Thin film-modified electrode and organic element using same

Abstract

The present invention provides an electrode with particularly excellent atmospheric stability and electron injectability, and an organic element using such an electrode. The present invention is a thin film-modified electrode including, on the electrode and adjacent: a layer containing a metal and an organic compound capable of coordinating to the metal; and a layer having a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal are adjacent to each other in that order. The thin film-modified electrode is characterized in that the organic compound is a compound in which, when the structure is optimized using the B3LYP functional / 6-31G** basis function in a calculation based on the density functional theory with aluminum atoms as the metal, the sum of the distances between metal-coordinating atoms in the organic compound and the aluminum atoms is 4.06 Å or less.

Description

Thin film modified electrode and organic element using same

[0001] The present invention relates to a thin-film modified electrode and an organic device using the same.

[0002] Organic electroluminescent devices are characterized by their thinness, softness, and flexibility, and displays using organic electroluminescent devices are capable of displaying images with higher brightness and resolution than the currently mainstream liquid crystal display devices and plasma display devices. Furthermore, because displays using organic electroluminescent devices have a wider viewing angle than liquid crystal display devices, they are expected to be used in televisions, mobile phone displays, and other applications, and are also expected to be used as lighting devices.

[0003] Organic devices such as organic electroluminescent devices, organic thin-film solar cells, and organic thin-film transistors have a structure in which an organic thin film is formed between two electrodes. These organic devices require charge transfer between the electrodes and the organic thin film, and extensive research has been conducted into hole-injection and electron-injection materials for use between the electrodes and the organic thin film. While alkali metals have been widely used as materials for injecting electrons into organic thin films, the use of alkali metals in electron injection layers has led to difficulties in long-term stable device operation on flexible substrates, which are prone to moisture penetration, due to the extremely low moisture resistance of the materials. In response to this issue, progress has been made in the development of electron injection layers that do not use alkali metals. Recently, organic electroluminescent devices using polyethyleneimine or polyethyleneimine-modified compounds as organic compounds for coatable electron injection layers have been reported (see Non-Patent Documents 1-3). Furthermore, it has been reported that smooth electron injection can be achieved by utilizing coordination reactions between nitrogen-containing heterocyclic compounds, such as pyridine and phenanthroline derivatives, and cathode elements. For example, it has been reported that a phenanthroline derivative having a nitrogen atom can promote electron emission from the metal atom due to its high coordination ability with metal ions, and can significantly lower the electron injection barrier at the electrode / organic layer interface, and that the use of a phenanthroline derivative between the electrode and the organic layer can improve the electron injection ability (Non-Patent Documents 4 to 6).

[0004] Tao Xiong and 3 others, "Applied Physics Letters," Vol. 93, 2008, pp. 123310-1; Yinhua Zhou and 21 others, "Science," No. 336, 2012, pp. 327; Jianshan Chen and 6 others, "Journal of Materials Chemistry," Vol. 22, 2012, pp. 5164; Hiroyuki Yoshida, "J. Phys. Chem. C20151194324459-24464), Vol. 119, 2015, p. 24459 Zhengyang Bin and seven others, Nature Communications, Vol. 10, 2019, p. 866 Hirohiko Fukagawa and eight others, Nature Communications, Vol. 11, 2020, p. 1

[0005] Although many materials that exhibit coordination reactions with cathode elements, such as the above-mentioned pyridine and phenanthroline derivatives, have been reported, no materials have yet been reported that are suitable for realizing an electrode that is particularly excellent in atmospheric stability and electron injection properties, and for realizing a device using such an electrode.

[0006] The present invention has been made in view of the above-mentioned current situation, and has an object to provide an electrode that is particularly excellent in atmospheric stability and electron injection properties, and an organic element using such an electrode.

[0007] The present inventors have investigated materials for realizing electrodes with particularly excellent atmospheric stability and electron injection properties. They have found that the sum of the distances between the metal-coordinating atom in an organic compound and the aluminum atom, calculated by performing a predetermined molecular orbital calculation on the organic compound using an aluminum atom as the coordinating atom, correlates with the atmospheric stability and electron injection properties of organic devices actually fabricated using the organic compound. Furthermore, the present inventors have found that a thin-film modified electrode with excellent electron injection properties can be obtained by forming on an electrode a layer containing an organic compound and a metal, or a layer having a laminated structure of an organic compound and a metal, such that the sum of the distances is 4.06 Å or less. Furthermore, the present inventors have found that an organic device fabricated using such a thin-film modified electrode can have excellent atmospheric stability and electron injection properties. Furthermore, the present inventors have found that the equilibrium density of an organic compound calculated by molecular dynamics simulation also correlates with the atmospheric stability of organic devices actually fabricated using the organic compound. Furthermore, the present inventors have found that the equilibrium density of an organic compound is 1.17 g / cm. ３ The present inventors have found that an organic element having excellent atmospheric stability can be obtained by fabricating an organic element in which a layer containing the above-described organic compound and metal or a layer having a structure in which a layer containing such an organic compound and a layer containing a metal are stacked on an electrode.

[0008] That is, the present invention is as follows: [1] A thin-film-modified electrode having, adjacent to an electrode, a layer containing a metal and an organic compound capable of coordinating to the metal, or a layer having a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal are adjacent to each other in this order, wherein the organic compound is a compound such that, when the structure is optimized using functional: B3LYP / basis function: 6-31G** in calculations based on Density Functional Theory in which the metal is an aluminum atom, the sum of the distances between the atom coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less.

[0009] [2] The thin-film modified electrode according to [1], wherein at least one of the metals has a work function of 4.0 eV or more.

[0010] [3] A thin-film modified electrode having, adjacent to an electrode, a layer containing a metal and an organic compound capable of coordinating to the metal, or a layer having a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal are adjacent to each other in this order, wherein the organic compound has an equilibrium density of intermolecular packing obtained by molecular dynamics calculation after optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G** in calculation based on Density Functional Theory, of 1.17 g / cm ３ A thin film modified electrode characterized by the compound having the above structure.

[0011] [4] The organic compound has an equilibrium density of 1.20 g / cm ３ The thin film modified electrode according to [3], characterized in that:

[0012] [5] The thin-film modified electrode according to any one of [1] to [4], wherein the metal is at least one selected from the group consisting of aluminum, magnesium, and silver.

[0013] [6] The thin-film modified electrode according to any one of [1] to [5], wherein the atom coordinated to the metal in the organic compound is at least one selected from the group consisting of a nitrogen atom, a sulfur atom, and an oxygen atom.

[0014] [7] An organic element comprising the thin-film modified electrode according to any one of [1] to [6].

[0015] [8] A lighting device comprising the organic element according to [7].

[0016] [9] A display device comprising the organic element according to [7].

[0017]

[10] A method for producing a thin-film-modified electrode, the method comprising: a first step of selecting an organic compound capable of coordinating to a metal, performing calculations based on Density Functional Theory with an aluminum atom as the coordinating metal, and optimizing the structure using functional: B3LYP / basis function: 6-31G**, such that the sum of distances between the atoms coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less; and a second step of forming, on an electrode, a layer containing the organic compound and the metal adjacent to each other, or sequentially forming a layer containing the metal and a layer containing the organic compound, using the organic compound and the metal selected in the first step.

[0018]

[11] A method for producing a thin film modified electrode, the method comprising: performing calculations based on Density Functional Theory on an organic compound capable of coordinating to a metal; optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**; and then determining that the equilibrium density of intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm. ３ a second step of forming a layer containing the organic compound and the metal adjacent to each other on an electrode, using the organic compound and the metal selected in the first step, or forming a layer containing the metal and a layer containing the organic compound in this order.

[0019]

[12] A method for producing an organic element, comprising the steps of: producing a thin-film modified electrode using the method for producing a thin-film modified electrode according to

[10] or

[11] ; and forming an organic layer on the obtained thin-film modified electrode.

[0020]

[13] A method for selecting an organic compound suitable as a material for an electron injection layer of an organic element to be formed in combination with a metal, the selection method comprising: performing calculations based on Density Functional Theory, in which the metal is an aluminum atom, on an organic compound that can be coordinated to a metal; optimizing the structure using functional: B3LYP / basis function: 6-31G**; and selecting an organic compound such that the sum of the distances between the atoms that coordinate to the metal in the organic compound and the aluminum atoms is 4.06 Å or less as the material for the electron injection layer of the organic element to be formed in combination with the metal.

[0021]

[14] A method for selecting an organic compound suitable for use as a material for an electron injection layer of an organic element to be formed in combination with a metal, the selection method comprising: performing calculations based on Density Functional Theory on an organic compound capable of coordinating with a metal; optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**; and then selecting an organic compound whose equilibrium density of intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm. ３ A method for selecting a material for an electron injection layer of an organic element, comprising selecting the organic compound as described above as a material for the electron injection layer of the organic element to be formed in combination with a metal.

[0022] According to the present invention, it is possible to provide a thin-film modified electrode having particularly excellent atmospheric stability and electron injection properties, and an organic element including the thin-film modified electrode. Furthermore, according to the present invention, it is possible to provide a lighting device and a display device including such an organic element, as well as a method for manufacturing such a thin-film modified electrode, a method for manufacturing such an organic element, and a method for selecting a material for the electron injection layer of such an organic element. Because the thin-film modified electrode of the present invention and an organic element using the same have excellent atmospheric stability and electron injection properties, they can be suitably used as organic electroluminescent elements, organic thin-film solar cells, organic thin-film transistors, etc.

[0023] 1 is a schematic diagram showing the layer structure of an organic element produced in an example. It is a diagram showing the measurement position of the deterioration width w of the light-emitting surface of the organic element in the example. It is a diagram plotting the relationship between the sum of the distance between the atom coordinated to the metal in the organic compound and the aluminum atom, as determined by molecular orbital calculation for the organic compound, and the shrink growth rate α of the organic element using the organic compound, for Examples 1-1 to 1-3, Comparative Examples 1-1 and 1-2, Examples 4-1 to 4-3, and Comparative Examples 4-1 and 4-2, in which Compounds 1 to 5 are used. It is a diagram plotting the relationship between the sum of the distance between the atom coordinated to the metal in the organic compound and the aluminum atom, as determined by molecular orbital calculation for the organic compound, and the voltage at which the luminance of the organic element using the organic compound becomes 100 nits, for Examples 1-1 to 1-3, Comparative Examples 1-1 and 1-2, Examples 4-1 to 4-3, and Comparative Examples 4-1 and 4-2, in which Compounds 1 to 5 are used. １ 1 is a diagram showing the H-NMR spectrum of Compound 9 synthesized in Synthesis Example 4. １ 1 is a diagram showing the H-NMR spectrum. It is a diagram plotting the relationship between the equilibrium density of intermolecular packing, obtained by molecular dynamics calculation, for the organic compounds represented by structural formulas (17) to (23) used in Examples 6 to 8 and Comparative Examples 5 to 8, and the shrink growth rate α of the organic elements using the organic compounds.

[0024] The present invention will be described in detail below. Note that a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

[0025] The thin-film modified electrode of the present invention has a layer containing a metal and an organic compound capable of coordinating to the metal, or a layer having a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal are adjacent to each other in this order on an electrode, and the thin-film modified electrode of the present invention uses, as the organic compound, (1) a compound in which the sum of the distances between the atom coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less when the structure is optimized using functional: B3LYP / basis function: 6-31G** in a calculation based on density functional theory with the metal being an aluminum atom, and (2) a compound in which the equilibrium density of intermolecular packing obtained by molecular dynamics calculation after the structure is optimized using functional: B3LYP-D3 / basis function: 6-31G** in a calculation based on density functional theory is 1.17 g / cm ３ Hereinafter, the electrode using the organic compound (1) above will be referred to as the first thin-film-modified electrode of the present invention, the electrode using the organic compound (2) above will be referred to as the second thin-film-modified electrode of the present invention, and the combination of the first and second thin-film-modified electrodes of the present invention will be referred to as the thin-film-modified electrode of the present invention.

[0026] <Thin-film-modified electrode of the first aspect of the present invention> The thin-film-modified electrode of the first aspect of the present invention utilizes a coordination reaction between a metal and an organic compound to improve electron injection. When an organic element is used in the atmosphere, the light-emitting surface deteriorates over time. The relationship between the extent of deterioration of the light-emitting surface and the elapsed time can be approximated using a diffusion equation (see Takeru Okada, et al. (2017), Jpn. J. Appl. Phys. 56 060305). The atmospheric stability of the organic element can be evaluated by calculating the rate of deterioration (shrinkage). As shown in the examples below, a correlation was confirmed between the shrink growth rate of organic elements fabricated using multiple organic compounds with different structures as compounds capable of coordinating to metals and the sum of the distances between the atoms coordinating to the metal in the organic compound and the aluminum atom when the structure of the organic compound was optimized using the functional: B3LYP / basis function: 6-31G**. This is thought to be because the short distance between the organic compound and the metal makes the coordination bond less susceptible to breakage by moisture or air. Furthermore, by using an organic compound with a sum of the distances of 4.06 Å or less in combination with a metal to which the organic compound can coordinate, an organic element with excellent electron injection properties and excellent atmospheric stability can be obtained. Note that the "sum of the distances between the atoms coordinating to the metal in the organic compound and the aluminum atom" refers to the sum of the distances between each of the multiple atoms coordinating to the metal in the organic compound when multiple atoms coordinating to the metal are present in the organic compound.

[0027] 1-1. First Thin-Film-Modified Electrode of the Present Invention The first thin-film-modified electrode of the present invention may have a layer adjacent to (in direct contact with) the electrode, the layer containing a metal and an organic compound capable of coordinating to the metal and having the sum of the distances set forth above of 4.06 Å or less, or may have a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal and having the sum of the distances set forth above of 4.06 Å or less are adjacent to each other in this order. However, the thin-film-modified electrode of the present invention preferably has two layers adjacent to the electrode, the layer containing a metal and the layer containing the organic compound, in this order (i.e., the electrode, the layer containing a metal, and the layer containing an organic compound capable of coordinating to the metal and having the sum of the distances set forth above of 4.06 Å or less, formed adjacent to each other in this order). This structure allows the coordination reaction between the metal and the organic compound to be more efficiently utilized to improve electron injection. Additionally, the strength of the bond reduces the risk of cleavage of the coordination bond by molecules such as water molecules and atmospheric oxygen.

[0028] When the thin-film-modified electrode of the first aspect of the present invention has a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal and having the sum of the distances of 4.06 Å or less are adjacent to each other in this order, the layer containing the metal may be any of a metal layer of a single metal, a mixed layer of a single metal and an oxide containing a small amount of oxygen atoms, a layer in which a mixed layer of two or more metals and a layer containing a single metal, a mixed layer of two or more metals, and a mixed layer of a mixed layer of two or more metals and an oxide containing a small amount of oxygen atoms. Furthermore, when the thin-film-modified electrode of the first aspect of the present invention has a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal and having the sum of the distances of 4.06 Å or less are adjacent to each other in this order, the layer containing the organic compound may further contain an electron transport material described below.

[0029] When the thin-film-modified electrode of the first aspect of the present invention has a layer adjacent to the electrode, the layer containing a metal and an organic compound capable of coordinating to the metal and having the sum of the distances of 4.06 Å or less, the thickness of the layer containing the metal and the organic compound is preferably 0.1 to 50 nm, more preferably 0.1 to 10 nm. When the thin-film-modified electrode of the first aspect of the present invention has two adjacent layers, a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal and having the sum of the distances of 4.06 Å or less, in this order, the thickness of the layer containing the metal is preferably 0.1 to 5 nm, more preferably 0.5 to 2 nm. Furthermore, the thickness of the layer containing the organic compound capable of coordinating to the metal and having the sum of the distances of 4.06 Å or less is preferably 0.5 to 10 nm, more preferably 1 to 5 nm, and even more preferably 1 to 3 nm. The thicknesses of these layers can be measured by a stylus profilometer, spectroscopic ellipsometry, or X-ray photoelectron spectroscopy.

[0030] In the first thin-film-modified electrode of the present invention, the metal contained in the layer adjacent to the electrode is not particularly limited as long as it can coordinate with an organic compound, but it is preferable that the metal contains one having a work function of 4.0 eV or more. The use of such a metal makes the thin-film-modified electrode stable in the atmosphere and excellent in electron injection properties. The metal more preferably has a work function of 4.2 eV or more, and even more preferably has a work function of 4.6 eV or more.

[0031] In the first thin-film modified electrode of the present invention, the metal contained in the layer adjacent to the electrode is preferably at least one selected from the group consisting of aluminum, magnesium, silver, zinc, copper, nickel, palladium, platinum, gold, cobalt, chromium, manganese, iron, tin, indium, titanium, zirconium, vanadium, niobium, tantalum, molybdenum, tungsten, indium, gallium, and cadmium. Using any of these metals can provide the thin-film modified electrode with superior electron injection properties and atmospheric stability. Among these, at least one selected from the group consisting of aluminum, magnesium, silver, zinc, and copper is more preferred, and at least one selected from the group consisting of aluminum, magnesium, and silver is even more preferred.

[0032] When the structure of the organic compound contained in the thin-film-modified electrode of the first aspect of the present invention is optimized using a functional: B3LYP / basis function: 6-31G** in a calculation based on Density Functional Theory in which the metal is an aluminum atom, the sum of the distances between the atoms coordinated to the metal in the organic compound and the aluminum atom may be 4.06 Å or less, but is preferably 4.055 Å or less, and more preferably 4.05 Å or less.

[0033] The organic compound is not particularly limited as long as the sum of the distances is 4.06 Å or less, but the atom that coordinates with the metal in the organic compound is preferably at least one selected from the group consisting of a nitrogen atom, a sulfur atom, and an oxygen atom. More preferred are organic compounds capable of multidentate coordination that have an electron-donating nitrogen atom in a heterocycle, and even more preferred are organic compounds having a fused heterocycle structure.

[0034] The organic compound capable of multidentate coordination, having an electron-donating nitrogen atom in a heterocycle and a fused heterocycle structure, includes a compound having a structure represented by the following general formula (1): That is, as the organic compound contained in the thin-film-modified electrode of the first aspect of the present invention, among the compounds having a structure represented by the following general formula (1), those which satisfy the requirement that the sum of the distances between the atom coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less are preferred.

[0035]

[0036] (In general formula (1), X １ , X ２ are the same or different and represent a nitrogen atom, an oxygen atom, a sulfur atom or a divalent linking group which may have a substituent. L represents a direct bond or a p-valent linking group. １ represents the number 0 or 1, and p represents a number from 1 to 4. q represents the number 0 or 1, and when p is 1, q is 0. R １ ~R ３ are the same or different and represent a monovalent substituent. １ ~m ３ are the same or different and represent a number from 0 to 3. １ ~R ３ is X １ , X ２ may be bonded to form a ring structure. １ If there are multiple R １ may be bonded to form a ring structure. ２ , R ３ The same applies to

[0037] X in the above general formula (1) １ , X ２ are the same or different and represent a nitrogen atom, oxygen atom, sulfur atom, or divalent linking group which may have a substituent. Examples of divalent linking groups include divalent hydrocarbon groups and groups in which some of the carbon atoms of a hydrocarbon group are substituted with a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. The hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably has 1, 2, or 6 carbon atoms. The hydrocarbon group may be linear, branched, cyclic, or a combination thereof. The divalent hydrocarbon group may be an alkylene group which is a saturated hydrocarbon group, or an unsaturated hydrocarbon group such as an alkenylene group or an alkynylene group. Specific examples of divalent hydrocarbon groups are those represented by the following formulas (2-1) to (2-4). In the following formulas (2-1) to (2-4), R represents a substituent. X, including R in (2-1) to (2-4), １ , X ２Specific examples of the substituent in R １ ~R ３ The monovalent substituents are the same as those of the above.

[0038]

[0039] In the general formula (1), L represents a direct bond or a p-valent linking group. Note that L becomes a direct bond only when p is 2. Examples of p-valent linking groups include nitrogen atoms, oxygen atoms, sulfur atoms, and carbon atoms, as well as groups formed by removing p hydrogen atoms from hydrocarbon groups and groups in which some of the carbon atoms of a hydrocarbon group have been substituted with a heteroatom such as a nitrogen atom, an oxygen atom, or a sulfur atom. When the p-valent linking group has carbon atoms, it preferably has 1 to 30 carbon atoms. More preferably, it has 1 to 20 carbon atoms. The hydrocarbon group may be linear, branched, cyclic, or a combination thereof. The hydrocarbon group may be a saturated hydrocarbon group, an unsaturated hydrocarbon group, or an aromatic hydrocarbon group. Examples of aromatic hydrocarbon groups include groups formed by removing hydrogen atoms from aromatic compounds such as a benzene ring, a naphthalene ring, an anthracene ring, a tetracene ring, a pentacene ring, a triphenylene ring, a pyrene ring, a fluorene ring, and an indene ring.

[0040] R in the above general formula (1) １ ~R ３are the same or different and represent a monovalent substituent. Examples of the monovalent substituent include a fluorine atom; a haloalkyl group such as a fluoromethyl group, a difluoromethyl group, or a trifluoromethyl group; a linear or branched alkyl group having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, or a tert-butyl group; a cyclic alkyl group having 5 to 7 carbon atoms such as a cyclopentyl group, a cyclohexyl group, or a cycloheptyl group; a linear or branched alkoxy group having 1 to 20 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, or an octyloxy group; a nitro group; a cyano group; an alkylamino group having an alkyl group having 1 to 10 carbon atoms such as a methylamino group, an ethylamino group, a dimethylamino group, or a diethylamino group; a pyrrolidino group, a piperidino group, or a cyclohexyloxy group; cyclic amino groups such as dino group and morpholino group; diarylamino groups such as diphenylamino group and carbazolyl group; acyl groups such as acetyl group, propionyl group and butyryl group; alkenyl groups having 2 to 30 carbon atoms such as styryl group; aryl groups having 5 to 20 carbon atoms which may be substituted with a halogen atom such as a fluorine atom, or an alkyl group, alkoxy group or amino group having 1 to 20 carbon atoms (specific examples of the aryl group are the same as those for the aromatic hydrocarbon groups described above); heterocyclic groups containing one or more of a nitrogen atom, sulfur atom and oxygen atom which may be substituted with a halogen atom such as a fluorine atom, or an alkyl group, alkoxy group or amino group having 1 to 20 carbon atoms (the heterocyclic group may be one consisting of only one ring, or may be a compound in which a plurality of compounds consisting of only one aromatic heterocycle are directly bonded together via one carbon atom, or may be a fused heterocyclic group).Specific examples of heterocyclic groups include specific examples of aromatic heterocyclic groups such as a thiophene ring, a furan ring, a pyrrole ring, a benzothiophene ring, a benzofuran ring, an indole ring, a dibenzothiophene ring, a dibenzofuran ring, a carbazole ring, a thiazole ring, a benzothiazole ring, an oxazole ring, a benzoxazole ring, an imidazole ring, a benzimidazole ring, a pyridine ring, a pyrimidine ring, a pyrazine ring, a pyridazine ring, a triazole ring, a benzotriazole ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, a benzothiadiazole ring, and a phenanthridine ring. ); ester groups, thioether groups, and groups formed by combining these groups are also included. These groups may be substituted with halogen atoms, hetero elements, alkyl groups, aromatic rings, etc.

[0041] The compound represented by the above general formula (1) includes a compound having a structure represented by the following general formula (3) which has only one phenanthroline skeleton, and this compound is also suitable as a material for forming the thin-film modified electrode of the first invention.

[0042]

[0043] (In general formula (3), R ４ , R ５ are the same or different and represent a dialkylamino group, a nitrogen-containing heterocyclic group, or an alkoxy group. ４ , m ５ are the same or different and represent the number 1 or 2. ４ If there are multiple R ４ may be bonded to form a ring structure. ５ The same applies to R ４ , R ５ The two alkyl groups in the dialkylamino group may be bonded to form a ring structure.

[0044] R in the above general (3) ４ , R ５are the same or different and represent a dialkylamino group, a nitrogen-containing heterocyclic group, or an alkoxy group. Dialkylamino groups preferably have an alkyl group having 1 to 20 carbon atoms, such as a methyl group or an ethyl group. More preferably, they have an alkyl group having 1 to 10 carbon atoms. The two alkyl groups in a dialkylamino group may have the same or different carbon atoms. Furthermore, amino groups in which two alkyl groups are linked, such as cyclic amino groups such as piperidino, pyrrolidino, and morpholino, are also preferred. Examples of cyclic amino groups include cyclic amino groups having a structure in which one or more linear or cyclic alkyl groups are further linked to a nitrogen-containing heterocycle; cyclic amino groups having a structure in which a group formed by linking one or more aromatic rings to a carbon atom or a linear alkyl group is linked to a nitrogen-containing heterocycle; and cyclic amino groups in which two alkyl groups linked to a nitrogen-containing heterocycle are linked to form a ring, resulting in a condensed structure of a nitrogen-containing heterocycle and a hydrocarbon ring. As the heterocyclic group containing a nitrogen atom, a triazolyl group, a benzotriazolyl group, etc. are preferred. As the alkoxy group, R １ ~R ３ is an alkoxy group.

[0045] Among the compounds having a structure represented by the general formula (1), examples of compounds that satisfy the requirement that the sum of the distances between the atom coordinated to the metal in the organic compound and the aluminum atom is 4.06 Å or less include those represented by the following formulas (4-1) to (4-5).

[0046]

[0047] The organic compound in the first aspect of the present invention may be a hexahydropyrimidopyrimidine compound having a structure represented by the following general formula (5).

[0048]

[0049] (In general formula (5), R ６represents an aromatic hydrocarbon group, an aromatic heterocyclic group, an aryl alkylene group, a divalent to tetravalent chain or cyclic hydrocarbon group which may have a substituent, a group formed by combining two or more of these groups, or a group formed by combining one or more of these groups with a nitrogen atom. ２ is an integer from 1 to 4.

[0050] It has been confirmed that the hexahydropyrimidopyrimidine compound having the structure represented by the above general formula (5) can coordinate with metal species, preventing reactions at the interface with oxygen or water entering from the outside, thereby improving the atmospheric stability of the device. Furthermore, as a result of the dipole generated by the interaction with the metal species, the electron injection ability of the thin film-modified electrode can be improved.

[0051] R in the above general formula (5) ６represents an aromatic hydrocarbon group, an aromatic heterocyclic group, an aryl alkylene group, a divalent to tetravalent linear or cyclic hydrocarbon group which may have a substituent, a group formed by combining two or more of these groups, or a group formed by combining one or more of these groups with a nitrogen atom. The aromatic hydrocarbon group and aromatic heterocyclic group preferably have 3 to 30 carbon atoms, more preferably have 4 to 24 carbon atoms, and even more preferably have 5 to 20 carbon atoms. Examples of the aromatic hydrocarbon group include compounds consisting of only one aromatic ring such as benzene; compounds in which multiple aromatic rings are directly bonded via one carbon atom, such as biphenyl and diphenylbenzene; and groups formed by removing 1 to 4 hydrogen atoms from any of the aromatic rings of fused-ring aromatic hydrocarbon compounds such as naphthalene, anthracene, phenanthrene, and pyrene. Examples of aromatic heterocyclic groups include compounds consisting of only one aromatic heterocycle, such as thiophene, furan, pyrrole, oxazole, oxadiazole, thiazole, thiadiazole, imidazole, pyridine, pyrimidine, pyrazine, and triazine; compounds in which multiple compounds consisting of only one aromatic heterocycle are directly bonded via one carbon atom (e.g., bipyridine); and groups formed by removing 1 to 4 hydrogen atoms from any of the aromatic heterocycles of fused-ring heteroaromatic hydrocarbon compounds, such as quinoline, quinoxaline, benzothiophene, benzothiazole, benzimidazole, benzoxazole, indole, carbazole, dibenzofuran, dibenzothiophene, acridine, and phenanthroline. Examples of aryl alkylene groups include groups formed by combining the above-mentioned aromatic hydrocarbon groups with alkylene groups having 1 to 3 carbon atoms. Divalent to tetravalent linear or cyclic hydrocarbon groups preferably have 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. The chain hydrocarbon group may be a straight chain or a branched chain. ６ may be a group formed by combining two or more of the above-mentioned aromatic hydrocarbon groups, aromatic heterocyclic groups, aryl alkylene groups, and divalent to tetravalent chain hydrocarbon groups. ６may be a group formed by combining one or more of the above-mentioned aromatic hydrocarbon groups, aromatic heterocyclic groups, aryl alkylene groups, and divalent to tetravalent chain hydrocarbon groups with a nitrogen atom. Examples of such groups include groups formed by removing 1 to 4 hydrogen atoms from trialkylamines such as trimethylamine or triphenylamine.

[0052] The aromatic hydrocarbon group, aromatic heterocyclic group, or aryl alkylene group may have one or more monovalent substituents. Examples of the monovalent substituent include R １ ~R ３ Specific examples of the monovalent substituent in the above general formula (5) include the same as those in the above general formula (5). ２ is an integer of 1 to 4, preferably 2 or 3.

[0053] The organic compound in the first aspect of the present invention may be a triazine compound having a structure represented by the following general formula (6).

[0054]

[0055] (In general formula (6), R ７ are the same or different and represent an aromatic hydrocarbon group, an aromatic heterocyclic group, an aryl alkylene group, a divalent to tetravalent chain or cyclic hydrocarbon group, which may have a substituent, or a group formed by combining two or more of these groups, or a group formed by combining one or more of these groups with a nitrogen atom. ３ is an integer from 0 to 3.

[0056] The triazine compound having the structure represented by the general formula (6) has electron transporting properties and can combine both electron injection and electron transport properties.

[0057] R in the above general formula (6) ７ Specific examples of R in general formula (5) include ６ Among these, groups formed by combining an aromatic hydrocarbon group with an aromatic heterocyclic group are preferred, and a phenyl group bonded to an aromatic heterocyclic ring such as a pyridine ring is preferred. ３ is an integer of 0 to 3, preferably 3.

[0058] The electrode in the first thin film modified electrode of the present invention is a cathode. The material of the cathode is preferably a material having a work function of 4.0 eV or more, such as ITO (indium tin oxide), IZO (indium zinc oxide), FTO (fluorine tin oxide), In ３ O ３ , SnO ２ , Sb-containing SnO ２ , conductive oxide materials such as Al-containing ZnO, and further silver or silver alloys. Among these, ITO, IZO, FTO, and silver are preferably used as the cathode material.

[0059] The average thickness of the cathode is not particularly limited, but is preferably 10 to 500 nm, more preferably 100 to 200 nm. For silver, it is preferably 5 to 40 nm, more preferably 10 to 20 nm. The average thickness of the cathode can be measured by a stylus profilometer or spectroscopic ellipsometry.

[0060] 2-1. Method for producing a thin-film modified electrode according to the first aspect of the present invention, and method for selecting a material for the electron injection layer of an organic element As described above, a thin-film modified electrode having excellent electron injection properties and atmospheric stability can be produced by selecting an organic compound suitable for electrode modification using calculations based on density functional theory, and then forming a layer on the electrode using the selected organic compound and a metal. The present invention also includes a method for producing such a thin-film-modified electrode, i.e., a method for producing a thin-film-modified electrode, comprising: a first step of selecting an organic compound capable of coordinating to a metal, performing calculations based on Density Functional Theory, with the coordinating metal being an aluminum atom, and optimizing the structure using the functional: B3LYP / basis function: 6-31G**, such that the sum of the distances between the atoms coordinating to the metal and the aluminum atom in the organic compound is 4.06 Å or less; and a second step of using the organic compound and the metal selected in the first step to form a layer containing the organic compound and the metal adjacent to each other on an electrode, or to sequentially form a layer containing the metal and a layer containing the organic compound. Furthermore, the present invention also includes a method for selecting a material for an electron injection layer of an organic element using the method for producing a thin-film-modified electrode of the present invention.

[0061] In the second step of the method for producing the thin-film-modified electrode of the first invention, the method for forming one layer containing the organic compound and the metal adjacent to each other on the electrode, or the method for forming a layer containing the metal and a layer containing the organic compound in this order, is the same as the method for forming an inorganic compound layer or an organic compound layer of an organic element described later.

[0062] <Second Thin-Film Modified Electrode of the Present Invention> The second thin-film modified electrode of the present invention also utilizes the fact that a high equilibrium density of an organic compound coordinating with a metal can suppress the diffusion of water molecules and improve atmospheric stability. As described above for the thin-film modified electrode of the first invention, when an organic element is used in the atmosphere, the light-emitting surface deteriorates over time. The relationship between the extent of deterioration of the light-emitting surface and elapsed time can be approximated using a diffusion equation, and the atmospheric stability of the organic element can be evaluated by calculating the rate of deterioration (shrinkage) from this. As shown in the examples described below, a relationship has been confirmed between the shrinkage rate of an organic element fabricated using multiple organic compounds with different structures as compounds capable of coordinating with a metal and the equilibrium density of intermolecular packing obtained by molecular dynamics calculations after optimizing the structure of the organic compound using the functional: B3LYP-D3 / basis function: 6-31G** in calculations based on Density Functional Theory. This is thought to be because a high density of the organic compound makes it more difficult for moisture and air to diffuse into the organic element. The equilibrium density obtained by molecular dynamics calculation is 1.17 g / cm ３ By using the organic compound described above in combination with a metal to which the organic compound can be coordinated, an organic element having excellent electron injection properties and excellent atmospheric stability can be obtained. Note that the "equilibrium density obtained by molecular dynamics calculation" is the density obtained by calculating the equilibrium intermolecular distances in a system in which the same molecules are adjacent (packed) in an amorphous state, based on molecular kinetic theory.

[0063] 1-2. Second Thin-Film Modified Electrode of the Present Invention The second thin-film modified electrode of the present invention has a metal on the electrode, adjacent to (in direct contact with) the metal, and a metal-containing compound capable of coordinating with the metal, the calculated equilibrium density of which is 1.17 g / cm ３ (ii) a layer containing a metal and an organic compound capable of coordinating with the metal and having an equilibrium density of 1.17 g / cm or more; ３The present invention may be applied to a structure in which a layer containing an organic compound having the above-mentioned equilibrium density of 1.17 g / cm or more is adjacent to the electrode, but it is also applicable to a structure in which two layers are adjacent to each other in this order: (i) a layer containing a metal and a layer containing the organic compound (i.e., an electrode, a layer containing a metal, a layer capable of coordinating with the metal, and the above-mentioned equilibrium density is 1.17 g / cm or more). ３ Preferably, the organic compound-containing layers are formed adjacent to each other in this order. With such a structure, the coordination reaction between the metal and the organic compound can be utilized more efficiently to improve electron injection. In addition, the formation of a high-density film can delay the diffusion of water molecules.

[0064] The thin film modified electrode of the second aspect of the present invention has (ii) a layer containing a metal and a metal-containing layer capable of coordinating with the metal and having an equilibrium density of 1.17 g / cm ３ In the case where the thin-film modified electrode of the present invention has a layer having a structure in which (i) a layer containing an organic compound having the above-mentioned properties and (ii) a layer containing an organic compound having the above-mentioned properties and (iii) a layer containing an organic compound having the above-mentioned properties and (iv) a layer containing an organic compound having the above-mentioned properties and (v) a layer containing an organic compound having the above-mentioned properties and (vi) a layer containing an organic compound having the above-mentioned properties and (vii ... ３ In the case where the layer containing the organic compound has a structure in which the layer containing the organic compound and the layer containing the organic compound are adjacent to each other in this order, the layer containing the organic compound may further contain an electron transport material described later.

[0065] The thin film modified electrode of the second aspect of the present invention is provided on and adjacent to the electrode, and (i) a metal and a cation capable of coordinating with the metal and having the above-mentioned equilibrium density of 1.17 g / cm ３ In the case where the thin-film-modified electrode of the second aspect of the present invention has a layer containing the metal and an organic compound having an equilibrium density of 1.17 g / cm or more, the thickness of the layer containing the metal and the organic compound is preferably 0.1 to 50 nm, more preferably 0.1 to 10 nm. ３In the case where the organic compound-containing layer is capable of coordinating with a metal and has an equilibrium density of 1.17 g / cm or more, and the organic compound-containing layer is adjacent to the metal in this order, the thickness of the metal-containing layer is preferably 0.1 to 5 nm, more preferably 0.5 to 2 nm. ３ The thickness of the layer containing the above organic compound is preferably 0.5 to 10 nm, more preferably 1 to 5 nm, and even more preferably 1 to 3 nm. The thickness of these layers can be measured by a stylus profilometer, spectroscopic ellipsometry, or X-ray photoelectron spectroscopy.

[0066] In the second thin-film-modified electrode of the present invention, the metal contained in the layer adjacent to the electrode is not particularly limited as long as it can coordinate with an organic compound. Specific examples and preferred metals of the metal contained in the layer adjacent to the electrode are the same as those of the first thin-film-modified electrode of the present invention.

[0067] Regarding the organic compound contained in the thin film-modified electrode of the second aspect of the present invention, the structure was optimized using the functional: B3LYP-D3 / basis function: 6-31G** in calculations based on the Density Functional Theory, and then the equilibrium density of the intermolecular packing obtained by molecular dynamics calculations was 1.17 g / cm ３ It is sufficient if it is 1.20 g / cm or more. ３ It is preferable that the density is equal to or higher than 1.25 g / cm. ３ That's all.

[0068] The organic compound has an equilibrium density of 1.17 g / cm ３Although there are no particular limitations on the organic compound as long as it satisfies the above requirements, it is preferred that the atom coordinating to the metal in the organic compound is at least one selected from the group consisting of nitrogen, sulfur, and oxygen atoms. More preferred are organic compounds capable of multidentate coordination having an electron-donating nitrogen atom in a heterocycle, and even more preferred are organic compounds having a fused heterocycle structure. Examples of the multidentate organic compounds having an electron-donating nitrogen atom in a heterocycle and a fused heterocycle structure include compounds having a structure represented by the general formula (1) above. That is, the organic compound contained in the thin-film-modified electrode of the second aspect of the present invention includes compounds having a structure represented by the general formula (1) above, and having an equilibrium density of 1.17 g / cm. ３ The compound represented by the general formula (1) above includes a compound having a structure represented by the general formula (3) above, which has only one phenanthroline skeleton, and this compound is also suitable as a material for forming the thin-film modified electrode of the second invention.

[0069] Among the compounds having a structure represented by the general formula (1), those having an equilibrium density of 1.17 g / cm ３ Examples of compounds that satisfy the above requirements include compounds represented by the following formulas (7-1) to (7-3).

[0070]

[0071] The organic compound in the second aspect of the present invention may be a hexahydropyrimidopyrimidine compound having a structure represented by the general formula (5). In this case, specific examples and preferred structures of the hexahydropyrimidopyrimidine compound having a structure represented by the general formula (5) are the same as those described above.

[0072] The organic compound in the second aspect of the present invention may be a triazine compound having a structure represented by the general formula (6). In this case, specific examples and preferred structures of the triazine compound having a structure represented by the general formula (6) are the same as those described above.

[0073] The electrode in the thin-film-modified electrode of the second invention is a cathode. The material of the cathode is the same as that of the electrode (cathode) in the thin-film-modified electrode of the first invention. The average thickness of the thin-film-modified electrode (cathode) of the second invention is also the same as that of the thin-film-modified electrode (cathode) of the first invention.

[0074] 2-2. Method for Producing a Thin-Film-Modified Electrode of the Second Present Invention, and Method for Selecting a Material for the Electron Injection Layer of an Organic Device As described above, a thin-film-modified electrode with excellent electron injection properties and atmospheric stability can be produced by selecting an organic compound suitable for electrode modification using calculations based on molecular dynamics, and then forming a layer on the electrode using the selected organic compound and a metal. This method for producing a thin-film-modified electrode involves performing calculations based on Density Functional Theory on an organic compound capable of coordinating with a metal, optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**, and then determining that the equilibrium density of the intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm. ３ The present invention also provides a method for producing a thin-film modified electrode, which comprises: a first step of selecting an organic compound satisfying the above requirements; and a second step of using the organic compound selected in the first step and a metal to form a layer containing the organic compound and a metal adjacent to each other on an electrode, or forming a layer containing a metal and a layer containing an organic compound in this order.

[0075] Furthermore, a method for selecting a material for the electron injection layer of an organic element using the same method for producing a thin-film modified electrode as the second invention, i.e., a method for selecting an organic compound suitable for the material of the electron injection layer of an organic element to be formed in combination with a metal, is provided, in which the selection method comprises performing calculations based on Density Functional Theory on an organic compound capable of coordinating with a metal, optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**, and then selecting an organic compound whose equilibrium density of intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm ３The present invention also provides a method for selecting a material for an electron injection layer of an organic element, characterized by selecting the organic compound described above in combination with a metal as a material for the electron injection layer of the organic element.

[0076] In the second step of the method for producing a thin-film-modified electrode of the second invention, the method of forming one layer containing the organic compound and the metal adjacent to each other on the electrode, or the method of forming a layer containing the metal and a layer containing the organic compound in this order, is the same as the method of forming an inorganic compound layer or an organic compound layer of an organic element described later.

[0077] 3. Organic Element and Manufacturing Method Thereof The organic element of the present invention is not particularly limited in its configuration as long as it includes the thin-film modified electrode of the first present invention or the thin-film modified electrode of the second present invention. However, it is preferable that the organic element has the following layers adjacent to each other in this order: a thin-film modified electrode, an electron transport layer, a light-emitting layer, a hole transport layer and / or a hole injection layer, and an anode. Each of these layers may consist of one layer or two or more layers. Furthermore, in the case of the thin-film modified electrode of the first present invention, the layer of the thin-film modified electrode containing an organic compound capable of coordinating to a metal and having the above-mentioned sum of distances of 4.06 Å or less further contains a layer containing an electron transport material. In the case of the thin-film modified electrode of the second present invention, the layer of the thin-film modified electrode containing an organic compound capable of coordinating to a metal and having the above-mentioned equilibrium density of 1.17 g / cm is preferably a layer containing an electron transport material. ３ When the layer containing the organic compound further contains an electron transport material, the electron transport layer may be omitted. In this case, the organic element has a thin-film modified electrode, a light-emitting layer, a hole transport layer and / or a hole injection layer, and an anode, arranged adjacent to each other in this order. In the organic element having the above configuration, when the element has only one of a hole transport layer and a hole injection layer, the layer is stacked adjacent to the light-emitting layer and the anode. When the element has both a hole transport layer and a hole injection layer, the layers are stacked adjacent to each other in the following order: light-emitting layer, hole transport layer, hole injection layer, and anode. The organic element of the present invention may be an organic element having a forward structure in which an anode is formed adjacent to a substrate, or an organic element having an inverted structure in which the thin-film modified electrode of the present invention is formed adjacent to a substrate. However, an organic element having an inverted structure is preferred in terms of achieving higher atmospheric stability.

[0078] As the material for the electron transport layer, any compound that can be usually used as a material for an electron transport layer can be used, and these compounds may be used in combination. ２ ), pyridine derivatives such as tris-1,3,5-(3'-(pyridin-3''-yl)phenyl)benzene (TmPhPyB), quinoline derivatives such as (2-(3-(9-carbazolyl)phenyl)quinoline (mCQ)), pyrimidine derivatives such as 2-phenyl-4,6-bis(3,5-dipyridylphenyl)pyrimidine (BPyPPM), pyrazine derivatives, bathophenanthroline (BPhen), phenanthroline derivatives such as 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), triazine derivatives such as 2,4-bis(4-biphenyl)-6-(4'-(2-pyridinyl)-4-biphenyl)-[1,3,5]triazine (MPT), triazole derivatives such as 3-phenyl-4-(1'-naphthyl)-5-phenyl-1,2,4-triazole (TAZ), oxazole derivatives such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole) ( oxadiazole derivatives such as 2,2',2''-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), imidazole derivatives such as 2,2',2''-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBI), aromatic ring carboxylic acid anhydrides such as naphthalene-1,4,5,8-tetracarboxylic dianhydride and 3,4,9,10-perylenetetracarboxylic dianhydride, aromatic ring carboxylic acid anhydrides such as N,N'-dimethyl-3,4,9,10-perylenetetracarboxylic diimide, Cyclic imide compounds, isoindigo derivatives and 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione derivatives (diketopyrrolopyrroles), compounds with a carbonyl group such as truxenone, 1,2,5-thiadiazole derivatives such as naphtho[1,2-c:5,6-c']bis[1,2,5]thiadiazole and benzo[c][1,2,5]thiadiazole, bis[2-(2-hydroxyphenyl)benzothiazolato]zinc (Zn(BTZ)), ２ ), tris(8-hydroxyquinolinato)aluminum (Alq ３), organic silane derivatives typified by silole derivatives such as 2,5-bis(6'-(2',2''-bipyridyl))-1,1-dimethyl-3,4-diphenylsilole (PyPySPyPy), anthracene derivatives such as 9-(1-naphthyl)-10-(2-naphthyl)anthracene (1,2-ADN), tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane (3TPYMB), and boron-containing compounds described in Japanese Patent Application Nos. 2012-228460, 2015-503053, 2015-053872, 2015-081108, and 2015-081109, and the like can be used alone or in combination. In addition to the above materials, aromatic hydrocarbon compounds, which are various hydrocarbon compounds having an aromatic ring, compounds having a nitrogen-boron bond, π-electron-rich heteroaromatic compounds containing aromatic rings such as pyrrole rings, furan rings, and thiophene rings, and compounds containing silole rings can also be used. ２ Phosphine oxide derivatives such as Alq ３ It is preferable to use a metal complex such as the above, a pyridine derivative such as TmPhPyB, or an anthracene derivative.

[0079] As described above, when the organic element of the present invention includes the first thin-film modified electrode of the present invention, a metal-containing layer and an organic compound capable of coordinating to the metal, the sum of the distances being 4.06 Å or less, are mixed with the electron transport material, and when the organic element of the present invention includes the second thin-film modified electrode of the present invention, a metal-containing layer and an organic compound capable of coordinating to the metal, the sum of the distances being 4.06 Å or less, are mixed with the electron transport material, and when the organic element of the present invention includes the second thin-film modified electrode of the present invention, a metal-containing layer and an organic compound capable of coordinating to the metal, the equilibrium density being 1.17 g / cm, the equilibrium density being 1.17 g / cm, the electron transport material is mixed with the electron transport material, and when the organic element of the present invention includes the second thin-film modified electrode of the present invention, a metal-containing layer and an organic compound capable of coordinating to the metal ... ３ When the organic compound and the electron transport material are mixed, the electron transport layer may not be necessary. Alternatively, a part of the electron transport material may be used as a hole blocking material to form a hole blocking layer. Separately, any material that can be normally used may be used as the material for the hole blocking layer, and may be used as needed.

[0080] When the organic element of the present invention has an electron transport layer, the average thickness of the electron transport layer is not particularly limited, but is preferably 10 to 150 nm, and more preferably 20 to 100 nm. The average thickness of the electron transport layer can be measured by a stylus profilometer or spectroscopic ellipsometry.

[0081] In the organic element of the present invention, the material for forming the light-emitting layer may be any compound that can be commonly used as a material for a light-emitting layer, and may be a low-molecular-weight compound or a high-molecular-weight compound, or a mixture of these. Note that, in the present invention, the term "low-molecular-weight material" refers to a material that is not a high-molecular-weight material (polymer), and does not necessarily refer to an organic compound with a low molecular weight.

[0082] The material for forming the light-emitting layer is, for example, bis[2-(2-benzothiazolyl)phenolato]zinc(II) (Zn(BTZ) ２ ) and tris[1-phenylisoquinoline]iridium(III) (Ir(piq) ３ For example, a three-coordinate iridium complex having 2,2'-bipyridine-4,4'-dicarboxylic acid as a ligand, such as factoris(2-phenylpyridine)iridium (Ir(ppy) ３ ), 8-hydroxyquinoline aluminum (Alq ３ ), tris(4-methyl-8-quinolinolato)aluminum(III) (Almq ３ ), 8-hydroxyquinoline zinc (Znq ２ ), (1,10-phenanthroline)-tris-(4,4,4-trifluoro-1-(2-thienyl)-butane-1,3-dionate) europium(III) (Eu(TTA) ３(phen)), various metal complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphine platinum(II); benzene-based compounds such as distyrylbenzene (DSB) and diaminodistyrylbenzene (DADSB); naphthalene-based compounds such as naphthalene and Nile Red; phenanthrene-based compounds such as phenanthrene; chrysene-based compounds such as chrysene and 6-nitrochrysene; perylene, N,N'-bis(2,5-di-t-butylphenyl perylene compounds such as 4-(di-cyanomethylene)-2-methyl-6-(para-dimethylaminostyryl)-4H-pyran (DCM); acridine compounds such as acridine; stilbene compounds such as stilbene; 2,5-dibenzothiophene; Thiophene compounds such as thiazolidinone, benzoxazole compounds such as benzoxazole, benzimidazole compounds such as benzimidazole, benzothiazole compounds such as 2,2'-(para-phenylenedivinylene)-bisbenzothiazole, butadiene compounds such as bistyryl(1,4-diphenyl-1,3-butadiene) and tetraphenylbutadiene, naphthalimide compounds such as naphthalimide, coumarin compounds such as coumarin, perinone compounds such as perinone, oxadiazole compounds such as oxadiazole, aldazine compounds, cyclopentadiene compounds such as 1,2,3,4,5-pentaphenyl-1,3-cyclopentadiene (PPCP), quinacridone compounds such as quinacridone and quinacridone red, pyridine compounds such as pyrrolopyridine and thiadiazolopyridine, spiro compounds such as 2,2',7,7'-tetraphenyl-9,9'-spirobifluorene, phthalocyanines (H ２ Pc), metal or metal-free phthalocyanine compounds such as copper phthalocyanine; and boron compound materials described in JP-A Nos. 2009-155325, 2011-184430, and 2011-6458.

[0083] The light-emitting layer may be composed of a host material and a guest material (e.g., a dopant), or may contain an exciplex formed of two types of organic compounds as a host. The mixing ratio of the guest material (e.g., a dopant) to the host material (e.g., an exciplex) is preferably 20% by mass or less, more preferably 10% by mass or less.

[0084] The average thickness of the light-emitting layer is not particularly limited, but is preferably 10 to 150 nm, and more preferably 20 to 100 nm. The average thickness of the light-emitting layer can be measured with a quartz crystal film thickness meter in the case of a low-molecular-weight compound, and with a contact step gauge in the case of a high-molecular-weight compound.

[0085] When the organic element of the present invention has a hole transport layer, the material for the hole transport layer may be any material that can be commonly used as a material for a hole transport layer, or a mixture of these materials may be used. Specifically, materials having a molecular structure with high donor properties, such as triarylamine, carbazole, phenoxazine, phenazine, acridine, azadibenzopyrene, or a julolidine skeleton, are preferred. More specifically, the following are preferred: m-MTDATA, TPT-1, TAPC, TPDI, HN-D1, HN-D2, N-TPA, EH44, PHZ-2Naph, TBDI, HT-01, N-DPA, spiro-MeO-TAD, Tris-PCz, α-NPD, TcTa, 2-SF-DMAC, 2-SF-PHX, SF-BCz, FATPA, and the like. Examples of materials for the hole transport layer include N4,N4'-bis(dibenzo[b,d]thiophen-4-yl)-N4,N4'-diphenylbiphenyl-4,4'-diamine (DBTPB), polyarylamine, fluorene-arylamine copolymer, fluorene-bithiophene copolymer, poly(N-vinylcarbazole), polyvinylpyrene, polyvinylanthracene, polythiophene, polyalkylthiophene, polyhexylthiophene, poly(p-phenylenevinylene), polythienylenevinylene, pyrene formaldehyde resin, ethylcarbazole formaldehyde resin, and derivatives thereof.

[0086]

[0087] These hole transport layer materials can also be used as mixtures with other compounds. For example, a mixture containing polythiophene that can be used as a hole transport layer material is poly(3,4-ethylenedioxythiophene / styrenesulfonic acid) (PEDOT / PSS).

[0088] When the organic element of the present invention has a hole transport layer, the average thickness of the hole transport layer is not particularly limited, but is preferably 10 to 150 nm, and more preferably 20 to 100 nm. The average thickness of the hole transport layer can be measured by a stylus profilometer or spectroscopic ellipsometry.

[0089] When the organic element of the present invention has a hole injection layer, the hole injection layer may be made of an inorganic material or an organic material. Inorganic materials are more stable than organic materials, and therefore, higher resistance to oxygen and water can be easily obtained compared to when an organic material is used. The inorganic material is not particularly limited, but examples thereof include vanadium oxide (V ２ O ５ ), molybdenum oxide (MoO ３ ), ruthenium oxide (RuO ２ As the organic material, low molecular weight materials such as dipyrazino[2,3-f:2',3'-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4-TCNQ), 2,2'-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCCNNQ), poly(3,4-ethylenedioxythiophene) / polystyrene sulfonate (PEDOT:PSS), etc. can be used.

[0090] The average thickness of the hole injection layer is not particularly limited, but is preferably 1 to 1,000 nm, and more preferably 5 to 50 nm. The average thickness of the hole injection layer can be measured during film formation using a quartz crystal film thickness meter, a stylus step meter, or spectroscopic ellipsometry.

[0091] In the organic element of the present invention, examples of materials used for the anode include ITO, IZO, Au, Pt, Ag, Cu, Al, and alloys containing these. Among these, ITO, IZO, Au, Ag, and Al are preferably used.

[0092] The average thickness of the anode is not particularly limited, but is preferably 10 to 1000 nm. More preferably, it is 30 to 150 nm. Even when an opaque material is used, the anode can be used as a top-emission or transparent anode by, for example, setting the average thickness to about 10 to 30 nm. The average thickness of the anode can be measured during film formation using a quartz crystal film thickness meter.

[0093] The organic element of the present invention may have, for example, a hole-blocking layer, an electron-blocking layer, etc., as needed to further improve the properties, etc. Materials commonly used for forming these layers can be used as materials for forming these layers, and the layers can be formed by methods commonly used for forming these layers.

[0094] After the final electrode of the laminated structure is formed, a passivation layer for protecting the surface may be formed thereon. Materials commonly used for forming these layers may be used as the material for the passivation layer. For example, the materials for the hole transport layer and / or the metal oxide layer described above may be used, but are not limited to these, as long as the combination can maintain insulation.

[0095] The average thickness of the passivation layer is not particularly limited, but is preferably 20 to 300 nm, and more preferably 50 to 200 nm. The average thickness of the passivation layer can be measured during film formation using a quartz crystal film thickness meter.

[0096] The substrate of the organic element of the present invention may be a substrate having a barrier layer formed thereon for sealing. Examples of materials for the substrate include resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyethersulfone, polymethyl methacrylate, polycarbonate, and polyarylate. Examples of materials for forming a barrier layer on the substrate include epoxy resin, acrylic resin, and parylene.

[0097] The average thickness of the substrate is preferably 10 to 150 μm, and more preferably 10 to 50 μm. The average thickness of the substrate can be measured using a digital caliper.

[0098] The organic element may further include a sealing layer on the passivation layer, which may be made of the same material as the substrate, and which preferably has the same thickness as the substrate.

[0099] In the organic element of the present invention, the method for forming the layer formed from an organic compound or the coating layer of an inorganic compound is not particularly limited, and various methods can be used as appropriate depending on the characteristics of the material. When a solution can be formed and applied, various coating methods can be used, such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, slit coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, and inkjet printing. Of these, spin coating and slit coating are preferred because they make it easier to control the film thickness. When no coating is required or when the solvent solubility is low, suitable examples include vacuum deposition and ESDUS (Evaporative Spray Deposition from Ultra-dilute Solution) method.

[0100] When the layer formed from the organic compound or the coating layer of the inorganic compound is formed by applying a solution or dispersion of the material, examples of solvents used to prepare the solution or dispersion include inorganic solvents such as nitric acid, sulfuric acid, ammonia, hydrogen peroxide, water, carbon disulfide, carbon tetrachloride, and ethylene carbonate; ketone-based solvents such as methyl ethyl ketone (MEK), acetone, diethyl ketone, methyl isobutyl ketone (MIBK), methyl isopropyl ketone (MIPK), and cyclohexanone; alcohol-based solvents such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol (DEG), and glycerin; diethyl ether, diisopropyl ether, 1,2-dimethoxyethane (DME), 1,4-dioxane, tetrahydrofuran (THF), tetrahydropyran (THP), anisole, diethylene glycol dimethyl ether (diglyme), and diethylene glycol ethyl ether (carbitol). aromatic hydrocarbon solvents such as toluene, xylene, and benzene; aromatic heterocyclic compound solvents such as pyridine, pyrazine, furan, pyrrole, thiophene, and methylpyrrolidone; amide solvents such as N,N-dimethylformamide (DMF) and N,N-dimethylacetamide (DMA); halogen compound solvents such as chlorobenzene, dichloromethane, chloroform, and 1,2-dichloroethane; ester solvents such as ethyl acetate, methyl acetate, and ethyl formate; sulfur compound solvents such as dimethyl sulfoxide (DMSO) and sulfolane; nitrile solvents such as acetonitrile, propionitrile, and acrylonitrile; and organic acid solvents such as formic acid, acetic acid, trichloroacetic acid, and trifluoroacetic acid, or mixed solvents containing any of these.Among these, non-polar solvents are preferred as the solvent, and examples thereof include aromatic hydrocarbon solvents such as xylene, toluene, cyclohexylbenzene, dihydrobenzofuran, trimethylbenzene, and tetramethylbenzene; aromatic heterocyclic compound solvents such as pyridine, pyrazine, furan, pyrrole, thiophene, and methylpyrrolidone; and aliphatic hydrocarbon solvents such as hexane, pentane, heptane, and cyclohexane, and these can be used alone or in combination.

[0101] The cathode, anode, and inorganic compound layers such as metal layers and oxide layers can be formed by sputtering, vacuum deposition, sol-gel, spray pyrolysis (SPD), atomic layer deposition (ALD), vapor phase deposition, liquid phase deposition, or the like. Bonding of metal foils can also be used to form the anode and cathode. These methods are preferably selected depending on the properties of the materials used for each layer, and different fabrication methods may be used for each layer. Among these, the metal oxide layer is more preferably formed using a vapor phase deposition method. Vapor phase deposition allows the organic compound layer to be formed cleanly and in good contact with the anode without damaging the surface, resulting in a more pronounced effect of having a hole injection layer made of the metal described above.

[0102] When sealing the organic element of the present invention, a conventional method can be used as the sealing step. For example, a method of adhering a sealing container in an inert gas or a method of directly forming a sealing film on the organic electroluminescent element can be used. In addition to these, a method of sealing with a moisture absorbent material can be used in combination.

[0103] When the organic element is used as an organic electroluminescent element, the element may be a top-emission type that extracts light on the side opposite to the substrate, or a bottom-emission type that extracts light on the side where the substrate is located.

[0104] The organic element of the present invention can be produced by producing the thin-film-modified electrode of the present invention and then forming an organic layer or the like constituting the organic element thereon. Such a method for producing an organic element, i.e., a method for producing an organic element comprising the steps of producing a thin-film-modified electrode using the method for producing a thin-film-modified electrode of the present invention and forming an organic layer on the resulting thin-film-modified electrode, also constitutes one aspect of the present invention. The method for producing an organic element of the present invention may also include steps other than those described above. Examples of such steps include a step of forming an inorganic compound layer before or after the step of forming the organic layer, or a step of forming an inorganic compound layer after the step of forming the organic layer and then forming another organic layer. These steps of forming an organic layer and a step of forming an inorganic compound layer can be performed by the methods for forming an organic compound layer and inorganic compound layer constituting the organic element described above.

[0105] 4. Uses of Organic Element The organic element of the present invention has excellent electron injection properties and atmospheric stability, and can be suitably used as an organic electroluminescent element, an organic thin-film solar cell, or a thin-film transistor. When the organic element of the present invention is used as an organic electroluminescent element, it can be suitably used as a material for a display device or a lighting device. Such organic electroluminescent elements, organic thin-film solar cells, and thin-film transistors using the organic element of the present invention, as well as display devices and lighting devices formed using the organic element of the present invention, also constitute part of the present invention.

[0106] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by weight" and "%" means "% by mass." Compounds used as the coordinating organic compound will be described below.

[0107] Synthesis Example 1 A compound represented by the following formula (8) was synthesized by the method shown below.

[0108]

[0109] In a 100 mL recovery flask, a mixture of 4,7-dichloro-1,10-phenanthroline (3.00 g) and pyrrolidine (19.5 mL) was heated to reflux in an oil bath at 100°C for 1 hour. The mixture was returned to room temperature and concentrated under reduced pressure. Water was added and then ultrasonically treated to precipitate a solid, which was then filtered off. The resulting solid was dried under reduced pressure and then dissolved in methanol (100 mL). Activated carbon was added to the mixture, and the mixture was stirred at room temperature for 1 hour, after which insoluble matter was filtered off. The filtrate was concentrated under reduced pressure, and the resulting solid was recrystallized from methanol (9 mL). The resulting solid was washed with a small amount of methanol and then dried under reduced pressure to obtain compound 1 (1.69 g, 44%) represented by formula (8) as a white solid.

[0110] Synthesis Example 2 Compound 2 represented by the following formula (9) was synthesized using the synthesis method described in WO 2012 / 045179.

[0111]

[0112] (Compound 3, Compound 4) Compound 3 represented by the following formula (10) was purchased from Aldrich, and compound 4 represented by the following formula (11) was purchased from Tokyo Chemical Industry Co., Ltd. and used.

[0113]

[0114] Comparative Synthesis Example 1 Compound 5 represented by the following formula (12) was synthesized using the synthesis method described in WO 2012 / 045179.

[0115]

[0116] (Compound 6, Compound 7) Compound 6 represented by the following formula (13) was purchased from Luminescence Technology Co., Ltd., and compound 7 represented by the following formula (14) was purchased from Tokyo Chemical Industry Co., Ltd. and used.

[0117]

[0118] Synthesis Example 3 Compound 8 represented by the following formula (15) was synthesized by the following method.

[0119]

[0120] Under an argon atmosphere, 1.65 g (6.6 mmol, 1.0 eq.) of 4,7-dichloro-1,10-phenanthroline, 4.98 g (39.7 mmol, 6.0 eq.) of octahydroisoindole, and 7 mL of 2-propanol were added to a test tube. This suspension was heated and stirred overnight in an oil bath at 80°C. After cooling, 4 mL of chloroform and water were added, and the mixture was allowed to stand to separate into two layers. The organic layer was separated and washed with water, and then concentrated, and 8 mL of methanol was added to the residue. The precipitated white solid was filtered, and the filter bed was washed with a small amount of methanol to obtain 2.25 g (2.28 mmol, yield: 80%) of compound 8. Figure 5 shows the structure of compound 8. １ The H-NMR spectrum is shown.

[0121] Synthesis Example 4 Compound 9 represented by the following formula (16) was synthesized by the following method.

[0122]

[0123] Under an argon atmosphere, 0.15 g (0.602 mmol, 1.0 eq.) of 4,7-dichloro-1,10-phenanthroline, 0.571 g (2.41 mmol, 4.0 eq.) of (S)-(-)-2-(diphenylmethyl)pyrrolidine, and 2 mL of degassed N-methylpyrrolidone were added to a 15 mL pressure test tube. The resulting suspension was heated in a 130°C oil bath and stirred for 6 hours. After cooling, 5 mL of 1N aqueous sodium hydroxide solution was added to the brown suspension while vigorously stirring, followed by 4 mL of chloroform. The mixture was stirred for 3 minutes and then allowed to stand to separate into two layers. The organic layer was concentrated, and the residue was purified using a silica gel column to obtain 0.61 g of a light brown viscous liquid. 8 mL of ethanol was added, and the mixture was subjected to ultrasonic irradiation until crystals precipitated. This suspension was left to stand overnight at 5°C, filtered, and the filter bed was washed with a small amount of methanol and then vacuum dried at 50°C to obtain 0.11 g (0.169 mmol, yield: 28%) of compound 9. １ The H-NMR spectrum is shown.

[0124] Synthesis Example 5 Compound 10 represented by the following structural formula (17) was synthesized by the method shown below.

[0125]

[0126] Under an argon atmosphere, 4,7-dibromo-1,10-phenanthroline (0.6 g, 1.78 mmol, 1.0 eq.), 1,2,3-triazole (0.61 g, 8.88 mmol, 5.0 eq.), and xylene (8 mL) were added to a 15 mL reactor. The suspension was heated to a bath temperature of 110°C and stirred for 5 hours. After cooling, the brown suspension was filtered, and the solid was dissolved in THF (20 mL) by heating. Toluene (20 mL) was added, and the resulting suspension was purified by column purification (NH-SiO ２ The resulting solid was washed with methanol (10 mL) and filtered under high vacuum at 80°C to obtain a pale brown solid (0.36 g) of compound 10 (0.32 g, 1.02 mmol, 57%) represented by structural formula (17), a mixture of several isomers.

[0127] Synthesis Example 6 Compound 11 represented by the following structural formula (18) was synthesized by the method shown below.

[0128]

[0129] Under an argon atmosphere, 4,7-dibromo-1,10-phenanthroline (0.6 g, 1.78 mmol, 1.0 eq.), 1,2,3-benzotriazole (0.70 g, 5.92 mmol, 4.0 eq.), and xylene (8 mL) were added to a 10 mL pressure test tube. The bath temperature of this suspension was raised to 120°C, and the suspension was heated and stirred for 6 hours. After cooling, the brown suspension was filtered, and the solid was dissolved in chloroform (100 mL) by heating, followed by gel filtration (NH-SiO ２ The gel was washed with heated chloroform, and the filtrate was concentrated to give a yellow-green solid (0.69 g). This was washed with heated dispersion in ethanol (20 mL), filtered, and dried at 80°C under high vacuum to give compound 11 (0.61 g, 1.47 mmol, 99%) represented by structural formula (18) as a yellow-green solid.

[0130] (Compound 12) Compound 12 represented by the following structural formula (19) was purchased from Aldrich and used.

[0131]

[0132] (Compound 13) Compound 13 represented by the following structural formula (20) was purchased from Tokyo Chemical Industry Co., Ltd. and used.

[0133]

[0134] Synthesis Example 7 Compound 14 represented by the following structural formula (21) was synthesized by the method shown below.

[0135]

[0136] 4,7-Dihydroxy-1,10-phenanthroline (3.83 g, 18.0 mmol, 1.0 eq.) and phosphorus oxychloride (60 mL) were placed in a 200 mL reactor. The suspension was stirred at a bath temperature of 130°C for 3 hours. After cooling, the solution was concentrated, and the residue was quenched with a 1:1 mixture of methanol / distilled water (80 mL) and 5% aqueous sodium bicarbonate. After neutralization was confirmed, the mixture was stirred at room temperature for 30 minutes. The precipitated solid was filtered, washed successively with tap water and methanol, and dried under high vacuum at 60°C for 8 hours to obtain 4,7-dichloro-1,10-phenanthroline (3.68 g, 15.2 mmol, 84%) as a light beige solid.

[0137] Under an argon atmosphere, 4,7-dichloro-1,10-phenanthroline (0.7 g, 2.81 mmol, 1.0 eq.), diphenylamine (1.9 g, 11.2 mmol, 4.0 eq.), NaOt-Bu (1.08 g, 11.2 mmol, 4.0 eq.), and degassed and dehydrated toluene (20 mL) were added to a 100 mL reaction vessel. To this suspension, palladium acetate (21 mg, 0.084 mmol, 0.03 eq.), t-Bu, and ３ A red solution containing 0.67 mL of P (0.5 M toluene solution) was added. The suspension was degassed under reduced pressure at room temperature for 15 minutes, then heated to a bath temperature of 100°C and stirred for 14 hours. After cooling to room temperature, the suspension was filtered through Celite, the filter bed was washed with toluene (30 mL), and the filtrate was concentrated. The residue was purified by column (SiO ２A brown solid (1.39 g) was obtained by subjecting the mixture to a distillation reaction (chloroform only → chloroform / methanol = 10 / 1) (45 g, chloroform only → chloroform / methanol = 10 / 1). This was recrystallized from heated ethanol to obtain compound 14 (1.13 g, 2.19 mmol, 78%) represented by structural formula (14) as a pale yellow solid.

[0138] Synthesis Example 8 Compound 15 represented by the following structural formula (22) was synthesized using the synthesis method described in WO 2012 / 045179.

[0139]

[0140] Synthesis Example 9 Compound 16 represented by the following structural formula (23) was synthesized using the synthesis method described in WO 2012 / 045179.

[0141]

[0142] Fabrication of Organic Element (Example 1-1) [Step 1] A glass substrate 1 (thickness: 0.7 mm) with an ITO electrode layer (cathode 2) was prepared. This substrate was subjected to UV ozone cleaning for 20 minutes. [Step 2] Next, in order to form an ultra-thin aluminum metal film 3 with a thickness of 1 nm, the substrate that had been subjected to the process of [Step 1] was introduced into a vacuum device, and 5 × 10 －５ The pressure was reduced to 0.2 Pa or less, and a thin-film modified electrode (2+3+4) was formed by vacuum deposition. [Step 3] Next, the material of formula (8) above was vapor-deposited to a thickness of 3 nm as the electron injection layer 4, producing a thin-film modified electrode (2+3+4). [Step 4] Next, 1,2-ADN was vapor-deposited to a thickness of 30 nm to form the electron transport layer 5. [Step 5] Then, 1,2-ADN and the dopant material BD-1 were mixed in a mass ratio of 19:1 to form a 25 nm light-emitting layer 6. [Step 6] Next, Tris-PCz was deposited to a thickness of 25 nm as the hole transport layer 7. [Step 7] Subsequently, HAT-CN was deposited to a thickness of 5 nm as the hole injection layer 8. [Step 8] Finally, a 120 nm thick anode 9 made of aluminum was formed by vacuum deposition. The anode 9 was formed using a stainless steel vapor deposition mask so that the vapor deposition surface would be a strip-like shape with a width of 3 mm. By the above steps [Step 1] to [Step 8], an organic element 1-1 having the configuration shown in FIG. 1 was fabricated.

[0143] (Examples 1-2, 1-3, 2-1, Comparative Examples 1-1, 1-2, 2-1) Organic elements 1-2, 1-3, 2-1 and comparative organic elements 1-1, 1-2, 2-1 were prepared in the same manner as in Example 1-1, except that in [Step 3], the compounds of the formulas (9) to (14) were used instead of the compound of the formula (8).

[0144] Example 3-1 The experiment of Example 1-1 was repeated at a different time under different measurement environments such as different temperature, humidity, etc. The element was fabricated in the same manner as in Example 1-1 to fabricate an organic element 3-1.

[0145] Examples 3-2 and 3-3 Organic elements 3-2 and 3-3 were prepared in the same manner as in Example 3-1, except that in [Step 3], the compounds of the formulas (15) and (16) were used instead of the compound of the formula (8).

[0146] Example 4-1 An organic element 4-1 was fabricated in the same manner as in Example 1-1, except that magnesium was used instead of aluminum in [Step 2].

[0147] Examples 4-2 and 4-3, Comparative Examples 4-1 and 4-2 Organic elements 4-2 and 4-3 and comparative organic elements 4-1 and 4-2 were prepared in the same manner as in Example 4-1, except that in [Step 3], the compounds of the formulas (9) to (12) were used instead of the compound of the formula (8).

[0148] Example 5-1 The experiment of Example 4-1 was repeated at a different time under different measurement environments such as different temperature, humidity, etc. The element was fabricated in the same manner as in Example 4-1 to fabricate an organic element 5-1.

[0149] Examples 5-2 and 5-3 Organic elements 5-2 and 5-3 were prepared in the same manner as in Example 5-1, except that in [Step 3], the compounds of the formulas (15) and (16) were used instead of the compound of the formula (8).

[0150] (Atmospheric Stability Evaluation) The organic element 1-1 produced in Example 1-1 was stored unsealed in a measuring device in an atmospheric environment at room temperature and normal pressure, and a constant current of 100 nits was applied every 30 minutes at the time of initial measurement, and the light-emitting surface was photographed. The image of the light-emitting surface was processed to extract the outline of the light-emitting surface, and the difference from the initial outline was calculated to calculate the deterioration width w of the light-emitting surface. The application of voltage to the organic element, measurement of luminance, and measurement of average relative humidity were performed using the following methods. The relationship between the deterioration width w of the light-emitting surface shown in Figure 2 and the elapsed time t from the start of light emission can be approximated to a square root function using a diffusion equation. The growth rate α of deterioration (shrinkage) was calculated by w ２ is defined as the slope of a linear approximation of the time t as a function of the elapsed time (i.e., w ２ The shrink growth rate α was calculated for organic element 1-1 from the observation results of the deterioration width w and the elapsed time t from the start of light emission, using the following equation (defined as αt + β). The shrink growth rate α was calculated in the same manner for organic elements 1-2 to 5-3 and comparative organic elements 1-1 to 4-2. The voltage at which the luminance reached 100 nits and the shrink growth rate α are shown in Tables 1 to 5. <Measurement of luminous characteristics of organic elements> Voltage was applied to the elements using a Keithley 2400 source meter. The luminance was measured using a Konica Minolta LS-110. <Measurement of average relative humidity during element storage> A hygrometer was placed in the chamber of the measurement device used to evaluate atmospheric stability, and the relative humidity was measured when images were taken. The average relative humidity values ​​during the observation period of the organic elements are shown in Tables 1 to 5.

[0151] (Molecular Orbital Calculations) For compounds 1 to 9, calculations were performed based on Density Functional Theory, with the metal being an aluminum atom, and the structures were optimized using functional: B3LYP / basis function: 6-31G**. The sum of the distances between the atoms coordinated to the metal in each compound and the aluminum atom was then calculated. For compounds 1 to 5 and 8 and 9, two nitrogen atoms contained in the phenanthroline skeleton coordinate to the aluminum atom, and therefore the sum of the two N-Al distances was calculated. For compounds 6 and 7, a nitrogen atom contained in the pyridine skeleton coordinates to the aluminum atom, and therefore the sum of the N-Al distances in the two pyridine skeletons was calculated. These results are shown in Tables 1 to 5. 3 and 4 show plots of the relationship between the sum of distances and the shrink growth rate α, and the relationship between the sum of distances and the voltage at which the luminance becomes 100 nits for Examples 1-1 to 1-3, Comparative Examples 1-1 and 1-2, Examples 4-1 to 4-3, and Comparative Examples 4-1 and 4-2, which used Compounds 1 to 5.

[0152]

[0153]

[0154]

[0155]

[0156]

[0157] As can be seen from Tables 1 and 4 and FIG. 3 , a correlation was confirmed between the shrink growth rate α and the sum of the distances between the metal-coordinated atoms and the aluminum atoms in each compound, as determined by molecular orbital calculations. It was confirmed that the shorter the distance between the metal-coordinated atoms and the metal atoms in the compound, the higher the resistance to moisture and the atmosphere, resulting in an organic device with high atmospheric stability. Furthermore, as can be seen from Tables 1 and 4 and FIG. 4 , a correlation was also confirmed between the sum of the distances and the voltage at which the luminance reached 100 nits. It was confirmed that the shorter the distance between the metal-coordinated atoms and the metal atoms in the compound, the higher the electron injection ability of the organic device. Furthermore, Table 2 confirmed that a correlation was also observed between the sum of the distances between the metal-coordinated atoms and the aluminum atoms in each compound, as determined by molecular orbital calculations, and the shrink growth rate α, even for compounds other than phenanthroline compounds. Furthermore, the results in Tables 1 to 5 confirmed that when the sum of the distances between the metal-coordinated atoms and the aluminum atoms in the compound was 4.06 Å or less, the organic device was able to exhibit both high atmospheric stability and high electron injection ability, regardless of the external environment.

[0158] Example 6 An organic element 6 having the structure shown in FIG. 1 was manufactured by the method described below and evaluated.

[0159] [Step 1] A glass substrate 1 (thickness: 0.7 mm) with an ITO electrode layer (cathode 2) was prepared. This substrate was subjected to UV ozone cleaning for 20 minutes.

[0160] [Step 2] Next, in order to form a 1 nm thick metal thin film layer 3 of aluminum, the substrate that has been subjected to the process of [Step 1] is introduced into a vacuum device, and 5×10 －５ The pressure was reduced to 0.1 Pa or less, and a film was formed by vacuum deposition.

[0161] [Step 3] Next, the material of the structural formula (17) was vapor-deposited to a thickness of 3 nm as the electron injection layer 4 to prepare a thin film modified electrode (2+3+4).

[0162] [Step 4] Next, a compound having the following structural formula:

[0163]

[0164] 1,2-ADN represented by the following formula was deposited to a thickness of 30 nm to form an electron transport layer 5.

[0165] [Step 5] Then, as the light-emitting layer 6, 1,2-ADN (host material) represented by the above structural formula and a compound represented by the following structural formula as a dopant material are mixed.

[0166]

[0167] and BD-1 represented by the formula (I) were formed to a thickness of 25 nm at a mass ratio (1,2-ADN:BD-1) of 19:1.

[0168] [Step 6] Next, a hole transport layer 7 was prepared by dissolving a compound having the following structural formula:

[0169]

[0170] Tris-PCz represented by the formula was formed to a thickness of 25 nm.

[0171] [Step 7] Subsequently, a hole injection layer 8 having the following structural formula:

[0172]

[0173] A 5 nm thick HAT-CN film was formed.

[0174] [Step 8] Finally, an anode 9 made of aluminum and having a thickness of 120 nm was formed by vacuum deposition. The anode 9 was formed using a stainless steel deposition mask so that the deposition surface would be a strip with a width of 3 mm.

[0175] By the above [Step 1] to [Step 8], an organic element 6 having the structure shown in FIG. 1 was fabricated.

[0176] Examples 7 and 8, Comparative Examples 5 to 8 The organic elements of Examples 7 and 8 and Comparative Examples 5 to 8 were fabricated in the same manner as in Example 6, except that in the above [Step 3], the compounds of the structural formulas (18) to (23) were used instead of the compound of the structural formula (17).

[0177] (Evaluation of atmospheric stability) Using the same method as in Examples 1-1 to 5-3, the shrink growth rate α was determined from the observation results of the deterioration width w and the elapsed time t from the start of light emission for the organic elements of Examples 6 to 8 and Comparative Examples 5 to 8. The shrink growth rate α is shown in Table 6.

[0178] (Optimization by Molecular Orbital Calculation and Molecular Dynamics Calculation) For the compounds represented by structural formulas (17) to (23), the steric structure was optimized using the functional: B3LYP-D3 / basis function: 6-31G** in calculations based on Density Functional Theory. The optimized molecular structure was expanded to an amorphous system of 128 molecules, and molecular dynamics calculations were performed under isobaric and isothermal conditions of 1.2 ns, 300 K, and 1.01325 bar. This calculation balanced the contributions of intermolecular bonding and non-bonding energy, and the final converged density was determined. These results are shown in Table 6. Furthermore, Figure 7 shows a graph plotting the relationship between equilibrium density and shrink growth rate α for the organic devices of Examples 6 to 8 and Comparative Examples 5 to 8, which used compounds represented by structural formulas (17) to (23).

[0179]

[0180] As can be seen from Table 6 and FIG. 7 , the relationship shown by the dotted line in the figure was confirmed between the calculated equilibrium density of each compound and the shrink growth rate α, and it was confirmed that the higher the equilibrium density of a compound, the higher the resistance to moisture and air, resulting in an organic element with high atmospheric stability.

[0181] The thin-film modified electrode of the present invention and the organic element using the same can be suitably used as an organic electroluminescent element, an organic thin-film solar cell, an organic thin-film transistor, or the like.

[0182] 1: Substrate 2: Cathode 3: Metal thin film layer 4: Electron injection layer 5: Electron transport layer 6: Light-emitting layer 7: Hole transport layer 8: Hole injection layer 9: Anode 10: Organic element

Claims

1. A thin-film modified electrode having, adjacent to an electrode, a layer containing a metal and an organic compound capable of coordinating to the metal, or a layer having a structure in which a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal are adjacent to each other in this order, wherein the organic compound is a compound such that, when the structure is optimized using functional: B3LYP / basis function: 6-31G** in calculations based on Density Functional Theory with the metal being an aluminum atom, the sum of the distances between the atom coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less.

2. The thin film modified electrode according to claim 1, wherein at least one of said metals has a work function of 4.0 eV or more.

3. A thin-film modified electrode having a layer containing a metal and an organic compound capable of coordinating to the metal, or a layer containing a metal and a layer containing an organic compound capable of coordinating to the metal, adjacent to the electrode, in this order, wherein the organic compound has an equilibrium density of intermolecular packing obtained by molecular dynamics calculation after optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G** in calculation based on Density Functional Theory, of 1.17 g / cm ３ The thin film modified electrode is characterized in that the compound is one of the above.

4. The organic compound has an equilibrium density of 1.20 g / cm ３ The thin film modified electrode according to claim 3, characterized in that:

5. The thin film modified electrode according to any one of claims 1 to 4, characterized in that the metal is at least one selected from the group consisting of aluminum, magnesium and silver.

6. A thin film modified electrode described in any one of claims 1 to 5, characterized in that the atom coordinated to the metal in the organic compound is at least one selected from the group consisting of nitrogen atoms, sulfur atoms, and oxygen atoms.

7. An organic device comprising the thin film modified electrode according to any one of claims 1 to 6.

8. A lighting device comprising the organic element according to claim 7.

9. A display device comprising the organic element according to claim 7.

10. A method for producing a thin-film modified electrode, comprising: a first step of selecting an organic compound capable of coordinating with a metal, the organic compound being selected such that the sum of the distances between the atom coordinating with the metal in the organic compound and the aluminum atom is 4.06 Å or less when the structure is optimized using functional: B3LYP / basis function: 6-31G** by performing calculations based on Density Functional Theory in which the coordinating metal is an aluminum atom; and a second step of using the organic compound and the metal selected in the first step to form a layer containing the organic compound and the metal adjacent to each other on an electrode, or to sequentially form a layer containing a metal and a layer containing an organic compound.

11. A method for producing a thin film modified electrode, comprising: performing calculations based on Density Functional Theory on an organic compound capable of coordinating with a metal; optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**; and determining that the equilibrium density of intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm. ３ and a second step of forming a layer containing the organic compound and the metal adjacent to an electrode using the organic compound selected in the first step, or forming a layer containing the metal and a layer containing the organic compound in this order.

12. A method for producing an organic element, comprising the steps of: producing a thin-film modified electrode using the method for producing a thin-film modified electrode according to claim 10 or 11; and forming an organic layer on the obtained thin-film modified electrode.

13. A method for selecting an organic compound suitable as a material for an electron injection layer of an organic element to be formed in combination with a metal, the selection method comprising the steps of: performing calculations based on Density Functional Theory, in which the metal is an aluminum atom, on an organic compound capable of coordinating to a metal; optimizing the structure using functional: B3LYP / basis function: 6-31G**; and selecting an organic compound such that the sum of the distance between the atom coordinating to the metal in the organic compound and the aluminum atom is 4.06 Å or less as a material for the electron injection layer of the organic element to be formed in combination with the metal.

14. A method for selecting an organic compound suitable for use as a material for an electron injection layer of an organic element formed in combination with a metal, the selection method comprising the steps of: performing calculations based on Density Functional Theory on an organic compound capable of coordinating with a metal; optimizing the structure using functional: B3LYP-D3 / basis function: 6-31G**; and determining that the equilibrium density of intermolecular packing obtained by molecular dynamics calculation is 1.17 g / cm. ３ A method for selecting a material for an electron injection layer of an organic element, comprising the steps of: selecting the organic compound as described above as a material for the electron injection layer of the organic element to be formed in combination with a metal.

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