JP2006019638A - Polarization light emitter, method for manufacturing same, polarization organic electroluminescence element, and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarization light emitter which emits light having a relatively high polarization degree, and thus can obtain a relatively high polarization degree without involving a large light energy loss such as light absorption of a light source as when a polarizing plate of a light absorption type is provided; a polarization organic EL element, a liquid crystal display device; and a method for manufacturing the polarization light emitter. <P>SOLUTION: In the polarization light emitter, a light emitting region 1 has a planar shape of an axis longer than the wavelength of emitted light and of an axis shorter than the wavelength, and light is emitted from the region 1. With respect to the light emitted from the region 1, the intensity of vibration light nearly parallel to the longer-axis direction of the region 1 is larger than the intensity of vibration light nearly parallel to the shorter-axis direction of the region 1. The polarization organic EL element, the liquid crystal display device, and the method for manufacturing the polarization light emitter are also provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel polarized light emitter that can be used in a liquid crystal display device and the like, a method for producing the same, and an organic electroluminescent element using the polarized light emitter.

  Some conventional transmissive liquid crystal display devices include a polarizing plate, for example. In order to perform full color display in a transmissive liquid crystal display device including such a polarizing plate, for example, a configuration in which a polarizing plate, a liquid crystal cell, a color filter, and a polarizing plate are arranged on a white light source may be taken. is there. As such a polarizing plate, generally used is a polymer film having a small birefringence, such as polyvinyl alcohol, in which molecules of a dichroic substance dissolved or adsorbed are stretched in one direction and oriented. Such a polarizing plate is of a light absorption type in which polarized light is obtained by absorbing light in one direction in an oriented dichroic substance.

In recent years, as a technique for obtaining polarized light, a method for obtaining polarized light using a cholesteric liquid crystal film (see Patent Documents 1 and 2), a method for obtaining polarized light using a difference in refractive index (see Patent Document 3), and the like have been proposed. .
In addition, as a technique for obtaining directly polarized light as emitted light, a method of obtaining polarized light emission by a device utilizing the fact that an oriented fluorescent material emits colored polarized light (see Patent Document 4), a fluorescent dye in a polymer matrix A method for obtaining polarized light emission by uniaxially orienting a fluorescent material by dispersing and stretching (see Patent Document 5), or a method for obtaining polarized light emission by adding a fluorescent material into a liquid crystal compound and spontaneously aligning the liquid crystal compound (Non-Patent Document) 1), or a method of imparting light emission to the liquid crystal compound itself to obtain polarized light emission (see Non-Patent Document 2).

However, in the case of the light absorption type polarizing plate, at least 50% of light incident from the light source, and in reality, 55 to 60% of light is absorbed, resulting in a large loss of light energy. Further, in the case of a color liquid crystal display device, light absorption by the color filter is also added, and the amount of transmitted light is reduced to 10% or less. And generally, the polarizing plate produced by stretching causes relaxation of the matrix polymer as the temperature rises, or from the decomposition of the dichroic substance such as iodine complex, and also relaxes the orientation of the dichroic substance. There is a problem that it leads to a significant decrease in polarization characteristics.
In the method of obtaining polarized light by utilizing the spontaneous alignment of the liquid crystal, the degree of polarization is generally low because the alignment of the liquid crystal itself is lower than the degree of alignment by stretching.

  In addition, there is a report example in which anisotropic light emission is obtained by incorporating an ultrafine structure into an organic electroluminescence element (Non-patent Document 3). In this report, a dielectric material photoresist material is coated on a transparent electrode (ITO electrode) to form an insulating layer of the photoresist material, and then a 400 nm ultrafine periodic structure is formed by photolithography using a phase shift mask. (Line and space with a width of 200 nm) is formed, and as shown in FIG. 6, an organic light emitting layer k is formed on the photoresist material j having a very fine periodic structure by spin coating so as to cover the photoresist material j. The electroluminescent element X is produced by forming a film and further depositing a metal electrode m. In the element X, in the region where the photoresist material j which is an insulating layer is present, no current flows between the metal electrode m and the ITO electrode i on the substrate h, so that the organic light emitting layer k exists as a result. It is designed to emit light from a region q having a width of 200 nm where no photoresist material j is present, and that portion does not emit light. However, although there is anisotropy in light emission, sufficient polarization has not been obtained, and the ratio (contrast) between the case where the polarizing plates are arranged parallel to the periodic structure and the case where they are arranged vertically is not good. It is enough.

JP-A-7-35925 Japanese Patent Laid-Open No. 10-301097 JP-A-10-125121 European Patent Application No. 0899350 JP 2001-174809 A Applied Physics Letters, Vol. 73, No. 11, p. 1595, 1998 Applied Physics Letters, 74, 10, 1400 Mitsugu, 1999 Applied Physics Letters, 74, 9, 1206, 1999

  Therefore, the present invention has a comparatively high degree of polarization of the emitted light, and therefore, without significant loss of light energy such as absorption of light from the light source as in the case of providing a light absorption type polarizing plate. It is an object of the present invention to provide a polarized light emitter capable of obtaining a high degree of polarization, a polarized organic electroluminescence element, a liquid crystal display device, and a method for producing a polarized light emitter.

This invention is made | formed in view of the said problem which a prior art has.
As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the light emitting region that emits light by excitation of the light emitting region has a long axis longer than the wavelength of the emitted light and the light emitted from the light emitting region. In the light emitted from the light emitting region, the intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting region is smaller than the minor axis direction of the light emitting region. It has been found that a polarized light emitter having a relatively high degree of polarization can be obtained by making the intensity greater than the intensity of vibration light in a substantially parallel direction, and the present invention has been completed.

  More specifically, the polarized light emitter as described above has a structural anisotropy in which the light emitting region has a major axis longer than the wavelength of the emitted light and a minor axis shorter than the wavelength of the emitted light. Since the minor axis is shorter than the wavelength of the emitted light, when this light emitting region is excited, the vibration of light in a direction substantially parallel to the minor axis direction is suppressed, and thus light that vibrates in that direction is generated. On the other hand, since light can vibrate only in the long axis direction of the light emitting region, only light that vibrates in the long axis direction is emitted, and as a result, a light emitting body that emits polarized light, and more specifically, polarized light having a relatively high degree of polarization. Can be a light emitter.

  The present invention is based on such knowledge, and in order to solve the above-described problem, the present invention is a light emitter including one or two or more light-emitting regions that emit light by excitation, and the light-emitting region is based on the wavelength of light emitted by the light emission. It has a planar shape consisting of a long major axis and a minor axis shorter than the wavelength of the emitted light, and in the light emitted from the light emitting region, vibration light in a direction substantially parallel to the major axis direction of the light emitting region. There is provided a polarized light emitter characterized in that the intensity is greater than the intensity of vibration light in a direction substantially parallel to the minor axis direction of the light emitting region.

  The term “substantially parallel” as used in the present invention is a concept that includes both a case where they are parallel and a case where they may be regarded as parallel.

  In the polarized light emitter according to the present invention, the light emitting region has a planar shape composed of a long axis longer than the wavelength of the emitted light by the light emission and a short axis shorter than the wavelength of the emitted light. Since the minor axis is shorter than the wavelength of the emitted light due to the light emission, when the light emitting region is excited, vibration of light in a direction substantially parallel to the minor axis direction of the light emitting region is suppressed, and accordingly However, since light can vibrate only in the long axis direction of the light emitting region, only light that vibrates in the long axis direction of the light emitting region is emitted. Thus, in the light emitted from the light emitting region, the intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting region is such that the intensity of vibration in a direction substantially parallel to the minor axis direction of the light emitting region. It can be greater than the intensity of light, thereby having a relatively high degree of polarization.

  As described above, according to the polarized light emitter according to the present invention, the emitted light itself has a relatively high degree of polarization, and therefore, a large light energy such as light absorption of a light source as in the case of providing a light absorption type polarizing plate. A relatively high degree of polarization can be obtained without loss.

  As a specific aspect of the polarized light emitter according to the present invention, the light emitting area includes two or more of the light emitting areas, and the light emitting areas are arranged separated by a non-light emitting area so that the major axis directions thereof are substantially parallel to each other. Can be illustrated. In this aspect, for example, (a) when having a periodic structure composed of the light-emitting region and the non-light-emitting region, (b) when the light-emitting region and the non-light-emitting region are alternately arranged in a stripe shape (C) The case where the above (a) and (b) are combined can be exemplified.

  In the polarized light emitter according to the present invention, the length of the long axis of the light emitting region is not particularly limited as long as it is longer than the wavelength of light emitted by the light emission, but it is 5 times or more of the light wavelength for ease of processing. The length is preferred. Further, the length of the short axis of the light emitting region is not particularly limited as long as it is shorter than the wavelength of the emitted light by the light emission, but the length of the short axis directly affects the polarization degree of the polarized light emitter. The length is preferably 0.8 times or less, more preferably 0.4 times or less of the light wavelength.

  Further, the intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting area is at least three times the intensity of vibration light in a direction substantially parallel to the minor axis direction of the light emission area. preferable.

  In the polarized light emitter according to the present invention, the light emitting region may be composed of, for example, a fluorescent light emitter. Thus, in the polarized light emitter in which the light emitting region is made of a fluorescent light emitter, the fluorescent light emitter can emit fluorescence by irradiating the fluorescent light emitter with predetermined light.

  Moreover, the polarized light emitter according to the present invention may include a substrate (for example, a transparent substrate), and the light emitting region may be formed on the substrate (for example, a transparent substrate).

  Thus, in order to manufacture the polarized light emitter according to the present invention, which includes a substrate (for example, a transparent substrate) and the light emitting region is formed on the substrate, the present invention includes, for example, the following polarized light A method for manufacturing a light emitter is also provided.

  That is, the present invention includes a forming step of forming a light emitting material layer including a light emitting region that emits light by being excited by light and / or electrolysis on a substrate (for example, a transparent substrate), and subsequent to the forming step. Removal that removes a predetermined unnecessary portion of the luminescent material layer so that the light emitting region has a long axis longer than the wavelength of light emitted by the light emission and a short axis shorter than the wavelength of light emitted by the light emission. And a method for producing a polarized light emitter including the steps.

  In this method of manufacturing a polarized light emitter, a light emitting material layer including a light emitting region that emits light by being excited by light and / or electrolysis is entirely formed on a substrate (for example, a transparent substrate). A predetermined unnecessary portion of the luminescent material layer is removed so as to have a shape composed of a long axis longer than the wavelength of light emitted by the light emission and a short axis shorter than the wavelength of light emitted by the light emission. Thus, the substrate is provided with a substrate (for example, a transparent substrate), and is composed of one or two or more light emitting regions that emit light by excitation, and have a long axis that is longer than the wavelength of light emitted by the light emission and a short axis that is shorter than the wavelength of the emitted light. The polarized light emitter according to the present invention in which a light emitting region having a planar shape is formed on the substrate can be manufactured.

  As described above, according to the method for manufacturing a polarized light emitter according to the present invention, the polarized light emitter according to the present invention in which the light emitting region is formed on the substrate (for example, a transparent substrate) can be manufactured. As such, it has a relatively high degree of polarization, and therefore a relatively high degree of polarization can be obtained without a large loss of light energy such as light absorption of a light source as in the case of providing a light absorption type polarizing plate. A polarized light emitter can be provided.

  In the method for manufacturing a polarized light emitter according to the present invention, in the removing step, the predetermined unnecessary portion of the light emitting material layer may be removed by a laser ablation method using optical interference, or the light emission may be performed by a photolithography method. The predetermined unnecessary portion of the conductive material layer may be removed.

  Furthermore, the present invention comprises a polarized organic electroluminescent device comprising the polarized light emitter according to the present invention, wherein the light emitting region is an organic electroluminescent light emitting region, and the polarized organic electroluminescent device according to the present invention, A liquid crystal display device using an electroluminescence element as a polarization backlight is also provided.

  According to the electroluminescence element and the liquid crystal display device, in any case, since the polarized light emitter according to the present invention is included, the emitted light itself has a relatively high degree of polarization, and therefore, a light absorption type polarizing plate is provided. A relatively high degree of polarization can be obtained without a large loss of light energy such as light absorption of the light source.

  As described above, according to the present invention, one or more light-emitting regions that emit light by excitation have a long axis that is longer than the wavelength of light emitted by the light emission, and a short axis that is shorter than the wavelength of the emitted light. By exciting this light emitting region, the emitted light itself has a relatively high degree of polarization, and therefore, a large amount of light such as light absorption by a light source as in the case of providing a light absorption type polarizing plate. It is possible to provide a polarized light emitter capable of obtaining a relatively high degree of polarization without energy loss, a polarized organic electroluminescence element, a liquid crystal display device, and a method for manufacturing a polarized light emitter.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view of a polarized light emitter A which is an example of a polarized light emitter according to the present invention and in which light emitting regions 1 and non-light emitting regions 2 emitting light by excitation are alternately arranged.
In the polarized light emitter A shown in FIG. 1, the light emitting region 1 has a planar shape composed of a long axis longer than the wavelength of the emitted light emitted by excitation of the region 1 and a short axis shorter than the wavelength of the emitted light. is doing. With such a shape, the light emitted from the light emitting region 1 having the planar shape has the intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting region 1, and the minor axis direction of the light emitting region 1. The polarized light emission can be larger than the intensity of the vibration light in a direction substantially parallel to the light. More specifically, the light emitting region 1 has a shape having a long axis longer than the wavelength of the emitted light and a short axis shorter than the wavelength of the emitted light, and the minor axis of the light emitting region 1 is shorter than the wavelength of the emitted light. Thus, when the light emitting region 1 is excited, the light can vibrate in a direction substantially parallel to the long axis direction of the light emitting region 1, but light in a direction substantially parallel to the short axis direction of the light emitting region 1 can be obtained. Since vibration is suppressed, a light emitting body that emits polarized light with a large amount of light that vibrates in a direction substantially parallel to the major axis direction can be obtained.

  As described above, according to the polarized light emitter A shown in FIG. 1, the emitted light itself has a relatively high degree of polarization, and accordingly, a large light energy such as light absorption of the light source as in the case of providing a light absorption type polarizing plate. A relatively high degree of polarization can be obtained without any loss.

  The length a in the major axis direction of the light emitting region 1 is not particularly limited as long as it is longer than the wavelength of the emitted light in this example, but it is preferably 5 times or longer than the light wavelength for ease of processing. . The length b in the minor axis direction of the light emitting region 1 is not particularly limited as long as it is shorter than the wavelength of the emitted light in this example, but the length of the minor axis directly affects the degree of polarization of the polarized light emitter. The length is preferably 0.8 times or less, more preferably 0.4 times or less of the light wavelength.

  In the polarized light emitter A shown in FIG. 1, the intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting region 1 is adjusted by adjusting the lengths a and b of the light emitting region 1. It is preferable that the intensity of vibration light in a direction substantially parallel to the minor axis direction is three times or more.

  In this polarized light emitter A, the light emitting region 1 having the planar shape includes one or more, in this example, a plurality of light emitting regions 1, and these light emitting regions 1 are non-light emitting so that the major axis directions thereof are substantially parallel to each other. They are separated by a region. The light emitting region 1 is a discontinuous structure as a whole of the light emitting region. Preferably, the light emitting region 1 and the non-light emitting region 2 are arranged so as to have a periodic structure. For example, as shown in FIG. 1, the periodic structure is formed by alternately arranging light emitting regions 1 and non-light emitting regions 2 in a stripe shape. The ratio of the short axis length b of the light emitting region to the sum of the short axis length b of the light emitting region 1 and the short axis length c of the non-light emitting region 2 is not particularly limited. In this example, the minor axis length b of the light emitting region 1 is about 0.12 μm, the minor axis length c of the non-light emitting region 2 is about 0.38 μm, and the ratio of the minor axis length b of the light emitting region 1 is about 24%. is there.

  In the polarized light emitter A shown in FIG. 1, the plurality of light emitting regions 1 are structured so as to be separated from each other by the non-light emitting regions 2, in other words, the light emitting regions as a whole are discontinuous structures. For example, it can be formed as follows. That is, after forming a light emitting material layer by providing a light emitting material including a light emitting region over the entire surface, light emission is performed so that the light emitting region included in the light emitting material layer remaining on the substrate has a desired shape. A predetermined unnecessary portion of the luminescent material is removed from the luminescent material layer. Examples of the removal method include a method of removing the luminescent material by a laser ablation method using optical interference, a method of removing the luminescent material by a photolithography method, and the like.

  Here, the present invention will be further described. When the polarized light emitter according to the present invention includes two or more light emitting regions, the light emitting regions are arranged so that the major axis directions thereof are substantially parallel to each other as described above. Except for having a shape that is separated by a non-light emitting region, it can have the same configuration as a conventionally known light emitter that emits light when excited by light or an electric field. For example, a conventionally known luminescent substance that emits light when excited by light or a laminated structure that emits light when excited by electrolysis can be exemplified.

  The luminescent substance is excited by light in any one of the wavelength ranges from ultraviolet light to visible light, for example, and any wavelength in the visible light wavelength region (for example, center wavelength 390 nm to 700 nm). Examples thereof include low-molecular and high-molecular light-emitting substances that emit light in the region, and known light-emitting substances can be widely used.

  Examples of the low-molecular light-emitting substance include terphenyl, quaterphenyl, polyphenyl, 1,7H-benzimidazo [2,1-a] benz [de] isoquinolin-7-one (BBQ), and the like. Oligophenylenes, 2- (4-biphenylyl) -5-phenyl-1,3,4-oxadiazole (PBD), 1,4, bis (5-phenyloxazol-2-yl) benzene (POPOP) Such as oxazole and oxadiazole derivatives, 7-hydroxycoumarin, 7-hydroxy-4-methylcoumarin (4-MC), 7-diethylamino-4-methylcoumarin (DAMC), coumarin derivatives such as coumarin 120, quinolinol derivatives, Phthalocyanine derivatives, fluorene and its derivatives, anthracene and its derivatives, rhodamine G, xanthene (pyronine, rhodamine, and fluorescein) dyes such as rhodamine 110, oxazine dyes such as cresyl violet and oxazine 1, stilbene dyes such as trans-4,4′-diphenylstilbene, and cyanine dyes And polyacetylene compounds, phenylene vinylene compounds, phenylene ethynylene compounds, five-membered and six-membered heterocyclic compounds, and the like. These compounds can be used alone or in combination. Further, since concentration quenching occurs under high concentration conditions, a dendrimer having the above low-molecular light-emitting substance as a core may be dispersed in a matrix polymer. Examples of polymer matrix materials include polymethyl methacrylate, polyacrylate, polycarbonate, polyvinyl alcohol, polyvinyl pyrrolidone, hydroxyethyl cellulose, cellulose acetate butyrate, cellulose propionate, polyvinyl chloride, polyethylene terephthalate, poly α-naphthalene methacrylate, polyvinyl naphthalene. , Poly n-butyl methacrylate, polycyclohexyl methacrylate, poly (4-methylpentene), epoxy, polysulfone, polyethersulfone, polyetherketone, polyarylate, polyimide, polyetherimide, polyethersulfone, polyacrylonitrile, polyethylene, poly Hydrogenated and copolymerized cyclopentadiene, polycyclohexadiene Hydrogenated products and copolymers, styrene-maleic anhydride copolymer, styrene-acrylonitrile copolymer, and the like tetrafluoroethylene-hexafluoropropylene copolymer benzocyclobutane copolymer. In addition, derivatives of these polymers can also be used.

  Examples of the high-molecular light-emitting substance include polyparaphenylene derivatives, polythiophene derivatives, polyparaphenylene derivatives, polysilane derivatives, polyacetylene derivatives, polyvinylcarbazole derivatives, polyfluorene derivatives, polyphenylene vinylene derivatives, and the like. it can. Specifically, for example, poly (2-methoxy-5- (2'-ethylhexyloxy) -1,4-phenylene vinylene) (MEH-PPV) can be mentioned.

  Examples of the laminated structure that is excited by electrolysis and emits light include known electroluminescence (hereinafter also referred to as EL (Electro Luminescence)) laminated structures. The EL laminated structure may be either an inorganic or organic EL laminated structure, and is preferably an organic EL laminated structure. Specific configurations of the EL laminated structure include, for example, an anode (hole injection electrode) / hole transport layer / light emitting layer / electron injection layer / cathode (electron injection electrode), anode / hole transport layer Various configurations can be selected, such as those consisting of / light-emitting layer / cathode, anode / light-emitting layer / cathode, and those containing a hole injection layer, and there is no particular limitation.

Conventionally known materials can be used for the materials such as the anode, cathode, hole injection layer, electron injection layer, and light emitting layer constituting the EL laminated structure. Examples of the anode material include metals such as Au (gold), CuI (copper iodide), ITO (indium tin oxide) (In (indium)), SnO ₂ (stannic oxide), and ZnO (oxidation). Examples of the cathode include co-evaporated magnesium and silver at an atomic ratio of about 10: 1, a calcium electrode, and aluminum doped with a small amount of lithium. An electrode or the like applied from the viewpoint of improving the electron injection efficiency by reducing the work function of the cathode can be applied, but is not particularly limited.

  Examples of the material for the hole injection layer (hole transport material) include triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino acids. Specific conductive polymer oligomers such as substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, polysilane compounds, aniline copolymers, thiophene oligomers, etc. . Specifically, for example, polyvinylcarbazole, 2,5-bis (4′-diethylaminophenyl) -1,3,4-oxadiazole and N, N-diphenyl- (3-methylphenyl) -1,1 ′ -Biphenyl-4,4'-diamine (TPD) and polyethylenedioxythiophene and polystyrene sulfonic acid (PEDOT / PSS) can be mentioned.

  Examples of the material for the electron injection layer (electron injection material) include nitro-substituted fluorenone derivatives, anthraquinodimethane derivatives, diphenylquinone derivatives, thiopyrandioxide derivatives, heterocyclic tetracarboxylic anhydrides such as naphthaleneperylene, carbodiimide, Examples include fluorenylidenemethane derivatives, anthraquinodimethane derivatives, anthrone derivatives, oxadiazole derivatives, 8-quinolinol derivatives, and other specific electron transfer compounds. Specifically, for example, tris (8-hydroxyquinolinate) aluminum, 2- (4′-tert-butylphenyl) -5- (4 ″ -biphenyl) -1,3,4-oxadiazole and 2 4,7-trinitro-9-fluorenone and the like.

  As specific examples of the light-emitting material for forming the light-emitting layer, for example, the organic light-emitting layer, known materials such as the low-molecular and high-molecular light-emitting substances can be used. The light emitting layer may be formed of only an organic light emitting material, or may be formed of a mixture of an organic light emitting material and a hole transport material and / or an electron injection material.

A preferable example of having the polarized light emitter according to the present invention is a polarized light emitting EL element having a polarized light emitter including a light emitting region composed of an EL laminated structure as described above.
The polarized light emitter of the present invention can be used as a backlight of an image display device including an image display unit that uses polarized light such as a liquid crystal display (LCD). At this time, a polarizing plate-less display can be realized by matching the direction in which the light emitting structure is directed in advance with the polarization incident direction of the image display unit. Further, the polarized light emitter of the present invention may be installed in the image display unit through a polarizing plate so that the light transmission axis of the polarizing plate and the major axis of the light emitting region coincide with each other. In this case, the angle error of the backlight assembled mainly in a separate unit can be eliminated, and light absorption by the polarizing plate can be achieved by matching the direction of polarized light emission by the polarized light emitter of the present invention with the light transmission axis of the polarizing plate. It can be minimized and a relatively bright display can be realized.

  Hereinafter, the present invention will be described with reference to examples and comparative examples, but the present invention is not limited thereto. 3A and 3B are partial schematic cross-sectional views of examples of the polarized light emitters prepared in Example 1 and Comparative Example 1, respectively. In addition, Example 2 and Comparative Example 2 are shown. FIGS. 4A to 4C are schematic cross-sectional views of a part of an example of the EL element created in -1 and 2-2, respectively. Further, FIG. 5 shows a schematic sectional view of a part of an example of the liquid crystal display device prepared in Example 3 and Comparative Example 3.

Example 1
A 0.6% by weight tetrachloroethane (TCE) solution of poly (2-methoxy-5- (2′-ethylhexyloxy) -1,4-phenylene vinylene) (MEH-PPV), which is a light-emitting polymer, was added to glass. On one surface of the substrate, spin coating was performed for 20 seconds at a rotation speed of 2000 rotations / minute, and drying was performed for 10 minutes with a dryer at 100 ° C. to form a light-emitting polymer thin film having a thickness of 150 nm.

  The thin luminescent polymer thin film is partially removed by reduction projection ablation processing of KrF excimer laser with a wavelength of 248 nm through a diffraction grating type mask M as shown in FIG. As shown, a striped structure 4 having a periodic structure that is 1/30 of the periodic structure of the mask was formed. The diffraction grating type mask M has a periodic structure with a pitch Pm of 15 μm, and the periodic structure composed of the light-emitting polymer thin film 41 on the glass substrate 3 has a pitch P of (15 μm / 30 =) 0.5 μm. It was confirmed by electron microscope observation. In the periodic structure, the width b of the region where the light-emitting polymer thin film 41 exists (light-emitting region) is 0.12 μm, and the width c of the region where the light-emitting polymer is removed (non-light-emitting region) is 0.38 μm. The width b of the light emitting region of the object 4 was smaller than the light emission wavelength (maximum wavelength 585 nm).

  Ultraviolet light L was irradiated from the other surface of the glass substrate 3 of the structure 4 to excite the MEH-PPV to emit fluorescence, and the fluorescence L1 was visually observed through a polarizing plate. When the light transmission axis of the polarizing plate was arranged parallel to the long axis of the stripe structure and observed, fluorescence L1 could be confirmed, and when arranged vertically, fluorescence L1 could not be confirmed. From this result, it was confirmed that the emitted light L1 from the structure 4 is polarized light, and the light emitter 10 including the obtained structure 4 is a polarized light emitter.

(Comparative Example 1)
2 except that a diffraction grating type mask M ′ having a periodic structure with a pitch Pm ′ of 60 μm as shown in FIG. 2 is used. As shown in FIG. On one surface, the periodic structure has a pitch P ′ of (60 μm / 30 =) 2 μm, the width (b ′) of the region where the light-emitting polymer thin film 41 exists (light-emitting region) is 1 μm, and the light-emitting polymer thin film 41 A structure 4 ′ having a stripe-like periodic structure in which the width c ′ of the region where no light is present (non-light emitting region) is 1 μm was produced. The width b ′ of the light emitting region of the structure 4 ′ was a value larger than the light emission wavelength (maximum wavelength 585 nm).

  Ultraviolet light L was irradiated from the other surface of the glass substrate 3 of this structure 4 'to excite MEH-PPV, and the fluorescence L1' was visually observed through a polarizing plate. The fluorescence L1 'could be observed whether the light transmission axis of the polarizing plate was parallel or perpendicular to the long axis of the stripe structure. From this result, it was confirmed that the emitted light L1 'from the structure 4' was not polarized.

(Example 2)
An ITO film having a thickness of 100 nm is formed on a glass substrate as a hole injection electrode by vapor deposition, and holes are formed thereon by spin coating using an aqueous dispersion of polyethylene dioxythiophene and polystyrene sulfonic acid (PEDOT / PSS). A 20 nm PEDOT / PSS thin film was formed as an injection layer. The aqueous dispersion of PEDOT / PSS is obtained by mixing 2.5 parts by weight of PSS with 1 part by weight of PEDOT and dispersing the mixture in water at a concentration of 1.5%. On top of that, an MEH-PPV layer having a thickness of 80 nm was formed by spin coating using a 0.45 wt% MEH-PPV / TCE solution. A 30 nm-thickness calcium layer is formed on the MEH-PPV layer as an electron injection electrode, and aluminum for suppressing the deterioration of calcium is further formed on the calcium layer by a vacuum deposition method with a thickness of 200 nm. Thus, an EL element was produced. As shown in FIG. 4A, this EL element is subjected to reduction projection ablation processing of a KrF excimer laser having a wavelength of 248 nm through the diffraction grating type mask M (see FIG. 2) similar to that in Example 1, as shown in FIG. The EL element 20 having the stripe-like structure 5 having a periodic structure 1/30 of the periodic structure of M was formed. At least the electron injection electrode 54 and the MEH-PPV layer 53 among the aluminum layer 55, the electron injection electrode 54, the MEH-PPV layer 53, the hole injection layer 52, and the ITO film 51 in the portion irradiated with the laser beam by the ablation process. The predetermined unnecessary part of was removed. The diffraction grating mask M has a periodic structure with a pitch Pm of 15 μm, and the periodic structure formed on the EL element 20 has a pitch P of (15 μm / 30 =) 0.5 μm. Similarly, the width b of the light emitting region was 0.12 μm. The width b of this light emitting region was a value smaller than the light emission wavelength (maximum wavelength 585 nm). When a DC voltage of 7 V was applied to the EL element 20, orange electroluminescence L2 could be confirmed visually. When the light transmission axis of the polarizing plate was arranged parallel to the long axis of the stripe structure and this light emission L2 was observed through the polarizing plate, it was confirmed that the light emission L2 was transmitted through the polarizing plate. On the other hand, when the light transmission axis of the polarizing plate was arranged perpendicular to the long axis of the stripe structure and this light emission L2 was observed through the polarizing plate, it was confirmed that the light emission L2 did not pass through the polarizing plate. From the above results, it was confirmed that the light emission L2 from the EL element 20 was polarized.

(Comparative Example 2-1)
The method of forming the stripe structure is the same as in Example 2 except that a diffraction grating mask M ′ having a periodic structure with a pitch Pm ′ of 60 μm as shown in FIG. As shown, an EL device having a stripe-shaped structure 5 ′ was produced. The diffraction grating mask M ′ has a periodic structure with a pitch Pm ′ of 60 μm, and the periodic structure formed on the MEH-PPV thin film has a pitch P ′ of (60 μm / 30 =) 2 μm. Similar to 1, the width b ′ of the light emitting region was 1 μm. The width b ′ of this light emitting region was larger than the light emission wavelength (maximum wavelength 585 nm). When a DC voltage of 7 V was applied to the EL element 20 ′ having the stripe-shaped structure 5 ′, orange electroluminescence L2 ′ could be visually confirmed. Even when the light transmission axis of the polarizing plate was arranged parallel to or perpendicular to the long axis of the stripe structure, light emission L2 ′ via the polarizing plate could be confirmed. From this, it was confirmed that the light emission L2 ′ from the EL element 20 ′ was not polarized.

(Comparative Example 2-2)
The EL element before ablation processed in Example 2 is subjected to reduction projection application processing of a KrF excimer laser having a wavelength of 248 nm through the same diffraction grating type mask M as in Example 2 (that is, Example 1). As shown in FIG. 4C, a stripe-shaped structure 5 ″ having a periodic structure that is 1/30 of the periodic structure of the mask M was formed. In this case, the application process was performed on the MEH-PPV layer 53. Half-etching to remove about half of the layer thickness was performed to obtain an EL element 20 ″ having a stripe-shaped structure 5 ″. The diffraction grating type mask M has a periodic structure with a pitch Pm of 15 μm, and the MEH The periodic structure formed on the -PPV layer 53 had a pitch P of (15 μm / 30 =) 0.5 μm. The EL element 20 having this stripe-shaped structure 5 ″ Electroluminescent L2 "orange a current of 7V to could be confirmed visually. Whether or not the light transmission axis of the polarizing plate is arranged parallel or perpendicular to the long axis of the stripe structure, light emission L2 ″ through the polarizing plate was confirmed. This light emission L2 ″ was transmitted through the polarizing plate. It was slightly brighter to place the axis parallel to the long axis of the stripe structure, but the contrast was insufficient. In the EL element of this example, the light emitting region exists in the MEH-PPV layer 53. In the structure 5 produced here, only about half of the MEH-PPV layer 53 is removed by half etching, and the remaining half is continuously present, so that the light emitting region is substantially continuously present. It seems to have done.

Example 3
An ITO transparent electrode 12 having a thickness of 100 nm is formed on the glass substrates 11a and 11b, a pair of the substrates is used, and a polyvinyl alcohol solution is applied and dried on the surface on the electrode 12 side by spin coating, followed by rubbing. The rubbing film | membrane 13 was created by processing. The concentration of the polyvinyl alcohol aqueous solution was 5%, and the thickness of the rubbing film was 500 nm. The transparent electrode 12 of one transparent substrate 11a is divided in advance by etching. Thereafter, the pair of substrates 11a and 11b are arranged so that the rubbing directions are orthogonal to each other so that the transparent electrode 12 is opposed to each other, and a gap adjusting material 14 is disposed between the pair of substrates 11a and 11b. After sealing the periphery with epoxy resin 15, liquid crystal 16 "ZLI-4792" (manufactured by Merck) is injected from the liquid crystal injection port to close the liquid crystal injection port. It was created (see FIG. 5). A polarizing plate 18 “NPF EGW1225DU” (manufactured by Nitto Denko Co., Ltd.) was pasted on both sides to prepare a normally white liquid crystal panel 30. As the backlight of the liquid crystal panel 30, the polarization EL element 20 of the second embodiment is arranged so that the long axis of the stripe structure and the light transmission axis of the polarizing plate 18 on the backlight side attached to the liquid crystal panel 30 are aligned. A device 40 was produced. Applying a voltage to the EL element 20 so that luminous intensity 200 cd / m ² of the EL device 20, when measuring the brightness on the liquid crystal panel 30 over was luminance of 180 cd / m ^2.

(Comparative Example 3)
A liquid crystal display device 40 ′ was produced in the same manner as in Example 3 except that the EL element 20 ′ produced in Comparative Example 2-1 was used as the backlight of the liquid crystal panel 30. EL device 20 applies a voltage to 'the luminous intensity of the EL element 20 so as to 200 cd / m ^2', were luminance of 80 cd / m ² when measured brightness to the liquid crystal panel 30 over.

It is an example of the polarized light emitter according to the present invention, and is a plan view schematically showing a polarized light emitter in which light emitting regions and non-light emitting regions that emit light by excitation are alternately arranged. It is a top view which shows roughly an example of the diffraction grating type mask used by the Example and the comparative example. FIG. (A) is a cross-sectional view schematically showing a part of an example of the polarized light emitter produced in Example 1, and FIG. (B) is a part of an example of the polarized light emitter produced in Comparative Example 1. FIG. FIG. (A) is a cross-sectional view schematically showing a part of an example of an EL element produced in Example 2, and FIG. (B) is a part of an example of an EL element produced in Comparative Example 2-1. FIG. 4C is a cross-sectional view schematically showing a part of an example of the EL element produced in Comparative Example 2-2. FIG. 10 is a cross-sectional view schematically showing a part of an example of a liquid crystal display device created in Example 3 and Comparative Example 3. It is a figure for demonstrating the conventional organic electroluminescent element which incorporates a very fine structure and obtains anisotropic light emission.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission area | region 2 Non-light emission area | region 3 Substrate 20 Polarization organic EL element 40 Liquid crystal display device 41, 53 Light-emitting material layer A Polarization light-emitting body a The length of the major axis b of the light emission area 1

Claims (12)

A light emitter comprising one or more light emitting regions that emit light upon excitation,
The light emitting region has a planar shape composed of a long axis longer than the wavelength of light emitted by the light emission and a short axis shorter than the wavelength of the emitted light,
In the light emitted from the light emitting region, the intensity of the vibration light in a direction substantially parallel to the major axis direction of the light emitting region is the intensity of the vibration light in a direction substantially parallel to the minor axis direction of the light emitting region. A polarized light emitter characterized by being larger than intensity. 2. The polarized light emitter according to claim 1, wherein the light emitting region includes two or more light emitting regions, and the light emitting regions are arranged separated by a non-light emitting region so that the major axis directions thereof are substantially parallel to each other. The polarized light emitter according to claim 2, having a periodic structure composed of the light emitting region and the non-light emitting region. The polarized light emitter according to claim 2 or 3, wherein the light emitting regions and the non-light emitting regions are alternately arranged in a stripe shape. The length of the major axis of the light emitting region is at least five times the wavelength of the emitted light by the light emission, and the length of the minor axis of the light emitting region is 0.8 times the wavelength of the emitted light by the light emission. The polarized light emitter according to any one of claims 1 to 4, which has the following length. The intensity of vibration light in a direction substantially parallel to the major axis direction of the light emitting region is at least three times the intensity of vibration light in a direction substantially parallel to the minor axis direction of the light emission region. The polarized light emitter according to any one of 5. The polarized light emitter according to any one of claims 1 to 6, wherein the light emitting region comprises a fluorescent light emitter. The polarized light emitter according to any one of claims 1 to 7, further comprising a substrate, wherein the light emitting region is formed on the substrate. A method for manufacturing a polarized light emitter for producing the polarized light emitter according to claim 8, comprising:
Forming a light emitting material layer including a light emitting region that emits light by being excited by light and / or electrolysis on a substrate; and
Following the forming step, the light emitting material layer has a predetermined unnecessary shape so that the light emitting region has a shape having a long axis longer than the wavelength of light emitted by the light emission and a short axis shorter than the wavelength of light emitted by the light emission. And a removing step of removing the portion. A method for producing a polarized light emitter. The method for manufacturing a polarized light emitter according to claim 9, wherein in the removing step, the predetermined unnecessary portion of the light emitting material layer is removed by a laser ablation method using optical interference. A polarized organic electroluminescent device comprising the polarized light emitter according to claim 1, wherein the light emitting region is an organic electroluminescent light emitting region. A liquid crystal display device comprising the polarizing organic electroluminescence element according to claim 11, wherein the polarizing organic electroluminescence element is used as a polarizing backlight.

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