ORGANIC ELECTRONIC DEVICE COMPRISING A COMPOUND OF FORMULA (1), DISPLAY DEVICE COMPRISING THE ORGANIC ELECTRONIC DEVICE AS WELL AS COMPOUNDS OF FORMULA (1) FOR USE IN ORGANIC ELECTRONIC DEVICES

Abstract

The present invention relates to an organic electronic device comprising a semiconductor layer which comprises a compound of formula (1).

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): ##STR00048## Wherein M is Na, K, Rb or Cs, B.sup.1 is selected from substituted or unsubstituted isopropyl, substituted or unsubstituted C.sub.4 to C.sub.12 alkyl, substituted or unsubstituted C.sub.6 to C.sub.12 aryl, substituted or unsubstituted C.sub.2 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, with F especially preferred, C.sub.1 to C.sub.3 perhalogenated, especially perfluorinated, alkyl or alkoxy, or (O).sub.lC.sub.mH.sub.2mC.sub.nHal.sub.n2n+1 with l=0 or 1, especially 0, m=1 or 2, especially 1 and n=1 to 3, especially 1 or 2 and Hal=halogen, especially F.

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) fulfill 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 pentafluorophenyl.

5. The organic electronic device of claim 1, whereby B.sup.1 and B.sup.2 are identical.

6. The organic electronic device of claim 1, whereby B.sup.1 and B.sup.2 are not identical.

7. The organic electronic device of claim 1, whereby the compound of formula (1) is free of alkoxy, COR.sup.1 and/or COOR.sup.1 groups.

8. The organic electronic device of claim 1, whereby the compound of formula (1) contains 12 carbon atoms or less.

9. The organic electronic device of claim 1, whereby the anion of compound (1) is selected from A-1 to A-53: ##STR00049## ##STR00050## ##STR00051## ##STR00052## ##STR00053## ##STR00054##

10. The organic electronic device of claim 1, whereby the at least one semiconductor layer is non-emissive.

11. 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).

12. 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.

13. The electronic organic device of claim 1, whereby the electronic organic device is selected from the group comprising an electroluminescent device or an organic light emitting diode.

14. A display device comprising an organic electronic device according to claim 1.

15. A compound of Formula (1): ##STR00055## wherein Formula (1) is represented by one of the following formulae (1a) or (1b): ##STR00056## wherein M is Na, K, Rb or Cs, B.sup.3 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.3 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.

Description

DESCRIPTION OF THE DRAWINGS

[0261] 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.

[0262] 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.

[0263] FIGS. 1 to 6

[0264] FIG. 1 is a schematic sectional view of an organic electronic device, according to an exemplary embodiment of the present invention;

[0265] FIG. 2 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention;

[0266] FIG. 3 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention.

[0267] FIG. 4 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention;

[0268] FIG. 5 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention.

[0269] FIG. 6 is a schematic sectional view of an organic light-emitting diode (OLED), according to an exemplary embodiment of the present invention.

[0270] Hereinafter, the FIGS. 1 to 6 are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

[0271] Herein, when a first element is referred to as being formed or disposed on or onto a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed directly on or directly onto a second element, no other elements are disposed there between.

[0272] FIG. 1 is a schematic sectional view of an organic electronic device 101, according to an exemplary embodiment of the present invention. The organic electronic device 101 includes a substrate (110), an anode layer (120), a semiconductor layer comprising a compound of Formula (1) (130), a photoactive layer (PAL) (151) and a cathode layer (190).

[0273] FIG. 2 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate (110), an anode layer (120), a semiconductor layer comprising a compound of Formula (1) (130), an emission layer (EML) (150) and a cathode layer (190).

[0274] FIG. 3 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate (110), an anode layer (120), a semiconductor layer comprising a compound of Formula (1) (130), a hole transport layer (HTL) (140), an emission layer (EML) (150), an electron transport layer (ETL) (160) and a cathode layer (190).

[0275] FIG. 4 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate (110), an anode layer (120), a semiconductor layer comprising a compound of Formula (1) (130), a hole transport layer (HTL) (140), an electron blocking layer (EBL) (145), an emission layer (EML) (150), a hole blocking layer (HBL) (155), an electron transport layer (ETL) (160), an optional electron injection layer (EIL) (180), and a cathode layer (190).

[0276] FIG. 5 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate (110), an anode layer (120) that comprises a first anode sub-layer (121) and a second anode sub-layer (122), a semiconductor layer comprising compound of Formula (1) (130), a hole transport layer (HTL) (140), an electron blocking layer (EBL) (145), an emission layer (EML) (150), a hole blocking layer (EBL) (155), an electron transport layer (ETL) (160) and a cathode layer (190).

[0277] FIG. 6 is a schematic sectional view of an organic light-emitting diode (OLED) 100, according to an exemplary embodiment of the present invention. The OLED 100 includes a substrate (110), an anode layer (120) that comprises a first anode sub-layer (121), a second anode sub-layer (122) and a third anode sub-layer (123), a semiconductor layer comprising compound of Formula (1) (130), a hole transport layer (HTL) (140), an electron blocking layer (EBL) (145), an emission layer (EML) (150), a hole blocking layer (EBL) (155), an electron transport layer (ETL) (160) and a cathode layer (190). The layers are disposed exactly in the order as mentioned before.

[0278] In the description above the method of manufacture an organic electronic device 101 of the present invention is for example started with a substrate (110) onto which an anode layer (120) is formed, on the anode layer (120), a semiconductor layer comprising compound of Formula (1) (130), a photoactive layer (151) and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.

[0279] In the description above the method of manufacture an OLED 100 of the present invention is started with a substrate (110) onto which an anode layer (120) is formed, on the anode layer (120), a semiconductor layer comprising compound of Formula (1) (130), optional a hole transport layer (140), optional an electron blocking layer (145), an emission layer (150), optional a hole blocking layer (155), optional an electron transport layer (160), optional an electron injection layer (180), and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.

[0280] The semiconductor layer comprising a compound of Formula (1) (130) can be a hole injection layer.

[0281] While not shown in FIG. 1 to FIG. 6, a capping layer and/or a sealing layer may further be formed on the cathode electrodes 190, in order to seal the OLEDs 100. In addition, various other modifications may be applied thereto.

[0282] 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

[0283] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.

[0284] Compounds of formula (1) may be prepared as described in W02017029370A1 and WO2018150050A1.

Sublimation Temperature

[0285] 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.sup.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.

[0286] 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.

[0287] 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.

[0288] Decomposition Temperature

[0289] The decomposition temperature, also named T.sub.dec, is determined in degree Celsius. The decomposition temperature is measured by loading a sample of 9 to 11 mg into a Mettler Toledo 100 L 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.

[0290] The decomposition temperature was determined based on the onset of the decomposition in TGA.

Calculated HOMO and LUMO

[0291] 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 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected.

General Procedure for Fabrication of OLEDs

[0292] For Examples 1 to 21 and comparative examples 1 to 3 in Table 2, a glass substrate with an anode layer comprising a first anode sub-layer of 120 nm Ag, a second anode sub-layer of 8 nm ITO and a third anode sub-layer of 10 nm ITO was cut to a size of 50 mm50 mm0.7 mm, ultrasonically washed with water for 60 minutes and then with isopropanol for 20 minutes. The liquid film was removed in a nitrogen stream, followed by plasma treatment, see Table 2, to prepare the anode layer. The plasma treatment was performed in an atmosphere comprising 97.6 vol.-% nitrogen and 2.4 vol.-% oxygen.

[0293] Then, a substantially covalent matrix compound and a compound of formula (1) were co-deposited in vacuum on the anode layer, to form a hole injection layer (HIL) having a thickness of 10 nm. The composition of the HIL can be seen in Table 2.

[0294] Then, the substantially covalent matrix compound was vacuum deposited on the HIL, to form a HTL having a thickness of 123 nm. The formula of the substantially covalent matrix compound in the HTL was identical to the substantially covalent matrix compound used in the HIL.

[0295] Then N-([1,1-biphenyl]-4-yl)-9,9-diphenyl-N-(4-(triphenylsilyl)phenyl)-9H-fluoren-2-amine (CAS 1613079-70-1) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.

[0296] Then 97 vol.-% H09 (Sun Fine Chemicals, Korea) as EML host and 3 vol. -% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant were deposited on the EBL, to form a blue-emitting first emission layer (EML) with a thickness of 20 nm.

[0297] Then a hole blocking layer was 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 EML.

[0298] Then the electron transporting layer having a thickness of 31 nm was formed on the hole blocking layer by depositing 50 wt.-% 4-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1-biphenyl]-4-carbonitrile and 50 wt.-% of LiQ.

[0299] Then Ag:Mg (90:10 vol.-%) was evaporated at a rate of 0.01 to 1 /s at 1.sup.7 mbar to form a cathode layer with a thickness of 13 nm on the electron transporting layer.

[0300] Then, compound of formula F2 was deposited on the cathode layer to form a capping layer with a thickness of 75 nm.

[0301] 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.

[0302] 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 an operating voltage U 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 0 V 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.

[0303] 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. 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.

[0304] To determine the voltage stability over time U(50h)-(1h), a current density of at 30 mA/cm.sup.2 was applied to the device. The operating voltage was measured after 1 hour and after 50 hours, followed by calculation of the voltage stability for the time period of 1 hour to 50 hours.

Technical Effect of the Invention

[0305] In order to investigate the usefulness of the inventive compounds, preferred materials were evaluated in view of their thermal properties.

TABLE-US-00002 TABLE 1 Properties of compounds of formula (1) and comparative examples 1 to 4: Name T.sub.dec [ C.] T.sub.dec-T.sub.subl [ C.] Comparative Cu [TFSI].sub.2 180 5-10 C. compound 1 Comparative Li [N(SO.sub.2C.sub.6F.sub.13).sub.2] Not compound 2 Sublimable Comparative Mg [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 >250 25 compound 3 Comparative Zn [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 >230 70 compound 4 A1 [00036] >404 C. >101 A2 [00037] >386 >97 A3 [00038] >360 >50 A4 [00039] >340 >50 A5 [00040] >362 >56 A6 [00041] >375 >55 A7 [00042] >361 >52 A8 [00043] >380 >64 A9 [00044] >460 >140 A10 [00045] >420 >100 A11 [00046] >390 >80 A12 [00047] >400 >110

[0306] In Table 1 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.

[0307] The decomposition temperature of Cu (TFSI).sub.2 is 180 C., see comparative example 1 in Table 1. The difference between decomposition and sublimation temperature is 10 C. A sublimation rate which is suitable for mass production cannot be achieved as a substantial amount of compound decomposes before it sublimes.

[0308] In contrast, Li[N(SO.sub.2C.sub.6F.sub.13).sub.2] is not sublimable, cf. comparative example 2 in Table 1.

[0309] Comparative example 3 comprises a magnesium complex. Comparative example 3 differs from comparative example 1 in the metal ion (Mg.sup.2+ instead of Cu.sup.2+) and the ligand (perfluorinated isopropyl groups instead of trifluoro methyl groups). The decomposition temperature is increased from 180 C. in comparative example 1 to >250 C. The difference between decomposition and sublimation temperature is 25 C. The yield after sublimation is 80%.

[0310] Comparative example 4 comprises a zinc complex. Comparative example 4 differs from comparative example 3 in the metal ion, namely Zn.sup.2+instead of Mg.sup.2+. The difference between decomposition and sublimation temperature is further improved to 70 C.

[0311] Compound A1 comprises a sodium complex. Compound A1 differs from comparative compound 2 in the metal ion (Na.sup.+ instead of Li.sup.+) and in the ligand (perfluorinated isopropyl groups instead of perfluorinated propyl groups). Compound A1 differs from comparative examples 3 and 4 in the metal ion (Na.sup.+ instead of Mg.sup.2+ or Zn.sup.2+). As can be seen in Table 1, the decomposition temperature is substantially increased. Additionally, the difference between decomposition and sublimation temperature is increased.

[0312] Compounds A2 to A4 differ from compound A1 in the ligands. As can be seen in Table 1, the thermal properties are improved over comparative compounds 1 to 4.

[0313] Compounds A5 to A8 differ from compounds A1 to A4 in the metal ion. As can be seen in Table 1, the thermal properties are improved over comparative compounds 1 to 4.

[0314] Compounds A9 to Al2 differ from compounds A1 to A8 in the ligand and metal ion. As can be seen in Table 1, the thermal properties are improved over comparative compounds 1 to 4.

[0315] It is apparent that the inventive compounds show a higher decomposition temperature and/or a much larger gap between decay and sublimation temperature.

[0316] As materials for organic electronics are typically purified by sublimation, a high decomposition temperature, a large offset between decomposition and sublimation temperature and/or a high yield after sublimation are highly desirable. Thereby, a high sublimation rate may be achievable.

[0317] In Table 2, OLED performance data for examples 1 to 21 and comparative examples 1 to 3 are shown.

[0318] The performance of a semiconductor layer comprising a compound of formula (1) and a substantially covalent matrix compound of formula F2 or F1 was evaluated, see Table 2.

[0319] The HOMO of compound of formula F2 is 4.69 eV and the HOMO of compound of formula F1 is 4.81 eV, when calculated using TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany) by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase.

[0320] Due to the poor thermal properties of comparative compounds 1 and 2, OLED performance of compounds of formula (1) was assessed against comparative compounds 3 and 4.

TABLE-US-00003 TABLE 2 Performance of organic electronic devices comprising compound of formula (1) Percentage of Matrix Voltage LT at U(50 h)- compound of compound U at 10 30 (1 h) at 30 Compound of formula (1) (cf. mA/cm.sup.2 mA/cm.sup.2 mA/cm.sup.2 formula (1) (vol.-%) above) [V] [h] [V] Comparative Mg 6 F2 3.88 32 0.19 example 1 [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 Comparative Zn 6 F2 3.85 10 0.29 example 2 [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 Example 1 A1 6 F2 3.85 74 0.03 Example 2 A2 6 F2 3.84 67 0.01 Example 3 A3 6 F2 3.82 79 0.02 Example 4 A4 6 F2 3.83 82 0.01 Example 5 A5 6 F2 3.83 56 0.05 Example 6 A6 6 F2 3.85 53 0.06 Example 7 A7 6 F2 3.84 63 0.04 Example 8 A8 6 F2 3.84 61 0.06 Example 17 A9 4 F2 3.90 62 0.013 Example 18 A10 4 F2 3.78 92 0.026 Example 19 A11 4 F2 3.91 70 0.024 Example 20 A11 6 F2 3.89 74 0.018 Example 21 A12 4 F2 3.85 86 0.105 Comparative Mg 6 F1 4.21 22 0.31 example 3 [N(SO.sub.2.sup.iC.sub.3F.sub.7).sub.2].sub.2 Example 9 A1 6 F1 3.71 135 0.03 Example 10 A2 6 F1 3.68 147 0.02 Example 11 A3 6 F1 3.69 128 0.03 Example 12 A4 6 F1 3.67 135 0.02 Example 13 A5 6 F1 3.73 116 0.04 Example 14 A6 6 F1 3.75 123 0.03 Example 15 A7 6 F1 3.78 115 0.02 Example 16 A8 6 F1 3.76 125 0.03

[0321] As can be seen in Table 2, OLED performance of a semiconductor layer comprising a compound of formula (1) may show reduced operating voltage U and/or improved lifetime and/or improved voltage stability over time compared to comparative compounds.

[0322] 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.