Patent Application
20230309398
The invention relates to light-emitting organic molecules and their use in organic light-emitting diodes (OLEDs) and in other optoelectronic devices.
The object of the present invention is to provide molecules which are suitable for use in optoelectronic devices.
This object is achieved by the invention which provides a new class of organic molecules.
Optoelectronic devices containing one or more light-emitting layers based on organics such as, e.g., organic light emitting diodes (OLEDs), light emitting electrochemical cells (LECs) and light-emitting transistors gain increasing importance. In particular, OLEDs are promising devices for electronic products such as screens, displays and illumination devices. In contrast to most optoelectronic devices essentially based on inorganics, optoelectronic devices based on organics are often rather flexible and producible in particularly thin layers. The OLED-based screens and displays already available today bear either good efficiencies and long lifetimes or good color purity and long lifetimes, but do not combine all three properties, i.e. good efficiency, long lifetime, and good color purity.
Thus, there is still an unmet technical need for optoelectronic devices which have a high quantum yield, a long lifetime, and a good color purity.
The color purity or color point of an OLED is typically provided by CIEx and CIEy coordinates, whereas the color gamut for the next generation display is provided by so-called BT-2020 and DCPI3 values. Generally, in order to achieve these color coordinates, top emitting devices are needed to adjust the color coordinates by changing the cavity. In order to achieve high efficiency in the top emitting devices while targeting this color gamut, a narrow emission spectrum in bottom emitting devices is also required.
The organic molecules according to the invention exhibit emission maxima in the sky blue, green or yellow spectral range. The organic molecules exhibit in particular emission maxima between 490 and 600 nm, more preferably between 500 and 560 nm, and even more preferably between 520 and 540 nm. Additionally, the molecules of the invention exhibit in particular a narrow emission—expressed by a small full width at half maximum (FWHM). The emission spectra of the organic molecules preferably show a full width at half maximum (FWHM) of less than or equal to 0.25 eV (0.25 eV), if not stated otherwise measured with 2% by weight of emitter in poly(methyl methacrylate) PMMA at room temperature. The photoluminescence quantum yields of the organic molecules according to the invention are, in particular, 10% or more.
The use of the molecules according to the invention in an optoelectronic device, for example, an organic light-emitting diode (OLED), leads to a narrow emission and high efficiency of the device. Corresponding OLEDs have a higher stability than OLEDs with known emitter materials and comparable color and/or by employing the molecules according to the invention in an OLED display, a more accurate reproduction of visible colors in nature, i.e. a higher resolution in the displayed image, is achieved. In particular, the molecules can be used in combination with an energy pump to achieve hyper-fluorescence or hyper-phosphorescence. In these cases, another species included in an optoelectronic device transfers energy to the organic molecules of the invention which then emit light.
The organic molecules according to the invention include or consist a structure of Formula I:
wherein
which is bonded to the structure of Formula I to the rest of the organic molecule via the position marked by the dotted line.
Q is at each occurrence independently selected from the group consisting of N and CR3.
R1 and R2 are at each occurrence independently selected from the group consisting of:
wherein optionally one or more hydrogen atoms are independently substituted by C1-C5-alkyl, CN, CF3 or Ph (=phenyl).
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-1:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-1 wherein R3 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-2:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-2 wherein R3 is hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-3:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-3 wherein R3 is hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-4:
In an even more preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-5:
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-6:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-6 wherein R2 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-7:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-7 wherein R2 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-8:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-8 wherein R2 is at each occurrence hydrogen.
In one embodiment of the invention, RI, RII, RIII, RIV, RV, RVI, RVII, RVIII, RIX, RX, RXI, RXII, RXIII, RXIV, RXV, RXVI, RXVII, and RXVIII are independently selected from the group consisting of: hydrogen; deuterium; halogen; CN; CF3; SiMe3; SiPh3;
In a preferred embodiment of the invention, RI, RII, RIII, RIV, RV, RVI, RVII, RVIII, RIX, RX, RXI, RXII, RXIII, RXIV, RXV, RXVI, RXVII, and RXVIII are independently selected from the group consisting of:
In an even more preferred embodiment of the invention, at least one pair of adjacent groups RI and RII, RII and RIII, or RIII and RIV forms an aromatic ring system which is fused to the adjacent benzene ring a and at least one pair of adjacent groups RV and RVI, RVI and RVII, or RVII and RVIII forms an aromatic ring system which is fused to the adjacent benzene ring b of general Formula I;
In one embodiment of the invention, R3, R4 and R5 are at each occurrence independently selected from the group consisting of hydrogen; deuterium; halogen; CN; CF3; SiMe3; SiPh3;
In a preferred embodiment of the invention, R3, R4, and R5 are at each occurrence independently selected from the group consisting of hydrogen, deuterium, halogen, Me, iPr, tBu, CN, CF3, SiMe3, SiPh3, and
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a:
In an even more preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a and R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-1:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-1 wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-2:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-2 wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-3:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-3 wherein R5 is at each occurrence hydrogen.
In a preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-4:
In an even more preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-4 and R5 is at each occurrence hydrogen.
In a particularly preferred embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-5:
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-6:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-6 wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-7:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-7 wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-8:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-a-8 wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-b:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-b wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-c:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-c wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-d:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-d wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-e:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-e wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-f:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-f wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-g:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-g wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-h:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-h wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-i:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-i wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-j:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-j wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-k:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-k wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-m:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-m wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-n:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-n wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-o:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-o wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-p:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-p wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-q:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-q wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-r:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-r wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-s:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-s wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-t:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-t wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-u:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-u wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-v:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-v wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-w:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-w wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-x:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-x wherein R5 is at each occurrence hydrogen.
In one embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-y:
In another embodiment of the invention, the organic molecule includes or consists of a structure of Formula I-y wherein R5 is at each occurrence hydrogen.
As used throughout the present application, the term “aromatic ring system” may be understood in the broadest sense as any bi- or polycyclic aromatic moiety, for which the following definitions apply.
As used throughout the present application, the terms “aryl” and “aromatic” may be understood in the broadest sense as any mono-, bi- or polycyclic aromatic moieties. Accordingly, an aryl group contains 6 to 60 aromatic ring atoms, and a heteroaryl group contains 5 to 60 aromatic ring atoms, of which at least one is a heteroatom. Notwithstanding, throughout the application the number of aromatic ring atoms may be given as subscripted number in the definition of certain substituents. In particular, the heteroaromatic ring includes one to three heteroatoms. Again, the terms “heteroaryl” and “heteroaromatic” may be understood in the broadest sense as any mono-, bi- or polycyclic hetero-aromatic moieties that include at least one heteroatom. The heteroatoms may at each occurrence be the same or different and be individually selected from the group consisting of N, O and S. Accordingly, the term “arylene” refers to a divalent substituent that bears two binding sites to other molecular structures and thereby serving as a linker structure. In case, a group in the exemplary embodiments is defined differently from the definitions given here, for example, the number of aromatic ring atoms or number of heteroatoms differs from the given definition, the definition in the exemplary embodiments is to be applied. According to the invention, a condensed (annulated) aromatic or heteroaromatic polycycle is built of two or more single aromatic or heteroaromatic cycles, which formed the polycycle via a condensation reaction.
In particular, as used throughout the present application the term “aryl group” or “heteroaryl group” includes groups which can be bound via any position of the aromatic or heteroaromatic group, derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, benzophenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridoimidazole, pyrazinoimidazole, quinoxalinoimidazole, oxazole, benzoxazole, naphthooxazole, anthroxazol, phenanthroxazol, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, 1,3,5-triazine, quinoxaline, pyrazine, phenazine, naphthyridine, carboline, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,2,3,4-tetrazine, purine, pteridine, indolizine and benzothiadiazole or combination(s) of the above mentioned groups.
As used throughout the present application, the term “cyclic group” may be understood in the broadest sense as any mono-, bi- or polycyclic moieties.
As used above and herein, the term “alkyl group” may be understood in the broadest sense as any linear, branched, or cyclic alkyl substituent. In particular, examples of the term alkyl include the substituents methyl (Me), ethyl (Et), n-propyl (nPr), i-propyl (iPr), cyclopropyl, n-butyl (nBu), i-butyl (iBu), s-butyl (sBu), t-butyl (tBu), cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neo-pentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neo-hexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2,2,2]octyl, 2-bicyclo[2,2,2]-octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, 2,2,2-trifluorethyl, 1,1-dimethyl-n-hex-1-yl, 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n-dec-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexadec-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl-n-dec-1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)-cyclohex-1-yl, 1-(n-butyl)-cyclohex-1-yl, 1-(n-hexyl)-cyclohex-1-yl, 1-(n-octyl)-cyclohex-1-yl and 1-(n-decyl)-cyclohex-1-yl.
As used above and herein, the term “alkenyl” includes any of linear, branched, and cyclic alkenyl substituents. The term alkenyl group exemplarily includes the substituents ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl.
As used above and herein, the term “alkynyl” includes any of linear, branched, and cyclic alkynyl substituents. The term alkynyl group exemplarily includes ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl.
As used above and herein, the term “alkoxy” includes any of linear, branched, and cyclic alkoxy substituents. The term alkoxy group exemplarily includes methoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy and 2-methylbutoxy.
As used above and herein, the term “thioalkoxy” includes any of linear, branched, and cyclic thioalkoxy substituents, in which the O of the exemplarily alkoxy groups is replaced by S.
As used above and herein, the terms “halogen” and “halo” may be understood in the broadest sense as being preferably fluorine, chlorine, bromine or iodine.
Whenever hydrogen (H) is mentioned herein, it could also be replaced by deuterium at each occurrence.
It is understood that when a molecular fragment is described as being a substituent or otherwise attached to another moiety, its name may be written as if it were a fragment (e.g. naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g. naphthalene, dibenzofuran). As used herein, these different ways of designating a substituent or attached fragment are considered to be equivalent.
In one embodiment, the organic molecules according to the invention have an excited state lifetime of not more than 250 μs, of not more than 150 μs, in particular of not more than 100 μs, more preferably of not more than 80 μs or not more than 60 μs, even more preferably of not more than 40 μs in a film of poly(methyl methacrylate) (PMMA) with 2% by weight of the organic molecule at room temperature.
In one embodiment of the invention, the organic molecules according to the invention represent thermally-activated delayed fluorescence (TADF) emitters, which exhibit a ΔEST value, which corresponds to the energy difference between the first excited singlet state (S1) and the first excited triplet state (T1), of less than 5000 cm−1, preferably less than 3000 cm1, more preferably less than 1500 cm1, even more preferably less than 1000 cm1 or even less than 500 cm1.
In a further embodiment of the invention, the organic molecules according to the invention have an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 480 to 580 nm, with a full width at half maximum of less than 0.30 eV, preferably less than 0.28 eV, more preferably less than 0.25 eV, even more preferably less than 0.23 eV or even less than 0.20 eV in a film of poly(methyl methacrylate) (PMMA) with 2% by weight of the organic molecule at room temperature.
Orbital and excited state energies can be determined either by means of experimental methods or by calculations employing quantum-chemical methods, in particular density functional theory calculations. The energy of the highest occupied molecular orbital EHOMO is determined by methods known to the person skilled in the art from cyclic voltammetry measurements with an accuracy of 0.1 eV. The energy of the lowest unoccupied molecular orbital ELUMO is determined as the onset of the absorption spectrum.
The onset of an absorption spectrum is determined by computing the intersection of the tangent to the absorption spectrum with the x-axis. The tangent to the absorption spectrum is set at the low-energy side of the absorption band and at the point at half maximum of the maximum intensity of the absorption spectrum.
The energy of the first excited triplet state T1 is determined from the onset of the emission spectrum at low temperature, typically at 77 K. For host compounds, where the first excited singlet state and the lowest triplet state are energetically separated by >0.4 eV, the phosphorescence is usually visible in a steady-state spectrum in 2-Me-THF. The triplet energy can thus be determined as the onset of the phosphorescence spectrum. For TADF emitter molecules, the energy of the first excited triplet state T1 is determined from the onset of the delayed emission spectrum at 77 K, if not otherwise stated measured in a film of PMMA with 2% by weight of the emitter. For both host and emitter compounds, the energy of the first excited singlet state S1 is determined from the onset of the emission spectrum (if not otherwise stated measured in a film of PMMA with 2% by weight of the emitter; host measured from neat film).
The onset of an emission spectrum is determined by computing the intersection of the tangent to the emission spectrum with the x-axis. The tangent to the emission spectrum is set at the high-energy side of the emission band and at the point at half maximum of the maximum intensity of the emission spectrum.
A further aspect of the invention relates to the use of an organic molecule according to the invention as a luminescent emitter or as an absorber, and/or as a host material and/or as an electron transport material, and/or as a hole injection material, and/or as a hole blocking material in an optoelectronic device.
The optoelectronic device may be understood in the broadest sense as any device based on organic materials that is suitable for emitting light in the visible or nearest ultraviolet (UV) range, i.e., in the range of a wavelength of from 380 to 800 nm. More preferably, the optoelectronic device may be able to emit light in the visible range, i.e., of from 400 to 800 nm.
In the context of such use, the optoelectronic device is more particularly selected from the group consisting of:
A light-emitting electrochemical cell includes three layers, namely a cathode, an anode, and an active layer, which contains the organic molecule according to the invention.
In a preferred embodiment in the context of such use, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC), an organic laser, and a light-emitting transistor.
In one embodiment, the light-emitting layer of an organic light-emitting diode includes the organic molecules according to the invention.
In one embodiment, the light-emitting layer of an organic light-emitting diode includes not only the organic molecules according to the invention but also a host material whose triplet (T1) and singlet (S1) energy levels are energetically higher than the triplet (T1) and singlet (S1) energy levels of the organic molecule.
A further aspect of the invention relates to a composition including or consisting of:
In a further embodiment of the invention, the composition has a photoluminescence quantum yield (PLQY) of more than 10%, preferably more than 20%, more preferably more than 40%, even more preferably more than 60% or even more than 70% at room temperature.
Compositions with at Least One Further Emitter
One embodiment of the invention relates to a composition including or consisting of:
The components or the compositions are chosen such that the sum of the weight of the components add up to 100%.
In a further embodiment of the invention, the composition has an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm.
In one embodiment of the invention, the at least one further emitter molecule F is a purely organic emitter.
In one embodiment of the invention, the at least one further emitter molecule F is a purely organic TADF emitter. Purely organic TADF emitters are known from the state of the art, e.g. Wong and Zysman-Colman (“Purely Organic Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes.”, Adv. Mater. 2017 June; 29(22)).
In one embodiment of the invention, the at least one further emitter molecule F is a fluorescence emitter, in particular a blue, a green, a yellow or a red fluorescence emitter.
In one embodiment of the invention, the at least one further emitter molecule F is a fluorescence emitter, in particular a red, a yellow or a green fluorescence emitter.
In a further embodiment of the invention, the composition, containing the at least one further emitter molecule F shows an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm, with a full width at half maximum of less than 0.30 eV, in particular less than 0.25 eV, preferably less than 0.22 eV, more preferably less than 0.19 eV or even less than 0.17 eV at room temperature, with a lower limit of 0.05 eV.
Composition wherein the at least one further emitter molecule F is a green fluorescence emitter
In a further embodiment of the invention, the at least one further emitter molecule F is a fluorescence emitter, in particular a green fluorescence emitter.
In one embodiment, the at least one further emitter molecule F is a fluorescence emitter selected from the following groups:
In a further embodiment of the invention, the composition has an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm, in particular between 485 nm and 590 nm, preferably between 505 nm and 565 nm, even more preferably between 515 nm and 545 nm.
Composition wherein the at least one further emitter molecule F is a red fluorescence emitter
In a further embodiment of the invention, the at least one further emitter molecule F is a fluorescence emitter, in particular a red fluorescence emitter.
In one embodiment, the at least one further emitter molecule F is a fluorescence emitter selected from the following groups:
In a further embodiment of the invention, the composition has an emission peak in the visible or nearest ultraviolet range, i.e., in the range of a wavelength of from 380 to 800 nm, in particular between 590 nm and 690 nm, preferably between 610 nm and 665 nm, even more preferably between 620 nm and 640 nm.
In one embodiment, the light-emitting layer EML of an organic light-emitting diode of the invention includes (or essentially consists of) a composition including or consisting of:
Preferably, energy can be transferred from the host compound H to the one or more organic molecules of the invention, in particular transferred from the first excited triplet state T1(H) of the host compound H to the first excited triplet state T1(E) of the one or more organic molecules according to the invention and/or from the first excited singlet state S1(H) of the host compound H to the first excited singlet state S1(E) of the one or more organic molecules according to the invention.
In one embodiment, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) in the range of from −5 eV to −6.5 eV and one organic molecule according to the invention E has a highest occupied molecular orbital HOMO(E) having an energy EHOMO(E), wherein EHOMO(H)>EHOMO(E).
In a further embodiment, the host compound H has a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H) and the one organic molecule according to the invention E has a lowest unoccupied molecular orbital LUMO(E) having an energy ELUMO(E), wherein ELUMO(H)>ELUMO(E).
In a further embodiment, the light-emitting layer EML of an organic light-emitting diode of the invention includes (or essentially consists of) a composition including or consisting of:
In one embodiment of the organic light-emitting diode of the invention, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) in the range of from −5 eV to −6.5 eV and the at least one further host compound D has a highest occupied molecular orbital HOMO(D) having an energy EHOMO(D), wherein EHOMO(H)>EHOMO(D). The relation EHOMO(H)>EHOMO(D) favors an efficient hole transport.
In a further embodiment, the host compound H has a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H) and the at least one further host compound D has a lowest unoccupied molecular orbital LUMO(D) having an energy ELUMO(D), wherein ELUMO(H)>ELUMO(D). The relation ELUMO(H)>ELUMO(D) favors an efficient electron transport.
In one embodiment of the organic light-emitting diode of the invention, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) and a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H), and
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition including or consisting of:
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Compositions, wherein the at least one further emitter molecule F is a green fluorescence emitter.
In a further embodiment, the light-emitting layer EML includes (or (essentially) consists of) a composition as described in Compositions with at least one further emitter, with the at least one further emitter molecule F as defined in Compositions, wherein the at least one further emitter molecule F is a red fluorescence emitter.
In one embodiment of the light-emitting layer EML including at least one further emitter molecule F, energy can be transferred from the one or more organic molecules of the invention E to the at least one further emitter molecule F, in particular transferred from the first excited singlet state S1(E) of one or more organic molecules of the invention E to the first excited singlet state S1(F) of the at least one further emitter molecule F.
In one embodiment, the first excited singlet state S1(H) of one host compound H of the light-emitting layer is higher in energy than the first excited singlet state S1(E) of the one or more organic molecules of the invention E: S1(H)>S1(E), and the first excited singlet state S1(H) of one host compound H is higher in energy than the first excited singlet state S1(F) of the at least one emitter molecule F: S1(H)>S1(F).
In one embodiment, the first excited triplet state T1(H) of one host compound H is higher in energy than the first excited triplet state T1(E) of the one or more organic molecules of the invention E: T1(H)>T1(E), and the first excited triplet state T1(H) of one host compound H is higher in energy than the first excited triplet state T1(F) of the at least one emitter molecule F: T1(H)>T1(F).
In one embodiment, the first excited singlet state S1(E) of the one or more organic molecules of the invention E is higher in energy than the first excited singlet state S1(F) of the at least one emitter molecule F: S1(E)>S1(F).
In one embodiment, the first excited triplet state T1(E) of the one or more organic molecules E of the invention is higher in energy than the first excited singlet state T1(F) of the at least one emitter molecule F: T1(E)>T1(F).
In one embodiment, the first excited triplet state T1(E) of the one or more organic molecules E of the invention is higher in energy than the first excited singlet state T1(F) of the at least one emitter molecule F: T1(E)>T1(F), wherein the absolute value of the energy difference between T1(E) and T1(F) is larger than 0.3 eV, preferably larger than 0.4 eV, or even larger than 0.5 eV.
In one embodiment, the host compound H has a highest occupied molecular orbital HOMO(H) having an energy EHOMO(H) and a lowest unoccupied molecular orbital LUMO(H) having an energy ELUMO(H), and
In a further aspect, the invention relates to an optoelectronic device including an organic molecule or a composition as described herein, more particularly in the form of a device selected from the group consisting of organic light-emitting diode (OLED), light-emitting electrochemical cell, OLED sensor (particularly gas and vapor sensors not hermetically externally shielded), organic diode, organic solar cell, organic transistor, organic field-effect transistor, organic laser and down-conversion element.
In a preferred embodiment, the optoelectronic device is a device selected from the group consisting of an organic light emitting diode (OLED), a light emitting electrochemical cell (LEC), and a light-emitting transistor.
In one embodiment of the optoelectronic device of the invention, the organic molecule according to the invention is used as emission material in a light-emitting layer EML.
In one embodiment of the optoelectronic device of the invention, the light-emitting layer EML consists of the composition according to the invention described herein.
When the optoelectronic device is an OLED, it may, for example, exhibit the following layer structure:
wherein the OLED includes each layer only optionally, and different layers may be merged together into, e.g., one or more layers, and the OLED may include more than one layer of each layer type defined above.
Furthermore, the optoelectronic device may optionally include one or more protective layers protecting the device from damaging exposure to harmful species in the environment including, exemplarily moisture, vapor and/or gases.
In one embodiment of the invention, the optoelectronic device is an OLED, which exhibits the following inverted layer structure:
wherein the OLED with an inverted layer structure includes each layer only optionally, and different layers may be merged together into, e.g., one or more layers, and the OLED may include more than one layer of each layer types defined above.
In one embodiment of the invention, the optoelectronic device is an OLED, which may exhibit stacked architecture. In this architecture, contrary to the typical arrangement, where the OLEDs are placed side by side, the individual units are stacked on top of each other. Blended light may be generated with OLEDs exhibiting a stacked architecture, in particular white light may be generated by stacking blue, green and red OLEDs. Furthermore, the OLED exhibiting a stacked architecture may optionally include a charge generation layer (CGL), which is typically located between two OLED subunits and typically consists of an n-doped layer and a p-doped layer with the n-doped layer of one CGL being typically located closer to the anode layer.
In one embodiment of the invention, the optoelectronic device is an OLED, which includes two or more emission layers between anode and cathode. In particular, this so-called tandem OLED includes three emission layers, wherein one emission layer emits red light, one emission layer emits green light and one emission layer emits blue light, and optionally may include further layers such as charge generation layers, blocking or transporting layers between the individual emission layers. In a further embodiment, the emission layers are adjacently stacked. In a further embodiment, the tandem OLED includes a charge generation layer between each two emission layers. In addition, adjacent emission layers or emission layers separated by a charge generation layer may be merged.
The substrate may be formed by any material or composition of materials. Most frequently, glass slides are used as substrates. Alternatively, thin metal layers (e.g., copper, gold, silver or aluminum films) or plastic films or slides may be used. This may allow for a higher degree of flexibility. The anode layer A is mostly composed of materials allowing to obtain an (essentially) transparent film. As at least one of the two electrodes should be (essentially) transparent in order to allow light emission from the OLED, either the anode layer A or the cathode layer C is transparent. Preferably, the anode layer A includes a large content or even consists of transparent conductive oxides (TCOs). Such anode layer A may exemplarily include indium tin oxide, aluminum zinc oxide, fluorine doped tin oxide, indium zinc oxide, PbO, SnO, zirconium oxide, molybdenum oxide, vanadium oxide, tungsten oxide, graphite, doped Si, doped Ge, doped GaAs, doped polyaniline, doped polypyrrol and/or doped polythiophene.
Preferably, the anode layer A (essentially) consists of indium tin oxide (ITO) (e.g., (InO3)0.9(SnO2)0.1). The roughness of the anode layer A caused by the transparent conductive oxides (TCOs) may be compensated by using a hole injection layer (HIL). Further, the HIL may facilitate the injection of quasi charge carriers (i.e., holes) in that the transport of the quasi charge carriers from the TCO to the hole transport layer (HTL) is facilitated. The hole injection layer (HIL) may include poly-3,4-ethylenedioxy thiophene (PEDOT), polystyrene sulfonate (PSS), MoO2, V2O5, CuPC or CuI, in particular a mixture of PEDOT and PSS. The hole injection layer (HIL) may also prevent the diffusion of metals from the anode layer A into the hole transport layer (HTL). The HIL may exemplarily include PEDOT:PSS (poly-3,4-ethylenedioxy thiophene: polystyrene sulfonate), PEDOT (poly-3,4-ethylenedioxy thiophene), mMTDATA (4,4′,4″-trs[phenyl(m-tolyl)amino]triphenylamine), Spiro-TAD (2,2′,7,7′-tetrakis(n,n-diphenylamino)-9,9′-spirobifluorene), DNTPD (N1,N1′-(biphenyl-4,4′-diyl)bis(N1-phenyl-N4,N4-di-m-tolylbenzene-1,4-diamine), NPB (N,N′-nis-(1-naphthalenyl)-N,N′-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine), NPNPB (N,N′-diphenyl-N,N′-di-[4-(N,N-diphenyl-amino)phenyl]benzidine), MeO-TPD (N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine), HAT-CN (1,4,5,8,9,11-hexaazatriphenylen-hexacarbonitrile) and/or Spiro-NPD (N,N′-diphenyl-N,N′-bis-(1-naphthyl)-9,9′-spirobifluorene-2,7-diamine).
Adjacent to the anode layer A or hole injection layer (HIL) typically a hole transport layer (HTL) is located. Herein, any hole transport compound may be used. Exemplarily, electron-rich heteroaromatic compounds such as triarylamines and/or carbazoles may be used as hole transport compound. The HTL may decrease the energy barrier between the anode layer A and the light-emitting layer EML. The hole transport layer (HTL) may also be an electron blocking layer (EBL). Preferably, hole transport compounds bear comparably high energy levels of their triplet states T1. Exemplarily the hole transport layer (HTL) may include a star-shaped heterocycle such as tris(4-carbazoyl-9-ylphenyl)amine (TCTA), poly-TPD (poly(4-butylphenyl-diphenyl-amine)), [alpha]-NPD (poly(4-butylphenyl-diphenyl-amine)), TAPC (4,4′-cyclohexyliden-bis[N,N-bis(4-methylphenyl)benzenamine]), 2-TNATA (4,4′,4″-tris[2-naphthyl(phenyl)amino]triphenylamine), Spiro-TAD, DNTPD, NPB, NPNPB, MeO-TPD, HAT-CN and/or TrisPcz (9,9′-diphenyl-6-(9-phenyl-9H-carbazol-3-yl)-9H,9′H-3,3′-bicarbazole). In addition, the HTL may include a p-doped layer, which may be composed of an inorganic or organic dopant in an organic hole-transporting matrix. Transition metal oxides such as vanadium oxide, molybdenum oxide or tungsten oxide may exemplarily be used as the inorganic dopant. Tetrafluorotetracyanoquinodimethane (F4-TCNQ), copper-pentafluorobenzoate (Cu(I)pFBz) or transition metal complexes may exemplarily be used as the organic dopant.
The EBL may exemplarily include mCP (1,3-bis(carbazol-9-yl)benzene), TCTA, 2-TNATA, mCBP (3,3-di(9H-carbazol-9-yl)biphenyl), tris-Pcz, CzSi (9-(4-tert-butylphenyl)-3,6-bis(triphenylsilyl)-9H-carbazole), and/or DCB (N,N′-dicarbazolyl-1,4-dimethylbenzene).
Adjacent to the hole transport layer (HTL), typically, the light-emitting layer EML is located. The light-emitting layer EML includes at least one light emitting molecule. Particularly, the EML includes at least one light emitting molecule according to the invention. Typically, the EML additionally includes one or more host material. Exemplarily, the host material is selected from CBP (4,4′-Bis-(N-carbazolyl)-biphenyl), mCP, mCBP Sif87 (dibenzo[b,d]thiophen-2-yltriphenylsilane), CzSi, Sif88 (dibenzo[b,d]thiophen-2-yl)diphenylsilane), DPEPO (bis[2-(diphenylphosphino)phenyl]ether oxide), 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole, T2T (2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine), T3T (2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine) and/or TST (2,4,6-tris(9,9′-spirobifluorene-2-yl)-1,3,5-triazine). The host material typically should be selected to exhibit first triplet (T1) and first singlet (S1) energy levels, which are energetically higher than the first triplet (T1) and first singlet (S1) energy levels of the organic molecule.
In one embodiment of the invention, the EML includes a so-called mixed-host system with at least one hole-dominant host and one electron-dominant host. In a particular embodiment, the EML includes exactly one light emitting molecule species according to the invention and a mixed-host system including T2T as the electron-dominant host and a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole as the hole-dominant host. In a further embodiment the EML includes 50-80% by weight, preferably 60-75% by weight of a host selected from CBP, mCP, mCBP, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzofuran-2-yl)phenyl]-9H-carbazole, 9-[3-(dibenzothiophen-2-yl)phenyl]-9H-carbazole, 9-[3,5-bis(2-dibenzofuranyl)phenyl]-9H-carbazole and 9-[3,5-bis(2-dibenzothiophenyl)phenyl]-9H-carbazole; 10-45% by weight, preferably 15-30% by weight of T2T and 5-40% by weight, preferably 10-30% by weight of light emitting molecule according to the invention.
Adjacent to the light-emitting layer EML, an electron transport layer (ETL) may be located. Herein, any electron transporter may be used. Exemplarily, electron-poor compounds such as, e.g., benzimidazoles, pyridines, triazoles, oxadiazoles (e.g., 1,3,4-oxadiazole), phosphinoxides and sulfone, may be used. An electron transporter may also be a star-shaped heterocycle such as 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi). The ETL may include NBphen (2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline), Alq3 (Aluminum-tris(8-hydroxyquinoline)), TSPO1 (diphenyl-4-triphenylsilylphenyl-phosphinoxide), BPyTP2 (2,7-di(2,2′-bipyridin-5-yl)triphenyle), Sif87 (dibenzo[b,d]thiophen-2-yltriphenylsilane), Sif88 (dibenzo[b,d]thiophen-2-yl)diphenylsilane), BmPyPhB (1,3-bis[3,5-di(pyridin-3-yl)phenyl]benzene) and/or BTB (4,4′-bis-[2-(4,6-diphenyl-1,3,5-triazinyl)]-1,1′-biphenyl). Optionally, the ETL may be doped with materials such as Liq. The electron transport layer (ETL) may also block holes or a hole blocking layer (HBL) is introduced.
The HBL may, for example, include BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline=Bathocuproine), BAlq (bis(8-hydroxy-2-methylquinoline)-(4-phenylphenoxy)aluminum), NBphen (2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline), Alq3 (Aluminum-tris(8-hydroxyquinoline)), TSPO1 (diphenyl-4-triphenylsilylphenyl-phosphinoxide), T2T (2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine), T3T (2,4,6-tris(triphenyl-3-yl)-1,3,5-triazine), TST (2,4,6-tris(9,9′-spirobifluorene-2-yl)-1,3,5-triazine), and/or TCB/TCP (1,3,5-tris(N-carbazolyl)benzol/1,3,5-trs(carbazol)-9-yl) benzene).
A cathode layer C may be located adjacent to the electron transport layer (ETL). For example, the cathode layer C may include or may consist of a metal (e.g., Al, Au, Ag, Pt, Cu, Zn, Ni, Fe, Pb, LiF, Ca, Ba, Mg, In, W, or Pd) or a metal alloy. For practical reasons, the cathode layer may also consist of (essentially) non-transparent metals such as Mg, Ca or Al. Alternatively or additionally, the cathode layer C may also include graphite and or carbon nanotubes (CNTs). Alternatively, the cathode layer C may also consist of nanoscalic silver wires.
An OLED may further, optionally, include a protection layer between the electron transport layer (ETL) and the cathode layer C (which may be designated as electron injection layer (EIL)). This layer may include lithium fluoride, cesium fluoride, silver, Liq (8-hydroxyquinolinolatolithium), Li2O, BaF2, MgO and/or NaF.
Optionally, also the electron transport layer (ETL) and/or a hole blocking layer (HBL) may include one or more host compounds.
In order to modify the emission spectrum and/or the absorption spectrum of the light-emitting layer EML further, the light-emitting layer EML may further include one or more additional emitter molecules F. Such an emitter molecule F may be any emitter molecule known in the art. Preferably such an emitter molecule F is a molecule with a structure differing from the structure of the molecules according to the invention. The emitter molecule F may optionally be a TADF emitter. Alternatively, the emitter molecule F may optionally be a fluorescent and/or phosphorescent emitter molecule which is able to shift the emission spectrum and/or the absorption spectrum of the light-emitting layer EML. For example, the triplet and/or singlet excitons may be transferred from the emitter molecule according to the invention to the emitter molecule F before relaxing to the ground state S0 by emitting light typically red-shifted in comparison to the light emitted by emitter molecule E. Optionally, the emitter molecule F may also provoke two-photon effects (i.e., the absorption of two photons of half the energy of the absorption maximum).
Optionally, an optoelectronic device (e.g., an OLED) may, for example, be an essentially white optoelectronic device. Exemplarily such a white optoelectronic device may include at least one (deep) blue emitter molecule and one or more emitter molecules emitting green and/or red light. Then, there may also optionally be energy transmittance between two or more molecules as described above.
As used herein, if not defined more specifically in the particular context, the designation of the colors of emitted and/or absorbed light is as follows:
With respect to emitter molecules, such colors refer to the emission maximum. Therefore, exemplarily, a deep blue emitter has an emission maximum in the range of from >420 to 480 nm, a sky-blue emitter has an emission maximum in the range of from >480 to 500 nm, a green emitter has an emission maximum in a range of from >500 to 560 nm, and a red emitter has an emission maximum in a range of from >620 to 800 nm.
A further embodiment of the present invention relates to an OLED, which emits light with CIEx and CIEy color coordinates close to the CIEx (=0.170) and CIEy (=0.797) color coordinates of the primary color green (CIEx=0.170 and CIEy=0.797) as defined by ITU-R Recommendation BT.2020 (Rec. 2020) and thus is suited for the use in Ultra High Definition (UHD) displays, e.g. UHD-TVs. In this context, the term “close to” refers to the ranges of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically top-emitting (top-electrode is transparent) devices are used, whereas test devices as used throughout the present application represent bottom-emitting devices (bottom-electrode and substrate are transparent). Accordingly, a further aspect of the present invention relates to an OLED, whose emission exhibits a CIEx color coordinate of between 0.15 and 0.45 preferably between 0.15 and 0.35, more preferably between 0.15 and 0.30 or even more preferably between 0.15 and 0.25 or even between 0.15 and 0.20 and/or a CIEy color coordinate of between 0.60 and 0.92, preferably between 0.65 and 0.90, more preferably between 0.70 and 0.88 or even more preferably between 0.75 and 0.86 or even between 0.79 and 0.84.
A further embodiment of the present invention relates to an OLED, which emits light with CIEx and CIEy color coordinates close to the CIEx (=0.708) and CIEy (=0.292) color coordinates of the primary color red (CIEx=0.708 and CIEy=0.292) as defined by ITU-R Recommendation BT.2020 (Rec. 2020) and thus is suited for the use in Ultra High Definition (UHD) displays, e.g. UHD-TVs. In this context, the term “close to” refers to the ranges of CIEx and CIEy coordinates provided at the end of this paragraph. In commercial applications, typically top-emitting (top-electrode is transparent) devices are used, whereas test devices as used throughout the present application represent bottom-emitting devices (bottom-electrode and substrate are transparent). Accordingly, a further aspect of the present invention relates to an OLED, whose emission exhibits a CIEx color coordinate of between 0.60 and 0.88, preferably between 0.61 and 0.83, more preferably between 0.63 and 0.78 or even more preferably between 0.66 and 0.76 or even between 0.68 and 0.73 and/or a CIEy color coordinate of between 0.25 and 0.70, preferably between 0.26 and 0.55, more preferably between 0.27 and 0.45 or even more preferably between 0.28 and 0.40 or even between 0.29 and 0.35.
Accordingly, a further aspect of the present invention relates to an OLED, which exhibits an external quantum efficiency at 14500 cd/m2 of more than 10%, more preferably of more than 13%, more preferably of more than 15%, even more preferably of more than 17% or even more than 20% and/or exhibits an emission maximum between 495 nm and 580 nm, preferably between 500 nm and 560 nm, more preferably between 510 nm and 550 nm, even more preferably between 515 nm and 540 nm and/or exhibits a LT97 value at 14500 cd/m2 of more than 100 h, preferably more than 250 h, more preferably more than 500 h, even more preferably more than 750 h or even more than 1000 h.
The optoelectronic device, in particular the OLED according to the present invention can be manufactured by any means of vapor deposition and/or liquid processing. Accordingly, at least one layer is
The methods used to manufacture the optoelectronic device, in particular the OLED according to the present invention are known in the art. The different layers are individually and successively deposited on a suitable substrate by means of subsequent deposition processes. The individual layers may be deposited using the same or differing deposition methods.
Vapor deposition processes exemplarily include thermal (co)evaporation, chemical vapor deposition and physical vapor deposition. For active matrix OLED display, an AMOLED backplane is used as substrate. The individual layer may be processed from solutions or dispersions employing adequate solvents. Solution deposition process exemplarily include spin coating, dip coating and jet printing. Liquid processing may optionally be carried out in an inert atmosphere (e.g., in a nitrogen atmosphere) and the solvent may optionally be completely or partially removed by means known in the state of the art.
The general synthesis scheme provides a synthesis scheme for organic molecules according to the invention, wherein RIX, RXI, RXIII, RXIV, RXVI, and RXVIII are all hydrogen, wherein at least one pair of adjacent groups RI and RII, RII and RIII, or RIII and RIV forms an aromatic ring system with the adjacent benzene ring a, and wherein at least one pair of adjacent groups RV and RVI, RVI and RVII, or RVII and RVIII forms an aromatic ring system with the adjacent benzene ring b.
Under N2 atmosphere, a two-necked flask was charged with 1,3-dibromo-2-chlorobenzene [81067-41-6] (1.0 equiv.), a diarylamine E1 (2.2 equiv.), Pd2(dba)3 [51364-51-3] (0.02 equiv.) and sodium tert-butoxide [865-48-5] (3.3 equiv.). Dry toluene (4 mL/mmol wrt. 1,3-dibromo-2-chlorobenzene) and tri-tert-butylphosphonium tetrafluoroborate [131274-22-1] (0.08 equiv.) were added and the resulting suspension was degassed for 10 min. Subsequently, the mixture was heated at 110° C. until completion (usually 1-5 h). After cooling down to room temperature (rt), water was added, the phases were separated, the aqueous layer was extracted with toluene and the combined organic layers were dried over MgSO4, filtered and concentrated. The crude product was purified with MPLC or recrystallization to obtain the corresponding product P1 as a solid.
Under nitrogen atmosphere, in a flame-dried two-necked flask, aryl chloride P1 (1.0 equiv.) was dissolved in degassed tert-butylbenzene. At 20° C., a solution of tert-butyllithium (1.9 M in pentane [594-19-4] (2.2 equiv.) was added dropwise. Subsequently, the mixture was stirred at 40° C. until completion of the lithiation. At 0° C., trimethyl borate [121-43-7] (6.0 equiv.) was injected slowly and stirring was continued at 20° C. until completion of the borylation. Subsequently, water was added and the resulting biphasic mixture was stirred at 20° C. for 15 min. Ethyl acetate was added, the phases were separated, and the combined organic layers were dried over MgSO4, filtered and concentrated. The crude product was purified by recrystallization to obtain the corresponding boronic acid P2 as a solid.
Under N2 atmosphere, a two-necked flask was charged with the boronic acid P2 (1.0 equiv.). Dry chlorobenzene was added, followed by aluminum chloride [7446-70-0] (10 equiv.) and N,N-diisopropylethylamine (DIPEA) [7087-68-5] (10 equiv.). The resulting mixture was heated at 120° C. until completion of the reaction. After cooling down to rt, the reaction was quenched with ice water. Subsequently, the phases were separated, and the aqueous layer was extracted with dichloromethane. The combined organic layers were dried over MgSO4, filtered and concentrated. The residue was purified by filtration over a plug of silica, followed by precipitation from dichloromethane solution through addition of acetonitrile. The desired material P3, was obtained as a solid.
Under N2 atmosphere, a two-necked flask was charged with P3 (1.0 equiv.), bis(pinacolato)diboron [73183-34-3] (5.0 equiv.), Pd2(dba)3 [51364-51-3] (0.02 equiv.), X-Phos [564483-18-7] (0.08 equiv.) and potassium acetate [127-08-2] (7.5 equiv.). Dry dioxane (20 mL/mmol of P3) was added and the resulting mixture was degassed for 10 min. Subsequently, the mixture was heated at 100° C. for 24 h. After cooling down to room temperature (rt), dichloromethane and water were added, the phases were separated, and the aqueous layer was extracted with dichloromethane. The combined organic layers were stirred at rt with MgSO4/Celite® (kieselgur)/charcoal for 10 min, filtered and concentrated. The crude product was used for further conversion without purification. The desired boronic ester P4 was obtained as a solid.
Under N2 atmosphere, a two-necked flask was charged with P4 (1.0 equiv.), a heteroaryl chloride E2, E3, E4 or E5 (3.0 equiv.), Pd(PPh3)4 [14221-01-3] (0.1 equiv.) and potassium carbonate [584-08-7] (3.5 equiv.). A mixture of DMF and water (10:1 by volume, 22 mL/mmol of P4) was added and the resulting mixture was degassed for 10 min. Subsequently, the mixture was heated at 150° C. for 4 h. After cooling down to room temperature (rt), the mixture was poured into water. The precipitated solid was filtered off and rinsed with ethanol. The crude product was purified by recrystallization to obtain the corresponding product M1, M2, M3 or M4 as a solid.
Cyclic voltammograms were measured from solutions having concentration of 10−3 mol/L of the organic molecules in dichloromethane or a suitable solvent and a suitable supporting electrolyte (e.g. 0.1 mol/L of tetrabutylammonium hexafluorophosphate). The measurements were conducted at room temperature under nitrogen atmosphere with a three-electrode assembly (Working and counter electrodes: Pt wire, reference electrode: Pt wire) and calibrated using FeCp2/FeCp2+ as internal standard. The HOMO data was corrected using ferrocene as internal standard against a saturated calomel electrode (SCE).
Molecular structures were optimized employing the BP86 functional and the resolution of identity approach (RI). Excitation energies were calculated using the (BP86) optimized structures employing Time-Dependent DFT (TD-DFT) methods. Orbital and excited state energies were calculated with the B3LYP functional. Def2-SVP basis sets (and an m4-grid for numerical integration were used. The Turbomole program package was used for all calculations.
Sample pretreatment: Spin-coating
Apparatus: Spin150, SPS euro.
The sample concentration was 10 mg/ml, dissolved in a suitable solvent.
Program: 1) 3 s at 400 U/min; 2) 20 sat 1000 U/min at 1000 Upm/s. 3) 10 s at 4000 U/min at 1000 Upm/s. After coating, the films were tried at 70° C. for 1 min.
Steady-state emission spectroscopy was measured by a Horiba Scientific, Modell FluoroMax-4 equipped with a 150 W Xenon-Arc lamp, excitation- and emissions monochromators and a Hamamatsu R928 photomultiplier and a time-correlated single-photon counting option. Emissions and excitation spectra were corrected using standard correction fits.
Excited state lifetimes were determined employing the same system using the TCSPC method with FM-2013 equipment and a Horiba Yvon TCSPC hub.
Data analysis (exponential fit) was done using the software suite DataStation and DAS6 analysis software. The fit was specified using the chi-squared-test.
For photoluminescence quantum yield (PLQY) measurements an Absolute PL Quantum Yield Measurement C9920-03G system (Hamamatsu Photonics) was used. Quantum yields and CIE coordinates were determined using the software U6039-05 version 3.6.0.
Emission maxima were given in nm, quantum yields Φ in % and CIE coordinates as x,y values.
PLQY was determined using the following protocol:
Quality assurance: Anthracene in ethanol (known concentration) was used as reference
Excitation wavelength: the absorption maximum of the organic molecule was determined and the molecule was excited using this wavelength
Quantum yields were measured for sample of solutions or films under nitrogen atmosphere. The yield was calculated using the equation:
wherein ηphoton denotes the photon count and Int. denotes the intensity.
HPLC-MS analysis was performed on an HPLC by Agilent (1100 series) with MS-detector (Thermo LTQ XL).
A typical HPLC method was as follows: a reverse phase column 4.6 mm×150 mm, particle size 3.5 μm from Agilent (ZORBAX Eclipse Plus 95 Å C18, 4.6×150 mm, 3.5 μm HPLC column) was used in the HPLC. The HPLC-MS measurements were performed at room temperature (rt) with the following gradients:
and using the following solvent mixtures:
An injection volume of 5 μL from a solution with a concentration of 0.5 mg/mL of the analyte was taken for the measurements.
Ionization of the probe was performed using an APCI (atmospheric pressure chemical ionization) source either in positive (APCI+) or negative (APCI−) ionization mode.
Optoelectronic devices, such as OLED devices, including organic molecules according to the invention can be produced via vacuum-deposition methods. If a layer contains more than one compound, the weight-percentage of one or more compounds was given in %. The total weight-percentage values amount to 100%, thus if a value was not given, the fraction of this compound equals to the difference between the given values and 100%.
The (not fully optimized) OLEDs were characterized using standard methods and measuring electroluminescence spectra, the external quantum efficiency (in %) in dependency on the intensity, calculated using the light detected by the photodiode, and the current. The OLED device lifetime was extracted from the change of the luminance during operation at constant current density. The LT50 value corresponds to the time, where the measured luminance decreased to 50% of the initial luminance, analogously LT80 corresponds to the time point, at which the measured luminance decreased to 80% of the initial luminance, and LT 95 to the time point, at which the measured luminance decreased to 95% of the initial luminance etc.
Accelerated lifetime measurements were performed (e.g. applying increased current densities). Exemplarily LT80 values at 500 cd/m2 were determined using the following equation:
wherein L0 denotes the initial luminance at the applied current density.
The values correspond to the average of several pixels (typically two to eight), the standard deviation between these pixels was given.
Example 1 was synthesized according to
The emission maximum of example 1 (2% by weight in PMMA) was at 527 nm, the full width at half maximum (FWHM) was 0.20 eV, the CIEy coordinate was 0.65 and the PLQY was 84%. The onset of the emission spectrum was determined at 2.48 eV.
Example 2 was synthesized according to
The invention pertains to an organic molecule for use in optoelectronic devices. The organic molecule has a structure of Formula I:
| Number | Date | Country | Kind |
|---|---|---|---|
| 20187640.6 | Jul 2020 | EP | regional |
This application is a U.S. National Phase patent Application of International Patent Application Number PCT/EP2021/070469, filed on Jul. 22, 2021, which claims priority to European Patent Application Number 20187640.6, filed on Jul. 24, 2020, the entire contents of all of which are incorporated herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/070469 | 7/22/2021 | WO |
