ORGANIC ELECTROLUMINESCENT DEVICE

Abstract

The present invention relates to an organic electroluminescent device including at least one light-emitting layer composed of one or more sublayers, wherein the one or more sublayers of the light-emitting layer as a whole include at least one host material H.sup.B, at least one phosphorescence material P.sup.B, at least one small FWHM emitter S.sup.B, and at least one TADF material E.sup.B, wherein the small FWHM emitter S.sup.B emits light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV.

Claims

1-14. (canceled)

15. An organic electroluminescent device, comprising at least one light-emitting layer comprising: at least one host material H.sup.B, which has a lowermost excited singlet state energy level E(S1.sup.H) and a lowermost excited triplet state energy level E(T1.sup.H); at least one phosphorescence material p.sup.B, which has a lowermost excited singlet state energy level E(S1.sup.P) and a lowermost excited triplet state energy level E(T1.sup.P); at least one small full width at half maximum (FWHM) emitter S.sup.B, which has a lowermost excited singlet state energy level E(S1.sup.S) and a lowermost excited triplet state energy level E(T1.sup.S), wherein the small FWHM emitter S.sup.B is to emit light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV; and at least one thermally activated delayed fluorescence (TADF) material E.sup.B, which has a lowermost excited singlet state energy level E(S1.sup.E) and a lowermost excited triplet state energy level E(T1.sup.E), wherein a relation expressed by the Formula (1) applies: $\begin{array}{cc}E\left(T{1}^H\right)>E\left(T{1}^P\right),& \left(1\right)\end{array}$ wherein each of the at least one TADF material E.sup.B comprises one or more first chemical moieties, independently of each other selected from an amino group, indolyl, carbazolyl, and derivatives thereof, each of which is optionally substituted, wherein these groups are each optionally bonded to a core structure of the respective TADF molecule via a nitrogen (N) or via a carbon (C) atom, and wherein substituents bonded to these groups optionally form mono- or polycyclic, aliphatic or aromatic, carbo- or heterocyclic ring systems; and one or more second chemical moieties, independently of each other selected from the group consisting of CN and an optionally substituted 1,3,5-triazinyl group, wherein the at least one small FWHM emitter S.sup.B is represented by Formula BNE-2 or a multimer thereof: ##STR00622## wherein, in Formula BNE-2, Z.sub.BNE is selected from the group consisting of O and S; R.sup.ab is at each occurrence independently selected from the group consisting of: hydrogen; deuterium; N(R.sup.BNE5b).sub.2; OR.sup.BNE5b; Si(R.sup.BNE5b).sub.3; B(OR.sup.BNE5b).sub.2; B(R.sup.BNE5b).sub.2; OSO.sub.2 RB.sup.NE5b; CF.sub.3; CN; F; Br; I; C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.BNE5b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE5b CCR.sup.BNE5b, CC, Si(R.sup.BNE5b).sub.2, Ge(R.sup.BNE5b).sub.2, Sn(R.sup.BNE5b).sub.2, CO, CS, CSe, CNR.sup.BNE5b P(O)(R.sup.BNE5b), SO, SO.sub.2, NR.sup.BNE5b, O, S, or CONR.sup.BNE5b; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.BNE5b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE5b CCR.sup.BNE5b, CC, Si(R.sup.BNE5b).sub.2, Ge(R.sup.BNE5b).sub.2, Sn(R.sup.BNE5b).sub.2, CO, CS, CSe, CNR.sup.BNE5b P(O)(R.sup.BNE5b), SO, SO.sub.2, NR.sup.BNE5b, O, S, or CONR.sup.BNE5b; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.BNE5b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE5b CCR.sup.BNE5b CC, Si(R.sup.BNE5b).sub.2, Ge(R.sup.BNE5b).sub.2, Sn(R.sup.BNE5b).sub.2, CO, CS, CSe, CNR.sup.BNE5b P(O)(R.sup.BNE5b), SO, SO.sub.2, NR.sup.BNE5b, O, S, or CONR.sup.BNE5b; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.BNE5b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE5b CCR.sup.BNE5b, CC, Si(R.sup.BNE5b).sub.2, Ge(R.sup.BNE5b).sub.2, Sn(R.sup.BNE5b).sub.2, CO, CS, CSe, CNR.sup.BNE5b P(O)(R.sup.BNE5b), SO, SO.sub.2, NR.sup.BNE5b, O, S, or CONR.sup.BNE5b; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.BNE5b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE5b CCR.sup.BNE5b CC, Si(R.sup.BNE5b).sub.2, Ge(R.sup.BNE5b).sub.2, Sn(R.sup.BNE5b).sub.2, CO, CS, CSe, CNR.sup.BNE5b P(O)(R.sup.BNE5b), SO, SO.sub.2, NR.sup.BNE5b, O, S, or CONR.sup.BNE5b; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.BNE5b C.sub.2-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.BNE5b and a single bond or a linking group linking two chemical structures of Formula BNE-2 with each other; R.sup.BNE5b is at each occurrence independently from each other selected from the group consisting of: hydrogen; deuterium; N(R.sup.BNE6b).sub.2; OR.sup.BNE6b; Si(R.sup.BNE6b).sub.3; B(OR.sup.BNE6b).sub.2; B(R.sup.BNE6b).sub.2; OSO.sub.2 RB.sup.NE6b; CF.sub.3; CN; F; Br; I; C.sub.1-C.sub.40-alkyl, which is optionally substituted with one or more substituents R.sup.BNE6b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE6bCCR.sup.BNE6b, CC, Si(R.sup.BNE6b).sub.2, Ge(R.sup.BNE6b).sub.2, Sn(R.sup.BNE6b).sub.2, CO, CS, CSe, CNR.sup.BNE6b, P(O)(R.sup.BNE6b), SO, SO.sub.2, NR.sup.BNE6b, O, S, or CONR.sup.BNE6b; C.sub.1-C.sub.40-alkoxy, which is optionally substituted with one or more substituents R.sup.BNE6b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE6bCCR.sup.BNE6b, CC, Si(R.sup.BNE6b).sub.2, Ge(R.sup.BNE6b).sub.2, Sn(R.sup.BNE6b).sub.2, CO, CS, CSe, CNR.sup.BNE6b, P(O)(R.sup.BNE6b), SO, SO.sub.2, NR.sup.BNE6b, O, S, or CONR.sup.BNE6b; C.sub.1-C.sub.40-thioalkoxy, which is optionally substituted with one or more substituents R.sup.BNE6b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE6bCCR.sup.BNE6b, CC, Si(R.sup.BNE6b).sub.2, Ge(R.sup.BNE6b).sub.2, Sn(R.sup.BNE6b).sub.2, CO, CS, CSe, CNR.sup.BNE6b, P(O)(R.sup.BNE6b), SO, SO.sub.2, NR.sup.BNE6b, O, S, or CONR.sup.BNE6b; C.sub.2-C.sub.40-alkenyl, which is optionally substituted with one or more substituents R.sup.BNE6b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE6bCCR.sup.BNE6b, CC, Si(R.sup.BNE6b).sub.2, Ge(R.sup.BNE6b).sub.2, Sn(R.sup.BNE6b).sub.2, CO, CS, CSe, CNR.sup.BNE6b, P(O)(R.sup.BNE6b), SO, SO.sub.2, NR.sup.BNE6b, O, S, or CONR.sup.BNE6b; C.sub.2-C.sub.40-alkynyl, which is optionally substituted with one or more substituents R.sup.BNE6b and wherein one or more non-adjacent CH.sub.2-groups are each optionally substituted by R.sup.BNE6bCCR.sup.BNE6b, CC, Si(R.sup.BNE6b).sub.2, Ge(R.sup.BNE6b).sub.2, Sn(R.sup.BNE6b).sub.2, CO, CS, CSe, CNR.sup.BNE6b, P(O)(R.sup.BNE6b), SO, SO.sub.2, NR.sup.BNE6b, O, S, or CONR.sup.BNE6b; C.sub.6-C.sub.60-aryl, which is optionally substituted with one or more substituents R.sup.BNE6b C.sub.2-C.sub.57-heteroaryl, which is optionally substituted with one or more substituents R.sup.BNE6b and a single bond or a linking group linking two chemical structures of Formula BNE-2 with each other; R.sup.BNE6b is at each occurrence independently from each other selected from the group consisting of: hydrogen; deuterium; OPh(Ph=phenyl); CF.sub.3; CN; F; C.sub.1-C.sub.6-alkyl, wherein one or more hydrogen atoms are each optionally, independently substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-alkoxy, wherein one or more hydrogen atoms are each optionally, independently substituted by deuterium, CN, CF.sub.3, or F; C.sub.1-C.sub.5-thioalkoxy, wherein one or more hydrogen atoms are each optionally, independently substituted by deuterium, CN, CF.sub.3, or F; C.sub.2-C.sub.5-alkenyl, wherein one or more hydrogen atoms are each optionally, independently substituted by deuterium, CN, CF.sub.3, or F; C.sub.2-C.sub.5-alkynyl, wherein one or more hydrogen atoms are each optionally, independently substituted by deuterium, CN, CF.sub.3, or F; C.sub.6-C.sub.18-aryl, which is optionally substituted with one or more C.sub.1-C.sub.6-alkyl substituents; C.sub.2-C.sub.17-heteroaryl, which is optionally substituted with one or more C.sub.1-C.sub.6-alkyl substituents; N(C.sub.6-C.sub.18-aryl).sub.2; N(C.sub.2-C.sub.17-heteroaryl).sub.2; N(C.sub.2-C.sub.17-heteroaryl)(C.sub.6-C.sub.18-aryl); and a single bond or a linking group linking two chemical structures of Formula BNE-2 with each other; and wherein any of the substituents R.sup.ab, R.sup.BNE5b and R.sup.BNE6b optionally and independently form a mono- or polycyclic, aliphatic, aromatic, heteroaromatic and/or benzo-fused ring system with one or more other substituents R.sup.ab, R.sup.BNE5b and/or R.sup.BNE6b.

16. The organic electroluminescent device according to claim 15, wherein each of the at least one TADF material E.sup.B has a lowest unoccupied molecular orbital LUMO(E.sup.B) having an energy E.sup.LUMO(E.sup.B), which is smaller than 2.6 eV.

17. The organic electroluminescent device according to claim 15, wherein each of the at least one TADF material E.sup.B has a E.sub.ST value, which corresponds to the energy difference between the lowermost excited singlet state energy E(S1.sup.E) and the lowermost excited triplet state energy E(T1.sup.E), of less than 0.4 eV; and has a photoluminescence quantum yield (PLQY) of more than 30%.

18. The organic electroluminescent device according to claim 15, wherein each of the at least one host material H.sup.B is a p-host HP, comprising: one first chemical moiety, comprising a structure according to any one selected from among the Formulas H.sup.P-I, H.sup.P-II, H.sup.P-III, H.sup.P-IV, H.sup.P-V, H.sup.P-VI, H.sup.P-VII, H.sup.P-VIII, H.sup.P-IX, and H.sup.P-X: ##STR00623## ##STR00624## ##STR00625## and one or more second chemical moieties, each comprising a structure according to any one selected from among Formulas H.sup.P-XI, H.sup.P-XII, H.sup.P-XIII, H.sup.P-XIV, H.sup.P-XV, H.sup.P-XVI, H.sup.P-XVII, H.sup.P-XVIII, and H.sup.P-XIX: ##STR00626## ##STR00627## wherein each of the one or more second chemical moieties which is present in the p-host H.sup.P is linked to the first chemical moiety via a single bond which is represented in the Formulas above by a dashed line wherein: Z.sup.1 is at each occurrence independently of each other selected from the group consisting of a direct bond, C(R.sup.II).sub.2, CC(R.sup.II).sub.2, CO, CNR.sup.II, NR.sup.II, O, Si(R.sup.II).sub.2, S, S(O), and S(O).sub.2; R.sup.I is at each occurrence independently of each other a binding site of a single bond linking the first chemical moiety to a second chemical moiety or is selected from the group consisting of: hydrogen, deuterium, Me, .sup.iPr, and .sup.tBu, and Ph, which is optionally substituted with one or more substituents independently of each other selected from the group consisting of: Me, .sup.iPr, .sup.tBu, and Ph; wherein at least one R.sup.I is a binding site of a single bond linking the first chemical moiety to a second chemical moiety; and R.sup.II is at each occurrence independently of each other selected from the group consisting of: hydrogen, deuterium, Me, .sup.iPr, .sup.tBu, and Ph, which is optionally substituted with one or more substituents independently of each other selected from the group consisting of: Me, .sup.iPr, .sup.tBu, and Ph; wherein two or more adjacent substituents R.sup.II optionally form an aliphatic or aromatic, carbo- or heterocyclic ring system so that the fused ring system consisting of a structure according to any one selected from among Formulas H.sup.P-XI, H.sup.P-XII, H.sup.P-XIII, H.sup.P-XIV, H.sup.P-XV, H.sup.P-XVI, H.sup.P-XVII, H.sup.P-XVIII, and H.sup.P-XIX as well as the additional rings optionally formed by adjacent substituents R.sup.II comprises in total 3-60 carbon atoms.

19. The organic electroluminescent device according to claim 15, wherein each of the at least one phosphorescence materials P.sup.B comprises a structure according to Formula P.sup.B-I, ##STR00628## wherein M is selected from the group consisting of Ir, Pt, Au, Eu, Ru, Re, Ag and Cu; n is an integer of 1 to 3; and X.sup.2 and Y.sup.1 together form at each occurrence independently from each other a bidentate mono-anionic ligand.

20. The organic electroluminescent device according to claim 15, wherein each of the at least one phosphorescence material p.sup.B comprises iridium.

21. The organic electroluminescent device according to claim 15, wherein each of the at least one small FWHM emitter S.sup.B is independently represented by Formula BNE-6 or Formula BNE-7: ##STR00629##

22. The organic electroluminescent device according to claim 15, wherein each of the at least one small FWHM emitter S.sup.B represented by Formula BNE-8: ##STR00630## wherein R.sup.ac is each independently selected from the group consisting of: hydrogen, D, Me, .sup.iPr, .sup.tBu CN, CF.sub.3, Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, and N(Ph).sub.2.

23. The organic electroluminescent device according to claim 15, wherein each of the at least one small FWHM emitter S.sup.B is independently represented by Formula BNE-9: ##STR00631## wherein R.sup.ac is each independently selected from the group consisting of: hydrogen, D, Me, .sup.iPr, .sup.tBu CN, CF.sub.3, Ph, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, pyridinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, pyrimidinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, carbazolyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, triazinyl, which is optionally substituted with one or more substituents independently from each other selected from the group consisting of Me, .sup.iPr, .sup.tBu, CN, CF.sub.3, and Ph, and N(Ph).sub.2.

24. The organic electroluminescent device according to claim 15, wherein the at least one phosphorescence material P.sup.B has emission maximum .sub.max(P.sup.B) with an energy E.sup.max(P.sup.B); and the at least one small full width at half maximum (FWHM) emitter S.sup.B has emission maximum .sub.max(S.sup.B) with an energy E.sup.max(S.sup.B), wherein the small FWHM emitter S.sup.B is to emit light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV; the at least one thermally activated delayed fluorescence (TADF) material E.sup.B has emission maximum .sub.max(E.sup.B) with an energy E.sup.max(E.sup.B); wherein (18) and (19) apply: $\begin{array}{cc}.Math.E^{\max }\left(P^B\right)-E^{\max }\left(S^B\right).Math.<0.2\mathrm{eV},& \left(18\right)\end{array}$ $\begin{array}{cc}.Math.E^{\max }\left(E^B\right)-E^{\max }\left(S^B\right).Math.<0.2\mathrm{eV}.& \left(19\right)\end{array}$

25. The organic electroluminescent device according to claim 24, wherein at least one selected from among the relations expressed by the formulas (23) to (25) apply: $\begin{array}{cc}510\mathrm{nm}<{}_{\max }\left(S^B\right)<550\mathrm{nm};& \left(24\right)\end{array}$ $\begin{array}{cc}440\mathrm{nm}<{}_{\max }\left(S^B\right)<470\mathrm{nm};& \left(23\right)\end{array}$ $\begin{array}{cc}610\mathrm{nm}<{}_{\max }\left(S^B\right)<665\mathrm{nm}.& \left(25\right)\end{array}$

26. The organic electroluminescent device according to claim 15, wherein the at least one light-emitter layer comprises: 30-99.7% by weight of the at least one host compound H.sup.B; 0.1-30% by weight of the at least one phosphorescence material p.sup.B; and 0.1-10% by weight of the at least one small FWHM emitter S.sup.B; and optionally 0.1-69.8% by weight of the at least one TADF material E.sup.B; and optionally 0-69.8% by weight of one or more solvents.

27. A method for generating light, comprising applying an electrical current to the organic electroluminescent device according to claim 15 to generate light.

28. The method according to claim 27, wherein the light generated is at a wavelength range selected from one of the following wavelength ranges: from 510 nm to 550 nm, or from 440 nm to 470 nm, or from 610 nm to 665 nm.

Description

EXAMPLES

Cyclic Voltammetry

[2189] Cyclic voltammograms of solutions having concentration of 10.sup.3 mol/I of the organic molecules in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g., 0.1 mol/I of tetrabutylammonium hexafluorophosphate) are measured. The measurements are conducted at room temperature and under nitrogen atmosphere with a three-electrode assembly (working and counter electrodes: Pt wire, reference electrode: Pt wire) and calibrated using FeCp.sub.2/FeCp.sub.2.sup.+as internal standard. HOMO and LUMO data is corrected using ferrocene (FeCp.sub.2) as internal standard against SCE.

Density Functional Theory Calculation

[2190] Molecular structures are optimized employing the BP86 functional and the resolution of identity approach (RI). Excitation energies are calculated using the (BP86) optimized structures employing Time-Dependent DFT (TD-DFT) methods. Orbital and excited state energies are calculated with the B3LYP functional. However, herein, orbital and excited state energies are preferably determined experimentally as stated above.

[2191] All orbital and excited state energies reported herein (see experimental results) have been determined experimentally. Def2-SVP basis sets and a m4-grid for numerical integration are used. The Turbomole program package is used for all calculations.

Photophysical Measurements

Sample Pretreatment: Vacuum-Evaporation

[2192] As stated before, photophysical measurements of individual compounds (for example organic molecules or transition metal complexes) that may be included in a light-emitting layer B of the organic electroluminescent device according to the present invention (i.e., host materials H.sup.B, TADF materials E.sup.B, phosphorescent materials P.sup.B, or small FWHM emitters S.sup.B) were typically performed using either neat films (in case of host materials H.sup.B) or films of the respective material in poly(methyl methacrylate) (PMMA) (for TADF materials E.sup.B, phosphorescent materials P.sup.B, and small FWHM emitters S.sup.B). These films were spin coated films and, unless stated differently for specific measurements, the concentration of the materials in the PMMA-films was 10% by weight for TADF materials E.sup.B and for phosphorescent materials P.sup.B or 1-5%, preferably 2% by weight, for small FWHM emitters S.sup.B. Alternatively (not preferred), and as stated previously, some photophysical measurements may also be performed from solutions of the respective molecules, for example in dichloromethane or toluene, wherein the concentration of the solution is typically chosen so that the maximum absorbance preferably is in a range of 0.1 to 0.5.

[2193] For the purpose of further studying compositions of certain materials as present in the EML of organic electroluminescent devices (according to the present invention or comparative), the samples for photophysical measurements were produced from the same materials used for device fabrication by vacuum deposition of 50 nm of the respective light-emitting layer B on quartz substrates. Photophysical characterization of the samples are conducted under nitrogen atmosphere.

Absorption Measurements

[2194] A Thermo Scientific Evolution 201 UV-Visible Spectrophotometer is used to determine the wavelength of the absorption maximum of the sample in the wavelength region above 270 nm. This wavelength is used as excitation wavelength for photoluminescence spectral and photoluminescence quantum yield measurements.

Photoluminescence Spectra

[2195] Steady-state emission spectra are recorded using a Horiba Scientific, Modell FluoroMax-4 equipped with a 150 W Xenon-Arc lamp, excitation- and emissions monochromators. The samples are placed in a cuvette and flushed with nitrogen during the measurements.

Photoluminescence Quantum Yield Measurements

[2196] For photoluminescence quantum yield (PLQY) measurements an integrating sphere, the Absolute PL Quantum Yield Measurement C9920-03G system (Hamamatsu Photonics) is used. The samples are kept under nitrogen atmosphere throughout the measurement. Photoluminescence quantum yields are determined using the software U6039-05 and given in %. The photoluminescence quantum yield is calculated using the equation:

[00050]${}_{\mathrm{PL}}=\frac{n_{\mathrm{photon}},\mathrm{emited}}{n_{\mathrm{photon}},\mathrm{absorbed}}=\frac{\frac{}{\mathrm{hc}}\left[{\mathrm{Int}}_{\mathrm{emitted}}^{\mathrm{sample}}\left(\right)-{\mathrm{Int}}_{\mathrm{abosrbed}}^{\mathrm{sample}}\left(\right)\right]d}{\frac{}{\mathrm{hc}}\left[{\mathrm{Int}}_{\mathrm{emitted}}^{\mathrm{reference}}\left(\right)-{\mathrm{Int}}_{\mathrm{abosrbed}}^{\mathrm{reference}}\left(\right)\right]d},$

[2197] wherein n.sub.photon denotes the photon count and Int. is the intensity. For quality assurance, anthracene in ethanol (known concentration) is used as reference.

TCSPC (Time-Correlated Single-Photon Counting)

[2198] Excited state population dynamics are determined employing Edinburgh Instruments FS5 Spectrofluorometers, equipped with an emission monochromator, a temperature stabilized photomultiplier as detector unit and a pulsed LED (310 nm central wavelength, 910 s pulse width) as excitation source. The samples are placed in a cuvette and flushed with nitrogen during the measurements.

Full Decay Dynamics

[2199] The full excited state population decay dynamics over several orders of magnitude in time and signal intensity is achieved by carrying out TCSPC measurements in 4 time windows: 200 ns, 1 s, and 20 s, and a longer measurement spanning>80 s. The measured time curves are then processed in the following way:

[2200] A background correction is applied by determining the average signal level before excitation and subtracting.

[2201] The time axes are aligned by taking the initial rise of the main signal as

REFERENCE

[2202] The curves are scaled onto each other using overlapping measurement time regions.

[2203] The processed curves are merged to one curve.

Data Analysis

[2204] Data analysis is done using monoexponential and bi-exponential fitting of prompt fluorescence(PF) and delayed fluorescence(DF) decays separately. The ratio of delayed fluorescence and prompt fluorescence (n- value) is calculated by the integration of respective photoluminescence decays in time.

[00051]$\frac{I_{\mathrm{DF}}\left(t\right)\mathrm{dt}}{I_{\mathrm{PF}}\left(t\right)\mathrm{dt}}=n$

[2205] The average excited state life time is calculated by taking the average of prompt fluorescence decay time and delayed fluorescence decay time, weighted with the respective contributions of PF and DF.

Production and Characterization of Organic Electroluminescence Devices

[2206] Via vacuum-deposition methods OLED devices including organic molecules according to the invention can be produced. If a layer contains more than one compound, the weight-percentage of one or more compounds is given in %. The total weight-percentage values amount to 100%, thus if a value is not given, the fraction of this compound equals to the difference between the given values and 100%.

[2207] The not fully optimized OLEDs are characterized using standard methods and measuring electroluminescence spectra, the external quantum efficiency (in %) in dependency on the intensity, calculated using the light detected by the photodiode, and the current. The FWHM of the devices is determined from the electroluminescence spectra as stated previously for photoluminescence spectra (fluorescence or phosphorescence). The reported FWHM refers to the main emission peak (i.e., the peak with the highest emission intensity). The OLED device lifetime is extracted from the change of the luminance during operation at constant current density. The LT50 value corresponds to the time point, where the measured luminance decreased to 50% of the initial luminance, analogously LT80 value corresponds to the time point, at which the measured luminance decreased to 80% of the initial luminance, LT97 value corresponds to the time point, at which the measured luminance decreased to 97% of the initial luminance etc.

[2208] Accelerated lifetime measurements are performed (e.g., applying increased current densities). Exemplarily LT80 values at 500 cd/m.sup.2 are determined using the following equation:

[00052]$\mathrm{LT}90\left(500\frac{{\mathrm{cd}}^2}{m^2}\right)=\mathrm{LT}80\left(L_0\right){\left(\frac{L_0}{500\frac{{\mathrm{cd}}^2}{m^2}}\right)}^{1.6},$ [2209] wherein L.sub.0 denotes the initial luminance at the applied current density. The values correspond to the average of several pixels (typically two to eight).

Experimental Results

Stack Materials

##STR00600## ##STR00601## ##STR00602## ##STR00603##

Host Materials H.SUP.B

##STR00604## ##STR00605## ##STR00606## ##STR00607##

TABLE-US-00001 TABLE 1H Properties of the host materials. Example E.sup.HOMO E.sup.LUMO E(S1) E(T1) compound [eV] [eV] [eV] [eV] H.sup.B HBM1 2.91 2.94 EBM1 5.54 2.46 3.08 2.36 mCBP 6.02 2.42 3.6 2.82 PYD2 6.08 2.55 3.53 2.81 H.sup.B-3 5.66 2.35 3.31 2.71 H.sup.B-4 5.85 2.43 3.42 2.84 H.sup.B-5 5.91 2.89 2.79 H.sup.B-6 5.94 2.93 3.01 2.78 H.sup.B-7 3.27 2.71 H.sup.B-8 2.94 2.70 H.sup.B-9 5.97 3.10 2.88 2.77 H.sup.B-10 3.15 2.75 H.sup.B-11 6.04 3.10 2.94 2.86 H.sup.B-12 6.23 3.02 3.21 2.76 H.sup.B-13 6.23 3.12 3.21 2.76 H.sup.B-14 5.99 2.48 3.51 2.97 H.sup.B-15 5.64 2.36 3.28 2.70 H.sup.B-16 5.68 2.55 3.13 2.81
TADF materials E.sup.B

##STR00608## ##STR00609## ##STR00610## ##STR00611## ##STR00612## ##STR00613##

TABLE-US-00002 TABLE 1E Properties of the TADF materials E.sup.B. Example E.sup.HOMO E.sup.LUMO E(S1) E(T1) .sub.max.sup.PMMA FWHM PLQY compound [eV] [eV] [eV] [eV] [nm] [eV] [%] E.sup.B E.sup.B-1 5.97 3.28 2.69 2.63 518 0.43 61 E.sup.B-2 5.97 3.31 2.66 2.72 526 0.43 43 E.sup.B-3 5.92 3.25 2.67 2.65 517 0.40 73 E.sup.B-4 6.00 3.37 2.63 2.65 525 0.40 54 E.sup.B-5 5.95 3.27 2.68 2.64 508 0.41 72 E.sup.B-6 5.94 3.24 2.70 2.64 509 0.41 74 E.sup.B-7 5.94 3.24 2.70 2.66 509 0.41 71 E.sup.B-8 5.93 3.33 2.60 2.59 525 0.39 71 E.sup.B-9 5.89 3.15 2.74 2.64 498 0.40 81 E.sup.B-10 5.99 3.34 2.65 2.65 520 0.42 54 E.sup.B-11 5.79 3.15 2.77 2.81 514 0.50 63 E.sup.B-12 6.07 3.19 2.88 2.80 477 0.42 83 E.sup.B-13 6.15 3.13 3.02 2.79 454 0.44 72 E.sup.B-14 6.03 3.01 3.02 2.97 459 0.45 72 E.sup.B-15 5.79 3.02 2.77 2.82 511 0.49 64 E.sup.B-16 5.71 3.07 2.64 2.59 517 0.38 68 E.sup.B-17 5.79 3.02 2.77 2.77 523 0.51 49 E.sup.B-18 5.80 3.04 2.76 522 0.52 52 E.sup.B-19 5.80 3.14 2.67 540 0.50 38 E.sup.B-20 5.71 3.06 2.65 2.60 510 0.37 69 E.sup.B-21 5.79 2.96 2.84 2.88 502 0.51 66 E.sup.B-22 5.97 2.94 2.92 2.87 473 0.44 79 E.sup.B-23 6.05 3.17 2.88 2.81 478 0.43 79 E.sup.B-24 5.92 3.00 2.92 2.87 475 0.44 79 E.sup.B-25 5.70 3.08 2.75 2.71 508 0.45 55

Phosphorescence Materials P.SUP.B

##STR00614## ##STR00615##

TABLE-US-00003 TABLE 1P Properties of the materials. Example HOMO LUMO.sub.CV E.sup.LUMO E(S1) E(T1) .sub.max.sup.PMMA FWHM compound [eV] [eV] [eV] [eV] [eV] [nm] [eV] P.sup.B Ir(ppy).sub.3 5.36 2.56.sup.a 509 0.38 P.sup.B-2 5.33 2.32 2.57.sup.b 522 0.34 P.sup.B-3 5.80 2.67 2.88.sup.c 482 0.40 P.sup.B-4 5.24 P.sup.B-5 518 0.33 [2210] wherein LUMO.sub.CV is the energy of the lowest unoccupied molecular orbital, which is determined by Cyclic voltammetry. .sup.aThe emission spectrum was recorded from a solution of Ir(ppy).sub.3 in chloroform. .sup.bThe emission spectrum was recorded from a 0.001 mg/mL solution of P.sup.B-2 in dichloromethane. .sup.cThe emission spectrum was recorded from a 0.001 mg/mL solution of P.sup.B-3 in toluene.

Small FWHM Emitters S.SUP.B

##STR00616## ##STR00617## ##STR00618## ##STR00619## ##STR00620## ##STR00621##

TABLE-US-00004 TABLE 1S Properties of the Small FWHM emitters S.sup.B. Example E.sup.HOMO E.sup.LUMO E(S1) E(T1) .sub.max.sup.PMMA FWHM compound [eV] [eV] [eV] [eV] [nm] [eV] S.sup.B S.sup.B-1 5.54 3.10 2.44 2.12 538 0.21 S.sup.B-2 5.53 3.04 2.49 2.26 525 0.18 S.sup.B-3 5.55 3.05 2.50 2.22 520 0.18 S.sup.B-4 5.48 3.05 2.43 2.25 537 0.17 S.sup.B-5 5.47 3.01 2.46 2.58 527 0.15 S.sup.B-6 5.56 3.03 2.53 2.19 518 0.22 S.sup.B-7 5.48 2.97 2.53 2.23 521 0.25 S.sup.B-8* 5.86 3.40 2.46 517 0.10 S.sup.B-9 5.47 2.66 2.81 460 0.14 S.sup.B-10 5.46 2.65 2.81 459 0.15 S.sup.B-11 5.33 2.51 2.82 458 0.16 S.sup.B-12 5.49 2.63 2.86 451 0.14 S.sup.B-13 2.79 464 0.24 S.sup.B-14 5.31 2.50 2.81 2.61 459 0.16 S.sup.B-15 5.40 2.66 2.74 468 0.12 S.sup.B-16 2.43 533 0.15 *measured in DCM (0.01 mg/mL; such a solution was used for photophysical measurements).

TABLE-US-00005 TABLE 2 Setup 1 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Material 10 100 nm Al 9 2 nm Liq 8 20 nm NBPhen 7 10 nm HBM1 6 50 nm H.sup.B:E.sup.B:P.sup.B:S.sup.B 5 10 nm H.sup.P 4 10 nm TCTA 3 50 nm NPB 2 5 nm HAT-CN 1 50 nm ITO substrate glass

[2211] In order to evaluate the results of the invention, comparison experiments were performed, wherein solely the composition of the emission layer (6) was varied. Additionally, the ratio of E.sup.B and S.sup.B was kept constant in the comparison experiments.

[2212] Results I: Variation of the content of the phosphorescence material P.sup.B in the light-emitting layer (emission layer, 6)

[2213] Composition of the light-emitting layer B of devices D1 to D4 (the percentages refer to weight percent):

TABLE-US-00006 Layer D1 D2 D3 D4 Emission H.sup.B (79%):E.sup.B H.sup.B (78%):E.sup.B H.sup.B (75%):E.sup.B H.sup.B (69%):E.sup.B layer (6) (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%):S.sup.B (4%):S.sup.B (10%):S.sup.B (1%) (1%) (1%) (1%)

[2214] Setup 1 from Table 2 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), E.sup.B-10 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B and B.sup.B-1 was used as the small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results I

TABLE-US-00007 EQE at Relative Voltage at 1000 lifetime FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at Device [eV] [nm] CIEx CIEy [Volt] [%] 1200 cd/m.sup.2 D1 0.17 530 0.31 0.64 5.53 21.0 1.00 D2 0.18 532 0.32 0.64 6.64 21.2 2.47 D3 0.20 532 0.34 0.62 7.41 18.1 1.21 D4 0.24 532 0.37 0.60 6.96 13.1 0.99

[2215] Comparing the device results, D and D2, similar optical properties (FWHM, .sub.max, CIEx and CIEy) and efficiency (EQE) can be observed, while for D2 an extension of the relative lifetime of 147% compared to D1 (from 1.00 to 2.47) can be observed. For D3 extension of the relative lifetime of 21% compared to D1 (from 1.00 to 1.21), while the relative lifetime of D4 decreased by 1% compared to D1 (from 1.00 to 0.99).

Results II: Variation of Composition of Components

[2216] Composition of the light-emitting layer B of devices D5 to D13 (the percentages refer to weight percent):

TABLE-US-00008 Layer D5 D6 D7 D8 Emission H.sup.B H.sup.B H.sup.B H.sup.B layer (6) (79%):H.sup.N (76%):H.sup.N (78%):H.sup.N (75%):H.sup.N (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (1%):S.sup.B (4%):S.sup.B (1%):S.sup.B (4%):S.sup.B (0%) (0%) (1%) (1%) Layer D9 D10 Emission H.sup.B (79.5%):E.sup.B H.sup.B (78.5%):E.sup.B layer (6) (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%):S.sup.B (0.5%) (0.5%)

[2217] Setup 1 from Table 2 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-11 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as the small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

[2218] Devices D5 and D6 are typical phosphorescence devices, which include a mixed-host system, i.e., H.sup.B and H.sup.N, and a phosphorescence emitter.

[2219] Device D7 and D8 are devices, which include a mixed-host system, i.e., H.sup.B and H.sup.N, a phosphorescence material, and a small FWHM emitter S.sup.B.

[2220] Device D9 is a device, which includes a Host H.sup.B, a TADF material E.sup.B, and a small FWHM emitter S.sup.B.

[2221] Devices D10 is a devices, which includes a Host H.sup.B, a TADF material E.sup.B a phosphorescence material P.sup.B, and a small FWHM emitter S.sup.B.

Device Results II

TABLE-US-00009 Relative Voltage at EQE at lifetime FWHM .sub.max 10 mA/cm.sup.2 1000 LT95 at Device [eV] [nm] CIEx CIEy [Volt] cd/m.sup.2 [%] 1200 cd/m.sup.2 D5 0.31 512 0.30 0.62 6.11 19.5 1.00 D6 0.31 514 0.30 0.63 5.77 21.7 1.89 D7 0.17 534 0.33 0.64 6.33 19.9 2.05 D8 0.17 534 0.33 0.64 6.19 22.9 3.50 D9 0.17 532 0.31 0.63 5.86 20.6 1.30 D10 0.18 532 0.32 0.64 6.74 24.9 13.34

[2222] Comparing the composition of the emission layer of devices D1 and D6 to D7 and D8, D7 and D8 contain additionally a small FWHM emitter S.sup.B, which is not present in D5 and D6. A longer lifetime, similar efficiency and smaller FWHM of the emission can be observed for D7 and D8.

[2223] Device D10 according to the present invention shows a superior overall performance over D9 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(PPY).sub.3).

[2224] Composition of the light-emitting layer B of devices D14 to D21 (the percentages refer to weight percent):

TABLE-US-00010 Layer D14 D15 D16 D17 D18 Emission H.sup.B H.sup.B H.sup.B H.sup.B H.sup.B layer (6) (80%):H.sup.N (79%):H.sup.N (79%):H.sup.N (78%):H.sup.N (79%):H.sup.N (0%):E.sup.B (20%):E.sup.B (0%):E.sup.B (20%):E.sup.B (0%):E.sup.B (20%):P.sup.B (0%):P.sup.B (20%):P.sup.B (0%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%):S.sup.B (0%):S.sup.B (1%):S.sup.B (1%):S.sup.B (0%) (0%) (1%) (1%) (0%) Layer D19 D20 D21 Emission H.sup.B (78%):H.sup.N H.sup.B (75%):H.sup.N H.sup.B (72%):H.sup.N layer (6) (0%):E.sup.B (0%):E.sup.B (0%):E.sup.B (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (1%):S.sup.B (4%):S.sup.B (7%):S.sup.B (1%) (1%) (1%)

[2225] Setup 1 from Table 2 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-10 was used as TADF material E.sup.B, P.sup.B-2 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results III

TABLE-US-00011 Relative Voltage at EQE at lifetime FWHM .sub.max 10 mA/cm.sup.2 1000 LT95 at Device [eV] [nm] CIEx CIEy [Volt] cd/m.sup.2 [%] 1200 cd/m.sup.2 D14 0.35 522 0.32 0.60 4.76 16.4 1.00 D15 0.29 516 0.30 0.63 6.49 22.7 0.29 D16 0.16 532 0.32 0.65 5.85 20.4 2.76 D17 0.17 532 0.31 0.65 6.60 22.4 0.52 D18 0.36 525 0.36 0.59 7.02 15.7 2.17 D19 0.17 532 0.33 0.64 7.28 20.4 4.75 D20 0.20 532 0.35 0.62 7.85 16.3 2.42 D21 0.20 534 0.36 0.61 7.26 13.6 2.57

[2226] As can be concluded from device results III, the absence of the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) results in an undesirably broad emission reflected by the FWHM values being significantly larger than 0.25 eV in all cases (see devices D14, D15, and D18). For D15, the very high EQE of 22.7% comes along with a significantly reduced lifetime. When using a small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) alongside either a TADF material E.sup.B (here exemplarily E.sup.B-10) or a phosphorescence material P.sup.B (here exemplarily P.sup.B-2), a narrow emission can be achieved, which is then reflected by the FWHM values being significantly smaller than 0.25 eV (see devices D16 and D17). At the same time, these devices exhibit high EQE-values of 20.4% and 22.4%, respectively. However, in terms of lifetime, all of these devices are clearly outcompeted by device D19, which was prepared according to the present invention. D19 also exhibits a very good efficiency (EQE of 20.4%) and a narrow emission (FWHM of 0.17 eV). In summary, the skilled artisan will acknowledge that D19 (according to the present invention) clearly shows the best overall device performance. The EML of D19 includes 1% of the phosphorescence material PB. Increasing this value to 4% (in D20) or even to 7% (in D21) results in a somewhat poorer device performance reflected by a slight increase of the FWHM to 0.20 eV, a reduction of the EQE to 16.3% or 13.6%, respectively, and a reduction of the device lifetime. Nevertheless, D20 and D21 each still display a good overall performance, in particular with regard to the device lifetime.

[2227] In the absence of the TADF material E.sup.B-10, an n-host (here exemplarily H.sup.B-5) was generally used to increase the electron mobility within the EML.

[2228] Composition of the light-emitting layer B of devices D22 to D29 (the percentages refer to weight percent):

TABLE-US-00012 Layer D22 D23 D24 D25 D26 Emission H.sup.B H.sup.B H.sup.B H.sup.B H.sup.B (80%):H.sup.N (79%):H.sup.N (78%):H.sup.N (78%):H.sup.N (78.5%):H.sup.N layer (6) (0%):E.sup.B (20%):E.sup.B (20%):E.sup.B (0%):E.sup.B (0%):E.sup.B (20%):P.sup.B (0%):P.sup.B (0%):P.sup.B (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%):S.sup.B (1%):S.sup.B (1%):S.sup.B (1%):S.sup.B (0%) (0%) (1%) (1%) (0.5%) Layer D27 D28 D29 Emission H.sup.B (79.5%):H.sup.N H.sup.B (75%):H.sup.N H.sup.B (75.5%):H.sup.N layer (6) (0%):E.sup.B (0%):E.sup.B (0%):E.sup.B (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (4%):S.sup.B (4%):S.sup.B (0.5%) (1%) (0.5%)

[2229] Setup 1 from Table 2 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-11 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results IV

TABLE-US-00013 Relative Voltage at EQE at lifetime FWHM .sub.max 10 mA/cm.sup.2 1000 LT95 at Device [eV] [nm] CIEx CIEy [Volt] cd/m.sup.2 [%] 1200 cd/m.sup.2 D22 0.41 518 0.29 0.55 4.93 22.5 1.00 D23 0.31 512 0.30 0.62 6.11 19.5 1.10 D24 0.17 534 0.33 0.64 6.33 19.9 2.26 D25 0.17 534 0.32 0.64 6.30 22.5 11.89 D26 0.18 532 0.32 0.64 6.74 24.9 14.72 D27 0.17 532 0.31 0.63 5.86 20.6 1.44 D28 0.16 534 0.33 0.64 5.94 21.6 8.95 D29 0.18 532 0.32 0.64 6.75 22.6 11.40

[2230] As can be concluded from device results IV, using the TADF material E.sup.B(here exemplarily E.sup.B-11) or the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) as the main emitter in the absence of a small FWHM emitter S.sup.B results in a relatively broad emission of the organic electroluminescent device, which is reflected by FWHM values of the main emission peak of clearly more than 0.25 eV (here 0.41 and 0.31 eV, respectively, see D22 and D23). Both, D22 and D23, exhibit high efficiencies (EQE of 22.5% and 19.5%, respectively). The addition of a small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) to for example the phosphorescent OLED D23 results in a significantly reduced FWHM of the main emission peak (then 0.17 eV) while slightly improving the EQE and the lifetime (see D24). However, device D24 as well as the OLEDs D22 and D23 are strongly outperformed by device D25, which was prepared according to the present invention. As compared to D22, D23, and D24, device D25 exhibits a dramatically prolonged lifetime, while still displaying an equally high efficiency and a narrow FWHM. The skilled artisan will acknowledge that the overall performance of device D25 according to the present invention is clearly superior to the performance of D22, D23, and D24. The overall device performance could be improved even further by reducing the content of the small FWHM emitter SB (here exemplarily S.sup.B-1) from 1% (in the EML of D25) to 0.5% (in the EML of D26). Again, a comparative example D27, not fulfilling the conditions of the present invention (exemplarily lacking the phosphorescence material P.sup.B) showed a drastically reduced lifetime and a somewhat reduced efficiency (EQE). Increasing the content of the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) from 1% in the devices D25 and D26 according to the present invention to 4% (in devices D28 and D29 according to the present invention) led to a reduction of the device lifetime and the efficiency. However, these devices (D28 and D29) still clearly outperform the aforementioned comparative devices which were manufactured according to the state of the art and not according to the present invention. In the absence of the TADF material E.sup.B 11, an n-host (here exemplarily H.sup.B-5) was generally used to increase the electron mobility within the EML.

TABLE-US-00014 TABLE 3 Setup 2 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Material 10 100 nm Al 9 2 nm Liq 8 20 nm NBPhen 7 10 nm HBM1 6 50 nm H.sup.B:E.sup.B:P.sup.B:S.sup.B 5 10 nm H.sup.P 4 10 nm TCTA 3 40 nm NPB 2 5 nm HAT-CN 1 50 nm ITO substrate glass

[2231] Composition of the light-emitting layer B of devices D30 to D32 (the percentages refer to weight percent):

TABLE-US-00015 Layer D30 D31 D32 Emission H.sup.B (79%):E.sup.B H.sup.B (76%):E.sup.B H.sup.B (75%):E.sup.B layer (6) (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%) (4%):S.sup.B (0%) (4%):S.sup.B (1%)
Setup 2 from Table 3 was used, wherein H.sup.B-1 (mCBP) was used as host material H.sup.B (p-host H.sup.P; also used as material for the electron blocking layer 5), E.sup.B-14 was used as TADF material E.sup.B, PB-.sub.3 was used as phosphorescence material p.sup.B and S.sup.B-14 was used as small FWHM emitter S.sup.B.
Device results V

TABLE-US-00016 EQE at Relative Voltage at 1000 lifetime FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at Device [eV] [nm] CIEx CIEy [Volt] [%] 1200 cd/m.sup.2 D30 0.17 462 0.14 0.15 6.07 15.8 1.00 D31 0.33 474 0.14 0.23 5.61 16.8 2.50 D32 0.19 462 0.14 0.16 6.03 19.4 1.75

[2232] Among the organic electroluminescent devices D30-D32, D32 according to the present invention shows the best overall performance when taking the narrow emission (small FWHM), the high EQE, and the relative lifetime into account.

[2233] Composition of the light-emitting layer B of devices D33 to D35 (the percentages refer to weight percent):

TABLE-US-00017 Layer D33 D34 D35 Emission H.sup.P (79%):E.sup.B H.sup.P (79%):E.sup.B H.sup.P (78%):E.sup.B layer (6) (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (0%):S.sup.B (1%) (1%):S.sup.B (0%) (1%):S.sup.B (1%)

[2234] Setup 2 from Table 3 was used, wherein H.sup.B-14 was used as host material H.sup.B (p-host H.sup.P; also used as material for the electron blocking layer 5), E.sup.B-14 was used as TADF material E.sup.B, P.sup.B-3 was used as phosphorescence material P.sup.B, and S.sup.B-14 was used as small FWHM emitter S.sup.B.

Device results VI

TABLE-US-00018 EQE at Relative Voltage at 1000 lifetime FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at Device [eV] [nm] CIEx CIEy [Volt] [%] 1200 cd/m.sup.2 D33 0.17 462 0.14 0.15 5.26 17.2 1.00 D34 0.35 474 0.15 0.25 6.07 13.5 0.75 D35 0.18 462 0.14 0.15 5.89 18.1 1.50

[2235] Among the organic electroluminescent devices D33-D35, D35 according to the present invention clearly shows the best overall performance when taking the narrow emission (small FWHM), the high EQE, and the relative lifetime into account.

[2236] As stated before, each light-emitting layer B according to the present invention may be a single layer or may be composed of two or more sublayers. Exemplary organic electroluminescent devices with a light-emitting layer B including two or more sublayers are shown below (see device results VII and VIII).

TABLE-US-00019 TABLE 4 Setup 3 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Sublayers Material 10 100 nm single layer Al 9 2 nm single layer Liq 8 20 nm single layer NBPhen 7 10 nm single layer HBM1 6 2 nm sublayer 11 H.sup.B:E.sup.B:P.sup.B:S.sup.B 8 nm sublayer 10 2 nm sublayer 9 8 nm sublayer 8 2 nm sublayer 7 8 nm sublayer 6 2 nm sublayer 5 8 nm sublayer 4 2 nm sublayer 3 8 nm sublayer 2 2 nm sublayer 1 5 10 nm single layer H.sup.P 4 10 nm single layer TCTA 3 50 nm single layer NPB 2 5 nm single layer HAT-CN 1 50 nm single layer ITO substrate glass

[2237] Composition of the light-emitting layer B of devices D36 to D38 (the percentages refer to weight percent):

TABLE-US-00020 Layer Sublayer D36 D37 D38 Emission 11 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N layer (6) (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%) 10 H.sup.B (79%):H.sup.N H.sup.B (80%):E.sup.B H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) (20%): (20%):P.sup.B (1%) 9 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%) 8 H.sup.B (79%):H.sup.N H.sup.B (80%):E.sup.B H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) (20%): (20%):P.sup.B (1%) 7 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%) 6 H.sup.B (79%):H.sup.N H.sup.B (80%):E.sup.B H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) (20%): (20%):P.sup.B (1%) 5 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%) 4 H.sup.B (79%):H.sup.N H.sup.B (80%):E.sup.B H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) (20%): (20%):P.sup.B (1%) 3 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%) 2 H.sup.B (79%):H.sup.N H.sup.B (80%):E.sup.B H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) (20%): (20%):P.sup.B (1%) 1 H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) (20%):S.sup.B (1%) (20%):S.sup.B (1%)

[2238] Setup 3 from Table 4 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-10 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B.

Device results VII

TABLE-US-00021 EQE at Relative Voltage at 1000 lifetime FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at Device [eV] [nm] CIEx CIEy [Volt] [%] 1200 cd/m.sup.2 D36 0.24 528 0.29 0.64 5.08 23.8 1.00 D37 0.21 530 0.31 0.63 5.80 18.0 3.87 D38 0.23 530 0.33 0.62 7.71 16.3 9.01

[2239] As can be concluded from device results VII, D38 according to the present invention shows a significantly prolonged lifetime as compared to D36 and D37. This comes along with a somewhat reduced, but still high efficiency (EQE). All three devices display a narrow emission which is expressed by FWHM values below 0.25 eV in all cases. D38 displays the best overall device performance, when taking the narrow emission, the still high EQE, and the very long lifetime into account.

TABLE-US-00022 TABLE 5 Setup 4 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Sublayers Material 10 100 nm single layer Al 9 2 nm single layer Liq 8 20 nm single layer NBPhen 7 10 nm single layer HBM1 6 5 nm sublayer 13 H.sup.B:E.sup.B:P.sup.B:S.sup.B 2 nm sublayer 12 5 nm sublayer 11 2 nm sublayer 10 5 nm sublayer 9 2 nm sublayer 8 5 nm sublayer 7 2 nm sublayer 6 5 nm sublayer 5 2 nm sublayer 4 5 nm sublayer 3 2 nm sublayer 2 5 nm sublayer 1 5 10 nm single layer H.sup.P 4 10 nm single layer TCTA 3 50 nm single layer NPB 2 5 nm single layer HAT-CN 1 50 nm single layer ITO substrate glass

[2240] Composition of the light-emitting layer B of device D39 (the percentages refer to weight percent):

TABLE-US-00023 Layer Sublayer D39 Emission 13 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) layer (6) 12 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 11 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) 10 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 9 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) 8 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 7 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) 6 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 5 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) 4 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 3 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%) 2 H.sup.B (79%):H.sup.N (20%):S.sup.B (1%) 1 H.sup.B (79%):E.sup.B (20%):P.sup.B (1%)

[2241] Setup 4 from Table 5 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-10 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and SB-.sub.1 was used as small FWHM emitter S.sup.B.

Device results VIII

TABLE-US-00024 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D39 0.23 528 0.33 0.62 6.21 15.3 0.73* *The lifetime is given relative to D38.

[2242] As can be concluded from device results VIII, reducing the thickness of the H.sup.B:E.sup.B:PB-sublayers from 8 nm (D38) to 5 nm (D39) while using a largely analogue stack architecture, did not result in an improved device performance. Nevertheless, D39 still displays a narrow emission, high EQE, and good lifetime.

[2243] Composition of the light-emitting layer B of devices D40 and D41 (the percentages refer to weight percent):

TABLE-US-00025 Layer D40 D41 Emission H.sup.B (79%):E.sup.B H.sup.B (75%):E.sup.B layer (6) (20%):P.sup.B (0%):S.sup.B (1%) (20%):P.sup.B (4%):S.sup.B (1%)

[2244] Setup 1 from Table 2 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P; also used as material for the electron blocking layer 5), E.sup.B-10 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device results IX

TABLE-US-00026 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D40 0.16 534 0.33 0.64 3.93 13.1 1.00 D41 0.18 534 0.35 0.63 5.09 12.9 3.02

[2245] As can be concluded from device results IX, device D41 according to the present invention shows a superior overall performance as compared to device D40 which lacks the TADF material E.sup.B (here exemplarily E.sup.B-10) when taking the narrow emission (FWHM), the efficiency (EQE), and most the device lifetime (LT95) into account.

TABLE-US-00027 TABLE 6 Setup 5 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Material 10 100 nm Al 9 2 nm Liq 8 20 nm NBPhen 7 10 nm HBM1 6 50 nm H.sup.B: E.sup.B: P.sup.B: S.sup.B 5 10 nm EBM1 4 10 nm TCTA 3 60 nm NPB 2 5 nm HAT-CN 1 50 nm ITO substrate glass

[2246] Composition of the light-emitting layer B of devices D42 to D44 (the percentages refer to weight percent):

TABLE-US-00028 Layer D42 D43 D44 Emission H.sup.B (79%): H.sup.B (78%): H.sup.B (78%): layer (6) H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): P.sup.B (0%): P.sup.B (1%): P.sup.B (1%): S.sup.B (1%) S.sup.B (1%) S.sup.B (1%)

[2247] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), H.sup.B-5 was used as host material H.sup.N, E.sup.B-10 was used as TADF material E.sup.B, P.sup.B-2 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device results X

TABLE-US-00029 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D42 0.18 532 0.33 0.64 3.81 14.4 1.00 D43 0.18 532 0.32 0.65 4.00 14.9 0.17 D44 0.18 534 0.33 0.64 4.31 14.8 1.77

[2248] As can be concluded from device results X, device D44 according to the present invention shows a superior overall performance as compared to device D43 which lacks the TADF material E.sup.B (here exemplarily E.sup.B-10) and device D42 which lacks the phosphorescence material P.sup.B (here exemplarily P.sup.B-2) when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account. In the absence of the TADF material E.sup.B-10, an n-host (here exemplarily H.sup.B-5) was used to increase the electron mobility within the EML.

[2249] Composition of the light-emitting layer B of devices D45 to D49 (the percentages refer to weight percent):

TABLE-US-00030 Layer D45 D46 D47 D48 D49 Emission H.sup.B (80%): H.sup.B (79%): H.sup.B (79%): H.sup.B (78%): H.sup.B (78%): layer (6) H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): P.sup.B (0%): P.sup.B (1%): P.sup.B (0%): P.sup.B (1%): P.sup.B (1%): S.sup.B (0%) S.sup.B (0%) S.sup.B (1%) S.sup.B (1%) S.sup.B (1%)

[2250] Setup 1 from Table 2 was used, wherein H.sup.B-4 was used as host material H.sup.B(p-host H.sup.P; also used as material for the electron blocking layer 5), H.sup.B-5 was used as host material H.sup.N, E.sup.B-10 was used as TADF material E.sup.B, P.sup.B-4 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device results XI

TABLE-US-00031 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D45 0.34 521 0.31 0.60 5.04 17.5 1.00 D46 0.25 522 0.32 0.63 5.91 27.0 0.72 D47 0.16 532 0.31 0.65 6.02 20.0 2.27 D48 0.17 531 0.32 0.65 6.56 22.5 0.64 D49 0.17 532 0.33 0.64 7.70 19.2 4.39

[2251] As can be concluded from device results XI, device D49 according to the present invention shows a superior overall performance as compared to device D48 which lacks the TADF material E.sup.B (here exemplarily E.sup.B-10) and device D47 which lacks the phosphorescence material P.sup.B (here exemplarily P.sup.B-4) and device D46 which employs P.sup.B-4 as the emitter material in spite of S.sup.B-1 and device D45 which employs E.sup.B-10 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account. In the absence of the TADF material E.sup.B-10, an n-host (here exemplarily H.sup.B-5) was used to increase the electron mobility within the EML.

[2252] Composition of the light-emitting layer B of devices D50 to D64 (the percentages refer to weight percent):

TABLE-US-00032 Layer D50 D51 D52 D53 D54 Emission H.sup.B (80%): H.sup.B (79%): H.sup.B (79%): H.sup.B (78%): H.sup.B (78%): layer (6) H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): P.sup.B (0%): P.sup.B (1%): P.sup.B (0%): P.sup.B (1%): P.sup.B (1%): S.sup.B (0%) S.sup.B (0%) S.sup.B (1%) S.sup.B (1%) S.sup.B (1%) Layer D55 D56 D57 D58 D59 Emission H.sup.B (75%): H.sup.B (75.5%): H.sup.B (72%): H.sup.B (72.5%): H.sup.B (65.5%): layer (6) H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): E.sup.B (20%): E.sup.B (20%): E.sup.B (20%): E.sup.B (20%): E.sup.B (30%): P.sup.B (4%): P.sup.B (4%): P.sup.B (7%): P.sup.B (7%): P.sup.B (4%): S.sup.B (1%) S.sup.B (0.5%) S.sup.B (1%) S.sup.B (0.5%) S.sup.B (0.5%) D60 D61 Emission H.sup.B (55.5%): H.sup.B (67.5%): layer (6) H.sup.N (0%): H.sup.N (0%): E.sup.B (40%): E.sup.B (30%): P.sup.B (4%): P.sup.B (3%): S.sup.B (0.5%) S.sup.B (0.5%)

[2253] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), H.sup.B-5 was used as host material H.sup.N, E.sup.B-11 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XII

TABLE-US-00033 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D50 0.35 530 0.34 0.57 3.51 11.0 1.00 D51 0.28 508 0.27 0.63 3.85 18.7 0.47 D52 0.17 534 0.32 0.64 3.67 12.7 0.90 D53 0.16 532 0.31 0.65 3.83 14.5 0.84 D54 0.19 532 0.32 0.65 4.29 17.5 1.91 D55 0.16 534 0.33 0.64 4.71 20.2 6.72 D56 0.17 532 0.32 0.65 4.75 19.0 10.71 D57 0.17 534 0.33 0.64 4.70 18.3 6.18 D58 0.18 532 0.32 0.64 4.69 16.9 7.21 D59 0.19 532 0.33 0.64 4.54 18.7 14.51 D60 0.20 532 0.34 0.63 4.22 16.9 14.27 D61 0.21 532 0.34 0.63 4.54 18.0 17.15

[2254] As can be concluded from device results XII, device D54 according to the present invention shows a superior overall performance as compared to device D53 which lacks the TADF material E.sup.B (here exemplarily E.sup.B-11) and device D52 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) and device D51 which employs Ir(ppy).sub.3as the emitter material in spite of S.sup.B-1 and device D50 which employs E.sup.B-11 as the emitter material in spite of SB-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account. When comparing the performance of devices D55 to D58, it can be concluded that the reduction of the concentration of the small FWHM emitter (here exemplarily S.sup.B-1) in the EML from 1% to 0.5% may result in a prolonged device lifetime. Devices D59 to D61 were also prepared according to the present invention and, especially in comparison with D55 according to the present invention, indicate that increasing the concentration of the TADF material E.sup.B (here exemplarily E.sup.B-11) from 20% to 30% or even to 40% may result in an improved overall device performance. The comparison between the devices D55 to D58 and between D60 and D61 indicates that in contrast, a low concentration of the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) is beneficial for the device performance. In the absence of the TADF material E.sup.B 11, an n-host (here exemplarily H.sup.B-5) was used to increase the electron mobility within the EML.

[2255] Composition of the light-emitting layer B of devices D62 to D71 (the percentages refer to weight percent):

TABLE-US-00034 Layer D62 D63 D64 D65 D66 Emission H.sup.B (80%): H.sup.B (79%): H.sup.B (79%): H.sup.B (78%): H.sup.B (79%): layer (6) H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): P.sup.B (0%): P.sup.B (1%): P.sup.B (0%): P.sup.B (1%): P.sup.B (1%): S.sup.B (0%) S.sup.B (0%) S.sup.B (1%) S.sup.B (1%) S.sup.B (0%) Layer D67 D68 D69 D70 D71 Emission H.sup.B (78%): H.sup.B (75%): H.sup.B (67%): H.sup.B (57%): H.sup.B (47%): layer (6) H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): E.sup.B (20%): E.sup.B (20%): E.sup.B (30%): E.sup.B (40%): E.sup.B (50%): P.sup.B (1%): P.sup.B (4%): P.sup.B (2.5%): P.sup.B (2.5%): P.sup.B (2.5%): S.sup.B (1%) S.sup.B (1%) S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0.5%)

[2256] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), H.sup.B-5 was used as host material H.sup.N, E.sup.B-11 was used as TADF material E.sup.B, P.sup.B.sub.-2 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XIII

TABLE-US-00035 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D62 0.35 530 0.34 0.57 3.51 10.98 1.00 D63 0.28 516 0.30 0.63 3.94 21.33 2.47 D64 0.17 534 0.32 0.64 3.64 13.74 1.81 D65 0.17 534 0.32 0.65 3.96 19.87 3.76 D66 0.16 520 0.33 0.61 4.30 15.09 5.17 D67 0.17 534 0.33 0.64 4.35 20.89 9.59 D68 0.17 534 0.34 0.64 4.65 21.9 19.51 D69 0.20 532 0.34 0.63 4.56 19.3 23.18 D70 0.22 532 0.35 0.62 4.24 17.2 17.96 D71 0.24 532 0.36 0.61 3.96 14.6 8.61

[2257] As can be concluded from device results XIII, device D67 according to the present invention shows a superior overall performance as compared to device D66 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D65 which lacks the TADF material E.sup.B (here exemplarily E.sup.B 11) and device D64 which lacks the phosphorescence material p.sup.B (here exemplarily P.sup.B-2) and device D63 which employs P.sup.B.sub.-2 as the emitter material in spite of S.sup.B-1 and device D62 which employs E.sup.B-11 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (FQE), and the device lifetime (LT95) into account. When comparing the performance of devices D67 to D71, it can be concluded that for the given set of materials, a concentration of 30% of E.sup.B-11 and 2.5% of P.sup.B.sub.-2 and of 0.5% of S.sup.B-1 afforded the best performing device (D69).

[2258] Composition of the light-emitting layer B of devices D72 to D79 (the percentages refer to weight percent):

TABLE-US-00036 Layer D72 D73 D74 D75 Emission H.sup.B (80%): H.sup.B (79%): H.sup.B (79%): H.sup.B (78%): layer (6) H.sup.N (0%): H.sup.N (20%): H.sup.N (0%): H.sup.N (20%): E.sup.B (20%): E.sup.B (0%): E.sup.B (20%): E.sup.B (0%): P.sup.B (0%): P.sup.B (1%): P.sup.B (0%): P.sup.B (1%): S.sup.B (0%) S.sup.B (0%) S.sup.B (1%) S.sup.B (1%) Layer D76 D77 D78 D79 Emission H.sup.B (78%): H.sup.B (78.5%): H.sup.B (75%): H.sup.B (75.5%): layer (6) H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): H.sup.N (0%): E.sup.B (20%): E.sup.B (20%): E.sup.B (20%): E.sup.B (20%): P.sup.B (1%): P.sup.B (1%): P.sup.B (4%): P.sup.B (4%): S.sup.B (1%) S.sup.B (0.5%) S.sup.B (1%) S.sup.B (0.5%)

[2259] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), H.sup.B-5 was used as host material H.sup.N, E.sup.B-11 was used as TADF material E.sup.B, P.sup.B-4 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XIV

TABLE-US-00037 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D72 0.26 528 0.34 0.57 3.67 10.6 1.00 D73 0.24 520 0.30 0.64 4.36 25.0 0.54 D74 0.17 534 0.32 0.64 3.78 14.0 1.18 D75 0.16 532 0.32 0.65 4.39 13.2 0.57 D76 0.17 534 0.33 0.64 4.72 19.6 3.65 D77 0.18 530 0.32 0.64 4.66 19.8 7.29 D78 0.17 534 0.34 0.64 5.71 23.5 19.39 D79 0.19 530 0.33 0.64 5.57 22.6 35.59

[2260] As can be concluded from device results XIV, device D76 according to the present invention shows a superior overall performance as compared to device D75 which lacks the TADF material E.sup.B (here exemplarily E.sup.B-11) and device D74 which lacks the phosphorescence material p.sup.B (here exemplarily P.sup.B-4) and device D73 which employs P.sup.B.sub.-4 as the emitter material in spite of S.sup.B-1 and device D72 which employs E.sup.B-11 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account. When comparing the performance of devices D76 to D79, it can be concluded that the reduction of the concentration of the small FWHM emitter S.sup.B (here exemplarily SB-1 from 1% to 0.5% may improve the overall device performance. Composition of the light-emitting layer B of devices D80 to D85 (the percentages refer to weight percent):

TABLE-US-00038 Layer D80 D81 D82 D83 D84 D85 Emission H.sup.B (70%): H.sup.B (79.5%): H.sup.B (69.5%): H.sup.B (66%): H.sup.B (75.5%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (20%): E.sup.B (30%): E.sup.B (30%): E.sup.B (20%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0.5%)

[2261] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-15 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XV

TABLE-US-00039 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D80 0.41 532 0.35 0.57 3.43 10.2 1.00 D81 0.19 530 0.32 0.63 3.45 12.8 0.88 D82 0.19 530 0.32 0.63 3.44 12.3 1.50 D83 0.38 518 0.36 0.59 4.50 13.2 4.50 D84 0.19 532 0.32 0.64 4.81 18.3 5.12 D85 0.19 532 0.33 0.63 4.54 17.7 9.23

[2262] As can be concluded from device results XV, device D84 according to the present invention shows a superior overall performance as compared to device D81 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3). Furthermore, D85 according to the present invention shows a superior overall performance as compared to device D83 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D81 which lacks the phosphorescence material P.sup.B (here exemplarily P.sup.B-4) and device D80 which employs E.sup.B-15 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (FOE), and the device lifetime (LT95) into account.

[2263] Composition of the light-emitting layer B of devices D86 to D90 (the percentages refer to weight percent):

TABLE-US-00040 Layer D86 D87 D88 D89 D90 Emission H.sup.B (70%): H.sup.B (79.5%): H.sup.B (69.5%): H.sup.B (75.5%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (20%): E.sup.B (30%): E.sup.B (20%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0.5%)

[2264] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-15 was used as TADF material E.sup.B, PB-.sub.2 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device results XVI

TABLE-US-00041 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D86 0.41 532 0.35 0.57 3.43 10.2 1.00 D87 0.19 530 0.32 0.63 3.45 12.8 0.55 D88 0.19 532 0.32 0.63 3.44 12.3 0.96 D89 0.19 532 0.32 0.64 5.14 19.0 1.98 D90 0.20 532 0.34 0.63 4.64 19.3 3.44

[2265] As can be concluded from device results XVI, devices D89 and D90 according to the present invention each show a superior overall performance as compared to device D87 and D88 which lack the phosphorescence material p.sup.B (here exemplarily PB-.sub.2) and device D86 which employs E.sup.B-15 as the emitter material in spite of SB-.sub.1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2266] Composition of the light-emitting layer B of devices D91 to D94 (the percentages refer to weight percent):

TABLE-US-00042 Layer D91 D92 D93 D94 Emission H.sup.B (70%): H.sup.B (69.5%): H.sup.B (66%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0%) S.sup.B (0.5%)

[2267] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-16 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

TABLE-US-00043 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D91 0.33 518 0.30 0.61 3.08 19.4 1.00 D92 0.18 532 0.31 0.64 3.25 18.7 1.72 D93 0.33 520 0.33 0.61 3.61 20.6 7.61 D94 0.18 534 0.33 0.64 3.83 24.7 18.21

[2268] As can be concluded from device results XVII, device D94 according to the present invention shows a superior overall performance as compared to device D93 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D92 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy)s) and device D91 which employs E.sup.B-16 as the emitter material in spite of S.sup.B-1 when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2269] Composition of the light-emitting layer B of devices D95 to D97 (the percentages refer to weight percent):

TABLE-US-00044 Layer D95 D96 D97 Emission H.sup.B (69.5%): H.sup.B (66%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0.5%) S.sup.B (0%) S.sup.B (0.5%)

[2270] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-17 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XVIII

TABLE-US-00045 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D95 0.20 532 0.33 0.63 3.64 11.3 1.00 D96 0.44 550 0.40 0.56 4.27 8.4 3.77 D97 0.24 534 0.37 0.61 4.42 13.5 4.49

[2271] As can be concluded from device results XVIII, device D97 according to the present invention shows a superior overall performance as compared to device D96 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D95 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3), when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

TABLE-US-00046 Layer D98 D99 D100 D101 Emission H.sup.B (70%): H.sup.B (69.5%): H.sup.B (66%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0%) S.sup.B (0.5%)

[2272] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-18 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XIX

TABLE-US-00047 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D98 0.40 535 0.37 0.57 3.68 8.7 1.00 D99 0.20 531 0.34 0.62 3.87 8.7 1.22 D100 0.43 546 0.39 0.57 4.52 9.8 5.85 D101 0.22 532 0.36 0.61 4.80 11.4 8.24

[2273] As can be concluded from device results XIX, device D101 according to the present invention shows a superior overall performance as compared to device D100 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D99 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) and device D98 which employs E.sup.B-18 as the emitter material in spite of SB-.sub.1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2274] Composition of the light-emitting layer B of devices D102 to D105 (the percentages refer to weight percent):

TABLE-US-00048 Layer D102 D103 D104 D105 Emission H.sup.B (70%): H.sup.B (69.5%): H.sup.B (66%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0%) S.sup.B (0.5%)

[2275] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-19 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XX

TABLE-US-00049 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D102 0.41 532 0.353 0.573 3.56 9.25 1.00 D103 0.19 531 0.324 0.631 3.64 12.31 1.70 D104 0.41 535 0.373 0.582 4.31 11.68 4.07 D105 0.20 532 0.339 0.628 4.51 16.97 8.31

[2276] As can be concluded from device results XX, device D105 according to the present invention shows a superior overall performance as compared to device D104 which lacks the small FWHM emitter S.sup.B (here exemplarily S.sup.B-1) and device D103 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) and device D102 which employs E.sup.B-19 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2277] Composition of the light-emitting layer B of devices D106 to D108 (the percentages refer to weight percent:

TABLE-US-00050 Layer D106 D107 D108 Emission H.sup.B (70%): H.sup.B (69.5%): H.sup.B (65.5%): layer (6) E.sup.B (30%): E.sup.B (30%): E.sup.B (30%): P.sup.B (0%): P.sup.B (0%): P.sup.B (4%): S.sup.B (0%) S.sup.B (0.5%) S.sup.B (0.5%)

[2278] Setup 5 from Table 6 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-21 was used as TADF material E.sup.B, Ir(ppy).sub.3 was used as phosphorescence material P.sup.B, and S.sup.B-1 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XXI

TABLE-US-00051 Relative EQE at lifetime Voltage at 1000 LT95 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D106 0.41 520 0.30 0.56 3.65 11.2 1.00 D107 0.18 528 0.29 0.63 3.61 12.4 1.69 D108 0.18 530 0.31 0.65 5.10 19.4 15.88

[2279] As can be concluded from device results XXI, device D108 according to the present invention shows a superior overall performance as compared to device D107 which lacks the phosphorescence material P.sup.B (here exemplarily Ir(ppy).sub.3) and device D106 which employs E.sup.B-21 as the emitter material in spite of S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2280] Composition of the light-emitting layer B of devices D109 to D110 (the percentages refer to weight percent):

TABLE-US-00052 Layer D109 D110 Emission H.sup.B (66.3%): H.sup.B (66.3%): layer (5) E.sup.B (30%): E.sup.B (30%): P.sup.B (3%): P.sup.B (3%): S.sup.B (0.7%) S.sup.B (0.7%)

TABLE-US-00053 TABLE 7 Setup 6 of exemplary organic electroluminescent devices (OLEDs). Layer Thickness Material 9 100 nm Al 8 2 nm Liq 7 46 nm Liq/ETL2 50:50 6 5 nm ETL4 5 40 nm H.sup.B: E.sup.B: P.sup.B: S.sup.B 4 10 nm HTL2 3 51 nm NPB 2 9 nm NPB:NDP-9 95:5 1 50 nm ITO substrate glass

[2281] Setup 6 from Table 7 was used, wherein H.sup.B-15 was used as host material H.sup.B (p-host H.sup.P), E.sup.B-25 was used as TADF material E.sup.B, P.sup.B-2 was used as phosphorescence material P.sup.B in example D109, P.sup.B-5 was used as phosphorescence material P.sup.B in example D10, and S.sup.B-16 was used as small FWHM emitter S.sup.B. A weight percentage of 0% means the absence of the material in the light-emitting layer B.

Device Results XXII

TABLE-US-00054 Relative EQE at lifetime Voltage at 1000 LT97 at FWHM .sub.max 10 mA/cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] cd/m.sup.2 D109 0.12 532 0.30 0.66 3.87 27.5 1.40 D110 0.12 532 0.31 0.66 4.08 24.5 1.00

[2282] As can be concluded from device results XXII, devices D109 and D110 according to the present invention each show a superior overall performance. Compared to D110 with PB-5 as phosphorescence material P.sup.B, D109 shows with P.sup.B-2 as phosphorescence material improved efficiency (EQE) and lifetime (LT97) whereas both D109 and D110 have a narrow emission (FWHM).