Light-emitting element, display device, and quantum dot dispersion

Abstract

A red light-emitting element (5R) comprises a lower electrode (22), an upper electrode (25), and a red light-emitting layer (24REM) that is provided between the lower electrode (22) and the upper electrode (25), wherein the red light-emitting layer (24REM) includes quantum dots (QD), a matrix (MR), and a matrix stabilizer (8) that includes a molecular structure bonded to an element for which there is a first shielding group (7a) including a first cyclic compound and a second shielding group (7b) including a second cyclic compound.

Description

Light-emitting element, display device, and quantum dot dispersion

[0001] The present disclosure relates to a light-emitting device, a display device, and a quantum dot dispersion.

[0002] In recent years, quantum dot light-emitting diodes (QLEDs), which are light-emitting elements containing quantum dots, and display devices equipped with QLEDs have been attracting a great deal of attention because of their ability to achieve low power consumption, thinness, high image quality, and the like.

[0003] In the field of QLEDs, active research is being conducted on quantum dot dispersions used to form the light-emitting layers of QLEDs.

[0004] For example, Patent Document 1 describes a light-emitting device having a light-emitting layer containing a semiconductor matrix and quantum dots.

[0005] Japanese Patent Publication "Patent Publication No. 2011-502333"

[0006] Patent Document 1 describes a case where the semiconductor matrix contained in the light-emitting layer is made of an organic material or an inorganic material.

[0007] When the semiconductor matrix contained in the light-emitting layer is made of an organic material or an inorganic material, the thickness of the semiconductor matrix in the light-emitting layer is formed to be greater than necessary, which causes a problem of increasing the driving voltage of the light-emitting device.Furthermore, when the semiconductor matrix contained in the light-emitting layer is made of an inorganic material, the inorganic film may crack or become distorted, which may cause a problem of deteriorating the light-emitting characteristics and reliability of the light-emitting device.

[0008] An object of one aspect of the present disclosure is to provide a light-emitting element and a display device having a light-emitting layer that can suppress an increase in driving voltage, a deterioration in light-emitting characteristics, and a deterioration in reliability, and a quantum dot dispersion liquid that can form such a light-emitting layer.

[0009] In order to solve the above-mentioned problems, the light-emitting element of the present disclosure comprises an anode, a cathode, and an emitting layer provided between the anode and the cathode, wherein the emitting layer comprises quantum dots, a matrix, and a matrix stabilizer comprising a molecular structure in which a first shielding group including a first cyclic compound and a second shielding group including a second cyclic compound are each bonded to a certain element, or a molecular structure in which the first shielding group and the second shielding group are bonded to a certain element.

[0010] In order to solve the above-mentioned problems, the display device of the present disclosure includes the light-emitting element.

[0011] In order to solve the above-mentioned problems, the quantum dot dispersion liquid of the present disclosure includes quantum dots; a precursor for forming a matrix; a matrix stabilizer having a molecular structure in which a first shielding group containing a first cyclic compound and a second shielding group containing a second cyclic compound are each bonded to a certain element, or a molecular structure in which the first shielding group and the second shielding group are bonded; and a solvent.

[0012] According to one aspect of the present disclosure, it is possible to provide a light-emitting element and a display device having a light-emitting layer that can suppress an increase in driving voltage, a deterioration in light-emitting characteristics, and a deterioration in reliability, and a quantum dot dispersion liquid that can form such a light-emitting layer.

[0013] 1 is a plan view showing a schematic configuration of a display device of Embodiment 1. FIG. 2 is a cross-sectional view showing a schematic configuration of a display region of the display device of Embodiment 1. FIG. 3 is a cross-sectional view showing a schematic configuration of a red light-emitting device provided in the display device of Embodiment 1, including a partially enlarged view of portion A. FIG. 4 is a diagram for explaining a region formed between quantum dots when two adjacent quantum dots among a plurality of quantum dots included in a red light-emitting layer provided in the red light-emitting device shown in FIG. 3 are arranged close to each other. FIG. 5 is a diagram showing a preparation process of a quantum dot dispersion liquid used in a process for forming a red light-emitting layer provided in the red light-emitting device shown in FIG. 3. FIG. 6 is a diagram showing a part of a process for forming a red light-emitting layer provided in the red light-emitting device shown in FIG. 3. FIG. 7 is a diagram showing an example of a cyclic compound that is a shielding group included in a matrix stabilizer that can be suitably used depending on the type of alkoxy group. FIG. 8 is a diagram showing the total molecular area, total molecular volume, and maximum molecular length of 3-(mercaptopropyl)trimethoxysilane (MPS), a methoxy group, TPCl (Trityl Chloride), and benzene, respectively.

[0014] The following describes an embodiment of the present disclosure with reference to Figures 1 to 8. For the sake of convenience, components having the same functions as those described in a specific embodiment will be denoted by the same reference numerals, and their description may be omitted.

[0015] First Embodiment FIG. 1 is a plan view showing a schematic configuration of a display device 1 according to a first embodiment.

[0016] As shown in Fig. 1, the display device 1 includes a frame area NDA and a display area DA. The display area DA of the display device 1 includes a plurality of pixels PIX, each of which includes a red subpixel RSP, a green subpixel GSP, and a blue subpixel BSP. In this embodiment, a case in which one pixel PIX is configured with a red subpixel RSP, a green subpixel GSP, and a blue subpixel BSP will be described as an example, but this is not limiting. For example, one pixel PIX may include subpixels of other colors in addition to the red subpixel RSP, the green subpixel GSP, and the blue subpixel BSP.

[0017] FIG. 2 is a cross-sectional view showing a schematic configuration of the display area DA of the display device 1 of the first embodiment.

[0018] As shown in Figure 2, in the display area DA of the display device 1, a barrier layer 3, a thin film transistor layer 4 including a transistor TR, a red light-emitting element 5R, a green light-emitting element 5G, a blue light-emitting element 5B and a bank 23, a sealing layer 6, and a functional film 39 are provided on a substrate 12 in this order from the substrate 12 side.

[0019] The red subpixel RSP provided in the display area DA of the display device 1 includes a red light-emitting element 5R (light-emitting element), the green subpixel GSP provided in the display area DA of the display device 1 includes a green light-emitting element 5G (light-emitting element), and the blue subpixel BSP provided in the display area DA of the display device 1 includes a blue light-emitting element 5B (light-emitting element). The red light-emitting element 5R included in the red subpixel RSP includes an anode which is the lower electrode 22, a functional layer 24R including a red light-emitting layer, and a cathode which is the upper electrode 25. The green light-emitting element 5G included in the green subpixel GSP includes an anode which is the lower electrode 22, a functional layer 24G including a green light-emitting layer, and a cathode which is the upper electrode 25. The blue light-emitting element 5B included in the blue subpixel BSP includes an anode which is the lower electrode 22, a functional layer 24B including a blue light-emitting layer, and a cathode which is the upper electrode 25. In the display device 1 shown in Figure 2, an example is given in which a functional layer 24R including a red light-emitting layer, a functional layer 24G including a green light-emitting layer, and a functional layer 24B including a blue light-emitting layer are provided for each sub-pixel of each color, but this is not limited to this, and one or more layers, for example, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer, which are included in the functional layer 24R including a red light-emitting layer, the functional layer 24G including a green light-emitting layer, and the functional layer 24B including a blue light-emitting layer, may be provided as a common layer (one layer) for each of the red sub-pixel RSP, the green sub-pixel GSP, and the blue sub-pixel BSP.

[0020] The substrate 12 may be, for example, a resin substrate made of a resin material such as polyimide, or a glass substrate. In this embodiment, since the display device 1 is a flexible display device, a case where a resin substrate made of a resin material such as polyimide is used as the substrate 12 will be described as an example, but this is not limiting. If the display device 1 is a non-flexible display device, a glass substrate can be used as the substrate 12.

[0021] The barrier layer 3 is a layer that prevents foreign substances such as water and oxygen from penetrating into the transistor TR, the red light-emitting element 5R, the green light-emitting element 5G, and the blue light-emitting element 5B, and can be composed of, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film of these, formed by the CVD method.

[0022] The transistor TR portion of the thin film transistor layer 4 including the transistor TR includes the semiconductor film SEM and doped semiconductor films SEM′ and SEM″, an inorganic insulating film 16, a gate electrode G, an inorganic insulating film 18, an inorganic insulating film 20, a source electrode S and a drain electrode D, and a planarization film 21, and the portion of the thin film transistor layer 4 including the transistor TR other than the transistor TR portion includes the inorganic insulating film 16, the inorganic insulating film 18, the inorganic insulating film 20, and the planarization film 21.

[0023] The semiconductor films SEM, SEM', and SEM'' may be made of, for example, low-temperature polysilicon (LTPS) or an oxide semiconductor (for example, an In-Ga-Zn-O based semiconductor). In this embodiment, the case where the transistor TR has a top-gate structure will be described as an example, but the present invention is not limited to this, and the transistor TR may also have a bottom-gate structure.

[0024] The gate electrode G and the source electrode S and drain electrode D can be made of a single layer or a multilayer film of a metal containing at least one of aluminum, tungsten, molybdenum, tantalum, chromium, titanium, and copper, for example.

[0025] The inorganic insulating films 16, 18 and 20 can be formed of, for example, a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film of these films, which are formed by the CVD method.

[0026] The planarizing film 21 can be made of a coatable organic material such as polyimide or acrylic.

[0027] The red light-emitting element 5R includes an anode, which is a lower electrode 22 above the planarization film 21, a functional layer 24R including a red light-emitting layer, and a cathode, which is an upper electrode 25. The green light-emitting element 5G includes an anode, which is a lower electrode 22 above the planarization film 21, a functional layer 24G including a green light-emitting layer, and a cathode, which is an upper electrode 25. The blue light-emitting element 5B includes an anode, which is a lower electrode 22 above the planarization film 21, a functional layer 24B including a blue light-emitting layer, and a cathode, which is an upper electrode 25. The insulating bank 23 covering the edge of the anode, which is the lower electrode 22, can be formed, for example, by applying an organic material such as polyimide or acrylic and then patterning it by photolithography. Although the present embodiment will be described taking the case where the bank 23 is provided as an example, the bank 23 may not be provided.

[0028] The sealing layer 6 is a light-transmitting film, and can be composed of, for example, an inorganic sealing film 26 that covers the cathode, which is the upper electrode 25, an organic film 27 that is above the inorganic sealing film 26, and an inorganic sealing film 28 that is above the organic film 27. The sealing layer 6 prevents foreign substances such as water and oxygen from penetrating into the red light-emitting element 5R, the green light-emitting element 5G, and the blue light-emitting element 5B.

[0029] The inorganic sealing films 26 and 28 are each an inorganic film, and may be formed, for example, by a CVD method using a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a laminated film thereof. The organic film 27 is a light-transmitting organic film with a planarizing effect, and may be formed, for example, using a coatable organic material such as acrylic. The organic film 27 may also be formed, for example, by an inkjet method. In this embodiment, the sealing layer 6 is formed of two inorganic films and one organic film disposed between the two inorganic films. However, the stacking order of the two inorganic films and one organic film is not limited to this. Furthermore, the sealing layer 6 may be formed solely of an inorganic film, solely of an organic film, one inorganic film and two organic films, or two or more inorganic films and two or more organic films.

[0030] The functional film 39 is a film having at least one of an optical compensation function, a touch sensor function, and a protection function, for example.

[0031] Fig. 3 is a cross-sectional view showing a schematic configuration of a red light-emitting element 5R provided in the display device 1 of embodiment 1, including a partial enlarged view of portion A. Fig. 4 is a diagram for explaining a region K formed between quantum dots QD1 and QD2 when two adjacent quantum dots QD1 and QD2 are arranged close to each other among the multiple quantum dots QD included in the red light-emitting layer 24REM provided in the red light-emitting element 5R shown in Fig. 3 .

[0032] 3, the red light-emitting element 5R includes an anode which is the lower electrode 22, a cathode which is the upper electrode 25, and a red light-emitting layer 24REM provided between the anode which is the lower electrode 22 and the cathode which is the upper electrode 25. The red light-emitting layer 24REM includes quantum dots QD, a matrix MR, and a matrix stabilizer 8 including a molecular structure in which a first shielding group 7a including a first cyclic compound, a second shielding group 7b including a second cyclic compound, and a third shielding group 7c including a third cyclic compound are each bonded to a certain element. In this embodiment, the matrix stabilizer 8 includes a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are each bonded to a certain element. However, the present invention is not limited to this example. The matrix stabilizer 8 may include a molecular structure in which two shielding groups, for example, a first shielding group 7a containing a first cyclic compound and a second shielding group 7b containing a second cyclic compound, are each bonded to a certain element. Alternatively, the matrix stabilizer 8 may include a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are bonded. Alternatively, the matrix stabilizer 8 may include a molecular structure in which two shielding groups, for example, a first shielding group 7a containing a first cyclic compound and a second shielding group 7b containing a second cyclic compound are bonded. The shielding groups (e.g., the first shielding group 7a, the second shielding group 7b, the third shielding group 7c, the fourth shielding group 7d, and the fifth shielding group 7e) are groups containing a cyclic compound contained in the light-emitting layer and have a molecular structure skeleton larger than that of an alkoxy group. Note that these shielding groups are not necessarily required to shield anything, as long as they are groups containing a cyclic compound contained in the light-emitting layer and have a molecular structure skeleton larger than that of an alkoxy group. In this embodiment, an example will be described in which a first charge transport layer 24HT is provided between the anode (lower electrode 22) and the red light-emitting layer 24REM, and a second charge transport layer 24ET is provided between the cathode (upper electrode 25) and the red light-emitting layer 24REM. However, this is not limiting, and at least one of the first charge transport layer 24HT and the second charge transport layer 24ET may be omitted.In this embodiment, the first charge transport layer 24HT is described as having a hole injection layer and a hole transport layer in this order from the anode side, which is the lower electrode 22, as an example. However, this is not limited thereto, and the first charge transport layer 24HT may be configured as either a hole transport layer or a hole injection layer. Furthermore, in this embodiment, the second charge transport layer 24ET is described as having an electron injection layer and an electron transport layer in this order from the cathode side, which is the upper electrode 25, as an example. However, this is not limited thereto, and the second charge transport layer 24ET may be configured as either an electron transport layer or an electron injection layer. Here, of the red light-emitting element 5R, green light-emitting element 5G, and blue light-emitting element 5B shown in FIG. 2 , the red light-emitting element 5R is described as an example. However, the green light-emitting element 5G and blue light-emitting element 5B may also have the same configuration as the red light-emitting element 5R.

[0033] The red light-emitting layer 24REM of the red light-emitting element 5R shown in FIG. 3 includes quantum dots QDs. The quantum dots QDs may have, for example, a core structure, a core / shell structure, a core / shell / shell structure, or a shell structure with a continuously varying core / shell ratio. The shell QDs may partially cover the core QDs, but it is more preferable for the shell QDs to completely cover the core QDs. The core material of the quantum dots QDs may be, for example, a II-VI group semiconductor crystal such as MgS, MgSe, MgTe, CaS, CaSe, CaTe, BaS, BaSe, BaTe, ZnS, ZnSe, ZnTe, CdS, CdSe, CdTe, PbS, PbSe, HgS, HgSe, or HgTe; a III-V group semiconductor crystal such as GaAs, GaP, InN, InAs, InP, or InSb; or Ga ３ S ２ , Ga ２ Se ３ , In ２ S ３ , In ２ Se ３ crystals of III-VI group semiconductors such as CuInGaS, AgInGaS, CuInGaS, AgInGaZnS, CuInGaSe, AgInGaSe, crystals of I-III-VI group semiconductors such as C and Si, crystals of IV group semiconductors such as CsPbI ３ , CsPbBr ３, CsPbCl ３ The shell material can be made of a semiconductor crystal with a perovskite structure such as the above. The shell material is selected from the same material group as the core material, and is preferably one that has a lattice constant close to that of the core material and a larger band gap than the core material.

[0034] The red light-emitting layer 24REM included in the red light-emitting element 5R shown in FIG. 3 includes a matrix MR. In this embodiment, the matrix MR includes an oxide containing a metalloid element, i.e., the matrix MR includes silicon oxide. However, the present invention is not limited to this. The matrix MR may include, for example, an oxide containing a metal element, an organic material, or a metal sulfide. Examples of metalloid elements include B, Si, Ge, As, Sb, and Te. The metal sulfide may include one or more metal elements selected from Zn, Mg, and Ga, such as zinc sulfide, magnesium zinc sulfide, gallium sulfide, tellurium zinc sulfide, magnesium sulfide, and gallium zinc sulfide. Examples of oxides containing a metal element or a metalloid element include, but are not limited to, silicon oxide, beryllium oxide, boron oxide, magnesium oxide, aluminum oxide, calcium oxide, scandium oxide, titanium oxide, manganese oxide, nickel oxide, gallium oxide, germanium oxide, arsenic oxide, strontium oxide, yttrium oxide, zirconium oxide, niobium oxide, molybdenum oxide, indium oxide, tin oxide, antimony oxide, barium oxide, cerium oxide, europium oxide, hafnium oxide, tantalum oxide, and thorium oxide.

[0035] As described above, in this embodiment, in order to form a matrix MR containing silicon oxide, a precursor of the matrix MR as shown in the following (Chemical Formula 1) can be used. Z in the following (Chemical Formula 1) is a functional group capable of coordinating with the quantum dots QD, and can be appropriately selected from a thiol group, an amine group, a carboxylic acid group, a phosphine group, etc. depending on the material of the quantum dots QD. In the following (Chemical Formula 1), R is C ｎ H ２ｎIn this embodiment, the precursor of the matrix MR is a compound in which the functional group capable of coordinating with the quantum dot QD is a thiol group, and C ｎ H ２ｎ Division C ３ H ６ In this embodiment, 3-(mercaptopropyl)trimethoxysilane (MPS) shown in Chemical Formula 3 below, in which all three alkoxy groups are methoxy groups, was used, but the present invention is not limited to this, as long as a matrix MR containing silicon oxide can be formed. Furthermore, in this embodiment, in order to form a matrix MR containing silicon oxide, tetramethoxysilane (tetramethyl orthosilicate (TMOS)) shown in Chemical Formula 4 below was used together with 3-(mercaptopropyl)trimethoxysilane (MPS) shown in Chemical Formula 3 below as a molecule that serves as both a precursor of the matrix MR and a crosslinking agent, but the present invention is not limited to this, as long as a matrix MR containing silicon oxide can be formed. The matrix MR may be filled in the red light-emitting layer 24REM, but as shown in FIG. 4 , a portion that fills the region K between at least two adjacent quantum dots (a first quantum dot QD1 and a second quantum dot QD2) among the multiple quantum dots QD contained in the red light-emitting layer 24REM can be considered a matrix. 4 is a region surrounded by two straight lines (common circumscribing lines) circumscribing the outer peripheries of the first quantum dot QD1 and the second quantum dot QD2 in a cross-sectional view, and the opposing outer peripheries of the first quantum dot QD1 and the second quantum dot QD2. As shown in FIG. 4, region K can exist even if the first quantum dot QD1 is close to the second quantum dot QD2.

[0036] As the matrix stabilizer 8, a molecule such as that shown in the following (Chemical Formula 2) can be used. X in the following (Chemical Formula 2) may be any of carbon, nitrogen, and silicon, or may be a cyclic compound. Two or more of Y1, Y2, Y3, and Y4 in the following (Chemical Formula 2) are cyclic compounds. In this embodiment, as the matrix stabilizer 8, a case will be described in which TPCl (Trityl Chloride) shown in the following (Chemical Formula 5) is used, in which X in the following (Chemical Formula 2) is carbon, Y1, Y2, and Y4 in the following (Chemical Formula 2) are each a phenyl group, which is a cyclic compound, and Y3 in the following (Chemical Formula 2) is chlorine; however, the present invention is not limited thereto. As shown in the following (Chemical Formula 5), ​​TPCl (Trityl Chloride) has a molecular structure in which each of the three phenyl groups becomes a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound, and each of first shielding group 7a containing a first cyclic compound, second shielding group 7b containing a second cyclic compound, and third shielding group 7c containing a third cyclic compound is bonded to a carbon atom.

[0037] During the formation of the silicon oxide-containing matrix MR, a sequential reaction of highly reactive groups, such as alkoxy groups and hydroxy groups, contained in the precursor of the matrix MR or in the intermediate formed by the matrix MR precursor can cause shrinkage of the silicon oxide-containing matrix MR, resulting in cracks in the silicon oxide-containing matrix MR and potentially reducing the light-emitting characteristics and reliability of the light-emitting device. Therefore, in this embodiment, the red light-emitting layer 24REM provided in the red light-emitting element 5R includes quantum dots QDs, the matrix MR, and a matrix stabilizer 8 containing a bulky trityl group. During the formation of the silicon oxide-containing matrix MR, the matrix stabilizer 8 physically masks highly reactive groups, such as alkoxy groups and hydroxy groups, thereby suppressing the sequential reaction of the silicon oxide. Therefore, a light-emitting element (e.g., the red light-emitting element 5R) and a display device 1 can be realized that include a light-emitting layer that can suppress degradation of the light-emitting characteristics and reliability. The above-described effects of the matrix stabilizer 8 can also be obtained for a matrix MR containing a metal sulfide.

[0038] Furthermore, during the formation of the silicon oxide-containing matrix MR, the thickness of the silicon oxide-containing matrix MR in the light-emitting layer may be increased beyond necessary thickness due to a sequential reaction of highly reactive groups, such as alkoxy groups and hydroxy groups, contained in the precursor of the matrix MR or in the intermediate formed by the matrix MR precursor, thereby increasing the driving voltage of the light-emitting device. Therefore, in this embodiment, the matrix stabilizer 8 containing a bulky trityl group physically shields (masks) highly reactive groups, such as alkoxy groups and hydroxy groups, during the formation of the silicon oxide-containing matrix MR, thereby suppressing the sequential reaction of silicon oxide. In other words, the matrix stabilizer 8 containing a highly sterically hindered trityl group acts as a spacer between silicon oxide networks, suppressing high-density shrinkage of silicon oxide. Therefore, a light-emitting device (e.g., red light-emitting device 5R) and a display device 1 having a light-emitting layer that can suppress an increase in the driving voltage of the light-emitting device can be realized. The above-described effects of the matrix stabilizer 8 can also be obtained for the metal sulfide-containing matrix MR. The matrix stabilizer 8 may be bonded to the matrix MR. Depending on the type of matrix stabilizer 8 and the type of the precursor of matrix MR, the matrix stabilizer 8 may not be able to form a bond with matrix MR, and in such cases, it is sufficient that matrix MR contains matrix stabilizer 8. Whether or not the matrix stabilizer 8 and matrix MR have formed a bond can be determined from the results of analysis such as TOF-SIMS or XPS.

[0039] 2 and 3 may be of either a top-emission type or a bottom-emission type. The red light-emitting element 5R, the green light-emitting element 5G, and the blue light-emitting element 5B have a stack structure in which the cathode, which is the upper electrode 25, is disposed above the anode, which is the lower electrode 22. To form the red light-emitting element 5R, the green light-emitting element 5G, and the blue light-emitting element 5B as a top-emission type, the anode, which is the lower electrode 22, should be formed from an electrode material that reflects visible light, and the cathode, which is the upper electrode 25, should be formed from an electrode material that transmits visible light. To form the bottom-emission type, the anode, which is the lower electrode 22, should be formed from an electrode material that transmits visible light, and the cathode, which is the upper electrode 25, should be formed from an electrode material that reflects visible light. On the other hand, in the case of an inverted stack structure in which the upper electrode 25, that is, the anode, is arranged as a layer above the lower electrode 22, that is, the cathode, in order to make it a top emission type, the lower electrode 22, that is, the cathode, can be formed from an electrode material that reflects visible light, and the upper electrode 25, that is, the anode, can be formed from an electrode material that transmits visible light, and in order to make it a bottom emission type, the lower electrode 22, that is, the cathode, can be formed from an electrode material that transmits visible light, and the upper electrode 25, that is, the anode, can be formed from an electrode material that reflects visible light.

[0040] The electrode material that reflects visible light is not particularly limited as long as it can reflect visible light and has electrical conductivity. Examples of the electrode material that reflects visible light include metal materials such as Al, Mg, Li, and Ag, alloys of the metal materials, laminates of the metal materials and transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), and laminates of the alloys and the transparent metal oxides.

[0041] On the other hand, the electrode material that transmits visible light is not particularly limited as long as it can transmit visible light and has conductivity, and examples thereof include transparent metal oxides (e.g., indium tin oxide, indium zinc oxide, indium gallium zinc oxide, etc.), thin films made of metal materials such as Al and Ag, and nanowires made of metal materials such as Al and Ag.

[0042] Fig. 5 is a diagram showing a process for preparing a quantum dot dispersion liquid used in a process for forming a red light-emitting layer provided in the red light-emitting element shown in Fig. 3. Fig. 6 is a diagram showing a part of a process for forming a red light-emitting layer provided in the red light-emitting element shown in Fig. 3.

[0043] 5, a process for preparing a quantum dot dispersion liquid is described, which includes quantum dots (QD), a precursor for forming a matrix (MR), a matrix stabilizer (8) including a molecular structure in which a first shielding group (7a) containing a first cyclic compound and a second shielding group (7b) containing a second cyclic compound are each bonded to a certain element, or a molecular structure in which the first shielding group (7a) and the second shielding group (7b) are bonded, and a solvent. Note that, here, a case is described in which the matrix stabilizer (8) includes a third shielding group (7c) containing a third cyclic compound, and the matrix stabilizer (8) includes a molecular structure in which the first shielding group (7a), the second shielding group (7b), and the third shielding group (7c) are each bonded to the certain element, but this is not limiting, and the matrix stabilizer (8) may also include a molecular structure in which the first shielding group (7a), the second shielding group (7b), and the third shielding group (7c) are bonded. As shown in step S1 of FIG. 5, a first solution containing 3-(mercaptopropyl)trimethoxysilane (MPS), tetramethoxysilane (tetramethyl orthosilicate (TMOS)), and a DMF solvent, and a second solution in which quantum dots QDs are dispersed in octane, are stirred for, for example, 8 hours or more and 12 hours or less, thereby precipitating a solid containing quantum dots QDs, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) in the intermediate layer, as shown in step S2 of FIG. 5. In step S3 of FIG. 5, the upper and lower layers of the solid containing quantum dots QDs, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) were extracted, and only the solid containing quantum dots QDs, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) was extracted.5, a third solution containing TPCl (Trityl Chloride) as a matrix stabilizer 8 and toluene as a solvent was added to the solid containing the quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)), and the solid containing the quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) was redispersed in toluene. Through these steps, a quantum dot dispersion liquid can be obtained in which the solid containing the quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)), and TPCl (Trityl Chloride) as a matrix stabilizer 8 are dispersed in toluene. The quantum dot dispersion liquid preparation process is not limited to this. After step S3 of FIG. 5 , as shown in step S4′ of FIG. 5 , a small amount of toluene may be added to a solid containing quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)), to obtain a solution in which a solid containing quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) is dispersed at a high concentration in toluene. Then, as shown in step S5 of FIG. 5 , a solution containing a high concentration of TPCl (Trityl Chloride), which is the matrix stabilizer 8, may be added to toluene to obtain a quantum dot dispersion liquid in which a solid containing quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)), and TPCl (Trityl Chloride), which is the matrix stabilizer 8, are dispersed in toluene.

[0044] A part of the process for forming the red light-emitting layer 24REM provided in the red light-emitting element 5R shown in Fig. 3 will be described with reference to Fig. 6. Step S11 in Fig. 6 is a process for forming a film by applying a quantum dot dispersion liquid in which a solid containing quantum dots QD, 3-(mercaptopropyl)trimethoxysilane (MPS), and tetramethoxysilane (tetramethyl orthosilicate (TMOS)), and TPCl (Trityl Chloride) as the matrix stabilizer 8 are dispersed in the toluene described above. Step S12 in Fig. 6 is a process for irradiating the film formed in step S11 in Fig. 6 with UV light. TPCl (Trityl Chloride) as the matrix stabilizer 8 is irradiated with UV light to form the TP ＋ part (trityl cation part) and Cl － Since the red light-emitting layer 24REM containing the matrix stabilizer 8 is liberated to the TP portion (chlorine ion portion), ＋ moiety (trityl cation moiety) and Cl － It contains Cl element, which is a part of the fluorine atom.

[0045] TPCl has bulky functional groups and acts as a matrix stabilizer 8 that shields highly reactive groups contained in the intermediate. ＋ Part and Cl － By liberating it in the emissive layer, 3-(mercaptopropyl)trimethoxysilane (MPS) mixed in the emissive layer is converted to TP ＋ By chemically bonding the TP-MPS to the QD, the TP-MPS can be formed. This TP-MPS reacts with the matrix MR formed of 3-(mercaptopropyl)trimethoxysilane (MPS) that covers the periphery of the quantum dot QD, allowing the TP-MPS to be contained in the matrix in a chemically bonded state.

[0046] As shown in step S13 of FIG. 6, quantum dots QD, a matrix MR containing silicon oxide, and a TP of TPCl (Trityl Chloride) as a matrix stabilizer 8 are mixed. ＋6, a red light-emitting layer 24REM including the portion TPLig can be obtained. After step S13 in FIG. 6, rinsing may be performed using, for example, toluene, as necessary, as shown in step S14 in FIG. 6. This rinsing step removes the TP of TPCl (Trityl Chloride), which is the matrix stabilizer 8 included in the red light-emitting layer 24REM. ＋ Part of the TPLig can be removed.

[0047] In this embodiment, in the quantum dot dispersion liquid preparation process shown in FIG. 5 , the matrix stabilizer 8 is described as an example using TPCl (Trityl Chloride), which has a molecular structure in which three phenyl groups are each bonded to a carbon atom, such as a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound, but the present invention is not limited thereto. To ensure bulkiness, one or more of the cyclic compounds contained in the matrix stabilizer 8 may contain an aromatic compound, a benzene ring, or a polycyclic compound. Furthermore, one or more of the cyclic compounds contained in the matrix stabilizer 8 may be a monocyclic compound in which the rings are formed of the same element, or a heterocyclic compound in which the rings are formed of two or more different elements. Furthermore, some of the cyclic compounds among the plurality of cyclic compounds contained in the matrix stabilizer 8 may be heterocyclic compounds, and the remaining portion of the cyclic compounds among the plurality of cyclic compounds contained in the matrix stabilizer 8 may be monocyclic compounds. Note that, because saturated cyclic compounds, which are the counter structure, have low chemical stability and are relatively prone to structural collapse, it is preferable that one or more of the first shielding group 7a, the second shielding group 7b, and the third shielding group 7c be unsaturated cyclic compounds. Furthermore, because aromatic compounds have high chemical stability among unsaturated cyclic compounds and are less prone to structural collapse, it is preferable that one or more of the first shielding group 7a, the second shielding group 7b, and the third shielding group 7c be aromatic compounds.

[0048] In this embodiment, an example has been described in which TPCl (Trityl Chloride) is used as the matrix stabilizer 8, and 3-(mercaptopropyl)trimethoxysilane (MPS) and tetramethoxysilane (tetramethyl orthosilicate (TMOS)) are used as the precursors for forming the matrix MR. However, the present invention is not limited to this example. For example, a molecule containing a trityl skeleton (a skeleton in which three phenyl groups are bonded to carbon) may be used as the matrix stabilizer 8, and at least one of a dialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs and a trialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs may be used as the precursors for forming the matrix MR. Furthermore, a molecule containing a trityl skeleton (a skeleton in which three phenyl groups are bonded to carbon) may be used as the matrix stabilizer 8, and at least one of a dialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs and a trialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs, and one or more selected from a tetraalkoxysilane compound, a trialkoxysilane compound, a dialkoxysilane compound, and a monoalkoxysilane compound may be used as a precursor for forming the matrix MR. The dialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs contains a functional group capable of coordinating to quantum dots QDs and a C ｎ H ２ｎ The trialkoxysilane compound includes a moiety (C is a carbon element, H is a hydrogen element, and n is a natural number of 1 or more) and a dialkoxysilane group, and includes a functional group capable of coordinating to the quantum dots QD. ｎ H ２ｎ The compound (C) of the dialkoxysilane compound containing a functional group capable of coordinating to the quantum dots QD or the compound (C) of the trialkoxysilane compound containing a functional group capable of coordinating to the quantum dots QD is also included. ｎ H ２ｎIn consideration of dispersibility in a solvent or the like, n in the moiety is preferably 1 or more and 20 or less, and more preferably 3 or more and 18 or less. In consideration of reactivity, the alkoxy group contained in each of the tetraalkoxysilane compound, trialkoxysilane compound, dialkoxysilane compound, monoalkoxysilane compound, dialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs, and trialkoxysilane compound containing a functional group capable of coordinating to quantum dots QDs, which can be used as a precursor for forming the matrix MR, is preferably selected from a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

[0049] 5, in the step of preparing the second solution in which the quantum dots QDs are dispersed in the solvent octane, an organic substance containing a functional group capable of coordinating with the quantum dots QDs, i.e., an organic ligand, may be used to ensure the dispersibility of the quantum dots QDs in octane. In such a case, when the quantum dot dispersion liquid shown in FIG. 5 contains X moles of an organic substance containing a functional group capable of coordinating with the quantum dots QDs, Y moles of a dialkoxysilane compound containing a functional group capable of coordinating with the quantum dots, and Z moles of a trialkoxysilane compound containing a functional group capable of coordinating with the quantum dots, ((Y + Z) / (X + Y + Z)) × 100% is preferably 20% or more and 100% or less, and more preferably 40% or more and 100% or less.

[0050] The matrix stabilizer 8 may contain a halogen element, such as TPCl (Trityl Chloride) used as the matrix stabilizer 8 in this embodiment, or may be a halide containing a trityl skeleton, such as Trityl Bromide, 4-Methoxytrityl Chloride, 4,4′-Dimethoxytrityl Chloride, 2-Chlorotrityl Chloride, 4,4′,4″-Tris(benzoyloxy)trityl Bromide, or Triphenylchlorosilane.

[0051] When the matrix MR contained in the red light-emitting layer 24REM contains an oxide containing a metal element or a metalloid element, and when a group containing a trityl skeleton (a skeleton in which three phenyl groups are bonded to carbon) of the matrix stabilizer 8 is represented by X, a halogen element of the matrix stabilizer 8 is represented by Y, an oxide containing a metal element or a metalloid element is represented by W, an organic group is represented by R, a sulfur element is represented by S, a nitrogen element is represented by N, a hydrogen element is represented by H, an oxygen element is represented by O, a carbon element is represented by C, and a chemical bond is represented by -, the matrix stabilizer 8 may exist in any of the states of X-Y, X-S-R-W, X-NH-R-W, and X-OOC-R-W.

[0052] Furthermore, when the matrix MR contained in the red light-emitting layer 24REM contains an oxide containing a metal element or a metalloid element, and when a group containing a trityl skeleton (a skeleton in which three phenyl groups are bonded to carbon) of the matrix stabilizer 8 is represented by X, an oxide containing a metal element or a metalloid element is represented by W, an organic group is represented by R, a sulfur element is represented by S, a nitrogen element is represented by N, a hydrogen element is represented by H, an oxygen element is represented by O, a carbon element is represented by C, and a chemical bond is represented by -, the matrix stabilizer 8 may exist in any of the states of X-S-R-W, X-NH-R-W, and X-OOC-R-W.

[0053] Furthermore, when the matrix MR contained in the red light-emitting layer 24REM contains an oxide containing a metal element or a metalloid element, and the oxide containing the metal element or the metalloid element is silicon oxide, and when a group containing a trityl skeleton (a skeleton in which three phenyl groups are bonded to carbon) of the matrix stabilizer 8 is represented by X, a silicon element is represented by Si, an organic group is represented by R, a sulfur element is represented by S, a nitrogen element is represented by N, a hydrogen element is represented by H, an oxygen element is represented by O, a carbon element is represented by C, and a chemical bond is represented by -, the matrix stabilizer 8 may exist in any of the states of X-S-R-Si-O-Si-, X-NH-R-Si-O-Si-, and X-OOC-R-Si-O-Si-.

[0054] In this embodiment, the case where a matrix MR precursor containing silicon oxide is used to form the matrix MR has been described as an example. However, this is not limiting. An organic material may also be used as the matrix MR precursor to form an organic matrix MR. Such an organic material may be, for example, a photosensitive resin containing a photosensitive group. Examples of the photosensitive group include an epoxy group and an oxacene group. In this case, the matrix stabilizer 8 can suppress the sequential reaction of the highly reactive photosensitive group contained in the matrix MR precursor or the intermediate formed by the matrix MR precursor. This prevents the matrix MR from being formed too thick in the light-emitting layer, thereby preventing the drive voltage of the light-emitting device from increasing.

[0055] Figure 7 shows examples of cyclic compounds that are suitable shielding groups contained in matrix stabilizers depending on the type of alkoxy group. Figure 8 shows the total molecular area, total molecular volume, and maximum molecular length for 3-(mercaptopropyl)trimethoxysilane (MPS), a methoxy group, TPCl (Trityl Chloride), and benzene. The results shown in Figures 7 and 8 are calculation results using a molecular model.

[0056] Alkoxy groups are highly reactive groups contained in matrix MR precursors for forming silicon oxide-containing matrices MR and in intermediates formed by the matrix MR precursors. The longer the alkyl groups contained in the alkoxy groups, the less reactive they become. Therefore, when reactivity is taken into consideration, methoxy groups (-OMe), ethoxy groups (-OEt), propoxy groups (-OPr), and butoxy groups (-OBu), as shown in Figure 7, are often used. As shown in Figures 7 and 8, the total area of ​​the methoxy groups (-OMe) is 53.241 Å. 2 (approximately 53 Å 2 ), and the total volume of the methoxy group (-OMe) is 32.433 Å 3 (approximately 32Å 3), the ellipticity of the methoxy group (-OMe) was 1.08252, the maximum length of the methoxy group (-OMe) was 4.688 Å (approximately 5 Å), and the maximum radius of the methoxy group (-OMe) was 2.580 Å. Also, as shown in Figure 7, the total area of ​​the ethoxy group (-OEt) was 75.553 Å. 2 The total area of ​​the propoxy group (-OPr) is 95.571 Å 2 and the total area of ​​the butoxy group (-OBu) is 115.622 Å 2 In order to suppress the successive reactions of the alkoxy groups, which are such highly reactive groups, the cyclic compounds contained in the matrix stabilizer 8 need to be bulky. Here, the total area of ​​the alkoxy groups is compared with the total area of ​​the cyclic compounds. If the total area of ​​the cyclic compounds is larger than the total area of ​​the alkoxy groups, the cyclic compounds are determined to have sufficient bulkiness to suppress the successive reactions of the alkoxy groups, and are indicated by a circle in Figure 7. If the total area of ​​the cyclic compounds is smaller than the total area of ​​the alkoxy groups, the cyclic compounds are determined to not have sufficient bulkiness to suppress the successive reactions of the alkoxy groups, and are indicated by an X in Figure 7.

[0057] The three-membered ring shown in FIG. 7, which is an example of a cyclic compound contained in the matrix stabilizer 8, is ethylene oxide, a three-membered heterocyclic compound, and its total area is 66.463 Å. 2 The four-membered ring shown in FIG. 7, which is an example of a cyclic compound contained in the matrix stabilizer 8, is oxetane, a four-membered heterocyclic compound, and its total area is 89.789 Å. 2 The five-membered ring shown in FIG. 7, which is an example of a cyclic compound contained in the matrix stabilizer 8, is oxolane, a five-membered heterocyclic compound, and its total area is 105.787 Å. 2 The six-membered ring shown in FIG. 7, which is an example of a cyclic compound contained in the matrix stabilizer 8, is oxane, a six-membered heterocyclic compound, and its total area is 123.037 Å. 2 The benzene ring shown in FIGS. 7 and 8, which is an example of the cyclic compound contained in the matrix stabilizer 8, has a total area of ​​103.794 Å. 2 (about 104Å 2 ), and its total volume is 80 Å 3The maximum length is 7 Å. As shown in FIG. 8, 3-(mercaptopropyl)trimethoxysilane (MPS) has a total area of ​​224 Å. 2 and its total volume is 172Å 3 The maximum length is 12 Å, and TPCl (Trityl Chloride) has a total area of ​​289 Å. 2 and its total volume is 247Å 3 and its maximum length is 12 Å. Among the cyclic compounds contained in the matrix stabilizer 8, the oxane, which is a six-membered heterocyclic compound, and the benzene ring, which is a six-membered monocyclic compound, described above, have the highest structural stability.

[0058] FIG. 7 shows examples of cyclic compounds that are suitable shielding groups contained in matrix stabilizers depending on the type of alkoxy group. In reality, as in TPCl (Trityl Chloride), multiple shielding groups cover one alkoxy group, so the total area of ​​the individual shielding groups does not necessarily need to be larger than the total area of ​​the alkoxy groups.

[0059] Furthermore, if the matrix stabilizer 8 contains only one cyclic compound, this cyclic compound may not be present completely randomly in the light-emitting layer, but may be present in a biased location, which may result in a case where the alkoxy groups are not covered. Therefore, in the case of TPCl (Trityl Chloride), the three phenyl groups act like partition plates fixed in three directions, improving the probability of covering the alkoxy groups. Thus, in order to improve the probability of covering the alkoxy groups, it is preferable that the matrix stabilizer 8, which is a single molecule, contains two or more cyclic compounds as shielding groups.

[0060] In the present embodiment, the case where TPCl (Trityl Chloride) having a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are each bonded to a carbon as shown in the above (Chemical Formula 5) has been described as an example of matrix stabilizer 8, but the present invention is not limited thereto, and matrix stabilizer 8 may also be 4-Methoxytrityl Chloride shown in the following (Chemical Formula 6), 2-Chlorotrityl Chloride shown in the following (Chemical Formula 7), Trityl Bromide shown in the following (Chemical Formula 8), or 4,4′-Dimethoxytrityl Chloride shown in the following (Chemical Formula 9).

[0061] In this embodiment, the matrix stabilizer 8 has a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are each bonded to a carbon atom. However, the present invention is not limited to this structure. For example, the matrix stabilizer 8 may have a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are each bonded to a silicon atom, as in triphenylchlorosilane shown in Chemical Formula 10 below. Alternatively, the matrix stabilizer 8 may have a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are each bonded to a nitrogen atom, as in TAPC shown in Chemical Formula 11 below and TPD shown in Chemical Formula 12 below.

[0062] Furthermore, the matrix stabilizer 8 may contain a halogen element, such as TPCl (Trityl Chloride) shown in the above (Chemical Formula 5), ​​4-Methoxytrityl Chloride shown in the following (Chemical Formula 6), 2-Chlorotrityl Chloride shown in the following (Chemical Formula 7), Trityl Bromide shown in the following (Chemical Formula 8), 4,4'-Dimethoxytrityl Chloride shown in the following (Chemical Formula 9), Triphenylchlorosilane shown in the following (Chemical Formula 10), Bromocresol Green shown in the following (Chemical Formula 21), Tetrakis(triphenylacetato)dirhodium(II) Dichloromethane Adduct shown in the following (Chemical Formula 22), Voriconazole shown in the following (Chemical Formula 23), and 4,4',4''-Tris(benzoyloxy)trityl Bromide shown in the following (Chemical Formula 24), but is not limited thereto.For example, TAPC shown in the following (chemical formula 11), TPD shown in the following (chemical formula 12), 9,9'-Spirobi[9H-fluorene] shown in the following (chemical formula 13), Triptycene shown in the following (chemical formula 14), Tris(4-aminophenyl)methane shown in the following (chemical formula 15), 2-[Bis(4-hydroxyphenyl)methyl]benzyl Alcohol shown in the following (chemical formula 16), 9-Phenylxanthen-9-ol shown in the following (chemical formula 17), 1,8,13-Trihydroxytriptycene shown in the following (chemical formula 18), 1-Tritylimidazole shown in the following (chemical formula 19), Thymol Blue shown in the following (chemical formula 20), Triphenylsilanol shown in the following (chemical formula 25), Octaphenylcyclotetrasiloxane shown in the following (chemical formula 26), and (S)-(-)-α,α-Diphenyl-2-pyrrolidinemethanol shown in the following (chemical formula 27). The matrix stabilizer 8 does not need to contain a halogen element, such as trimethylsilyl ether, 3,5-bis(tert-butyldiphenylsilyloxy)benzyl alcohol shown in the following (chemical formula 28), 1,2:3,4-diepoxybutane shown in the following (chemical formula 29), 9-phenyl-9'-(triphenylsilyl)-3,3'-bicarbazole shown in the following (chemical formula 30), TPBi shown in the following (chemical formula 31), and 1,2,3,4-tetraphenyl-1,3-cyclopentadiene shown in the following (chemical formula 32).

[0063] Alternatively, the matrix stabilizer 8 may be a molecule in which some of the cyclic compounds are heterocyclic compounds and the remaining cyclic compounds are monocyclic compounds, such as 1-Tritylimidazole shown in Chemical Formula 19 below, voriconazole shown in Chemical Formula 23 below, and (S)-(-)-α,α-Diphenyl-2-pyrrolidinemethanol Trimethylsilyl Ether shown in Chemical Formula 27 below. Alternatively, the matrix stabilizer 8 may be a molecule in which one or more of the cyclic compounds are polycyclic compounds, such as 9,9'-Spirobi[9H-fluorene] shown in Chemical Formula 13 below, 9-Phenyl-9'-(triphenylsilyl)-3,3'-bicarbazole shown in Chemical Formula 30 below, and TPBi shown in Chemical Formula 31 below.

[0064] Further, examples of the matrix stabilizer 8 include a molecular structure in which two or more shielding groups, for example, a first shielding group 7a containing a first cyclic compound and a second shielding group 7b containing a second cyclic compound are bonded, such as 1,2:3,4-Diepoxybutane shown in the following (Chemical Formula 29), 9-Phenyl-9'-(triphenylsilyl)-3,3'-bicarbazole shown in the following (Chemical Formula 30), TPBi shown in the following (Chemical Formula 31), and 1,2,3,4-Tetraphenyl-1,3-cyclopentadiene shown in the following (Chemical Formula 32). A molecule having any of the following structures may be used: a molecular structure in which a shielding group 7a, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are bonded together; a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, a third shielding group 7c containing a third cyclic compound, and a fourth shielding group 7d containing a fourth cyclic compound are bonded together; and a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, a third shielding group 7c containing a third cyclic compound, a fourth shielding group 7d containing a fourth cyclic compound, and a fifth shielding group 7e containing a fifth cyclic compound are bonded together.

[0065] 9,9'-Spirobi[9H-fluorene] shown in the following (Chemical Formula 13) is a molecule having a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, a third shielding group 7c containing a third cyclic compound, and a fourth shielding group 7d containing a fourth cyclic compound are each bonded to a carbon atom, but it is also a molecule having a molecular structure in which two shielding groups consisting of polycyclic compounds, for example, a first shielding group containing a first cyclic compound and a second shielding group containing a second cyclic compound, are bonded. 9-Phenyl-9'-(triphenylsilyl)-3,3'-bicarbazole shown in the following (Chemical Formula 30) is a molecule having a molecular structure in which a first shielding group 7a containing a first cyclic compound, a second shielding group 7b containing a second cyclic compound, and a third shielding group 7c containing a third cyclic compound are bonded, but it is also a molecule having a molecular structure in which three phenyl groups are bonded to silicon.

[0066] [Additional Notes] 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.

[0067] The present disclosure can be used in light-emitting devices, display devices, and quantum dot dispersions.

[0068] 1 Display device 4 Thin film transistor layer 5R Red light-emitting element (light-emitting element) 5G Green light-emitting element (light-emitting element) 5B Blue light-emitting element (light-emitting element) 7a First shielding group including a first cyclic compound 7b Second shielding group including a second cyclic compound 7c Third shielding group including a third cyclic compound 7d Fourth shielding group including a fourth cyclic compound 7e Fifth shielding group including a fifth cyclic compound 8 Matrix stabilizer 22 Lower electrode 23 Bank 24R Functional layer including a red light-emitting layer 24G Functional layer including a green light-emitting layer 24B Functional layer including a blue light-emitting layer 24REM Red light-emitting layer 24HT First charge transport layer 24ET Second charge transport layer 25 Upper electrode 26, 28 Inorganic sealing film 27 Organic film 39 Functional film QD Quantum dot MR Matrix PIX Pixel RSP Red sub-pixel GSP Green sub-pixel BSP Blue sub-pixel DA Display area NDA Frame area

Claims

1. An anode, a cathode, and a light-emitting layer provided between the anode and the cathode, wherein the light-emitting layer includes quantum dots, a matrix, and a matrix stabilizer including a molecular structure in which each of a first shielding group including a first cyclic compound and a second shielding group including a second cyclic compound is bonded to an element or a molecular structure in which the first shielding group and the second shielding group are bonded together. A light-emitting device.

2. The light-emitting device according to claim 1, wherein at least one of the first shielding group and the second shielding group is an unsaturated cyclic compound.

3. The light-emitting device according to claim 1 or 2, wherein at least one of the first shielding group and the second shielding group is an aromatic compound.

4. The matrix stabilizer includes a third shielding group including a third cyclic compound, and the matrix stabilizer includes a molecular structure in which each of the first shielding group, the second shielding group, and the third shielding group is bonded to the element or a molecular structure in which the first shielding group, the second shielding group, and the third shielding group are bonded together. The light-emitting device according to any one of claims 1 to 3.

5. The light-emitting device according to any one of claims 1 to 4, wherein the element is any one of carbon, nitrogen, and silicon.

6. The light-emitting device according to any one of claims 1 to 4, wherein the element is carbon or silicon.

7. The light-emitting device according to any one of claims 1 to 6, wherein the matrix includes an oxide containing a metal element or a metalloid element.

8. The light-emitting device according to claim 7, wherein the oxide is silicon oxide.

9. The light-emitting device according to any one of claims 1 to 8, wherein the matrix stabilizer is contained in the matrix.

10. The light-emitting device according to any one of claims 1 to 8, wherein the matrix stabilizer is bonded to the matrix.

11. The light-emitting device according to claim 3, wherein the matrix stabilizer includes a trityl skeleton.

12. The light-emitting device according to claim 11, wherein the matrix stabilizer includes a halogen element.

13. The light-emitting device according to any one of claims 1 to 12, wherein the light-emitting layer includes a halogen element.

14. The matrix contains an oxide containing a metal element or a metalloid element. When a group containing the trityl skeleton of the matrix stabilizer is X, the halogen element of the matrix stabilizer is Y, the oxide is W, the organic group is R, the sulfur element is S, the nitrogen element is N, the hydrogen element is H, the oxygen element is O, the carbon element is C, and the chemical bond is —, the matrix stabilizer exists in any one of the states of X—Y, X—S—R—W, X—NH—R—W, and X—OOC—R—W. The light-emitting element according to claim 12.

15. The matrix contains an oxide containing a metal element or a metalloid element. When a group containing the trityl skeleton of the matrix stabilizer is X, the oxide is W, the organic group is R, the sulfur element is S, the nitrogen element is N, the hydrogen element is H, the oxygen element is O, the carbon element is C, and the chemical bond is —, the matrix stabilizer exists in any one of the states of X—S—R—W, X—NH—R—W, and X—OOC—R—W. The light-emitting element according to claim 11.

16. The matrix contains an oxide containing a metal element or a metalloid element. The oxide is silicon oxide. When a group containing the trityl skeleton of the matrix stabilizer is X, the silicon element is Si, the organic group is R, the sulfur element is S, the nitrogen element is N, the hydrogen element is H, the oxygen element is O, the carbon element is C, and the chemical bond is —, the matrix stabilizer exists in any one of the states of X—S—R—Si—O—Si—, X—NH—R—Si—O—Si—, and X—OOC—R—Si—O—Si—. The light-emitting element according to claim 11.

17. A display device including the light-emitting element according to any one of claims 1 to 16.

18. A quantum dot dispersion including a quantum dot, a precursor for forming a matrix, a matrix stabilizer including a molecular structure in which each of a first shielding group including a first cyclic compound and a second shielding group including a second cyclic compound is bonded to an element, or a molecular structure in which the first shielding group and the second shielding group are bonded, and a solvent.

19. The quantum dot dispersion according to claim 18, wherein at least one of the first shielding group and the second shielding group is an unsaturated cyclic compound.

20. The quantum dot dispersion according to claim 18 or 19, wherein at least one of the first shielding group and the second shielding group is an aromatic compound.

21. The matrix stabilizer includes a third shielding group containing a third cyclic compound, and the matrix stabilizer includes a molecular structure in which each of the first shielding group, the second shielding group, and the third shielding group is bonded to a certain element, or a molecular structure in which the first shielding group, the second shielding group, and the third shielding group are bonded together. The quantum dot dispersion liquid according to any one of claims 18 to 20.

22. The certain element is any one of carbon, nitrogen, and silicon. The quantum dot dispersion liquid according to any one of claims 18 to 21.

23. The certain element is carbon or silicon. The quantum dot dispersion liquid according to any one of claims 18 to 21.

24. The matrix stabilizer includes a trityl skeleton, and the precursor for forming the matrix is at least one of a dialkoxysilane compound containing a coordinating functional group to the quantum dot and a trialkoxysilane compound containing a coordinating functional group to the quantum dot. The quantum dot dispersion liquid according to claim 20.

25. The matrix stabilizer includes a trityl skeleton, and the precursor for forming the matrix includes at least one of a dialkoxysilane compound containing a coordinating functional group to the quantum dot and a trialkoxysilane compound containing a coordinating functional group to the quantum dot, and one or more selected from a tetraalkoxysilane compound, a trialkoxysilane compound, a dialkoxysilane compound, and a monoalkoxysilane compound. The quantum dot dispersion liquid according to claim 20.

26. The alkoxy group contained in each of the dialkoxysilane compound containing a coordinating functional group to the quantum dot, the trialkoxysilane compound containing a coordinating functional group to the quantum dot, the tetraalkoxysilane compound, the trialkoxysilane compound, the dialkoxysilane compound, and the monoalkoxysilane compound is selected from a methoxy group, an ethoxy group, a propoxy group, and a butoxy group. The quantum dot dispersion liquid according to claim 25.

27. The dialkoxysilane compound containing a coordinating functional group to the quantum dot includes the coordinating functional group to the quantum dot, C ｎ H ２ｎ part (C is a carbon element, H is a hydrogen element, and n is a natural number of 1 or more), and a dialkoxysilane group. The trialkoxysilane compound containing a coordinating functional group to the quantum dot includes the coordinating functional group to the quantum dot, C ｎ H ２ｎ part (C is a carbon element, H is a hydrogen element, and n is a natural number of 1 or more), and a trialkoxysilane group. The quantum dot dispersion liquid according to any one of claims 24 to 26.

28. The n of the C in the dialkoxysilane compound containing a coordinating functional group to the quantum dot or the trialkoxysilane compound containing a coordinating functional group to the quantum dot ｎ H ２ｎ portion is 1 or more and 20 or less, and the quantum dot dispersion liquid according to claim 27.

29. The n of the C of the dialkoxysilane compound containing a coordinating functional group to the quantum dot or the trialkoxysilane compound containing a coordinating functional group to the quantum dot ｎ H ２ｎ in the portion is 3 or more and 18 or less. The quantum dot dispersion liquid according to claim 27.

30. The coordinating functional group to the quantum dot is any one of a thiol group, an amine group, a carboxylic acid group, and a phosphine group. The quantum dot dispersion liquid according to any one of claims 24 to 29.

31. When it contains X moles of an organic substance containing a coordinating functional group to the quantum dot, Y moles of a dialkoxysilane compound containing a coordinating functional group to the quantum dot, and Z moles of a trialkoxysilane compound containing a coordinating functional group to the quantum dot, ((Y + Z) / (X + Y + Z))×100% is 20% or more and 100% or less. The quantum dot dispersion liquid according to any one of claims 24 to 30.

32. When it contains X moles of an organic substance containing a coordinating functional group to the quantum dot, Y moles of a dialkoxysilane compound containing a coordinating functional group to the quantum dot, and Z moles of a trialkoxysilane compound containing a coordinating functional group to the quantum dot, ((Y + Z) / (X + Y + Z))×100% is 40% or more and 100% or less. The quantum dot dispersion liquid according to any one of claims 24 to 30.

33. The matrix stabilizer contains a halogen element. The quantum dot dispersion liquid according to any one of claims 18 to 32.

34. The matrix stabilizer is a halide containing a trityl skeleton. The quantum dot dispersion liquid according to any one of claims 24 to 32.

35. The matrix stabilizer is any one of Trityl Chloride, Trityl Bromide, 4-Methoxytrityl Chloride, 4,4‘-Dimethoxytrityl Chloride, 2-Chlorotrityl Chloride, 4,4‘,4‘‘-Tris(benzoyloxy)trityl Bromide, and Triphenylchlorosilane. The quantum dot dispersion liquid according to claim 34.

36. The precursor for forming the matrix is an organic material. The quantum dot dispersion liquid according to any one of claims 18 to 23.

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