JP3672127B2 - Optical element manufacturing method and optical element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing an optical element and an optical element, and is a self-luminous flat display, and in particular, a method for manufacturing an optical element suitable for an organic electroluminescent display using an organic thin film as an electroluminescent layer, And an optical element thereof.
[0002]
[Prior art]
In recent years, the importance of human-machine interfaces has been increasing, especially in multimedia-oriented products. In order for humans to operate a machine more comfortably and efficiently, it is necessary to extract information from the machine to be operated in a succinct, instantaneous, and sufficient amount without error. Research has been conducted on display elements.
[0003]
In addition, with the miniaturization of machines, the demand for miniaturization and thinness of display elements is increasing day by day.
[0004]
For example, downsizing of laptop information processing devices that are integrated with display elements, such as notebook personal computers and notebook word processors, has made remarkable progress, and as a result, technologies related to liquid crystal displays that are display elements Innovation is also great.
[0005]
Today, liquid crystal displays are used as interfaces for various products, and are often used not only in laptop-type information processing equipment but also in products that we use everyday, such as small TVs, watches, and calculators. .
[0006]
These liquid crystal displays have been studied as the center of display elements as a human-machine interface, ranging from small to large capacity display devices, taking advantage of the low-voltage driving and low power consumption of liquid crystals.
[0007]
However, since this liquid crystal display is not self-luminous, it requires a backlight, and this backlight drive requires more power than driving the liquid crystal. There are restrictions on use.
[0008]
Furthermore, since the viewing angle is narrow, the liquid crystal display is not suitable for a large display element such as a large display, and the display method is based on the orientation state of the liquid crystal molecules. It is also a big problem.
[0009]
From the viewpoint of the driving method, the active matrix method, which is one of the driving methods, exhibits a response speed sufficient for handling moving images. However, since a TFT (thin film transistor) driving circuit is used, the screen size is increased due to pixel defects. Is difficult. Use of a TFT drive circuit is not preferable from the viewpoint of cost reduction.
[0010]
Another driving method, the simple matrix method, is low in cost and relatively easy to increase the screen size, but has a problem that it does not have a response speed sufficient to handle moving images.
[0011]
On the other hand, plasma display elements, inorganic electroluminescent elements, organic electroluminescent elements and the like have been studied as self-luminous display elements.
[0012]
A plasma display element uses plasma light emission in a low-pressure gas for display and is suitable for an increase in size and capacity, but has problems in terms of thickness reduction and cost. In addition, a high voltage AC bias is required for driving, which is not suitable for portable devices.
[0013]
As for the inorganic electroluminescent element, a green light emitting display or the like has been commercialized. However, like the plasma display element, it is an AC bias drive, and several hundred volts are required for the drive, and full color is considered difficult. .
[0014]
On the other hand, the electroluminescence phenomenon caused by organic compounds has been studied for a long time since the discovery of the light emission phenomenon caused by carrier injection into the anthracene single crystal that generates strong fluorescence in the first half of the 1960s. And since it was a single crystal, it was carried out as a basic study of carrier injection into an organic material.
[0015]
However, since Tang et al. Of Eastman Kodak in 1987 announced an organic thin-film electroluminescent device with an amorphous light-emitting layer that can be driven at low voltage and capable of high-intensity light emission, R, G, B Research and development of these three primary colors, such as light emission, stability, brightness increase, layered structure, and production method, are actively conducted.
[0016]
Furthermore, as a characteristic of organic materials, various new materials have been invented by molecular design, etc., and have excellent characteristics such as direct current low voltage driving, thinness, self-luminous property, etc. Applied research is also being actively conducted.
[0017]
An organic electroluminescent element (hereinafter sometimes referred to as an organic EL element) has a film thickness of 1 μm or less, and converts electric energy into light energy by injecting a current to emit light in a planar shape. It has ideal characteristics as a light-emitting display device.
[0018]
FIG. 22 shows an example of a conventional organic EL element 10. The organic EL element 10 includes an ITO (Indium Tin Oxide) transparent electrode 5, a hole transport layer 4, a light emitting layer 3, an electron transport layer 2, and a cathode (for example, an aluminum electrode) 1 on a transparent substrate (for example, a glass substrate) 6. For example, the films are sequentially formed by vacuum deposition.
[0019]
Then, by selectively applying a DC voltage 17 between the transparent electrode 5 as the anode and the cathode 1, holes as carriers injected from the transparent electrode 5 pass through the hole transport layer 4 and from the cathode 1. The injected electrons move through the electron transport layer 2 and electron-hole recombination occurs. From this, light emission 18 having a predetermined wavelength is generated and can be observed from the transparent substrate 6 side.
[0020]
For the light emitting layer 3, for example, a light emitting material such as anthracene, naphthalene, phenanthrene, pyrene, chrysene, perylene, butadiene, coumarin, acridine, stilbene, or the like may be used. This can be contained in the electron transport layer 2.
[0021]
FIG. 23 shows another conventional example. In this example, the light-emitting layer 3 is omitted, and the electron transport layer 2 contains a mixture of the above zinc complex or phosphor, so that the electron transport layer 2 2 shows an organic EL element 20 configured to emit light 18 having a predetermined wavelength from the interface between the hole transport layer 4 and the hole transport layer 4.
[0022]
FIG. 24 shows a specific example of the organic EL element. That is, a laminate of each organic layer (hole transport layer 4, light-emitting layer 3 or electron transport layer 2) is disposed between the cathode 1 and the anode 5, and these electrodes are crossed in a matrix to form a stripe shape. A signal voltage is applied in time series by a luminance signal circuit 40 and a control circuit 41 with a built-in shift register, and light is emitted at each of a number of intersection positions (pixels).
[0023]
Therefore, with such a configuration, it can be used not only as a display but also as an image reproducing apparatus. Note that the stripe pattern described above can be arranged for each color of red (R), green (G), and blue (B), and can be configured for full color or multicolor.
[0024]
In a display device composed of a plurality of pixels using such an organic EL element, the organic thin film layers 2, 3, and 4 that emit light are generally sandwiched between the transparent electrode 5 and the metal electrode 1, and the transparent electrode 5 side Flashes on.
[0025]
However, the organic EL elements as described above still have unsolved problems.
[0026]
For example, degradation of these organic electroluminescent devices is a major problem. The cause of the degradation is due to the thermal degradation of organic materials due to heat generated by light emission, the influence of moisture and oxygen mixed during production, and the cathode. Although peeling from the organic layer due to the oxidation of the electrode is considered, it is not clear and is considered to be a combined factor of these causes.
[0027]
When an organic electroluminescent element is applied to a display device or the like, the influence of the above factors on the lifetime of the element is a big problem. Therefore, it is desirable to provide a sealing film to protect the organic layer and the metal electrode, and then to form a vacuum consistently up to the sealing film structure.
[0028]
However, for example, when an insulating sealing film is provided, when the insulating sealing film is produced in a vacuum deposition apparatus, the influence of radiant heat during the deposition of the insulating sealing film is large, and the organic layer including the light emitting layer is not affected. It turns out that the impact is concerned.
[0029]
[Problems to be solved by the invention]
The present invention has been made in view of the circumstances as described above, and has a method for producing a long-life optical element exhibiting good stability even in the atmosphere with little deterioration of the organic layer, and its optical The object is to provide an element.
[0030]
[Means for Solving the Problems]
  That is, the present inventionOn the strip pattern anode,Organic layer including light emitting regionAnd cathode in the same pattern with a common mask in this orderAfter vacuum deposition, keep the vacuumCovering the cathode and the organic layer over their entire surface and sidesConductive sealing filmIn a strip pattern crossing the anodeFormationFurther, an insulating sealing film is formed to cover the conductive sealing film at a position where the anode and the cathode overlap with each other while maintaining a vacuum.The present invention relates to a method for manufacturing an optical element.
  The present invention also provides:On the strip pattern anode,Organic layer including light emitting regionAnd the cathode are deposited in the same pattern in this order,SaidshadowPoles and saidCover the organic layer over all of these surfaces and sidesConductive sealing filmFormed in a strip pattern intersecting the anodeIsAn insulating sealing film is formed to cover the conductive sealing film at a position where the anode and the cathode overlap.An optical element is also provided.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
  In the manufacturing method of the present invention, an insulating sealing film is formed on the conductive sealing film while maintaining a vacuum.In this case, a conductive sealing film and an insulating sealing film are sequentially formed by vacuum deposition.It is desirable.
[0033]
And said element is an organic hole transport layer, an organic light emitting layer and / or an organic electron transport layer, a metal electrode, an electroconductive sealing film, on the said transparent electrode of the optically transparent base | substrate provided with the transparent electrode. It is desirable to sequentially stack the insulating sealing film under vacuum film formation conditions.
[0034]
As a result, the above method becomes a suitable method for producing an organic electroluminescent element, and this element is suitable as an element for a color display.
[0035]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
[0036]
Example 1
FIG. 1 is a cross-sectional view showing an organic EL element 31 manufactured according to Example 1 based on the present invention. FIG. 1 may show one of the pixels PX formed in a dot shape on the glass substrate 6 as shown in FIG.
[0037]
As shown in FIG. 1, the organic EL device according to this example includes a transparent electrode 5 (anode) made of ITO (Indium Tin Oxide) on a glass substrate 6, a hole transport layer 4, and a light emitting layer 3 that also serves as an electron transport layer. And an electrode 1 (cathode) made of a lithium-aluminum (LiAl) alloy is laminated, and constitutes the same single hetero type laminate as FIG. 23 described above.
[0038]
A conductive sealing film 7 and an insulating sealing film 8 are sequentially formed on the electrode 1 so as to cover the side surfaces of the element. These sealing films are formed by the method of this example using a vacuum vapor deposition apparatus described later.
[0039]
The structure shown in FIG. 1 can also be applied to a double hetero type organic EL element in which the electron transport layer 2 shown in FIG. 22 is independently provided.
[0040]
FIG. 2 is a plan view showing a specific example of the organic EL element 30 produced by a vacuum vapor deposition apparatus. That is, an ITO transparent electrode 5 having a size l of 2 mm × 2 mm is deposited on a glass substrate 6 having a size L of 30 mm × 30 mm to a thickness of about 100 nm by the above-described vacuum deposition apparatus, and then the entire surface is made of SiO.₂9 is vapor-deposited and etched into a predetermined pixel pattern to form a large number of openings 15 where the transparent electrodes 5 are respectively exposed. Therefore, SiO₂By using the vapor deposition mask 22 shown in FIG. 3, the organic layers 4 and 3 and the metal electrode 1 are sequentially formed on the light emitting area (pixel) PX of 2 mm × 2 mm.
[0041]
FIG. 3 is a plan view schematically showing the positional relationship of various vapor deposition masks used for producing the organic EL element in this example, and shows the openings of the respective masks. That is, the organic layers 4, 3 and the electrode 1 are formed by the opening 22 a of the mask 22, and then the elements 23 in the same row perpendicular to the ITO transparent electrode 5 are electrically conductive by the opening 23 a of the mask 23. The insulating sealing film 7 is formed, and finally the insulating sealing film 8 is formed for each element by the opening 24a of the mask 24, whereby the element having the shape as shown in FIG. 1 is manufactured.
[0042]
Each of these masks 22, 23, 24 is arranged in a vacuum vapor deposition apparatus 11 as shown in FIG. Inside the apparatus, a pair of support means 13 fixed below the arm 12 is provided, and between the both fixing means 13, 13, the transparent glass substrate 6 is faced downward, and the masks 22, 23, A stage mechanism (not shown) that can set 24 is provided. A predetermined number of various evaporation sources 28 are arranged below the glass substrate and the mask. Each vapor deposition source is heated by a resistance heating method using a power source 29. For this heating, an EB (electron beam) heating method or the like is used as necessary.
[0043]
Next, a specific manufacturing process of the organic EL element according to this example will be described.
[0044]
FIG. 5 shows a case where the ITO transparent electrode 5 is deposited on the same glass substrate 6 as that shown in FIG.₂9 is a plan view showing a state in which a large number of openings 15 are formed by etching a predetermined pixel pattern to form a large number of openings 15 and the transparent electrode 5 is exposed in the openings 15, with a part omitted. It is a thing. In the following, each manufacturing stage shown in FIGS. 6 to 11 is shown by the A-A cross section of part a of FIG.
[0045]
First, as shown in FIG. 5, on the ITO transparent electrode 5 provided with a film thickness of about 100 nm on a 30 mm × 30 mm glass substrate 6, SiO 2₂9 was vapor-deposited, and this was patterned to produce a cell for producing an organic EL element in which areas other than the light emitting region 15 of 2 mm × 2 mm were masked.
[0046]
Thereby, the state of FIG. 8 is formed. 6 is a cross-sectional view taken along the line AA in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 6, both showing a state in which the ITO transparent electrode 5 is formed. SiO on the transparent electrode 5₂Shows a state where is deposited and patterned.
[0047]
Next, the cell produced as described above is put in the vacuum vapor deposition apparatus shown in FIG. 4, and TPD (N, N′-diphenyl-N, N′-di (3) is used using the vapor deposition mask 22 as shown in FIG. -Methylphenyl) 4,4'-diaminobiphenyl) (see the structural formula of FIG. 15) was deposited by vacuum deposition to a thickness of about 50 nm under vacuum (deposition rate 2-4 [mu] / sec). Thereby, TPD was vapor-deposited from the opening 22a of the mask 22, and the hole transport layer 4 was formed.
[0048]
Subsequently, with the same vapor deposition mask, Alq which is an aluminum-quinoline complex is formed on the hole transport layer 4 deposited as described above._Three(Tris (8-quinolinol) aluminum) (see the structural formula in FIG. 14) was deposited to a thickness of about 50 nm (deposition rate 2 to 4 mm / sec), and light emitting layer (also serving as an electron transport layer: the same applies hereinafter) 3 was formed.
[0049]
Subsequently, with the same deposition mask, a LiAl alloy (Li content: 2.5%) was deposited on the light emitting layer 3 as a cathode electrode to a thickness of about 2 k２ (deposition rate: 11 to 13 速度 / sec). 1 was formed.
[0050]
Next, as shown in FIG. 10, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 k ^ (deposition rate 30 to 40 mm / sec). Thereby, gold was deposited from the opening 23a of the mask 23, and the conductive sealing film 7 was formed so as to cover the surface of the stacked body of the organic layers 4 and 3 and the electrode 1 as shown in the figure.
[0051]
Finally, as shown in FIG. 11, the mask is changed to a vapor deposition mask 24 and SiO 2 is formed on the conductive sealing film 7.₂Was vapor-deposited to a thickness of 2 k 速度 (deposition rate 50 to 60Å / sec). As a result, the SiO2 from the opening 24a of the mask 24₂And an insulating sealing film 8 covering the conductive sealing film 7 was formed, and an organic EL element 31 as shown in FIG. 1 was produced.
[0052]
In this way, in this example, since the organic layer to the insulating sealing film are continuously deposited (by a vacuum consistent process) by changing the deposition mask in the same vacuum deposition apparatus, The device can be manufactured without being exposed to the atmosphere.
[0053]
12 is an enlarged cross-sectional view of a part of FIG. 11 manufactured as described above (corresponding to the cross-section along line AA in FIGS. 3 and 5), and FIG. 13 is a cross-sectional view along line XIII-XIII in FIG. This corresponds to a cross section taken along line BB in FIGS. 3 and 5.
[0054]
The organic EL device thus fabricated was left in the atmosphere for one month after fabrication, and the characteristics of this device were measured. As a result, the applied voltage was about 1200 cd / m at an applied voltage of 6V.²This result was almost the same as the result measured immediately after the device was fabricated. Further, almost no dark spots were generated, and the sealing effect by the sealing films 7 and 8 was remarkable.
[0055]
According to this example, since the conductive sealing film 7 provided on the electrode 1 is continuously formed in the same vacuum deposition apparatus, the conductive sealing film 7 is an underlying organic layer and In addition to protecting the electrode and preventing the oxidation of the electrode 1, this is further covered with SiO.₂By sealing with the insulating sealing film 8 which consists of this, the effect of preventing the oxidation of the electrode 1 and preventing the deterioration of the organic layer is further enhanced.
[0056]
Since the conductive sealing film 7 made of gold is interposed under the insulating sealing film 8, deterioration of the organic layer due to radiant heat during the deposition of the insulating sealing film 8 is prevented. For this purpose, the conductive sealing film 7 needs to be thickly formed as a buffer layer during vapor deposition, and the above thickness (about 10 k10) is sufficient.
[0057]
When the conductive sealing film 7 is made of a material having good thermal conductivity such as metal, it can be expected to effectively dissipate the radiant heat, which is advantageous for preventing deterioration of the organic layer.
[0058]
Moreover, since the top of the organic layer is continuously formed in the same vacuum deposition apparatus, the productivity is high and there is no influence of oxygen in the atmosphere during the production. In addition, each sealing film described above provides an organic EL element having good stability even when used in the air.
[0059]
And each effect mentioned above by this example is acquired similarly in the other example based on this invention mentioned later.
[0060]
Example 2
Also in this example, up to the light emitting layer 3 was formed using the vapor deposition mask 22 shown in FIG. The materials and the like used up to the light emitting layer 3 are the same as those in Example 1 (the same applies to each example described later), and thus the description thereof is omitted.
[0061]
Subsequently, with the same deposition mask, a lithium-aluminum (LiAl) alloy (lithium content 2.5%) was deposited on the light emitting layer 3 as a cathode electrode to a thickness of about 2 kÅ (deposition rate of 11 to 13〜 / sec) A metal electrode 1 was formed.
[0062]
Next, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 kÅ (deposition rate 30 to 40Å / sec) to form the conductive sealing film 7.
[0063]
Finally, the mask is changed to the vapor deposition mask 24 and alumina (Al₂O_Three) Was vapor-deposited to a thickness of 2 k 速度 (deposition rate of 50 to 60 絶 縁 / sec) to form an insulating sealing film 8, and an organic EL element 32 was produced as shown in FIG.
[0064]
The organic EL device thus fabricated was left in the atmosphere for one month after fabrication, and the characteristics of the device were measured. As a result, the applied voltage was about 1100 cd / m at 6V.²This result was almost the same as the result measured immediately after the device was fabricated. Further, almost no dark spots were generated, and the sealing effect by the sealing films 7 and 8 was observed.
[0065]
Example 3
Also in this example, a strontium-aluminum (SrAl) alloy (strontium content 2%) is used as a cathode electrode with the same vapor deposition mask on the light emitting layer 3 formed in the same manner as in Example 1 based on the present invention. Was deposited to a thickness of about 2 k (deposition rate of 11 to 13Å / sec) to form a metal electrode 1.
[0066]
Next, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 k ^ (deposition rate 30 to 40 mm / sec) to form the conductive sealing film 7. .
[0067]
Finally, the mask is changed to the vapor deposition mask 24 and SiO 2 is formed on the conductive sealing film 7.₂Was deposited to a thickness of 2 kÅ (deposition rate of 50 to 60Å / sec) to form an insulating sealing film 8, and an organic EL element 33 was produced as shown in FIG. 17.
[0068]
The organic EL device thus fabricated was left in the atmosphere for one month after fabrication, and the characteristics of this device were measured. As a result, the applied voltage was about 1000 cd / m at an applied voltage of 7V.²This result was almost the same as the result measured immediately after the device was fabricated. Further, almost no dark spots were generated, and the sealing effect by the sealing films 7 and 8 was observed.
[0069]
Example 4
Also in this example, based on the present invention, a strontium-aluminum (SrAl) alloy (strontium content 2%) was used as a cathode electrode on the light emitting layer 3 formed in the same manner as in Example 1 as described above, with the same vapor deposition mask. The metal electrode 1 was formed by vapor deposition to a thickness of about 2 k 約 (deposition rate of 11 to 13Å / sec).
[0070]
Next, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 k ^ (deposition rate 30 to 40 mm / sec) to form the conductive sealing film 7. .
[0071]
Finally, the mask is changed to the vapor deposition mask 24 and alumina (Al₂O_Three) Was vapor-deposited to a thickness of 2 k 速度 (deposition rate 50-60〜 / sec) to form an insulating sealing film 8, and an organic EL element 34 was produced as shown in FIG.
[0072]
The organic EL device thus fabricated was left in the atmosphere for one month after fabrication, and the characteristics of the device were measured. As a result, the applied voltage was about 1200 cd / m at an applied voltage of 8V.²The result was almost the same as the result measured immediately after the device was produced, and the sealing effect by the sealing films 7 and 8 was observed.
[0073]
Example 5
In this example, as a comparative example, a strontium-aluminum (SrAl) alloy (strontium content ratio) is formed on the light emitting layer 3 formed in the same manner as in the above-described Example 1 as in the above-described Example 3 as a cathode electrode with the same vapor deposition mask. 2%) was vapor-deposited at a thickness of about 2 kÅ (deposition rate of 11 to 13Å / sec) to form a metal electrode 1.
[0074]
Finally, the mask is changed to the vapor deposition mask 24 and the SiO 2 is formed on the metal electrode 1.₂Was vapor-deposited to a thickness of 2 k 速度 (deposition rate of 50 to 60Å / sec) to form an insulating sealing film 8, and an organic EL element 35 was produced as shown in FIG. Therefore, in this example, the conductive sealing film 7 is not provided.
[0075]
When the organic EL device thus fabricated was measured immediately after fabrication, the organic layer was deteriorated by the radiant heat generated during the deposition of the insulating sealing film 8, and almost no light emission was observed. Therefore, the effect of providing the conductive sealing film adjacent to the insulating sealing film as in Example 3 was proved.
[0076]
Example 6
In this example, as a comparative example, a lithium-aluminum (LiAl) alloy (lithium content 2) was used on the light emitting layer 3 formed in the same manner as in the above-described Example 1 as in the above-described Example 1 as a cathode electrode with the same mask. 0.5%) was vapor-deposited at a thickness of about 2 kÅ (deposition rate of 11 to 13Å / sec) to form a metal electrode 1.
[0077]
After this, the inside of the vapor deposition apparatus was once returned from the vacuum to the atmospheric pressure, and further evacuated again.
[0078]
Next, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 k ^ (deposition rate 30 to 40 mm / sec) to form the conductive sealing film 7. .
[0079]
Finally, the mask is changed to the vapor deposition mask 24 and SiO 2 is formed on the conductive sealing film 7.₂Was vapor-deposited to a thickness of 2 k 速度 (deposition rate of 50 to 60sec / sec) to form an insulating sealing film 8, and an organic EL element 36 was produced as shown in FIG.
[0080]
The organic EL device thus fabricated was left in the atmosphere for one month after fabrication, and the characteristics of the device were measured. As a result, the applied voltage was about 500 cd / m at an applied voltage of 13V.²However, this result was greatly deteriorated compared with the result measured immediately after the device was fabricated. Also, a lot of dark spots were generated.
[0081]
That is, the adverse effect due to the exposure of the element to the atmosphere before the formation of the conductive sealing film 7 is prominent, and the importance of forming the conductive sealing film 7 under vacuum conditions has been proved. It was.
[0082]
Example 7
In this example, a lithium-aluminum alloy (LiAl) (with a lithium content of 2.5) is formed on the light-emitting layer 3 formed in the same manner as in the above-described Example 1 as in the above-described Example 1 as a cathode electrode with the same mask. %) Was vapor-deposited at a thickness of about 2 kÅ (deposition rate of 11 to 13Å / sec) to form a metal electrode 1.
[0083]
Next, the mask was changed to the vapor deposition mask 23, and gold (Au) was vapor-deposited on the metal electrode 1 to a thickness of about 10 kÅ (deposition rate 30 to 40Å / sec) to form the conductive sealing film 7. .
[0084]
After this, the inside of the vapor deposition apparatus was once returned from the vacuum to the atmospheric pressure, and further evacuated again.
[0085]
Finally, the mask is changed to the vapor deposition mask 24 and the conductive sealing film 7 is made of SiO.₂Was vapor-deposited to a thickness of 2 k 速度 (deposition rate of 50 to 60sec / sec) to form an insulating sealing film 8, and an organic EL element 37 was produced as shown in FIG.
[0086]
The organic EL device thus fabricated was left in the atmosphere for 1 month after fabrication, and the characteristics of this device were measured. As a result, the applied voltage was about 900 cd / m at 9V.²However, this result was deteriorated compared with the result measured immediately after the device was fabricated. Also, dark spots were increasing.
[0087]
That is, an adverse effect due to exposure of the element to the atmosphere before the formation of the insulating sealing film 8 appears, and the importance of performing all film formation under vacuum conditions has been proved.
[0088]
As mentioned above, although the Example of this invention was described, the above-mentioned Example can be variously modified based on the technical idea of this invention.
[0089]
For example, materials for the anode electrode, the electron transport layer, the hole transport layer, and the cathode electrode can be appropriately selected and used. If it is a hole transport layer, a hole transporting organic substance such as a diamine derivative, a benzidine derivative, a styrylamine derivative, a triphenylmethane derivative, or a hydrazone derivative may be used. Similarly, an electron transporting organic material such as a quinolinol dielectric, a perylene derivative, a bisstyryl derivative, or a pyrazine derivative may be used for the electron transport layer.
[0090]
The light-emitting layer may be a host-guest light-emitting layer. In that case, the guest material may be any material that has sublimation properties, and is not limited to a fluorescent dye. For example, a pigment such as quinacridone may be used.
[0091]
The light emitting layer may be a single hetero type organic EL device having an electron transport layer or a hole transport layer.
[0092]
As the cathode electrode material, it is preferable to use a metal having a low work function from the vacuum level of the electrode material in order to efficiently inject electrons in addition to the above-described materials, for example, indium (In), Use low work function metals such as magnesium (Mg), silver (Ag), calcium (Ca), barium (Ba), and lithium (Li) alone or as an alloy with other metals with increased stability. May be.
[0093]
Further, in the present invention, ITO is used as a transparent electrode in order to take out organic electroluminescence from the anode electrode side. Of course, in order to inject holes efficiently, the anode electrode material from the vacuum level is used. High work function such as gold, tin dioxide-antimony mixture (SnO₂+ Sb), an electrode such as a zinc oxide-aluminum mixture (ZnO + Al) may be used.
[0094]
The conductive sealing film may be a material other than a metal material. For example, a conductive organic material made of polyoxadiazole may be vapor-deposited and then subjected to vapor deposition polymerization. Any conductive metal material may be used as long as it exhibits good conductivity. For example, a metal such as tungsten (W), aluminum (Al), gold (Au), silver (Ag), or the like may be used alone or in an alloy. Moreover, you may use the electroconductive sealing film which doped the minority carrier to the diamond-like carbon thin film. However, it is preferable to use a material that is not easily oxidized.
[0095]
The insulating sealing film may be any material that can be deposited, for example, silicon monoxide (SiO), silicon dioxide (SiO2).₂), Alumina (Al₂O_Three), Germanium dioxide (GeO)₂), Aluminum nitride (AlN), and the like can be manufactured by resistance heating evaporation, electron beam heating evaporation, sputtering, or the like.
[0096]
In the above-described embodiments, the mono-color organic EL element is mainly described. However, by selecting a light-emitting material, full-color or multi-color organic EL that emits three colors of R, G, and B is used. The element can be manufactured by the method described above. In addition, the present invention can be applied to organic EL elements that can be used not only for displays but also for light sources, and can also be applied to other optical uses.
[0097]
[Effects of the invention]
  As described above, the present invention, when manufacturing an optical element in which an electrode is provided on a laminate of organic layers including a light emitting region,The organic layer including the light emitting region and the cathode are arranged in the same pattern in this order on the strip-shaped anode using a common mask.After vacuum deposition, keep the vacuumCovering the cathode and the organic layer over their entire surface and sidesConductive sealing filmIn a strip pattern crossing the anodeFormationFurther, an insulating sealing film is formed to cover the conductive sealing film at a position where the anode and the cathode overlap with each other while maintaining a vacuum.Because of the atmosphereshadowIn addition to preventing oxidation of the electrode, it is possible to prevent deterioration of the organic layer due to radiant heat when forming an insulating sealing film on the conductive sealing film.In addition, the insulating sealing film can further enhance the effect of preventing the oxidation of the cathode and the deterioration of the organic layer.it can. Therefore, it is possible to provide an optical element that exhibits good stability in the atmosphere and has a long lifetime.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an organic EL device according to an embodiment of the present invention.
FIG. 2 is a plan view of a specific example of the organic EL element.
FIG. 3 is an enlarged plan view showing the positional relationship of various masks used for manufacturing the organic EL element.
FIG. 4 is a schematic cross-sectional view of a vacuum evaporation apparatus used for manufacturing the organic EL element.
FIG. 5 shows SiO deposited on a glass substrate in manufacturing the organic EL device.₂It is a top view which shows the state which etched to the predetermined pixel pattern.
FIG. 6 is a schematic cross-sectional view of the main part showing one stage of the manufacturing process of the organic EL element.
7 is a cross-sectional view taken along line VII-VII in FIG.
FIG. 8 is a schematic cross-sectional view of the main part showing another step of the manufacturing process.
FIG. 9 is a schematic cross-sectional view of the main part showing another stage of the manufacturing process.
FIG. 10 is a schematic cross-sectional view of the main part showing another step of the manufacturing process.
FIG. 11 is a schematic cross-sectional view of a substantial part showing still another step in the manufacturing process.
FIG. 12 is an enlarged cross-sectional view showing a main part of the completed organic EL element.
13 is a cross-sectional view taken along line XIII-XIII in FIG.
FIG. 14 is a structural formula of an aluminum-quinoline complex used as a light emitting layer material of the organic EL element.
FIG. 15 is a structural formula of TPD used as a hole transport layer material of the organic EL element.
FIG. 16 is a schematic cross-sectional view of an organic EL device according to another embodiment of the present invention.
FIG. 17 is a schematic cross-sectional view of an organic EL device according to another embodiment of the present invention.
FIG. 18 is a schematic cross-sectional view of an organic EL device according to still another embodiment of the present invention.
FIG. 19 is a schematic cross-sectional view of an organic EL device according to a comparative example of the present invention.
FIG. 20 is a schematic cross-sectional view of an organic EL device according to another comparative example of the present invention.
FIG. 21 is a schematic cross-sectional view of an organic EL device according to still another comparative example of the present invention.
FIG. 22 is a schematic cross-sectional view showing an organic EL element according to a conventional example.
FIG. 23 is a schematic cross-sectional view of an organic EL element according to another conventional example.
FIG. 24 is a schematic perspective view showing a specific example of the organic EL element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Electrode (cathode), 2 ... Electron transport layer, 3 ... Light emitting layer, 4 ... Hole transport layer,
5 ... ITO transparent electrode, 6 ... glass substrate, 7 ... conductive sealing film,
8 ... Insulating sealing film, 9 ... SiO₂Film, 11 ... Vacuum deposition device, 15 ... Opening
22, 23, 24 ... mask, 22a, 23a, 24a ... opening, 28 ... vapor deposition source, 29 ... power supply,
30, 31, 32, 33, 34, 35, 36, 37 ... Organic EL element, PX ... Pixel

Claims (9)

An organic layer including a light emitting region and a cathode are vacuum-deposited in the same pattern in this order using a common mask on the strip-shaped anode, and then the cathode and the organic layer are placed on the surface and side surfaces while maintaining the vacuum. A conductive sealing film covering the entire surface of the conductive sealing film is formed in a belt-like pattern intersecting with the anode, and the insulating sealing film covers the conductive sealing film at a position where the anode and the cathode overlap with each other while maintaining a vacuum. A method for manufacturing an optical element, wherein a sealing film is formed . The method according to claim 1 , wherein the conductive sealing film and the insulating sealing film are sequentially formed by a vacuum deposition method. The method according to claim 1 , wherein an organic electroluminescent device is produced. Vacuum the organic hole transport layer, organic light emitting layer and / or organic electron transport layer, metal electrode, conductive sealing film and insulating sealing film on the transparent electrode of the optically transparent substrate provided with the transparent electrode. The method according to claim 3 , wherein the layers are sequentially laminated under film forming conditions. The method according to claim 3 , wherein an element for a color display is manufactured. On the anode of the belt-shaped pattern, the light emitting region and the organic layer and the cathode including a is deposited in the same pattern in this order, the negative electrode and the organic layer conductive cover throughout these surfaces and side sealing film An optical element in which an insulating sealing film is formed in a strip pattern intersecting with the anode and covering the conductive sealing film at a position where the anode and the cathode overlap . The optical element according to claim 6 , which is configured as an organic electroluminescent element. An organic hole transport layer, an organic light emitting layer and / or an organic electron transport layer, a metal electrode, a conductive sealing film, and an insulating sealing film are sequentially formed on the transparent electrode of the optically transparent substrate provided with the transparent electrode. The optical element according to claim 7 , wherein the optical element is laminated. 8. The optical element according to claim 7 , wherein the optical element is configured as an element for a color display.

Images