Organic electroluminescence element

Abstract

The present invention relates to a light-emitting layer for use in an organic electroluminescent device, where the light-emitting layer is obtained from the co-evaporation of a composition comprising a mixture of two structurally different compounds, both of which have an evaporation temperature between 150 and 400° C. The present invention also relates to a method for preparing such a light-emitting layer.

Description

[Technical field]

[0001] The present invention relates to an emissive layer for use in an organic electroluminescent device, where the emissive layer is obtained by co-evaporation of a composition comprising a mixture of two structurally different compounds, both having an evaporation temperature of 150-400° C. The present invention also relates to a method for preparing such an emissive layer. The present invention further relates to a composition of a mixture of two materials which can be advantageously used in an organic light emitting device and which allows the preparation of an emissive layer composed of multiple components, in particular four or more components. The present invention relates to the selection of two materials having different properties which can be evaporated simultaneously and which allow the preparation of an organic electroluminescent device with improved lifetime. The co-evaporation of two materials induces a homogeneous deposition and facilitates the manufacturing process of an electroluminescent device comprising more than three compounds in the emissive layer. Summary of the Invention [Problem to be solved by the invention]

[0002] Organic electroluminescent devices, including one or more organic-based light-emitting layers, such as organic light-emitting diodes (OLEDs), light-emitting electrochemical cells (LECs) and light-emitting transistors, are becoming increasingly important. In particular, OLEDs are promising devices for electronic products, such as screens, displays and lighting devices. In contrast to most electroluminescent devices that are essentially inorganic-based, organic-based organic electroluminescent devices are usually somewhat flexible and can be manufactured, especially in thin films. OLED-based screens and displays already available today offer good efficiency and long life, or good color purity and long life, but none of the three properties, i.e., good efficiency, long life and good color purity, are combined.

[0003] The color purity or color point of an OLED is generally given by CIEx and CIEy coordinates, while the color gamut of a next-generation display is given by so-called BT-2020 and DCPI3 values. In general, to obtain such color coordinates, the upper light-emitting element needs to modify the cavity to adjust the color coordinates. To target such color gamut while achieving high efficiency in the upper light-emitting element, a narrow emission spectrum is required in the lower light-emitting element.

[0004] Conventional phosphorescent emitters exhibit somewhat broad emission, which is reflected by the broad emission of phosphorescent-based OLEDs (PHOLEDs), which typically have a full width at half maximum (FWHM) of the emission spectrum greater than 0.25 eV. The broad emission spectrum of the PHOLED in the bottom device results in a large loss of outcoupling efficiency for top light-emitting device structures targeting the BT-2020 and DCPI tri-color regions.

[0005] In addition, phosphorescent materials are typically based on transition metals, such as iridium, which is generally not abundant and is therefore a very expensive material in an OLED stack. Therefore, transition metal-based materials have the greatest potential for reducing the cost of OLEDs. Reducing the transition metal content in an OLED stack is a key performance indicator for pricing OLED-applied products.

[0006] In recent years, some fluorescent or thermally-activated-delayed-fluorescence (TADF) compounds have been developed that exhibit somewhat narrower emission spectra, typically exhibiting an emission spectrum FWHM of 0.25 eV or less, and are therefore suitable for achieving the BT-2020 and DCPI tricolor regions. However, such fluorescent and TADF compounds generally suffer from low efficiency due to short lifetimes, as well as efficiency degradation at higher luminances (i.e., roll-off behavior in OLEDs), e.g., due to exciton-polaron annihilation or exciton-exciton annihilation.

[0007] The doped light-emitting layer of the organic light-emitting device of the prior art is formed by co-evaporation from two independently controlled vacuum evaporation sources, which can be referred to as containers. The container is any container that can be used as a source for (co)evaporation of the first and second compounds. Optionally, such a container can be a crucible. In an evaporative deposition process useful for forming a doped organic light-emitting layer, the concentration of the light-emitting dopant in the host layer formed is controlled by controlling the evaporation rate of the dopant material from the dopant evaporation source and controlling the evaporation deposition rate of the host compound from the host evaporation source. Such independently controlled co-evaporation has been effective in producing doped organic light-emitting devices with acceptable luminous efficiency in research and device development environments. However, the aforementioned co-evaporation process has at least two disadvantages that can be overcome by the present invention. One disadvantage is that the evaporation rate of the compounds used in the light-emitting layer is precisely controlled, particularly the incorporation of a relatively low concentration of dopant, such as 0.01 to 0.1 mole percent, into the doped layer of the host compound. Another disadvantage is that co-evaporation is relatively wasteful in terms of material utilization in that each evaporation co-evaporation source must be activated and adjusted to the desired vapor flow rate before layer formation begins on the previously formed organic layer of the device. Typically, a mechanical shutter is used to protect the device until the time required to adjust the vapor flow rate of the host compound and the vapor flow rate of the dopant material is reached. Such waste of material not only increases the cost of the device, but also increases the difficulty of maintaining the evaporation deposition system.

[0008] Co-evaporation of a host compound and a phosphorescent emitter from one container is described in EP-A 1156536 and US 10,074,806. [Means for solving the problem]

[0009] Surprisingly, it has been found that an emissive layer of an organic electroluminescent device in which two compounds are co-evaporated as a pre-mixed composition from one container can not only overcome the shortcomings of the prior art, but also provides an increased lifetime compared to an emissive layer of an organic electroluminescent device in which all compounds of the emissive layer are co-evaporated from individual containers for each compound. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention relates to an organic electroluminescent device comprising one or more light-emitting layers, wherein the light-emitting layers are obtained by evaporation of a composition comprising a mixture of a first compound and a second compound provided in a container, the first compound having a different chemical structure than the second compound, the first compound having an evaporation temperature T1 between 150 and 400° C., the second compound having an evaporation temperature T2 between 150 and 400° C., and the evaporation temperature is less than 1×10 -6 Torr or 1×10 -8 Torr (preferably, approximately 1×10 -7 The deposition rate is measured in a vacuum deposition chamber at a constant pressure of 1000 .mu.m (1.0 .mu.m) / sec (0.8 Å / sec), the temperature difference T1-T2 is in the range of -40°C to 40°C, preferably -20°C to 20°C, more preferably -10°C to 10°C, and the first compound and the second compound are selected from a host compound and a thermally activated delayed fluorescence (TADF) compound, respectively, and preferably at least one of the first compound and the second compound is a TADF compound.

[0011] In a further embodiment of the invention, the first compound and the second compound are TADF compounds.

[0012] In a preferred embodiment of the invention, at least one of the first compound and the second compound is a host compound.

[0013] In a more preferred embodiment of the present invention, the first compound is a host compound and the second compound is a TADF compound.

[0014] It is an object of the present invention to provide a method for producing a pre-doped emissive layer, comprising the steps of: (I) providing a composition of a first compound and a second compound; (II) optionally homogenizing the composition by grinding and / or by heating to a temperature above the melting points of the first compound and the second compound, depending on which compound has the higher melting point, to liquefy the composition and then cooling; and (III) evaporating the composition from one material source and optionally co-evaporating an additional compound in a vacuum deposition process.

[0015] As is well known in the art of fractional distillation of two or more components of a mixture, when the vapor pressures of each component of the mixture are the same or close, separation of the components by sublimation (evaporation) is virtually impossible.

[0016] The present invention uses a mixture of a first compound and a second compound, where the first compound has a given evaporation temperature T and the second compound has an evaporation temperature in the range of (T-40)°C to (T+40)°C, preferably in the range of (T-20)°C to (T+20)°C, more preferably in the range of (T-10)°C to (T+10)°C.

[0017] The present invention therefore also relates to a method for producing a light-emitting layer, comprising the steps of:

[0018] (i) mixing a first compound and a second compound together to form a homogenous mixture, where the first compound has a different chemical structure than the second compound, where the first compound has an evaporation temperature T1 between 150 and 400° C., and the second compound has an evaporation temperature T2 between 150 and 400° C., where the evaporation temperature is less than 1×10 -6 Torr or 1×10 -8measured in a vacuum deposition chamber at a deposition rate of 0.08 nm / sec (0.8 Å / sec) at a constant pressure of 10 Torr, wherein the temperature difference T1-T2 is in the range of -40°C to 40°C, preferably -20°C to 20°C, more preferably -10°C to 10°C, wherein the first compound and the second compound are selected from a host compound and a thermally activated delayed fluorescence (TADF) compound, respectively, and preferably at least one of the first compound and the second compound is a TADF compound; and (ii) co-evaporating a homogenous mixture of a first compound and a second compound from one vessel, wherein additional compounds are selectively co-evaporated from one or more additional vessels.

[0019] That is, the present invention also provides a method for mixing a first compound and a second compound together to form a homogenous mixture, wherein the first compound has a different chemical structure than the second compound, wherein the first compound has an evaporation temperature T1 between 150 and 400° C., and the second compound has an evaporation temperature T2 between 150 and 400° C., wherein the evaporation temperature is less than 1×10 -6 Torr or 1×10 -8 Torr (preferably, approximately 1×10 -7 the temperature difference T1-T2 is in the range of -40°C to 40°C, preferably -20°C to 20°C, more preferably (T-10)°C to (T+10)°C, wherein the first compound and the second compound are selected from host compounds and thermally activated delayed fluorescence (TADF) compounds, preferably at least one of the first compound and the second compound is a TADF compound, and wherein a homogenous mixture of the first compound and the second compound is evaporated together from one container, wherein a further compound may be evaporated together from a supplemental container.

[0020] The step of co-evaporating the homogenous mixture of the first and second compounds from a single vessel (step (ii)) may be carried out under any conditions.

[0021] In one embodiment, this is 1×10 -5 Less than 1x10 Torr, preferably less than 1x10 -6 Less than 1×10 Torr -7 Less than Torr or 1×10 -8 It is performed at a constant pressure range of less than Torr. The temperature is adjusted for the desired deposition rate, for example, in the range of 0.1-10 Å / s (angstroms per second), 0.5-5 Å / s, 0.7-1 Å / s, (approximately) 0.8 Å / s, etc.

[0022] In one embodiment, this is 1×10 -5 Less than 1x10 Torr, preferably less than 1x10 -6 Less than 1×10 Torr -7 Less than Torr or 1×10 -8 It is carried out at a range of pressures below a certain pressure of Torr and at a temperature above the vaporization temperature of the compound of interest, for example, above 150°C, above 200°C, or above 300°C.

[0023] In one embodiment, this is 1×10 -6 Torr or 1×10 -8 This is accomplished at a pressure range of up to 100 Torr and at a temperature above the vaporization temperature of the compound of interest, for example, above 150°C, above 200°C, or above 300°C.

[0024] The method of the present invention also relates to the manufacture of an organic electroluminescent device. Thus, the method of the present invention may also include a further step (iii) of assembling an organic electroluminescent device comprising the light-emitting layer obtained from step (ii). Step (iii) may optionally include a step of co-evaporating one or more further compounds to prepare one or more further layers of the organic electroluminescent device.

[0025] Such a light-emitting layer is according to the invention.The method is therefore also for producing an electroluminescent device.

[0026] As used throughout this specification, the term "mixture" is understood as a combination of two different compounds, which are not chemically linked, where the compounds maintain their chemical properties and where the physical properties of the combined compounds differ from those of the compounds themselves.

[0027] As used throughout this specification, the term "homogeneous mixture" is understood to be a mixture that has a constant composition throughout the mixture.

[0028] In a preferred embodiment, one or more further compounds of the light-emitting layer are co-evaporated from one or more further reservoirs.

[0029] In a preferred embodiment, the light-emitting layer of the organic electroluminescent device comprises at least: (i) a composition comprising a mixture of a first compound and a second compound; and (ii) one further host or emitter compound.

[0030] In a more preferred embodiment, the light-emitting layer of the organic electroluminescent device comprises at least one small FWHM emitter.

[0031] In the context of the present invention, a small full width at half maximum (FWHM) emitter can generally be any emitter with an emission spectrum exhibiting a full width at half maximum of 0.25 eV or less (≦0.25) measured from a spin-coated film having 1-5 wt. % of the emitter in poly(methyl methacrylate) PMMA, in particular 2 wt. %, at room temperature (i.e. (approximately) 20° C.). Alternatively, a small FWHM emitter S B The emission spectra of the emitters S are typically measured at room temperature (i.e., (approximately) 20 °C) in dichloromethane or toluene at 0.001–0.2 mg / mL. B can be measured in a solution.

[0032] As known to those skilled in the art, the emitter (e.g., a small FWHM emitter S BThe full width at half maximum (FWHM) of the emission spectrum of the small emitter S is easily determined from the respective emission spectra (fluorescence spectrum for fluorescent emitters and phosphorescence spectrum for phosphorescent emitters). B In this case, the fluorescence spectrum is generally used. All recorded FWHM values ​​generally indicate the main emission peak (i.e. the peak with the highest intensity). The means of determining the FWHM (herein preferably recorded in electron volts eV) are part of the common knowledge of the skilled person. For example, if the main emission peak of the emission spectrum is determined by dividing the two wavelengths λ 2 obtained in nanometers (nm) from the emission spectrum, the FWHM is calculated as 1 and λ 2 When half the maximum emission (i.e., 50% of the maximum emission intensity) is reached at , the FWHM in electron volts (eV) is typically (and herein) determined using the following equation:

[0033]

number

[0034] In a more preferred embodiment, the light-emitting layer of the organic electroluminescent device comprises at least: (i) a first compound; (ii) a second compound, (iii) one small FWHM emitter, and (iv) Phosphorescent emitters.

[0035] In the context of the present invention, a delayed fluorescent material is a material that can reach an excited singlet state (generally, the lowest excited triplet state T1) from an excited triplet state by reverse intersystem crossing (RISC; i.e., up-intersystem crossing or reverse intersystem crossing) and can emit light when returning from the excited singlet state (generally, S1) thus reached to the electronic ground state. The time scale (generally, microsecond range) at which the observed fluorescence emission occurs after RISC from an excited triplet state (generally, T1) to an excited singlet state (generally, S1) is slower than the time scale (generally, nanosecond range) at which direct (i.e., immediate) fluorescence occurs, and is therefore referred to as delayed fluorescence (DF). When RISC from an excited triplet state (generally, T1) to an excited singlet state (generally, S1) occurs via thermal activation and the excited singlet state thus filled emits light (delayed fluorescence emission), the process is referred to as thermally activated delayed fluorescence (TADF). Therefore, a TADF compound is a material that can emit thermally activated delayed fluorescence (TADF) as described above. The energy difference ΔE between the lowest excited singlet state energy level E(S1) and the lowest excited triplet state energy level E(T1) of the fluorescent emitter is ST It is known to those skilled in the art that when ΔE decreases, the transfer from the lowest excited triplet state to the lowest excited singlet state by RISC occurs with high efficiency. Therefore, TADF compounds generally have a small ΔE ST That it has a value forms part of the general knowledge of the person skilled in the art (see below).

[0036] The generation of (thermally activated) delayed fluorescence is analyzed, for example, based on decay curves obtained from time-resolved (i.e., transient) photoluminescence (PL) measurements. PL emission from a TADF compound is separated into an emission component from an excited singlet state (generally, S1) generated by initial excitation and an emission component from an excited singlet state (generally, S1) generated via an excited triplet state (generally, T1) by RISC. In general, there is a significant time difference between the emission from the excited singlet state (generally, S1) formed by initial excitation and the emission from the excited singlet state (generally, S1) reached from the excited triplet state (generally, T1) via RISC.

[0037] TADF compounds are preferably involved in full decay dynamics and satisfy the following two conditions: (i) the decay dynamics exhibit two time domains, one typically in the nanosecond (ns) range and the other typically in the microsecond (μs) range; and (ii) The emission spectral morphology is consistent in the two time domains.

[0038] Here, the portion of light emitted in the first decay region is considered as immediate fluorescence, and the portion of light emitted in the second decay region is considered as delayed fluorescence. PL measurements are performed using spin-coated films of 1–10 wt %, specifically 10 wt %, of each emitter (i.e., the hypothesized TADF compound) in poly(methyl methacrylate) (PMMA).

[0039] To assess whether preferred criterion (i) is met (i.e. the decay dynamics show two time domains, one typically in the nanosecond (ns) range and the other typically in the microsecond (μs) range), TCSPC (Time Correlated Single Photon Counting) is typically used (see below) and the entire decay dynamics is typically analysed as described below. Alternatively, transient photoluminescence measurements with spectral resolution can be performed (see below).

[0040] To assess whether preferred criterion (ii) is met (i.e., the morphology of the emission spectra in the two time domains coincides), transient photoluminescence measurements with spectral resolution are typically performed (see below).

[0041] In a preferred embodiment, the TADF compound is characterized by: (i) exhibiting a ΔE value corresponding to the energy difference between the lowest excited singlet state energy E (S1E) and the lowest excited triplet state energy E (T1E) of less than 0.4 eV; and (ii) exhibiting a photoluminescence quantum yield (PLQY) of greater than 30%;

[0042] In a preferred embodiment of the present invention, the TADF compound is represented by the formula TI:

[0043] [Chemical formula TI] JPEG2025507275000002.jpg39170 Here, in the chemical formula TI, X T N and CR Ta is selected from the group consisting of Z T are, in each case independently of one another, a direct bond, CR Tb R Tc , C=CR Tb R Tc , C=O, C=NR Tb , N.R. Tb , O, SiR Tb R Tc , S, S(O) and S(O) 2 is selected from the group consisting of L T is a substituted or unsubstituted C 6 -C 60 Arylene and substituted or unsubstituted C 3 -C 57 heteroarylene; Ar T is a substituted or unsubstituted C 6 -C 60Aryl and substituted or unsubstituted C 3 -C 57 heteroaryl; ta is an integer selected from 1 and 2; R Ta , R Tb and R Tc are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R T5 ) 2 , OR T5 , Si(R T5 ) 3 , B(OR T5 ) 2 , O.S.O. 2 R T5 , C.F. 3 ,CN,F,Br,I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R T5 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R T5 C=CR T5 , C≡C, Si(R T5 ) 2 , Ge(R T5 ) 2 , Sn(R T5 ) 2 , C=O, C=S, C=Se, C=NR T5 , P(=O)(R T5 ), SO, SO 2 , N.R. T5 , O, S or CONR T5 is replaced by C 1 -C 40 Alkoxy, This can be optionally substituted with one or more substituents R T5 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R T5 C=CR T5 , C≡C, Si(R T5 ) 2 , Ge(R T5 )2 , Sn(R T5 ) 2 , C=O, C=S, C=Se, C=NR T5 , P(=O)(R T5 ), SO, SO 2 , N.R. T5 , O, S or CONR T5 is replaced by C 1 -C 40 Thioalkoxy, This can be optionally substituted with one or more substituents R T5 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R T5 C=CR T5 , C≡C, Si(R T5 ) 2 , Ge(R T5 ) 2 , Sn(R T5 ) 2 , C=O, C=S, C=Se, C=NR T5 , P(=O)(R T5 ), SO, SO 2 , N.R. T5 , O, S or CONR T5 is replaced by C 2 -C 40 Alkenyl, This can be optionally substituted with one or more substituents R T5 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R T5 C=CR T5 , C≡C, Si(R T5 ) 2 , Ge(R T5 ) 2 , Sn(R T5 ) 2 , C=O, C=S, C=Se, C=NR T5 , P(=O)(R T5 ), SO, SO 2 , N.R. T5 , O, S or CONR T5 is replaced by C 2 -C 40 Alkynyl, This can be optionally substituted with one or more substituents R T5 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R T5 C=CR T5 , C≡C, Si(R T5 ) 2 , Ge(R T5 ) 2 , Sn(R T5 ) 2 , C=O, C=S, C=Se, C=NR T5 , P(=O)(R T5 ), SO, SO 2 , N.R. T5 , O, S or CONR T5 is replaced by Optionally, one or more substituents R T5 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R T5 C replaced with 3 -C 57 Heteroaryl, R T5 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,F,Br,I, C 1 -C 40 Alkyl, C 1 -C 40 Alkoxy, C 1 -C 40 Thioalkoxy, C 2 -C 40 Alkenyl, C 2 -C 40 Alkynyl, C 6 -C 60 Aryl, C 3 -C 57 Heteroaryl.

[0044] In a more preferred embodiment of the invention, the TADF compound comprises: - one or more first chemical moieties independently selected from amino, indolyl, carbazolyl and derivatives thereof, each of which is optionally substituted, wherein the groups are attached to the core structure of the respective TADF molecule via a nitrogen (N) or carbon (C) atom, and the substituents attached to the groups can form a monocyclic or polycyclic, aliphatic or aromatic or heteroaromatic, carbocyclic or heterocyclic ring system; -1 or more optionally substituted 1,3,5-triazinyl groups.

[0045] Those skilled in the art know that the term "derivatives thereof" means that the respective parent structure is selectively substituted or any atom within the respective parent structure is replaced, for example, with an atom of another element.

[0046] In one embodiment of the present invention, each TADF compound comprises: - one or more first chemical moieties each comprising or consisting of a structure according to formula DI,

[0047] [Chemical formula DI] JPEG2025507275000003.jpg46170 -Optionally, CN, CF 3 and one or more second chemical moieties, each independently selected from a structure according to any one of formulas AI, A-II, A-III, and A-IV;

[0048] [Chemical formula AI] JPEG2025507275000004.jpg37170

[0049] [Chemical formula A-II] JPEG2025507275000005.jpg38170

[0050] [Chemical formula A-III] JPEG2025507275000006.jpg30170

[0051] [Chemical formula A-IV] JPEG2025507275000007.jpg37170 - one third chemical moiety comprising or consisting of a structure according to any one of the chemical formulae LI, L-II, L-III, L-IV, LV, L-VI, L-VII and L-VIII,

[0052] [Chemical formula LI] JPEG2025507275000008.jpg44170

[0053] [Chemical formula L-II] JPEG2025507275000009.jpg78170

[0054] [Chemical formula L-III] JPEG2025507275000010.jpg59170

[0055] [Chemical formula L-IV] JPEG2025507275000011.jpg59170

[0056] [Chemical formula LV] JPEG2025507275000012.jpg87170

[0057] [Chemical formula L-VI] JPEG2025507275000013.jpg87170

[0058] [Chemical formula L-VII] JPEG2025507275000014.jpg86170

[0059] [Chemical formula L-VIII] JPEG2025507275000015.jpg111170 Where: the one or more first chemical moieties and optionally the one or more second chemical moieties are covalently bonded to a third chemical moiety via a single bond; In the chemical formula DI, # represents a single bond attachment site linking each first chemical moiety of formula DI to a third chemical moiety; Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=CR 1 R 2 , C=O, C=NR 1 , N.R. 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b , R d , R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , B(OR 3 ) 2 , O.S.O. 2 R 3 , C.F. 3 , CN, F, Cl, Br, I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R3 ), SO, SO 2 , N.R. 3 , O, S or CONR 3 is replaced by C 1 -C 40 Alkoxy, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R 3 ), SO, SO 2 , N.R. 3 , O, S or CONR 3 is replaced by C 1 -C 40 Thioalkoxy, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R 3 ), SO, SO 2 , N.R. 3 , O, S or CONR 3 is replaced by C 2 -C 40 Alkenyl, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R 3 ), SO, SO 2 , N.R. 3 , O, S or CONR 3 is replaced by C 2 -C 40 Alkynyl, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R 3 ), SO, SO 2 , N.R. 3 , O, S or CONR 3 is replaced by Optionally, one or more substituents R 3 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 3 C replaced with 3 -C 60 Heteroaryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 4 ) 2 , OR 4 , Si(R 4 ) 3 , B(OR 4 ) 2, O.S.O. 2 R 4 , C.F. 3 ,CN,F,Br,I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4 C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4 , P(=O)(R 4 ), SO, SO 2 , N.R. 4 , O, S or CONR 4 is replaced by C 1 -C 40 Alkoxy, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4 C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4 , P(=O)(R 4 ), SO, SO 2 , N.R. 4 , O, S or CONR 4 is replaced by C 1 -C 40 Thioalkoxy, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4 , P(=O)(R 4 ), SO, SO 2 , N.R. 4 , O, S or CONR 4 is replaced by C 2 -C 40 Alkenyl, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4 C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4 , P(=O)(R 4 ), SO, SO 2 , N.R. 4 , O, S or CONR 4 is replaced by C 2 -C 40 Alkynyl, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4 C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4 , P(=O)(R 4 ), SO, SO 2 , N.R. 4, O, S or CONR 4 is replaced by Optionally, one or more substituents R 4 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 4 C replaced with 3 -C 57 Heteroaryl, wherein optionally, the optional substituent R a , R b , R d , R 1 , R 2 , R 3 and R 4 are, independently of each other, R a , R b , R d , R 1 , R 2 , R 3 and R 4 together with one or more adjacent substituents selected from R 4 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, OPh, CF 3 ,C.N.,F. C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 1 -C 5 Alkoxy, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 1 -C 5 Thioalkoxy, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 2 -C5 Alkenyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 2 -C 5 Alkynyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 6 -C 18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 substituted with alkyl, Ph or CN; C 3 -C 17 Heteroaryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, Ph or C 1 -C 5 is substituted with alkyl, N(C 6 -C 18 Aryl) 2 , N(C 3 -C 17 Heteroaryl) 2 , and N(C 3 -C 17 Heteroaryl)(C 6 -C 18 aryl), a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, In the chemical formulas AI, A-II, A-III, and A-IV, the dashed lines represent single bonds connecting the respective second chemical moieties according to formula AI, A-II, A-III, or A-IV to a third chemical moiety; Q 1are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 9 ) 2 , OR 9 , Si(R 9 ) 3 , B(OR 9 ) 2 , O.S.O. 2 R 9 , C.F. 3 , CN, F, Cl, Br, I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9 , C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9, O, S or CONR 9 is replaced by C 1 -C 40 Alkoxy, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9 , C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9 , O, S or CONR 9 is replaced by C 1 -C 40 Thioalkoxy, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9 , C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9 , O, S or CONR 9 is replaced by C 2 -C 40 Alkenyl, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9, C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9 , O, S or CONR 9 is replaced by C 2 -C 40 Alkynyl, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9 , C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9 , O, S or CONR 9 is replaced by Optionally, one or more substituents R 9 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 9 C replaced with 3 -C 60 Heteroaryl, R 9 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 10 ) 2 , OR 10 , Si(R 10 ) 3 , B(OR 10 ) 2 , O.S.O. 2 R 10 , C.F.3 , CN, F, Cl, Br, I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 10 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R 10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by C 1 -C 40 Alkoxy, This can be optionally substituted with one or more substituents R 10 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R 10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by C 1 -C 40 Thioalkoxy, This can be optionally substituted with one or more substituents R 10 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by C 2 -C 40 Alkenyl, This can be optionally substituted with one or more substituents R 10 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R 10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by C 2 -C 40 Alkynyl, This can be optionally substituted with one or more substituents R 10 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R 10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by Optionally, one or more substituents R 10 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 10 C replaced with 3 -C 60 Heteroaryl, R 10 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, OPh, CF 3 ,C.N.,F. C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 1 -C 5 Alkoxy, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 1 -C 5 Thioalkoxy, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 2 -C 5 Alkenyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 2 -C 5 Alkynyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 6 -C 18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 substituted with alkyl, Ph or CN; C 3 -C 17 Heteroaryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, Ph or C 1 -C 5 is substituted with alkyl, N(C 6 -C 18 Aryl) 2 , N(C 3 -C 17 Heteroaryl) 2 , and N(C 3 -C 17 Heteroaryl)(C 6 -C 18 aryl), R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0060] [Chemical formula EWG-I] JPEG2025507275000016.jpg29170 Here, R X is R 6 where, in the formula EWG-I, at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring, which is fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; In the chemical formulas LI, L-II, L-III, L-IV, LV, L-VI, L-VII and L-VIII, Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 At least one Q is selected from 3 is nitrogen (N), R 11are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, F, Cl, Br, I, C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are replaced with deuterium; C 6 -C 18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 Alkyl group, C 6 -C 18 substituted with aryl groups, F, Cl, Br and I; R 12 is R 6 It is defined as follows:

[0061] In a preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=CR 1 R 2 , C=O, C=NR 1 , N.R. 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b , R d , R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 , CN, F, Cl, Br, I, C 1 -C 40Alkyl, This can be optionally substituted with one or more substituents R 3 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 3 C=CR 3 , C≡C, Si(R 3 ) 2 , Ge(R 3 ) 2 , Sn(R 3 ) 2 , C=O, C=S, C=Se, C=NR 3 , P(=O)(R 3 ), SO, SO 2 , N.R. 3 , O, S or CONR 5 is replaced by Optionally, one or more substituents R 3 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 3 C replaced with 3 -C 60 Heteroaryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 4 ) 2 , OR 4 , Si(R 4 ) 3 , C.F. 3 ,CN,F,Br,I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 4 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 4 C=CR 4 , C≡C, Si(R 4 ) 2 , Ge(R 4 ) 2 , Sn(R 4 ) 2 , C=O, C=S, C=Se, C=NR 4, P(=O)(R 4 ), SO, SO 2 , N.R. 4 , O, S or CONR 4 is replaced by Optionally, one or more substituents R 4 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 4 C replaced with 3 -C 57 Heteroaryl, wherein optionally, the optional substituent R a , R b , R d , R 1 , R 2 , R 3 and R 4 are, independently of each other, R a , R b , R d , R 1 , R 2 , R 3 and R 4 together with one or more adjacent substituents selected from R 4 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,C.N.,F. C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 6 -C 18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 substituted with alkyl, Ph or CN; C 3 -C 17 Heteroaryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 substituted with alkyl or Ph; N(C 6 -C 18 Aryl) 2 , N(C 3 -C 17 Heteroaryl) 2 , and N(C 3 -C 17 Heteroaryl)(C 6 -C 18 aryl), a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 9 ) 2 , OR 9 , Si(R 9) 3 , B(OR 9 ) 2 , O.S.O. 2 R 9 , C.F. 3 , CN, F, Cl, Br, I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 9 is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 9 C=CR 9 , C≡C, Si(R 9 ) 2 , Ge(R 9 ) 2 , Sn(R 9 ) 2 , C=O, C=S, C=Se, C=NR 9 , P(=O)(R 9 ), SO, SO 2 , N.R. 9 , O, S or CONR 9 is replaced by Optionally, one or more substituents R 9 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 9 C replaced with 3 -C 60 Heteroaryl, R 9 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 10 ) 2 , OR 10 , Si(R 10 ) 3 , B(OR 10 ) 2 , O.S.O. 2 R 10 , C.F. 3 , CN, F, Cl, Br, I, C 1 -C 40 Alkyl, This can be optionally substituted with one or more substituents R 10is replaced by Here, one or more non-adjacent CH 2 The group is optionally R 10 C=CR 10 , C≡C, Si(R 10 ) 2 , Ge(R 10 ) 2 , Sn(R 10 ) 2 , C=O, C=S, C=Se, C=NR 10 , P(=O)(R 10 ), SO, SO 2 , N.R. 10 , O, S or CONR 10 is replaced by Optionally, one or more substituents R 10 C replaced with 6 -C 60 Aryl, and Optionally, one or more substituents R 10 C replaced with 3 -C 60 Heteroaryl, R 10 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, OPh, CF 3 ,C.N.,F. C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, CN, CF 3 or replaced by F, C 6 -C 18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 substituted with alkyl, Ph or CN; C 3 -C 17 Heteroaryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, Ph or C 1 -C 5 is substituted with alkyl, N(C 6 -C18 Aryl) 2 , N(C 3 -C 17 Heteroaryl) 2 , and N(C 3 -C 17 Heteroaryl)(C 6 -C 18 aryl), R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0062] [Chemical formula EWG-I] JPEG2025507275000017.jpg29170 Here, R X is R 6 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring, which is fused to the structure of formula A-IV, and which is fused to one or more substituents R 10 wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are replaced with deuterium; C 6 -C18 Aryl, wherein optionally one or more hydrogen atoms are independently selected from deuterium, C 1 -C 5 Alkyl group and C 6 -C 18 substituted with an aryl group, R 12 is R 6 It is defined as wherein the maximum number of first and second chemical moieties attached to a third chemical moiety is determined by the number of binding sites available on the third chemical moiety (i.e., the number of substituents R 11 (the number of first and second chemical moieties), and in accordance with the foregoing definition, each TADF compound includes at least one first chemical moiety, at least one second chemical moiety, and exactly one third chemical moiety.

[0063] In a more preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=CR 1 R 2 , C=O, C=NR 1 , N.R. 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b , R d , R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 , CN, F, Cl, Br, I, Optionally, one or more substituents R 3 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 3 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 3 C replaced with 3 -C 17 Heteroaryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 4 ) 2 , Si(R 4 ) 3 , C.F. 3 ,C.N.,F. Optionally, one or more substituents R 4 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 4 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 4 C replaced with 3 -C 17 Heteroaryl, wherein optionally, the optional substituent R a , R b , R d , R 1 , R 2 and R 3 are, independently of each other, R a , R b , R d , R 1 , R 2 and R 3 together with one or more adjacent substituents selected from 5 is selectively substituted with R 4 and R 5 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,F,Me,i Pr, t Bu, N(Ph) 2 , and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 9 ) 2 , OR 9 , Si(R 9 ) 3 , C.F. 3 ,C.N.,F. Optionally, one or more substituents R 9 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 9C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 9 C replaced with 3 -C 17 Heteroaryl, R 9 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 10 ) 2 , OR 10 , Si(R 10 ) 3 , C.F. 3 ,C.N.,F. Optionally, one or more substituents R 10 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 10 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 10 C replaced with 3 -C 17 Heteroaryl, R 10 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, C.F. 3 ,CN,F,N(Ph) 2 , and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Bu, Ph, CN, CF 3 or replaced by F, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0064] [Chemical formula EWG-I] JPEG2025507275000018.jpg29170 Here, R X is R 6 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring, which is fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, C 1 -C 5 Alkyl, wherein optionally one or more hydrogen atoms are replaced with deuterium; Deuterium, Me, i Pr, t C optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph 6 -C 18 Aryl, R 12 is R 6 It is defined as follows:

[0065] In a more preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=O, NR 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , Rb , R d , R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 , C.N., Optionally, one or more substituents R 3 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 3 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 3 C replaced with 3 -C 17 Heteroaryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,F,Me, i Pr, t Bu, N(Ph) 2 , Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, wherein optionally, the optional substituent R a , R b , R d , R 1 and R 2 are, independently of each other, R a , R b , R d , R 1 and R 2 together with one or more adjacent substituents selected from wherein the fused ring system thus formed, consisting of the structure according to formula D1 and the attached rings formed by adjacent substituents, contains a total of 13 to 40 ring atoms, preferably 13 to 30 ring atoms, more preferably 16 to 30 ring atoms; a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 9 ) 2 , OR 9 , Si(R 9 ) 3 , C.F. 3 ,C.N.,F. Optionally, one or more substituents R 9 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 9 C replaced with6 -C 18 Aryl, and Optionally, one or more substituents R 9 C replaced with 3 -C 17 Heteroaryl, R 9 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, C.F. 3 ,CN,F,N(Ph) 2 , and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Bu, Ph, CN, CF 3 or replaced by F, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0066] [Chemical formula EWG-I] JPEG2025507275000019.jpg29170 Here, R X is R 6 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring, which is fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; R 12 is R 6 It is defined as follows:

[0067] In a more preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=O, NR 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b and R d are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 ,CN,Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, triazinyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me,i Pr, t Substituted with Bu and Ph, pyrimidinyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, pyridinyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 , C.N., Optionally, one or more substituents R 3 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 3 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 3 C replaced with 3 -C 17 Heteroaryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,F,Me, i Pr, t Bu, and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, wherein optionally, the optional substituent R a , R b , R d , R 1 and R 2 are, independently of each other, Ra , R b , R d , R 1 and R 2 together with one or more adjacent substituents selected from wherein the fused ring system thus formed, consisting of the structure according to formula D1 and the attached rings formed by adjacent substituents, contains a total of 13 to 40 ring atoms, preferably 13 to 30 ring atoms, more preferably 16 to 30 ring atoms; a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 9 ) 2 , OR 9 , Si(R 9 ) 3 , C.F.3 ,C.N.,F. Optionally, one or more substituents R 9 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 9 C replaced with 6 -C 18 Aryl, and Optionally, one or more substituents R 9 C replaced with 3 -C 17 Heteroaryl, R 9 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, C.F. 3 ,CN,F,N(Ph) 2 , and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Bu, Ph, CN, CF 3 or replaced by F, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0068] [Chemical formula EWG-I] JPEG2025507275000020.jpg29170 Here, R X is R 6 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring, which is fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of one another, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of one another, selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; R 12 is R 6 It is defined as follows:

[0069] In a more preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=O, NR 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b and R d are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R 3 ) 2 , OR 3 , Si(R 3 ) 3 , C.F. 3 ,CN,Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, iPr, t Substituted with Bu and Ph, R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, Deuterium, OR 3 , Si(R 3 ) 3 , Optionally, one or more substituents R 3 C replaced with 1 -C 5 Alkyl, Optionally, one or more substituents R 3 C replaced with 6 -C 18 Aryl, R 3 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,F,Me, i Pr, t Bu, and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, wherein optionally, the optional substituent R a , R b , R d , R 1 and R 2 are, independently of each other, R a , R b , R d , R 1 and R 2 together with one or more adjacent substituents selected from wherein the fused ring system thus formed, consisting of the structure according to formula D1 and the attached rings formed by adjacent substituents, contains a total of 13 to 40 ring atoms, preferably 13 to 30 ring atoms, more preferably 16 to 30 ring atoms; a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, Deuterium, OPh, N(Ph) 2 , Si(Me) 3 , Si(Ph) 3 , C.F. 3 ,CN,F,Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0070] [Chemical formula EWG-I] JPEG2025507275000021.jpg29170 Here, R X is R 6 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Deuterium, Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; R 12 is R 6 It is defined as follows:

[0071] In a more preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=O, NR 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of Ra , R b and R d are, in each occurrence, independently selected from the group consisting of: Hydrogen, Deuterium, N(Ph) 2 , Si(Me) 3 , Si(Ph) 3 , C.F. 3 ,CN,Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, and carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, wherein optionally, the optional substituent R a , R b , R d , R 1 and R 2 are, independently of each other, R a , R b , R d , R 1 and R 2 together with one or more adjacent substituents selected from wherein the fused ring system thus formed, consisting of the structure according to formula D1 and the attached rings formed by adjacent substituents, contains a total of 13 to 40 ring atoms, preferably 13 to 30 ring atoms, more preferably 16 to 30 ring atoms; a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, Deuterium, N(Ph) 2 , Si(Me) 3 , Si(Ph) 3 , Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, and carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0072] [Chemical formula EWG-I] JPEG2025507275000022.jpg30170 Here, R X is R 6 However, CN or CF 3 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, Deuterium, Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; R 12 is R 6 It is defined as follows:

[0073] In a particularly preferred embodiment of the present invention, Z 2 are, in each case independently of one another, a direct bond, CR 1 R 2 , C=O, NR 1 , O, SiR 1 R 2 , S, S(O) and S(O) 2 is selected from the group consisting of R a , R b and R d are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, CF 3 ,CN,Me, i Pr, t Bu, and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, R 1 and R 2 are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, wherein optionally, the optional substituent R a , R b , R d , R 1 and R 2 are, independently of each other, R a , R b , R d , R 1 and R 2 together with one or more adjacent substituents selected from wherein the fused ring system thus formed, consisting of the structure according to formula D1 and the attached rings formed by adjacent substituents, contains a total of 13 to 40 ring atoms, preferably 13 to 30 ring atoms, more preferably 16 to 30 ring atoms; a is an integer, 0 or 1; b is an integer, in each case 0 or 1, where both b are always identical; where when integer a is 1, both integers b are 0, and when both integers b are 1, integer a is 0, Q 1 are in each case, independently of one another, nitrogen (N), CR 6 and CR 7 provided that in formula AI, two adjacent groups Q 1 are not nitrogen (N), and here, the group Q of the formula AI 1 If none of the groups is nitrogen (N), the group Q 1 At least one of them is CR 7 and Q 2 are, in each case independently of one another, nitrogen (N) and CR 6 with the proviso that in formulae A-II and A-III, at least one group Q 2 is nitrogen (N) and two adjacent groups Q 2 are not both nitrogen (N), R 6 and R 8 are, in each occurrence, independently selected from the group consisting of: Hydrogen, Deuterium, N(Ph) 2 , Me, i Pr, t Bu, Ph, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, t Substituted with Bu and Ph, carbazolyl, where optionally one or more hydrogen atoms are independently selected from deuterium, Me, i Pr, tSubstituted with Bu and Ph, R 7 are, in each case independently of one another, CN, CF 3 and a structure according to formula EWG-I,

[0074] [Chemical formula EWG-I] JPEG2025507275000023.jpg30170 Here, R X is R 6 However, CN or CF 3 where at least one R X The group is CN or CF 3 and wherein in formula A-IV, two adjacent groups R 8 optionally forms an aromatic ring fused to the structure of formula A-IV, wherein the fused ring system thus formed optionally contains a total of 9 to 18 ring atoms; Q 3 are, in each case independently of one another, nitrogen (N) and CR 12 , with the proviso that at least one Q 3 is nitrogen (N), R 11 are, in each occurrence, independently of each other, a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, or are, independently of each other, selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Deuterium, Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; R 12 is R 6 It is defined as follows:

[0075] In a preferred embodiment of the present invention, a is always 1 and b is always 0.

[0076] In a preferred embodiment of the present invention, Z 2 is a direct bond in each case.

[0077] In a preferred embodiment of the present invention, R a is hydrogen in each case.

[0078] In a preferred embodiment of the present invention, R a and R d is hydrogen in each case.

[0079] In a preferred embodiment of the present invention, Q 3 is nitrogen (N) in each case.

[0080] In one embodiment of the invention, in formula EWG-I, at least one group R X is CN.

[0081] In a preferred embodiment of the invention, in the formula EWG-I, exactly one group R X is CN.

[0082] In a preferred embodiment of the invention, in formula EWG-I, exactly one R X The group is CN, and in formula EWG-I, R X The base is CF 3 isn't it.

[0083] Examples of first chemical moieties according to the present invention are given below, but this is not meant to limit the invention to these examples: JPEG2025507275000024.jpg207170JPEG2025507275000025.jpg236170JPEG2025507275000026.jpg57170 where the above definitions apply.

[0084] Examples of second chemical moieties according to the present invention are given below, but this is not meant to limit the invention to these examples: JPEG2025507275000027.jpg235170JPEG2025507275000028.jpg26170 where the above definitions apply.

[0085] In a preferred embodiment of the present invention, the TADF compound has the formula E B -I, E B -NO B -III, E B -IV, E B -V, E B -VI,E B -VII, E B -VIII, E B -IX, E B -X and E B -XI:

[0086] [Chemical formula E B -I] JPEG2025507275000029.jpg51170

[0087] [Chemical formula E B -II] JPEG2025507275000030.jpg75170

[0088] [Chemical formula E B -III] JPEG2025507275000031.jpg52170

[0089] [Chemical formula E B -IV] JPEG2025507275000032.jpg52170

[0090] [Chemical formula E B -V] JPEG2025507275000033.jpg41170

[0091] [Chemical formula E B -VI] JPEG2025507275000034.jpg75170

[0092] [Chemical formula E B -VII] JPEG2025507275000035.jpg76170

[0093] [Chemical formula E B -VIII] JPEG2025507275000036.jpg75170

[0094] [Chemical formula E B -IX] JPEG2025507275000037.jpg69170

[0095] [Chemical formula E B -X] JPEG2025507275000038.jpg81170

[0096] [Chemical formula E B -XI] JPEG2025507275000039.jpg102170 Where: R 13 is R 11 where R 13 is not a single bond attachment site linking the first or second chemical moiety to a third chemical moiety, R Y CN and CF 3 or R Y comprises or consists of a structure according to the formula BN-I:

[0097] [Chemical formula BN-I] JPEG2025507275000040.jpg29170 This is because the single bond represented by the dashed line gives the chemical formula E B -I, E B -NO B -III, E B -IV, E B -V, E B -VI,E B -VII, EB -VIII or E B -IX, where exactly one R BN The group is CN, and the other two R BN Both groups are hydrogen (H), Otherwise the above definitions apply.

[0098] In a preferred embodiment of the present invention, R 13 is hydrogen in each case.

[0099] In one embodiment of the present invention, R Y is CN in each case.

[0100] In one embodiment of the present invention, R Y In each case, CF 3 It is.

[0101] In one embodiment of the present invention, R Y is in each case the structure represented by the chemical formula BN-I.

[0102] In a preferred embodiment of the present invention, R Y are each independently selected from CN and the structure represented by the chemical formula BN-I.

[0103] In a preferred embodiment of the present invention, each TADF compound has the formula E, to which the above definitions apply. B -I, E B -NO B -III, E B -IV, E B -V, E B -VI,E B -VII and E B -X.

[0104] In a preferred embodiment of the present invention, each TADF compound has the formula E, to which the above definitions apply. B -I, E B -NO B-III, E B -V and E B -X.

[0105] In one embodiment of the invention, the host compound comprises or consists of: -Chemical formula H P -I, H P -II, H P -III, H P -IV, H P -V, H P -VI, H P -VII, H P -VIII, H P -IX and H P -X,

[0106] [Formula H P -I] JPEG2025507275000041.jpg31170

[0107] [Formula H P -II] JPEG2025507275000042.jpg25170

[0108] [Formula H P -III] JPEG2025507275000043.jpg47170

[0109] [Formula H P -IV] JPEG2025507275000044.jpg101170

[0110] [Formula H P -V] JPEG2025507275000045.jpg87170

[0111] [Formula H P -VI] JPEG2025507275000046.jpg87170

[0112] [Formula H P -VII] JPEG2025507275000047.jpg80170

[0113] [Formula H P -VIII] JPEG2025507275000048.jpg47170

[0114] [Formula H P -IX] JPEG2025507275000049.jpg43170

[0115] [Formula H P -X] JPEG2025507275000050.jpg43170 - Chemical formula H P -XI, H P -XII, H P -XIII, H P -XIV, H P -XV, H P -XVI, H P -XVII, H P -XVIII and H P -XIX,

[0116] [Formula H P -XI] JPEG2025507275000051.jpg45170

[0117] [Formula H P -XII] JPEG2025507275000052.jpg47170

[0118] [Formula H P -XIII] JPEG2025507275000053.jpg47170

[0119] [Formula HP -XIV] JPEG2025507275000054.jpg46170

[0120] [Formula H P -XV] JPEG2025507275000055.jpg46170

[0121] [Formula H P -XVI] JPEG2025507275000056.jpg80170

[0122] [Formula H P -XVII] JPEG2025507275000057.jpg85170

[0123] [Formula H P -XVIII] JPEG2025507275000058.jpg86170

[0124] [Formula H P -XIX] JPEG2025507275000059.jpg83170Here, the host, particularly the p-host compound H P is linked to the first chemical moiety via a single bond represented by a dashed line in said formula; Where: Z 1 are, in each case independently of one another, a direct bond, C(R II ) 2 , C=C(R II ) 2 , C=O, C=NR II , N.R. II , O, Si(R II ) 2 , S, S(O) and S(O) 2 is selected from the group consisting of R Iare, in each occurrence, independently of each other, a single bond attachment site linking the first chemical moiety to the second chemical moiety or are selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; Here, at least one R I is a single bond attachment site linking the first chemical moiety to the second chemical moiety; R II is selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; where two or more adjacent substituents R II optionally forming a monocyclic or polycyclic, aliphatic or aromatic or heteroaromatic, carbocyclic or heterocyclic ring system and having the chemical formula H P -XI, H P -XII, H P -XIII, H P -XIV, H P -XV, H P -XVI, H P -XVII, H P -XVIII and H P -XIX and adjacent substituent R II and an additional ring optionally formed by, the fused ring system contains a total of 8 to 60 carbon atoms, preferably 12 to 40 carbon atoms, and more preferably 14 to 32 carbon atoms.

[0125] In a more preferred embodiment of the present invention, Z 1 is in each case a direct bond, and the adjacent substituent R IIare not linked to form an additional ring system.

[0126] In a more preferred embodiment of the present invention, the host is selected from the group consisting of the following structures: JPEG2025507275000060.jpg179170JPEG2025507275000061.jpg198170JPEG2025507275000062.jpg135170

[0127] In a preferred embodiment of the present invention, the host compound has the formula H N -I, H N -II and H N -III, which comprises or consists of a structure according to any one of:

[0128] [Formula H N -I] JPEG2025507275000063.jpg35170

[0129] [Formula H N -II] JPEG2025507275000064.jpg54170

[0130] [Formula H N -III] JPEG2025507275000065.jpg86170 Here, R III and R IV are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, CN, CF 3 , Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; and Chemical formula H N -IV, H N -V, H N -VI, H N -VII, HN -VIII, H N -IX, H N -X, H N -XI, H N -XII, H N -XIII and H N -XIV,

[0131] [Formula H N -IV] JPEG2025507275000066.jpg47170

[0132] [Formula H N -V] JPEG2025507275000067.jpg49170

[0133] [Formula H N -VI] JPEG2025507275000068.jpg49170

[0134] [Formula H N -VII] JPEG2025507275000069.jpg50170

[0135] [Formula H N -VIII] JPEG2025507275000070.jpg49170

[0136] [Formula H N -IX] JPEG2025507275000071.jpg43170

[0137] [Formula H N -X] JPEG2025507275000072.jpg43170

[0138] [Formula H N -XI] JPEG2025507275000073.jpg43170

[0139] [Formula H N -XII] JPEG2025507275000074.jpg43170

[0140] [Formula H N -XIII] JPEG2025507275000075.jpg43170

[0141] [Formula H N -XIV] JPEG2025507275000076.jpg45170 Where: The dashed line represents the chemical formula H N -IV, H N -V, H N -VI, H N -VII, H N -VIII, H N -IX, HN-X, H N -XI, H N -XII, H N -XIII and H N The structure of any one of -XIV is N -I, H N -II and H N -III, X 1 is oxygen (O), sulfur (S) or carbon (R V ) 2 and R V are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, i Pr, t Bu, and Me, i Pr, t Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; where two or more adjacent substituents R V optionally forming a monocyclic or polycyclic, aliphatic or aromatic or heteroaromatic, carbocyclic or heterocyclic ring system and having the chemical formula HN -IV, H N -V, H N -VI, H N -VII, H N -VIII, H N -IX, H N -X, H N -XI, H N -XII, H N -XIII and H N -XIV and adjacent substituent R V and an additional ring optionally formed by Here, the chemical formula H N -I and H N In II, at least one substituent R III is CN.

[0142] In a more preferred embodiment of the present invention, the host compound is selected from the group consisting of the following structures: JPEG2025507275000077.jpg99170 JPEG2025507275000078.jpg178170

[0143] In one embodiment of the present invention, the host compound does not include any phosphine oxide groups, and in particular the host compound is not bis[2-(diphenylphosphino)phenyl]ether oxide (DPEPO).

[0144] As used throughout this specification, the terms "aryl" and "aromatic" are understood in the broadest sense as any monocyclic, bicyclic or polycyclic aromatic moiety. Thus, an aryl group contains 6 to 60 aromatic ring atoms, and a heteroaryl group contains 5 to 60 aromatic ring atoms, of which at least one is a heteroatom. Nevertheless, throughout this specification, the number of aromatic ring atoms is given in subscript numbers in the definitions of specific substituents. In particular, a heteroaromatic ring contains 1 to 3 heteroatoms. Furthermore, the terms "heteroaryl" and "heteroaromatic" are understood in the broadest sense as any monocyclic, bicyclic or polycyclic heteroaromatic moiety containing at least one heteroatom. The heteroatoms in each case may be the same or different and may be individually selected from the group consisting of N, O and S. Thus, the term "arylene" refers to a divalent substituent that possesses two attachment sites to other molecular structures and serves as a linker structure. In exemplary embodiments, if a group is defined differently from the definitions given herein, for example, if the number of aromatic ring atoms or the number of heteroatoms differs from the definitions given, the definitions in the exemplary embodiments apply. In accordance with the present invention, a fused (annulated) aromatic or heteroaromatic polycycle is composed of two or more single aromatic or heteroaromatic rings that form the polycycle via a condensation reaction.

[0145] In particular, as used throughout this specification, the term "aryl group" or "heteroaryl group" refers to any of the following: benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, benzphenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene; pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthridine, pyridoimidazole ... and pyrazinoimidazole, quinoxalinoimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, 1,3,5-triazine, quinoxaline, pyrazine, phenazine, naphthyridine, carboline, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3,4-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or a group that can be attached via any position of the aromatic or heteroaromatic group derived from a combination of the aforementioned groups.

[0146] As used throughout this specification, the term "cyclic group" is understood in its broadest sense to refer to any monocyclic, bicyclic or polycyclic moiety.

[0147] As used throughout this specification, the term "alkyl group" is understood in the broadest sense as any linear, branched or cyclic alkyl substituent. In particular, the term "alkyl" includes the substituents methyl (Me), ethyl (Et), n-propyl (N-propyl ... ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl (Et), ethyl ( n Pr), i-propyl ( i Pr), cyclopropyl, n-butyl ( n Bu), i-Butyl ( i Bu), s-Butyl ( s Bu), t-Butyl ( tBu), cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neo-pentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neo-hexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n -octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2,2,2]octyl, 2-bicyclo[2,2,2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, 2,2,2-trifluoroethyl, 1,1-dimethyl-n-hex-1-yl, 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n- des-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexades-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl-n-dec-1-yl, 1,1-diethyl-n-dodec- 1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)-cyclohex-1-yl, 1-(n-butyl)-cyclohex-1-yl, 1-(n-hexyl)-cyclohex-1-yl, 1-(n-octyl)-cyclohex-1-yl and 1-(n-decyl)-cyclohex-1-yl.

[0148] As used throughout this specification, the term "alkenyl" includes straight-chain, branched and cyclic alkenyl substituents. The term "alkenyl group" includes, for example, the substituents ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl.

[0149] As used throughout this specification, the term "alkynyl" includes straight-chain, branched and cyclic alkynyl substituents. The term "alkynyl group" includes, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl.

[0150] As used throughout this specification, the term "alkoxy" includes straight chain, branched and cyclic alkoxy substituents. The term "alkoxy group" includes, for example, methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy and 2-methylbutoxy.

[0151] As used throughout this specification, the term "thioalkoxy" includes straight chain, branched and cyclic thioalkoxy substituents, where the O in the exemplary alkoxy group is replaced with an S.

[0152] As used throughout this specification, the terms "halogen" and "halo" are also understood in the broadest sense, preferably fluorine, chlorine, bromine or iodine.

[0153] When a molecular fragment is described as being a substituent or attached to another moiety, the name may be described as just the fragment (e.g., naphthyl, dibenzofuryl) or as the whole molecule (e.g., naphthalene, dibenzofuran). As used herein, the above ways of describing a substituent or an attached fragment are considered equivalent.

[0154] In one embodiment of the present invention, the organic molecule according to the present invention has a molecular weight of 5000 cm -1 Less than 3000 cm -1 less than 1500 cm -1 less than 1000 cm -1 Less than or extremely less than 500cm -1ΔE, which corresponds to the energy difference between the first excited singlet state (S1) and the first excited triplet state (T1), is less than ST Figure 1 shows thermally activated delayed fluorescence (TADF) emitters exhibiting luminescence (luminescence) values.

[0155] The orbital energies and excited state energies are determined via experimental and quantum chemical methods, in particular computational methods using density functional theory calculations. The highest occupied molecular orbital energy E HOMO is determined to an accuracy of 0.1 eV from cyclic voltammetry measurements by methods known to those skilled in the art. The lowest unoccupied molecular orbital energy E LUMO is determined as the onset of the absorption spectrum.

[0156] The onset of the absorption spectrum is determined by calculating the intersection of a tangent to the absorption spectrum with the x-axis, the tangent to the absorption spectrum being set at the low energy side of the absorption band and at half maximum of the maximum intensity of the absorption spectrum.

[0157] The energy of the first excited triplet state T1 is determined from the onset of the emission spectrum at a low temperature, typically 77 K (TADF compound E B In the case of 10 wt% E in PMMA B Spin-coated films of 100 nm are commonly used, resulting in small FWHM emitter S B In this case, 1 to 5% by weight, preferably 2% by weight, of S in PMMA is used. B A spin-coated film of the host compound H is commonly used. B In the case of each host compound H B Spin-coated knit films of 100 nm or less are commonly used and measurements are typically performed at room temperature (i.e., about 20° C.). For example, as disclosed in EP 2 690 681 A1, small ΔE ST TADF compound E having a value BIt is observed that in the case of , both intersystem crossing and reverse intersystem crossing occur even at low temperatures. As a result, the emission spectrum at 77K contains emission from both the S1 and T1 states. However, as also stated in EP2690681A1, the contribution / value of the triplet energy is generally considered to be predominant. In host compounds where the first excited singlet state and the lowest triplet state differ in energy by >0.4 eV, phosphorescence is mainly seen in the steady state spectrum in 2-Me-THF. The triplet energy is therefore determined as the onset of the phosphorescence spectrum. In TADF compound molecules, the energy of the first excited triplet state T1 is determined from the onset of the delayed emission spectrum at 77K, which is measured in a film of PMMA with 10% by weight of emitter, unless otherwise specified. For both the host and emitter compounds, the energy of the first excited singlet state S1 is determined from the onset of the emission spectrum, which is measured in a film of 10% by weight of the host or emitter compound in PMMA, unless otherwise specified. The onset of the emission spectrum is determined by calculating the intersection point of a tangent to the emission spectrum with the x-axis. The tangent to the emission spectrum is set at the high energy side of the emission band (i.e., the emission band increases as it goes from high to low energy values) and at the half-maximum point of the maximum intensity of the emission spectrum.

[0158] A further aspect of the invention relates to the use of the organic molecules according to the invention as light emitters in optoelectronic devices.

[0159] The optoelectronic element is understood in the broadest sense as any element based on organic materials suitable for emitting light in the visible or near ultraviolet (UV) range, i.e. in the wavelength range from 380 to 800 nm. More preferably, the optoelectronic element is capable of emitting light in the visible range, i.e. in the wavelength range from 400 to 800 nm.

[0160] In the context of such applications, the optoelectronic element is more particularly selected from the group consisting of: Organic Light Emitting Diode (OLED), Light-emitting electrochemical cells, OLED sensors, especially gas and steam sensors that are not completely isolated from the outside, Organic diodes, ·Organic solar cells, Organic transistors, Organic field-effect transistors, Organic lasers, and Down conversion element.

[0161] In a preferred embodiment in the context of such an application, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC) and a light emitting transistor.

[0162] Optoelectronic Devices In a further aspect, the present invention relates to an optoelectronic device comprising the organic molecule or composition described above, more particularly in the form of a device selected from the group consisting of organic light emitting diodes (OLEDs), light emitting electrochemical cells, OLED sensors, in particular gas and vapor sensors that are not completely sealed off from the outside, organic diodes, organic solar cells, organic transistors, organic field effect transistors, organic lasers and down conversion devices.

[0163] In a preferred embodiment, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC) and a light emitting transistor.

[0164] In one embodiment of the optoelectronic device of the present invention, the organic molecules according to the present invention are emitter material in the light-emitting layer EML.

[0165] In one embodiment of the optoelectronic device of the present invention, the light-emitting layer EML consists of the composition according to the present invention as described above.

[0166] For example, when the optoelectronic device is an OLED, it has the following layer structure: 1. Substrate 2. Anode layer A 3. Hole injection layer (HIL) 4. Hole transport layer (HTL) 5.Electron blocking layer (EBL) 6. Emitting layer (EML) 7. Hole Blocking Layer (HBL) 8.Electron transport layer (ETL) 9.Electron injection layer (EIL) 10. Cathode layer C Here, the OLED may optionally include each layer and different layers may be combined, such that the OLED includes one or more layers of each layer type defined above.

[0167] The optoelectronic device may also optionally include one or more protective layers that protect the device from damaging exposure to harmful substances in the environment including, for example, moisture, vapors and / or gases.

[0168] In one embodiment of the present invention, the optoelectronic device is an OLED having the following inverted layer structure: 1. Substrate 2. Cathode layer C 3.Electron injection layer (EIL) 4.Electron transport layer (ETL) 5. Hole Blocking Layer (HBL) 6. Light-emitting layer B 7.Electron blocking layer (EBL) 8. Hole transport layer (HTL) 9. Hole injection layer (HIL) 10. Anode layer A Here, an OLED having an inverted layer structure may optionally include each layer and different layers may be combined, and the OLED may include one or more layers of each layer type defined above.

[0169] In one embodiment of the present invention, the optoelectronic element is an OLED that can have a stacked structure. In this structure, individual units are stacked on top of each other, unlike the common arrangement in which OLEDs are arranged side by side. Mixed light is generated by an OLED that exhibits a stacked structure, and in particular, white light is generated by stacking a blue OLED, a green OLED, and a red OLED. An OLED that exhibits a stacked structure may also optionally include a charge generation layer (CGL), which is generally located between two OLED subunits and is generally configured as an n-doped layer and a p-doped layer. Generally, the n-doped layer of one CGL is located closer to the anode layer.

[0170] In one embodiment of the present invention, the optoelectronic device is an OLED that includes two or more light-emitting layers between an anode and a cathode. In particular, the so-called tandem OLED includes three light-emitting layers, where one light-emitting layer emits red light, one light-emitting layer emits green light, and one light-emitting layer emits blue light, and may optionally include additional layers between each light-emitting layer, such as a charge generation layer, a charge blocking layer, or a charge transport layer. In a further embodiment, the light-emitting layers are stacked adjacently. In a further embodiment, the tandem OLED includes a charge generation layer between each two light-emitting layers. Also, adjacent light-emitting layers or light-emitting layers separated by a charge generation layer can be merged.

[0171] The substrate is made of any material or composition of materials. Mostly, a glass slide is used as the substrate. Alternatively, a thin metal layer (e.g. copper, gold, silver or aluminum film) or a plastic film or a plastic slide can be used, which allows a higher level of flexibility. The anode layer A is made of a material that allows obtaining a mostly (essentially) transparent film. Since at least one of the two electrodes must be (essentially) transparent to allow light emission from the OLED, one of the anode layer A or the cathode layer C is transparent. Preferably, the anode layer A is rich in or consists of transparent conductive oxides (TCOs). Such an anode layer A may comprise, for example, indium tin oxide, aluminum zinc oxide, fluorine doped tin oxide, indium zinc oxide, PbO, SnO, zirconium oxide, molybdenum oxide, vanadium oxide, tungsten oxide, graphite, doped Si, doped Ge, doped GaAs, doped polyaniline, doped polypyrrole and / or doped polythiophene.

[0172] Preferably, the anode layer A consists (essentially) of indium tin oxide (ITO). The roughness of the anode layer A due to the transparent conductive oxide (TCO) is also mitigated by using a hole injection layer (HIL). The HIL also facilitates the injection of similar charge carriers (i.e. holes) in that the transport of similar charge carriers from the TCO to the hole transport layer (HTL) is promoted. The hole injection layer (HIL) can be made of poly-3,4-ethylenedioxythiophene (PEDOT), polystyrenesulfonic acid (PSS), MoO 2 , V 2 O 5, CuPC or CuI, in particular a mixture of PEDOT and PSS. The hole injection layer (HIL) can also prevent diffusion of metals from the anode layer A into the hole transport layer (HTL). For example, the HIL can be poly-3,4-ethylenedioxythiophene:polystyrenesulfonate (PEDOT:PSS), poly-3,4-ethylenedioxythiophene (PEDOT), 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine (mMTDATA), 2,2',7,7'-tetrakis(n,n-diphenylamino)-9,9'-spirobifluorene (Spiro-TAD), N1,N1'-(biphenyl-4,4'-diyl)bis(N1-phenyl-N4,N4-di-m-tolylbenzene-1,4-diamine (DNTPD), N,N'-nis-(1-naphthalene-2-yl)phenylamine (NAPH), N,N'-bis ... It is also composed of N,N'-triphenyl-N,N'-bis-(1,1'-biphenyl)-4,4'-diamine (NPB), N,N'-diphenyl-N,N'-di-[4-(N,N-diphenylamino)phenyl]benzidine (NPNPB), N,N,N',N'-tetrakis(4-methoxyphenyl)benzidine (MeO-TPD), 1,4,5,8,9,11-hexaazatriphenylene-hexacarbonitrile (HAT-CN) and / or N,N'-diphenyl-N,N'-bis-(1-naphthyl)-9,9'-spirobifluorene-2,7-diamine (Spiro-NPD).

[0173] Adjacent to the anode layer A or the hole injection layer (HIL) is generally a hole transport layer (HTL). Any hole transport compound can be used here. For example, electron-rich heteroaromatic compounds such as triarylamines and / or carbazoles are also used as hole transport compounds. The HTL can reduce the energy barrier between the anode layer A and the light-emitting layer (EML). The hole transport layer (HTL) can also be an electron blocking layer (EBL). Preferably, the hole transport compound has a triplet state T1 with a relatively high energy level. For example, the hole transport layer (HTL) may be tris(4-carbazolyl-9-ylphenyl)amine (TCTA), poly(4-butylphenyl-diphenylamine) (poly-TPD), poly(4-butylphenyl-diphenylamine) (α-NPD), 4,4'-cyclohexylidene-bis[N,N-bis(4-methylphenyl)benzenamine] (TAPC), 4,4',4"-tris[2-naphthyl(phenyl)-amino]triphenylamine (2-TNATA), Spiro-TAD, DNTPD, NPB, NPNPB, MeO-TPD, HAT-CN, and / or 9,9' The HTL may also comprise a star-shaped heterocyclic compound such as 9-diphenyl-6-(9-phenyl-9H-carbazol-3-yl)-9H,9'H-3,3'-bicarbazole (TrisPcz). The HTL may also comprise a p-doped layer consisting of an inorganic or organic dopant in an organic hole-transporting matrix. The inorganic dopant may be, for example, a transition metal oxide such as vanadium oxide, molybdenum oxide or tungsten oxide. The organic dopant may be, for example, tetrafluorotetracyanoquinodimethane (F 4 -TCNQ), copper-pentafluorobenzoate (Cu(I)pFBz) or transition metal complexes can be used.

[0174] The EBL may include, for example, 1,3-bis(carbazol-9-yl)benzene (mCP), TCTA, 2-TNATA, 3,3-di(9H-carbazol-9-yl)biphenyl (mCBP), 3,5-di(9H-carbazol-9-yl)phenyl]triphenylsilane (SiMCP), DPEPO, tris-Pcz, 9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole (CzSi), and / or N,N'-dicarbazolyl-1,4-dimethylbenzene (DCB).

[0175] Adjacent to the hole transport layer (HTL) is generally located an emissive layer (EML). The emissive layer (EML) comprises at least one emissive molecule. In particular, the EML comprises at least one emissive molecule according to the present invention. In one embodiment, the emissive layer comprises only organic molecules according to the present invention. Generally, the EML further comprises one or more host compounds. For example, the host compound may be 4,4'-bis-(N-carbazolyl)-biphenyl (CBP), mCP, mCBP, dibenzo[b,d]thiophen-2-yltriphenylsilane (Sif87), CzSi, 3,5-di(9H-carbazol-9-yl)phenyl]triphenylsilane (SiMCP), dibenzo[b,d]thiophen-2-yl)diphenylsilane (Sif88), bis[2-(diphenylphosphino)phenyl]etheroxide (DPEPO), 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, ... [3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole, 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T), 2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine (T3T) and / or 2,4,6-tris(9,9'-spirobifluoren-2-yl)-1,3,5-triazine (TST). The host compound should generally be selected to exhibit a first triplet (T1) and a first singlet (S1) energy level that is energetically higher than the first triplet (T1) and first singlet (S1) energy levels of the organic molecule.

[0176] In one embodiment of the present invention, the EML comprises a so-called mixed host system, which has at least one hole-dominant host and one electron-dominant host. In a particular embodiment, the EML comprises a mixed host system comprising exactly one light-emitting organic molecule according to the present invention, T2T as an electron-dominant host, and a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole, and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole as a hole-dominant host. In a further embodiment, the EML comprises 50-80% by weight, preferably 60-75% by weight, of a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole, 10-45% by weight, preferably 15-30% by weight, of T2T, and 5-40% by weight, preferably 10-30% by weight, of an emissive molecule according to the present invention.

[0177] Adjacent to the light-emitting layer (EML) may be an electron-transporting layer (ETL). Any electron transporter may be used here. Exemplarily, electron-deficient compounds such as benzimidazole, pyridine, triazole, oxadiazole (e.g., 1,3,4-oxadiazole), phosphine oxides, and sulfones may be used. The electron transporter may also be a star-shaped heterocycle such as 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi). The ETL may be 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen), aluminum-tris(8-hydroxyquinoline) (Alq 3 ), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TSPO1), 2,7-di(2,2'-bipyridin-5-yl)triphenyl (BPyTP2), dibenzo[b,d]thiophen-2-yltriphenylsilane (Sif87), dibenzo[b,d]thiophen-2-yl)diphenylsilane (Sif88), 1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene (BmPyPhB) and / or 4,4'-bis-[2-(4,6-diphenyl-1,3,5-triazinyl)]-1,1'-biphenyl (BTB). Optionally, the ETL is also doped with a material such as Liq. The electron transport layer (ETL) can also block holes. Alternatively, a hole blocking layer (HBL) is introduced.

[0178] Examples of HBL include 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline = bathocuproine (BCP), bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum (BAlq), 2,9-bis(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen), and aluminum-tris(8-hydroxyquinoline) (Alq 3), diphenyl-4-triphenylsilylphenyl-phosphine oxide (TSPO1), 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T), 2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine (T3T), 2,4,6-tris(9,9'-spirobifluoren-2-yl)-1,3,5-triazine (TST), and / or 1,3,5-tris(N-carbazolyl)benzene / 1,3,5-tris(carbazol-9-yl)benzene (TCB / TCP).

[0179] Adjacent to the electron transport layer (ETL) may be a cathode layer C. The cathode layer C may, for example, comprise or consist of a metal (e.g. Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, LiF, Ca, Ba, Mg, In, W or Pd) or a metal alloy. For practical reasons, the cathode layer C may also consist of an (essentially) opaque metal such as Mg, Ca or Al. Alternatively or additionally, the cathode layer C may also comprise graphite and / or carbon nanotubes (CNTs). Alternatively, the cathode layer C may also comprise or consist of nanoscale silver wires.

[0180] The OLED may optionally further include a protective layer (also called an electron injection layer (EIL)) between the electron transport layer (ETL) and the cathode layer C. The layer may be any of lithium fluoride, cesium fluoride, silver, 8-hydroxyquinolinolatolithium (Liq), Li 2 O, BaF 2 , MgO and / or NaF.

[0181] Optionally, the electron transport layer (ETL) and / or the hole blocking layer (HBL) may also comprise one or more host compounds.

[0182] To additionally modify the emission spectrum and / or absorption spectrum of the emissive layer EML, the emissive layer EML may further comprise one or more additional emitter molecules F. Such emitter molecules F may be any emitter molecule known in the art. Preferably, such emitter molecules F are molecules having a structure different from that of the molecules according to the invention. The emitter molecules F may alternatively be TADF compounds. Alternatively, the emitter molecules F may alternatively be fluorescent and / or phosphorescent emitter molecules capable of shifting the emission spectrum and / or absorption spectrum of the emissive layer EML. For example, triplet and / or singlet excitons may be converted to the ground state S 0 Before being relaxed to , the organic emitter molecule according to the invention can be transferred to the emitter molecule F, which can emit light that is typically red-shifted compared to the light emitted by the organic molecule. Optionally, the emitter molecule F can also induce a two-photon effect (i.e., absorption of two photons that are half the maximum absorbed energy).

[0183] Alternatively, the optoelectronic device (e.g., an OLED) may be, for example, an essentially white optoelectronic device. For example, such a white optoelectronic device may comprise at least one (deep) blue emitter molecule and one or more emitter molecules emitting green and / or red light. And, optionally, there may be energy transfer between two or more molecules, as described above.

[0184] As used herein, unless more specifically defined in a particular context, the hue designations of emitted and / or absorbed light are as follows: Purple: >380~420nm wavelength range Deep blue: wavelength range >420~480nm Sky blue: Wavelength range >480~500nm Green: >500~560nm wavelength range Yellow: >560~580nm wavelength range Orange: >580~620nm wavelength range Red: Wavelength range of >620~800nm.

[0185] Associated with the emitter molecule, such hues exhibit maximum emission, so for example, a deep blue emitter has a maximum emission in the range >420-480 nm, a sky blue emitter has a maximum emission in the range >480-500 nm, a green emitter has a maximum emission in the range >500-560 nm, and a red emitter has a maximum emission in the range >620-800 nm.

[0186] Further embodiments of the present invention relate to OLEDs that emit light having CIEx and CIEy color coordinates close to the CIEx (=0.131) and CIEy (=0.046) color coordinates of primary blue (CIEx=0.131 and CIEy=0.046) as defined by ITU-R Recommendation BT.2020 (Rec.2020), which are suitable for use in UHD (Ultra High Definition) displays, such as UHD-TVs. In this paragraph, the term "close" refers to the range of CIEx and CIEy coordinates provided at the end of this paragraph. While in commercial applications, a top light-emitting element (where the top electrode is transparent) is typically used, the test element used throughout the present invention shows a bottom light-emitting element (where the bottom electrode and substrate are transparent). The CIEy color coordinates of the blue element decrease by up to 2 times when changing from the bottom light-emitting element to the top light-emitting element, but the CIEx remains almost the same (Okinaka et al. doi:10.1002 / sdtp.10480).Accordingly, a further embodiment of the present invention relates to an OLED whose emission exhibits a CIEx color coordinate of 0.02 to 0.30, preferably 0.03 to 0.25, more preferably 0.05 to 0.20, even more preferably 0.08 to 0.18, or even more preferably 0.10 to 0.15, and / or a CIEy color coordinate of 0.00 to 0.45, preferably 0.01 to 0.30, more preferably 0.02 to 0.20, even more preferably 0.03 to 0.15, or even more preferably 0.04 to 0.10.

[0187] Further embodiments of the present invention relate to OLEDs that emit light with CIEx and CIEy color coordinates close to the CIEx (=0.170) and CIEy (=0.797) color coordinates of primary green (CIEx=0.170 and CIEy=0.797) as defined by ITU-R Recommendation BT.2020 (Rec.2020), which are suitable for use in UHD displays, e.g., UHD-TVs. In this paragraph, the term "close" refers to the range of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically a top light-emitting element (where the top electrode is transparent) is used, while the test element used throughout the present invention shows a bottom light-emitting element (where the bottom electrode and substrate are transparent). The CIEy color coordinates of the blue element decrease by up to two times when changing from a bottom light-emitting element to a top light-emitting element, while the CIEx remains almost unchanged (Okinaka et al. doi:10.1002 / sdtp.10480). Thus, a further embodiment of the present invention relates to an OLED whose emission exhibits CIEx color coordinates of 0.06 to 0.34, preferably 0.07 to 0.29, more preferably 0.09 to 0.24, even more preferably 0.12 to 0.22, or even more preferably 0.14 to 0.19, and / or CIEy color coordinates of 0.75 to 1.20, preferably 0.76 to 1.05, more preferably 0.77 to 0.95, even more preferably 0.78 to 0.90, or even more preferably 0.79 to 0.85.

[0188] Further embodiments of the present invention relate to OLEDs that emit light with CIEx and CIEy color coordinates close to the CIEx (=0.708) and CIEy (=0.292) color coordinates of primary red (CIEx=0.708 and CIEy=0.292) as defined by ITU-R Recommendation BT.2020 (Rec.2020), which are suitable for use in UHD displays, e.g., UHD-TVs. In this paragraph, the term "close" refers to the range of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically a top light-emitting element (where the top electrode is transparent) is used, while the test element used throughout the present invention shows a bottom light-emitting element (where the bottom electrode and substrate are transparent). The CIEy color coordinates of the blue element decrease by up to two times when changing from a bottom light-emitting element to a top light-emitting element, while the CIEx remains almost unchanged (Okinaka et al. doi:10.1002 / sdtp.10480). Thus, a further embodiment of the present invention relates to an OLED whose emission exhibits CIEx colour coordinates of 0.60 to 0.88, preferably 0.61 to 0.83, more preferably 0.63 to 0.78, even more preferably 0.66 to 0.76 or even more preferably 0.68 to 0.73, and / or CIEy colour coordinates of 0.25 to 0.70, preferably 0.26 to 0.55, more preferably 0.27 to 0.45, even more preferably 0.28 to 0.40 or even more preferably 0.29 to 0.35.

[0189] Thus, a further aspect of the present invention is 2 and / or an external quantum efficiency of more than 8%, preferably more than 10%, more preferably more than 13%, even more preferably more than 15%, or even more than 20%; and / or an emission maximum between 420 nm and 500 nm, preferably between 430 nm and 490 nm, more preferably between 440 nm and 480 nm, even more preferably between 450 nm and 470 nm; and / or an emission maximum of less than 500 cd / m 2In particular, the present invention relates to OLEDs exhibiting LT80 values ​​of greater than 100 h, preferably greater than 200 h, more preferably greater than 400 h, even more preferably greater than 750 h, or even more preferably greater than 1000 h.

[0190] The optoelectronic device, in particular the OLED according to the invention, may be produced by any means of vapor deposition and / or liquid processes. Thus, at least one layer may be - Produced by the sublimation process; -Manufactured by organic vapor phase deposition process, - Produced by a carrier gas sublimation process; - Solution processed or printed.

[0191] The methods used to manufacture optoelectronic devices, in particular OLEDs, according to the present invention are known in the art. The different layers are deposited individually and successively on a suitable substrate by subsequent deposition steps. The individual layers may be deposited using the same or different deposition methods.

[0192] For example, the vapor deposition process includes premix evaporation, thermal (co)evaporation, chemical vapor deposition, and physical vapor deposition. For active matrix OLED displays, an AMOLED backplane is used as the substrate. Individual layers are also processed from solutions or dispersions using appropriate solvents. For example, solution deposition processes include spin coating, dip coating, and jet printing. Solution processing is optionally performed in an inert atmosphere (e.g., nitrogen atmosphere), and the solvent is completely or partially removed by means known in the art.

[0193] Working Example Cyclic Voltammetry Cyclic voltammograms are performed at concentrations of 10 to 150 nm in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g., 0.1 mol / L tetrabutylammonium hexafluorophosphate). -3The measurement is performed at room temperature in a nitrogen atmosphere using a three-electrode assembly (working electrode and counter electrode: Pt wire, reference electrode: Pt wire) and FeCp 2 / FeCp 2 + The HOMO data were corrected using ferrocene as an internal standard relative to a saturated calomel electrode (SCE).

[0194] Density functional theory calculations The molecular structures were optimized using the BP86 function and the Resolution of Identity (RI) approach. The excitation energies were calculated with the Time-Dependent DFT (TD-DFT) method using the (BP86) optimized structures. The orbital energies and excited state energies were calculated with the B3LYP function. For numerical integration, the Def2-SVP basis set and m4-grid were used. The Turbomole program package was used for all calculations.

[0195] photophysical measurements Sample preparation: spin coating Equipment: Spin150, SPS euro Sample concentration is 10 mg / ml dissolved in an appropriate solvent.

[0196] Program: 1) 400 U / min for 3 sec, 1000 U / min for 20 sec (1000U / min). 3) 4000 U / min for 10 sec (1000U / min). After coating, the film was dried at 70° C. for 1 min.

[0197] Photoluminescence spectroscopy and time-correlated single photon counting (TCSPC) Steady-state emission spectroscopy is measured using a Model FluoroMax-4 (Horiba Scientific) equipped with a 150 W Xenon-Arc lamp, excitation and emission monochromators, a Hamamatsu R928 photomultiplier tube, and time-correlated single photon counting options. Standard correction fits are used to correct the emission and excitation spectra.

[0198] The excited state lifetimes are determined using the same system using the TCSPC method with an FM-2013 instrument and a Horiba Yvon TCSPC hub.

[0199] Excitation light source: NanoLED 370 (wavelength: 371 nm, pulse duration: 1.1 ns) NanoLED 290 (wavelength: 294nm, pulse duration: <1ns) SpectraLED 310 (wavelength: 314nm) SpectraLED 355 (wavelength: 355nm) Data analysis (exponential fit) is performed using the software suite DataStation and DAS6 analysis software. The fit is determined using the chi-squared test.

[0200] Photoluminescence quantum yield measurement For photoluminescence quantum yield (PLQY) measurements, an Absolute PL quantum yield measurement C9920-03G system (Hamamatsu Photonics) was used. Quantum yields and CIE coordinates were determined using the software U6039-05 version 3.6.0.

[0201] Emission maxima are given in nm, quantum yields Φ are given in %, and CIE coordinates are given as x,y values.

[0202] The PLQY is determined using the following protocol: 1) Quality assurance: Anthracene (known concentration) in ethanol is used as the standard.

[0203] 2) Excitation wavelength: The absorption maximum of the organic molecule is determined and that wavelength is used to excite the molecule.

[0204] 3) Measurement The quantum yield is measured on solution or film samples in a nitrogen atmosphere. The yield is calculated using the following equation:

[0205]

number

[0206] Fabrication and characterization of organic electroluminescent devices The OLED device containing the organic molecules according to the present invention can also be manufactured by vacuum deposition method. When a layer contains one or more compounds, the weight percentage of one or more compounds is indicated in %. The total weight percentage value is 100%, so when no value is specified, the fraction of the compound is the same as the difference between the specified value and 100%.

[0207] Non-fully optimized OLEDs are characterized by measuring the electroluminescence spectrum using standard methods and the intensity- and current-dependent external quantum efficiency (%) calculated using the light and current detected by a photodiode. The lifetime of the OLED device is extracted from the change in luminance while operating at a constant current density. The LT50 value corresponds to the time when the measured luminance has decreased to 50% of the initial luminance, similarly LT80 corresponds to the point when the measured luminance has decreased to 80% of the initial luminance, and LT97 corresponds to the point when the measured luminance has decreased to 97% of the initial luminance.

[0208] Accelerated lifetime measurements are performed (e.g. by applying increased current densities), e.g. 500cd / m 2 In the present invention, the LT80 value is determined using the following formula:

[0209]

number

[0210] Values ​​refer to the average of multiple pixels (typically 2-8) and the standard deviation across the pixels is provided. The figures show the data series for one OLED pixel.

[0211] HPLC-MS HPLC-MS analysis is performed on an Agilent HPLC (1100 series) equipped with an MS-detector (Thermo LTQ XL).

[0212] For example, a typical HPLC method is as follows: A reverse phase column 3.0 mm×100 mm, particle size 2.7 μm from Agilent (Poroshell 120EC-C18, 3.0×100 mm, 2.7 μm HPLC column) is used for HPLC. HPLC-MS measurements are performed at room temperature with the following gradient:

[0213] [Table 1]

[0214] The following solvent mixtures containing 0.1% formic acid were used:

[0215] [Table 2]

[0216] From an analyte solution of 0.5 mg / mL concentration, an injection volume of 2 μL is used for the measurement.

[0217] Ionization of the probe is performed in an APCI (atmospheric pressure chemical ionization) source using positive (APCI+) or negative (APCI-) ionization mode, or using an APPI (atmospheric pressure photoionization) source.

[0218] example Table 1 shows that <10 -6 1 shows the evaporation temperatures (Tevap) of exemplary first and second compounds disclosed herein at a deposition rate of 0.8 Å / s at a pressure of 1000 torr. -6 The temperature is adjusted until the desired deposition rate of 0.8 Å / s is reached at a pressure of <10 torr. -6 The temperature required to obtain a deposition rate of 0.8 Å / s at a pressure of 1000 torr is the evaporation temperature given in Table 1. The evaporation temperature is used to determine the first and second compounds.

[0219] Exemplary first and second compounds according to the invention are shown below: JPEG2025507275000083.jpg50170 T1 JPEG2025507275000084.jpg51170 T2 JPEG2025507275000085.jpg50170 T3 JPEG2025507275000086.jpg54170 H1 JPEG2025507275000087.jpg54170 H2 JPEG2025507275000088.jpg59170 H3 JPEG2025507275000089.jpg54170 H4

[0220] [Table 3]

[0221] Based on the data shown in Table 3, a pair of one host (H) compound and one TADF compound (T) is exemplarily used to manufacture two devices, where the first device D1 is manufactured by the method described in the present invention, the first compound is represented by host compound H3, the second compound is represented by TADF compound T2, and compound H3 and compound T2 are mixed together and evaporated together from one container in a thermal evaporation device. The evaporation temperature difference between host compound H3 and TADF compound T2 is 10°C, which is in a preferred range of + / -10°C. A composition consisting of a mixture of the first compound H3 and the second compound T2 is obtained by mixing the two compounds together and heating the mixture above the melting point to homogenize the mixture. The homogenized mixture of compound H3 and compound T2 is cooled to room temperature and used as it is in one container of the thermal evaporation device. For comparison, comparative example C1 was manufactured by a conventional co-evaporation process in which host compound H3 and TADF compound T2 are evaporated from separate containers. The compositions of the emissive layers of Device Example D1 and Comparative Device Example C1 were obtained using standard HPLC measurements as previously described, and are shown in Table 4.

[0222] Further compounds used in the device examples are shown below: JPEG2025507275000091.jpg54170 ETL1 JPEG2025507275000092.jpg68170 HBL1 JPEG2025507275000093.jpg56170 P1 JPEG2025507275000094.jpg54170 DABNA1 JPEG2025507275000095.jpg59170 TADF1 JPEG2025507275000096.jpg81170 HOST1 JPEG2025507275000097.jpg42170 HTL1

[0223] [Table 4]

[0224] Element D1 is 1000cd / m 2 The external quantum efficiency (EQE) was 28.1% at 1200cd / m 2 The LT97 value at 10 mA / cm was determined to be 6306 hours from accelerated lifetime measurements. 2 The emission maximum is at 532 nm with a FWHM of 42 nm at . The corresponding CIE y value is 0.64.

[0225] The comparative example element C1 has a brightness of 1000 cd / m 2 It showed an external quantum efficiency (EQE) of 26.3% at 1200cd / m 2 The LT97 value at 10 mA / cm was determined to be 3016 hours from accelerated lifetime measurements. 2 The emission maximum is at 532 nm with a FWHM of 42 nm at . The corresponding CIE y value is 0.64.

Claims

1. obtained by evaporation of a composition comprising a mixture of a first compound and a second compound provided in a single container; the first compound has a different chemical structure than the second compound; The first compound has an evaporation temperature T1 of 150 to 400°C, and the second compound has an evaporation temperature T2 of 150 to 400°C; The evaporation temperature is 1×10 －６ Torr to 1 x 10 －８ Measured in a vacuum deposition chamber at a deposition rate of 0.08 nm / sec (0.8 Å / sec) at a constant pressure of 100 Torr, the temperature difference T1-T2 is in the range of −40° C. to 40° C., preferably −20° C. to 20° C., more preferably −10° C. to 10° C.; The light-emitting layer for use in an organic electroluminescent device, wherein the first compound and the second compound are selected from a host compound and a thermally activated delayed fluorescence (TADF) compound, respectively, and at least one of the first compound and the second compound is a TADF compound.

2. 10. The light-emitting layer of claim 1, wherein one or more additional compounds of the light-emitting layer are co-evaporated from one or more additional containers.

3. 2. The organic electroluminescent device according to claim 1, wherein the light-emitting layer comprises at least: (i) a composition comprising a mixture of a first compound and a second compound; and (ii) one additional host or emitter compound.

4. 10. The organic electroluminescent device of claim 1, wherein the light-emitting layer comprises at least one small full width at half maximum (FWHM) emitter.

5. 2. The organic electroluminescent device according to claim 1, wherein the light-emitting layer comprises at least: (i) a first compound; (ii) a second compound; (iii) one small FWHM emitter, and (iv) Phosphorescent emitters.

6. 10. The composition of claim 1, wherein the TADF compound is characterized by: (i) exhibiting a ΔEST value corresponding to the energy difference between the lowest excited singlet state energy E (S1E) and the lowest excited triplet state energy E (T1E) of less than 0.4 eV; and (ii) exhibit a photoluminescence quantum yield (PLQY) of greater than 30%;

7. The composition of claim 1, wherein the TADF compound is represented by the following chemical formula T-I: [Chemical formula TI] In the chemical formula T-I, X Ｔ is N and CR Ｔａ is selected from the group consisting of Z Ｔ are in each case, independently of one another, a direct bond, CR Ｔｂ R Ｔｃ , C=CR Ｔｂ R Ｔｃ , C═O, C═NR Ｔｂ , N.R. Ｔｂ , O, SiR Ｔｂ R Ｔｃ , S, S(O) and S(O) ２ is selected from the group consisting of L Ｔ is a substituted or unsubstituted C ６ -C ６０ Arylene, and substituted or unsubstituted C ３ -C ５７ heteroarylene; Ar Ｔ is a substituted or unsubstituted C ６ -C ６０ Aryl, and substituted or unsubstituted C ３ -C ５７ heteroaryl; ta is an integer selected from 1 and 2; R Ｔａ , R Ｔｂ and R Ｔｃ are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, N(R Ｔ５ ) ２ , OR Ｔ５ , Si(R Ｔ５ ) ３ , B(OR Ｔ５ ) ２ , OSO ２ R Ｔ５ , C.F. ３ ,CN,F,Br,I, C １ -C ４０ Alkyl, This may optionally be one or more substituents R Ｔ５ is replaced by Here, one or more non-adjacent CH ２ The group is optionally R Ｔ５ C=CR Ｔ５ , C≡C, Si(R Ｔ５ ) ２ , Ge(R Ｔ５ ) ２ , Sn(R Ｔ５ ) ２ , C=O, C=S, C=Se, C=NR Ｔ５ , P(=O)(R Ｔ５ ), SO, SO ２ , N.R. Ｔ５ , O, S or CONR Ｔ５ is replaced by C １ -C ４０ Alkoxy, This may optionally be one or more substituents R Ｔ５ is replaced by Here, one or more non-adjacent CH ２ The group is optionally R Ｔ５ C=CR Ｔ５ , C≡C, Si(R Ｔ５ ) ２ , Ge(R Ｔ５ ) ２ , Sn(R Ｔ５ ) ２ , C=O, C=S, C=Se, C=NR Ｔ５ , P(=O)(R Ｔ５ ), SO, SO ２ , N.R. Ｔ５ , O, S or CONR Ｔ５ is replaced by C １ -C ４０ thioalkoxy, This may optionally be one or more substituents R Ｔ５ is replaced by Here, one or more non-adjacent CH ２ The group is optionally R Ｔ５ C=CR Ｔ５ , C≡C, Si(R Ｔ５ ) ２ , Ge(R Ｔ５ ) ２ , Sn(R Ｔ５ ) ２ , C=O, C=S, C=Se, C=NR Ｔ５ , P(=O)(R Ｔ５ ), SO, SO ２ , N.R. Ｔ５ , O, S or CONR Ｔ５ is replaced by C ２ -C ４０ alkenyl, This may optionally be one or more substituents R Ｔ５ is replaced by Here, one or more non-adjacent CH ２ The group is optionally R Ｔ５ C=CR Ｔ５ , C≡C, Si(R Ｔ５ ) ２ , Ge(R Ｔ５ ) ２ , Sn(R Ｔ５ ) ２ , C=O, C=S, C=Se, C=NR Ｔ５ , P(=O)(R Ｔ５ ), SO, SO ２ , N.R. Ｔ５ , O, S or CONR Ｔ５ is replaced by C ２ -C ４０ Alkynyl, This may optionally be one or more substituents R Ｔ５ is replaced by Here, one or more non-adjacent CH ２ The group is optionally R Ｔ５ C=CR Ｔ５ , C≡C, Si(R Ｔ５ ) ２ , Ge(R Ｔ５ ) ２ , Sn(R Ｔ５ ) ２ , C=O, C=S, C=Se, C=NR Ｔ５ , P(=O)(R Ｔ５ ), SO, SO ２ , N.R. Ｔ５ , O, S or CONR Ｔ５ is replaced by Optionally, one or more substituents R Ｔ５ C substituted with ６ -C ６０ aryl, and Optionally, one or more substituents R Ｔ５ C substituted with ３ -C ５７ heteroaryl, R Ｔ５ are, in each occurrence, independently of one another, selected from the group consisting of: Hydrogen, deuterium, CF ３ ,CN,F,Br,I, C １ -C ４０ Alkyl, C １ -C ４０ Alkoxy, C １ -C ４０ thioalkoxy, C ２ -C ４０ alkenyl, C ２ -C ４０ Alkynyl, C ６ -C ６０ aryl, C ３ -C ５７ Heteroaryl.

8. 10. The composition of claim 1, wherein the host compound comprises or consists of: -Chemical formula H Ｐ -I, H Ｐ -II, H Ｐ -III, H Ｐ -IV, H Ｐ -V, H Ｐ -VI, H Ｐ -VII, H Ｐ -VIII, H Ｐ -IX and H Ｐ a first chemical moiety that comprises or consists of a structure according to any one of -X; and [Chemical formula H] Ｐ -I] [Chemical formula H] Ｐ -II] [Chemical formula H] Ｐ -III] [Chemical formula H] Ｐ -IV] [Chemical formula H] Ｐ -V] [Chemical formula H] Ｐ -VI] [Chemical formula H] Ｐ -VII] [Chemical formula H] Ｐ -VIII] [Chemical formula H] Ｐ -IX] [Chemical formula H] Ｐ -X] - each with the chemical formula H Ｐ -XI, H Ｐ -XII, H Ｐ -XIII, H Ｐ -XIV, H Ｐ -XV, H Ｐ -XVI, H Ｐ -XVII, H Ｐ -XVIII and H Ｐ -XIX, [Chemical formula H] Ｐ -XI] [Chemical formula H] Ｐ -XII] [Chemical formula H] Ｐ -XIII] [Chemical formula H] Ｐ -XIV] [Chemical formula H] Ｐ -XV] [Chemical formula H] Ｐ -XVI] [Chemical formula H] Ｐ -XVII] [Chemical formula H] Ｐ -XVIII] [Chemical formula H] Ｐ -XIX] Here, the host, particularly the p-host compound H Ｐ each of the one or more second chemical moieties present in where: Z １ are, in each case independently of one another, a direct bond, C(R ＩＩ ) ２ , C=C(R ＩＩ ) ２ , C═O, C═NR ＩＩ , N.R. ＩＩ , O, Si(R ＩＩ ) ２ , S, S(O) and S(O) ２ is selected from the group consisting of R Ｉ are, in each occurrence independently of one another, a single bond attachment site linking the first chemical moiety to the second chemical moiety or are selected from the group consisting of: Me, ｉ Pr, ｔ Bu, and Me, ｉ Pr, ｔ Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; where at least one R Ｉ is a single bond attachment site linking the first chemical moiety to the second chemical moiety; R ＩＩ are, in each occurrence, independently selected from the group consisting of: Hydrogen, deuterium, Me, ｉ Pr, ｔ Bu, and Me, ｉ Pr, ｔ Ph optionally substituted with one or more substituents independently selected from the group consisting of Bu and Ph; where two or more adjacent substituents R ＩＩ optionally forming a monocyclic or polycyclic, aliphatic or aromatic or heteroaromatic, carbocyclic or heterocyclic ring system, of the formula H Ｐ -XI, H Ｐ -XII, H Ｐ -XIII, H Ｐ -XIV, H Ｐ -XV, H Ｐ -XVI, H Ｐ -XVII, H Ｐ -XVIII and H Ｐ -XIX and an adjacent substituent R ＩＩ and any additional rings optionally formed by the fused ring system contain a total of 8 to 60 carbon atoms, preferably 12 to 40 carbon atoms, more preferably 14 to 32 carbon atoms.

9. 1. A method for producing a light-emitting layer, comprising the steps of: (i) mixing a first compound and a second compound together to form a homogeneous mixture, wherein the first compound has a different chemical structure than the second compound, the first compound having an evaporation temperature T1 of 150 to 400° C., and the second compound having an evaporation temperature T2 of 150 to 400° C., the evaporation temperature being greater than 1×10 －６ Torr to 1 x 10 －８ the temperature difference T1-T2 is in the range of -40°C to 40°C, preferably -20°C to 20°C, more preferably -10°C to 10°C, measured in a vacuum deposition chamber at a deposition rate of 0.08 nm / sec (0.8 Å / sec) at a constant pressure of 100 Torr; the first compound and the second compound are selected from a host compound and a thermally activated delayed fluorescence (TADF) compound, respectively, and at least one of the first compound and the second compound is a TADF compound; (ii) co-evaporating a homogeneous mixture of said first compound and said second compound from one vessel, wherein additional compounds are selectively co-evaporated from one or more additional vessels.

10. 10. The method of claim 9, wherein the organic electroluminescent device comprises an emissive layer comprising at least: (i) a first compound; (ii) a second compound; (iii) one small FWHM emitter, and (iv) Phosphorescent emitters.

11. 11. The method of claim 9 or 10, comprising the steps of: (i) providing a composition according to any one of claims 1 to 8; (ii) homogenizing said composition, optionally by: a. Grinding, and / or b. heating the composition to a temperature above the melting point of the first compound and the second compound, depending on which compound has the higher melting point, to liquefy the composition, and then allowing it to cool; and / or c. dissolving the composition in a solvent or mixture of solvents and then removing the solvent; (iii) evaporating the composition; and (iv) Optionally co-evaporating a further compound.

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