JP2003282854A - Optical sensor element, optical sensor device and its driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new optical sensor element and device at lower cost and high sensitivity with an easy matrix control by a simple manufacturing method. <P>SOLUTION: The optical sensor element has, on a support, a gate electrode, a source electrode and a drain electrode which are positioned through an insulating layer with respect to the gate electrode and are connected to each other by an organic semiconductor layer, and an electric charge generation layer positioned opposite to the insulating layer on a side of the source electrode and the drain electrode. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel optical sensor element, an optical sensor device and a driving method thereof.

[0002]

2. Description of the Related Art Conventionally, a CCD (Charge Coup) is used.
red Device) and CMOS (Complement)
nary Metal-Oxide-Semicon
Although a photosensor device using an inductor or the like and a photosensor device as an assembly thereof are used, they have the drawbacks of low production efficiency and high cost because they are manufactured by a vacuum dry process.

On the other hand, as an optical sensor using an organic semiconductor, which is considered to be advantageous in manufacturing, it is disclosed in Japanese Patent Laid-Open No. 5-5561
No. 0, No. 6-29514 discloses one in which a condensed polycyclic aromatic thin film is formed on a semiconductor substrate, electrodes are provided on the substrate side and the thin film side, and light is detected from changes in electrical characteristics due to light irradiation.
Describes a method in which a plurality of electrodes are provided in contact with a fullerene thin film, and a current value according to the intensity of light irradiated with an electric field applied is detected.

However, these organic photosensors have a performance problem of low photocarrier generation efficiency and low sensitivity, and as an optical sensor device, TF is used in addition to the photoelectric conversion section.
Since it is necessary to separately provide a switching element such as a T (thin film transistor) element, there is a problem that the structure becomes complicated.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide an inexpensive optical sensor element and device which can be manufactured by a simple manufacturing method. Secondly, it is to provide a novel optical sensor element and device with high sensitivity and easy matrix control.

[0006]

Means for Solving the Problems The above-mentioned objects of the present invention are as follows: 1) A gate electrode on a support, and a source electrode located on the support via an insulating layer and connected by an organic semiconductor layer. An optical sensor element having a drain electrode and a charge generation layer located opposite to the insulating layer on the source electrode and drain electrode sides, 2) a plurality of gate electrodes arranged in parallel on the support, A plurality of source electrodes and drain electrodes, which are located in a direction orthogonal to the gate electrode via an insulating layer and are connected by an organic semiconductor layer, are alternately arranged, and an insulating layer is provided on the source electrode and drain electrode sides. An optical sensor device having a charge generation layer located opposite to the above, 1) and 2), 3) having a charge transport layer between the organic semiconductor layer and the charge generation layer, and 4) the organic semiconductor being a π-conjugated system. Is a high molecular compound 5) The support is made of a high molecular compound, 6) The gate electrode is formed of a transparent conductive film, 7) The radiation having energy higher than the ultraviolet energy is converted into visible light on the light incident surface side. 8) Having a scintillator, 8) Having a color separation filter on the light incident surface side, 9) Arranging in a direction orthogonal to the gate electrode while applying a bias voltage to the gate electrode when driving the photosensor device. The method for driving the photosensor device, in which scanning for detecting the photocurrent value of each photosensor element is sequentially performed on each gate electrode.

That is, the present inventor has applied the bias voltage between the source electrode and the drain electrode in the above-mentioned element structure,
When light is irradiated with the gate electric field applied by the gate electrode, the photocharges generated in the charge generation layer move to the organic semiconductor layer, which lowers the electric resistance of the organic semiconductor layer,
A current flows between the source electrode and the drain electrode, and it is considered that an optical sensor can be constructed by detecting the current value, and the present invention has been accomplished.

The present invention will be described in detail below. The material of each of the source, drain and gate electrodes of the optical sensor element of the present invention is not particularly limited as long as it is a conductive material, and platinum, gold, silver, nickel, chromium, copper, iron, tin, antimony lead, Tantalum, indium, palladium, tellurium, 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, potassium-alloy, magnesium, lithium, aluminum, magnesium / copper mixture, magnesium /
A silver mixture, a magnesium / aluminum mixture, a magnesium / indium mixture, an aluminum / aluminum oxide mixture, a lithium / aluminum mixture and the like are used, but platinum, gold, silver, copper, aluminum, indium, ITO and carbon are particularly preferable. Or a known conductive polymer whose conductivity is improved by doping or the like,
For example, conductive polyaniline, conductive polypyrrole, conductive polythiophene, a complex of polyethylenedioxythiophene and polystyrene sulfonic acid, and the like are also suitably used. Among them, those having a low electric resistance on the contact surface with the semiconductor layer are preferable.

As a method of forming the electrode, a method of forming an electrode using a known photolithography method or a lift-off method on a conductive thin film formed by a method such as vapor deposition or sputtering using the above-mentioned raw materials, aluminum, copper, etc. There is a method of performing thermal transfer on the metal foil, and etching using a resist such as an inkjet.

The particle size is 1 to 50 nm, preferably 1 to 1
An electrode formed by heating and fusing 0 nm metal fine particles may be used. As the metal material, platinum, gold, silver, nickel, chromium, copper, iron, tin, tantalum, indium, cobalt, palladium, tellurium, rhenium, iridium, aluminum, ruthenium, germanium, molybdenum,
Tungsten, zinc, etc. can be used, but platinum, gold, silver, copper, cobalt, chromium, iridium, nickel, palladium, molybdenum, and tungsten having a work function of 4.5 eV or more are particularly preferable.

A liquid, paste or ink is applied and patterned by dispersing fine particles made of these metals in a dispersion medium which is water or an arbitrary organic solvent, using a dispersion stabilizer mainly made of an organic material. .

As a method for producing such a metal fine particle dispersion, a physical production method such as a gas evaporation method, a sputtering method, and a metal vapor synthesis method, or a metal ion in a liquid phase such as a colloid method or a coprecipitation method is used. A chemical production method of producing metal fine particles by reduction is mentioned, and preferably, JP-A No. 11-768.
No. 00, No. 11-80647, No. 11-319538, the colloid method described in JP-A No. 2000-239853, 2000-123634, 2000-124157,
The dispersions produced by the gas evaporation method described in 2001-35255, 2001-35814, 2001-53028, and JP-A 2001-254185.
These dispersions are applied and molded into an electrode pattern, then the solvent is dried, and further heat-treated in the range of 100 ° C. to 300 ° C., preferably 150 ° C. to 200 ° C. to thermally fuse the metal fine particles. By doing so, an electrode is formed.

The conductive polymer solution or dispersion or the metal fine particle dispersion may be directly patterned by ink jet, or may be formed from a coating film by lithographic or laser ablation. Further, a method of patterning an ink containing a conductive polymer or conductive fine particles, a conductive paste or the like by a printing method such as letterpress, intaglio, planographic printing or screen printing can also be used.

Although various insulating films can be used as the insulating layer according to the present invention, an inorganic oxide film having a high relative dielectric constant is particularly preferable. As the inorganic oxide, silicon oxide,
Aluminum oxide, tantalum oxide, titanium oxide, tin oxide, vanadium oxide, barium strontium titanate, barium titanate zirconate, lead zirconate titanate, lead lanthanum titanate, strontium titanate, barium titanate, barium magnesium fluoride, Examples thereof include bismuth titanate, strontium bismuth titanate, strontium bismuth tantalate, bismuth niobate tantalate, and yttrium trioxide. Of these, preferred are silicon oxide, aluminum oxide, tantalum oxide, and titanium oxide. Inorganic nitrides such as silicon nitride and aluminum nitride can also be preferably used.

As a method for forming the above film, a dry process such as a vacuum vapor deposition method, 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 or the like. Wet processes 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 can be used depending on the material.

The wet process is a method in which fine particles of an inorganic oxide are dispersed in an arbitrary organic solvent or water using a dispersion auxiliary agent such as a surfactant, if necessary, and then dried, or an oxide precursor is used. A so-called sol-gel method is used in which a solution of a body, for example, an alkoxide body is applied and dried.

Of these, the atmospheric pressure plasma method and the sol-gel method are preferable. The method for forming an insulating film by the plasma film forming process under atmospheric pressure is a process of discharging under atmospheric pressure or a pressure near atmospheric pressure, plasma-exciting a reactive gas, and forming a thin film on a substrate. Regarding the method, JP-A-11-61406, JP-A-11-133205, and JP-A-200200
0-121804, 2000-147209, 20
No. 00-185362. As a result, a highly functional thin film can be formed with high productivity.

As the organic compound film, polyimide, polyamide, polyester, polyacrylate, photocurable resin of photoradical polymerization type, photocationic polymerization type, or copolymer containing an acrylonitrile component, polyvinylphenol, polyvinyl alcohol, It is also possible to use novolac resin, cyanoethyl pullulan, or the like.

As a method of forming the organic compound film, the wet process is preferable. The inorganic oxide film and the 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.

A π-conjugated material is used as the organic semiconductor material forming the organic semiconductor layer according to the present invention. For example, polypyrroles such as polypyrrole, poly (N-substituted pyrrole), poly (3-substituted pyrrole), poly (3,4-disubstituted pyrrole), polythiophene, poly (3
-Substituted thiophenes), poly (3,4-disubstituted thiophenes), polythiophenes such as polybenzothiophenes,
Polyisothianaphthenes such as polyisothianaphthene,
Poly (phenylene vinylenes) such as poly (phenylene vinylene), poly (p-phenylene vinylenes) such as poly (p-phenylene vinylene)
Phenylene vinylenes), polyaniline, poly (N-substituted aniline), poly (3-substituted aniline), poly (2,2)
3-substituted aniline) and other polyanilines, polyacetylene and other polyacetylenes, polydiacetylene and other polydiacetylenes, polyazulene and other polyazylenes, polypyrene and other polypyrenes, polycarbazole, poly (N-substituted carbazole) and other polycarbazoles. , Polyselenophenes such as polyselenophene,
Polyfurans such as polyfuran and polybenzofuran, poly (p-phenylene) 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, ovaren, quaterylene, Derivatives obtained by substituting a part of carbons of polyacenes such as circumanthracene and polyacenes with atoms such as N, S and O and functional groups such as carbonyl groups (triphenodioxazine, triphenodithiazine, hexacene-6,15- For example, polymers such as quinone), polyvinylcarbazole, polyphenylene sulfide, and polyvinylene sulfide, and polycondensates described in JP-A No. 11-195790 can be used.

Further, for example, α-sexithiophene α, ω-dihexyl-α-sexithiophene, which is a thiophene hexamer, having the same repeating unit as these polymers,
α, ω-dihexyl-α-kinkethiophene, α, ω-
Oligomers such as bis (3-butoxypropyl) -α-sexithiophene and styrylbenzene derivatives can also be preferably used.

Further, copper phthalocyanine and JP-A-11-2
51601, metal phthalocyanines such as fluorine-substituted copper phthalocyanine, naphthalene 1,4,5,8-tetracarboxylic acid diimide, N, N′-bis (4-trifluoromethylbenzyl) naphthalene 1,4,5,8 -With tetracarboxylic acid diimide, N, N'-bis (1
H, 1H-perfluorooctyl), N, N'-bis (1H, 1H-perfluorobutyl) and N, N'-dioctylnaphthalene 1,4,5,8-tetracarboxylic acid diimide derivative, naphthalene 2,3,6 , 7 Tetracarboxylic acid diimides and other naphthalene tetracarboxylic acid diimides, and anthracene 2,3,6,7-tetracarboxylic acid diimides and other anthracene tetracarboxylic acid diimides and other condensed ring tetracarboxylic acid diimides, C
Fullerenes such as ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₄ , SWNT
Examples thereof include carbon nanotubes, merocyanine dyes, and hemicyanine dyes.

Among these π-conjugated materials, thiophene, vinylene, phenylenevinylene, phenylenevinylene, p-phenylene, their substitution products or two or more of these repeating units are used as repeating units, and the number of repeating units is n. Is 4 to 10 and the number of repeating units is n.
Is 20 or more, at least one selected from the group consisting of condensed polycyclic aromatic compounds such as pentacene, fullerenes, condensed ring tetracarboxylic acid diimides, and metal phthalocyanines is preferable, and a π-conjugated polymer is particularly preferable. .

As other organic semiconductor materials,
Tetrathiafulvalene (TTF) -Tetracyanoquinodimethane (TCNQ) complex, Bisethylenetetrathiafulvalene (BEDTTTF) -Perchloric acid complex, BEDTT
Organic molecular complexes such as TF-iodine complex and TCNQ-iodine complex can also be used. Further, σ-conjugated polymers such as polysilane and polygermane, and JP-A-2000-2
The organic / inorganic hybrid material described in 60999 can also be used.

In the present invention, the organic semiconductor layer may include, for example, acrylic acid, acetamide, dimethylamino group,
Materials having functional groups such as cyano group, carboxyl group, and nitro group, and materials serving as acceptors that accept electrons, such as benzoquinone derivatives, tetracyanoethylene and tetracyanoquinodimethane, and their derivatives,
For example, materials having functional groups such as amino groups, triphenyl groups, alkyl groups, hydroxyl groups, alkoxy groups, and phenyl groups, substituted amines such as phenylenediamine, anthracene, benzanthracene, substituted benzanthracenes, pyrene, substituted pyrene, and carbazole. And a derivative thereof, tetrathiafulvalene and a derivative thereof, and the like, containing a material that serves as a donor that is an electron donor,
A so-called doping process may be performed.

The above-mentioned doping means introducing an electron-donating molecule (acceptor) or an electron-donating molecule (donor) into the thin film as a dopant. Therefore, the doped thin film is a thin film containing the condensed polycyclic aromatic compound and the dopant. As the dopant used in the present invention, either an acceptor or a donor can be used.

Cl ₂ , Br ₂ , and I are used as the acceptor.
₂ , halogen such as ICl, ICl ₃ , IBr, IF, P
F ₅ , AsF ₅ , SbF ₅ , BF ₃ , BC1 ₃ , BBr ₃ , S
Lewis acids such as O ₃ , HF, HC1, HNO ₃ , H ₂ S
O ₄ , HClO ₄ , FSO ₃ H, ClSO ₃ H, CF ₃ SO ₃
Protonic acid such as H, acetic acid, formic acid, organic acid such as amino acid, FeCl ₃ , FeOCl, TiCl ₄ , ZrCl ₄ ,
HfCl ₄ , NbF ₅ , NbCl ₅ , TaCl ₅ , MoCl
₅ , WF ₅ , WCl ₆ , UF ₆ , LnCl ₃ (Ln = La,
Ce, Nd, Pr, and other lanthanoids and transition metal compounds such as Y), Cl ⁻ , Br ⁻ , I ⁻ , ClO ₄ ⁻ , P
Examples thereof include electrolyte anions such as F ₆ ⁻ , AsF ₅ ⁻ , SbF ₆ ⁻ , BF ₄ ⁻ , and sulfonate anion.

As the donor, Li, Na, K, R
Alkali metals such as b and Cs, alkaline earth metals such as Ca, Sr and Ba, Y, La, Ce, Pr, Nd and S
Rare earth metals such as m, Eu, Gd, Tb, Dy, Ho, Er and Yb, ammonium ion, R ₄ P ⁺ , R ₄ As ⁺ ,
Examples thereof include R ₃ S ⁺ and acetylcholine.

As a method for doping these dopants, it is possible to use a method of previously forming a thin film of an organic semiconductor and then introducing the dopant, and a method of introducing the dopant when forming the thin film of the organic semiconductor. As the doping of the former method, vapor phase doping using a gas state dopant, liquid phase doping in which a solution or liquid dopant is brought into contact with the thin film to dope, and solid state dopant is brought into contact with the thin film to perform diffusion doping The solid-state doping method can be used. In liquid phase doping, the efficiency of doping can be adjusted by applying electrolysis. In the latter method, a mixed solution or dispersion of the organic semiconductor compound and the dopant may be simultaneously applied and dried. For example, when using a vacuum evaporation method, a dopant can be introduced by co-evaporating a dopant with an organic semiconductor compound. When the thin film is formed by the sputtering method, the dopant can be introduced into the thin film by sputtering using a binary target of the organic semiconductor compound and the dopant. Still other methods include chemical doping, such as electrochemical doping, photoinitiated doping and the like, eg publication “Industrial Materials” 34, No. 4,
Any of the physical doping methods such as the ion implantation method shown on page 55 (1986) can be used.

As methods for producing these organic thin films, vacuum vapor deposition method, molecular beam epitaxial growth method, ion cluster beam method, low energy ion beam method, ion plating method, CVD method, sputtering method, plasma polymerization method, electrolytic polymerization method. , Chemical polymerization method, spray coating method, spin coating method, blade coating method, dip coating method,
A casting method, a roll coating method, a bar coating method, a die coating method, an LB method and the like can be mentioned, and they can be used depending on the material. However, among these, from the viewpoint of productivity, spin coating, blade coating, dip coating, roll coating, bar coating, die coating, etc. that can easily and precisely form a thin film using a solution of an organic semiconductor are available. Be preferred.

The thickness of the thin film made of these organic semiconductors is not particularly limited, but the characteristics of the obtained transistor are often largely influenced by the thickness of the active layer made of an organic semiconductor. Varies depending on the organic semiconductor, but is generally 1 μm or less, and particularly preferably 10 to 300 nm.

Since the present invention reflects the photocharges (carriers) generated in the charge generation layer as the value of the current flowing between the source electrode and the drain electrode, the carriers may be either electrons or holes. When the layer is p-type, holes are preferable as the main carriers of photocurrent between the source electrode and the drain electrode, and when the organic semiconductor layer is n-type, the main carriers are preferably electrons.

A charge transport layer is preferably provided between the charge generation layer and the organic semiconductor layer to promote the movement of carriers.

The charge generating layer comprises an azo pigment such as Sudan Red or Diane Blue as a charge generating substance, a quinone pigment such as pyrenequinone or anthanthrone, an indigo pigment such as indigo or thioindigo, and an azurenium salt pigment.
Layers in which phthalocyanine pigments such as copper phthalocyanine, metal-free phthalocyanine, and titanyl phthalocyanine are dispersed in binder resins such as polyester, polycarbonate, polystyrene, polyvinyl butyral, polyvinyl acetate, acrylic resin, polyvinylpyrrolidone, ethyl cellulose, and cellulose acetate butyrate. Obtained as.

That is, the charge generating substance and the binder resin are, for example, hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane; ketones such as methyl ethyl ketone and cyclohexanone; ethyl acetate and butyl acetate. And the like; alcohols such as methanol, ethanol, propanol, butanol, methylcellosolve, ethylcellosolve and the like; ethers such as tetrahydrofuran and 1,4-dioxane; amines such as pyridine and diethylamine; N, Nitrogen compounds such as amides such as N-dimethylformamide; Other fatty acids and phenols; Sulfur such as carbon disulfide and triethyl phosphate; and ball mills, homomixers, sand mills in one or more solvents such as phosphorus compounds. By ultrasonic dispersion , Dissolved, dispersed to prepare a coating solution, which dip, spray, blade, applied by the method of coating a roll or the like can be formed and dried.

The mass ratio of the binder resin to the charge generating substance in the charge generating layer is about 0 to 10: 1 to 50, and the thickness of the charge generating layer formed is about 0.01 to 10 μm, preferably 0.1 to 10. It is 5 μm.

Known silver halide may be used as the charge generating substance. Spectrally sensitized silver halide grains having sensitivity to blue, green and red (BGR) light may be mixed and contained in the charge generation layer.

The charge-transporting layer formed adjacent to the charge-generating layer is prepared by dissolving or dispersing the charge-transporting substance in a suitable solvent alone or with a binder resin using an applicator, bar coater, dip coater or the like. It is obtained by coating and drying.

As the charge transport substance, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazolidine derivatives,
Bisimidazolidine derivative, styryl compound, hydrazone compound, pyrazoline derivative, oxazolone derivative, benzothiazole derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9 -Vinylanthracene, styryl compounds, amine derivatives, distyryl compounds (above p-type),
Benzoquinone compounds, anthraquinone compounds, naphthoquinone compounds, naphthalenediimide compounds, fluorenone compounds, thiopyran compounds, indane compounds, indandione compounds, cyclopentadiene compounds and their nitro derivatives, cyano derivatives, dicyanomethylene derivatives , Malonsan ester derivative, phenylimino derivative (above n-type) and the like.

Examples of the binder resin for forming the charge transport layer include polystyrene, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin and alkyd. Resins, polycarbonate resins, silicone resins, melamine resins, copolymer resins containing two or more repeating units of these resins, or insulating resins thereof, as well as polymer organic semiconductors such as polyvinylcarbazole. The solvent for dissolving and dispersing the charge transport material and the binder resin can be selected from the solvents for forming the charge generation layer and used.

The charge transport material is 20 to 200 parts by weight, preferably 30 to 150 parts by weight, per 100 parts by weight of the binder resin.
The charge transport layer preferably has a thickness of 5 to 50 μm.

As the method for applying the composition of each layer, known methods such as dipping, spin coating, knife coating, bar coating, blade coating, squeeze coating, reverse roll coating, gravure roll coating, curtain coating, spray coating, die coating and the like are further known. A coating method can be used, and a coating method capable of continuous coating or thin film coating is preferably used.

The support is composed of glass or a flexible resin sheet, and for example, a polymer film can be used as the sheet. Examples of the polymer film include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (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. By using such a plastic film, it is possible to reduce the weight as compared with the case of using a glass substrate, it is possible to enhance the portability, and it is possible to improve the resistance to impact.

The light incident surface may be any side of the structure described later, but when the side having the gate electrode is used as the light incident surface, the gate electrode is made of indium oxide, tin oxide, zinc oxide,
It is preferable to use a transparent conductive film such as F-doped tin oxide, Al-doped zinc oxide, Sb-doped tin oxide, ITO, or an In ₂ O ₃ —ZnO-based amorphous transparent conductive film.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be shown below with reference to the drawings, but the invention is not limited thereto.

FIG. 1 is a model view showing a structural example of the photosensor element of the present invention. Although the system having a charge transport layer is shown here, the effect of the present invention can be obtained without the layer. In addition, the optical sensor element is formed sequentially from the support side.

In FIG. 1A, a charge generation layer 2 and a charge transport layer 3 are formed in this order on a support 1, and a source electrode 5 and a drain electrode 6 connected by an organic semiconductor layer 4 thereon. Is provided, and the gate electrode 8 is formed by being covered with the insulating layer 7.

In FIG. 1B, the charge generation layer 2, the charge transport layer 3 and the organic semiconductor layer 4 are provided in the gap between the source electrode 5 and the drain electrode 6 formed on the support 1 and covered with the insulating layer 7. To form the gate electrode 8.

FIG. 1C shows the gate electrode 8 on the support 1.
Is formed, the source electrode 5 and the drain electrode 6 are provided on the insulating layer 7, and the charge transport layer 3 and the charge generating layer 2 are formed in this order by coating with the organic semiconductor layer 4.

In these, the source electrode 5 and the drain electrode 6 may be formed as a continuous electrode film and cut by laser ablation or the like to form a gap.

FIG. 1D is a modified example of FIG. 1C and shows another example of a mode in which the source electrode 5 and the drain electrode 6 are connected by the organic semiconductor layer 4. In this case, the source electrode 5 is provided on the insulating layer 7, the organic semiconductor layer 4 is applied, and the drain electrode 6 is formed.

FIG. 2 is a model diagram for explaining the photodetection mechanism of the photosensor element of the present invention.

In any of the structures shown in FIG. 1, the charge generation layer receives light and generates photocharges according to the product of the spectral sensitivity of the layer and the spectral distribution intensity of incident light. In FIG. 2, photocharges (holes) generated in the charge generation layer 2
Is injected into the organic semiconductor layer 4 through the charge transport layer 3 provided as necessary by the gate electric field applied by the gate electrode 8 that is negatively applied, and moves to the insulating layer 7 side. As a result, the charge density of the organic semiconductor layer 4 is increased and the resistance value is drastically reduced. The bias voltage applied between the source electrode 5 and the drain electrode 6 reflects the current value flowing through both electrodes. Can be used as an optical sensor.

FIG. 3 shows a circuit configuration of the photosensor element described above. That is, when the main carrier is a hole, the photocurrent can be monitored by applying a negative voltage to the gate electrode and a bias voltage between the source electrode and the drain electrode. The gate voltage is preferably 0 to -50V, and the bias voltage between the source electrode and the drain electrode is preferably 0 to -50V, although it depends on the structure of the device.

When the main carrier is an electron, the polarity may be reversed, and after the photocurrent measurement, it is preferable to discharge the residual charge in the charge generation layer or in the vicinity thereof.

As shown in FIG. 4, when a scintillator 9 for converting various radiations into visible light is provided on the light incident surface side of the element, it can be used as a radiation sensor and can be used as a radiation sensor, such as ultraviolet rays, gamma rays, It is effective for detecting electron beams. For example, an X-ray diagnostic image can be obtained by using a scintillator that uses a phosphor that converts X-rays into visible light.

As the scintillator, for example, as in the case of a radiation intensifying screen, as the basic structure, one having a support and a phosphor layer and a protective layer provided on one surface thereof can be used. As the phosphor layer, For example, for alpha ray detection, Z
nS doped with Ag or Cu, NaI doped with Tl for gamma ray detection, LiI doped with Sn for neutron detection, and the like can be formed by dispersion coating or vapor deposition. it can.

FIG. 5 is a model view showing the photosensor device 10 by active driving, which is based on the element whose photodetection mechanism has been described with reference to FIGS. (A) shows a side cross section,
(B) is a plan view.

In the figure, a plurality of gate electrodes 8 are arranged in parallel on a support 1, and an insulating layer 7 is formed on the gate electrodes 8.
Are formed, and a plurality of source electrodes 5 and drain electrodes 6 are alternately arranged on the gate electrode 8 in a direction orthogonal to each other to form a matrix, which are connected by the organic semiconductor layer 4, and charge transport is performed thereon. The photosensor device 10 is constituted by including the layer 3 and the charge generation layer 2 in this order. In this configuration, the gate electrode 8 also serves as a scanning line, and the area shown in the figure serves as a unit pixel, and pixels arranged in the column direction in the figure are connected by a common source electrode 5 and drain electrode 6.

FIG. 6 is an equivalent matrix circuit when active driving is performed in the device of FIG.

In the figure, reference numeral 100 denotes a photodetector, which is a signal line 5
Initialization transistors 65-1 to 65-n, to which drain electrodes are connected, are provided at -1 to 5-n. The source electrodes of the transistors 65-1 to 65-n are grounded. The gate electrode is the reset line 65.
Connected with 1.

Scan lines 8-1 to 8-m and reset line 651
Are connected to the scan drive circuit 20. One of the scan lines 8-1 to 8-m from the scan driving circuit 20 to the scan line 8-
When the read signal RS is supplied to p (p is any value from 1 to m), the transistors 4- (p, 1) to 4- (p, n) connected to the scanning line 8-p are turned on. Turned on,
Photocurrents that reflect the carriers generated by the light irradiation are read out to the signal lines 5-1 to 5-n, respectively. Signal line 5-
1 to 5-n are signal converters 31-1 of the signal selection circuit 30.
To 31-n and connected to signal converters 31-1 to 31-n.
1-n generates voltage signals SV-1 to SV-n proportional to the current values read on the signal lines 5-1 to 5-n.
The voltage signals SV-1 to SV-n output from the signal converters 31-1 to 31-n are supplied to the register 32.

In the register 32, the supplied voltage signals are sequentially selected, and the A / D converter 33 converts the voltage signals into digital optical signals for one scanning line (for example, 12 to 14 bits), and the control circuit 40. Scan lines 8-1 to
The read signal RS is supplied to each 8-m via the scan drive circuit 20.
Are supplied to perform scanning, and a digital signal for each scanning line is taken in to generate an optical signal. This optical signal is supplied to the control circuit 40. The scan drive circuit 20 supplies the reset signal RT to the reset line 351 to turn on the transistors 65-1 to 65-n, and also supplies the read signal RS to the scan lines 8-1 to 8-m. When the transistors 4- (1,1) to 4- (m, n) are turned on,
The stored carriers are transistors 65-1 to 65-n.
The light is emitted via the light source and can be initialized.

The control circuit 40 includes a memory section 41 and an operation section 4.
2 are connected, and the operation of the optical sensor device 10 is controlled based on the operation signal PS from the operation unit 42. Further, the optical signal data DS can be input to the display unit 43 from the control circuit 40.

Reference numeral 44 is an external power source, and 45 is a connector, through which the optical sensor device 10 can be integrated with other devices to exchange optical signal data DFE to perform image formation, for example.

On the light incident surface side of the optical sensor device 10 of FIG. 5, for example, an array as shown in FIG. 7 (R is a red filter, G is
By providing a color separation filter by repeating a green filter and a blue filter), an optical sensor device (image reading device) capable of detecting a full-color image can be configured.

The color separation filter is provided for color-separating the image information into the three primary colors, and various structures can be adopted. For example, yellow, green and cyan filters are mosaic patterns or stripes. Or a method of arranging filters of three colors of red, green and blue in a mosaic or stripe form. As a method of arranging the color separation filters in a mosaic pattern, a grid-shaped array method represented by a Bayer array, an array in which triangles, hexagons, or circles are spread can be cited. The arrangement of each color may be regular or may be arranged at random.

Various known methods can be used to manufacture this color separation filter. A typical color separation filter manufacturing method is a pigment dispersion method in which a photosensitive resin layer in which a pigment is dispersed is formed on a substrate and a monochromatic pattern is obtained by patterning this, and a material for dyeing on the substrate. A water-soluble polymer material is applied and patterned by a photolithography process into a desired shape, and then the resulting pattern is immersed in a dyeing bath to obtain a colored pattern. A dyeing method, a pigment is dispersed in a thermosetting resin. Then, printing is repeated three times to apply R, G, and B separately, and then a resin is thermally cured to form a colored layer. A printing method in which a coloring liquid containing a dye is used as an ink-transmissive substrate There is an inkjet method in which a colored pixel portion is formed by discharging the colored liquid onto the surface and drying the colored liquid.

[0069]

The optical sensor element and device of the present invention need not be provided with a fine active element other than the photoelectric conversion section, and can be manufactured under atmospheric pressure by a method such as coating, printing, a lithographic method, and an inkjet method. Therefore, it is possible to provide a novel optical sensor element and device at low cost, with high sensitivity, easy matrix control.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a configuration example of an optical sensor element of the present invention.

FIG. 2 is a model diagram for explaining a light detection mechanism of an optical sensor element of the present invention.

FIG. 3 is a diagram showing a circuit configuration of the optical sensor element of FIG.

FIG. 4 is a diagram showing an example in which a scintillator is provided on the light incident surface side of an element to serve as a radiation sensor.

FIG. 5 is a model view showing an optical sensor device configured based on the element described in the light detection mechanism in FIGS.

6 is a diagram showing an equivalent matrix circuit when active driving is performed in the device of FIG.

FIG. 7 is a diagram showing an example of an arrangement in the case where a color separation filter is provided on the light incident surface side of the optical sensor device of FIG.

[Explanation of symbols]

1 support 2 Charge generation layer 3 Charge transport layer 4 Organic semiconductor layer 5 Source electrode 6 drain electrode 7 Insulation layer 8 gate electrode 9 scintillator 10 Optical sensor device

Claims (15)

[Claims] 1. A gate electrode, a source electrode and a drain electrode which are located on the support through an insulating layer with respect to the gate electrode and are connected by an organic semiconductor layer, and a source electrode and a drain electrode side. An optical sensor element comprising an insulating layer and a charge generation layer located opposite to the insulating layer. 2. The photosensor element according to claim 1, further comprising a charge transport layer between the organic semiconductor layer and the charge generation layer. 3. The optical sensor element according to claim 1, wherein the organic semiconductor is a π-conjugated polymer compound. 4. The photosensor element according to claim 1, 2 or 3, wherein the support is made of a polymer compound. 5. The optical sensor element according to claim 1, wherein the gate electrode is formed of a transparent conductive film. 6. The photosensor element according to claim 1, further comprising a scintillator on the light incident surface side, which converts radiation having energy higher than ultraviolet energy into visible light. 7. The optical sensor element according to claim 1, further comprising a color separation filter on the light incident surface side. 8. A plurality of gate electrodes arranged in parallel on a support, and a plurality of gate electrodes positioned in the direction orthogonal to the gate electrodes via an insulating layer and connected by an organic semiconductor layer. An optical sensor device comprising source electrodes and drain electrodes alternately, and a charge generation layer located opposite to the insulating layer on the source electrode and drain electrode sides. 9. The photosensor device according to claim 8, further comprising a charge transport layer between the organic semiconductor layer and the charge generation layer. 10. The optical sensor device according to claim 8, wherein the organic semiconductor is a π-conjugated polymer compound. 11. The optical sensor device according to claim 8, wherein the support is made of a polymer compound. 12. The optical sensor device according to claim 8, wherein the gate electrode is formed of a transparent conductive film. 13. The optical sensor device according to claim 8, further comprising a scintillator on the light incident surface side for converting radiation having energy higher than ultraviolet energy into visible light. 14. The optical sensor device according to claim 8, further comprising a color separation filter on the light incident surface side. 15. When driving the photosensor device according to claim 8, the photocurrent of each photosensor element arranged in a direction orthogonal to the gate electrode while applying a bias voltage to the gate electrode. A method for driving an optical sensor device, wherein scanning for detecting a value is sequentially performed on each gate electrode.