Active OLED display, method of manufacturing an active OLED display, and compound

Abstract

The present invention relates to an active OLED display, a method of manufacturing an active OLED display and a compound. In particular, the present invention relates to a display device comprising: - a plurality of OLED pixels comprising at least two OLED pixels, the OLED pixels comprising an anode, a cathode and an organic layer stack, wherein the organic layer stack is arranged between and in contact with the cathode and the anode and comprises a first electron transport layer, a first hole transport layer and a first light emitting layer disposed between the first hole transport layer and the first electron transport layer, and - a drive circuit, wherein for the plurality of OLED pixels the first hole transport layer is disposed in the organic layer stack as a common hole transport layer that is common to the plurality of OLED pixels and comprises (i) at least one first hole transport matrix compound consisting of covalently bound atoms, and (ii) at least one p-type electrical dopant.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201880013739.2, filed on February 20, 2018, entitled "Active OLED Display, Method for Preparing Active OLED Display and Compound". Technical Field

[0002] This invention relates to an active OLED display, a method for fabricating an active OLED display, and compounds. Specifically, this disclosure relates to an active OLED display having a plurality of OLED pixels and containing non-oxidizing p-type dopants in a hole injection and / or hole transport layer shared by at least two pixels, a method for fabricating said active OLED display, and compounds particularly suitable for said display. Background Technology

[0003] For active OLED displays comprising multiple OLED pixels sharing a common hole transport layer, challenging requirements are placed on the semiconductor materials used in the layer disposed between the anode and the emissive layer and shared by the multiple pixels. On the one hand, the material should enable each pixel to be driven independently at the lowest possible operating voltage. On the other hand, so-called electrical crosstalk between adjacent pixels should be avoided. These conflicting requirements are taught in application WO2016 / 050834, which is incorporated herein by reference, by means of an electrical conductivity of 1 × 10⁻⁶. -3 S·m -1 Up to 1×10 -8 S·m -1 Within the range, the most advantageous position is at 1×10 -5 S·m -1 Up to 1×10 -6 S·m -1 These low-conductivity p-type doped hole transport layers can be achieved by using conventional redox dopants, such as strongly electron-accepting axialene compounds, in matrices that are poorly dopable in terms of their deep HOMO levels. However, there is a continuous need for p-type dopants that meet these criteria and improve other parameters, such as fabrication performance and device stability. Summary of the Invention

[0004] One objective is to provide improved active-matrix OLED displays and improved materials capable of achieving such improvements. On one hand, electrical crosstalk between adjacent pixels of the active-matrix OLED display should be reduced. On the other hand, the improved materials should enable robust display manufacturing, for example, robust display manufacturing with respect to improved device stability during any processing step, including processing of the device or a particular layer thereof at elevated temperatures.

[0005] The objective is achieved by a display device, the display device comprising:

[0006] - A plurality of OLED pixels containing at least two OLED pixels, each OLED pixel comprising an anode, a cathode, and an organic stack, wherein the organic stack

[0007] -Arranged between and in contact with the cathode and anode, and

[0008] -Comprising a first electron transport layer, a first hole transport layer, and a first light-emitting layer disposed between the first hole transport layer and the first electron transport layer, and

[0009] - A driving circuit configured to drive the pixels of the plurality of OLED pixels individually.

[0010] For the plurality of OLED pixels, the first hole transport layer is disposed in the organic layer stack as a common hole transport layer shared by the plurality of OLED pixels, and the first hole transport layer comprises:

[0011] (i) at least one hole transport matrix compound consisting of covalently bonded atoms, and

[0012] (ii) at least one p-type electro-doper, said p-type electro-doper is selected from metal salts and electrically neutral metal complexes comprising a metal cation and at least one anionic ligand consisting of at least four covalently bonded atoms and / or at least one anion.

[0013] The metal cation of the p-type electro-doper is selected from: alkali metals; alkaline earth metals, Pb, Mn, Fe, Co, Ni, Zn, Cd; rare earth metals in oxidation state (II) or (III); Al, Ga, In; and Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W in oxidation state (IV) or lower.

[0014] In one embodiment, the anion and / or anion ligand is bonded to the metal cation of the p-type dopant via an oxygen atom, preferably via two oxygen atoms.

[0015] It should be understood that the term "binding" encompasses the structure of the p-type dopant in which the distance between the metal cation and one or more oxygen atoms is shorter than the distance between the metal cation and any other atom of the anion and / or anionic ligand.

[0016] For example, solid-state structure studies of some divalent and / or trivalent metal bis(sulfonyl)imide complexes have revealed that the bis(sulfonyl)imide ligand may be attached to the central metal atom via the oxygen atom of the sulfonyl group rather than via the nitrogen atom of the imide, which may in fact be arranged further away from the central metal atom than the oxygen atom.

[0017] In one embodiment, the anion and / or anionic ligand binds to the oxygen atom of the metal cation in the metal salt and / or metal complex, and has a lower basicity in dichloroethane than at least one non-oxygen atom of the anion and / or anionic ligand.

[0018] Similarly, in another embodiment, each oxygen atom of the metal cation bound to the anion and / or anionic ligand in the metal salt and / or metal complex has a lower basicity in dichloroethane than at least one non-oxygen atom of the anion and / or anionic ligand. It should be understood that the basicity of the atom in the anion and / or anionic ligand in an environment, such as 1,2-dichloroethane, is inversely proportional to the acidity of the corresponding tautomer form of the electrically neutral conjugate acid formed by adding one or more protons in the same environment. The measurement of acidity in 1,2-dichloroethane, as a general tool for comparing various different acids, is described in the Journal of Organic Chemistry (2011), 76(2), pp. 391-395. It should be understood that if the basicity of a particular atom in the anion and / or anionic ligand must be evaluated, the “corresponding tautomer form” of the electrically neutral conjugate acid is the acid formed by adding a proton to that particular atom.

[0019] In one embodiment, the anion and / or anion ligand is composed of at least 5, preferably at least 6, more preferably at least 7, even more preferably at least 8, and most preferably at least 9 covalently bonded atoms.

[0020] In one embodiment, the anion and / or anion ligand comprises at least one atom selected from B, C, and N.

[0021] In one embodiment, the anion and / or anionic ligand comprises at least two atoms selected from B, C, and N covalently bonded to each other.

[0022] In one embodiment, the anion and / or anionic ligand comprises at least one peripheral atom selected from H, N, O, F, Cl, Br, and I. "Peripheral atom" should be understood as an atom covalently bonded to only one atom of the anion and / or anionic ligand. Conversely, atoms covalently bonded to at least two other atoms of the anion and / or anionic ligand are classified as internal atoms.

[0023] A covalent bond should be understood as any binding interaction between two atoms being evaluated that shares electron density, where such binding is stronger than van der Waals dispersion interactions; for simplicity, a binding energy of 10 kJ / mol can be considered as a lower limit for arbitrariness. In this sense, the term includes coordinate bonds or hydrogen bonds. However, anionic and / or anionic ligands containing hydrogen bonds are not particularly preferred.

[0024] In one embodiment, the anion and / or anion ligand comprises at least one electron-withdrawing group selected from haloalkyl, haloaryl, haloarylalkyl, haloalkylsulfonyl, haloarylsulfonyl, haloarylalkylsulfonyl, and cyano. It should be understood that, for simplicity, haloaryl means "haloaryl or haloaryl", haloarylalkyl means "haloarylalkyl or haloarylalkyl", haloarylsulfonyl means "haloarylsulfonyl or haloarylsulfonyl", and haloarylalkylsulfonyl means "haloarylalkylsulfonyl or haloarylalkylsulfonyl".

[0025] In one embodiment, the electron-withdrawing group is a perhalogenated group. It should be understood that the term "halogenated" means that at least one hydrogen atom in a group containing an outer or inner hydrogen atom is replaced by an atom selected from F, Cl, Br, and I. It should also be understood that in a perhalogenated group, all hydrogen atoms contained in the unsubstituted group are replaced by atoms independently selected from F, Cl, Br, and I. Therefore, a perfluorinated group should be understood as a perhalogenated group in which all halogen atoms replacing hydrogen atoms are fluorine atoms.

[0026] In one embodiment, the metal cation of the p-type dopant is selected from Li(I), Na(I), K(I), Rb(I), Cs(I), Mg(II), Ca(II), Sr(II), Ba(II), Sn(II), Pb(II), Mn(II), Fe(II), Co(II), Ni(II), Zn(II), Cd(II), Al(III), rare earth metals in oxidation state (III), V(III), Nb(III), Ta(III), Cr(III), Mo(III), W(III), Ga(III), In(III), and Ti(IV), Zr(IV), Hf(IV), Sn(IV).

[0027] In one embodiment, in the p-type dopant molecule, the atom of the anion and / or anion ligand closest to the metal cation is a C or N atom.

[0028] In one embodiment, the electroneutrally neutral conjugate acid formed from the anion and / or anionic ligand by adding one or more protons in 1,2-dichloroethane is more acidic than HCl, preferably more acidic than HBr, more preferably more acidic than HI, even more preferably more acidic than fluorosulfuric acid, and most preferably more acidic than perchloric acid.

[0029] In one embodiment, the lowest unoccupied molecular orbital energy level of the p-type electro-doped agent, calculated by standard quantum chemistry and expressed on an absolute vacuum scale, is at least 0.5 eV higher than the highest occupied orbital energy level of the covalent hole transport compound, calculated by standard quantum chemistry. Preferably, it is at least 0.6 eV higher, more preferably at least 0.8 eV higher, even more preferably at least 1.0 eV higher, and most preferably at least 1.2 eV higher.

[0030] The standard quantum chemical method can be the software package TURBOMOLE, which uses the DFT functional B3LYP and the basis set def2-TZVP.

[0031] In one embodiment, the first hole transport matrix compound is an organic compound, preferably an organic compound containing a conjugated system of at least 6, more preferably at least 10 delocalized electrons; further preferably, the first hole transport matrix compound contains at least one triarylamine structural moiety, more preferably, the first hole transport matrix compound contains at least two triarylamine structural moieties.

[0032] The objective is also achieved by a method for preparing a display device conforming to any of the foregoing embodiments, the method comprising at least one step of subjecting the hole transport matrix compound and the p-type electro-doper to contact each other at a temperature above 50°C.

[0033] It should be understood that "mutual contact" means the presence of two components in a condensed phase or their existence in two condensed phases sharing a common phase interface.

[0034] The method may further include the following: under low pressure, preferably below 1×10⁻⁶ -2 At pressures of Pa and temperatures above 50°C, more preferably below 5 × 10⁻⁶ Pa, the following conditions apply. -2 Pressure of Pa and temperature above 80°C, or even more preferably below 1×10 Pa. -3 The pressure is Pa and the temperature is above 120°C, most preferably below 5 × 10 Pa. -4 At least one step of evaporating the p-type dopant at a pressure of Pa and a temperature above 150°C.

[0035] In one embodiment, the method may include the following steps, wherein:

[0036] (i) Disperse the p-type dopant and the first hole transport matrix compound in a solvent.

[0037] (ii) The dispersion system is deposited on a solid support, and

[0038] (iii) Evaporate the solvent at an elevated temperature.

[0039] In one embodiment, the p-type dopant may be used in the form of a solid hydrate.

[0040] In another embodiment, the p-type dopant can be used as an anhydrous solid containing less than 0.10% by weight of water, preferably less than 0.05% by weight of water.

[0041] The objective is also achieved by a compound having formula (I).

[0042]

[0043] in

[0044] It is an x-valent cation selected from alkali metals, alkaline earth metals, rare earth metals and metals of Al, Ga, In, Sn, Pb, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Zn and Cd;

[0045] x is 1 for M selected from alkali metals; 2 for M selected from alkaline earth metals, Pb, Mn, Fe, Co, Ni, Zn, and Cd; 2 or 3 for M selected from rare earth metals; 3 for Al, Ga, and In; 2, 3, or 4 for Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W; and 2 or 4 for Sn.

[0046] B 1 and B 2 Independently selected from fully halogenated C3 to C4 atoms 20 Alkyl, C3 to C 20 cycloalkyl or C3 to C 20 Arylalkyl;

[0047] The condition is that compounds having formula (I) that satisfy the following conditions are excluded:

[0048] a) M is selected from alkali metals, Mg, Ca, and Zn, and B 1 and B 2 Independently selected from perfluorinated straight-chain primary alkyl groups, or

[0049] b) M is Li, and B 1 and B 2It is perfluoroisopropyl.

[0050] In one embodiment, M is selected from Mg(II), Mn(II), and Zn(II).

[0051] In one embodiment, the compound conforming to formula (I) is provided in solid form, preferably in solid form containing less than 0.10% by weight of water, more preferably in solid form containing less than 0.05% by weight of water, and most preferably in solid crystalline form containing less than 0.05% by weight of water.

[0052] In another embodiment, the compound conforming to formula (I) is provided in the form of a solid crystalline hydrate, preferably in the form of a solid crystalline hydrate with a water content in the following range:

[0053] (i) 30.33 mol% to 36.33 mol%, preferably 31.00 mol% to 35.66 mol%, more preferably 31.00 mol% to 35.66 mol%, even more preferably 31.66 mol% to 35.00 mol%, even more preferably 32.33 mol% to 34.33 mol%, most preferably 33.00 mol% to 33.66 mol%; or

[0054] (ii) 18.20 mol% to 21.80 mol%, preferably 18.60 mol% to 21.40 mol%, more preferably 19.00 mol% to 21.00 mol%, even more preferably 19.40 mol% to 20.60 mol%, and most preferably 19.80 mol% to 20.20 mol%.

[0055] Invention Effects

[0056] An important property of materials contained in organic semiconductor devices is their conductivity. In display devices, such as those described in WO2016 / 050834, having a structured anode and at least two pixels sharing at least one hole transport and / or hole injection layer, the limited conductivity of the shared layer can be advantageous for achieving low levels of unwanted electrical crosstalk in the display. On the other hand, the very low conductivity of the shared layer can increase the operating voltage of the display. WO2016 / 050834 teaches a range of conductivity representing a trade-off between these conflicting requirements.

[0057] However, the authors of this application have surprisingly discovered that p-type electrodopers based on some metal salts and metal complexes can prepare p-type doped materials and / or p-type doped layers under certain conditions, which provide stable hole injection from prior art anodes to prior art hole transport matrices without substantially increasing the concentration of free charge carriers to levels corresponding to the conductivity observed in pure matrices.

[0058] This surprising discovery provides the opportunity to build a display based on WO2016 / 050834 that operates at a completely comparable voltage, although the hole transport and / or hole injection layer shared by the multiple pixels has a lower voltage than the 1×10 disclosed in WO2016 / 050834. -5 S·m -1 Up to 1×10 -6 S·m -1 The dopant of this disclosure enables the display device of WO2016 / 050834 to operate efficiently with conductivity levels in the p-type doped layer shared by the plurality of pixels approaching or below the detection limit of the available measurement procedures. Therefore, the dopant of this application can also suppress electrical crosstalk in OLED displays and provides new opportunities for designing high-efficiency OLED displays exhibiting very low levels of electrical crosstalk. These observations made by the authors will be described in further detail.

[0059] In the earlier application EP15181385, filed by the applicant and now published as EP 3 133 663 and incorporated herein by reference, some authors described the use of certain metal imides such as

[0060]

[0061] It has been successfully used as a hole injection material in organic electronic devices.

[0062] In parallel with further research on similar metal imide compounds, the authors surprisingly discovered some structurally completely different compounds, namely metal borate complexes, such as...

[0063]

[0064] It can also be used in a similar way.

[0065] In another application, EP17209023, some authors disclosed a compound E3 prepared by sublimation of a zinc sulfonamide complex, which has C 42 F 48 N6O 13 The composition of S6Zn4 is that it is crystallized in a monoclinic lattice belonging to space group P1 21 1, where the unit cell dimension is . α = 90°; β=113.2920(10); γ = 90°, and the unit cell volume is This compound has Figure 5 The structure shown comprises a central divalent oxygen anion surrounded by a first coordination sphere consisting of four tetrahedral zinc divalent cations and a second coordination sphere consisting of six sulfonamide ligands, the sulfonamide ligands bridging all six sides of the Zn4 cluster with a triatomic –NSO- bridge.

[0066] Most surprisingly, the authors found that all these structurally different compounds exhibited two distinct modes of p-type doping activity, depending on the processing conditions during the preparation of the doped materials and / or layers.

[0067] In the first mode, semiconductor materials and / or layers doped with these compounds (which can be collectively referred to as metal salts and / or electrically neutral metal complexes with anionic ligands) exhibit well-measurable conductivity, only slightly lower than that of materials and / or layers doped with typical redox p-type dopant. This mode appears to occur when the doped material and / or layer is in contact with even trace amounts of oxygen.

[0068] In the second mode, semiconductor materials and / or layers doped from the disclosed metal salts and / or electrically neutral metal complexes containing anionic ligands exhibit almost unmeasurable conductivity. This mode occurs when oxygen is strictly avoided from approaching the doped material and / or layer throughout the processing. The authors found that, despite the extremely low conductivity of the materials and / or layers in the second mode, devices containing these materials and / or layers, particularly as hole transport or hole injection layers, still exhibit electrical properties corresponding to excellent hole injection.

[0069] The existence of the two modes of p-type doping activity described above provides the disclosed p-type dopants with unique versatility for use in organic electronic devices, particularly displays containing anodes constructed in multiple pixels sharing a common hole transport layer. The conductivity of the common p-type doped layer can be set within the limits taught in WO2016 / 050834 using the first doping mode, or below these limits using the second doping mode.

[0070] Furthermore, recent research by the authors provides clues that materials and / or layers doped with the proposed metal salts and / or metal complexes can exhibit favorable thermal stability, particularly in materials provided according to the second p-type doping mode described above. These properties are also particularly suitable for the use of the disclosed p-type dopants in AMOLED displays, as the necessity of constructing these displays as separate pixels typically requires thermal treatment of the p-type doped layers or another treatment that may lead to unavoidable heating of the pre-deposited p-type doped layers.

[0071] In a particular embodiment of the invention, the authors provide a new amide compound comprising a larger fluorinated side chain compared to the compound tested in EP15181385. This change produces advantageous storage properties for the new compound, which is substantially non-hygroscopic and remains solid even at high air humidity, while LiTFSI and similar TFSI salts are prone to deliquescence.

[0072] Detailed description

[0073] The electrical conductivity of a thin-layer sample can be measured, for example, by the so-called two-point method. In this case, a voltage is applied to the thin layer and the current flowing through it is measured. By taking into account the geometry of the contact points and the layer thickness of the sample, the resistivity and the corresponding conductivity are derived. The experimental setup used by the authors of this application for conductivity measurement enables the deposition of p-type doped layers and conductivity measurements under controlled conditions, particularly for controlled contact between the deposited layer and an oxygen-containing atmosphere. In this regard, the entire deposition-measurement sequence can be performed using solution processing techniques in a glove box or chamber containing a controlled atmosphere, or entirely in a vacuum chamber using vacuum thermal evaporation (VTE) as an alternative method particularly suitable for materials and / or layers doped in the second mode.

[0074] The conductivity of the first hole transport layer can be less than 1×10⁻⁶. -6 S·m -1 Preferably less than 1×10 -7 S·m -1 More preferably less than 1×10 -8 S·m -1 Alternatively, if the detection limit of the conductivity measurement method used is less than 1 × 10⁻⁶. - 6 S·m -1 Preferably, the conductivity of the first hole transport layer is lower than the detection limit.

[0075] The first hole transport layer (HTL) can be formed for multiple OLED pixels in the OLED display. In one embodiment, the first HTL can extend to all pixels in the multiple pixels of the OLED display. Similarly, the cathode can be formed as a common cathode for the multiple pixels. The common cathode can extend to all pixels in the multiple pixels of the OLED display. Each individual pixel can have its own anode, which may not touch the anodes of other individual pixels.

[0076] Optionally, for one or more of the plurality of OLED pixels, a hole blocking layer, an electron injection layer, and / or an electron blocking layer may be provided after the organic layer.

[0077] Furthermore, the active OLED display has a driving circuit configured to drive each pixel of the plurality of pixels disposed in the OLED display separately. In one embodiment, the step of driving separately may include controlling the driving current applied to each pixel separately.

[0078] The first HTL is made of a hole transport matrix (HTM) material electrically doped with the p-type dopant. The hole transport matrix material can be electrically doped with more than one p-type dopant. It should be understood that the HTM material can consist of one or more HTM compounds, and the term hole transport material is a broader term used throughout this application for all semiconductor materials containing at least one hole transport matrix compound. There are no particular limitations on the hole transport matrix material. Generally, it is any material composed of covalently bonded atoms that allows the embedding of the p-type dopant. In this sense, infinite inorganic crystals primarily having covalent bonds, such as silicon or germanium, or highly cross-linked inorganic glasses, such as silicate glasses, do not fall within the definition of the hole transport matrix material. Preferably, the hole transport matrix material can consist of one or more organic compounds.

[0079] The first hole transport layer may have a thickness of less than 50 nm, less than 40 nm, less than 30 nm, less than 20 nm, or less than 15 nm.

[0080] The first hole transport layer may have a thickness greater than 3nm, greater than 5nm, greater than 8nm, or greater than 10nm.

[0081] In one embodiment of the first hole transport layer, the p-type dopant may be uniformly and isotropically distributed. In another embodiment, the p-type dopant may be uniformly mixed with the matrix, but the concentration of the p-type dopant may exhibit a gradient across the layer. In one embodiment, the first hole transport layer may comprise a sublayer, wherein the amount of the p-type dopant, by weight and / or volume, may exceed the total amount of other components that may be additionally included in the layer.

[0082] In one embodiment, the weight concentration of the p-type dopant may exceed 50% based on the total weight of the sublayer; or, relative to the total weight of the layer, the p-type dopant may account for at least 75% by weight, or at least 90% by weight, or at least 95% by weight, or at least 98% by weight, or at least 99% by weight, or at least 99.5% by weight, or at least 99.9% by weight. For simplification purposes, any sublayer of the first transport layer prepared by simply depositing the p-type dopant may be referred to as a pure (hole-injected) p-type dopant sublayer.

[0083] This can also be applied to any other layer in the display device that, similar to the first hole transport layer, may contain a similar combination of hole transport matrices in contact with metal salts and / or metal complexes.

[0084] For example, a pixel included in the display device may include a hole-generating layer, which in one embodiment may be composed of a hole transport matrix uniformly doped with the p-type dopant. In another embodiment, the hole-generating layer may include a sublayer, wherein the amount of the p-type dopant, by weight and / or volume, exceeds the total amount of the other components.

[0085] The anode can be made of a transparent conductive oxide (TCO) such as indium tin oxide (ITO) or aluminum zinc oxide (AZO). Alternatively, the anode can be made of one or more thin metal layers, producing a semi-transparent anode. In another embodiment, the anode can be made of a thick metal layer that is opaque to visible light.

[0086] The OLED pixel may include an electron blocking layer (EBL) disposed between the first hole transport layer and the light-emitting layer. The EBL may be in direct contact with the first HTL and EML. The electron blocking layer may be an undoped layer made of an organic hole transport matrix material (in other words, it may be free of electrical dopants). The composition of the organic hole transport matrix material of the first hole transport layer may be the same as that of the organic hole transport matrix material of the electron blocking layer. In another embodiment of the invention, the compositions of the two hole transport matrix materials may be different.

[0087] The EBL can have a layer thickness greater than 30nm, greater than 50nm, greater than 70nm, greater than 100nm, or greater than 110nm.

[0088] The thickness of the EBL can be less than 200 nm, less than 170 nm, less than 140 nm, or less than 130 nm. Compared to the EBL, the common HTL can be about an order of magnitude thinner.

[0089] The highest occupied molecular orbital (HOMO) energy level of each compound forming the electron blocking layer, expressed on an absolute scale relative to a vacuum energy level of zero, may be higher than the HOMO energy level of any compound forming the hole transport matrix material of the common hole transport layer.

[0090] The hole mobility of the organic matrix material of the electron blocking layer can be equal to or higher than the hole mobility of the matrix material of the hole transport layer.

[0091] The hole transport matrix (HTM) material of the common HTL and / or EBL can be selected from compounds containing conjugated systems with delocalized electrons, wherein the conjugated system contains lone pairs of electrons of at least two tertiary amine nitrogen atoms.

[0092] Suitable compounds for the hole transport matrix material used in the doped hole transport layer and / or common hole transport layer can be selected from known hole transport matrix (HTM), such as triarylamine compounds. The HTM used in the doped hole transport material can be a compound comprising a conjugated system containing delocalized electrons, wherein the conjugated system contains lone pairs of electrons from at least two tertiary amine nitrogen atoms. Examples are N4,N4'-bis(naphthyl-1-yl)-N4,N4'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (HT1) and N4,N4,N4”,N4”tetra([1,1'-biphenyl]-4-yl)-[1,1':4',1”-terphenyl]-4,4”-diamine (HT4). The synthesis of terphenyldiamine (HTM) is described, for example, in WO 2011 / 134458 A1, US 2012 / 223296 A1, or WO2013 / 135237 A1; the 1,3-phenylenediamine matrix is ​​described, for example, in WO 2014 / 060526 A1. These documents are incorporated herein by reference. Many triarylamines (HTM) are commercially available.

[0093] The OLED display's light-emitting layer may comprise multiple sub-regions, each sub-region being assigned to one of the pixels from the plurality of pixels. Preferably, the light-emitting layer of each pixel corresponding to a sub-region of the display's light-emitting layer does not overlap with the light-emitting layers of adjacent pixels. In the display manufacturing process, the organic layer containing the EML of each pixel can be patterned in top-emitting, bottom-emitting, or bottom-emitting microcavities using known methods such as fine metal mask (FMM), laser-induced thermal imaging (LITI), and / or inkjet printing (IJP) (see, for example, Chung et al., (2006), 70.1: Invited Paper: Large-Sized Full Color AMOLED TV: Advancements and Issues, SID Symposium Digest of Technical Papers, 37:1958–1963. doi:10.1889 / 1.2451418; Lee et al., (2009), 53.4: Development of 31-Inch Full-HD AMOLED TV Using LTPS-TFT and RGB FMM, SID Symposium Digest of Technical Papers). Papers, 40:802–804 (doi:10.1889 / 1.3256911). RGB layout is available.

[0094] For the plurality of OLED pixels, a common electron transport layer may be formed by an electron transport layer in an organic stack of the plurality of OLED pixels.

[0095] The common electron transport layer may comprise an organic electron transport matrix (ETM) material. Furthermore, the common electron transport layer may comprise one or more n-type dopants. Suitable compounds for the ETM contain aromatic or heteroaromatic structural components, as disclosed in documents EP 1 970 371 A1 or WO 2013 / 079217 A1.

[0096] The cathode can be made of a metal or metal alloy with low work function. Transparent cathodes made of TCO are also known in the art.

[0097] The organic layer stack can be made of an organic compound with a molecular weight of less than 2000 g / mol. In an optional embodiment, the organic compound can have a molecular weight of less than 1000 g / mol. Attached Figure Description

[0098] Other embodiments will now be described in more detail by way of example with reference to the accompanying drawings. The drawings show:

[0099] Figure 1 A schematic diagram of an active OLED display having multiple OLED pixels.

[0100] Figure 2 This is a schematic cross-sectional view of an organic light-emitting diode (OLED) conforming to an exemplary embodiment of the present invention.

[0101] Figure 3 This is a schematic cross-sectional view of an OLED conforming to an exemplary embodiment of the present invention.

[0102] Figure 4 This is a schematic cross-sectional view of a tandem OLED including a charge generation layer, which conforms to an exemplary embodiment of the present invention.

[0103] Figure 5 The crystal structure of the inverted coordination complex E3 is shown, which has the outlined molecular formula C3. 42 F 48 N6O 13 S6Zn4. Detailed Implementation

[0104] Figure 1 A schematic diagram of an active OLED display 1 is shown, which has a plurality of OLED pixels 2, 3, 4 disposed in the OLED display 1.

[0105] In the OLED display 1, each pixel 2, 3, 4 is provided with an anode 2a, 3a, 4a connected to a driving circuit (not shown). Various devices capable of serving as driving circuits for active matrix displays are known in the art. In one embodiment, the anodes 2a, 3a, 4a are made of TCO, such as ITO.

[0106] A cathode 6 is disposed on top of an organic stack comprising an electrically doped hole transport layer (HTL) 7, an electron blocking layer (EBL) 5, and an emissive layer (EML) having sub-regions 2b, 3b, and 4b assigned to pixels 2, 3, and 4 and respectively disposed within the electron transport layer (ETL) 9. For example, the sub-regions 2b, 3b, and 4b can provide an RGB combination (R – red, G – green, B – blue) for a color display. In another embodiment, the pixels for each color can comprise a similar white OLED, provided with a suitable combination of color filters. Display pixels 2, 3, and 4 operate independently by applying separate drive currents to pixels 2, 3, and 4 via anodes 2a, 3a, and 4a and cathode 6.

[0107] Figure 2 This is a schematic cross-sectional view of an organic light-emitting diode (OLED) 100, which may represent an OLED pixel in a display device conforming to an exemplary embodiment of the present invention. The OLED 100 includes a substrate 110, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an emissive layer (EML) 150, and an electron transport layer (ETL) 160. The electron transport layer (ETL) 160 is formed directly on the EML 150. An electron injection layer (EIL) 180 is disposed on the electron transport layer (ETL) 160. A cathode 190 is disposed directly on the electron injection layer (EIL) 180.

[0108] Instead of a single electron transport layer 160, an electron transport layer stack (ETL) may optionally be used.

[0109] Figure 3 This is a schematic cross-sectional view of OLED 100, which may represent an OLED pixel in a display device conforming to another exemplary embodiment of the present invention. Figure 3 and Figure 2 The difference is Figure 3 The OLED 100 includes an electron blocking layer (EBL) 145 and a hole blocking layer (HBL) 155.

[0110] refer to Figure 3 The OLED 100 includes a substrate 110, an anode 120, a hole injection layer (HIL) 130, a hole transport layer (HTL) 140, an electron blocking layer (EBL) 145, an emissive layer (EML) 150, a hole blocking layer (HBL) 155, an electron transport layer (ETL) 160, an electron injection layer (EIL) 180, and a cathode electrode 190.

[0111] Figure 4 This is a schematic cross-sectional view of a series OLED 200, which may represent an OLED pixel in a display device conforming to another exemplary embodiment of the present invention. Figure 4 and Figure 3 The difference is Figure 3 OLEDs also include a charge generation layer and a second light-emitting layer.

[0112] refer to Figure 4The OLED 200 includes a substrate 110, an anode 120, a first hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first electron blocking layer (EBL) 145, a first light-emitting layer (EML) 150, a first hole blocking layer (HBL) 155, a first electron transport layer (ETL) 160, an n-type charge generation layer (n-type CGL) 185, a hole generation layer (p-type charge generation layer; p-type GCL) 135, a second hole transport layer (HTL) 141, a second electron blocking layer (EBL) 146, a second light-emitting layer (EML) 151, a second hole blocking layer (EBL) 156, a second electron transport layer (ETL) 161, a second electron injection layer (EIL) 181, and a cathode 190.

[0113] Despite Figure 2 , Figure 3 and Figure 4 Not shown, but a sealing layer can be further formed on the cathode electrode 190 to seal OLEDs 100 and 200. Furthermore, various other modifications can be made to it.

[0114] Synthesis example

[0115] LiPFPI

[0116]

[0117] 1.0 g (1.29 mmol) of N-(bis(perfluorophenyl)phosphoyl)-P,P-bis(perfluorophenyl)phosphamide was dissolved in 20 mL of anhydrous toluene and cooled to 0 °C. 10 mg (12.9 mmol, 1.0 eq) of lithium hydride was added. The mixture was heated to reflux for 2 h. After cooling to room temperature, the product was precipitated with 20 mL of n-hexane, filtered, and washed with n-hexane (2 × 10 mL). After drying under high vacuum, 0.62 g (61%) of the product was given as a white solid.

[0118] ZnPFPI

[0119]

[0120] 2.0 g (2.57 mmol) of N-(bis(perfluorophenyl)phosphoyl)-P,P-bis(perfluorophenyl)phosphamide was dissolved in 50 mL of anhydrous toluene and cooled to 0 °C. A 0.9 M diethylzinc solution in 1.6 mL (1.40 mmol, 0.55 eq) hexane was added. The mixture was heated to reflux for 2 h. After cooling to room temperature, the product was precipitated with 50 mL of n-hexane, filtered, and washed with n-hexane (2 × 10 mL). After drying under high vacuum, 1.05 g (51%) of the product was given as a white solid.

[0121] Lithium bis((perfluorohexyl)sulfonyl)amide

[0122] Step 1: Lithium bis((perfluorohexyl)sulfonyl)amide

[0123]

[0124] 10.25 g (25.7 mmol) of perfluorohexylsulfonamide was dissolved in 100 mL of anhydrous THF in a dry Schlenk flask. 0.51 g (64.2 mmol, 2.5 eq) of lithium hydride was added to the ice-cooled solution under Ar gas countercurrent. 10.33 g (25.7 mmol, 1.0 eq) of perfluorohexylsulfonyl chloride was added dropwise to the resulting suspension. The mixture was heated to 60 °C for about 18 h. The mixture was cooled to room temperature, filtered, and the solvent was removed under reduced pressure. The residue was treated with 50 mL of toluene and concentrated again. The crude product was washed with 50 mL of hexane, the solid was filtered off, and dried under vacuum. 13.49 g (67%) of the product was given as a pale yellow powder.

[0125] Step 2: Lithium bis((perfluorohexyl)sulfonyl)amine

[0126]

[0127] 5.0 g (6.35 mmol) of bis((perfluorohexyl)sulfonyl)amide was dissolved in 100 mL of diethyl ether, and 40 mL of 25% aqueous sulfuric acid solution was carefully added under ice-cooling. The mixture was stirred vigorously for 15 min. The organic phase was separated, dried over magnesium sulfate, and 5 mL of toluene was added to prevent foaming, and the solvent was evaporated under reduced pressure. The residue was purified using a flask-to-flask distillation apparatus at about 140 °C and about 4 Pa. 3.70 g (75%) of product was obtained as a pale yellow waxy solid.

[0128] Step 3: Lithium bis((perfluorohexyl)sulfonyl)amide

[0129]

[0130] 1.0 g (1.28 mmol) of bis((perfluorohexyl)sulfonyl)amine was dissolved in 5 mL of anhydrous methyl tert-butyl ether (MTBE). 12 mg (1.24 mmol, 1.0 eq) of LiH was added under reverse flow of Ar gas. The reaction mixture was stirred overnight, followed by removal of the solvent under reduced pressure. The pale pink solid residue was dried under vacuum at 60 °C. 0.89 g (88%) of product was given as a grayish-white solid.

[0131] Electrospray ionization mass spectrometry (MS-ESI) was used to detect the intermediate bis((perfluorohexyl)sulfonyl)amine and the Li salt at m / z 780 (anion C). 12 F 26 The significant presence of NO4S2 confirmed the expected synthesis results.

[0132] Zinc bis((perfluorohexyl)sulfonyl)amide

[0133]

[0134] 1.0 g (1.28 mmol) of bis((perfluorohexyl)sulfonyl)amine was dissolved in 6 mL of anhydrous MTBE. 0.71 mL (0.64 mmol, 0.5 eq) of diethylzinc solution was added dropwise. The reaction mixture was stirred overnight and the solvent was removed under reduced pressure. After drying under vacuum at 60 °C, 0.794 g (78%) of a light pink solid was obtained.

[0135] Similarly, bis(perfluoropropyl)sulfonylamide zinc (CAS 1040352-84-8, ZnHFSI) was prepared.

[0136] Zinc bis((perfluoroprop-2-yl)sulfonyl)amide

[0137]

[0138] 0.5 g (1.04 mmol) of bis((perfluoroprop-2-yl)sulfonyl)amine was dissolved in 10 mL of anhydrous MTBE. A solution of diethylzinc in 0.47 mL (0.52 mmol, 0.5 eq) hexane was added dropwise, and the mixture was stirred overnight at room temperature. 10 mL of hexane was added, and the resulting solid precipitate was filtered off and dried under high vacuum. 0.34 g (33%) of the product was given as a white solid.

[0139] Magnesium bis((perfluoroprop-2-yl)sulfonyl)amide

[0140]

[0141] 0.5 g (1.04 mmol) of bis((perfluoroprop-2-yl)sulfonyl)amine was dissolved in 10 mL of anhydrous MTBE, and a solution of dibutylmagnesium in 0.52 mL (0.52 mmol, 0.5 eq) heptane was added dropwise. The mixture was stirred overnight at room temperature. The solvent was removed under reduced pressure, and the residue was dried under high vacuum. 0.38 g (74%) of the product was given as a white powder.

[0142] Lithium tris(4,5,6,7-tetrafluoro-3-(trifluoromethyl)-1H-indazol-1-yl)borohydride (PB-1)

[0143] Step 1: 4,5,6,7-Tetrafluoro-3-(trifluoromethyl)-1H-indazole

[0144]

[0145] 11.09 g (45.1 mmol) of perfluoroacetophenone was dissolved in 100 mL of toluene. The solution was cooled in an ice bath and 2.3 mL (2.37 g, 47.3 mmol, 1.05 eq) of hydrazine hydrate was added dropwise. The mixture was heated under reflux for 3 days. After cooling to room temperature, the mixture was washed twice with 100 mL of saturated sodium bicarbonate aqueous solution and twice with 100 mL of water, dried over magnesium sulfate, and the solvent was removed under reduced pressure. The yellow oily residue was distilled from one flask to another at a temperature of about 140 °C and a pressure of about 12 Pa. The crude product was dissolved in hot hexane and the solution was stored at -18 °C. The precipitated solid was filtered off and the suspension was washed twice in 10 mL of hexane. 5.0 g (43%) of product was obtained as a pale yellow solid.

[0146] GCMS: Confirmed the expected M / z (mass / charge) ratio of 258.

[0147] Step 2: Lithium tris(4,5,6,7-tetrafluoro-3-(trifluoromethyl)-1H-indazol-1-yl)borohydride

[0148]

[0149] 5.1 g (19.8 mmol) of 4,5,6,7-tetrafluoro-3-(trifluoromethyl)-1H-indazole was added to a baked Schlenk flask under Ar gas countercurrent and treated with 3 mL of toluene. Freshly crushed lithium borohydride was added to the starting material. The mixture was heated to 100 °C until hydrogen formation ceased (approximately 4 h). After slight cooling, 15 mL of hexane was added, and the mixture was heated to reflux for 10 min and cooled to room temperature. The precipitated solid was filtered off, washed with 10 mL of hot hexane, and dried under high vacuum. 2.55 g (49%) of product was obtained as a grayish-white solid.

[0150] Lithium tris(3,5-bis(trifluoromethyl)-1H-pyrazole-1-yl)borohydride (PB-2)

[0151]

[0152] 2.0 g (9.8 mmol, 5 eq) of 3,5-bis(trifluoromethyl)pyrazole was dissolved in 5 mL of anhydrous toluene in a dried Schlenk flask. 43 mg (1.96 mmol, 1 eq) of freshly ground lithium borohydride was added under Ar gas countercurrent, and the mixture was heated to reflux for 3 days. The solvent and excess starting material were removed by distillation under reduced pressure, and the residue was crystallized from n-hexane chloride. 0.25 g (20%) of the product was given as a white solid.

[0153] Lithium tris(4,5,6,7-tetrafluoro-3-(perfluorophenyl)-1H-indazol-1-yl)borohydride (PB-3)

[0154] Step 1: 4,5,6,7-Tetrafluoro-3-(perfluorophenyl)-1H-indazole

[0155]

[0156] 20.0 g (54.8 mmol) of perfluorobenzophenone was dissolved in 200 mL of toluene. 4.0 mL (4.11 g, 82.1 mmol, approximately 1.5 eq) of hydrazine hydrate was added dropwise to the ice-cooled solution. 40 g of sodium sulfate was added, and the mixture was heated to reflux for 2 days. After cooling, 10 mL of acetone was added to the reaction mixture, and the resulting suspension was stirred at room temperature for 1 h. The solid was filtered off, washed thoroughly with 4 × 50 mL of toluene, and the organic fractions were combined and washed twice with a saturated aqueous sodium bicarbonate solution. The solvent was removed under reduced pressure, and the residue was purified by column chromatography. 7.92 g (41%) of the product was given as a pale yellow solid.

[0157] GC-MS: Confirmed the expected M / z (mass / charge) ratio of 356.

[0158] Step 2: Lithium tris(4,5,6,7-tetrafluoro-3-(perfluorophenyl)-1H-indazol-1-yl)borohydride

[0159]

[0160] In a dried Schlenk flask, 1.02 g (2.86 mmol, 3.0 eq) of 4,5,6,7-tetrafluoro-3-(perfluorophenyl)-1H-indazole was dissolved in 5 mL of chlorobenzene. Freshly crushed lithium borohydride (21 mg, 0.95 mmol, 1.0 eq) was added under Ar gas countercurrent. The mixture was heated to 150 °C for 2 days and then cooled to room temperature. The solvent was removed under reduced pressure, and the residue was dried under high vacuum. The crude product was further purified by drying in a flask-to-flask apparatus at a temperature of about 150 °C and a pressure of about 12 Pa. 0.57 g (70%) of the product was given as a grayish-white solid.

[0161] Lithium tri(3-cyano-5,6-difluoro-1H-indazol-1-yl)borohydride (PB-4)

[0162]

[0163] Freshly pulverized lithium borohydride (15 mg, 0.7 mmol, 1.0 eq) was placed in a dried pressure tube, and 0.5 g (2.79 mmol, 4.0 eq) of 5,6-difluoro-1H-indazole-3-carboxynitrile was added under reverse flow of Ar gas, followed by flushing with 1 mL of toluene. The pressure tube was sealed and heated to approximately 160 °C for about 21 h. After cooling to room temperature, the mixture was treated with 5 mL of hexane in an ultrasonic water bath for about 30 min. The precipitated solid was filtered off and washed with hexane (total 20 mL). After drying, 0.48 g of a pale yellow solid was obtained.

[0164] Tris(3,5-bis(trifluoromethyl)-1H-pyrazole-1-yl)zinc borohydride(II))(PB-5

[0165]

[0166] 0.57 g (0.91 mmol) of lithium tris(3,5-bis(trifluoromethyl)-1H-pyrazol-1-yl)borohydride was dissolved in 6 mL of N,N-dimethylformamide. An aqueous solution of 62 mg zinc dichloride in 1 mL of water was added dropwise. 20 mL of water was then added, and the mixture was treated in an ultrasonic water bath for 2 h. The precipitate was filtered off and dried under high vacuum. 0.485 g (82%) of the product was obtained as a white solid.

[0167] Exemplary compound E3

[0168] Precursor compound E2 was prepared according to reaction scheme 1.

[0169]

[0170] Reaction diagram 1: Synthesis of bis((1,1,1-trifluoro-N-(perfluorophenyl)methyl)-sulfonamide)zinc

[0171] Step 1: Synthesis of 1,1,1-trifluoro-N-(perfluorophenyl)sulfonamide

[0172] A 250 mL Schlenk flask was heated under vacuum and purged with nitrogen after cooling. Perfluoroaniline was dissolved in 100 mL toluene, and the solution was cooled to -80 °C. A 1.7 M solution of tert-butyllithium in hexane was added dropwise over 10 min using a syringe. The reaction solution changed from clear to turbid and was stirred at -80 °C for 1 h. Subsequently, the solution was allowed to warm to -60 °C, and 1.1 eq of trifluoromethanesulfonic anhydride was added dropwise. The cooling bath was then removed, and the reaction mixture was allowed to slowly warm to ambient temperature and stirred overnight, resulting in a light orange color. Additionally, a white solid was formed. The precipitated byproduct lithium trifluoromethanesulfonate was filtered off by vacuum filtration through a sintered glass filter and washed with 2 × 30 mL toluene and 30 mL n-hexane. The orange filtrate was evaporated and dried under high vacuum to form crystals. The crude product was then purified by flask-to-flask distillation (135 °C @ 1.2 × 10⁻⁶). -1 mbar) yielded a colorless crystalline solid (major fraction).

[0173] 1 H NMR[d 6 -DMSO, ppm] δ: 13.09 (s, 1H, NH).

[0174] 13 C{ 1 H}NMR[d 6 -DMSO,ppm]δ:116.75(m,Ci-C6F5),120.74(q, 1 J CF =325Hz,CF3),136.39,138.35(2m, 2 J CF =247Hz,m-C6F5),137.08,139.06(2m, 2 J CF =247Hz,p-C6F5),142.98,144.93(2m, 2 J CF =247,Hzo-C6F5).

[0175] 19 F NMR[d 6 -DMSO, ppm] δ: -77.45(m,CF3), -148.12(m,C6F5), -160.79(m,p-C6F5), -164.51(m,C6F5).

[0176] ESI-MS: m / z-neg = 314 (MH).

[0177] EI-MS: m / z=315(M), 182(M-SO2CF3), 69(CF3).

[0178] Step 2: Synthesis of bis((1,1,1-trifluoro-N-(perfluorophenyl)methyl)-sulfonamide)zinc

[0179] A 100 mL Schlenk flask was heated under vacuum and purged with nitrogen after cooling. 1,1,1-trifluoro-N-(perfluorophenyl)methanesulfonamide was dissolved in 10 mL of toluene, and 0.5 eq of diethylzinc in hexane was added dropwise to the solution using a syringe at ambient temperature. During the addition, a mist formed in the flask, and the reaction solution became jelly-like and cloudy. The solution was stirred at this temperature for 30 min. Then, 30 mL of n-hexane was added, forming a white precipitate, which was then filtered through a sintered glass filter (well 4) under an inert atmosphere. The filter cake was washed twice with 15 mL of n-hexane and dried under high vacuum at 100 °C for 2 h.

[0180] Yield: 660 mg (0.95 mmol, 60% of 1,1,1-trifluoro-N-(perfluorophenyl)methanesulfonamide), as a white solid.

[0181] 13 C{ 1 H}NMR[d 6 -DMSO,ppm]δ:121.68(q, 1 J CF =328Hz,CF3),123.56(m,Ci-C6F5),133.98,135.91(2m, 2 J CF =243Hz,p-C6F5),136.15,138.13(2m, 2 J CF =249Hz,m-C6F5),142.33,144.24(2m, 2 J CF =240,Hzo-C6F5).

[0182] 19 F NMR[d 6 -DMSO, ppm] δ: -77.52(m,CF3), -150.43(m,C6F5), -166.77(m,C6F5), -168.23(m,p-C6F5).

[0183] ESI-MS: m / z-neg=314 (M-Zn-L).

[0184] EI-MS: m / z=692 (M), 559 (M-SO2CF3), 315 (C6F5NHSO2CF3), 182 (C6F5NH), 69 (CF3).

[0185] Exemplary compound E3

[0186] 9.1g of E2 was subjected to a temperature of 240℃ and 10 -3 Sublimation occurs under Pa pressure.

[0187] Yield: 5.9g (65%).

[0188] The sublimated material forms colorless crystals. A crystal of suitable shape and size (0.094 × 0.052 × 0.043 mm) is then... 3 The sample was enclosed in a glass capillary under an Ar atmosphere and analyzed using monochromatic X-ray radiation (λ = 71.073 pm) from a source with a molybdenum cathode on a Kappa Apex II diffractometer (Bruker-AXS, Karlsruhe, Germany). A total of 37,362 reflections were collected in the θ range of 1.881 to 28.306°.

[0189] The structure was analyzed by the direct method (SHELXS-97, Sheldrick, 2008) and refined using the full matrix least squares method (SHELXL-2014 / 7, Olex2 (Dolomanov, 2017)).

[0190] Table 1. Auxiliary materials used in device embodiments

[0191]

[0192]

[0193] ABH-113 is the main body of the luminescent material, while NUBD-370 and DB-200 are blue phosphor dopants, both of which can be commercially available from SFC, Korea.

[0194] Prior to use in the vacuum deposition process, the auxiliary materials and test compounds, including commercially available sulfonyl imide salts such as MgTFSI (Alfa Aesar, CAS 133385-16-1), MnTFSI (Alfa Aesar, CAS 207861-55-0), ScTFSI (Alfa Aesar, CAS 176726-07-1), Fe(III)(TFSI) (Alfa Aesar, CAS 207861-59-4), and LiNFSI (American Custom Chemicals Corporation, CAS 119229-99-1), were purified by preparative vacuum sublimation.

[0195] Device Examples

[0196] Example 1 (bottom-emitting white OLED pixel, containing a metal complex or metal salt concentrated in a pure hole-generating sublayer as a p-type dopant)

[0197] On a glass substrate with a 90 nm thick ITO anode, the following layers were deposited: a 10 nm thick hole injection layer made of F1 doped with 8 wt% PD-2; a 140 nm thick undoped hole transport layer made of pure F1; a 20 nm thick first light-emitting layer formed of ABH113 doped with 3 wt% BD200 (both supplied by SFC, Korea); a 25 nm thick first electron transport layer made of pure F2; and a 10 nm thick charge generation layer made of F3 doped with 5 wt% Yb. Electron generation portion of the green layer (n-type CGL); 2 nm thick intermediate layer made of F4; hole generation portion of the charge generation layer made of PB-1 (p-type CGL) 30 nm thick; second hole transport layer made of pure F1 10 nm thick; second light-emitting layer 20 nm thick with the same thickness and composition as the first light-emitting layer; first electron transport layer made of pure F2 25 nm thick; electron injection layer (EIL) made of F3 doped with 5 wt% Yb 10 nm thick; 100 nm Al cathode.

[0198] All layers were deposited via vacuum thermal evaporation (VTE).

[0199] At 10mA / cm 2 At current densities, the device's 8V operating voltage is highly comparable to that of the same device containing commercially available prior art p-type dopant instead of PB-1. Precise calibration of the measurement equipment required for brightness / efficiency comparisons was not performed in this experiment.

[0200] Example 2 (bottom-emitting blue OLED pixel, containing a metal complex or metal salt concentrated in a pure hole-injection sublayer as a p-type dopant)

[0201] On the same glass substrate with an ITO anode as in Example 1, the following layers were subsequently deposited by VTE: a 10 nm thick hole injection layer made of compound PB-1; a 120 nm thick HTL made of pure F1; a 20 nm thick EML made of ABH113 doped with 3 wt% NUBD370 (both supplied by SFC, Korea); a 36 nm thick EIL / ETL made of F2 doped with 50 wt% LiQ; and a 100 nm thick Al cathode.

[0202] The comparative device comprises a HIL made of compound CN-HAT (CAS 105598-27-4) instead of PB-1.

[0203] The device of this invention achieves 15 mA / cm at an operating voltage of 5.2V. 2 The current density is 5.4% and the external quantum efficiency (EQE) is 5.4%, while the comparative device exhibits the same current density at a significantly higher voltage of 5.4V, but with a significantly lower EQE of 4.9%.

[0204] Example 3 (bottom-emitting blue OLED pixel, comprising a hole injection sublayer composed of a hole transport matrix uniformly doped with metal complexes or metal salts)

[0205] On the same glass substrate with an ITO anode as in Example 2, the following layers were subsequently deposited by VTE: a 10 nm thick hole injection layer made of matrix compound F2 doped with 8 wt% PB-1; a 120 nm thick HTL made of pure F1; a 20 nm thick EML made of ABH113 doped with 3 wt% NUBD370 (both supplied by SFC, Korea); a 36 nm thick EIL / ETL made of F2 doped with 50 wt% LiQ; and a 100 nm thick Al cathode.

[0206] The device of this invention achieves 15 mA / cm at 5.6V. 2 The current density and EQE of 5.6% for the LT97 (at 15 mA / cm²) 2 The operating time required for the brightness to decrease to 97% of its initial value under the given current density is 135 hours.

[0207] Example 4 (white display pixel, comprising a hole-generating sublayer composed of a hole transport matrix uniformly doped with metal complexes or metal salts)

[0208] In a device prepared similarly to that in Example 1, the pure PB-1 layer was replaced with a layer of the same thickness consisting of F2 doped with 35% by weight of PB-1.

[0209] Example 5 (Blue display pixel, containing a metal complex or metal salt concentrated in a pure hole-injection sublayer as a p-type dopant)

[0210] Table 2a schematically describes the model device.

[0211] Table 2a

[0212]

[0213] *E3 was also tested as a layer only 1nm thin.

[0214] Results for two exemplary p-type dopants are provided in Table 2b.

[0215] Table 2b

[0216]

[0217] Example 6 (Blue display pixel, comprising a hole injection sublayer composed of a hole transport matrix uniformly doped with metal complexes or metal salts)

[0218] Table 3a schematically describes the model device.

[0219] Table 3a

[0220]

[0221] #Molar quantity based on metal atoms

[0222] Results for two exemplary p-type dopants are provided in Table 3b.

[0223] Table 3b

[0224]

[0225]

[0226] Example 7 (Blue display pixel, containing a metal complex or metal salt concentrated in a pure hole-generating sublayer as a p-type dopant)

[0227] Table 4a schematically describes the model device.

[0228] Table 4a

[0229]

[0230]

[0231] Results for two exemplary p-type dopants are provided in Table 4b.

[0232] Table 4b

[0233]

[0234] Example 8 (blue display pixel, comprising a hole-generating sublayer composed of a hole transport matrix uniformly doped with metal complexes or metal salts)

[0235] Table 5a schematically describes the model device.

[0236] Table 5a

[0237]

[0238]

[0239] #Molar quantity based on metal atoms

[0240] Results for two exemplary p-type dopants are provided in Table 5b.

[0241] Table 5b

[0242]

[0243]

[0244] The features described above and disclosed in the appended claims may be, individually and in any combination thereof, material for implementing aspects of this disclosure made in the independent claims in various forms.

[0245] Key symbols and abbreviations used throughout this application:

[0246] CV cyclic voltammetry

[0247] Differential Scanning Calorimetry (DSC)

[0248] EBL Electron Blocking Layer

[0249] EIL Electron Injection Layer

[0250] EML emissive layer

[0251] eq. equivalent

[0252] ETL (Electron Transport Layer)

[0253] ETM Electron Transport Matrix

[0254] Fc Diceroxide

[0255] Fc +Ferrocene ions

[0256] HBL Hole Blocking Layer

[0257] HIL Hole Injection Layer

[0258] HOMO highest occupied molecular orbital

[0259] HPLC (High Performance Liquid Chromatography)

[0260] HTL Hole Transport Layer

[0261] p-type HTL p-type doped first hole transport layer

[0262] HTM Hole Transport Matrix

[0263] ITO (Indium Tin Oxide)

[0264] LUMO (lowest unoccupied molecular orbital)

[0265] mol% (mole percentage)

[0266] NMR (Nuclear Magnetic Resonance)

[0267] OLED Organic Light Emitting Diode

[0268] OPV (Organic Photovoltaic Devices)

[0269] QE (Quantum Efficiency)

[0270] R f Retention factor in TLC

[0271] RGB Red-Green-Blue

[0272] TCO transparent conductive oxide

[0273] TFT thin-film transistor

[0274] T g Glass transition temperature

[0275] TLC (Thin Layer Chromatography)

[0276] % by weight

Claims

1. A display device comprising: - A plurality of OLED pixels containing at least two OLED pixels, said OLED pixel comprising an anode, a cathode, and an organic stack, wherein said organic stack - Arranged between and in contact with the cathode and anode, and - Includes a first electron transport layer, a first hole transport layer, and a first light-emitting layer disposed between the first hole transport layer and the first electron transport layer, and - A driving circuit configured to drive the pixels of the plurality of OLED pixels respectively. For the plurality of OLED pixels, the first hole transport layer is disposed in the organic layer stack as a common hole transport layer shared by the plurality of OLED pixels, and the first hole transport layer comprises: (i) at least one hole transport matrix compound consisting of covalently bonded atoms, and (ii) at least one p-type electro-doper, said p-type electro-doper is selected from metal salts and selected from electrically neutral metal complexes, said electrically neutral metal complexes comprising a metal cation and at least one anionic ligand consisting of at least five covalently bonded atoms and / or at least one anion, The metal cation of the p-type electro-doper is selected from Na(I), K(I), Rb(I), Cs(I); alkaline earth metals, Pb(II), Mn, Fe, Co, Ni, Zn, Cd; rare earth metals in oxidation state (II) or (III); Sn(II); and Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W in oxidation state (IV) or lower.

2. The display device according to claim 1, wherein the anion and / or anion ligand comprises at least one atom selected from B, C, and N.

3. The display device according to claim 1, wherein the anion and / or anionic ligand comprises at least two atoms selected from B, C and N bonded together by covalent bonds.

4. The display device according to claim 1, wherein the anion and / or anion ligand comprises at least one peripheral atom selected from H, N, O, F, Cl, Br and I.

5. The display device according to claim 1, wherein the anion and / or anion ligand comprises at least one electron-withdrawing group, the electron-withdrawing group being selected from halogenated alkyl, halogenated aryl, halogenated heteroaryl, halogenated arylalkyl, halogenated heteroarylalkyl, halogenated alkylsulfonyl, halogenated arylsulfonyl, halogenated heteroarylsulfonyl, halogenated arylalkylsulfonyl, halogenated heteroarylalkylsulfonyl, and cyano.

6. The display device according to claim 5, wherein the electron-withdrawing group is a fully halogenated group.

7. The display device according to claim 6, wherein the electron-withdrawing group of the fully halogenated group is a perfluorinated group.

8. The display device according to claim 1, wherein the metal cation of the p-type electro-doper is selected from Na(I), K(I), Rb(I), Cs(I); Mg(II), Ca(II), Sr(II), Ba(II), Sn(II), Pb(II), Mn(II), Fe(II), Co(II), Ni(II), Zn(II), Cd(II), Al(III); rare earth metals in oxidation state (III), V(III), Nb(III), Ta(III), Cr(III), Mo(III), W(III), Ga(III), In(III), and selected from Ti(IV), Zr(IV), Hf(IV), Sn(IV).

9. The display device according to claim 2, wherein in the p-type electrodoper, the atom of the anion and / or the anionic ligand closest to the metal cation is a C or N atom.

10. The display device of claim 1, wherein the electrically neutral conjugate acid formed from the anion and / or anion ligand by adding one or more protons is more acidic in 1,2-dichloroethane than in HCl.

11. The display device of claim 1, wherein the lowest unoccupied molecular orbital energy level of the p-type electrodoperitone, calculated by standard quantum chemistry and expressed on an absolute vacuum scale, is at least 0.5 eV higher than the highest occupied orbital energy level of the first hole transport matrix compound, calculated by standard quantum chemistry, wherein the standard quantum chemistry uses the software package TURBOMOLE, which utilizes the DFT functional B3LYP and the basis set def2-TZVP.

12. The display device according to claim 1, wherein the first hole transport matrix compound is an organic compound.

13. A method for preparing a display device according to any one of the preceding claims, the method comprising at least one step of treating a first hole transport matrix compound and a p-type electro-doper in contact with each other at a temperature above 50°C.

14. The method of claim 13, wherein (i) The p-type electrodoper and the first hole transport matrix compound are dispersed in a solvent. (ii) The dispersion system is deposited on a solid support, and (iii) Evaporate the solvent at an elevated temperature.

15. The method of claim 13, further comprising wherein, at a depth of less than 1 × 10⁻⁶, the method further comprises wherein, the depth of ... -2 At least one step of evaporating the p-type electrodoped agent under a pressure of Pa and a temperature above 150°C.

16. The method of claim 13, wherein the p-type electro-doper is used in the form of a solid hydrate.

17. The method of claim 15, wherein the p-type electrodoperitone is used as an anhydrous solid containing less than 0.10% by weight of water.

18. A compound of formula (I) (I)， in M x It is an x-valent cation selected from alkali metals, alkaline earth metals, rare earth metals and metals of Al, Ga, Sn, Pb, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, Ni, Zn and Cd; x is 1 for M selected from alkali metals; 2 for M selected from alkaline earth metals, Pb, Mn, Fe, Co, Ni, Zn, and Cd; 2 for M selected from rare earth metals; 3 for Al and Ga; 2, 3, or 4 for Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W; and 2 or 4 for Sn. B 1 and B 2 Independently selected from fully halogenated C3 to C4 atoms 20 Alkyl, C3 to C 20 cycloalkyl or C3 to C 20 Arylalkyl; The condition is that compounds having formula (I) that satisfy the following conditions are excluded: a) M is selected from alkali metals, Mg, Ca, and Zn, and B 1 and B 2 Independently selected from perfluorinated straight-chain primary alkyl groups, or b) M is Li, and B 1 and B 2 It is perfluoroisopropyl.

19. The compound according to claim 18, wherein M is selected from Mg(II), Mn(II) and Zn(II).

20. The compound according to claim 18, wherein the compound is in solid form.

21. The compound according to claim 18, wherein the compound is in the form of a solid crystalline hydrate.

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