JP2008210819A - Light-emitting device, manufacturing method of light-emitting device, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device in which an equivalent dispersion effect or the like is obtained with a simpler structure. <P>SOLUTION: The light-emitting device, in which a plurality of thin films 20, 21, 22, 23, 70, 60, 55, 50, 33, 43, 42, 41 including a light-emitting layer 60 are laminated, is provided with an external waviness structure 31 to demonstrate a dispersion function having a directionality on any of the interfaces of the thin films. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting device, a method for manufacturing the light emitting device, and an electronic apparatus.

  Organic electroluminescence devices (hereinafter referred to as organic EL devices) as exposure heads in display devices used in electronic devices such as mobile phones, personal computers and PDAs (Personal Digital Assistants), and image forming devices such as digital copying machines and printers The light-emitting device such as “ As this type of light-emitting device, one having a multilayer structure in which a plurality of thin films having various refractive indexes including a light-emitting layer are stacked is known.

  Although the refractive index of the light emitting layer varies depending on the material, it is generally about 1.55 to 2.3 at 550 nm and is generally larger than air (n = 1.0) or glass (n = 1.5). It is. Therefore, the light emitted from the high refractive index layer passes through the interface entering the low refractive index layer from the high refractive index layer at least once before reaching the air layer (n = 1.0) where the viewer is present. Therefore, most of the light becomes a waveguide mode propagating in the lateral direction of the substrate due to total reflection at the interface, and may not contribute to display.

  Therefore, conventionally, an uneven structure or a fine periodic structure is formed at any interface of the laminated thin films to express a scattering effect, a diffraction effect, a photonic crystal effect, and to suppress the total reflection amount of emitted light, A technique for increasing light that becomes a radiation mode is known (see Patent Document 1 or 2).

JP 2001-76864 A Japanese Patent Laid-Open No. 2004-22438

  In the technique disclosed in Patent Document 1, unevenness is formed on a glass substrate to avoid light confinement, thereby improving light extraction efficiency. Specifically, the unevenness is formed by a sacrificial oxide film. In the technique disclosed in Patent Document 2, in the top emission structure, the reflective layer of the lower substrate has irregularities, and the refractive index of the layer that flattens the irregularities is larger than the refractive index of the light emitting layer. It is said. In such a conventional technique, a complicated process is required to form a fine structure and flatten the upper portion of the structure. The present invention is intended to provide a configuration that can obtain an equivalent scattering effect and the like with a simpler configuration, and the present invention provides a method that can obtain an equivalent scattering effect and the like in a simpler process. The purpose is to do.

  In order to solve the above problems, a light-emitting device of the present invention is a light-emitting device in which a plurality of thin films including a light-emitting layer are stacked, and has a scattering function having directivity at any interface of the thin film. It has a swell structure that develops.

  According to such a light emitting device, a wavy structure having directional scattering is formed at any layer interface of the light emitting device, so that the light is totally reflected at the interface between the high refractive index layer and the low layer as in the past. It is possible to reduce the amount of light and increase the light emitted into the air.

  The waviness structure may be composed of a plurality of irregularities arranged at random, and the irregularities may have a smooth surface (that is, an irregular structure without corners).

  By adopting such a swell structure, it becomes possible to realize directional scattering more reliably.

  The waviness structure may be configured such that a distance between adjacent convex portions is in a range of 300 nm to 1200 nm.

  In this way, by configuring the distance between adjacent convex portions to be approximately the wavelength of visible light, it is possible to suitably scatter light of each color. When the distance between adjacent convex portions is less than 300 nm, the structure does not have the function of directionally scattering near-ultraviolet light most strongly and directionally scatter visible light, and the above effect may not be obtained. The near-infrared light is most strongly directionally scattered and the visible light is directionally scattered. Thus, the above effect may not be obtained.

  The waviness structure may be configured such that the distance between adjacent convex portions is in the range of −250 nm to +250 nm of the spectral peak wavelength of the emission color in the light emitting layer.

  As described above, when the distance between the adjacent convex portions is configured in the range of −250 nm to +250 nm of the spectrum peak wavelength of the emission color, the color light can be suitably scattered. When the distance between adjacent convex portions is less than -250 nm of the spectrum peak wavelength of the emission color, directional scattering does not appear at any wavelength of the emission spectrum, and the above effect may not be obtained. If it exceeds, directional scattering will not be exhibited at any wavelength of the emission spectrum, and the above effect may not be obtained.

  The waviness structure may be configured such that the height between the convex top portion and the concave bottom portion is in the range of 50 nm to 500 nm.

  As described above, when the height between the convex top and the concave bottom is less than 50 nm, sufficient scattering may not be realized. When the height exceeds 500 nm, for example, a flattening process such as forming a flattening film or the like of another member is performed. May be difficult.

  The waviness structure may occupy 30% or more of the total area of the thin film interface.

  By adopting such a swell structure, it becomes possible to realize directional scattering more reliably. If the area occupied by the wavy structure is less than 30% of the total area of the thin film interface, light may not be sufficiently scattered.

  Next, in order to solve the above-described problem, a method for manufacturing a light-emitting device according to the present invention includes a plurality of thin films including a light-emitting layer stacked, and a scattering function having directivity at any interface of the thin film. A method of manufacturing a light-emitting device having a swell structure that expresses a swell structure, including a swell structure forming step of forming a swell structure by forming a film of mesoporous silica by a spin coating method.

  According to such a manufacturing method, it is possible to easily form a wavy structure made of a mesoporous silica film, and thus, it is possible to easily realize a directional scattering mechanism.

  In the undulating structure forming step, film forming conditions can be designed so that the film made of the mesoporous silica has a thickness of 10 nm to 300 nm.

  By designing so as to have such a film thickness, the formed undulation structure has a height between the convex top portion and the concave bottom portion in the range of 50 nm to 500 nm, and preferably exhibits the above-described effects of the present invention. It becomes possible.

  The swell structure forming step includes a step of spin coating a silicon alkoxide solution having a solid content concentration of 3 wt% to 8 wt% at a rotation speed of 1500 rpm to 4000 rpm, and 300 ° C. to 400 ° C. in a vacuum for 0.5 hours to 5 hours. And a step of performing firing for a period of time.

  By adopting such a process, it is possible to easily and reliably form the undulation structure. In other words, in the present invention, in the formation process of the undulation structure, the concentration of the solution supplied by the spin coating method, the rotation speed during film formation, and the firing conditions are within the above ranges, so that the desired undulation structure is reliably formed. Is possible.

  Next, in order to solve the above-described problem, an electronic apparatus of the present invention includes the light-emitting device. Such an electronic device can realize display with excellent visibility by the light-emitting device.

  The present invention will be described in detail below.

This embodiment shows a part of the present invention and does not limit the present invention, and can be arbitrarily changed within the scope of the technical idea of the present invention. Moreover, in each figure shown below, in order to make each layer and each member the size which can be recognized on drawing, the scale is varied for each layer and each member.
(Organic EL panel)
First, an embodiment of an organic EL panel according to the light emitting device of the present invention will be described.

  FIG. 1 is a schematic diagram showing a wiring structure of the organic EL panel 1.

  The organic EL panel 1 of the present embodiment is of an active matrix type using thin film transistors (hereinafter referred to as TFTs) as switching elements, and a plurality of scanning lines 101. Each of the scanning lines 101 and the signal lines 102 has a wiring configuration including a plurality of signal lines 102 extending in a direction intersecting at right angles and a plurality of power supply lines 103 extending in parallel to the signal lines 102. Pixels X are formed in the vicinity of the intersection.

  Of course, according to the technical idea of the present invention, an active matrix using TFT or the like is not essential, and the same effect can be obtained even if the present invention is implemented using a substrate for a simple matrix and simple matrix driving is performed.

  A data line driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, a scanning line driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.

  Further, each pixel X has a switching TFT (switching element) 112 to which a scanning signal is supplied to the gate electrode via the scanning line 101, and a pixel signal supplied from the signal line 102 via the switching TFT 112. Is electrically connected to the power supply line 103 via the driving TFT 123, and a driving TFT (switching element) 123 to which the pixel signal held by the holding capacitor 113 is supplied to the gate electrode. Then, a pixel electrode (first electrode) 23 into which a driving current flows from the power line 103 and a light emitting functional layer 110 sandwiched between the pixel electrode 23 and the cathode (second electrode) 50 are provided. Yes.

  Next, specific modes of the organic EL panel 1 of the present embodiment will be described with reference to FIGS. Here, FIG. 2 is a plan view schematically showing the configuration of the organic EL panel 1. FIG. 3 is a cross-sectional view schematically showing a unit pixel group of an organic EL element constituting the organic EL panel 1.

  First, the configuration of the organic EL panel 1 will be described with reference to FIG.

  FIG. 2 is a diagram showing the organic EL panel 1 that causes the light emitting functional layer 110 to emit light by various wirings, TFTs, pixel electrodes, and various circuits formed on the substrate 20.

  As shown in FIG. 2, the organic EL panel 1 includes pixels X (see FIG. 1) in which a substrate 20 having electrical insulation and pixel electrodes 23 connected to the switching TFT 112 are arranged in a matrix on the substrate 20. ) And at least a pixel portion 3 (inside the one-dot chain line frame in FIG. 2) that is substantially rectangular in a plan view and is located on the pixel X.

  In the present embodiment, the pixel unit 3 includes an actual display area 4 (within the two-dot chain line in the figure) in the center and a dummy area 5 (one-dot chain line and two-dot chain line) arranged around the actual display area 4. Between the two areas).

  In the actual display area 4, the red pixel XR, the green pixel XG, and the blue pixel XB, which respectively emit red light (R), green light (G), and blue light (B), are regularly arranged in the horizontal direction of the paper. Has been placed. In addition, each of the color pixels XR, XG, and XB is arranged in the same color in the vertical direction on the paper surface, and forms a so-called stripe arrangement. Each of the color pixels XR, XG, and XB includes a light emitting functional layer 110 that emits light of each color of RGB in accordance with the operation of the TFTs 112 and 123 described above. Each of the color pixels XR, XG, and XB forms a unit to form a unit pixel group Px (described later), and the unit pixel group Px performs full color display by mixing RGB light emission colors. ing. Accordingly, a full color image is displayed in the actual display area 4 configured by arranging the unit pixel groups Px in a matrix.

  Further, scanning line driving circuits 80 and 80 are arranged on both sides of the actual display area 4 in FIG. The scanning line driving circuits 80 and 80 are provided on the lower layer side of the dummy region 5.

  Further, an inspection circuit 90 is disposed above the actual display area 4 in FIG. 2, and the inspection circuit 90 is disposed on the lower layer side of the dummy area 5. This inspection circuit 90 is a circuit for inspecting the operating state of the organic EL panel 1, and includes, for example, inspection information output means (not shown) for outputting the inspection result to the outside, and the organic EL during production or at the time of shipment. The panel 1 is configured to be able to inspect the quality and defects.

  The driving voltages of the scanning line driving circuit 80 and the inspection circuit 90 are applied from a predetermined power supply unit through a driving voltage conduction unit (not shown). Further, the drive control signal and drive voltage to the scanning line drive circuit 80 and the inspection circuit 90 are supplied from a predetermined main driver that controls the operation of the organic EL panel 1 and a drive control signal conduction unit (not shown) and drive voltage conduction. It is transmitted and applied via a unit (not shown). The drive control signal in this case is a command signal from a main driver or the like related to control when the scanning line drive circuit 80 and the inspection circuit 90 output signals.

(First embodiment of organic EL element)
Next, with reference to FIG. 3, the structure of the unit pixel group of the organic EL element will be described for the first embodiment of the organic EL element constituting the organic EL panel 1. FIG.

  In FIG. 3, the pixel electrode 23, the light emitting functional layer 110, and the cathode 50 constituting the organic EL element will be described in detail, and it is assumed that a driving TFT 123 is connected to the pixel electrode 23. Further, the pixel electrode 23 is formed in each of the red pixel XR, the green pixel XG, and the blue pixel XB, and emits light for each pixel by the driving TFT 123 as shown in FIG.

  As shown in FIG. 3, the unit pixel group Px of the organic EL element (organic EL device) 1 </ b> A includes a light emitting functional layer 110 sandwiched between the pixel electrode 23 and the cathode 50 on the substrate 20. In addition, a color filter substrate 40 disposed to face the substrate 20 is provided, and the electrodes 23 and 50 and the light emitting functional layer 110 are disposed between the substrate 20 and the color filter substrate 40. A region between the substrate 20 and the color filter substrate 40 is a region in which a filler 33 is filled in a region surrounded by the sealing material 32.

  In addition, the light emitting functional layer 110 has different light emitting materials for each of the red pixel XR, the green pixel XG, and the blue pixel XB, and emits each color of red R, green G, and blue B. Yes. The light emitted from the light emitting functional layer 110 passes through the color filter substrate 40 and is emitted. Therefore, the organic EL element 1A (organic EL panel 1) of the present embodiment constitutes a top emission type.

  The substrate 20 is a transparent substrate, and a glass substrate is used in this embodiment. The glass substrate material has a refractive index of 1.54 for light having a wavelength of 550 nm. In addition, a reflective layer 21 made of a thin aluminum layer is formed on the substrate 20, and the light emitted from the light emitting functional layer 110 is reflected toward the color filter substrate 40. A protective layer 22 is formed on the reflective layer 21, and a pixel electrode 23 as an anode is formed on the protective layer 22.

  The pixel electrode 23 is a transparent conductive film such as ITO (Indium-Tin Oxide) or IZO (Indium Zinc Oxide), or a composite oxide of tin oxide, indium oxide and zinc oxide. In the present embodiment, an ITO film is employed. The ITO film has a refractive index of 1.82 for light having a wavelength of 550 nm.

  As a method for forming such a pixel electrode 23, a transparent conductive film is formed on the entire surface of the substrate 20 (actually, the entire surface through the protective layer 22) by sputtering, and then wet etching with a resist mask interposed. By performing the processing, the pixel electrode 23 is patterned and formed corresponding to each of the red pixel XR, the green pixel XG, and the blue pixel XB.

  The light emitting functional layer 110 includes a hole transport layer (light emitting functional layer) 70 formed on the pixel electrode 23, an organic EL layer (light emitting functional layer) 60 formed on the hole transport layer 70, and the organic It is composed of a laminate including an electron transport layer (light emitting functional layer) 55 formed on the EL layer 60.

  The hole transport layer 70 is a layer film having a function of transporting / injecting holes into the organic EL layer 60. As a material for forming such a hole transport layer 70, in the case of a polymer material, in particular, a dispersion of 3,4-polyethylenediosithiophene / polystyrene sulfonic acid (PEDOT / PSS), that is, polystyrene sulfonic acid as a dispersion medium. A dispersion in which 3,4-polyethylenedioxythiophene is dispersed and further dispersed in water is preferably used.

  In addition, as a forming material of the positive hole transport layer 70, various things can be used, without being limited to the said thing. For example, a material obtained by dispersing polystyrene, polypyrrole, polyaniline, polyacetylene or a derivative thereof in an appropriate dispersion medium such as the aforementioned polystyrene sulfonic acid can be used. As the low molecular weight material, an ordinary hole injection material such as copper phthalocyanine, m-MTDATA, TPD, α-NPD, or the like can be used in the vapor deposition method.

  As a material for forming the organic EL layer 60, a known light emitting material capable of emitting fluorescence or phosphorescence is used. Further, by providing the organic EL layers 60R, 60G, and 60B in each of the red pixel XR, the green pixel XG, and the blue pixel XB, the organic EL element 1A capable of full color display is obtained.

  Specifically, as a material for forming the organic EL layer 60 (60R, 60G, 60B), as a polymer material, (poly) fluorene derivative (PF), (poly) paraphenylene vinylene derivative (PPV), polyphenylene derivative (PP) , Polyparaphenylene derivatives (PPP), polyvinylcarbazole (PVK), polythiophene derivatives, polysilanes such as polymethylphenylsilane (PMPS), and the like are preferably used. In addition, these polymer materials include polymer materials such as perylene dyes, coumarin dyes, rhodamine dyes, rubrene, perylene, 9,10-diphenylanthracene, tetraphenylbutadiene, Nile red, coumarin 6, and quinacridone. It can also be used by doping a low molecular weight material such as. As a low molecular weight material, a host material such as Alq3 or DPVBi, doped with Nile Red, DCM, rubrene, perylene, rhodamine, or the like, or a host alone can be used in a vapor deposition method. Further, as a material for forming the red organic EL layer 60R, for example, MEHPPV (poly (3-methoxy6- (3-ethylhexyl) paraphenylenevinylene) is used, and as a material for forming the green organic EL layer 60G, for example, polydioctylfluorene is used. For example, polydioctylfluorene may be used as a material for forming the blue organic EL layer 60B from a mixed solution of F8BT (an alternating copolymer of dioctylfluorene and benzothiadiazole).

The electron transport layer 55 is a layer film having a function of transporting / injecting electrons into the organic EL layer 60. As a material for forming such an electron transport layer 55, for example, an alkaline earth metal such as LiF or SrF ₂ or an alkali metal compound is employed.

  The cathode 50 is a counter electrode facing the pixel electrode 23. The cathode 50 includes a first cathode made of a low work function metal provided on the organic EL layer 60, and a second cathode provided on the first cathode and protecting the first cathode. is there. The metal having a low work function for forming the first cathode is preferably a metal having a work function of 3.0 eV or less, specifically, Ca (work function; 2.6 eV), Sr (work function; 2 .1 eV) and Ba (work function; 2.5 eV) are preferably used. The second cathode is provided to cover the first cathode and protect it from oxygen, moisture, and the like, and to increase the conductivity of the entire cathode 50. Since the organic EL element 1A of the present embodiment is a top emission type in which emitted light is extracted from the color filter substrate 40 side, the cathode 50 has translucency.

  Next, the organic EL element 1 </ b> A including the light emitting functional layer 110 of each color between the pixel electrode 23 and the cathode 50 is sealed with the thin film sealing layer 51. On the thin film sealing layer 51, a color filter substrate 40 is formed in a region surrounded by the sealing material 32 via a filler 33. The color filter substrate 40 is disposed on the substrate 41 disposed on the viewing side of the organic EL device 1, the directional scattering layer 35 disposed on the substrate 41, and the directional scattering layer 35. The color filter layer 42 and an overcoat layer 43 covering the color filter layer 42 are provided.

  The substrate 41 is a transparent substrate, and a glass substrate is used in this embodiment. The glass substrate material has a refractive index of 1.54 for light having a wavelength of 550 nm. Further, the directional scattering layer 35 is made of a mesoporous silica film, and a undulating structure 31 is formed on the surface layer. The undulation structure 31 is capable of expressing a scattering function having directivity, and is configured by a plurality of irregularities (convex portions 31a and concave portions 31b) arranged at random as shown in FIGS. The unevenness has a smooth surface.

  Here, in the undulation structure 31, the distance between the adjacent convex portions 31a, 31a is configured in the range of 300 nm to 1200 nm as shown in FIG. 4, and between the top of the convex portion 31a and the bottom of the concave portion 31b. As shown in FIG. 5, the height of is comprised in the range of 50 nm-500 nm. With the undulation structure 31 having such a distance between the convex portions and the height, a scattering function having directivity can be suitably expressed. The wavy structure 31 occupies 30% or more of the total area of the directional scattering layer 35.

  By providing such a directional scattering layer 35, a directional scattering function is manifested in the visible light region, and when the undulation structure 31 is less than 30% of the total area of the directional scattering layer 35, the visible light region. May not produce sufficient directional scattering. In addition, when the height between the top part of the convex part 31a and the bottom part of the concave part 31b exceeds 500 nm, when the undulation structure 31 is flattened, a crack is generated in the flattening layer, and the reliability of the panel is insufficient. There are cases where it is dismissed

  On the directional scattering layer 35, a color filter layer 42 of each color of red (R), green (G), and blue (B) is formed, and an overcoat layer 43 that covers the color filter layer 42 is further formed. . The substrate 41, the directional scattering layer 35, the color filter layer 42, and the overcoat layer 43 constitute the color filter substrate 40.

  In the unit pixel group Px having the above-described configuration, a bank (partition wall) may be formed between the red pixel XR, the green pixel XG, and the blue pixel XB. In this case, a light emitting functional layer made of a polymer material can be formed by a droplet discharge method. Further, the bank is preferably composed of a bank made of an inorganic material and an organic bank made of an organic material. Moreover, it is preferable that lyophilicity is imparted to the surface of the inorganic bank and lyophobic property is imparted to the surface of the organic bank. Accordingly, when the light emitting functional layer 110 is formed by the droplet discharge method, the droplet can be retained between the banks. Further, the light emitting functional layer 110 may be made of a low molecular material. In this case, since the light emitting functional layer is formed using a mask vapor deposition method, it is not necessary to form a bank. The low molecular weight light emitting functional layer preferably includes a hole transport layer and an electron injection buffer layer.

  In the organic EL element 1A configured as described above, when a current flows between the pixel electrode 23 and the cathode 50, the organic EL layer 60 (60B, 60G, 60R) emits light, and the emitted light passes through the cathode 50. The light is emitted from the color filter substrate 40 side, or reflected from the reflective layer 21 formed on the substrate 20 side and then emitted from the color filter substrate 40 side through the cathode 50. At this time, since the directional scattering layer 35 is formed on the color filter substrate 40, the emitted light is preferably scattered and the viewing angle can be widened.

  FIG. 6 shows the result of detecting directional scattered light in transmission by making light (450 nm) incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °). It is. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). Further, FIG. 7 shows the result of detecting directional scattered light in reflection by making light (450 nm) incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °). It is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). 6 and 7, the detection intensity in the incident direction is normalized as 1 for transmission, and the detection intensity in the regular reflection direction is normalized as 1 for reflection.

  Thus, according to the directional scattering layer 35 used in this embodiment, a detection peak due to directional scattering is confirmed at ± 25 ° with respect to the incident light or reflected light direction in the vicinity of the blue wavelength in the vicinity of the blue wavelength. It was done. Unlike the diffraction effect when the undulation structure 31 realizes such directional scattering and forms a concavo-convex structure having a regular period, even if the incident light angle changes, the incident light is almost the same angle. A part of is scattered with the same directivity.

  In the above embodiment, the detection peak due to directional scattering is ± 25 ° with respect to the direction of incident light or reflected light, but the angle of directional scattered light is changed by changing the average value of the undulation depth. Can be controlled. FIG. 8 shows the relationship between the depth of the wavy structure 31 at 450 nm and the angle of directional scattering. Thus, by changing the average value of the depth of the undulation structure 31, the directional scattering angle can be various.

  On the other hand, FIG. 9 shows the result of detecting the directional scattered light in the transmission with light (550 nm) incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °). It is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). Further, FIG. 10 shows the result of detecting directional scattered light in reflection by making light (550 nm) incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °). It is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). In FIGS. 9 and 10, the detection intensity in the incident direction is normalized as 1 for transmission, and the detection intensity in the regular reflection direction is normalized as 1 for reflection.

  As described above, according to the directional scattering layer 35 used in the present embodiment, even in the vicinity of the green wavelength, detection peaks due to directional scattering were confirmed in both transmission and reflection, and directional scattering was obtained. However, higher directional scattering was obtained in the vicinity of the blue wavelength than in the vicinity of the green wavelength.

  Further, FIG. 11 shows the result of detecting directional scattered light in transmission by entering light (650 nm) from various angles (0 °, 15 °, 30 °, 60 °) with respect to the directional scattering layer 35. It is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). FIG. 12 shows the result of detecting the directional scattered light in the reflection by entering light (650 nm) from various angles (0 °, 15 °, 30 °, 60 °) with respect to the directional scattering layer 35. It is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). In FIGS. 11 and 12, the detection intensity in the incident direction is normalized as 1 for transmission, and the detection intensity in the regular reflection direction is normalized as 1 for reflection.

  Thus, according to the directional scattering layer 35 used in the present embodiment, even in the vicinity of the red wavelength, detection peaks due to directional scattering were confirmed in both transmission and reflection, and directional scattering was obtained. However, higher directional scattering was obtained in the vicinity of the blue wavelength than in the vicinity of the red wavelength.

  That is, the directional scattering layer 35 used in the present embodiment has obtained directional scattering in blue, green, and red, and the light extraction efficiency in the red pixel XR, the green pixel XG, and the blue pixel XB. Can alleviate the problem. Further, the efficiency of directional scattering is large in the blue region having a short wavelength as described above, and a particularly high directional scattering effect can be obtained. The blue light extraction efficiency can be greatly improved, so that the color temperature of the panel can be increased.

  In addition, specific comparison is described in the fourth embodiment to be described later, but the directional scattering layer 35 does not include the directional scattering layer 35 because the direction of light emitted at various angles changes. As compared with the organic EL device, the effect of reducing the color shift when viewed from the front and oblique directions for each color is also obtained. In particular, since the directional scattering function can obtain a larger effect as the wavelength is shorter, the color shift can be greatly reduced in blue in which the color change is easily recognized as a luminance change when viewed from a wide angle. Therefore, the white balance when viewed from a wide angle can be improved.

(Second Embodiment of Organic EL Element)
Next, the structure of the unit pixel group of the organic EL element will be described with reference to FIG. 13 for the second embodiment of the organic EL element constituting the organic EL panel 1.

  FIG. 13 is a view corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 are the same components and the same members unless otherwise specified. Shall be.

  In the organic EL element 1B of the second embodiment, the configuration of the color filter substrate 40 is different from that of the organic EL element 1A of the first embodiment. Specifically, the color filter substrate 40 includes a substrate 41 made of a translucent member such as a glass material, a color filter layer 42 (42B, 42G, 42R) formed on the substrate 41, and the color filter layer 42. The directional scattering layer 35 formed to cover the directional scattering layer 35 and the overcoat layer 43 formed on the directional scattering layer 35 are provided.

  Also in this case, the directional scattering layer 35 includes the undulating structure 31 and realizes suitable directional scattering, which can reduce the problems of light extraction efficiency and panel color temperature.

(3rd Embodiment of an organic EL element)
Next, with reference to FIG. 14, the structure of the unit pixel group of the organic EL element will be described for the third embodiment of the organic EL element constituting the organic EL panel 1. FIG.

  FIG. 14 is a diagram corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 denote the same components and members unless otherwise specified. Shall be.

  In the organic EL element 1C of the third embodiment, the configuration of the color filter substrate 40 is different from the organic EL element 1A of the first embodiment. Specifically, the color filter substrate 40 includes a substrate 41 made of a translucent member such as a glass material, a color filter layer 42 (42B, 42G, 42R) formed on the substrate 41, and the color filter layer 42. The overcoat layer 43 is formed so as to cover the surface, and the directional scattering layer 35 is formed on the overcoat layer 43.

  Also in this case, the directional scattering layer 35 includes the undulating structure 31 and realizes suitable directional scattering, which can reduce problems of light extraction efficiency, viewing angle, and panel color temperature.

(4th Embodiment of an organic EL element)
Next, with reference to FIG. 15, the structure of the unit pixel group of the organic EL element will be described for the fourth embodiment of the organic EL element constituting the organic EL panel 1. FIG.

  FIG. 15 is a diagram corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 are the same components and the same members unless otherwise specified. Shall be.

  In the organic EL element 1D of the fourth embodiment, the configuration of the color filter substrate 40 is different from the organic EL element 1A of the first embodiment. Specifically, the color filter substrate 40 includes a substrate 41 made of a translucent member such as a glass material, a color filter layer 42 (42B, 42G, 42R) formed on the substrate 41, and the color filter layer 42. And a directional scattering layer 35 on the surface side (other surface side) different from the color filter layer 42 of the substrate 41.

  Also in this case, the directional scattering layer 35 includes the undulating structure 31 and realizes suitable directional scattering, which can reduce problems of light extraction efficiency, viewing angle, and panel color temperature.

  In each of the first to fourth embodiments, the color filter layer 42 and the overcoat layer 43 use a coating method (spin coating method, etc.) or a vacuum thin film creation method (sputtering, vapor deposition method, etc.). Formed.

  In the case where the directional scattering layer 35 is not provided as in the conventional case or the scattering layer having a concavo-convex structure formed periodically is provided, the light emitted from the light emitting functional layer is guided in the glass substrate under the total reflection condition. The light extraction efficiency decreases. However, in the organic EL device 1 according to this embodiment including the directional scattering layer 35, a part of the light propagating in the lateral direction is scattered with a directivity at an angle equal to or less than the total reflection, and thus is emitted to the outside of the substrate. The extraction efficiency is increased, and the total amount of energy radiated into the air when driven at the same current density can be increased. FIG. 16 is a graph of the energy radiated into the air on the viewer side with respect to the current density when all colors of red (R), green (G), and blue (B) are turned on to display white. As can be seen from this graph, the organic EL device 1 (example) according to this embodiment can increase the energy extraction efficiency at the same current density as compared with the comparative example that does not include the directional scattering layer 35. did it.

  Moreover, since the direction of the light emitted with various angles changes, the organic EL device 1 (example) according to this embodiment including the directional scattering layer 35 is more than the comparative example not including the directional scattering layer 35. The effect of reducing the color shift when viewed from the front and diagonal in each color is also obtained. In particular, the directional scattering function can obtain a greater effect as the wavelength is shorter, and thus the above-described effect can be obtained more in blue when the color change is easily recognized as a luminance change when viewed from a wide angle. Blue color shift can be greatly reduced. Therefore, the white balance when viewed from a wide angle can be improved.

  FIG. 17 is a table showing the results of measuring the chromaticity observed from the 0 ° direction and the 45 ° direction with only the blue pixel XB turned on. It can be seen that the organic EL device 1 (example) according to the present embodiment including the directional scattering layer 35 can greatly reduce the color shift as compared with the comparative example not including the directional scattering layer 35.

  FIG. 18 is a table showing the results of measuring the chromaticity observed from the 0 ° direction and the 45 ° direction when all of red, green, and blue are lit and white is displayed. The organic EL device 1 (example) according to the present embodiment including the directional scattering layer 35 is capable of greatly reducing the color shift even in the case of white display as compared with the comparative example not including the directional scattering layer 35. I understand.

  In each of the above embodiments, the directional scattering layer 35 having the undulation structure 31 is formed in any layer of the color filter substrate 40. However, the substrate 20 side on which the pixel electrode 23 is formed (that is, the light emitting functional layer 110 is formed). The directional scattering layer 35 having the same waviness structure 31 may be formed in any layer on the formed substrate side).

(Fifth Embodiment of Organic EL Element)
Next, with reference to FIG. 19, the structure of the unit pixel group of the said organic EL element is demonstrated about 5th Embodiment of the organic EL element which comprises the organic EL panel 1. FIG.

  FIG. 19 is a view corresponding to FIG. 3 showing the first embodiment of the organic EL element, and the same reference numerals as those shown in FIG. Shall be.

  The organic EL element 1E of the fifth embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the substrate 20 side including the pixel electrode 23.

  The organic EL element 1E includes a directional scattering layer 35 on a substrate 20 made of a light-transmitting material such as glass, and pixel electrodes 23 are arranged in a predetermined pattern on the directional scattering layer 35 via a protective layer 22. It is formed for each of XB, XG, and XR. The directional scattering layer 35 has the undulation structure 31 as in the above-described embodiments, and has a directional scattering function.

  On the pixel electrode 23, a hole transport layer 70, an organic EL layer 60, a light emitting functional layer 110 including an electron transport layer 55, and a cathode 50 are formed, and sealing that covers the stacked body from the pixel electrode 23 to the cathode 50 A layer 51 is formed on the protective layer 22. The organic EL layer 60 is formed by patterning the blue organic EL layer 60B, the green organic EL layer 60G, and the red organic EL layer 60R for each of the pixels XB, XG, and XR.

  Here, since the organic EL element 1E is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum.

  Also in the organic EL element 1E of this embodiment as described above, the directional scattering layer 35 includes the undulation structure 31 and realizes suitable directional scattering, and the problem of the light extraction efficiency and the color temperature of the panel and the viewing angle. It is supposed to reduce the problem.

(6th Embodiment of an organic EL element)
Next, with reference to FIG. 20, the structure of the unit pixel group of the organic EL element in the sixth embodiment of the organic EL element constituting the organic EL panel 1 will be described.

  FIG. 20 is a diagram corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 denote the same components and members unless otherwise specified. Shall be.

  The organic EL element 1 </ b> F according to the sixth embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the side of the substrate 20 including the pixel electrode 23.

  The organic EL element 1 </ b> F includes a protective layer 22 on a substrate 20 made of a translucent material such as glass, and includes a directional scattering layer 35 on the protective layer 22. A laminated body including the pixel electrode 23, the light emitting functional layer 110, and the cathode 50, and the sealing agent 51 are formed on the directional scattering layer 35. The directional scattering layer 35 has the undulating structure 31 as in the above-described embodiments, and has a directional scattering function. Here, since the organic EL element 1F is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum.

  Also in the organic EL element 1F of this embodiment as described above, the directional scattering layer 35 includes the undulation structure 31 and realizes suitable directional scattering, and the problem of the light extraction efficiency and the color temperature of the panel and the viewing angle. It is supposed to reduce the problem.

(Seventh Embodiment of Organic EL Element)
Next, with reference to FIG. 21, the structure of the unit pixel group of the organic EL element in the seventh embodiment of the organic EL element constituting the organic EL panel 1 will be described.

  21 is a view corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 denote the same components and members unless otherwise specified. Shall be.

  The organic EL element 1 </ b> G of the seventh embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the side of the substrate 20 including the pixel electrode 23.

  The organic EL element 1G includes a protective layer 22 on a substrate 20 made of a light-transmitting material such as glass, and on the opposite side of the surface of the substrate 20 where the protective layer 22 is formed (the other surface side of the substrate 20). A directional scattering layer 35 is provided. Then, a laminated body including the pixel electrode 23, the light emitting functional layer 110, and the cathode 50, and the sealing agent 51 are formed on the protective layer 22. The directional scattering layer 35 has the undulation structure 31 as in the above-described embodiments, and has a directional scattering function. Here, since the organic EL element 1G is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum.

  Also in the organic EL element 1G of this embodiment as described above, the directional scattering layer 35 includes the undulation structure 31 and realizes suitable directional scattering, and the problem of light extraction efficiency, the color temperature of the panel, and the viewing angle. It is supposed to reduce the problem.

(Method for forming directional scattering layer 35)
The directional scattering layer 35 used in each of the above embodiments can be formed by the following method. Specifically, the swell structure 31 is obtained by forming a thin film made of mesoporous silica to a thickness of 10 nm to 230 nm (for example, 150 nm). Here, a mesoporous silica film is obtained by spin-coating a silicon alkoxide solution having a solid content concentration of about 5% at a rotation speed of 2500 rpm for 30 seconds, and then performing a baking process at 350 ° C. for 1 hour in a vacuum. . The mesoporous silica film formed by such a method has the undulation structure 31 and exhibits a directional scattering function.

  In order to design the distance between the convex portions, the height between the convex top portions and the concave bottom portions of the waviness structure 31 within the above-described ranges, the solid content concentration of the silicon alkoxide solution is set to 3 wt% to 8 wt%, and the spin coat rotation speed Is preferably designed at 1500 rpm to 4000 rpm. The firing temperature is preferably 300 ° C. to 400 ° C., and the firing time is preferably 0.3 hours to 5 hours.

  In addition to the above-described method, for example, by applying plasma treatment for a predetermined time (for example, several tens of seconds) to a coating film formed of an organic material, an inorganic material, or an organic-inorganic hybrid material, the coating film is undulated. A structure can also be added.

  Moreover, a wavy structure can also be provided to the said coating film by grind | polishing with respect to the formed coating film using the solution which suspended the slurry agent of 0.1 micrometer-10 micrometers.

  Furthermore, a waviness structure can be imparted by vapor deposition or sputtering. When a film is formed by a vacuum film forming method at a high rate of about 100 nm / s, a cluster is generated, so that the above-described swell structure can be generated.

  In addition, a waviness structure can also be imparted by a method such as embedding a nanoscale resin or applying a coating agent having the same refractive index after embedding.

  In particular, the use of a mesoporous silica material is particularly preferable because only a coating process such as spin coating and a baking process are performed and the burden of the process is relatively small.

(Eighth Embodiment of Organic EL Element)
The organic EL panel 1 of the above embodiment includes a blue pixel XB, a green pixel XG, and a red pixel XR so as to enable full color display. For example, as shown in FIG. The configuration of the present invention can also be adopted for the EL panel. FIG. 22 is a schematic diagram showing a cross-sectional configuration of a monochromatic bottom emission type organic EL element 1H. FIG. 22 is a diagram corresponding to FIG. 3 showing the organic EL element of the first embodiment. The same reference numerals as those shown in FIG. 3 are the same components and the same members unless otherwise specified. Shall be.

  The organic EL element 1 </ b> H of the eighth embodiment includes a single organic EL layer 60, and the light emitted from the light emitting functional layer 110 capable of emitting monochromatic (here, blue) light includes the pixel electrode 23. This is a monochromatic bottom emission type organic EL device that emits light from the side.

  The organic EL element 1H includes a directional scattering layer 35 on a substrate 20 made of a translucent material such as glass, and an anode 23 is formed on the directional scattering layer 35 with a protective layer 22 interposed therebetween. The directional scattering layer 35 has the undulation structure 31 as in the above-described embodiments, and has a directional scattering function.

  On the anode 23, a hole transport layer 70, an organic EL layer 60, a light emitting functional layer 110 including an electron transport layer 55, and a cathode 50 are formed, and a sealing layer that covers the laminate from the anode 23 to the cathode 50. 51 is formed on the protective layer 22. The organic EL layer 60 is made of an organic EL material that can emit blue light. Here, since the organic EL element 1H is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum. Also in the organic EL element 1H of this embodiment, the directional scattering layer 35 includes the undulation structure 31 and realizes suitable directional scattering, which can reduce the problems of light extraction efficiency and viewing angle. ing.

  Here, the undulation structure 31 included in the directional scattering layer 35 of the organic EL element 1H of the eighth embodiment is configured to exhibit the strongest directional scattering in the emission wavelength range of the emission color. FIG. 23 is a graph showing the spectral peak of the emission color of the organic EL layer 60. In the present embodiment, the undulation structure 31 has a random concavo-convex structure, and the average value of the undulation period is generally within the range of ± 250 nm of the spectrum peak wavelength of the emission color. That is, since the emission peak wavelength of the organic EL layer 60 of the present embodiment is 420 nm, the average value of the period of waviness is designed to be 170 nm to 670 nm.

  In the organic EL element 1H configured as described above, when a current flows between the pixel electrode 23 and the cathode 50, the organic EL layer 60 emits light, and the emitted light (blue light) passes through the anode 23 to the substrate 20 side. Or is reflected from the cathode 50 and then emitted from the substrate 20 via the anode 23. At this time, since the directional scattering layer 35 is formed on the substrate 20, the emitted light is preferably scattered and the viewing angle can be widened.

  In FIG. 24A, light (wavelength 420 nm) is incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °), and directional scattered light in transmission is detected. The result is shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). In FIG. 24B, light (420 nm) is incident on the directional scattering layer 35 from various angles (0 °, 15 °, 30 °, 60 °) to detect directional scattered light in reflection. The results are shown. The horizontal axis indicates the light receiving angle (°), and the vertical axis indicates the detection intensity (au). In FIGS. 24A and 24B, the detection intensity in the incident direction is normalized as 1 for transmission, and the detection intensity in the regular reflection direction is normalized as 1 for reflection.

  Thus, according to the directional scattering layer 35 used in this embodiment, a detection peak due to directional scattering is confirmed at ± 25 ° with respect to the incident light or reflected light direction in the vicinity of the blue wavelength in the vicinity of the blue wavelength. When the average of the undulation period approximately coincides with the wavelength, strong directional scattering appeared. Unlike the diffraction effect when a concavo-convex structure having a regular period is formed by such a undulation structure 31, even if the incident light angle changes, the incident light is almost at the same angle. Some scatter with the same directivity.

  FIG. 25A is a diagram showing transmission characteristics when the period of undulation is changed at each of incident light wavelengths of 420 nm, 550 nm, and 680 nm. FIG. 25B is an incident light wavelength of 420 nm. It is a figure which shows the reflection characteristic when changing the period of a wave | undulation in each of 550 nm and 680 nm. In FIGS. 25A and 25B, the horizontal axis indicates the average value of the waviness period, and the vertical axis indicates the absolute intensity of the detected directional scattered light.

  Shapes with different waviness periods can be formed by changing the formation film thickness of mesoporous silica from 80 nm to 200 nm. For example, when a mesoporous silica layer is formed with a film thickness of approximately 130 nm, the waviness period is 500 nm to 1050 nm, and the average period can be about 650 nm.

  The average values of the waviness periods in which directional scattered light was detected at incident light wavelengths of 420 nm, 550 nm, and 680 nm were 170 nm to 670 nm, 300 nm to 800 nm, and 430 nm to 930 nm, respectively, and −250 nm with respect to the incident light wavelength. It was in the range of ˜ + 250 nm. In the above embodiment, the detection peak due to directional scattering is ± 25 ° with respect to the incident light or reflected light direction, but the angle of the directional scattered light can be changed by changing the average value of the undulation depth. Can be controlled.

(Ninth embodiment of organic EL element)
Next, with reference to FIG. 26, the cross-sectional structure of the organic EL element in the ninth embodiment of the organic EL element constituting the organic EL panel will be described.

  26 is a view corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 are the same as those shown in FIG. 3 unless otherwise specified. Shall be.

  The organic EL element 1 </ b> I of the ninth embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the side of the substrate 20 including the pixel electrode 23.

  The organic EL element 1 </ b> I includes a protective layer 22 on a substrate 20 made of a light-transmitting material such as glass, and includes a directional scattering layer 35 on the protective layer 22. On the directional scattering layer 35, the pixel electrode 23, the monochromatic (blue) light emitting functional layer 110, a laminate composed of the cathode 50, and the sealant 51 are formed. The directional scattering layer 35 has the undulation structure 31 as in the above-described embodiments, and has a directional scattering function. Here, since the organic EL element 1I is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum.

  Also in the organic EL element 1I of this embodiment as described above, the directional scattering layer 35 includes the undulation structure 31 and realizes suitable directional scattering, which can reduce the problems of light extraction efficiency and viewing angle. ing.

(10th Embodiment of an organic EL element)
Next, with reference to FIG. 27, the cross-sectional structure of the organic EL element in the tenth embodiment of the organic EL element constituting the organic EL panel will be described.

  27 is a view corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 denote the same components and members unless otherwise specified. Shall be.

  The organic EL element 1J of the tenth embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the substrate 20 side including the pixel electrode 23.

  The organic EL element 1J includes a protective layer 22 on a substrate 20 made of a light-transmitting material such as glass, and on the opposite side of the surface of the substrate 20 where the protective layer 22 is formed (the other surface side of the substrate 20). A directional scattering layer 35 is provided. Then, a laminated body including the pixel electrode 23, the light emitting functional layer 110, and the cathode 50, and the sealing agent 51 are formed on the protective layer 22. The directional scattering layer 35 has the undulation structure 31 as in the above-described embodiments, and has a directional scattering function. Here, since the organic EL element 1J is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, For example, it is made of aluminum.

  Also in the organic EL element 1J of this embodiment as described above, the directional scattering layer 35 includes the wavy structure 31 and realizes suitable directional scattering. In particular, in the blue pixel XB, there are problems of light extraction efficiency and viewing angle. Can be reduced.

  Note that when the protective layer 22 or the anode 23 is formed on the undulation structure 31 as in the eighth and ninth embodiments, since the undulation depth is very small, the occurrence of cracks and the like does not occur. It is possible to form a layer structure. Moreover, the directional scattering layer 35 provided with the wavy structure 31 can also be formed on the surface on the viewer side (that is, on the sealing layer 51). The directional scattering layer 35 included in each of the organic EL elements of the eighth to tenth embodiments can also be formed by forming a mesoporous silica film as described above as a thin film.

(11th Embodiment of an organic EL element)
Next, with reference to FIG. 28, the structure of the unit pixel group of the organic EL element in the eleventh embodiment of the organic EL element constituting the organic EL panel will be described.

  28 is a drawing corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 denote the same components and the same members unless otherwise specified. Shall be.

  The organic EL element 1K of the eleventh embodiment is a bottom emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the substrate 20 side including the pixel electrode 23. The light emitting functional layer 110 is formed by patterning the blue organic EL layer 60B, the green organic EL layer 60G, and the red organic EL layer 60R for each pixel, thereby enabling full color display. The blue emission spectrum peak wavelength is 440 nm, the green emission spectrum peak wavelength is 520 nm, and the red emission spectrum peak wavelength is 630 nm.

  The organic EL element 1 </ b> K includes a directional scattering layer 35 on a substrate 20 made of a light-transmitting material such as glass, and a protective layer 22 is formed on the substrate 20 including the directional scattering layer 35. On the protective layer 22, a stacked body including the pixel electrode 23, the light emitting functional layer 110, and the cathode 50, and a sealing agent 51 are formed. Since the organic EL element 1K is a bottom emission type, the pixel electrode 23 is made of a light-transmitting conductive material, for example, ITO (indium tin oxide), while the cathode 50 is a light-reflective conductive material, for example, It is made of aluminum.

  Here, the directional scattering layer 35 is patterned as a blue directional scattering layer 35B, a green directional scattering layer 35G, and a red directional scattering layer 35R for each pixel of each color, and each directional scattering layer 35B, 35G, 35R has different undulation structures 31B, 31G, and 31R. Specifically, in the blue directional scattering layer 35B of the blue pixel, the undulation period of the undulation structure 31B is approximately 200 nm to 690 nm, and the average value of the undulation period is approximately 450 nm. In the green directional scattering layer 35G of the green pixel, the undulation period of the undulation structure 31G is about 270 nm to 770 nm, and the average value of the undulation period is about 510 nm. In the red directional scattering layer 35R of the red pixel, the undulation period of the undulation structure 31R is approximately 400 nm to 980 nm, and the average value of the undulation period is approximately 650 nm.

  Each of the directional scattering layers 35B, 35G, and 35R is formed by spin and flexographic printing by dividing the alkoxysilane solution into several times, for example, so that the mesoporous silica films are formed with thicknesses of 175 nm, 155 nm, and 135 nm, respectively. Alternatively, it can be formed by using an inkjet method or the like.

  Also in the organic EL element 1K of this embodiment as described above, the patterned directional scattering layers 35B, 35G, and 35R are provided with the undulating structures 31B, 31G, and 31R, and realize suitable directional scattering. It is said that the problem of extraction efficiency and viewing angle can be reduced. Specifically, when the R, G, and B colors are turned on and white is displayed as compared with an organic EL element that does not include the directional scattering layer 35, the viewer has 1.5 times the energy. It was possible to take out to the air layer.

  In this embodiment, the directional scattering layer having a wave structure corresponding to the wavelength of the color is formed on all the color pixels. However, in order to improve the color of the panel, there is a color for which the extraction efficiency is particularly desired to be increased. In this case, the directional scattering layer 35 may be selectively formed only in the portion corresponding to the pixel.

  In addition, in a full-color organic EL panel, when a single color is desired to increase the extraction efficiency, even when a directional scattering layer 35 having a wave structure corresponding to the color is formed on the entire surface of the substrate, It is possible to selectively improve the light extraction efficiency.

  Further, the interface for forming the directional scattering layers 35B, 35G, and 35R for each color is not limited to the interface between the substrate 20 and the protective layer 22 as shown in FIG. 28, and for example, as shown in FIG. 29, between the protective layer 22 and the anode 23. The directional scattering layers 35B, 35G, and 35R may be formed on the outer surface of the substrate 20 (a surface different from the surface on which the protective layer 22 is formed) as shown in FIG.

(12th Embodiment of an organic EL element)
Next, with reference to FIG. 31, the cross-sectional structure of the organic EL element will be described for the twelfth embodiment of the organic EL element constituting the organic EL panel.

  FIG. 31 is a drawing corresponding to FIG. 3 showing the first embodiment of the organic EL element. The same reference numerals as those shown in FIG. 3 are the same as those shown in FIG. 3 unless otherwise specified. Shall be.

  The organic EL element 1N of the twelfth embodiment is a top emission type organic EL element in which light emitted from the light emitting functional layer 110 is emitted from the color filter substrate 40 side formed on the cathode 50 side. In particular, the light emitting functional layer 110 is composed of a blue monochromatic organic EL layer 60, and the organic EL element 1N is of a monochromatic top emission method. That is, the monochromatic top which includes the single organic EL layer 60 and emits light emitted from the light emitting functional layer 110 capable of emitting monochromatic (blue here) light from the substrate 40 side including the blue color filter layer 42B. This is an emission type organic EL element.

  The organic EL element 1N includes a reflective layer 21 on a substrate 20 made of a light-transmitting material such as glass, and an anode 23 is formed on the reflective layer 21 with a protective layer 22 interposed therebetween. On the anode 23, a hole transport layer 70, an organic EL layer 60, a light emitting functional layer 110 including an electron transport layer 55, and a cathode 50 are formed, and a sealing layer that covers the laminate from the anode 23 to the cathode 50. 51 is formed on the protective layer 22. A filler 33 filled in a region surrounded by the sealant 32 is disposed on the sealing layer 51, and the color filter substrate 40 is formed thereon.

  The color filter substrate 40 includes a substrate 41, a directional scattering layer 35 disposed on the inner surface side (filler 33 side) of the substrate 41, and a blue color filter disposed on the inner surface side of the directional scattering layer 35. A layer 42B and an overcoat layer 43 disposed on the inner surface side of the directional scattering layer 35 including the color filter layer 42B are configured.

  Also in the organic EL element 1N of this embodiment, the directional scattering layer 35 includes the undulating structure 31 and realizes suitable directional scattering, which can reduce the problems of light extraction efficiency and viewing angle. ing. In the case of the present embodiment, since the undulation depth is very small, it is possible to form a layer structure on the upper part without causing cracks and the like.

  Further, the interface on which the directional scattering layer 35 is formed in the color filter substrate 40 is not limited to the interface between the substrate 41 and the color filter layer 42B as shown in FIG. 31, for example, an organic EL element 1O shown in FIG. Further, it can be disposed at the interface between the overcoat layer 43 and the filler 33, or can be disposed on the outer surface side (a surface side different from the filler 33) of the substrate 41 as in the organic EL element 1P shown in FIG. Or you may arrange | position in the interface of the color filter layer 42B and the overcoat layer 43 like the organic EL element 1Q shown in FIG.

  Although several embodiments of the light emitting device of the present invention have been described above, the present invention is not limited to such a form.

  For example, the light-emitting device of the above embodiment includes the directional scattering layer 35 having the wavy structure 31 at the interface between the substrate 41 and the color filter layer 42, and the directional scattering layer 35 is disposed at the interface between the other thin films. Can be set. Specifically, the substrate 20, the reflective layer 21, the protective layer 22, the anode 23, the hole transport layer 70, the light emitting layer 60, the electron transport layer 55, the cathode 50, the filler 33, the overcoat layer 43, and the color filter layer 42. It can be disposed at any interface of the substrate 41.

  For example, the configuration of the present invention can also be applied to the case where the organic EL layer (light emitting layer) is white display of low molecular organic EL and two or more light emitting layers are laminated. In this case, the interface for forming the directional scattering layer is not particularly limited as in the above embodiment.

  Here, when there are two or more emission spectrum peaks, two directional scattering layers each having a wavy structure (that is, a wavy period of ± 250 nm of each peak wavelength) having a configuration matched to each peak wavelength. By superimposing the above, the light extraction efficiency can be increased, and the viewing angle can be suitably widened. Further, even when a directional scattering layer having a wavy structure corresponding to only one of the spectral peak wavelengths (that is, the wavy period is ± 250 nm of the peak wavelength) is provided, about 1.2 times to 1.5 times the energy can be taken out to the air layer on the viewer side.

  The same applies to the case of three peaks, each of which forms a directional scattering layer having a wavy structure (that is, the waviness period is ± 250 nm of each peak wavelength) having a configuration matched to each peak wavelength. Alternatively, a directional scattering layer having a wave structure (that is, a wave period of ± 250 nm of each peak wavelength) having a configuration matched to any two peak wavelengths is formed, or any one peak wavelength By forming a directional scattering layer having a wave structure having a configuration matched to (that is, a wave period of ± 250 nm of the peak wavelength), the effect according to the present invention can be exhibited.

  In addition, in the emission spectrum of two peaks, the emission intensity of green in particular is originally low, and the color rendering function of the panel may be insufficient. In this case, it is possible to selectively and efficiently emit light of a color with low emission intensity by forming a wave structure corresponding to a wavelength of a color with low emission intensity (that is, a wave period of ± 250 nm of the peak wavelength). It can be taken out to the air layer and can be used to enhance the color rendering properties of the panel.

  In addition, a wave structure corresponding to the emission spectrum peak wavelength (that is, the wave period is ± 250 nm of the peak wavelength) may be formed on the top emission full color organic EL element as shown in FIG. it can. In pixels arranged in a matrix form, it is formed by separately applying light emitting material by mask vapor deposition, creating white light emission by using a microcavity, even if using a microcavity by separately applying a light emitting material, A scattering effect is obtained in the same way. Specifically, using a light emitting material having a blue emission spectrum peak of 465 nm, a green spectrum peak of 525 nm, and a red spectrum peak of 630 nm, a wave structure can be formed at a matrix position corresponding to each color pixel. Here, in the blue portion, the swell period is approximately 200 nm to 730 nm, and the average value of the swell period is approximately 450 nm. In the green portion, the swell period is approximately 300 nm to 775 nm, and the average value of the swell period is approximately. The undulation structure can be formed so that the undulation period is approximately 400 nm to 980 nm and the average value of the undulation period is approximately 650 nm in the red portion so as to be 550 nm. In this case, when each of the red, green, and blue pixels is lit and white is displayed, 1.62 times as much energy as in the case where the undulation structure is not provided can be taken out to the air layer where the viewer is present.

  In such a structure, an alkoxysilane solution is divided into several times and spin, flexographic printing, or an ink jet method is adopted so that a mesoporous silica film is formed with a thickness of 170 nm, 140 nm, and 135 nm. Can be formed. In this case, by forming mesoporous silica with a film thickness of approximately 40 nm to 200 nm as an example, a structure that expresses directional scattering in the visible light region can be formed. For example, it was possible to form a swell structure expressing directional scattering in the wavelength region of red in the film thickness of 110 nm to 140 nm, green in the film thickness of 140 nm to 159 nm, and blue in the film thickness of 160 nm to 230 nm.

In addition to forming a structure that corresponds to the wavelength of the color for all pixels of each color, and to improve the color of the panel, if there is a color that you want to improve the extraction efficiency, select only the part corresponding to that pixel. A wavy structure may be formed. In addition, in a full color display, when a single color is desired to improve the extraction efficiency, a wavy structure having a wavy period corresponding to the spectral peak wavelength of the color may be formed on the entire surface of the substrate.
(Electronics)
Next, the electronic apparatus of the present invention will be described.

  The electronic device has the organic EL panel 1 described above as a display unit, and specifically, the one shown in FIG.

  FIG. 35A is a perspective view showing an example of a mobile phone. In FIG. 35A, a mobile phone 1000 includes a display unit 1001 using the organic EL panel 1 described above.

  FIG. 35B is a perspective view showing an example of a wristwatch type electronic apparatus. In FIG. 35B, a timepiece 1100 includes a display unit 1101 using the organic EL panel 1 described above.

  FIG. 35C is a perspective view showing an example of a portable information processing apparatus such as a word processor or a personal computer. 35C, the information processing device 1200 includes an input unit 1201 such as a keyboard, a display unit 1202 using the organic EL panel 1 described above, and an information processing device body (housing) 1203.

  Each of the electronic devices shown in FIGS. 35A to 35C includes the display units 1001, 1101, and 1202 each including the organic EL panel (organic EL device) 1 described above, and thus the display unit is configured. As a result, the luminance of the organic EL device is increased and the color shift is suppressed.

The schematic diagram which shows the wiring structure of the organic electroluminescent panel which concerns on the organic electroluminescent apparatus of this invention. The top view which shows typically the structure of the organic electroluminescent panel which concerns on the organic electroluminescent apparatus of this invention. 1 is a cross-sectional view schematically showing a configuration of an organic EL element according to a first embodiment of the present invention. The top view which shows typically the structure of the wave | undulation structure with which the organic EL element which concerns on 1st Embodiment is provided. The side view which shows typically the structure of the wave | undulation structure with which the organic EL element which concerns on 1st Embodiment is provided. The figure which shows the detection result of the directional scattered light (450 nm) in transmission of the directional scattering layer which concerns on 1st Embodiment. The figure which shows the detection result of the directional scattered light (450 nm) in the reflection of the directional scattering layer which concerns on 1st Embodiment. The table | surface which shows the relationship between the depth of the wave | undulation structure in 450 nm, and the angle of directional scattering. The figure which shows the detection result of the directional scattered light (550 nm) in the transmission of the directional scattering layer which concerns on 1st Embodiment. The figure which shows the detection result of the directional scattered light (550 nm) in the reflection of the directional scattering layer which concerns on 1st Embodiment. The figure which shows the detection result of the directional scattered light (650 nm) in the transmission of the directional scattering layer which concerns on 1st Embodiment. The figure which shows the detection result of the directional scattered light (650 nm) in the reflection of the directional scattering layer which concerns on 1st Embodiment. Sectional drawing which shows typically the structure of the organic EL element which concerns on 2nd Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 3rd Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 4th Embodiment of this invention. The organic EL element which concerns on 1st Embodiment WHEREIN: The graph of the energy radiated | emitted in the air by the side of the viewer with respect to the current density when displaying white. The table | surface which shows the result of having measured only the blue pixel XB in the organic EL element which concerns on 1st Embodiment, and having measured the chromaticity observed from the 0 degree direction and the 45 degree direction. The table | surface which shows the result of having measured the chromaticity observed from the 0 degree direction and 45 degree direction when displaying white in the organic EL element which concerns on 1st Embodiment. Sectional drawing which shows typically the structure of the organic EL element which concerns on 5th Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 6th Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 7th Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 8th Embodiment of this invention. The graph which shows the spectrum peak of the luminescent color of an organic electroluminescent layer. The figure which shows the detection result of the directional scattered light (650 nm) in transmission (a) and reflection (b) of the directional scattering layer which concerns on 9th Embodiment. The figure which shows the transmission characteristic (a) and reflection characteristic (b) when changing the period of a wave | undulation about a different incident light wavelength. Sectional drawing which shows typically the structure of the organic EL element which concerns on 9th Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 10th Embodiment of this invention. Sectional drawing which shows typically the structure of the organic EL element which concerns on 11th Embodiment of this invention. Sectional drawing which shows the structure of the other modification of an organic EL element typically. Sectional drawing which shows the structure of the other modification of an organic EL element typically. Sectional drawing which shows typically the structure of the organic EL element which concerns on 12th Embodiment of this invention. Sectional drawing which shows the structure of the other modification of an organic EL element typically. Sectional drawing which shows the structure of the other modification of an organic EL element typically. Sectional drawing which shows the structure of the other modification of an organic EL element typically. The figure which shows an electronic device provided with the organic electroluminescent apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Substrate, 21 ... Reflective layer, 22 ... Protective layer, 23 ... Anode (pixel electrode), 31 ... Waviness structure, 33 ... Filler, 35 ... Directional scattering layer, 40 ... Color filter substrate, 41 ... Substrate, 42 ... color filter layer, 43 ... overcoat layer, 50 ... cathode (counter electrode), 55 ... electron transport layer, 60 ... light emitting layer, 70 ... hole transport layer.

Claims (10)

A light emitting device in which a plurality of thin films including a light emitting layer are laminated,
A light emitting device comprising a wave structure that exhibits a scattering function having directivity at any interface of the thin film.   The light-emitting device according to claim 1, wherein the undulation structure includes a plurality of irregularities arranged at random, and the irregularities have a smooth surface.   The light emitting device according to claim 2, wherein the waviness structure is configured such that a distance between adjacent convex portions is in a range of 300 nm to 1200 nm.   3. The light emitting device according to claim 2, wherein the waviness structure is configured such that a distance between adjacent convex portions is in a range of −250 nm to +250 nm of a spectral peak wavelength of an emission color in the light emitting layer.   5. The light-emitting device according to claim 2, wherein the undulation structure is configured such that a height between a convex top portion and a concave bottom portion is in a range of 50 nm to 500 nm.   5. The light emitting device according to claim 1, wherein the waviness structure occupies 30% or more of the total area of the interface of the thin film. A method of manufacturing a light-emitting device comprising a plurality of thin films including a light-emitting layer, and having a waved structure that expresses a scattering function having directivity at any interface of the thin film,
A method of manufacturing a light-emitting device, comprising a wavy structure forming step of forming a wavy structure by forming a film of mesoporous silica by a spin coating method.   8. The method for manufacturing a light emitting device according to claim 7, wherein, in the undulating structure forming step, film forming conditions are designed so that the film made of the mesoporous silica has a thickness of 10 nm to 300 nm.   The swell structure forming step includes a step of spin coating a silicon alkoxide solution having a solid content concentration of 3 wt% to 8 wt% at a rotation speed of 1500 rpm to 4000 rpm, and 300 ° C. to 400 ° C. in a vacuum for 0.5 hours to 5 hours. The method for manufacturing a light emitting device according to claim 7, further comprising a step of performing baking for a time.   An electronic apparatus comprising the light-emitting device according to claim 1.

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