Organic Compound of Formula (I) for Use in Organic Electronic Devices, an Organic Electronic Device Comprising a Compound of Formula (I) and a Display Device Comprising the Organic Electronic Device

Abstract

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

Claims

1. A compound of formula (I) ##STR00575## whereby A.sup.1 is selected from formula (II) ##STR00576## X.sup.1 is selected from CR.sup.1; X.sup.2 is selected from CR.sup.2 or N; X.sup.3 is selected from CR.sup.3 or N; X.sup.4 is selected from CR.sup.4 or N; X.sup.5 is selected from CR.sup.5 or N; R.sup.1 is selected from D or H, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 (if present) are independently selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F, D or H, whereby when any of R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is present, then the corresponding X.sup.2, X.sup.3, X.sup.4 and X.sup.5 is not N; with the proviso that either at least one R.sup.2 to R.sup.5 is selected from selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F; or at least one X.sup.2 to X.sup.5 is N; A.sup.2 and A.sup.3 are independently selected from formula (III) ##STR00577## wherein Ar is independently selected from 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 on Ar are independently selected from CN, partially or perfluorinated C.sub.1 to C.sub.6 alkyl, halogen, Cl, F, D; and R′ is selected from Ar, substituted or unsubstituted C.sub.6 to C.sub.18 aryl or C.sub.3 to C.sub.18 heteroaryl, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, F or CN; and wherein the asterix “*” denotes the binding position.

2. The compound of claim 1, selected of the formula (IV) ##STR00578## whereby B.sup.1 is selected from formula (V) ##STR00579## B.sup.3 and B.sup.5 are Ar and B.sup.2, B.sup.4 and B.sup.6 are R′.

3. The compound of claim 1 whereby formula (II) does not include the following moieties: ##STR00580##

4. The compound of claim 1 whereby formula (III) does not include the following moieties: ##STR00581##

5. The compound of claim 1, whereby A.sup.1 differs from A.sup.2 and/or A.sup.3.

6. The compound of claim 1, whereby X.sup.3 is selected from N or CR.sup.3, wherein R.sup.3 is selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl.

7. The compound of claim 1, whereby one of R.sup.2 and R.sup.3 is selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl and at least one R.sup.2 to R.sup.5 is independently selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F.

8. The compound of claim 1, whereby R.sup.5 is D or H.

9. The compound of claim 1, whereby at least two out of R.sup.2 to R.sup.5 are independently selected from halogen, Cl, F.

10. An organic electronic device comprising an anode layer, a cathode layer and at least one organic semiconductor layer, wherein the at least one organic semiconductor layer is arranged between the anode layer and the cathode layer; and wherein the at least one organic semiconductor layer comprises a compound of claim 1.

11. The organic electronic device of claim 10, whereby the organic semiconductor layer comprises a composition comprising a compound of formula (IV) and at least one compound of formula (IVa) to (IVd) ##STR00582##

12. The organic electronic device of claim 10, whereby the organic electronic device comprises at least one photoactive layer and the at least one of the at least one organic semiconductor layers is arranged between the anode layer and the at least one photoactive layer.

13. The organic electronic device of claim 10, whereby the organic electronic device comprises at least two photoactive layers, wherein at least one of the at least one organic semiconductor layers is arranged between the first and the second photoactive layer.

14. The organic electronic device of claim 10, whereby the electronic organic device is an electroluminescent device.

15. A display device comprising an organic electronic device according to claim 10.

Description

DESCRIPTION OF THE DRAWINGS

[0262] 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.

[0263] 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.

[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 OLED, according to an exemplary embodiment of the present invention.

[0267] Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

[0268] 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.

[0269] FIG. 1 is a schematic sectional view of an organic electronic device 100, according to an exemplary embodiment of the present invention. The organic electronic device 100 includes a substrate 110, an anode layer 120 and a hole injection layer (HIL) (130) which may comprise a compound of formula (I). The HIL 130 is disposed on the anode layer 120. Onto the HIL 130, a photoactive layer (PAL) 170 and a cathode layer 190 are disposed.

[0270] 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 and a hole injection layer (HIL) 130 which may comprise a compound of formula (I). The HIL 130 is disposed on the anode layer 120. Onto the HIL 130, a hole transport layer (HTL) 140, an emission layer (EML) 150, an electron transport layer (ETL) 160, an electron injection layer (EIL) 180 and a cathode layer 190 are disposed. Instead of a single electron transport layer 160, optionally an electron transport layer stack (ETL) can be used.

[0271] FIG. 3 is a schematic sectional view of an OLED 100, according to another exemplary embodiment of the present invention. FIG. 3 differs from FIG. 2 in that the OLED 100 of FIG. 3 comprises an electron blocking layer (EBL) 145 and a hole blocking layer (HBL) 155.

[0272] Referring to FIG. 3, the OLED 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130 which may comprise a compound of formula (I), 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 electron injection layer (EIL) 180 and a cathode layer 190.

[0273] While not shown in FIG. 1, FIG. 2 and FIG. 3, a sealing and/or capping layer may further be formed on the cathode layer 190, in order to seal the organic electronic device 100. In addition, various other modifications may be applied thereto.

[0274] 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

[0275] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.

[0276] Compounds of formula (I) may be prepared as described in EP2180029A1 and WO2016097017A1.

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 6-31G* 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

[0278] For bottom emission devices, see 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 layer.

[0279] Then, 88 vol.-% compound of formula F3 and 12 vol.-% compound of formula (I) according to Table 3 were co-deposited in vacuum on the anode layer, to form a HIL having a thickness of 10 nm. The composition of the HIL can be seen in Table 3.

[0280] Then, compound of formula F3 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 co-deposited on the EBL, to form a first blue-emitting EML with a thickness of 20 nm.

[0283] Then the hole blocking layer (HBL) 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 (ETL) having a thickness of 25 nm is formed on the hole blocking layer by co-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.-% LiQ.

[0285] Then, the cathode layer having a thickness of 100 nm is formed on the ETL by depositing Al at a rate of 0.01 to 1 Å/s at 10.sup.7 mbar.

[0286] 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.

[0287] 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/cm2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.

[0288] In bottom emission devices, the emission is predominately Lambertian and quantified in percent external quantum efficiency (EQE). To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm.sup.2.

[0289] In top emission devices, the emission is forward directed, non-Lambertian and also highly dependent on the micro-cavity. Therefore, the efficiency EQE will be higher compared to bottom emission devices. To determine the efficiency EQE in % the light output of the device is measured using a calibrated photodiode at 10 mA/cm.sup.2.

[0290] Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm.sup.2, using a Keithley 2400 source meter, and recorded in hours.

[0291] 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.

Technical Effect of the Invention

[0292] In Table 1 and 2 are shown LUMO levels for inventive compounds A1 to A101 and comparative example 1 (=C1). As comparative compound (referred to as C1) a compound with A.sup.1 to A.sup.3=Phenyl and R′═CN was used. LUMO levels were calculated with the program package 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.

[0293] Comparative compound 1 has the formula has a LUMO level of −3.81 eV.

[0294] As can be seen in Table 1 and Table 2, the LUMO level of inventive compounds A1 to A101 is more negative compared to comparative compound C1.

[0295] A more negative LUMO level is beneficial, as matrix compounds with more negative HOMO level are enabled.

[0296] Surprisingly, it was found that the effect on lowering the LUMO may most pronounced if at least one X.sup.2, X.sup.3 and/or X.sup.4 are selected from CR.sup.2, CR.sup.3 and/or CR.sup.4, wherein the substituent selected from CN, partially fluorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl or F, and/or at least one X.sup.2, X.sup.3 and/or X.sup.4 are selected from N.

TABLE-US-00002 TABLE 1 Calculated LUMO levels of compounds of formula (I) wherein A.sup.1, A.sup.2 and A.sup.3 are selected the same Calculated LUMO A.sup.1, A.sup.2 and A.sup.3 [eV] A1 [00336] −4.43 A2 [00337] −4.41 A3 [00338] −4.45 A4 [00339] −4.63 A5 [00340] −4.73 A6 [00341] −4.7 A7 [00342] −4.73 A8 [00343] −4.62 A9 [00344] −5.14 A10 [00345] −5.14 A11 [00346] −4.85 A12 [00347] −4.65 A13 [00348] −4.95 A14 [00349] −4.87 A15 [00350] −5.14 A16 [00351] −4.53 A17 [00352] −4.78 A18 [00353] −4.71 A19 [00354] −5.02 A20 [00355] −4.98 A21 [00356] −5.16 A22 [00357] −4.96 A23 [00358] −4.24 A24 [00359] −4.39 A25 [00360] −4.31 A26 [00361] −4.46 A27 [00362] −4.85 A28 [00363] −4.65 A29 [00364] −5.26 A30 [00365] −5.04 A31 [00366] −5.12 A32 [00367] −5.38

TABLE-US-00003 TABLE 2 Calculated LUMO levels of compounds of formula (I) wherein A.sup.1 and A.sup.2 may be selected the same or differently and A.sup.1 and A.sup.3 are not identical Calculated A.sup.1 A.sup.2 A.sup.3 LUMO [eV] A33 [00368] [00369] [00370] −4.91 A34 [00371] [00372] [00373] −4.71 A35 [00374] [00375] [00376] −4.91 A36 [00377] [00378] [00379] −4.71 A37 [00380] [00381] [00382] −4.94 A38 [00383] [00384] [00385] −4.93 A39 [00386] [00387] [00388] −4.97 A40 [00389] [00390] [00391] −5 A41 [00392] [00393] [00394] −5.04 A42 [00395] [00396] [00397] −4.88 A43 [00398] [00399] [00400] −5.03 A44 [00401] [00402] [00403] −5.06 A45 [00404] [00405] [00406] −4.87 A46 [00407] [00408] [00409] −4.94 A47 [00410] [00411] [00412] −5.03 A48 [00413] [00414] [00415] −4.83 A49 [00416] [00417] [00418] −4.86 A50 [00419] [00420] [00421] −4.92 A51 [00422] [00423] [00424] −4.65 A52 [00425] [00426] [00427] −5.11 A53 [00428] [00429] [00430] −5 A54 [00431] [00432] [00433] −5.17 A55 [00434] [00435] [00436] −4.98 A56 [00437] [00438] [00439] −5.16 A57 [00440] [00441] [00442] −5.08 A58 [00443] [00444] [00445] −4.88 A59 [00446] [00447] [00448] −4.96 A60 [00449] [00450] [00451] −5.01 A61 [00452] [00453] [00454] −4.83 A62 [00455] [00456] [00457] −5.11 A63 [00458] [00459] [00460] −5.03 A64 [00461] [00462] [00463] −5.08 A65 [00464] [00465] [00466] −4.98 A66 [00467] [00468] [00469] −4.89 A67 [00470] [00471] [00472] −4.98 A68 [00473] [00474] [00475] −5.17 A69 [00476] [00477] [00478] −4.98 A70 [00479] [00480] [00481] −5.16 A71 [00482] [00483] [00484] −5.06 A72 [00485] [00486] [00487] −4.97 A73 [00488] [00489] [00490] −5.05 A74 [00491] [00492] [00493] −5.03 A75 [00494] [00495] [00496] −5.13 A76 [00497] [00498] [00499] −5.09 A77 [00500] [00501] [00502] −5.08 A78 [00503] [00504] [00505] −5.12 A79 [00506] [00507] [00508] −4.93 A80 [00509] [00510] [00511] −5.18 A81 [00512] [00513] [00514] −4.99 A82 [00515] [00516] [00517] −5.17 A83 [00518] [00519] [00520] −5.11 A84 [00521] [00522] [00523] −4.87 A85 [00524] [00525] [00526] −4.92 A86 [00527] [00528] [00529] −4.89 A87 [00530] [00531] [00532] −4.94 A88 [00533] [00534] [00535] −5.08 A89 [00536] [00537] [00538] −4.88 A90 [00539] [00540] [00541] −5.01 A91 [00542] [00543] [00544] −5.21 A92 [00545] [00546] [00547] −5.02 A93 [00548] [00549] [00550] −5.14 A94 [00551] [00552] [00553] −5.24 A95 [00554] [00555] [00556] −5.14 A96 [00557] [00558] [00559] −5.17 A97 [00560] [00561] [00562] −4.97 A98 [00563] [00564] [00565] −5.14 A99 [00566] [00567] [00568] −5.25 A100 [00569] [00570] [00571] −5.06 A101 [00572] [00573] [00574] −5.32

[0297] In Table 3 performance data for organic electroluminescent devices comprising a hole injection layer (HIL) comprising comparative and inventive compounds are shown:

TABLE-US-00004 TABLE 3 Organic electronic devices comprising an hole injection layer (HIL) comprising comparative and inventive compounds. U at 10 mA/cm.sup.2 EQE at 10 mA/cm.sup.2 LT at 30 mA/cm.sup.2 [V] [%] [h] C1 7.5 7 <10 A5 3.9 8.9 85 A7 3.76 9.3 122 A11 3.74 9.4 129 A13 3.7 9.6 130 A14 3.73 9.5 125 A15 3.6 10.2 135 A19 3.8 9.8 128 A20 3.7 9.7 124 A29 3.5 10 123 A31 3.6 10.1 120 A33 3.8 10.4 140 A35 3.9 9.8 136 A37 4.1 9.6 127 A41 3.6 10.3 136 A47 3.7 10.5 145 A54 3.5 10.6 138 A64 3.6 9.4 120 A71 3.7 9.1 130 A75 3.5 8.9 125 A88 3.6 8.5 123 A94 3.5 9.7 132 A100 3.7 8.6 117

[0298] As can be seen from Table 3, the operating voltage U for devices according to invention is lower than for the comparative compounds.

[0299] As can be seen in Table 3, the external quantum efficiency EQE and lifetime LT for devices according to invention are increased compared to comparative compounds.

[0300] A low operating voltage and/or high efficiency may be beneficial for reduced power consumption and improved battery life, in particular in mobile devices.

[0301] A long lifetime is beneficial for long-time stability of devices.

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.