JP3463971B2 - Organic active EL light emitting device - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an organic active E
The present invention relates to an L light emitting device. More specifically, the present invention relates to an organic active EL light emitting device that is preferably used for consumer and industrial display devices, color displays and the like.

[0002]

2. Description of the Related Art Conventionally, in an organic EL light emitting device (display), a technique is known in which an XY matrix is simply driven to display an image (JP-A-2-3).
7385, JP-A-3-233891, etc.). However, in such simple driving, line-sequential driving is performed. Therefore, when the number of scans is as large as several hundreds, the required instantaneous luminance is several hundred times the observed luminance, which causes the following problems. It was

(1) The driving voltage becomes high. Since the voltage is usually 2 to 3 times or more higher than that under the DC steady voltage, the efficiency is lowered. Therefore, power consumption increases. (2) Since the amount of current that instantaneously flows is several hundred times, the organic light emitting layer is likely to deteriorate. (3) As in the case of (2), since the energizing current is very large, the voltage drop of the electrode wiring becomes a problem.

As a method for solving the above (1) to (3), the following active matrix drive has been proposed. That is, a display has been disclosed in which ZnS, which is an inorganic substance, is used as a phosphor, and further active matrix driving is performed (US Pat. No. 4,143,297).
issue). However, in this technique, since the inorganic phosphor is used, the driving voltage is as high as 100 V or more, which is a problem. A similar technique is the IEEE Trans Select.
ron Devices, 802 (1971). On the other hand, a large number of displays using organic phosphors for active matrix driving have been recently developed (Japanese Patent Laid-Open Nos. 7-122360 and 7-12).
No. 2361, No. 7-153576, No. 8-54836, No. 7-111341, No. 7-313290, No. 8-109.
370, JP-A-8-129359, JP-A-8-241047, and JP-A-8-227276.
Issue Bulletin). In the above technique, the driving voltage is drastically reduced to 10 V or less by using the organic phosphor, and the efficiency is 3 lm / w or more when the highly efficient organic phosphor is used.
It has extremely high efficiency in the range of 15 lm / w, and the driving voltage of the high-definition display is 1/2 to 1/3 as compared with the simple driving, and the power consumption can be reduced. However, the following points were a problem.

(1) Normally, α-S is formed on a transparent substrate.
i, TFT (thin fi) made of polysilicon, etc.
At least one or two lm transistors are provided for each pixel, and a large number of scan electrode lines and signal electrode lines are further provided on the substrate to select and turn on the TFTs. An insulating film made of silicon nitride or silicon oxide is provided on the TFT to insulate the TFT element and the organic EL element.
However, the thickness of the TFT is 0.2 μm to 1 μm including the gate, drain, and source electrodes, and there is unevenness. Therefore, it is necessary to avoid this and form the lower EL electrode, and a non-light emitting portion occurs in the pixel. I couldn't avoid it. When the light is extracted from the transparent substrate side, the scanning electrode lines and the signal electrode lines also block the light, so that the aperture ratio of the pixel (the ratio of the portion actually emitting light to the pixel) is small. For example, JP-A-7-122362
The one disclosed in Japanese Patent Laid-Open Publication No. 2003-242242 has an aperture ratio of only 56%, and there is a problem that a good image cannot be obtained in the non-light emitting portion. At the same time, the device shown in FIG. 3 of JP-A-8-241047 has a problem that it is difficult to obtain high brightness.

(2) When the lower EL electrode is formed in the opening of the insulating film covering the TFT as shown in FIG. 3 of JP-A-8-241047, the pattern edge of the insulating film is made good. Since it is technically difficult to carry out etching, problems such as etching residue are likely to occur, and a light emission defect occurs, which is a problem.

(3) On the other hand, when the light is taken out from the side opposite to the substrate side, the aperture ratio becomes large and a good image may be obtained. However, since the interlayer insulating film covering the TFT is not normally flattened, defects of the organic EL element formed on the upper surface frequently occur due to the unevenness of the TFT, which becomes a problem. The organic EL element has an organic layer of 0.05 μm to 0.2 μm.
Since it is a thin layer with a thickness of μm, defects are easily generated due to the unevenness of the lower part. Therefore, as shown in FIGS. 1 and 2 of Japanese Patent Application Laid-Open No. 8-54836, an organic EL device is provided other than the portions where the scanning electrode lines, the signal electrode lines, and the TFTs are formed.
It was usual to form the device. Therefore, the aperture ratio of the conventional one is unavoidable.

The conventional technique will be described more specifically. FIG. 5 is a circuit diagram of an organic TFT EL in the related art. A plurality of gate lines (scan electrode lines) and source lines (signal electrode lines) are formed on the substrate to form an XY matrix. Two TFTs 21 and 22 per pixel are connected to the gate line and the source line as shown in FIG. 5, and a second TF is provided in one pixel.
A capacitor 23 for holding the gate of T22 at a constant potential is formed, and the second TFT 22 drives the organic EL element 3 shown by the diagonal lines in the figure.

FIG. 6 shows a sectional view of the pixel taken along the line AA 'in the figure. As shown in FIG. 7, the second TFT 22 is formed by using polysilicon as an active layer. The polysilicon island 71 has a thickness of 200 nm, the gate SiO _{2 has} a thickness of 100 nm, and the polysilicon gate 73 has a thickness of 30 nm.
0 nm, the thickness of SiO ₂ surrounding the polysilicon gate is 5
00 nm. As can be seen from the figure, the TFT portion has unevenness by the thickness of the polysilicon island 71 and the polysilicon gate 73. Convex part is 500-600
protruding by nm. Therefore, even if there is an intention to form an organic EL element on the TFT, this unevenness easily causes disconnection of the lower electrode, the organic layer, and the counter electrode, so that a good organic EL light emitting pixel cannot be formed. Further, in this conventional technique, light is extracted from the lower electrode ITO 31, that is, from the substrate 1 side. Therefore T
Since the FT, the gate line, and the source line block light, there is a problem that the aperture ratio of the pixel becomes small.

As another conventional technique, as shown in FIG. 8, there is a technique in which a hole injection electrode 81 (usually transparent) which is a counter electrode is provided on the upper portion. However,
Also in this technique, since the TFT portion has irregularities, the electron injection electrode 82 is formed so as to avoid this portion, and the pixel which emits light is formed. In addition, the unevenness on the gate electrode 83, the source electrode 84, and the drain electrode 85 remains a problem, so that the organic layer 32 is formed avoiding this portion.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a large aperture ratio and effectively prevents the occurrence of image defects, and enables high quality image display. An object is to provide an active EL light emitting device.

[0012]

To achieve the above object, according to the present invention, the following organic active EL light emitting device is provided. A plurality of thin film transistors (TFTs) on a substrate and a TFT driven by the TFTs
In an organic active EL light emitting device having a plurality of organic EL elements arranged corresponding to
A flattened interlayer insulating film is provided between the lower electrode of the element and the terminals of the TFT and the lower electrode of the organic EL element are electrically connected through a contact hole provided in the interlayer insulating film. Connected, the lower electrode is Au / Mo, Au / W,
An organic active EL light emitting device comprising an alloy of at least one selected from the group consisting of Au / Cr, Au / Ta, Au / Al and Pt / Al. A plurality of thin film transistors (TFTs) and this TF are provided on the substrate.
In an organic active EL light-emitting device driven by T and having a plurality of organic EL elements arranged corresponding to TFTs, a planarized interlayer insulating film is provided between the TFT and the lower electrode of the organic EL element. There is provided, and the lower electrode terminal and an organic EL element of the TFT is electrically connected through a contact hole formed in the interlayer insulating film, Yes
The counter electrode of the EL device is a cathode containing an amorphous transparent electrode.
Organic active EL light emitting device, characterized in that there. In an organic active EL light emitting device having a plurality of thin film transistors (TFTs) and a plurality of organic EL elements arranged corresponding to the TFTs, which are driven by the TFTs, on a substrate, the TFT and the organic EL elements are A flattened interlayer insulating film is provided between the lower electrode and the TFT.
And the lower electrode of the organic EL element are electrically connected to each other through a contact hole provided in the interlayer insulating film,
The lower electrode is composed of Mo, W, Cr or Ta, Pt, Au or
Is an organic active EL light-emitting device characterized by a combination of Ni .

[0013]

In a preferred embodiment, the aperture ratio (the ratio of the portion that actually emits light to the pixel) is 7
An organic active EL light-emitting device having 5% or more is provided.

To achieve the above object, the present invention further provides the following organic active EL light emitting device. On a substrate, there are a plurality of scanning electrode lines and signal electrode lines arranged in an XY matrix, and electric switches arranged in the vicinity of the scanning electrode lines and signal electrode lines, and the electric switches scan. In an organic active EL light emitting device in which an organic EL element in a unit pixel coupled to the electric switch emits light or stops emitting light by performing a switch operation with a signal pulse and a signal pulse, the electric switch emits light. Pixel-selecting thin film transistor (first transistor), and organic E
Interlayer insulation formed of at least one thin film transistor (second transistor) for driving the L element, and flattened between the first and second transistors and the lower electrode of the organic EL element. A film is provided, the drain of the second transistor and the lower electrode of the organic EL element are electrically connected, and the lower electrode is Au /
Mo, Au / W, Au / Cr, Au / Ta, Au / Al
And an organic active EL comprising at least one alloy selected from the group consisting of Pt / Al
Light emitting device. On a substrate, there are a plurality of scanning electrode lines and signal electrode lines arranged in an XY matrix, and electric switches arranged in the vicinity of the scanning electrode lines and signal electrode lines, and the electric switches scan. In an organic active EL light emitting device in which an organic EL element in a unit pixel coupled to the electric switch emits light or stops emitting light by performing a switch operation with a signal pulse and a signal pulse, the electric switch emits light. A thin film transistor (first transistor) for selecting a pixel and one or more thin film transistors (second transistor) for driving an organic EL element, respectively, and the first and second transistors and the organic EL element. A flattened interlayer insulating film is arranged between the lower electrode of the element,
In addition, the drain of the second transistor and the organic EL
The lower electrode of the element is electrically connected, the organic EL device
An organic active EL light-emitting device , wherein the counter electrode is a cathode including an amorphous transparent electrode . XY on the board
It has a plurality of scanning electrode lines and signal electrode lines arranged in a matrix, and an electric switch arranged in the vicinity of the scanning electrode lines and the signal electrode lines. In the organic active EL light emitting device in which an organic EL element in a unit pixel coupled to the electric switch emits light or stops emitting light to perform an image display by performing a switch operation with the electric switch, the electric switch selects a thin film pixel for emitting light. A transistor (first transistor) and a thin film transistor (second transistor) for driving an organic EL element, each of which is formed of one or more, and the first and second transistors and a lower electrode of the organic EL element. A flattened interlayer insulating film is provided between the second transistor and the drain of the second transistor. The lower electrode of the organic EL element is electrically connected, and the lower electrode, Mo, W, Cr or Ta,
An organic active EL light-emitting device, which is a combination of Pt, Au or Ni .

Furthermore, in a preferred embodiment, organic E
Provided is an organic active EL light emitting device in which a counter electrode of an L element is transparent .

[0017]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a sectional view schematically showing an embodiment of the organic active EL light emitting device of the present invention, which is a sectional view taken along the line AA ′ in FIG. Figure 2
It is explanatory drawing which shows the drive circuit of the organic EL element used for this invention. FIG. 3 is a plan view schematically showing an embodiment of the organic active EL light emitting device of the present invention. Figure 4
It is sectional drawing which shows typically the process of patterning the polysilicon layer of the thin film transistor used for this invention into an island.

One embodiment of the organic active EL light emitting device of the present invention corresponds to a plurality of thin film transistors (TFT) 2 on a substrate 1 and a TFT 2 driven by the TFT 2, as shown in FIG. A plurality of organic EL elements 3 are provided, a flattened interlayer insulating film 4 is provided between the TFT 2 and the lower electrode 31 of the organic EL element 3, and the drain terminal of the TFT 2 and the organic The lower electrode 31 of the EL element 3 is electrically connected via a contact hole 41 provided in the interlayer insulating film 4.

The organic EL element is driven by the TFT as follows. As shown in FIGS. 2 and 3,
A plurality of scanning electrode lines (Y
_{j to} Y _{j + n} ) and the signal electrode lines (X _{i to} X _{i + n} ) and the electrode lines (Y _{j to} Y _{j + n} ) and (X _{i to} X _{i + n} ) It has an electric switch (TFT2). This electric switch is formed by one or more of each of a first transistor (Tr1) 21 and a second transistor (Tr2) 22. The electric switch performs a switching operation with the scan signal pulse and the signal pulse, so that the organic E in the unit pixel coupled to the electric switch
The L element 3 emits light or stops emitting light to display an image.

The first transistor (Tr1) 2
1 selects a light emitting pixel. The second transistor (Tr2) 22 has a function of driving the organic EL element.

The interlayer insulating film 4 is disposed between the first transistor (Tr1) 21 and the second transistor (Tr2) 22 and the lower electrode 31 of the organic EL element 3, and further, Second transistor (Tr2
2) and the lower electrode 31 of the organic EL element are electrically connected.

A more specific description will be given below. The organic EL element 3 used in the present invention is driven by an active matrix circuit as shown in FIG. A desired first transistor by a pulse transmitted via the scanning electrode lines (gate lines) (Y _{j to} Y _{j + n} ) and a pulse transmitted via the signal electrode lines (X _{i to} X _{i + n} ). (Tr1) 21 is selected, and the capacitor 23 formed between the common electrode line (C _{i to} C _{i + n} ) and the source of the first transistor (Tr1) 21 is charged. As a result, the gate of the second transistor (Tr2) 22 has a constant potential, and the second transistor (Tr2) 22 is turned on. This ON state is held until the next gate pulse is transmitted, and the second transistor (Tr2) 2
The current continues to be supplied to the lower electrode 31 of the organic EL element 3 connected to the drain terminal of No. 2.

Further, in the present invention, as shown in FIG. 1, a thin film transistor 2 (first transistor (Tr1), second transistor (Tr2)) and gate lines ( _Yj to _{Yj + n).} ), Signal electrode lines (X _{i to} X _{i + n} )
An interlayer insulating film 4 is provided on the interlayer insulating film 4, and the interlayer insulating film 4 is flattened.

The lower electrode 31 of the organic EL element 3 is provided on the interlayer insulating film 4, and the drain of the second transistor (Tr2) is provided through the contact hole 41 formed in the interlayer insulating film 4. The terminal and the lower electrode 31 are electrically connected.

Further, the lower electrode is provided on the first transistor (Tr1) 21, the second transistor (Tr2) 22, the signal electrode line and the gate line 46 as shown in FIG. Note that, in FIG. 3, the portion surrounded by the alternate long and short dash line shows the lower electrode 31 of the organic EL element.

Each component will be described below. 1. Substrate The substrate used in the present invention is insulative and is preferably a transparent material such as quartz or glass. Here, being transparent means having a property of transmitting sufficient light for practical use in an organic active EL light emitting device. For example, a material that transmits 50% or more of light in a desired frequency range is considered to be transparent. The low temperature glass is a glass that melts or distorts at a temperature of about 600 ° C or higher.

2. Thin Film Transistor In the present invention, a thin film transistor (TFT) is used for driving an organic EL element, and specifically, as an electric switch, one or more of a first transistor (Tr1) and a second transistor (Tr2) are provided. It is formed. The active layer of Tr1 and Tr2 is a portion shown as n ⁺ / i / n ⁺ in FIG. 1, where n ⁺ is an N-type doped portion and i is a non-doped portion. The doped portion of the active layer may be P ⁺ -doped P ⁺ . This active layer is preferably formed of polysilicon. Polysilicon exhibits sufficient stability against electric current as compared with amorphous Si.

Other preferred materials include organic semiconductors. Thiofene oligomer, poly (P
-Phenylene vinylene) and the like.

Polysilicon may be deposited by various CVD methods, but preferably by plasma CVD method.
As shown in (a), α-Si is laminated.

After that, as shown in FIG.
Annealing and crystallization with an excimer laser such as a (248 nn) laser (SID'96, Digest
oftechnical papers P17-2
8). The preferable film thickness of α-Si is 40 to 200 nm. For the excimer laser annealing, it is preferable to maintain the substrate temperature at 100 to 300 ° C.
It is preferable to anneal with a laser beam having an energy amount of ˜300 mJ / cm ² .

The polysilicon layer is also photolithographically patterned into islands, as shown in FIG. 4 (c). The substrate used is a crystalline material such as quartz, but is preferably a less expensive material such as low temperature glass. TF when glass substrate is used
The entire fabrication of the T-EL avoids glass melting or distortion, allowing out-diffusion of the dopant (out-di) into the active region.
performed at a low process temperature to avoid fusion. In this way, all the manufacturing steps for the glass substrate must be carried out below 1000 ° C, preferably below 600 ° C.

Next, as shown in FIG. 4D, an insulating gate material 42 is laminated on the polysilicon island 71 and the surface of the insulating substrate 1. The insulating material is preferably plasma enhanced CVD (PECVD) or low pressure CVD
Silicon dioxide deposited by chemical vapor deposition (CVD) such as (LPCVD). The thickness of the gate oxide insulating layer is preferably about 100-200 nm. The substrate temperature is preferably 250 to 400 ° C., and annealing is performed in the range of 300 to 600 in order to obtain a higher quality insulated gate material.
It is preferably applied at 1 to 3 hours at a temperature of ℃.

At the next stage, as shown in FIG.
The gate electrode 43 is formed by vapor deposition or sputtering. A preferable film thickness is 200 to 500 nm.

Next, as shown in FIGS. 4 (f) to 4 (h),
The gate electrode 43 is patterned. However, here A
When using a 1-gate, it is preferable to perform the anodization twice for insulation. The details of anodic oxidation are disclosed in Japanese Patent Publication No. 8-15120.

Next, as shown in FIG. 4I, an n ⁺ or P ⁺ region is formed by ion doping. As another method, there is the following technique using polysilicon as a gate. In this technique, the polysilicon gate electrode 43 shown in FIG. 1 is stacked on the gate insulating layer, and the pattern is formed by photolithography on the polysilicon island so that the source and drain regions are formed in the polysilicon region after ion implantation. Be converted. The gate electrode material is preferably polysilicon formed from amorphous silicon. The ion implant is made conductive with an N-type dopant, which is preferably arsenic. The polysilicon gate electrode also serves as the bottom electrode of the capacitor. In this way manufacturing can be less complex and less expensive. Gate bus 4 shown in FIG.
6 is applied and patterned on the insulating layer. The gate bus is preferably a metal silicide such as tungsten silicide (WSi). This is because the sheet resistance of the metal silicide can be set to several Ω / □ or less.

However, a metal such as Al alloy, Al, Cr, W or Mo may be used instead of the metal silicide such as WSi. In such a case, there is an advantage that a lower sheet resistance value is realized. Further, TaN may be used as the gate. In the next step, an insulating film made of silicon dioxide, silicon nitride, polyimide or the like is applied over the entire surface.

Next, signal electrode lines and scan electrode lines are formed. A metal wire of Al alloy, Al, Cr, W, Mo or the like is formed by photolithography, and Tr1,
The contact of the drain, source, etc. of Tr2 is made at the place where the insulating film is opened. This insulating film is the same as 52 in FIG.
Indicated by the symbol. Among the above, SiO ₂ is, for example, TE
Substrate temperature 2 with OS (tetraethoxysilane) as gas
The temperature can be set between 50 and 400 ° C. and obtained by PECVD. The substrate temperature is 100 to 3 by ECR-CVD.
It can also be obtained at 00 ° C.

3. Interlayer Insulating Film The flattened interlayer insulating film used in the present invention can be formed by the following method (1) or (2). (1) Film formation by spin coating of polyimide coating film A commercially available coating liquid is used as the polyimide, and the contact hole 41 shown in FIG. 1 is formed by etching to open the drain connection portion. Further, the insulating film 52 and the gate insulating film 42 are opened by etching to expose the drain. Polyimide is a preferred example because it provides a planarized surface. (2) Etchback method by plasma etching Various CVD methods, plasma CVD, PECVD (plasma enhanced CVD), LPCVD (low pressure CVD)
The silica is preferably formed into a film having a thickness of 1 μm to 3 μm by a method or the like. Further, polymer coating is applied to the entire surface. Further, by using reactive ion etching (RIE), gas species CF
Etching is performed using a mixed gas of ₄ and oxygen. The etching film thickness is preferably 0.5 μm to 2 μm. By this method, a flattened interlayer insulating film (SiO ₂ ) can be obtained. This method includes silica, PSG, and BSG.
(Phosphorus silica glass, boron silica glass) may be used, or a silicon nitride compound such as Si ₃ N ₄ may be used.

4. Organic EL Element In the organic EL element used in the present invention, an organic material layer (organic layer) having at least a recombination region and a light emitting region is used. Since the recombination region and the light emitting region are usually present in the light emitting layer, in the present invention, only the light emitting layer may be used as the organic layer, but if necessary, other than the light emitting layer, for example, a hole injection layer, An electron injection layer, an organic semiconductor layer, an electron barrier layer, an adhesion improving layer, etc. can also be used.

Next, a typical constitutional example of the organic EL element used in the present invention will be shown. Of course, it is not limited to this. Transparent electrode (anode) / light emitting layer / electrode (cathode) Transparent electrode (anode) / hole injection layer / light emitting layer / electrode (cathode) Transparent electrode (anode) / light emitting layer / electron injection layer / electrode (cathode) Transparent electrode (Anode) / hole injection layer / light emitting layer / electron injection layer / electrode (cathode) anode / organic semiconductor layer / light emitting layer / cathode anode / organic semiconductor layer / electron barrier layer / light emitting layer / cathode anode / hole injection layer Examples of the structure include / light emitting layer / adhesion improving layer / cathode. Of these, the usual configuration is preferably used.

(4) -1. The light emitting material of the light emitting layer organic EL element is mainly an organic compound, and specific examples thereof include the following compounds depending on a desired color tone. First, in the case of obtaining violet light emission from the ultraviolet region, compounds represented by the following general formula can be mentioned.

[0042]

[Chemical 1]

In this general formula, X represents the following compound.

[0044]

[Chemical 2]

Here, n is 2, 3, 4 or 5.
In addition, Y represents the following compound.

[0046]

[Chemical 3]

Phenyl group, phenylene group of the above compound,
Naphthyl group, alkyl group having 1 to 4 carbon atoms, alkoxy group, hydroxyl group, sulfonyl group, carbonyl group, amino group,
A dimethylamino group, a diphenylamino group, or the like may be substituted alone or in plural. Also, these may be bonded to each other to form a saturated 5-membered ring or 6-membered ring. Further, those having a phenyl group, a phenylene group, or a naphthyl group bonded at the para position are preferable for forming a smooth vapor-deposited film having good bonding properties. Specifically, they are the following compounds. In particular,
A p-quaterphenyl derivative and a p-quinquephenyl derivative are preferable.

[0048]

[Chemical 4]

[0049]

[Chemical 5]

[0050]

[Chemical 6]

[0051]

[Chemical 7]

Next, in order to obtain blue to green emission, for example, a fluorescent whitening agent such as a benzothiazole type, a benzimidazole type, a benzoxazole type, a metal chelated oxinoid compound, and a styrylbenzene type compound are listed. You can

Specific examples of the compound name include those disclosed in JP-A-59-194393. Typical examples thereof include 2,5-bis (5,7-di-t-pentyl-2-benzoxazolyl) -1,3,4-thiadiazole and 4,4′-bis (5,7-t- Pentyl-2-benzoxazolyl) stilbene, 4,4′-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] stilbene, 2,5-bis (5 , 7-Di-t-pentyl-2-benzoxazolyl) thiophene, 2,5-bis [5-
α, α-Dimethylbenzyl-2-benzoxazolyl]
Thiophene, 2,5-bis [5,7-di- (2-methyl-2-butyl) -2-benzoxazolyl] -3,4 diphenylthiophene, 2,5-bis (5-methyl-2)
-Benzoxazolyl) thiophene, 4,4'-bis (2-benzoxazolyl) biphenyl, 5-methyl-
2- [2- [4- (5-methyl-2-benzoxazolyl) phenyl] vinyl] benzoxazole, 2- [2
-(4-Chlorophenyl) vinyl] naphtho [1,2-
d] Benzoxazoles such as oxazole, 2-2 ′
Benzothiazoles such as-(p-phenylenedivinylene) -bisbenzothiazole, 2- [2- [4- (2-benzimidazolyl) phenyl] vinyl] benzimidazole, 2- [2- (4-carboxyphenyl) vinyl ]
Fluorescent brighteners such as benzimidazole series such as benzimidazole can be mentioned. In addition, other useful compounds are Chemistry of Synthetic Soybean 1
971, 628-637 and 640.

As the chelated oxinoid compound, for example, those disclosed in JP-A-63-295695 can be used. Typical examples thereof are tris (8-quinolinol) aluminum, bis (8-quinolinol) magnesium, bis (benzo [f] -8-quinolinol) zinc, bis (2-methyl-).
8-quinolinolate) aluminum oxide, tris (8-quinolinol) indium, tris (5-methyl-8-quinolinol) aluminum, 8-quinolinol lithium, tris (5-chloro-8-quinolinol) gallium, bis (5- Chloro-8-quinolinol) calcium, poly [zinc (II) -bis (8-hydroxy-5-)
8-hydroxyquinoline-based metal complex such as quinolinonyl) methane] and dilithium epinetridione.

As the styrylbenzene compound, for example, those disclosed in European Patent No. 0319881 and European Patent No. 0373582 can be used. As typical examples thereof, 1,4-bis (2-methylstyryl) benzene and 1,4-bis (3
-Methylstyryl) benzene, 1,4-bis (4-methylstyryl) benzene, distyrylbenzene, 1,4-
Bis (2-ethylstyryl) benzene, 1,4-bis (3-ethylstyryl) benzene, 1,4-bis (2-
Methylstyryl) -2-methylbenzene, 1,4-bis (2-methylstyryl) -2-ethylbenzene and the like can be mentioned.

The distyrylpyrazine derivative disclosed in JP-A-2-252793 can also be used as a material for the light emitting layer. Typical examples are 2,
5-bis (4-methylstyryl) pyrazine, 2,5-bis (4-ethylstyryl) pyrazine, 2,5-bis [2
-(1-naphthyl)) vinyl] pyrazine, 2,5-bis (4-methoxystyryl) pyrazine, 2,5-bis [2
Examples thereof include-(4-biphenyl) vinyl] pyrazine and 2,5-bis [2- (1-pyrenyl) vinyl] pyrazine. Others, such as European Patent No. 0
The polyphenyl compound disclosed in the specification of 387715 can also be used as a material for the light emitting layer.

Further, in addition to the above-described optical brightener, metal chelated oxinoid compound, styrylbenzene compound, etc., for example, 12-phthaloperinone (J. Appl.
Phys., 27, L713 (1988)), 1, 4
-Diphenyl-1,3-butadiene, 1,1,4,4-
Tetraphenyl-1,3 butadiene (above Appl. Phys.
Lett., Volume 56, L799 (1990)), naphthalimide derivative (JP-A-2-305886), perylene derivative (JP-A-2-189890), oxadiazole derivative (JP-A-2-216791). Publication, or the oxadiazole derivative disclosed by Hamada et al. At the 38th Joint Lecture on Applied Physics), aldazine derivative (JP-A-2-220393), pyrazirine derivative (JP-A-2-220394), Cyclopentadiene derivative (JP-A-2-289675), pyrrolopyrrole derivative (JP-A-2-296891),
Styrylamine derivatives (Appl. Phys. Lett., Volume 56,
L799 (1990)), coumarin-based compounds (Japanese Patent Laid-Open No. 2-191694), International Publication WO90 / 1.
3148 and Appl. Phys. Lett., Vol 58, 18, P1982 (1991)
The polymer compounds and the like as described in 1) can also be used as the material of the light emitting layer.

In the present invention, an aromatic dimethylidyne compound (European Patent No. 0388876) is used as a material for the light emitting layer.
No. 8 and those disclosed in JP-A-3-231970) are preferably used. As a specific example, 1,4
-Phenylenedimethyridin, 4,4-Phenylenedimethylidene, 2,5-Xylylenedimethylidene, 2,6
-Naphthylene dimethylidene, 1,4-biphenylene dimethylidene, 1,4-p-terephenylene dimethylidene, 9,10-anthracene diyl dimethylidene, 4,4'-bis (2,2- Di-t-butylphenylvinyl) biphenyl, (hereinafter abbreviated as DTBPBBi), 4,4′-bis (2,2-diphenylvinyl) biphenyl (hereinafter abbreviated as DPVBi), and the like, and derivatives thereof. You can

Further, compounds represented by the general formula (R ₂ -Q ₃ -AL-OL) described in JP-A-5-258862 are also included. (In the above formula, L is a phenyl moiety. Unlucky carbon atom 6
~ 24 hydrocarbons, OL is a phenylate ligand, Q is a substituted 8-quinolinolate ligand,
R ₂ represents an 8-quinolinolate ring substituent selected sterically to hinder the attachment of two substituted 8-quinolinolate ligands to the aluminum atom. Specifically, bis (2-methyl) -8-quinolinolato) (para-
Phenylphenolate) aluminum (III) (hereinafter P
C-7), bis (2-methyl-8-quinolinolate)
(1-naphtholato) aluminum (III) (hereinafter PC
-17) and the like. In addition, JP-A-6-9953
There is a method of obtaining highly efficient mixed emission of blue and green by using doping according to Japanese Patent Laid-Open Publication No. 2003-242242. In this case, examples of the host include the above-described luminescent material, and examples of the dopant include strong fluorescent dyes from blue to green, such as coumarin-based or similar fluorescent dyes used as the above-described host. it can. Specifically, as the host, a light emitting material having a distyrylarylene skeleton, particularly preferably DPVBi, and as a dopant, diphenylaminovinylarylene, particularly preferably, for example, N, N-diphenylaminovinylbenzene (D
PAVB) can be mentioned.

The light-emitting layer that emits white light is not particularly limited, but the following can be given. A white light emitting element is described as an example of an element that uses tunnel injection as well as one that defines the energy level of each layer of the organic EL laminated structure and emits light by using tunnel injection (European Patent Publication No. 0390551). What has been done (JP-A-3-23)
Japanese Patent Laid-Open No. 0584/1990)
JP-A-220390 and JP-A-2-216790) A light-emitting layer is divided into a plurality of layers, each of which is composed of a material having a different emission wavelength (JP-A-4-51491) Blue light-emitting body (fluorescence peak 380 nm to 480 nm) And a green light emitter (480 nm to 580 nm) are laminated,
Further, a structure containing a red phosphor (Japanese Patent Application Laid-Open No. 6-
No. 207170) A structure in which the blue light emitting layer contains a blue fluorescent dye, the green light emitting layer has a region containing a red fluorescent dye, and further contains a green phosphor (JP-A-7-142169).
Among them, the one having the constitution is preferably used. Also,
An example of a red phosphor that emits red light is shown in [Chemical formula 8].

[0061]

[Chemical 8]

As a method for forming a light emitting layer using the above-mentioned material, a known method such as a vapor deposition method, a spin coating method or an LB method can be applied. The light emitting layer is preferably a molecular deposition film. Here, the molecular deposition film refers to a thin film formed by depositing a material compound in a vapor phase state or a film formed by solidifying a material compound in a solution state or a liquid phase state, and usually this molecular deposition film. Is
It can be classified from a thin film (molecular cumulative film) formed by the LB method based on a difference in agglomeration structure, higher order structure, and functional difference caused by the difference. Also, JP-A-57-517
As disclosed in Japanese Patent Publication No. 81-81, a light emitting layer is also formed by dissolving a binder such as a resin and a material compound in a solvent to form a solution, and then thinning the solution by a spin coating method or the like. be able to. The thickness of the light emitting layer thus formed is not particularly limited and can be appropriately selected depending on the situation. Usually, the range of 5 nm to 5 μm is preferable. The light emitting layer of the organic EL element also has the following functions. That is, an injection function; a function capable of injecting holes from an anode or a hole injection layer when an electric field is applied, a function capable of injecting electrons from a cathode or an electron injection layer; a transport function; injected charges (electrons and holes ) By the force of an electric field, a light emission function; a function of providing a field for recombination of electrons and holes and connecting this to light emission. However, the easiness of injecting holes and the easiness of injecting electrons may be different, and the transport capacity represented by the mobility of holes and electrons may be large or small. It is preferable to move.

(4) -2. Hole Injecting Layer Next, the hole injecting layer is not necessarily required for the element used in the present invention, but it is preferable to use it for improving the light emitting performance. This hole injection layer is a layer that assists hole injection into the light emitting layer, has a high hole mobility,
The ionization energy is usually as small as 5.5 eV or less.
As such a hole injection layer, a material that transports holes to the light emitting layer at a lower electric field is preferable, and further, the mobility of holes is at least 10 when an electric field of 10 ⁴ to 10 ⁶ V / cm is applied. ^More preferably, it is ⁻⁶ cm ² / V · sec.
The hole injecting material is not particularly limited as long as it has the above-described preferable properties, and is conventionally used as a hole charge transporting material in an optical transmission material or a positive electrode of an EL element. Any known material used for the hole injection layer can be selected and used.

Specific examples include, for example, a triazole derivative (see US Pat. No. 3,112,197), an oxadiazole derivative (see US Pat. No. 3,189,447), an imidazole derivative (JP-B-1) 37-1
No. 6096, etc.), polyarylalkane derivatives (US Pat. Nos. 3,615,402 and 3,82).
No. 0,989, No. 3,542,544, Japanese Patent Publication No. 45-555, No. 51-10983, JP-A No. 51-93224, 55-171.
No. 05, No. 56-4148, No. 55-108.
No. 667, No. 55-156953, No. 56-
36656, etc.), pyrazoline derivatives and pyrazolone derivatives (US Pat. Nos. 3,180,729, 4,278,746 and JP-A-55-8).
No. 8064, No. 55-88065, No. 49-
No. 105537, No. 55-51086, No. 5
6-80051, 56-88141, 57-45545, 54-112637, 55-74546, etc.), phenylenediamine derivatives (US Pat. No. 3,615,404). Description, Japanese Patent Publication No. 51-10105, 46-3712
Japanese Patent Publication No. 47-25336, Japanese Patent Laid-Open No. 54-53.
No. 435, No. 54-110536, No. 54-
119925), arylamine derivatives (U.S. Pat. No. 3,567,450, U.S. Pat. No. 3,1).
No. 80,703, No. 3,240,597, No. 3,658,520, No. 4,23.
2,103, 4,175,961, 4,012,376, and JP-B-49-3.
5702, 39-27577, and JP-A-5
No. 5-144250, No. 56-119132, No. 56-22437, West German Patent No. 1,11.
0518, etc.), amino-substituted chalcone derivatives (see US Pat. No. 3,526,501, etc.),
Oxazole derivatives (disclosed in US Pat. No. 3,257,203, etc.), styrylanthracene derivatives (see JP-A-56-46234, etc.), fluorenone derivatives (see JP-A-54-110837, etc.) ),
Hydrazone derivatives (U.S. Pat. No. 3,717,462, JP-A-54-59143, JP-A-55-520)
63, 55-52064, 55-46.
No. 760, No. 55-85495, No. 57-1.
No. 1350, No. 57-148749, No. 2-311591, etc.), Stilbene derivatives (No. 61-210363, No. 61-2284).
No. 51, No. 61-14642, No. 61-72.
No. 255, No. 62-47646, No. 62-3.
6674, 62-10652, and 62-
No. 30255, No. 60-93445, No. 60
-94462, 60-174749, 60-175052, etc.), silazane derivatives (U.S. Pat. No. 4,950,950), polysilanes (JP-A-2-204996), Aniline-based copolymer (JP-A-2-28263), JP-A-1-
Examples thereof include conductive polymer oligomers (particularly thiophene oligomers) disclosed in Japanese Patent Publication No. 211399. As the material for the hole injection layer, the above-mentioned materials can be used, but a porphyrin compound (JP-A-63-
No. 2956965, etc.), aromatic tertiary amine compounds and styrylamine compounds (US Pat. No. 4,127,412, JP-A-53-27033).
No. 54-58445 and No. 54-1496.
34, 54-64299, 55-79.
No. 450, No. 55-144250, No. 56-
119132, 61-295558, 61-98353, 63-295695, etc.), and it is particularly preferable to use an aromatic tertiary amine compound. Typical examples of the porphyrin compound include porphine, 1,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), 1,10,
15,20-Tetraphenyl-21H, 23H-porphine zinc (II), 5,10,15,20-tetrakis (pentafluorophenyl) -21H, 23H-porphine, silicon phthalocyanine oxide, aluminum phthalocyanine chloride, phthalocyanine (metal-free ),
Examples thereof include dilithium phthalocyanine, copper tetramethylphthalocyanine, copper phthalocyanine, chromium phthalocyanine, zinc phthalocyanine, lead phthalocyanine, titanium phthalocyanine oxide, Mg phthalocyanine and copper octamethylphthalocyanine. Further, as typical examples of the aromatic tertiary amine compound and the styrylamine compound, N, N, N ′, N′-tetraphenyl-4,4′-diaminophenyl, N, N′-diphenyl-N, N'-bis- (3-methylphenyl)-[1,
1'-biphenyl] -4,4'-diamine (hereinafter TPD
Abbreviated), 2,2-bis (4-di-p-tolylaminophenyl) propane, 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane, N, N, N ′,
N'-tetra-p-tolyl-4,4'-diaminophenyl, 1,1-bis (4-di-p-tolylaminophenyl) -4-phenylcyclohexane, bis (4-dimethylamino-2-methylphenyl) ) Phenylmethane, bis (4-di-p-tolylaminophenyl) phenylmethane, N, N'-diphenyl-N, N'-di (4-methoxyphenyl) -4,4'-diaminobiphenyl, N,
N, N ', N'-tetraphenyl-4,4'-diaminophenyl ether, 4,4'-bis (diphenylamino) quadriphenyl, N, N, N-tri (p-tolyl) amine, 4- (Di-p-tolylamino) -4'-
[4 (di-p-tolylamino) styryl] stilbene,
4-N, N-diphenylamino- (2-diphenylvinyl) benzene, 3-methoxy-4′-N, N-diphenylaminostilbenzene, N-phenylcarbazole,
Having two fused aromatic rings in the molecule described in U.S. Pat. No. 5,061,569, for example 4,4'-
Bis [N- (1-naphthyl) -N-phenylamino] biphenyl (hereinafter abbreviated as NPD), and also JP-A-4-
The three triphenylamine units described in Japanese Patent No. 308688 are linked in a starburst type 4,
4 ′, 4 ″ -tris [N- (3-methylphenyl) -N
-Phenylamino] triphenylamine (hereinafter MTDA
(Abbreviated as TA)) and the like. Further, in addition to the above-mentioned aromatic dimethylidyne compounds shown as materials for the light emitting layer, inorganic compounds such as p-type-Si and p-type SiC can be used as materials for the hole injection layer. The hole injection layer can be formed by forming the above compound into a thin film by a known method such as a vacuum vapor deposition method, a spin coating method, a casting method, and an LB method. The thickness of the hole injection layer is not particularly limited, but is usually 5 nm to 5 μm.
m. This hole-injection layer may be composed of a single layer made of one or more of the above-mentioned materials, or one in which a hole-injection layer made of a compound different from the hole-injection layer is laminated. May be The organic semiconductor layer is a layer that assists hole injection or electron injection into the light emitting layer, and preferably has a conductivity of 10 ^-10 S / cm or more. As a material for such an organic semiconductor layer,
Conductive oligomers such as thiophene-containing oligomers and arylamine-containing oligomers, and conductive dendrimers such as arylamine-containing dendrimers can be used.

(4) -3 Electron Injection Layer On the other hand, the electron injection layer is a layer for assisting injection of electrons into the light emitting layer, has a high electron mobility, and the adhesion improving layer is one of the electron injection layers. In particular, it is a layer made of a material having good adhesion to the cathode. Preferable examples of the material used for the electron injection layer include a metal complex of 8-hydroxyquinoline or a derivative thereof, or an oxadiazole derivative. Further, as a material used for the adhesion improving layer, a metal complex of 8-hydroxyquinoline or its derivative is particularly suitable. Specific examples of the metal complex of 8-hydroxyquinoline or a derivative thereof include metal chelate oxinoid compounds containing a chelate of oxine (generally 8-quinolinol or 8-hydroxyquinoline). On the other hand, the oxadiazole derivative is represented by the general formulas (II), (III) and (IV)

[0066]

[Chemical 9]

(In the formula, Ar ^{10 to} Ar ¹³ each represent a substituted or unsubstituted aryl group, and Ar ¹⁰ and Ar ¹¹ and A
r ¹² and Ar ¹³ may be the same or different from each other and each represents an Ar ¹⁴ substituted or unsubstituted arylene group. ) And electron transfer compounds. Here, examples of the aryl group include a phenyl group, biphenyl group, anthranyl group, perylenyl group, and pyrenyl group, and examples of the arylene group include a phenylene group, a naphthylene group, a biphenylene group, anthracenylene group, a penenylenene group, and a pyrenylene group. To be Also,
As a substituent, an alkyl group having 1 to 10 carbon atoms, 1 carbon atom
Alkoxy groups or cyano groups of 10 to 10 are mentioned. The electron transfer compound is preferably one capable of forming a thin film. The following can be mentioned as specific examples of the electron transfer compound.

[0068]

[Chemical 10]

(4) -4. Lower electrode An anode or a cathode is provided as a lower electrode of the organic EL element. A metal having a high work function or a transparent electrode is preferable as the anode. Preferred examples are ITO, In-Zn-
Examples include transparent oxide electrodes such as O, SnO ₂ : Sb, and ZnO: Al. Other preferable examples include Pt and A
Although u, Ni and the like can be mentioned, since Pt, Au and the like have weak adhesion, it is preferable to use a combination of Au / high melting point metal. Here, as preferable examples of the high melting point metal, Mo, W,
Examples thereof include Cr and Ta. Au / Al, P
Preferable examples include t / Al, An / Al alloy, Pt / Al alloy and the like.

Preferred examples of the cathode include metal boride (LaB _{6 and the} like), rare earth metal silicides, and low work metal compounds such as TiN. Mg: A
Conventionally used metal alloys such as g and Al: Li are inferior in corrosion resistance and are not necessarily suitable for use as the lower electrode.

(4) -5. Counter electrode To realize the feature of the present invention, that is, high aperture ratio,
It is preferable to extract light from the counter electrode 33 as shown in FIG. For this purpose, the transparency is preferably 30 and the light transmittance is 30.
% Or more transparent electrodes are required. When the counter electrode is an anode, ITO (In-Sn-O), In-Zn-O,
SnO ₂ : Sb, ZnO: Al and the like can be preferably used.

In the case of a cathode rather than an anode, an alloy film containing 0.1 to 5 mol% of an alkali metal or an alkaline earth metal and having a film thickness of 15 nm or less is preferably used because it has a light transmittance. be able to. As the base material of the alloy, Al, In, Zn, Pb, Bi or the like can be preferably used. Further ITO transparent electrode on the alloy thin _{film, In-ZnO, SnO 2:} S, ZnO: A
If 1 or the like is laminated, the surface resistance value is 20Ω / □ or less, which is relatively low resistance, which is preferable. The transparent electrode is preferably amorphous, for example, In-Zn-O. This is because the amorphous material has no grain boundary and thus has excellent moisture resistance and prevents the active alkali metal or alkaline earth metal at the interface between the cathode and the organic layer from being oxidized. Furthermore, the amorphous conductive oxide film is used for the room temperature substrate.
A sheet resistance value of 0Ω / □ or less can be obtained. IT that is crystalline
O has a high resistance at room temperature and is about 100Ω / □.

When a transparent electrode is laminated, the above alloy film does not have to be a continuous film forming a layer, and even an island-shaped discontinuous film can be used to conduct electricity to the entire electrode. it can.

(4) -6. Preparation of Organic EL Element (Example) A light emitting layer, a transparent electrode (anode), a hole injecting layer if necessary, and an electron injecting layer if necessary are formed by the materials and methods described above, and further an electrode (cathode). By forming the, an organic EL element can be manufactured. Also, an organic EL element can be manufactured from the electrode to the transparent electrode in the reverse order of the above.

An example of manufacturing an organic EL device having a structure in which a transparent electrode / hole injection layer / light emitting layer / electron injection layer / electrode are sequentially provided on a supporting substrate will be described below. First, a transparent electrode is prepared by forming a thin film of a transparent electrode material on a suitable substrate by a method such as vapor deposition or sputtering so as to have a film thickness of 1 μm or less, preferably 10 to 200 nm. Next, a hole injection layer is provided on this transparent electrode. The hole injection layer can be formed by the vacuum deposition method, the spin coating method, the casting method, the LB method or the like as described above, but a uniform film is easily obtained and pinholes are less likely to occur. From the viewpoints of the above, it is preferable to form by the vacuum deposition method. When the hole injection layer is formed by a vacuum deposition method, the deposition conditions vary depending on the compound used (the material of the hole injection layer), the crystal structure or recombination structure of the target hole injection layer, etc. Vapor deposition source temperature 50-450
° C, degree of vacuum 10 ^-7 to 10 ^-3 torr, vapor deposition rate 0.01
-50 nm / sec, substrate temperature -50 to 300 ° C, and film thickness 5 nm to 5 µm are preferably selected as appropriate.

Next, the formation of the light emitting layer in which the light emitting layer is provided on the hole injecting layer is also carried out by using the desired organic light emitting material by the vacuum vapor deposition method,
It can be formed by thinning the organic light-emitting material by a method such as sputtering, spin coating, or casting, but it is formed by the vacuum deposition method because it is easy to obtain a homogeneous film and pinholes are not easily generated. Preferably. When the light emitting layer is formed by the vacuum vapor deposition method, the vapor deposition conditions can be selected from the same range of conditions as those for the hole injection layer, although the conditions vary depending on the compound used.

Next, an electron injection layer is provided on this light emitting layer. Similar to the hole injecting layer and the light emitting layer, it is preferable to form the film by the vacuum vapor deposition method because it is necessary to obtain a uniform film. The vapor deposition conditions can be selected from the same range as the hole injection layer and the light emitting layer.

Finally, the electrodes can be laminated to obtain an organic EL device. The electrodes are made of metal,
A vapor deposition method or sputtering can be used. However, in order to protect the underlying organic layer from damage during film formation,
The vacuum deposition method is preferred.

In the production of the organic EL element described so far, it is preferable to consistently produce from the transparent electrode to the electrode by vacuuming once.

When a direct current voltage is applied to the organic EL element, the transparent electrode has a positive polarity and the electrode has a negative polarity.
Light emission can be observed when a voltage of V is applied. Moreover, even if a voltage is applied with the opposite polarity, no current flows and no light emission occurs. When an alternating voltage is further applied, uniform light emission is observed only when the transparent electrode has a positive polarity and the electrode has a negative polarity. The waveform of the alternating current applied may be arbitrary. Here, in order to fabricate an organic EL element that emits light by being separated and arranged in a plane, stripe-shaped transparent electrodes and electrodes are crossed, a DC voltage is applied to each electrode, and XY is caused to emit light at the crossing portions. Dot matrix method and either transparent electrodes or electrodes are formed in a dot shape, and the TFT (Thin Film Tr
An active matrix method in which a switching element such as an ansister) applies a DC voltage only to a specific dot portion to emit light. For example, the stripe-shaped transparent electrode and the electrode can be formed by etching or lift-off by a photolithography method, or by a method such as masking vapor deposition.

[Examples] The present invention will be described in more detail below with reference to examples. Example 1 (Production of Active Matrix Substrate) An α-Si film having a thickness of 50 nm was formed on a glass substrate (white plate glass) by LPCVD using Si ₂ H ₆ as a gas. The substrate temperature was 450 ° C. Next, the XeCl excimer laser was swept and annealed. 188mJ on the first stage
Irradiation energy of / cm ² and the second step is 290 mJ /
The irradiation energy was cm ² . This makes α-S
i was changed to polysilicon. Next, poly-Si islands were provided in a predetermined pattern. The etching was performed using CF ₄ as a gas species. Next, SiO ₂ which is a gate insulating film is removed by E
A film having a thickness of 100 nm was formed by CR-CVD at a substrate temperature of 200 ° C. Next, as a gate electrode, TaN (60 μΩ · cm
Was deposited by sputtering and patterned. At the same time, the gate bus was also patterned. Also, the lower electrode of the capacitor was processed. Next, P ions of 4 × 10 ¹⁵ ions / cm ² and energy of 80 keV were implanted into the drain and source regions by ion implantation.
Next, the substrate is heated in inert N ₂ at 300 ° C. for 3 hours,
Ions were activated so that doping was effectively performed. The composition of ion-implanted polysilicon is 2 kΩ
Activated with a sheet resistance value of / □. Next, SiO ₂ was deposited as an insulating layer by ECRCVD. The film thickness is 300
was nm. Next, the source bus (signal line) was formed into a film. Al is sputtered to provide a film thickness of 200 nm, and at the same time, the common electrode line shown in FIG. 2, the upper electrode of the capacitor, the source of Tr2 and the common electrode line are connected, T
The connection between the source of r1 and the signal line was also patterned.
The necessary contact holes were previously opened in SiO ₂ . Next, SiO ₂ was laminated by ECRCVD to a film thickness of 600 nm. Next, a photoresist having a film thickness of 3 μm was spin-coated on the entire surface and covered.
Next, the uppermost SiO ₂ was flattened by an etch-back method by using RIE as a gas species of CF ₄ / O ₂ . Next, Tr
The drain part of 2 is opened, and an alloy of Al: Si (Si 1 wt%) is formed to a film thickness of 50 nm.
(n10% by weight) was formed into a film having a thickness of 50 nm. The substrate temperature at this time was 200 ° C. Al: Si with a stylus film thickness meter
When the flatness of SiO ₂ before film formation of ITO was examined, it was 0.15 μm or less. As a result, Al: Si
And ITO is poly Si, Tr1,
It could be provided on top of Tr2. This is a remarkable effect of the present invention. The pixel size of this embodiment is 25.
0 μm × 100 μm, on the other hand, the size of ITO gives an effective light emitting pixel size, but 240 μm × 90
was μm. Since the lower electrodes of the organic EL are provided on the Tr1, Tr2, gate, source and common electrode lines, an extremely large aperture ratio of 86% was obtained.

(Production of Organic EL Layer and Counter Electrode) The active matrix substrate obtained above was subjected to ultrasonic cleaning in isopropyl alcohol for 1 minute. Next, on this substrate, a 4,4′-bis [N, N-di (3-methylphenyl) amino] -4 ″ -phenyl-triphenylamine film having a film thickness of 80 nm (hereinafter abbreviated as “TPD74 film”). .) Was formed into a film. This TPD74 film functions as a first hole injection layer. Subsequent to the formation of this TPD74 film, a 20 nm-thick 4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl film (hereinafter abbreviated as "NPD film") is formed on this TPD74 film. .) Was deposited. This NPD film is a second hole injection layer (hole transport layer)
Function as. Further, following the film formation of the NPD film, 4,4′-bis (2,2) having a film thickness of 40 nm is formed on the NPD film.
-Diphenyl vinyl) biphenyl film (hereinafter "DPVBi
"Membrane" is abbreviated. ) Was deposited. This DPVBi film is
Functions as a blue light emitting layer. Then, following the formation of the DPVBi film, a 20 nm thick tris (8-quinolinol) aluminum film (hereinafter referred to as “Alq
"Membrane" is abbreviated. ) Was deposited. This Alq film functions as an electron injection layer. Next, an alloy film of Mg and Ag was deposited. The vapor deposition rate is 1.4 nm using the two-source vapor deposition method:
The film thickness was set to 0.1 nm and the film thickness was 10 nm. Next, an In-Zn-O film having a thickness of 200 nm was formed by sputtering. The In-Zn-O film is an amorphous oxide film, and
(In + Zn) = 0.83 using an In -Zn O based sputtering target is, Ar: vacuum a mixed gas of O ₂ as an atmosphere 0.2 Pa, sputtering power 2w
It was performed under the condition of / cm ² . Mg: Ag / In-ZnO
The laminated film functioned as a cathode, and its transmittance was 65%.

(Operation Test) An operation test of the light emitting device obtained above was conducted. Test pattern is 100 cd /
It was confirmed that the output was blue with a brightness of m ² . Since the lower electrode is provided on the flattened insulating film, the aperture ratio is large and the pixel dot boundaries are not conspicuous in the image display for a natural display, and there are few pixel defects and the total number of pixels (320 x 240). It was 1% or less.

[Comparative Example 1] An organic EL light emitting device was prepared in the same manner as in Example 1 except that the uppermost SiO ₂ was not flattened and a lower electrode of Al: Si / ITO was formed. Was produced. However, when this light emitting device was tested, the pixel defect was more than 10%. When the defective pixel was observed in detail, it was observed that a short circuit occurred at the position where Tr1 and Tr2 were provided or that no light was emitted due to the disconnection of the electrode. Therefore, it was found that the insulating film under the flattened lower electrode of the present invention is effective.

Comparative Example 2 In Example 1, Al: S
The same procedure as in Example 1 was carried out except that the lower electrode of i / ITO was patterned so as to avoid the Tr1, Tr2 portions, the gate bus portion and the source bus portion.
When the test was conducted, the aperture ratio decreased to 67%,
In the pixel display, the boundary of pixel dots was conspicuous, and good display could not be obtained.

[0086]

As described above, according to the present invention, the aperture ratio is large and the occurrence of image defects is effectively prevented.
It is possible to provide an organic active EL light emitting device capable of displaying a high quality image.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the line AA of FIG. 3, schematically showing an embodiment of an organic active EL light emitting device of the present invention.

FIG. 2 is an explanatory diagram showing a drive circuit for an organic EL element used in the present invention.

FIG. 3 is a plan view schematically showing an embodiment of the organic active EL light emitting device of the present invention.

FIG. 4 is a cross-sectional view schematically showing a process of patterning a polysilicon layer of a thin film transistor used in the present invention into an island.

FIG. 5 is a circuit diagram of a conventional organic TFT EL.

6 is a cross-sectional view taken along the line AA ′ in FIG.

FIG. 7 is a cross-sectional view showing another example of a conventional organic TFT EL.

FIG. 8 is a sectional view showing another example of a conventional organic TFT EL.

[Explanation of symbols]

1 substrate 2 Thin film transistor (TFT) 21 First Transistor (Tr1) 22 Second transistor (Tr2) 23 condenser 3 Organic EL element 31 Lower electrode 32 organic layers 33 Counter electrode 4 Interlayer insulation film 41 contact holes 42 Gate insulating layer 43 Gate electrode 44 Silicon active layer 46 gate line 52 insulating film 54 contact holes 62 Source 70 Polysilicon layer 71 Polysilicon Island 72 Gate insulation layer 73 Polysilicon gate electrode 81 Hole injection electrode 82 Electron injection electrode 83 Gate electrode 84 Source electrode

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H05B 33/00-33/28

Claims (8)

(57) [Claims] 1. A plurality of thin film transistors (TFTs) on a substrate, and a TFT driven by the TFTs.
In an organic active EL light emitting device having a plurality of organic EL elements arranged corresponding to, a flattened interlayer insulating film is provided between the TFT and the lower electrode of the organic EL element, and the TFT Terminal and organic EL
The lower electrode of the device is electrically connected through a contact hole provided in the interlayer insulating film, and the lower electrode is Au / Mo, Au / W, Au / Cr, Au /
An organic active EL light-emitting device characterized by comprising at least one alloy selected from the group consisting of Ta, Au / Al and Pt / Al. 2. A plurality of thin film transistors (TFTs) on a substrate and a TFT driven by the TFTs.
In an organic active EL light emitting device having a plurality of organic EL elements arranged corresponding to, a flattened interlayer insulating film is provided between the TFT and the lower electrode of the organic EL element, and the TFT Terminal and organic EL
The lower electrode of the device is electrically connected through a contact hole provided in the interlayer insulating film, and the counter electrode of the organic EL device is a cathode including an amorphous transparent electrode.
Organic active EL light emitting device, characterized in that it. 3. A plurality of thin film transistors (TFTs) on a substrate and a TFT driven by the TFTs.
In an organic active EL light emitting device having a plurality of organic EL elements arranged corresponding to, a flattened interlayer insulating film is provided between the TFT and the lower electrode of the organic EL element, and the TFT Terminal and organic EL
The lower electrode of the element is electrically connected through a contact hole provided in the interlayer insulating film, and the lower electrode is Mo, W, Cr or Ta and Pt, Au or
Is a combination of Ni and the organic active EL light-emitting device. 4. The aperture ratio (the ratio of the portion that actually emits light to the pixel) is 75% or more .
The organic active EL light emitting device according to any one of claims. 5. A plurality of scanning electrode lines and signal electrode lines arranged in an XY matrix on a substrate, and electric switches arranged in the vicinity of the scanning electrode lines and signal electrode lines, In this organic active EL light emitting device, which performs image switching by causing the organic EL element in the unit pixel coupled to the electric switch to emit or stop emitting light by performing a switch operation with the scanning signal pulse and the signal pulse by the electric switch, The electric switch is formed of one or more thin film transistors (first transistor) for selecting a light emitting pixel and one or more thin film transistors (second transistor) for driving the organic EL element, and the first and second electric switches are provided. A flattened interlayer insulating film is provided between the transistor and the lower electrode of the organic EL element. And the drain of Lunge star, and the lower electrode of the organic EL element is electrically connected to the lower electrode is Au / Mo, Au / W, Au / Cr, Au /
An organic active EL light-emitting device characterized by comprising at least one alloy selected from the group consisting of Ta, Au / Al and Pt / Al. 6. A plurality of scan electrode lines and signal electrode lines arranged in an XY matrix on a substrate, and electric switches arranged in the vicinity of the scan electrode lines and signal electrode lines, In this organic active EL light emitting device, which performs image switching by causing the organic EL element in the unit pixel coupled to the electric switch to emit or stop emitting light by performing a switch operation with the scanning signal pulse and the signal pulse by the electric switch, The electric switch is formed of one or more thin film transistors (first transistor) for selecting a light emitting pixel and one or more thin film transistors (second transistor) for driving the organic EL element, and the first and second electric switches are provided. A flattened interlayer insulating film is provided between the transistor and the lower electrode of the organic EL element. And the drain of Lunge star, and the lower electrode of the organic EL element is electrically connected to the counter electrode of the organic EL element, a cathode including an amorphous transparent electrode
Organic active EL light emitting device, characterized in that it. 7. A plurality of scan electrode lines and signal electrode lines arranged in an XY matrix on a substrate, and an electric switch arranged in the vicinity of the scan electrode lines and signal electrode lines, In this organic active EL light emitting device, which performs image switching by causing the organic EL element in the unit pixel coupled to the electric switch to emit or stop emitting light by performing a switch operation with the scanning signal pulse and the signal pulse by the electric switch, The electric switch is formed of one or more thin film transistors (first transistor) for selecting a light emitting pixel and one or more thin film transistors (second transistor) for driving the organic EL element, and the first and second electric switches are provided. A flattened interlayer insulating film is provided between the transistor and the lower electrode of the organic EL element. And the drain of Lunge star, and the lower electrode of the organic EL element is electrically connected to the lower electrode, and Mo, W, Cr or Ta, Pt, Au The
Is a combination of Ni and the organic active EL light-emitting device. Wherein said counter electrode of the organic EL element, an organic active EL light emitting device according to claim 5 or 7, wherein the transparent.