound, wherein the first hole injection sub-layer is arranged closer to the anode layer comprising at least a first anode sub-layer and a second anode sub-layer and the second hole injection sub-layer is arranged closer to the at least one emission layer; preferably the matrix compound consists of a covalent matrix compound. According to one embodiment of the organic electronic device, the hole injection layer may comprise a first hole injection sub-layer consisting essentially of the metal complex of formula (I) or formulae (Ia) to (Id) and a second hole injection sub-layer comprising a matrix compound comprising of at least one arylamine compound, diarylamine compound, triarylamine compound and/or compound of formulae (IIIa) or (IIIb), wherein the first hole injection sub-layer is arranged closer to the anode layer comprising at least a first anode sub-layer and a second anode sub-layer and the second hole injection sub-layer is arranged closer to the at least one emission layer.
In the context of the present specification the term “consisting essentially of” especially means and/or includes a concentration of ≥90% (vol/vol) more preferred ≥95% (vol/vol) and most preferred ≥99% (vol/vol).
According to one embodiment of the organic electronic device, wherein the hole injection layer may be arranged in direct contact with the anode layer comprising at least a first anode sub-layer and a second anode sub-layer.
According to one embodiment of the present invention, wherein the organic electronic device may comprise the hole injection layer comprising the metal complex of formula (I) or formulae (Ia) to (Id) and the matrix compound comprising at least one arylamine compound, diarylamine compound, triarylamine compound and/or a compound of formulae (IIIa) or (IIIb), wherein in formula (I) or formulae (Ia) to (Id) M is selected from Ce(IV), Zr(IV) or Hf(IV), preferably M is Ce(IV) or Hf(IV).
According to another embodiment, wherein the organic electronic device can be a light emitting device or a display device.
According to one aspect of the present invention, there is provided an organic electronic device comprising: a substrate; an anode layer comprising at least two anode sublayers or more comprises at least a first anode sub-layer and a second anode sub-layer formed on the substrate; a hole injection layer comprising a metal complex of formula (I), a hole transport layer, at least a first emission layer, an electron transport layer and a cathode layer.
According to another aspect of the present invention, there is provided an organic electronic device comprising: a substrate; an anode layer comprising at least two anode sublayers or more comprises a first anode sub-layer and a second anode sub-layer formed on the substrate, a hole injection of the present invention comprising a first and a second hole injection sub-layer, a hole transport layer, at least a first emission layer, an optional hole blocking layer, an electron transport layer, an optional electron injection layer, and a cathode layer,
According to another aspect of the present invention, there is provided an organic electronic device comprising: a substrate; an anode layer comprising at least two anode sublayers or more comprises a first anode sub-layer and a second anode sub-layer formed on the substrate; a hole injection layer comprising a matrix compound or a compound of formulae (IIIa) or (IIIb) and a metal complex of formula (I) or formulae (Ia) to (Id), a hole transport layer, an electron blocking layer, at least a first emission layer, a hole blocking layer, an electron transport layer and a cathode layer.
According to another aspect of the present invention, there is provided an organic electronic device comprising a substrate; an anode layer comprising at least two anode sublayers or more comprises a first anode sub-layer and a second anode sub-layer formed on the substrate, a hole injection of the present invention comprising a first hole injection and a second hole injection sub-layer, a hole transport layer, an electron-blocking layer, at least a first emission layer, a hole blocking layer, an electron transport layer, an optional electron injection layer, and a cathode layer,
According to another aspect of the present invention, there is provided an organic electronic device comprising: a substrate; an anode layer comprising at least two anode sublayers or more comprises a first anode sub-layer and a second anode sub-layer formed on the substrate, a hole injection layer comprising a matrix compound or a compound of formulae (IIIa) or (IIIb) and a metal complex of formula (I) or formulae (Ia) to (Id), a hole transport layer, an electron blocking layer, at least a first emission layer, a hole blocking layer, an electron transport layer, an optional electron injection layer, and a cathode layer.
According to another aspect of the present invention, there is provided an OLED comprising: a substrate; an anode layer comprising a first anode sub-layer and a second anode sub-layer formed on the substrate, a hole injection of the present invention comprising a first hole injection and a second hole injection sub-layer, a hole transport layer, an electron blocking layer, at least a first emission layer, a hole blocking layer, an electron transport layer, an optional electron injection layer, and a cathode layer,
According to various embodiments of the present invention, there may be provided further layers arranged between the above mentioned layers, on the substrate or on the top electrode.
For example, the organic electronic device according to
According to another aspect of the present invention, there is provided a method of manufacturing an organic electronic device, the method using:
The methods for deposition that can be suitable comprise:
According to various embodiments of the present invention, there is provided a method using:
According to various embodiments of the present invention, the method may further include forming the layers in the following order on the hole injection layer, at least one layer selected from the group consisting of forming a hole transport layer, forming a hole blocking layer, forming a first emission layer, forming a hole blocking layer, forming an electron transporting layer and/or forming an electron injection layer and/or forming a cathode layer.
According to various embodiments of the present invention, the method may further include the steps for forming an organic electronic device, wherein
According to various embodiments, the organic electronic device may have the following layer structure, wherein the layers having the following order:
According to one embodiment, the organic electronic device of the present invention is formed by deposition of the hole injection layer in vacuum.
According to another aspect, it is provided an electronic device comprising at least one organic light emitting device according to any embodiment described throughout this application, preferably, the electronic device comprises the organic light emitting diode in one of embodiments described throughout this application. More preferably, the organic electronic device is a display device.
According to another aspect of the invention, a metal complex of formula I is provided represented by formula (Ia):
According to one embodiment, wherein for the metal complex of formula (I) according to the present invention represented by formula (Ia) the following formula is excluded:
Thereby, the thermal stability, for example decomposition temperature, and/or rate onset temperature may be obtained in a range suitable for mass production of organic electronic devices.
According to another embodiment, wherein the metal complex has the formula (Ia):
Preferably, A2 may be selected from partially or perfluorinated isopropyl, more preferred A2 is selected from perfluorinated isopropyl.
According to an embodiment, A1 is selected from substituted C6 to C12 aryl, wherein at least one substituent of A1 is selected from partially or perfluorinated C1 to C16 alkyl or CN, preferably at least two substituents are selected from partially or perfluorinated C1 to C16 alkyl or CN.
According to an embodiment, A1 is selected from substituted C6 to C12 aryl, wherein at least one substituent of A1 is selected from CF3 or CN, preferably at least two substituents are selected from CF3 or CN.
According to an embodiment, A1 is selected from formulas D1 to D34 and/or D38 to D71. According to one embodiment, wherein the metal complex has the formula (Ia):
Preferably, A2 may be selected from partially or perfluorinated C1 to C4 alkyl.
According to an embodiment, the metal complex of formula (Ia) is selected from formulae H4 to H13:
Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples. Reference will now be made in detail to the exemplary aspects.
The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations.
Additional details, characteristics and advantages of the object are disclosed in the dependent claims and the following description of the respective figures which in an exemplary fashion show preferred embodiments according to the invention. Any embodiment does not necessarily represent the full scope, however, and reference is made therefore to the claims and herein for interpreting the scope. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention as claimed.
Hereinafter, the
Herein, when a first element is referred to as being formed or disposed “on” or “onto” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” or “directly onto” a second element, no other elements are disposed there between.
While not shown in
Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples.
The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.
The compound of formulae (IIIa) and (IIIb) and metal complexes of formula (I) or formulae (Ia) to (Id) may be prepared by methods known in the art.
The decomposition temperature Tdec is measured by loading a sample of 9 to 11 mg into a Mettler Toledo 100 μL aluminum pan without lid under nitrogen in a Mettler Toledo TGA-DSC 1 machine. The following heating program was used: 25° C. isothermal for 3 min; 25° C. to 600° C. with 10 K/min.
The decomposition temperature was determined based on the onset of the decomposition in TGA.
The decomposition temperature indicates the temperature at which the compound decomposes. The higher the decomposition temperature the higher the thermal stability of a compound.
The rate onset temperature (TRO) is determined by loading 100 mg compound into a VTE source. As VTE source a point source for organic materials may be used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10−5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the compound is detected with a QCM detector which detects deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in {acute over (Å)}ngstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTF source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.
To achieve good control over the evaporation rate of an organic compound, the rate onset temperature may be in the range of 100 to 300° C. If the rate onset temperature is below 100° C. the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is above 300° C. the evaporation rate may be too low which may result in low tact time and decomposition of the organic compound in VTE source may occur due to prolonged exposure to elevated temperatures.
The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.
The HOMO and LUMO levels of the matrix compound, compound of formula (IIIa) or a compound of formula (IIIb) are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected.
If calculated by this method, the HOMO level of N2,N2,N2′,N2′,N7,N7,N7′,N7′-octakis(4-methoxyphenyl)-9,9′-spirobi[fluorene]-2,2′,7,7′-tetraamine is −4.27 eV.
The LUMO levels of the metal complex or metal complex of formula (I) and formulae (Ia) to (Id) are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized energies of the LUMO are obtained from a single point calculation at the B3LYP Def-TZVP D3BJ in the gas phase, from a geometry optimization at the B3LYP Def-SV(P) D3BJ level of theory. If more than one conformation is viable, the conformation with the lowest total energy is selected.
In Table A are shown LUMO levels for metal complexes of formula (I) represented by formula (Ia) which were calculated by the method described above.
As can be seen in Table A, the LUMO levels of metal complexes of formula (I) represented by formula (Ia) have LUMO levels further away from vacuum level compared to comparative compound CC-1 and comparative compound CC-2.
Without being bound by theory, a LUMO level further away from vacuum level may enable particularly efficient injection into adjacent layers comprising compounds with a HOMO level further away from vacuum level.
For Examples 1 to 25 in Table 3, a glass substrate with an anode layer comprising a first anode sub-layer of 120 nm Ag, a second anode sub-layer of 8 nm ITO and a third anode sub-layer of 10 nm ITO was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment to prepare the anode layer. The plasma treatment was performed in an atmosphere comprising 97.6 vol.-% nitrogen and 2.4 vol.-% oxygen at 75 W for 30 seconds.
Then, the matrix compound and the metal complex were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm. The composition of the hole injection layer can be seen in Table 3.
Then, the matrix compound was vacuum deposited on the HIL, to form a HTL having a thickness of 123 nm. The matrix compound in the HTL is selected the same as the matrix compound in the HIL. The matrix compound can be seen in Table 3.
Then N-(4-(dibenzo[b,d]furan-4-yl)phenyl)-N-(4-(9-phenyl-9H-fluoren-9-yl)phenyl)-[1,1′-biphenyl]-4-amine (CAS 1824678-59-2) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
Then 97 vol.-% H09 as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant were deposited on the EBL, to form a blue-emitting first emission layer (EML) with a thickness of 20 nm.
Then a hole blocking layer was formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer EML.
Then the electron transporting layer having a thickness of 31 nm was formed on the hole blocking layer by depositing 50 wt.-% 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile and 50 wt.-% of LiQ.
Then Ag:Mg (90:10 vol.-%) was evaporated at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode layer with a thickness of 13 nm on the electron transporting layer.
Then, F3 was deposited on the cathode layer to form a capping layer with a thickness of 75 nm.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
For comparative example 1 in Table 3, a 15 Ω/cm2 glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment in nitrogen atmosphere at a power of 100 W for 75 seconds to prepare the anode layer.
Then, 90 vol.-% F3 and 10 vol.-% MC-1 were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm.
Then, F3 was vacuum deposited on the HIL, to form a HTL having a thickness of 123 nm.
Then, the EBL, EML, HBL and ETL are deposited in this order on the HTL, as described for example 1 above.
Then Al was evaporated at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode layer with a thickness of 100 nm on the electron transporting layer.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
For comparative example 2 in Table 3, a glass substrate was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment in nitrogen atmosphere at a power of 100 W for 75 seconds, to prepare the substrate.
Then, 100 nm Ag was deposited in vacuum on the substrate to form the anode layer.
Then, 90 vol.-% F3 and 10 vol.-% MC-1 were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm.
Then, F3 was vacuum deposited on the HIL, to form a HTL having a thickness of 123 nm.
Then, the EBL, EML, HBL and ETL, cathode layer and capping layer are deposited in this order on the HTL, as described for example 1 above.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing a voltage in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.
In bottom emission devices, the emission is predominately Lambertian and quantified in percent external quantum efficiency (EQE). The light is emitted through the anode layer. To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm2.
In top emission devices, the emission is forward directed through the cathode layer, non-Lambertian and also highly dependent on the micro-cavity. Therefore, the efficiency EQE will be higher compared to bottom emission devices. To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm2.
Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm2, using a Keithley 2400 sourcemeter, and recorded in hours.
The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.
To determine the voltage stability over time U(100 h)−(1 h), a current density of at 30 mA/cm2 was applied to the device. The operating voltage was measured after 1 hour and after 100 hours, followed by calculation of the voltage stability for the time period of 1 hour to 100 hours. A low value for U(100 h)−(1 h) denotes an improvement in stability of operating voltage over time.
In Table 1 are shown the decomposition temperatures Tdec and rate onset temperatures TRO for metal complexes of formula (I) and formulae (Ia) to (Id).
1) n.d. = not determined
As can be seen in Table 1, the metal complexes of formula (I) and formulae (Ia) to (Id) have decomposition temperatures and/or rate onset temperatures suitable for mass production of organic electronic devices.
In Table 2 are shown the HOMO levels and rate onset temperatures TRO for matrix compounds of formula (I). HOMO levels were calculated using TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase.
As can be seen in Table 2, the matrix compound of formula (IIIa) or (IIIb) have rate onset temperatures suitable for mass production of organic electronic devices.
In Table 3 are shown data for organic electronic devices comprising a hole injection layer comprising a metal complex of formula (I) or formula (Ia) to (Id).
In comparative example 1, the anode layer consists of ITO. As can be seen in Table 3, the operating voltage is 5.06 V, the voltage increase over time is 1.87 V and the lifetime is 32 hours.
In comparative example 2, the anode layer consists of Ag. As can be seen in Table 3, the operating voltage is very high at >10 V. Therefore, the voltage stability over time and the lifetime have not been determined.
In example 1, the organic electronic device comprises an anode layer according to invention. As can be seen in Table 3, the operating voltage is improved to 3.93 V, the voltage stability over time has been improved to 0.06 V and the lifetime is 115 hours.
In example 2, the hole injection layer comprises the same metal complex as in example 1. However, the doping concentration has been reduced from 10 vol.-% in example 1 to 5 vol.-% in example 2. As can be seen in Table 3, the operating voltage is 4.01 V, the voltage stability over time is 0.16 V and the lifetime is improved to 120 hours.
In example 3, the hole injection layer comprises metal complex MC-2. As can be seen in Table 3, the operating voltage is improved to 3.84 V, the voltage stability over time is improved to 0.08 V and the lifetime is still high at 107 hours.
In examples 4 and 5, the hole injection layer comprises metal complex MC-2 at higher concentration. As can be seen in Table 3, the operating voltage is improved further to 3.62 V, the voltage stability over time is improved to 0.01 V and the lifetime is still high at 107 and 111 hours, respectively.
In examples 6 to 11, the hole injection layer comprises metal complex MC-1 and matrix compound F18 at a range of concentrations. The HOMO of the matrix compound is −4.73 eV, see Table 2. As can be seen in Table 3, the operating voltage, voltage stability over time and lifetime are improved over comparative example 1.
In examples 12 to 19, the hole injection layer comprises metal complex MC-2 and matrix compound F18 at a range of concentrations. As can be seen in Table 3, the operating voltage, voltage stability over time and lifetime are improved over comparative example 1.
In examples 20 to 22, the hole injection layer comprises metal complex MC-1 and matrix compound F4 at a range of concentrations. The HOMO of the matrix compound is −4.82 eV, see Table 2. As can be seen in Table 3, the operating voltage, voltage stability over time and lifetime are improved over comparative example 1.
In examples 23 to 25, the hole injection layer comprises metal complex MC-2 and matrix compound F4 at a range of concentrations. As can be seen in Table 3, the operating voltage, voltage stability over time and lifetime are improved over comparative example 1.
In summary, an improvement in operating voltage, voltage stability over time and/or lifetime has been obtained.
A lower operating voltage may be important for the battery life of organic electronic devices, in particular mobile devices.
An improvement in voltage stability over time and/or lifetime may be important for the long-term stability of organic electronic devices.
2) n.d. = not determined
The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by way of example only and is not intended as limiting. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.
| Number | Date | Country | Kind |
|---|---|---|---|
| 21197752.5 | Sep 2021 | EP | regional |
| 21214669.0 | Dec 2021 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/075942 | 9/19/2022 | WO |
