ELECTROLUMINESCENT DEVICES

Abstract

The present invention describes electronic devices and compositions that can be used in electronic devices.

Claims

1.-25. (canceled)

26. A fluorescent electronic device comprising a sensitizer and a fluorescent emitter, wherein the sensitizer is a phosphorescent compound and wherein at least one of the two following conditions (I) or (II) must be satisfied:
S.sub.1.sup.K(FE)−S.sub.1.sup.K(S)≥X  (I)
S.sub.1.sup.max(FE)−S.sub.1.sup.max(S)≥Y  (II) where the parameters used are as follows: X, Y are each −0.5 eV S.sub.1.sup.K(FE) is the energy of the first excited singlet state of the fluorescent emitter which is ascertained from the edge of the first maximum on the short-wavelength side of the normalized photoluminescence spectrum of the fluorescent emitter; S.sub.1.sup.K(S) is the energy of the first excited state of the sensitizer which is ascertained from the edge of the first maximum on the short-wavelength side of the normalized photoluminescence spectrum of the sensitizer; S.sub.1.sup.max(FE) is the energy of the first excited singlet state of the fluorescent emitter which is ascertained from the location of the first maximum at short wavelengths of the photoluminescence spectrum of the fluorescent emitter; S.sub.1.sup.max(S) is the energy of the first excited state of the sensitizer which is ascertained from the location of the first maximum at short wavelengths of the photoluminescence spectrum of the sensitizer; wherein the photoluminescence spectra of the sensitizer and of the fluorescent emitter are determined from solution at a concentration of 1 mg in 100 ml of toluene at room temperature.

27. The electronic device according to claim 26, wherein the fluorescent emitter is a sterically shielded compound having a shielding factor (SF) of not less than 0.45.

28. The device according to claim 26, wherein X and Y are −0.4 eV.

29. The device according to claim 26, wherein both conditions (I) and (II) are satisfied.

30. The device according to claim 26, wherein excitation energy is transferred from the sensitizer to the fluorescent emitter and the fluorescent emitter emits excitation energy absorbed by the sensitizer by fluorescence.

31. The device according to claim 26, wherein the photoluminescence emission spectrum of the sensitizer overlaps with the absorption spectrum of the fluorescent emitter.

32. The device according to claim 26, wherein the metal-to-ligand charge transfer (MLCT) band of the photoluminescence spectrum of the sensitizer overlaps with the absorption spectrum of the fluorescent emitter.

33. The device according to claim 26, wherein the magnitude of the triplet metal-to-ligand charge transfer (.sup.3MLCT) band of the photoluminescence spectrum of the sensitizer and the absorption maximum of the fluorescent emitter satisfies the following condition (III):
|λ.sub.em.sup.3.sup.MLCT(S)−λ.sub.abs.sup.max (FE)|≤V  (III) where V is 0.5 eV; and where λ.sub.em.sup.3.sup.MLCT(S) is the triplet metal-to-ligand charge transfer (.sup.3MLCT) band of the photoluminescence spectrum of the sensitizer and is found from the edge in the photoluminescence spectrum of the sensitizer and λ.sub.abs.sup.max (FE) is the peak absorption wavelength of the first maximum at long wavelengths of the fluorescent emitter, where the values are each calculated in electron volts.

34. The device according to claim 26, wherein the following condition (IV) is satisfied
λ.sub.em.sup.3.sup.MLCT(S)−λ.sub.abs.sup.max (FE)≤W  (IV) where W is 0.5 eV; and where λ.sub.em.sup.3.sup.MLCT(S) is the triplet metal-to-ligand charge transfer (.sup.3MLCT) band of the photoluminescence spectrum of the sensitizer and is found from the edge in the photoluminescence spectrum of the sensitizer and λ.sub.abs.sup.max(FE) is the peak absorption wavelength of the first maximum at long wavelengths of the fluorescent emitter, where the values are each calculated in electron volts.

35. The device according to claim 26, wherein the sensitizer is a phosphorescent compound from the group of the organometallic complexes.

36. The device according to claim 26, wherein the sensitizer is a phosphorescent compound from the group of organometallic complexes containing Cu, Ir, Pt, Rh, Ru, Os or Pd.

37. The device according to claim 26, wherein the fluorescent emitter is a purely organic compound devoid of metals or metal ions.

38. The device according to claim 26, wherein the fluorescent emitter is a purely organic compound devoid of metals or metal ions, selected from the group of the fused aromatics having 6 to 60 aromatic ring atoms.

39. The device according to claim 26, wherein the fluorescent emitter is a purely organic compound devoid of metals or metal ions, selected from the group of the pyrenes, perylenes, rubrenes, anthracenes, fluorenes and indenofluorenes.

40. The device according to claim 26, wherein the fluorescent emitter is a purely organic compound devoid of metals or metal ions, with aromatic groups in substituted form.

41. The device according to claim 26, wherein both the sensitizer and the fluorescent emitter are in the same layer.

42. The device according to claim 26, wherein the sensitizer and the fluorescent emitter are in the emission layer.

43. The device according to claim 26, wherein the layer in which the sensitizer and the fluorescent emitter are present contains a further material selected from the group consisting of electron transport materials, hole conductor materials, quantum materials, bipolar hosts, wide band gap materials, phosphorescent emitters, fluorescent emitters, and materials having delayed fluorescence.

44. The device according to claim 26, wherein the layer in which the sensitizer and the fluorescent emitter are present does not contain any further material.

45. The device according to claim 26, wherein the sensitizer and the fluorescent emitter are in different layers adjoining one another.

46. The device according to claim 45, wherein the device contains a region having the layer sequence [SL/FEL].sub.n-SL where n is an integer from 1 to 5, SL is a layer containing the sensitizer and FEL is a layer containing the fluorescent emitter, and wherein the sensitizers in the different SL layers may be different from one another and wherein the fluorescent emitters in different FEL layers may be different from one another.

47. A composition comprising at least one sensitizer and at least one fluorescent emitter, wherein the sensitizer is a phosphorescent compound and wherein at least one of the two following conditions (I) and (II) must be satisfied:
S.sub.1.sup.K(FE)−S.sub.1.sup.K(S)≥X  (I)
S.sub.1.sup.max(FE)−S.sub.1.sup.max(S)≥Y  (II) and where the symbols used have the meaning given in claim 26.

48. The composition according to claim 47, wherein the composition comprises at least one further material selected from the group consisting of electron transport materials, electron injection materials, electron blocker materials, hole transport materials, hole injection materials, hole blocker materials, n-dopants, p-dopants, quantum materials, host or matrix materials, wide band gap materials, phosphorescent emitters, fluorescent emitters, and emitters having delayed fluorescence.

49. A formulation comprising the composition according to claim 47 and at least one solvent.

50. A electronic device comprising at least one composition according to claim 47.

Description

FIGURES

[0149] FIG. 1 shows the photoluminescence spectra of the compounds FE-03 and PS-01.

[0150] FIG. 2 shows the electroluminescence spectrum from Experiment 6.

[0151] The devices of the invention and devices comprising the compositions of the invention feature the following surprising advantages over the prior art: [0152] 1. The devices of the invention and the devices comprising the compositions of the invention have improved performance data, especially efficiency, lifetime and operating voltage, compared to compounds and compositions from the prior art. [0153] 2. The devices of the invention and the devices comprising the compositions of the invention enable use of a practicable or somewhat elevated concentration of the fluorescent emitter compared to the prior art, which has the advantage of better processibility of the emitting layer. [0154] 3. The compositions and formulations of the invention enable simple inexpensive processing of electronic devices, for example including simple processing from solution. They are therefore suitable for commercial utilization and mass production. [0155] 4. The compositions of the invention and formulations of the invention have improved stability, which facilitates the storage of the compositions and formulations.

[0156] It should be pointed out that variations of the embodiments described in the present invention are covered by the scope of this invention. Any feature disclosed in the present invention may, unless this is explicitly ruled out, be exchanged for alternative features which serve the same purpose or an equivalent or similar purpose. Thus, any feature disclosed in the present invention, unless stated otherwise, should be considered as an example of a generic series or as an equivalent or similar feature.

[0157] All features of the present invention may be combined with one another in any manner, unless particular features and/or steps are mutually exclusive. This is especially true of preferred features of the present invention. Equally, features of non-essential combinations may be used separately (and not in combination).

[0158] It should also be pointed out that many of the features, and especially those of the preferred embodiments of the present invention, should themselves be regarded as inventive and not merely as some of the embodiments of the present invention. For these features, independent protection may be sought in addition to or as an alternative to any currently claimed invention.

[0159] The technical teaching disclosed with the present invention may be abstracted and combined with other examples.

[0160] The invention is illustrated in more detail by the examples which follow, without any intention of restricting it thereby.

[0161] The person skilled in the art will be able to use the details given, without exercising inventive skill, to produce further electronic devices of the invention and hence to execute the invention over the entire scope claimed.

EXAMPLES

Example 1: Photophysical Measurements

[0162] 1.1) Determination of S.sub.1.sup.max from the Peak Emission Wavelength λ.sub.max

[0163] To determine the peak emission wavelength of the sensitizer and the fluorescent emitter, the particular material is dissolved in toluene. A concentration of 1 mg/100 ml is used here. The solution is excited in a Hitachi F-4500 fluorescence spectrometer with a wavelength adapted to the material to be analysed in each case. The measurement is effected at room temperature. The peak emission wavelength λ.sub.max is the wavelength at which the emission spectrum obtained attains its first maximum proceeding from short wavelengths (FIG. 1). The first maximum here is typically also the global maximum of the spectrum. But if the first maximum of the emission spectrum does not correspond to the global maximum, however, the first maximum has a high intensity in the normalized emission spectrum, the intensity of the first maximum in that case being at least 0.5 or more.

1.2) Determination of S.sub.1.sup.K from the Emission Edge

[0164] To determine the emission edge of the sensitizer and the fluorescent emitter, a tangent to the normalized photoluminescence spectrum is drawn at the steepest rise before the first maximum at short wavelengths. The point of intersection of this tangent with the x axis gives the wavelength of the emission edge λ.sub.edge (as shown in FIG. 1).

[0165] The above-described photophysical measurements give the peak emission wavelengths and emission edges for the sensitizer and fluorescent emitter in Table 1. The shielding factor (SF) is likewise listed for the fluorescent emitter.

TABLE-US-00002 TABLE 1 Emission wavelengths, energies of the excited states and shielding factors Sensitizer λ.sub.max [nm] λ.sub.edge [nm] S.sub.1.sup.max (eV) S.sub.1.sup.K (eV) SF PS-01 465 442 2.67 2.81 PS-02 473 458 2.62 2.71 PS-03 509 486 2.44 2.55 PS-04 494 448 2.51 2.77 PS-05 460 408 2.70 3.04 FE-01 459 441 2.70 2.81 0.41 FE-02 457 443 2.71 2.8 0.55 FE-03 469 455 2.64 2.73 0.72 FE-04 556 527 2.23 2.35 0.47 FE-05 566 529 2.19 2.34 0.60 FE-06 575 535 2.16 2.32 0.67 FE-07 573 535 2.16 2.32 0.65

Example 2: Synthesis of Fluorescent Emitters

[0166] The perylenes used here can be prepared by the principle detailed below.

Synthesis Scheme:

[0167] ##STR00062##

where X.sup.1 to X.sup.3 represent any substituents.

Synthesis of the Triflate:

[0168] ##STR00063##

where the R.sup.1 to R.sup.3 groups have the same meaning as the X.sup.1 to X.sup.3 groups.

[0169] A baked-out flask flooded with Ar and equipped with a precision glass stirrer is initially charged with 2,5,8,11-tetra-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)perylene (38.0 g, 50.3 mmol, 1.0 equiv.), 3-phenyl-[1,1′-biphenyl]-2-yl trifluoromethanesulfonate (95.1 g, 251.3 mmol, 5.0 equiv.), tetrakis(triphenylphosphine)palladium (5.81 g, 5.0 mmol, 0.1 equiv.) and sodium metaborate tetrahydrate (69.3 g, 502.5 mmol, 10.0 equiv.). THF (1500 ml) and water (500 ml) are added thereto and the reaction mixture is stirred under reflux for 3 d. The crude product is purified by means of column chromatography. The desired product is isolated as a yellow solid (16 g, 13.7 mmol, 27.3%).

Synthesis of 2,5,8,11-tetrakis(2,6-dimethylphenyl)perylene [FE-02]

[0170] ##STR00064##

[0171] A baked-out four-neck flask flooded with Ar and equipped with a precision glass stirrer is initially charged with 2,5,8,11-tetra-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)perylene (40.0 g, 52.9 mmol, 1.0 equiv.), 2-bromo-1,3-dimethylbenzene (293.7 g, 212.8 ml, 1587.0 mmol, 30.0 equiv.) and caesium carbonate (137.9 g, 423.2 mmol, 8.0 equiv.). Toluene (2000 ml) is added and the reaction mixture is degassed with Ar for 20 min. Subsequently, tetrakis(triphenylphosphine)palladium (6.11 g, 5.3 mmol, 0.1 equiv.) is added and the reaction mixture is degassed for a further 20 min. Subsequently, the reaction is stirred under reflux for 72 h. The reaction mixture is filtered. The mother liquor is concentrated, the resulting suspension is filtered, and methanol (1000 ml) is added to the resultant mother liquor. In the course of this, a solid precipitates out. All the solids are combined and subjected to hot extraction with toluene three times over AlOx. Yet another hot extraction is conducted over AlOx with a mixture of toluene and heptane (1:1). The resulting solid is recrystallized twice from toluene and once from 1,4-dioxane. The desired product is isolated as a yellow solid (5.0 g, 7.47 mmol, 14.1%). Subsequently, the solids are sublimed (4.5 g, 6.73 mmol, 12.7%).

Synthesis of 2,5,8,11-tetrakis(2,6-diphenylphenyl)perylene [FE-03]

[0172] ##STR00065##

[0173] A baked-out four-neck flask flooded with Ar and equipped with a precision glass stirrer is initially charged with 2,5,8,11-tetra-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)perylene (38.0 g, 50.3 mmol, 1.0 equiv.), 1,3-diphenylphenyl triflate (95.1 g, 251.3 mmol, 5.0 equiv.) and sodium metaborate tetrahydrate (69.3 g, 502.5 mmol, 10.0 equiv.). THF (1500 ml) and water (500 ml) are added and the reaction mixture is degassed with Ar for 20 min. Subsequently, tetrakis(triphenylphosphine)palladium (5.81 g, 5.0 mmol, 0.1 equiv.) is added and the reaction mixture is degassed with Ar for a further 20 min. Subsequently, the reaction is stirred under reflux for 72 h. The reaction mixture is cooled down and subjected to hot extraction with toluene over AlOx. This operation is repeated twice more, before the solids are recrystallized from toluene (700 ml). The recrystallization is conducted five times more before the desired product can be isolated as a yellow solid (16 g, 13.7 mmol, 27.3%). Subsequently, the solids are sublimed (6.8 g, 5.8 mmol, 11.6%).

Example 3: Organic Electroluminescent Devices

Production of the OLEDs

[0174] Glass plaques which have been coated with structured ITO (indium tin oxide) in a thickness of 50 nm are subjected to wet cleaning (dishwasher, Merck Extran detergent). The substrates are then treated with UV/ozone for 15 minutes. Thereafter, a 20 nm PEDOT:PSS layer is spun onto the substrates (2800 rpm). The substrates are baked once again on a hotplate at 180° C. for 10 minutes. After the production, the OLEDs are encapsulated for protection against oxygen and water vapour. The exact layer construction of the electroluminescent OLEDs (organic light-emitting diodes) can be found in the examples. The materials required for production of the OLEDs are shown in Table 4.

[0175] All materials are applied by thermal vapour deposition in a vacuum chamber. The emission layer(s) here always consist(s) of at least one matrix material (host material), a (phosphorescent) sensitizer (PS) and a fluorescent emitter (FE). Sensitizers and fluorescent emitters (FE) are added to the host material (H) in a particular proportion by volume by coevaporation. Details given in such a form as H-01:PS-01 (5%):FE-01 (3%) mean here that the material H-01 is present in the layer in a proportion by volume of 92%, PS-01 in a proportion of 5% and FE-01 in a proportion of 3%. Analogously, the electron transport layer may also consist of a mixture of two materials.

[0176] The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra (EL) and current-voltage-luminance (UIL) characteristics are measured, from which it is possible to determine the external quantum efficiency (EQE, measured in %) assuming Lambertian emission characteristics. The parameter U100 refers to the voltage which is required for a luminance of 100 cd/m.sup.2. EQE100 refers to the external quantum efficiency at an operating luminance of 100 cd/m.sup.2.

[0177] The lifetime LD is defined as the time after which the luminance drops from the starting luminance to a certain proportion L1 in the course of operation with constant current. A figure of j0=10 mA/cm.sup.2, L1=80% means that the luminance in the course of operation at 10 mA/cm.sup.2 falls to 80% of its starting value after the time LD.

[0178] Phosphorescent sensitizers used are the compounds PS-01, PS-02, PS-03, PS-04 and PS-05. Fluorescent emitters used are the materials FE-01, FE-02, FE-03, FE-04, FE-05, FE-06 and FE-07.

OLEDs with Blue Emission:

[0179] The OLEDs consist of the following layer sequence which is applied to the substrate after the PEDOT:PSS treatment:

[0180] For Exp. 1-16: 20 nm HTM:p-D (95%:5%), 30 nm HTM, 10 nm H-02, 25 nm H-01:PS:FE, 10 nm H-01, 20 nm ETM:LiQ (50%:50%), aluminium (100 nm).

[0181] For Exp. 17-22: 20 nm HTM:p-D (95%:5%), 20 nm HTM, 10 nm H-03, 30 nm H-01:PS:FE, 10 nm H-01, 20 nm ETM:LiQ (50%:50%), 3 nm LiQ, aluminium (100 nm).

[0182] For Exp. 23-28, substrates with 50 nm of ITO that have been subjected to wet cleaning (dishwasher, Merck Extran detergent) are used. Thereafter, the substrates are baked at 250° in a nitrogen atmosphere for 15 min. The OLEDs consist of the following layer sequence which is applied to the substrate after baking: 20 nm HTM:p-D (95%:5%), 180 nm HTM, 20 nm H-03, 25 nm H-01:PS-04:FE, 10 nm H-01, 20 nm ETM:LiQ (50%:50%), aluminium (100 nm).

[0183] Table 2 lists the results for various combinations of host, sensitizer and fluorescent emitter. EQE and voltage at 100 cd/m.sup.2 are reported for the corresponding experiments. X here represents S.sub.1.sup.K(FE)-S.sub.1.sup.K(S) and Y represents S.sub.1.sup.max(FE)-S.sub.1.sup.max(S).

TABLE-US-00003 TABLE 2 Experiments with blue-emitting OLEDs EQE100 U100 LD X Y Exp. Host Sensitizer FE [%] [V] [h] [eV] [eV] SF 1 H-01 PS-01 (15%) FE-01 (1%) 10.16 3.78 3.5 0.0 0.03 0.41 2 H-01 PS-01 (15%) FE-01 (2%) 6.77 3.91 7 0.0 0.03 0.41 3 H-01 PS-01 (15%) FE-01 (3%) 5.34 4 12.5 0.0 0.03 0.41 4 H-01 PS-01 (15%) FE-02 (2%) 9.32 3.89 3.5 −0.1 0.04 0.55 5 H-01 PS-01 (15%) FE-02 (3%) 7.7 4.06 4 −0.1 0.04 0.55 6 H-01 PS-01 (15%) FE-03 (1%) 19.67 3.63 1.8 −0.08 −0.03 0.72 7 H-01 PS-01 (15%) FE-03 (2%) 17.93 3.67 2.75 −0.08 −0.03 0.72 8 H-01 PS-01 (15%) FE-03 (3%) 14.77 3.68 4 −0.08 −0.03 0.72 9 H-01 PS-02 (5%) FE-01 (1%) 13 3.33 12.5 0.1 0.08 0.41 10 H-01 PS-02 (5%) FE-01 (2%) 9.5 3.37 26 0.1 0.08 0.41 11 H-01 PS-02 (5%) FE-01 (3%) 8.4 3.4 34 0.1 0.08 0.41 12 H-01 PS-02 (5%) FE-02 (2%) 12.3 3.28 12 0.09 0.09 0.55 13 H-01 PS-02 (5%) FE-02 (3%) 11.2 3.28 0.09 0.09 0.55 14 H-01 PS-02 (5%) FE-03 (1%) 18.7 3.23 8.5 0.02 0.02 0.72 15 H-01 PS-02 (5%) FE-03 (2%) 15.8 3.24 38 0.02 0.02 0.72 16 H-01 PS-02 (5%) FE-03 (3%) 13.5 3.28 16 0.02 0.02 0.72 17 H-01 PS-05 (20%) FE-01 (1%) 4.43 2.70 2.5 −0.23 0.00 0.41 18 H-01 PS-05 (20%) FE-01 (2%) 3.52 2.78 4.5 −0.23 0.00 0.41 19 H-01 PS-05 (20%) FE-01 (3%) 3.10 2.78 6.5 −0.23 0.00 0.41 20 H-01 PS-05 (20%) FE-03 (1%) 8.14 2.56 1.4 −0.31 −0.06 0.72 21 H-01 PS-05 (20%) FE-03 (2%) 7.46 2.58 1.9 −0.31 −0.06 0.72 22 H-01 PS-05 (20%) FE-03 (3%) 7.01 2.59 2.5 −0.31 −0.06 0.72 23 H-01 PS-04 (20%) FE-01 (1%) 10.17 2.79 39 0.04 0.19 0.41 24 H-01 PS-04 (20%) FE-01 (2%) 7.42 2.85 72 0.04 0.19 0.41 25 H-01 PS-04 (20%) FE-01 (3%) 5.68 2.92 119 0.04 0.19 0.41 26 H-01 PS-04 (20%) FE-03 (1%) 15.54 2.73 29 −0.04 0.13 0.72 27 H-01 PS-04 (20%) FE-03 (2%) 14.14 2.73 40 −0.04 0.13 0.72 28 H-01 PS-04 (20%) FE-03 (3%) 12.95 2.75 54 −0.04 0.13 0.72
Fluorescent Compounds with Higher Shielding Parameter SF in the Emission Layer Comprising a Phosphorescent Sensitizer

[0184] By comparison with FE-01 having an SF value of only 0.41, the fluorescent emitter FE-02 (SF=0.55) gives a much higher efficiency (Exp. 4 with EQE100=9.32% vs. Exp. 2 with EQE100=6.77%). The rise in efficiency is even greater in the case of use of the fluorescent emitter FE-03 (SF=0.72) (Exp. 7 with EQE100=17.9%).

[0185] In a reference experiment with PS-01 and without use of FE, a phosphorescent device is obtained with EQE100=21.72% and U100=3.67 V. Astonishingly, the efficiency of the device of the invention is only a little lower than that of the phosphorescent device. Moreover, the lifetime can, however, be distinctly improved with an FE. In Experiment 6, the device of the invention gives a lifetime improved by a factor of 2 compared to the device without a fluorescent emitter at j.sub.0=10 mA/cm.sup.2, L1=80%.

[0186] A higher efficiency is also obtained at a higher shielding factor in the case of use of PS-05 as sensitizer. Comparing Examples 17 and 20 or 18 and 21 or 19 and 22, it can be seen that FE-03 in the same construction gives much better EQE100 values than FE-01.

Effect of the Concentration of the Fluorescent Emitter

[0187] With rising concentration of the fluorescent emitter, there is a significant rise in the lifetime of the OLED (for example Exp. 8 vs. Exp. 6)

[0188] If FE-01 is used as emitter together with another phosphorescent sensitizer (PS-02) as in Experiment 9, this gives an EQE100=13%, U100=3.33 V.

[0189] The results from Table 2 make it clear that there is an unexpected physically and statistically significant rise in the efficiency (EQE) when there is a rise in the shielding factor (Table 1). Moreover, it can surprisingly be stated that the efficiency (EQE) is still at a very high level even though the X value and the Y value becomes greater and even positive. Moreover, there is a rise in the lifetime with increasing X and Y values. This can also be shown with use of the sensitizer/emitter combinations PS-04 with FE-01 and FE-03 (Exp. 23-28).

OLEDs with Yellow Emission

[0190] The OLEDs consist of the following layer sequence which is applied to the substrate: 20 nm HTM:p-D (95%:5%), 30 nm HTM, 10 nm H-02, 15 nm H-01:PS-03:FE, 10 nm H-01, 40 nm ETM:LiQ (50%:50%), aluminium (100 nm). The different combinations in the emission layer are compiled in Table 3:

TABLE-US-00004 TABLE 3 Experiments with yellow-emitting OLEDs EQE100 U100 LD X Y Exp. Host Sensitizer FE [%] [V] [h] [eV]] [eV] SF 17 H-01 PS-03 (10%) FE-04 11.15 3.8 238 −0.2 −0.21 0.47 (1%) 18 H-01 PS-03 (10%) FE-04 7.44 3.86 509 −0.2 −0.21 0.47 (2%) 19 H-01 PS-03 (10%) FE-04 5.92 4 772 −0.2 −0.21 0.47 (3%) 20 H-01 PS-03 (10%) FE-05 20.17 3.75 207 −0.21 −0.25 0.6 (1%) 21 H-01 PS-03 (10%) FE-05 18.5 3.72 270 −0.21 −0.25 0.6 (2%) 22 H-01 PS-03 (10%) FE-05 18.7 3.79 302 −0.21 −0.25 0.6 (3%) 23 H-01 PS-03 (10%) FE-06 19.59 3.52 17 −0.23 −0.28 0.67 (1%) 24 H-01 PS-03 (10%) FE-06 19.17 3.75 26 −0.23 −0.28 0.67 (2%) 25 H-01 PS-03 (10%) FE-06 18.8 3.68 31 −0.23 −0.28 0.67 (3%) 26 H-01 PS-03 (10%) FE-07 23.1 3.73 90 −0.23 −0.28 0.65 (1%) 27 H-01 PS-03 (10%) FE-07 21.06 3.75 27 −0.23 −0.28 0.65 (2%) 28 H-01 PS-03 (10%) FE-07 19.6 3.75 25 −0.23 −0.28 0.65 (3%)

[0191] Entirely analogously to the blue-emitting OLEDs, the same effects can be observed with the yellow-emitting OLEDs that contain a different class of fluorescent emitters.

TABLE-US-00005 TABLE 4 Structural formulae of the materials for the OLEDs [00066] HTM [00067] p-D [00068] ETM [00069] LiQ [00070] H-01 [00071] H-02 [00072] H-03 [00073] PS-01 [00074] PS-02 [00075] PS-03 [00076] FE-01 [00077] PS-04 [00078] PS-05 [00079] FE-02 [00080] FE-03 [00081] FE-04 [00082] FE-05 [00083] FE-06 [00084] FE-07