Organic electronic device comprising an inverse coordination complex and a method for preparing the same
11696493 · 2023-07-04
Assignee
Inventors
Cpc classification
H10K85/381
ELECTRICITY
International classification
Abstract
The present invention relates to an organic electronic device comprising at least one inverse coordination complex, the N inverse coordination complex comprising: (i) a core consisting of one atom or of a plurality of atoms forming together a covalent cluster; (ii) a first coordination sphere consisting of at least four electropositive atoms having each individually an electronegativity according to Allen of less than 2,4; and (iii) a second coordination sphere comprising a plurality of ligands; wherein the first coordination sphere is closer to the core than the second coordination sphere; and all atoms of the core have a higher electronegativity according to Allen than any of the electropositive atoms of the first coordination sphere and a method for preparing the same.
Claims
1. An organic electronic device comprising at least one inverse coordination complex, the inverse coordination complex comprising: (i) a core consisting of one atom or of a plurality of atoms forming together a covalent cluster; (ii) a first coordination sphere consisting of at least four electropositive atoms having each individually an electronegativity according to Allen of less than 2.4; and (iii) a second coordination sphere comprising a plurality of ligands; wherein the first coordination sphere is closer to the core than the second coordination sphere; all atoms of the core have a higher electronegativity according to Allen than any of the electropositive atoms of the first coordination sphere; and at least one ligand of the second coordination sphere is covalently bound to at least two atoms of the first coordination sphere; wherein the organic electronic device comprises, between a first electrode and a second electrode, an organic semiconducting layer comprising the at least one inverse coordination complex, wherein the organic semiconducting layer is a charge injection layer, a charge transport layer, or a charge generation layer, and wherein the charge injection layer is a hole injection layer, the charge transport layer is a hole transport layer, and/or the charge generation layer is a hole generation layer.
2. The organic electronic device according to claim 1, wherein the electropositive atoms of the first coordination sphere are independently selected from atoms having an electronegativity according to Allen of less than 2.3.
3. The organic electronic device according to claim 1, wherein the electropositive atoms are independently selected from metal ions in the oxidation state (II).
4. The organic electronic device according to claim 1, wherein the core consists of one atom which is O in the oxidation state (-II).
5. The organic electronic device according to claim 1, wherein the first coordination sphere consists of four electropositive atoms having an electronegativity according to Allen of less than 2.4, respectively in the oxidation state (II), and the four electropositive atoms are tetrahedrally coordinated to the core.
6. The organic electronic device according to claim 1, wherein at least one ligand of the second coordination sphere is a bidentate anionic ligand formed by deprotonation of an alpha-gamma tautomerizable protic acid and bridging two electropositive atoms of the first coordination sphere.
7. The organic electronic device according to claim 6, wherein the at least one ligand is a carboxylate anion or is represented by the general formula (I) ##STR00017## wherein R.sup.1 and R.sup.2 are independently selected from the groups, consisting of C.sub.1 to C.sub.30 hydrocarbyl groups and C.sub.2 to C.sub.30 heterocyclic group, wherein R.sup.1 and/or R.sup.2 may optionally be substituted with at least one of CN, F, Cl, Br and I.
8. The organic electronic device according to claim 7, wherein the core consists of one chalcogen atom selected from O, S, Se and Te in the oxidation state (-II); the first oxidation sphere consists of four electropositive atoms which are four metal atoms in the oxidation state (II) and which are tetrahedrally coordinated to the core, and the second coordination sphere consists of six ligands having the general formula (I).
9. The organic electronic device according to claim 8, wherein each ligand of the second coordination sphere is coordinated to two different metal atoms of the first coordination sphere.
10. The organic electronic device according to claim 9, wherein the organic semiconducting layer further comprises at least one organic matrix compound.
11. The organic electronic device according to claim 1, wherein the organic electronic device is an electroluminescent device.
12. The organic electronic device according to claim 11, wherein the electroluminescent device is an organic light emitting diode.
13. A method for preparing an organic electronic device according to claim 1, the method comprising the steps of (a) evaporating the inverse coordination complex; and (b) depositing the inverse coordination complex on a solid support.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, of which:
(2)
(3)
(4)
(5)
EMBODIMENTS OF THE INVENTIVE DEVICE
(6) Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below, in order to explain the aspects of the present invention, by referring to the figures.
(7) Herein, when a first element is referred to as being formed or disposed “on” 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” a second element, no other elements are disposed there between.
(8)
(9) Instead of a single electron transport layer 160, optionally an electron transport layer stack (ETL) can be used.
(10)
(11) Referring to
(12)
(13) Referring to
(14) While not shown in
(15) 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.
Experimental Part
Preparation of Inventive Metal Complexes
(16) Exemplary Compound E2
(17) The Compound Has Been Prepared According to Scheme 1
(18) ##STR00011##
Step 1: Synthesis of 1,1,1-trifluoro-N-(perfluorophenyl)methanesulfonamide
(19) A 250 mL Schlenk flask was heated in vacuum and after cooling was purged with nitrogen. Perfluoroaniline was dissolved in 100 mL toluene and the solution was cooled to −80° C. A 1.7 M t-Butyllithium solution was added dropwise via syringe over 10 min. The reaction solution changed from clear to cloudy and was stirred for 1 h at −80° C. After that, the solution was allowed to warm to −60° C. and 1.1 eq of trifluoromethanesulfonic anhydride was added dropwise to the solution. Then the cooling bath was removed and the reaction mixture was allowed to warm slowly to ambient temperature and stirred overnight, whereby the color changed to light orange. Additionally, a white solid formed. The precipitated by-product lithium trifluoromethanesulfonate was filtered off by suction filtration over a sintered glass filter and washed with 2×30 mL toluene and 30 mL n-hexane. The orange filtrate was evaporated and dried in high vacuum forming crystals. The crude product was then purified by bulb-to-bulb distillation (135° C. @ 1.2×10.sup.−1 mbar) resulting in a crystalline colorless solid (main fraction).
(20) .sup.1H NMR [d.sup.6-DMSO, ppm] δ: 13.09 (s, 1H, N-H).
(21) .sup.13C{.sup.1H} NMR [d.sup.6-DMSO, ppm] δ: 116.75 (m, C.sub.i-C.sub.6F.sub.5), 120.74 (q, .sup.1J.sub.CF=325 Hz, CF.sub.3), 136.39, 138.35 (2 m, .sup.2J.sub.CF=247 Hz, m-C.sub.6F.sub.5), 137.08, 139.06 (2 m, .sup.2J.sub.CF=247 Hz, p-C.sub.6F.sub.5), 142.98, 144.93 (2 m, .sup.2J.sub.CF=247, Hz o-C.sub.6F.sub.5).
(22) .sup.19F NMR [d.sup.6-DMSO, ppm] δ: −77.45 (m, CF.sub.3), −148.12 (m, C.sub.6F.sub.5), −160.79 (m, p-C.sub.6F.sub.5), −164.51 (m, C.sub.6F.sub.5).
(23) ESI-MS: m/z-neg=314 (M-H).
(24) EI-MS: m/z=315 (M), 182 (M-SO.sub.2CF.sub.3), 69 (CF.sub.3).
(25) Step 2: Synthesis of bis((1,1,1-trifluoro-N-(perfluorophenyl)methyl)-sulfonamido)zinc
(26) A 100 mL Schlenk flask was heated in vacuum and after cooling was purged with nitrogen. 1,1,1-Trifluoro-N-(perfluorophenyl)methanesulfonarnide was dissolved in 10 mL toluene and 0.5 eq of diethylzinc in hexane was added dropwise to the solution via syringe at ambient temperature. During the addition a fog was forming and the reaction solution became jelly and cloudy. The solution was stirred for further 30 min at this temperature. After that, 30 mL n-hexane were added and a white precipitate formed, which was filtered over a sintered glass filter (pore 4) under inert atmosphere. The filter cake was twice washed with 15 mL n-hexane and dried in high vacuum at 100° C. for 2 h
(27) Yield: 660 mg (0.95 mmol, 60% based on 1,1,1-trifluoro-N-perfluorophenyl)methanesulfonamide) as a white solid.
(28) .sup.13C{.sup.1H} NMR [d.sup.6-DMSO, ppm] δ: 121.68 (q, .sup.1J.sub.CF=328 Hz, CF.sub.3), 123.56 (m, C.sub.i-C.sub.6F.sub.5), 133.98, 135.91 (2 m, .sup.2J.sub.CF=243 Hz, p-C.sub.6F.sub.5), 136.15, 138.13 (2 m, .sup.2J.sub.CF=249 Hz, m-C.sub.6F.sub.5), 142.33, 144.24 (2 m, .sup.2J.sub.CF=240, Hz o-C.sub.6F.sub.5).
(29) .sup.19F NMR [d.sup.6-DMSO, ppm] δ: −77.52 (m, CF.sub.3), −150.43 (m, C.sub.6F.sub.5), −166.77 (m, C.sub.6F.sub.5), −168.23 (m, p-C.sub.6F.sub.5).
(30) ESI-MS: m/z-neg=314 (M-Zn-L).
(31) EI-MS: m/z=692 (M), 559 (M-SO.sub.2CF.sub.3) 315 (C.sub.6F.sub.5NHSO.sub.2CF.sub.3), 182 (C.sub.6F.sub.5NH), 69 (CF.sub.3).
Exemplary Compound E.SUB.3
(32) 9.1 g E.sub.2 has been sublimed at the temperature 240° C. and pressure 10.sup.−3 Pa. yield 5.9 g (65%).
(33) The sublimed material formed colorless crystals. One crystal of an appropriate shape and size (0.094×0.052×0.043 mm.sup.3) has been closed under Ar atmosphere in a glass capillary and analyzed on Kappa Apex II diffractometer (Bruker-AXS, Karlsruhe, Germany) with monochromatic X-ray radiation from a source provided with molybdenum cathode (λ=71.073 pm). Overall 37362 reflexions were collected within the theta range 1.881 to 28.306°.
(34) The structure was resolved by direct method (SHELXS-97, Sheldrick, 2008) and refined with a full-matrix least-squares method (SHELXL-2014/7, Olex2 (Dolomanov, 2017).
(35) Further investigations showed that a complex having an oxygen dianion core tetrahedrally surrounded by four Zn dications bridged with six trifluoracetate bidentate anionic ligands is similarly active as a p-dopant as compound E.sub.3. This complex having composition C.sub.12F.sub.18O.sub.13Zn.sub.4 is obtainable by vacuum sublimation of a commercially available compound having CAS number 1299489-47-6 and according to XRD analysis of a monocrystal obtained by sublimation, it may form a trigonal crystal lattice belonging to the space group R-3c, with unit cell dimensions at the temperature 296 K a=23.376(6) Å, α=59.989(10)°; b=23.376(6) Å, β=59.989(10)°; c=23.376(6) Å; γ=59.989(10)°.
(36) In the solid crystalline phase, the number of molecules having the chemical formula C.sub.12F.sub.18O.sub.13Zn.sub.4 and comprised in the unit cell of the crystal lattice may be Z=12.
(37) In the solid crystalline phase, the unit cell volume at temperature 296 K may be 9030(7) Å.sup.3 and calculated density may be 2.109 g/cm.sup.3.
Device Experiments
Generic Procedures
(38) OLEDs with two emitting layers were prepared to demonstrate the technical benefit of an organic electronic device comprising a hole injection layer and/or a hole generating layer according to the present invention. As proof-of-concept, the tandem OLEDs comprised two blue emitting layers.
(39) A 15 Ω/cm.sup.2 glass substrate with 90 nm ITO (available from Corning Co.) was cut to a size of 150 mm×150 mm×0.7 mm, ultrasonically cleaned with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and cleaned again with UV ozone for 30 minutes, to prepare a first electrode.
(40) The organic layers are deposited sequentially on the ITO layer at 10.sup.−5 Pa, see Table 1 and 2 for compositions and layer thicknesses. In the Tables 1 to 3, c refers to the concentration, and d refers to the layer thickness.
(41) Then, the cathode electrode layer is formed by evaporating aluminum at ultra-high vacuum of 10.sup.−7 mbar and deposing the aluminum layer directly on the organic semiconductor layer. A thermal single co-evaporation of one or several metals is performed with a rate of 0, 1 to 10 nm/s (0.01 to 1 Å/s) in order to generate a homogeneous cathode electrode with a thickness of 5 to 1000 nm. The thickness of the cathode electrode layer is 100 nm.
(42) The device is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which comprises a getter material for further protection.
(43) Current voltage measurements are performed at the temperature 20° C. using a Keithley 2400 source meter, and recorded in V.
Experimental Results
Materials Used in Device Experiments
(44) The formulae of the supporting materials mentioned below are as follows:
(45) F1 is
(46) ##STR00012##
(47) biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine, CAS 1242056-42-3;
(48) F2 is
(49) ##STR00013##
(3-(dibenzo[c,h]acridin-7-yl)phenyl)diphenylphosphine oxide, CAS 1440545-22-1;
(50) F3 is
(51) ##STR00014##
2,4-diphenyl-6-(3′-(triphenylen-2-yl)-[1,1′-biphenyl]-3-yl)-1,3,5-triazine, CAS 1638271-85-8;
(52) F4 is
(53) ##STR00015##
1,3-bis(9-phenyl-1,10-phenanthrolin-2-yl)benzene, CAS 721969-94-4;
(54) PD-2 is
(55) ##STR00016##
4,4′,4″-((1E,′E,1″E)-cyclopropane-1,2,3-triylidenetris (cyanomethanylylidene))tris(2,3,5,6-tetrafluorobenzonitrile), CAS 1224447-88-4.
(56) LiQ is lithium 8-hydroxyquinolinolate; ZnPc is zinc phtalocyanine;
(57) ABH-113 is an emitter host and NUBD-370 and DB-200 are blue fluorescent emitter dopants, all commercially available from SFC, Korea.
(58) ITO is indium tin oxide.
Standard Procedures
(59) Voltage Stability
(60) OLEDs are driven by constant current circuits. Those can supply a constant current over a given voltage range. The wider the voltage range, the wider the power losses of such devices. Hence, the change of driving voltage upon driving needs to be minimized.
(61) The driving voltage of an OLED is temperature dependent. Therefore, voltage stability needs to be judged in thermal equilibrium. Thermal equilibrium is reached after one hour of driving.
(62) Voltage stability is measured by taking the difference of the voltage after 50 hours and after 1 hour driving at a constant current density. Here, a current density of 30 mA/cm.sup.2 is used. Measurements are done at room temperature.
dU[V]=U(50 h, 30 mA/cm.sup.2)−U(1 h, 30 mA/cm.sup.2)
Example 1
(63) Use of an inverse coordination complex as a neat hole injection layer in a blue OLED
(64) Table 1a schematically describes the model device.
(65) TABLE-US-00002 TABLE 1a c d Material [wt %] [nm] ITO 100 90 B2 or E3 100 3* F1 100 120 ABH113:NUBD370 97:3 20 F2:LIQ 50:50 36 Al 100 100 *E3 has been tested also as a layer only 1 nm thin.
(66) The results are given in Table 1b
(67) TABLE-US-00003 TABLE 1b U* EQE* U(50 h) − U(1 h)** [V] [%] CIE-y* [V] 3 nm B2 5.28 6.6 0.090 0.275 (reference) 3 nm E3 5.38 5.7 0.094 0.246 1 nm E3 5.11 5.4 0.096 0.040 *j = 15 mA/cm.sup.2 **j = 30 mA/cm.sup.2
(68) This example shows that inverse coordination complexes are useful as a neat HIL comprised in an OLED.
Example 2
(69) Use of an inverse coordination complex as a p-dopant a hole injection layer comprised in a blue OLED
(70) Table 2a schematically describes the model device.
(71) TABLE-US-00004 TABLE 2a c d Material [wt %] [nm] ITO 100 90 F1:p-dopant 92:8 10 (mol %#) F1 100 120 ABH113:NUBD370 3 20 F2:LiQ 50 36 Al 100 100 #based on molar amount of metal atoms
(72) The results are given Table 2b
(73) TABLE-US-00005 TABLE 2b U* EQE* U(50 h) − U(1 h)** [V] [%] CIE-y* [V] B2 8.06 7.1 0.095 0.639 (reference) E3 5.15 5.7 0.094 −0.015 *j = 15 mA/cm.sup.2 **j = 30 mA/cm.sup.2
(74) This example shows that inverse coordination complexes are us p-dopants for a HIL comprising a hole transport matrix.
(75) Blue OLED comprising B2 coordination complex as a p-dopant in a neat hole injection layer combined with a p-doped hole injection layer.
Example 3
(76) Blue tandem OLED comprising an inverse coordination complex as a neat hole generation layer
(77) Table 3a schematically describes the model device.
(78) TABLE-US-00006 TABLE 3a c d Material [wt %] [nm] ITO 100 90 F1:PD-2 92:8 10 F1 100 145 ABH113:BD200 97:3 20 F3 100 26 F4:Li 99:1 10 ZnPc 100 2 p-dopant 100 1 F1 100 30 ABH113:BD200 97:3 20 F3 100 26 F4:Li 99:1 10 Al 100 100
(79) The results are given in Table 3b
(80) TABLE-US-00007 TABLE 3b U* EQE* [V] [%] CIE-y* 1 nm B2 10.65 6.3 0.066 (reference) 1 nm E3 7.52 13.5 0.083 *j = 10 mA/cm.sup.2 **j = 30 mA/cm.sup.2
(81) The results show that inverse coordination complexes might be suitable as a neat CGL.
Example 4
(82) Blue tandem OLED comprising an inverse coordination complex as a p-dopant in a hole generation layer
(83) Table 4a schematically describes the model device.
(84) TABLE-US-00008 TABLE 4a c d Material [wt %] [nm] ITO 100 90 F1:PD-2 92:8 10 F1 100 145 ABH113:BD200 97:3 20 F3 100 25 F4:Li 99:1 10 ZnPc 100 2 F1:p-dopant 84:16 10 (mol %)# F1 100 30 ABH113:BD200 97:3 20 F3 100 26 F4:Li 99:1 10 Al 100 100 #based on molar amount of metal atoms
(85) The results are given in Table 4b
(86) TABLE-US-00009 TABLE 4b U* EQE* U(50 h) − U(1 h)** [V] [%] CIE-y* [V] B2 8.98 13.4 0.082 (reference) E3 7.75 14.2 0.087 0.094 *j = 10 mA/cm.sup.2 **j = 30 mA/cm.sup.2
(87) The results demonstrate that inverse metal complexes may be useful also in this embodiment of a tandem OLED.
(88) From the foregoing detailed description and examples, it will be evident that modifications and variations can be made to the compositions and methods of the invention without departing from the spirit and scope of the invention. Therefore, it is intended that all modifications made to the invention without departing from the spirit and scope of the invention come within the scope of the appended claims.