WO2022157907A1 - 発光素子、表示デバイス、発光素子の製造方法 - Google Patents
発光素子、表示デバイス、発光素子の製造方法 Download PDFInfo
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- WO2022157907A1 WO2022157907A1 PCT/JP2021/002160 JP2021002160W WO2022157907A1 WO 2022157907 A1 WO2022157907 A1 WO 2022157907A1 JP 2021002160 W JP2021002160 W JP 2021002160W WO 2022157907 A1 WO2022157907 A1 WO 2022157907A1
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- layer
- light
- silicide
- emitting device
- emitting
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- 238000004519 manufacturing process Methods 0.000 title claims description 33
- 229910021332 silicide Inorganic materials 0.000 claims abstract description 312
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- RBTKNAXYKSUFRK-UHFFFAOYSA-N heliogen blue Chemical compound [Cu].[N-]1C2=C(C=CC=C3)C3=C1N=C([N-]1)C3=CC=CC=C3C1=NC([N-]1)=C(C=CC=C3)C3=C1N=C([N-]1)C3=CC=CC=C3C1=N2 RBTKNAXYKSUFRK-UHFFFAOYSA-N 0.000 description 1
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- WUAPFZMCVAUBPE-UHFFFAOYSA-N rhenium atom Chemical compound [Re] WUAPFZMCVAUBPE-UHFFFAOYSA-N 0.000 description 1
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- 150000003852 triazoles Chemical class 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
- 238000007740 vapor deposition Methods 0.000 description 1
Images
Classifications
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/14—Carrier transporting layers
- H10K50/15—Hole transporting layers
-
- H—ELECTRICITY
- H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
- H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- H05B33/00—Electroluminescent light sources
- H05B33/10—Apparatus or processes specially adapted to the manufacture of electroluminescent light sources
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/14—Carrier transporting layers
- H10K50/16—Electron transporting layers
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K2102/00—Constructional details relating to the organic devices covered by this subclass
- H10K2102/301—Details of OLEDs
- H10K2102/331—Nanoparticles used in non-emissive layers, e.g. in packaging layer
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
Definitions
- the present invention relates to a light-emitting element and a display device provided with the light-emitting element.
- Patent Document 1 discloses a light-emitting device having a light-emitting element containing semiconductor nanocrystals.
- the light-emitting device described in Patent Document 1 has a charge transport layer between the light-emitting layer and the electrode.
- a light-emitting element of the present disclosure includes a first electrode, a first charge transport layer, a silicide layer containing silicide, a light-emitting layer, and a second electrode arranged in this order. , the first charge transport layer and the light emitting layer are adjacent to each other with the silicide layer interposed therebetween.
- the method for manufacturing a light-emitting element of the present disclosure includes a first electrode, a first charge transport layer, a silicide layer containing silicide, a light-emitting layer, and a second electrode arranged in this order, 1.
- a silicide layer forming step of forming a silicide layer is included.
- another method for manufacturing a light-emitting device includes a first electrode, a first charge transport layer, a silicide layer containing silicide, a light-emitting layer, and a second electrode arranged in this order, A method for manufacturing a light-emitting device in which the first charge transport layer and the light-emitting layer are adjacent to each other through the silicide layer, wherein A silicide layer forming step of forming the silicide layer by heat treatment is included.
- FIG. 1 is a schematic plan view showing a display device according to Embodiment 1;
- FIG. 2 is an enlarged cross-sectional view showing a cross section of the display area of the display device according to Embodiment 1.
- FIG. 4 is a flow chart for explaining a method of manufacturing the display device according to Embodiment 1.
- FIG. 4 is an enlarged cross-sectional view showing an example of a cross-section of a layered body formed in a manufacturing process of a silicide layer according to Embodiment 1;
- FIG. 5 is a graph showing the relationship between the particle size of nanoparticles in a laminate and the melting point of the nanoparticles in the silicidation process according to Embodiment 1.
- FIG. 5 is a graph showing an example of element concentration distribution of a silicide layer according to Embodiment 1.
- FIG. 4 is an enlarged cross-sectional view showing another example of the cross section of the laminate formed in the manufacturing process of the silicide layer according to Embodiment 1;
- FIG. 5 is a graph showing another example of the element concentration distribution of the silicide layer according to Embodiment 1.
- FIG. FIG. 10 is an enlarged cross-sectional view showing a cross section of each layer of a light emitting device according to a comparative example;
- FIG. 4 is a schematic energy band diagram, a schematic charge distribution graph, and a schematic electric field graph of a hole-transport layer and a light-emitting layer for explaining a problem of a light-emitting element according to a comparative embodiment
- FIG. 1 is a schematic energy band diagram, a schematic charge distribution graph, and a schematic electric field graph of a hole transport layer, a silicide layer, and a light emitting layer, for explaining the effect of the light emitting device according to Embodiment 1; be.
- FIG. 10 is an enlarged cross-sectional view showing a cross-section of each layer of the light-emitting device according to Embodiment 2;
- FIG. 11 is an enlarged cross-sectional view showing a cross section of each layer of a light-emitting device according to Embodiment 3;
- FIG. 11 is an enlarged cross-sectional view showing a cross section of each layer of a light-emitting device according to Embodiment 4;
- FIG. 11 is an enlarged cross-sectional view showing a cross section of each layer of a light-emitting device according to Embodiment 5;
- FIG. 2 is a schematic plan view of the display device 1 according to this embodiment.
- FIG. 3 is a schematic cross-sectional view of the display device 1 according to this embodiment, and is a cross-sectional view taken along line A1-A1 in FIG.
- the display device 1 includes a display region DS including a plurality of sub-pixels, each sub-pixel having a light-emitting element (to be described later), and a frame region surrounding the display region DS. and NA.
- a terminal T to which a signal for driving each light emitting element in the display area DS is input may be formed in the frame area NA.
- the display device 1 includes a substrate 3 and light-emitting elements 2 positioned in each of a plurality of pixels on the substrate 3.
- the display device 1 according to this embodiment includes a plurality of light emitting elements 2 at positions overlapping the display area DS in plan view.
- the substrate 3 may be formed at a position overlapping both the display area DS and the frame area NA in plan view, and the terminals T may be formed on the substrate 3 .
- the direction from the substrate 3 of the display device 1 to the light emitting element 2 is described as "upward direction”, and the direction opposite to the "upward direction” is described as "downward direction”.
- a plan view of the display device 1 indicates a state in which the display device 1 is viewed from above in a substantially normal direction of the upper surface of the display area DS.
- the substrate 3 includes a support substrate Sub, a plurality of thin film transistors Tr, and a planarizing film F shown in FIG.
- the support substrate Sub may be, for example, a glass substrate, or, if the display device 1 is a rigid display device, a flexible support film such as a PET film.
- a plurality of thin film transistors Tr and a planarization film F are formed on a support substrate Sub.
- the thin film transistor Tr includes a gate electrode G, a passivation film Pas, and a channel layer C stacked in this order. Further, the thin film transistor Tr includes a source electrode S and a drain electrode D on the channel layer C and electrically connected through the channel layer C. As shown in FIG. 3, the thin film transistor Tr includes a gate electrode G, a passivation film Pas, and a channel layer C stacked in this order. Further, the thin film transistor Tr includes a source electrode S and a drain electrode D on the channel layer C and electrically connected through the channel layer C. As shown in FIG.
- Each drain electrode D is electrically connected to each pixel electrode of each light emitting element 2, which will be described later.
- the thin film transistor Tr controls the amount of current flowing from the source electrode S to the drain electrode D via the channel layer C.
- FIG. thereby, each of the thin film transistors Tr drives the light emission of each light emitting element 2 individually.
- the planarization film F is formed to reduce irregularities on the support substrate Sub caused by the thin film transistor Tr.
- the planarizing film F may be made of, for example, a resin containing polyimide.
- the light-emitting elements 2 are formed on the substrate 3 and each light-emitting element 2 is individually partitioned by banks B on the substrate 3 .
- the bank B may be made of the same material as the planarizing film F, for example, a resin containing polyimide.
- the light-emitting elements 2 and the banks B are further covered with a sealing layer for sealing each light-emitting element 2 and protecting it from foreign matter containing moisture, or the like.
- a capping layer or the like may be formed to improve the efficiency of light extraction.
- FIG. 1 is a schematic cross-sectional view showing an enlarged cross-section of a light-emitting element 2 and the periphery of the light-emitting element 2 according to the present embodiment, and an enlarged view of a region A2 indicated by a dotted line in FIG. Specifically, FIG. 1 shows an enlarged view of only a portion of each layer of the light emitting device 2 and a portion of the upper side of the substrate 3 .
- the light emitting device 2 includes, from the substrate 3 side, an anode 4 as a first electrode, a hole transport layer 6 as a first charge transport layer, a light emitting layer 8, and a An electron transport layer 10 and a cathode 12 as a second electrode are arranged in this order. Furthermore, the light-emitting device 2 according to this embodiment includes a silicide layer 14 between the hole-transporting layer 6 and the light-emitting layer 8 .
- the hole transport layer 6 and the light emitting layer 8 are adjacent to each other with the silicide layer 14 interposed therebetween.
- the two layers “adjacent” means a portion where the two layers are in contact with each other, or a thin film in which the two layers are thin enough to allow carriers to tunnel. indicates that there is at least one of the portions arranged through In other words, when two layers are "adjacent", it includes the case where the other layer exists between the two layers and the other layer does not exist between the two layers.
- two layers "adjacent to each other through a specific layer” indicates that each of the two layers and the specific layer are adjacent to each other.
- a thin film having such a thin film thickness that carriers can tunnel exists between the specific layer and each of the two layers. This includes when Further in other words, when two layers are "adjacent through a certain layer", another layer exists in part between the specific layer and each of the two layers, and the other part includes cases where the layer does not exist.
- the light emitting device 2 according to this embodiment includes the electron transport layer 10 as described above.
- the provision of the electron transport layer 10 in the light-emitting device 2 according to this embodiment is not essential for achieving at least one of the effects described below.
- the anode 4 of the light emitting element 2 is formed individually for each sub-pixel of the display device 1, for example. Also, the anode 4 is electrically connected to the drain electrode D of the thin film transistor Tr. Therefore, each light emitting element 2 is driven individually by controlling the voltage applied to each anode 4 by the thin film transistor Tr. Therefore, the anode 4 functions as a pixel electrode of the light emitting element 2 . As the light emitting element 2 is driven by the thin film transistor Tr, holes are injected from the anode 4 to the light emitting layer 8 side.
- the anode 4 includes a conductive member.
- the anode 4 may be, for example, a metal film made of a metal such as Al, Mg, Li, Ag, or an alloy of these metals.
- the anode 4 may have a single metal film, or may have a plurality of laminated metal films.
- the anode 4 may have a thin film of a conductive oxide such as ITO or IZO, or an oxide semiconductor such as an InGaZnO system.
- the cathode 12 is formed, for example, in common for a plurality of sub-pixels of the display device 1, and is applied with a constant voltage. Therefore, the light emitting element 2 is driven by the thin film transistor Tr, and a potential difference with the anode 4 is generated, whereby electrons are injected from the cathode 12 to the light emitting layer 8 side.
- Cathode 12 may comprise, for example, the material that anode 4 may comprise, or may comprise the same material as anode 4 .
- At least one of the anode 4 and the cathode 12 has translucency and transmits at least the light from the light emitting layer 8 .
- the light-emitting element 2 extracts light from the light-emitting layer 8 through at least one of the anode 4 and the cathode 12 having translucency.
- one of the anode 4 and the cathode 12 may reflect light from the light-emitting layer 8 . Thereby, the light extraction efficiency from the light emitting element 2 can be improved.
- the display device 1 when the anode 4 has translucency and the cathode 12 has light reflectivity, light from the light emitting element 2 is extracted from the substrate 3 side.
- the display device 1 allows the light from each light-emitting element 2 to It can be taken out from the substrate 3 side.
- the display device 1 functions as a bottom emission display device.
- the display device 1 when the anode 4 is light reflective and the cathode 12 is light transmissive, light from the light emitting element 2 is extracted from the opposite side of the substrate 3 .
- the display device 1 functions as a top emission type display device in which light from each light emitting element 2 is extracted from the side opposite to the substrate 3 .
- the display device 1 is preferably a top-emission display device.
- the charge transport layer is a layer having a function of transporting charges, in other words, at least one of electrons and holes, from each electrode to the light-emitting layer side.
- a charge transport layer primarily means at least one of an electron transport layer or a hole transport layer.
- charge transport layer may refer to at least one of an electron injection layer or a hole injection layer.
- a charge transport layer refers to an electron transport layer and an electron injection layer together, a hole transport layer and a hole injection layer together, or an electron transport layer, an electron injection layer, and a hole Sometimes the terms transport layer and hole injection layer are collectively referred to.
- the hole transport layer 6 is a layer having a function of transporting holes injected from the anode 4 to the light emitting layer 8 side.
- the hole transport layer 6 may contain an organic material, or may contain an inorganic material.
- the organic material may contain, for example, TFB or PVK.
- the hole transport layer 6 contains an inorganic material the inorganic material may contain NiO, MgNiO, Cr 2 O 3 , MoO 3 , WO 3 or the like.
- the hole transport layer 6 may contain a conventionally known material having a hole transport property.
- the electron transport layer 10 is a layer having a function of transporting electrons injected from the cathode 12 to the light emitting layer 8 side.
- the electron transport layer 10 may contain an organic material, or may contain an inorganic material.
- the organic material may contain, for example, an aluminum-quinolinolate complex-based compound or a triazole-based compound.
- the electron transport layer 10 may contain ZnO, MgZnO, or the like.
- the electron transport layer 10 may contain a conventionally known material having an electron transport property.
- a hole-injecting layer having a function of transporting holes injected from the anode 4 to the hole-transporting layer 6 is provided between the anode 4 and the hole-transporting layer 6.
- the light emitting device 2 may further include an electron injection layer having a function of transporting electrons injected from the cathode 12 to the electron transport layer 10 between the cathode 12 and the electron transport layer 10 .
- the hole-injection layer is made of molybdenum (Mo), tungsten (W), vanadium (V), ruthenium (Ru), rhenium (Re), or iridium (Ir). It may contain an oxide.
- the hole injection layer may comprise oxides of Group VIIIB (Groups 8, 9 and 10) metals including Nickel (Ni), Palladium (Pd), and the like.
- the hole injection layer may also include oxides of lanthanides, including lanthanum (La), cerium (Ce), neodymium (Nd), and the like.
- the hole injection layer may contain oxides of platinum (Pt), gold (Au) and silver (Ag).
- the hole injection layer may comprise mixtures of any composition of the above oxides.
- organic compounds containing polyethylenedioxythiophene polysulfonic acid (PEDOT:PSS), starburst amine, etc., or organometallic compounds containing copper phthalocyanine, etc. can be used for the hole injection layer.
- the light-emitting layer 8 is a layer containing a light-emitting material that emits light by electronic excitation due to recombination of carriers. For example, recombination of holes from the anode 4 and electrons from the cathode 12 in the light-emitting layer 8 produces excitons in the light-emitting layer 8 . The excitons then excite electrons of the light-emitting material to an excitation level. After that, when the excited electrons in the light-emitting material transition from the excited level to the ground level, the light-emitting layer 8 emits a wavelength corresponding to the energy difference between the excited level and the ground level. light is produced.
- the light-emitting material of the light-emitting layer 8 may contain an organic light-emitting material, or may contain an inorganic light-emitting material.
- the organic light-emitting material may be, for example, an organic light-emitting material used as a light-emitting material for an organic EL element, and conventionally known organic light-emitting materials can be employed.
- the inorganic light-emitting material may contain, for example, quantum dots that emit light by carrier injection, in other words, semiconductor nanoparticles. A luminescent material can be employed.
- the light emitted by the light-emitting layer 8 can be appropriately designed by changing the type of light-emitting material included in the light-emitting layer 8 and changing the wavelength of the light emitted from the light-emitting material.
- the display device 1 includes, as the light emitting elements 2, a red light emitting element having a light emitting layer 8 that emits red light, a green light emitting element having a light emitting layer 8 that emits green light, and a blue light emitting element having a light emitting layer 8 that emits blue light. and a light emitting element.
- the display device 1 forms one pixel with one red sub-pixel having a red light-emitting element, one green sub-pixel having a green light-emitting element, and one blue sub-pixel having a blue light-emitting element. You may thus, by arranging a plurality of the pixels in the display area DS, the display device 1 becomes a display device capable of color display.
- the silicide layer 14 is a layer containing a plurality of silicides 16 shown in FIG.
- the silicide 16 refers to a compound of a metal element and Si.
- at least one silicide 16 has a polarized electron cloud in its molecule, so that the silicide 16 has polarity.
- At least one of the silicides 16 having polarity is positioned so that the side where the intramolecular electron cloud is negatively biased faces the light-emitting layer 8 side.
- the direction of the dipole moment 16D of the silicide 16 is the direction from the light emitting layer 8 to the hole transport layer 6.
- the majority of the silicides 16 included in the silicide layer 14 have a dipole moment 16D in the direction from the light emitting layer 8 toward the hole transport layer 6. Therefore, the silicide layer 14 as a whole has a dipole moment in the direction from the light emitting layer 8 to the hole transport layer 6 .
- the direction of the dipole moment 16D of the silicide 16 is not limited to the direction along the stacking direction of each layer of the light emitting element 2 as shown in FIG. Specifically, in the present embodiment, the direction of the dipole moment 16D of the silicide 16 is slightly different from the direction perpendicular to the stacking direction of the layers of the light emitting element 2 from the light emitting layer 8 to the hole transport layer 6. Any direction will do. In other words, the direction of the dipole moment 16D of the silicide 16 may deviate from the lamination direction of the layers of the light emitting element 2 .
- a metal material that forms a compound with Si can be appropriately used as the metal material included in the silicide 16 .
- the molecular structure of the silicide 16 may have a structure expressed as MSi x , where M is a metal element and a real number x is used.
- the stoichiometry of silicide 16 may be MSi or MSi2 .
- the term "layer” or “film” in this specification does not necessarily mean that the whole has a uniform film shape.
- the “layer” or “film” containing the silicide 16 may have a discontinuous structure including discontinuities in part thereof, and a structure in which it can be confirmed that at least part of it has a thickness.
- the silicide layer 14 has a continuous structure. More preferably, the entire silicide layer 14 has a uniform film shape.
- FIG. 4 is a flow chart for explaining the manufacturing method of the display device 1 according to this embodiment.
- the substrate 3 is formed (step S2).
- the substrate 3 is formed, for example, by forming the thin film transistor Tr for each sub-pixel on the support substrate Sub, and then planarizing the substrate 3 by coating the planarizing film F.
- the thin film transistor Tr may be formed, for example, by alternately repeating film formation of each layer by a conventionally known method including CVD or sputtering, and patterning of each layer by photolithography or the like.
- the planarizing film F may be formed by applying a resin material such as polyimide by a conventionally known coating method such as an inkjet method or a spin coating method.
- an anode 4 is formed on the substrate 3 (step S4).
- the anode 4 may be formed by a conventionally known anode forming method. Specifically, for the anode 4, for example, a layer containing a conductive material is formed on the substrate 3 by a CVD method, a sputtering method, a vacuum deposition method, or the like, and then the conductive material is deposited by photolithography or the like.
- the containing layer may be formed by patterning it sub-pixel by sub-pixel.
- a bank B is formed between sub-pixels on the substrate 3 (step S6).
- the bank B may be formed by applying a resin material such as polyimide by a conventionally known coating method such as an inkjet method or a spin coating method, and patterning the resin material by photolithography or the like. good.
- the bank B may be formed at a position covering the peripheral edge of the anode 4 .
- the bank B is patterned so that at least a portion of the anode 4 closer to the center than the peripheral end of the anode 4 is exposed from the bank B in plan view of the display device 1 .
- the hole transport layer 6 may be formed by a conventionally known method for forming a hole transport layer. Specifically, the hole-transporting layer 6 is formed by, for example, depositing a material having a hole-transporting property on the sub-pixels by vacuum deposition using a metal mask having an opening for each sub-pixel. may Alternatively, the hole transport layer 6 may be formed by applying a material having a hole transport property and then patterning the material for each sub-pixel by photolithography, lift-off method, or the like.
- a silicide layer 14 is then formed.
- a method of forming the silicide layer 14 by heat-treating a laminate of metal and Si will be described as an example.
- reaction temperature required for heat treatment for silicidation of a metal is roughly proportional to the melting point of the metal, but compared to the melting point, the reaction temperature for silicidation is overwhelmingly low.
- reaction temperature for siliciding a metal is 1/2 or less of the eutectic temperature of the metal and Si. This is because the silicided state is significantly more stable than the constituent elements alone, so the heat of formation of silicide is negative, and the absolute value of the heat of formation is as high as several hundred kJ/mol.
- the reaction temperature for siliciding bulk Fe is 340°C
- the reaction temperature for siliciding bulk Ni is 250°C.
- the substrate 3, the anode 4, and the hole transport layer 6 below the silicide layer 14, which were previously formed, are included.
- step S10 metal nanoparticles and Si nanoparticles, which are materials for the silicide layer 14, are stacked on each hole transport layer 6 (step S10).
- FIG. 5 is a schematic cross-sectional view of the laminate 18A formed in step S10.
- FIG. 5 only the cross section of the laminate 18A is extracted and shown, but the lower side of the figure is the substrate 3 side of the display device 1. As shown in FIG. 5, only the cross section of the laminate 18A is extracted and shown, but the lower side of the figure is the substrate 3 side of the display device 1. As shown in FIG. 5, only the cross section of the laminate 18A is extracted and shown, but the lower side of the figure is the substrate 3 side of the display device 1. As shown in FIG.
- the laminate 18A is formed by stacking a metal nanoparticle layer 22 in which a plurality of metal nanoparticles 20 are arranged and a Si nanoparticle layer 26 in which a plurality of Si nanoparticles 24 are arranged so as to be in contact with each other.
- laminate 18A includes metal nanoparticle layer 22 on the hole transport layer 6 side.
- the metal nanoparticles 20 are metal nanoparticles contained in the silicide 16, and the Si nanoparticles 24 are Si nanoparticles.
- the metal nanoparticles 20 in the metal nanoparticle layer 22 and the Si nanoparticles 24 in the Si nanoparticle layer 26 do not have to be arranged in a regular manner, as shown in FIG.
- the metal nanoparticle layer 22 may be formed by applying a colloidal solution containing the metal nanoparticles 20 onto the hole transport layer 6 .
- the Si nanoparticle layer 26 may be formed by applying a colloidal solution containing the Si nanoparticles 24 onto the metal nanoparticle layer 22 after the metal nanoparticle layer 22 is formed.
- the colloidal solution is subjected to heat treatment, for example, by heating at 50° C. for 10 minutes, thereby forming the colloidal solution. may be volatilized.
- the metal nanoparticles 20 have a particle size R20 and the Si nanoparticles 24 have a particle size R24.
- the particle size R20 and the particle size R24 are preferably 50 nm or less, more preferably 20 nm or less, for reasons described later.
- the reaction temperature when nanoparticles are silicided depends on the melting point of the nanoparticles.
- the melting point of nanoparticles also depends on the particle size of the nanoparticles.
- FIG. 6 is a graph showing the relationship between the melting point of nanoparticles and the particle size of the nanoparticles.
- the horizontal axis represents the particle size of the nanoparticles
- the vertical axis represents the value obtained by dividing the melting point of the nanoparticles by the melting point when the element of the nanoparticles is bulk.
- the vertical axis takes the ratio of the melting point of the nanoparticles of the member to the melting point of the bulk member.
- the values on the vertical axis in FIG. 6 indicate the ratio between the melting point of various metal nanoparticles and the bulk melting point of the metal.
- the ratio depends on the particle size of the nanoparticles, regardless of the type of metal. Therefore, the relationship shown in FIG. 6 can be applied to all metals.
- the melting point of the nanoparticles does not change significantly regardless of the particle size.
- the particle size of the nanoparticles is 50 nm or less, it is clear that the smaller the particle size, the lower the melting point of the nanoparticles, compared to the bulk melting point.
- the melting point of the nanoparticles is about 50% or less of the melting point of the bulk, and when the particle size of the nanoparticles is 10 nm or less, the melting point of the nanoparticles is less than about 20 percent of the bulk melting point.
- the particle size R20 and the particle size R24 are 50 nm or less, the melting points of the metal nanoparticles 20 and the Si nanoparticles 24 can be lowered, and the metal nanoparticles 20 and the Si nanoparticles 24 are silicided.
- the reaction temperature required for the conversion can be lowered.
- the particle size R20 and the particle size R24 are 20 nm or less, the reaction temperature required for silicidation of the metal nanoparticles 20 and the Si nanoparticles 24 is further lowered, and damage to the structure below the laminate 18A is prevented. can be lowered sufficiently.
- step S10 the layered body 18A is heat-treated to silicidize the metal nanoparticles 20 and the Si nanoparticles 24 to form the silicide 16, thereby forming the silicide layer 14 (step S12).
- the silicide layer 14 including the silicide 16 is formed by subjecting the laminate 18A to heat treatment at about 100° C. for 30 minutes to 60 minutes. It is possible to form
- the metal nanoparticle layer 22 included in the laminate 18A is positioned closer to the hole transport layer 6 than the Si nanoparticle layer 26 in the step of heating the laminate 18A. Therefore, in step S12, silicidation of metal nanoparticles 20 progresses in a state where metal nanoparticles 20 are located in hole transport layer 6 more than Si nanoparticles 24 are. Therefore, the silicide layer 14 is formed so that the position of the metal element of each molecule of the silicide 16 is closer to the hole transport layer 6 than the position of the Si element.
- the graph of FIG. 7 is a graph showing an example of the relationship between the position in the thickness direction from the hole transport layer 6 and the concentration of the element at that position in the silicide layer 14 formed from the laminate 18A.
- the metal element is indicated by a solid line
- the Si element is indicated by a dotted line.
- the vertical axis represents the position of the silicide layer 14 in the thickness direction from the hole transport layer 6, and the vertical axis represents the concentration of each element at that position.
- the metal concentration in the silicide layer 14 is higher on the hole transport layer 6 side than on the light emitting layer 8 side, and gradually decreases from the hole transport layer 6 side toward the light emitting layer 8 side. ing.
- the Si concentration in the silicide layer 14 is lower on the hole transport layer 6 side than on the light emitting layer 8 side, and gradually increases from the hole transport layer 6 side toward the light emitting layer 8 side.
- Metal element contained in silicide Here, the types of metal elements contained in the silicide 16 of the silicide layer 14 will be described. The presence or absence of polarity of the silicide 16 and the direction of the dipole moment caused by the polarity change depending on the metal element contained in the silicide 16 . The relationship between the metal element contained in the silicide 16 and the direction of the dipole moment of the silicide 16 will be described with reference to Table 1 below.
- the "element” column indicates the type of each metal element.
- the group of each metal element in the periodic table is also shown according to the old CAS system.
- n and m indicating the number of electrons contained in the d orbital of the outermost shell of each metal element are natural numbers, for example, the d orbital in the outermost shell is the nd orbital.
- ndm is entered in the column of "d-orbital electron”.
- the “electronegativity” column shows the electronegativity of each metal element.
- the “melting point [°C]” column indicates the bulk melting point of each metal element in degrees Celsius.
- the column of "silicide” shows the stoichiometric composition that the silicide can have when each metal element is silicided to form the silicide.
- the column “Direction of Dipole Moment” indicates the direction of the dipole moment of the silicide containing each metal element when the silicide has polarity.
- M ⁇ Si is written in the column of "direction of dipole moment"
- the direction of the dipole moment of silicide is the direction from the metal element to the Si element.
- the direction of the dipole moment of silicide is the direction from the Si element to the metal element. If the silicide is a metal element that does not have polarity, the column of "direction of dipole moment" is blank.
- Table 1 shows the electronegativity of Si element and the melting point in the bulk state.
- the outermost shell of a single metal atom contains 5 or less d electrons
- the metal when the metal is silicided, all the d electrons in the outermost shell are accommodated in bonding orbitals, making it a good conductor and generating polarity. do not have.
- the outermost shell of one metal atom contains 6 or more d electrons
- the metal when the metal is silicided, some of the electrons contained in the outermost d electrons are accommodated in antibonding orbitals. .
- a bandgap is formed in the silicide containing electrons in the anti-bonding orbital, and the electron cloud is biased in the molecule, resulting in polarity.
- the direction of the dipole moment of silicide having polarity is determined by the difference in electronegativity between the metal element contained in the silicide and Si. Electronegativity corresponds to the degree to which an element attracts electrons, and elements with higher electronegativity tend to attract electrons. Therefore, in silicide of a metal element having lower electronegativity than Si, electrons in the molecule are attracted to Si rather than to the metal element, so the direction of the dipole moment is from Si to the metal element. On the other hand, in silicide of a metal element having a higher electronegativity than Si, electrons in the molecule are more attracted to the metal element than to Si, so the direction of the dipole moment is from the metal element to Si.
- the direction of the dipole moment 16D of the silicide 16 is the direction from the light emitting layer 8 to the hole transport layer 6.
- the layered product 18A subjected to the heat treatment in step S12 in the present embodiment contains the metal nanoparticles 20 closer to the hole transport layer 6 than the Si nanoparticles 24 are. Therefore, in the silicide 16 formed by heat-treating the laminate 18A, the metal concentration derived from the metal nanoparticles 20 is higher than the Si concentration derived from the Si nanoparticles 24 on the hole transport layer 6 side.
- the electronegativity of the metal element should be lower than that of the Si element. Therefore, referring to Table 1, at least one of Fe, Co, and Ni can be adopted as the metal element contained in the metal nanoparticle layer 22 of the laminate 18A. Ni has almost the same electronegativity as Si, and in particular, Ni has slightly higher electronegativity than Si. However, it is generally known that the direction of the dipole moment of Ni silicide is from Si to Ni.
- Fe, Co, or Ni has a low melting point compared to other VIIIB group (8, 9 and 10) metal elements. Therefore, when the metal element contained in the silicide layer 16 is Fe, Co, or Ni, the reaction temperature required for silicidation of the stacked body 18A is lowered, and damage to layers below the silicide layer 14 is reduced. preferable from this point of view. Further, it is preferable that the metal element contained in the silicide 16 is Fe, Co, or Ni from the viewpoint of cost reduction for forming the silicide layer 14 and from the viewpoint of environmental consideration.
- FIG. 8 is a schematic cross-sectional view of a laminate 18B, which is another example of the laminate formed in step S10. In FIG. 8, only the cross section of the laminate 18B is extracted and shown, but the lower side of the figure is the substrate 3 side of the display device 1. As shown in FIG.
- the laminate 18B includes a Si nanoparticle layer 26 on the hole transport layer 6 side of the metal nanoparticle layer 22 .
- Each of the metal nanoparticle layer 22 and the Si nanoparticle layer 26 included in the laminate 18B may have the same configuration as each of the metal nanoparticle layer 22 and the Si nanoparticle layer 26 included in the laminate 18A.
- the graph of FIG. 9 is a graph showing an example of the relationship between the position in the thickness direction from the hole transport layer 6 and the concentration of the element at that position in the silicide layer 14 formed from the laminate 18B.
- the metal element is indicated by a solid line and the Si element is indicated by a dotted line.
- the vertical axis represents the position of the silicide layer 14 in the thickness direction from the hole transport layer 6, and the vertical axis represents the concentration of each element at that position.
- the metal concentration in the silicide layer 14 is lower on the hole transport layer 6 side than on the light emitting layer 8 side, and gradually increases from the hole transport layer 6 side toward the light emitting layer 8 side. ing.
- the Si concentration in the silicide layer 14 is higher on the hole transport layer 6 side than on the light emitting layer 8 side, and gradually decreases from the hole transport layer 6 side toward the light emitting layer 8 side.
- the laminate 18B includes metal nanoparticles 20 closer to the hole transport layer 6 than the Si nanoparticles 24 are. Therefore, in the silicide 16 formed by heat-treating the laminate 18B in step S12, the metal concentration derived from the metal nanoparticles 20 is lower than the Si concentration derived from the Si nanoparticles 24 on the hole transport layer 6 side.
- the silicide 16 having the direction of the dipole moment 16D in the direction from the light emitting layer 8 to the hole transport layer 6 shown in FIG.
- the electronegativity of the metal element should be higher than the electronegativity of the Si element. Therefore, referring to Table 1, at least one of Ru, Os, Rh, Ir, Pd, or Pt can be adopted as the metal element contained in the metal nanoparticle layer 22 of the laminate 18B.
- the method of forming the silicide layer 14 is not limited to the method of sequentially executing steps S10 and S12 described above.
- the silicide layer 14 may be obtained by previously forming the silicide 16 in a separate process and forming a thin film of the silicide 16 on the hole transport layer 6 by sputtering using the silicide 16 as a material.
- the silicide layer 14 formed by the above method is a substantially non-polar layer as a whole regardless of the polarity of the silicide 16 .
- the silicide layer 14 is formed by a sputtering method using the silicide 16 as a material, the above-described heat treatment for silicidation of the metal nanoparticle layer 22 and the Si nanoparticle layer 26 is not required. Therefore, by adopting the above method, the process of forming the silicide layer 14 is simplified, and damage to layers below the silicide layer 14 due to the above heat treatment is reduced.
- the metal nanoparticles 20 included in the metal nanoparticle layer 22 formed in step S10 are the metal elements of Group IVB (group 4), Group VB (group 5), and Group VIB (group 6) shown in Table 1. It may be nanoparticles.
- the silicide 16 formed in step S12 is substantially non-polar, the silicide layer 14 including the silicide 16 is substantially non-polar as a whole.
- the laminate 18A or the laminate 18B in the present embodiment may include a SiO 2 nanoparticle layer containing a plurality of SiO 2 nanoparticles instead of the Si nanoparticle layer 26 .
- the heat treatment in step S 12 removes O from the SiO 2 nanoparticles, leaving only Si derived from the SiO 2 nanoparticles in the silicide 16 . Therefore, the silicide layer 14 described above can be obtained from the laminate of the SiO 2 nanoparticles and the metal nanoparticles by the same method as described above.
- the light emitting layer 8 is formed (step S14).
- the light-emitting layer 8 may be formed by conventionally known techniques including, for example, vapor deposition using a metal mask, photolithography using a photoresist, or a lift-off method.
- the step of forming the light-emitting layer 8 is performed for each light-emitting color of the light-emitting elements 2. It may be repeated while changing the material of 8.
- the electron transport layer 10 is formed (step S16).
- the electron transport layer 10 may be formed by the same method as the hole transport layer 6, except for the materials used.
- the cathode 12 is formed (step S18).
- the cathode 12 may be formed by the same method as the anode 4 except that it is formed in common for a plurality of sub-pixels. However, if a voltage can be applied to the cathode 12 for each sub-pixel, the cathode 12 may be formed individually for each light-emitting element 2 like the anode 4 .
- the light-emitting element 2 is formed, and the manufacturing process of the display device 1 is completed.
- a capping layer may be formed by sputtering or the like, or a sealing layer may be formed by CVD or coating.
- FIG. 10 is a schematic cross-sectional view of a light emitting device 2A according to a comparative embodiment, showing a cross section at a position corresponding to the schematic cross-sectional view of FIG.
- the light-emitting device 2A according to the comparative example has the same configuration as the light-emitting device 2 according to the present embodiment, except that the silicide layer 14 is not provided and the hole transport layer 6 and the light-emitting layer 8 are in direct contact with each other.
- the hole transport layer 6 and the light emitting layer 8 are in direct contact.
- an interface level is normally formed at the interface between the hole transport layer 6 and the light emitting layer 8 . Therefore, carrier traps occur at the interface between the hole transport layer 6 and the light emitting layer 8 of the light emitting device 2A according to the comparative embodiment. Holes transported from the anode 4 may be trapped in the carrier traps. As a result, in the light-emitting element 2A according to the comparative embodiment, the concentration of holes transported to the light-emitting layer 8 is reduced, and the carrier balance in the light-emitting layer 8 may deteriorate.
- the light emitting device has a silicide layer 14 between the hole transport layer 6 and the light emitting layer 8 .
- the silicide layer 14 is formed by heat-treating the metal nanoparticle layer 22 and the Si nanoparticle layer 26 at a low temperature to silicidize them. Therefore, the silicide 16 included in the silicide layer 14 has a stable level. Therefore, the silicide layer 14 containing the silicide 16 can inactivate the level generated at the interface with the hole transport layer 6 and the light emitting layer 8 which are in contact with each other.
- the silicide layer 14 when the silicide layer 14 is formed by sputtering using the silicide 16 as a material, the silicide layer 14 containing the silicide 16 densely and having a stable level can be obtained. Therefore, even when the silicide layer 14 is formed by a sputtering method using the silicide 16 as a material, the silicide layer 14 does not cause the level generated at the interface between the hole transport layer 6 and the light-emitting layer 8 that are in contact with each other. can be activated.
- the light emitting device 2 in the light emitting device 2 according to the present embodiment, carrier traps generated at the interface between the hole transport layer 6 and the silicide layer 14 and at the interface between the silicide layer 14 and the light emitting layer 8 are reduced. improve the efficiency of hole injection. Therefore, the light-emitting device 2 according to the present embodiment can improve the efficiency of carrier injection into the light-emitting layer 8, so that the light-emitting efficiency of the device as a whole can be improved.
- the display device 1 including a plurality of light-emitting elements 2 with improved luminous efficiency can perform display more efficiently with the light-emitting elements 2, thereby reducing power consumption.
- the display device 1 can perform high-luminance display while reducing the voltage applied to each light-emitting element 2 . Therefore, the display device 1 can reduce the shortening of the life of the light emitting element 2 due to driving the light emitting element 2 at a high voltage.
- the silicide layer 14 When the silicide layer 14 is formed by heat-treating the metal nanoparticle layer 22 and the Si nanoparticle layer 26, the metal nanoparticle layer 22 and the Si nanoparticle layer 26 may be substantially completely silicided. In this case, the silicide layer 14 becomes a continuous film of the silicide 16 . Thereby, the silicide layer 14 efficiently reduces direct contact between the hole transport layer 6 and the light emitting layer 8 without the silicide 16 interposed therebetween. Therefore, the silicide layer 14, which is a continuous film of the silicide 16, efficiently reduces carrier traps formed between the hole transport layer 6 and the light emitting layer 8. FIG.
- the silicide layer 14 when the silicide layer 14 is formed by sputtering the silicide 16, the silicide layer 14 may contain the silicide 16 having a columnar structure or a granular structure.
- the silicide layer 14 is formed by sputtering the silicide 16
- the energy of the silicide 16 flying onto the hole transport layer 6 is large, even after the silicide 16 reaches the hole transport layer 6, the silicide 16 is moves relatively long on the hole transport layer 6 .
- the longer the silicide 16 travels on the hole transport layer 6 the more stable the silicide 16 will be incorporated on the hole transport layer 6 .
- the silicide 16 moves over the hole transport layer 6 for a long time, the silicide 16 is preferentially incorporated into defects of the silicide layer 14 during film formation.
- the silicide layer 14 formed under the condition that the energy of the silicide 16 flying onto the hole transport layer 6 is large includes the silicide 16 having a columnar structure or a granular structure. Therefore, the silicide layer 14 including the silicide 16 having a columnar structure or a granular structure becomes a dense film with reduced defects. Therefore, the silicide layer 14 comprising the columnar or granular silicide 16 improves the efficiency of transporting holes from the hole-transporting layer 6 to the light-emitting layer 8 due to the reduction of defects that can cause carrier trapping. .
- the specific structure of the silicide 16 of the silicide layer 14, the presence or absence of polarity, and the direction of the dipole moment 16D are determined by, for example, the CBED method (convergent electron diffraction method), and the electron beam transmitted through the silicide layer 14 is diffracted. It can be verified by obtaining an image.
- the CBED method is one of modes of transmission electron microscopes in which an electron beam is focused on a sample to obtain a diffraction image.
- the diffraction image of the electron beam is modulated depending on the electron density distribution of the silicide layer 14 . Therefore, the diffraction image has a contrast corresponding to the electron density of the silicide layer 14 .
- the electron density distribution corresponding to the dipole moment of the silicide layer 14 can be known.
- a diffraction image of a transmitted electron beam obtained by the CBED method has a resolution corresponding to the lattice length of silicide molecules. Therefore, a cross-sectional image of the silicide layer 14 can be obtained by the CBED method.
- An energy band diagram 111 in FIG. 11 is a diagram showing a schematic energy band state of the hole transport layer 6 and the light emitting layer 8 of the light emitting device 2A according to the comparative embodiment.
- the hole-transporting layer 6 and the light-emitting layer 8 are in contact with each other. Therefore, as shown in the energy band diagram 111, the energy bands of the hole-transporting layer 6 and the light-emitting layer 8 are curved so that the Fermi levels f of the hole-transporting layer 6 and the light-emitting layer 8 match. occur.
- the bending of the energy band is caused by movement of carriers contained in the hole-transporting layer 6 and the light-emitting layer 8 .
- electrons move to the vicinity of the interface with the light-emitting layer 8
- holes move to the vicinity of the interface with the hole-transporting layer 6 .
- Graph 112 and graph 113 in FIG. is as shown in Graph 112 is a graph showing a schematic charge distribution in the hole transport layer 6 and the light emitting layer 8 according to the comparative form, and graph 113 is a schematic electric field generated in the hole transport layer 6 and the light emitting layer 8 according to the comparative form. is a graph showing the intensity of
- the horizontal axis represents the position in the thickness direction of each layer of the light emitting element 2 from the anode 4 side.
- the vertical axis of the graph 112 indicates the amount of electric charge at the position, which is positive when holes are distributed and negative when electrons are distributed.
- the vertical axis represents the intensity of the electric field generated at the relevant position, and the direction from the light-emitting layer 8 to the hole transport layer 6 is positive.
- Each position on the horizontal axis of graphs 112 and 113 corresponds to each position shown in energy band diagram 111 .
- the total amount of electron charges that have moved to the vicinity of the interface with the light-emitting layer 8 in the hole-transporting layer 6 and the amount of electrons that have moved to the vicinity of the interface with the hole-transporting layer 6 in the light-emitting layer 8 substantially coincides with the total amount of charge of .
- the spread of the hole distribution in the light emitting layer 8 from the interface with the hole transport layer 6 is wider than the spread of the electron distribution in the hole transport layer 6 from the interface with the light emitting layer 8 . This is because the carrier density of the hole transport layer 6 is higher than that of the light emitting layer 8 and the light emitting layer 8 is close to intrinsic.
- the electric field strength in the direction from the hole transport layer 6 to the light emitting layer 8 generated near the interface with the light emitting layer 8 in the hole transport layer 6 increases. Accordingly, as shown in the energy band diagram 111, the bandgap at the interface between the hole transport layer 6 and the light-emitting layer 8 is greatly curved toward the low energy value side.
- the barrier for hole injection from the hole-transporting layer 6 to the light-emitting layer 8 at the interface between the hole-transporting layer 6 and the light-emitting layer 8 is increased. Therefore, in the light-emitting element 2A according to the comparative embodiment, the efficiency of hole injection into the light-emitting layer 8 is lowered, and the concentration of holes in the light-emitting layer 8 is lowered. This leads to a decrease in luminous efficiency of the light emitting element 2A.
- the energy band diagram 121 in FIG. 12 is a diagram showing the schematic energy band states of the hole transport layer 6 and the light emitting layer 8 of the light emitting device 2 according to this embodiment.
- a graph 122 is a graph showing schematic charge distributions in the hole transport layer 6, the silicide layer 14, and the light emitting layer 8 according to this embodiment.
- a graph 123 is a graph showing roughly the intensity of the electric field generated in the hole transport layer 6, the silicide layer 14, and the light emitting layer 8 according to this embodiment.
- the silicide layer 14 exists between the hole transport layer 6 and the light emitting layer 8 . Therefore, the energy band diagram 121, the graph 122, and the graph 123 show a space corresponding to the silicide layer 14 between the hole transport layer 6 and the light emitting layer 8 for convenience of explanation. Also, the definition of each axis in each of graphs 122 and 123 corresponds to the definition of each axis in each of graphs 112 and 113 .
- the silicide 16 included in the silicide layer 14 is formed so that the dipole moment 16D of the silicide 16 is directed from the light-emitting layer 8 to the hole transport layer 6 . Therefore, the silicide 16 is formed so that the side on which the electron cloud is positively biased is on the hole transport layer 6 side, and the side on which the electron cloud is negatively biased is on the light emitting layer 8 side.
- the electric field strength in the direction from the hole-transport layer 6 to the light-emitting layer 8 generated near the interface with the light-emitting layer 8 in the hole-transport layer 6 is lower than that of the comparative embodiment. lower than Therefore, as shown in the energy band diagram 121, the bending of the bandgap of the hole transport layer 6 at the interface with the light emitting layer 8 to the low energy side is also reduced compared to the comparative example. As a result, in the above structure, the barrier for hole injection from the hole transport layer 6 to the light emitting layer 8 is lowered.
- the barrier for hole injection from the hole-transporting layer 6 to the light-emitting layer 8 at the interface between the hole-transporting layer 6 and the light-emitting layer 8 is lowered. Therefore, in the light-emitting element 2 according to this embodiment, the efficiency of hole injection into the light-emitting layer 8 is improved, the concentration of holes in the light-emitting layer 8 is increased, and the light-emitting efficiency of the light-emitting element 2 is improved.
- the silicide 16 of a part of the silicide layer 14 has polarity
- the direction of the polarity of the silicide 16 may not be controlled and the direction may be determined at random.
- the silicide 16 is aligned by spontaneous polarization.
- the effect of improving the efficiency of hole injection into the light emitting layer 8 is obtained when the light emitting element 2 is driven at a high voltage. can get.
- the light-emitting element 2 having the silicide layer 14 in which a portion of the silicide 16 has polarity improves the luminous efficiency during high-luminance driving.
- the molecular structure of the silicide 16 has a structure expressed as MSi x , where M is a metal element and a real number x is used as described above, and the stoichiometric composition of the silicide 16 is MSi, 0.8 ⁇ x ⁇ 1.2 may be satisfied.
- the stoichiometric composition of the silicide 16 is MSi2
- 1.6 ⁇ x ⁇ 2.4 may be satisfied.
- the amount of an element contained in the molecules of the silicide 16 exceeds ⁇ 20% of the stoichiometric composition, the conductivity due to the metal and Si contained in the silicide 16 is affected, and the silicide 16 having no polarity is formed. Sometimes. Therefore, the formation of non-polar silicide 16 can be reduced when the value of x is in the range described above.
- the film thickness of the silicide layer 14 may be 20 nm or less. This reduces the increase in electrical resistance of the entire light emitting element 2 . Furthermore, when the silicide 16 of the silicide layer 14 is non-polar, the thickness of the silicide layer 14 may be 5 nm or less. In this case, even if the polarity of the silicide 16 of the silicide layer 14 does not reduce the barrier for injection of carriers into the light-emitting layer 8, carriers can efficiently pass through the silicide layer 14 due to the tunnel effect.
- the metal concentration and Si concentration in the silicide layer 14 may differ depending on the position in the film thickness direction.
- the direction of the dipole moment 16D of the silicide 16 can be controlled more efficiently by appropriately designing the metal concentration and Si concentration at each position.
- FIG. 13 is a schematic cross-sectional view showing an enlarged cross-section of the light-emitting element 2 and the surroundings of the light-emitting element 2 according to this embodiment, and is a cross-sectional view at a position corresponding to the cross-section shown in FIG.
- members having the same function are given the same name and reference numerals, and the same description will not be repeated unless there is a difference in configuration.
- the display device 1 according to this embodiment differs from the display device 1 according to the previous embodiment in the direction of the dipole moment 16D of the silicide 16 included in the silicide layer 14 of the light emitting element 2 .
- at least one of the silicides 16 having polarity is positioned so that the side where the intramolecular electron cloud is negatively biased faces the hole transport layer 6 side.
- the direction of the dipole moment 16D of the silicide 16 is the direction from the hole transport layer 6 to the light emitting layer 8.
- the majority of the silicides 16 included in the silicide layer 14 have a dipole moment 16D in the direction from the hole-transporting layer 6 toward the light-emitting layer 8. Therefore, the silicide layer 14 as a whole has a dipole moment in the direction from the hole-transporting layer 6 toward the light-emitting layer 8 .
- the display device 1 according to this embodiment has the same configuration as the display device 1 according to the previous embodiment.
- the display device 1 according to this embodiment is manufactured by the same manufacturing method as the manufacturing method of the display device 1 according to the previous embodiment.
- the metal nanoparticles 20 are, for example, group IVB (group 4), group VB (group 5), and group VIB (group 6) in Table 1. ) metal elements.
- the metal nanoparticles 20 are selected from, for example, group VIIIB (groups 8, 9 and 10) metal elements in Table 2.
- the silicide layer 14 having the silicide 16 having the dipole moment 16D in the direction from the hole transport layer 6 to the light emitting layer 8 can be formed by the same method as the method for forming the silicide layer 14 in the previous embodiment.
- the light-emitting device 2 since the level of the silicide 16 of the silicide layer 14 is stable, the light-emitting device 2 according to the present embodiment has the interface between the hole transport layer 6 and the silicide layer 14 and the silicide layer 14 and the light-emitting layer 8 to reduce carrier traps generated at the interface. Therefore, the light-emitting device 2 according to this embodiment can improve the efficiency of hole injection into the light-emitting layer 8 and improve the luminous efficiency of the device as a whole.
- the dipole moment 16D of the silicide 16 is in the direction from the hole transport layer 6 to the light-emitting layer 8. Therefore, due to the circumstances described with reference to FIG. 12 in the previous embodiment, in the light-emitting device 2 according to this embodiment, the barrier for hole injection from the hole transport layer 6 to the light-emitting layer 8 is increased.
- the efficiency of electron transport from the cathode 12 to the light-emitting layer 8 may be low, the concentration of holes in the light-emitting layer 8 may be high, and the carrier balance in the light-emitting layer 8 may be disturbed.
- the hole injection barrier from the hole transport layer 6 to the light-emitting layer 8 is increased, so that the hole concentration in the light-emitting layer 8 is lowered, and the balance with the electron concentration is improved. Therefore, the light-emitting element 2 according to this embodiment reduces the excess of holes in the light-emitting layer 8 and improves the carrier balance, thereby improving the light-emitting efficiency.
- the metal nanoparticle layer 22 and the Si nanoparticle layer 26 are only partially silicided. may have been
- the metal nanoparticle layer 22 and the Si nanoparticle layer 26 may be silicided at positions in contact with at least one of the light emitting layer 8 and the electron transport layer 10 .
- the silicide layer 14 includes an aggregate structure of nanoparticles of silicide 16 in contact with at least one of the light emitting layer 8 and the electron transport layer 10 .
- the silicide layer 14 can cover at least one surface of the light-emitting layer 8 or the electron transport layer 10 with the nanoparticles of the silicide 16 without gaps.
- electrical contact between the nanoparticles of the silicide 16 becomes point contact, and the transport rate of electrons between the silicides 16 decreases. Therefore, since the silicide layer 14 having the above structure reduces the efficiency of electron transport between the silicide layers 16, the excess holes in the light-emitting layer 8 can be reduced more efficiently.
- FIG. 14 is a schematic cross-sectional view showing an enlarged cross-section of the light-emitting element 2 according to this embodiment and the periphery of the light-emitting element 2, and is a cross-sectional view at a position corresponding to the cross-section shown in FIG.
- the display device 1 according to the present embodiment differs from the display device 1 according to the first embodiment in the formation position of the silicide layer 14 among the layers of the light emitting element 2 .
- the light-emitting device 2 according to this embodiment is formed between the light-emitting layer 8 and the electron transport layer 10 .
- the light emitting layer 8 and the electron transport layer 10 are adjacent to each other with the silicide layer 14 interposed therebetween.
- the direction of the dipole moment 16D of the silicide 16 included in the silicide layer 14 is the direction from the electron transport layer 10 toward the light emitting layer 8.
- the display device 1 according to this embodiment has the same configuration as the display device 1 according to the first embodiment.
- the method for manufacturing the display device 1 according to the present embodiment executes step S8 and then step S14, and after step S14, step S10 and step S12. The difference is that it executes Therefore, in step S14, the light-emitting layer 8 is formed on the hole transport layer 6, and in step S10, the layered body 18A or the layered body 18B is formed on the light-emitting layer 8.
- step S14 the light-emitting layer 8 is formed on the hole transport layer 6, and in step S10, the layered body 18A or the layered body 18B is formed on the light-emitting layer 8.
- the manufacturing method of the display device 1 according to this embodiment is manufactured by the same manufacturing method as the manufacturing method of the display device 1 according to the first embodiment.
- the light-emitting device 2 includes a silicide layer 14 containing a silicide 16 with a stable level between the light-emitting layer 8 and the electron transport layer 10 . Therefore, the light emitting device 2 according to this embodiment reduces carrier traps generated at the interface between the light emitting layer 8 and the silicide layer 14 and at the interface between the silicide layer 14 and the electron transport layer 10 .
- the efficiency of electron transport from the cathode 12 to the light-emitting layer 8 may be low, the concentration of electrons in the light-emitting layer 8 may be low, and the carrier balance in the light-emitting layer 8 may be lost.
- the silicide layer 14 according to the present embodiment reduces carrier traps generated from the electron transport layer 10 to the light emitting layer 8, and improves the efficiency of electron transport from the electron transport layer 10 to the light emitting layer 8. do. Therefore, the light-emitting device 2 according to this embodiment can improve the efficiency of electron injection into the light-emitting layer 8 and improve the luminous efficiency of the device as a whole.
- the direction of the dipole moment 16D of the silicide 16 included in the silicide layer 14 is the direction from the electron transport layer 10 toward the light emitting layer 8. Therefore, in the light-emitting device 2 according to the present embodiment, the barrier for electron injection from the electron-transporting layer 10 to the light-emitting layer 8 is lowered due to the circumstances described with reference to FIG. 12 in the first embodiment. Therefore, in the light-emitting device 2 according to this embodiment, the efficiency of electron injection into the light-emitting layer 8 is improved, the concentration of electrons in the light-emitting layer 8 is increased, and the light-emitting efficiency of the light-emitting device 2 is improved.
- FIG. 15 is a schematic cross-sectional view showing an enlarged cross-section of the light-emitting element 2 and the surroundings of the light-emitting element 2 according to this embodiment, and is a cross-sectional view at a position corresponding to the cross-section shown in FIG.
- the display device 1 according to the present embodiment differs from the display device 1 according to the first embodiment in the formation position of each layer of the light emitting element 2 .
- the light-emitting element 2 according to this embodiment includes, from the substrate 3 side, the cathode 12, the electron transport layer 10, the silicide layer 14, the light-emitting layer 8, the hole transport layer 6, and the anode 4 in this order. Place and include. Therefore, in this embodiment, the light emitting layer 8 and the electron transport layer 10 are adjacent to each other with the silicide layer 14 interposed therebetween.
- the cathode 12 is a pixel electrode formed for each light emitting element 2 and electrically connected to each thin film transistor Tr, and the anode 4 is a common electrode formed commonly to the plurality of light emitting elements 2. is. Therefore, in this embodiment, each light emitting element 2 can be driven by controlling the voltage applied to each cathode 12 by the thin film transistor Tr. Further, in the present embodiment, the direction of the dipole moment 16D of the silicide 16 included in the silicide layer 14 is the direction from the light emitting layer 8 toward the electron transport layer 10. FIG.
- the display device 1 according to this embodiment has the same configuration as the display device 1 according to the first embodiment.
- the manufacturing method of the display device 1 according to the present embodiment can be manufactured by the same method except for the execution order of each step in the manufacturing method of the display device 1 according to the first embodiment. Specifically, in the method for manufacturing the light emitting device 2 according to the present embodiment, steps S2, S18, S6, S16, S10, S12, S14, S8, and S4 are executed in order of steps shown in FIG. .
- step S18 is executed by forming the cathode 12 in an island shape for each sub-pixel by the same method as step S4 in the first embodiment. Further, step S4 is performed by forming the anode 4 in common for a plurality of sub-pixels by the same method as step S18 in the first embodiment.
- the light-emitting device 2 according to this embodiment includes a silicide layer 14 containing a silicide 16 with a stable level between the light-emitting layer 8 and the electron transport layer 10, as in the light-emitting device 2 according to the previous embodiment. ing. For this reason, the light-emitting device 2 according to this embodiment can improve the efficiency of electron injection into the light-emitting layer 8 for the same reason as described in the previous embodiment, and can improve the luminous efficiency of the device as a whole.
- the dipole moment 16D of the silicide 16 is in the direction from the light-emitting layer 8 to the electron transport layer 10. For this reason, due to the circumstances described with reference to FIG. 12 in Embodiment 1, in the light-emitting device 2 according to this embodiment, the barrier for electron injection from the electron-transporting layer 10 to the light-emitting layer 8 is increased.
- the silicide layer 14 increases the barrier for electron injection from the electron-transporting layer 10 to the light-emitting layer 8, thereby reducing the concentration of electrons in the light-emitting layer 8 and the concentration of holes. Improves balance with Therefore, the light-emitting device 2 according to this embodiment reduces excess electrons in the light-emitting layer 8 and improves carrier balance, thereby improving light-emitting efficiency.
- FIG. 16 is a schematic cross-sectional view showing an enlarged cross-section of the light-emitting element 2 and the surroundings of the light-emitting element 2 according to this embodiment, and is a cross-sectional view at a position corresponding to the cross-section shown in FIG.
- the light-emitting element 2 further includes a silicide layer 28 between the light-emitting layer 8 and the electron transport layer 10, as compared with the display device 1 according to the first embodiment.
- Silicide layer 28 has the same structure as silicide layer 14 .
- silicide layer 28 includes a plurality of silicides 30 .
- the silicide 30 has the same configuration as the silicide 16, and at least a portion of the silicide 30 has polarity and a dipole moment 30D in the direction from the light emitting layer 8 to the electron transport layer 10.
- the display device 1 according to this embodiment has the same configuration as the display device 1 according to the first embodiment.
- the display device 1 according to this embodiment is the same as the method for manufacturing the display device 1 according to the previous embodiment except that a step of forming a silicide layer 28 is included between steps S14 and S16. Manufactured by the method of Silicide layer 28 is formed in any manner with silicide layer 14 .
- the light-emitting device 2 includes a silicide layer 14 containing a silicide 16 with a stable level between the hole-transporting layer 6 and the light-emitting layer 8 .
- the light-emitting device 2 according to this embodiment includes a silicide layer 28 containing a silicide 30 with a stable level between the light-emitting layer 8 and the electron transport layer 10 .
- the light-emitting device 2 according to this embodiment can improve the efficiency of both hole injection and electron injection into the light-emitting layer 8, and can improve the luminous efficiency of the device as a whole.
- the dipole moment 16D of the silicide 16 is in the direction from the hole transport layer 6 toward the light emitting layer 8, and the dipole moment 30D of the silicide 30 is in the direction from the light emitting layer 8 to the electron transport layer 10. It is the direction to go. Therefore, in the present embodiment, the barrier for hole injection from the hole transport layer 6 to the light emitting layer 8 is lowered and the barrier for electron injection from the electron transport layer 10 to the light emitting layer 8 is increased. Therefore, the light-emitting element 2 according to this embodiment improves the concentration of holes in the light-emitting layer 8 and reduces the concentration of electrons in the light-emitting layer 8 .
- the light-emitting device 2 more efficiently reduces the excess of electrons in the light-emitting layer 8, improves the carrier balance in the light-emitting layer 8, and improves the luminous efficiency of the light-emitting device 2 as a whole.
- the present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.
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Abstract
Description
<表示デバイスの概要>
図2は、本実施形態に係る表示デバイス1の概略平面図である。図3は、本実施形態に係る表示デバイス1の概略断面図であり、図2における、A1-A1線矢視断面図である。
本実施形態に係る発光素子2について、図1を参照し、より詳細に説明する。図1は、本実施形態に係る発光素子2および当該発光素子2の周囲の断面を拡大して示す概略断面図であり、図3に点線にて示す領域A2について拡大して示す図である。具体的に、図1は、発光素子2の各層の一部分、および、基板3の上部側の一部分のみを拡大して示す。
本実施形態に係る発光素子2のアノード4は、例えば、表示デバイス1のサブ画素ごとに、個別に形成される。また、アノード4は、薄膜トランジスタTrのドレイン電極Dと電気的に接続する。このため、薄膜トランジスタTrによって、各アノード4に印加される電圧が制御されることにより、各発光素子2が個別に駆動される。このため、アノード4は、発光素子2の画素電極として機能する。発光素子2が薄膜トランジスタTrによって駆動されることにより、アノード4からは、発光層8側に、正孔が注入される。
本明細書において、電荷輸送層とは、電荷、換言すれば、電子または正孔の少なくとも一方を、各電極から発光層側に輸送する機能を有する層である。電荷輸送層は、主に、電子輸送層または正孔輸送層の少なくとも一方を意味する。加えて、電荷輸送層は、電子注入層または正孔注入層の少なくとも一方を意味していてもよい。例えば、本明細書において、電荷輸送層は、電子輸送層と電子注入層とをまとめて、正孔輸送層と正孔注入層とをまとめて、または、電子輸送層と電子注入層と正孔輸送層と正孔注入層とをまとめて意味することがある。
発光層8は、キャリアの再結合による電子励起により発光する発光材料を備えた層である。例えば、発光層8において、アノード4からの正孔と、カソード12からの電子とが再結合することにより、発光層8に励起子が生成される。次いで、当該励起子により、発光材料の電子が励起準位まで励起される。この後、当該発光材料中の、励起された電子が、励起準位から基底準位に遷移する際に、発光層8から、励起準位と基底準位とのエネルギー差に相当する波長を有した光が生じる。
シリサイド層14は、図1に示す、シリサイド16を複数含む層である。本実施形態において、シリサイド16は、金属元素とSiとの化合物を指す。特に本実施形態においては、少なくとも一つのシリサイド16が、分子内に電子雲の偏りを有するために、当該シリサイド16は、極性を有している。
本実施形態に係る表示デバイス1の製造方法について、図4を参照して説明する。図4は、本実施形態に係る表示デバイス1の製造方法について説明するためのフローチャートである。
次いで、シリサイド層14を形成する。本実施形態においては、金属とSiとの積層体に対する熱処理により、シリサイド層14を形成する手法を例に挙げて説明する。
そこで、本実施形態においては、金属とSiとのナノ粒子が、バルクの状態と比較して、その融点が低下することを利用する。シリサイド層14の形成工程においては、はじめに、各正孔輸送層6上に、シリサイド層14の材料となる、金属ナノ粒子とSiナノ粒子とを積層する(ステップS10)。
図5に示すように、金属ナノ粒子20は、粒径R20を有し、Siナノ粒子24は、粒径R24を有する。ここで、粒径R20および粒径R24は、後述する理由から、50nm以下であることが好ましく、20nm以下であることがさらに好ましい。
ステップS10に次いで、積層体18Aに対し熱処理を行い、金属ナノ粒子20とSiナノ粒子24とをシリサイド化して、シリサイド16を形成することにより、シリサイド層14を形成する(ステップS12)。ここで、例えば、粒径R20および粒径R24が、25nm以下である場合、積層体18Aに対し、100℃程度にて30分から60分の熱処理を行うことにより、シリサイド16を含むシリサイド層14を形成することが可能である。
ここで、シリサイド層14のシリサイド16が含む金属元素の種類について説明する。シリサイド16が含む金属元素によって、シリサイド16の極性の有無、および当該極性により生じる双極子モーメントの方向は変化する。シリサイド16が含む金属元素と、当該シリサイド16の双極子モーメントの方向との関係について、以下の表1を参照して説明を行う。
なお、ステップS10において形成される積層体の構成は、図5に示す積層体18Aの構成に限定されない。ステップS10において形成される積層体の他の構成の例を、図8を参照して説明する。図8は、ステップS10により形成される積層体の他の例である、積層体18Bの概略断面図である。図8においては、積層体18Bの断面のみを抜き出して示しているが、図に向かって下側を、表示デバイス1の基板3側としている。
本実施形態において、シリサイド層14を形成する方法は、上述したステップS10およびステップS12を順に実行する手法に限られない。例えば、シリサイド層14は、予めシリサイド16を別工程において形成し、当該シリサイド16を材料としたスパッタ法により、正孔輸送層6上にシリサイド16の薄膜を形成することにより得られてもよい。
シリサイド層14の形成に次いで、発光層8を形成する(ステップS14)。発光層8は、例えば、メタルマスクを用いた蒸着法、フォトレジストを用いたフォトリソグラフィ、あるいは、リフトオフ法等を含む、従来公知の手法により形成されてもよい。表示デバイス1が、互いに発光色が異なる発光素子2を備える場合、発光素子2の発光色ごとに、発光層8の形成工程を、発光色ごとに、当該発光層8の形成位置と、発光層8の材料とを変更しつつ、繰り返し実行してもよい。
本実施形態に係る発光素子が奏する効果を、比較形態に係る発光素子と比較することにより説明する。図10は、比較形態に係る発光素子2Aの概略断面図であり、図1の概略断面図と対応する位置における断面を示す。比較形態に係る発光素子2Aは、本実施形態に係る発光素子2と比較して、シリサイド層14を備えず、正孔輸送層6と発光層8とが直接接する点を除き、同一の構成を備える。
シリサイド層14が、金属ナノ粒子層22とSiナノ粒子層26との熱処理により形成する場合、金属ナノ粒子層22とSiナノ粒子層26とは、略完全にシリサイド化されていてもよい。この場合、シリサイド層14は、シリサイド16の連続膜となる。これにより、当該シリサイド層14は、正孔輸送層6と発光層8とが、シリサイド16を介することなく直接接することを効率よく低減する。したがって、シリサイド16の連続膜であるシリサイド層14は、正孔輸送層6と発光層8との間に形成されるキャリアトラップをより効率よく低減する。
本実施形態に係る発光素子がさらに奏する効果を、図11と図12とを参照することにより説明する。
<補記>
シリサイド16の分子構造が、上述したように、Mを金属元素とし、実数xを用いて、MSixと表される構造を有し、当該シリサイド16の化学量論組成が、MSiである場合、0.8≦x≦1.2であってもよい。また、当該シリサイド16の化学量論組成が、MSi2である場合、1.6≦x≦2.4であってもよい。
<双極子モーメントの反転>
図13は、本実施形態に係る発光素子2および当該発光素子2の周囲の断面を拡大して示す概略断面図であり、図1に示す断面と対応する位置における断面図である。なお、本明細書において、同一の機能を有する各部材には、同一の名称および参照符号を付し、構成の差異がない限り、同じ説明は繰り返さない。
<シリサイド層の形成位置の変更例>
図14は、本実施形態に係る発光素子2および当該発光素子2の周囲の断面を拡大して示す概略断面図であり、図1に示す断面と対応する位置における断面図である。
<インバーテッド構造>
図15は、本実施形態に係る発光素子2および当該発光素子2の周囲の断面を拡大して示す概略断面図であり、図1に示す断面と対応する位置における断面図である。
<シリサイド層が二層の構造>
図16は、本実施形態に係る発光素子2および当該発光素子2の周囲の断面を拡大して示す概略断面図であり、図1に示す断面と対応する位置における断面図である。
2 発光素子
3 基板
4 アノード
6 正孔輸送層
8 発光層
10 電子輸送層
12 カソード
14、28 シリサイド層
16、30 シリサイド
16D、30D 双極子モーメント
18A、18B 積層体
20 金属ナノ粒子
22 金属ナノ粒子層
24 Siナノ粒子
26 Siナノ粒子層
Tr 薄膜トランジスタ
Claims (34)
- 第1電極と、第1電荷輸送層と、シリサイドを含むシリサイド層と、発光層と、第2電極とを、この順に配置して備え、
前記第1電荷輸送層と前記発光層とが、前記シリサイド層を介して互いに隣接する発光素子。 - 前記シリサイド層は、柱状構造、または、粒状構造の前記シリサイドを含む請求項1に記載の発光素子。
- 前記シリサイド層は、前記シリサイドの連続膜である請求項1に記載の発光素子。
- 前記シリサイド層は、前記発光層および前記第1電荷輸送層の少なくとも一方と接する前記シリサイドのナノ粒子の集合構造を含む請求項1に記載の発光素子。
- 少なくとも一部の前記シリサイドが極性を有する請求項1から4の何れか1項に記載の発光素子。
- 前記シリサイドの少なくとも一部の双極子モーメントの方向が、前記発光層から前記第1電荷輸送層へ向かう方向である請求項5に記載の発光素子。
- 前記シリサイドの少なくとも一部の双極子モーメントの方向が、前記第1電荷輸送層から前記発光層へ向かう方向である請求項5に記載の発光素子。
- 前記第1電極がアノードであり、前記第2電極がカソードであり、前記第1電荷輸送層が正孔輸送層である請求項1から7の何れか1項に記載の発光素子。
- さらに、前記発光層と前記第2電極との間に、第2電荷輸送層を配置して備え、
前記第2電荷輸送層が電子輸送層である請求項8に記載の発光素子。 - 前記第1電極がカソードであり、前記第2電極がアノードであり、前記第1電荷輸送層が電子輸送層である請求項1から7の何れか1項に記載の発光素子。
- さらに、前記発光層と前記第2電極との間に、第2電荷輸送層を配置して備え、
前記第2電荷輸送層が正孔輸送層である請求項10に記載の発光素子。 - さらに、前記発光層と前記第2電荷輸送層との間に、前記シリサイド層をさらに備え、
前記発光層と前記第2電荷輸送層とが、前記シリサイド層を介して互いに隣接する請求項9または11に記載の発光素子。 - Mを金属元素として、前記シリサイドの分子構造が、実数xを用いて、MSixと表され、
前記シリサイドの化学量論組成がMSiの場合、0.8≦x≦1.2であり、前記シリサイドの化学量論組成がMSi2の場合、1.6≦x≦2.4である請求項1から12の何れか1項に記載の発光素子。 - 前記Mは、原子1つあたり6個以上のd電子を有する金属元素である請求項13に記載の発光素子。
- 前記Mは、Fe、Ni、Co、Ru、Os、Rh、Ir、Pd、およびPtからなる群から少なくとも1種を含む金属元素である請求項13または14に記載の発光素子。
- 前記Mは、Fe、Ni、およびCoからなる群から少なくとも1種を含む金属元素である請求項13または14に記載の発光素子。
- 前記シリサイド層の膜厚が20nm以下である請求項1から16の何れか1項に記載の発光素子。
- 前記シリサイドのSi濃度の分布が、前記シリサイド層の膜厚方向の位置によって異なる請求項1から17の何れか1項に記載の発光素子。
- 前記シリサイドの金属濃度の分布が、前記シリサイド層の膜厚方向の位置によって異なる請求項1から18の何れか1項に記載の発光素子。
- 前記シリサイド層が、Siナノ粒子の層と金属ナノ粒子の層とを積層した積層体に対する熱処理によって形成された請求項1から19の何れか1項に記載の発光素子。
- 前記シリサイド層が、SiO2ナノ粒子の層と金属ナノ粒子の層とを積層した積層体に対する熱処理によって形成された請求項1から19の何れか1項に記載の発光素子。
- 前記Siナノ粒子の粒径が50nm以下である請求項20に記載の発光素子。
- 前記Siナノ粒子の粒径が20nm以下である請求項22に記載の発光素子。
- 前記金属ナノ粒子の粒径が50nm以下である請求項20から23の何れか1項に記載の発光素子。
- 前記金属ナノ粒子の粒径が20nm以下である請求項24に記載の発光素子。
- 複数の画素を有する表示領域を備え、
基板と、該基板上の複数の画素のそれぞれに位置する、前記請求項1から25の何れか1項に記載の発光素子とを備え、
前記基板が、前記発光素子をそれぞれ駆動する複数の薄膜トランジスタを備えた表示デバイス。 - 前記発光素子は、前記基板側に前記第1電極を備えた請求項26に記載の表示デバイス。
- 前記発光素子は、前記基板側に前記第2電極を備えた請求項26に記載の表示デバイス。
- 第1電極と、第1電荷輸送層と、シリサイドを含むシリサイド層と、発光層と、第2電極とを、この順に配置して備え、前記第1電荷輸送層と前記発光層とが、前記シリサイド層を介して互いに隣接する発光素子の製造方法であって、
Siナノ粒子の層と金属ナノ粒子の層とを積層した積層体に対する熱処理により前記シリサイド層を形成するシリサイド層形成工程を含む発光素子の製造方法。 - 第1電極と、第1電荷輸送層と、シリサイドを含むシリサイド層と、発光層と、第2電極とを、この順に配置して備え、前記第1電荷輸送層と前記発光層とが、前記シリサイド層を介して互いに隣接する発光素子の製造方法であって、
SiO2ナノ粒子の層と金属ナノ粒子の層とを積層した積層体に対する熱処理により前記シリサイド層を形成するシリサイド層形成工程を含む発光素子の製造方法。 - 前記Siナノ粒子の粒径が50nm以下である請求項29に記載の発光素子の製造方法。
- 前記Siナノ粒子の粒径が20nm以下である請求項31に記載の発光素子の製造方法。
- 前記金属ナノ粒子の粒径が50nm以下である請求項29から32の何れか1項に記載の発光素子の製造方法。
- 前記金属ナノ粒子の粒径が20nm以下である請求項33に記載の発光素子の製造方法。
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