Organic Electronic Device Comprising a Compound of Formula (I), Display Device Comprising the Organic Electronic Device as Well as Compounds of Formula (I) for Use in Organic Electronic Devices

Abstract

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

Claims

1. An organic electronic device comprising an anode layer, a cathode layer and a charge generation layer, wherein the charge generation layer comprises a p-type charge generation layer and a n-type charge generation layer, wherein the p-type charge generation layer comprises a compound of formula (I) ##STR00406## whereby A.sup.1 is selected from formula (II) ##STR00407## X.sup.1 is selected from CR.sup.1 or N; 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, 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.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is present, then the corresponding X.sup.1, X.sup.2, X.sup.3, X.sup.4 and X.sup.5 is not N; with the proviso that one of the following requirements a) to e) are fulfilled: a) At least one R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is independently selected from CN, partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F, and at least one remaining R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 is selected D or H; b) R.sup.1 or R.sup.2 are selected from CN or partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl and at least one remaining R.sup.1 to R.sup.5 is independently selected from CN, partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl or F; c) R3 is selected from partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl and at least one of R.sup.1, R.sup.2, R.sup.4 and R.sup.5 is independently selected from CN, partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl or F; d) at least two R.sup.1 to R.sup.5 are independently selected from CN or partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl; or e) at least one X.sup.1 to X.sup.5 is N and at least two X.sup.1 to X.sup.5 are selected from CR.sup.1 to CR.sup.5; A.sup.2 and A.sup.3 are independently selected from formula (III) ##STR00408## 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 wherein “*” denotes the binding position. 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 flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, F or CN.

2. The organic electronic device of claim 1, whereby the p-type charge generation layer comprises a compound of formula (IV) ##STR00409## whereby B.sup.1 is selected from formula (V) ##STR00410## B.sup.3 and B.sup.5 are Ar and B.sup.2, B.sup.4 and B.sup.6 are R′.

3. The organic electronic device of claim 1, whereby in formula (II) R.sup.3 is selected from CN or partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl and at least one R.sup.1, R.sup.2, R.sup.4, R.sup.5 is selected from H or D.

4. The organic electronic device of claim 1, whereby in formula (II) at least one X.sup.1 to X.sup.5 is N and at least one R.sup.1 to R.sup.5 is selected from CN, partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F.

5. The organic electronic device of claim 1, whereby in formula (II) R.sup.1 to R.sup.5 are independently selected from CN, partially flurorinated or perfluorinated C.sub.1 to C.sub.8 alkyl, halogen, Cl, F

6. The organic electronic device of claim 1, whereby A.sup.2 and A.sup.3 are identical.

7. The organic electronic device of claim 1, whereby A.sup.1 is different from A.sup.2 and/or A.sup.3.

8. The organic electronic device of claim 1, whereby the p-type charge generation layer comprises a composition comprising a compound of formula (IV) and at least one compound of formula (IVa) to (IVd) ##STR00411##

9. The organic electronic device of claim 1, wherein the p-type charge generation layer further comprises a substantially covalent matrix compound.

10. The organic electronic device of claim 1, further comprising a hole injection layer, wherein the hole injection layer is arranged between the anode layer and the charge generation layer and whereby the hole injection layer comprises a compound of formula (I) or (IV).

11. The organic electronic device of claim 1, whereby the p-type charge generation layer and the hole injection layer comprise an identical compound of formula (I) or (IV).

12. The organic electronic device of claim 1, whereby the p-type charge generation layer and the hole injection layer comprise an identical substantially covalent matrix compound.

13. The organic electronic device of claim 1, whereby the electronic organic device is an electroluminescent device.

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

15. A compound of formula (I) of claim 1, wherein formula (II) is selected from the group consisting of: ##STR00412## ##STR00413##

Description

DESCRIPTION OF THE DRAWINGS

[0230] 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.

[0231] 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.

[0232] FIG. 1 is a schematic sectional view of an OLED comprising a charge generation layer, according to an exemplary embodiment of the present invention.

[0233] FIG. 2 is a schematic sectional view of a stacked OLED comprising a charge generation layer, according to an exemplary embodiment of the present invention.

[0234] Hereinafter, the figures are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following figures.

[0235] 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.

[0236] FIG. 1 is a schematic sectional view of an OLED 100, according to one exemplary embodiment of the present invention.

[0237] Referring to FIG. 1 the OLED 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL1) 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 n-type charge generation layer (n-CGL) 185, a p-type charge generation layer (p-GCL) 135 which may comprise a compound of Formula (I), a second hole transport layer (HTL2) 141, and electron injection layer (EIL) 180 and a cathode layer 190. The HIL may comprise a compound of Formula (I).

[0238] FIG. 2 is a schematic sectional view of a stacked OLED 100, according to another exemplary embodiment of the present invention. FIG. 2 differs from FIG. 1 in that the OLED 100 of FIG. 1 further comprises a second emission layer.

[0239] Referring to FIG. 2 the OLED 100 includes a substrate 110, an anode layer 120, a hole injection layer (HIL) 130, a first hole transport layer (HTL) 140, a first electron blocking layer (EBL) 145, a first emission layer (EML) 150, a first hole blocking layer (HBL) 155, a first electron transport layer (ETL) 160, an n-type charge generation layer (n-CGL) 185, a p-type charge generation layer (p-GCL) 135 which may comprise compound of Formula (I), a second hole transport layer (HTL) 141, a second electron blocking layer (EBL) 146, a second emission layer (EML) 151, a second hole blocking layer (EBL) 156, a second electron transport layer (ETL) 161, an electron injection layer (EIL) 180 and a cathode layer 190. The HIL may comprise a compound of Formula (I).

[0240] 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 hole injection layer 130, a first hole transport layer 140, optional a first electron blocking layer 145, a first emission layer 150, optional a first hole blocking layer 155, optional at least one first electron transport layer 160, an n-CGL 185, a p-CGL 135, a second hole transport layer 141, optional a second electron blocking layer 146, a second emission layer 151, an optional second hole blocking layer 156, an optional at least one second electron transport layer 161, an optional electron injection layer (EIL) 180 and a cathode layer 190 are formed, in that order or the other way around.

[0241] While not shown in FIGS. 1 and 2, 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.

[0242] 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

[0243] The invention is furthermore illustrated by the following examples which are illustrative only and non-binding.

[0244] Compounds of formula (I) may be prepared as described in EP2180029A1 and WO2016097017A1.

Calculated HOMO and LUMO

[0245] 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

[0246] For OLEDs comprising a CGL, see Table 2, a glass substrate 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 substrate.

[0247] Then, the anode layer having a thickness of 100 nm is formed on the substrate by depositing Ag at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar.

[0248] Then, a hole injection layer (HIL) having a thickness of 10 nm is formed on the anode layer by co-depositing a substantially covalent matrix compound and a p-dopant. The composition of the HIL can be seen in Table 2.

[0249] Then, a first hole transport layer (HTL1) having a thickness of 34 nm is formed on the HIL by depositing the substantially covalent matrix compound. The composition of the HTL can be seen in Table 2.

[0250] Then, an electron blocking layer (EBL) having a thickness of 5 nm is formed on the HTL1 by depositing N-([1,1′-biphenyl]-4-yl)-9,9-diphenyl-N-(4-(triphenylsilyl)phenyl)-9H-fluoren-2-amine.

[0251] Then, an emission layer (EML) having a thickness of 20 nm is formed on the EBL by co-depositing 97 vol.-% H09 (Sun Fine Chemicals, Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, Korea) as fluorescent blue dopant.

[0252] Then, a hole blocking layer (HBL) is formed with a thickness of 5 nm is formed on the emission layer by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine.

[0253] Then, an electron transporting layer (ETL) having a thickness of 20 nm is formed on the hole blocking layer by co-depositing 50 wt.-% 2-([1,1′-biphenyl]-4-yl)-4-(9,9-diphenyl-9H-fluoren-4-yl)-6-phenyl-1,3,5-triazine and 50 wt.-% LiQ.

[0254] Then, the n-CGL having a thickness of 10 nm is formed on the ETL by co-depositing 99 vol.-% 2,2′-(1,3-Phenylene)bis[9-phenyl-1,10-phenanthroline] and 1 vol.-% Li.

[0255] Then, the p-CGL is formed on the n-CGL by co-depositing a substantially covalent matrix compound and a compound of formula (I). The composition and thickness of the p-CGL can be seen in Table 2.

[0256] Then, a second hole transport layer (HTL2) having a thickness of 81 nm is formed on the p-CGL by depositing a substantially covalent matrix compound. The composition of the HTL2 can be seen in Table 2.

[0257] Then, an electron injection layer (EIL) having a thickness of 2 nm is formed on the HTL2 by depositing Yb.

[0258] Then, the cathode layer having a thickness of 13 nm is formed on the EIL by co-depositing Ag:Mg (90:10 vol.-%) at a rate of 0.01 to 1 Å/s at 10.sup.−7 mbar.

[0259] Then, a capping layer having a thickness of 75 nm is formed on the cathode layer by depositing compound of formula F3.

[0260] 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.

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.

[0261] 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/cm2.

[0262] 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.

[0263] 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.

[0264] 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.

[0265] The increase in operating voltage U over time “U rise (50-1 h)” is measured by determining the difference in operating voltage at 30 mA/cm.sup.2 after 1 hour and after 50 hours.

Technical Effect of the Invention

[0266] In Table 1 are shown LUMO levels for Examples A1 to A59 and comparative example 1 (=C.sub.1). As comparative compound (referred to as C1) a compound with A.sup.1 to A.sup.3=pentafluorphenyl and R′ ═CN was used.

[0267] 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

TABLE-US-00002 TABLE 1 Calculated LUMO level of compounds of formula (I) LUMO A.sup.1 A.sup.2 A.sup.3 [eV] Comparative compound 1 [00225] [00226] [00227] −4.58 A1 [00228] [00229] [00230] −4.79 A2 [00231] [00232] [00233] −4.75 A3 [00234] [00235] [00236] −4.92 A4 [00237] [00238] [00239] −4.82 A5 [00240] [00241] [00242] −4.83 A6 [00243] [00244] [00245] −4.95 A7 [00246] [00247] [00248] −5.12 A8 [00249] [00250] [00251] −5.51 A9 [00252] [00253] [00254] −4.91 A10 [00255] [00256] [00257] −5.10 A11 [00258] [00259] [00260] −5.36 A12 [00261] [00262] [00263] −5.32 A13 [00264] [00265] [00266] −5.09 A14 [00267] [00268] [00269] −5.07 A15 [00270] [00271] [00272] −5.00 A16 [00273] [00274] [00275] −5.25 A17 [00276] [00277] [00278] −5.18 A18 [00279] [00280] [00281] −5.20 A19 [00282] [00283] [00284] −5.12 A20 [00285] [00286] [00287] −5.23 A21 [00288] [00289] [00290] −5.07 A22 [00291] [00292] [00293] −5.07 A23 [00294] [00295] [00296] −5.19 A24 [00297] [00298] [00299] −5.06 A25 [00300] [00301] [00302] −5.10 A26 [00303] [00304] [00305] −5.28 A27 [00306] [00307] [00308] −5.10 A28 [00309] [00310] [00311] −4.98 A29 [00312] [00313] [00314] −5.15 A30 [00315] [00316] [00317] −5.23 A31 [00318] [00319] [00320] −5.34 A32 [00321] [00322] [00323] −5.10 A33 [00324] [00325] [00326] −5.03 A34 [00327] [00328] [00329] −5.36 A35 [00330] [00331] [00332] −5.36 A36 [00333] [00334] [00335] −5.33 A37 [00336] [00337] [00338] −5.34 A38 [00339] [00340] [00341] −5.51 A39 [00342] [00343] [00344] −5.31 A40 [00345] [00346] [00347] −5.29 A41 [00348] [00349] [00350] −4.99 A42 [00351] [00352] [00353] −5.12 A43 [00354] [00355] [00356] −5.16 A44 [00357] [00358] [00359] −5.33 A45 [00360] [00361] [00362] −5.21 A46 [00363] [00364] [00365] −5.07 A47 [00366] [00367] [00368] −4.71 A48 [00369] [00370] [00371] −4.73 A49 [00372] [00373] [00374] −4.71 A50 [00375] [00376] [00377] −5.50 A51 [00378] [00379] [00380] −4.91 A52 [00381] [00382] [00383] −4.66 A53 [00384] [00385] [00386] −4.95 A54 [00387] [00388] [00389] −5.33 A55 [00390] [00391] [00392] −5.58 A56 [00393] [00394] [00395] −5.36 A57 [00396] [00397] [00398] −5.50 A58 [00399] [00400] [00401] −4.96 A59 [00402] [00403] [00404] −5.61

[0268] Table 2 (cf. p. 75) shows the setup of several devices according to one comparative and several inventive examples.

[0269] As comparative compound (referred to as C1) a compound with A.sup.1 to A.sup.3=pentafluorophenyl and R′═CN was used.

[0270] In comparative example 1 and examples 2 to 5, the hole injection layer comprises compound C2. In C2, A.sup.1 to A.sup.3 are

##STR00405##

[0271] A low operating voltage U may be beneficial for reduced power consumption and improved battery life, in particular in mobile devices.

[0272] A high external quantum efficiency EQE may be beneficial for reduced power consumption and improved battery life, in particular in mobile devices.

[0273] An improved lifetime LT and improved voltage rise over time may be beneficial for long lifetime of organic electronic devices.

[0274] 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.

TABLE-US-00003 TABLE 2 Organic electronic devices comprising a p-type charge generation layer (p-CGL) comprising a compound of formula (I) and a substantially organic matrix compound Com- Com- pound pound of U at EQE LT at U rise p-dopant formula Thick- 15 at 15 30 (50-1 h) Composi- in the Composi- Composi- (1) in p- ness p- Composi- mA/ mA/ mA/ at 30 tion of the HIL tion of the tion of the CGL CGL tion of the cm.sup.2 cm.sup.2 cm.sup.2 mA/cm.sup.2 HIL [vol.-%] HTL1 p-CGL [vol.-%] [nm] HTL2 [V] [%] [h] [V] Compara- F10: C2 8 F10 F5: C1 10.1 86 F9 8.2 5.4 30 >1 tive e Ex. 1 Example 1 F10: C2 8 F10 F5: A40 10.1 86 F5 6.08 9.8 100 0.07 Example 2 F10: C2 7.9 F10 F5: A32 9.8 86 F5 6.28 10.3 97 0.05 Example 3 F10: C2 8 F10 F5: A30 12 86 F5 6.09 9.8 96 0.04 Example 4 F10: C2 8.3 F10 F10: A42 9.6 81 F10 5.96 10.2 95 0.06 Example 5 F10: C2 8.3 F10 F10: A40 9.9 86 F10 5.89 8.8 66 0.27 Example 6 F10: A32 8.5 F10 F10: A32 10.8 86 F10 5.92 9.1 58 0.28 Example 7 F10: A30 9.2 F10 F10: A30 11.8 86 F10 5.89 8.5 97 0.05 Example 8 F10: C2 8.1 F10 F10: A39 10.1 81 F10 5.96 10.3 97 0.14 Example 9 F3: C2 3.00 F3 F3: A27 9.90 10 F3 4.81 5.7 100 0.01 Example 10 F3: A12 8.1 F3 F3: A12 10.3 10 F3 6.3 8.54 94 0.03 Example 11 F3: A50 8.1 F3 F3: A50 10 10 F3 6.14 8.68 83 0.05