JP2022031152A - Display panel and display device - Google Patents

Abstract

To provide a display panel in which color purity is improved using a combination of optical resonator structure and a color filter.SOLUTION: A display panel is provided, comprising a plurality of pixels which include self-luminous elements and color filters facing the self-luminous elements, at least one of the plurality of self-luminous elements is a green light emitting element, the green light emitting element has a light transmissive metal film electrode, a green light emitting layer and a light reflective electrode laminated in an order close to the color filter to constitute optical resonator structure enhancing light intensity of a first wavelength, and a color filter facing the green light emitting element has light transmittance less than or equal to 50% for the light which has longer wavelength than the first wavelength and which has the second wavelength having a higher visibility characteristic as a green color than the first wavelength.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a display panel including a light emitting element utilizing an electric field emission phenomenon and a quantum dot effect, and a display device using the display panel.

In recent years, display devices using light emitting elements such as organic EL elements utilizing the electroluminescence phenomenon of organic materials and QLEDs utilizing the quantum dot effect are becoming widespread. The light emitting element has a basic structure in which a light emitting layer is arranged between a pair of electrodes, and when a voltage is applied between the electrodes, holes and electrons are recombinated and the light emitting layer emits light.

The so-called top-emission type light emitting element that emits light above the substrate has a light-reflecting electrode on the substrate side and a light semi-transparent electrode on the opposite side. A part of the light generated in the light emitting layer is transmitted directly through the light semitransparent electrode, and a part is reflected by the light reflecting electrode or the light semitransparent electrode and propagates in the light emitting element. Then it emits. As a technique for improving the light extraction efficiency, a so-called resonator structure is used in which the optical path length in the light emitting element is designed so that these lights are strengthened by interference.

In a display panel for color display, such a light emitting element forms sub-pixels of each RGB color, and adjacent RGB sub-pixels are combined to form a unit pixel in color display. In general, a display panel using a light emitting element uses a configuration that suppresses the reflection of external light in order to suppress the deterioration of visibility due to the reflection of external light by the reflective electrodes provided on each pixel. (See, for example, Patent Document 1-3). Further, as a method for improving the color purity, for example, a configuration by a combination of a resonator structure and a color filter is used (see, for example, Patent Document 4).

Japanese Unexamined Patent Publication No. 2018-32016 Japanese Unexamined Patent Publication No. 2012-185992 Japanese Unexamined Patent Publication No. 2014-183024 International Publication No. 2001/39554

In the structure described in Patent Document 4, the light intensity at the peak wavelength of the light extracted from the light emitting element and the wavelength in the vicinity thereof are controlled to improve the color purity. However, the structure described in Patent Document 4 has a problem that the color purity may decrease when there is a region having high human visual sensitivity characteristics in a wavelength region not near the peak wavelength of the light extracted from the light emitting element. ..

The present disclosure has been made in view of the above problems, and provides a display panel for improving color purity by using a combination of an optical resonator structure and a color filter that does not adversely affect the aperture ratio and luminous efficiency. With the goal.

The display panel according to one aspect of the present disclosure is a display panel including a plurality of pixels including a self-luminous element and a color filter facing the self-luminous element, and at least one of the plurality of self-luminous elements is green. It is a light emitting element, and in the green light emitting element, a light transmitting metal thin film electrode, a green light emitting layer, and a light reflecting electrode are laminated in the order of proximity to the color filter to obtain light intensity of a first wavelength. The second color filter, which has a strengthening optical resonator structure and faces the green light emitting element, has a wavelength longer than the first wavelength and is greener than the first wavelength and has high visual sensitivity characteristics. The light transmission rate is 50% or less with respect to the light having a wavelength.

According to the display panel of the above aspect, the reflectance of the pixel provided with the green light emitting layer with respect to the light of the second wavelength can be suppressed. Therefore, for the pixel provided with the green light emitting layer, the light having the first wavelength, which is the desired light, is efficiently emitted, and the light having the second wavelength having high visibility characteristics is included in the light reflected from the outside light. It is possible to suppress the resulting decrease in color purity.

It is sectional drawing which shows typically the structure of the organic EL display panel which concerns on embodiment. It is a schematic cross-sectional view explaining the interference of light in the optical resonator structure formed in the organic EL element 1. (A) is a graph showing the emission spectrum of the organic EL element 1 (G) and the transmission spectrum of the conventional color filter (G). (B) is a graph showing the Y value of the CIE color matching function. (C) is a graph showing the external light reflection characteristic of the organic EL element (G) having an optical resonator structure. (A) is a graph showing the spectrum of reflected light when external light corresponding to a C light source is incident on an organic EL element (G) having an optical resonator structure. (B) is a transmission spectrum of the color filter (G) according to Examples 1 and 2 and Comparative Example. (A) is a graph showing the spectrum of the reflected light of the sub-pixel 2 (G). (B) is a graph showing the relationship between the 565 nm transmittance of the color filter (G) and the light reflectance of the sub-pixel 2 (G). It is a flowchart which shows the manufacturing process of the display panel which concerns on embodiment. It is a partial cross-sectional view schematically showing a part of the manufacturing process of the display panel which concerns on embodiment. FIG. The state in which the insulating layer is formed, (c) is the state in which the pixel electrode material is formed on the interlayer insulating layer, (d) is the state in which the pixel electrode is formed, and (e) is the state in which the interlayer insulating layer and pixels are formed. The state where the partition wall material layer is formed on the electrode is shown. It is a partial cross-sectional view schematically showing a part of the manufacturing process of the display panel which concerns on embodiment. FIG. (C) indicates a state in which a hole transport layer is formed on the hole injection layer, and (d) indicates a state in which a light emitting layer is formed on the hole injection layer. It is a partial cross-sectional view schematically showing a part of the manufacturing process of the display panel which concerns on embodiment. FIG. The state where the electron injection transport layer is formed on the electron injection transport layer, (c) shows the state where the counter electrode is formed on the electron injection transport layer, and (d) shows the state where the sealing layer is formed on the counter electrode. .. It is a partial cross-sectional view schematically showing a part of the manufacturing process of the display panel which concerns on embodiment. FIG. A state in which a light-shielding curtain is formed, (c) indicates a state in which a color filter is formed on an upper substrate, and (d) indicates a state in which a color filter substrate is attached to a light emitting element substrate. It is a block diagram which shows the structure of the display device which concerns on embodiment.

<< Background to one aspect of this disclosure >>
It is known that a display panel provided with a light emitting element has a problem that contrast and reflection occur due to the reflection of external light by the electrodes. Therefore, for example, there is a technique for suppressing external light reflection using a circular polarizing plate and a technique for suppressing external light reflection by an electrode using a color filter layer provided with a black matrix as described in Patent Document 4. However, the circularly polarizing plate has light absorption characteristics, and the black matrix lowers the aperture ratio of the display panel. Therefore, in either case, the luminous efficiency is lowered, the power consumption is increased, and the panel life is shortened. Can cause.

On the other hand, as described in Patent Document 4, a technique for suppressing external light reflection using an optical resonator structure is also known. As shown in the schematic cross-sectional view of FIG. 2, the optical cavity structure includes, for example, light that passes through a path C ₁ that is directly emitted from the light emitting center, and a light semitransmissive electrode and a light reflecting electrode from the light emitting center. This is a structure in which the optical distance is adjusted so that the light passing through the path C ₂ , which is reflected and emitted in the order of, intensifies each other. Since the optical resonator structure functions as a filter that increases the transmittance of the light having the same wavelength as the extracted light with respect to the external light, the reflectance of the light having the same wavelength as the extracted light is low, and the contrast with respect to the external light is lowered. It also functions as a deterrent configuration. Therefore, according to this configuration, it is possible to improve the contrast and increase the light purity in the wavelength of the extracted light and the wavelength band in the vicinity thereof. However, the optical resonator structure has no effect on the wavelength of the extracted light and the wavelength band outside the wavelength band in the vicinity thereof. Therefore, if there is a wavelength with high human visual sensitivity characteristics in the wavelength band outside the wavelength range of the extracted light, the wavelength does not function as a suppression configuration for external light reflection, so that the color purity does not become sufficiently high. There can be. In particular, in a color panel using three RGB colors, the peak wavelength of the green (G) light emitting element is around 530 nm, but the peak wavelength of the sensitivity of M pyramidal cells (Y value in the CIE color function) is around 555 nm. , The color purity of the green light emitting element tends to decrease.

In view of the above problems, the inventor has studied a configuration for improving color purity by using a combination of an optical cavity structure and a color filter that does not adversely affect the aperture ratio and luminous efficiency, and has reached the present disclosure. be.

<< Aspects of disclosure >>
The display panel according to one aspect of the present disclosure is a display panel including a plurality of pixels including a self-luminous element and a color filter facing the self-luminous element, and at least one of the plurality of self-luminous elements is green. It is a light emitting element, and in the green light emitting element, a light transmitting metal thin film electrode, a green light emitting layer, and a light reflecting electrode are laminated in the order of proximity to the color filter to obtain light intensity of a first wavelength. The second color filter, which has a strengthening optical resonator structure and faces the green light emitting element, has a wavelength longer than the first wavelength and is greener than the first wavelength and has high visual sensitivity characteristics. The light transmission rate is 50% or less with respect to the light having a wavelength.

According to the display panel of the above aspect, the reflectance of the pixel provided with the green light emitting layer with respect to the light of the second wavelength can be suppressed. Therefore, for the pixel provided with the green light emitting layer, the light having the first wavelength, which is the desired light, is efficiently emitted, and the light having the second wavelength having high visibility characteristics is included in the light reflected from the outside light. It is possible to suppress the resulting decrease in color purity.

Further, in the display panel according to the above aspect, the following may be performed.

In the CIE color matching function, the Y value corresponding to the second wavelength may be larger than the Y value corresponding to the first wavelength.

According to the above aspect, it is possible to suppress the influence of external light reflection of the light of the second wavelength, which is easier to see than the light of the first wavelength but has low color purity. Further, the first wavelength may be 530 nm or less, and the second wavelength may be a wavelength in the range of 545 nm to 565 nm. Further, the second wavelength may be a wavelength selected from a wavelength in the range of 545 nm to 565 nm. Therefore, for example, the first wavelength may be 530 nm or less, and the second wavelength may be 565 nm. Alternatively, the first wavelength may be 530 nm or less, and the second wavelength may be 555 nm. Further, the first wavelength may be 530 nm or less, and the second wavelength may be 545 nm.

According to the above aspect, the contrast of the pixel is improved by using green light having high color purity as the first wavelength and suppressing external light reflection of light having a second wavelength which is easy to see but has low color purity. The color purity can be increased.

Further, the color filter facing the self-luminous element may have a light transmittance of 70% or more at the first wavelength.

According to the above aspect, the light extraction efficiency can be improved without lowering the brightness of the light of the first wavelength, and the color purity can also be improved.

Further, in the display panel, the aperture ratio of the pixel including the green light emitting element may be 50% or more.

According to the above aspect, the life of the display panel can be extended.

Further, the display panel according to one aspect of the present disclosure is a display panel including a plurality of pixels including a self-luminous element and a color filter facing the self-luminous element, and is at least one of the plurality of self-luminous elements. Is a green light emitting element, and in the green light emitting element, a light transmitting metal thin film electrode, a green light emitting layer, and a light reflecting electrode are laminated in order of proximity to the color filter, and light having a first wavelength is emitted. The second pixel, which has an optical resonator structure for enhancing the intensity and includes the green light emitting element, has a wavelength longer than the first wavelength and is greener than the first wavelength and has high visual sensitivity characteristics. A second filter having a light transmission rate of 50% or less with respect to light having a wavelength is further provided.

Also in the display panel of the above aspect, the reflectance of the pixel provided with the green light emitting layer with respect to the light of the second wavelength can be suppressed. Therefore, for the pixel provided with the green light emitting layer, the light having the first wavelength, which is the desired light, is efficiently emitted, and the light having the second wavelength having high visibility characteristics is included in the light reflected from the outside light. It is possible to suppress the resulting decrease in color purity.

Further, the display device according to one aspect of the present disclosure is a display panel including the display panel according to one aspect of the present disclosure.

According to the above aspect, it is possible to realize a display device having the same effect as the display panel according to one aspect of the present disclosure.

Further, in the method for manufacturing a display panel according to one aspect of the present disclosure, a plurality of light-reflecting electrodes are formed on a substrate, a light emitting layer is formed above each of the plurality of light-reflecting electrodes, and the plurality of light-reflecting electrodes are formed. A light-transmitting metal thin film electrode is formed above the light emitting layer to form an optical resonator structure, and a color filter is formed above the metal thin film electrode and above each of the plurality of light emitting layers. In the formation of the light emitting layer, at least one light emitting layer is a green light emitting layer, and in the formation of the color filter, the transmission characteristic of the color filter above the green light emitting layer is set to the first peak wavelength of the optical resonator structure. The light transmittance is 50% or less with respect to the light of the second wavelength, which is longer than the first wavelength and has higher visual sensitivity characteristics as green than the first wavelength. do.

Even in the display panel manufactured by the method for manufacturing the display panel according to the above aspect, the reflectance of the pixel provided with the green light emitting layer with respect to the light of the second wavelength can be suppressed. Therefore, for the pixel provided with the green light emitting layer, the light having the first wavelength, which is the desired light, is efficiently emitted, and the light having the second wavelength having high visibility characteristics is included in the light reflected from the outside light. It is possible to suppress the resulting decrease in color purity.

<< Embodiment >>
Hereinafter, embodiments of the display panel according to the present disclosure will be described. The following description is an example for explaining the configuration, action, and effect according to one aspect of the present disclosure, and is not limited to the following forms except for the essential part of the present disclosure. In addition, including the following explanation, the upper and lower positions in the present specification and claims indicate the relative positional relationship with respect to the light emission direction, and are not necessarily the absolute upper and lower positions (in the vertical direction). Does not match the relationship. Further, in the present specification and claims, the reference numeral "-" used to indicate the numerical range includes the numerical values at both ends thereof.

1. 1. Schematic Configuration of Display Panel FIG. 1 is a partial cross-sectional view of an organic EL display panel 100 (see FIG. 11) as a display panel according to an embodiment. The organic EL display panel 100 includes a plurality of pixels composed of sub-pixels 2 (R), 2 (G), and 2 (B) that emit light of three colors (red, green, and blue). The organic EL display panel 100 includes a light emitting element substrate 30 including organic EL elements 1 (R), 1 (G), and 1 (B) as light emitting elements, and a color filter substrate 40 including a color filter and a black matrix. The combination of the organic EL element 1 (R) and the color filter 43 (R) is the sub-pixel 2 (R), and the combination of the organic EL element 1 (G) and the color filter 43 (G) is the sub-pixel 2 (G). ), The combination of the organic EL element 1 (B) and the color filter 43 (B) constitutes the sub-pixel 2 (B), respectively. FIG. 1 shows a cross section of one pixel composed of one sub-pixel 2 (R), two (G), and two (B) sub-pixels.

In the organic EL display panel 100, each organic EL element 1 is a so-called top emission type that emits light forward (upper in the z direction in FIG. 1).

Since the organic EL element 1 (R), the organic EL element 1 (G), and the organic EL element 1 (B) have substantially the same configurations, they will be described as the organic EL element 1 when they are not distinguished.

2. 2. Detailed configuration of display panel (2.1) Configuration of light emitting element substrate 30 As shown in FIG. 1, the organic EL element 1 includes a substrate 11, an interlayer insulating layer 12, a pixel electrode 13, a partition wall 14, and a hole injection layer 15. It includes a hole transport layer 16, a light emitting layer 17, an intermediate layer 18, an electron injection transport layer 19, a counter electrode 20, and a sealing layer 21. The pixel electrode 13 and the counter electrode 20 correspond to the light-reflecting electrode and the light translucent electrode of the present disclosure, respectively.

The substrate 11, the interlayer insulating layer 12, the intermediate layer 18, the electron injection transport layer 19, the counter electrode 20, and the sealing layer 21 are not formed for each pixel, but a plurality of organics included in the light emitting device substrate 30. It is commonly formed in the EL element 1.

<Board>
The substrate 11 includes a base material 111 which is an insulating material and a TFT (Thin Film Transistor) layer 112. A drive circuit is formed in the TFT layer 112 for each sub-pixel. As the base material 111, for example, a glass substrate, a quartz substrate, a plastic substrate, or the like can be adopted. As the plastic material, either a thermoplastic resin or a thermosetting resin may be used. For example, polyimide (PI), polyetherimide (PEI), polysulfone (PSu), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN).
, Polybutylene terephthalate, styrene-based, polyolefin-based, polyurethane-based, and other various thermoplastic elastomers, epoxy resin, unsaturated polyester, silicone resin, polyurethane, etc., or copolymers, blends, polymer alloys, etc. mainly containing these. Can be mentioned. From these, it is possible to select one type or a laminated body in which two or more types are laminated so as to have durability against the process temperature.

<Interlayer insulation layer>
The interlayer insulating layer 12 is formed on the substrate 11. The interlayer insulating layer 12 is made of a resin material and is for flattening a step on the upper surface of the TFT layer 112. Examples of the resin material include positive photosensitive materials. Moreover, as such a photosensitive material, an acrylic resin, a polyimide resin, a siloxane resin, a phenol resin and the like can be mentioned. Further, although not shown in the cross-sectional view of FIG. 1, contact holes are formed in the interlayer insulating layer 12 for each sub-pixel.

<Pixel electrode>
The pixel electrode 13 is formed on the interlayer insulating layer 12. The pixel electrode 13 is provided for each pixel and is electrically connected to the TFT layer 112 through a contact hole provided in the interlayer insulating layer 12.

In this embodiment, the pixel electrode 13 functions as a light-reflecting anode.

Specific examples of metal materials having light reflectivity include Ag (silver), Al (aluminum), aluminum alloys, Mo (molybdenum), APC (alloys of silver, palladium and copper), and ARA (silver, rubidium, gold). , MoCr (alloy of molybdenum and chromium), MoW (alloy of molybdenum and tungsten), NiCr (alloy of nickel and chromium) and the like.

The pixel electrode 13 may be composed of a metal layer alone, but as a laminated structure in which a layer made of a metal oxide such as ITO (indium tin oxide) or IZO (indium zinc oxide) is laminated on the metal layer. May be good.

<Septum>
The partition wall 14 is formed on the pixel electrode 13 in a state where a part of the upper surface of the pixel electrode 13 is exposed and the peripheral region thereof is covered. The region (hereinafter referred to as “opening”) on the upper surface of the pixel electrode 13 that is not covered with the partition wall 14 corresponds to a subpixel. That is, the partition wall 14 has an opening 14a provided for each subpixel.

In the present embodiment, the partition wall 14 is formed on the interlayer insulating layer 12 in the portion where the pixel electrode 13 is not formed. That is, in the portion where the pixel electrode 13 is not formed, the bottom surface of the partition wall 14 is in contact with the upper surface of the interlayer insulating layer 12.

The partition wall 14 is made of, for example, an insulating organic material (for example, acrylic resin, polyimide resin, novolak resin, phenol resin, etc.). The partition wall 14 functions as a structure for preventing the applied ink from overflowing when the light emitting layer 17 is formed by the coating method, and a vapor deposition mask is used when the light emitting layer 17 is formed by the vapor deposition method. Functions as a structure for mounting. In the present embodiment, the partition wall 14 is made of a resin material, and examples of the material of the partition wall 14 include an acrylic resin, a polyimide resin, a siloxane resin, and a phenol resin. In this embodiment, a phenol-based resin is used.

<Hole injection layer>
The hole injection layer 15 is provided on the pixel electrode 13 for the purpose of promoting the injection of holes (holes) from the pixel electrode 13 into the light emitting layer 17. Specific examples of the material of the hole injection layer 15 include a conductive polymer material such as PEDOT / PSS (a mixture of polythiophene and polystyrene sulfonic acid).

The hole injection layer 15 may be formed of an oxide of a transition metal. Specific examples of the transition metal include Ag (silver), Mo (molybdenum), Cr (chromium), V (vanadium), W (tungsten), Ni (nickel), Ir (iridium) and the like. This is because the transition metal has a plurality of oxidation numbers, so that a plurality of levels can be taken, and as a result, hole injection becomes easy and contributes to a reduction in the driving voltage. In this case, the hole injection layer 15 preferably has a large work function.

The hole injection layer 15 may have a laminated structure in which a conductive polymer material is laminated on an oxide of a transition metal.

<Hole transport layer>
The hole transport layer 16 has a function of transporting the holes injected from the hole injection layer 15 to the light emitting layer 17, and efficiently transports the holes from the hole injection layer 15 to the light emitting layer 17. It is made of an organic material with high hole mobility. The hole transport layer 16 is formed by applying and drying an organic material solution. As the organic material forming the hole transport layer 16, polyfluorene or a derivative thereof, or a polymer compound such as polyarylamine or a derivative thereof can be used.

Further, the hole transport layer 16 includes a triazole derivative, an oxadiazole derivative, an imidazole derivative, a polyarylalkane derivative, a pyrazoline derivative and a pyrazolone derivative, a phenylenediamine derivative, an arylamine derivative, an amino-substituted chalcone derivative, an oxazole derivative, and a styrylanthracene derivative. It may be formed by using a fluorenone derivative, a hydrazone derivative, a stilben derivative, a porphyrin compound, an aromatic tertiary amine compound and a styrylamine compound, a butadiene compound, a polystyrene derivative, a hydrazone derivative, a triphenylmethane derivative, or a tetraphenylbenzene derivative. .. Particularly preferably, a porphyrin compound, an aromatic tertiary amine compound, a styrylamine compound and the like may be used. In this case, the hole transport layer 16 is formed by a vacuum vapor deposition method. The material and manufacturing method of the hole transport layer 16 are not limited to those described above, and any material having a hole transport function may be used, and any manufacturing method that can be used for manufacturing the hole transport layer 16 can be used. May be formed with.

<Light emitting layer>
The light emitting layer 17 is formed in the opening 14a. The light emitting layer 17 has a function of emitting light of each color of R, G, and B by recombination of holes and electrons. As the material of the light emitting layer 17, a known material can be used.

When the light emitting element 1 is an organic EL element, the organic light emitting material contained in the light emitting layer 17 includes, for example, an oxinoid compound, a perylene compound, a coumarin compound, an azacmarin compound, an oxazole compound, an oxadiazole compound, a perinone compound, and pyrolopyrrole. Compounds, naphthalene compounds, anthracene compounds, fluorene compounds, fluoranthene compounds, tetracene compounds, pyrene compounds, coronen compounds, quinolone compounds and azaquinolone compounds, pyrazoline derivatives and pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stylben compounds. , Diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound, pyrylium compound, thiapyrylium compound, serenapyrilium compound, tellropyrylium compound, aromatic aldaziene compound, oligophenylene compound, thioxanthene Fluorescent substances such as compounds, cyanine compounds, acrydin compounds, metal complexes of 8-hydroxyquinoline compounds, metal complexes of 2-bipyridine compounds, complexes of shift salts and Group III metals, oxine metal complexes, and rare earth complexes can be used. .. Further, a known phosphorescent substance such as a metal complex that emits phosphorescence such as tris (2-phenylpyridine) iridium can be used. Further, the light emitting layer 17 is formed by using polyfluorene or a derivative thereof, polyphenylene or a derivative thereof, a polymer compound such as polyarylamine or a derivative thereof, or a mixture of the low molecular weight compound and the high molecular weight compound. May be good. The light emitting element 1 may be an inorganic EL element, and an inorganic light emitting material can be used as the material of the light emitting layer 17. Further, the light emitting element 1 may be a quantum dot light emitting device (QLED; Quantum-dot Light Emitting Diode), and a material having a quantum dot effect can be used as the material of the light emitting layer 17.

<Middle layer>
The intermediate layer 18 is formed on the light emitting layer 17 and contains a fluoride or quinolinium complex of a metal material having electron injectability. The metal material is selected from alkali metals and alkaline earth metals. Specific examples of the alkali metal are Li (lithium), Na (sodium), K (potassium), Rb (rubidium), Cs (cesium), and Fr (francium). Specific examples of the alkaline earth metal are Ca (calcium), Sr (strontium), Ba (barium), and Ra (radium). In this embodiment, NaF (sodium fluoride) is included.

<Electron injection transport layer>
The electron injecting and transporting layer 19 is formed on the intermediate layer 18, and the organic material having electron transporting property is doped with a metal material for improving electron injecting property. Here, doping refers to the substantially even distribution of metal atoms or metal ions of a metal material in an organic material, specifically forming a single phase containing the organic material and a trace amount of the metal material. Point to that. It is preferable that no other phase, particularly a phase consisting only of a metal material such as a metal piece or a metal film, or a phase containing a metal material as a main component exists. Further, in a single phase containing an organic material and a trace amount of metal material, the concentration of metal atoms or metal ions is preferably uniform, and the metal atoms or metal ions are preferably not aggregated. As the metal material, it is preferable to select from rare earth metals, and Yb (ytterbium) is more preferable. In this embodiment, Yb is selected. Further, the doping amount of the metal material in the electron injection transport layer 19 is preferably 3 to 60 wt%. In this embodiment, it is 20 wt%.

Examples of the organic material having an electron transport property include π-electron low molecular weight organic materials such as an oxadiazole derivative (OXD), a triazole derivative (TAZ), and a phenanthroline derivative (BCP, Bphen).

<Counter electrode>
The counter electrode 20 is made of a light translucent conductive material and is formed on the electron injection transport layer 19. In this embodiment, the counter electrode 20 functions as a cathode.

The light reflecting surface at the interface of the counter electrode 20 with the electron injection transport layer 19 forms a resonator structure in pairs with the light reflecting surface at the interface with the hole injection layer 15 of the pixel electrode 13. Therefore, when the light emitted from the light emitting layer 17 is incident on the counter electrode 20 from the electron injection transport layer 19, a part of the light needs to be reflected to the electron injection transport layer 19. Therefore, it is preferable that the refractive index differs between the counter electrode 20 and the electron injection transport layer 19. Therefore, the counter electrode 20 is preferably a metal thin film. The film thickness of the metal layer is about 1 nm to 50 nm in order to ensure light translucency.

Examples of the material of the counter electrode 20 include a silver alloy containing Ag and Ag as main components, and an Al alloy containing Al and Al as main components. Examples of the Ag alloy include magnesium-silver alloy (MgAg) and indium-silver alloy. Ag basically has a low resistivity, and Ag alloy is preferable in that it has excellent heat resistance and corrosion resistance and can maintain good electrical conductivity for a long period of time. Examples of the Al alloy include a magnesium-aluminum alloy (MgAl) and a lithium-aluminum alloy (LiAl). Examples of other alloys include lithium-magnesium alloys and lithium-indium alloys. In this embodiment, the counter electrode 20 is a thin film of Ag.

<Sealing layer>
The sealing layer 21 is made of a translucent material and is formed on the counter electrode 20.

The sealing layer 21 functions as a sealing layer that protects the light emitting layer 17, the intermediate layer 18, and the like from moisture and the like. Further, the interface between the counter electrode 20 and the sealing layer 21 may be paired with the light reflecting surface at the interface with the hole injection layer 15 of the pixel electrode 13 to form a resonator structure. Examples of the material of the sealing layer 21 include silicon nitriding (SiON) and silicon nitride (SiN). The sealing layer 21 may further contain a resin material such as an acrylic resin or a silicone resin.

(2.2) Configuration of Color Filter Substrate 40 As shown in FIG. 1, the color filter substrate 40 includes an upper substrate 41, a light-shielding film 42, and a color filter 43.

<Upper board>
The upper substrate 41 is a translucent substrate that supports the light-shielding film 42 and the color filter 43. Further, the upper substrate 41 may have a function of improving the rigidity of the organic EL display panel 100 and a function of preventing the intrusion of moisture, air, etc. together with the sealing layer 21. As the upper substrate 41, for example, a glass substrate, a quartz substrate, a plastic substrate, or the like can be adopted.

<Light-shielding film>
As shown in FIG. 1, the light-shielding film 42 has an opening at a position facing each organic EL element 1, and shields light from a position corresponding to the position between two adjacent organic EL elements 1. The light-shielding film 42 is a black resin layer for preventing visible light having wavelengths corresponding to R, G, and B from being transmitted, and is made of, for example, a resin material containing a black pigment. As the resin material, for example, acrylic resin, polyimide resin, novolak resin, phenol resin and the like can be used. As the black pigment, for example, a carbon black pigment, a titanium black pigment, a metal oxide pigment, or the like can be used.

<Color filter>
As shown in FIG. 1, the color filter 43 is provided in the opening of the light-shielding film 42 so as to face each of the organic EL elements 1. The color filter 43 is a transparent layer used for transmitting visible light having wavelengths corresponding to R, G, and B, and the color filter 43 (R) receives light emitted from the organic EL element 1 (R). The color filter 43 (G) corrects the light emitted from the organic EL element 1 (G), and the color filter 43 (B) corrects the light emitted from the organic EL element 1 (B) to correct the contrast and color purity. Has a function to improve. The color filter 43 is made of, for example, a resin material containing a dye.

The color filter 43 (G) has a transmittance of 70% or more at the peak wavelength (wavelength around 520 nm) amplified in the resonator structure of the organic EL element 1 (G). Further, in the wavelength range of 545 nm to 565 nm, there is a wavelength having a transmittance of 50% or less. That is, the wavelength having a transmittance of 50% or less is a wavelength selected from a wavelength in the range of 545 nm to 565 nm, and may be, for example, 565 nm, 555 nm, or 545 nm. Details will be described later.

(2.3) Bonding layer The bonding layer 50 is a bonding layer for attaching the light emitting element substrate 30 and the color filter substrate 40 so as to face each other, and also from moisture and air to the light emitting element substrate 30 and the color filter substrate 40. Has a function to protect. The bonding layer 50 is made of a translucent resin material such as an acrylic resin, a silicone resin, or an epoxy resin.

3. 3. External Light Reflection Suppression Configuration (3.1) Optical Resonant Structure FIG. 2 is a diagram illustrating light interference in the optical resonator structure of the organic EL element 1 according to the present embodiment. The optical resonator structure is formed between the surface of the pixel electrode 13 on the hole injection layer 15 side and the surface of the counter electrode 20 on the electron injection transport layer 19 side. Further, the second optical resonator structure is configured between the surface of the pixel electrode 13 on the hole injection layer 15 side and the surface of the second optical adjustment layer 212 on the first optical adjustment layer 211 side. The light emitting layer 17 exists inside the first resonator structure and inside the second resonator structure.

FIG. 2 shows the main paths of light emitted from the light emitting layer 17. The path C ₁ is a path in which the light emitted from the light emitting layer 17 toward the counter electrode 20 passes through the counter electrode 20 without being reflected. In the path C ₂ , the light emitted from the light emitting layer 17 to the counter electrode 20 side is reflected by the surface of the counter electrode 20 on the electron injection transport layer 19 side, and further on the surface of the pixel electrode 13 on the hole injection layer 15 side. It is a path that is reflected and passes through the light emitting layer 17 and the counter electrode 20. In the resonator structure, interference occurs between the light emitted by the path C ₁ and the light emitted by the path C ₂ , and the light is emitted from the light emitting element 1.

The difference in the optical distance between the path C ₁ and the path C ₂ corresponds to the optical film thickness L _1t , which is the sum of the optical film thickness L ₀ and the optical film thickness L ₁ shown in FIG. Here, the optical film thickness is a value obtained by integrating the refractive index of the film with the film thickness, and more specifically, the optical film thickness L _1t is the refractive index of the hole injection layer 15 × the hole injection layer 15. , The refractive index of the hole transport layer 16 × the film thickness of the hole transport layer 16, the refractive index of the light emitting layer 17 × the film thickness of the light emitting layer 17, the refractive index of the intermediate layer 18 × the film thickness of the intermediate layer 18. It is a value obtained by adding all the refractive index of the electron injection transport layer 19 × the film thickness of the electron injection transport layer 19. Similarly, the difference in the optical distance between the path C ₁ and the path C ₃ corresponds to the optical film thickness L _2t , which is the sum of the optical film thickness L ₀ and the optical film thickness L ₂ shown in FIG.

In the resonator structure, the optical film thickness L _1t is set so that the light emitted by the path C ₁ and the light emitted by the path C ₂ intensify each other.

In the organic EL element 1 (G), for example, the optical film thickness L _1t is set so as to intensify light having a wavelength of 520 nm. Similarly, in each of the organic EL element 1 (R) and the organic EL element 1 (B), the optical film thickness L _1t is set so as to intensify the light having a desired wavelength. Since this resonator structure can be said to be a filter having improved transmittance of light having a desired wavelength, the transmittance of light having a desired wavelength is high with respect to external light, that is, light having a desired wavelength. Functions as a filter with low reflectance.

(3.2) External light reflection and luminous efficiency characteristics FIG. 3 (a) is a graph showing the emission spectrum of the organic EL element 1 (G) and the transmission spectrum of the color filter (G) of the comparative example (conventional type). be.

As shown in the emission spectrum 101 of FIG. 3A, the emission spectrum of the organic EL element 1 (G) having a resonator structure for strengthening the peak wavelength has a characteristic that the wavelength is around 520 nm (about 520 to 530 nm) as a peak. Has. On the other hand, the transmission spectrum 102 of the color filter (G) of the comparative example is designed so as not to transmit light having a shorter wavelength than around 460 nm and light having a longer wavelength than around 650 nm in order to improve color purity. There is.

On the other hand, the profile of the Y value in the CIE color matching function, which indicates the human visual sensitivity characteristic, particularly the sensitivity of the M pyramidal cell, becomes maximum near the wavelength of 555 nm, as shown in FIG. 3 (b). Since the peak wavelength of G having a high color purity is about 520 to 530 nm, reflected light having a wavelength of 540 nm or more, particularly reflected light having a wavelength of around 555 nm, causes a decrease in the color purity of the sub-pixel. Here, the intensity Y of the reflected light is shown as follows using the intensity I of the light from the incident light source, the aperture ratio A of the sub-pixel, and the reflectance R of the sub-pixel.

Y = I × A × R… (Equation 1)
Here, the intensity I of the light from the incident light source does not depend on the structure of the display panel, and when the aperture ratio A of the sub-pixel 2 is lowered, the current density to the organic EL element 1 increases. There is an adverse effect on life. Therefore, in order to suppress external light reflection without reducing the luminous efficiency of the organic EL element 1, it is preferable to reduce the reflectance R of the sub-pixel for the wavelength for which external light reflection is desired to be suppressed.

The reflectance R of the sub-pixel of the display panel is shown as follows, where the light transmittance of the color filter of the sub-pixel is T _F and the light reflectance of the organic EL element having a resonator structure is _RA .

R = _RA × T _F ² … (Equation 2)
As described above, since the resonator structure is designed so that the emission peak is in the vicinity of the wavelength of 520 nm, the reflectance _RA has a characteristic that the reflectance is low in the vicinity of 520 to 530 nm as shown in FIG. 3 (c). It becomes. Therefore, assuming that the incident light source is the C light source, as shown in FIG. 4A, the reflected light spectrum 115 without the color filter is shown by integrating the incident light spectrum 113 and the reflectance spectrum 114. It peaks at a wavelength of 550 to 570 nm. As shown in FIG. 3 (b), since the light having a wavelength of 550 to 570 nm has higher luminosity factor than the light having a wavelength of 520 nm, the reflected light having a wavelength of 550 to 570 nm has the color purity of the sub-pixel 2 (G). It causes a decrease. That is, in the absence of the color filter, when external light is incident on the sub-pixel 2 (G) in the light emitting state, the color purity of the sub-pixel 2 (G) is lowered.

(3.3) Characteristics of Color Filter The following, regarding the spectrum of reflected light in the presence of a color filter, the color filter (Example 1, Example 2) according to one aspect of the present disclosure and the conventional color filter (comparison). Example) will be explained in comparison with.

FIG. 4B shows transmission spectra for each of Examples 1 and 2 and Comparative Example of the color filter. In any of the color filters, the transmittance of the resonator structure of the organic EL element 1 (G) at the extraction wavelength (near 520 nm to 530 nm) is about 90%. On the other hand, the transmittance near 565 nm, which is the peak wavelength of the Y value in the CIE color matching function, is 63% in the spectrum 121 of Comparative Example, 50% in the spectrum 122 of Example 1, and the spectrum of Example 2. At 123, it is 34%. As described above, since the reflected light passes through the color filter twice in the propagation path, the reflection spectrum when the color filter is present is the reflection spectrum 115 when the color filter is not present, as shown in Equation 2. On the other hand, it is a value obtained by integrating the square of the transmittance of the color filter.

FIG. 5A shows the reflection spectrum of the reflected light, in which Comparative Example corresponds to the spectrum 131, Example 1 corresponds to the spectrum 132, and Example 2 corresponds to the spectrum 133. As described above, the spectrum 113 shows the Y color matching function in the CIE color matching function, and the spectrum 115 shows the reflected light in the absence of the color filter. As shown in FIG. 5A, in Comparative Example 131, there are two wavelengths, one is around 520 nm, which is the extraction wavelength of the resonator of the organic EL element 1 (G), and the other is around 555 nm, which is the peak wavelength of the Y value in the CIE color matching function. There is a peak in the place. That is, since the reflected light includes light having a peak wavelength of 550 to 570 nm, the reflected light reduces the color purity of the sub-pixel 2 (G). On the other hand, in Example 1 (132) and Example 2 (133), a peak exists in the vicinity of 520 nm, which is the extraction wavelength of the resonator of the organic EL element 1 (G), but the peak of the Y value in the CIE color matching function. No peak can be confirmed near the wavelength of 555 nm. That is, since the component having a wavelength of 550 to 570 nm in the reflected light can be suppressed, it is possible to suppress the situation where the color purity of the sub-pixel 2 (G) is lowered by the reflected light. In order to sufficiently increase the brightness of the sub-pixel 2 (G), the transmittance of the color filter in the vicinity of 520 nm, which is the extraction wavelength of the resonator of the organic EL element 1 (G), is preferably at least 70%. ..

(3.4) Relationship between reflectance and aperture ratio FIG. 5 (b) shows the relationship between the reflectance of the color filter 43 (G) and the light reflectance of the sub-pixel 2 (G). As shown in FIG. 5B, when the transmittance of light having a wavelength of 565 nm in the color filter 43 (G) is 50%, the light reflectance of the sub-pixel 2 (G) is about 17%. At this time, assuming that the reflectances of the other sub-pixels 2 (R) and 2 (B) are the same, if the aperture ratio of the sub-pixel 2 (G) is 50%, the reflection of the organic EL display panel 100 The rate is 3%. Considering the quality of the display panel, sufficient image quality can be obtained if the reflectance is 3% or less. Therefore, if the aperture ratio is 50%, the transmittance of light having a wavelength of 565 nm in the color filter 43 (G). Is preferably 50% or less. When the aperture ratio of the sub-pixel is 80%, the reflectance of the sub-pixel 2 (G) needs to be about 12% or less, so that the transmittance of light having a wavelength of 565 nm in the color filter 43 (G) is high. It is preferably 24% or less.

4. Summary As described above, according to the display panel according to one aspect of the present disclosure, in the green light emitting element, the efficiency of extracting light of a desired wavelength due to the resonator structure formed between the pixel electrode and the counter electrode. It is possible to improve the emission intensity and the color purity at the same time. Further, the color filter (G) is configured to have a wavelength having a transmittance of 50% or less in the wavelength range of 545 nm to 565 nm. That is, by setting the transmittance of the light near the wavelength of 555 nm to 50% or less in the color filter (G), the reflectance of the light near the wavelength of 555 nm is sufficiently lowered, and the color purity due to the reflected light is lowered. Can be deterred. Therefore, it is possible to improve the efficiency of the light emitting element by improving the light extraction efficiency and lowering the drive voltage, to extend the life of the light emitting element, and to improve the color purity. Further, since the reflectance can be reduced without using the black matrix, the aperture ratio can be easily improved, and the efficiency and the life of the light emitting element can be further extended by reducing the driving voltage.

5. Manufacturing Method of Display Panel The manufacturing method of the display panel will be described with reference to the drawings. FIG. 6 is a flowchart showing a manufacturing process of the display panel. 7 (a) to (e), FIGS. 8 (a) to 8 (d), FIGS. 9 (a) to (d), and FIGS. 10 (a) to 10 (d) are shown in each process of manufacturing the display panel. It is a schematic cross-sectional view which shows the state.

(1) Preparation of Substrate 11 First, as shown in FIG. 7A, a TFT layer 112 is formed on the substrate 111 to form the substrate 11 (step S10). The TFT layer 112 can be formed by a known method for manufacturing a TFT.

(2) Formation of the interlayer insulating layer 12 Next, as shown in FIG. 7B, the interlayer insulating layer 12 is formed on the substrate 11 (step S20). The interlayer insulating layer 12 can be laminated and formed by using, for example, a plasma CVD method, a sputtering method, or the like.

Next, a dry etching method is performed on the source electrode of the TFT layer in the interlayer insulating layer 12 to form a contact hole. The contact hole is formed so that the surface of the source electrode is exposed at the bottom thereof.

Next, a connection electrode layer is formed along the inner wall of the contact hole. A part of the upper part of the connection electrode layer is arranged on the interlayer insulating layer 12. For the formation of the connection electrode layer, for example, a sputtering method can be used, and after forming a metal film, patterning is performed using a photolithography method and a wet etching method.

(3) Formation of Pixel Electrode 13 Next, as shown in FIG. 7 (c), the pixel electrode material layer 130 is formed on the interlayer insulating layer 12. The pixel electrode material layer 130 can be formed by using, for example, a vacuum vapor deposition method, a sputtering method, or the like.

Next, as shown in FIG. 7D, the pixel electrode material layer 130 is patterned by etching to form a plurality of pixel electrodes 13 partitioned by subpixels (step S30).

(4) Formation of the partition wall 14 Next, as shown in FIG. 7 (e), the partition wall material layer 140 is coated on the pixel electrode 13 and the interlayer insulating layer 12 with the partition wall layer resin which is the material of the partition wall 14. Form. The partition wall material layer 140 uses a spin coating method or the like on the pixel electrode 13 and the interlayer insulating layer 12 in which a solution obtained by dissolving a phenol resin, which is a resin for the partition wall layer, in a solvent (for example, a mixed solvent of ethyl lactate and GBL) is used. It is formed by applying it uniformly. Then, the partition wall 14 is formed by pattern exposure and development on the partition wall material layer 140 (FIG. 8A), and the partition wall 14 is fired (step S40). Thereby, the opening 14a which becomes the formation region of the light emitting layer 17 is defined. The partition wall 14 is fired, for example, at a temperature of 150 ° C. or higher and 210 ° C. or lower for 60 minutes.

Further, in the step of forming the partition wall 14, the surface of the partition wall 14 may be further surface-treated with a predetermined alkaline solution, water, an organic solvent, or the like, or may be subjected to plasma treatment. This is done for the purpose of adjusting the contact angle of the partition wall 14 with respect to the ink (solution) applied to the opening 14a, or for the purpose of imparting water repellency to the surface.

(5) Formation of Hole Injection Layer 15 Next, as shown in FIG. 8B, an ink jet head 410 containing the constituent material of the hole injection layer 15 is applied to the opening 14a defined by the partition wall 14. It is discharged from the nozzle 401 of Nozzle 401, applied onto the pixel electrode 13 in the opening 14a, and fired (dried) to form the hole injection layer 15 (step S50).

The film formation of the hole injection layer 15 is not limited to the coating method, and may be formed by a method such as thin film deposition. Further, when the hole injection layer 15 is formed by vapor deposition or sputtering, holes made of the material of the hole injection layer 15 are formed on the pixel electrode material layer 130 after the formation of the pixel electrode material layer 130 in step 30. The injection material layer may be formed, and the pixel electrode material layer 130 and the hole injection material layer may be patterned in the same patterning step to form a laminated structure of the pixel electrode 13 and the hole injection layer 15.

(6) Formation of Hole Transport Layer 16 Next, as shown in FIG. 8C, an ink jet head 420 containing the constituent material of the hole transport layer 16 is applied to the opening 14a defined by the partition wall 14. It is discharged from the nozzle 402 of Nozzle 402, applied onto the hole injection layer 15 in the opening 14a, and fired (dried) to form the hole transport layer 16 (step S60).

The film formation of the hole transport layer 16 is not limited to the coating method, and may be formed by a method such as thin film deposition. Further, when all the film formation of the pixel electrode 13, the hole injection layer 15, and the hole transport layer 16 is performed by thin film deposition or sputtering, each layer may be patterned by the same patterning step as described above.

(7) Formation of the light emitting layer 17 Next, as shown in FIG. 8D, ink containing the constituent material of the light emitting layer 17 is applied to the nozzle 403R of the inkjet head 430R, the nozzle 403G of the inkjet head 430G, and the inkjet head 430B. It is discharged from each of the nozzles 403B, applied onto the hole transport layer 16 in the opening 14a, and fired (dried) to form the light emitting layer 17 (step S70).

(8) Formation of Intermediate Layer 18 Next, as shown in FIG. 9A, the intermediate layer 18 is formed on the light emitting layer 17 and the partition wall 14 (step S80). The intermediate layer 18 is formed, for example, by forming NaF, which is a fluoride of an alkali metal, in common with each subpixel by a vacuum vapor deposition method.

(9) Formation of Electron Injection Transport Layer 19 Next, as shown in FIG. 9B, an electron injection transport layer 19 is formed on the intermediate layer 18 (step S90). The electron-injection transport layer 19 is formed, for example, by forming an electron-transporting organic material and ytterbium, which is a doped metal, in common with each subpixel by a co-deposited method.

(10) Formation of the counter electrode 20 Next, as shown in FIG. 9 (c), the counter electrode 20 is formed on the electron injection transport layer 19 (step S100). The counter electrode 20 is formed by, for example, forming a metal material such as Ag or Al into a film by a sputtering method or a vacuum vapor deposition method.

(11) Formation of Sealing Layer 21 Next, as shown in FIG. 9D, the sealing layer 21 is formed (step S110). The sealing layer 21 can be formed by, for example, a sputtering method or a CVD method using SiON or SiN.

With the completion of this step, the light emitting element substrate 30 is completed.

(12) Formation of the light-shielding film 42 Next, as shown in FIG. 10A, the material of the light-shielding film 42 is applied onto the upper substrate 41 to form the light-shielding material film 42. Then, the light-shielding material film 42 is subjected to pattern exposure and development to form the light-shielding film 42 and fired (FIG. 10 (b), step S120).

(13) Formation of Color Filter 43 Next, as shown in FIG. 10 (c), the material of the color filter 43 is separately applied to the gaps of the light-shielding film 42 and fired to form the color filter 43. The film formation of the color filter 43 is not limited to the coating method, and for example, the color filter material layer may be formed as a solid film, and the color filter 43 may be formed by pattern exposure and development.

(14) Attaching the substrate Finally, as shown in FIG. 10D, the material of the bonding layer 50 is applied onto the sealing layer 21 of the light emitting element substrate 30, and the upper substrate is attached.

6. Overall Configuration of Display Device FIG. 11 is a schematic block diagram showing a configuration of a display device 1000 provided with a display panel 100. As shown in FIG. 11, the display device 1000 includes a display panel 100 and a drive control unit 200 connected to the display panel 100. The drive control unit 200 includes four drive circuits 210 to 240 and a control circuit 250.

In the actual display device 1000, the arrangement of the drive control unit 200 with respect to the display panel 100 is not limited to this.

<< Other variants of the embodiment >>
(1) In the above embodiment, the organic EL element 1 which is a light emitting element includes a hole injection layer 15, a hole transport layer 16, an intermediate layer 18, and an electron injection transport layer 19, but it is not always the case. It does not have to be a form configuration. It may not have any one or more, or it may have another functional layer. For example, the intermediate layer 18 may not be provided, or may be replaced with the intermediate layer 18, or an electron transport layer may be provided between the intermediate layer 18 and the light emitting layer 17.

Further, the method for manufacturing each functional layer is merely an example, and for example, the light emitting layer 17 may be formed by a vapor deposition method, or the color filter 43 may be formed by a printing method.

(2) In the above embodiment, the display panel is provided with three types of light emitting elements that emit light in each of R, G, and B, but at least one type of light emitting element may be a green light emitting element. The type of light emitting element may be one type, or may be three or more types. Here, the type of the light emitting element refers to the variation of each element constituting the light emitting element, and if the film thickness of the light emitting layer or the functional layer is different even if the light emitting color is the same, the type of the light emitting element is different. Can be thought of. Further, the arrangement of the light emitting elements is not limited to the arrangement of RGBRGB ..., And may be the arrangement of RGBBGRRGB ..., And an auxiliary electrode layer or other non-light emitting region may be provided between the light emitting elements.

Further, in the embodiment, the intermediate layer 18, the electron injection transport layer 19, and the counter electrode 20 are formed as a common film, but the film thickness may be changed for each light emitting element.

(3) In the embodiment, in the organic EL element 1, the interface between the pixel electrode 13 and the hole injection layer 15 and the interface between the counter electrode 20 and the electron injection transport layer 19 form an optical cavity structure. .. However, the surface of the optical resonator structure on the color filter 43 side is not limited to the interface between the counter electrode 20 and the electron injection transport layer 19, and may be, for example, the interface between the counter electrode 20 and the sealing layer 21. Alternatively, for example, an optical adjustment layer may be provided between the counter electrode 20 and the sealing layer 21 and may be an interface between the counter electrode 20 and the optical adjustment layer, or a plurality of optical adjustment layers may be provided adjacent to each other. It may be the interface between the two optical adjustment layers.

(4) In the embodiment, the transmittance of the color filter 43 (G) is such that the transmittance of light having a wavelength near 555 nm (light having a wavelength selected from a wavelength in the range of 545 nm to 565 nm) is 50% or less. However, it is assumed that the sub-pixel 2 includes an organic EL element 1 (G), a conventional color filter, and a reflection suppression filter having a light transmittance of 50% or less near a wavelength of 555 nm. May be good. At this time, as the reflection suppression filter, for example, an edge filter that does not allow light having a wavelength of 555 nm or more may be used. The reflection suppression filter may be provided, for example, in the color filter substrate 40 by being laminated on the color filter 43 (G), or on the light emitting element substrate 30 on the counter electrode 20 of the organic EL element 1 (G). May be done.

(5) In the embodiment, the pixel electrode is an anode and the counter electrode is a cathode, but the pixel electrode may be a cathode and the counter electrode may be an anode.

(6) Although the display panel and the display device according to the present disclosure have been described above based on the embodiments and modifications, the present invention is not limited to the above embodiments and modifications. By arbitrarily combining the embodiments obtained by applying various modifications to the above-described embodiments and modifications, and the components and functions of the embodiments and modifications without departing from the spirit of the present invention. The realized form is also included in the present invention.

The present invention manufactures a display panel using a light emitting element having an optical resonator structure, which has high color purity and luminous efficiency and has an improved aperture ratio while suppressing a decrease in color purity due to external light reflection. Is useful for.

100 Organic EL display panel 1 Organic EL element 2 Sub-pixel 11 Substrate 12 Interlayer insulation layer 13 Pixel electrode 14 Partition wall 15 Hole injection layer 16 Hole transport layer 17 Light emitting layer 18 Intermediate layer 19 Electron injection transport layer 20 Opposite electrode 21 Sealing Layer 30 Light emitting element substrate 40 Color filter substrate 41 Upper substrate 42 Light-shielding film 43 Color filter

Claims (10)

A display panel including a plurality of pixels including a self-luminous element and a color filter facing the self-luminous element.
At least one of the plurality of self-luminous elements is a green light emitting element.
The green light emitting element has an optical resonator structure in which a light transmitting metal thin film electrode, a green light emitting layer, and a light reflecting electrode are laminated in order of proximity to the color filter to enhance the light intensity of the first wavelength. And
The color filter facing the green light emitting element has a longer wavelength than the first wavelength and has a higher light transmittance than the second wavelength light having a higher visual sensitivity characteristic as green than the first wavelength. Is less than 50% display panel. The display panel according to claim 1, wherein in the CIE color matching function, the Y value corresponding to the second wavelength is larger than the Y value corresponding to the first wavelength. The display panel according to claim 1 or 2, wherein the first wavelength is 530 nm or less and the second wavelength is 565 nm. The display panel according to claim 1 or 2, wherein the first wavelength is 530 nm or less and the second wavelength is 555 nm. The display panel according to claim 1 or 2, wherein the first wavelength is 530 nm or less and the second wavelength is 545 nm. The display panel according to any one of claims 1 to 5, wherein the color filter facing the self-luminous element has a light transmittance of 70% or more at the first wavelength. The display panel according to any one of claims 1 to 6, wherein in the display panel, the aperture ratio of the pixel including the green light emitting element is 50% or more. A display panel including a plurality of pixels including a self-luminous element and a color filter facing the self-luminous element.
At least one of the plurality of self-luminous elements is a green light emitting element.
The green light emitting element has an optical resonator structure in which a light transmitting metal thin film electrode, a green light emitting layer, and a light reflecting electrode are laminated in order of proximity to the color filter to enhance the light intensity of the first wavelength. And
The pixel including the green light emitting element has a light transmittance of 50 with respect to light having a wavelength longer than that of the first wavelength and having a higher visual sensitivity characteristic as green than the first wavelength. A display panel further comprising a second filter that is less than or equal to%. A display device including the display panel according to any one of claims 1 to 8. Multiple light-reflecting electrodes are formed on the substrate,
A light emitting layer is formed above each of the plurality of light reflecting electrodes, and a light emitting layer is formed.
A light-transmitting metal thin film electrode is formed above the plurality of light emitting layers to form an optical resonator structure.
A color filter is formed above the metal thin film electrode and above each of the plurality of light emitting layers.
In the formation of the light emitting layer, at least one light emitting layer is a green light emitting layer.
In the formation of the color filter, the transmission characteristic of the color filter above the green light emitting layer is a wavelength longer than the first wavelength when the peak wavelength of the optical resonator structure is the first wavelength. A method for manufacturing a display panel having a light transmittance of 50% or less with respect to light of the second wavelength, which is greener than the first wavelength and has higher visual sensitivity characteristics.

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