JPH11109890A - Plasma address type organic el device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma address type organic EL device with which a highly minute picture with a large area can be realized at a low cost. SOLUTION: This plasma address type organic EL device comprises a plasma address part and an EL element drive part. The address part comprises a substrate 1, walls 2 arranged on the substrate 1, a dielectric layer 3 provided on the walls 2, and plasma channel switches 4 made in the groove between the walls 2. Electrodes 5 for electric capacity and signal electrode lines 7 are provided on the dielectric layer 3, and AT plasma production, the electric capacity produced between the electrode 5 for electric capacity, the signal electrode line 7 and plasma is electrically charged by the voltage applied to the signal electrode line 7. The EL element drive part comprises organic EL element arranged at every address and one transistor which is adjacently in contact with them and energized in response to the charge of the electric capacity to drive the elements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma addressed organic EL (electroluminescence) device suitable as a flat panel display for realizing a large area and high definition image.

[0002]

BACKGROUND ART An organic EL device is a display device that can replace a liquid crystal panel display. This organic EL device
Forming a luminous body thin film made of organic EL on a glass substrate,
It emits light by applying a voltage to the transparent electrode,
It does not require a backlight compared to liquid crystal displays,
It has been developed to realize a high-brightness flat panel display.

[0003] Two types of organic EL devices, a simple matrix type and an active matrix type, are being studied as in the liquid crystal display. FIG. 6 schematically shows a conventional simple matrix type EL device. In the figure,
A large number of anode lines 102 are provided in parallel on a substrate 101, and an organic hole injection layer 105 and an organic light emitting layer 10
4 is provided above the anode line 102.
A large number of cathode lines 103 are provided so as to intersect orthogonally, and the surface thereof is covered with a protective film 106.

In this structure, in order to make one pixel of the XY coordinates emit light, if the anode line 102 is a scanning line in the X direction, one of them is selected and a voltage is applied, and the other line is applied. 0 V or a negative voltage is applied. on the other hand,
A negative voltage or 0 V is applied to one of the cathode lines 103, which is a Y-direction signal line, corresponding to the pixel of the selected line to be made to emit light, and a positive voltage is applied to the cathode line 103, which is a signal line, corresponding to the pixel not to emit light. By applying a voltage and performing the same operation on the next adjacent line, the pixel at the coordinates to be obtained is made to emit light, and a series of raster scans is repeated one after another to display one frame.

Further, a TFT type organic EL device has been proposed as an active matrix type organic EL device. FIG. 7 shows a circuit diagram of the device. In the figure, E
The L element 206 is selected by an active circuit provided for each pixel, and continuously emits light. The active circuit is T
It is composed of two transistors T1 and T2 made of FT and a capacitor Cs for storing electric charges.

In this EL device, when the scanning line Yj is selected and the signal line Xi + 1 is selected at the same time, the element T1 selected at the same time is energized.
Performs electrical storage. Even when the next scanning line Yj + 1 is selected and the element T1 is de-energized, the element T2 can be kept energized by the potential generated by the electric storage of the capacitor Cs, and the EL 206 can be kept emitting light.

[0007]

However, both the simple matrix system and the active matrix system have the following problems. First, in the simple matrix system, as the number of scanning lines increases, the selection time becomes shorter. For this reason, an instantaneous luminance that is several times the number of lines of the average luminance to be driven is required. For example, when the number of lines is 480 in both the X and Y directions and the average luminance is 200 nit (cd / cm ² , the same applies hereinafter), an instantaneous luminance of 96,000 nits per dot is required. Further, the aperture ratio of the pixel is 60-
Since it is 80%, 100,000 nit or more is required, and the organic EL material that can realize this is limited. At present, there are Alq, distyryl arylene, and the like as organic EL materials that realize ultra-high brightness light emission. However, these EL materials have a short life when such instantaneous brightness is required, and can be put to practical use. Did not.

[0008] The magnitude of the current flowing through the scanning line also becomes a problem. For example, a 20 cm square EL having a pixel size of 200 μm square and 1000 × 1000 dots
It has been estimated that a 0.8 A scanning current is required for the device. If the scanning current becomes large, a voltage drop occurs due to the resistance of the scanning line, which results in an increase in current consumption and a non-uniform display of the light emitting device.

On the other hand, in the active matrix system, it is not necessary to cause the EL element to emit light instantaneously, and thereby it is not necessary to realize a super-high luminance, nor does the current of the scanning line become huge, A high-definition light emitting device can be realized. However, a drawback of this EL device is its difficulty in processing. As a semiconductor material used for the transistors T1 and T2, durable polysilicon or silicon single crystal is required to keep the transistor T2 energized. Therefore, production of polysilicon and fine pattern processing are required, which is costly. Further, precisely forming two TFTs per pixel requires a complicated process, which causes a reduction in yield when a large-sized display is realized.

Therefore, it is difficult to realize a flat panel display having a size of 15 inches square or more, which is compatible with a high-definition graphic control chip such as SVGA, XGA, and UXGA standards.
In particular, in the case of the active matrix system, even if it can be realized, it is extremely expensive, and it has been difficult to commercialize it.

An object of the present invention is to provide a plasma addressed organic EL device which can realize a large-area, high-definition image at low cost.

[0012]

The plasma addressed organic EL device of the present invention comprises a plasma address section and an EL element driving section, wherein the plasma address section includes a substrate, a partition provided on the substrate, Dielectric layer provided on the partition, a plurality of inter-partition grooves carved in parallel in the partition,
A plasma channel switch having a plasma-capable gas and at least a pair of plasma-forming discharge electrodes sealed in each of the grooves, and a plasma channel switch on the plasma channel switch; A plurality of signal electrode lines provided orthogonal to the groove; and, when plasma is generated by the plasma channel switch, a voltage applied to the signal electrode line selectively causes a signal electrode line and a plasma to be generated. The EL element driving section is configured to charge the capacitance generated by the organic EL element, and the organic EL element is disposed on the surface of the substrate for each address formed by the intersection of the plasma channel switch and the signal electrode line. And each organic EL
A switching transistor that is adjacent to and connected to the element and is energized in response to the charging of the capacitance and drives the organic EL element.

As described above, in the apparatus of the present invention, the conventional T
Addressing is performed by a plasma channel switch instead of FT. Plasma channel switch
A large number can be provided in a large area at a density corresponding to the pixel formation density, and can be manufactured at low cost.

Further, in the present invention, the electric capacity comprises at least two electric capacities, a first electric capacity and a second electric capacity, and the first electric capacity sandwiches the plasma channel switch and the dielectric layer. Generated between the electrodes for capacitance arranged in the, the second capacitance is generated at a position where the first insulating layer is sandwiched at the intersection of the signal electrode line and the electrode for capacitance, It is preferable that a gate electrode or a base electrode of a switching transistor is connected to the capacitance electrode, and a drain electrode, a collector electrode or an emitter electrode is connected to a lower electrode of the organic EL element.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing one pixel of the EL device according to the present invention, and FIGS. 2 to 4 are cross-sectional views of each part of FIG. In these figures, an EL device includes a substrate 1 made of glass or the like, a partition wall 2 formed on the substrate 1,
A dielectric layer 3 formed on the partition 2, a plasma channel switch 4, which is arranged in parallel in the X direction inside the partition 2 and has an upper surface facing the dielectric layer 3, An apparatus including an electrode for electric capacitance 5 having one end connected thereto, a plurality of signal electrode lines 7 arranged in parallel in the Y direction on the upper end of the electrode for electric capacitance 5 with a first insulating layer 6 interposed therebetween, and an apparatus including the signal electrode line 7 A second insulating layer 8 covering the surface, and by these, the coordinate positions (Xi, Yj), (Xi + 1, Yj + 1) of each pixel orthogonal to the X direction and the Y direction.
And an address portion corresponding to.

In the vicinity of the electrode 5, a square EL element 9 constituting one pixel is arranged on the dielectric layer 3, and the surface is viewed from the second insulating layer 8. A switching transistor 10 of the MOS or TFT type is disposed adjacent to the gate electrode 10. The drain 10 a is connected to the lower electrode of the EL element 9, the source 10 b is connected to the signal electrode line 7, and the gate 10 c is connected to the electrode for electric capacitance. 5
To form an organic EL element driving unit.

Each plasma channel switch 4 has an anode 4a and a cathode 4b opposed to each other at the inner bottom of a groove engraved in the partition wall 2 and whose upper surface is covered with the dielectric layer 3, and is capable of generating plasma inside. A rare gas is sealed. Then, when a voltage is applied between the anode 4a and the cathode 4b, the rare gas becomes plasma. Using the lower surface of the dielectric layer 3 as a virtual electrode, the potential becomes the same as the potential of the anode 4a. At this time, when a voltage is applied to the signal electrode line 7, charges are accumulated in the electrodes 5, and the EL element is held in the ON state by the accumulated charges, and has a function as a switch element.

Further, by the above operation, the first capacitance is stored in the electrode 5 and at the same time, the second insulating layer 6 is used as a dielectric in the overlapping portion of the electrode 5 and the signal electrode line 7. Electric capacity is stored. Thereby, the electrode 5
A potential divided by the first and second electric capacitances is generated, but the electrode 5 is connected to the gate 10c of the transistor 10, the transistor 10 is turned on, and when the transistor 10 is turned on, the source 10b and the drain 10
A low resistance state is established between the points a and the switch is turned on. Therefore, since the lower electrode of the EL element 9 is connected to the signal electrode line 7, light is emitted when an appropriate potential is applied to the opposite electrode of the EL element 9.

When the potential between the anode 4a and the cathode 4b is returned to 0 (zero) from this state, there is no conduction between the anode 4a and the virtual electrode. Even at this time, the state where the electric charge is accumulated in the electric capacity remains, the electrode 5 continues to retain the electric potential, the voltage is applied to the gate 10c of the transistor 10, and the transistor 10 maintains the conducting state. The EL element 9 keeps emitting light. As described above, by repeating the energization of the signal electrode line 7 of the corresponding address while accumulating the electric capacity of the corresponding address by the plasma discharge of the corresponding plasma channel switch 4,
Active matrix driving is performed on the pixel at the corresponding position.

In performing the above driving, there is a case where it is desired to extinguish a pixel at a certain address. At this time, if the anode 4b corresponding to the pixel and the cathode 4b adjacent to the pixel are energized to generate plasma and at the same time 0 potential is applied to the signal electrode line 7, the electric capacity is completely discharged. As a result, the transistor 10 in the corresponding pixel is turned off, and the EL element 9 is turned off.

FIG. 5 is an equivalent circuit diagram corresponding to one pixel of the above EL device. In the figure, when a discharge is performed between the anode 4a and the cathode 4b of the plasma channel switch 4, the sealed gas changes from a ground state to an excited state, plasma is generated, and a portion adjacent to the dielectric layer 3 is used as a virtual electrode G. The same potential as the anode potential is generated at this position. That is, the plasma channel switch 4 becomes conductive.

At this time, when a potential V1 is applied between the signal electrode line 7 and the anode 4a, both the first electric capacity and the second electric capacity are charged. During this charging, the electric capacity electrode 5 has a potential divided by the first and second electric capacities, and the transistor 10 is turned on. On the other hand, a light emitting voltage V2 is applied between the source 10a of the transistor 10 and the opposing electrode of the EL element 9, and the transistor 1
When 0 is applied, the EL element 9 emits light.

In the embodiment shown in the figure, the transistor 10 is a MOS or TFT transistor, but a bipolar transistor can also be used. In this case, the gate may be replaced with one of the base, the source, and the drain as the collector, and the other may be replaced with the emitter.

Next, the material composition of each element constituting the above EL device and the specific processing method will be described item by item.

Plasma address portion: [Substrate] A transparent or opaque smooth substrate having heat resistance is used. The required heat resistance is required to be higher than the temperature applied when providing the partition walls or bonding the dielectric layers. A particularly preferred heat resistant temperature is 5
It is 00 ° C or higher. Preferred materials include blue plate glass, white plate glass, and ceramics.

[Partition] The partition is made of an insulating material and preferably has a height of 100 μm to 500 μm. For this reason,
It is formed by printing a glass paste by screen printing, baking it, or applying the glass paste to the entire surface, then applying a mask on the glass paste surface, and shaving off the non-mask surface by sandblasting. Specific preferred materials include oxide glass. Further, as another preferable example of the method of forming the partition wall, there is a method of forming a groove by etching a glass plate used as the substrate. In this case, partition walls are formed between the grooves.

[Anode and Cathode] A low-resistance metal material is used. Specific preferred materials include Ag, N
i, Pd, Au, Cu and the like. These are provided in metal paste, pattern printed by screen printing,
Then, by firing, a fine line pattern is obtained. The preferred thickness after firing is 1 to 20 μm, and the preferred sheet resistance is 1 mΩ / □ to 1Ω / □. The width after firing is preferably from 10 μm to 300 μm. As another forming method, there is a method in which a metal paste such as an Ag paste is coated on the entire surface, and after baking, a photoresist is provided thereon, exposed and developed to form a patterned mask, etched, and patterned. .

[Plasmaized gas] A preferable gas for plasma conversion is a rare gas, for example, He,
One selected from Ne, Ar, Xe or He-
Ne mixed gas, He-Ne-Ar mixed gas, He-Ne
There is a -Xe mixed gas. Particularly preferably, He having a short plasma duration is recommended. Immediately after the discharge is stopped, the plasma transitions from the excited state to the original ground state, and desirably returns to the non-plasma state, and its duration is 10 μS or less, particularly preferably 5 μS or less.

[Dielectric Layer] As the dielectric layer, glass, ceramic or the like having a thickness of preferably 200 μm or less and 5 μm or more is used. The reason for limiting the film thickness is 200
If it exceeds μm, the above-mentioned first capacitance becomes small, and an appropriate potential is not applied to the gate of the transistor. 5μ
If the thickness is smaller than m, it is difficult to provide a dielectric layer on the entire surface, and the mechanical strength is also reduced. Therefore, it is desirable to set the above numerical range. As a specific glass used for the dielectric layer, there is 50 μm thin glass (commercially available from Shot Corporation, Nippon Electric Glass Co., Ltd.).

[Signal Electrode Line] The signal electrode line is composed of a thin film electrode, and its film thickness is preferably 100 nm to 5 μm. As a material, a sheet resistance of 1 Ω / □ or less can be realized.
l or Al alloy, for example, Al-Si, Al-
Cu, Al-Ti, Al-Mo, Al-W, Al-S
Mo, Mo-T, a kind selected from c, Al-Nd
a alloy, Ta, etc. are preferable. The signal electrode line is preferably provided by sputtering, and is etched by photolithography. Examples of the etching method include wet etching, plasma etching, and RIE (reactive ion etching).

[Electrode for Electric Capacitance] An electrode formed on the inter-partition groove and on the dielectric layer, and is preferably used commonly as an electrode for the first electric capacity and the second electric capacity. It is composed of a groove film metal and has a thickness of 10 nm to 5 μm.
Is preferred. Particularly preferably, it is 10 nm to 1 μm.
The material is Al or an Al alloy, for example, A
l-Si, Al-Cu, Al-Ti, Al-Mo, Al
A kind selected from -W, Al-Sc, Al-Nd;
Mo, Mo-Ta alloy, Ta and the like are preferable, and particularly preferably those capable of being anodized. This is because when the anodization, that is, the cathodic oxidation can be performed, the first insulating layer can be anodized, so that it is not necessary to newly provide an oxide film or the like. If a metal is used, a gate oxide of a transistor can be formed using the metal.

[First insulating layer] An insulating film sandwiched between a signal electrode line or a conductive layer connected to the signal electrode line and an electrode for electric capacitance, and having a withstand voltage of 0.5 MV / cm to 1 MV / cm.
0 MV / cm is required, it is preferable that there is no defect and there is no pinhole. Preferred materials include SiO ₂ ,
SiOx (1 ≦ x <2), SiNx (1/2 ≦ x ≦ 4 /
3), an oxide formed by anodizing one kind selected from SiON, SiAlON, Al, Mo, Ta and an Al alloy or a Mo alloy. Preferred manufacturing methods include sputtering, thermal CVD, and ECR-CV.
D method, ion beam sputtering and the like.

EL element driving section: [Transistor] As a preferred embodiment, a part of FIG.
An enlarged sectional structure of the FT transistor is shown. Materials constituting the semiconductor layer of this transistor include polysilicon, CdSe, CdSiSe, and CdSixSe.
₁₋ x (0 <x <1). When a transistor drives an EL element, a current flowing between a drain and a source becomes 0.1 μA or more, and thus these materials are selected as materials which are not deteriorated by the current. Another preferred material is an all-conjugated polymer (Conjugate).
d Polymer), and particularly preferably selected from polyphenylenevinylene, polyphenylenevinylene and derivatives thereof. Still further preferred organic semiconductors include thiophene-containing oligomers and tetracene derivatives.

Here, among the above conjugated organic semiconductors,
A method for synthesizing polyphenylenevinylene, polychenylenevinylene, and polyarylenevinylene will be briefly described. These synthetic methods are already known, and Polymer 1
990, Vol. 31, 1137, Polym. C
ommun. 1987, Vol. 28, 261, P
1989, Vol. 30, 1041 pages,
And WO92-03490, and also disclosed in Japanese Patent Application Laid-Open No. 1-254,734. The following chemical formula (hereinafter simply referred to as formula) 1

[0035]

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The polymerization reaction is carried out while reacting the monomer (1) shown in the above with an alkali in water / methyl alcohol 1: 1 to obtain a precursor polymer (2). Here, a typical L ¹ is a group represented by Formula 2.

[0037]

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There is a In the formula 2, R ¹ and R ^{2 each} have 1 to 1 carbon atoms.
0 hydrocarbon groups, which may be linked to each other to form an unsaturated ring. X- represents a counter ion consisting of halogen. Ar ^{1 in the} general formula 1 is an aromatic hydrocarbon group or a heterocyclic group having 4 or more carbon atoms. Then, the precursor polymer (2) obtained by the formula 1 is preferably used at 150 ° C to 3 ° C.
By heating at 50 ° C. for 1 to 20 hours, the desired polyarylenevinylene represented by the following formula 3 can be obtained.

[0039]

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Further, in addition to (1) as a starting material, if (1) ′ and (1) shown in the following formula 4 are mixed and subjected to the same treatment, an intermediate represented by the formula 5 is obtained as an intermediate. Obtain body (3).

[0041]

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[0042]

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Here, L ¹ and L ² may be different in the same meaning, and Ar ¹ and Ar ² may be different in the same meaning. When the obtained intermediate (3) is further heated, a copolymer polymer represented by the following formula 6 can be obtained.

[0044]

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At the time of heating, if a small amount of an acid, for example, HCl is added, the reaction proceeds more and the conjugated system is extended.

The gate, drain,
As the source electrode, a normal metal electrode can be used, and the same material as the above-described signal electrode line and the electrode for electric capacity can be used. Therefore, it is desirable that the source electrode be made of the same material as the signal electrode line. This is because both electrodes can be formed in one process. For the same reason, the gate electrode is preferably made of the same material as the capacitance electrode, and the drain electrode is also preferably made of the same material as the lower electrode of the EL element.

It should be noted that in the transistor having the above structure, one of the advantages of the present invention is that, since the selection of the pixel is performed by the plasma channel switch, the transistor is used only for driving the EL element. It is a point. As a result, the ON-OFF ratio, which is the current ratio between the conduction and the non-conduction of the transistor, may be about 10 ² . On the other hand, when an active matrix is composed of two conventional TFTs, the on-off ratio needs to be 10 ⁶ or more. This is because the selection of the luminescent pixel does not last for one frame, and when the organic semiconductor is used, the on-off ratio cannot reach 10 ⁶ or more.

Therefore, the fact that the on-off ratio of the transistor used in the present invention is required to be about 10 ² significantly improves the yield of the active matrix of the present invention, and reduces the use of an organic semiconductor, which has been conventionally difficult to use. It is possible to use.

[Second insulating layer] This is an insulating film for preventing a short circuit between the counter electrode of the EL element, the transistor, and the electrode for electric capacity. Therefore, the same material as that of the first insulating layer can be used, and an organic polymer can also be used. Specific preferred materials include polyimide, polyacrylate, polyamide, polyolefin having a cyclic structure,
Polyquinoline, ladder-type polysilicon and the like are listed. Further, the above organic polymer is preferable because patterning can be performed only by exposing and developing a photosensitive material with a photomask. Specifically, photosensitive polyimide, photosensitive acrylate, and the like are commercially available and can be easily obtained.

[EL Element] Conventionally known organic EL elements and electrodes may be used. Specifically, as a light emitting material,
A green light-emitting material such as a tris (8-hydroxyquinolino) Al complex is provided on the lower electrode in a thin film having a thickness of 10 to 100 nm. Other light emitting materials include distyryl arylene derivatives, polyphenylene vinylene derivatives, and the like. It is preferable to provide a hole injecting layer or a hole transporting layer between the light emitting layer made of such a light emitting material and the anode because further improvement in performance can be expected. Materials used for the hole injection layer and the hole transport layer include triarylamine derivatives and arylamine oligomers. Arylamine derivatives and arylamine oligomers represented by the following formula 7 or 8 are examples of suitable compounds. As the anode,
In-Sn-O oxide, In-Zn-O oxide, SnO
₂ : Sb is preferably used. As the cathode, A
l: Li alloy, Mg: Ag alloy and the like are preferably used.

[0051]

Next, embodiments of the present invention will be described. However, the present invention is not limited only to the following examples.

(Example) [Processing of Substrate, Processing of Plasma Channel Switch] An Ag paste was printed by screen printing on a glass substrate having a length of 32 cm, a width of 40 cm and a thickness of 1.1 mm, and a width of 8
480 thin line lines of 0 μm and pitch of 600 μm were formed. The printing thickness was 12 to 13 μm. Before baking the fine line of the Ag paste, A is printed by screen printing at a distance of 50 μm below the Ag paste line.
A thin line of g paste was printed. The printing thickness was again 12 to 13 μm. The Ag paste used here is NP4028A manufactured by Noritake Company.

Next, the substrate was heated at 150 ° C. in a firing furnace.
After drying for 5 minutes, baking was performed at 550 ° C. for 10 minutes. The line formed first by screen printing is the anode, and the line printed later is the cathode. Next, partition walls were formed by screen printing. A glass paste for partition walls (NP-7853N manufactured by Noritake Company) was printed so that the already formed Ag thin line was located between the partition walls. The partition wall width was 350 μm, the pitch was 600 μm, and the number of partition lines was 481. After drying at 150 ° C. for 5 minutes, the same process was repeated five times. This is because the film pressure per operation is 20 μm. Next, the substrate is heated at 550 ° C.
Firing was performed for 10 minutes in a firing furnace. Partition wall thickness is 150 μm
Met. Next, a thin glass plate having a thickness of 50 μm was bonded onto the partition walls. At the time of bonding, a rare gas He gas was sealed at a pressure of 60 mB. The bonding seal was made of low melting point glass.

[Processing of Electrode on Substrate Surface] Next, a first electric capacity and a gate electrode connected thereto were formed. The substrate after the noble gas sealing is set in a sputtering apparatus, and an Al: Ti (Ti concentration 3 atomic%) thin film is
m was formed. Next, a first insulating film and a gate insulating layer having a thickness of 100 nm were formed as anodic oxidation. As a condition of the anodic oxidation, an electrolyte solution prepared by adding an ammonium aqueous solution to a mixed solution of ammonium tartrate solution and ethylene glycol (1: 9 (volume ratio)) to adjust the pH to 7.0 was used. The substrate was immersed in this electrolyte solution, and an anodic oxidation was performed by applying an applied voltage of 160 V to a portion where oxidation was desired to be formed as an anode and a platinum mesh electrode as a cathode.

The following treatment was performed on the Al: Ti thin film so that a voltage could be applied only to a portion to be oxidized before anodic oxidation. First, patterning of the capacitance electrode and the gate electrode is performed by a photolithographic method, and then the silver paste is screen-printed to a width of 20 mm.
640 lines were printed at 0 μm at a pitch of 600 nm. Silver paste is used as a power supply line during anodic oxidation,
It is connected to the capacitance electrode. After the anodic oxidation, the substrate was immersed in a butyl acetate solution for washing, and the power supply line of the silver paste was removed. Next, signal electrode lines were formed. A as metal used for signal electrode line
1: Using a Ti thin film, the film was formed by sputtering with a thickness of 200 nm. Next, by photolithography, width 80
640 lines having a width of 600 μm and a pitch of 600 μm were formed in a line so as to be perpendicular to the groove direction between the partition walls in plan view.

[Processing of Transistor and EL Lower Electrode] Next, an EL lower electrode, a drain and a source of the transistor were formed. For this purpose, In-Zn-
A conductive oxide material made of O was applied by sputtering to a thickness of 100 nm. Sputtering conditions are as follows: atmosphere gas: argon: oxygen: 1000: 2.8
(Volume ratio), the degree of vacuum was 0.2 Pa, and the sputtering output was 2 W / cm ² . The drain, source, and EL lower electrode were patterned by photolithography. The gate length was 300 μm, and the distance between the drain and the source was 10 μm. Next, a polyphenylene vinylene precursor synthesized in Reference Example described later was spin-coated to obtain a precursor polymer film having a thickness of 50 μm. In this state, the substrate was heated at 250 ° C. for 10 hours to obtain a polyphenylene vinylene film. This film is used as a semiconductor layer of a transistor. Next, a photosensitive acrylate resin (V289 manufactured by Nippon Steel Chemical Co., Ltd.) was spin-coated on the entire surface,
Photosensitive so that only the EL lower electrode portion is an opening,
After development, it was dried. This acrylate resin layer functions as a second insulating layer.

[Processing of EL Element] The substrate obtained by the above steps was placed in a UV / ozone incinerator and treated for 30 minutes. This step was for removing polyphenylene vinylene on the EL lower electrode, and the surface temperature was 130 ° C. After the above pre-processing, TP expressed by the following equation 7
D74 was vacuum-deposited with a thickness of 80 nm, and a TPD represented by the following formula 8 was further vacuum-deposited with a thickness of 20 nm. Where T
PD74 functions as a hole injection layer, and TPD functions as a hole transport layer. Next, a tris (8-hydroxyxynolino) Al complex (Alq) as a green light emitting material was vacuum-deposited at 60 nm. Next, a 200 nm Al: Li (Li concentration 0.5 atomic%) alloy cathode was formed by a vacuum evaporation method. All of them were continuously formed without releasing the vacuum layer into the air.

[0058]

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[0059]

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As described above, the pixel pitch is 600 × 600 μm.
m, Plasma-addressed organic E with 640 × 480 pixels
The main body of the L device was obtained, after which a flat panel cable for external connection was mounted on the main body, a driving device was connected to the main body, and other necessary exterior parts were provided. Thus, a prototype was completed. The dimensions of the main body of the prototype device were 32 cm long and 40 cm wide, almost in the same manner as the starting glass substrate.
m, the thickness is 1.1 mm, and the effective screen is 19 inches.

[Evaluation of Driving of Apparatus] A DC power supply of 150 V as a power supply for plasma generation, a 220 V power supply as a power supply for energizing a signal electrode line, and a 10 V power supply as a power supply for driving an organic EL of the prototype device were prepared. Connected to the device. As a driving method, a plasma is generated in the selected groove, and at the same time, a signal electrode line is selected and the electric capacity 220 is selected.
V was applied. As the second electric capacity, a voltage of 20 V is recorded.

Then, when current was applied to each part, it was visually confirmed that the organic EL element of the selected pixel emitted light with sufficient luminance. The measured value of the luminance was 150 nit. Since the active driving is performed, a luminance of 480 times (the number of lines) is not required instantaneously as compared with a simple matrix. This was confirmed by observing the light emission waveform using a Si photodiode. That is, when the output voltage value of the photodiode whose luminance was corrected was confirmed by a storage oscilloscope, the pixel emitting light showed
It was observed that almost 150 nits were maintained during one frame.

When a simple figure stored in the frame memory connected to the driving device was displayed, it was visually confirmed that the light emission of the figure was uniform and there was no voltage drop due to the signal electrode line. Was. 150ni in a simple matrix drive method with a normal duty of 1/240
The current density for obtaining a brightness of t is at least 1500 m
A / cm ^{2 is} required, and non-uniformity of light emission due to electrode line resistance is a serious problem. On the other hand, in the prototype device, since the current density for obtaining the same luminance was 5 mA / cm ² , there was no problem with the voltage drop due to the electrode resistance, and it was confirmed that the uniformity of the emission luminance was extremely high.

Although the above-mentioned prototype device is processed and manufactured in a manner similar to a manual process in all processes, the size and number of pixels of the device are limited. Can be a larger and higher definition flat panel display. Further, it is of course possible to produce not only monochrome images but also images corresponding to RGB 256-tone color images.

Reference Example Next, a method for synthesizing the above-mentioned polychenylenevinylene precursor will be described. 0.8 g of α-α′-bis (tetrahydrothiophenium chloride) -chenylene was deoxygenated through dry N ₂ . Thereafter, the mixture was ice-cooled, 9 ml of 0.4 Mol NaOH was added, and the mixture was stirred at 0 ° C. for 3.5 hours. This reaction is performed with 0.4 Mol HCl
It was terminated by adding 0.9 ml. The obtained viscous liquid was filtered with a cellulose membrane filter over 4 days with distilled water. Next, vacuum degassing was performed to completely remove the solvent. The obtained product was dissolved in 4 ml of methyl alcohol to obtain a polymer solution represented by the following general formula 9, which is a precursor polymer of polychenylenevinylene, and this polymer solution was used for semiconductor production in the above-described example. .

[0066]

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[0067]

According to the plasma addressed EL device of the present invention, the following effects can be obtained. In an active matrix drive type EL device, one switching transistor may be provided for one pixel, but a large number of plasma channel switches used for addressing can be provided in a large area, so that the structure and manufacturing are simple. It can be manufactured at a low cost and can be adequately applied to a large screen of 15 inches or more and a high-definition flat panel display. Since the selection of the pixel is performed by the plasma channel switch, the transistor is used only for driving the EL element, and the transistor is turned on and off by the current ratio of the conduction to the non-conduction of the transistor.
Since the off ratio is only required to be about 10 ² , the production yield can be greatly improved, and furthermore, for example, an organic semiconductor which is difficult to use conventionally can be used.

[Brief description of the drawings]

FIG. 1 is a plan view showing one pixel of a plasma addressed EL device according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 1;

FIG. 5 is an equivalent circuit diagram of one pixel of the EL device.

FIG. 6 is a schematic perspective view showing a partial cross section of a conventional simple matrix type EL device.

FIG. 7 is an electric circuit diagram of a conventional active matrix type EL device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Partition wall 3 Dielectric layer 4 Plasma channel switch 5 Electrode for electric capacity 6 First insulating layer (dielectric) 7 Signal electrode line 8 Second insulating layer 9 Organic EL element 10 Transistor

Claims (2)

[Claims] 1. A plasma addressing section comprising: a substrate; a partition provided on the substrate; a dielectric layer provided on the partition; and a plasma addressing section provided in the partition. A plurality of grooves between partition walls engraved in parallel, a plasma channel switch having at least a pair of plasma-forming gas and at least one pair of plasma-forming discharge electrodes sealed in each of the grooves, A plurality of signal electrode lines provided orthogonally to the groove between the partition walls in plan view on the dielectric layer, and added to the signal electrode line when plasma is generated by the plasma channel switch. The EL device driver is configured to selectively charge the electric capacitance generated between the signal electrode line and the plasma by the applied voltage. An organic EL element provided for each address formed by an intersection of the plasma channel switch and the signal electrode line,
A plasma-addressable organic device, comprising: one switching transistor that is adjacent to and connected to each organic EL element and is energized in response to charging of the capacitance and drives the organic EL element. EL device. 2. The plasma-addressed organic EL device according to claim 1, wherein the capacitance is at least two capacitances, a first capacitance and a second capacitance, wherein the first capacitance is a plasma channel switch. And a second capacitance is generated at a position where the first insulating layer is sandwiched at the intersection of the signal electrode line and the capacitance electrode, with the second capacitance being generated between the capacitance electrodes arranged with the dielectric layer interposed therebetween. A gate electrode or a base electrode of the switching transistor is connected to the capacitance electrode, a drain electrode,
A plasma-addressed organic EL device, wherein a collector electrode or an emitter electrode is connected to a lower electrode of the organic EL element.