Compound of Formula (I), a Semiconductor Material Comprising at Least One Compound of Formula (I), a Semiconductor Layer Comprising at Least One Compound of Formula (I) and an Electronic Device Comprising at Least One Compound of Formula (I)
20230242562 · 2023-08-03
Inventors
- Vladimir Uvarov (Dresden, DE)
- Max Peter Nüllen (Dresden, DE)
- Ulrich Heggemann (Dresden, DE)
- Markus Hummert (Dresden, DE)
- Steffen Willmann (Dresden, DE)
- Regina Luschtinetz (Dresden, DE)
Cpc classification
H10K85/331
ELECTRICITY
H10K85/371
ELECTRICITY
C07D209/86
CHEMISTRY; METALLURGY
International classification
Abstract
The present invention relates to a compound of Formula (I) wherein M is a metal; L is a charge-neutral ligand, which coordinates to the metal M; n is an integer selected from 1 to 4, which corresponds to the oxidation number of M; m is an integer selected from 0 to 2; R1, R2 and R3 are substituents, wherein at least one R1, R2 and/or R3 is selected from a substituted C6 to C24 aryl group, wherein at least one substituent of the substituted C6 to C24 aryl group is selected from CN or partially or fully fluorinated C1 to C12 alkyl. The present invention also relates to a semiconductor material comprising at least one compound of formula (I), an semiconductor layer comprising at least one compound of formula (I) and an electronic device comprising at least one compound of formula (I). Exemplary compounds are e.g. metal complexes of 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile, such as e.g. Fe, Al and Cu complexes thereof.
##STR00001##
Claims
1. A compound represented by Formula I: ##STR00058## wherein M is a metal; L is a charge-neutral ligand, which coordinates to the metal M; n is an integer selected from 1 to 4, which corresponds to the oxidation number of M; m is an integer selected from 0 to 2; R.sup.1, R.sup.2 and R.sup.3 are independently selected from H, D, substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.1 to C.sub.12 alkoxy, substituted or unsubstituted C.sub.6 to C.sub.24 aryl, and substituted or unsubstituted C.sub.2 to C.sub.24 heteroaryl group, wherein at least one substituent is selected from halogen, F, Cl, CN, substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, partially or fully fluorinated C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.1 to C.sub.12 alkoxy, partially or fully fluorinated C.sub.1 to C.sub.12 alkoxy, substituted or unsubstituted C.sub.6 to C.sub.18 aryl, and substituted or unsubstituted C.sub.2 to C.sub.18 heteroaryl, wherein the substituents of the substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, substituted or unsubstituted C.sub.1 to C.sub.12 alkoxy, substituted or unsubstituted C.sub.6 to C.sub.18 aryl, and substituted or unsubstituted C.sub.2 to C.sub.18 heteroaryl are selected from halogen, F, Cl, CN, C.sub.1 to C.sub.6 alkyl, CF.sub.3, OCH.sub.3, OCF.sub.3; wherein at least one R.sup.1, R.sup.2 and/or R.sup.3 is selected from a substituted C.sub.6 to C.sub.24 aryl group, wherein at least one substituent of the substituted C.sub.6 to C.sub.24 aryl group is selected from CN or partially or fully fluorinated C.sub.1 to C.sub.12 alkyl.
2. The compound according to claim 1, wherein the metal M is selected from alkali, alkaline earth, transition, rare earth metal or group III to V metal, Li(I), Na(I), K(I), Cs(I), Mg(II), Ca(II), Sr(II), Ba(II), Sc(III), Y(III), Ti(IV), V(III-V), Cr(III-VI), Mn(II), Mn(III), Fe(II), Fe(III), Co(II), Co(III), Ni(II), Cu(I), Cu(II), Zn(II), Ag(I), Au(I), Au(III), Al(III), Ga(III), In(III), Sn(II), Sn(IV), or Pb(II).
3. The compound according to claim 1, wherein L is selected from the group comprising H.sub.2O, C.sub.2 to C.sub.40 mono- or multi-dentate ethers and C.sub.2 to C.sub.40 thioethers, C.sub.2 to C.sub.40 amines, C.sub.2 to C.sub.40 phosphine, C.sub.2 to C.sub.20 alkyl nitrile or C.sub.2 to C.sub.40 aryl nitrile, or a compound according to Formula (II); ##STR00059## wherein R.sup.6 and R.sup.7 are independently selected from C.sub.1 to C.sub.20 alkyl, C.sub.1 to C.sub.20 heteroalkyl, C.sub.6 to C.sub.20 aryl, heteroaryl with 5 to 20 ring-forming atoms, halogenated or perhalogenated C.sub.1 to C.sub.20 alkyl, halogenated or perhalogenated C.sub.1 to C.sub.20 heteroalkyl, halogenated or perhalogenated C.sub.6 to C.sub.20 aryl, halogenated or perhalogenated heteroaryl with 5 to 20 ring-forming atoms, at least one R.sup.6 and R.sup.7 are bridged and form a 5 to 20 member ring, two R.sup.6 or two R.sup.7 are bridged and form a 5 to 40 member ring or form a 5 to 40 member ring comprising an unsubstituted or C.sub.1 to C.sub.12 substituted phenanthroline.
4. The compound according to claim 1, wherein n is an integer selected from 1, 2 and 3, which corresponds to the oxidation number of M.
5. The compound according to claim 1, wherein m is an integer selected from 0 or 1.
6. The compound according to claim 1, wherein at least one R.sup.1, R.sup.2 or R.sup.3 is an aryl group selected from a group comprising a substituted C.sub.6 to C.sub.24 aryl group or a substituted phenyl group, wherein the substituted aryl group comprises at least one or two CN substituents, the substituted aryl group comprises at least one or two CN substituents and one to three CF.sub.3 substituents, the substituted aryl group comprises one CN substituent and one to four CF.sub.3 substituents, the substituted aryl group comprises at least one CN or CF.sub.3 substituents and at least one F substituents, or the substituted aryl group comprises at least one CN and CF.sub.3 substituents and at least one F substituents.
7. The compound according to claim 1, wherein R.sup.1 or R.sup.2 is selected from a substituted C.sub.6 to C.sub.24 aryl group, wherein at least one substituent of the substituted C.sub.6 to C.sub.24 aryl group is selected from CN, partially or fully fluorinated C.sub.1 to C.sub.12 alkyl, or CF.sub.3; R.sup.3 is selected from substituted or unsubstituted C.sub.1 to C.sub.12 alkyl, wherein the substituents of the substituted C.sub.1 to C.sub.12 alkyl of R.sup.2 and R.sup.3 are selected from halogen, F, Cl, CN, substituted or unsubstituted C.sub.1 to C.sub.12 alkoxy, partially or fully fluorinated C.sub.1 to C.sub.12 alkoxy, substituted or unsubstituted C.sub.6 to C.sub.18 aryl, and substituted or unsubstituted C.sub.2 to C.sub.18 heteroaryl.
8. The compound according to claim 1, wherein the at least one substituted C.sub.6 to C.sub.24 aryl group of R.sup.1, R.sup.2 or R.sup.3 is selected from the following Formulas D1 to D19: ##STR00060## ##STR00061## ##STR00062## wherein the “*” denotes the binding position.
9. The compound according to claim 1, wherein the compound represented by Formula I is selected from the following Formulas E1 to E38: ##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067## ##STR00068## ##STR00069## ##STR00070## ##STR00071##
10. The compound according to claim 1, wherein the compound represented by Formula I is selected from the following Formulas G1 to G76: ##STR00072## ##STR00073## ##STR00074## ##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088##
11. An organic semiconductor material comprising at least one compound of Formula I according to claim 1.
12. An organic semiconductor material according to claim 11, wherein the material comprises in addition at least one organic aromatic matrix compound.
13. An organic semiconductor layer comprising a compound of Formula I according to claim 1.
14. An organic electronic device comprising an organic semiconductor material according to claim 11.
15. The organic electronic device according to claim 14, wherein the electronic device is a light emitting device, thin film transistor, a battery, a display device, a photovoltaic cell, the organic electronic device is part of a display device, or the organic electronic device is part of a lighting device.
Description
DESCRIPTION OF THE DRAWINGS
[0382] 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.
[0383] 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 embodiment 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.
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[0388]
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[0390]
[0391]
[0392]
[0393]
[0394]
[0395]
[0396] 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 (I) (130), a photoactive layer (151) and a cathode electrode 190 are formed, exactly in that order or exactly the other way around.
[0397] In the description above the method of manufacture an OLED 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 (I) (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.
[0398] The semiconductor layer comprising a compound of Formula (I) (130) can be a hole injection layer.
[0399] While not shown in
[0400] 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.
Preparation of Compound of Formula (I)
[0401] Compounds of Formula (I) may be prepared as described below:
Synthesis of 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile
[0402] ##STR00053##
To 4.68 g (195 mmol) of sodium hydride in a flame-dried Schlenk flask 200 mL dry glyme were added via a double-needle cannula. The suspension was cooled with an ice-batch and 20 mL (195 mmol) acetylacetone were added drop wise during 30 min. After 10 min 12.28 mL (97.4 mmol) of perfluorobenzonitrile were added with a syringe during 60 min. The mixture was stirred at room temperature overnight and then the added to 0.5 L water and acidified with conc. hydrochloric acid to a pH of 1. The product was extracted with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulphate, filtered and the solvent removed under reduced pressure. The crude product was slurry washed in methanol, filtered off and washed with methanol and hexane.
Yield: 17,8 g (67%)
Synthesis of Compound G10
[0403] ##STR00054##
7.5 g (27.5 mmol) 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile were dissolved in 20 mL THF. A solution of 1.48 g (9.15 mmol) iron trichoride in 10 ml water waster added and 0.77 g (9.15 mmol) sodium bicarbonate was added portion wise. Additional 100 ml water were added and the mixture was stirred overnight. After adding 50 ml methanol the precipitate was filtered off and washed with a small amount of water and dried in vacuum overnight.
Yield: 6.9 g (87%)
Synthesis of Compound G11
[0404] ##STR00055##
3 g (10.9 mmol) 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile were dissolved in a mixture of MeOH/H2O (15 ml/6 ml). 0.92 g (10.9 mmol) of sodium bicarbonate was added portion wise followed by a solution of 0.49 g (3.66 mmol) of aluminium trichloride in 2 ml of water. Formed solid was filtered-off, rinsed with water and dried in in high vacuum overnight.
Yield: 2.8 g (92%)
Synthesis of Compound G12
[0405] ##STR00056##
2.73 g (10 mmol) 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile were dissolved in 50 mL of methanol/ethyl acetate (2:1 ratio). 1.0 g (5 mmol) copper(II)acetate-monohydrate were dissolved in 50 ml water/acetonitrile(1:1) and the solution of 4-(2,4-dioxopent-3-yl)-2,3,5,6-tetrafluorobenzonitrile was added. The suspension was stirred for 3 days at room temperature, filtered off and washed with water/acetonitrile. The product was dried overnight in vacuum.
Yield: 2.71 g (90%)
[0406] Further compounds according to invention may be prepared by the methods described above or by methods known in the art.
Sublimation Temperature
[0407] 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. 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.
Rate Onset Temperature
[0408] 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 Angstrom 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.
[0409] 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.
[0410] 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.
General Procedure for Fabrication of Electronic Devices Comprising a Semiconductor Layer Comprising a Metal Complex and a Matrix Compound
[0411] For inventive examples 1 to 15 and comparative examples 1 to 9 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 mm×50 mm×0.7 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 to prepare the anode layer. The plasma treatment was performed in an atmosphere comprising 97.6 vol.-% nitrogen and 2.4 vol.-% oxygen at 75 W for 35 seconds.
[0412] Then, the matrix compound and the metal complex 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 hole injection layer can be seen in Table 2. In inventive examples 1 to 15, a compound of Formula (I) is used.
[0413] Matrix compound HTM-1 has the following Formula:
##STR00057##
[0414] Then, the matrix compound was vacuum deposited on the HIL, to form an HTL having a thickness of 123 nm. The matrix compound in the HTL is selected the same as the matrix compound in the HIL.
[0415] Then N-([1,1′-biphenyl]-4-yl)-9,9-diphenyl-N-(4-(triphenylsilyl)phenyl)-9H-fluoren-2-amine was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
[0416] Then 97 vol.-% H09 as EML host (Sun Fine Chemicals, Korea) and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue emitter dopant was deposited on the EBL, to form a blue-emitting first emission layer (EML) with a thickness of 20 nm.
[0417] 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.
[0418] 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.
[0419] Then Ag:Mg (90:10 vol.-%) was evaporated at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar to form a cathode layer with a thickness of 13 nm on the electron transporting layer.
[0420] Then, HTM-1 was deposited on the cathode layer to form a capping layer with a thickness of 75 nm.
[0421] 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.
[0422] 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 0.1 V 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.
[0423] 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.
[0424] 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.
[0425] To determine the voltage stability over time U(100 h)-(1 h), 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 100 hours, followed by calculation of the voltage stability for the time period of 1 hour to 100 hours.
Technical Effect Table 1
[0426] In Table 1 are shown physical properties of compounds of Formula (I), see inventive compounds 1 to 7, and of comparative compounds 1 to 6.
[0427] As can be seen in Table 1, the sublimation temperature of comparative compounds 1 to 6 can either not be measured due to decomposition of the compound or the sublimation temperature is in the range of 95 to 120° C.
[0428] The rate onset temperature of comparative compounds 1 to 6 is the range of <100 to 101° C., see Table 1.
[0429] Inventive compound 1 is a Cu(II) complex of Formula (I). Inventive compound 1 differs from comparative compound 1 in the substituted aryl substituent. The sublimation temperature is increased from 110-120° C. in comparative compound 1 to 245° C. in inventive compound 1. The rate onset temperature is also improved to 187° C.
[0430] Inventive compound 2 is a Fe(III) complex of Formula (I). The sublimation temperature is further improved 262° C. The rate onset temperature is further improved to 196° C.
[0431] Inventive compound 3 is a Al(III) complex of Formula (I). The sublimation temperature is further improved 277° C. The rate onset temperature is improved to 194° C.
[0432] Inventive compound 4 is a Fe(III) complex of Formula (I) comprising four CF.sub.3 substituents. The sublimation temperature is 224° C. The rate onset temperature is very high at 197° C.
[0433] Inventive compounds 5 to 7 are Cu(II) complexes of Formula (I) comprising at least two substituents independently selected from CF.sub.3 and/or CN. The sublimation temperature and rate onset temperature are improved compared to comparative compounds 1 to 6.
[0434] In summary, the thermal stability, sublimation temperature and/or rate onset temperature of compounds of Formula (I) is substantially improved over the state of the art.
OLED Performance Data Table 2
[0435] In Table 2 are shown OLED performance data for an increase in operating voltage over time U(100 h)-U(1 h) and lifetime LT97 for inventive examples 1 to 15 and comparative examples 1 to 3.
[0436] In comparative example 1, the semiconductor layer comprises 3 vol.-% metal complex La(fod).sub.3. The increase in operating voltage over time is 1.07 V. The lifetime is 30 h.
[0437] In inventive example 1, the semiconductor layer comprises 3 vol.-% G12. The increase in operating voltage over time is reduced to 0.3 V. The lifetime is improved to 85 h.
[0438] In inventive example 2, the semiconductor layer comprises 3 vol.-% G10. The increase in operating voltage over time is 0.33 V. The lifetime is further improved to 119 h.
[0439] In inventive example 3, the semiconductor layer comprises 3 vol.-% G11. The increase in operating voltage over time is 0.6 V. The lifetime is further improved to 178 h.
[0440] In comparative example 2, the semiconductor layer comprises 5 vol.-% metal complex La(fod).sub.3. The increase in operating voltage over time is 0.85 V. The lifetime is 24 h.
[0441] In inventive example 4, the semiconductor layer comprises 5 vol.-% G12. The increase in operating voltage over time is 0.42 V. The lifetime is further improved to 180 h.
[0442] In inventive example 5, the semiconductor layer comprises 5 vol.-% G10. The increase in operating voltage over time is 0.23 V. The lifetime is high at 96 h.
[0443] In inventive example 6, the semiconductor layer comprises 5 vol.-% G11. The increase in operating voltage over time is 0.65 V. The lifetime is still high at 95 h.
[0444] In comparative example 3, the semiconductor layer comprises 10 vol.-% metal complex La(fod).sub.3. The increase in operating voltage over time is 0.89 V. The lifetime is 15 h.
[0445] In inventive example 7, the semiconductor layer comprises 10 vol.-% G12. The increase in operating voltage over time is 0.6 V. The lifetime is high at 172 h.
[0446] In inventive example 8, the semiconductor layer comprises 10 vol.-% G10. The increase in operating voltage over time is 0.28 V. The lifetime is high at 109 h.
[0447] In inventive example 9, the semiconductor layer comprises 10 vol.-% G11. The increase in operating voltage over time is 0.68 V. The lifetime is further improved to 250 h.
[0448] In inventive examples 10 and 11, the semiconductor layer comprises a Fe(III) complex of Formula (I) comprising four CF.sub.3 substituents at two different percentages. The stability of operating voltage over time and lifetime are improved compared to comparative examples 1 to 3.
[0449] In inventive examples 12 to 15, the semiconductor layer comprises a Cu(II) complex of Formula (I) comprising at least two substituents selected from CF.sub.3 and/or CN. The stability of operating voltage over time and lifetime are improved compared to comparative examples 1 to 3.
[0450] In summary, in a semiconductor layer comprising a compound of Formula (I) the increase in operating voltage is substantially reduced and the lifetime substantially increased compared to the state of the art.
[0451] A reduced increase in operating voltage over time is an indication for improved stability of the electronic device. An increase in lifetime is important for improved stability of the electronic device.
TABLE-US-00001 TABLE 1 Properties of comparative compounds 1 to 6 and compounds of Formula (I) Sublimation Rate onset temperature Tsubl, temperature T.sub.RO, Example Compound [° C.] [° C.] Comparative compound 1 Cu(acac)2 110-120 <100 Comparative compound 2 Cu(tfac)2 95-100 <100 Comparative compound 3 Bi(tfac)3 decomposition <100 Comparative compound 4 Bi(hfac)3 decomposition <100 Comparative compound 5 Bi(fod)3 120 <100 Comparative compound 6 La(fod).sub.3 170 101 Inventive compound 1 G12 245 187 Inventive compound 2 G10 262 196 Inventive compound 3 G11 277 194 Inventive compound 4 G58 224 197 Inventive compound 5 G60 245 170 Inventive compound 6 G72 249 181 Inventive compound 7 G73 277 191
TABLE-US-00002 TABLE 2 Performance of an electroluminescent device comprising a metal complex Percentage metal Percentage matrix U(100 h)- LT97 complex in semi- compound in semi- U(1 h) RT Metal conductor layer Matrix conductor layer (30 mA/cm.sup.2) (30 mA/cm.sup.2) complex [vol.-%] compound [vol.-%] [V] [h] Comparative example 1 La(fod).sub.3 3 HTM-1 97 1.07 30 Inventive example 1 G12 3 HTM-1 97 0.3 85 Inventive example 2 G10 3 HTM-1 97 0.33 119 Inventive example 3 G11 3 HTM-1 97 0.6 178 Comparative example 2 La(fod).sub.3 5 HTM-1 95 0.85 24 Inventive example 4 G12 5 HTM-1 95 0.42 180 Inventive example 5 G10 5 HTM-1 95 0.23 96 Inventive example 6 G11 5 HTM-1 95 0.65 95 Comparative example 3 La(fod).sub.3 10 HTM-1 90 0.89 15 Inventive example 7 G12 10 HTM-1 90 0.6 172 Inventive example 8 G10 10 HTM-1 90 0.28 109 Inventive example 9 G11 10 HTM-1 90 0.68 250 Inventive example 10 G58 6 HTM-1 94 0.71 84 Inventive example 11 G58 10 HTM-1 90 0.73 87 Inventive example 12 G60 18 HTM-1 82 0.77 57 Inventive example 13 G72 5 HTM-1 95 0.29 106 Inventive example 14 G72 10 HTM-1 90 0.08 87 Inventive example 15 G73 10 HTM-1 90 0.48 87
[0452] 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.