JP4762062B2 - Sintered body, film, and organic electroluminescence element - Google Patents

Description

  The present invention relates to a sintered body for forming an oxide thin film used for a transparent conductive film such as a liquid crystal display, an organic electroluminescence element, and a touch panel by a sputtering method.

  The transparent conductive oxide film usually has n-type conductive semiconductor properties, and is a liquid crystal display device, an organic electroluminescence (EL) display device, a radiation detection element, a transparent tablet for terminal equipment, and heat generation for preventing condensation on the window glass. It is used in a wide variety of applications such as membranes, antistatic membranes or selective permeation membranes for solar collectors.

  As a means for forming an oxide thin film, a spray method using thermal decomposition of a compound, a chemical film formation method such as a CVD method, and a physical film formation method such as a vacuum evaporation method or a sputtering method are known. Among these, sputtering is generally employed because it can be formed in a large area and a low resistance film can be formed with good reproducibility. In the sputtering method, a flat oxide sintered target is usually used.

  By the way, when sputtering using a flat target with a generally used magnetron sputtering apparatus, erosion proceeds to a specific location on the target surface in order to perform sputtering while controlling the plasma with a magnet. There is a problem that the deepest erosion portion determines the life of the target. For this reason, the utilization efficiency of the target was as low as about 20 to 30%.

  In response to this problem, it has been proposed to increase the utilization efficiency of the target by making the target cylindrical. The magnetron sputtering method using a cylindrical target is a method in which a magnetic field generating means is installed inside a cylindrical target, and sputtering is performed by rotating the target while cooling from the inside of the target. By this method, it is possible to make the utilization efficiency of the target about 60 to 70%.

As a method for producing a cylindrical target, for example, a target film forming method by a thermal spraying method has been proposed in the field of ceramic targets (see Patent Documents 1 and 2).
Patent Document 3 discloses a cylindrical ITO (indium tin oxide) sintered target and a method for manufacturing the same.
However, when a film formed using a cylindrical ITO sintered target is used for an electrode of an organic EL element, there is a problem that the performance of the element is lower than when a normal flat target is used.
JP-A-60-181270 JP-A-5-214525 JP-A-10-68072

  An object of the present invention is to provide a sintered body which is a cylindrical sintered body and gives a film which does not deteriorate the performance of an organic EL element or the like when used as a sputtering target.

According to the present invention, the following sintered bodies and the like are provided.
1. A sintered body comprising indium oxide, and one or more oxides selected from the group consisting of zinc oxide, oxides of lanthanoid elements, oxides of alkali metal elements, and oxides of alkaline earth metal elements. A sintered body having a cylindrical shape.
2. 2. The sintered body according to 1, wherein the sintered body has a cylindrical shape or a cylindrical shape having different diameters on the bottom surface and the top surface.
3. 3. The sintered body according to 1 or 2, wherein the density is 80% to 100% of the theoretical density.
4). The sintered body according to any one of 1 to 3, wherein the average particle diameter of the oxide is 1 μm or more and 10 μm or less.
5. The sintered body according to any one of 1 to 3, wherein the bulk resistance value is 50 mΩ · cm or less.
6). The sintered body according to any one of 1 to 5, wherein the thickness is 1 mm or more and 10 mm or less.
7). The film | membrane formed by sputtering method using the sintered compact in any one of said 1-6 as a sputtering target.
8). An organic electroluminescence device having an organic layer including an organic light emitting layer between a cathode and an anode, wherein the cathode and / or anode is the film according to 7.

  When the film obtained by sputtering the sintered body of the present invention is used, for example, as an electrode of an organic EL element, the light emission intensity of the element can be improved and deterioration can be suppressed.

The sintered body of the present invention includes indium oxide and one or more oxides selected from the group consisting of zinc oxide, an oxide of a lanthanoid element, an oxide of an alkali metal element, and an oxide of an alkaline earth metal element. It is a sintered compact containing. By forming a film using such a sintered body, a decrease in adhesion between the obtained film and the organic layer is suppressed. For this reason, the emitted light intensity of an organic EL element improves, and deterioration can be suppressed.
In addition, electroconductivity can be stabilized by using indium oxide as an essential component.

Examples of the lanthanoid element oxide constituting the sintered body include samarium oxide, cerium oxide, gadolinium oxide, and neodymium oxide. Preferred are samarium oxide and cerium oxide.
Examples of the alkali metal oxide include cesium oxide, lithium oxide, and potassium oxide. Preferred are cesium oxide and lithium oxide.
Examples of the alkaline earth metal element oxide include MgO and CaO.
In addition, the oxide which comprises a sintered compact can use the thing of the powdery body currently sold for industrial use etc. Moreover, you may use the compound which becomes an oxide by sintering, such as carbonate of each element, as a raw material.

In particular, the sintered body of the present invention is preferably composed of a ternary system of indium oxide, zinc oxide, and a lanthanoid oxide or an alkali metal oxide. FIG. 1 is a view showing a preferred composition range of the sintered body of the present invention. It is preferable that the ratio (atomic%) of each metal element in the sintered body is within the region indicated by the points A to D in FIG.
In FIG. 1, the coordinates of each point (In, Zn, lanthanoid element or alkali metal element) are A (98, 2, 0), B (95, 0, 5), C (50, 50, 0), D (70, 0, 30).

The sintered body of the present invention has a cylindrical shape. The cylindrical space of the sintered body is for installing magnetic field generating means during sputtering. Specific examples of the sintered body include a cylindrical shape, a rectangular parallelepiped having a cylindrical portion, and a shape having a trapezoidal longitudinal section (a cylindrical shape having different diameters of circles on the bottom surface and the top surface).
2 to 4 are schematic perspective views showing examples of the shape of the sintered body. 2 is an example of a cylindrical shape, FIG. 3 is an example of a cylindrical shape in which the diameters of the circles constituting the bottom surface and the upper surface are different, and FIG. 4 is an example of a rectangular parallelepiped. All have the hole 14 penetrated from the 1st surface 12 (upper surface) of the sintered compact 11 which forms an outer peripheral part to the 2nd surface 13 (bottom surface) which opposes.
The thickness of the sintered body is preferably 1 mm or more and 10 mm or less, and particularly preferably 2 mm or more and 5 mm or less. Thereby, the sintered compact with few thermal stresses and few cracks can be obtained.

The sintered body of the present invention preferably has a density of 80% to 100% of the theoretical density. Thereby, abnormal discharge at the time of sputtering is suppressed, and plasma confinement can be carried out reliably. The density of the sintered body is particularly preferably 90% or more and 100% or less of the theoretical density.
The density of the sintered body can be adjusted by the sintering temperature, the particle size of the raw material powder, the press molding pressure, and the like.

The average particle size of the oxide in the sintered body of the present invention is preferably 1 μm or more and 10 μm or less. If the average particle size is outside this range, the discharge is not stable, and the amount of particles generated may increase. The average particle size of the oxide is particularly preferably 1 μm or more and 3 μm or less.
The average particle diameter is a value obtained from a secondary electron image photograph of an electron beam microanalyzer (EPMA). The average particle size of the oxide can be controlled by adjusting the particle size of the raw material such as oxide used.

  The bulk resistance value of the sintered body is preferably 50 mΩ · cm or less. If the bulk resistance value deviates from this range, the discharge is not stable, and the amount of particles generated may increase. The bulk resistance value is particularly preferably 10 mΩ · cm or less.

The sintered body of the present invention can be manufactured by a thermal spraying method or a sintering method.
1. Production of Sintered Body by Thermal Spraying In the production by thermal spraying, when the oxide powder thermal spraying is used, several types of thermal spraying such as plasma thermal spraying, high-speed gas thermal spraying, and gas thermal spraying can be used.

  In the production of a sintered body, the amount of oxygen present in the sintered body is important. In order to adjust the oxygen content, it is possible to perform thermal spraying in a shielding gas in which the oxygen amount is adjusted and the atmosphere is protected and adjusted with a non-oxidizing gas such as Ar, Ne, and He. As a result, a uniform and stable sprayed oxide layer without changing the chemical composition can be obtained. In order to improve the adhesion of the thermal spray coating, it is desirable that the cylindrical support or the like before the thermal spray coating is provided with irregularities with appropriate dimensions such as roughening the outer surface or forming grooves.

Furthermore, after the raw material powder having an average primary particle diameter of 2.0 μm or less is granulated, the oxide powder roasted at 800 to 1,500 ° C. can be suitably used as a sprayed powder having high fluidity.
In the present invention, by using an appropriate thermal spray powder, the adhesion of the sintered body layer is improved, and a sintered body having a uniform distribution with an average particle size of 10 μm or less is obtained. Further, oxygen in the sintered body is obtained. The content and bulk resistance value can be stably and easily obtained at the above values.

In the present invention, the density of the sintered body layer formed by thermal spraying is 5.0 g / cm ³ or more, and the oxygen content in the layer is 97% or more and less than 100% of the theoretical value. It is important that the density of the sintered body layer formed by thermal spraying is 5.0 g / cm ³ or more. When the density is less than 5.0 g / cm ³ , the specific resistance of the thin film formed by sputtering deteriorates, and due to the thermal effect during sputtering, peeling from the support or the oxide target itself Defects such as cracks are likely to occur.
Further, in order to maintain the film characteristics depending on the amount of oxygen, it is most suitable to use a material in which the oxygen content in the sintered body layer is in the range of 97% to less than 100% of the theoretical value.

2. Production of Sintered Body by Sintering Method When a sintered body is produced by a sintering method, a conventionally known method can be used. It is an essential requirement that the density of the sintered body is 5.0 g / cm ³ or more and the oxygen content in the oxide layer is 97% or more and less than 100% of the theoretical value.
As the sintered body material, the average particle diameter of the raw material used is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and particularly preferably 0.1 to 5 μm. If it is less than 0.01 μm, it tends to agglomerate. In addition, when the particle diameter of raw material powder exceeds 10 micrometers, it can also adjust and use so that an average particle diameter may enter into the said range using a ball mill, a roll mill, a pearl mill, a jet mill etc.
Hereinafter, an example in which a sintered body of indium oxide and zinc oxide (IZO sintered body) is manufactured in the order of the mixing step, the molding step, and the sintering step will be described.

(1) Mixing step The mixing is preferably performed by putting indium oxide and zinc oxide powder in a mixer such as a ball mill, jet mill, pearl mill, and the like and mixing them. The mixing time is preferably 1 to 100 hours, more preferably 5 to 50 hours, and particularly preferably 10 to 50 hours. If it is less than 1 hour, mixing is not sufficient, and if it exceeds 100 hours, it is not economical. There is no restriction | limiting in particular in mixing temperature, Room temperature is preferable.

  The mixed powder of indium oxide and zinc oxide after mixing may be calcined to promote the formation of a hexagonal layered compound. The calcination temperature is preferably 800 to 1500 ° C, more preferably 900 to 1400 ° C, and particularly preferably 1000 to 1300 ° C. Below 800 ° C., no hexagonal layered compound is formed, and above 1500 ° C., evaporation of indium oxide or zinc oxide occurs. The calcination time is preferably 1 to 100 hours, more preferably 2 to 50 hours, and particularly preferably 3 to 30 hours. If it is less than 1 hour, the hexagonal layered compound is not sufficiently produced, and if it exceeds 100 hours, it is not economical.

  The calcined product is preferably pulverized in order to make the particle size in the range of 0.01 to 10 μm. Grinding is done in the same way as mixing. Moreover, in order to promote the production | generation of a hexagonal layered compound, it is better to repeat calcination and grinding | pulverization.

  The mixed powder or calcined powder of indium oxide and zinc oxide may be granulated to improve the fluidity and filling property during molding. Granulation is performed by a conventional method such as a spray dryer. In the case of the spray drying method, an aqueous powder solution or an alcohol solution is used, and polyvinyl alcohol or the like is used as a binder mixed in the solution. The granulation conditions vary depending on the solution concentration and the added amount of the binder, but are adjusted so that the average particle size of the granulated product is 1 to 100 μm, preferably 5 to 100 μm, particularly preferably 10 to 100 μm. If the average particle size of the granulated product exceeds 100 μm, the fluidity and filling properties at the time of molding are poor and there is no granulation effect.

(2) Molding step Molding of the mixed powder of indium oxide and zinc oxide, calcined powder or granulated powder is performed by die molding, casting molding, injection molding or the like. Polyvinyl alcohol, methylcellulose, polywax, oleic acid or the like may be used as a molding aid. The molding pressure is preferably 10 kg / cm ^{2 to} 100 t / cm ² , more preferably 20 kg / cm ^{2 to 1} t / cm ² . The molding time is preferably 10 minutes to 10 hours. When the molding pressure is less than 20 kg / cm ² , when the molding time is less than 10 minutes, the density of the sintered body obtained after sintering cannot be increased, and the bulk resistance of the sintered body increases. There is a fear.

(3) Sintering process It is preferable to sinter the molded product by atmospheric pressure firing. As other sintering methods, there are HIP (hot isostatic pressing) sintering, hot press sintering, etc., but atmospheric pressure sintering is superior in terms of economy.
As for sintering temperature, 1200-1600 degreeC is preferable, More preferably, it is 1250-1550 degreeC, More preferably, it is 1300-1500 degreeC. Below 1200 ° C, hexagonal layered compound In ₂ O ₃ (ZnO) m (m = 2 to 7) is not generated. When it exceeds 1600 ° C, indium oxide or zinc oxide sublimates, resulting in a composition shift or formation. M of the hexagonal layered compound In ₂ O ₃ (ZnO) m to be larger than 7 increases the volume resistivity of the obtained sintered body.

(4) Surface polishing process The mechanical surface polishing process may be either dry or wet, but is uniform over the entire surface of the sintered body while maintaining the accuracy of shape and dimensional processing. In order to perform such processing, it is preferable to perform as follows.
When performing a dry surface polishing process, a dry barrel process or a dry blast process is preferably employed.
When dry barrel processing is employed, a known barrel processing apparatus such as a rotary type, a vibration type, or a centrifugal type can be used. When a rotary device or a centrifugal device is used, the rotational speed is preferably 50 to 300 rpm. When using a vibration type device, the number of amplitudes is preferably 0.3 to 10 mm. As a medium to be used, a resin medium in which abrasive powder is kneaded is preferable. The abrasive powder is not particularly limited as long as it has higher hardness than the sintered body to be cleaned, but ceramic powder such as Al ₂ O ₃ and ZrO ₂ , diamond powder, etc. are preferably used. . The processing time varies depending on the capacity of the sintered body. In general, it is preferably 60 seconds or longer, but in view of sufficient effects and efficiency, the treatment time is preferably 15 minutes or shorter.

When using dry blasting, select the material, particle size, and projection pressure of the projecting material, taking into account the hardness of the sintered body so that the projecting material does not sink into the surface of the sintered body. This is very important.
In the case of performing wet surface polishing processing, wet barrel processing is preferably employed. The barrel processing apparatus, media, processing conditions, and the like may be the same as those for dry barrel processing. After the wet surface polishing processing, it is desirable to immediately transfer the sintered body into the liquid medium so that the processing powder generated during the processing does not stick to the surface of the sintered body. As a suitable aspect, the aspect moved to the water in an ultrasonic cleaning tank, the aspect transferred to the water in the washing tank for temporarily storing a sintered compact before performing ultrasonic cleaning, etc. are mentioned.
Comparing the dry surface polishing process with the wet surface polishing process, the former is less likely to cause the processing powder generated during processing to stick to the surface of the sintered body, and no polishing liquid is required. It is preferable from the point of not requiring the washing step.

The sintered body of the present invention can be used as a sputtering target by, for example, spraying and adhering raw material powder to a support to form an oxide layer (sintered body layer) on the support.
In addition, the oxide powder, which is a raw material, is prepared by a conventionally known method (hot press, HIP, CIP, casting, etc.), and after being mounted on a support, the inside of the sintered body is cut through. You may make it cylindrical. The support corresponds to a backing plate used for a flat target.

FIG. 5 is a schematic cross-sectional view showing an example of a sputtering target.
The sputtering target includes a substantially cylindrical tube portion 21, a support body 20 having a connection portion 22 for connection to a sputtering apparatus, and a sintered body 31 formed on the inner surface of the tube portion 21.

  As the support, a metal plate having good thermal conductivity used in a conventional backing plate can be used. Specifically, it is more preferable to use a support made of Ti or Mo because peeling of the target and the support can be effectively prevented. However, the use of other metals as the support is not limited. Further, an undercoat layer that relieves stress caused by a difference in thermal expansion coefficient between the sintered body layer and the support of the present invention can be applied before the oxide powder spraying.

For example, an undercoat layer such as Ti or Mo can be provided on a metal support having relatively good thermal conductivity. Moreover, in order to improve the adhesiveness between these materials, an undercoat layer can also be provided through a film of Ni or the like.
The undercoat layer is not limited to a single layer, and may be a multilayer film. For the formation of the undercoat layer, a coating method such as plating, sputtering, or vapor deposition can be used. In the case of thermal spraying of oxide powder, it is more convenient and preferable to use a thermal spray coating method.

In the target using the sintered body of the present invention, the sintered density is preferably at least 5.2 g / cm ³ or more in order to prevent peeling from the supporting metal body due to thermal stress and arcing during use. A more preferable sintered density is 5.4 g / cm ³ or more, and further preferably 5.6 g / cm ³ or more.

The sintered body of the present invention can be suitably used as a material for forming a transparent conductive film, for example, the above-described sputtering target. And the film | membrane obtained from this sintered compact is used for transparent conductive films, such as a liquid crystal display, an organic electroluminescent element, and a touch panel. In particular, the lifetime of the element can be improved by using it as an electrode of an organic EL element.
The organic EL device of the present invention is an organic EL device having an organic layer including an organic light emitting layer between a cathode and an anode. There is no limitation in particular about the organic layer containing an organic light emitting layer, A well-known structure is employable. The same applies to other components. In the present invention, since the cathode and / or the anode is the above-described film, the lifetime of the element can be improved.

It is presumed that the light emission intensity and the device lifetime are improved in the EL device of the present invention for the following reason. That is, a sputtering method using a cylindrical target is particularly suitable for film formation on an organic film because plasma damage to a substrate that is a film formation target can be suppressed. However, when an ITO target is used, damage to the deposited ITO film itself is also reduced, so that ITO crystallization is promoted. For this reason, the adhesiveness with an organic layer falls by the stress of crystallization, and malfunctions, such as a non-light-emitting region appear, arise.
On the other hand, since the sintered body of the present invention is amorphous, there is no generation of stress due to crystallization, and the effect that a film can be formed with low plasma damage can be fully enjoyed. Therefore, when the film is formed by sputtering using a cylindrical target instead of a flat target, the organic EL element is more effective when the sintered body of the present invention is used than the conventional ITO sintered body. A suitable membrane is obtained.

  Next, the present invention will be described based on examples. However, the conditions shown in the examples are only examples showing one condition, and the range of various conditions that can be applied is not limited to the scope of the claims. It is included.

Production Example 1
The indium oxide used was produced by depositing metal indium as indium hydroxide by an electrolytic method and baking this indium hydroxide. As the zinc oxide powder, a Tokyo Chemical product (average particle size of 1 μm) was used. These indium oxide powder (1000 g) and zinc oxide powder (200 g) were mixed, finely pulverized, granulated, and then fired at 1300 ° C. to obtain a thermal spray powder (IZO powder).
As a cylindrical support, a Ti cylindrical support having an inner diameter of 50 mmφ, an outer diameter of 70 mmφ, and a length of 500 mm was prepared. The surface of this cylindrical support was roughened.
Plasma spraying was performed on the cylindrical support using the IZO powder for thermal spraying.
For plasma spraying, a voltage was applied using Ar gas to form an IZO film having a thickness of 4 mm.

The IZO cylindrical (cylindrical) target thus obtained has a density of 5.3 g / cm ³ , an oxygen content of 98% of the theoretical value, an oxide average particle size of 1.2 μm, and a bulk resistance value of 9 It was 4 mΩ · cm.
The density of the target was measured by Archimedes method after peeling the sintered body after thermal spraying. The density ratio is a ratio to the theoretical density.
The theoretical value and actual measurement value of the oxygen content were measured with an electron beam microanalyzer (EPMA).
The average particle diameter was determined from a secondary electron image photograph of an electron beam microanalyzer (EPMA).
The bulk resistance value was obtained by a four-end needle method.

Next, sputtering was performed on the substrate using this IZO cylindrical target, and the sheet resistance and transmittance of the obtained transparent conductive film were investigated. As a result, an IZO film that can be used for LCD (liquid crystal) was formed. The film formation characteristics were equivalent to those of a flat ITO sputtering target with good quality.
Further, during the sputtering operation, peeling between the support and the target or generation of cracks in the target layer was not observed.

In addition, Ni or In was sprayed as an undercoat layer on a support made of Mo or Ti, and IZO powder was sprayed in the same manner as described above. In this case, the same result as above was obtained.
In addition, this target shows much higher utilization efficiency than the flat target.

Production Example 2
In Production Example 1, a cylindrical target was prepared in the same manner except that cerium oxide was used instead of zinc oxide, and was sputtered onto the substrate. The resulting transparent conductive film had various sheet resistance and transmittance characteristics. As a result of investigation, an IZO film that can be used for LCD (liquid crystal) was formed. The film formation characteristics were equivalent to those of a flat ITO sputtering target with good quality.

Production Example 3
268 g of 99.8% pure indium oxide (In ₂ O ₃ ) powder (average particle size 1 μm) and 32 g of 99.5% pure zinc oxide (ZnO) powder (average particle size 1 μm) were used as raw materials. Was put in a polyimide pot together with ethanol and alumina balls, and mixed for 2 hours in a planetary ball mill. The obtained mixed powder was calcined at 1000 ° C. for 5 hours in an air atmosphere, and the obtained fired product was again placed in a polyimide pot together with ethanol and alumina balls, and pulverized for 2 hours with a planetary ball mill. Water and polyvinyl alcohol are added to the powder obtained as described above, mixed, and then granulated by a spray dryer to obtain a mixed oxide having an average particle size of 10 μm composed of indium oxide and zinc oxide. It was.
Next, the above mixed oxide powder is put into a mold, pre-formed at a pressure of 100 kg / cm ² by a mold press molding machine, and then at a pressure of 4 t / cm ^{2 by} a cold isostatic press molding machine. By compacting, a molded product having a columnar shape with a diameter of 105 mm and a height of 100 mm was obtained.

This molded product was put in a sintering furnace and sintered at 1500 ° C. for 4 hours in an air atmosphere to obtain an oxide sintered body. Next, this oxide sintered body was set on a lathe and processed into a cylindrical shape having an outer diameter of 100 mm, an inner diameter of 95 mm, and a height of 100 mm. This was fixed to the backing plate using an In bonder to obtain a target made of the target oxide sintered body.
The IZO cylindrical target thus obtained is an IZO having a density of 5.8 g / cm ³ , an oxygen content of 97% of the theoretical value, an average particle size of 1.2 μm, and a bulk resistance value of 9.4 mΩ · cm. there were.

Next, sputtering was performed on the substrate using this IZO cylindrical target, and the sheet resistance and transmittance of the obtained transparent conductive film were examined. As a result, an IZO film that could be used for LCD (liquid crystal) was formed. It was. The film formation characteristics were equivalent to those of a flat ITO sputtering target with good quality.
Further, during the sputtering operation, peeling between the support and the target or generation of cracks in the target layer was not observed.

Example 1
(Manufacture of organic EL elements 1)
1.1 mm thick glass was used as the substrate, and 50 nm of Cr was formed as the anode by sputtering. The glass with Cr was ultrasonically cleaned with isopropyl alcohol for 5 minutes, then with pure water for 5 minutes, and finally ultrasonically cleaned again with isopropyl alcohol for 5 minutes. The transparent support substrate after cleaning is fixed to a substrate holder of a commercially available vacuum deposition apparatus [manufactured by Nippon Vacuum Technology Co., Ltd.], and N, N′-diphenyl-N, N′-bis- (3 200 mg of (methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (hereinafter referred to as TPDA), and 4,4 ′-(2,2- 200 mg of diphenylvinyl) biphenyl (hereinafter referred to as DPVBi) was added, and the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁴ Pa.

  Next, the resistance heating boat containing TPDA is heated to 215 to 220 ° C., and TPDA is deposited on the glass with Cr at a deposition rate of 0.1 to 0.3 nm / sec. An injection layer was formed. The substrate temperature at this time was room temperature. Without removing this from the vacuum chamber, the above-mentioned molybdenum resistance heating boat containing DPVBi is heated to 220 ° C., and DPVBi is deposited on the hole injection layer at a deposition rate of 0.1 to 0.2 nm / sec. Thus, a light emitting layer having a thickness of 40 nm was formed. The substrate temperature at this time was also room temperature.

  As described above, the substrate on which the anode, the hole injection layer, and the light emitting layer were sequentially formed was taken out of the vacuum chamber, and a stainless steel mask was placed on the light emitting layer and fixed to the substrate holder again. Next, 200 mg of an aluminum chelate complex (Alq: tris (8-quinolinol) aluminum) was placed in a resistance heating boat made of molybdenum and mounted in a vacuum chamber.

Next, using the cylindrical sputtering target produced in Production Example 1 , IZO was deposited to a thickness of 120 nm on Alq. Thus, the organic EL element was obtained by providing the anode, the hole injection layer, the light emitting layer, the electron injection layer, and the IZO layer (cathode) on the glass substrate with Cr.

When a voltage of 9 V was applied to the organic EL element, a light emission intensity of 150 cd / m ² was obtained. Further, when the device was subjected to a life test at room temperature and 2000 hours, the emission intensity decreased to 90 cd / m ² . The surface of the device after the life test was observed with an optical microscope from the cathode side, but no change was observed.
Table 1 shows the physical properties of the targets used and the evaluation results of the produced organic EL elements. In the “Evaluation” column in the table, “O” indicates that the organic EL element can withstand a general test, and “X” indicates that the element has a fatal defect such as a small light emitting region or no light emission.

Reference example 1
An organic EL device was prepared and evaluated in the same manner as in Example 1 except that the target manufactured in Manufacturing Example 2 (ICeO target) was used. The results are shown in Table 1.

Reference example 2
Instead of zinc oxide, with a purity of 99.5% _Cs 2 CO ₃ (average particle diameter 5 [mu] m), the sintering temperature was 1000 ° C., further more obtained by processing the thickness of the sintered body to 7mm is prepared In the same manner as in Example 3 , a target (ICsO) was produced. Further, an organic EL element was produced and evaluated in the same manner as in Example 1 except that the cathode was formed using this target. The results are shown in Table 1.

Example 2
A target (IZO) was produced in the same manner as in Production Example 3 except that zinc oxide having an average particle diameter of 5 μm was used and the thickness of the sintered body was processed to 1 mm. Further, an organic EL element was produced and evaluated in the same manner as in Example 1 except that the cathode was formed using this target. The results are shown in Table 1.

Example 3
A target (IZO) was produced in the same manner as in Production Example 3 except that zinc oxide having an average particle diameter of 1.5 μm was used and the thickness of the sintered body was processed to 10 mm. Further, an organic EL element was produced and evaluated in the same manner as in Example 1 except that the cathode was formed using this target. The results are shown in Table 1.

Comparative Example 1
A target (ITO) was produced in the same manner as in Production Example 3 except that indium oxide-tin oxide (ITO) having an average particle diameter of 2 μm was used as a raw material. Further, an organic EL element was produced and evaluated in the same manner as in Example 1 except that the cathode was formed using this target. The results are shown in Table 1.

Comparative Example 2
Using a disc-shaped (flat plate) IZO target (In ₂ O ₃ : ZnO = 90: 10 wt%; made by Mitsui Kinzoku Co., Ltd., 4 inch φ) for the cathode film formation, the IZO cathode is produced on Alq by magnetron sputtering. An organic EL device was prepared and evaluated in the same manner as in Example 1 except that the film was formed. The results are shown in Table 1.

Comparative Example 3
In Example 3 , tin oxide was used instead of zinc oxide to produce a disk-shaped (flat plate) ITO target. Using this ITO target, an organic EL element was produced and evaluated in the same manner as in Example 1 . The results are shown in Table 1.

Example 4
(Manufacture of organic EL elements 2)
Using a 1.1 mm-thick glass as the substrate and the target produced in Production Example 1 as the anode, 100 nm of IZO was formed by sputtering. This glass with IZO was ultrasonically washed with isopropyl alcohol for 5 minutes, then washed with pure water for 5 minutes, and finally ultrasonically washed again with isopropyl alcohol for 5 minutes. The transparent support substrate after cleaning is fixed to a substrate holder of a commercially available vacuum deposition apparatus [manufactured by Nippon Vacuum Technology Co., Ltd.], and N, N′-diphenyl-N, N′-bis- (3 200 mg of (methylphenyl)-(1,1′-biphenyl) -4,4′-diamine (hereinafter referred to as TPDA), and 4,4 ′-(2,2-diphenyl) in another molybdenum resistance heating boat 200 mg of vinyl) biphenyl (hereinafter referred to as DPVBi) was added, and the inside of the vacuum chamber was depressurized to 1 × 10 ⁻⁴ Pa.

  Next, the resistance heating boat containing TPDA is heated to 215 to 220 ° C., and TPDA is deposited on the glass with IZO at a deposition rate of 0.1 to 0.3 nm / sec. An injection layer was formed. The substrate temperature at this time was room temperature. Without removing this from the vacuum chamber, the above-mentioned molybdenum resistance heating boat containing DPVBi is heated to 220 ° C., and DPVBi is deposited on the hole injection layer at a deposition rate of 0.1 to 0.2 nm / sec. Thus, a light emitting layer having a thickness of 40 nm was formed. The substrate temperature at this time was also room temperature.

As described above, the substrate on which the anode, the hole injection layer, and the light emitting layer were sequentially formed was taken out of the vacuum chamber, and a stainless steel mask was placed on the light emitting layer and fixed to the substrate holder again. Next, 200 mg of an aluminum chelate complex (Alq: tris (8-quinolinol) aluminum) was placed in a resistance heating boat made of molybdenum and mounted in a vacuum chamber.
Further, 8 g of silver (Ag) ingot was put into an alumina-coated tungsten basket, 1 g of bismuth (Bi) ribbon was put into another molybdenum boat, and 1 g of magnesium (Mg) was put into another molybdenum boat. After that, the inside of the vacuum chamber is reduced to 2 × 10 ⁻⁴ Pa, and a boat containing Alq is first heated to 280 ° C. to deposit Alq at a deposition rate of 0.3 nm / sec to 20 nm, and an electron injection layer is formed. A film was formed.

Next, Ag is simultaneously deposited at a rate of 9 nm / sec, Bi is 0.8 nm / sec, and Mg is 0.2 nm / sec, thereby obtaining a cathode composed of an Ag—Bi—Mg deposited film having a thickness of 2 nm in 12 seconds. It was. Thus, the organic EL element was obtained by providing the anode, the hole injection layer, the light emitting layer, the electron injection layer, and the cathode on the glass substrate with IZO.
When a voltage of 9 V was applied to the organic EL device thus obtained, a light emission intensity of 150 cd / m ² was obtained.

Further, when the device was subjected to a life test for 2000 hours at room temperature, the emission intensity decreased to 90 cd / m ² . The surface of the device after the life test was observed with an optical microscope from the cathode side, but no change was observed.
Table 2 shows the physical properties of the targets used and the evaluation results of the produced organic EL elements.

Example 5
An organic EL element was produced and evaluated in the same manner as in Example 4 except that the target produced in Production Example 3 was used for forming the anode. The results are shown in Table 2.

Reference example 3
A target (ICeO) was produced in the same manner as in Production Example 3 , except that CeO ₂ (purity 99.5%) having an average particle diameter of 1 μm was used instead of zinc oxide.
An organic EL device was prepared and evaluated in the same manner as in Example 4 except that this target was used for forming the anode. The results are shown in Table 2.

Reference example 4
A target (ISmO) was prepared in the same manner as in Production Example 3 , except that Sm ₂ O ₃ (purity 99.5%) having an average particle diameter of 2 μm was used instead of zinc oxide and the thickness of the sintered body was processed to 1 mm. Was made.
An organic EL device was prepared and evaluated in the same manner as in Example 4 except that this target was used for forming the anode. The results are shown in Table 2.

Reference Example 5
A target (ISmO) was prepared in the same manner as in Production Example 3 , except that Sm ₂ O ₃ (purity 99.5%) having an average particle diameter of 5 μm was used instead of zinc oxide and the thickness of the sintered body was processed to 5 mm. Was made.
An organic EL device was prepared and evaluated in the same manner as in Example 4 except that this target was used for forming the anode. The results are shown in Table 2.

Example 6
Using 268 g of indium oxide with a purity of 99.8%, 16 g of zinc oxide with a purity of 99.8% and 16 g of cerium oxide with a purity of 99.8% as raw materials, these were put together with ethanol and alumina balls in a polyimide pot, and a planetary ball mill For 2 hours. Thereafter, a target composed of an oxide sintered body was obtained in the same manner as in Production Example 3 . The thickness of the sintered body was processed to 7 mm.
The IZCO cylindrical target thus obtained had a density of 5.5 g / cm ³ , an oxygen content of 95% of the theoretical value, an average particle size of 9 μm, and a bulk resistance value of 20 mΩ · cm.
An organic EL device was prepared and evaluated in the same manner as in Example 4 except that this target was used for forming the anode. The results are shown in Table 2.

  The sintered body of the present invention is suitable for a sputtering target for producing a transparent conductive film. In addition, the transparent conductive film formed using the sintered body of the present invention includes a liquid crystal display device, an organic EL display device, a radiation detection element, a transparent tablet for terminal equipment, a heating film for preventing condensation on window glass, and an antistatic film. Or it can use for the selective permeation | transmission film | membrane for solar collectors, etc.

It is the figure which showed the suitable composition range of the sintered compact of this invention. It is a schematic perspective view which shows an example of the shape of the sintered compact of this invention. It is a schematic perspective view which shows an example of the shape of the sintered compact of this invention. It is a schematic perspective view which shows an example of the shape of the sintered compact of this invention. It is a schematic sectional drawing of an example of a sputtering target.

Explanation of symbols

11 Sintered body 12 First surface (upper surface)
13 Second surface (bottom surface)
14 hole 20 support body 21 cylinder part 22 connection part 31 sintered compact

Claims (6)

An organic electroluminescence device having an organic layer including an organic light emitting layer between a cathode and an anode,
The cathode and / or anode,
A sintered body containing indium oxide and zinc oxide and having a cylindrical shape manufactured by a sintering method or a thermal spraying method is used as a sputtering target, and is a film formed by a sputtering method.
An organic electroluminescence device characterized by that.   The organic electroluminescent element according to claim 1, wherein the sintered body has a cylindrical shape or a cylindrical shape having different diameters on the bottom surface and the top surface.   The organic electroluminescence element according to claim 1 or 2, wherein the density of the sintered body is 80% or more and 100% or less of the theoretical density.   The organic electroluminescence device according to any one of claims 1 to 3, wherein the oxide has an average particle size of 1 µm to 10 µm.   The organic electroluminescent element according to claim 1, wherein the sintered body has a bulk resistance value of 50 mΩ · cm or less.   The organic electroluminescent element according to claim 1, wherein the sintered body has a thickness of 1 mm or more and 10 mm or less.

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