JP2003317970A - Spherical organic el device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL device and an organic EL display providing a wide angle of visibility and saving power when manufacturing the organic EL device easily manufacturable into a wide angle of visibility and preferably a large screen color organic EL display. <P>SOLUTION: This spherical organic EL device is provided with an EL layer partially formed on the spherical electrode and a transparent electrode formed on the EL layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL element, and more particularly to an organic EL element capable of providing a power saving type organic EL display having a wide viewing angle.

[0002]

2. Description of the Related Art The use of EL elements as self-luminous planar display elements has been attracting attention. Among them, an organic thin film EL display using an organic substance as a light emitting material has high luminous efficiency such as high brightness light emission even when an applied voltage is a little less than 10 V, and can emit light with a simple element structure. It is expected to be applied to advertisements in which the pattern of illuminating is displayed and other low-priced displays for simple display.

In such an organic EL display, for example, when it is used as an outdoor display, it is required to improve the viewing angle and reduce the power consumption which increases with the increase in area. Further, in the case of a color display, since there is a problem in productivity because a precise patterning technique is used for conventional RGB color separation, there is a need for improvement.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to realize a wide viewing angle and power saving when an organic EL element having a wide viewing angle and easily manufactured, preferably a large-area color organic EL display is manufactured. It is to provide an organic EL element and an organic EL display which can be performed.

[0005]

The present inventor has completed the present invention by finding that the above problems can be solved by making the electrodes of the EL element spherical, and preferably by using spherical solar cells as the spherical electrodes.

Therefore, in the spherical organic EL element of the present invention, the EL layer is partially formed on the spherical electrode,
It is characterized in that a transparent electrode is formed on the layer.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Spherical Organic EL Element The spherical organic EL element of the present invention comprises a spherical electrode partially covered with E
The L layer is formed, and the transparent electrode is formed on the EL layer. In the present invention, the term "spherical" is used in a broader sense than the term "general spherical" including not only a true spherical shape but also a part of a spherical surface such as a hemisphere, and a convex curved surface.

FIG. 1 is a sectional view illustrating a preferred embodiment of such a spherical organic EL element. P-type silicon 1, n-type silicon 2, light emitting layer 3, in order from the center of the spherical organic EL element.
Hole transport layer 4, transparent electrode 5, first plastic protective film 6
Is formed, and the base material side is the first plastic protective film 6, the first aluminum foil electrode 7,
Base 8, insulating layer 9, second aluminum foil electrode 10, second
A plastic protective film 11 is laminated. Then, the first aluminum foil electrode 7 is electrically connected to the transparent electrode 5,
The aluminum foil electrode 10 is electrically connected to the p-type silicon 1, but the n-type silicon 2, the light emitting layer 3, and the hole transport layer 4 are not directly electrically connected to any of the electrodes.

Spherical Electrode The spherical electrode used in the present invention is made of a conductive material and has a convex curved surface, preferably a spherical portion, in at least a part thereof. Typically hemispherical,
A true spherical shape can be mentioned.

In the present invention, this spherical electrode preferably constitutes a solar cell, and more preferably Si.
It consists of solar cells. In this case, typically, the central portion of the spherical solar cell can be p-type Si and the outer portion can be n-type Si, but conversely the central portion can be n-type Si and the outer portion can be p-type Si. .

As described above, the spherical organic EL element having a spherical electrode as a solar cell can emit light while generating electric power by an external ray such as sunlight and / or a ray of self-emission of EL.

EL Layer In the spherical organic EL element of the present invention, the EL layer is partially formed on the spherical electrode at a place to emit light. The EL layer provided in the spherical organic EL element of the present invention is not limited as long as it causes electroluminescence. The thickness is usually 100 to 300 nm.

The EL layer of the present invention further comprises, as its constituent elements, a light-emitting layer as an essential layer, a hole-transporting layer for transporting holes and an electron-transporting layer for transporting electrons to the light-emitting layer as an optional layer, and A hole injection layer for injecting holes into the light emitting layer or the hole transport layer and an electron injection layer for injecting electrons into the light emitting layer or the electron transport layer can be provided. Typically, a light emitting layer and a hole transport layer are provided.

Examples of the material forming these EL layers include the following.

(Light Emitting Layer) <Dye System> Cyclopentadiene derivative, tetraphenylbutadiene derivative, triphenylamine derivative, oxadiazole derivative, pyrazoloquinoline derivative, distyrylbenzene derivative, distyrylarylene derivative, silole derivative, thiophene ring Compounds, pyridine ring compounds, perinone derivatives, perylene derivatives, oligothiophene derivatives, trifumanylamine derivatives, oxadiazole dimers, birazolin dimers <metal complex type> aluminum quinolinol complex, benzoquinolinol beryllium complex, benzoxazole zinc complex,
Benzothiazole zinc complex, azomethylzinc complex, porphyrin zinc complex, eurobium complex, etc., having Al, Zn, Be or the like as a central metal or a rare earth metal such as Tb, Eu or Dy and having an oxadiazole as a ligand, A metal complex having a thiadiazole, phenylpyridine, phenylbenzimidazole, quinoline structure, or the like.

<Polymer> Polyparaphenylene vinylene derivative, polythiophene derivative, polyparaphenylene derivative, polysilane derivative, polyacetylene derivative, polyvinylcarbazole, etc., polyfluorene derivative (doping material) perylene derivative, coumarin derivative,
Rubrene derivative, quinacridone derivative, squalium derivative, porphyrin derivative, styryl dye, tetracene derivative, pyrazoline derivative, decacyclene, phenoxazone (hole injection layer (anode buffer material)) phenylamine system, starburst amine system, phthalocyanine system, oxidation Oxides such as vanadium, molybdenum oxide, ruthenium oxide, and aluminum oxide, amorphous carbon, polyaniline, polythiophene derivatives (electron injection layer (cathode buffer material)) aluminum lithium, lithium fluoride, strontium, magnesium oxide, magnesium fluoride, fluorinated Strontium, calcium fluoride, barium fluoride, aluminum oxide, strontium oxide, calcium, polymethylmethacrylate, sodium polystyrenesulfonate Um (hole transport layer) triphenylamines, bis, pyrazoline derivatives, stilbene compounds, oxadiazole derivatives, phthalocyanine derivatives, heterocyclic compounds typified by porphyrin derivatives, having monomers in the side chain as a polymer system Polycarbonates, styrene derivatives, polyvinylcarbazole, polythiophenes, polysilanes (electron transport layer) oxadiazoles, aluminum quinolinol complexes, etc. that form stable radical anions and have a large ionization potential.
3,4-Oxadiazole derivative, 1,2,4-triazole derivative transparent electrode The transparent electrode used in the present invention is made of a conductive transparent material and is provided on the EL layer. Examples of such a material include ITO, IZO, and SnO ₂ .
The thickness is preferably 100 to 250 nm.

Spherical Organic EL Display The spherical organic EL display of the present invention comprises a spherical organic EL element in which an EL layer is partially formed on a spherical electrode on a substrate and a transparent electrode is formed on the EL layer. , A plurality of the base material and the spherical electrode are arranged so as to be in contact with each other, on the display surface on which the transparent electrode is formed and the display back surface on the base material side, respectively, electrodes, preferably data lines and scan lines or scan lines, respectively. And a data line.

In a preferred embodiment of this spherical organic EL display, the spherical electrodes of the spherical organic EL element are Si constituting a solar cell, and the red light emitting layer and the hole transport layer are partially and sequentially formed on the spherical Si. Layer, a spherical organic EL element on which a transparent electrode is formed, and a spherical organic EL element on which a green light emitting layer, a hole transport layer, and a transparent electrode are partially sequentially formed on a spherical Si.
A spherical organic EL display for full-color display, which includes an element and a spherical organic EL element in which a blue light emitting layer, a hole transport layer, and a transparent electrode are partially formed on the spherical Si in order, can be mentioned. Further, it is not limited to the full-color display using the R, G, and B light-emitting layers as described above, and a display of a single color, a two-color, or the like can be provided as desired. Such a spherical organic EL display of the present invention is
It is easy to increase the area and the manufacturing process can be simplified.

Base Material The base material used in the spherical organic EL display of the present invention is one in which a plurality of spherical organic EL elements are arranged, and preferably a large number of spherical organic EL elements can be arranged as pixels. It is preferable that the transparent electrode of the spherical organic EL element and the electrode that is electrically connected to the spherical electrode are provided. Further, it may be a material that is not a flexible material.

Specifically, for example, as shown in FIG. 1, the first plastic protective film 6, the first aluminum foil electrode 7, the substrate 8, the insulating layer 9 are arranged in this order from the light emitting surface side in the upper part of the figure. An example in which the second aluminum foil electrode 10 and the second plastic protective film 11 are laminated is given.

Video Display In the spherical organic EL display of the present invention, a video display can be performed in the same manner as a conventional general display. In this case, for example, scan lines and data lines orthogonal to each other should be provided on the display surface and the display back surface or the display back surface and the display surface, and the display surface side line should be electrically connected to the transparent electrode and the display back surface side line should be electrically connected to the spherical electrode. You can display a movie with.

Further, for example, a moving image can be displayed by electronically operating the extinction path (EL extinction power source) and the emission path (EL emission auxiliary power source) to control the emission of each element.

Self-Power Generation Property The spherical organic EL element and the spherical organic EL display of the present invention are such that the spherical electrode is a solar cell so that it emits light while generating electricity by external light rays and / or light rays of its own EL emission. can do. In this way, the spherical organic EL element is caused to emit light by supplying either or both of the self-generated power and the external power generated in this way, so that it is possible to emit light with a low power supply as compared with the case of using only the external power.

As a preferred embodiment of the spherical organic EL display of the present invention, a storage battery for storing electric power generated by self-power generation may be provided, and a spherical organic EL element which does not emit light is used for emitting self-generated power. Can also be

Application of Spherical Organic EL Display The spherical organic EL display of the present invention can be used in various applications similar to conventional general displays. Preferred applications include, for example, those requiring a wide viewing angle, those used outdoors in the sunlight, and those having a large area. Specific examples include a large-area outdoor signboard on which a display image is fixed, a large-area outdoor display for displaying moving images, and a low-priced display with rough display dots.

When used for such an application, there is an advantage that, for example, in the daytime when there is an irradiation light beam, color display with a large area and low power consumption is possible. Further, since the solar cell has a spherical shape, sufficient power generation is possible even when the sun is set, and since the spherical light emitting element has a wide viewing angle, it is excellent. Further, as a large area display, it is possible to inexpensively supply a signboard that has an impact as a signboard for attracting customers during the daytime and evening, and as a small area display, it can be used as a power saving display for day and night.

Manufacturing method of spherical organic EL device and display
Method The method for producing the spherical organic EL device and the display of the present invention is not particularly limited, but the method can be performed as follows, for example.

(Spherical Organic EL Element) Texas Instruments
Co., Ltd., Kyoto Semiconductor Co., Hokkaido Industrial Testing Laboratory, etc., to deposit Si spheres (inner p type, outer n type, diameter 1 mm or less) used in spherical Si solar cells under an inert gas such as argon. Thus, the mean free path of the molecule is shortened to form a light emitting layer, a hole transport layer and a transparent electrode having a uniform thickness.

(Display Fixed Display) FIG. 2 illustrates a method for manufacturing the display fixed display. An electrode substrate (aluminum foil or the like) having holes as shown in FIG. 2A is prepared. Next, as shown in FIG. 2B, the spherical organic EL elements and the spherical solar cells for power generation are embedded in an arrangement according to the display pattern, for example, about 170 cells / cm ² . Next, as shown in FIG. 2C, the n layer in the holed portion is etched from the back surface, and after insulation treatment with polyimide or the like, an extraction electrode (aluminum foil or the like) from p-type Si is formed on the back surface. Furthermore, FIG.
As shown in (d), a plastic protective film or the like is formed or laminated on the display surface and the back surface, and an auxiliary power source, a storage battery and an electronic switch are installed as shown in FIG. 2 (e).
A self-powered monochrome display can be manufactured. When the brightness is insufficient, external power is supplied to assist light emission and display is possible.

(Fixed display color display) A fixed display color display can be manufactured in the same manner as in the case of a single color except that three colors of R, G and B are used as the spherical organic EL element.

FIG. 3 illustrates a method of manufacturing a display fixed color display. Similar to fixed display monochromatic display,
An electrode substrate (aluminum foil or the like) having holes as shown in FIG. 3A is prepared. Next, as shown in FIG. 3B, R, G, B
Three colors of spherical organic EL elements and, if necessary, spherical solar cells for power generation are arranged according to the display pattern, for example, about 170 /
Embed in cm ² . Next, as shown in FIG. 3C, the n layer in the holed portion is etched from the back surface, and after insulation treatment with polyimide or the like, an extraction electrode (aluminum foil or the like) from p-type Si is formed on the back surface. Further, as shown in FIG. 3D, a plastic protective film or the like is formed or laminated on the display surface and the back surface, and an auxiliary power source, a storage battery and an electronic switch are installed as shown in FIG. Self-powered display fixed color display can be manufactured. When the brightness is insufficient, external power is supplied to assist light emission and display is possible.

(Display Variable Color Display) FIG. 4 illustrates a method of manufacturing a display variable (movable image display) color display. 4A, an aluminum foil line electrode is transferred to a display surface on a substrate (either flexible or bulk substrate), and holes are punched as shown in FIG. 4B. Next, spherical organic EL elements of R, G, and B colors are embedded in the punch holes at, for example, about 170 pieces / cm ² .
Next, as shown in FIG. 4 (d), the n layer in the holed portion is etched from the back surface and subjected to insulation treatment with polyimide or the like, and then a portion thereof is removed to expose the p-type Si and the electrode (aluminum foil). The line electrode) is formed so as to cross the display surface.
Next, as shown in FIG. 4E, a plastic protective film is formed or rubbed on the display surface and the back surface. Further, as shown in FIGS. 4F and 4G, an extinction power source 4 for applying a reverse bias for extinction for controlling the brightness.
3 and two auxiliary light sources 45 are provided outside. A display variable color display for displaying a moving image can be manufactured by switching the light emitting path 44 and the extinguishing path 43 while scanning the scanning line 42 and controlling the current of the data line 41 at the same time.

FIG. 5 shows an example of the display system of the display variable color display. FIG. 5A is an example of a case where a pixel is made to emit light in the daytime with sunlight. Since the p-type silicon 1 and the n-type silicon 2 that receive sunlight act as solar cells, the spherical organic EL can be closed by closing the external circuit.
Make the device emit light. The surplus power generated by the power generation can be consumed by some circuit (for example, converted into heat by a variable resistor) to protect the element, but can be stored in a rechargeable battery (auxiliary battery) as necessary. .

FIG. 5 (b) shows an example in which the pixels are caused to emit light in the nighttime when there is not much brightness. The spherical organic EL element is caused to emit light by the light emitting battery (the lower battery in the figure). The light emitting battery may also be used as a rechargeable battery (upper battery in the figure), and in that case, switching between the charging battery and the light emitting battery can be performed by switching a switch.

FIG. 5 (c) shows an example of extinguishing pixels in the sunlight in the daytime. The p-type silicon 1 and the n-type silicon 2 which receive sunlight act as a solar cell and can charge a rechargeable battery (battery in the figure).

FIG. 5D shows an example of extinguishing pixels in the nighttime when the brightness is not so high. Since the brightness is not so high, the spherical organic EL element does not emit light even if the external circuit is closed.

In the production of the spherical organic EL display of the present invention, a transparent electrode may be previously formed on the spherical organic EL element and then placed on the base material. It is possible to employ a method of patterning the transparent electrode before forming the protective film.

[0038]

According to the present invention, it is possible to provide an organic EL device having a wide viewing angle and which can be easily manufactured. Further, when a large-area color organic EL display is manufactured, it is possible to provide an organic EL element capable of realizing a wide viewing angle and power saving and such an organic EL display.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a preferred embodiment of a spherical organic EL element of the present invention.

FIG. 2 is an explanatory view illustrating the method for manufacturing a display-fixed monochrome display of the present invention.

FIG. 3 is an explanatory view illustrating a method for manufacturing a display fixed color display of the present invention.

FIG. 4 is an explanatory view illustrating the method for manufacturing the display variable color display of the present invention.

FIG. 5 is an explanatory diagram illustrating a display system of the display variable color display of the present invention.

[Explanation of symbols]

1 p-type silicon 2 n-type silicon 3 light emitting layer 4 Hole transport layer 5 Transparent electrode 6 First plastic protective film 7 1st aluminum foil electrode 8 base 9 Insulation layer 10 Second aluminum foil electrode 11 Second plastic protective film 41 data line (back side formation) 42 scanning lines (surface formation) 43 Quenching power path 44 luminous path 45 Auxiliary light source

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05B 33/14 H01L 31/04 A Q F term (reference) 3K007 AB03 AB17 AB18 CB01 CC00 DB03 5C094 AA12 AA22 AA43 BA01 BA12 BA27 CA19 CA20 DA06 DA13 DB01 DB04 EA05 FA02 FA04 FB14 GA10 HA01 5F051 AA01 BA05 BA11 DA01 DA03 DA20 FA06 HA20 JA17 JA20 5G435 AA01 BB05 CC09 CC12 FF11 HH13 KK05 LL19

Claims (9)

[Claims] 1. An EL layer is partially formed on a spherical electrode,
A spherical organic EL device, wherein a transparent electrode is formed on the EL layer. 2. The spherical organic EL device according to claim 1, wherein the EL layer comprises a light emitting layer and a hole transporting layer. 3. The spherical electrode comprises Si which constitutes a solar cell.
The spherical organic EL element according to claim 1, which is 4. A spherical organic EL device in which an EL layer is partially formed on a spherical electrode on a base material and a transparent electrode is formed on the EL layer is contacted with the base material and the spherical electrode. Spherical organic EL display in which a plurality of electrodes are formed, and electrodes are respectively formed on the display surface on which the transparent electrode is formed and the display back surface on the base material side. 5. The spherical organic EL device, wherein the spherical electrode of the spherical organic EL element is Si constituting a solar cell, and a red light emitting layer, a hole transporting layer, and a transparent electrode are partially sequentially formed on the spherical Si. Element, spherical organic EL element in which a green light emitting layer, a hole transport layer, and a transparent electrode are partially formed on a spherical Si layer, and a blue light emitting layer, a hole transport layer, a transparent layer are sequentially formed on a spherical Si layer. A spherical organic EL element having electrodes formed thereon, and a data line and a scan line or a scan line and a data line, respectively, are formed on the display surface on which the transparent electrode is formed and the display back surface on the side of the base material. The spherical organic EL display according to claim 4, which is formed by: 6. The spherical organic EL display according to claim 5, which emits light while generating electric power by an external light ray and / or a self-luminous light ray of EL light emission. 7. The spherical organic EL display according to claim 5, wherein the display is performed by supplying either or both of self-generated electric power and external electric power. 8. The spherical organic EL display according to claim 5, further comprising a storage battery that stores the electricity generated by the spherical Si. 9. The spherical organic EL display according to claim 5, wherein the electronic switching of the extinction path and the light emission path is performed to control the light emission of each element.
Video display method.