ORGANIC ELECTROLUMINESCENT DEVICE

20230329023 · 2023-10-12

Inventors

Cpc classification

International classification

Abstract

The invention relates to a an organic electroluminescent device including at least one light-emitting layer B composed of one or more sublayers, wherein the one or more sublayers of the light-emitting layer B 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 optionally at least one TADF material E.sup.B, wherein S.sup.B emits light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV.

Claims

1-15. (canceled)

16. An organic electroluminescent device comprising: at least one light-emitting layer, the at least one light-emitting layer comprising one or more sublayers, wherein the one or more sublayers are adjacent to each other and as a whole comprises: at least one host material; at least one phosphorescence material; and at least one emitter to emit light with a full width at half maximum (FWHM) of less than or equal to 0.25 eV; and optionally at least one thermally activated delayed fluorescence (TADF) material, and wherein an outermost sublayer from the one or more sublayers comprises at least one material selected from the group consisting of the at least one phosphorescence material, the at least one emitter, and the at least one TADF material.

17. The organic electroluminescent device according to claim 16, wherein at least one sublayer of the one or more sublayers comprises the at least one TADF material.

18. The organic electroluminescent device according to claim 16, wherein at least one sublayer from the one or more sublayers comprises exactly one TADF material and exactly one phosphorescence material.

19. The organic electroluminescent device according to claim 16, wherein the at least one light-emitting layer comprises a first sublayer and a second sublayer, and wherein the first sublayer comprises exactly one TADF material and the second sublayer comprises exactly one phosphorescence material and exactly one emitter.

20. The organic electroluminescent device according to claim 16, wherein: the at least one host material has a lowermost excited singlet state energy level E(S1.sup.H) and a lowermost excited triplet state energy level E(T1.sup.H); the at least one phosphorescence material has a lowermost excited singlet state energy level E(S1.sup.P) and a lowermost excited triplet state energy level E(T1.sup.P); the at least one emitter has a lowermost excited singlet state energy level E(S1.sup.S) and a lowermost excited triplet state energy level E(T1.sup.S); and E(T1.sup.H)>E(T1.sup.P) and E(T1.sup.P)>E(S1.sup.S).

21. The organic electroluminescent device according to claim 16, wherein: the one or more sublayers comprises the at least one TADF material; the at least one host material has a lowermost excited singlet state energy level E(S1.sup.H) and a lowermost excited triplet state energy level E(T1.sup.H); the at least one phosphorescence material has a lowermost excited singlet state energy level E(S1.sup.P) and a lowermost excited triplet state energy level E(T1.sup.P); the at least one TADF material has a lowermost excited singlet state energy level E(S1.sup.E) and a lowermost excited triplet state energy level E(T1.sup.E); and E(T1.sup.H)>E(T1.sup.E) and E(T1.sup.E)>E(T1.sup.P).

22. The organic electroluminescent device according to claim 16, wherein the at least one TADF material has (i) a ΔE.sub.ST value, which corresponds to an energy difference between a lowermost excited singlet state energy level E(S1.sup.E) and a lowermost excited triplet state energy level E(T1.sup.E), of less than 0.4 eV; and (ii) a photoluminescence quantum yield (PLQY) of more than 30%.

23. The organic electroluminescent device according to claim 16, wherein: each host material of the at least one host material has a highest occupied molecular orbital HOMO(H.sup.B) having an energy E.sup.HOMO(H.sup.B); each phosphorescence material of the at least one phosphorescence material has a highest occupied molecular orbital HOMO(P.sup.B) having an energy E.sup.HOMO(P.sup.B); each emitter from the at least one emitter has a highest occupied molecular orbital HOMO(S.sup.B) having an energy E.sup.HOMO(S.sup.B); and E.sup.HOMO(P.sup.B)>E.sup.HOMO(H.sup.B) and E.sup.HOMO(P.sup.B)>E.sup.HOMO(S.sup.B).

24. The organic electroluminescent device according to claim 16, wherein: each host material of the at least one host material has a lowest unoccupied molecular orbital LUMO(H.sup.B) having an energy E.sup.LUMO(H.sup.B); each phosphorescence material the at least one phosphorescence material has a lowest unoccupied molecular orbital LUMO(P.sup.B) having an energy E.sup.LUMO(P.sup.B); each emitter from the at least one emitter has a lowest unoccupied molecular orbital LUMO(S.sup.B) having an energy E.sup.LUMO(S.sup.B); each TADF material from the at least one TADF material has a lowest unoccupied molecular orbital LUMO(E.sup.B) having an energy E.sup.LUMO(E.sup.B); and E.sup.LUMO(E.sup.B)<E.sup.LUMO(H.sup.B) and E.sup.LUMO(E.sup.B)<E.sup.LUMO(P.sup.B).

25. The organic electroluminescent device according to claim 16, wherein the one or more sublayers as a whole comprises: (i) 30-99.8% by weight of the at least one host material; (ii) 0.1-30% by weight of the at least one phosphorescence material; (iii) 0.1-10% by weight of the at least one emitter; (iv) 0-69.8% by weight of the at least one TADF material; and (v) 0-69.8% by weight of one or more solvents.

26. The organic electroluminescent device according to claim 16, wherein: the at least one phosphorescence material has a lowermost excited singlet state energy level E(S1.sup.P) and a lowermost excited triplet state energy level E(T1.sup.P); the at least one emitter has a lowermost excited singlet state energy level E(S1.sup.S) and a lowermost excited triplet state energy level E(T1.sup.S); and a difference between E(T1.sup.P) and E(S1.sup.S) is smaller than 0.3 eV.

27. The organic electroluminescent device according to claim 16, wherein: the at least one phosphorescence material has a highest occupied molecular orbital HOMO(P.sup.B) having an energy E.sup.HOMO(P.sup.B); the at least one emitter has a highest occupied molecular orbital HOMO(S.sup.B) having an energy E.sup.HOMO(S.sup.B); and a difference between E.sup.HOMO(P.sup.B) and E.sup.HOMO(S.sup.B) is smaller than 0.3 eV.

28. The organic electroluminescent device according to claim 16, wherein: the at least one emitter has a lowest unoccupied molecular orbital LUMO(S.sup.B) having an energy E.sup.LUMO(S.sup.B); the at least one TADF material has a lowest unoccupied molecular orbital LUMO(E.sup.B) having an energy E.sup.LUMO(E.sup.B); and a difference between E.sup.LUMO(S.sup.B) and E.sup.LUMO(E.sup.B) is smaller than 0.3 eV.

29. A method for generating light, the method comprising applying an electrical current to the organic electroluminescent device according to claim 16 to generate light.

30. The method according to claim 29, wherein the light has a wavelength of: (i) from 510 nm to 550 nm, or (ii) from 440 nm to 470 nm, or (iii) from 610 nm to 665 nm.

31. The organic electroluminescent device according to claim 16, wherein: the at least one host material has a lowermost excited singlet state energy level E(S1.sup.H) and a lowermost excited triplet state energy level E(T1.sup.H); the at least one phosphorescence material has a lowermost excited singlet state energy level E(S1.sup.P) and a lowermost excited triplet state energy level E(T1.sup.P); and the at least one emitter has a lowermost excited singlet state energy level E(S1.sup.S) and a lowermost excited triplet state energy level E(T1.sup.S); and the at least one TADF material has a lowermost excited singlet state energy level E(S1.sup.E) and a lowermost excited triplet state energy level E(T1.sup.E).

32. The organic electroluminescent device according to claim 17, wherein the at least one TADF material has a lowermost excited singlet state energy level E(S1.sup.E) and a lowermost excited triplet state energy level E(T1.sup.E).

Description

EXAMPLES

[1984] Cyclic Voltammetry

[1985] Cyclic voltammograms of solutions having concentration of 10.sup.−3 mol/l of the organic molecules in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g., 0.1 mol/l 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 was corrected using ferrocene as internal standard against SCE.

[1986] Density Functional Theory Calculation

[1987] 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.

[1988] All orbital and excited state energies reported herein (see experimental results) have been determined experimentally. Def2-SVP basis sets and an m4-grid for numerical integration were used. The Turbomole program package was used for all calculations.

[1989] Photophysical Measurements

[1990] Sample Pretreatment: Vacuum-Evaporation

[1991] 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.

[1992] 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.

[1993] Absorption Measurements

[1994] 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 quantum yield measurements.

[1995] Photoluminescence Spectra

[1996] 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.

[1997] Photoluminescence Quantum Yield Measurements

[1998] 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. Quantum yields are determined using the software U6039-05 and given in %. The yield is calculated using the equation:

[00005] $Φ_{PL} = \frac{n_{photon}, emited}{n_{photon}, absorbed} = \frac{\int \frac{λ}{hc} [Int \begin{matrix} sample \\ emitted \end{matrix} (λ) - Int \begin{matrix} sample \\ absorbed \end{matrix} (λ)] d λ}{\int \frac{λ}{hc} [Int \begin{matrix} reference \\ emitted \end{matrix} (λ) - Int \begin{matrix} reference \\ absorbed \end{matrix} (λ)] d λ}$ [1999] 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.

[2000] TCSPC (Time-Correlated Single-Photon Counting)

[2001] Excited state population dynamics are determined employing Edinburgh Instruments FS5 Spectrofluoremeters, equipped with an emission monochromator, a temperature stabilized photomultiplier as detector unit and a pulsed LED (310 nm central wavelength, 910 μs pulse width) as excitation source. The samples are placed in a cuvette and flushed with nitrogen during the measurements.

[2002] Full Decay Dynamics

[2003] 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 μs, and 20 μs, and a longer measurement spanning >80 μs. The measured time curves are then processed in the following way:

[2004] A background correction is applied by determining the average signal level before excitation and subtracting.

[2005] The time axes are aligned by taking the initial rise of the main signal as reference.

[2006] The curves are scaled onto each other using overlapping measurement time regions.

[2007] The processed curves are merged to one curve.

[2008] Data Analysis

[2009] Data analysis was done using monoexponential and bi-exponential fitting of prompt fluorescence (PF) and delayed fluorescence (DF) decays separately. The ratio of delayed and prompt fluorescence (n-value) is calculated by the integration of respective photoluminescence decays in time.

[00006] $\frac{\int I_{DF} (t) dt}{\int I_{PF} (t) dt} = n$

[2010] The average excited state life time is calculated by taking the average of prompt and delayed fluorescence decay time, weighted with the respective contributions of PF and DF.

[2011] Production and Characterization of Organic Electroluminescence Devices

[2012] 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%.

[2013] 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, where the measured luminance decreased to 50% of the initial luminance, analogously LT80 corresponds to the time point, at which the measured luminance decreased to 80% of the initial luminance, LT97 to the time point, at which the measured luminance decreased to 97% of the initial luminance etc.

[2014] 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:

[00007] $LT 80 (500 \frac{{cd}^{2}}{m^{2}}) = LT 80 (L_{0}) {(\frac{L_{0}}{500 \frac{{cd}^{2}}{m^{2}}})}^{1.6}$ [2015] 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

[2016] Stack Materials

##STR00532## ##STR00533## ##STR00534##

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

[2017] ##STR00535## ##STR00536## ##STR00537##

TABLE-US-00002 TABLE 1E Properties of the TADF materials E.sup.B. Example E.sup.HOMO E.sup.LUMO E(S1) E(T1) λ.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

Phosphorescence Materials P.SUP.B

[2018] ##STR00538##

TABLE-US-00003 TABLE 1P Properties of the materials. Example HOMO LUMO.sub.CV E.sup.LUMO E(S1) E(T1) λ.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 [2019] 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

[2020] ##STR00539## ##STR00540## ##STR00541##

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) λ.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 *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

[2021] 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.

[2022] Results I: Variation of the Content of the Phosphorescence Material P.sup.B in the Light-Emitting Layer (Emission Layer, 6)

[2023] 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 (0%):S.sup.B (1%) (20%):P.sup.B (1%):S.sup.B (1%) (20%):P.sup.B (4%):S.sup.B (1%) (20%):P.sup.B (10%):S.sup.B (1%)

[2024] 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 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.

Device Results I

[2025]

TABLE-US-00007 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2026] Comparing the device results, D1 and D2, similar optical properties (FWHM, λ.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).

[2027] Results II: Variation of Composition of Components

[2028] 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 D9 D10 Emission H.sup.B (79%):H.sup.N H.sup.B (76%):H.sup.N H.sup.B (78%):H.sup.N H.sup.B (75%):H.sup.N 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 (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (20%):P.sup.B (1%):S.sup.B (0%) (4%):S.sup.B (0%) (1%):S.sup.B (1%) (4%):S.sup.B (1%) (0%):S.sup.B (0.5%) (1%):S.sup.B (0.5%)

[2029] 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.

[2030] 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.

[2031] 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.

[2032] 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.

[2033] 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

[2034]

TABLE-US-00009 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2035] Comparing the composition of the emission layer of devices D5 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.

[2036] Device 010 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).

[2037] 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 (80%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (78%):H.sup.N H.sup.B (79%):H.sup.N layer (6) (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 (0%) (1%):S.sup.B (0%) (0%):S.sup.B (1%) (1%):S.sup.B (1%) (1%):S.sup.B (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 (1%) (4%):S.sup.B (1%) (7%):S.sup.B (1%)

[2038] 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

[2039]

TABLE-US-00011 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2040] 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 P.sup.B. 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 still display a good overall performance, in particular with regard to the device lifetime.

[2041] 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.

[2042] 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 (80%):H.sup.N H.sup.B (79%):H.sup.N H.sup.B (78%):H.sup.N H.sup.B (78%):H.sup.N H.sup.B (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 (0%) (1%):S.sup.B (0%) (1%):S.sup.B (1%) (1%):S.sup.B (1%) (1%):S.sup.B (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 (0.5%) (4%):S.sup.B (1%) (4%):S.sup.B (0.5%)

[2043] 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

[2044]

TABLE-US-00013 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2045] 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 S.sup.B (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

Composition of the Light-Emitting Layer B of Devices D30 to D32 (the Percentages Refer to Weight Percent):

[2046]

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%)

[2047] 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, 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 V

[2048]

TABLE-US-00016 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2049] 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.

[2050] 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%)

[2051] 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

[2052]

TABLE-US-00018 EQE at Relative Voltage at 1000 lifetime FWHM λ.sub.max 10 mA/cm.sup.2 cd/m.sup.2 LT95 at 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2053] 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.

[2054] 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 Lig 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

[2055] 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%)

[2056] 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

[2057]

TABLE-US-00021 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max cm.sup.2 cd/m.sup.2 1200 Device [eV] [nm] CIEx CIEy [Volt] [%] 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

[2058] 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

[2059] 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%): layer (6) E.sup.B (20%): P.sup.B (1%) 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%)

[2060] 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 S.sup.B-1 was used as small FWHM emitter S.sup.B.

Device Results VIII

[2061]

TABLE-US-00024 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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.

[2062] As can be concluded from device results VIII, reducing the thickness of the H.sup.B:E.sup.B:P.sup.B-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.

[2063] 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%): H.sup.B (75%): layer (6) E.sup.B (20%): E.sup.B (20%): P.sup.B (0%): P.sup.B (4%): S.sup.B (1%) S.sup.B (1%)

[2064] 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

[2065]

TABLE-US-00026 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2066] 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

Composition of the Light-Emitting Layer B of Devices D42 to D44 (the Percentages Refer to Weight Percent):

[2067]

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%)

[2068] 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

[2069]

TABLE-US-00029 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2070] 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.

[2071] 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%)

[2072] 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

[2073]

TABLE-US-00031 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2074] 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.B51 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 (FOE), 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.

[2075] 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 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%): S.sup.B (0%) P.sup.B (1%): P.sup.B (0%): P.sup.B (1%): P.sup.B (0%): S.sup.B (0%) S.sup.B (1%) S.sup.B (1%) Layer D54 D55 D56 D57 Emission H.sup.B (78%): H.sup.B (75%): H.sup.B (75.5%): H.sup.B (72%): 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 (4%): P.sup.B (4%): P.sup.B (7%): S.sup.B (1%) S.sup.B (1%) S.sup.B (0.5%) S.sup.B (1%) D58 D59 D60 D61 Emission H.sup.B (72.5%): H.sup.B (65.5%): H.sup.B (55.5%): H.sup.B (67.5%): 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 (30%): E.sup.B (40%): E.sup.B (30%): P.sup.B (7%): P.sup.B (4%): P.sup.B (4%): P.sup.B (3%): S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0.5%) S.sup.B (0.5%)

[2076] 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

[2077]

TABLE-US-00033 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2078] 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.3 as 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 S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (FOE), 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.

[2079] 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%)

[2080] 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-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

[2081]

TABLE-US-00035 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2082] 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-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 (EQE), 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-2 and of 0.5% of S.sup.B-1 afforded the best performing device (D69).

[2083] 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%): E.sup.B (20%): H.sup.B (75%): H.sup.B (75.5%): layer (6) H.sup.N (0%): H.sup.B (78.5%): H.sup.N (0%): H.sup.N (0%): E.sup.B (20%): H.sup.N (0%): 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%)

[2084] 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

[2085]

TABLE-US-00037 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2086] 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-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 S.sup.B-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):

[2087]

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

[2088] 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.B15V 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

[2089]

TABLE-US-00039 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2090] 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 (EQE), and the device lifetime (LT95) into account.

[2091] 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%)

[2092] 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, 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 XVI

[2093]

TABLE-US-00041 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2094] As can be concluded from device results XVI, devices D89 and D90 according to the present invention show a superior overall performance as compared to device D87 and D88 which lack the phosphorescence material P.sup.B (here exemplarily P.sup.B-2) and device D86 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 (EQE), and the device lifetime (LT95) into account.

[2095] 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%)

[2096] 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.

Device Results XVII

[2097]

TABLE-US-00043 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2098] 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).sub.3) 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.

[2099] Composition of the Light-Emitting Layer B of Devices D91 to D94 (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%)

[2100] 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

[2101]

TABLE-US-00045 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2102] 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.

[2103] Composition of the Light-Emitting Layer B of Devices D98 to D101 (the Percentages Refer to Weight Percent):

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%)

[2104] 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

[2105]

TABLE-US-00047 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2106] 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 S.sup.B-1, when taking the narrow emission (FWHM), the efficiency (EQE), and the device lifetime (LT95) into account.

[2107] 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%)

[2108] 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

[2109]

TABLE-US-00049 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2110] 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.

[2111] 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%)

[2112] 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

[2113]

TABLE-US-00051 Voltage Relative at EQE at lifetime 10 mA/ 1000 LT95 at FWHM λ.sub.max 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

[2114] 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.

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