Patent Application
20230284470
The present disclosure relates to an organic electroluminescent device comprising a light-emitting layer and a hole transport zone, and an organic electroluminescent compound.
A small molecular green organic electroluminescent device (OLED) was first developed by Tang, et al., of Eastman Kodak in 1987 by using TPD/ALq3 bi-layer consisting of a light-emitting layer and a charge transport layer. Thereafter, the development of OLEDs was rapidly effected and OLEDs have been commercialized. At present, OLEDs primarily use phosphorescent materials having excellent luminous efficiency in panel implementation. In many applications such as TVs and lightings, the lifetime of OLEDs is insufficient and higher efficiency of OLEDs is still required. Typically, the higher the luminance of an OLED, the shorter the lifetime the OLED has. Thus, an OLED which has high luminous efficiency and/or long lifetime is required for long time usage and high resolution displays.
In order to enhance luminous efficiency, driving voltage and/or lifetime, various materials or concepts for an organic layer of an OLED have been proposed. However, they were not satisfactory in practical use.
Korean Patent Application Laying-Open No. 2020-0099833 discloses a condensed ring compound. However, the aforementioned reference does not specifically disclose an organic electroluminescent device comprising a specific combination of compounds claimed in the present disclosure and a compound according to the present disclosure. In addition, there is still a need to develop a light-emitting material having more improved performances, for example, improved driving voltage, luminous efficiency, and/or lifetime properties compared to organic electroluminescent compounds and organic electroluminescent devices previously disclosed.
The objective of the present disclosure is to provide an organic electroluminescent device having lower driving voltage, higher luminous efficiency and/or improved lifetime properties by comprising a light-emitting layer and a hole transport zone comprising a specific combination of compounds. Another objective of the present disclosure is to provide an organic electroluminescent compound capable of providing an organic electroluminescent device having improved driving voltage and/or luminous efficiency properties.
As a result of intensive studies to solve the technical problems, the present inventors found that the above objective can be achieved by an organic electroluminescent compound represented by the following Formula 1; or an organic electroluminescent device comprising a first electrode, a second electrode, a light-emitting layer between the first electrode and the second electrode, and a hole transport zone between the first electrode and the light-emitting layer, wherein the hole transport zone has a triplet energy of not less than 2.7 eV and comprises a compound represented by the following formula 1, and the light-emitting layer comprises a compound having a triazinyl group.
In Formula 1,
L1 to L4, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (C3-C30)cycloalkylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;
R1 to R6, Ar1, and Ar2, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino; or may be linked to an adjacent substituent(s) to form a ring(s); and
a, c, d, and f, each independently, represent an integer of 1 to 4; b represents an integer of 1 to 3; and e represents an integer of 1 to 5, where if there are plural R1 to R6, each of R1 to each of R6 may be the same or different.
An organic electroluminescent compound according to the present disclosure exhibits performances suitable for using in an organic electroluminescent device. In addition, an organic electroluminescent device having lower driving voltage, higher luminous efficiency, and/or improved lifetime properties compared to the conventional organic electroluminescent device is provided by comprising the compound according to the present disclosure or a specific combination of compounds according to the present disclosure, and it is possible to produce a display system or lighting system using the same.
Hereinafter, the present disclosure will be described in detail. However, the following description is intended to explain the present disclosure and is not meant in any way to restrict the scope of the present disclosure.
The term “organic electroluminescent compound” in the present disclosure means a compound that may be used in an organic electroluminescent device, and may be comprised in any layer constituting an organic electroluminescent device, as necessary.
The term “an organic electroluminescent material” in the present disclosure means a material that may be used in an organic electroluminescent device, and may comprise at least one compound. The organic electroluminescent material may be comprised in any layer constituting an organic electroluminescent device, as necessary. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material (including a host material and a dopant material), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.
An organic electroluminescent device of the present disclosure comprises a first electrode; a second electrode facing the first electrode; a light-emitting layer between the first electrode and the second electrode; and a hole transport zone between the first electrode and the light-emitting layer. In addition, the organic electroluminescent device of the present disclosure may comprise an electron transport zone between the light-emitting layer and the second electrode. One of the first electrode and the second electrode may be an anode, and the other may be a cathode.
A hole transport zone of the present disclosure is meant to be a zone wherein holes are transported between the first electrode and the light-emitting layer, and may comprise, for example, one or more of a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, and an electron blocking layer. The hole injection layer, the hole transport layer, the hole auxiliary layer, the light-emitting auxiliary layer, and the electron blocking layer, respectively, may be a single layer, or a multi-layer in which two or more layers are stacked. According to one embodiment of the present disclosure, the hole transport zone may comprise at least one hole transport layer. A hole transport layer of the present disclosure may be at least one layer of a plurality of hole transport layers, and may comprise at least one of the hole auxiliary layer, the light-emitting auxiliary layer and the electron blocking layer. In addition, according to another embodiment of the present disclosure, the hole transport zone comprises a first hole transport layer and a second hole transport layer, wherein the first hole transport layer may be placed between a first electrode and a light-emitting layer, and the second hole transport layer may be placed between the first hole transport layer and the light-emitting layer and may be a layer acting as a hole transport layer, a light-emitting auxiliary layer, a hole auxiliary layer, and/or an electron blocking layer. Further, the hole injection layer may be doped with a p-dopant.
The hole transport layer may be placed between an anode (or a hole injection layer) and a light-emitting layer, and may promote the hole transport from the anode to the light-emitting layer and also may confine electrons transported from a cathode within the light-emitting layer. The light-emitting auxiliary layer may be placed between the anode and the light-emitting layer, or between the cathode and the light-emitting layer. When the light-emitting auxiliary layer is placed between the anode and the light-emitting layer, it can be used for promoting the hole injection and/or hole transport, or for preventing the overflow of electrons. When the light-emitting auxiliary layer is placed between the cathode and the light-emitting layer, it can be used for promoting the electron injection and/or electron transport, or for preventing the overflow of holes. Also, the hole auxiliary layer may be placed between the hole transport layer (or hole injection layer) and the light-emitting layer, and may be effective to promote or block the hole transport rate (or hole injection rate), thereby enabling the charge balance to be controlled. Further, the electron blocking layer may be placed between the hole transport layer (or hole injection layer) and the light-emitting layer, and can confine the excitons within the light-emitting layer by blocking the overflow of electrons from the light-emitting layer to prevent a light-emitting leakage. When an organic electroluminescent device includes two or more hole transport layers, the hole transport layer, which is further included, may be used as a light-emitting auxiliary layer, a hole auxiliary layer, an electron blocking layer, etc. The light-emitting auxiliary layer, the hole auxiliary layer and/or the electron blocking layer may have an effect of improving the luminous efficiency and/or the lifetime of an organic electroluminescent device.
The electron transport zone may be placed between a light-emitting layer and a cathode, and may comprise at least one of an electron buffer layer, a hole blocking layer, an electron transport layer, and an electron injection layer, and preferably at least one of an electron transport layer and an electron injection layer. The electron buffer layer can improve the problem of altering luminance due to the change of current characteristic in a device when exposed to high temperature in a process of manufacturing a panel, and can control a charge flow property. The electron buffer layer may be multi-layers in order to control the injection of the electron and improve the interfacial properties between the light-emitting layer and the electron injection layer, wherein each of the multi-layers may use two compounds simultaneously. The hole blocking layer or the electron transport layer may also be multi-layers, wherein each of the multi-layers may use a plurality of compounds. In addition, the electron injection layer may be doped with an n-dopant.
Herein, the term “(C1-C30)alkyl” is meant to be a linear or branched alkyl having 1 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 1 to 10, and more preferably 1 to 6. The above alkyl may include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl, etc. The term “(C3-C30)cycloalkyl” or “(C3-C30)cycloalkylene” is meant to be a mono- or polycyclic hydrocarbon having 3 to 30 ring backbone carbon atoms, in which the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The above cycloalkyl may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclohexylmethyl, etc. The term “(3- to 7-membered)heterocycloalkyl” is meant to be a cycloalkyl having 3 to 7 ring backbone atoms and including at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, and preferably the group consisting of O, S, and N. The above heterocycloalkyl may include tetrahydrofuran, pyrrolidine, thiolan, tetrahydropyran, etc. The term “(C6-C30)aryl” or “(C6-C30)arylene” is meant to be a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 ring backbone carbon atoms, and may be partially saturated. The above aryl may comprise a spiro structure. The above aryl may include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, diphenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, benzophenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, spiro[fluorene-benzofluorene]yl, spiro[cyclopentene-fluorene]yl, spiro[dihydroindene-fluorene]yl, azulenyl, tetramethyl-dihydrophenanthrenyl, etc. Specifically, the above aryl may include phenyl, 1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, benzanthryl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, 9-phenanthryl, naphthacenyl, pyrenyl, 1-chrysenyl, 2-chrysenyl, 3-chrysenyl, 4-chrysenyl, 5-chrysenyl, 6-chrysenyl, benzo[c]phenanthryl, benzo[g]chrysenyl, 1-triphenylenyl, 2-triphenylenyl, 3-triphenylenyl, 4-triphenylenyl, 1-fluorenyl, 2-fluorenyl, 3-fluorenyl, 4-fluorenyl, 9-fluorenyl, benzo[a]fluorenyl, benzo[b]fluorenyl, benzo[c]fluorenyl, dibenzofluorenyl, 2-biphenylyl, 3-biphenylyl, 4-biphenylyl, o-terphenyl, m-terphenyl-4-yl, m-terphenyl-3-yl, m-terphenyl-2-yl, p-terphenyl-4-yl, p-terphenyl-3-yl, p-terphenyl-2-yl, m-quaterphenyl, 3-fluoranthenyl, 4-fluoranthenyl, 8-fluoranthenyl, 9-fluoranthenyl, benzofluoranthenyl, o-tolyl, m-tolyl, p-tolyl, 2,3-xylyl, 3,4-xylyl, 2,5-xylyl, mesityl, o-cumenyl, m-cumenyl, p-cumenyl, p-tert-butylphenyl, p-(2-phenylpropyl)phenyl, 4′-methylbiphenyl, 4″-tert-butyl-p-terphenyl-4-yl, 9,9-dimethyl-1-fluorenyl, 9,9-dimethyl-2-fluorenyl, 9,9-dimethyl-3-fluorenyl, 9,9-dimethyl-4-fluorenyl, 9,9-diphenyl-1-fluorenyl, 9,9-diphenyl-2-fluorenyl, 9,9-diphenyl-3-fluorenyl, 9,9-diphenyl-4-fluorenyl, 11,11-dimethyl-1-benzo[a]fluorenyl, 11,11-dimethyl-2-benzo[a]fluorenyl, 11,11-dimethyl-3-benzo[a]fluorenyl, 11,11-dimethyl-4-benzo[a]fluorenyl, 11,11-dimethyl-5-benzo[a]fluorenyl, 11,11-dimethyl-6-benzo[a]fluorenyl, 11,11-dimethyl-7-benzo[a]fluorenyl, 11,11-dimethyl-8-benzo[a]fluorenyl, 11,11-dimethyl-9-benzo[a]fluorenyl, 11,11-dimethyl-10-benzo[a]fluorenyl, 11,11-dimethyl-1-benzo[b]fluorenyl, 11,11-dimethyl-2-benzo[b]fluorenyl, 11,11-dimethyl-3-benzo[b]fluorenyl, 11,11-dimethyl-4-benzo[b]fluorenyl, 11,11-dimethyl-5-benzo[b]fluorenyl, 11,11-dimethyl-6-benzo[b]fluorenyl, 11,11-dimethyl-7-benzo[b]fluorenyl, 11,11-dimethyl-8-benzo[b]fluorenyl, 11,11-dimethyl-9-benzo[b]fluorenyl, 11,11-dimethyl-10-benzo[b]fluorenyl, 11,11-dimethyl-1-benzo[c]fluorenyl, 11,11-dimethyl-2-benzo[c]fluorenyl, 11,11-dimethyl-3-benzo[c]fluorenyl, 11,11-dimethyl-4-benzo[c]fluorenyl, 11,11-dimethyl-5-benzo[c]fluorenyl, 11,11-dimethyl-6-benzo[c]fluorenyl, 11,11-dimethyl-7-benzo[c]fluorenyl, 11,11-dimethyl-8-benzo[c]fluorenyl, 11,11-dimethyl-9-benzo[c]fluorenyl, 11,11-dimethyl-10-benzo[c]fluorenyl, 11,11-diphenyl-1-benzo[a]fluorenyl, 11,11-diphenyl-2-benzo[a]fluorenyl, 11,11-diphenyl-3-benzo[a]fluorenyl, 11,11-diphenyl-4-benzo[a]fluorenyl, 11,11-diphenyl-5-benzo[a]fluorenyl, 11,11-diphenyl-6-benzo[a]fluorenyl, 11,11-diphenyl-7-benzo[a]fluorenyl, 11,11-diphenyl-8-benzo[a]fluorenyl, 11,11-diphenyl-9-benzo[a]fluorenyl, 11,11-diphenyl-10-benzo[a]fluorenyl, 11,11-diphenyl-1-benzo[b]fluorenyl, 11,11-diphenyl-2-benzo[b]fluorenyl, 11,11-diphenyl-3-benzo[b]fluorenyl, 11,11-diphenyl-4-benzo[b]fluorenyl, 11,11-diphenyl-5-benzo[b]fluorenyl, 11,11-diphenyl-6-benzo[b]fluorenyl, 11,11-diphenyl-7-benzo[b]fluorenyl, 11,11-diphenyl-8-benzo[b]fluorenyl, 11,11-diphenyl-9-benzo[b]fluorenyl, 11,11-diphenyl-10-benzo[b]fluorenyl, 11,11-diphenyl-1-benzo[c]fluorenyl, 11,11-diphenyl-2-benzo[c]fluorenyl, 11,11-diphenyl-3-benzo[c]fluorenyl, 11,11-diphenyl-4-benzo[c]fluorenyl, 11,11-diphenyl-5-benzo[c]fluorenyl, 11,11-diphenyl-6-benzo[c]fluorenyl, 11,11-diphenyl-7-benzo[c]fluorenyl, 11,11-diphenyl-8-benzo[c]fluorenyl, 11,11-diphenyl-9-benzo[c]fluorenyl, 11,11-diphenyl-10-benzo[c]fluorenyl, 9,9,10,10-tetramethyl-9,10-dihydro-1-phenanthrenyl, 9,9,10,10-tetramethyl-9,10-dihydro-2-phenanthrenyl, 9,9,10,10-tetramethyl-9,10-dihydro-3-phenanthrenyl, 9,9,10,10-tetramethyl-9,10-dihydro-4-phenanthrenyl, etc.
The term “(3- to 30-membered)heteroaryl” or “(3- to 30-membered)heteroarylene” is meant to be an aryl or arylene having 3 to 30 ring backbone atoms, and including at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P. The number of heteroatoms is preferably 1 to 4. The above heteroaryl or heteroarylene may be a monocyclic ring, or a fused ring condensed with at least one benzene ring; and may be partially saturated. In addition, the above heteroaryl or heteroarylene may be one formed by linking at least one heteroaryl or aryl group to a heteroaryl group via a single bond(s); and may comprise a spiro structure. The above heteroaryl may include a monocyclic ring-type heteroaryl such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, etc., and a fused ring-type heteroaryl such as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, dibenzoselenophenyl, naphthobenzofuranyl, naphthobenzothiophenyl, benzofuroquinolyl, benzofuroquinazolinyl, benzofuronaphthyridinyl, benzofuropyrimidinyl, naphthofuropyrimidinyl, benzothienoquinolyl, benzothienoquinazolinyl, benzothienonaphthyridinyl, benzothienopyrimidinyl, naphthothienopyrimidinyl, pyrimidoindolyl, benzopyrimidoindolyl, benzofuropyrazinyl, naphthofuropyrazinyl, benzothienopyrazinyl, naphthothienopyrazinyl, pyrazinoindolyl, benzopyrazinoindolyl, benzoimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, benzocarbazolyl, dibenzocarbazolyl, phenoxazinyl, phenanthridinyl, benzodioxolyl, dihydroacridinyl, benzotriazolyl, phenazinyl, imidazopyridyl, chromenoquinazolinyl, thiochromenoquinazolinyl, dimethylbenzopyrimidinyl, indolocarbazolyl, indenocarbazolyl, etc. More specifically, the above heteroaryl may include 1-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, pyrazinyl, 2-pyridinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 6-pyrimidinyl, 1,2,3-triazin-4-yl, 1,2,4-triazin-3-yl, 1,3,5-triazin-2-yl, 1-imidazolyl, 2-imidazolyl, 1-pyrazolyl, 1-indolidinyl, 2-indolidinyl, 3-indolidinyl, 5-indolidinyl, 6-indolidinyl, 7-indolidinyl, 8-indolidinyl, 2-imidazopyridinyl, 3-imidazopyridinyl, 5-imidazopyridinyl, 6-imidazopyridinyl, 7-imidazopyridinyl, 8-imidazopyridinyl, 3-pyridinyl, 4-pyridinyl, 1-indolyl, 2-indolyl, 3-indolyl, 4-indolyl, 5-indolyl, 6-indolyl, 7-indolyl, 1-isoindolyl, 2-isoindolyl, 3-isoindolyl, 4-isoindolyl, 5-isoindolyl, 6-isoindolyl, 7-isoindolyl, 2-furyl, 3-furyl, 2-benzofuranyl, 3-benzofuranyl, 4-benzofuranyl, 5-benzofuranyl, 6-benzofuranyl, 7-benzofuranyl, 1-isobenzofuranyl, 3-isobenzofuranyl, 4-isobenzofuranyl, 5-isobenzofuranyl, 6-isobenzofuranyl, 7-isobenzofuranyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 1-isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5-isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl, 2-quinoxalinyl, 5-quinoxalinyl, 6-quinoxalinyl, 1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl, 9-carbazolyl, azacarbazol-1-yl, azacarbazol-2-yl, azacarbazol-3-yl, azacarbazol-4-yl, azacarbazol-5-yl, azacarbazol-6-yl, azacarbazol-7-yl, azacarbazol-8-yl, azacarbazol-9-yl, 1-phenanthridinyl, 2-phenanthridinyl, 3-phenanthridinyl, 4-phenanthridinyl, 6-phenanthridinyl, 7-phenanthridinyl, 8-phenanthridinyl, 9-phenanthridinyl, 10-phenanthridinyl, 1-acridinyl, 2-acridinyl, 3-acridinyl, 4-acridinyl, 9-acridinyl, 2-oxazolyl, 4-oxazolyl, 5-oxazolyl, 2-oxadiazolyl, 5-oxadiazolyl, 3-furazanyl, 2-thienyl, 3-thienyl, 2-methylpyrrol-1-yl, 2-methylpyrrol-3-yl, 2-methylpyrrol-4-yl, 2-methylpyrrol-5-yl, 3-methylpyrrol-1-yl, 3-methylpyrrol-2-yl, 3-methylpyrrol-4-yl, 3-methylpyrrol-5-yl, 2-tert-butylpyrrol-4-yl, 3-(2-phenylpropyl)pyrrol-1-yl, 2-methyl-1-indolyl, 4-methyl-1-indolyl, 2-methyl-3-indolyl, 4-methyl-3-indolyl, 2-tert-butyl-1-indolyl, 4-tert-butyl-1-indolyl, 2-tert-butyl-3-indolyl, 4-tert-butyl-3-indolyl, 1-dibenzofuranyl, 2-dibenzofuranyl, 3-dibenzofuranyl, 4-dibenzofuranyl, 1-dibenzothiophenyl, 2-dibenzothiophenyl, 3-dibenzothiophenyl, 4-dibenzothiophenyl, 1-naphtho-[1,2-b]-benzofuranyl, 2-naphtho-[1,2-b]-benzofuranyl, 3-naphtho-[1,2-b]-benzofuranyl, 4-naphtho-[1,2-b]-benzofuranyl, 5-naphtho-[1,2-b]-benzofuranyl, 6-naphtho-[1,2-b]-benzofuranyl, 7-naphtho-[1,2-b]-benzofuranyl, 8-naphtho-[1,2-b]-benzofuranyl, 9-naphtho-[1,2-b]-benzofuranyl, 10-naphtho-[1,2-b]-benzofuranyl, 1-naphtho-[2,3-b]-benzofuranyl, 2-naphtho-[2,3-b]-benzofuranyl, 3-naphtho-[2,3-b]-benzofuranyl, 4-naphtho-[2,3-b]-benzofuranyl, 5-naphtho-[2,3-b]-benzofuranyl, 6-naphtho-[2,3-b]-benzofuranyl, 7-naphtho-[2,3-b]-benzofuranyl, 8-naphtho-[2,3-b]-benzofuranyl, 9-naphtho-[2,3-b]-benzofuranyl, 10-naphtho-[2,3-b]-benzofuranyl, 1-naphtho-[2,1-b]-benzofuranyl, 2-naphtho-[2,1-b]-benzofuranyl, 3-naphtho-[2,1-b]-benzofuranyl, 4-naphtho-[2,1-b]-benzofuranyl, 5-naphtho-[2,1-b]-benzofuranyl, 6-naphtho-[2,1-b]-benzofuranyl, 7-naphtho-[2,1-b]-benzofuranyl, 8-naphtho-[2,1-b]-benzofuranyl, 9-naphtho-[2,1-b]-benzofuranyl, 10-naphtho-[2,1-b]-benzofuranyl, 1-naphtho-[1,2-b]-benzothiophenyl, 2-naphtho-[1,2-b]-benzothiophenyl, 3-naphtho-[1,2-b]-benzothiophenyl, 4-naphtho-[1,2-b]-benzothiophenyl, 5-naphtho-[1,2-b]-benzothiophenyl, 6-naphtho-[1,2-b]-benzothiophenyl, 7-naphtho-[1,2-b]-benzothiophenyl, 8-naphtho-[1,2-b]-benzothiophenyl, 9-naphtho-[1,2-b]-benzothiophenyl, 10-naphtho-[1,2-b]-benzothiophenyl, 1-naphtho-[2,3-b]-benzothiophenyl, 2-naphtho-[2,3-b]-benzothiophenyl, 3-naphtho-[2,3-b]-benzothiophenyl, 4-naphtho-[2,3-b]-benzothiophenyl, 5-naphtho-[2,3-b]-benzothiophenyl, 1-naphtho-[2,1-b]-benzothiophenyl, 2-naphtho-[2,1-b]-benzothiophenyl, 3-naphtho-[2,1-b]-benzothiophenyl, 4-naphtho-[2,1-b]-benzothiophenyl, 5-naphtho-[2,1-b]-benzothiophenyl, 6-naphtho-[2,1-b]-benzothiophenyl, 7-naphtho-[2,1-b]-benzothiophenyl, 8-naphtho-[2,1-b]-benzothiophenyl, 9-naphtho-[2,1-b]-benzothiophenyl, 10-naphtho-[2,1-b]-benzothiophenyl, 2-benzofuro[3,2-d]pyrimidinyl, 6-benzofuro[3,2-d]pyrimidinyl, 7-benzofuro[3,2-d]pyrimidinyl, 8-benzofuro[3,2-d]pyrimidinyl, 9-benzofuro[3,2-d]pyrimidinyl, 2-benzothio[3,2-d]pyrimidinyl, 6-benzothio[3,2-d]pyrimidinyl, 7-benzothio[3,2-d]pyrimidinyl, 8-benzothio[3,2-d]pyrimidinyl, 9-benzothio[3,2-d]pyrimidinyl, 2-benzofuro[3,2-d]pyrazinyl, 6-benzofuro[3,2-d]pyrazinyl, 7-benzofuro[3,2-d]pyrazinyl, 8-benzofuro[3,2-d]pyrazinyl, 9-benzofuro[3,2-d]pyrazinyl, 2-benzothio[3,2-d]pyrazinyl, 6-benzothio[3,2-d]pyrazinyl, 7-benzothio[3,2-d]pyrazinyl, 8-benzothio[3,2-d]pyrazinyl, 9-benzothio[3,2-d]pyrazinyl, 1-silafluorenyl, 2-silafluorenyl, 3-silafluorenyl, 4-silafluorenyl, 1-germafluorenyl, 2-germafluorenyl, 3-germafluorenyl, 4-germafluorenyl, 1-dibenzoselenophenyl, 2-dibenzoselenophenyl, 3-dibenzoselenophenyl, 4-dibenzoselenophenyl, etc. Furthermore, “halogen” includes F, Cl, Br, and I.
In addition, “ortho (o-),” “meta (m-),” and “para (p-)” are prefixes, which represent the relative positions of substituents respectively. Ortho indicates that two substituents are adjacent to each other, and for example, when two substituents in a benzene derivative occupy positions 1 and 2, it is called an ortho position. Meta indicates that two substituents are at positions 1 and 3, and for example, when two substituents in a benzene derivative occupy positions 1 and 3, it is called a meta position. Para indicates that two substituents are at positions 1 and 4, and for example, when two substituents in a benzene derivative occupy positions 1 and 4, it is called a para position.
Herein, “substituted” in the expression “substituted or unsubstituted” means that a hydrogen atom in a certain functional group is replaced with another atom or another functional group, i.e., a substituent, and also includes that the hydrogen atom is replaced with a group formed by a linkage of two or more substituents of the above substituents. For example, the “group formed by a linkage of two or more substituents” may be pyridine-triazine. That is, pyridine-triazine may be interpreted as a heteroaryl substituent, or as substituents in which two heteroaryl substituents are linked. Herein, the substituent(s) of the substituted alkyl, the substituted aryl, the substituted arylene, the substituted heteroaryl, the substituted heteroarylene, the substituted cycloalkyl, the substituted cycloalkylene, the substituted alkoxy, the substituted trialkylsilyl, the substituted dialkylarylsilyl, the substituted alkyldiarylsilyl, the substituted triarylsilyl, the substituted fused ring group of an aliphatic ring(s) and an aromatic ring(s), the substituted mono- or di-alkylamino, the substituted mono- or di-alkenylamino, the substituted alkylalkenylamino, the substituted mono- or di-arylamino, the substituted alkylarylamino, the substituted mono- or di-heteroarylamino, the substituted alkylheteroarylamino, the substituted alkenylarylamino, the substituted alkenylheteroarylamino, and the substituted arylheteroarylamino, each independently, are at least one selected from the group consisting of deuterium; a halogen; a cyano; a carboxyl; a nitro; a hydroxyl; a phosphine oxide; a (C1-C30)alkyl; a halo(C1-C30)alkyl; a (C2-C30)alkenyl; a (C2-C30)alkynyl; a (C1-C30)alkoxy; a (C1-C30)alkylthio; a (C3-C30)cycloalkyl; a (C3-C30)cycloalkenyl; a (3- to 7-membered)heterocycloalkyl; a (C6-C30)aryloxy; a (C6-C30)arylthio; a (3- to 30-membered)heteroaryl unsubstituted or substituted with at least one of deuterium and a (C6-C30)aryl(s); a (C6-C30)aryl unsubstituted or substituted with at least one of deuterium and a (3- to 30-membered)heteroaryl(s); a tri(C1-C30)alkylsilyl; a tri(C6-C30)arylsilyl; a di(C1-C30)alkyl(C6-C30)arylsilyl; a (C1-C30)alkyldi(C6-C30)arylsilyl; an amino; a mono- or di-(C1-C30)alkylamino; a mono- or di-(C2-C30)alkenylamino; a mono- or di-(C6-C30)arylamino unsubstituted or substituted with a (C1-C30)alkyl(s); a mono- or di-(3- to 30-membered)heteroarylamino; a (C1-C30)alkyl(C2-C30)alkenylamino; a (C1-C30)alkyl(C6-C30)arylamino; a (C1-C30)alkyl(3- to 30-membered)heteroarylamino; a (C2-C30)alkenyl(C6-C30)arylamino; a (C2-C30)alkenyl(3- to 30-membered)heteroarylamino; a (C6-C30)aryl(3- to 30-membered)heteroarylamino; a (C1-C30)alkylcarbonyl; a (C1-C30)alkoxycarbonyl; a (C6-C30)arylcarbonyl; a (C6-C30)arylphosphine; a di(C6-C30)arylboronyl; a di(C1-C30)alkylboronyl; a (C1-C30)alkyl(C6-C30)arylboronyl; a (C6-C30)aryl(C1-C30)alkyl; and a (C1-C30)alkyl(C6-C30)aryl, which may be further substituted with deuterium. According to one embodiment of the present disclosure, the substituent(s), each independently, are at least one selected from the group consisting of deuterium; a cyano; a (C1-C20)alkyl; a (5- to 25-membered)heteroaryl unsubstituted or substituted with deuterium; a (C6-C25)aryl unsubstituted or substituted with deuterium; and a tri(C6-C25)arylsilyl. According to another embodiment of the present disclosure, the substituent(s), each independently, are at least one selected from the group consisting of deuterium; a cyano; a (C1-C10)alkyl; a (5- to 20-membered)heteroaryl unsubstituted or substituted with deuterium; a (C6-C18)aryl unsubstituted or substituted with deuterium; and a tri(C6-C18)arylsilyl. For example, the substituent(s), each independently, may be at least one selected from the group consisting of deuterium; a cyano; a tert-butyl; a phenyl unsubstituted or substituted with deuterium; a naphthyl unsubstituted or substituted with deuterium; a biphenyl; a dibenzofuranyl; a dibenzothiophenyl; a carbazolyl; and a triphenylsilyl.
In the present disclosure, “a ring formed by a linkage of adjacent substituents” means that at least two adjacent substituents are linked or fused to each other to form a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof. The ring may be preferably a substituted or unsubstituted, mono- or polycyclic, (3- to 26-membered) alicyclic or aromatic ring, or the combination thereof, and more preferably a mono- or polycyclic, (5- to 25-membered) aromatic ring unsubstituted or substituted with at least one of a (C6-C18)aryl(s) and a (3- to 20-membered)heteroaryl(s). In addition, the formed ring may contain at least one heteroatom selected from the group consisting of B, N, O, S, Se, Si, and P, preferably at least one heteroatom selected from the group consisting of N, O, S, and Si. For example, the ring may be a benzene ring, a cyclopentane ring, an indane ring, a fluorene ring, a phenanthrene ring, an indole ring, a xanthene ring, etc.
In the present disclosure, heteroaryl, heteroarylene, and heterocycloalkyl may, each independently, contain at least one heteroatom selected from the group consisting of B, N, O, S, Se, Si, and P. In addition, the heteroatom may be bonded to at least one selected from the group consisting of hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, and a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino.
The hole transport zone of the present disclosure may consist of a plurality of layers, wherein at least one layer of the plurality of layers may comprise the compound represented by Formula 1. The layer comprising the compound represented by Formula 1, or the other layer may comprise any compound conventionally used as a hole transport zone material. According to one embodiment of the present disclosure, the hole transport zone of the present disclosure, for example, at least one of a light-emitting auxiliary layer, a hole auxiliary layer, a hole transport layer, and a second hole transport layer may comprise the compound represented by Formula 1. The compound represented by Formula 1 has a triplet energy of not less than 2.7 eV. According to another embodiment, the compound represented by Formula 1 has a refractive index of not greater than 1.74.
According to one embodiment of the present disclosure, Formula 1 is represented by any one of the following formulas 1-1 to 1-3.
In Formulas 1 and 1-1 to 1-3, L1 to L4, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (C3-C30)cycloalkylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene. According to one embodiment of the present disclosure, L1 to L4, each independently, represent a single bond, or a substituted or unsubstituted (C6-C25)arylene. According to another embodiment of the present disclosure, L1 to L4, each independently, represent a single bond, or an unsubstituted (C6-C18)arylene. For example, L1 to L4, each independently, may be a single bond or a phenylene, etc.
In Formulas 1 and 1-1 to 1-3, R1 to R6, Ar1, and Ar2, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino; or may be linked to an adjacent substituent(s) to form a ring(s).
According to one embodiment of the present disclosure, Ar1 and Ar2, each independently, represent a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, Ar1 and Ar2, each independently, represent a (C1-C10)alkyl unsubstituted or substituted with a (C6-C18)aryl(s); a (C6-C18)aryl unsubstituted or substituted with deuterium; or an unsubstituted (5- to 20-membered)heteroaryl. For example, Ar1 and Ar2, each independently, may be a propyl substituted a phenyl(s), a tert-butyl, a phenyl unsubstituted or substituted with deuterium, a biphenyl, a dibenzothiophenyl, a dibenzofuranyl, or a dibenzoselenophenyl, etc.
According to one embodiment of the present disclosure, R1 to R6, each independently, represent hydrogen, deuterium, a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, a substituted or unsubstituted (5- to 25-membered)heteroaryl, or a substituted or unsubstituted mono- or di-(C6-C25)arylamino. According to another embodiment of the present disclosure, R1 to R6, each independently, represent hydrogen, deuterium, a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s), or an unsubstituted di(C6-C18)arylamino. For example, R1 to R6, each independently, may be hydrogen, deuterium, a carbazolyl unsubstituted or substituted with a phenyl(s), a benzocarbazolyl, a diphenylamino, or a phenylnaphthylamino, etc.
In Formulas 1 and 1-1 to 1-3, a, c, d, and f, each independently, represent an integer of 1 to 4; b represents an integer of 1 to 3; and e represents an integer of 1 to 5, where if there are plural R1 to R6, each of R1 to each of R6 may be the same or different.
A light-emitting layer of the present disclosure may consist of a plurality of layers, wherein at least one layer of the plurality of light-emitting layers may comprise a compound having a triazinyl group. According to one embodiment of the present disclosure, the compound having a triazinyl group may be represented by at least one of the following Formulas 2-1 to 2-3.
In Formulas 2-1 to 2-3, Xa and V, each independently, represent —N(Lc-R14)—, —C(R15)(R16)—, —O—, or —S—.
In Formulas 2-1 to 2-3, La to Lc, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (C3-C30)cycloalkylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene. According to one embodiment of the present disclosure, La to Lc, each independently, represent a single bond, or a substituted or unsubstituted (C6-C25)arylene. According to another embodiment of the present disclosure, La to Lc, each independently, represent a single bond, or a (C6-C18)arylene unsubstituted or substituted with a (C6-C18)aryl(s) or a tri(C6-C18)arylsilyl(s). For example, La to Lc, each independently, may be a single bond, a phenylene unsubstituted or substituted with at least one of a phenyl(s) and a triphenylsilyl(s), a naphthylene, or a biphenylene, etc.
In Formulas 2-1 to 2-3, Ara and Arb, each independently, represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl. According to one embodiment of the present disclosure, Ara and Arb, each independently, represent a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, Ara and Arb, each independently, represent a (C6-C18)aryl unsubstituted or substituted with at least one selected from the group consisting of a cyano(s), a (C1-C10)alkyl(s), a (C6-C18)aryl(s), a (5- to 25-membered)heteroaryl(s), and a tri(C6-C18)arylsilyl(s); or a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s). For example, Ara and Arb, each independently, may be a phenyl unsubstituted or substituted with a cyano(s), a tert-butyl(s), a dibenzofuranyl(s), a carbazolyl(s), or a triphenylsilyl(s); a naphthyl; a biphenyl; a diphenylfluorenyl; a terphenyl; a triphenylenyl; a dibenzothiophenyl; a dibenzofuranyl; or a carbazolyl unsubstituted or substituted with a phenyl(s) or a biphenyl(s), etc.
In Formulas 2-1 to 2-3, R7 to R16, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or may be linked to an adjacent substituent(s) to form a ring(s).
According to one embodiment of the present disclosure, R7 to R13, each independently, represent hydrogen, deuterium, a cyano, a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, a substituted or unsubstituted (5- to 25-membered)heteroaryl, or a substituted or unsubstituted tri(C6-C25)arylsilyl. According to another embodiment of the present disclosure, R7 to R13, each independently, represent hydrogen, a cyano, a (C6-C25)aryl unsubstituted or substituted with a tri(C6-C18)arylsilyl(s), a (5- to 20-membered)heteroaryl unsubstituted or substituted with a (C6-C18)aryl(s), or an unsubstituted tri(C6-C18)arylsilyl. For example, R7 to R13, each independently, may be hydrogen, a cyano, a phenyl unsubstituted or substituted with a triphenylsilyl(s), a biphenyl, a spirobifluorenyl, a carbazolyl unsubstituted or substituted with a phenyl(s), a dibenzothiophenyl unsubstituted or substituted with a phenyl(s), or a triphenylsilyl, etc.
According to one embodiment of the present disclosure, R14 to R16, each independently, represent a substituted or unsubstituted (C1-C20)alkyl, a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, R14 to R16, each independently, represent an unsubstituted (C1-C10)alkyl, or an unsubstituted (C6-C18)aryl. For example, R14 may be a phenyl or a biphenyl, etc., and R15 and R16, each independently, may be a methyl or a phenyl, etc. R15 and R16 may be the same as or different from each other.
In Formulas 2-1 to 2-3, g, i, and k to m, each independently, represent an integer of 1 to 4; h represents an integer of 1 to 3; and j represents an integer of 1 or 2, where if there are plural R7 to R13, each of R7 to each of R13 may be the same or different.
According to one embodiment of the present disclosure, Formula 2-1 represented by the following formula is excluded.
According to one embodiment of the present disclosure, the light-emitting layer of the present disclosure may further comprise a compound represented by the following Formula 3.
In Formula 3, Lb and Lc, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene. According to one embodiment of the present disclosure, Lb and Lc, each independently, represent a single bond, a substituted or unsubstituted (C6-C25)arylene, or a substituted or unsubstituted (5- to 25-membered)heteroarylene. According to another embodiment of the present disclosure, Lb and Lc, each independently, represent a single bond, a (C6-C18)arylene unsubstituted or substituted with deuterium, or a (5- to 20-membered)heteroarylene unsubstituted or substituted with deuterium. For example, Lb and Lc, each independently, may be a single bond, a phenylene, a naphthylene, a dibenzofuranylene, a dibenzothiophenylene, or a carbazolylene, etc., which may be substituted with one or more deuterium.
In Formula 3, Arc and Ard, each independently, represent a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, or a substituted or unsubstituted tri(C6-C30)arylsilyl. According to one embodiment of the present disclosure, Arc and Ard, each independently, represent a substituted or unsubstituted (C6-C25)aryl, or a substituted or unsubstituted (5- to 25-membered)heteroaryl. According to another embodiment of the present disclosure, Arc and Ard, each independently, represent a (C6-C18)aryl unsubstituted or substituted with deuterium; or a (5- to 20-membered)heteroaryl unsubstituted or substituted with at least one of deuterium and a (C6-C18)aryl(s). For example, Arc and Ard, each independently, may be a phenyl; a naphthyl; a biphenyl; a terphenyl; a triphenylenyl; a dibenzofuranyl unsubstituted or substituted with a phenyl(s); a dibenzothiophenyl unsubstituted or substituted with a phenyl(s); or a carbazolyl substituted with a phenyl(s) or a naphthyl(s), etc., which may be further substituted with deuterium.
In Formula 3, R17 to R20, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino; or may be linked to an adjacent substituent(s) to form a ring(s). For example, R17 to R20, each independently, may be hydrogen or deuterium.
In Formula 3, n and q, each independently, represent an integer of 1 to 4; and o and p, each independently, represent an integer of 1 to 3, where if there are plural R17 to R20, each of R17 to each of R20 may be the same or different.
The present disclosure provides an organic electroluminescent compound represented by Formula 1. According to one embodiment of the present disclosure, Formula 1 may be represented by any one of the following formulas 1′-1 to 1′-3.
In Formulas 1 and 1′-1 to 1′-3,
L1 to L4, each independently, represent a single bond, a substituted or unsubstituted (C6-C30)arylene, a substituted or unsubstituted (C3-C30)cycloalkylene, or a substituted or unsubstituted (3- to 30-membered)heteroarylene;
R1 to R6, Ar1, and Ar2, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted fused ring group of a (C3-C30) aliphatic ring(s) and a (C6-C30) aromatic ring(s), an amino, a substituted or unsubstituted mono- or di-(C1-C30)alkylamino, a substituted or unsubstituted mono- or di-(C2-C30)alkenylamino, a substituted or unsubstituted (C1-C30)alkyl(C2-C30)alkenylamino, a substituted or unsubstituted mono- or di-(C6-C30)arylamino, a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino, a substituted or unsubstituted mono- or di-(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C1-C30)alkyl(3- to 30-membered)heteroarylamino, a substituted or unsubstituted (C2-C30)alkenyl(C6-C30)arylamino, a substituted or unsubstituted (C2-C30)alkenyl(3- to 30-membered)heteroarylamino, or a substituted or unsubstituted (C6-C30)aryl(3- to 30-membered)heteroarylamino; or may be linked to an adjacent substituent(s) to form a ring(s); with the proviso that -L1-Ar1 does not include a naphthyl or a naphthylene.
In Formulas 1′-1 to 1-3, Ar3 and Ar4, each independently, represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl. According to one embodiment of the present disclosure, Ar3 and Ar4, each independently, represent a substituted or unsubstituted (C6-C25)aryl. According to another embodiment of the present disclosure, Ar3 and Ar4, each independently, represent a (C6-C18)aryl unsubstituted or substituted with a (C6-C18)aryl(s). For example, Ar3 and Ar4, each independently, may be a phenyl unsubstituted or substituted with a phenyl(s), or a naphthyl, etc.
In Formulas 1′-1 to 1-3, L5 represents a single bond; a′ represents an integer of 1 to 3; and b′ and c′, each independently, represent an integer of 0 or 1, where there are plural R1, each of R1 may be the same or different.
Preferred embodiments of L1 to L4, R1 to R6, Ar1, and Ar2 are as defined in Formula 1.
The compound represented by Formula 1 may be at least one selected from the group consisting of the following compounds, but is not limited thereto.
The compound having a triazinyl group may be at least one selected from the group consisting of the following compounds, but is not limited thereto.
The compound represented by Formula 3 may be at least one selected from the group consisting of the following compounds, but is not limited thereto.
In the compounds, Dn represents that n number of hydrogens are replaced with deuterium; and n represents an integer of 1 or more, preferably an integer of 4 or more, and more preferably an integer of 8 or more. When being deuterated to the number of the lower limit or more, the bond dissociation energy related to deuteration may be sufficiently increased to exhibit improved lifetime property. The upper limit of n is determined by the number of hydrogens capable of being substituted in each compound.
According to one embodiment of the present disclosure, the present disclosure can provide a compound represented by any one of Formulas 1, 2-1 to 2-3, and 3. Specifically, the present disclosure can provide at least one compound of compounds T-1 to T-35, compounds H1-1 to H1-150, and compounds H2-1 to H2-180. In addition, the present disclosure provides an organic electroluminescent material or an organic electroluminescent device comprising at least one of the above compounds. The organic electroluminescent material may consist of the organic electroluminescent compound alone, or may further comprise conventional materials comprised in an organic electroluminescent material.
According to one embodiment of the present disclosure, the present disclosure can provide a combination of the compound represented by Formula 1, and at least one of at least one compound represented by any one of Formulas 2-1 to 2-3 and the compound represented by Formula 3. Specifically, the present disclosure can provide a combination of at least one of compounds T-1 to T-35, and at least one of compounds H1-1 to H1-150 and H2-1 to H2-180, which may be used in an organic electroluminescent device. It may be a combination of a hole transport zone material and a host material of a light-emitting layer.
The organic electroluminescent compounds represented by Formulas 1, 2-1 to 2-3, and 3 of the present disclosure may be comprised in any one layer of a light-emitting layer, a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron transport layer, an electron buffer layer, an electron injection layer, an interlayer, a hole blocking layer, and an electron blocking layer and, if necessary, preferably in at least one of a light-emitting layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron transport layer, an electron buffer layer, a hole blocking layer, and an electron blocking layer. When comprised in a light-emitting layer, the organic electroluminescent compound of the present disclosure may be used as at least one of a single host material or a co-host material. According to one embodiment of the present disclosure, the organic electroluminescent compounds represented by Formulas 2-1 to 2-3 and 3 may be comprised as a host material in a light-emitting layer, and the organic electroluminescent compound represented by Formula 1 may be comprised in at least one of a hole injection layer, a hole transport layer, a hole auxiliary layer, and a light-emitting auxiliary layer.
The compounds represented by formulas 1, 2-1 to 2-3, and 3 according to the present disclosure may be produced by synthetic methods known to one skilled in the art, in particular by synthetic methods disclosed in a number of patent publications. For example, the compounds represented by Formulas 1 and 1′-1 to 1′-3 may be produced by referring to the following reaction schemes 1 to 3, but is not limited thereto. For example, the compounds represented by Formulas 2-1 to 2-3 may be produced by referring to Korean Patent Application Laid-Open Nos. 2020-0026083 (published on Mar. 10, 2020), 2010-0108903 (published on Oct. 8, 2010), and 2013-0130236 (published on Dec. 2, 2013), etc., but is not limited thereto. For example, the compound represented by Formula 3 may be produced by referring to Japanese Patent No. 3139321 (published on Dec. 15, 2000) and Korean Patent No. 2283849 (published on Aug. 2, 2021), etc., but is not limited thereto.
In Reaction Schemes 1 to 3, X, X1, and X2, each independently, represent a halogen; and L1 to L5, Ar1 to Ar4, R1 to R6, a to f, and a′ to c′ are as defined in Formulas 1 and 1′-1 to 1′-3.
Although illustrative synthesis examples of the compound represented by Formulas 1 and 1′-1 to 1′-3 are described above, one skilled in the art will be able to readily understand that all of them are based on a Buchwald-Hartwig cross-coupling reaction, an N-arylation reaction, a H-mont-mediated etherification reaction, a Miyaura borylation reaction, a Suzuki cross-coupling reaction, an Intramolecular acid-induced cyclization reaction, a Pd(II)-catalyzed oxidative cyclization reaction, a Grignard reaction, a Heck reaction, a Cyclic Dehydration reaction, an SN1 substitution reaction, an SN2 substitution reaction, and a Phosphine-mediated reductive cyclization reaction, etc., and the reactions above proceed even when substituents which are defined in Formulas 1 and 1′-1 to 1′-3 above, but are not specified in the specific synthesis examples, are bonded.
Also, the deuterated compound of the present disclosure may be prepared in a similar manner by using deuterated precursor materials, or more generally may be prepared by treating the non-deuterated compound with a deuterated solvent or D6-benzene in the presence of an H/D exchange catalyst such as a Lewis acid, e.g., aluminum trichloride or ethyl aluminum chloride. In addition, the degree of deuteration can be controlled by changing the reaction conditions such as the reaction temperature. For example, the number of n in a compound can be controlled by adjusting the reaction temperature and time, the equivalent of the acid, etc.
According to one embodiment of the present disclosure, the doping concentration of a dopant compound with respect to a host compound in the light-emitting layer may be less than about 20 wt %.
The dopant comprised in the organic electroluminescent device of the present disclosure may be at least one phosphorescent or fluorescent dopant, and is preferably a phosphorescent dopant. The phosphorescent dopant material applied to the organic electroluminescent device of the present disclosure is not particularly limited, but may be a complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), and preferably ortho-metallated complex compounds of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), and more preferably ortho-metallated iridium complex compounds.
The dopant comprised in the organic electroluminescent device of the present disclosure may comprise a compound represented by the following formula 101, but is not limited thereto.
In Formula 101,
L is selected from the following structures 1 to 3:
R100 to R103, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a cyano, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to an adjacent substituent(s) to form a ring(s), e.g., a substituted or unsubstituted quinoline, a substituted or unsubstituted benzofuropyridine, a substituted or unsubstituted benzothienopyridine, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuroquinoline, a substituted or unsubstituted benzothienoquinoline, or a substituted or unsubstituted indenoquinoline, together with pyridine;
R104 to R107, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a cyano, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to an adjacent substituent(s) to form a substituted or unsubstituted ring(s), e.g., a substituted or unsubstituted naphthalene, a substituted or unsubstituted fluorene, a substituted or unsubstituted dibenzothiophene, a substituted or unsubstituted dibenzofuran, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuropyridine, or a substituted or unsubstituted benzothienopyridine, together with benzene;
R201 to R220, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium and/or a halogen(s), a substituted or unsubstituted (C3-C30)cycloalkyl, or a substituted or unsubstituted (C6-C30)aryl; or may be linked to an adjacent substituent(s) to form a substituted or unsubstituted ring(s); and
s represents an integer of 1 to 3.
The specific examples of the dopant compound are as follows, but are not limited thereto.
The organic electroluminescent device of the present disclosure may emit white light by further comprising at least one light-emitting layer, which comprises a blue, a red, or a green electroluminescent compound known in the field, besides the compound of the present disclosure. If necessary, it may further comprise a yellow or an orange light-emitting layer.
In the organic electroluminescent device of the present disclosure, preferably, at least one layer selected from the group consisting of a chalcogenide layer, a metal halide layer, and a metal oxide layer (hereinafter, “a surface layer”) may be placed on an inner surface(s) of one or both electrode(s). Specifically, a chalcogenide (including oxides) layer of silicon or aluminum is preferably placed on an anode surface of an electroluminescent medium layer, and a metal halide layer or a metal oxide layer is preferably placed on a cathode surface of an electroluminescent medium layer. Such a surface layer provides operation stability for the organic electroluminescent device. Preferably, the chalcogenide includes SiOx(1≤X≤2), AlOx(1≤X≤1.5), SiON, SiAlON, etc.; the metal halide includes LiF, MgF2, CaF2, a rare earth metal fluoride, etc.; and the metal oxide includes Cs2O, Li2O, MgO, SrO, BaO, CaO, etc.
In addition, in the organic electroluminescent device of the present disclosure, a mixed region of an electron transport compound and a reductive dopant, or a mixed region of a hole transport compound and an oxidative dopant may be placed on at least one surface of a pair of electrodes. In this case, the electron transport compound is reduced to an anion, and thus it becomes easier to inject and transport electrons from the mixed region to the light-emitting medium. Furthermore, the hole transport compound is oxidized to a cation, and thus it becomes easier to inject and transport holes from the mixed region to the light-emitting medium. Preferably, the oxidative dopant includes various Lewis acids and acceptor compounds; and the reductive dopant includes alkali metals, alkali metal compounds, alkaline earth metals, rare-earth metals, and mixtures thereof. The reductive dopant layer may be employed as a charge-generating layer to produce an organic electroluminescent device having two or more light-emitting layers and emitting white light.
The organic electroluminescent material according to one embodiment of the present disclosure may be used as a light-emitting material for a white organic light-emitting device. The white organic light-emitting device has been suggested to have various structures such as a side-by-side structure or a stacking structure depending on the arrangement of R (red), G (green) or YG (yellow green), and B (blue) light-emitting parts, or color conversion material (CCM) method, etc. The organic electroluminescent material according to one embodiment of the present disclosure may also be used in an organic electroluminescent device comprising a quantum dot (QD).
In order to form each layer of the organic electroluminescent device of the present disclosure, dry film-forming methods such as vacuum evaporation, sputtering, plasma, ion plating methods, etc., or wet film-forming methods such as ink jet printing, nozzle printing, slot coating, spin coating, dip coating, flow coating methods, etc., can be used. When the first and second host compounds of the present disclosure are used to form a film, a co-evaporation process or a mixture-evaporation process is carried out.
When using a wet film-forming method, a thin film can be formed by dissolving or diffusing materials forming each layer into any suitable solvent such as ethanol, chloroform, tetrahydrofuran, dioxane, etc. The solvent can be any one where the materials forming each layer can be dissolved or diffused, and where there are no problems in film-formation capability.
In addition, it is possible to produce a display system, for example, a display system for smart phones, tablets, notebooks, PCs, TVs, or cars; or a lighting system, for example an outdoor or indoor lighting system, by using the organic electroluminescent device of the present disclosure.
Hereinafter, the preparation method of the compounds according to the present disclosure and the properties thereof, and driving voltage and luminous efficiency of an organic electroluminescent device (OLED) comprising a plurality of host materials according to the present disclosure will be explained in detail with reference to the representative compounds of the present disclosure. The following examples only describe the properties of the compound according to the present disclosure and the OLED comprising the same, but the present disclosure is not limited to the following examples.
Compound 1 (10.2 g, 41.5 mmol), Compound 2 (17.0 g, 41.5 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.90 g, 2.08 mmol), tri-tert-butylphosphine (2.05 mL, 4.15 mmol, 50% toluene solution), sodium tert-butoxide (7.98 g, 83.0 mmol), and 206 mL of o-xylene were added to a flask and refluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound 1-1 (19.0 g, 79.6%).
Compound 1-1 (19.0 g, 33.1 mmol), iodobenzene (11.1 mL, 99.3 mmol), copper iodide (3.15 g, 16.5 mmol), cesium carbonate (21.5 g, 66.2 mmol), and 170 mL of o-xylene were added to a flask and refluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-8 (7.7 g, 35.8%).
Compound 3 (15.0 g, 36.5 mmol), Compound 4 (16.0 g, 40.2 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.67 g, 1.83 mmol), tri-tert-butylphosphine (1.8 mL, 3.65 mmol, 50% toluene solution), sodium tert-butoxide (7.02 g, 73.1 mmol), and 200 mL of toluene were added to a flask and refluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-4 (22.0 g, 82.8%).
Compound 3 (15.0 g, 36.5 mmol), Compound 5 (16.0 g, 40.2 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.67 g, 1.83 mmol), tri-tert-butylphosphine (1.8 mL, 3.65 mmol, 50% toluene solution), sodium tert-butoxide (7.02 g, 73.1 mmol), and 200 mL of toluene were added to a flask and refluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-5 (18.0 g, 67.8%).
Compound 1 (14.4 g, 59 mmol), Compound 6 (20.0 g, 49 mmol). tris(dibenzylideneacetone)dipalladium(0) (2.24 g, 2.4 mmol), tri-tert-butylphosphinc (2.4 mL, 4.9 mmol. 50% toluene solution), sodium tert-butoxide (7 g, 73.3 mmol), and 244 mL of o-xylene were added to a flask and refluxed for 3 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound 1-2 (29.0 g, 103%).
Compound 1-2 (29.0 g, 50 mmol), iodobenzene (28 mL, 250 mmol), copper iodide (33.6 g, 176.6 mmol), cesium carbonate (57.5 g, 126.1 mmol), and 170 mL of o-xylene were added to a flask and rcfluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-2 (8.7 g. 26.5%).
Compound 1 (11.15 g, 45 mmol), Compound 7 (20.0 g, 41 mmol), tris(dibenzylideneacetone)dipalladium(0) (1.86 g, 2.1 mmol), tri-tert-butylphosphine (2.0 mL, 4.1 mmol, 50% toluene solution), sodium tert-butoxide (5.9 g, 61.8 mmol), and 206 mL of o-xylene were added to a flask and refluxed for 1 hour. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound 1-3 (20.1 g, 74.99%).
Compound 1-3 (20.0 g, 30.7 mmol), iodobenzene (10.3 mL, 92.2 mmol), copper iodide (20.48 g, 107.6 mmol), cesium carbonate (35 g, 107.6 mmol), and 153 mL of o-xylene were added to a flask and refluxed for 18 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-3 (9.5 g, 42.5%).
Compound 1-1 (11.0 g, 19.1 mmol), 3-iodo biphenyl (16 g, 57.4 mmol), copper iodide (3.6 g, 19.1 mmol), cesium carbonate (15.5 g, 48 mmol), and 190 mL of o-xylene were added to a flask and refluxed for 17 hours. The reaction solution was cooled to room temperature, and the solvent was removed by a rotary evaporator. Thereafter, the residue was purified by column chromatography to obtain white solid compound T-1 (5.1 g, 37%).
An OLED according to the present disclosure was produced. A transparent electrode indium tin oxide (ITO) thin film (10 Ω/sq) on a glass substrate for an OLED (GEOMATEC CO. LTD., Japan) was subjected to an ultrasonic washing with acetone and isopropyl alcohol, sequentially, and then was stored in isopropyl alcohol. The ITO substrate was then mounted on a substrate holder of a vacuum vapor deposition apparatus. Compound HI-1 was introduced into a cell of the vacuum vapor deposition apparatus as a hole injection compound, and Compound T-8 was introduced into another cell of the vacuum vapor deposition apparatus as hole transport compound. The two materials were evaporated at different rates, and the hole injection compound was deposited in an amount of 7 wt % based on the total amount of the hole injection compound and the hole transport compound to form a hole injection layer having a thickness of 10 nm. Next, Compound T-8 was deposited on the hole injection layer to form a hole transport layer having a thickness of 110 nm. After forming the hole injection layer and the hole transport layer, a light-emitting layer was formed thereon as follows: Compound H1-121 and Compound H2-2 were introduced into two cells of the vacuum vapor deposition apparatus as hosts, and Compound D-133 was introduced into another cell as a dopant. The two host materials were evaporated at different rates of 2:1, and the dopant was simultaneously deposited in a doping amount of 10 wt % based on the total amount of the hosts and the dopant to form a light-emitting layer having a thickness of 40 nm on the hole transport layer. Next, Compound B-1 as an electron buffer material was deposited on the light-emitting layer to form an electron buffer layer having a thickness of 5 nm. Then, Compound ETL-1 and Compound EIL-1 were deposited in a weight ratio of 5:5 to form an electron transport layer having a thickness of 30 nm. After depositing Compound EIL-1 as an electron injection layer having a thickness of 2 nm on the electron transport layer, an Al cathode having a thickness of 80 nm was deposited on the electron injection layer by another vacuum vapor deposition apparatus.
OLEDs were produced in the same manner as in Device Example 1-1, except that the compounds as shown in Table 1 below were respectively used as the hole transport compound in the hole injection layer and the hole transport layer instead of compound T-8.
OLEDs were produced in the same manner as in Device Example 1-1, except that the compounds as shown in Table 1 below were respectively used as the hole transport compound in the hole injection layer and the hole transport layer instead of compound T-8.
The driving voltage, current efficiency, and CIE x,y (1931) color coordinate at a luminance of 1,000 nit of the OLEDs produced in the Device Examples and the Comparative Examples are provided in Table 1 below.
From Table 1 above, it can be confirmed that the OLEDs using a specific combination of compounds according to the present disclosure as a host material and a hole transport material exhibit lower or equivalent driving voltage and higher current efficiency, compared to the OLEDs comprising the conventional compound as a hole transport material. In addition, it can be confirmed that the hole transport compounds according to the present disclosure show improved luminous properties compared to the conventional material.
The triplet energy of the compounds used in the hole transport layer in the Device Examples and the Comparative Examples was obtained by the following method: The triplet energy may be obtained through molecular orbital calculation. For the molecular orbital calculation, Gaussian16 (Gaussian Inc., the United States) generally used for molecular calculation was used. Firstly, ground state energy was optimized by DFT (Density Functional Theory) calculation using the basis set of B3LYP method and 6-31G(d). Based on the obtained three dimensional coordinate and energy of the material, the triplet energy was calculated by TDDFT (Time Dependent DFT) applying the basis set of B3LYP method and 6-31G(d) as in the ground state energy calculation. The triplet energy of the hole transport compounds calculated in the specified method above is provided in Table 2 below.
The compounds used in the Device Examples and the Comparative Example are shown in Table 3 below.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0028802 | Mar 2022 | KR | national |
