JPH1092201A - Light emitting device, light emitting device driving method, and light emitting device array - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible application of an electrochemical light emitting component (ELC) to a display and provide a light emitting device with its superior characteristics, a driving method of the light emitting device, and a light emitting device array. SOLUTION: A light emitting device 17 of the present invention is comprises a substrate 11, a pair of comb-shaped electrodes 12a and 12b provided on the substrate 11, and a luminescent layer 15 provided into contact with the comb- shaped electrodes 12a and 12b and including a luminescent substance and an electrolyte. The number N of element electrodes 13a and 13b constituting the pair of the comb-shaped electrodes 12a and 12b, a resistance value R(ohm) on both ends in a longitudinal direction of the element electrodes 13a and 13b, and a luminescent area S(cm<2> ) thereof meets a condition of inequality R/N<100/S.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device that emits light by electrochemically injecting carriers into a light emitting layer, a driving method of the light emitting device, and a light emitting device array.

[0002]

2. Description of the Related Art An organic EL device is a self-luminous type light emitting device, and can freely change the emission color in principle. Because this full-color display is possible and it is possible to form a light-weight, thin, and large-area light-emitting surface,
It is expected to be applied to displays.

In the injection type EL device conventionally known as the organic EL device, carriers (electrons and holes) are injected from an electrode into an organic light emitting layer or an organic charge transport layer by a tunnel process or a Schottky process. . However, the injection efficiency was insufficient, and it was difficult to obtain sufficient luminance. In order to improve the charge injection efficiency, a work function of Ca having a small work function as an electrode material,
It is only necessary to use a metal with low durability such as Mg or Li, or to drive at a high voltage.
The deterioration of the element progresses rapidly, such as microscopic peeling of the interface of the organic light emitting layer and formation of a dark spot due to oxidation of the electrode, which is impractical.

An electrochemiluminescent device (hereinafter, referred to as an ECL device) has been devised by Heeger et al. As a solution to such a drawback of the injection type EL device.
This ECL element uses a light-emitting layer composed of a mixture of an organic light-emitting material and an electrolyte, etc., instead of the organic light-emitting layer and the organic charge transport layer of the conventional injection-type EL element, and this is disposed between a pair of electrodes. It is arranged so as to be in contact with the surface.
When an appropriate voltage is applied to this ECL element, the electrolyte is ionized, and an electric double layer is formed at the interface between the electrode and the light emitting layer. As a result, a high electric field is applied to the interface between the electrode and the light emitting layer, and the injected charges are compensated by the ions near the electrodes, so that the injection of the charges can occur very easily.
Therefore, a highly durable metal such as platinum can be used as an electrode material, and a long element life and sufficient luminance at a relatively low voltage can be obtained.

[0005] However, the ECL element is still in the research stage, and many problems remain as described below for its practical use, particularly for application to displays and the like.

The light emission of the ECL element is formed by forming an electric double layer near the electrodes as described above, forming electrons and holes from the anode and the cathode until the electrons and holes are injected and accumulated in the light emitting layer, and then forming the electrons and holes respectively. Hopping towards the opposite pole and recombining in the recombination region. When the electric double layer is formed, an electric field is less likely to be applied to the light emitting layer, so that electrons and holes injected into the light emitting layer have to move due to thermal diffusion. Therefore, in order for electrons and holes to recombine in the recombination region, a concentration gradient of electrons and holes must be formed in the light emitting layer. However, in order for the concentration gradient of electrons and holes to be sufficiently formed, they must be electrically compensated. That is, it is necessary to form an ion concentration gradient corresponding to the electron and hole concentration gradients. However, the formation of the ion concentration gradient is very time-consuming because it is limited by the ion diffusion speed, as in the diffusion of electrons and holes. Further, once the application of the voltage is stopped for the concentration gradient of the formed ions, the ions are uniformly dispersed in the light emitting layer with the lapse of time, and the concentration gradient eventually disappears. For this reason, a startup time of about several minutes is required from the application of the voltage to the start of light emission, which is impractical for use as a display.

[0007] Further, in this ECL element, when the application of the voltage is stopped from the lighting state and the voltage is immediately applied again, the response speed from the re-application of the voltage to the light emission is as low as several milliseconds. The range of application as a display was narrowed.

Further, since the ECL element is a current driving element, when a comb-shaped electrode is used as an electrode, the effect of the voltage drop caused by the resistance of the comb-shaped electrode is large, and the unevenness of the luminance, the increase of the applied voltage, and the power consumption are reduced. Invites an increase. Also,
The element life realized by the conventional ECL element is still insufficient, and it is desired to further improve the element life for widespread practical use.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a light emitting device having a short rise time and a high response speed.

Another object of the present invention is to provide a high response speed,
It is an object of the present invention to provide a light-emitting element with improved luminance, no increase in applied voltage, and a long element life.

It is still another object of the present invention to provide a method for driving a light emitting element which can increase the response speed.

It is still another object of the present invention to provide a light emitting element array which can be applied to a display.

[0013]

In order to solve the above problems, the present invention (claim 1) provides a pair of electrodes and a light emitting layer provided between the pair of electrodes and containing a light emitting substance and an electrolyte. Wherein the electrolyte is a salt composed of a cation and an anion each having a molecular weight of 200 or more.

The present invention (Claim 2) is characterized in that in the light emitting device (Claim 1), the electrolyte is a solid electrolyte comprising a complex of a matrix and a salt.

The present invention (Claim 3) comprises a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a luminescent substance and an electrolyte. , The number N of elementary electrodes constituting the pair of comb electrodes
(Book), resistance value R at both ends in the longitudinal direction of the elementary electrode
(Ohms) and the luminescent area S (cm ² ) are inequality R
A light-emitting element characterized by satisfying a relationship of / N <100 / S is provided.

The present invention (claim 4) comprises a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a luminescent substance and an electrolyte. And a light-emitting element, characterized in that the thickness of the element electrode constituting the comb-shaped electrode in the direction perpendicular to the substrate surface is 0.5 μm or more.

The present invention (claim 5) comprises a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a luminescent substance and an electrolyte. And a light-emitting element characterized in that the surface of the elementary electrode constituting the comb-shaped electrode is electrically conductive and porous.

The present invention (claim 6) comprises a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a light-emitting substance and an electrolyte. In the driving method of the light emitting element, an average voltage of 10 to 90% per unit time with respect to the driving voltage is applied to the pair of comb-shaped electrodes in the same direction as the driving voltage when the light is not emitted. Provide a way.

The present invention (claim 7) provides a light emitting device comprising: a substrate; a pair of comb-shaped electrodes provided on the substrate; and a light-emitting layer provided in contact with the comb-shaped electrode and containing a luminescent substance and an electrolyte. In an active matrix type light emitting element array in which unit pixels composed of current control transistors and capacitors are arranged in a matrix, N rows,
A source electrode of a current control transistor in M columns and one electrode of a capacitor are connected to N rows of scan electrode lines, and one comb electrode of a light emitting element of the unit pixel is connected to a drain electrode of the current control transistor. The other comb-shaped electrode of the light-emitting element is connected to a signal electrode line in a column different from the M column.

The present invention (claim 8) provides a light emitting device comprising: a substrate; a pair of comb-shaped electrodes provided on the substrate; and a light-emitting layer provided in contact with the comb-shaped electrode and containing a luminescent substance and an electrolyte. In an active matrix type light emitting element array in which unit pixels composed of current control transistors and capacitors are arranged in a matrix, N rows,
One of the comb-shaped electrodes of the light-emitting element of the unit pixel is connected to the drain electrode of the current control transistor of the M-column unit pixel, and the other comb-shaped electrode of the light-emitting element of the unit pixel and N rows;
A light-emitting element array is provided in which the other comb-shaped electrodes of the light-emitting elements of the unit pixels in the (M + 1) column are connected to each other.

The present invention (claim 9) is characterized in that in the light emitting element array (claim 8), the other comb-shaped electrodes of the light emitting elements adjacent in the signal electrode line direction are connected to each other. I do.

The present invention (claim 10) provides a light emitting device comprising: a substrate; a pair of comb-shaped electrodes provided on the substrate; and a light-emitting layer provided in contact with the comb-shaped electrode and containing a luminescent substance and an electrolyte. In a simple matrix type light emitting element array in which unit pixels composed of a current control transistor and a capacitor are arranged in a matrix, scanning electrode lines and signal electrode lines intersect on the same substrate via an insulating layer. A light emitting element array is provided, wherein the light emitting element is connected to the scanning electrode line and the signal electrode line via a contact hole.

Hereinafter, the light emitting device of the present invention will be described in more detail.

The ECL element has a light emitting layer made of a mixture of a light emitting substance and an electrolyte sandwiched between a pair of electrodes.

The light-emitting substance contained in the light-emitting layer is not particularly limited as long as it is an organic light-emitting material that emits fluorescence in the visible light region and the ultraviolet light region, but aromatic conjugated polymers such as polyparaphenylene and polyacetylene. Aliphatic conjugated polymers, polycyclic, heterocyclic conjugated polymers such as polythiophene, heteroatom-containing conjugated polymers such as polyaniline,
Composite conjugated polymers such as polyphenylenevinylene, and polysilane-based conjugated polymers are preferably used.

The electrolyte used in the present invention is a salt containing a cation and an anion. Examples of the cation include alkali metal ions such as Li ⁺ , Na ⁺ , K ⁺ , Rb ⁺ , and Cs ⁺ , and Mg ^{2. +} , Ca ²⁺ , Sr ²⁺ , alkaline earth metal ions such as Ba ²⁺ , lanthanoid ions such as Eu ²⁺ , R ₄ N ⁺ , R ₄ P ⁺ , R ₄ As ⁺ , R ₃
Included organic ions such as S ⁺ and acetylcholine, and noble metal ions such as Ag ⁺ are used. The anions include Cl ⁻ , Br ⁻ , I ⁻ , ClO ₄ ⁻ , P
F ₆ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , BF ⁻ , CF ₃ SO
₃ ⁻ , ClSO ₃ ⁻ , FSO ₃ ⁻ , SO ₄ ²⁻ , N
O ₃ ⁻ , F ^{− and the} like can be used.

The ratio of the luminescent substance to the electrolyte is 10
It is preferably from 90 to 90% by weight, more preferably from 20 to 80% by weight, and most preferably from 40 to 70% by weight.

The above-mentioned electrolyte can be used in the form of a so-called solid electrolyte, which is a complex with a matrix capable of dissolving and dissociating the electrolyte and generating carriers. The organic or inorganic matrix can be contained in an amount of 10 to 90% by weight based on the light emitting layer. Examples of the organic matrix include compounds having a polyether skeleton such as polyethylene oxide and polypropylene oxide represented by the following chemical formulas 1 and 2;
And compounds having a polyester skeleton such as polyethylene succinate and poly-β-propiolactone represented by 4 and 4; compounds having a polyamine skeleton such as polyethyleneimine represented by the following chemical formulas 5 and 6; It is preferred to be composed of a compound having a polysulfide skeleton such as a polyalkylene sulfide, a compound having a polysiloxane skeleton, a compound having a polyphosphazene skeleton, and the like.

[0029]

Embedded image The polyether may be an amorphous polymer represented by the following chemical formulas 8 to 20.

[0030]

Embedded image

Embedded image In addition, the polyether is represented by the following reaction products of Chemical Formulas 1 to 5 and Chemical Formulas 21 to 23,
An amorphous polyether crosslinked product while maintaining the mechanical strength may be used.

[0031]

Embedded image

Embedded image As the inorganic matrix, metal oxides and inorganic glasses can be used.

When the electrolyte is used in the form of a solution, the light emitting layer of the light emitting device of the present invention may contain 10 to 90% by weight of a solvent. When the potential window of the solvent is narrower than the oxidation and reduction potentials of the luminescent substance, the oxidization or reduction of the solvent occurs preferentially, so that no light emission is observed. Therefore, it is desirable that the potential window of the solvent is wider than the oxidation and reduction potentials of the luminescent material. In addition, this solvent needs to dissolve the electrolyte and the luminescent material and ionize the electrolyte. Therefore, the relative dielectric constant ε _r of the solvent is preferably 20 or more. As the solvent, methanol, ethanol, 1-propanol, 2-propanol, tetrahydrofuran, 1,4-dioxane, monoglyme (1,2
-Dimethoxyethane), acetone, 4-methyl-2-pentanone, acetylacetone, acetonitrile, propionitrile, ammonia, ethylenediamine, pyridine, formamide, N-methylformamide, dimethylformamide, dimethylacetamide, hexamethylphosphoramide, N- Methylpyrrolidone, dimethylsulfoxide, sulfolane, nitromethane, nitrobenzene,
Examples include dichloromethane, propylene carbonate, ethylene carbonate, acetic acid, acetic anhydride, 1,2-dichloroethane, benzonitrile and the like.

The light emitting layer may include a porous polymer thin film such as polyethylene, polyacrylonitrile, and polypropylene, in addition to the light emitting substance and the electrolyte.
When this porous polymer thin film is used, the element can be suitably sealed because the electrolyte solution can be impregnated and the solution can be made into a gel.

As described above, in order to cause the ECL element to emit light, it is necessary to form a concentration gradient of these ions in the light emitting layer. The inclination disappears. The present inventors have found that when an electrolyte having a molecular weight of each of the cation and the anion of 200 or more is used, the concentration gradient of the ions in the light emitting layer can be maintained.

The molecular weight of each of the cation and the anion is preferably 500 or more, more preferably 3,
000 or more, more preferably 100,000 or more. The upper limit is not particularly limited, but is usually 5,0.
Not more than 00,000.

The molecular weight of the polymer compound in the present invention indicates a weight average molecular weight.

When an electrolyte having such a counter ion having a molecular weight is used, since the molecular weight of the ion is large, the diffusion speed of the ion in the light emitting layer is slowed down. Thereafter, the concentration gradient can be maintained. Therefore, the rise time from the application of the voltage to the start of light emission is shortened, and the response speed is improved.

As described above, the concentration gradient of ions can be maintained, but the ions used in the light emitting device of the present invention have a large molecular weight of 200 or more and a low diffusion rate in the light emitting layer. It is difficult to form a concentration gradient by applying a voltage to the substrate. Therefore, instead of using ions having a high molecular weight from the beginning, a mixture containing an electrolyte consisting of an ion pair each having a reactive functional group or a reactive site and preferably having a molecular weight of 200 or less and a luminescent substance is used. Forming, forming a light emitting layer made of the above mixture so as to be in contact with the electrode pair, applying a voltage to the light emitting layer, and then reacting the ions, thereby forming a concentration gradient of ions in the light emitting layer. .

That is, first, it is possible to cause self-polymerization, bonding with a luminescent substance, bonding with a matrix, or bonding reaction with other substances contained in the luminescent layer by heating or light irradiation. Then, a cation and an anion having a sufficiently small molecular weight so as to be able to move in the light emitting layer by applying a voltage are mixed with the light emitting substance. Next, if necessary, an organic or inorganic matrix, a solvent, a plasticizer, or the like is further added to the mixture, and the mixture is applied so as to be in contact with the electrode pair to form a light emitting layer. Further, a voltage is applied to the light emitting layer by the electrode pair or the external electrode to form a concentration gradient of ions in the light emitting layer. While this concentration gradient is maintained, treatment such as heating or light irradiation is performed to activate the reactive sites of the ions in the light emitting layer, self-polymerize the ions, bond with the light emitting substance, and react with the matrix. Or a binding reaction with other substances contained in the light emitting layer to cause the ion to have a molecular weight of 200 or more.

According to this method, an ion concentration gradient can be easily formed in the light emitting layer, and the ion concentration gradient can be fixed, so that a device having good startup and response can be manufactured. . The molecular weight of the ions used here is desired to be small enough to be able to move in the light-emitting layer by application of a voltage, but it is sufficient if it is 300 or less, preferably 200 or less.
More preferably, it is 120 or less. In addition, examples of the reactive functional group include a hydroxyl group, a silanol group, an alkoxy group, an alkoxysilyl group, a hydrosilyl group, an amino group, a carbonyl group, an aldehyde group, a carboxyl group, a cyano group, a vinyl group, and an epoxy group. . As the reactive site, a carbon-carbon double bond, a carbon-carbon triple bond,
And an ester bond. In this method, for example, cations represented by the following chemical formulas 24 to 27 can be used as cations having a reactive site.

[0041]

Embedded image As the anion having a reactive site, for example, anions represented by the following chemical formulas 28 to 30 can be used.

[0042]

Embedded image In this formula, R represents an alkyl group, R = CH ₃ , C
₂ H ₅ , C ₃ H _{7 and the} like. Each R may be the same or different.

The electrodes used in the ECL element include a parallel plate electrode and a comb electrode. A parallel plate electrode is one in which a pair of plate electrodes are arranged in parallel with a light emitting layer interposed therebetween. The term “comb-shaped electrode” refers to an arrangement in which a pair of comb-shaped electrodes are combined and arranged such that the elementary electrodes forming the teeth of one electrode enter between the elementary electrodes of the other electrode.

When parallel plate electrodes are used, it is preferable that at least one of the electrodes is a transparent or translucent electrode. The distance between the electrodes is uniform in the plane, and is 0.0
It is preferable that it is kept at 1 to 50 μm.

When a comb-shaped electrode is used, a pair of comb-shaped electrodes must be arranged on a substrate. In that case, examples of the substrate include glass, ceramics, hard plastic, and a semiconductor substrate. The use of a transparent substrate is preferable because light emission can be extracted from the substrate side.

Since the ECL element is a current-driven type light emitting element, it has a current control transistor for one pixel and a first-stage transistor for applying a voltage to its gate.
One is needed. Further, in order to supply a sufficient current, a thicker electrode line is required as compared with a voltage-driven array. Therefore, when light is extracted from the transparent substrate side using a transparent substrate such as a glass substrate, the aperture ratio is reduced by the two transistors and the electrode wires. On the other hand, when a semiconductor substrate such as silicon is used, a transistor can be formed on the semiconductor substrate, and light emission can be extracted from a direction opposite to the substrate surface. .

As the material of the electrodes, Pt, Au, Pd,
Ag, Hg, Cu, Pb, Sn, Ni, Co, Ti, I
n, Cd, Fe, Ga, Cr, Zn, V, Mn, Ce,
Al, Nd, Mg, Na, Ca, Sr, Ba, K, R
Examples include metals such as b, Cs, W, and Li, alloys containing these metals, and carbon.

When a comb-shaped electrode is used as an electrode, the characteristics of the light-emitting element vary greatly depending on the shape and material of the electrode. The present inventors set the number of element electrodes constituting the comb-shaped electrode pair to N
(Book), the resistance value at both ends in the longitudinal direction of the elementary electrode is R
(Ohms) and the light emitting area is S (cm ² )
It has been found that when R.S / N is less than 100, particularly excellent device characteristics can be obtained. This R / S /
N is substantially proportional to the product of the average value of the resistance in the longitudinal direction of each element electrode constituting the comb-shaped electrode and the light emitting area per element electrode. As this value is smaller, the voltage drop due to the resistance of the comb-shaped electrode is less likely to occur, so that it is possible to make it difficult to cause uneven brightness, increase in applied voltage, and increase in power consumption, and further reduce the response speed. Therefore, it is possible to prevent the element life from being shortened due to an increase in voltage application. This range is preferably R.S / N <100, more preferably R.S / N <30, and even more preferably R.S / N <3.

Further, the surface distance d (μ
m) and the height h (μm) of the element electrode constituting the comb-shaped electrode in the direction perpendicular to the substrate is h / d> 0.1,
It is possible to improve the luminance, reduce the applied voltage, shorten the response speed, and improve the element life. This range is preferably h / d> 1. This is for the following reason.

Of the lines of electric force connecting the adjacent element electrodes, the lines of electric force connecting the surfaces of the opposing element electrodes perpendicular to the element electrode surface are the shortest, and the holes and electrons are the same in the light emitting layer. It is thought that it moves by hopping along.
Therefore, if the height h is increased and the surface distance d is reduced,
Since many holes or electrons pass through the shortest distance, the response speed is shortened, the luminous efficiency is improved,
Brightness is improved.

When the height h increases, the electrode area per substrate area increases, and when the surface distance d decreases, the accumulation of electrons and holes required for light emission can be reduced, so that the applied voltage can be reduced. And the element life is improved. However, since the interplanar spacing d of the comb electrodes is about 5 μm, this is equivalent to increasing the height h. That is, the height h should be 0.5 μm or more, and more preferably 5 μm or more. When the height of the elementary electrode is in this range, the electrode area per substrate area increases, and the current density at the electrode interface is reduced. Further, the width of the element electrode in the direction perpendicular to the surface facing the adjacent element electrode can be shortened without reducing the surface area of the element electrode, and the electrode use efficiency per substrate area can be increased.

When a comb electrode is used as the electrode, the elementary electrode is
It is preferable that the surface is covered with an electrically conductive porous material such as platinum black or polyaniline. The effective area of the comb-shaped electrode of the ECL element is defined by the height, width, electrode spacing, and the like of the element electrodes. The emission luminance of the ECL element is almost proportional to the current flowing through the element. Decreases exponentially with the increase of. Therefore, increasing the effective area of the comb-shaped electrode improves the life characteristics of the element. It is preferable that the surface of the elementary electrode is covered with an electrically conductive porous material, because the surface area capable of performing an electrochemical reaction is increased, and the effective area is substantially increased.

When a solid electrolyte is used as the electrolyte, the ECL element is prepared by dissolving a mixture of a luminescent material and a solid electrolyte in the above-mentioned solvent and subjecting the mixture to a method such as spin coating, casting, dipping, bar coating, or roll coating. The light-emitting layer is formed by coating on the comb-shaped electrode and the substrate by using. After forming this light emitting layer, the solvent may be removed by drying. When a solution electrolyte is used as the electrolyte, the light emitting layer can be formed by a method such as casting or dipping.

Generally, the ECL element on which the light emitting layer is formed is covered with a moisture-proof sheet. As the moisture-proof sheet, a metal foil such as aluminum or a metal laminated film made of aluminum and polyethylene can be used. When sealing the ECL element using a moisture-proof sheet, it is preferable to use a hot-melt sealing material. Silica powder, molecular sieve, nylon-6, and nylon 6,6
It is more preferable to include a hygroscopic agent such as a superabsorbent resin powder.

The thus obtained ECL device of the present invention is usually driven by a DC voltage of about 0.5 to 10 V,
It indicates a current value of 0.1 to 1,000 mA / cm ² ,
It shows a light emission luminance of about 05 to 10,000 cd / m ² .
Further, the emission color can be freely adjusted by selecting light-emitting materials having different emission wavelengths.

When the ECL element is driven, it is preferable to apply an average voltage of 10 to 90% per unit time with respect to the driving voltage when light is not emitted, and more preferably 30 to 80%. When the above voltage is applied during non-emission, the concentration gradient of ions in the light-emitting layer formed during emission is maintained, holes and electrons are supplied, and depletion of the recombination region can be prevented. Can greatly improve the response speed. The voltage applied during non-light emission is 10% of the drive voltage
In the following cases, the ion concentration gradient cannot be sufficiently maintained, the recombination region is depleted, and if it exceeds 90%, the light emitting element is deteriorated. It is not preferable because the contrast between the adjacent light emitting elements is reduced. The applied voltage is not necessarily required to be a constant voltage as long as it is in the same direction as that during driving, and may be changed periodically.

The ECL elements described above, particularly the ECL elements using comb electrodes, can be arranged in a matrix to form a light emitting element array. When incorporated into an array and applied to a display in this way, the EC
Since the L element has a longer element life than the conventional injection type EL element, it is considered that the L element is used for an application that is driven continuously for a long time. In this case, high durability is required,
It is necessary to minimize defects caused by disconnection or short circuit, but since this ECL element is a current-driven element, the load on the circuit is greater than that of a voltage-driven element.
Disconnection or short circuit is likely to occur. Further, if the resistance of the circuit itself is high, the luminance characteristics of the display are reduced. Accordingly, it is desired to reduce the resistance of the circuit itself and the number of intersections of wirings, improve the luminance characteristics, and reduce the incidence of defects generated when driving the light emitting element array.

When an ECL element using a comb-shaped electrode is arranged in a matrix along with a current control transistor and a capacitor to form an active matrix type array, an ECL element connected to the drain electrode of the current control transistor is used. It is preferable to connect the other end of the electrode to a signal electrode line different from the signal electrode line to which the first-stage transistor connected to the gate electrode of the current controlling transistor is connected.

In a normal active matrix type array, one electrode of an ECL element is connected to the ground for each element. The ground line is usually arranged parallel to the signal electrode line or the scan electrode line, but such an arrangement requires that the ground line intersect the signal electrode line or the scan electrode line. Further, in the array, in addition to the signal electrode lines and the scanning electrode lines, further ground lines exist, so that the entire length of the long wiring is required.

On the other hand, in the light emitting element array of the present invention, one electrode of the ECL element is connected to the signal electrode line, and the signal electrode line also serves as the ground line. Since it is not necessary to provide a ground line separately from the scanning electrode line, the total length of the wiring and the number of intersections thereof can be reduced, and the incidence of defects due to disconnection, short circuit, and the like can be reduced.

When a forward diode is inserted between the ECL element and the signal electrode line or between the ECL element and the current control transistor, the light-emitting elements in the non-selected pixels are reversely biased, so that a recombination region is formed. This is preferable because it is possible to prevent depletion of the semiconductor element and prevent a reduction in response speed and a deterioration in element performance.

Further, among a pair of comb-shaped electrodes of two light emitting elements adjacent in the scanning electrode line direction, electrodes different from the electrode connected to the drain electrode of the current control transistor may be connected to each other. .

In a normal active matrix type light emitting element array, one electrode of the ECL element is separately connected to the ground via a contact hole for each element. In particular, when the light emitting element array is of a type that extracts light from the substrate side, it is necessary to make the ground line thin in order to increase the aperture ratio, and the resistance value of the ground line tends to increase.

On the other hand, according to the present invention, since one electrode of the ECL element is connected on the same layer as one electrode of the ECL element adjacent in the scanning electrode line direction, the supporting portion for supporting each element electrode is provided. It can be used as a ground line, and the cross-sectional area perpendicular to the longitudinal direction of the support can be increased. Therefore, it is possible to reduce the resistance of the wiring connecting the ECL element and the ground, and it is possible to reduce the voltage drop and the electrode deterioration due to the resistance of the wiring and increase the current density.

According to the present invention, when light is extracted from the substrate side, the support portion of the element electrode functions as a ground line, so that it is not necessary to provide a separate ground line, so that a normal light emitting element array can be used. Compared with this, the decrease in the aperture ratio is small, and the entire substrate surface can be used as the light emitting surface.

When this light-emitting element and the other light-emitting element adjacent to the light-emitting element in the signal electrode line direction are connected to the other end of the electrode connected to the drain electrode of the current control transistor, the wiring is further reduced. This is preferable because voltage drop and electrode deterioration due to resistance can be reduced and current density can be increased.

With this connection, the ground lines are wired not only in the scanning electrode line direction but also in the signal electrode line direction, so that a ground line network is formed, and the resistance of the wiring is further reduced. . Therefore,
Since a voltage drop is unlikely to occur and a high contrast can be obtained, it is particularly effective when a part of a dark part is brightly displayed.

Even in such a connection, if a forward diode is inserted between the ECL element and the current control transistor, the light-emitting elements in the non-selected pixels are reverse-biased to deplete the recombination region. This is preferable because it is possible to prevent a reduction in response speed and a deterioration in element performance.

When a display is manufactured by incorporating this ECL element into a simple matrix type array, it is necessary to reduce the resistance of the circuit as described above, so that the scanning electrode lines and signal electrode lines have a sufficient thickness. However, in a normal light emitting element array, not all light emitting element arrays are light emitting surfaces due to the thick scanning electrode lines and signal electrode lines. Therefore, the light emitting area of the light emitting element array is reduced. In addition, since not all light-emitting element arrays are light-emitting surfaces, in a normal array, it is necessary to manufacture light-emitting elements, then incorporate the light-emitting elements into the array, and make electrical connections from the light-emitting surface side, which complicates the manufacturing process. , Which is one cause of increasing the manufacturing cost. Such a high manufacturing cost may prevent the light emitting element array using the ECL element from being used for inexpensive equipment, and may be one of the causes of narrowing the range of application as a display. Therefore, it is desired to increase the light emitting area in the light emitting element array and to simplify the manufacturing process.

When constructing a simple matrix type light emitting element array using ECL light emitting elements using comb-shaped electrodes, scanning electrode lines and signal electrode lines intersect on the same substrate via an insulating layer. When each light emitting element is connected to the scanning electrode line and the signal electrode line via the contact hole, it is possible to form a light emitting layer after forming a wiring and a comb-shaped electrode in the array. Therefore, the manufacturing process can be simplified, the manufacturing cost can be reduced, and the reduction of the light emitting area by the scanning electrode and the signal electrode can be prevented, so that the substrate surface can be used effectively.

[0071]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a specific structure of a light emitting device according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view schematically showing a light-emitting element using a comb electrode according to one embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes an insulating substrate, and a pair of comb-shaped electrodes 12
a and 12b are installed in combination with each other at predetermined intervals. A light emitting layer 15 is provided on the substrate 11 and the pair of electrodes 12a and 12b, and a light emitting element 17 is configured.

The comb electrodes 12a and 12b are composed of a large number of element electrodes 13a and 13b arranged in parallel with each other, and a support portion 14a for supporting one end of each element electrode 13a and 13b.
14b. The elementary electrode 13a of one comb-shaped electrode 12a and the elementary electrode 13b of the other comb-shaped electrode 12b are:
They are arranged alternately so as to engage each other. A predetermined voltage is applied by a power supply 16 between the support portions 14a and 14b of the comb electrodes 12a and 12b.

FIG. 2 is a perspective view showing a light emitting device using parallel plate electrodes according to another embodiment of the present invention.

In the light emitting device 25 shown in FIG. 2, a pair of plate electrodes 21 and 22 are arranged to face each other in parallel.
The light emitting layer 23 is sandwiched between them. Plate electrode 2
A predetermined voltage is applied between the first and the second 22 by the power supply 24.

FIG. 3 is a perspective view showing another example of the electrode. In this example, the electrodes 31 and 32 are arranged in a right-angle spiral combination, and a power supply 33 is provided between the electrodes 31 and 32.
, A predetermined voltage is applied.

Hereinafter, various examples and comparative examples of the present invention will be described.

[0079]

【Example】

(Example 1) First, a platinum film having a thickness of 10 nm is laminated on a glass substrate 11 by a sputtering method. Next, a resist having a predetermined pattern is formed on the platinum film, and a reaction is performed using the resist as a mask. The platinum film was etched by reactive ion etching (RIE) to form a pair of comb electrodes. Subsequently, on this glass substrate and a pair of comb-shaped electrodes, 1 g of a luminescent substance represented by the following chemical formula 31 and 0.1 g of an electrolyte composed of a cation and an anion represented by the following chemical formulas 32 and 30, respectively: A solution of 0.1 g of polysiloxane represented by the following chemical formula 33 and a solution of 10 mg of aluminum triisopropoxide in methylene chloride were applied in argon gas, and left at 80 ° C. for 5 hours while applying a voltage of 3 V between the electrodes. For 1 hour to obtain a light-emitting element.

[0080]

Embedded image The elementary electrodes of the comb-shaped electrode of the light-emitting element obtained as described above are 10 mm in length, 5 μm in width, and 10 nm in height, and are arranged in parallel so that the distance between opposing surfaces is 15 μm. Form a row. In addition, the pair of comb-shaped electrodes was set so that the surface interval between the opposing element electrodes was 5 μm. It was confirmed that the cation and the anion in this light emitting layer each had a molecular weight of 200 or more.

Example 2 A light emitting device was manufactured in the same manner as in Example 1 except that 50 mg of polysiloxane was used and 0.1 g of polyethylene oxide was used as an organic matrix. It was confirmed that the cation and the anion in the light emitting layer each had a molecular weight of 200 or more.

Comparative Example 1 A light emitting device was manufactured in the same manner as in Example 1 except that lithium trifluoromethanesulfonium (LiCF ₃ SO ₃ ) was used as an electrolyte.

Comparative Example 2 A light emitting device was manufactured in the same manner as in Example 2 except that lithium trifluoromethanesulfonium was used as the electrolyte.

For each of the light emitting devices manufactured as described above, the rise time and the response speed were measured. The rise time was measured by measuring the time required for lighting when a voltage of 3 V was applied, and the response speed was measured at a constant current of 10 mA, and the comb electrodes were short-circuited for 1 minute. When the application of the voltage was started immediately, the time was measured from the reapplication of the voltage until the luminance reached 90% of the luminance when the device was driven at a constant current of 10 mA. Table 1 shows the results.

[0085]

[Table 1] As is clear from Table 1, the conventional light-emitting elements shown in Comparative Examples 1 and 2 take several minutes from application of a voltage to light emission, whereas the light-emitting elements according to the present invention shown in Examples 1 and 2 are , The light emission starts almost simultaneously with the application of the voltage. Regarding the response speed, the conventional light emitting device requires several milliseconds, whereas the light emitting device according to the present invention requires 1/1 times the required speed.
Only about 0 times are needed. Therefore, according to the present invention, the start-up time can be reduced and the response speed can be increased.

In the first and second embodiments, the case where a comb-shaped electrode is used as an electrode has been described. However, similar effects can be obtained when the electrodes shown in FIGS. 2 and 3 are used.

(Embodiment 3) FIG. 4 shows an enlarged view of a comb-shaped electrode used in a light emitting device according to this embodiment.

In FIG. 4, the surface surrounded by the broken line is
The light-emitting surface of this light-emitting element has an area of S (c
m ² ). The height 47 of the elementary electrode is h (μ
m), and the inter-electrode distance 48 is represented by d (μm).

The light emitting device according to this embodiment has
Assuming that the resistance in the longitudinal direction of a and 43b is R (ohm) and the number of elementary electrodes 43a and 43b in the range surrounded by the broken line in FIG. 4 is N (number), the inequality R · S / N <100 The relationship is shown in ohm · cm ² .

The light emitting device according to this example was manufactured as follows.

First, a platinum film having a thickness of 10 nm was laminated on a glass substrate by a sputtering method. Next, a resist having a predetermined pattern is formed on the platinum film, and the platinum film is etched by reactive ion etching (RIE) using the resist as a mask. As shown in FIG.
a and 42b were formed. Subsequently, on this glass substrate and the comb electrodes 42a and 42b, 1 g of a luminescent substance represented by the following chemical formula 34, 0.15 g of lithium trifluoromethanesulfonium, and 0.85 g of polyethylene oxide
g of methylene chloride solution in argon gas
By drying in a vacuum at 0 ° C. for 3 hours, the light-emitting substance represented by the following chemical formula 34 was changed to a light-emitting substance represented by the following chemical formula 35, and a light-emitting element was obtained. The thickness of the light emitting layer after drying was 10 μm, and the moisture contained in the light emitting layer was 10 ppm.

[0092]

Embedded image In such a light emitting element, the comb-shaped electrodes 42a, 42b
Have a length of 10 m
m, width 5 μm, and height 10 nm. In any of the comb-shaped electrodes, the distance between the element electrodes commonly connected at the ends is 15 μm. Therefore, when the element electrodes 43a and 43b are alternately combined as shown in the figure, the element electrodes 43a And the element electrode 43b has an interval of 5 μm.

The dimensions of the comb electrodes 42a and 42b are
It is 10 mm × 10 mm.

At this time, the resistance values R of the element electrodes 43a and 43b are 21,400 ohms, and the resistance values R of the element electrodes 43a and 43b are
Was 1,000 and the light emitting area S was 1.0 cm ² . That is, R · S / N is 21.4 ohm · cm
^{Was 2} .

Comparative Example 3 A light emitting device was manufactured in the same manner as in Example 3, except that the heights of the element electrodes 43a and 43b were 1.5 nm. The RS / N at this time was 140 ohm · cm ² .

(Embodiment 4) A pair of comb-shaped electrodes 42a, 42
A light emitting device was produced in the same manner as in Example 3, except that b was produced by the method described below.

First, a 50-nm-thick titanium film, a 150-nm-thick nickel film, and a 50-nm-thick
nm palladium films were sequentially laminated by a sputtering method. Next, a resist having a predetermined pattern was formed on the laminated film, and gold was electroplated (plating solution made of Tanaka precious metal, thickness 5 μm) using the resist as a mask. After stripping the resist, the palladium film and the nickel film were stripped with dilute aqua regia and the titanium film was stripped with dilute hydrofluoric acid to form a pair of comb-shaped electrodes 42a and 42b as shown in FIG. Here, the height 47 of the element electrode 43a of the comb-shaped electrode 42a is 5
μm, the width is 2 μm, the distance between the electrodes 43a and 43b is 5 μm, and the light emitting surface is 10 mm × 10 m.
m.

The element electrodes 43 of the comb electrodes 42a and 42b
a, 43b have a resistance R of 24 ohms and the element electrodes 42a, 4b
The number N of 3b is 1,420, and the emission area S is 1.0 cm.
^{Was 2} . That is, R · S / N was 0.017 ohm · cm ² . The thickness of the light-emitting layer of the light-emitting element after drying was 10 μm, and the amount of water contained in the light-emitting layer was 10 pp.
m.

(Reference Example 1) The water content in the light emitting layer was 100 p
A light-emitting device similar to that of Example 4 was produced except that the pm was used.

(Example 5) After a pair of comb-shaped electrodes 42a and 42b were prepared as shown in Example 4, a porous surface was obtained by hydrophilizing the surfaces of the pair of comb-shaped electrodes 42a and 42b. Coated with polyethylene. 0.2 mol / l of a luminescent substance represented by the following chemical formula 36:
A propylene carbide solution containing 0.5 mol / l lithium trifluoromethanesulfonium was dropped in argon gas to fill the pair of comb electrodes 42a and 42b and polyethylene with this solution. Place the electrode and substrate filled with this solution on the ethylene vinyl acetate copolymer sheet, place the ethylene vinyl acetate copolymer sheet laminated with aluminum foil on the polyethylene filled with the solution, and hot melt both sheets. Sealing was performed by a method to obtain a light emitting device.

[0101]

Embedded image (Reference Example 2) A light emitting device was produced in the same manner as in Example 5, except that porous polyethylene was not used.

(Embodiment 6) A pair of comb-shaped electrodes 42a, 42
b), 3 g of chloroplatinic acid was added to 100 parts of ion-exchanged water.
dissolved in 1 ml of hydrochloric acid and 30 mg of lead acetate.
A light-emitting element was manufactured in the same manner as in Example 4, except that plating with platinum was performed using a plating solution to which was added.

Examples 3 to 6 obtained as described above
The following measurements were performed on the light-emitting elements of Comparative Example 3 and Reference Examples 1 and 2. That is, after applying a DC voltage of 3 V to these light emitting elements and performing forming for 3 minutes,
A constant current drive of 0 mA was performed, and the initial luminance and voltage at that time were measured. Next, the response speed was measured by the above-described method, and the luminance half-life time when driving at a constant current of 2 mA was measured. Examples 3 to 5, Reference Example 1 and Comparative Example 3
The device of Example 6 was measured in a pure argon atmosphere, and the devices of Example 6 and Reference Example 2 were measured in the air. Table 2 shows the measurement results.

[0104]

[Table 2] The following can be seen from Table 2 above. That is, each of the light emitting elements of Example 3 and Comparative Example 3 has an R / S / N of 21.4.
Since the characteristics were ohm · cm ² and 140 ohm · cm ² , the characteristics of Example 3 were found in all of the initial luminance, the applied voltage, the response speed, and the luminance half-life time.
The element has better characteristics.

In each of the third embodiment and the fourth embodiment, R · S
/ N is less than 100 ohm · cm ² , but in the light emitting device of Example 3, the height 47 of the element electrodes 43a and 43b is 10n.
m, whereas the light emitting device of Example 4 is 5 μm. For this reason, the element of Example 4 is superior to the element of Example 3 in all characteristics.

In the fourth embodiment and the fifth embodiment, the solid electrolyte is prepared by using the electrolyte together with the organic matrix in the fourth embodiment, while the propylene carbide solution is used as the electrolyte in the fifth embodiment. They differ in that they are filled with polyethylene. Therefore, comparing the characteristics of the two, the element of Example 4 is superior in luminance and element life, and the element of Example 5 is superior in applied voltage and response speed. Further, comparing the devices of Example 4 and Comparative Example 3, the device of Example 5 is superior in all characteristics.

Embodiment 4 and Embodiment 6 are different from Embodiment 4 in that the elementary electrode 45 is subjected to platinum black treatment in Embodiment 6, and therefore, the element of Embodiment 6 in all characteristics. Is better.

As described above, the R / S / N is less than 100 ohm · cm ² , and the height 47 of the element electrodes 43a and 43b is 5 μm.
m or more, it can be seen that in any of the cases where the element electrodes 43a and 43b are electrically conductive and porous, it is possible to improve the luminance, reduce the applied voltage, shorten the response speed, and improve the element life.

Note that the device of Example 4 and the device of Reference Example 1
Only the water content in the light emitting layer is different. Comparing the respective characteristics, the element of Reference Example 1 is much inferior in the life characteristic to the element of Example 4. This is a water molecule or OH
^- reduction of the oxide with hydrogen ions or water molecules ions, it would proceed at a lower 1.3V approximately of the applied voltage than the driving voltage of the light-emitting element, the ion inactivation of the electrolyte by the water molecules, It is considered that the luminous efficiency was reduced due to quenching of the ionized radicals of the luminescent substance by water molecules. That is, the lower the water content in the light emitting layer, the lower the luminous efficiency is likely to occur, and the better the life characteristics. The water content is preferably 100 ppm or less, particularly preferably 20 ppm or less.

Further, the difference between Example 5 and Reference Example 2 is that the element of Reference Example 2 does not use porous polyethylene. Comparing the respective characteristics, the device of Reference Example 2 is significantly inferior in luminance and device life.
This is an element using a solution-like electrolyte.If porous polyethylene is used, the mixture solution in which the electrolyte is dissolved is impregnated into the porous polyethylene and becomes a gel, which facilitates sealing. If not used, the solution will leak.

The light emitting device of Example 5 has the same luminance characteristics as the light emitting device of Example 4 using no porous polyethylene. This is because porous polyethylene is unlikely to hinder the movement of ions and the hopping of electrons and holes. Further, the light emitting device of Example 5 shows the same life characteristics as the light emitting device of Example 4 measured in argon, although the characteristics are measured in the atmosphere. This indicates that a light-emitting element having practically sufficient performance can be obtained by the light-emitting element sealing method described in Example 5.

Similarly to the device of Example 5, the devices of Examples 3, 4 and 6 were covered with an ethylene-vinyl acetate copolymer sheet and sealed, and the characteristics were measured in the air. The same luminance half life as obtained was obtained.

(Example 7) The response speed when a constant current of 0.05% during driving was applied to the light emitting device of Example 5 during non-emission was measured. That is, the light emitting device of Example 5 has 10
After applying a constant current of mA and measuring the initial luminance at that time, a constant current of 5 μA was passed. Thereafter, a constant current of 10 mA was passed again, and the time from when the current was increased to 10 mA to when the luminance reached 90% of the initial luminance was measured. As a result, the response speed was 50 microseconds.

When the response speed obtained in Example 7 was compared with the response speed of the light emitting device of Example 5 driven by a normal driving method, it was 1000 microseconds in the method shown in Example 5. On the other hand, in the method of the seventh embodiment, 5
0 microseconds, which is a significant improvement. Therefore, when the light is not emitted, the driving voltage averages 1 unit time per unit time.
By applying a constant voltage of 0 to 90% to the ECL element, the response speed can be increased.

(Embodiment 8) FIG. 5 is a circuit diagram of an active matrix type light emitting element array according to this embodiment.

As shown in FIG. 5, this light-emitting element array has an ECL comprising a comb-shaped electrode and a light-emitting layer containing an electrolyte.
The elements are arranged and connected together with a current controlling transistor and a capacitor in a matrix. Source electrode of current control transistor 51 and capacitor 5
One of the two electrodes is connected to the scanning electrode line 57. An ECL element 53 using a comb-shaped electrode is connected to a drain electrode of the current control transistor 51, and the other end is connected to a signal electrode line 56. Further, the other electrode of the capacitor 52 and the gate electrode of the current control transistor 51 are connected to the drain electrode of the first-stage transistor 54, the source electrode of which is connected to the signal electrode line 55, Are connected to the scanning electrode lines 58.

According to such a connection configuration of the light emitting element array, it is possible to reduce the total length and the number of intersections of the wiring, thereby reducing the incidence of defects due to disconnection, short circuit, and the like. As a result, the quality of the display can be improved.

FIG. 6 shows an actual layout of a light emitting element array based on the circuit configuration of FIG.

In this figure, the gate electrode of the current control transistor 51 is arranged so as to overlap the scan electrode line 57 via an insulating layer. Due to the arrangement of the gate electrode, the insulating layer, and the scan electrode line 57, since these have a capacitance component, the capacitor 52 that holds the voltage of the gate electrode
Also serves as.

FIG. 13 shows an actual layout of a normal light emitting element array.

Conventionally, as shown in FIG. 13, the capacitor 132 and the current controlling transistor 131 are arranged at different places, and the capacitor 132 blocks a part of the light emitting portion.

On the other hand, in the light emitting element array of this embodiment shown in FIG. 5, since the gate electrode and the like of the current control transistor 51 also serve as a capacitor, a decrease in the aperture ratio is small and the capacitance of the capacitor is increased. can do.

(Embodiment 9) FIG. 7 is a circuit diagram of an active matrix type light emitting element array according to this embodiment.

As shown in FIG. 7, except that one electrode of the ECL element 63 is connected to the electrode line 69.
In the same manner as the ECL element.

FIG. 8 is a schematic view of a light emitting element array according to this embodiment.

In FIG. 8, the drain electrode of the current control transistor 61 and one of the comb electrodes of the ECL element 63 (not shown) are connected via the contact hole 60. The other comb-shaped electrode of the ECL element 63 is connected to the other comb-shaped electrode of the adjacent ECL element in the scanning electrode line direction via an electrode line 69.

The light emitting element array of this example was manufactured as follows.

First, a circuit was formed on a Si substrate, and a 10 μm thick insulating layer of a photosensitive polyimide film was formed on the circuit. A contact hole 60 is provided in the polyimide film,
Further, the contact hole 60 was filled with gold by electroplating so that the drain electrode of the current control transistor 61 and one electrode of the ECL element 63 could be connected. Next, a comb-shaped electrode and an electrode wire 69 were formed on the polyimide film by the method described in Example 4, and a light-emitting layer was applied to this to obtain a light-emitting element array.

In this light emitting element array, the ECL element 63
Is connected to the electrode of the adjacent ECL element via the electrode line 69, it is possible to reduce the voltage drop and the electrode deterioration due to the resistance of the wiring and increase the current density.

FIG. 9 is a diagram showing the actual arrangement of the light emitting element array of this embodiment with the ECL element attached.

In this figure, one comb-shaped electrode of the ECL element is connected between adjacent ones in the electrode line 69 direction. Further, since the ECL element and the drain electrode of the current controlling transistor are connected via the contact hole, the light emitting surface can be made wider than the light emitting element array shown in FIG.

(Embodiment 10) FIG. 10 shows an actual layout of a light emitting element array of this embodiment.

As shown in this figure, adjacent electrode lines 69 are connected by an electrode line 70,
And the electrode lines 70 form a network of electrode lines in the light emitting element array.

This light emitting element array was manufactured as follows.

First, a circuit was formed on a Si substrate, and a 10 μm thick insulating layer of a photosensitive polyimide film was formed on the circuit. A contact hole 60 is provided in the polyimide film,
Further, the contact hole 60 was filled with gold by electroplating so that the drain electrode of the current control transistor 61 and one electrode of the ECL element 63 could be connected. Next, a comb-shaped electrode, an electrode line 69, and an electrode line 70 were formed on the polyimide film by the method described in Example 4, and a light-emitting layer was applied thereto to obtain a light-emitting element array.

In this light emitting element array, since the adjacent electrode lines 69 are connected to each other by the electrode lines 70, the voltage drop and the electrode deterioration caused by the wiring resistance are further reduced as compared with the ninth embodiment. Thus, the current density can be increased.

(Embodiment 11) FIG. 11 is a schematic diagram of a light emitting element array of this embodiment. FIG. 12 is an enlarged view of one pixel of the light emitting element array in FIG. As shown in these figures, two contact holes are provided per pixel.

This light emitting element array was manufactured as follows.

First, a copper wiring layer was formed by electroplating on a conductive plate having a pattern of electrode lines arranged in parallel, and an insulating layer was formed on the wiring layer by electrodeposition. Next, these layers were transferred to a glass substrate to form first electrode lines. Subsequently, the above operation was repeated again to form a second electrode line so as to intersect with the first electrode line.
One of the first and second electrode lines is used as the signal electrode lines 85 and 86, and the other is the scanning electrode lines 87 and 8
Used as 8. On this electrode wire, a polyimide film having a thickness of 10 μm was formed. 1
Two contact holes 89, 90 are provided for each pixel,
This was filled with gold by electroplating so that the signal electrode line 85 and the scanning electrode line 87 could be connected to the comb-shaped electrode pair 84.
Further, by forming the comb-shaped electrode pair 84 by the method described in the fourth embodiment, the supporting portion 81 of the comb-shaped electrode is connected to the scanning electrode 87 via the contact hole 89, and the supporting portion 82 is formed in the contact hole 90. Connected to the signal electrode 85 via A light emitting layer was applied to this to obtain a light emitting element array driven by a simple matrix.

In the light-emitting element array driven by simple matrix obtained as described above, the scanning electrode lines and the signal electrode lines intersect on the same substrate, and the electrode lines and the comb-shaped electrodes are connected via the contact holes. Is cheaper,
The light emitting surface is not reduced by the scanning electrodes and the signal electrodes, and the substrate surface can be used effectively.

[0141]

As described above, according to the present invention,
By using a salt composed of a cation and an anion having a molecular weight of 200 or more as an electrolyte constituting the light-emitting layer, a light-emitting element having a short startup time and a high response speed can be obtained.

Further, by using a comb-shaped electrode having a predetermined configuration as an electrode, the response speed is increased, the luminance is improved, and
A light-emitting element having a long lifetime can be obtained without increasing the applied voltage.

By applying an average voltage of 10 to 90% of the drive voltage per unit time in the same direction as the drive voltage during non-emission, the response speed can be increased.

Furthermore, by arranging a plurality of ECL elements in a matrix with a predetermined connection form, it is possible to reduce the voltage drop by reducing the resistance of the circuit without reducing the light emitting area, thereby preventing the luminance drop. it can.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a light-emitting element according to one embodiment of the present invention.

FIG. 2 is a perspective view illustrating a light-emitting element according to one embodiment of the present invention.

FIG. 3 is a perspective view illustrating an example of an electrode used for a light-emitting element according to one embodiment of the present invention.

FIG. 4 is a perspective view of a comb electrode used for a light-emitting element according to one embodiment of the present invention.

FIG. 5 is a circuit diagram of a light-emitting element array according to one embodiment of the present invention.

FIG. 6 is an actual layout view of a light-emitting element array according to one embodiment of the present invention.

FIG. 7 is a circuit diagram of a light-emitting element array according to one embodiment of the present invention.

FIG. 8 is a schematic view of a light-emitting element array according to one embodiment of the present invention.

FIG. 9 is an actual layout view of a light-emitting element array according to one embodiment of the present invention.

FIG. 10 is an actual layout view of a light-emitting element array according to one embodiment of the present invention.

FIG. 11 is a schematic view of a light-emitting element array according to one embodiment of the present invention.

FIG. 12 is a schematic view of a light-emitting element array according to one embodiment of the present invention.

FIG. 13 is an actual layout diagram of a normal light emitting element array.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Substrate 12a ... Comb electrode 12b ... Comb electrode 13a ... Element electrode 13b ... Element electrode 14a ... Support part 14b ... Support part 15 ... Light emitting layer 16 ... Power supply 17 ... Light emitting element 21 ... Flat electrode 22 ... Flat electrode 23 ... Light emitting layer 24 ... power supply 25 ... light emitting element 31 ... electrode 32 ... electrode 33 ... power supply 42a ... comb electrode 42b ... comb electrode 43a ... element electrode 43b ... element electrode 44a ... support part 44b ... support part 46 ... power supply 47 ... height 48 ... distance 51: Current control transistor 52: Capacitor 53: Light emitting element 54: First stage transistor 55: Signal electrode line 56: Signal electrode line 57: Scan electrode line 58: Scan electrode line 60: Contact hole 61: Current control transistor 62: Capacitor 63: Light-emitting element 64: First-stage transistor 65: Signal electrode line 66: Signal Polar line 67 ... Scan electrode line 68 ... Scan electrode line 69 ... Electrode line 70 ... Electrode line 81 ... Support part 82 ... Support part 83 ... Element electrode 84 ... Comb electrode 85 ... Signal electrode line 86 ... Signal electrode line 87 ... Scan electrode Line 88 Scanning electrode line 89 Contact hole 90 Contact hole 131 Current control transistor 132 Capacitor 133 Light emitting element 134 First transistor 135 Signal electrode line 136 Signal electrode line 137 Scanning electrode line 138 Scanning electrode Line 139… Ground line

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Sano 1st, Komukai Toshiba-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Inside the Toshiba R & D Center Co., Ltd. No. 1, Toshiba-cho, Toshiba R & D Center (72) Inventor Norio Takami 72, Horikawa-cho, Saiwai-ku, Kawasaki, Kanagawa 33 Isogocho Inside Toshiba Production Technology Research Institute

Claims (10)

[Claims] 1. A semiconductor device comprising: a pair of electrodes; and a light-emitting layer provided between the pair of electrodes and including a light-emitting substance and an electrolyte, each of the electrolytes comprising a cation and an anion having a molecular weight of 200 or more. A light-emitting element, which is a salt. 2. The light emitting device according to claim 1, wherein the electrolyte is a solid electrolyte comprising a complex of a matrix and a salt. 3. A substrate comprising: a substrate; a pair of comb-shaped electrodes provided on the substrate; and a light-emitting layer provided in contact with the comb-shaped electrode and containing a light-emitting substance and an electrolyte. The number N (pieces) of elementary electrodes, the resistance value R (ohm) at both ends in the longitudinal direction of the elementary electrodes, and the light emitting area S (cm ² ) satisfy the inequality R / N <100 / S. A light-emitting element, comprising: 4. A comb-shaped electrode comprising a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrode and containing a luminescent substance and an electrolyte. A light emitting element, wherein a thickness of the elementary electrode in a direction perpendicular to the substrate surface is 0.5 μm or more. 5. A comb-shaped electrode comprising a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrode and containing a light-emitting substance and an electrolyte. A light emitting device, wherein the surface of the elementary electrode is electrically conductive and porous. 6. A method for driving a light-emitting element including a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrode and including a light-emitting substance and an electrolyte, A method for driving a light emitting device, comprising applying an average voltage of 10 to 90% per unit time with respect to a drive voltage to the pair of comb electrodes in a non-emission state in the same direction as the drive voltage application direction. 7. A light-emitting element, a current-controlling transistor, and a capacitor each including a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a light-emitting substance and an electrolyte. In the active matrix type light emitting element array in which the unit pixels composed of are arranged in a matrix, the source electrode of the current control transistor in N rows and M columns and one electrode of the capacitor are N
One of the light emitting elements of the unit pixel is connected to the drain electrode of the current control transistor, and the other of the light emitting elements is connected to the scanning electrode line of the row.
A light-emitting element array which is connected to signal electrode lines in a column different from the column. 8. A light-emitting element, a current-controlling transistor, and a capacitor comprising a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrode and containing a light-emitting substance and an electrolyte. In the active matrix type light emitting element array in which the unit pixels composed of are arranged in a matrix, one comb-shaped electrode of the light emitting element of the unit pixel is connected to the drain electrode of the current control transistor of the unit pixel of N rows and M columns. A light emitting element array, wherein the other comb-shaped electrode of the light-emitting element of the unit pixel and the other comb-shaped electrode of the light-emitting element of the unit pixel in N rows and (M + 1) columns are connected to each other. 9. The light emitting element array according to claim 8, wherein the other comb-shaped electrodes of the light emitting elements adjacent to each other in the signal electrode line direction are connected to each other. 10. A light-emitting element, a current-controlling transistor, and a capacitor comprising a substrate, a pair of comb-shaped electrodes provided on the substrate, and a light-emitting layer provided in contact with the comb-shaped electrodes and containing a light-emitting substance and an electrolyte. In a simple matrix type light emitting element array in which unit pixels consisting of are arranged in a matrix, scanning electrode lines and signal electrode lines intersect on the same substrate via an insulating layer, and each light emitting element,
The scanning electrode line and the signal electrode line are connected via a contact hole.