Organic Electronic Device Comprising a Compound of Formula (I), Display Device Comprising the Organic Electronic Device as Well as Compounds of Formula (I) for Use in Organic Electronic Devices
20230056322 · 2023-02-23
Inventors
Cpc classification
H10K85/371
ELECTRICITY
International classification
Abstract
The present invention relates to an organic electronic device comprising a semiconductor layer which comprises a compound of formula (1).
##STR00001##
Claims
1. An organic electronic device comprising an anode, a cathode, at least one photoactive layer and at least one semiconductor layer, wherein the at least one semiconductor layer is arranged between the anode and the at least one photoactive layer; and wherein the at least one semiconductor layer comprises a compound of Formula (1): ##STR00031## Wherein B.sup.1 is selected from substituted or unsubstituted C.sub.3 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, B.sup.2 is selected from substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, wherein the substituents on B.sup.1 and B.sup.2 are independently selected from D, C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN; wherein R.sup.1 is selected from C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy; wherein at least one of the substituents on B.sup.1 and/or B.sup.2 is selected from C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN.
2. The organic electronic device of claim 1 whereby the substituents on B.sup.1 and B.sup.2 are independently selected from halogen, C.sub.1 to C.sub.3 perhalogenated alkyl or alkoxy, or —(O).sub.l—C.sub.mH.sub.2m—C.sub.nH.sub.2m—C.sub.nHal.sub.n2n+1 with l=0 or 1, m=1 or and n=1 to 3 and Hal=halogen.
3. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is substituted alkyl and the substituents of the alkyl moiety are fluorine with the number n.sub.F (of fluorine substituents) and n.sub.H (of hydrogens) follow the equation: n.sub.F>n.sub.H+2.
4. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is selected from perfluorinated alkyl or aryl.
5. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is substituted C.sub.3 to C.sub.6 linear or cyclic alkyl.
6. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is aryl or heteroaryl, whereby the substituents of the aryl and/or heteroaryl moiety are selected from hydrogen, halogen, F, CN or trifluoro methyl.
7. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is phenyl or six-membered heteroaryl, which is substituted with at least one trifluoro methyl group in ortho- or meta-position to the substituted sulfoxide moiety.
8. The organic electronic device of claim 1, whereby at least one of B.sup.1 and B.sup.2 is phenyl or six-membered heteroaryl, which is substituted twice with trifluoro methyl groups in meta-position to the substituted sulfoxide moiety.
9. The organic electronic device of claim 1, whereby the at least one semiconductor layer is non-emissive.
10. The organic electronic device of claim 1, whereby at least one of the semiconductor layers is a hole-injection layer, which consists essentially of the compound of formula (1).
11. The organic electronic device of claim 1, whereby at least one of the at least one semiconductor layers further comprises a substantially covalent matrix compound.
12. The electronic organic device of claim 1, whereby the electronic organic device is an electroluminescent device.
13. A display device comprising an organic electronic device according to claim 1.
14. A compound of formula (1a): ##STR00032## wherein B.sup.3 and B.sup.4 are independently selected from substituted or unsubstituted C.sub.3 alkyl, wherein the substituents on B.sup.3 and B.sup.4 are independently selected from D, C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN; wherein R.sup.1 is selected from C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy; wherein at least one of the substituents on B.sup.3 and/or B.sup.4 are selected from C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR.sup.1, COOR.sup.1, halogen, F or CN.
15. A compound of formula (Ib): ##STR00033## whereby B.sup.5 is selected from substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, R.sup.2 to R.sup.6 are independently selected from H, F, CN, halogen, substituted or unsubstituted C.sub.1 to C.sub.6 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.3 to C.sub.12 heteroaryl, wherein the substituents on B.sup.5 and/or R.sup.2 to R.sup.6 are independently selected from D, C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy, COR′, COOR.sup.7, halogen, F or CN; wherein R.sup.7 is selected from C.sub.6 aryl, C.sub.3 to C.sub.9 heteroaryl, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.3 to C.sub.6 branched alkyl, C.sub.3 to C.sub.6 cyclic alkyl, C.sub.3 to C.sub.6 branched alkoxy, C.sub.3 to C.sub.6 cyclic alkoxy, partially or perfluorinated C.sub.1 to C.sub.16 alkyl, partially or perfluorinated C.sub.1 to C.sub.16 alkoxy, partially or perdeuterated C.sub.1 to C.sub.6 alkyl, partially or perdeuterated C.sub.1 to C.sub.6 alkoxy.
Description
DESCRIPTION OF THE DRAWINGS
[0250] The aforementioned components, as well as the claimed components and the components to be used in accordance with the invention in the described embodiments, are not subject to any special exceptions with respect to their size, shape, material selection and technical concept such that the selection criteria known in the pertinent field can be applied without limitations.
[0251] Additional details, characteristics and advantages of the object of the invention are disclosed in the dependent claims and the following description of the respective figures which in an exemplary fashion show preferred embodiments according to the invention. Any embodiment does not necessarily represent the full scope of the invention, however, and reference is made therefore to the claims and herein for interpreting the scope of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the present invention as claimed.
[0252]
[0253]
[0254]
[0255]
[0256]
[0257] Instead of a single electron transport layer 161, optional an electron transport layer stack (ETL) can be used.
[0258]
[0259] Referring to
[0260] In the description above the method of manufacture an OLED of the present invention is started with a substrate 110 onto which an anode electrode 120 is formed, on the anode electrode 120, an hole injection layer 130, hole transport layer 140, an emission layer 150, optional a hole blocking layer 155, optional at least one electron transport layer 161, optional at least one electron injection layer 180, and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.
[0261] While not shown in
[0262] Hereinafter, one or more exemplary embodiments of the present invention will be described in detail with, reference to the following examples. However, these examples are not intended to limit the purpose and scope of the one or more exemplary embodiments of the present invention.
DETAILED DESCRIPTION
[0263] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.
[0264] In the following the preparation of several inventive compounds is shown, using the following General Method:
[0265] The sulfonamide ligands were synthesized by methods known in the literature.
[0266] The sulfonamide ligand was dissolved in MeOH (ca. 5 ml/g) and 0.55 eq Ag.sub.2CO.sub.3 were added. The reaction mixture was stirred overnight at room temperature. Excess silver carbonate was filtered off and washed with a small amount of methanol. The liquid phases were combined and the solvent was removed under reduced pressure. The remaining solid was dried in high vacuum. The crude material was purified by sublimation under reduced pressure.
As comparative examples, the following compounds were used:
TABLE-US-00003 Comparative example No Structure 1 Ag N(SO.sub.2CF.sub.3).sub.2 2 Mg [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 3 Zn [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2
Sublimation Temperature
[0267] Under Nitrogen in a glovebox, 0.5 to 5 g compound are loaded into the evaporation source of a sublimation apparatus. The sublimation apparatus consist of an inner glass tube consisting of bulbs with a diameter of 3 cm which are placed inside a glass tube with a diameter of 3.5 cm. The sublimation apparatus is placed inside a tube oven (Creaphys DSU 05/2.1). The sublimation apparatus is evacuated via a membrane pump (Pfeiffer Vacuum MVP 055-3C) and a turbo pump (Pfeiffer Vacuum THM071 YP). The pressure is measured between the sublimation apparatus and the turbo pump using a pressure gauge (Pfeiffer Vacuum PKR 251). When the pressure has been reduced to 10.sup.−5 mbar, the temperature is increased in increments of 10 to 30 K till the compound starts to be deposited in the harvesting zone of the sublimation apparatus. The temperature is further increased in increments of 10 to 30 K till a sublimation rate is achieved where the compound in the source is visibly depleted over 30 min to 1 hour and a substantial amount of compound has accumulated in the harvesting zone.
[0268] The sublimation temperature, also named T.sub.subl, is the temperature inside the sublimation apparatus at which the compound is deposited in the harvesting zone at a visible rate and is measured in degree Celsius.
[0269] In the context of the present invention, the term “sublimation” may refer to a transfer from solid state to gas phase or from liquid state to gas phase.
Decomposition Temperature
[0270] The decomposition temperature, also named T.sub.dec, is determined in degree Celsius.
[0271] The decomposition temperature is measured by loading a sample of 9 to 11 mg into a Mettler Toledo 100 μL aluminum pan without lid under nitrogen in a Mettler Toledo TGA-DSC 1 machine. The following heating program was used: 25° C. isothermal for 3 min; 25° C. to 600° C. with 10 K/min.
[0272] The decomposition temperature was determined based on the onset of the decomposition in TGA.
Rate Onset Temperature
[0273] The rate onset temperature (T.sub.RO) is determined by loading 100 mg compound into a VTE source. As VTE source a point source for organic materials may be used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10.sup.−5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the compound is detected with a QCM detector which detects deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in {acute over (Å)}ngstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTE source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.
[0274] To achieve good control over the evaporation rate of an organic compound, the rate onset temperature may be in the range of 200 to 255° C. If the rate onset temperature is below 200° C. the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is above 255° C. the evaporation rate may be too low which may result in low tact time and decomposition of the organic compound in VTE source may occur due to prolonged exposure to elevated temperatures.
[0275] The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.
Reduction Potential
[0276] The reduction potential is determined by cyclic voltammetry with potentiostatic device Metrohm PGSTAT30 and software Metrohm Autolab GPES at room temperature. The redox potentials given at particular compounds were measured in an argon de-aerated, dry 0.1M THF solution of the tested substance, under argon atmosphere, with 0.1M tetrabutylammonium hexafluorophosphate supporting electrolyte, between platinum working electrodes and with an Ag/AgCl pseudo-standard electrode (Metrohm Silver rod electrode), consisting of a silver wire covered by silver chloride and immersed directly in the measured solution, with the scan rate 100 mV/s. The first run was done in the broadest range of the potential set on the working electrodes, and the range was then adjusted within subsequent runs appropriately. The final three runs were done with the addition of ferrocene (in 0.1M concentration) as the standard. The average of potentials corresponding to cathodic and anodic peak of the studied compound, after subtraction of the average of cathodic and anodic potentials observed for the standard Fc.sup.+/Fc redox couple, afforded finally the values reported above. All studied compounds as well as the reported comparative compounds showed well-defined reversible electrochemical behaviour.
Calculated HOMO and LUMO
[0277] The HOMO and LUMO are calculated with the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31 G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected. The HOMO and LUMO levels are recorded in electron volt (eV).
General Procedure for Fabrication of OLEDs
[0278] For OLEDs, see Example 7 to 11, Example 14 to 15 and comparative examples 4 and 5 in Table 3, a 15 Ω/cm.sup.2 glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 50 mm×50 mm×0.7 mm, ultrasonically washed with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and washed again with UV ozone for 30 minutes, to prepare the anode.
[0279] Then, 92 mol.-% Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 8 mol.-% compound of formula (1) was vacuum deposited on the anode, to form a HIL having a thickness of 10 nm. In comparative examples 4 and 5, the compounds shown in Table 3 were used in place of compounds of formula (1).
[0280] Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the HIL, to form a first HTL having a thickness of 128 nm.
[0281] Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
[0282] Then 97 vol.-% H09 (Sun Fine Chemicals, Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue dopant were deposited on the EBL, to form a first blue-emitting emission layer (EML) with a thickness of 20 nm.
[0283] Then a hole blocking layer is formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer.
[0284] Then, the electron transporting layer having a thickness of 31 nm is formed on the hole blocking layer by depositing 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile and LiQ in a ratio of 50:50 vol.-%.
[0285] Al is evaporated at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar to form a cathode with a thickness of 100 nm.
[0286] A cap layer of Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine is formed on the cathode with a thickness of 75 nm.
[0287] The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
[0288] To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing a voltage in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m.sup.2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm.sup.2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.
[0289] Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm.sup.2, using a Keithley 2400 sourcemeter, and recorded in hours.
[0290] The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.
[0291] To determine the voltage stability over time U(100 h)-(1 h) and U(100 h-50 h), a current density of at 30 mA/cm.sup.2 was applied to the device. The operating voltage was measured after 1 hour, after 50 hours and after 100 hours, followed by calculation of the voltage stability for the time period of 1 hour to 100 hours and for a time period of 50 hours to 100 hours.
Technical Effect of the Invention
[0292] In order to investigate the usefulness of the inventive compound preferred materials were tested in view of their thermal properties
[0293] As materials for organic electronics are typically purified by sublimation, a large offset between decomposition and sublimation temperature T.sub.dec−T.sub.subl are highly desirable. Thereby, a high sublimation rate may be achievable.
TABLE-US-00004 TABLE 2 Properties of compounds of formula (1) and comparative examples 1 to 3 T.sub.dec Td.sub.ec-T.sub.sub1 Name [° C.] [° C.] Comparative Ag TFSI 320 5-10° C. example 1 Comparative Mg [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 >250 ≥25 example 2 Comparative Zn [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 >230 ≥70 example 3 Example 1 Ag [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2] 350 ≥50 Example 2 Ag [N(SO.sub.2C.sub.3F.sub.7).sub.2] >330 ≥50 Example 3 Ag [N(SO.sub.2C.sub.4F.sub.9).sub.2] >330 ≥20 Example 4 Ag [N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)] >330 ≥20 Example 5
[0294] In Table 2 are shown the temperature at which thermal decomposition is observed (T.sub.dec), difference between decomposition and sublimation temperature T.sub.dec−T.sub.subl and yield after purification through sublimation. It is apparent that the inventive compounds show a higher decomposition temperature and/or a much larger gap between decay and sublimation temperature
[0295] Further, the change in operating voltage over time was determined for period between 1 hour and 100 hours and for the period between 50 and 100 hours for several devices comprising comparative and inventive compounds.
[0296] A low increase or even decrease in operating voltage over time is highly desirable, as the power consumption over time does not increase. Low power consumption is important for long battery life, in particular in mobile devices.
[0297] In Table 3 are shown the properties of organic electronic devices comprising compounds of formula (1) and comparative examples 4 and 5.
TABLE-US-00005 TABLE 3 Properties of organic electronic device comprising compound of formula 1 and comparative examples 4 and 5 Chemical structure of the U(100 h)-(1 h) @ U(100 h)-(50 h) @ compound contained in the device 30 mA/cm.sup.2 30 mA/cm.sup.2 Comparative Mg [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 0.12 0.05 example 4 Comparative Zn [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 0.37 0.14 example 5 Example 7 Ag [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2] −0.04 0.02 Example 8 Ag [N(SO.sub.2C.sub.3F.sub.7).sub.2] −0.10 0.01 Example 9 Ag [N(SO.sub.2C.sub.4F.sub.9).sub.2] −0.10 0.01 Example 10 Ag [N(SO.sub.2CF.sub.3)(SO.sub.2C.sub.4F.sub.9)] −0.15 0.01 Example 11
[0298] It is apparent that the devices according to the invention show a much better performance than the comparative devices.
[0299] The particular combinations of elements and features in the above detailed embodiments are exemplary only; the interchanging and substitution of these teachings with other teachings in this and the patents/applications incorporated by reference are also expressly contemplated. As those skilled in the art will recognize, variations, modifications, and other implementations of what is described herein can occur to those of ordinary skill in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the foregoing description is by way of example only and is not intended as limiting. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. The invention's scope is defined in the following claims and the equivalents thereto. Furthermore, reference signs used in the description and claims do not limit the scope of the invention as claimed.