WO2012017751A1

WO2012017751A1 - Organic light emitting element, organic light emitting device, and color conversion method

Info

Publication number: WO2012017751A1
Application number: PCT/JP2011/064392
Authority: WO
Inventors: 大江　昌人; 近藤　克己
Original assignee: シャープ株式会社
Priority date: 2010-08-04
Filing date: 2011-06-23
Publication date: 2012-02-09

Abstract

Disclosed is an organic light emitting element which comprises: an organic EL light emitting unit that contains at least one organic layer including a light emitting layer and a pair of electrodes that sandwich the organic layer; a fluorescence conversion layer that is arranged on the light extraction side of the organic EL light emitting unit and performs fluorescence conversion of the incident light; and a wavelength conversion layer that is arranged between the organic EL light emitting unit and the fluorescence conversion layer, converts the wavelength of the light emitted from the organic EL light emitting unit and then discharges the resulting light toward the fluorescence conversion layer side.

Description

Organic light emitting device, organic light emitting device, and color conversion method

The present invention relates to an organic light emitting device, an organic light emitting device, and a color conversion method.
This application claims priority on August 4, 2010 based on Japanese Patent Application No. 2010-175521 filed in Japan, the contents of which are incorporated herein by reference.

In general, an electroluminescence (EL) element is self-luminous and has high visibility and is a completely solid element. Therefore, the EL element has excellent impact resistance and is easy to handle. Therefore, the EL element is attracting attention as a light emitting element in various display devices. The EL element includes an inorganic EL element using an inorganic compound as a light emitting material and an organic EL element using an organic compound as a light emitting material. Among these, organic EL elements have been actively researched for practical use since the applied voltage can be significantly reduced.

Conventionally, in order to make an organic EL element a multicolor light emitting element, pixels emitting red, green and blue are juxtaposed as one unit. Thereby, full colorization is performed by creating various colors typified by white (for example, see Non-Patent Document 1). In order to realize this, a method of forming red, green, and blue pixels by separately coating the organic light emitting layer by a mask vapor deposition method using a shadow mask is adopted. However, in this method, mask processing accuracy, mask alignment accuracy, and mask enlargement are major issues. In particular, in the field of large displays typified by television, the size of the mother glass for taking out the substrate has increased from the sixth generation (G6) to G8 and G10, and the substrate size has been increasing. Since the conventional method requires a mask having a size equal to or larger than the substrate size, it is necessary to manufacture and process a mask corresponding to a large substrate. Since this mask requires a very thin metal (general film thickness: 50 nm to 100 nm), it is difficult to increase the size of the mask.

低下 Lowering of mask processing accuracy and alignment accuracy causes color mixing due to mixing of the light emitting layers. In order to prevent such a decrease in accuracy, it is necessary to increase the width of the insulating layer normally provided between the pixels. However, when the area of the pixel is determined, the area of the non-light emitting portion is reduced and the aperture ratio of the pixel is lowered, leading to a decrease in luminance, an increase in power consumption, and a decrease in lifetime. Further, in the conventional manufacturing method, the organic material that is the vapor deposition source is disposed below the substrate, and the organic layer is formed by depositing and vaporizing constituent particles of the vapor deposition source from the bottom upward. Yes. For this reason, as the substrate and the mask are increased in size, the mask is bent at the central portion, which causes color mixture of the light emitting layer as described above. In extreme cases, a portion where the organic layer is not formed is formed, which may lead to defects due to leakage of the upper and lower electrodes. Furthermore, in the conventional method, when the mask is used a specific number of times, the mask deteriorates and becomes unusable. Therefore, an increase in the size of the mask leads to an increase in display cost. In particular, the cost problem is regarded as the biggest problem in the organic EL display.

A light conversion method is disclosed in which a fluorescent material that absorbs light in the light emitting region of the organic light emitting layer and emits fluorescence in the visible light region is used as a filter without coating the organic light emitting layer for each color (for example, Patent Documents). 1 and 2). An example of this light conversion type organic light emitting device is shown in FIG.
An organic light emitting device 200 illustrated in FIG. 12 includes an organic EL 210, a green pixel, a red pixel, and a blue pixel between a substrate 230 and a transparent substrate 240. The organic EL 210 sandwiches a light emitting layer 211 that emits blue to blue green light with a pair of

electrodes

212 and 213. The green pixel has a fluorescence conversion layer 220G that absorbs blue to blue-green light emitted from the organic EL 210 and emits green light. The red pixel has a fluorescence conversion layer 220R that absorbs blue to blue-green light emitted from the organic EL 210 and emits red light. The blue pixel may be provided with a blue color filter (not shown) for the purpose of improving color purity as necessary. By combining the green pixel, the red pixel, and the blue pixel, red, green, and blue light can be emitted to the transparent substrate 240 side to emit full color.
Such a light conversion method is superior to the above-described separate coating method in that it is not necessary to pattern the organic light emitting layer and can be easily manufactured, and in terms of cost. For this reason, display devices that perform full color conversion using a light conversion method are promising and research and development are underway.

Japanese Patent Laid-Open No. 3-152897 JP-A-5-258860

However, in a light conversion method such as the organic light emitting device 200 shown in FIG. 12, an organic EL 210 that emits light in a blue region is used as a light source. A material that emits light in a blue region, in particular, a blue phosphorescent material, is inferior in terms of light emission efficiency (luminance) and life compared to a red light emitting material and a green light emitting material, and is under development. Therefore, in the conventional structure in which blue light is emitted from the organic EL and the light is color-converted by the fluorescence conversion layer, it is not possible to obtain an organic light-emitting element with high emission efficiency and long life. In order to excite the fluorescent material contained in the phosphor conversion layer and convert it into red or green fluorescence, the excitation light of the fluorescent material requires light in the blue to blue-green region with a shorter wavelength than the converted fluorescence. However, there is no blue phosphorescent material with high efficiency (high brightness) and long life.
One embodiment of the present invention provides a high-efficiency (high luminance) organic light-emitting element, an organic light-emitting device, and a color conversion method.

The present inventors arrange an organic light emitting element suitable for the purpose by arranging a layer having a function of converting the wavelength of light emitted from the organic EL light emitting part between the organic EL light emitting part and the fluorescence conversion layer. I found that I could do it.

An organic light emitting device according to an aspect of the present invention includes an organic EL light emitting unit including at least one organic layer including a light emitting layer and a pair of electrodes sandwiching the organic layer, and extracts light from the organic EL light emitting unit. A fluorescence conversion layer that is disposed on the surface side and converts fluorescence of incident light, and is disposed between the organic EL light emitting unit and the fluorescence conversion layer, and converts the wavelength of light emitted from the organic EL light emitting unit. And a wavelength conversion layer that emits light toward the fluorescence conversion layer.
In the organic light emitting device according to one aspect of the present invention, the electrode is a reflective electrode, and the optical film thickness between the reflective interfaces defined by the pair of reflective electrodes is light emitted from the organic EL light emitting unit. May be set so as to enhance the intensity of light of a specific wavelength.
In the organic light-emitting device according to one aspect of the present invention, the wavelength conversion layer may convert the wavelength of light emitted from the organic EL light-emitting unit into one half.
In the organic light emitting device according to the aspect of the present invention, the wavelength conversion layer may be configured by stacking a plurality of layers in which polarization directions are alternately reversed.

In the organic light emitting device according to the aspect of the present invention, the wavelength conversion layer may be configured by alternately stacking semiconductor layers and dielectric layers.
In the organic light emitting device according to an aspect of the present invention, each of the plurality of layers constituting the wavelength conversion layer may be made of a unipolarized dielectric material.
In the organic light emitting device according to an aspect of the present invention, the dielectric material may be made of a material selected from the group consisting of a ferroelectric material, a glass material, and a polymer material.
In the organic light emitting device according to one aspect of the present invention, the organic EL light emitting unit may emit light in a red region.
In the organic light emitting device according to one aspect of the present invention, the organic EL light emitting unit may emit light in a green region.

The organic light emitting device according to one aspect of the present invention further includes a light reflective layer on a light extraction surface side of the light converted by the wavelength conversion layer, and a surface from which the light from the light reflective layer and the organic EL light emitting unit is extracted. The optical film thickness of the reflective interface defined by the reflective electrode on the side may be set so as to enhance the intensity of light of a specific wavelength among the light converted in wavelength in the wavelength conversion layer.
In the organic light-emitting device according to an aspect of the present invention, the wavelength conversion layer converts light emitted from the organic EL light-emitting portion into light in an ultraviolet region to a blue region, and the fluorescence conversion layer converts the light in the wavelength conversion layer. The emitted light may be converted into light in the green region or light in the red region.
In the organic light-emitting device according to one aspect of the present invention, the fluorescence conversion layer can perform at least two types of color conversion, one of which is color conversion that converts light converted by the wavelength conversion layer into light in a green region. And the other one is color conversion for converting light converted by the wavelength conversion layer into light in the red region, and the organic light emitting element may be a multicolor light emitting element.
In the organic light emitting device according to one embodiment of the present invention, a color filter may be further provided on the side of emitting the light converted by the fluorescence conversion layer.

The organic light emitting device according to an aspect of the present invention may be configured to be provided with a drive unit that drives the organic EL light emitting unit of the organic light emitting device in the organic light emitting device.
The color conversion method according to one aspect of the present invention emits light from an organic EL light emitting unit including at least one organic layer including a light emitting layer, and a pair of electrodes sandwiching the organic layer, By converting the wavelength of the light emitted from the organic EL light emitting unit by the wavelength conversion layer disposed between the fluorescence conversion layer that converts the incident light to fluorescence, and emitting the converted light to the fluorescence conversion layer side, The light converted by the wavelength conversion layer is converted to fluorescence by the fluorescence conversion layer to generate visible light.
In the color conversion method according to an aspect of the present invention, the wavelength conversion layer may convert the wavelength of light emitted from the organic EL light emitting unit into one half.
In the color conversion method according to an aspect of the present invention, the wavelength conversion layer may be a stacked body including a plurality of layers in which polarization directions are alternately reversed.
In the color conversion method according to the aspect of the present invention, the wavelength conversion layer may be a stacked body in which semiconductor layers and dielectric layers are alternately stacked.

According to one embodiment of the present invention, a high-efficiency (high luminance) organic light-emitting element, an organic light-emitting device, and a color conversion method can be provided.

It is a schematic sectional drawing which shows an example of the organic light emitting element which concerns on 1st Embodiment of this invention. It is a top view of the organic light emitting element shown in FIG. It is a figure explaining wavelength conversion by quasi phase matching (QPM), and is a figure explaining the relation between polarization reversal and propagation distance. It is a figure explaining wavelength conversion by quasi phase matching (QPM), and is a figure explaining a QPM device typically. It is a schematic diagram which shows an example of the wavelength conversion layer of the organic light emitting element which concerns on 1 aspect of this invention. It is a schematic diagram which shows the other example of the wavelength conversion layer of the organic light emitting element which concerns on 1 aspect of this invention. It is a schematic sectional drawing which shows the other example of the organic light emitting element which concerns on 1st Embodiment of this invention. It is a schematic sectional drawing which shows an example of the organic light emitting element which concerns on 2nd Embodiment of this invention. It is a schematic sectional drawing which shows an example of the organic light emitting element which concerns on 3rd Embodiment of this invention. It is a schematic sectional drawing which shows an example of the organic light emitting element which concerns on 4th Embodiment of this invention. It is a schematic block diagram which shows the other example of the organic light emitting element which concerns on 4th Embodiment of this invention. It is a figure which shows an example of the connection structure of the wiring structure of an organic light-emitting device provided with the organic light-emitting element which concerns on 1 aspect of this invention, and a drive unit, and a drive circuit. It is a schematic sectional drawing which shows an example of the conventional organic light emitting element of a color conversion system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of FIGS. 1 to 10, each member is shown with a different scale so that each member has a size that can be recognized on the drawing.
[First Embodiment]
FIG. 1 is a schematic cross-sectional view illustrating an example of the organic light-emitting device according to the first embodiment of the present invention, and FIG. 2 is a top view of the organic light-emitting device shown in FIG.
An organic light emitting device 20 shown in FIG. 1 includes a substrate 1, an organic EL light emitting unit (light source) 10, a sealing substrate 9, a fluorescence conversion layer 8R, a green fluorescence conversion layer 8G, a blue fluorescence conversion layer 8B, and a wavelength conversion. Layer 18. The substrate 1 has a TFT (Thin Film Transistor) circuit 2. The organic EL light emitting unit (light source) 10 is provided on the substrate 1 via the interlayer insulating film 3 and the planarizing film 4. The fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B are partitioned by the black matrix 7 and arranged in parallel on one surface of the sealing substrate 9. The wavelength conversion layer 18 is disposed between the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B.
The substrate 1 and the sealing substrate 9 are arranged such that the organic EL light emitting unit 10 and the fluorescence conversion layers 8R, 8G, and 8B face each other with the sealing material 6 and the wavelength conversion layer 18 interposed therebetween. The organic EL light emitting unit 10 and the wavelength conversion layer 18 are covered with the inorganic sealing film 5. In the organic EL light emitting unit 10, an organic EL layer (organic layer) 17 is sandwiched between the first electrode 12 and the second electrode 16. A reflective electrode 11 is formed on the lower surface of the first electrode 12. The organic EL layer (organic layer) 17 is a stack of a hole transport layer 13, a light emitting layer 14, and an electron transport layer 15. The reflective electrode 11 and the first electrode 12 are connected to one of the TFT circuits 2 by a wiring 2 b provided through the interlayer insulating film 3 and the planarizing film 4. The second electrode 16 is connected to one of the TFT circuits 2 by a wiring 2 a provided through the interlayer insulating film 3, the planarizing film 4 and the edge cover 19.

The wavelength conversion layer 18 converts the wavelength of the light emitted from the organic EL light emitting unit 10 and emits it to the fluorescence conversion layers 8R, 8G, and 8B side. The light emitted from the wavelength conversion layer 18 and incident on the fluorescence conversion layers 8R, 8G, and 8B is converted into red, green, and blue light by the fluorescence conversion layers 8R, 8G, and 8B, respectively. Injected to the sealing substrate 9 side. Therefore, in the organic light emitting device 20 of the present embodiment, the wavelength of the light emitted from the organic EL light emitting unit 10 that is a light source is converted by the wavelength conversion layer 18. This wavelength-converted light enters each of the fluorescence conversion layers 8R, 8G, and 8B. The incident light is converted into fluorescence in each of the fluorescence conversion layers 8R, 8G, and 8B, and emitted to the sealing substrate 9 side (observer side) as light of three colors of red, green, and blue. Yes. In addition, the detail of the structure of each part which comprises the organic light emitting element 20 shown in FIG. 1 is mentioned later.

The organic light emitting device 20 of the present embodiment shows an example in which the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B are juxtaposed one by one in FIG. . However, as shown in the top view of FIG. 2, the fluorescence conversion layers 8R, 8G, and 8B surrounded by a broken line extend in a stripe shape along the y-axis, and each

fluorescence conversion layer

8R, 8G along the x-axis. , 8B are sequentially arranged in a two-dimensional stripe arrangement. The example shown in FIG. 2 shows an example in which each RGB pixel (each

fluorescence conversion layer

8R, 8G, 8B) is arranged in stripes, but the present invention is not limited to this, and the arrangement of each RGB pixel is a mosaic. A conventionally known RGB pixel array such as an array or a delta array may be used.

A TFT circuit 2 and various wirings (not shown) are formed on the substrate 1. An interlayer insulating film 3 and a planarizing film 4 are sequentially stacked so as to cover the upper surface of the substrate 1 and the TFT circuit 2.
As the substrate 1, for example, an inorganic material substrate made of glass, quartz or the like, a plastic substrate made of polyethylene terephthalate, polycarbazole, polyimide or the like, an insulating substrate such as a ceramic substrate made of alumina or the like, aluminum (Al), iron (Fe ), Etc., a substrate on which an insulating material such as silicon oxide (SiO ₂ ) is coated on the surface, or a method of anodizing the surface of a metal substrate made of Al or the like Although the board | substrate etc. which performed the insulation process are mentioned by this, this invention is not limited to these. Among these, since it becomes possible to form a bending part and a bending part without stress, it is preferable to use a plastic substrate or a metal substrate. It is more preferable to use a substrate in which a plastic substrate is coated with an inorganic material and a substrate in which a metal substrate is coated with an inorganic insulating material. As a result, it is possible to eliminate the deterioration of the organic EL light emitting unit 10 due to the permeation of moisture, which may occur when a plastic substrate is used as the substrate of the organic EL light emitting unit 10. In addition, it is possible to eliminate a leak (short circuit) caused by the protrusion of the metal substrate that may occur when the metal substrate is used as the substrate of the organic EL light emitting unit 10.

In order to form the TFT circuit 2 on the base material 1, it is preferable to use a substrate that does not melt at a temperature of 500 ° C. or less and does not cause distortion. When a metal substrate is used as the substrate 1, it is preferable to use a metal substrate formed of an iron-nickel alloy having a linear expansion coefficient of 1 × 10 ⁻⁵ / ° C. or less. Since a general metal substrate has a thermal expansion coefficient different from that of glass, it is difficult to form the TFT circuit 2 on the metal substrate with an available production apparatus. However, using a metal substrate formed of an iron-nickel alloy having a linear expansion coefficient of 1 × 10 ⁻⁵ / ° C. or less, and matching the linear expansion coefficient with glass, the TFT circuit 2 is conventionally formed on the metal substrate. It can be formed at low cost using the production apparatus. Moreover, when using a plastic substrate as the base material 1, the heat-resistant temperature is very low. Therefore, it is possible to transfer and form the TFT circuit 2 on the plastic substrate by forming the TFT circuit 2 on the glass substrate and then transferring the TFT substrate 2 to the plastic substrate.

The TFT circuit 2 is formed on the substrate 1 in advance before the organic EL light emitting unit 10 is formed, and functions as a switching device and a driving device. As the TFT circuit 2, a conventionally known TFT circuit 2 can be used. In this embodiment, a metal-insulator-metal (MIM) diode can be used instead of the TFT for switching and driving.
The TFT circuit 2 can be formed using a known material, structure, and formation method. As the material of the active layer of the TFT circuit 2, for example, amorphous silicon (amorphous silicon), polycrystalline silicon (polysilicon), microcrystalline silicon, inorganic semiconductor materials such as cadmium selenide, zinc oxide, indium oxide-oxide Examples thereof include oxide semiconductor materials such as gallium-zinc oxide, and organic semiconductor materials such as polythiophene derivatives, thiophene oligomers, poly (p-ferylene vinylene) derivatives, naphthacene, and pentacene. Examples of the structure of the TFT circuit 2 include a stagger type, an inverted stagger type, a top gate type, and a coplanar type.

As a method for forming the active layer constituting the TFT circuit 2, for example, there are the following methods. (1) A method in which impurities are ion-doped into amorphous silicon formed by a plasma enhanced chemical vapor deposition (PECVD) method. (2) Amorphous silicon was formed by a low pressure chemical vapor deposition (LPCVD) method using silane (SiH ₄ ) gas, and the amorphous silicon was crystallized by a solid phase growth method to obtain polysilicon. Thereafter, ion doping is performed by ion implantation. (3) After amorphous silicon is formed by LPCVD method using Si ₂ H ₆ gas or PECVD method using SiH ₄ gas, annealed by laser such as excimer laser, and amorphous silicon is crystallized to obtain polysilicon , A method of performing ion doping (low temperature process). (4) A polysilicon layer is formed by LPCVD method or PECVD method, and a gate insulating film is formed by thermal oxidation at 1000 ° C. or higher, and an n ⁺ polysilicon gate electrode is formed thereon, and then an ion Doping method (high temperature process). (5) A method of forming an organic semiconductor material by an inkjet method or the like. (6) A method for obtaining a single crystal film of an organic semiconductor material.

The gate insulating film of the TFT circuit 2 used in this embodiment can be formed using a known material. Examples thereof include SiO ₂ formed by PECVD, LPCVD, etc., or SiO ₂ obtained by thermally oxidizing a polysilicon film. Further, the signal electrode line, the scanning electrode line, the common electrode line, the first drive electrode, and the second drive electrode of the TFT circuit 2 used in the present embodiment can be formed using a known material, for example, tantalum. (Ta), aluminum (Al), copper (Cu), and the like.

The interlayer insulating film 3 can be formed using a known material, for example, silicon oxide (SiO ₂ ), silicon nitride (SiN or Si ₂ N ₄ ), tantalum oxide (TaO or Ta ₂ O). ₅ )) or an organic material such as an acrylic resin or a resist material.
Examples of the method for forming the interlayer insulating film 3 include a dry process such as a chemical vapor deposition (CVD) method and a vacuum deposition method, and a wet process such as a spin coating method. Moreover, it can also pattern by the photolithographic method etc. as needed.
In the organic light emitting device 20 of the present embodiment, as described later, light emitted from the organic EL light emitting unit 10 is extracted from the side opposite to the substrate 1 (the wavelength conversion layer 18 and the fluorescence conversion layers 8R, 8G, and 8B side). . Therefore, in order to prevent external light from entering the TFT circuit 2 formed on the substrate 1 and changing the TFT characteristics, the interlayer insulating film 3 (light-shielding insulating film) having light-shielding properties is used. Is preferred. In the present embodiment, the interlayer insulating film 3 and the light-shielding insulating film can be used in combination. Examples of the light-shielding insulating film include those obtained by dispersing pigments or dyes such as phthalocyanine and quinaclone in polymer resins such as polyimide, color resists, black matrix materials, inorganic insulating materials such as Ni _x Zn _y Fe ₂ O _{4, and the} like. It is done.

The flattening film 4 is provided to prevent a defect or the like of the organic EL light emitting unit 10 from being generated due to unevenness of the surface of the TFT circuit 2. Examples of the defect of the organic EL light emitting unit 10 include a pixel electrode defect, an organic EL layer defect, a counter electrode disconnection, a pixel electrode and counter electrode short circuit, and a breakdown voltage decrease. Note that the planarization film 4 can be omitted.
The planarization film 4 can be formed using a known material, and examples thereof include inorganic materials such as silicon oxide, silicon nitride, and tantalum oxide, and organic materials such as polyimide, acrylic resin, and resist material. Examples of the method for forming the planarizing film 4 include a dry process such as a CVD method and a vacuum deposition method, and a wet process such as a spin coating method, but the present invention is not limited to these materials and the forming method. Further, the planarizing film 4 may have a single layer structure or a multilayer structure.

On the planarizing film 4, an organic EL light emitting unit 10 that is a light source (light emitting source) is formed. The organic EL light emitting unit 10 includes a first electrode 12, a second electrode 16, and an organic EL layer (organic layer) 17. The first electrode 12 is an anode. The second electrode 16 is a cathode disposed so as to face the first electrode 12. The organic EL layer (organic layer) 17 is composed of at least one layer including the light emitting layer 14 sandwiched between the first electrode 12 and the second electrode 16. The first electrode 12 and the second electrode 16 function as a pair as an anode or a cathode of the organic EL light emitting unit 10. That is, when the first electrode 12 is an anode, the second electrode 16 is a cathode. When the first electrode 12 is a cathode, the second electrode 16 is an anode. In FIG. 1 and the following description, a case where the first electrode 12 is an anode and the second electrode 16 is a cathode will be described as an example. When the first electrode 12 is a cathode and the second electrode 16 is an anode, the hole injection layer and the hole transport layer are arranged on the second electrode side 16 in a laminated structure of an organic EL layer (organic layer) 17 described later. The electron injection layer and the electron transport layer may be on the first electrode 12 side.

As an electrode material for forming the first electrode 12 and the second electrode 16, a known electrode material can be used. As a material for forming the first electrode 12 that is an anode, from the viewpoint of efficiently injecting holes into the organic EL layer 17, gold (Au), platinum (Pt), a work function of 4.5 eV or more, Metals such as nickel (Ni) and oxides (ITO) made of indium (In) and tin (Sn), oxides made of tin (Sn) (SnO ₂ ), oxides made of indium (In) and zinc (Zn) (IZO) etc. are mentioned. In addition, as an electrode material for forming the second electrode 16 serving as a cathode, lithium (Li), calcium (with a work function of 4.5 eV or less) from the viewpoint of more efficiently injecting electrons into the organic EL layer 17 ( Examples thereof include metals such as Ca), cerium (Ce), barium (Ba), and aluminum (Al), or alloys such as Mg: Ag alloy and Li: Al alloy containing these metals.

The first electrode 12 and the second electrode 16 can be formed by a known method such as an EB (electron beam) vapor deposition method, a sputtering method, an ion plating method, or a resistance heating vapor deposition method using the above materials. The present invention is not limited to these forming methods. If necessary, the formed electrode can be patterned by a photolithographic fee method or a laser peeling method, or a patterned electrode can be directly formed by combining with a shadow mask.
The film thickness of the first electrode 12 and the second electrode 16 is preferably 50 nm or more. When the film thicknesses of the first electrode 12 and the second electrode 16 are less than 50 nm, the wiring resistance increases, so that the drive voltage may increase.

In the organic light emitting device 20 of the present embodiment, light emitted from the light emitting layer 14 of the organic EL light emitting unit 10 that is a light source is emitted from the wavelength conversion layer 18 and the fluorescence conversion layers 8R, 8G, and 8B side. Therefore, it is preferable to use a translucent electrode as the second electrode 16. As the material of the semitransparent electrode, a metal semitransparent electrode alone or a combination of a metal semitransparent electrode and a transparent electrode material can be used, and silver is preferable from the viewpoint of reflectance and transmittance. The film thickness of the semitransparent electrode is preferably 5 nm to 30 nm. When the film thickness of the semi-transparent electrode is less than 5 nm, when using the microcavity effect described later, there is a possibility that light cannot be sufficiently reflected and the interference effect cannot be obtained sufficiently. Moreover, when the film thickness of a semi-transparent electrode exceeds 30 nm, since the light transmittance falls rapidly, there exists a possibility that a brightness | luminance and efficiency may fall.
As will be described later, in order to obtain the microcavity effect, the first electrode 12 and the second electrode 16 need to be reflective electrodes.

In the organic light emitting device 20 of this embodiment, the extraction efficiency of light emission from the light emitting layer 14 is used as the first electrode 12 located on the side opposite to the side from which light emission from the light emitting layer 14 of the organic EL light emitting unit 10 that is a light source is extracted. In order to increase the brightness, it is preferable to use a highly reflective electrode (reflecting electrode) that reflects light. Examples of electrode materials used in this case include reflective metal electrodes such as aluminum, silver, gold, aluminum-lithium alloys, aluminum-neodymium alloys, and aluminum-silicon alloys, transparent electrodes, and reflective metal electrodes (reflective electrodes). The electrode etc. which combined these are mentioned. FIG. 1 shows an example in which the first electrode 12 that is a transparent electrode is formed on the planarizing film 4 via the reflective electrode 11.

Further, in the organic light emitting device 20 of the present embodiment, the first electrode 12 positioned on the substrate 1 side (the side opposite to the side from which the light emission from the light emitting layer 14 is extracted) is connected to each pixel (each

fluorescence conversion layer

8R, 8G, A plurality of parallel arrangements are provided corresponding to 8B). An edge cover 19 made of an insulating material is formed so as to cover each edge portion (end portion) of the adjacent first electrode 12. The edge cover 19 is provided for the purpose of preventing leakage between the first electrode 12 and the second electrode 16. The edge cover 19 can be formed using an insulating material by a known method such as an EB (Electron Beam) vapor deposition method, a sputtering method, an ion plating method, a resistance heating vapor deposition method, or the like. Although patterning can be performed by a lithography method, the present embodiment is not limited to these forming methods. Moreover, a conventionally well-known material can be used as an insulating material layer which comprises the edge cover 19, and it does not specifically limit in this embodiment. The insulating material layer constituting the edge cover 19 needs to transmit light, and examples thereof include SiO, SiON, SiN, SiOC, SiC, HfSiON, ZrO, HfO, and LaO.

The film thickness of the edge cover 19 is preferably 100 nm to 2000 nm. By setting the film thickness of the edge cover 19 to 100 nm or more, sufficient insulation is maintained, and leakage occurs between the first electrode 12 and the second electrode 16 to prevent an increase in power consumption and non-light emission. be able to. Further, by setting the film thickness of the edge cover 19 to 2000 nm or less, it is possible to prevent the productivity of the film forming process from being lowered and the disconnection of the second electrode 16 in the edge cover 19 from occurring.
Further, the reflective electrode 11 and the first electrode 12 are connected to one of the TFT circuits 2 by a wiring 2 b provided through the interlayer insulating film 3 and the planarizing film 4. The second electrode 16 is connected to one of the TFT circuits 2 by a wiring 2 a provided through the interlayer insulating film 3, the planarizing film 4 and the edge cover 19.

Wiring

2a, 2b should just be comprised from the electroconductive material, and is not specifically limited. The

wirings

2a and 2b are made of, for example, a material such as Cr, Mo, Ti, Ta, Al, Al alloy, Cu, and Cu alloy. The

wirings

2a and 2b are formed by a conventionally known method such as a sputtering or CVD method and a mask process.

The organic EL layer (organic layer) 17 may have a single layer structure of the light emitting layer 14 or a multilayer structure such as a stacked structure of the hole transport layer 13, the light emitting layer 14, and the electron transport layer 15 as shown in FIG. good. Specific examples of the organic EL layer (organic layer) 17 include the following configurations, but the present embodiment is not limited thereto. In the following configuration, the hole injection layer and the hole transport layer 13 are arranged on the first electrode 12 side that is an anode. The electron injection layer and the electron transport layer 15 are disposed on the second electrode 16 side that is a cathode.
(1) Light emitting layer 14
(2) Hole transport layer 13 / light emitting layer 14
(3) Light emitting layer 14 / electron transport layer 15
(4) Hole transport layer 13 / light emitting layer 14 / electron transport layer 15
(5) Hole injection layer / hole transport layer 13 / light emitting layer 14 / electron transport layer 15
(6) Hole injection layer / hole transport layer 13 / light emitting layer 14 / electron transport layer 15 / electron injection layer (7) Hole injection layer / hole transport layer 13 / light emitting layer 14 / hole preventing layer / electron Transport layer 15
(8) Hole injection layer / hole transport layer 13 / light emitting layer 14 / hole prevention layer / electron transport layer 15 / electron injection layer (9) Hole injection layer / hole transport layer 13 / electron prevention layer / light emission Layer 14 / Hole prevention layer / Electron transport layer 15 / Electron injection layer Here, the light emitting layer 14, hole injection layer, hole transport layer 13, hole prevention layer, electron prevention layer, electron transport layer 15 and electron injection Each of the layers may have a single layer structure or a multilayer structure.

The light-emitting layer 14 may be composed only of an organic light-emitting material, or may be composed of a combination of a light-emitting dopant (organic light-emitting material) and a host material, and optionally includes a hole transport material, an electron transport material, Additives (donor, acceptor, etc.) may be included. The light emitting layer 14 may have a configuration in which these materials are dispersed in a polymer material (binding resin) or an inorganic material.
From the viewpoint of luminous efficiency and lifetime, a material in which an organic light emitting material that is a light emitting dopant is dispersed in a host material is preferable. The light emitting layer 14 recombines the holes injected from the first electrode 12 and the electrons injected from the second electrode 16, so that light in the green region or light in the red region (green region to red region; wavelength 500 nm). (Up to 780 nm) light is emitted (emitted).

As the organic light emitting material used for the light emitting layer 14, a conventionally known light emitting material for organic EL can be used, and a material that emits light in a green region to a red region (wavelength: 500 nm to 780 nm) can be used. As the organic light emitting material, either a low molecular weight organic light emitting material or a high molecular weight organic light emitting material can be used. As the organic light emitting material, either a fluorescent material or a phosphorescent material can be used. From the viewpoint of reducing power consumption, it is preferable to use a phosphorescent material having high light emission efficiency.

The green low molecular luminescent material is an organic luminescent material, it is possible to use a green low molecular luminescent material legacy known organic EL, for example, coumarin derivatives, quinacridone, tris (8-quinolinato) aluminum (Alq _3), Bis (benzoquinolinolato) beryllium (BeBq ₂ ), 10- (2-benzothiazoyl) -1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H, 5H, 11H— A fluorescent material such as benzo [1] pyrano [678-ij] quinolizine-11-one (C545T) or a phosphorescent material such as tris (2-phenylpyridine) iridium (Ir (ppy) ₃ ) can be used.

As the red low molecular light emitting material which is an organic light emitting material, conventionally known red low molecular light emitting materials for organic EL can be used. For example, rubrene, phenanthroline europium (Eu (TTA) ₃ (phen)), Fluorescent materials such as-(disyl-anomethylene) -2-t-butyl-6 (1,1,7,7-tetramethyljurididyl-9-enyl) -4H-pyran (DCJTB), bis (2,4 Phosphorescent materials such as -diphenyl-quinoline) iridium (III) acetyl lanate (Ir (ppy) ₂ (acac)), tris (1-phenylisoquinoline) iridium (III) (Ir (Pic) ₃ ) can be used .

As the polymer light-emitting material that is an organic light-emitting material, conventionally known polymer light-emitting materials that emit light in the green region to red region for organic EL can be used, for example, poly (p-vinylphenylene vinylene) derivatives. (PPV), polyfluorene derivative (PDAF), poly (p-vinylphenylene) derivative (PPP), carbazole derivative (PVK), or the like can be used. These light emitting materials can be used as long as they emit light in a green region to a red region, although the emission wavelength is changed by introducing a substituent into a side chain.

Further, when the organic light emitting material which is a light emitting dopant and a host material are used in combination as the light emitting layer 14, a conventionally known organic EL host material can be used as the host material. Examples of such host materials include the above-described low-molecular organic light-emitting materials, the above-described high-molecular organic light-emitting materials, 4,4′-bis (carbazole) biphenyl, 9,9-di (4-dicarbazole-benzyl) fluorene ( Carbazole such as CPF), 3,6-bis (triphenylsilyl) carbazole (mCP), poly (N-octyl-2,7-carbazole-O-9,9-dioctyl-2,7-fluorene) (PCF) Derivatives, aniline derivatives such as 4- (diphenylphosphoyl) -N, N-diphenylaniline (HM-A1), 1,3-bis (9-phenyl-9H-fluoren-9-yl) benzene (mDPFB), 1 , 4-Bis (9-phenyl-9H-fluoren-9-yl) benzene (pDPFB) and the like, 1,3,5-tris [4- (Diphenylamino) phenyl] benzene (TDAPB), 1,4-bistriphenylsilylbenzene (UGH-2) and the like.

The hole injection layer and the hole transport layer 13 are used for the purpose of more efficiently injecting holes from the first electrode 12 serving as an anode and transporting (injecting) them to the light emitting layer 14. 14. The electron injection layer and the electron transport layer 15 are formed between the second electrode 16 and the light emitting layer 14 for the purpose of more efficiently injecting electrons from the second electrode 16 serving as a cathode and transporting (injecting) them to the light emitting layer 14. Between.
Each of these hole injection layer, hole transport layer 13, electron injection layer, and electron transport layer 15 can use a conventionally known material, and may be composed of only the materials exemplified below. An additive (donor, acceptor, etc.) may optionally be included, and a structure in which these materials are dispersed in a polymer material (binding resin) or an inorganic material may be employed.

Examples of the material constituting the hole transport layer 13 include oxides such as vanadium oxide (V ₂ O ₅ ) and molybdenum oxide (MoO ₂ ), inorganic p-type semiconductor materials, porphyrin compounds, N, N′-bis ( Aromatics such as 3-methylphenyl) -N, N′-bis (phenyl) -benzidine (TPD), N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine (NPD) Low molecular weight materials such as tertiary amine compounds, hydrazone compounds, quinacridone compounds, styrylamine compounds, polyaniline (PANI), polyaniline-camphor sulfonic acid (polyaniline-camphorsulfonic acid; PANI-CSA), 3,4-polyethylenedioxy Thiophene / polystyrene sulfonate (PEDOT / PSS), poly (triphenylamine) derivative (Poly -TPD), polyvinylcarbazole (PVCz), poly (p-phenylene vinylene) (PPV), poly (p-naphthalene vinylene) (PNV), and other polymer materials.

As a material used for the hole injection layer, the highest occupied molecular orbital (HOMO) is more preferable than the material used for the hole transport layer 13 in that holes are more efficiently injected and transported from the first electrode 12 serving as the anode. It is preferable to use a material having a low energy level. As the hole transport layer 13, it is preferable to use a material having a higher hole mobility than the material used for the hole injection layer.
Examples of the material for forming the hole injection layer include phthalocyanine derivatives such as copper phthalocyanine, 4,4 ′, 4 ″ -tris (3-methylphenylphenylamino) triphenylamine, and 4,4 ′, 4 ″ -tris. (1-naphthylphenylamino) triphenylamine, 4,4 ′, 4 ″ -tris (2-naphthylphenylamino) triphenylamine, 4,4 ′, 4 ″ -tris [biphenyl-2-yl (phenyl) amino ] Triphenylamine, 4,4 ', 4 "-tris [biphenyl-3-yl (phenyl) amino] triphenylamine, 4,4', 4" -tris [biphenyl-4-yl (3-methylphenyl) Amination of amino] triphenylamine, 4,4 ′, 4 ″ -tris [9,9-dimethyl-2-fluorenyl (phenyl) amino] triphenylamine, etc. Examples thereof include oxides such as a compound, vanadium oxide (V ₂ O ₅ ), and molybdenum oxide (MoO ₂ ), but are not limited thereto.

In order to improve the hole injection and transport properties, it is preferable to dope the hole injection layer and the hole transport layer 13 with an acceptor. As an acceptor, a conventionally well-known material can be used as an acceptor material for organic EL.
Acceptor materials include Au, Pt, W, Ir, POCl ₃ , AsF ₆ , Cl, Br, I, vanadium oxide (V ₂ O ₅ ), molybdenum oxide (MoO ₂ ), and other inorganic materials, TCNQ (7, 7 , 8,8, -tetracyanoquinodimethane), TCNQF4 (tetrafluorotetracyanoquinodimethane), TCNE (tetracyanoethylene), HCNB (hexacyanobutadiene), DDQ (dicyclodicyanobenzoquinone), etc. Examples thereof include compounds, compounds having a nitro group such as TNF (trinitrofluorenone) and DNF (dinitrofluorenone), and organic materials such as fluoranyl, chloranil and bromanyl. Among these, compounds having a cyano group such as TCNQ, TCNQF4, TCNE, HCNB, and DDQ are more preferable because they can increase the carrier concentration effectively.
As the electron blocking layer, the same materials as those described above as the hole transport layer 13 and the hole injection layer can be used.

Examples of the material constituting the electron transport layer 15 include an inorganic material that is an n-type semiconductor, an oxadiazole derivative, a triazole derivative, a thiopyrazine dioxide derivative, a benzoquinone derivative, a naphthoquinone derivative, an anthraquinone derivative, a diphenoquinone derivative, a fluorenone derivative, Low molecular materials such as benzodifuran derivatives; polymer materials such as poly (oxadiazole) (Poly-OXZ) and polystyrene derivatives (PSS).
Examples of the material constituting the electron injection layer include fluorides such as lithium fluoride (LiF) and barium fluoride (BaF ₂ ), and oxides such as lithium oxide (Li ₂ O).
As a material used for the electron injection layer, the energy level of the lowest unoccupied molecular orbital (LUMO) is higher than that of the material used for the electron transport layer 15 in that electrons are injected and transported more efficiently from the second electrode 16 serving as the cathode. It is preferable to use a material having a high value. As the material used for the electron transport layer 15, it is preferable to use a material having higher electron mobility than the material used for the electron injection layer.

In order to further improve the electron injection and transport properties, the electron injection layer and the electron transport layer 15 are preferably doped with a donor. As a donor, a conventionally well-known material can be used as a donor material for organic EL.
Donor materials include inorganic materials such as alkali metals, alkaline earth metals, rare earth elements, Al, Ag, Cu, and In, anilines, phenylenediamines, N, N, N ′, N′-tetraphenylbenzidine, N , N′-bis- (3-methylphenyl) -N, N′-bis- (phenyl) -benzidine, N, N′-di (naphthalen-1-yl) -N, N′-diphenyl-benzidine, etc. Benzidines, triphenylamine, 4,4 ′, 4 ″ -tris (N, N-diphenyl-amino) -triphenylamine, 4,4 ′, 4 ″ -tris (N-3-methylphenyl-N Triphenylamines such as -phenyl-amino) -triphenylamine, 4,4 ', 4 "-tris (N- (1-naphthyl) -N-phenyl-amino) -triphenylamine, N, N' -Di- (4-methyl-fur Nyl) -N, N'-diphenyl-1,4-phenylenediamine and other aromatic tertiary amine compounds such as phenanthrene, pyrene, perylene, anthracene, tetracene, pentacene, etc. There are organic materials such as compounds (however, the condensed polycyclic compound may have a substituent), TTFs (tetrathiafulvalene), dibenzofuran, phenothiazine, and carbazole. Among these, a compound having an aromatic tertiary amine as a skeleton, a condensed polycyclic compound, and an alkali metal are more preferable because the carrier concentration can be increased more effectively.
As the hole blocking layer, the same materials as those described above as the electron transport layer 15 and the electron injection layer can be used.

As a method for forming the light emitting layer 14, the hole transport layer 13, the electron transport layer 15, the hole injection layer, the electron injection layer, the hole prevention layer, the electron prevention layer and the like constituting the organic EL layer 17, the above materials are used as solvents. Using a coating liquid for forming an organic EL layer dissolved and dispersed in a coating method such as spin coating method, dipping method, doctor blade method, discharge coating method, spray coating method, ink jet method, letterpress printing method, intaglio printing method , A method of forming by a known wet process such as a screen printing method, a printing method such as a micro gravure coating method, or the above-described materials by resistance heating vapor deposition, electron beam (EB: Electron Beam) vapor deposition, molecular beam epitaxy ( MBE: Molecular Beam Epitaxy, sputtering, organic vapor deposition (OVPD: Organic V) Method for forming por Phase Deposition) method or the like of the known dry process, or may be a method of forming by a laser transfer method or the like. When the organic EL layer 17 is formed by a wet process, the organic EL layer forming coating solution may contain additives for adjusting the physical properties of the coating solution, such as a leveling agent and a viscosity modifier. .

The film thickness of each layer constituting the organic EL layer 17 is usually about 1 nm to 1000 nm, and more preferably 10 nm to 200 nm. If the film thickness of each layer constituting the organic EL layer 17 is less than 10 nm, it may not be possible to obtain originally required physical properties (charge (electron, hole) injection characteristics, transport characteristics, confinement characteristics); There is a risk of pixel defects due to foreign matter such as dust. Moreover, when the film thickness of each layer constituting the organic EL layer 17 exceeds 200 nm, the driving voltage increases, which may lead to an increase in power consumption.

In the organic light emitting device 20 of the present embodiment, the first electrode 12 and the second electrode 16 in the organic EL light emitting unit 10 are reflective electrodes having light reflectivity. The optical film thickness L between the reflective interfaces defined by the pair of

reflective electrodes

12 and 16 is set so as to enhance the intensity of light of a specific wavelength among the light emitted from the light emitting layer 14. preferable. Here, “light of a specific wavelength” means light in the green region to red region (wavelength 500 nm to 780 nm). Specifically, when the wavelength to be enhanced is λ, the optical film thickness L is set so as to satisfy the optical film thickness L between reflective interfaces L = (λ / 2) × 2 m (where m is an integer). You only have to set it.

By setting the optical film thickness L in this way, a microcavity effect (multiple reflection interference effect) appears between the first electrode 12 (reflecting electrode) and the second electrode 16 (semi-transparent electrode) which are reflective electrodes. Further, the light extraction efficiency can be improved. More specifically, by setting the optical film thickness L of the organic EL light emitting unit 10 as described above, the light emitted from the light emitting layer 14 is repeatedly reflected between the first electrode 12 and the second electrode 16 facing each other. At this time, light in the green region to red region is intensified by multiple interference and is emitted from the second electrode 16 to the wavelength conversion layer 18 side. As a result, the intensity of light in the green region to red region incident on the wavelength conversion layer 18 is increased, and the wavelength is converted by the wavelength conversion layer 18 and emitted to the fluorescence conversion layers 8R, 8G, and 8B side. As a result, the wavelength conversion efficiency in the wavelength conversion layer 18 can be increased. For example, the light intensity when assuming that one photon (photon) is present in a microcavity of 1 μm is about 3000 W / cm ² . This value is sufficient to produce a nonlinear effect even with one photon. Since the wavelength conversion efficiency in the wavelength conversion layer 18 can be increased in this way, the amount of red, green, and blue light that is fluorescently converted in each

phosphor conversion layer

8R, 8G, and 8B increases, and organic light emission occurs. The light extraction efficiency of the element 20 can be improved, and the organic light-emitting element 20 with good light emission efficiency can be obtained.

A wavelength conversion layer 18 is formed on the organic EL light emitting unit 10.
The wavelength conversion layer 18 is a layer having a function of converting the wavelength of light emitted from the organic EL light emitting unit 10 and emitting it to the fluorescence conversion layers 8R, 8G, and 8B. Examples of the wavelength conversion layer 18 include a layer that can convert the wavelength of light emitted from the organic EL light emitting unit 10 to be short. Specifically, the wavelength conversion layer 18 uses a second-order nonlinear optical effect such as second-harmonic generation (SHG) to change the wavelength of light incident into the wavelength conversion layer 18 to 2. One that converts to a fraction is mentioned. By using the wavelength conversion layer 18 that is SHG, the wavelength of the light in the red region to the green region emitted from the organic EL light emitting unit 10 is converted to half and converted into the light in the ultraviolet region to the blue region. The light in the ultraviolet region to the blue region can be emitted to the fluorescence conversion layers 8R, 8G, and 8B. For example, when light having a wavelength of 600 nm is emitted from the organic EL light emitting unit 10, the wavelength conversion layer 18 that is SHG converts the light to a wavelength having a wavelength of 300 nm that is a half wavelength, and the light having a wavelength of 300 nm is converted into each fluorescence conversion layer 8R. , 8G, and 8B.

SHG can be considered that two photons having an angular frequency ω are converted into one photon having an angular frequency 2ω in terms of quantum mechanics. At this time, an energy conservation law expressed by the following formula (1) is established between related photons. At the same time, the momentum conservation law expressed by the following equation (2) holds, and this is the phase matching condition.

(Where k _{1 is} the wave vector of the fundamental wave, k _{2 is} the wave vector of the second harmonic)

In order to realize wavelength conversion of light waves such as SHG with high efficiency, it is important to achieve phase matching between interacting different wavelength light waves. By providing the medium with periodicity, it is possible to perform pseudo phase matching. Such quasi-phase matching (QPM: Quasi-Phase Matching) has a structure in which the sign of the nonlinear optical coefficient is inverted with a period Λ along the propagation axis of the nonlinear optical crystal, and the wave vector of the nonlinear polarization and the light wave to be generated This is a method of achieving phase matching by compensating for the difference from the wave vector with the wave vector κ (| κ | = K = 2π / Λ) of the periodic structure. For wavelength conversion by quasi phase matching, Robert W. Body, “Nonlinear Optics” (Academic Press, New York), p. 84-88, JP 2003-307758 A, JP 2001-337355 A, and the like.

3A and 3B are diagrams illustrating wavelength conversion by quasi phase matching (QPM), and FIG. 3A is a diagram illustrating a relationship between polarization reversal and propagation distance. In FIG. 3A, a two-dot chain line indicates a case where there is no polarization inversion in a medium through which light passes. A solid line indicates a case where there is a polarization inversion in a medium through which light passes. FIG. 3B is a diagram schematically illustrating the QPM device. In FIG. 3B, the arrows indicate the movement of polarization.
In general, when phase matching is not achieved, there is a difference in phase velocity between the fundamental wave light and the generated wavelength converted light. Therefore, wavelength converted light that is generated one after another as the fundamental wave propagates in the crystal. Occurs with a slight phase shift. The generated wavelength-converted lights are gradually increased in intensity as they are added, but when the phase difference between the wavelength-converted lights generated at two points separated by a certain distance Lc becomes π, they cancel each other and conversely the intensity. Attenuates. As a result, the intensity of the wavelength-converted light is periodically increased and decreased as indicated by a two-dot chain line in FIG. 3A. In the QPM device, as shown in FIGS. 3A and 3B, a periodically poled structure is formed by periodically inverting the crystal polarization for each distance Lc called a coherent length. As can be seen from the principle of quasi-phase matching, the period of polarization inversion Λ is twice as long as the coherent length Lc with a pair of positive and negative polarization regions as a pair.
Further, as one of the features of the QPM device, the corresponding wavelength and conversion method (harmonic generation, optical parametric oscillation, etc.) can be customized by adjusting the polarization inversion period Λ. For example, in the second harmonic generation device, the polarization inversion period Λ can be expressed by the following equation (3). As shown in the following formula (3), the polarization inversion period is determined by the incident fundamental wave wavelength.

(Where λ is the fundamental wavelength, n _{ω is the} refractive index with respect to the fundamental wavelength, and n _{2ω is} the refractive index with respect to the second harmonic.)

The QPM device can select the orientation that forms the domain-inverted structure, and can use highly nonlinear constants that cannot be realized with conventional birefringence phase matching. Is possible. Thus, by using the QPM technology, highly efficient wavelength conversion corresponding to various wavelengths can be realized.

The wavelength conversion layer 18 is not particularly limited as long as it is a layer that generates SHG, and a multi-layer structure using quasi phase matching (QPM) considering the phase matching described above can also be used.
As shown in FIGS. 3A and 3B, the wavelength conversion layer 18 is preferably formed by laminating a plurality of layers in which the polarization directions are alternately reversed, and has a polarization reversal period Λ (that is, coherent). A structure in which a plurality of layers are laminated so as to periodically invert the polarization of the crystal is preferable (for each length Lc).
As the wavelength conversion layer 18 which is the second harmonic generation (SHG) using QPM, a layer formed by laminating a plurality of layers in which polarization directions are alternately reversed can be cited. In particular,
(1) A laminated body 18A (FIG. 4) in which each layer is made of a single-polarized dielectric material, and a plurality of

layers

18a and 18b whose polarization directions are alternately reversed are laminated.
(2) A laminated body 18B (FIG. 5) configured by alternately laminating semiconductor layers 18c and dielectric layers 18d.

As the dielectric material constituting the wavelength conversion layer 18, which is a laminated body (wavelength conversion layer) 18 A in which a plurality of

layers

18 a and 18 b each made of a single-polarized dielectric material are laminated, a ferroelectric material is used. Examples include body materials, glass materials, and polymer materials.
Examples of the ferroelectric material constituting the wavelength conversion layer 18 include those conventionally known as ferroelectric materials, such as LiNbO ₃ (LN), LiTaO ₃ (LT), and KTiOPO ₄ (KTP) having a congruent composition. , Β-BaB ₂ O ₄ (BBO), KNbO ₃ (KN), KH ₂ PO ₄ (KDP), LiB ₃ O ₅ (LBO), CsLiB ₆ O ₁₂ (CLBO), Ta ₂ O ₅ , Nb ₂ O ₃ , AgGaS ₂ , ZnGeP ₂ (ZGP), GaAs, GaN, MgO: LiNbO _3, ZnO: LiNbO _{3 and the} like.

Examples of the glass material constituting the wavelength conversion layer 18 include SiO ₂ , GeO ₂ SiO ₂ , quartz glass, and silicate fiber.
Examples of the polymer material constituting the wavelength conversion layer 18 include 4- (N-methyl-N- (4′-nitrophenyl) aminomethyl) styrene, 4- (N-methyl-N- (4′-cyanophenyl). ) Aminomethyl) styrene, 4- (N- (4′-nitrophenyl) aminomethyl) styrene, 4- (N- (4′-cyanophenyl) aminomethyl) styrene, urea, di (p-nitrophenyl) urea 4-ethoxy-4′-methoxychalcone, p-nitroaniline, N-methyl-2-methyl-4-nitroaniline, N, N-dimethylamino-2-acetylamino-4-nitroaniline and the like. Moreover, the structure which introduce | transduced these to the polymeric side chain, and the dispersed polymer substance may be sufficient. However, in consideration of absorption in the ultraviolet region to the blue region, the above-described inorganic materials such as the ferroelectric material and the glass material are preferable.

When the wavelength conversion layer 18 is a stacked body (wavelength conversion layer) 18B configured by alternately stacking the semiconductor layers 18c and the dielectric layers 18d, the semiconductor layer 18c having a large second-order nonlinear optical constant, Dielectric layers 18d having a small nonlinear optical constant are periodically and alternately stacked, thereby generating second harmonic generation (SHG) using QPM. Examples of the material constituting the semiconductor layer 18c of the wavelength conversion layer 18B include ZnO, ZnS, GaN, and CuCl. As a material for forming the dielectric layer 18d of the wavelength conversion layer _{_{18B, TiO 2, SiO 2,}} HfO 2 , and the like.

The thicknesses of the plurality of layers constituting the wavelength conversion layer 18 are calculated from the above formula (3) and the like according to the material of the wavelength conversion layer 18 and the wavelength of light emitted from the organic EL light emitting unit 10. Further, it may be adjusted as appropriate.
Further, the thickness of the entire wavelength conversion layer 18 is not particularly limited and can be appropriately changed. For example, the thickness can be set to about 1 μm to 100 μm. In addition, the formation method of the wavelength conversion layer 18 is not specifically limited, A conventionally well-known method can be used as a formation method of the wavelength conversion layer of the 2nd harmonic generation (SHG) using QPM, for example, ion It can be formed by a method such as a beam sputtering method or a plasma deposition method.

The organic light emitting device 20 of the present embodiment has a second harmonic generation (SHG) wavelength having a QPM structure between the light extraction side of the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B. The conversion layer 18 is disposed. As a result, the wavelength of the green region to red region light emitted from the organic EL light emitting unit 10 is converted into a half wavelength in the wavelength conversion layer 18 to obtain ultraviolet region to blue region light. The fluorescence conversion layers 8R, 8G, and 8B can be emitted.

An inorganic sealing film 5 made of SiO, SiON, SiN or the like is formed so as to cover the upper surface of the wavelength conversion layer 18 and the side surfaces of the organic EL light emitting unit 10 and the wavelength conversion layer 18. The inorganic sealing film 5 can be formed by depositing an inorganic film such as SiO, SiON, SiN or the like by plasma CVD, ion plating, ion beam, sputtering, or the like. In addition, since the inorganic sealing film 5 takes out the light wavelength-converted in the wavelength conversion layer 18, it needs to be light transmissive.
Further, on the inorganic sealing film 5, the sealing substrate 9 is arranged so that the respective fluorescence conversion layers 8R, 8G, and 8B and the organic EL light emitting unit 10 face each other with the wavelength conversion layer 18 interposed therebetween. On the one surface of the sealing substrate 9, a red fluorescence conversion layer 8R, a green fluorescence conversion layer 8G, and a blue fluorescence conversion layer 8B that are partitioned and arranged in parallel by the black matrix 7 are formed. A sealing material 6 is sealed between the inorganic sealing film 5 and the sealing substrate 9. That is, the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B that are disposed to face the organic EL light emitting unit 10 are each surrounded by the black matrix 7 and sealed. It is enclosed in a sealing region surrounded by the material 6.

As the sealing substrate 9, the same thing as the board | substrate 1 mentioned above can be used. In the organic light emitting device 20 of the present embodiment, since the emitted light is extracted from the sealing substrate 9 side (the observer observes the display by the light emission from the outside of the sealing substrate 9), the sealing substrate 9 is a light-transmitting material. Need to use.
A conventionally known sealing material can be used for the sealing material 6, and a conventionally known sealing method can also be used as a method for forming the sealing material 6.
Specifically, for example, when an inert gas such as nitrogen gas or argon gas is used as the sealing material 6, a method of sealing the inert gas such as nitrogen gas or argon gas with a sealing substrate 9 such as glass. Is mentioned. In this case, it is further preferable to mix a moisture absorbent such as barium oxide in the enclosed inert gas because deterioration of the organic EL due to moisture can be effectively reduced.
Moreover, as the sealing material 6, resin (curable resin) can also be used. In this case, on the inorganic sealing film 5 of the substrate 1 on which the organic EL element 10, the wavelength conversion layer 18 and the inorganic sealing film 5 are formed, or on which the fluorescent conversion layers 8R, 8G, and 8B are formed. A curable resin (a photocurable resin or a thermosetting resin) is applied on each of the fluorescence conversion layers 8R, 8G, and 8B of the substrate 9 by using a spin coating method or a laminating method. And the board | substrate 1 and the sealing substrate 9 are bonded together through a resin layer, and photocuring or thermosetting is carried out. Thereby, the sealing material 6 can be formed. By providing the sealing material 6, oxygen and moisture can be prevented from entering the organic EL light emitting unit 10 from the outside, and the life of the organic EL light emitting unit 10 can be improved. In addition, the sealing material 6 needs to have a light transmittance.

In the organic light emitting device 20, light in the red region to green region emitted from the organic EL light emitting unit 10 that is a light source is wavelength-converted by the wavelength conversion layer 18 and light in the ultraviolet region to blue region (wavelength 250 nm to 400 nm). The light in the ultraviolet region to the blue region is incident on the fluorescence conversion layers 8R, 8G, and 8B.
The red fluorescence conversion layer 8R absorbs the light in the ultraviolet region to the blue region converted in wavelength by the wavelength conversion layer 18, converts the light into the light in the red region, and emits the light in the red region to the sealing substrate 9 side. .
The green fluorescence conversion layer 8G absorbs the light in the ultraviolet region to the blue region that has been wavelength-converted in the wavelength conversion layer 18, converts it to light in the green region, and emits light in the green region to the sealing substrate 9 side. .
The blue fluorescence conversion layer 8 B absorbs the ultraviolet light that has been wavelength-converted by the wavelength conversion layer 18, converts the light into the blue light, and emits the blue light to the sealing substrate 9 side.
Thus, by setting it as the structure which provides the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B, the light emitted from the organic EL light emission part 10 is converted into the wavelength conversion layer 18 and each fluorescence conversion layer 8R, Full color conversion can be achieved by converting light of red, green, and blue from the sealing substrate 9 side after conversion at 8G and 8B.
In addition, when the light wavelength-converted in the wavelength conversion layer 18 is light in a blue region, the blue fluorescence conversion layer 8B can be omitted. For the purpose of improving the viewing angle characteristics and extraction efficiency of light in the blue region, a functional layer configured by dispersing transparent particles in a binder resin may be provided. For the purpose of increasing color purity, a blue color filter may be provided.

The red fluorescence conversion layer 8R absorbs and excites light in the ultraviolet region to blue region that has been wavelength-converted by the wavelength conversion layer 18, and emits fluorescence in the red region (converts light having a wavelength different from that of the light source). A phosphor material that can be used. As a phosphor material for converting light in the ultraviolet region to blue region into light in the red region, conventionally known phosphor materials can be used, and both organic phosphor materials and inorganic phosphor materials are used. be able to. Specifically, for example, cyanine dyes such as 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran, 1-ethyl-2- [4- (p-dimethylamino) Pyridine dyes such as phenyl) -1,3-butadienyl] -pyridinium-perchlorate, and rhodamine dyes such as rhodamine B, rhodamine 6G, rhodamine 3B, rhodamine 101, rhodamine 110, basic violet 11, sulforhodamine 101, etc. Organic red phosphor material, Y ₂ O ₂ S: Eu ³⁺ , YAlO ₃ : Eu ³⁺ , Ca ₂ Y ₂ (SiO ₄ ) ₆ : Eu ³⁺ , LiY ₉ (SiO ₄ ) ₆ O ₂ : Eu ³⁺ , YVO ₄ ^{^{_{_{: Eu 3+, CaS: Eu 3+}}}} , Gd 2 O 3: Eu 3+, Gd 2 O 2 S: Eu 3+, _{^{_{_{(P, V) O 4:}}}} Eu 3+, Mg 4 GeO 5.5 F: Mn 4+, Mg 4 GeO 6: Mn 4+, K 5 Eu 2.5 (WO 4) 6.25, Na 5 Eu 2.5 Examples thereof include inorganic red phosphor materials such as (WO ₄ ) _6.25 , K ₅ Eu _2.5 (MoO ₄ ) _6.25 , and Na ₅ Eu _2.5 (MoO ₄ ) _6.25 .

The green fluorescence conversion layer 8G absorbs and excites the ultraviolet to blue light converted in wavelength by the wavelength conversion layer 18 and emits green fluorescence (converts light having a wavelength different from that of the light source). A phosphor material that can be used. As a phosphor material for converting light in the ultraviolet region to blue region into light in the green region, conventionally known phosphor materials can be used, and both organic phosphor materials and inorganic phosphor materials are used. be able to. Specifically, for example, 2,3,5,6-1H, 4H-tetrahydro-8-trifluoromethylquinolidine (9,9a, 1-gh) coumarin (coumarin 153), 3- (2′-benzothiazolyl) ) -7-diethylaminocoumarin (coumarin 6), 3- (2′-benzimidazolyl) -7-N, N-diethylaminocoumarin (coumarin 7) and other coumarin dyes, basic yellow 51, solvent yellow 11, solvent yellow 116, etc. Organic green phosphor materials such as naphthalimide dyes, (BaMg) Al ₁₆ O ₂₇ : Eu ²⁺ , Mn ²⁺ , Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ , (SrBa) Al ₁₂ Si ₂ O ₈ : Eu ²⁺ , (BaMg) ₂ SiO ₄ : Eu ²⁺ , Y ₂ SiO ₅ : Ce ³⁺ , Tb ³⁺ , Sr ₂ P ₂ O _7- Sr ₂ B ₂ O ₅ : Eu ²⁺ , (BaCaMg) ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu ²⁺ , Zr ₂ SiO ₄ , MgAl ₁₁ O ₁₉ : Ce Examples thereof include inorganic green phosphor materials such as ³⁺ , Tb ³⁺ , Ba ₂ SiO ₄ : Eu ²⁺ , Sr ₂ SiO ₄ : Eu ²⁺ , and (BaSr) SiO ₄ : Eu ²⁺ .

The blue fluorescence conversion layer 8B can absorb and excite light in the ultraviolet region wavelength-converted by the wavelength conversion layer 18 to emit blue region fluorescence (convert to light having a wavelength different from that of the light source). A phosphor material is included. As a phosphor material that converts light in the ultraviolet region into light in the blue region, a conventionally known phosphor material can be used, and either an organic phosphor material or an inorganic phosphor material can be used. . Specifically, for example, stilbene dyes such as 1,4-bis (2-methylstyryl) benzene, trans-4,4′-diphenylstilbenzene, and coumarin dyes such as 7-hydroxy-4-methylcoumarin. Organic blue phosphor materials such as Sr ₂ P ₂ O ₇ : Sn ⁴⁺ , Sr ₄ Al ₁₄ O ₂₅ : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , SrGa ₂ S ₄ : Ce ³⁺ , CaGa ₂ S ₄ : Ce ³⁺ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ : Eu ²⁺ , (Sr, Ca, Ba ₂ , Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , BaAl ₂ SiO ₈ : Eu ²⁺ _{_{_{^{, Sr 2 P 2 O 7:}}}} Eu 2+, Sr 5 (PO 4) 3 Cl: Eu 2+, (Sr, Ca, Ba) 5 (PO 4) 3 Cl: Eu 2+ _{_{_{^{BaMg 2 Al 16 O 27: Eu}}}} 2+, (Ba, Ca) 5 (PO 4) 3 Cl: Eu 2+, Ba 3 MgSi 2 O 8: Eu 2+, Sr 3 MgSi 2 O 8: inorganic blue ^{Eu 2+,} etc. Examples include phosphor materials.

Among the phosphor materials included in the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B described above, an inorganic phosphor material is used because stability such as deterioration due to excitation light and light emission is improved. It is preferable to do. The inorganic red phosphor may be subjected to a surface modification treatment as necessary. Examples of the surface modification treatment include chemical treatment using a silane coupling agent, physical treatment using addition of submicron-order fine particles, and combinations thereof.
Further, when an inorganic phosphor material is used, it is preferable to use an inorganic phosphor material having an average particle diameter (d50) of 1 μm to 50 μm. If the average particle size (d50) is less than 1 μm, the luminous efficiency of the phosphor material may be rapidly reduced. Further, if the average particle diameter (d50) exceeds 50 μm, it becomes difficult to form a flat film, and depletion occurs between each of the fluorescence conversion layers 8R, 8G, and 8B and the organic EL light emitting unit 10. (Depletion (refractive index: 1.0) between the organic EL light emitting part (refractive index: about 1.7) and each fluorescence conversion layer (refractive index: about 2.3)). Thereby, the light from the organic EL light emitting unit 10 may not efficiently reach the fluorescence conversion layers 8R, 8G, and 8B, and the light emission efficiency of each of the fluorescence conversion layers 8R, 8G, and 8B may decrease.

The red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B may be composed of only the above-described phosphor material, and optionally contain additives such as polymer, silica, and metal particles. Also good. The red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B may have a configuration in which a phosphor material is dispersed in an inorganic material such as a binder resin or silica. Among these, those in which a phosphor material is dispersed in a binder resin are preferable.
A conventionally well-known thing can be used as binder resin, It does not specifically limit. It is preferable to use a photosensitive resin as the binder resin because patterning can be performed by a photolithography method. Here, as the photosensitive resin, one of photosensitive resins having a reactive vinyl group (photocurable resist material) such as acrylic acid resin, methacrylic acid resin, polyvinyl cinnamate resin, and hard rubber resin. The seeds can be used alone or in admixture of two or more.

The red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B can be formed by a conventionally known method. For example, the above-described phosphor material and a resin material such as a binder resin are dissolved and dispersed in a solvent. Using the applied fluorescent conversion layer forming coating solution, spin coating method, dipping method, doctor blade method, discharge coating method, spray coating method and other coating methods, ink jet method, letterpress printing method, intaglio printing method, screen printing method Further, it can be formed by a wet process such as a printing method such as a micro gravure coating method. Also, known dry processes such as resistance heating vapor deposition, electron beam (EB) vapor deposition, molecular beam epitaxy (MBE), sputtering, organic vapor deposition (OVPD) using the above-mentioned phosphor, or It can also be formed by a laser transfer method or the like.

In the case where a phosphor material dispersed in a binder resin or an inorganic material is used as the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B, the fluorescence conversion layers 8R, 8G, 8B The content of the phosphor material is not particularly limited and can be changed as appropriate. The content of the phosphor material in each

fluorescence conversion layer

8R, 8G, 8B is preferably 1% by mass to 50% by mass with respect to the total amount of each

fluorescence conversion layer

8R, 8G, 8B. More preferably, the content is 30% by mass.

The film thickness of the red fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B can usually be about 100 nm to 100 μm, and preferably 1 μm to 100 μm. If the thickness of each of the fluorescence conversion layers 8R, 8G, and 8B is less than 100 nm, the light in the ultraviolet region to the blue region that has been wavelength-converted by the wavelength conversion layer 18 cannot be sufficiently absorbed, resulting in a decrease in luminous efficiency. In other words, the color purity may be deteriorated by the blue transmitted light mixed with the converted fluorescence. Further, if the thickness of each of the fluorescence conversion layers 8R, 8G, and 8B exceeds 100 μm, the light in the ultraviolet region to the blue region that has been wavelength-converted by the wavelength conversion layer 18 is already sufficiently absorbed, leading to an increase in efficiency. In other words, there is a possibility that the production cost will be increased because the material is merely consumed. Further, in order to increase the absorption of light emitted from the wavelength conversion layer 18 and reduce the transmitted light in the blue region to the extent that the color purity is not adversely affected, the films of the respective fluorescence conversion layers 8R, 8G, and 8B The thickness is preferably 1 μm or more.

Further, it is preferable that the surface of each

fluorescence conversion layer

8R, 8G, 8B opposite to the sealing substrate 9 is flattened by a flattening film or the like (not shown). Accordingly, when the organic EL light emitting unit 10 and the respective fluorescence conversion layers 8R, 8G, and 8B are brought into close contact with each other with the sealing material 6 interposed therebetween, the organic EL light emitting unit 10 and the respective fluorescence conversion layers 8R, 8G, It can prevent depletion between 8B. And the adhesiveness of the board | substrate 1 in which the organic electroluminescent light emission part 10 was formed, and the sealing substrate 9 in which each

fluorescent substance layer

8R, 8G, 8B was formed can be raised. As the planarizing film, the same one as the planarizing film 4 described above can be used.

It is preferable that a black matrix 7 is formed between each fluorescence conversion layer adjacent to each

fluorescence conversion layer

8R, 8G, 8B. As the black matrix 7, conventionally known materials and forming methods can be used, and are not particularly limited. Among them, the light that is incident on and scattered by the fluorescence conversion layers 8R, 8G, and 8B is further reflected by the fluorescence conversion layers 8R, 8G, and 8B, such as a metal having light reflectivity. Preferably it is.

In addition, when the light wavelength-converted in the wavelength conversion layer 18 is light in a blue region, the blue fluorescence conversion layer 8B can be omitted. A functional layer may be provided at the position of the blue fluorescence conversion layer 8B for the purpose of improving the viewing angle characteristics and extraction efficiency of light in the blue region. This functional layer is configured by dispersing transparent particles in a binder resin. When the functional layer is provided, the thickness of the functional layer is usually 10 μm to 100 μm, preferably 20 μm to 50 μm.
As the binder resin used in the functional layer, conventionally known resins can be used, and are not particularly limited, but those having optical transparency are preferable. The transparent particles are not particularly limited as long as they can scatter and transmit light in the blue region wavelength-converted by the wavelength conversion layer 18. For example, polystyrene having an average particle size of 25 μm and a standard deviation of particle size distribution of 1 μm. Particles or the like can be used. Further, the content of the transparent particles in the functional layer can be appropriately changed and is not particularly limited. The functional layer can be formed by a conventionally known method, and is not particularly limited. For example, using a coating solution in which a binder resin and transparent particles are dissolved and dispersed in a solvent, a spin coating method, By a known wet process such as a dipping method, a doctor blade method, a coating method such as a discharge coating method, a spray coating method, an inkjet method, a relief printing method, an intaglio printing method, a screen printing method, a printing method such as a micro gravure coating method, etc. Can be formed.

The organic light emitting device 20 of the present embodiment has the following configuration. In the organic light emitting device 20 having the fluorescence conversion layers 8R, 8G, and 8B for color-converting the light emitted from the organic EL light emitting unit 10, the wavelength conversion layer 18 is provided between the organic EL light emitting unit 10 and the fluorescence conversion layers 8R, 8G, and 8B. Is arranged. The organic light emitting element 20 uses an organic EL light emitting unit 10 that emits light in a green region to a red region as a light source. The organic light emitting element 20 converts the light emitted from the organic EL light emitting unit 10 into a wavelength in the wavelength conversion layer 18 to obtain light in the ultraviolet region to the blue region, and converts the light in the ultraviolet region to the blue region into the fluorescence conversion layers 8R, 8G, Full-colorization is realized by emitting to 8B and converting the fluorescence into red, green, and blue light in each of the fluorescence conversion layers 8R, 8G, and 8B. In the organic light emitting device of the prior art, a blue light emitting material with insufficient brightness and life is used as the light source. However, according to the organic light emitting device 20 of the present embodiment, the brightness and life superior to the blue light emitting material as the light source. The organic EL light emitting unit 10 that emits light in the green region to the red region having the above can be used, and the luminance and lifetime can be improved.

In addition, it is preferable that the organic light emitting element 20 of this embodiment is provided with a polarizing plate on the light extraction side (on the sealing substrate 9). As the polarizing plate, a combination of a conventionally known linearly polarizing plate and a λ / 4 plate can be used. Here, by providing a polarizing plate, it is possible to prevent external light reflection from the first electrode 12 and the second electrode 16 and external light reflection on the surface of the substrate 1 or the sealing substrate 9, and organic light emission. The contrast of the element 20 can be improved.

Further, in the organic light emitting element 20 shown in FIG. 1, the wavelength conversion layer 18 is disposed on the organic EL light emitting unit 10, and the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B are included in the wavelength conversion layer 18. Although the example which opposes via the inorganic sealing film 5 and the sealing material 6 was shown, this embodiment is not limited to this. If the wavelength conversion layer 18 is disposed between the light extraction side (second electrode 16 side) of the organic light emitting element 20 and each of the fluorescence conversion layers 8R, 8G, and 8B, the organic material of the above-described embodiment is used. The same effects as the light emitting element 20 can be obtained.

FIG. 6 is a schematic cross-sectional view showing an example of an organic light-emitting element that can achieve the same effects as the organic light-emitting element 20 of the present embodiment described above. An organic light emitting element 20B shown in FIG. 6 includes a substrate 1, an organic EL light emitting unit (light source) 10, a sealing substrate 9, a fluorescence conversion layer 8R, a green fluorescence conversion layer 8G, a blue fluorescence conversion layer 8B, and a wavelength conversion. It is schematically composed of the layer 18. The substrate 1 includes a TFT (Thin Film Transistor) circuit 2. The organic EL light emitting unit (light source) 10 is provided on the substrate 1 via the interlayer insulating film 3 and the planarizing film 4. The fluorescence conversion layer 8 R, the green fluorescence conversion layer 8 G, and the blue fluorescence conversion layer 8 B are partitioned by the black matrix 7 and arranged in parallel on one surface of the sealing substrate 9. The wavelength conversion layer 18 is disposed between the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B. The substrate 1 and the sealing substrate 9 are arranged so that the organic EL light emitting unit 10 and the fluorescence conversion layers 8R, 8G, and 8B face each other with the sealing material 6 and the wavelength conversion layer 18 interposed therebetween. The organic EL light emitting unit 10 is covered with the inorganic sealing film 5, and the wavelength conversion layer 18 is formed on the inorganic sealing film 5. In the organic EL light emitting unit 10, an organic EL layer (organic layer) 17 is sandwiched between the first electrode 12 and the second electrode 16. The organic EL layer (organic layer) 17 is a stack of a hole transport layer 13, a light emitting layer 14, and an electron transport layer 15. A reflective electrode 11 is formed on the lower surface of the first electrode 12. The reflective electrode 11 and the first electrode 12 are connected to one of the TFT circuits 2 by a wiring 2 b provided through the interlayer insulating film 3 and the planarizing film 4. The second electrode 16 is connected to one of the TFT circuits 2 by a wiring 2 a provided through the interlayer insulating film 3, the planarizing film 4 and the edge cover 19.

As in the organic light emitting element 20 B shown in FIG. 6, the inorganic sealing film 5 is formed so as to cover the upper surface and the side surface of the organic EL light emitting unit 10, and the wavelength conversion layer 18 is formed on the inorganic sealing film 5. Even in this case, the same effects as those of the organic light emitting device 20 of the present embodiment described above can be obtained. Further, in the organic light emitting device 20B shown in FIG. 6, even if the wavelength conversion layer 18 and each of the fluorescence conversion layers 8R, 8G, and 8B are in contact with each other, the same effects as those of the organic light emitting device 20 of the present embodiment described above can be obtained. Can do. The same applies to the embodiments described later.

[Second Embodiment]
FIG. 7 is a schematic cross-sectional view illustrating an example of an organic light-emitting device according to the second embodiment of the present invention.
7 includes a substrate 1, an organic EL light emitting unit (light source) 10, a sealing substrate 9, a fluorescence conversion layer 8R, a green fluorescence conversion layer 8G, a blue fluorescence conversion layer 8B, and a wavelength conversion. The layer 18 and the light reflective layer 31 are roughly configured. The substrate 1 includes a TFT (Thin Film Transistor) circuit 2. The organic EL light emitting unit (light source) 10 is provided on the substrate 1 with the interlayer insulating film 3 and the planarizing film 4 interposed therebetween. The fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B are partitioned by the black matrix 7 and arranged in parallel on one surface of the sealing substrate 9. The wavelength conversion layer 18 is disposed between the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B. The light reflective layer 31 is disposed on the light extraction side of the wavelength conversion layer 18. In the substrate 1 and the sealing substrate 9, the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B are opposed to each other with the sealing material 6, the light reflective layer 31, and the wavelength conversion layer 18 therebetween. Is arranged. The organic EL light emitting unit 10 and the wavelength conversion layer 18 are covered with the inorganic sealing film 5. In the organic EL light emitting unit 10, a hole transport layer 13, and an organic EL layer (organic layer) 17 in which a light emitting layer 14 and an electron transport layer 15 are stacked are sandwiched between a first electrode 12 and a second electrode 16. ing. A reflective electrode 11 is formed on the lower surface of the first electrode 12. The reflective electrode 11 and the first electrode 12 are connected to one of the TFT circuits 2 by a wiring 2 b provided through the interlayer insulating film 3 and the planarizing film 4. The second electrode 16 is connected to one of the TFT circuits 2 by a wiring 2 a provided through the interlayer insulating film 3, the planarizing film 4 and the edge cover 19.
In the organic light emitting device 30 shown in FIG. 7, the same components as those of the organic

light emitting devices

20 and 20B of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In addition to the configuration of the organic light emitting device 20 of the first embodiment, the organic light emitting device 30 of the present embodiment is on the light extraction side (each

fluorescence conversion layer

8R, 8G, 8B side) of the wavelength conversion layer 18. The light reflective layer 31 is disposed. The light reflective layer 31 has light reflectivity and is formed of a material such as Ag, Al, Cr, Mo, Au, ITO, or an alloy thereof. The film thickness of the light reflective layer 31 can be changed as appropriate, for example, about 10 nm to 1 μm, and is formed by a method such as vapor deposition or sputtering.

In the fluorescent display device 30 of the present embodiment, the second electrode 16 in the organic EL light emitting unit 10 is a reflective electrode having light reflectivity, and the light reflective layer 31 is provided on the light extraction side of the wavelength conversion layer 18. The optical film thickness L ₂ between the reflective interfaces defined by the reflective electrode 16 and the light reflective layer 31 is set so as to enhance the intensity of light of a specific wavelength among the light converted in wavelength in the wavelength conversion layer 18. It is preferable that Here, “light of a specific wavelength” means light in the ultraviolet region to blue region (wavelength 250 nm to 400 nm) obtained by wavelength conversion of light in the green region to red region (wavelength 500 nm to 780 nm). Specifically, when the wavelength to be enhanced is λ, the optical film satisfies the optical film thickness L ₂ = (λ / 2) × 2m ₂ (where m ₂ is an integer) between the reflective interfaces. the thickness _{L 2} may be set.

By thus setting the optical film thickness L _2, microcavity effects (multiple reflection interference effect) is expressed between the second electrode 16 is a reflective electrode (translucent electrode) and the light reflective layer 31 Furthermore, the light extraction efficiency can be improved. More specifically, by setting as the optical film thickness L ₂ of the wavelength conversion layer 18 of the wavelength-converted light at a wavelength conversion layer 18, second electrode 16 face each other, between light reflective layer 31 Reflects repeatedly. At this time, the light in the ultraviolet region to the blue region is strengthened by the multiple interference and is emitted from the light reflective layer 31 to the respective fluorescence conversion layers 8R, 8G, and 8B. As a result, the intensity of light in the ultraviolet region to the blue region incident on the fluorescence conversion layers 8R, 8G, and 8B is increased, and the fluorescence conversion is performed in the fluorescence conversion layers 8R, 8G, and 8B, and from the sealing substrate 9 side. The amount of red, green, and blue light emitted increases. The light extraction efficiency of the organic light emitting device 30 can be further improved, and the organic light emitting device 30 with good light emission efficiency can be obtained.

[Third Embodiment]
FIG. 8 is a schematic cross-sectional view showing an example of an organic light-emitting device according to the third embodiment of the present invention.
8 includes a substrate 1, an organic EL light emitting unit (light source) 10, a sealing substrate 9, a red color filter 41R, a green color filter 41G, a blue color filter 41B, and a fluorescence conversion layer 8R. The green fluorescence conversion layer 8G, the blue fluorescence conversion layer 8B, and the wavelength conversion layer 18 are schematically configured. The substrate 1 includes a TFT (Thin Film Transistor) circuit 2. The organic EL light emitting unit (light source) 10 is provided on the substrate 1 with the interlayer insulating film 3 and the planarizing film 4 interposed therebetween. The red color filter 41 R, the green color filter 41 G, and the blue color filter 41 B are color filters that are partitioned by the black matrix 7 and arranged in parallel on one surface of the sealing substrate 9. The fluorescence conversion layer 8R, the green fluorescence conversion layer 8G, and the blue fluorescence conversion layer 8B are partitioned into the black matrix 7 by matching colors on the

color filters

41R, 41G, and 41B formed on one surface of the sealing substrate 9. Are arranged in parallel. The wavelength conversion layer 18 is disposed between the organic EL light emitting unit 10 and each of the fluorescence conversion layers 8R, 8G, and 8B. The substrate 1 and the sealing substrate 9 are disposed so that the organic EL light emitting unit 10 and the fluorescence conversion layers 8R, 8G, and 8B face each other with the sealing material 6 and the wavelength conversion layer 18 interposed therebetween. The organic EL light emitting unit 10 and the wavelength conversion layer 18 are covered with the inorganic sealing film 5. In the organic EL light emitting unit 10, an organic EL layer (organic layer) 17 is sandwiched between the first electrode 12 and the second electrode 16. The organic EL layer (organic layer) 17 is a stack of a hole transport layer 13, a light emitting layer 14, and an electron transport layer 15. A reflective electrode 11 is formed on the lower surface of the first electrode 12. The reflective electrode 11 and the first electrode 12 are connected to one of the TFT circuits 2 by a wiring 2 b provided through the interlayer insulating film 3 and the planarizing film 4. The second electrode 16 is connected to one of the TFT circuits 2 by a wiring 2 a provided through the interlayer insulating film 3, the planarizing film 4 and the edge cover 19.
In the organic light emitting device 40 shown in FIG. 8, the same components as those of the organic

light emitting devices

20 and 20B of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In addition to the configuration of the organic light emitting device 20B of the first embodiment, the organic light emitting device 40 of the present embodiment includes a red fluorescence conversion layer 8R, a green fluorescence conversion layer 8G, a blue fluorescence conversion layer 8B, and a sealing substrate 9.

Color filters

41R, 41G, and 41B are interposed therebetween. The

color filters

41R, 41G, and 41B are formed on the light extraction side (sealing substrate 9 side) corresponding to the color of light emitted from the fluorescence conversion layers 8R, 8G, and 8B. A red color filter 41R is provided on the fluorescence emission side of the red fluorescence conversion layer 8R. A green color filter 41G is provided on the fluorescence emission side of the green fluorescence conversion layer 8G. A blue color filter 41B is provided on the fluorescence emission side of the blue fluorescence conversion layer 8B.

The

color filters

41R, 41G, and 41B are not particularly limited, and conventionally known color filters can be used. In addition, the

color filters

41R, 41G, and 41B can be formed by a conventionally known method, and the film thickness can be adjusted as appropriate.
Thus, by providing the

color filters

41R, 41G, 41B between the sealing substrate 9 on the light extraction side (observer side) and the fluorescence conversion layers 8R, 8G, 8B, the light is emitted from the organic light emitting element 40. The color purity of red, green, and blue can be increased, and the color reproduction range of the organic light emitting element 40 can be expanded. Further, the red color filter 41R formed on the red fluorescence conversion layer 8R and the green color filter 41G formed on the green fluorescence conversion layer 8G absorb the blue component and the ultraviolet component of external light. Therefore, it is possible to reduce or prevent light emission of the

fluorescence conversion layers

8R and 8G due to external light, and it is possible to reduce or prevent a decrease in contrast.

Although FIG. 8 shows an example in which the blue color filter 41B is provided on the blue fluorescence conversion layer 8B as a pixel emitting blue, the present embodiment is not limited to this. When the light subjected to wavelength conversion in the wavelength conversion layer 18 is light in the blue region, the blue fluorescence conversion layer 8B can be omitted. Instead of the blue fluorescence conversion layer 8B, the functional layer described in the first embodiment may be provided.

[Fourth Embodiment]
FIG. 9 is a schematic cross-sectional view showing an example of an organic light-emitting device according to the fourth embodiment of the present invention.
The organic light emitting device 50 shown in FIG. 9 includes an organic EL light emitting unit (light source) 10, a wavelength conversion layer 18, a light reflective layer 31, a sealing material 6, a fluorescence conversion layer 51, and a sealing substrate 9. It is roughly composed. The organic EL light emitting unit (light source) 10 is provided on the substrate 1. The wavelength conversion layer 18 is provided on the organic EL light emitting unit 10. The light reflective layer 31 is provided on the wavelength conversion layer 18. The sealing material 6 is provided on the light reflective layer 31. The fluorescence conversion layer 51 is provided on the sealing material 6. The sealing substrate 9 is provided on the fluorescence conversion layer 51. The organic EL light emitting unit 10 is configured by an organic EL layer (organic layer) 17 sandwiched between a first electrode 12 and a second electrode 16.
In the organic light emitting device 50 shown in FIG. 9, the same components as those of the organic

light emitting devices

20, 20B, 30, 40 of the first to third embodiments are denoted by the same reference numerals, and the description thereof is omitted.
The organic light emitting device 50 shown in FIG. 9 differs from the first to third embodiments in that a single fluorescence conversion layer 51 is disposed instead of the three fluorescence conversion layers 8R, 8G, and 8B. Is different in that it is. The fluorescence conversion layer 51 may be any of the fluorescence conversion layers 8R, 8G, and 8B described in the first embodiment, and can be appropriately changed according to the wavelength region (color) of light that is desired to be emitted from the sealing substrate 9. .

In the organic light emitting device 50 of the present embodiment, the light in the green region to the red region emitted from the organic EL light emitting unit 10 that is a light source is wavelength-converted by the wavelength conversion layer 18 to obtain an ultraviolet region to a blue region. By converting fluorescence in the ultraviolet region to blue region in the fluorescence conversion layer 51, when the red fluorescence conversion layer 8R is disposed as the fluorescence conversion layer 51, red light is emitted to the sealing substrate 9 side. When the green fluorescence conversion layer 8G is arranged as the fluorescence conversion layer 51, green light is emitted to the sealing substrate 9 side. When the blue fluorescence conversion layer 8B is arranged as the fluorescence conversion layer 51, blue light is emitted to the sealing substrate 9 side.
The organic light emitting device 50 according to the present embodiment includes the light reflecting layer 31 disposed on the light extraction side of the wavelength conversion layer 18, so that the wavelength conversion layer 18 converts the wavelength as described above in the second embodiment. Since the emitted light is amplified by the microcavity effect, it can also function as an organic laser element.

FIG. 10 is a schematic configuration diagram illustrating an example of an organic laser 60 using the organic light emitting device 50 of the present embodiment as an organic laser device.
An organic laser 60 shown in FIG. 10 is roughly composed of a pencil-type main body 66, a condenser lens 65, a light emitting circuit 63, an organic light emitting element 50, a booster circuit 62, a battery 61, and a lighting switch 64. Yes. The condenser lens 65 is disposed inside the distal end portion of the main body 66. The light emitting circuit 63 is arranged in the central portion inside the main body 66. The organic light emitting element 50 is an organic laser element disposed between the light emitting circuit 63 and the condenser lens 66. The booster circuit 62 is sequentially arranged in the rear part of the light emitting circuit 63 along the longitudinal direction of the main body 66. The lighting switch 64 is disposed on the outer periphery of the main body 66 so as to be electrically connected to the light emitting circuit 63. The organic light emitting element (organic laser element) 50, the light emitting circuit 63, the booster circuit 62, and the battery 61 are electrically connected by wiring. By operating the lighting switch 64, the voltage from the battery 61 is boosted by the booster circuit 62, and the first electrode 12 and the second electrode 16 of the organic light emitting element (organic laser element) 50 are energized via the light emitting circuit 63. Thus, the organic EL light emitting unit 10 can emit light, and laser light can be emitted from the organic light emitting element (organic laser element) 50. The light emitted from the organic light emitting element (organic laser element) 50 is condensed by the condenser lens 65 and emitted to the outside of the main body 66. The organic light emitting device 50 of the present embodiment can be applied to an organic laser, a laser pointer, etc. by using it as an organic laser device as in the example shown in FIG.

As mentioned above, although the organic light emitting element which is 1 aspect of this invention was demonstrated, this invention is not limited to said embodiment. For example, when the organic light emitting device includes a color filter, a diffusion plate may be disposed on the light extraction side of the color filter. In the organic light-emitting element which is one embodiment of the present invention, a method for driving the organic EL light-emitting portion is not particularly limited, and an active driving method or a passive driving method may be used. The organic EL light emitting unit is preferably driven by an active driving method. By adopting the active drive method, it is preferable because the light emission time of the organic EL light emitting unit can be extended compared to the passive drive method, the drive voltage for obtaining a desired luminance can be reduced, and the power consumption can be reduced. . In addition, the organic light-emitting element which is one embodiment of the present invention has a structure in which light is extracted from the reverse method of the substrate on which the active element is formed, thereby ignoring the TFT circuit, the wiring, and the like so as to have a high aperture ratio. Is possible.

Next, an organic light-emitting device which is one embodiment of the present invention is described.
An organic light-emitting device which is one embodiment of the present invention includes the above-described organic light-emitting element which is one embodiment of the present invention and a drive unit which drives the organic EL light-emitting portion of the organic light-emitting element which is one embodiment of the present invention. .
As an organic light-emitting device according to an aspect of the present invention, FIG. 11 shows an example of a wiring structure of an organic light-emitting device including the organic light-emitting element 20 of the first embodiment and a drive unit, and a drive circuit connection configuration. In the organic light emitting device of this embodiment, scanning lines 101 and signal lines 102 are wired in a matrix in a plan view with respect to the substrate 1 of the organic light emitting element 20. Each scanning line 101 is connected to a scanning circuit 103 provided on one side edge of the substrate 1. Each signal line 102 is connected to a video signal driving circuit 104 provided at the other side edge of the substrate 1. More specifically, a driving element such as a thin film transistor is incorporated in each of the intersections between the scanning line 101 and the signal line 102, and a pixel electrode is connected to each driving element. These pixel electrodes correspond to the reflective electrodes 11 of the organic light emitting element 20 having the structure shown in FIG. 1, and these reflective electrodes 11 correspond to the first electrodes 12.

The scanning circuit 103 and the video signal driving circuit 104 are electrically connected to the controller 105 via

control lines

106, 107, and 108. The operation of the controller 105 is controlled by the central processing unit 109. In addition, a power supply circuit 112 is connected to the scanning circuit 103 and the video signal driving circuit 104 via

power supply wirings

110 and 111 separately.
A drive unit that drives the organic EL light emitting unit 10 of the organic light emitting element 20 includes a scanning line 101, a signal line 102, a scanning circuit 103, and a video signal driving circuit 104. A TFT circuit 2 of the organic light emitting element 20 shown in FIG. 1 is incorporated in each region partitioned by the scanning line 101 and the signal line 102.
By applying a voltage to the organic EL layer (organic layer) 17 sandwiched between the first electrode 12 and the second electrode 16 of the desired pixel by the drive unit having such a configuration, the organic EL corresponding to the pixel is obtained. The light emitting unit 10 can emit light, and visible region light can be emitted from the corresponding pixel, so that a desired color or image can be displayed.

In the organic light emitting device of the present embodiment, the case where the organic light emitting element 20 of the first embodiment is provided is illustrated, but the present embodiment is not limited thereto, and any organic light emitting element according to the present invention described above may be used. Either can be suitably provided.
The organic light-emitting device which is one embodiment of the present invention is a high-efficiency (high luminance) organic light-emitting device by including the above-described organic light-emitting element which is one embodiment of the present invention.

Next, the color conversion method of this embodiment will be described.
In the color conversion method of the present embodiment, an organic EL light-emitting unit in which at least one organic layer including a light-emitting layer is sandwiched between a pair of electrodes, and a fluorescence conversion layer that converts incident light into fluorescence. A wavelength conversion layer that converts the wavelength of the light emitted from the organic EL light emitting unit and emits the light to the fluorescence conversion layer side, and converts the wavelength of the light emitted from the organic EL light emitting unit to the wavelength conversion The light is converted by the layer, and the converted light is fluorescently converted by the fluorescence conversion layer to generate visible light.
As the organic EL light emitting part, the fluorescence conversion layer, and the wavelength conversion layer in the color conversion method of the present embodiment, the organic EL light emitting part, the fluorescence conversion layer, and the wavelength conversion layer mentioned in the organic light emitting element of the above embodiment are used. The same thing is mentioned.

Since the materials for the green region to the red region have been developed as light emitting materials with high efficiency (high luminance) and a long lifetime, the organic EL light emitting section is preferably provided with materials for the green region to the red region. Therefore, the organic EL light emitting part preferably emits light in the green region to red region.
As a wavelength conversion layer, the layer which can convert the wavelength of the light light-emission from the organic electroluminescent light emission part short is mentioned. Specifically, the wavelength conversion layer converts the wavelength of light incident in the wavelength conversion layer into a half by using a second-order nonlinear optical effect such as second harmonic generation (SHG). Things. The SHG wavelength conversion layer is placed between the organic EL light emitting part and the fluorescence conversion layer, and the light emitted from the organic EL light emitting part is incident on the wavelength conversion layer and emitted from the organic EL light emitting part to green. The wavelength of the light in the region is converted to half and converted into light in the ultraviolet region to blue region. Light in the visible region can be generated by making the light in the ultraviolet region to blue region incident on the fluorescence conversion layer and performing fluorescence conversion in the fluorescence conversion layer.

The wavelength conversion layer is preferably the same as the organic light emitting device 20 of the first embodiment. As shown in FIGS. 3A and 3B, it is preferable that a plurality of layers in which the polarization directions are alternately reversed are stacked. It is preferable that a plurality of layers are laminated so as to periodically invert the polarization of the crystal so as to have a polarization inversion period Λ (that is, for each coherent length Lc).
Examples of the wavelength conversion layer that is second harmonic generation (SHG) using QPM include a layer formed by laminating a plurality of layers in which polarization directions are alternately reversed. Specifically, as the wavelength conversion layer that is second harmonic generation (SHG) using QPM, each layer shown in FIG. 4 is composed of a single-polarized dielectric material, and the polarization directions are alternately changed. A laminated body 18A in which a plurality of

inverted layers

18a and 18b are laminated is preferable. Further, as a wavelength conversion layer that is second-order harmonic generation (SHG) using QPM, a stacked body 18B configured by alternately stacking semiconductor layers 18c and dielectric layers 18d shown in FIG. 5 is preferable. Can be mentioned.

The wavelength conversion layer 18, the wavelength conversion layer (laminated body) 18 A, the material constituting the wavelength conversion layer (laminated body) 18 B, the film thickness of each layer, and the like are as follows. The same materials as those mentioned above can be mentioned.

In the color conversion method of the present embodiment, a wavelength conversion layer is disposed between the organic EL light emitting unit and the fluorescence conversion layer, the wavelength of the light emitted from the organic EL light emitting unit is converted in the wavelength conversion layer, and the converted light is converted into light. By entering the fluorescence conversion layer and performing fluorescence conversion, the light emitted from the organic EL light emitting unit is color-converted, and visible light can be emitted from the fluorescence conversion layer. Further, in the color conversion method of the present embodiment, organic EL light emission is achieved by arranging a second harmonic generation (SHG) wavelength conversion layer having a QPM structure between the organic EL light emitting unit and the fluorescence conversion layer. The wavelength of the green to red light emitted from the light is converted to half in the wavelength conversion layer to make the light in the ultraviolet to blue region, and this converted light is incident on the fluorescence conversion layer and converted to fluorescence. By doing so, visible light can be generated.
According to the color conversion method of the present embodiment, an organic EL light emitting unit that emits light in a green region to a red region having luminance and lifetime superior to those of a blue light emitting material can be used as a light source. Since visible light can be generated by color-converting light from the part, visible light with excellent luminance and lifetime can be generated using the organic EL light-emitting part as a light source.

Hereinafter, examples of the present invention will be described in more detail, but the present invention is not limited to the following examples.

Example 1
An organic light emitting device 20 having the configuration shown in FIG. 1 was produced by the following procedure.
A reflective electrode was formed on a 0.7 mm thick glass substrate by a sputtering method so as to have a film thickness of 100 nm. An indium-tin oxide (ITO) film was formed on the reflective electrode by sputtering so as to have a film thickness of 20 nm. A reflective electrode (anode) was formed as the first electrode. Next, the first electrode was patterned into 90 stripes having a width of 2 mm by a conventional photolithography method.
Next, SiO ₂ was deposited to 200 nm on the first electrode by a sputtering method, and patterned to cover the edge portion of the first electrode by a conventional photolithography method to form an edge cover. Here, a short side of 10 μm from the end of the first electrode is covered with SiO ₂ .
Subsequently, this was washed with water, then subjected to pure water ultrasonic cleaning for 10 minutes, acetone ultrasonic cleaning for 10 minutes, and isopropyl alcohol vapor cleaning for 5 minutes, and dried at 100 ° C. for 1 hour.

Next, the dried substrate was fixed to a substrate holder in an inline type resistance heating vapor deposition apparatus, and the pressure was reduced to a vacuum of 1 × 10 ⁻⁴ Pa or less. Each organic layer was formed.
First, as a hole injection material, 1,1-bis-di-4-tolylamino-phenyl-cyclohexane (TAPC) was used to form a hole injection layer having a thickness of 100 nm by resistance heating vapor deposition. Next, N, N′-di-1-naphthyl-N, N′-diphenyl-1,1′-biphenyl-1,1′-biphenyl-4,4′-diamine (NPD) is used as a hole transport material. A hole transport layer having a film thickness of 40 nm was formed on the hole injection layer by resistance heating vapor deposition.
Next, a red organic light emitting layer (thickness: 30 nm) was formed on the hole transport layer. This red organic light-emitting layer comprises 1,4-bis-triphenylsilyl-benzene (UGH-2) (host material) and tris (1-phenylisoquinoline) iridium (III) Ir (pic) ₃ ) (red phosphorescent dopant) ) At a deposition rate of 1.5 を / sec and 0.2 Å / sec.
Subsequently, a hole blocking layer (thickness: 10 nm) was formed on the blue organic light emitting layer using 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and then tris. An electron transport layer (thickness: 30 nm) was formed using (8-hydroxyquinoline) aluminum (Alq ₃ ).
Next, an electron injection layer (thickness: 0.5 nm) was formed on the electron transport layer using lithium fluoride (LiF).

Thereafter, a translucent electrode was formed as the second electrode. First, the substrate formed up to the electron injection layer as described above was fixed to a metal vapor deposition chamber. A shadow mask for forming the second electrode (a mask having an opening so that the second electrode can be formed in a stripe shape having a width of 2 mm in a direction opposite to the stripe of the first electrode produced above) and the electron injection layer The formed substrate is aligned, and magnesium and silver are co-deposited on the surface of the electron injection layer by a vacuum deposition method at a deposition rate of 0.1 Å / sec and 0.9 Å / sec, respectively, to form magnesium silver in a desired pattern. Formation (thickness: 1 nm). Furthermore, silver is formed in a desired pattern (thickness: 19 nm) at a deposition rate of 1 cm / sec for the purpose of emphasizing the interference effect and preventing voltage drop due to wiring resistance at the second electrode. Thus, the second electrode was formed. Here, the produced organic EL light emitting part exhibits a microcavity effect between the reflective electrode (first electrode) and the semi-transmissive electrode (second electrode), and can increase the light intensity incident on the wavelength conversion layer. It was. Here, the transmittance of the semitransparent electrode was adjusted to 10%, the emission peak due to the microcavity effect (interference effect) was adjusted to 680 nm, and the half-value width was adjusted to 10 nm.

Next, wavelength conversion is performed by forming a BBO (β-BaB ₂ O ₄ ) thin film on the second electrode of the organic EL light emitting part by laser pulse vapor deposition, and laminating 10 layers so as to alternately invert polarization. A layer was formed. Each layer formed a laminated film having a thickness of 1.7 μm and a period of 3.4 μm.
Next, an inorganic sealing film made of 1 μm SiO ₂ was patterned by plasma CVD from the edge of the display portion to a sealing area of 2 mm in the vertical and horizontal directions using a shadow mask. Thus, an organic EL light emitting unit substrate was produced.

Subsequently, a red fluorescence conversion layer, a green fluorescence conversion layer, and a blue fluorescence conversion layer were formed on a glass substrate having a thickness of 0.7 mm.
The red fluorescence conversion layer was formed by first adding 15 g of ethanol and 0.22 g of γ-glycidoxypropyltriethoxysilane to 0.16 g of Aerosil (trade name, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 5 nm at an open system room temperature For 1 hour. Next, the mixture after stirring and 20 g of red phosphor K ₅ Eu _2.5 (WO ₄ ) _6.25 were transferred to a mortar, thoroughly mixed, heated in an oven at 70 ° C. for 2 hours, and further heated to 120 ° C. Heated in an oven for 2 hours to obtain surface-modified K ₅ Eu _2.5 (WO ₄ ) _6.25 . Next, 30 g of polyvinyl alcohol dissolved in a mixed solution (300 g) of water / dimethyl sulfoxide = 1/1 was added to 10 g of K ₅ Eu _2.5 (WO ₄ ) _6.25 subjected to surface modification, and dispersed. By stirring with a machine, a red fluorescent conversion layer-forming coating solution was prepared. The prepared red fluorescent conversion layer forming coating solution was applied to a desired position with a width of 3 mm on the glass substrate by a screen printing method. Subsequently, a red fluorescence conversion layer having a thickness of 70 μm was formed on the glass substrate by heating and drying in a vacuum oven (conditions of 200 ° C. and 10 mmHg) for 4 hours.

The green fluorescence conversion layer is formed by first adding 15 g of ethanol and 0.22 g of γ-glycidoxypropyltriethoxysilane to 0.16 g of aerosil (trade name, manufactured by Nippon Aerosil Co., Ltd.) having an average particle diameter of 5 nm at an open room temperature. For 1 hour. Next, the mixture after stirring and the green phosphor Ba ₂ SiO ₄ : Eu ²⁺ 20 g were transferred to a mortar, mixed well, heated in an oven at 70 ° C. for 2 hours, and further heated in an oven at 120 ° C. for 2 hours. The surface modified Ba ₂ SiO ₄ : Eu ²⁺ was obtained. Next, 30 g of polyvinyl alcohol dissolved in a mixed solution (300 g) of water / dimethyl sulfoxide = 1/1 is added to 10 g of Ba ₂ SiO ₄ : Eu ²⁺ subjected to surface modification, and the mixture is stirred by a disperser. A coating liquid for forming a green fluorescence conversion layer was prepared. The prepared green fluorescent conversion layer forming coating solution was applied to a desired position with a width of 3 mm on the glass substrate by a screen printing method. Subsequently, a green fluorescent conversion layer having a thickness of 70 μm was formed on the glass substrate by heating and drying in a vacuum oven (200 ° C., 10 mmHg conditions) for 4 hours.

The blue fluorescent conversion layer is formed by first adding 15 g of ethanol and 0.22 g of γ-glycidoxypropyltriethoxysilane to 0.16 g of aerosil (trade name, manufactured by Nippon Aerosil Co., Ltd.) having an average particle size of 5 nm at an open room temperature. For 1 hour. Next, the mixture after stirring and the blue phosphor BaMgAl ₁₀ O ₁₇ : Eu ²⁺ 20 g were transferred to a mortar, mixed well, heated in an oven at 70 ° C. for 2 hours, and further heated in an oven at 120 ° C. for 2 hours. The surface modified BaMgAl ₁₀ O ₁₇ : Eu ²⁺ was obtained. Next, 30 g of polyvinyl alcohol dissolved in a mixed solution of water / dimethyl sulfoxide = 1/1 (300 g) was added to 10 g of the surface-modified BaMgAl ₁₀ O ₁₇ : Eu ²⁺ and stirred by a disperser. A blue fluorescent conversion layer forming coating solution was prepared. The produced blue fluorescent conversion layer forming coating solution was applied to a desired position with a width of 3 mm on the glass substrate by a screen printing method. Subsequently, a blue fluorescent conversion layer having a thickness of 70 μm was formed on the glass substrate by heating and drying in a vacuum oven (200 ° C., 10 mmHg) for 4 hours.

Next, the organic EL light emitting unit substrate and the fluorescence conversion layer substrate produced as described above were aligned using an alignment marker formed outside the display unit. At this time, a thermosetting resin was applied to the fluorescence conversion layer substrate in advance, and both substrates were brought into close contact with each other through the thermosetting resin, and cured by heating at 90 ° C. for 2 hours. In addition, the bonding process of both the substrates was performed in a dry air environment (water content: −80 ° C.) for the purpose of preventing the organic EL light emitting portion from being deteriorated by water.
Finally, an organic light emitting device was manufactured by connecting terminals formed in the periphery to an external power source.

A desired good image could be obtained by applying a desired current to the desired stripe-shaped electrode from an external power source to the produced organic light emitting device. From this result, according to the organic light-emitting element which is one embodiment of the present invention, it is possible to obtain the desired good by using the existing red phosphorescent light emitting material without using the blue light emitting material such as the blue phosphorescent material under development. It was confirmed that a simple pixel can be obtained.

(Example 2)
An organic light emitting device 20 having the configuration shown in FIG. 1 was produced.
The organic light emitting device of Example 2 is different from Example 1 in that the wavelength conversion layer 18B shown in FIG. 5 is used as the wavelength conversion layer.
The wavelength conversion layer is formed by using an Ar ion beam sputtering method on the second electrode of the organic EL light emitting portion, a ZnO layer 50 nm as an SHG active semiconductor layer and a TiO ₂ layer 25 nm as an SHG inactive dielectric layer. By alternately forming a total of 10 layers.
A desired good image could be obtained by applying a desired current to the desired stripe electrode from an external power source to the produced organic light emitting device. As a result, according to the organic light emitting device of this example, a desired good pixel can be obtained by using an existing green phosphorescent light emitting material without using a blue light emitting material such as a developing blue phosphorescent material. It was confirmed that it can be obtained.

(Example 3)
An organic light emitting device 30 having the configuration shown in FIG. 7 was produced.
The organic light emitting device of Example 3 is different from Example 1 in that 1,3,5-tris [4- (diphenylamino) phenyl] benzene (TDAPB) is emitted as the host material of the light emitting layer of the organic EL light emitting part. As the material (dopant), fac-tris (2-phenylpyridine) iridium (III) [Ir (ppy) ₃ ] that emits green phosphorescence was used, the microcavity effect was that the emission peak was adjusted to 580 nm, and A light reflective layer (thickness 0.05 μm, transmittance 5%) is formed on the emission side surface of the wavelength conversion layer by vapor deposition, and is paired with the second electrode (semi-transmissive cathode) of the organic EL light emitting unit. This is a point provided with a microcavity effect of light (wavelength 290 nm) converted by the wavelength conversion layer.
A desired good image could be obtained by applying a desired current to the desired stripe electrode from an external power source to the produced organic light emitting device. From this result, according to the organic light-emitting element which is one embodiment of the present invention, it is possible to obtain the desired good by using the existing red phosphorescent light emitting material without using the blue light emitting material such as the blue phosphorescent material under development. It was confirmed that a simple pixel can be obtained. Further, due to the microcavity effect of the wavelength-converted light, the fluorescence conversion layer was irradiated with strong light, so that the luminance increased by 5% compared to Example 1.

Example 4
An organic light emitting device 50 having the configuration shown in FIG. 9 was produced.
The organic light emitting device of Example 4 is different from Example 1 in that the three-color fluorescence conversion layer is not used and only the green fluorescence conversion layer is provided. Further, the organic light emitting device of Example 4 is different from Example 1 in the same manner as in Example 3. The light reflective layer (thickness 0.1 μm, transmittance 1%) is also provided on the emission side of the wavelength conversion layer. And having a microcavity effect of light (wavelength 340 nm) converted by the wavelength conversion layer as a pair with the second electrode (semi-transmissive cathode) of the organic EL light emitting unit.
By applying the produced organic light emitting device to the first electrode and the second electrode from an external power source, green light having a large directivity having a wavelength of 540 nm and a half width of 3 nm was obtained. As a result, according to the organic light-emitting element which is one embodiment of the present invention, green directivity can be obtained by using an existing phosphorescent light-emitting material without using a blue light-emitting material such as a blue phosphorescent material under development. High light was able to be obtained. In addition, a simple organic laser pointer as shown in FIG. 10 could be obtained using the organic light emitting device prepared in Example 4.

High-efficiency (high brightness) organic light-emitting elements, organic light-emitting devices, and color conversion methods can be provided.

DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... TFT circuit, 3 ... Interlayer insulating film, 4 ... Planarization film, 5 ... Inorganic sealing film, 6 ... Sealing material, 7 ... Black matrix, 8R ... Red fluorescence conversion layer, 8G ... Green fluorescence Conversion layer, 8B ... Blue fluorescence conversion layer, 9 ... Sealing substrate, 10 ... Organic EL light emitting part (light source), 11 ... Reflective electrode, 12 ... First electrode (reflective electrode), 13 ... Hole transport layer, 14 Luminescent layer, 15 electron transport layer, 16 second electrode (reflective electrode), 17 organic EL layer (organic layer), 18 wavelength conversion layer, 19 edge cover, 20, 20B, 30, 40, 50: Organic light emitting device.

Claims

An organic EL light emitting unit including at least one organic layer including a light emitting layer, and a pair of electrodes sandwiching the organic layer;
A fluorescence conversion layer that is disposed on the surface side from which light from the organic EL light emitting unit is extracted and converts incident light to fluorescence;
Organic light emission having a wavelength conversion layer that is disposed between the organic EL light emitting unit and the fluorescence conversion layer, converts a wavelength of light emitted from the organic EL light emission unit, and emits the light to the fluorescence conversion layer side element.
The electrode is a reflective electrode, and the optical film thickness between the reflective interfaces defined by the pair of reflective electrodes enhances the intensity of light of a specific wavelength among the light emitted from the organic EL light emitting unit. The organic light emitting device according to claim 1, which is set as follows.
The organic light-emitting element according to claim 1, wherein the wavelength conversion layer converts the wavelength of light emitted from the organic EL light-emitting unit into one half.
The organic light-emitting element according to claim 1, wherein the wavelength conversion layer is formed by laminating a plurality of layers whose polarization directions are alternately reversed.
The organic light-emitting element according to claim 1, wherein the wavelength conversion layer is configured by alternately laminating semiconductor layers and dielectric layers.
The organic light-emitting device according to claim 4, wherein each of a plurality of layers constituting the wavelength conversion layer is made of a single-polarized dielectric material.
The organic light emitting device according to claim 6, wherein the dielectric material is made of a material selected from the group consisting of a ferroelectric material, a glass material, and a polymer material.
The organic light-emitting device according to claim 1, wherein the organic EL light-emitting unit emits light in a red region.
The organic light-emitting device according to claim 1, wherein the organic EL light-emitting unit emits light in a green region.
A light reflective layer is further provided on the light extraction surface side of the light converted by the wavelength conversion layer,
The optical film thickness of the reflective interface determined by the reflective electrode on the surface side from which the light from the light emitting layer and the organic EL light emitting unit is extracted is the intensity of light of a specific wavelength among the light converted in wavelength in the wavelength converting layer. The organic light-emitting device according to claim 2, wherein the organic light-emitting device is set so as to enhance the resistance.
The wavelength conversion layer converts light emitted from the organic EL light emitting unit into light in an ultraviolet region to a blue region, and converts the light converted by the wavelength conversion layer into light in a green region or red region. The organic light-emitting device according to claim 1, which converts the light into the light of
The fluorescence conversion layer is capable of at least two types of color conversion, one of which is color conversion for converting light converted by the wavelength conversion layer into light of a green region, and the other is the wavelength conversion layer. The organic light emitting device according to claim 1, wherein the organic light emitting device is a multicolor light emitting device.
The organic light emitting device according to claim 1, further comprising a color filter on a side of emitting the light converted by the fluorescence conversion layer.
The organic light-emitting device according to claim 1, wherein the organic light-emitting device is provided with a drive unit that drives the organic EL light-emitting unit.
Light is emitted from an organic EL light emitting unit including at least one organic layer including a light emitting layer and a pair of electrodes sandwiching the organic layer,
The wavelength conversion layer disposed between the organic EL light emitting unit and the fluorescence conversion layer that converts incident light to fluorescence converts the wavelength of the light emitted from the organic EL light emitting unit to the fluorescence conversion layer side. Shoot into and
A color conversion method for generating visible light by fluorescently converting light converted by the wavelength conversion layer by the fluorescence conversion layer.
The color conversion method according to claim 15, wherein the wavelength conversion layer converts a wavelength of light emitted from the organic EL light emitting unit into a half.
The color conversion method according to claim 15, wherein the wavelength conversion layer is a stacked body formed by stacking a plurality of layers whose polarization directions are alternately reversed.
The color conversion method according to claim 15, wherein the wavelength conversion layer is a stacked body formed by alternately stacking semiconductor layers and dielectric layers.