JP2006253164A - Organic transistor and display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic light emitting transistor having an arrangement and a function for applying an organic semiconductor material which is in an initial stage that a light emitting phenomenon has been just ascertained to a display. <P>SOLUTION: In the organic transistor where an organic semiconductor layer 2 is provided between a pair of first electrode 3 and a second electrode 4 and a third electrode 6 is provided in a region where the organic semiconductor layer 2 is formed through an insulation layer 5, a voltage is applied between the pair of electrodes within the light emitting range of the organic semiconductor layer, a voltage is also applied to the third electrode, and the length of the electrode in the opposing region is set longer than the distance between the pair of opposing electrodes. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an organic transistor and related technology, and more particularly to an organic thin film transistor having a light emission phenomenon and a display device using the same.

With the spread of information terminal devices, there is a demand for higher performance and diversification of device functions, and there is an increasing need for flat panel displays as computer displays. In addition, with the progress of the information society, there has been an increased opportunity to provide information that has been provided in paper media in an electronic form. As a mobile display medium that is thin, light, and portable, electronic paper can be used. Or there is a growing need for digital paper.
In general, in a flat display device, a display medium is formed using an element utilizing liquid crystal, organic EL, electrophoresis, or the like. In such a display medium, a technique using an active drive element formed of a thin film transistor (TFT) as an image drive element has become mainstream in order to ensure uniformity of screen brightness, screen rewrite speed, and the like. Here, the TFT element is usually formed by sequentially forming a semiconductor thin film such as a-Si (amorphous silicon) or p-Si (polysilicon) or a metal thin film such as a source, drain, or gate electrode on a glass substrate. Manufactured by stacking. The manufacture of flat panel displays using TFT elements usually requires high-precision photolithographic processes in addition to vacuum equipment such as CVD and sputtering and thin film forming processes that require high-temperature treatment processes. The load of is very large. Furthermore, along with the recent needs for larger display screens, the amount of cost increase associated with manufacturing has become enormous.
In recent years, research and development of organic TFT elements using organic semiconductor materials has been actively promoted as a technique to compensate for the disadvantages of conventional TFT elements (see Patent Document 1, Non-Patent Document 1, etc.). Since this organic TFT element can be manufactured by a low-temperature process, a light and difficult-to-break resin substrate can be used instead of a conventional glass substrate that is heavy and easily broken, and a resin film is used as a support. It is said that a flexible display can be realized (see Non-Patent Document 2). Further, by using an organic semiconductor material that can be manufactured by a wet process such as printing or coating under atmospheric pressure, a display with excellent productivity and a very low cost can be realized.
On the other hand, a light-emitting transistor has been reported as a part of research results of organic TFT elements using such organic semiconductor materials (see Non-Patent Document 3). If this is used, there is a possibility that a display having a novel configuration in which both are integrated can be realized without forming the display medium and the image driving element separately as in the conventional case.
Japanese Patent Laid-Open No. 10-190001 Advanced Material 2002, 2nd issue, page 99 (review) SID '02 Digest p.57 The 65th JSAP Scientific Lecture Proceedings 1163 pages

However, this research is still an elementary stage that the light emission phenomenon has been confirmed, and the concrete way to apply it to the display is a situation where we have to wait for further research. .
The present invention has been made in view of such circumstances, and a first object thereof is to propose an organic light-emitting transistor having a novel configuration and function.
A second object is to propose a specific configuration of such an organic light emitting transistor.
A third object is to propose another specific configuration of such an organic light emitting transistor.
A fourth object is to propose yet another specific configuration of such an organic light emitting transistor.
A fifth object is to propose a new configuration for stably functioning such an organic light-emitting transistor.
The sixth object is to propose another novel configuration for stably functioning such an organic light emitting transistor.
A seventh object is to propose a display device using such an organic light emitting transistor.
The eighth object is to propose a color display device using such an organic light emitting transistor.

In order to achieve the above object, according to the present invention, first, an organic semiconductor material is provided between a pair of electrodes including a first electrode and a second electrode, and an insulating layer is interposed in the region where the organic semiconductor material is provided. An organic transistor having a structure in which a third electrode is provided, applying a voltage within a range in which the organic semiconductor material emits light between the pair of electrodes, and further applying a voltage to the third electrode, In the organic transistor for controlling light emission, the electrode length of the facing region is made longer than the distance between the electrodes facing the pair of electrodes.
Second, in the organic transistor according to the first aspect, the configuration in which the electrode length of the region facing the pair of electrodes is longer than the distance between the electrodes facing each other is that the pair of electrodes are opposed to each other. The side which carries out is mutually comb-tooth-shaped, and it was set as the structure by which the comb tooth | gear was mutually put in the structure.
Thirdly, in the organic transistor according to the first or second aspect, the organic semiconductor material emits light in a region where the pair of electrodes are opposed to each other, and the light emitting region has an elongated shape. A pair of electrodes was constructed.
Fourth, in the organic transistor according to any one of the first to third aspects, a plurality of light emitting regions opposed to the pair of electrodes are formed in a matrix shape, and three adjacent regions are formed. The elongated shape of each light emitting region is such that the light emitting region has a substantially square shape.
Fifth, in the organic transistor according to any one of the first to fourth aspects, an organic transistor substrate on which a plurality of the organic transistors are arranged is arranged in a vacuum-tight state.
Sixthly, in the organic transistor according to any one of the first to fourth aspects, an organic transistor substrate on which a plurality of the organic transistors are arranged is disposed in an inert gas atmosphere.
Seventhly, a display device is formed by utilizing ON / OFF of light emission of the organic transistor described in the fifth or sixth.
Eighthly, in the display device according to the seventh aspect, a filter is disposed at a position facing the light emitting surface of the organic transistor.

As an effect of the present invention, according to the first aspect of the present invention, an organic semiconductor material is provided between a pair of electrodes including the first electrode and the second electrode, and an insulating layer is provided in the region provided with the organic semiconductor material. An organic transistor having a structure in which a third electrode is provided, wherein a voltage is applied between the pair of electrodes within a range in which the organic semiconductor material emits light, and a voltage is further applied to the third electrode. In the organic transistor for controlling light emission, the electrode length of the facing region is made longer than the distance between the electrodes where the pair of electrodes are facing each other, so that the transistor operation and the light emitting operation can be performed by the same element. A novel organic light-emitting transistor has been proposed. In addition, the organic light-emitting transistor has a very high luminous efficiency because the electrode length of the facing region is longer than the distance between the electrodes facing the pair of electrodes.
According to the invention of claim 2, in such an organic transistor, the configuration in which the electrode length of the facing region is longer than the distance between the electrodes facing the pair of electrodes is Since the opposing sides are comb-toothed, and the comb teeth are in a mutually interleaved structure, the length of the electrodes in the opposing area can be increased efficiently, resulting in very light emission An efficient organic light-emitting transistor could be obtained.
According to the invention of claim 3, in such an organic transistor, the organic semiconductor material is caused to emit light in a region where the pair of electrodes are opposed to each other, and the pair of the pair of electrodes is formed so that the light emitting region has an elongated shape. Since the electrode is configured, an organic light-emitting transistor having still another novel configuration capable of performing the transistor operation and the light-emitting operation with the same element has been proposed.
According to the invention of claim 4, in such an organic transistor, a plurality of light emitting regions opposed to the pair of electrodes are formed in a matrix shape, and a light emitting region having a substantially square shape is formed by three adjacent regions. Since each of the light emitting regions is formed into an elongated shape, another organic light emitting transistor having another novel configuration capable of performing the transistor operation and the light emitting operation with the same element has been proposed.

According to the invention of claim 5, in such an organic transistor, since the organic transistor substrate on which a plurality of the organic transistors are arranged is arranged in a vacuum-tight state, in addition to the above effects, the element function can be stably expressed. Became.
According to the invention of claim 6, in such an organic transistor, since the organic transistor substrate in which a plurality of the organic transistors are arranged is arranged in an inert gas atmosphere, in addition to the above effect, the element function is stably expressed. I can do it now.
According to the seventh aspect of the present invention, since the display device is formed by utilizing ON / OFF of the light emission of such an organic transistor, a self-luminous display device having a novel configuration in which the transistor operation and the light emission operation are performed by the same element is provided. I was able to propose.
According to the invention of claim 8, in such a display device, since the filter is disposed at a position opposite to the light emitting surface of the organic transistor, the self-light emitting type having a novel configuration in which the transistor operation and the light emitting operation are performed by the same element. A color display device could be proposed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The light-emitting organic thin film transistor element of the present invention includes a top gate type having a source electrode and a drain electrode in contact with an organic semiconductor layer on a support, and a gate electrode on the support via a gate insulating layer. First, it is roughly classified into a bottom gate type having a gate electrode and having a source electrode and a drain electrode connected by an organic semiconductor layer through a gate insulating layer. ) Is as shown in FIGS.
FIG. 1 shows an example of the layer structure of a top-gate type light-emitting organic thin film transistor element, in which an organic semiconductor layer 2 is formed on a substrate or sheet constituting a support 1 and further electrically connected to the organic semiconductor layer 2. The source electrode 3 as the first electrode and the drain electrode 4 as the second electrode are arranged in a predetermined arrangement with a predetermined interval, and a gate insulating layer is formed in a region corresponding to the pair of electrodes 3 and 4. 5 has a gate electrode 6 as a third electrode. In other words, the gate insulating layer 5 is disposed so as to cover the upper surface of the organic semiconductor layer 2 and the source electrode 3 and the drain electrode 4, and further, an appropriate position on the upper surface of the gate insulating layer 5 (corresponding to between the source electrode 3 and the drain electrode 4. At a position where the gate electrode 6 is disposed. A voltage is applied between the source electrode 3 and the drain electrode 4 within a range in which the organic semiconductor layer 2 emits light, and a voltage is further applied to the gate electrode 6 to control light emission.
Here, by using a translucent material as described later as the substrate material constituting the support 1, light can be extracted from the support 1 side to the outside (in the direction of arrow A in FIG. 1).
Alternatively, although the material and the like will be described later, light can be extracted from the gate electrode 6 side to the outside (in the direction of arrow B in FIG. 1) by using the gate insulating layer 5 and the gate electrode 6 as a light-transmitting material. It becomes possible.

FIG. 2 shows an example of the layer structure of a bottom-gate light-emitting organic thin film transistor element, in which a gate electrode 6 is arranged on the substrate or sheet upper surface constituting the support 1 and the gate is covered so as to cover the upper surface of the support and the gate electrode 6. The insulating layer 5 is disposed, and the organic semiconductor layer 2 is formed on the gate electrode 5 so as to cover it. Furthermore, the source electrode 3 and the drain electrode 4 are joined and arranged on the upper surface of the organic semiconductor layer 2 at a predetermined interval. The gate electrode 5 is disposed so as to be located between the source electrode 3 and the drain electrode 4. In other words, the electrode layer as the gate electrode (third electrode) 6, the gate insulating layer 5, and the organic semiconductor layer 2 are formed on the support 1 in this order, and are further electrically connected to the organic semiconductor layer 2. A pair of electrode layers composed of a source electrode (first electrode) 3 and a drain electrode (second electrode) 4 are formed, and the region of the organic semiconductor layer 2 is sealed with an element protective layer 7. is there. Then, a voltage is applied between the source electrode 3 and the drain electrode 4 within a range in which the organic semiconductor layer 2 emits light, and a voltage is further applied to the gate electrode 6, so that the substrate 1 or the sheet constituting the support 1 is formed. The electrode layer as the gate electrode 6, the gate insulating layer 5, and the organic semiconductor layer 2 are formed in this order, and a pair of electrode layers including the source electrode 3 and the drain electrode 4 that are electrically connected to the organic semiconductor layer 2 are formed. In addition, the region of the organic semiconductor layer 2 is sealed by the element protective layer 7. A voltage is applied between the source electrode 3 and the drain electrode 4 within a range in which the organic semiconductor layer 2 emits light, and a voltage is further applied to the gate electrode 6 to control light emission.
Here, by using a light-transmitting material as described later as a substrate material constituting the support 1, the gate electrode 6 and the gate insulating layer 5 are also supported by using a light-transmitting material as described later. Light can be extracted from the body 1 side to the outside (in the direction of arrow A in FIG. 2).
Alternatively, it is possible to extract light in the direction of the arrow B in FIG. 2 by forming the element protective layer 7 with a light-transmitting material such as silicon oxide to form a sealing structure. As will be described later, when the entire organic transistor is sealed in a vacuum-tight state or placed in an inert gas atmosphere, the element protective layer shown here is used. 7 may be omitted.

FIG. 3 shows a modified configuration example of a bottom gate type light emitting organic thin film transistor element, in which a substrate made of a conductive material or a semiconductor material is provided with a function as a support 1 and a gate electrode 6. A gate insulating layer 5 is formed so as to cover a substrate (gate electrode 6) made of a conductive material or a semiconductor material, and the organic semiconductor layer 2 and a source electrode 3 and a drain electrode electrically connected thereto are further formed on the gate insulating layer 5. A pair of electrode layers made of 4 are formed, and finally an element protection layer 7 is formed to form a sealing structure. The organic semiconductor layer 2 is formed so as to cover the gate insulating layer 5 and the electrodes 3 and 4. A voltage is applied between the source electrode 3 and the drain electrode 4 within a range where the organic semiconductor layer 2 emits light, and a voltage is further applied to the gate electrode 6 so that light emission can be controlled.
Here, by forming the element protective layer 7 with a light-transmitting material such as silicon oxide, light can be extracted to the outside (in the direction of arrow A in FIG. 3).
As will be described later, in the case where the entire organic transistor is sealed in a vacuum-tight state or placed in an inert gas atmosphere, the element protective layer 7 shown here is used. Is not necessary.

As the material of the organic semiconductor layer 2 used in the light emitting organic thin film transistor element of the present invention according to each of the above embodiments, a π-conjugated material is used, for example, polypyrrole, poly (N-substituted pyrrole), poly (3-substituted pyrrole). ), Polypyrroles such as poly (3,4-disubstituted pyrrole), polythiophene, poly (3-substituted thiophene), poly (3,4-disubstituted thiophene), polythiophenes such as polybenzothiophene, polyisothianaphthene Such as polyisothianaphthenes, polychenylene vinylenes such as polychenylene vinylene, poly (p-phenylene vinylenes) such as poly (p-phenylene vinylene), polyaniline, poly (N-substituted aniline), poly ( 3-substituted anilines), polyanilines such as poly (2,3-substituted anilines), polyacetyl Polyacetylenes such as polydiacetylene, polydiacetylenes such as polydiacetylene, polyazulenes such as polyazulene, polypyrenes such as polypyrene, polycarbazoles such as polycarbazole and poly (N-substituted carbazole), and polyselenophene such as polyselenophene , Polyfurans such as polyfuran and polybenzofuran, poly (p-phenylene) s such as poly (p-phenylene), polyindoles such as polyindole, polypyridazines such as polypyridazine, naphthacene, pentacene, hexacene, heptacene , Dibenzopentacene, tetrabenzopentacene, pyrene, dibenzopyrene, chrysene, perylene, coronene, terylene, ovalene, quaterrylene, carbons of polyacenes and polyacenes Derivatives substituted with functional groups such as N, S, O, and carbonyl groups (triphenodioxazine, triphenodithiazine, hexacene-6, 15-quinone, etc.), polyvinylcarbazole, polyphenylene sulfide, poly Polymers such as vinylene sulfide can be used.
In addition, α-sexual thiophene α, ω-dihexyl-α-sexual thiophene, α, ω-dihexyl-α-kinkethiophene, α, ω-bis (which is a thiophene hexamer having the same repeating unit as these polymers, for example. Oligomers such as 3-butoxypropyl) -α-sexithiophene and styrylbenzene derivatives can also be suitably used.

Furthermore, metal phthalocyanines such as copper phthalocyanine and fluorine-substituted copper phthalocyanine, naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N'-bis (4-trifluoromethylbenzyl) naphthalene 1,4,5,8 N, N′-bis (1H, 1H-perfluorooctyl), N, N′-bis (1H, 1H-perfluorobutyl) and N, N′-dioctylnaphthalene 1,4,5, with tetracarboxylic acid diimide 8-tetracarboxylic acid diimide derivatives, naphthalene 2, 3, 6, 7 naphthalene tetracarboxylic acid diimides such as tetracarboxylic acid diimide, and anthracene tetracarboxylic acid diimides such as anthracene 2, 3, 6, 7-tetracarboxylic acid diimide Condensed ring tetracarboxylic acid diimides such as C60, C70, C7 6, fullerenes such as C78 and C84, carbon nanotubes such as SWNT, dyes such as merocyanine dyes and hemicyanine dyes.
Among these π-conjugated materials, thiophene, vinylene, chelenylene vinylene, phenylene vinylene, p-phenylene, a substituent thereof, or two or more of these are used as a repeating unit, and the number n of the repeating units is 4 to 4 At least one selected from the group consisting of an oligomer of 10 or a polymer in which the number n of repeating units is 20 or more, a condensed polycyclic aromatic compound such as pentacene, fullerenes, condensed ring tetracarboxylic acid diimides, and metal phthalocyanine. Species are preferred.
Other organic semiconductor materials include tetrathiafulvalene (TTF) -tetracyanoquinodimethane (TCNQ) complex, bisethylenetetrathiafulvalene (BEDTTTTF) -perchloric acid complex, BEDTTTTF-iodine complex, TCNQ-iodine complex. Organic molecular complexes such as can also be used. Furthermore, σ conjugated polymers such as polysilane and polygermane can also be used.

例えば下記一般式（Ｉ）で表わされるカルボニル化合物

［一般式（Ｉ）中、Ａ１、Ａ２はそれぞれ置換または無置換の単環または多環式のアリレン基またはヘテロアリレン基を表わす。Ｒ１は水素、置換または無置換のアルキル基、置換または無置換のアリール基を表わす。Ｖは−Ｏ−、−Ｓ−、−ＮＲ２−（Ｒ２は置換または無置換の単環または多環式のアリレン基、もしくは置換または無置換の単環または多環式のヘテロアリレン基を表わす）を表わし、ｎは≧０を表わす］、及び下記一般式（ＩＩ）で表わされるリン化合物

［一般式（ＩＩ）中、Ａ３、Ａ４はそれぞれ置換または無置換の単環または多環式のアリレン基またはヘテロアリレン基を表わす。Ｒ３は水素、置換または無置換のアルキルまたはアリールまたはヘテロアリール基を表わす。Ｗは−Ｏ−、−Ｓ−、−ＮＲ４−（Ｒ４は置換または無置換の単環または多環式のアリレン基、もしくは置換または無置換の単環または多環式のヘテロアリレン基を表わす。ｍは≧０を表わす。ＸはＰＯ（ＯＲ５）２（Ｒ５は低級アルキル基）またはＰ（Ｒ６）３＋Ｙ―（Ｒ６は置換または無置換のアリール基、もしくは置換または無置換のアルキル基を表わし、Ｙはハロゲン原子を表わす）を表わす］を反応させ、炭素−炭素二重結合を含有する下記一般式（ＩＩＩ）

の繰り返し単位をもつ重合体が製造される。 The light-emitting organic semiconductor material of the present invention has, for example, a polymer having a repeating unit represented by the following general formula as a main component. Such a material will be described in more detail together with its synthesis method.

For example, a carbonyl compound represented by the following general formula (I)

[In General Formula (I), A1 and A2 each represent a substituted or unsubstituted monocyclic or polycyclic arylene group or heteroarylene group. R1 represents hydrogen, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. V represents —O—, —S—, —NR 2 — (R 2 represents a substituted or unsubstituted monocyclic or polycyclic arylene group, or a substituted or unsubstituted monocyclic or polycyclic heteroarylene group). And n represents ≧ 0], and a phosphorus compound represented by the following general formula (II)

[In General Formula (II), A3 and A4 each represent a substituted or unsubstituted monocyclic or polycyclic arylene group or heteroarylene group. R3 represents hydrogen, a substituted or unsubstituted alkyl, aryl or heteroaryl group. W represents —O—, —S—, —NR 4 — (R 4 represents a substituted or unsubstituted monocyclic or polycyclic arylene group, or a substituted or unsubstituted monocyclic or polycyclic heteroarylene group, m. Represents ≧ 0, X represents PO (OR5) 2 (R5 is a lower alkyl group) or P (R6) 3 + Y— (R6 represents a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group; Represents a halogen atom), and the following general formula (III) containing a carbon-carbon double bond:

A polymer having the following repeating unit is produced.

This will be described in more detail below.
Suitable basic compounds include all known basic compounds as long as they are uniformly dissolved in a non-aqueous solvent. However, in view of the ability to form phosphonate carbanions, the basicity point is considered. To metal alkoxides, metal hydrides, organolithium compounds, etc., such as potassium t-butoxide, sodium t-butoxide, lithium t-butoxide, potassium 2-methyl-2-butoxide, sodium 2-methyl-2-butoxide, sodium methoxy Sodium ethoxide, potassium ethoxide, potassium methoxide, sodium hydride, potassium hydride, methyl lithium, ethyl lithium, propyl lithium, n-butyl lithium, s-butyl lithium, t-butyl lithium, phenyl lithium, lithium Naphthylide, Richiu Amide, and lithium diisopropylamide.
As the solvent for dissolving the base, a solvent that forms a stable solution with the base to be used must be selected, but as other factors, those having a high solubility of the base are preferable, and the high molecular weight product produced in the reaction system is also preferred. Those that do not impair the solubility in the reaction solvent are good. Further, the solvent in which the high molecular weight product to be formed dissolves well is good. Depending on the characteristics of the base used and the high molecular weight to be produced, generally known alcohols and ethers are used. It can be arbitrarily selected from a system, an amine system, a hydrocarbon solvent and the like.

Examples of a combination of a base and a solvent for uniformly dissolving the base include, for example, a methanol solution of sodium methoxide, an ethanol solution of sodium ethoxide, a 2-propanol solution of potassium t-butoxide, and 2-methyl-2-methyl ester of potassium t-butoxide. Propanol solution, potassium t-butoxide in tetrahydrofuran, potassium t-butoxide in dioxane, n-butyllithium in hexane, methyllithium in ether, lithium t-butoxide in tetrahydrofuran, lithium diisopropylamide in cyclohexane, potassium bis There are various combinations of solutions including a toluene solution of trimethylsilylamide and the like, and some solutions are easily available as commercial products. From the viewpoint of mild reaction conditions and ease of handling, a metal alkoxide-based solution is preferably used, such as solubility of the polymer to be produced, ease of handling, efficiency of the reaction, solubility of the polymer to be produced, etc. From the viewpoint, an ether system of metal t-butoxide is more preferably used, and a tetrahydrofuran solution of potassium t-butoxide is more preferably used.
By mixing a solution in which the stoichiometrically equal amount of phosphorus compound and aldehyde compound is mixed with the above-mentioned base solution containing at least twice the molar amount of the base, the polymerization reaction proceeds easily and is preferably controlled to a narrow molecular weight distribution. The obtained high molecular weight polymer can be easily obtained. Usually, it is sufficient to use the same amount of the base as the polymerization active site of the phosphorus compound, but there is no problem even if an excessive amount is used.
In the above polymerization reaction, a base solution may be added to the solution of the phosphorus compound and the aldehyde compound, a solution of the phosphorus compound and the aldehyde compound may be added to the base solution, and may be added to the reaction system in the same order. There are no restrictions.
The polymerization time in the above polymerization reaction may be appropriately set according to the reactivity of the monomers used or the molecular weight of the desired polymer, but is preferably 0.2 hours to 30 hours. Moreover, the sealing agent for sealing the terminal of a polymer can be added during or after the reaction, and can be added at the start of the reaction.
The reaction temperature in the above polymerization reaction does not need to be controlled in particular, and the polymerization reaction proceeds well at room temperature. However, it is possible to heat or cool to a milder condition in order to increase the reaction efficiency.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the light-emitting organic semiconductor material of the present invention is not limited by these examples unless it exceeds the gist.
Various measurements were performed by the following methods. The number average molecular weight (Mn), the weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) of the polymer are measured by gel permeation chromatography (GPC). The measurement was performed in terms of polystyrene using dispersed polystyrene as a standard.

ジアルデヒドを０．８５２ｇ（２．７０ｍｍｏｌ）、及び以下の化学式に示す

ジホスホネートを１．５２５ｇ（２．７０ｍｍｏｌ）を入れ、窒素置換してテトラヒドロフラン７５ｍｌを加えた。この溶液にカリウムｔ−ブトキシドの１．０ｍｏｌｄｍ−３テトラヒドロフラン溶液６．７５ｍｌ（６．７５ｍｍｏｌ）を滴下し、室温で２０時間撹拌した後、ベンジルホスホネート及びベンズアルデヒドを順次加え、さらに２時間３０分撹拌した。酢酸およそ１ｍｌを加えて反応を終了し、溶液を水洗した。溶媒を減圧留去し、残渣をテトラヒドロフラン１５ｍｌ及びメタノール８０ｍｌを用いて再沈澱による精製を行い、以下の化学式に示す重合体を１．０７ｇ得た。

得られた重合体の分子量及び分子量分布を測定したところ、収率：７３％、重量平均分子量（Ｍｗ）：１０４０００、数平均分子量（Ｍｎ）：３６０００、分子量分布（Ｍｗ／Ｍｎ）：２．８９、重合体：６３であった。
上記実施例は一例であるが、他の材料であってもよい。例えば、ペンタセン等前駆体が溶媒に可溶であるものは、以下に述べる液体噴射原理等により形成した前駆体の膜を熱処理して目的とする有機材料の薄膜を形成してもよい。
このようにして得られた高分子量の重合体である本発明の発光型有機半導体材料は、スピンコート法、キャスト法、ディップ法、液体噴射法、ドクターブレード法、スクリーン印刷法等の公知の成膜方法によってクラックのない、強度、靭性、耐久性等に優れた良好な薄膜を作製することが可能である。
特に液体噴射原理による方法（インクジェット法ともいう）は、後述の電極パターン形成にも適用することができる汎用性の高い技術であるため、本発明の発光型有機薄膜トランジスタ素子製作の有効な手段となるので、その製作装置に関して検討した結果をここで説明する。 <Example of material synthesis>
Shown in the following chemical formula in a 100 ml four-necked flask

0.852 g (2.70 mmol) of dialdehyde and shown in the following chemical formula

1.525 g (2.70 mmol) of diphosphonate was added, nitrogen substitution was performed, and 75 ml of tetrahydrofuran was added. To this solution, 6.75 ml (6.75 mmol) of a 1.0 moldm-3 tetrahydrofuran solution of potassium t-butoxide was added dropwise and stirred at room temperature for 20 hours. Then, benzylphosphonate and benzaldehyde were added successively, and the mixture was further stirred for 2 hours and 30 minutes. . About 1 ml of acetic acid was added to terminate the reaction, and the solution was washed with water. The solvent was distilled off under reduced pressure, and the residue was purified by reprecipitation using 15 ml of tetrahydrofuran and 80 ml of methanol to obtain 1.07 g of a polymer represented by the following chemical formula.

When the molecular weight and molecular weight distribution of the obtained polymer were measured, yield: 73%, weight average molecular weight (Mw): 104000, number average molecular weight (Mn): 36000, molecular weight distribution (Mw / Mn): 2.89 Polymer: 63.
The above embodiment is an example, but other materials may be used. For example, when a precursor such as pentacene is soluble in a solvent, a thin film of a target organic material may be formed by heat-treating a precursor film formed according to the liquid jet principle described below.
The light-emitting organic semiconductor material of the present invention, which is a high molecular weight polymer thus obtained, is a known component such as a spin coat method, a cast method, a dip method, a liquid jet method, a doctor blade method, and a screen printing method. It is possible to produce a good thin film excellent in strength, toughness, durability, etc. without cracks by a film method.
In particular, a method based on the principle of liquid ejection (also referred to as an ink jet method) is a highly versatile technique that can be applied to electrode pattern formation described later, and thus is an effective means for manufacturing a light-emitting organic thin film transistor element of the present invention. Therefore, the results of studies on the manufacturing apparatus will be described here.

  FIG. 4 is a view for explaining one embodiment of a manufacturing apparatus that can be used for manufacturing a light-emitting organic thin film transistor element of the present invention. In the figure, 11 is a discharge head unit (discharge head), and 12 is a discharge head unit. Carriage for movement, 13 is a substrate holder, 14 is a light emitting organic thin film transistor element substrate or sheet, 15 is a solution supply tube, 16 is a signal supply cable, 17 is a discharge head control box (including a solution tank), 18 Is a X-direction scan motor for the carriage 12, 19 is a Y-direction scan motor for the carriage 12, 20 is a computer, 21 is a control box, and 22 (22X1, 22Y1, 22X2, 22Y2) is a substrate positioning / holding means. In this case, the ejection head 11 is moved by carriage scanning on the front surface of the substrate or sheet 14 placed on the substrate holder 13 and sprayed with the solution. This example is an example in which the ejection head 11 moves by carriage scanning. However, even in a manufacturing apparatus (not shown) configured such that the ejection head 11 is fixed and the substrate or the sheet 11 moves. Good. That is, an apparatus in which the ejection head 11 and the substrate or the sheet 11 move relatively is a manufacturing apparatus that can be used for manufacturing the light-emitting organic thin film transistor element of the present invention. The droplet applying device (discharge head) of the discharge head unit 11 may be any mechanism as long as it can discharge a given amount of liquid droplets in particular, and is based on an ink jet principle capable of forming a droplet of about 0.05 pl to several hundred pl in particular. Mechanism is desirable.

Examples of the ink jet system include a system disclosed in US Pat. No. 3,683,212 (Zoltan system), a system disclosed in US Pat. No. 3,747,120 (Stemme system), and US Pat. No. 3,946,398. As in the disclosed method (Kyser method), an electrical signal is applied to the piezo-vibration element, the electrical signal is converted into mechanical vibration of the piezo-oscillation element, and droplets are discharged from a fine nozzle according to the mechanical vibration. Are generally called a drop-on-demand system.
As other methods, there are methods (Sweet method) disclosed in US Pat. No. 3,596,275, US Pat. No. 3,298,030, and the like. This generates a recording liquid droplet with a controlled charge amount by a continuous vibration generation method, and the generated charge amount controlled droplet flies between deflection electrodes to which a uniform electric field is applied. Thus, recording is performed on a recording member, which is usually called a continuous flow method or a charge control method.
As another method, there is a method disclosed in Japanese Patent Publication No. 56-9429. This is a method in which bubbles are generated in a liquid, and droplets are ejected and ejected from fine nozzles by the action force of the bubbles, which is called a thermal ink jet method or a bubble jet (registered trademark) method.
There are a drop-on-demand method, a continuous flow method, a thermal ink jet method, and the like as a method for ejecting droplets as described above, and the method may be appropriately selected as necessary.
In the present invention, in such a light emitting organic thin film transistor device manufacturing apparatus (FIG. 4), the substrate 14 is determined by adjusting the holding position by the substrate positioning / holding means 22 of this device. Although simplified in FIG. 4, the substrate positioning / holding means 22 is brought into contact with each side of the substrate 14 and can be finely adjusted in the submicron order in the X direction and the Y direction perpendicular thereto. The discharge head control box 17, the computer 20, the control box 21 and the like are connected, and the positioning information, fine adjustment displacement information, etc., the position information of the droplet application, the timing, etc. can be fed back constantly.
Furthermore, the manufacturing apparatus that can be used for manufacturing such a light-emitting organic thin film transistor element has a rotation position adjustment mechanism that is not shown (not visible because it is located under the substrate 14) in addition to the position adjustment mechanism in the X and Y directions. is doing.
In relation to this, the shape of the light-emitting organic thin film transistor element substrate of the present invention, the arrangement of element groups to be formed, and the like will be described first.

The light-emitting organic thin film transistor element substrate of the present invention includes a glass substrate, a ceramic substrate, various plastic substrates including PET, a semiconductor substrate such as Si, a glass / epoxy substrate, a polyimide, depending on the purpose and application, as will be described later. A flexible substrate made of a polymer film such as a film, a polyamideimide film, a polyamide film, or a polyester film is preferably used. For example, various plastic substrates and polymer films are effective for the production of various functional devices typified by light-emitting organic thin film transistor elements of the present invention, or pattern wiring substrates that require weight reduction.
Furthermore, in such device fabrication, heat is often applied during the process, and in high-precision device fabrication, it is necessary to consider the problem of device accuracy degradation due to thermal expansion. For example, in the present invention, in order to manufacture a highly accurate light-emitting organic thin film transistor element, the linear expansion coefficient α (= 1 / l ₀ · dl / dt, l ₀ is the length at 0 ° C., l is t ° C. A polymer material having a low linear expansion coefficient close to the linear expansion coefficient of a metal material having a length of 293K (20 ° C.) and α / K ⁻¹ = 20 to 50 × 10 ⁻⁶ or less is suitable. Used for.
An example of such a low thermal expansion transparent substrate is a composite material in which a transparent polymer material is reinforced with a biological transparent nanofiber reinforced fiber having a diameter of about 50 to 100 nm, and the transmittance of parallel light is 90 to 95%. Is obtained.

The shapes of various plastic substrates and polymer films used for the light-emitting organic thin film transistor element substrate of the present invention are those of a light-emitting organic thin film transistor element substrate that is economically produced, supplied, or finally manufactured. From the application, it is rectangular. That is, the two vertical and horizontal sides constituting the rectangular shape are substrates in which the two vertical sides are parallel to each other, the two horizontal sides are parallel to each other, and the vertical and horizontal sides form a right angle.
In the present invention, the light emitting organic thin film transistor element groups to be formed are arranged in a matrix with respect to such a substrate, and two directions perpendicular to each other of the matrix are the vertical side or the horizontal side of the substrate. The light emitting organic thin film transistor element group is arranged so as to be parallel to the direction. The reason why the light emitting organic thin film transistor element groups are arranged in a matrix and the reason why the vertical and horizontal sides of the substrate are parallel to two orthogonal directions of the matrix will be described below.
As shown in FIG. 4, in the light-emitting organic thin film transistor device manufacturing apparatus applicable to the present invention, after the positional relationship between the substrate 14 and the solution ejection port surface of the discharge head unit 11 is first determined, the position control is particularly performed. Never do. That is, the ejection head unit 11 ejects the solution while performing a relative movement in the X and Y directions parallel to the formation surface of the light emitting organic thin film transistor element group while maintaining a certain distance from the substrate 14. In other words, the X direction and the Y direction are two directions orthogonal to each other. When the substrate is positioned, the vertical direction or the horizontal side of the substrate is formed so as to be parallel to the Y direction or the X direction. Since the two light emitting organic thin film transistor element groups are parallel to each other in the matrix arrangement, highly precise light emitting organic thin film transistor element group formation or electrode pattern formation can be performed only by the mechanism of spraying while performing relative movement. Can do. In other words, if the substrate shape, the matrix arrangement of the light-emitting organic thin film transistor element group, and the relative movement device in two orthogonal X and Y directions are formed as in the present invention, the light-emitting organic thin film transistor element or electrode pattern is formed. If the positioning of the substrate before the droplet ejection is accurately performed, a highly accurate matrix-like arrangement of light-emitting organic thin film transistor element groups can be obtained.

Here, the description returns to the rotational position adjustment mechanism. As described above, in the present invention, the substrate is accurately positioned before performing the droplet ejection for forming the light emitting organic thin film transistor element, only the relative movement in the X and Y directions is performed, and no other control is performed. It is intended to obtain a highly accurate matrix arrangement of light emitting organic thin film transistor element groups. In this case, a problem is a shift in the rotation direction (the rotation direction with respect to the axis orthogonal to the plane determined by the two directions X and Y) when the substrate is first positioned.
In order to correct this shift in the rotational direction, the present invention has a rotational position adjustment mechanism (not shown) that is not shown (not shown) as described above. By correcting the displacement in the rotation direction and positioning the sides of the substrate, the apparatus of the present invention can obtain a highly accurate matrix arrangement of light-emitting organic thin film transistor element groups by relative movement only in the X and Y directions.
The rotation position adjustment mechanism has been described above as a separate mechanism from 22 (22X1, 22Y1, 22X2, 22Y2) in the substrate positioning / holding means of FIG. 4 (not visible under the substrate 14). It is also possible to provide the substrate positioning / holding means 22 with a rotational position adjusting mechanism. For example, the substrate positioning / holding means 22 is brought into contact with the side of the substrate 14 so that the entire position of the substrate positioning / holding means 22 can be adjusted in the X direction or the Y direction. The angle adjustment is possible if two screws provided at a distance are moved independently at a portion that contacts the side of the substrate 14. The rotational position control information is also connected to the ejection head control box 17, the computer 20, the control box 21 and the like in the same manner as the positioning information and fine adjustment displacement information in the X and Y directions, and the droplet application position information, Timing, etc. can be constantly fed back.
The above description is based on the premise that the substrate or sheet suitably used in the present invention is basically rectangular, except that a semiconductor substrate such as Si is supplied as a round wafer. Therefore, in this case, one straight side called an orientation flat (orientation flat) indicating the direction of the crystal orientation axis may be brought into contact with the substrate positioning / holding means 22.

Next, other means and configuration for positioning will be described. In the above description, the substrate positioning / holding means 22 is brought into contact with the side of the substrate 14 so that the entire position of the substrate positioning / holding means 22 can be adjusted in the X direction or the Y direction. An example in which strip-like patterns are provided in two directions orthogonal to each other on the substrate, not on the sides of the substrate 14 will be described. As described above, in the present invention, the light-emitting organic thin film transistor element group is formed on the substrate in a matrix form, but here, the above-described two orthogonal band-like patterns are orthogonal to each other in this matrix. It is formed so as to be parallel to the two directions. Such a pattern can be easily formed on a substrate by a photofabrication technique.
Next, a liquid discharge head suitably applied to the formation of the light-emitting organic thin film transistor element of the present invention will be described with reference to FIGS. This example is an example of 7 nozzles.
The nozzle section head constituting the liquid discharge head 11 is provided with a piezo element 46 as an energy action section in a flow path 45 into which a solution 56 is introduced. When a pulsed signal voltage is applied to the piezo element 46 to distort the piezo element 46 as shown in FIG. 5A, the volume of the flow path 45 is reduced and a pressure wave is generated. A droplet 43 is discharged from 65. FIG. 5B shows a state in which the piezoelectric element 46 is no longer distorted and the volume of the flow path 45 is increased.
Here, the solution 56 introduced into the flow path 45 just before the nozzle 65 has passed through the filter 57 shown in FIG. In the present invention, the filter 57 is thus provided in the discharge head, and the filter removal function is provided in the vicinity of the nozzle 65. By doing so, foreign particles in the solution of the present invention are trapped so as not to cause deterioration in performance of the electrode pattern formed on the substrate or the pattern due to the organic light emitting material. Such a filter 57 can be incorporated into the ejection head 11 as shown in FIG. 6 by using a small simple filter. The ejection head 11 itself can also be made compact.
As such a filter 57, for example, a stainless mesh filter is preferably used, and the pore diameter (filter mesh size to lower limit of the size of foreign matter that can be removed) is set to 0.2 μm to 2 μm.

Next, another example of the liquid discharge head suitably applied to the formation of the light-emitting organic thin film transistor element of the present invention will be described with reference to FIG. This example is an example of a thermal type (bubble type) liquid discharge head, and the driving force of droplet ejection is the growth action force of film boiling bubbles generated instantaneously in a solution.
The liquid discharge head shown here is of a type in which droplets are ejected from a short channel portion through which a solution flows, and is called an edge shooter type.
Here, an example in which the number of nozzles 65 of the liquid discharge head is four is shown. The liquid discharge head is formed by bonding a heating element substrate 66 and a lid substrate 67. The heating element substrate 66 is formed on a silicon substrate 68 by an individual electrode 69, a common electrode 70, and an energy application unit by a wafer process. It is comprised by forming the heat generating body 71 which is.
On the other hand, the lid substrate 67 is formed with a groove 74 for forming a flow path into which the solution is introduced, and a recessed area 75 for forming a common liquid chamber for storing the solution introduced into the flow path. The heat generating substrate 66 and the lid substrate 67 are joined as shown in FIG. 7 to form a flow path and a common liquid chamber. In the state where the heating element substrate 66 and the lid substrate 67 are joined, the heating element 71 is located on the bottom surface of the flow path, and one end of the solution introduced into these flow paths is located at the end of the flow path. A nozzle 65 for ejecting the portion as a droplet is formed. Here, the nozzle shape is rectangular, but it may be round. Note that a solution inlet 76 for supplying a solution into the supply liquid chamber by a supply means (not shown) is formed on the plate surface of the lid substrate 67.

In the formation of the light emitting organic thin film transistor element of the present invention, a light emitting organic thin film transistor element, an electrode pattern or the like is formed by a plurality of droplets. That is, the pattern is formed by overstrike or contacting dots. Therefore, when such a multi-nozzle type liquid discharge head is used, a light-emitting organic thin film transistor element can be formed very efficiently. In this example, a four-nozzle liquid discharge head is shown. However, the present invention is not necessarily limited to four nozzles. Needless to say, the larger the number of nozzles, the more efficient the formation of the light-emitting organic thin film transistor element. . However, this does not mean that simply increasing the number of liquid discharge heads will increase the cost and the probability of clogging of the injection nozzles will increase. The balance of the production efficiency of the organic thin film transistor element).
FIG. 8 is a view of the multi-nozzle type liquid discharge head manufactured as described above as viewed from the nozzle side. In the present invention, as shown in FIG. 9, such a multi-nozzle type liquid discharge head 11 is provided for each solution to be ejected (organic semiconductor material solution and electrode forming solution) and mounted on a carriage. FIG. 10 is a perspective view thereof.
9 and 10, the multi-nozzle type liquid discharge heads are labeled A, B, C, and D, respectively, but each of the liquid discharge heads A, B, C, and D has a nozzle portion corresponding to each liquid. Different types of solutions (for example, a solution of an organic semiconductor material and an electrode forming solution) can be ejected for each liquid discharge head while being configured to be separated for each discharge head. Alternatively, each solution is mounted on a carriage as an independent head unit so that the solutions do not mix on the nozzle surface.
The manufacturing apparatus applied to the formation of the light emitting organic thin film transistor element of the present invention is to produce a light emitting organic thin film transistor element by spraying and applying an organic semiconductor material solution and an electrode forming solution. As shown in this example, a plurality of types of solutions can be sprayed. For example, a light-emitting organic thin film transistor element that combines a solution for forming an electrode pattern and a solution of an organic semiconductor material can be easily obtained. Can be formed.

Next, another feature of the manufacturing apparatus applied to the formation of the light emitting organic thin film transistor element of the present invention will be described. Here, the results of studying how to deposit a droplet on the substrate after droplet ejection and form a good pattern are shown.
As described above, in the manufacturing apparatus applied to the formation of the light-emitting organic thin film transistor element of the present invention, the discharge head unit 11 is formed on the pattern or the surface on which the light-emitting organic thin film transistor element group is formed while maintaining a certain distance from the substrate 14. A pattern or a light emitting organic thin film transistor element group is formed while performing relative movement in the X and Y directions in parallel. In other words, the ejection head unit 11 translates relative to the substrate surface with respect to the substrate 14, or the substrate 14 translates relative to the ejection head unit 11.
At that time, each time the solution is sprayed to form a pattern or a light-emitting organic thin film transistor element group, if the relative movement is stopped and sprayed, a highly accurate pattern or light-emitting organic thin film transistor element group can be formed. Is possible. However, since the productivity is remarkably lowered, the solution is sequentially ejected without stopping the relative movement. In that case, the relative movement speed (for example, the X-direction movement speed of the carriage in FIG. 4) should not be determined merely by improving productivity, but also from the viewpoint of forming a highly accurate pattern or functional device group. Must be considered.
In examining the manufacturing apparatus applied to the formation of the light-emitting organic thin-film transistor element of the present invention, this point is studied earnestly, and when spraying such a solution, the spraying speed may be higher than the relative movement speed. I realized it was necessary. In this manner, when the ejection head unit 11 is moved relative to each other in the X and Y directions while maintaining a certain distance from the substrate 14, the solution is ejected to form a pattern or an optical organic thin film transistor element group. The solution droplets are deposited and formed on the substrate 14 at the speed of the combined vector of the relative speed and the jet speed. Regarding the positional accuracy, the droplet is attached to the target position by appropriately selecting the ejection timing in consideration of the distance between the substrate 14 and the solution ejection port surface of the ejection head unit 11 and the speed of the combined vector. Can be made.
However, even if the target can be attached to the target position, if the relative speed is too high, the attached droplet flows on the substrate 14 by being dragged by the relative speed, and the pattern has a good shape. Alternatively, the optical organic thin film transistor element group cannot be formed. In examining the manufacturing apparatus applied to the formation of the light-emitting organic thin film transistor element of the present invention, this point is particularly studied. An example of the study results is shown below. In this example, an apparatus as shown in FIG. 4 is used, and the X direction moving speed of the carriage 12 and the ejection speed of the ejection head unit 11 are changed, so that a good droplet can be deposited on the substrate 14 and a good pattern can be formed. It was investigated whether it was possible.

FIG. 11 shows an example of the pattern used for the test. Here, an Ag fine particle-containing solution was sprayed to form a wiring pattern in which the dot patterns of the solution were connected between two rows of adjacent element electrodes (between ITO transparent electrodes), and the pattern formation status was evaluated. Is. Evaluation evaluated the pattern after formation under the microscope, and judged good / bad ((circle) / x). FIG. 11A is good (◯), and each dot pattern does not have a good round shape as shown in FIG. 11B, becomes an oval shape, and the landing position on the substrate is the original aim. Anything that deviates from the position of and touches the adjacent dot pattern is defective (x).
In addition to the evaluation of the shape, the resistance value between the upper and lower ITO transparent electrodes was measured to evaluate the resistance value fluctuation due to disconnection due to poor dot position accuracy or contact with adjacent (left and right) dots (○: Resistance value as intended, x: resistance value out of aim).

Details of the experimental conditions are shown below. The substrate used is a glass substrate with an ITO transparent electrode, and the above-mentioned Ag fine particle-containing solution (here, a fine particle diameter of 0.005 μm is used) is the discharge head (nozzle diameter Φ5 μm) shown in FIG. In combination, a pattern as shown in FIG. 11 was formed. For simplicity, FIG. 11 shows a diagram in which a space between a pair of ITO transparent electrodes is filled with 4 dots. However, in actuality, dots of about Φ8 μm are arranged in about 1 row in the vertical direction. Approximately 100 pieces are driven at a pitch of 4 μm, and the upper and lower ITO transparent electrodes (interelectrode distance 0.4 mm) are connected. In addition, a similar pattern is formed adjacent to the ITO transparent electrode and the ITO transparent electrode with a center-to-center distance of 12 μm.
The used ejection head is a piezo-type ejection head having 64 nozzles (ejection ports) and an arrangement density of 100 dpi. The ejection head and the substrate move relative to each other (here, the substrate is fixed and the ejection head is scanned by carriage). In addition, pattern formation was performed while maintaining a center-to-center distance of 12 μm.
The driving voltage for droplet ejection changes the input voltage to the piezoelectric element from 15V to 22V in order to change the ejection speed. The driving frequency was 12 kHz. In an ejection head using such a piezo element, the injection speed can be changed by changing the input voltage to the piezo element, but at the same time the mass of the ejected droplet also changes, so the drive waveform (rising waveform including striking and (Falling waveform) was controlled so that the mass of the ejected droplets was always almost constant (1 pl), and only the ejection speed was changed.
Also, the droplet shape during droplet flight is separately ejected and observed under the same conditions as pattern formation, and the drive waveform is such that the shape becomes a substantially round droplet just before adhering to the substrate surface (2 mm in the present invention example). Were controlled and jetted (FIG. 12). Note that even if a rounded spherical shape is not obtained and the columnar shape extends in the flight direction, the length can be easily reduced to three times the diameter (l ≦ 3d) by simply controlling the drive waveform. (FIG. 13). At that time, a driving condition (driving waveform) that does not involve a plurality of minute droplets behind the flying droplet as described later (FIG. 14) was selected. The results are shown below.

Table 1
Experiment Injection speed Carriage speed in X direction Pattern formation status Resistance No. Vj (m / s) Vc (m / s)
1 3 1 ○ ○
2 3 2 ○ ○
3 3 3 × ×
4 3 4 × ×
5 5 1 ○ ○
6 5 2 ○ ○
7 5 3 ○ ○
8 5 4 ○ ○
9 5 5 × ×
10 5 6 × ×
11 7 2 ○ ○
12 7 3 ○ ○
13 7 4 ○ ○
14 7 5 ○ ○
15 7 6 ○ ○
16 7 7 × ×
17 7 8 × ×
18 10 4 ○ ○
19 10 6 ○ ○
20 10 8 ○ ○
21 10 10 × ×
22 10 12 × ×
23 10 14 × ×
24 12 4 ○ ○
25 12 6 ○ ○
26 12 8 ○ ○
27 12 10 ○ ○
28 12 12 × ×
29 12 14 × ×

From the above results, it can be seen that when the carriage moving speed in the X direction is equal to or higher than the ejection speed, a good pattern cannot be formed, and the resistance value between the electrodes is not intended. In other words, in the manufacturing apparatus applied to the formation of the light-emitting organic thin film transistor element of the present invention, the organic semiconductor material-containing solution is applied onto the substrate by using a discharge head using a piezo element and dried. It can be seen that when the light emitting organic thin film transistor element is formed, the speed of the droplet ejected from the ejection head must be faster than the moving speed of the carriage in the X direction.
Although this example is an example in which the ejection head is scanned by carriage, it is also applied to the case where the ejection head is fixed and the substrate is moved as described above. That is, the speed of the ejected droplets must be faster than the relative movement speed of the ejection head and the substrate.
In addition, the droplet flying condition this time was set to a driving condition (driving waveform) that does not involve a plurality of minute droplets behind the flying droplet as described above. As a result, the plurality of minute droplets never adhered to unnecessary portions, and a very good pattern formation could be performed.
Even if the flying droplets are in the form of a column extending in the flying direction, the length of the flying droplets is made within 3 times the diameter (l ≦ 3d) by driving waveform control (FIG. 13). The formed dots also had a shape close to a perfect circle, and a good pattern could be formed.
Other light emitting organic semiconductor material layer fabrication methods include vacuum deposition, molecular beam epitaxial growth, ion cluster beam, low energy ion beam, ion plating, CVD, sputtering, plasma polymerization, electrolysis Examples thereof include a polymerization method and a chemical polymerization method, which can be used depending on the material.
The film thickness of these organic semiconductor layers is not particularly limited, but the characteristics of the obtained light-emitting transistor are often greatly influenced by the film thickness of the organic semiconductor layer, and the film thickness varies depending on the organic semiconductor. Generally, it is preferably 1 μm or less, particularly preferably 10 to 300 nm.

In the light-emitting organic transistor element of the present invention, platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, tantalum, indium, palladium, tellurium are used as electrode materials for the gate electrode, source electrode and drain electrode , Rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, tin oxide / antimony, indium tin oxide (ITO), fluorine doped zinc oxide, zinc, carbon, graphite, glassy carbon, silver paste and carbon paste, lithium, Beryllium, sodium, magnesium, potassium, calcium, scandium, titanium, manganese, zirconium, gallium, niobium, sodium, sodium-potassium alloy, magnesium, lithium, aluminum, magnesium / Gold mixture, magnesium / copper mixture, a magnesium / silver mixture, a magnesium / aluminum mixture, magnesium / indium mixture, aluminum / aluminum oxide mixture, a lithium / aluminum mixture, or the like is used. Moreover, when it is set as the structure which takes out the light generate | occur | produced as mentioned above from the electrode surface side, it is set as a transparent electrode with translucent materials, such as ITO.
Alternatively, these materials are used alone or in combination with a plurality of layers. Specifically, a magnesium / gold mixture and gold combination, a magnesium / copper mixture and gold combination, a magnesium / silver mixture and gold combination, a magnesium / aluminum mixture and gold combination, a magnesium / indium mixture and gold combination, A combination of aluminum / aluminum oxide mixture and gold, a combination of lithium / aluminum mixture and gold, a combination of magnesium and gold, a combination of aluminum and gold, a combination of chromium and gold, or a magnesium / gold mixture Gold / aluminum combinations, magnesium / copper mixtures with gold / aluminum combinations, magnesium / silver mixtures with gold / aluminum combinations, magnesium / aluminum mixtures with gold / aluminum combinations, Combination of nesium / indium with gold and aluminum, aluminum / aluminum oxide mixture with gold and aluminum, lithium / aluminum mixture with gold and aluminum, magnesium with gold with aluminum, aluminum with gold with aluminum, It can be used as a three-layer structure like a combination of chromium, gold and aluminum.

Needless to say, a silicon semiconductor material can be used in addition to such a conductive metal material. In particular, as in the configuration example shown in FIG. 3, an n + silicon semiconductor substrate is preferably used as the gate electrode 6 in the case where the gate electrode 6 has a support function.
Alternatively, a known conductive polymer whose conductivity has been improved by doping or the like, for example, conductive polyaniline, conductive polypyrrole, or conductive polythiophene (such as a complex of polyethylenedioxythiophene and polystyrenesulfonic acid) is also preferably used.
The material for forming the source electrode and the drain electrode is preferably a material having low electrical resistance at the contact surface with the semiconductor layer among the materials listed above, and in the case of a p-type semiconductor, platinum, gold, silver, ITO, conductive polymer And carbon are preferred.
These electrode layers and patterns are vacuum deposition, molecular beam epitaxial growth, ion cluster beam, low energy ion beam, ion plating, CVD, sputtering, plasma polymerization, electrolytic polymerization, chemical polymerization, It is formed by combining film formation technology such as spray coating method, spin coating method, blade coating method, dip coating method, casting method, roll coating method, bar coating method, die coating method, etc. and photolithography / etching method or lift-off method. The
Alternatively, a method based on a liquid jet principle as described above when forming the light-emitting organic semiconductor material layer is also a good method using a contacted or direct manufacturing method. Moreover, you may manufacture by printing methods, such as a letterpress, an intaglio, a planographic printing, and screen printing.
When a source electrode, a drain electrode, or the like is formed using such a solution or paste-like material, a fluid electrode material such as a solution, paste, ink, or dispersion containing the above conductive material is used. Among them, a fluid electrode material containing a conductive polymer or metal fine particles containing platinum, gold, silver, or copper is preferable. The solvent or dispersion medium is preferably a solvent or dispersion medium containing 60% or more, preferably 90% or more of water, in order to suppress damage to the organic semiconductor.

As a fluid electrode material containing metal fine particles, a metal fine particle having a particle diameter of 1 to 50 nm, preferably 1 to 10 nm, is dispersed in water or any organic solvent using a dispersion stabilizer as necessary. A material dispersed therein is used.
Platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony, lead, tantalum, indium, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum, tungsten, zinc, etc. Can be used.
As a method for producing such a dispersion of fine metal particles, metal ions are reduced in the liquid phase, such as a physical generation method such as gas evaporation method, sputtering method, or metal vapor synthesis method, colloid method, or coprecipitation method. A chemical production method for producing metal fine particles may be mentioned, and the dispersion suitably used is preferably a dispersion of metal fine particles produced by a colloid method or a gas evaporation method.
Various insulating films can be used as the gate insulating layer of the organic thin film transistor element of the present invention, and an inorganic oxide film having a high relative dielectric constant is particularly preferable. Inorganic oxides include silicon oxide, aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium zirconate titanate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, Examples thereof include barium titanate, barium magnesium fluoride, bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth tantalate niobate, and yttrium trioxide. Of these, silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide are preferable. Inorganic nitrides such as silicon nitride and aluminum nitride can also be suitably used.

Examples of the method for forming the film include a vacuum process, a molecular beam epitaxial growth method, an ion cluster beam method, a low energy ion beam method, an ion plating method, a CVD method, a sputtering method, an atmospheric pressure plasma method, and a spray process. Wet processes such as coating methods, spin coating methods, blade coating methods, dip coating methods, casting methods, roll coating methods, bar coating methods, die coating methods, and other wet processes such as printing and ink jet patterning methods, etc. Can be used depending on the material. Alternatively, in the case where the silicon semiconductor substrate has a support function and a gate electrode function (FIG. 3), the silicon semiconductor substrate may be thermally oxidized to form a silicon oxide film.
The wet process is a method of applying and drying a liquid in which inorganic oxide fine particles are dispersed in an arbitrary organic solvent or water using a dispersion aid such as a surfactant as required, or an oxide precursor, for example, A so-called sol-gel method in which a solution of an alkoxide body is applied and dried is used.
Of these, the atmospheric pressure plasma method described above is preferable. It is also preferable that the gate insulating layer is composed of an anodized film or the anodized film and an insulating film. The anodized film is preferably sealed. The anodized film is formed by anodizing a metal that can be anodized by a known method.
Examples of the metal that can be anodized include aluminum and tantalum, and the anodizing method is not particularly limited, and a known method can be used. An oxide film is formed by anodizing. Any electrolyte solution that can form a porous oxide film can be used as the anodizing treatment. Generally, sulfuric acid, phosphoric acid, oxalic acid, chromic acid, boric acid, sulfamic acid, benzenesulfone, and the like can be used. An acid or the like, a mixed acid obtained by combining two or more of these, or a salt thereof is used. The treatment conditions for anodization vary depending on the electrolyte used, and thus cannot be specified in general. In general, the electrolyte concentration is 1 to 80% by mass, the electrolyte temperature is 5 to 70 ° C., and the current density. A range of 0.5 to 60 A / dm ² , a voltage of 1 to 100 volts, and an electrolysis time of 10 seconds to 5 minutes are suitable. A preferred anodizing treatment is a method in which an aqueous solution of sulfuric acid, phosphoric acid or boric acid is used as the electrolytic solution and the treatment is performed with a direct current, but an alternating current can also be used. The concentration of these acids is preferably 5 to 45% by mass, and the electrolytic treatment is preferably performed for ²⁰ to 250 seconds at an electrolyte temperature of 20 to 50 ° C. and a current density of 0.5 to 20 A / dm ² .

In addition, as an organic compound film, polyimide, polyamide, polyester, polyacrylate, photo radical polymerization type, photo cation polymerization type photo curable resin, or a copolymer containing an acrylonitrile component, polyvinyl phenol, polyvinyl alcohol, novolac resin, Further, cyanoethyl pullulan or the like can also be used.
As the method for forming the organic compound film, the wet process is preferable.
An inorganic oxide film and an organic oxide film can be laminated and used together. The thickness of these insulating films is generally 50 nm to 3 μm, preferably 100 nm to 1 μm.
When an organic semiconductor is formed on the gate insulating layer, an arbitrary surface treatment may be performed on the surface of the gate insulating layer. A silane coupling agent such as octadecyltrichlorosilane, trichloromethylsilazane, alkane phosphoric acid, alkane sulfonic acid, alkane carboxylic acid or the like is preferably used.
Note that when the gate insulating layer is configured to extract the light generated as described above to the outside through the gate insulating layer, the gate insulating layer is formed of a light-transmitting material such as silicon oxide to effectively transmit the light. It is made to take out.
A preferred example of the support in the present invention is a resin. For example, in the configuration example shown in FIGS. 1 and 2, a plastic film sheet can be used. Examples of the plastic film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), polyetherimide, polyetheretherketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate (PC), Examples thereof include films made of cellulose triacetate (TAC), cellulose acetate propionate (CAP), and the like. Thus, by using a plastic film, the weight can be reduced as compared with the case of using a glass substrate, the portability can be improved, and the resistance to impact can be improved. In addition, since it is flexible, a flexible light-emitting organic thin film transistor element sheet can be realized, and it can also be used for applications such as bending.
Also in this case, in the case where the light generated as described above is taken out through the substrate or sheet as the support 1, a translucent material is selected from the above materials and effective. To take out light.

An element protective layer 7 made of a translucent member is provided on the light emitting organic thin film transistor element of the present invention. The element protective layer 7 includes the above-described inorganic oxide or inorganic nitride, and is preferably formed by the atmospheric pressure plasma method described above. In particular, silicon oxide, which is a light-transmitting material, is preferable, which shields and seals the organic semiconductor material from oxygen and water vapor in the air, improves the durability of the thin film transistor element, and has an effect of light emitted from the organic semiconductor material. Can be taken out to the outside. A typical element configuration example (cross-sectional view) is shown in FIG. 15, and the light emitted from the organic semiconductor layer 2 can be extracted in the direction of arrow A through the translucent element protective layer 7.
A more specific device structure of the light-emitting organic thin film transistor element will be described with reference to FIG. 16, which is a modified bottom gate type configuration example. FIG. 16 is a plan view, and the cross-sectional structure and configuration are as shown in FIG. 15, but the dimensions and the like do not match. FIG. 17 shows pattern shapes and main dimensions of the source electrode 3 and the drain electrode 4.
In this example, for example, the entire pair of electrodes including the source electrode 3 that is the first electrode and the drain electrode 4 that is the second electrode disposed at a predetermined interval on the gate insulating layer 5 is embedded. An organic semiconductor layer 2 made of such an organic semiconductor material is stacked, and a gate electrode 6 as a third electrode is provided in a region where the organic semiconductor layer 2 is provided via a gate insulating layer 5 positioned below. This is an organic transistor having the following structure. Here, a voltage is applied between the source electrode 3 and the drain electrode 4 within a range in which the organic semiconductor material emits light, and a voltage is further applied to the gate electrode 6 to control ON / OFF of light emission or light emission amount. It is. At this time, it has been found that light is emitted more efficiently by increasing the electrode length of the facing region than the distance between the source electrode 3 and the drain electrode 4 facing each other.

This will be further described with reference to a schematic diagram of the main part of FIG. In FIG. 17, only the pattern of the source electrode 3 and the drain electrode 4 is shown in order to simplify the configuration. (A) is a case where the electrode length w of the region where the source electrode 3 and the drain electrode 4 face each other is shorter than the distance l between the source electrode 3 and the drain electrode 4 (l> w), and (b) Is a case where the electrode length w of the region where the source electrode 3 and the drain electrode 4 face each other is longer than the distance l between the source electrode 3 and the drain electrode 4 (l <w).
In the case as shown in FIG. 17A, the potential difference between the source electrode 3 and the drain electrode 4 must be large, and the light emission efficiency is also bad. In other words, light is emitted well even at low energy.
More preferably, the electrode pattern is formed so that the ratio (l / w) of both is 1/2000 to 1/2. In that case, the electrode shape of a simple rectangular pattern as shown in (b) is not impossible, but more preferably, the pattern shape is such that the ratio (l / w) between them can be taken large. . FIG. 18 shows an example of such a pattern shape.
In this example, the opposite sides of the pattern of the source electrode 3 and the drain electrode 4 have a comb-tooth shape, and the comb teeth have a structure in which they are interleaved with each other. By doing so, the electrode length w of the region where the source electrode 3 and the drain electrode 4 are opposed to each other can be increased. Although not shown, the outer peripheral length where the comb teeth are opposed is the electrode length w of the region where the source electrode 3 and the drain electrode 4 are opposed. In the figure, l is the distance between the source electrode 3 and the drain electrode 4.

FIG. 19 is different from the example of FIG. 18 in that the number of comb teeth of the electrodes 3 and 4 is not the same, but the pattern shape and main pattern of the source electrode 3 and the drain electrode 4 when good light emission is obtained. It is an example showing various dimensions. In this example, the distance l between the source electrode 3 and the drain electrode 4 is 1 μm, and the electrode length w of the region where the source electrode 3 and the drain electrode 4 face each other is about 989 μm (= 100 μm × 9 + 10 μm × 8 + 1 μm). × 9), and the ratio (l / w) of both is about 1/1000.
Such a device is manufactured, for example, by a process as shown in FIG. (A) shows, for example, a substrate that is configured to serve as the support 1 and the gate electrode 6 and is made of a Si semiconductor substrate and is provided with silicon oxide as the gate insulating layer 5 on the surface. A source electrode 3 and a drain electrode 4 having a pattern as shown in the figure are formed by thin film formation, photolithography, and etching ((b)). Next, the organic semiconductor layer 2 is formed ((c)), and finally the element protective layer 7 is formed ((d)) to complete.
In this example, since the support 1 and the gate electrode 6 are combined, a Si semiconductor substrate is used. However, in order to form a large number of such light-emitting organic thin film transistor elements in a large area as will be described later. If a member used as the gate electrode 6 here is a glass substrate, a ceramic substrate, or the like as the support 1, it can be manufactured at low cost. Moreover, the above-mentioned plastic film sheet can be used. In such a case, silicon oxide, which is a light-transmitting material, is used as the gate insulating layer 5, and a transparent glass substrate and plastic film sheet are also used. Further, the gate electrode (not shown) also uses a light-transmitting material such as ITO so that light generated from the side of the support 1 (the member used as the gate electrode 6) opposite to the arrow A in FIG. become.

にＲｕｂｒｅｎｅを１．８ｗｔ％添加したものを炭酸ジメチルに溶かし、前述のような液体噴射原理により、前記ソース電極３及びドレイン電極４の上から、インクジェット記録でいうところのベタ打ちと同じ要領で非接触、塗布したものである。乾燥後の有機半導体層２の厚さは、約１２０ｎｍであった。
有機半導体層２の乾燥後、素子保護層７として、スパッタリングにより、酸化ケイ素を有機半導体層２を完全に封止できるように全面に０．５μｍの厚さで形成し、発光型有機薄膜トランジスタ素子は完成する。 Although the pattern shape and main dimensions are shown in FIG. 19, it is not necessarily limited to this. For example, FIG. 21 shows another example of the electrode pattern.
15 and 16, reference numeral 6 denotes a Si semiconductor substrate having a thickness of 0.6 mm in which silicon oxide is formed to a thickness of about 350 nm as the gate insulating layer 5, and is configured to serve as the support 1 and the gate electrode 6. is there. Reference numerals 3 and 4 denote a source electrode and a drain electrode, respectively, which have a two-layer structure in which a magnesium / gold mixture (ratio of 1: 1) is formed to 15 nm, and then gold is further formed to 30 nm. In this example, the pattern formation as shown was performed by photolithography-etching after the electrode material thin film was formed.
FIG. 19 shows the prototype electrode dimensions and the like, but the present invention is not limited to these dimensions. In this example, the distance (channel width) of the region (channel length, 1 μm in this example) where the distance between the source electrode 3 and the drain electrode 4 is constant is about 989 μm (= 100 μm × 9 + 10 μm × 8 + 1 μm × 9) as a whole. It becomes.
The organic semiconductor layer 2 is, for example, a polymer represented by the following chemical formula (described above)

A solution obtained by adding 1.8% by weight of rubrene to dimethyl carbonate is dissolved in dimethyl carbonate, and the liquid jet principle as described above is applied to the non-printing process from above the source electrode 3 and the drain electrode 4 in the same manner as solid printing in the ink jet recording. Touched and applied. The thickness of the organic semiconductor layer 2 after drying was about 120 nm.
After the organic semiconductor layer 2 is dried, silicon oxide is formed as an element protective layer 7 by sputtering to a thickness of 0.5 μm over the entire surface so that the organic semiconductor layer 2 can be completely sealed. Complete.

Next, other features of the present invention will be described. As described above, in the present invention, the electrode length w of the facing region is made longer than the interelectrode distance l between the source electrode 3 and the drain electrode 4 facing each other, more preferably the source electrode 3 and the drain electrode. 4 by making the ratio (l / w) of the interelectrode distance 1 and the electrode length w of the region where the source electrode 3 and the drain electrode 4 face each other to be 1/2000 to 1/2. It is characteristic that it emits light well. In other words, in FIG. 17, an electrode pattern is formed so that the light emitting region (the organic semiconductor material layer between the source electrode 3 and the drain electrode 4) has an elongated shape, and the ratio (l / w) To be 1/2000 to 1/2.
An example is shown in FIG. FIG. 22A shows the light emitting region of FIG. 17B. The region (inside) indicated by a thick broken line is the light emitting region 8, and the shape of the light emitting region is an elongated shape (rectangular shape). Similarly, the light emitting region 8 in the embodiment of FIGS. 22B and 18 is indicated by a thick broken line. In this case, the true light-emitting region 8 is an organic semiconductor material layer having no comb-like electrode pattern, but the region 8 (inside) indicated by a thick broken line as a whole is the light-emitting region, and its shape is an elongated shape. (Rectangular). In addition, as a structure for obtaining a similar elongated light emitting region 8, the lengths of the comb teeth of the pattern of the source electrode 3 and the drain electrode 4 are increased as shown in FIG. It is good.
In addition, a plurality of light emitting regions facing each other with a pair of electrodes 3 and 4 are formed in a matrix, and each of the adjacent light emitting regions is formed in an elongated shape in a substantially square light emitting region. Thus, the transistor operation and the light emitting operation can be performed by the same element, and another useful and novel organic light emitting transistor can be provided.
As is apparent from the above description, in the present invention, in order to emit light more efficiently, the pattern configuration of the source electrode 3 and the drain electrode 4 is determined so that the light emitting region has an elongated shape.
The configuration example of the light-emitting organic thin film transistor element of the present invention and the example of the material that is preferably used have been described above. Next, a more specific use example of the present invention will be described. The present invention is used as a light emitting element by utilizing the characteristics of an organic thin film transistor with a light emitting phenomenon.

Usually, an organic transistor element uses an element driving function, and functions as a display in combination with a display device such as a liquid crystal, an electrophoretic element, or an organic EL element separately formed as shown in FIG.
FIG. 23 is a schematic equivalent circuit diagram showing an example of an organic transistor sheet 88 on which a plurality of organic transistor elements are arranged. In order to simplify the drawing, a 3 × 3 matrix arrangement is used. However, in reality, the organic transistor sheet 88 includes organic transistor elements 91 arranged in a matrix of the order of several thousand × several thousands to several tens of thousands × tens of thousands. Have Reference numeral 89 denotes a gate bus line of the gate electrode of each organic transistor element 91, and reference numeral 90 denotes a source bus line of the source electrode of each organic transistor element 91. An output element 93 is connected to the drain electrode of each organic transistor element 91. The output element 91 is, for example, a liquid crystal or an electrophoretic element, and constitutes a pixel in the display device. In the illustrated example, the output element 91 is shown as an equivalent circuit in which a liquid crystal is composed of a resistor and a capacitor. Reference numeral 92 denotes a storage capacitor, 94 denotes a vertical drive circuit, and 95 denotes a horizontal drive circuit.
On the other hand, in the present invention, since the organic transistor element itself can also serve as the light emitting element, it is not necessary to separately form a display device such as a liquid crystal, an electrophoretic element, or an organic EL element, and a plurality of organic transistor elements are provided. By arranging the individual transistors in a matrix and turning on / off the light emission of the organic transistor, it can function as a display device as it is. Further, not only the ON / OFF control but also the light emission amount can be changed by changing the gate voltage stepwise, so that it can function as a display device rich in gradation expression. That is, a self-luminous display having a very simple configuration that does not require the conventional output element 93 shown in FIG. 23 can be realized. At that time, if color filters of R, G, and B (red, green, and blue), which are the three primary colors of light, are arranged so as to cover each light emitting region at a position facing the light emitting surface of the organic transistor, respectively. Thus, a completely new self-luminous color display device capable of performing the transistor operation and the light emitting operation with the same element is realized.

At this time, one pixel is formed by R, G, and B. Therefore, if the light emitting region is formed in an elongated shape (rectangular shape), the light emitting regions of the organic transistor elements arranged in a matrix are shortened. It can be densely arranged in the hand direction, and when viewed as a pixel (when viewing three colors of RGB as a group), the aspect ratio becomes three times (since three organic transistor elements are arranged to constitute one pixel). Thus, a self-luminous color display device capable of realizing a high-quality display without being a long and narrow shape can be obtained.
Here, each organic transistor element is individually protected by a light-transmitting and sealing material such as silicon oxide as described above. Thereby, reliable sealing performance can be realized.
On the other hand, considering the production cost, it is also a good method to coat all the transistor elements of the organic transistor sheet 88 of FIG. 2 with a material such as silicon oxide. In particular, when manufacturing a display having a size of 100 mm × 100 mm or more, it is better to seal the entire element on the sheet than to seal each element individually.
As another sealing means, the organic transistor sheet 88 of FIG. 24 itself can be housed in a case to realize a display device. FIG. 24 shows an example of the configuration. In the figure, 88 is an organic transistor sheet, 96 is a case bottom plate, 97 is a case frame, 98 is a protective substrate, 99 is a sealing member, and 100 is a gap.

Such a display device is assembled in the order as shown in FIGS. FIG. 25A shows a case in which an organic transistor sheet 88 composed of a case bottom plate 96 and a case frame 97 is accommodated. 25B, an organic transistor sheet 88 having organic transistor elements (not shown) arranged in a matrix of the order of several thousand × several thousands to several tens of thousands × tens of thousands as shown in FIG. Further, a protective substrate 98 is provided in the vicinity of the organic transistor element surface formed as shown in FIG. Finally, as shown in FIG. 25 (d), the inside of the case is sealed and sealed with a seal member 99.
At this time, there is a gap 100 between the organic transistor sheet 88 and the protective substrate 98. In order to make the organic transistor element emit light in this gap, a vacuum airtight of 1 × 10 ⁻¹ to 1 × 10 ⁻⁸ Torr. Kept in a state. More preferably, it is preferable to maintain a vacuum degree of about 1 × 10 ⁻³ to 1 × 10 ⁻⁸ Torr in order to increase the light emission efficiency and maintain a stable light emission state. The gap distance is preferably small and should be less than the thickness of the protective substrate 98 even if it is large. This is because the protective substrate 98 is deformed by the atmospheric pressure because the inside is in a vacuum state. In the worst case, the protective substrate 98 may be less than the thickness because it may be damaged by atmospheric pressure. Specifically, if the thickness of the protective substrate 98 is 0.5 to 10 mm and the gap is less than that, the protective substrate 98 will not be damaged even in a vacuum state as described above. . It is more preferable that the gap is almost absent. That is, it is also a good method to bring the organic transistor sheet 88 and the protective substrate 98 into close contact.
In addition, as a material for the protective substrate 98, a light-transmitting member is selected in order to extract emitted light to the outside through this, and Pyrex (registered trademark) glass manufactured by Corning Inc. is preferably used. Alternatively, in consideration of impact resistance, chemically strengthened glass FL3.2 manufactured by Nippon Sheet Glass Co., Ltd. is preferably used.
As another preferred configuration, injecting an inert gas such as nitrogen gas into the gap 100 region between the organic transistor sheet 88 and the protective substrate 98 to obtain a sealed state can also provide high luminous efficiency.
The color filter described above may be disposed on the protective substrate 98 or may be disposed between the organic transistor sheet 88 and the protective substrate 98. Alternatively, the color filter itself made of a glass substrate or the like may also serve as the protective substrate 98.

The above-described light-emitting organic thin film transistor element (without the element protective layer 7) of the present invention (FIGS. 15 and 16) has a gate voltage at a drain voltage of −90 V in a vacuum hermetic state of 1 × 10 ⁻² Torr as described above. When changing the light emission starts at -60 V, a luminance of about 1000 cd / m ² at -70V, so on about 1300 cd / m ² in luminance at -80 V, continuously luminance in accordance with a change in the gate voltage The maximum brightness of about 1600 cd / m ² was obtained at −90V.
In a vacuum hermetic state of 1 × 10 ⁻³ Torr, a maximum luminance of about 2000 cd / m ² was obtained at a drain voltage of −90 V and a gate voltage of −90 V. Further, in a vacuum hermetic state of 1 × 10 ⁻⁷ Torr, a maximum luminance of about 2500 cd / m ² was obtained at a drain voltage of −90 V and a gate voltage of −90 V. In addition, even under nitrogen gas injection instead of the vacuum confidential state, the maximum luminance of about 2400 cd / m ² was obtained at the gate voltage of −90 V at the drain voltage of −90 V. Next, when a device in which an element protective layer 7 (silicon oxide) was formed on the entire surface with a thickness of 0.5 μm and sealed on the light-emitting organic thin film transistor element was evaluated in ordinary air, the drain voltage was −90 V. It was found that a maximum luminance of about 2200 cd / m ² was obtained at a gate voltage of −90 V, and that it functioned even in air if sealed well.

It is a figure which shows the layer structural example (top gate type) of the organic transistor element of this invention. It is a figure which shows the layer structural example (bottom gate type) of the organic transistor element of this invention. It is a figure which shows the modification structural example of the organic transistor element of this invention. It is a figure for demonstrating one Example of the droplet jet manufacturing apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure explaining the droplet ejection principle of the discharge head using a piezoelectric element used suitably for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure which shows the structure of the discharge head using a piezoelectric element used suitably for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure which shows the example of the liquid discharge head of a thermal system (bubble system) used suitably for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. FIG. 5 is a diagram of a multi-nozzle type liquid discharge head viewed from the nozzle side. It is the figure which laminated | stacked for every solution which injects a multi-nozzle type liquid discharge head, and was unitized. It is a perspective view of the liquid discharge head unitized. It is a figure which shows the example of the test pattern used in order to find the conditions which perform favorable pattern formation with the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure for demonstrating the example of the droplet flying shape at the time of ejecting with the action force by mechanical displacement with the discharge head used for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure for demonstrating the example of the other droplet flight shape at the time of ejecting with the action force by mechanical displacement with the discharge head used for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure for demonstrating the example of the droplet flight shape at the time of ejecting with the action force by a film boiling bubble with the discharge head used for the apparatus which manufactures the light emitting organic thin-film transistor element of this invention. It is a figure which shows the structural example of the light emitting organic transistor element of this invention. It is a top view which shows the structural example of the light emitting organic transistor element of this invention. It is a figure explaining the electrode length w of the area | region where the source electrode and the drain electrode have opposed the distance l between the source electrodes of the light emitting organic transistor element of this invention, and a drain electrode. A pattern in which the ratio (l / w) between the distance l between the source electrode and the drain electrode of the light-emitting organic transistor element of the present invention and the electrode length w of the region where the source electrode and the drain electrode face each other can be increased. It is a figure which shows an example of a shape. It is a figure which shows the electrode pattern shape and main dimension of the structural example shown in FIG. It is a figure explaining the manufacturing process of the structural example shown in FIG. It is a figure which shows the example of another electrode pattern. It is a figure explaining the shape of the light emission area | region of the light emitting organic transistor element of this invention. It is a schematic equivalent circuit diagram of an example of an organic transistor sheet in which a plurality of organic transistor elements are arranged. It is a figure which shows the example of a display structure using the light emission type organic transistor element of this invention. FIG. 25 is a diagram illustrating an assembly method of the display shown in FIG. 24.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Support body, 2 ... Organic-semiconductor layer, 3 ... Source electrode, 4 ... Drain electrode, 5 ... Gate insulating layer, 6 ... Gate electrode, 7 ... Element protection layer, 11 ... Discharge head unit (discharge head), 12 ... Carriage, 13 ... Substrate holder, 14 ... Light-emitting organic thin film transistor element substrate or sheet, 15 ... Solution supply tube, 16 ... Signal supply cable, 17, 21 ... Control box, 18 ... X direction scan motor, 19 ... Y direction Scan motor, 20 ... computer, 22 ... substrate positioning / holding means, 43 ... droplet, 45 ... flow path, 46 ... piezo element, 56 ... solution, 57 ... filter, 65 ... nozzle, 66 ... heating element substrate, 67 ... Lid substrate 68 ... Silicon substrate 69 ... Individual electrode 70 ... Common electrode 71 ... Heating element 74 ... Groove 75 ... Recessed area 76 ... Solution inlet 8 ... Organic transistor sheet, 89 ... Gate bus line, 90 ... Source bus line, 91 ... Organic transistor element, 92 ... Storage capacitor, 93 ... Output element, 94 ... Vertical drive circuit, 95 ... Horizontal drive circuit, 96 ... Case bottom plate, 97 ... Case frame, 98 ... Protective substrate, 99 ... Seal member, 100 ... Gap

Claims (8)

  An organic transistor having a structure in which an organic semiconductor material is provided between a pair of electrodes including a first electrode and a second electrode, and a third electrode is provided in an area where the organic semiconductor material is provided via an insulating layer. In the organic transistor that applies a voltage between the pair of electrodes within a range in which the organic semiconductor material emits light, further applies a voltage to the third electrode, and controls the light emission, the pair of electrodes includes An organic transistor characterized in that the electrode length of the facing region is made longer than the distance between the facing electrodes.   2. The organic transistor according to claim 1, wherein the pair of electrodes have a configuration in which opposing sides are in a comb-tooth shape, and the comb teeth are in a mutually interleaved structure.   3. The pair of electrodes is configured so that the organic semiconductor material emits light in a region where the pair of electrodes are opposed to each other, and the light emitting region has an elongated shape. Organic transistor.   A plurality of light emitting regions opposed to the pair of electrodes are formed in a matrix, and each of the adjacent light emitting regions is formed into an elongated shape in a substantially square light emitting region in three adjacent regions. The organic transistor according to any one of claims 1 to 3, characterized in that:   The organic transistor according to claim 1, wherein an organic transistor substrate on which a plurality of the organic transistors are arranged is arranged in a vacuum-tight state.   The organic transistor according to any one of claims 1 to 4, wherein an organic transistor substrate on which a plurality of the organic transistors are arranged is disposed in an inert gas atmosphere.   A display device using ON / OFF of light emission of the organic transistor according to claim 5.   The display device according to claim 7, wherein a filter is disposed at a position facing the light emitting surface of the organic transistor.

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