Light emitting element

Abstract

A light-emitting element (1) comprises a positive electrode (11) and a negative electrode (16), and further comprises at least one functional layer that is located between the positive electrode (11) and the negative electrode (16) and includes a 1O2 scavenger (31), which is an aprotic singlet-oxygen scavenger.

Description

Light emitting device and method for manufacturing the same

[0001] The present disclosure relates to a light-emitting device and a method for manufacturing the same.

[0002] A light-emitting element called a QLED (quantum dot light-emitting diode) uses quantum dots as a light-emitting material in its light-emitting layer.

[0003] It is known that quantum dots are degraded by oxygen. Within the light-emitting device, oxygen exists in the atmosphere that has entered the light-emitting device, oxygen in the solvent that remains in the light-emitting device, oxygen contained in the materials, etc.

[0004] When ground-state oxygen (triplet oxygen) is irradiated with excitation light such as ultraviolet light in the presence of a photosensitizer, the triplet oxygen is excited to generate singlet oxygen. Quantum dots function as photosensitizers. Many photosensitizers are compounds that transition from the ground state to a singlet excited state by absorbing light, and then rapidly undergo intersystem crossing to the triplet excited state. Singlet oxygen oxidizes the quantum dots.

[0005] Quantum dots are generally referred to as semiconductor nanoparticles because their composition is derived from semiconductor materials. Patent Document 1 discloses that singlet oxygen is removed and deterioration of semiconductor nanoparticles is suppressed by coordinating antioxidant ligands to the surfaces of semiconductor nanoparticles.

[0006] Japanese Patent Publication No. 2017-025220

[0007] However, when an antioxidant ligand is coordinated to a quantum dot, there is a problem that, for example, the dispersibility of the quantum dot changes, and when the quantum dot is used in a light-emitting device, the light-emitting characteristics and reliability of the device are reduced.

[0008] An object of one aspect of the present disclosure is to provide a light-emitting device that suppresses deterioration of quantum dots due to singlet oxygen and has high luminous efficiency and reliability, and a method for manufacturing the same.

[0009] In order to solve the above problem, a light-emitting element according to one embodiment of the present disclosure comprises a first electrode and a second electrode, and at least one functional layer containing an aprotic singlet oxygen scavenger between the first electrode and the second electrode.

[0010] In order to solve the above problem, a light-emitting element according to one embodiment of the present disclosure includes a first electrode and a second electrode, and at least one functional layer between the first electrode and the second electrode, the functional layer containing at least one compound selected from the group consisting of a tertiary amine, a carotenoid, an ethylenic compound, naphthalene and its derivatives, and anthracene and its derivatives.

[0011] In order to solve the above problems, a method for manufacturing a light-emitting element according to one aspect of the present disclosure is a method for manufacturing a light-emitting element comprising a first electrode and a second electrode, and at least one functional layer between the first electrode and the second electrode, and includes a functional layer formation step of forming the at least one functional layer, in which at least one functional layer containing an aprotic singlet oxygen scavenger is formed as the functional layer.

[0012] In order to solve the above problems, a method for manufacturing a light-emitting element according to one embodiment of the present disclosure is a method for manufacturing a light-emitting element comprising a first electrode and a second electrode, and at least one functional layer between the first electrode and the second electrode, and includes a functional layer formation step of forming the at least one functional layer, in which at least one functional layer is formed containing at least one compound selected from the group consisting of tertiary amines, carotenoids, ethylenic compounds, naphthalene and its derivatives, and anthracene and its derivatives.

[0013] According to one aspect of the present disclosure, it is possible to provide a light-emitting device that suppresses deterioration of quantum dots due to singlet oxygen and has high luminous efficiency and reliability, and a method for manufacturing the same.

[0014] FIG. 5 is a cross-sectional view schematically showing an example of a light-emitting device according to embodiment 1. FIG. 6 is a flowchart showing a method for manufacturing the light-emitting device shown in FIG. 1. FIG. 7 is a cross-sectional view schematically showing an example of a light-emitting device according to embodiment 2. FIG. 8 is a flowchart showing a method for manufacturing the light-emitting device shown in FIG. 3. FIG. 9 is a cross-sectional view schematically showing an example of a light-emitting device according to embodiment 3. FIG. 10 is a flowchart showing a method for manufacturing the light-emitting device shown in FIG. 11. FIG. 12 is a cross-sectional view schematically showing an example of a light-emitting device according to embodiment 4.

[0015] An embodiment of the present disclosure will be described in detail below. Hereinafter, a layer formed in a process earlier than the layer to be compared will be referred to as a "lower layer," and a layer formed in a process later than the layer to be compared will be referred to as an "upper layer." In the following description, the expression "A to B" for two numbers A and B means "greater than or equal to A and less than or equal to B" unless otherwise specified. Furthermore, compositions represented by chemical formulas in this disclosure are preferably stoichiometric. However, this does not exclude compositions other than stoichiometric.

[0016] For the sake of convenience, components having the same functions as those previously described will be denoted by the same reference numerals, and their description will not be repeated. In the second and subsequent embodiments described below, differences from the previously described embodiments will be described. It goes without saying that the same modifications as those of the previously described embodiments are possible in the second and subsequent embodiments, even if no special explanation is given.

[0017] A light-emitting element according to one aspect of the present disclosure includes a first electrode, a second electrode, and at least one functional layer provided between the first electrode and the second electrode. In the present disclosure, the layers between the first electrode and the second electrode are collectively referred to as the functional layer.

[0018] The functional layer may be a single layer type consisting of only a light-emitting layer, or may be a multi-layer type including a light-emitting layer and a functional layer other than the light-emitting layer.

[0019] The light-emitting element is a self-luminous element known as a nano-LED (light-emitting diode) or a QLED (quantum dot light-emitting diode), and the light-emitting layer in the light-emitting element is a quantum dot light-emitting layer containing quantum dots as a light-emitting material. Therefore, the light-emitting element includes, as the functional layer, the quantum dot light-emitting layer, or includes the quantum dot light-emitting layer and a first functional layer other than the quantum dot light-emitting layer.

[0020] One of the first electrode and the second electrode is an anode and the other is a cathode. The light-emitting element may have a conventional structure in which the anode is a lower electrode and the cathode is an upper electrode, or may have an inverted structure in which the cathode is a lower electrode and the anode is an upper electrode.

[0021] The light-emitting element includes at least one functional layer between the first electrode and the second electrode, the functional layer including the aprotic singlet oxygen scavenger. The functional layer including the aprotic singlet oxygen scavenger may be a light-emitting layer or the first functional layer. For example, the light-emitting element includes at least one of the light-emitting layer and the first functional layer, the light-emitting layer including the aprotic singlet oxygen scavenger.

[0022] Therefore, the method for manufacturing the light-emitting element includes a first electrode, a second electrode, and at least one functional layer between the first electrode and the second electrode, and includes a functional layer forming step of forming the at least one functional layer. In the functional layer forming step, at least one functional layer containing an aprotic singlet oxygen scavenger is formed as the functional layer. For example, in the functional layer forming step, at least one of the light-emitting layer containing the aprotic singlet oxygen scavenger and the first functional layer containing the aprotic singlet oxygen scavenger is formed.

[0023] According to one aspect of the present disclosure, by forming at least one functional layer containing an aprotic singlet oxygen scavenger as the functional layer, it is possible to suppress deterioration of quantum dots due to singlet oxygen, thereby providing a light-emitting device with high luminous efficiency and reliability. For example, by including an aprotic singlet oxygen scavenger in at least one of the light-emitting layer and the first functional layer, which are included in the at least one functional layer, it is possible to suppress deterioration of quantum dots due to singlet oxygen, thereby providing a light-emitting device with high luminous efficiency and reliability.

[0024] Hereinafter, the light-emitting layer may be referred to as "EML" and the quantum dots may be referred to as "QD". In addition, among the functional layers, the functional layer other than the EML will be referred to as the "first functional layer". In addition, singlet oxygen will be referred to as " １ O ２ " and the singlet oxygen scavenger is described as " １ O ２ "Scavenger."

[0025] [Embodiment 1] As an example, １ O ２ The light-emitting element will be described in more detail below, taking the case where a scavenger is included as an example.

[0026] (Schematic Configuration of Light-Emitting Element) FIG. 1 is a cross-sectional view schematically showing an example of a light-emitting element 1 according to this embodiment.

[0027] Hereinafter, the electron transport layer will be referred to as "ETL", the hole transport layer as "HTL", and the hole injection layer as "HIL".

[0028] The light-emitting device 1 shown in FIG. 1 includes an anode 11, a HIL 12, a HTL 13, an EML 14, an ETL 15, and a cathode 16, in this order from the bottom.

[0029] 1 illustrates, as an example, a case where the light-emitting element 1 has a conventional structure in which the anode 11 is a lower electrode and the cathode 16 is an upper electrode. However, this embodiment is not limited to this. As described above, the light-emitting element 1 may have an inverted structure in which the cathode 16 is a lower electrode and the anode 11 is an upper electrode. In this case, the stacking order of the functional layers is reversed from that shown in FIG. 1. In other words, the light-emitting element 1 may have a configuration in which the cathode 16, the ETL 15, the EML 14, the HTL 13, the HIL 12, and the anode 11 are stacked in this order from the bottom.

[0030] 1, the anode 11 is formed on a substrate 10. The substrate 10 functions as a support for supporting each layer from the anode 11 to the cathode 16. Therefore, the light-emitting element 1 may include the substrate 10 as a support.

[0031] The substrate 10 may be, for example, a rigid inorganic substrate such as a glass substrate, or a flexible substrate mainly composed of a resin such as polyimide. The substrate 10 may be provided with a TFT (thin film transistor), a capacitive element, etc. (not shown).

[0032] The anode 11 is an electrode that supplies holes to the EML 14 when a voltage is applied thereto. The cathode 16 is an electrode that supplies electrons to the EML 14 when a voltage is applied thereto. The anode 11 and the cathode 16 each contain a conductive material and are connected to a power supply (not shown) so that a voltage is applied between them.

[0033] At least one of the anode 11 and the cathode 16 is a translucent electrode. Either the anode 11 or the cathode 16 may be a so-called reflective electrode that is light-reflective. The light-emitting element 1 can extract light from the translucent electrode side.

[0034] When the light-emitting element 1 is a top-emission type light-emitting element that emits light from the upper electrode side, a translucent electrode is used for the upper electrode and a reflective electrode is used for the lower electrode, whereas when the light-emitting element 1 is a bottom-emission type light-emitting element that emits light from the lower electrode side, a translucent electrode is used for the lower electrode and a reflective electrode is used for the lower electrode.

[0035] The translucent electrode is formed of a conductive translucent material such as ITO (indium tin oxide) or IZO (indium zinc oxide).

[0036] On the other hand, the reflective electrode is formed of a conductive light-reflective material, such as a metal such as Al (aluminum) or Ag (silver), or an alloy containing these metals. The reflective electrode may be formed by laminating a layer made of the above-mentioned light-transmitting material and a layer made of the above-mentioned light-reflective material.

[0037] The HIL 12 is a charge injection layer that contains a HIL material (hole transport material) having hole transport properties as a functional material and has a hole injection function that increases the efficiency of hole injection from the anode 11 to the HIL 13. Examples of the HIL material include a composite (PEDOT:PSS) of poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrene sulfonic acid (PSS).

[0038] The HTL 13 is a charge transport layer that contains a HTL material (hole transport material) having hole transport properties as a functional material and has a hole transport function that increases the efficiency of hole transport to the EML 14 . The HTL material may be, for example, an organic hole transport material such as poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-4-sec-butylphenyl))diphenylamine)] (TFB), poly(4-butyltriphenylamine) (p-TPD), poly(9-vinylcarbazole) (PVK), [9,9'-[1,2-phenylenebis(methylene)]bis[N3,N3,N6,N6-tetrakis(4-methoxyphenyl)-9H-carbazole-3,6-diamine] (V886), or 7,7'-bi[1,4]benzoxazino[2,3,4-kl]phenoxazine (HN-D1), or an inorganic hole transport material such as nanoparticles of a p-type oxide semiconductor such as nickel oxide (NiO). Among these, nanoparticles of p-type oxide semiconductors are preferred as the HTL material due to their high chemical stability, and NiO nanoparticles are particularly preferred from the viewpoints of hole transport properties and energy levels.

[0039] In the present disclosure, "nanoparticles" refers to dots (particles) consisting of particles with a maximum width of less than 1000 nm. The shape of the nanoparticles is not particularly limited as long as it satisfies the above maximum width, and is not limited to a spherical three-dimensional shape (circular cross-sectional shape). For example, they may have a polygonal cross-sectional shape, a rod-like three-dimensional shape, a branch-like three-dimensional shape, a three-dimensional shape with an uneven surface, or a combination thereof.

[0040] The ETL 15 is a charge transport layer that contains an ETL material (electron transport material) having electron transport properties as a functional material and has an electron transport function that increases the efficiency of electron transport to the EML 14. Examples of the ETL material include nanoparticles of n-type oxide semiconductors and nanoparticles of organometallic complexes. Examples of n-type oxide semiconductors include n-type metal oxides such as zinc oxide (ZnO) and zinc magnesium oxide (ZnMgO). Examples of organometallic complexes include tris(8-quinolinol)aluminum complex (Alq3). The ETL material may also be an organic material such as (2,2′,2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) or bathocuproine (BCP).

[0041] In particular, oxygen adsorption to n-type oxide semiconductors results in defect-type adsorption, which creates an electron-deficient layer on the surface of the oxide semiconductor. Therefore, when a large amount of oxygen adsorbs to nanoparticles of n-type oxide semiconductors such as ZnO and ZnMgO, the oxygen traps electrons, thereby changing the ETL characteristics. Specifically, the adsorbed oxygen consumes some of the electrons flowing through the oxide semiconductor nanoparticles, reducing the electron supply. Therefore, when the carrier balance of the light-emitting element 1 is electron-excessive, electron injection into the EML 14 can be suppressed, thereby adjusting the carrier balance. Therefore, using n-type oxide semiconductor nanoparticles as the ETL material improves the luminescence characteristics and the external quantum efficiency (EQE). Therefore, n-type oxide semiconductor nanoparticles are preferred as the ETL material. Among these, the ETL material preferably contains at least one of ZnO nanoparticles and ZnMgO nanoparticles due to their high chemical stability. From the viewpoints of electron transport properties and energy levels, ZnMgO nanoparticles are particularly preferred.

[0042] The EML 14 contains a light-emitting material as a functional material, which is nano-sized QDs 21 corresponding to the emitted color, and is a layer that emits light by recombination of holes transported from the anode 11 and electrons transported from the cathode 16.

[0043] QDs 21 are nanoparticle dots with a maximum width of 100 nm or less. As mentioned above, QDs are generally referred to as semiconductor nanoparticles because their composition is derived from semiconductor materials. QDs are also sometimes referred to as nanocrystals because their structure, for example, has a specific crystalline structure.

[0044] The shape of the QD21 is not particularly limited as long as it satisfies the above-mentioned maximum width, and is not limited to a spherical three-dimensional shape (circular cross-sectional shape). For example, it may have a polygonal cross-sectional shape, a rod-like three-dimensional shape, a branch-like three-dimensional shape, a three-dimensional shape with an uneven surface, or a combination thereof.

[0045] The QD21 may be a core type, or may be a core-shell type or a core-multishell type containing a core and a shell. When the QD21 contains a shell, the core is located at the center and the shell is provided on the surface of the core. While it is desirable for the shell to cover the entire core, it is not necessary for the shell to completely cover the core. The QD21 may also be a two-component core type, a three-component core type, or a four-component core type. The QD21 may also contain doped nanoparticles or have a compositionally graded structure.

[0046] The core can be made of, for example, Si, Ge, CdSe, CdS, CdTe, InP, GaP, InN, ZnSe, ZnS, ZnTe, CdSeTe, GaInP, ZnSeTe, etc. The shell can be made of, for example, CdS, ZnS, CdSSe, CdTeSe, CdSTe, ZnSSe, ZnSTe, ZnTeSe, AIP, etc.

[0047] The emission wavelength of QD21 can be varied by adjusting the particle size, composition, etc. QD21 is a QD that emits visible light, and by appropriately adjusting the particle size and composition of QD21, it is possible to realize, for example, red light, green light, or blue light.

[0048] QDs are commercially available, and commercially available QDs are generally provided in the form of a quantum dot dispersion containing an organic ligand. Hereinafter, quantum dot dispersions containing quantum dots (QDs), regardless of whether they contain an organic ligand, may be referred to as "QD dispersions." QDs can be synthesized by any method. For example, a wet method is used to synthesize QDs, and the particle size of the QDs is controlled by coordinating organic ligands to the surface of the QDs. The organic ligand is used as a dispersant to improve the dispersibility of QDs in the QD dispersion, and is also used to improve the surface stability and storage stability of the QDs.

[0049] Therefore, an organic ligand may be coordinated to QD21. Alternatively, a desired organic or inorganic ligand may be coordinated to QD21 by ligand exchange or the like. The type of the ligand is not particularly limited, and various known ligands may be used.

[0050] As described above, the light-emitting element 1 shown in FIG. １ O ２ It contains a scavenger 31 (singlet oxygen scavenger). Therefore, EML14 is a scavenger of QD21 and １ O ２ and a scavenger 31.

[0051] １ O ２ The scavenger 31 does not consume and remove oxygen in the system, but inactivates it. １ O ２ is quenched to produce ground state triplet oxygen ( ３ O ２ ) to calm the condition.

[0052] As mentioned above, １ O ２ The scavenger 31 contains an aprotic １ O ２ A scavenger is used. １ O ２ A scavenger is a compound that does not contain heteroatoms such as oxygen or nitrogen, or that contains heteroatoms but does not have hydrogen atoms directly bonded to them. １ O​２ The capture agent is shown. １ O ２ The scavenger 31 is aprotic １ O ２ The reason for using a scavenger is as follows.

[0053] Aprotic １ O ２ Unlike scavengers, proton-based compounds have a structure in which hydrogen atoms are directly bonded to heteroatoms. １ O ２ The scavenger, regardless of the amount used, １ O ２ Upon addition of the scavenger, the proton system １ O ２ The capture agent coordinates to QD21.

[0054] Therefore, the proton system １ O ２ The scavenger, even if only in small amounts, coordinates with QD21 when added. １ O ２ Depending on the amount of the capture agent used, the proton system for QD21 can be １ O ２ The coordination ratio between the capture agent and the ligand previously coordinated to QD21 changes. １ O ２ The greater the amount of the scavenger coordinated, the greater the possibility that the luminescence characteristics will deteriorate and that the stability of the material will be adversely affected. In particular, proton-based scavenger compounds consisting of bifunctional molecules containing two or more primary amino groups and / or secondary amino groups, which are coordinating functional groups, in one molecule are １ O ２ Coordination of the capture agent to the QD21 significantly reduces the dispersibility of the QD21. １ O ２ If a scavenger is coordinated, the dispersibility of the QD21 changes, and the light-emitting characteristics and reliability of the light-emitting element 1 are reduced.

[0055] However, aprotic １ O ２As described above, the capture agent does not contain a hetero element such as oxygen or nitrogen, or even if it contains a hetero element, a hydrogen element is not directly bonded to the hetero element, and the capture agent does not have a coordinating functional group that can coordinate to QD21. The coordinating functional group is also called a ligand coordinating group.

[0056] The coordinating functional group may be at least one selected from the group consisting of a thiol group, a primary amino group, a secondary amino group, a carboxy group, a primary phosphonic group, a secondary phosphonic group, a primary phosphine group, a secondary phosphine group, a primary phosphine oxide group, and a secondary phosphine oxide group.

[0057] １ O ２ The capture agent 31 does not have a coordinating functional group, does not react with the QD21, and does not act as a ligand. １ O ２ The capture agent 31 does not coordinate with the QD21, and there is no risk of adversely affecting the dispersibility or luminescence properties of the QD21.

[0058] Here, "coordination" means that the ligand binds to the surface of QD21. １ O ２ The capture agent 31 does not coordinate with the QD21. １ O ２ This shows that capture agent 31 does not bind to the surface of QD21.

[0059] Included in the functional layer １ O ２ The scavenger 31 can be identified by analyzing the elements and molecular structure contained in each location using, for example, TOF-SIMS (time-of-flight secondary ion mass spectrometry) or the like.

[0060] the above １ O ２ The scavenger 31 may be, for example, an energy absorbing aprotic １ O ２ Scavenger (energy-absorbing aprotic singlet oxygen scavenger), oxidizable aprotic １ O ２ Examples of such scavengers include oxidizable aprotic singlet oxygen scavengers. ​

[0061] Energy-absorbing aprotic １ O ２ What is a scavenger? １ O ２ It is an aprotic singlet oxygen scavenger that absorbs the energy of the oxygen and converts it back to triplet oxygen. ３ O ２ The energy absorbing aprotic singlet oxygen scavenger is １ O ２ Absorbing the energy of ３ O ２ By returning to １ O ２ Repeatedly erase.

[0062] Oxidizable aprotic １ O ２ The scavenger is oxidized １ O ２ of ３ O ２ Return to aprotic １ O ２ It is a scavenger. Oxidizable aprotic １ O ２ The scavenger is oxidized by itself. １ O ２ By erasing １ O ２ It acts as a vanguard against oxidation of QD21 by attack from the β-glucan, and loses its function after oxidation.

[0063] the above １ O ２ The scavenger 31 is an energy absorbing aprotic １ O ２ Scavenger and oxidizable aprotic １ O ２ It is preferable that the catalyst contains at least one of an energy absorbing aprotic scavenger and an energy absorbing aprotic scavenger. １ O ２ More preferably, it contains a scavenger.

[0064] the above １ O ２The scavenger 31 may be, for example, at least one compound selected from the group consisting of tertiary amines, carotenoids, ethylenic compounds, naphthalene and its derivatives, and anthracene and its derivatives. １ O ２ As the capture agent 31, these exemplary １ O ２ It is desirable to include at least one selected from the group consisting of scavengers.

[0065] aprotic heteroatoms with no hydrogen atoms directly bonded １ O ２ The scavenger is an energy-absorbing aprotic １ O ２ Functions as a scavenger. Non-heteroatom aprotic １ O ２ The scavengers are mainly oxidizable aprotic １ O ２ Used as a scavenger, but energy-absorbing aprotic １ O ２ It may also be used as a scavenger.

[0066] Energy-absorbing aprotic １ O ２ aprotic heteroatoms containing no hydrogen atoms directly bonded to them, used as scavengers １ O ２ Examples of the scavenger include tertiary amines, ethylenic compounds containing a hetero element, naphthalenes containing a hetero element (naphthalene derivatives), and anthracenes containing a hetero element (anthracene derivatives).

[0067] the above １ O ２ A monomer is used for the scavenger 31. A monomer refers to a compound with a molecular weight of 1,000 or less. A polymer has a large number of repeating unit structures (monomers) and generally has about 1,000 or more atoms, or is polymerized to a molecular weight of 10,000 or more. An oligomer has a small number of repeating unit structures (monomers) and generally has a molecular weight of 1,000 to 10,000.

[0068] the above １ O ２ The capture agent 31 may contain an oligomer or a polymer, but is not particularly limited to polymerized or oligomerized capture agents. １ O ２ The molecules of the scavenger are large. In addition, polymers are basically highly insulating, which may lead to a decrease in the luminescence characteristics. １ O ２ The scavenger 31 is preferably a monomer. １ O ２ By using a monomer as the capture agent 31, the gaps between adjacent QDs 21 can be filled, １ O ２ Efficiently suppress attacks on QD21 by １ O ２ can be erased.

[0069] therefore, １ O ２ For the tertiary amine, ethylenic compound containing a hetero element, naphthalenes containing a hetero element (naphthalene derivatives), and anthracenes containing a hetero element (anthracene derivatives) used as the scavenger 31, monomers are preferably used.

[0070] Examples of the tertiary amine include triethylamine, N,N-dimethylaniline, 1,4-diazabicyclo[2.2.2]octane (DABCO), 1-ethylimidazole, etc. Examples of the ethylenic compound containing a hetero element include 1,2-diethoxyethene, etc.

[0071] Examples of naphthalenes containing a hetero element include naphthalene derivatives in which at least one of the carbon elements constituting the naphthalene ring or at least one of the hydrogen elements bonded to the naphthalene ring is substituted with a hetero element, and the hydrogen element is not directly bonded to the hetero element.

[0072] Examples of anthracenes containing a hetero element include anthracene derivatives in which at least one of the carbon atoms constituting the anthracene ring or at least one of the hydrogen atoms bonded to the anthracene ring is substituted with a hetero element, and the hydrogen atom is not directly bonded to the hetero element. Examples of such anthracenes include dimethoxyanthracene and 9,10-bis(4-methoxyphenyl)anthracene.

[0073] Oxidizable aprotic １ O ２ Non-heteroatom aprotic scavenger １ O ２ Examples of the scavenger include ethylenic compounds containing no heteroelements, naphthalenes containing no heteroelements (naphthalene, naphthalene derivatives), anthracenes containing no heteroelements (anthracene, anthracene derivatives), and 1,2,3,4-tetraphenyl-1,3-cyclopentadiene in which only phenyl groups are substituted on cyclopentadiene containing no heteroelements.

[0074] Examples of ethylenic compounds that do not contain a hetero element include tetramethylethylene and cyclopentene.

[0075] Examples of naphthalenes that do not contain heteroelements include naphthalenes in which at least one of the carbon atoms constituting the naphthalene ring or at least one of the hydrogen atoms bonded to the naphthalene ring may be substituted with an element other than a heteroelement. Examples of such naphthalenes include naphthalene, dimethylnaphthalene, etc.

[0076] Examples of anthracenes that do not contain a hetero element include anthracenes in which at least one of the carbon atoms constituting the anthracene ring or at least one of the hydrogen atoms bonded to the anthracene ring may be substituted with an element other than a hetero element.

[0077] In addition, the above １ O ２The scavenger 31 may be a carotenoid as described above. Examples of the carotenoid include aprotic carotenoids such as lycopene, α-carotene, and β-carotene. These exemplary carotenoids are aprotic carotenoids that do not contain heteroelements. １ O ２ These exemplary carotenoids are oxidizable aprotic scavengers depending on the conditions and complex factors. １ O ２ They may be used as scavengers or as energy-absorbing aprotic １ O ２ It may also be used as a scavenger.

[0078] １ O ２ These aprotic １ O ２ The scavenger may be used alone or in a suitable mixture of two or more types. １ O ２ The scavenger 31 may be any of these aprotic １ O ２ Among the scavengers, tertiary amines are preferred, and among these tertiary amines, at least one selected from the group consisting of 1,4-diazabicyclo[2.2.2]octane, triethylamine, and N,N-dimethylaniline is more preferred.

[0079] Therefore, the light-emitting element 1 is １ O ２ It is preferable that the scavenger 31 contains a tertiary amine. It is more preferable that the light-emitting element 1 contains, as the tertiary amine, at least one selected from the group consisting of 1,4-diazabicyclo[2.2.2]octane, triethylamine, and N,N-dimethylaniline.

[0080] However, the method used in this embodiment １ O ２ The scavenger 31 is an aprotic １ O ２ The present invention is not limited to the scavenger. １ O ２ ​The scavenger 31 may be, for example, a furan or a furan derivative.

[0081] In this embodiment, the ratio of QD21 to 1 part by weight in EML14 １ O ２ The content ratio of the scavenger 31 is preferably in the range of 0.001 part by weight or more and 1 part by weight or less. １ O ２ If the content ratio of the scavenger 31 exceeds 1 part by weight, the film quality of the EML 14 may be deteriorated. Also, a decrease in the proportion of QD21 contained in the EML 14 may significantly deteriorate the luminescence characteristics. １ O ２ When the content ratio of the scavenger 31 is less than 0.001 parts by weight, １ O ２ There is a risk that the deterioration of the QD21 due to the heat generation may not be sufficiently suppressed.

[0082] (Method for Manufacturing Light-Emitting Device 1) Hereinafter, a method for manufacturing a light-emitting device according to one embodiment of the present disclosure will be described, taking the method for manufacturing the light-emitting device 1 shown in FIG. 1 as an example.

[0083] FIG. 2 is a flowchart showing a method for manufacturing the light-emitting element 1 shown in FIG.

[0084] 2, the method for manufacturing the light-emitting element 1 shown in Fig. 1 first forms an anode 11 on a substrate 10 (step S1, anode formation step). Next, a functional layer formation step is performed in which multiple functional layers are formed on the anode 11. The functional layer formation step according to this embodiment includes the following steps S2 to S5 and S11.

[0085] In this embodiment, as the functional layer formation process, after step S1, first, the HIL 12 is formed on the anode 11 (step S2, HIL formation process). Then, the HTL 13 is formed (step S3, HTL formation process). The method up to this point is the same as the manufacturing method of a general QLED.

[0086] On the other hand, QD21 and １ O ２A QD dispersion (quantum dot dispersion) containing a scavenger 31 and a solvent is prepared (manufactured) (step S11, QD dispersion preparation step).

[0087] The solvent may be a non-polar solvent such as hexane, etc. The concentration of the QDs 21 in the QD dispersion is not particularly limited and may be set appropriately depending on the design value of the layer thickness of the EML 14, etc.

[0088] In the above QD dispersion, １ O ２ The content ratio of the scavenger 31 to 1 part by weight of QD21 in EML14 is １ O ２ The content ratio of the scavenger 31 is set to be in the range of 0.001 parts by weight or more and 1 part by weight or less. １ O ２ The content ratio of the scavenger 31 is set to, for example, within the range of 0.001 parts by weight or more and 1 part by weight or less. １ O ２ If the content ratio of the scavenger 31 exceeds 1 part by weight, the film quality of the formed EML 14 may be degraded. Also, the reduction in the proportion of QDs 21 contained in the formed EML 14 may significantly degrade the luminescence characteristics. On the other hand, １ O ２ When the content ratio of the scavenger 31 is less than 0.001 parts by weight, １ O ２ There is a risk that the deterioration of the QD21 due to the heat generation may not be sufficiently suppressed.

[0089] Next, the QD dispersion is used to form the EML 14 (step S4, EML formation step). Note that step S11 may be performed before step S4.

[0090] In step S4, the QD dispersion is first applied to the HTL 13, which serves as the underlayer for the EML 14 (step S4a, QD dispersion application step). This forms a coating of the QD dispersion. The QD dispersion can be applied by, for example, spin coating.

[0091] Next, the coating film is heated or the like to remove the solvent contained in the coating film (i.e., the coated QD dispersion liquid) and dry the coating film (step S4b, solvent removal step). １ O ２ The EML 14 is formed containing the capture agent 31 .

[0092] The QDs 21 may be coordinated with a ligand, and the QD dispersion liquid and the EML 14 may contain a known ligand.

[0093] Next, the ETL 15 is formed (step S5, ETL forming step), and then the cathode 16 is formed (step S6, cathode forming step), thereby completing the light emitting element 1 shown in FIG.

[0094] The method for manufacturing the light-emitting element 1 includes the steps of: １ O ２ The manufacturing method is the same as that of a general QLED except for the addition of the scavenger 31. The anode 11 and the cathode 16 can be formed by, for example, vapor deposition, sputtering, inkjet printing, or the like. Each functional layer constituting the light-emitting element 1 can be formed by, for example, coating. Each functional layer can be formed by, for example, spin coating, vacuum deposition, inkjet printing, or the like.

[0095] (Specific Example of Method for Manufacturing Light-Emitting Element 1) Next, an example of a method for manufacturing the light-emitting element 1 shown in Fig. 1 will be described. As described above, the light-emitting element 1 shown in Fig. 1 is manufactured by depositing the anode 11, HIL 12, HTL 13, EML 14, ETL 15, and cathode 16 in this order on the substrate 10, for example.

[0096] In this embodiment, as an example, an ITO layer was formed on a substrate 10 as the anode 11. Next, a solution containing PEDOT:PSS was applied by spin coating onto the ITO layer, and the solvent was then evaporated by baking, thereby forming a PEDOT:PSS layer as the HIL 12. Next, a solution containing TFB was applied by spin coating onto the PEDOT:PSS layer, and the solvent was then evaporated by baking, thereby forming a TFB layer as the HTL 13.

[0097] On the other hand, QDs having an InP / ZnS core / shell structure and a number average particle size (diameter) of 10 nm were dispersed in hexane as a solvent to a concentration of 6 mg / mL. １ O ２ DABCO was added to the hexane at a ratio of 5 mg / mL as a scavenger 31. This resulted in a QD dispersion containing 5 mg of DABCO per 6 mg of QDs in 1 mL of hexane.

[0098] The QD dispersion was then spin-coated onto the TFB layer at 200 rpm for 30 seconds. The hexane was then evaporated by baking at 80°C for 10 minutes, forming an EML 14 containing the QDs and DABCO, e.g., a layer thickness of 20 nm, on the TFB layer. A dispersion containing ZnMgO nanoparticles was then spin-coated onto the EML 14, followed by baking to evaporate the solvent, forming a ZnMgO nanoparticle layer as the ETL 15. An Al layer was then formed on the ZnMgO nanoparticle layer as the cathode 16.

[0099] (Effect) As mentioned above, QD21 functions as a photosensitizer. When QD21 is excited, it releases ground-state oxygen, which is ３ O ２ Energy is transferred to １ O ２ is generated and QD21 is oxidized. Thus, in the presence of a photosensitizer, ３ O ２ When excitation light is irradiated onto ３ O ２ is excited １ O ２ The inside of the light-emitting element 1 contains oxygen from the atmosphere that has entered the light-emitting element 1, oxygen in the solvent that remains in the light-emitting element 1, oxygen contained in the materials, and the like. １ O ２ When the generation of SiO 2 and the oxidation of the QD21 surface occur repeatedly, non-luminescent oxides are formed in islands on the surface of the QD21, gradually reducing the luminescence intensity of the QD21. １ O ２The generation of can be confirmed by the observation of characteristic phosphorescence (about 1270 nm).

[0100] However, according to this embodiment, as described above, EML14 １ O ２ aprotic scavenger 31 １ O ２ The inclusion of a scavenger prevents the generation of QD21 without adversely affecting its dispersibility or luminescence properties. １ O ２ of ３ O ２ Return to １ O ２ Erase.

[0101] Therefore, according to this embodiment, it is possible to suppress deterioration of QD21 due to oxidation without adversely affecting the dispersibility or luminous characteristics of QD21, and it is possible to provide a light-emitting element 1 with high luminous efficiency and reliability.

[0102] Furthermore, the presence of oxygen in the system, such as the ZnMgO nanoparticles of ETL15, is advantageous in terms of light-emitting properties. １ O ２ The scavenger 31 only deactivates the excited state of oxygen, but does not remove oxygen. Therefore, according to this embodiment, it is possible to suppress the deterioration of the luminescence properties of QD21 while allowing oxygen and QD21 to coexist in the system.

[0103] Furthermore, the QDs 21 are oxidized when exposed to the atmosphere or solvents during the manufacturing process. For example, fluorescent light also functions as an excitation light. １ O ２ By including the scavenger 31, the scavenger 31 can prevent the generation of ions after the formation of the light-emitting element 1. １ O ２ This not only protects the QD21 from the １ O ２ It is also possible to protect the QD21 from

[0104] Furthermore, according to this embodiment, the QD dispersion liquid １ O ２ By simply mixing the scavenger 31, the process itself is not changed. １ O２ It is possible to form an EML14 light-emitting layer containing the scavenger 31. Therefore, according to this embodiment, it is possible to use existing equipment as is, and the above method can be easily introduced.

[0105] [Embodiment 2] A light-emitting device according to one aspect of the present disclosure may include an EML 14 and a first functional layer as the at least one functional layer, as shown in Embodiment 1. In the light-emitting device according to this embodiment, the first functional layer is adjacent to the EML 14 and includes an oxygen-element-containing compound, and the EML 14 １ O ２ The EML 14 includes a scavenger 31, and the EML 14 has a portion closer to the first functional layer than the center of the EML 14 in the thickness direction. １ O ２ The density of the scavenger 31 is higher in the portion farther from the first functional layer than in the center of the thickness direction of the EML 14. １ O ２ It may be higher than the density of the scavenger 31 .

[0106] In addition, the light emitting element is １ O ２ The density of the scavenger 31 may be higher in a portion closer to the first functional layer in the thickness direction of the EML 14. １ O ２ The density distribution of the scavenger 31 does not need to increase linearly (i.e., linearly, continuously) as it approaches the first functional layer, but may increase in a stepwise manner. １ O ２ The density of the scavenger 31 is higher in the portion closer to the first functional layer. １ O ２ This indicates that the density of the scavenger 31 may be linearly higher in the thickness direction of the EML 14 in the portion closer to the first functional layer, or may be stepwise higher in the portion closer to the first functional layer.

[0107] Below, we will explain an example where the first functional layer is a carrier transport layer, and also an example where the above-mentioned light-emitting element has a conventional structure and the carrier transport layer as the first functional layer is ETL15.

[0108] FIG. 3 is a cross-sectional view schematically illustrating an example of a light-emitting element 41 according to this embodiment.

[0109] 3 includes, as an example, an anode 11, an HIL 12, an HTL 13, an EML 14, an ETL 15, and a cathode 16, in this order from the bottom up, similar to the light-emitting element 1 shown in embodiment 1. Furthermore, similar to the light-emitting element 1, the ETL 15 contains, as an ETL material containing oxygen elements (oxygen-containing compound), nanoparticles of, for example, n-type metal oxides such as ZnO and ZnMgO, or organometallic complexes containing oxygen elements such as Alq3. １ O ２ The capture agent 31 is mixed in the EML 14 .

[0110] However, as shown in FIG. 3, the light emitting element 41 has a portion of the EML 14 that is closer to the ETL 15 than the center of the EML 14 in the thickness direction. １ O ２ The density of the scavenger 31 is higher in the portion farther from the ETL 15 than in the center of the thickness direction of the EML 14. １ O ２ Higher than the density of the capture agent 31, more specifically, in the EML 14 １ O ２ The density of the scavenger 31 is higher in the portion closer to the ETL 15. The light-emitting element 41 differs from the light-emitting element 1 in this respect.

[0111] (Manufacturing Method of Light-Emitting Element 41) FIG. 4 is a flowchart showing a manufacturing method of the light-emitting element 41 shown in FIG.

[0112] In the method for manufacturing the light-emitting element 41 shown in Fig. 3, steps S1 (anode formation step) to S3 (HTL formation step) are performed in the same manner as in the method for manufacturing the light-emitting element 1 described above, as shown in Fig. 4. In this embodiment, a QD dispersion containing QDs 21 and a solvent is then used to form an EML 14 containing QDs 21 (step S4, EML formation step). As in the first embodiment, a nonpolar solvent such as hexane is used as the solvent. The concentration of QDs 21 in the QD dispersion is not particularly limited and may be appropriately set depending on the design value of the EML 14 layer thickness, etc.

[0113] In this embodiment, １ O ２ The QD dispersion liquid not containing a scavenger is applied to the HTL 13 to form a coating film of the QD dispersion liquid, and then the coating film is heated or otherwise treated to remove the solvent contained in the coating film. １ O ２ The EML 14, which does not contain a scavenger, is first formed. Note that, in this embodiment, the QD dispersion liquid may be prepared prior to step S4. The method up to this point is similar to the general method for manufacturing QLEDs.

[0114] On the other hand, in this embodiment, as shown in FIG. １ O ２ Contains a scavenger 31 and a solvent １ O ２ A scavenger solution is prepared (manufactured) (step S21, １ O ２ (Scavenger solution preparation step) As the solvent, for example, an amphoteric solvent such as isopropyl alcohol (IPA) or ethanol is used. １ O ２ in the scavenger solution １ O ２ The concentration of the capture agent 31 in EML14 １ O ２ The density distribution of the scavenger 31 may be appropriately set according to the layer thickness of the EML 14 and the like so as to achieve a desired density distribution, and is not particularly limited.

[0115] Next, the above EML14 is １ O ２ A scavenger solution is supplied to １ O ２ The capture agent solution is allowed to permeate the EML 14 (step S31, １ O ２ (Scavenger solution supplying step) Step S21 may be performed before Step S31.

[0116] In step S31, first, １ O ２ On EML14 without capture agent, １ O ２ The capture agent solution is added dropwise. １ O ２The capture agent solution is applied to the EML 14. １ O ２ The capture agent solution is allowed to penetrate. １ O ２ The scavenger solution is applied by, for example, spin coating.

[0117] Next, １ O ２ The coated EML14 with the scavenger solution is heated, etc. １ O ２ The solvent contained in the capture agent solution is removed (step S32, solvent removal step). １ O ２ The EML 14 is formed containing the capture agent 31 .

[0118] Thereafter, step S5 (ETL formation step) and step S6 (cathode formation step) are performed in the same manner as in the manufacturing method of the light emitting element 1. In this way, the light emitting element 41 shown in FIG.

[0119] The method for manufacturing the light-emitting element 41 is the same as the method for manufacturing the light-emitting element 1, except for the points mentioned above.

[0120] (Specific Example of Method for Manufacturing Light-Emitting Element 41) Next, an example of a method for manufacturing the light-emitting element 41 shown in FIG. 3 will be described.

[0121] In this embodiment, as an example, an ITO layer was formed as the anode 11 on a 25 mm square substrate 10 serving as a support. Next, a solution containing PEDOT:PSS was spin-coated onto the ITO layer, and the solvent was then evaporated by baking, thereby forming a PEDOT:PSS layer as the HIL 12. Next, a solution containing TFB was spin-coated onto the PEDOT:PSS layer, and the solvent was then evaporated by baking, thereby forming a TFB layer as the HTL 13.

[0122] On the other hand, QDs 21, which had a core / shell structure of InP / ZnS and a number-average particle size (diameter) of 10 nm, were dispersed in hexane as a solvent to a concentration of 13 mg / mL, thereby preparing a QD dispersion containing the QDs and the solvent.

[0123] The QD dispersion was then spin-coated onto the TFB layer at 200 rpm for 30 seconds, followed by baking at 80°C for 10 minutes to volatilize the hexane, forming a 20 nm-thick QD layer (EML14) on the TFB layer.

[0124] on the other hand, １ O ２ DABCO as the capture agent 31 was dispersed in IPA as the solvent so that the concentration was 20 mg / mL. １ O ２ As a scavenger solution, a DABCO-IPA solution with a concentration of 20 mg / mL was prepared.

[0125] Next, 200 μL of the DABCO-IPA solution was dropped onto the QD layer formed on the 25 mm square substrate 10 as described above, and after 30 seconds, the DABCO-IPA solution was spin-coated at a spin speed of 3000 rpm for 60 seconds.

[0126] Immediately after the start of spin coating, 200 μL of IPA was dropped three times (total of 600 μL) as a rinse solution during spin coating to clean the QD layer and remove excess DABCO.

[0127] Then, the IPA was evaporated by baking at 80°C for 10 minutes, and the QD21 and １ O ２ EML14 was formed containing scavenger 31.

[0128] Next, a dispersion containing ZnMgO nanoparticles was spin-coated onto the QD layer, and the solvent was evaporated by baking to form a ZnMgO nanoparticle layer as ETL 15. Next, an Al layer was formed as cathode 16 on this ZnMgO nanoparticle layer.

[0129] DABCO penetrated into the QD layer and was mixed in the QD layer. Although some DABCO remained on the surface of the QD layer, it was not formed as a DABCO layer on the QD layer, and the thickness of the laminate was hardly increased by DABCO.

[0130] The added DABCO remained in the QD layer with a density distribution, with the DABCO density higher in the upper layer (the ZnMgO nanoparticle layer side) of the QD layer than in the lower layer, with the DABCO density increasing toward the upper layer of the QD layer. Note that, here, "upper layer side" refers to the upper layer side of the QD layer relative to the center in the thickness direction (the portion closer to the ZnMgO nanoparticle layer), and "lower layer side" refers to the lower layer side of the QD layer relative to the center in the thickness direction (the portion farther from the ZnMgO nanoparticle layer).

[0131] (Effects) As described above, in the light-emitting device 41 shown in FIG. 3, the first functional layer adjacent to the EML 14, for example, the ETL 15, contains an oxygen-containing compound, and the EML 14 １ O ２ The EML 14 includes a scavenger 31. The scavenger 31 is located in a portion of the EML 14 closer to the ETL 15 than the center of the EML 14 in the thickness direction. １ O ２ The density of the scavenger 31 is higher in the portion farther from the ETL 15 than in the center of the thickness direction of the EML 14. １ O ２ The density of the trapping agent 31 is higher than that of the trapping agent 31. More specifically, １ O ２ The density of the scavenger 31 is higher in the portion closer to the EML 14 in the thickness direction of the EML 14 .

[0132] Therefore, according to this embodiment, the oxygen-containing compound is efficiently generated in the portion of the EML 14 that is close to the EML 14. １ O ２ can be captured.

[0133] In this embodiment, the ratio of EML14 to 1 part by weight of QD21 is １ O ２ For the same reasons as in the first embodiment, the content of the scavenger 31 is preferably in the range of 0.001 part by weight or more and 1 part by weight or less.

[0134] However, according to this embodiment, １ O ２ Compared with the case where the same conditions were used except that the capture agent 31 was uniformly mixed throughout the EML 14, １ O２ The amount of scavenger 31 used can be reduced.

[0135] In EML14 １ O ２ As the proportion of the scavenger 31 increases, the influence on the film-forming properties and surface roughness of the EML 14 increases. １ O ２ If the amount of the scavenger 31 used is large, it may have a negative effect on the light emission. １ O ２ Since the amount of the scavenger 31 used can be reduced, １ O ２ This can reduce the risk that the scavenger 31 will have the above-mentioned adverse effect on the EML 14. Furthermore, it is possible to reduce material costs and suppress the cost required for manufacturing the light-emitting device.

[0136] In this embodiment, the ratio of 1 part by weight of EML14 to 1 part by weight of QD21 is １ O ２ The content ratio of the scavenger 31 is EML14 １ O ２ As a result of supplying the capture agent solution, it permeated into EML14. １ O ２ This is the content ratio of the scavenger 31 and the QD 21. In this embodiment, since cleaning is performed with the rinse liquid as described above, in this case, the content ratio of the scavenger 31 and the QD 21 that has permeated into the EML 14 is １ O ２ The content ratio of the scavenger 31 remaining in the EML 14 after removal with the rinse liquid is １ O ２ The content ratio of the scavenger 31 is shown.

[0137] According to this embodiment, as described above, on the EML 14, １ O ２ Contains a scavenger 31 and a solvent １ O ２ A capture agent solution is supplied and allowed to permeate the EML 14, thereby forming a capture agent solution in the EML 14. １ O ２ The density distribution of the scavenger 31 can be adjusted.

[0138] In this embodiment, as described above, the QD dispersion １O ２ Addition of scavenger 31 results in QD21 in one solution. １ O ２ Instead of forming a mixed film with the capture agent 31, １ O ２ Forming an EML 14 that does not contain a capture agent 31, １ O ２ The capture agent solution is supplied and allowed to penetrate. １ O ２ The longer the contact time with the scavenger solution, １ O ２ The capture agent solution can be permeated into the EML 14. １ O ２ If the capture agent solution is supplied to the EML 14 and then immediately removed, １ O ２ The capture agent solution can be supplied only near the surface of the EML 14. １ O ２ The density distribution of the scavenger 31 can be intentionally adjusted.

[0139] Also, １ O ２ The density distribution of the scavenger 31 is, for example, １ O ２ It can also be adjusted by the viscosity of the capture agent solution. １ O ２ The density distribution of the scavenger 31 varies depending on the solvent and １ O ２ It can be changed depending on the type of capture agent 31, １ O ２ in the scavenger solution １ O ２ It can also be changed by the concentration of the scavenger 31.

[0140] Also, １ O ２ The density distribution of the scavenger 31 is, for example, １ O ２ The amount of the scavenger solution １ O ２ Supplying the scavenger solution １ O ２ The adjustment can also be made by adjusting the wettability of the scavenger solution receiving layer.１ O ２ The density distribution of the scavenger 31 is １ O ２ It can also be adjusted by the wettability of EML14 with the scavenger solution.

[0141] １ O ２ The scavenger solution supply layer １ O ２ When the scavenger solution is added dropwise, １ O ２ In the layer receiving the scavenger solution １ O ２ Wettability of the scavenger solution ( １ O ２ A layer to which a scavenger solution is supplied. １ O ２ polar-nonpolar relationship with the scavenger solution) １ O ２ In the layer receiving the scavenger solution １ O ２ The way the capture agent solution spreads (affinity) is different. １ O ２ In the layer receiving the scavenger solution １ O ２ The wettability of the scavenger solution depends not only on the mutual affinity but also on １ O ２ It also depends on the shape of the scavenger solution receiving layer (for example, the size, shape, and number of irregularities). １ O ２ In the layer to which the scavenger solution is supplied １ O ２ The scavenger solution becomes difficult to penetrate, and the density distribution becomes easily uneven. １ O ２ In the layer to which the scavenger solution is supplied １ O ２ The scavenger solution penetrates more easily, density distribution is less likely to occur, and the density distribution becomes more uniform. １ O ２ The wettability of the layer to which the scavenger solution is supplied depends on, for example, the polarity of the ligand, the length of the ligand chain, １ O ２ The particle size and shape of nanoparticles such as QD21 contained in the capture agent solution supply layer can also be changed.

[0142] Also,​１ O ２ The density distribution of the scavenger 31 is, for example, １ O ２ The boiling point of the solvent used in the scavenger solution can also be adjusted. Although it is also affected by the processing environment, the lower the boiling point of the solvent, the more easily it volatilizes. Therefore, １ O ２ If a solvent with a low boiling point is used for the scavenger solution, １ O ２ The scavenger solution １ O ２ The penetration depth into the scavenger solution supply layer becomes shallow, and the density distribution becomes more likely to become uneven. １ O ２ If a solvent with a high boiling point is used for the scavenger solution, the solvent will not volatilize easily. １ O ２ The scavenger solution １ O ２ The penetration depth into the layer to which the scavenger solution is supplied becomes deeper.

[0143] Also, １ O ２ The density distribution of the scavenger 31 can be adjusted by, for example, the processing environment. １ O ２ When removing the solvent contained in the scavenger solution, if the solvent removal (drying) is performed in a reduced pressure or dry environment, the evaporation of the solvent is accelerated. Therefore, if step S32 is performed in such an environment, the density distribution is likely to become uneven. Note that the "dry environment" here refers to a situation where there is little solvent vapor, not just water.

[0144] Also, １ O ２ The density distribution of the scavenger 31 is １ O ２ The density distribution can also be adjusted by the temperature of the scavenger solution and the temperature of the processing environment. Generally, the higher the temperature of the solution used and the temperature of the processing environment, the more the evaporation of the solvent is promoted, and the more likely the density distribution to become biased.

[0145] Furthermore, if the ambient atmosphere is circulated and ventilated during the treatment, the evaporation of the solvent is promoted, which tends to cause deviation in the density distribution. １ O ２ The density distribution of the capture agent 31 can also be adjusted by the treatment operation method.

[0146] In this way, １ O ２ The density distribution of the scavenger 31 can be adjusted by various methods, and by combining the above-mentioned conditions, it is possible to adjust the density distribution to any desired value. １ O ２ As mentioned above, the density distribution of the scavenger 31 does not necessarily have to change linearly.

[0147] 3 and 4, the light-emitting element 41 has a conventional structure, and the first functional layer is the ETL 15. However, this embodiment is not limited to this. The light-emitting element 41 may have an inverted structure, and the first functional layer may be the HTL 13. The HTL 13 may contain an oxygen-element-containing compound such as nanoparticles of a p-type oxide semiconductor such as NiO, and the EML 14 may have a portion closer to the HTL 13 than the center of the EML 14 in the thickness direction. １ O ２ The density of the scavenger 31 is set to be greater in the portion farther from the HTL 13 than in the center of the thickness direction of the EML 14. １ O ２ By making the density higher than that of the capturing agent 31, the same effect as that described above can be obtained. １ O ２ The density of the scavenger 31 may be higher in the portion closer to the HTL 13. Even when the first functional layer is the HTL 13, the density of the scavenger 31 in the EML 14 may be higher in the portion closer to the HTL 13. １ O ２ The density distribution of the scavenger 31 does not need to increase linearly as it approaches the first functional layer, but may increase in stages.

[0148] [Embodiment 3] In embodiments 1 and 2, EML14 １ O ２The case where the scavenger 31 is included has been described as an example. However, as mentioned above, １ O ２ The capture agent may be contained in at least one of the EML 14 and the first functional layer contained in the at least one functional layer.

[0149] Hereinafter, a light-emitting device according to one embodiment of the present disclosure includes, as the at least one functional layer, an EML 14 and a first functional layer, the first functional layer being adjacent to the EML 14, and １ O ２ An example in which a scavenger 31 is included will be described.

[0150] In addition, below, we will explain an example where the first functional layer is a carrier transport layer, and also an example where the above-mentioned light-emitting element has a conventional structure and the carrier transport layer as the first functional layer is ETL15.

[0151] FIG. 5 is a cross-sectional view schematically illustrating an example of a light-emitting element 51 according to this embodiment.

[0152] 5 includes, in this order from the bottom up, an anode 11, an HIL 12, an HTL 13, an EML 14, an ETL 15, and a cathode 16, as in the light-emitting devices of Embodiments 1 and 2. As in the light-emitting devices of Embodiments 1 and 2, the ETL 15 includes nanoparticles 52 as an ETL material containing oxygen (oxygen-containing compound), such as an n-type metal oxide such as ZnO or ZnMgO, or an organometallic complex containing oxygen, such as Alq3.

[0153] However, the light emitting element 51, as shown in FIG. １ O ２ A scavenger 31 is mixed in the ETL 15. The light-emitting device 51 differs from the light-emitting devices shown in the first and second embodiments in this respect.

[0154] In this embodiment, the ratio of nanoparticles 52 to 1 part by weight in ETL15 is １ O ２ The content ratio of the scavenger 31 is preferably in the range of 0.001 part by weight or more and 1 part by weight or less.１ O ２ If the content of the scavenger 31 exceeds 1 part by weight, the film quality of the ETL 15 may be deteriorated. １ O ２ When the content ratio of the scavenger 31 is less than 0.001 parts by weight, １ O ２ was not captured sufficiently and could not be captured １ O ２ may enter the EML 14 and cause deterioration of the QD 21. １ O ２ There is a risk that the deterioration of the QD21 due to the heat generation may not be sufficiently suppressed.

[0155] (Manufacturing Method of Light-Emitting Element 51) FIG. 6 is a flowchart showing a manufacturing method of the light-emitting element 51 shown in FIG.

[0156] 3, as shown in Fig. 4, steps S1 (anode formation step) to S4 (EML formation step) are performed in the same manner as in the above-described method for manufacturing the light-emitting element 1. The method up to this point is the same as that for manufacturing a general QLED.

[0157] On the other hand, the EML material containing nanoparticles 52 as an oxygen element-containing compound １ O ２ An EML material dispersion containing a scavenger 31 and a solvent is prepared (manufactured) (step S41, EML material dispersion preparation step). As shown in FIG. 6, the nanoparticles 52 (EML material) may be, for example, ZnMgO nanoparticles (hereinafter referred to as "ZnMgO-NP"). In this embodiment, as an example, the EML material dispersion is prepared by mixing ZnMgO-NP and １ O ２ A ZnMgO-NP dispersion containing a scavenger 31 and a solvent is prepared.

[0158] The solvent may be, for example, an amphoteric solvent such as IPA, ethanol, etc. The concentration of the ETL material in the EML material dispersion may be appropriately set depending on the design value of the layer thickness of the ETL 15, and is not particularly limited.

[0159] In the ETL material dispersion, the amount of nanoparticles 52 is １ O ２ The content ratio of the scavenger 31 to the nanoparticles 52 in the ETL15 is １ O ２ The content ratio of the scavenger 31 is set to be in the range of 0.001 part by weight or more and 1 part by weight or less. １ O ２ The content ratio of the scavenger 31 is set to, for example, within the range of 0.001 part by weight or more and 1 part by weight or less. １ O ２ If the content ratio of the scavenger 31 exceeds 1 part by weight, the film quality of the formed ETL 15 may be deteriorated. １ O ２ When the content ratio of the scavenger 31 is less than 0.001 parts by weight, １ O ２ was not captured sufficiently and could not be captured １ O ２ may enter the EML 14 and cause deterioration of the QD 21. １ O ２ There is a risk that the deterioration of the QD21 due to the heat generation may not be sufficiently suppressed.

[0160] Next, the ETL 15 is formed using the ETL material dispersion (for example, the ZnMgO-NP dispersion) (Step S5, ETL formation step). Note that Step S41 may be performed before Step S5.

[0161] In step S41, first, the ETL material dispersion (e.g., the ZnMgO-NP dispersion) is applied onto the EML 14, which will be the underlayer of the ETL 15 (step S5a, ETL material dispersion application step). This forms a coating film of the ETL material dispersion. The ETL material dispersion is applied by, for example, spin coating.

[0162] Next, the coating film is heated or the like to remove the solvent contained in the coating film (i.e., the applied ETL material dispersion liquid) and dry the coating film (step S5b, solvent removal step). １ O ２ The ETL 15 is formed containing the scavenger 31.

[0163] The nanoparticles 52 may have a ligand coordinated thereto, and the ETL material dispersion liquid and the ETL 15 may contain a known ligand as the ligand.

[0164] Thereafter, the cathode 16 is formed (step S6, cathode forming step), thereby forming the light emitting element 51 shown in FIG.

[0165] The method for manufacturing the light-emitting element 51 includes the steps of: １ O ２ Except for the addition of the scavenger 31, the manufacturing method is the same as that of a general QLED.

[0166] (Specific Example of Method for Manufacturing Light-Emitting Element 51) Next, an example of a method for manufacturing the light-emitting element 51 shown in FIG. 5 will be described.

[0167] In this embodiment, as an example, an ITO layer was formed on a substrate 10 as the anode 11. Next, a solution containing PEDOT:PSS was applied by spin coating onto the ITO layer, and the solvent was then evaporated by baking, thereby forming a PEDOT:PSS layer as the HIL 12. Next, a solution containing TFB was applied by spin coating onto the PEDOT:PSS layer, and the solvent was then evaporated by baking, thereby forming a TFB layer as the HTL 13.

[0168] On the other hand, QDs 21, which had a core / shell structure of InP / ZnS and a number-average particle size (diameter) of 10 nm, were dispersed in hexane as a solvent to a concentration of 13 mg / mL, thereby preparing a QD dispersion containing the QDs and the solvent.

[0169] The QD dispersion was then spin-coated onto the TFB layer at 200 rpm for 30 seconds, followed by baking at 80°C for 10 minutes to volatilize the hexane, forming a 20 nm-thick QD layer (EML14) on the TFB layer.

[0170] On the other hand, as nanoparticles 52, ZnMgO-NP having a number average particle size (diameter) of 10 nm was dispersed in ethanol as a solvent so that the concentration was 25 mg / mL. １ O ２ DABCO was added to the ethanol at a ratio of 10 mg / mL as a scavenger 31. In this way, a ZnMgO-NP dispersion containing 10 mg of DABCO per 25 mg of ZnMgO-NP in 1 mL of ethanol was prepared.

[0171] Next, the ZnMgO-NP dispersion was spin-coated onto the QD layer at a spin speed of 200 rpm for 30 seconds. The ethanol was then evaporated by baking at 80°C for 10 minutes to form an ETL 15 containing the ZnMgO-NP and DABCO, with a thickness of, for example, 50 nm, on the QD layer. Next, an Al layer was formed on the ETL 15 as the cathode 16.

[0172] (Effects) According to this embodiment, as described above, the at least one functional layer includes, for example, the EML 14 and the first functional layer, and the first functional layer is adjacent to the EML 14, １ O ２ By including the scavenger 31, １ O ２ This can reduce the risk of viruses entering the EML 14.

[0173] In particular, carrier transport materials containing oxygen elements (oxygen element-containing compounds), such as nanoparticles of metal oxides and nanoparticles of organometallic complexes containing oxygen elements, １ O ２ Nanoparticles 52 such as ZnMgO also function as a photosensitizer, １ O ２The QDs 21 and the nanoparticles 52 such as ZnMgO are in contact with each other at the stacking interface. １ O ２ The migration of oxidizes QD21.

[0174] However, as mentioned above, for example, ETL15 １ O ２ aprotic scavenger 31 １ O ２ By including a capture agent, ETL15 is converted to EML14. １ O ２ In addition, the ETL 15 can reduce the risk of １ O ２ aprotic scavenger 31 １ O ２ By including a scavenger, EML14 can １ O ２ Compared with the case where a scavenger is included, the above aprotic １ O ２ The risk that the capture agent will adversely affect EML14 can be reduced.

[0175] In addition, in the second embodiment, １ O ２ The capture agent solution penetrates into EML14. １ O ２ However, the time during which the scavenger solution contacts the EML 14 by applying the ETL material dispersion onto the EML 14 in step S5a (the ETL material dispersion application step) is extremely short, whether the application is by spin coating or inkjet coating. Therefore, in FIG. 5, the EML 14 is slightly in contact with the scavenger solution. １ O ２ The example shown is a case where a scavenger 31 is included. １ O ２ It can be said that the capture agent 31 hardly penetrates the EML 14 .

[0176] (Variation 1) As described above, the present embodiment has also been described by taking as an example a case where the light-emitting element 51 has a conventional structure and the first functional layer is the ETL 15. However, the present embodiment is not limited to this.

[0177] FIG. 7 is a cross-sectional view schematically showing an example of a light-emitting element 61 according to the first modification.

[0178] 7 includes, in the same order from the bottom up, an anode 11, an HIL 12, an HTL 13, an EML 14, an ETL 15, and a cathode 16, as in the light-emitting element 51 shown in FIG. 5. In this modification, the HTL 13 contains nanoparticles 62 of a p-type metal oxide such as NiO as an HTL material containing oxygen elements (oxygen-containing compound). As shown in FIG. 7, the light-emitting element 61 includes: １ O ２ A scavenger 31 is mixed into the HTL 13 .

[0179] As described above, carrier transport materials containing oxygen elements (oxygen element-containing compounds), such as nanoparticles of metal oxides and nanoparticles of organometallic complexes containing oxygen elements, １ O ２ Nanoparticles such as NiO also function as photosensitizers, １ O ２ Therefore, when the HTL 13 adjacent to the QD 21 contains nanoparticles 62 such as NiO as an HTL material containing oxygen (oxygen-containing compound) as described above, the HTL 13 generates １ O ２ The migration of the ions oxidizes the QDs 21. Therefore, the first functional layer may be the HTL 13.

[0180] In any case, the first functional layer １ O ２ aprotic scavenger 31 １ O ２ By including a scavenger, the first functional layer １ O ２ In addition, the first functional layer can reduce the risk of penetration of １ O ２ aprotic scavenger 31１ O ２ By including a scavenger, EML14 can １ O ２ Compared with the case where a scavenger is included, the above aprotic １ O ２ The risk that the capture agent will adversely affect EML14 can be reduced.

[0181] As described above, whether the first functional layer is ETL15 or HTL13, the ratio of the nanoparticles per 1 part by weight in the first functional layer is １ O ２ For the same reasons as those mentioned above, the content of the scavenger 31 is preferably in the range of 0.001 part by weight or more and 1 part by weight or less.

[0182] Furthermore, whether the first functional layer is the ETL 15 or the HTL 13 as described above, the functional layer formation step includes the steps of forming the EML 14 including the QDs 21, １ O ２ and forming a first functional layer including a scavenger 31, １ O ２ The risk that the capture agent 31 will adversely affect the EML 14 can be reduced.

[0183] (Variation 2) In FIGS. 5 and 7, the first functional layer adjacent to the EML 14 is a carrier transport layer, and the carrier transport layer includes a carrier transport material containing an oxygen element (oxygen element-containing compound), and １ O ２ The above description has been given taking the case where the scavenger 31 is included as an example, but the light emitting device according to this embodiment is not limited to this.

[0184] The light-emitting device according to this embodiment includes, for example, an EML 14, a first functional layer, and a second functional layer provided between the first electrode and the first functional layer, as the at least one functional layer, the second functional layer including an oxygen-element-containing compound, and the first functional layer including １ O ２ A scavenger 31 may be included.

[0185] In the following, an example will be described in which the first functional layer is the HTL 13 and the second functional layer is the HIL 12.

[0186] FIG. 8 is a cross-sectional view schematically showing an example of a light-emitting element 63 according to this modification.

[0187] As an example, the light-emitting element 63 shown in FIG. 8 includes an anode 11, a HIL 12, a HTL 13, an EML 14, an ETL 15, and a cathode 16, in this order from the bottom up, similar to the light-emitting elements shown in the first and second embodiments. As described above, the HIL 12 uses, for example, PEDOT:PSS as the HIL material. PEDOT:PSS is an HIL material containing oxygen (an oxygen-containing compound). In this way, when the second functional layer is, for example, the HIL 12 and the HIL 12 contains an oxygen-containing compound, as shown in FIG. 8, the HTL 13 as the first functional layer １ O ２ It may contain a scavenger 31. In this case, the HTL 13 may be made of an HTL material that does not contain oxygen elements, such as the TFB.

[0188] In this way, the second functional layer contains an oxygen element-containing compound, and the first functional layer １ O ２ By including the scavenger 31, the second functional layer １ O ２ Before moving, in the first functional layer, １ O ２ Also in this case, the first functional layer, not the EML 14, １ O ２ By including the scavenger 31, １ O ２ The risk that the capture agent 31 will adversely affect the EML 14 can be reduced.

[0189] In this case, in the first functional layer (HTL13 in the example shown in FIG. 8), a portion closer to the second functional layer (HIL12 in the example shown in FIG. 8) than the center in the thickness direction of the first functional layer １ O ２ The density of the scavenger 31 is higher in a portion of the first functional layer farther from the second functional layer than in the center of the thickness direction of the first functional layer. １ O ２It is desirable that the density of the scavenger 31 is higher than that of the scavenger 31. In this case, for example, １ O ２ It is more desirable that the density of the scavenger 31 is higher in a portion closer to the second functional layer (HIL 12 in the example shown in FIG. 8) in the thickness direction of the first functional layer. １ O ２ The density distribution of the scavenger 31 does not need to increase linearly as it approaches the second functional layer, but may increase in a stepwise manner. １ O ２ The density of the scavenger 31 is higher in the portion closer to the second functional layer. １ O ２ This indicates that the density of the capture agent 31 may be linearly higher in the thickness direction of the first functional layer in the portion closer to the second functional layer, or may be stepwise higher in the portion closer to the second functional layer.

[0190] In this case, the oxygen-containing compound is efficiently absorbed in the first functional layer in a portion close to the second functional layer containing the oxygen-containing compound. １ O ２ It is also possible to capture １ O ２ Compared to the case where the same conditions were used except that the scavenger 31 was uniformly mixed throughout the first functional layer, １ O ２ The amount of the scavenger 31 used can be reduced. １ O ２ This can reduce the risk of the scavenger 31 having an adverse effect, and can also reduce material costs and manufacturing costs.

[0191] 5, 7, and 8, the light-emitting element according to this embodiment has been described as having a conventional structure. However, the light-emitting element according to this embodiment may have an inverted structure. Even when the light-emitting element has an inverted structure, the first functional layer may be either the HTL 13 or the ETL 15.

[0192] [Embodiment 4] As described above, the light-emitting device includes the EML 14 and the first functional layer as at least one functional layer, and the first functional layer is １ O ２ When the first functional layer contains the scavenger 31 and the oxygen-element-containing compound, the first functional layer is not limited to a layer having a carrier transport function as in embodiment 3. The first functional layer may be any of the ETL 15, the electron injection layer (hereinafter referred to as "EIL"), the HTL 13, the HIL, and the intermediate layer.

[0193] Here, the "intermediate layer" refers to a functional layer other than the ETL 15, EIL, HTL 13, and HIL that is added for various purposes. The ETL 15 may also function as an electron transport layer and an electron injection layer. The HTL 13 or HIL may also function as a hole transport layer and a hole injection layer.

[0194] The above-mentioned purposes include, for example, passivation, adjustment of carrier balance (e.g., preventing excessive injection of carriers into the EML 14 due to insertion of an insulating material), improvement of wettability, and suppression of reactions of interlayer materials (e.g., interactions such as quenching and alteration due to chemical reactions).

[0195] Examples of materials for the intermediate layer include metal oxides and self-assembled films (self-assembled monolayers, hereinafter referred to as "SAMs").

[0196] As described above, the ETL 15 uses nanoparticles 52 of, for example, n-type metal oxides such as ZnO and ZnMgO, or organometallic complexes containing oxygen such as Alq3, as the ETL material containing oxygen elements (oxygen-element-containing compounds). The HTL 13 uses nanoparticles 62 of, for example, p-type metal oxides such as NiO, as the HTL material containing oxygen elements (oxygen-element-containing compounds). In the third embodiment, as a modified example, the HTL material containing oxygen elements (oxygen-element-containing compounds) is nanoparticles 62 of, for example, p-type metal oxides such as NiO, as described above. However, the organic hole transport material such as V886 or HN-D1 is also an HTL material containing oxygen elements (oxygen-element-containing compounds). The HIL 12 uses, for example, PEDOT:PSS as the HIL material containing oxygen elements (oxygen-element-containing compounds). The intermediate layer is made of, for example, Al ２ O ３ Examples of the SAM used in the intermediate layer include films made of [2-(3,6-dimethoxy)-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), [2-(9H-carbazol-9-yl)ethyl]phosphonic acid (2PACz), a silane coupling agent, etc.

[0197] Furthermore, as described above, when any of the functional layers around EML14, such as ETL15, EIL, HTL13, HIL, and the intermediate layer, contains an oxygen-element-containing compound, the functional layer containing the oxygen-element-containing compound may further contain a crosslinking agent.

[0198] The crosslinking agent may be a photocrosslinking agent or a thermal crosslinking agent. Examples of the crosslinking agent include a crosslinking agent containing at least one epoxy group. Examples of the crosslinking agent include 1,2-epoxyoctane and diglycidyl-1,2-cyclohexanedicarboxylate.

[0199] These crosslinking agents contain, as described above, for example, epoxy groups as functional groups that are easily chemically reactive by light, heat, etc., and may be mixed into any of the layers. These crosslinking agents may be used, for example, to crosslink EML14, HTL13, etc. in order to chemically stabilize them.

[0200] The light emitting device according to this embodiment will be described below by giving a specific example.

[0201] FIG. 9 is a cross-sectional view schematically illustrating an example of a light-emitting element 71 according to this embodiment.

[0202] The light-emitting element 1 shown in FIG. 9 includes an anode 11, an HIL 12, an HTL 13, a SAM 81, an EML 14, an ETL 15, an EIL 82, and a cathode 16, in this order from the bottom.

[0203] 9 illustrates an example in which the light-emitting element 1 has a conventional structure. However, the present embodiment is not limited to this, and the light-emitting element 71 may have an inverted structure.

[0204] In addition, in FIG. 9, as an example, the functional layers between the anode 11 and the cathode 16 are １ O ２ The case where a scavenger 31 is included is shown as an example.

[0205] The light-emitting element 71 shown in FIG. 9 includes the SAM 81 as an intermediate layer between the anode 11 and the cathode 16, as described above, and also includes an EIL 82. １ O ２ It contains a scavenger 31. Except for this, the light-emitting element 71 shown in Fig. 9 has the same configuration as the light-emitting elements according to the first to third embodiments.

[0206] The EIL 82 is a charge injection layer that contains an EIL material (electron transport material) having electron transport properties as a functional material and has an electron injection function that increases the efficiency of electron injection from the cathode 16 to the ETL 15. A conventionally known electron transport material can be used as the EIL material for the EIL 82. The EIL 82 may contain, for example, Alq3 as an oxygen-containing compound. Furthermore, as described above, the EIL 82 may contain, for example, a crosslinking agent containing an epoxy group. The EIL 82 can be formed by the same method as the ETL 15.

[0207] The SAM 81 shown in Figure 9 is a hole-transporting buffer layer that is used to improve hole transport properties and wettability of the QD dispersion applied to the SAM 81, and also functions as a buffer layer to prevent chemical alteration of the QDs 21 due to direct contact between the HTL material, such as NiO, and the QDs 21. The SAM 81 is provided between the anode 11 and the EML 14 (e.g., between the HTL 13 and the EML 14 as shown in Figure 9). The SAM 81 can be made of, for example, an organic insulating material. Alternatively, the SAM 81 may be made of a hole-transporting material.

[0208] In the following, a method for forming the SAM 81 will be described using an example in which the SAM 81 is a self-assembled film made of MeO-2PACz and the HTL 13 that serves as the base layer of the SAM 81 contains NiO nanoparticles as the nanoparticles 62.

[0209] The SAM 81 can be formed by, for example, applying an EBL material solution containing an EBL material onto the HTL 13 by spin coating, and then volatilizing the solvent by baking.

[0210] In this embodiment, MeO-2PACz was dispersed in ethanol as a solvent to a concentration of 0.01 mol / L to prepare an MeO-2PACz-ethanol solution as the EBL material solution. Next, the MeO-2PACz-ethanol solution was spin-coated at a spin speed of 300 rpm for 30 seconds onto a NiO-NP layer formed as the HTL 13 on a 25 mm square substrate 10. The substrate was then baked at 100°C for 10 minutes to volatilize the ethanol, thereby forming an MeO-2PACz layer as the SAM 81 on the NiO-NP layer.

[0211] The MeO-2PACz layer １ O ２ To incorporate the scavenger 31, for example, after forming the MeO-2PACz layer, the PACz layer is mixed with the scavenger 31 as shown in the second embodiment. １ O ２ After the scavenger solution was applied, １ O ２ The solvent contained in the scavenger solution may be removed. １ O ２ By adding the scavenger 31, MeO-2PACz and １ O ２ A SAM 81 including a capture agent 31 may be formed.

[0212] In either case, the amount of the oxygen-containing compound in each functional layer is １ O ２ For the same reasons as those described in the first to third embodiments, the content of the scavenger 31 is preferably in the range of 0.001 part by weight or more and 1 part by weight or less.

[0213] In FIG. 9, as described above, as an example, all the functional layers between the anode 11 and the cathode 16 are １ O ２ The light-emitting element 1 according to one embodiment of the present disclosure includes a scavenger 31 between the anode 11 and the cathode 16. １ O ２ It is sufficient to provide at least one layer containing the scavenger 31. Therefore, in the step of forming the functional layer,１ O ２ At least one layer containing the scavenger 31 may be formed.

[0214] 9 has been described with reference to an example in which the intermediate layer is a SAM 81, but as described above, the intermediate layer is a functional layer other than the ETL 15, the EIL, the HTL 13, and the HIL that is added for various purposes. The intermediate layer may be, for example, a hole-blocking layer or an electron-blocking layer, or may be a passivation layer.

[0215] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0216] 1, 41, 51, 61, 63, 71 Light-emitting element 11 Anode (first electrode or second electrode) 12 HIL (functional layer, first functional layer, second functional layer) 13 HTL (functional layer, first functional layer) 14 EML (emitting layer) 15 ETL (functional layer, first functional layer) 16 Cathode (first electrode or second electrode) 21 QD (quantum dot) 31 １ O ２ Capture agent 52, 62 Nanoparticles 81 SAM (intermediate layer, functional layer, first functional layer) 82 EIL (functional layer, first functional layer, second functional layer)

Claims

1. A first electrode and a second electrode are provided, At least one functional layer including an aprotic singlet oxygen scavenger is provided between the first electrode and the second electrode; a light-emitting layer including quantum dots and a first functional layer other than the light-emitting layer are provided between the first electrode and the second electrode, the first functional layer is adjacent to the light-emitting layer and contains an oxygen-element-containing compound; the light-emitting layer comprises the aprotic singlet oxygen scavenger, A light-emitting element characterized in that the density of the aprotic singlet oxygen scavenger in a portion of the light-emitting layer that is closer to the first functional layer than the center of the thickness direction of the light-emitting layer is higher than the density of the aprotic singlet oxygen scavenger in a portion of the light-emitting layer that is farther from the first functional layer than the center of the thickness direction of the light-emitting layer.

2. 2. The light-emitting element according to claim 1, wherein the aprotic singlet oxygen scavenger comprises at least one compound selected from the group consisting of tertiary amines, carotenoids, ethylenic compounds, naphthalene and its derivatives, and anthracene and its derivatives.

3. 3. The light-emitting device according to claim 1, further comprising a tertiary amine as the aprotic singlet oxygen scavenger.

4. 4. The light-emitting device according to claim 3, wherein the tertiary amine comprises at least one selected from the group consisting of 1,4-diazabicyclo[2.2.2]octane, triethylamine, and N,N-dimethylaniline.

5. 3. The light-emitting device according to claim 1, wherein the aprotic singlet oxygen scavenger is a monomer.

6. The light-emitting element according to claim 1 , wherein the density of the aprotic singlet oxygen scavenger in the light-emitting layer is higher in a portion closer to the first functional layer in the thickness direction of the light-emitting layer.

7. A first electrode and a second electrode are provided, At least one functional layer including an aprotic singlet oxygen scavenger is provided between the first electrode and the second electrode; a light-emitting layer including quantum dots, a first functional layer other than the light-emitting layer, and a second functional layer provided between the first electrode and the second electrode as functional layers; The second functional layer contains an oxygen-containing compound, the first functional layer comprises the aprotic singlet oxygen scavenger, A light-emitting element characterized in that the density of the aprotic singlet oxygen scavenger in a portion of the first functional layer closer to the second functional layer than the center of the thickness direction of the first functional layer is higher than the density of the aprotic singlet oxygen scavenger in a portion of the first functional layer farther from the second functional layer than the center of the thickness direction of the first functional layer.

8. The light-emitting element according to claim 7, characterized in that the density of the aprotic singlet oxygen scavenger in the first functional layer is higher in the thickness direction of the first functional layer in a portion closer to the second functional layer.