JP2014199794A - Organic el element, printer head, exposure device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL element which is excellent in productivity and is improved in reliability.SOLUTION: Provided is a top emission type organic EL element 1 comprising a first electrode 11, an ITO layer 12, an organic compound layer 13 including a light-emitting layer, a second electrode 14, an adhesion layer 18, and a sealing layer 15 formed on a substrate 10, and light emission from the light-emitting layer is partitioned by banks 16. The second electrode 14 covers the first electrode 11, the ITO layer 12, the organic compound layer 13, and the banks 16. The sealing layer 15 covers the second electrode 14. The adhesion layer 18 is discontinuously formed outside the second electrode 14 and on a joint surface with the sealing layer 15.

Description

  The present invention relates to a top emission type organic EL element, a printer head, an exposure apparatus, and an image forming apparatus.

  Conventionally, an electro-optical device such as an organic EL display device has an element structure in which an anode, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, an electron injection layer, a cathode, and the like are laminated on a substrate. Are known.

  Such an organic EL element has a lifetime as a light-emitting element due to alteration of the hole injection layer, hole transport layer, light-emitting layer, electron transport layer, and electron injection layer made of an organic material due to the intrusion of oxygen or moisture in the atmosphere. There was a problem of shortening.

  Furthermore, not only organic EL materials, but also organic materials such as bank materials that isolate the light-emitting region have a large volume expansion in a high temperature environment due to heat generation during external environment or energization, and the generated stress is different from that of inorganic materials such as electrodes. There is a problem in that moisture and the like enter due to the occurrence and peeling at the interface, resulting in a decrease in durability of the light emitting element.

  Therefore, in order to prevent the penetration of oxygen and moisture from the external environment, a sealing structure that is usually covered with a glass plate or a metal plate and bonded with a sealing material such as resin has been proposed (Patent Document 1).

  However, since the sealing material also has a large amount of oxygen and moisture permeation, it is necessary to provide a space using a getter material that absorbs moisture at high speed so as not to reach the element. Moreover, the organic EL element using such a glass cap has the problem that manufacturing cost rises, and also has the fault that a display element becomes thick.

  As an organic EL element that addresses such a problem, a method of forming an inorganic film as a sealing layer is known (Patent Document 2). In particular, it is known that silicon nitride can form a film with very few pinholes, is excellent in suppressing oxygen permeation and moisture permeation, and can substantially block such permeation.

  However, despite the high blocking ability of the silicon nitride film itself, the deterioration of the organic EL element often appears significantly. The cause is that oxygen and moisture enter from the interface between the silicon nitride film and the underlayer. When the adhesion at the interface between the silicon nitride film and the underlayer is insufficient, the sealing structure is incomplete, and as a result, the organic EL element is deteriorated.

  The present invention has been made in view of the above prior art, that is, an object of the present invention is to provide an organic EL element that is excellent in productivity and improved in reliability.

  As a result of intensive studies, the present inventors have found that the second electrode covers the first electrode, the ITO (indium tin oxide) layer, the organic compound layer, and the bank, and the sealing layer covers the second electrode. In the above-mentioned top emission type organic EL element, it has been found that the above-mentioned problems can be solved by forming the adhesion layer discontinuously outside the second electrode and on the bonding surface with the sealing layer.

  That is, according to the present invention, a first electrode, an ITO layer, an organic compound layer including a light emitting layer, a second electrode, an adhesion layer, and a sealing layer are formed on a substrate, and light emission from the light emitting layer is separated by a bank. A top emission type organic EL device, wherein the second electrode covers the first electrode, the ITO layer, the organic compound layer and the bank, and the sealing layer is the second The organic EL element is characterized in that the adhesive layer is formed discontinuously on the outer surface of the second electrode and on the bonding surface with the sealing layer.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in productivity and can provide the organic EL element which improved reliability.

It is a block diagram concerning one embodiment of an organic EL device concerning the present invention. FIG. 2 is a plan view of the configuration diagram of FIG. 1. It is a block diagram which concerns on one Embodiment of the organic EL element which is not contained in this invention. It is a block diagram of an example of an organic EL element. FIG. 5 is a plan view of the configuration diagram of FIG. 4. It is a block diagram of arrangement | positioning of the organic EL element in one Embodiment of the printer head concerning this invention. It is a block diagram in one Embodiment of the exposure apparatus which concerns on this invention. 1 is a configuration diagram in an embodiment of an image forming apparatus according to the present invention.

  Hereinafter, the present invention will be described with reference to embodiments. However, the present invention is not limited to the following embodiments, and can be arbitrarily modified and implemented without departing from the gist thereof.

  The organic EL device according to the present invention includes a first electrode 11, an ITO (indium tin oxide) layer 12, an organic compound layer 13 including a light emitting layer, a second electrode 14, an adhesion layer 18, and a sealing on a substrate 10. A top emission type organic EL element 1 in which a layer 15 is formed and light emission from the light emitting layer is divided by a bank 16, wherein the second electrode 14 is the first electrode 11, The ITO layer 12, the organic compound layer 13, and the bank 16 are covered, the sealing layer 15 covers the second electrode 14, and the adhesion layer 18 is discontinuous outside the second electrode. It is characterized by being formed.

Hereinafter, modes for carrying out the present invention will be described.
As shown in FIG. 1, the organic EL element configuration used in the present invention is reflective on the substrate 10 and patterned first electrode 11, ITO patterned in the same shape as the first electrode 11. The layer 12, the organic compound layer 13 including the light emitting layer, and the second electrode 14 having translucency are stacked in this order. Here, the light emitting region is divided by the bank 16, the second electrode 14 covers the first electrode 11, the ITO layer 12, the organic compound layer 13, and the bank 16, and the sealing layer 15 is the second. The electrode 14 is covered. Further, the adhesion layer 18 is discontinuously formed outside the second electrode 14 and on the bonding surface with the sealing layer 15.

Hereinafter, each constituent material and formation process will be described.
The substrate 10 of the organic EL element shown in FIG. 1 can be one generally used for organic EL elements, and is not particularly limited, but has excellent surface smoothness, waterproofness, etc. A glass substrate, a silicon substrate and a plastic substrate are preferred. In addition, since the top emission type organic EL element has a configuration in which emitted light is extracted from the opposite side of the substrate 10, either a transparent substrate or an opaque substrate can be used.

  The first electrode 11 used in the present invention is not particularly limited as long as it has conductivity and reflectivity, and a known metal, alloy, organic conductive material, or the like can be used. For example, Ag, Ag alloy (AgNdCu, AgPdCu, etc.), Al, etc. are mentioned. Among them, Al has a high reflectance and is useful as the first electrode 11. These may be used alone or in combination of two or more.

  Although there is no restriction | limiting in the thickness of the 1st electrode 11, the film thickness with a low specific resistance and ensuring high reflection is preferable. The film thickness is preferably 20 nm to 500 nm, and more preferably 50 nm to 200 nm.

  The first electrode 11 is formed by a known vacuum film formation such as sputtering or vapor deposition or various printing methods. In these processes, patterning using a shadow mask or the like is possible. Fine patterning is also possible by photolithography.

The ITO layer 12 used in the present invention has a hole injection layer function. Therefore, the film thickness for ensuring conductivity is not necessarily required, and may be 10 nm or more that can be formed as a continuous film. As the film formation method, the same method as that of the first electrode 11 can be used.
Moreover, although a hole injection layer can be used also in the organic compound layer 13 described later, it is preferable to use the ITO layer 12 separately from the hole injection layer of the organic compound layer 13. By using the ITO layer 12, holes can be stably injected, and the light emission reliability in the organic EL element is improved.

The organic compound layer 13 used in the present invention is specifically divided into a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. The material is not particularly limited, and the layer may be omitted when the functions are combined. For example, when the hole injection layer has a hole transport function, the hole transport layer is omitted.
The layers constituting the organic compound layer 13 are not shown in FIG. 1, but are stacked on the ITO layer 12 in the order of a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. It is preferable.

For the hole injection layer, copper phthalocyanine (CuPc), 4,4,4-tris (3-methylphenylphenylamino) triphenylamine (m-TDATA), poly (3,4-ethylenedioxythiophene) -polystyrene Examples include sulfonic acid (PEDOT / PSS) and vanadium oxide.
Examples of materials having hole injection and hole transport include triphenyldiamine derivatives, oxadiazole derivatives, polyphylyl derivatives, stilbene derivatives, poly (vinyl carbazole), poly (thiophene), and other conductive polymers. . A typical example is bis (N- (1-naphthyl-N-phenyl) benzidine) (α-NPD). As a thing used for a positive hole injection layer or a positive hole transport layer, 1 type may be sufficient and 2 or more types may be sufficient. The structure of α-NPD used in the examples described later is shown in the following formula.

  Any known light-emitting material can be suitably used for the light-emitting layer, and either a material that functions alone or a material that functions as a mixed layer of a host material and a light-emitting dopant, a charge transport dopant, or the like may be used. A typical example is an aluminum quinolinol complex (Alq3). As a thing used for a light emitting layer, 1 type may be sufficient and 2 or more types may be sufficient. The structure of Alq3 used in the examples described later is shown in the following formula.

  The organic EL element obtained by the present invention has a structure in which light emitted from the light emitting layer is divided by the bank 16. The bank 16 can be made of a known material and is manufactured by a known method. For example, it can be prepared by photolithography using DL-1000 (manufactured by Toray).

  A known material such as an aluminum quinolinol complex (Alq3) or a phenanthroline compound can be used for the electron transport layer. One type may be used for the electron transport layer, or two or more types may be used.

  As the electron injection layer, an extremely thin film of an alkaline earth metal or an alkaline earth metal compound can be used. For example, LiF, KF, and MgO are preferable. As the material used for the electron injection layer, one type may be used, or two or more types may be used.

The second electrode 14 used in the present invention is not particularly limited as long as it has conductivity and translucency. However, since it is directly formed on the organic compound layer 13, the second electrode 14 is formed by a vacuum deposition method. A metal thin film is preferably used. For example, a thin film of gold, platinum, silver, aluminum, chromium, magnesium, or an alloy thereof can be used. Among these, a magnesium alloy is preferably used for reasons such as energy level compatibility and stability with the electron injection layer.
Further, the silver-containing thin film has good conductivity and reflectance, and is advantageous for forming a top emission type resonator structure. Therefore, more preferably, the magnesium alloy contains at least silver.

  The second electrode 14 preferably has a thickness of 5 nm to 20 nm. If the thickness is less than 5 nm, sufficient reflectivity as a resonator structure cannot be obtained, and if it exceeds 20 nm, the reflectivity increases, which is disadvantageous as a resonator structure.

A metal thin film can be used as the adhesion layer 18. The material of the second electrode 14 is preferably the same as the material of the adhesion layer 18, and the adhesion layer 18 is preferably a metal thin film formed by a vacuum evaporation method, like the second electrode 14. As described above, for example, a thin film of gold, platinum, silver, aluminum, chromium, magnesium or an alloy thereof can be used, and among these, a magnesium alloy is preferably used. More preferably, the magnesium alloy contains at least silver.
In consideration of productivity, the adhesion layer 18 is preferably the same layer, the same material, and the same thickness as the second electrode 14.

  The sealing layer 15 is made of, for example, an inorganic compound, and is particularly preferably a silicon compound, that is, silicon nitride or silicon oxide. Other than silicon compounds, for example, they may be formed from alumina, tantalum oxide, or the like.

  As the sealing layer 15, it is good also as a laminated structure in the layer which consists of a different silicon compound. Or it is good also as a laminated structure of a silicon compound layer and an alumina layer. Alternatively, a laminated structure of a silicon compound layer and an organic layer may be used. When the stress of the silicon compound layer is large, the stress relaxation effect particularly in these laminated structures is increased.

  Further, in addition to the above, a laminated structure of silicon nitrides having different composition ratios may be used. Or it is good also as a structure which makes the composition non-uniform | heterogenous and makes the density | concentration change continuously or discontinuously, without making it a laminated structure.

  In addition, the thickness of the sealing layer 15 is preferably 50 nm to 2000 nm. If it is less than 50 nm, the film barrier property cannot be sufficiently secured, and if it is more than 2000 nm, there is a possibility that film cracking due to stress occurs.

Next, a schematic diagram of the plan view of FIG. 1 is shown in FIG.
The second electrode 14 is formed so as to cover a region where the first electrode 11, the ITO layer 12, the organic compound layer 13, and the bank 16 are formed. By doing in this way, an interface is formed between the sealing layer 15 to be formed next and the second electrode 14, the adhesion with the sealing layer 15 is remarkably improved, and oxygen from the interface is increased. , Moisture infiltration can be suppressed.

  An adhesion layer 18 is formed outside the region where the second electrode 14 is formed and on the bonding surface between the substrate 10 and the sealing layer 15, and the second electrode 14 and the sealing layer 15 The adhesion at the interface can be further improved. By providing the adhesion layer 18, the adhesion at the interface is improved because the interaction force with the sealing layer 15 is increased. In this case, by making the shape discontinuous, it is not electrically connected to the second electrode 14 and short-circuit suppression with the first electrode 11 can be obtained.

In addition, it is preferable that the adhesion layer 18 and the second electrode 14 are not electrically connected by discontinuously forming the adhesion layer 18 outside the second electrode 14.
In FIG. 1, an adhesion layer 18 is formed outside the second electrode 14. The adhesion layer 18 may be formed outside the second electrode 14 and on the bonding surface with the sealing layer 15, and may be formed directly on the substrate 10 or directly on the substrate 10. Not necessary. In addition, the adhesion layer 18 is not in contact with the second electrode 14, but with this configuration, the adhesion layer 18 is electrically separated from the second electrode 14. Deterioration can be avoided.
FIG. 2 is a plan view illustrating an example of the organic EL element of the present invention, in which an adhesion layer 18 is formed outside the second electrode 14. The adhesion layer 18 is formed so as to surround the outside of the second electrode 14, but it is preferable that the adhesion layer 18 is interrupted in the vicinity of the wiring and does not have a continuous structure. By adopting such a configuration, as described above, in addition to improving the adhesion of the interface, which is the original function of the adhesion layer, it is possible to suppress the first electrode 11 and the second electrode 14 from being short-circuited. it can.

  The sealing layer 15 in the organic EL element of the present invention has a configuration covering the second electrode 14. As described above, the second electrode 14 is configured to cover the first electrode 11 and the like from the viewpoint of adhesion with the sealing layer 15. Therefore, by covering the second electrode 14 with the sealing layer 15, the adhesion between the sealing layer 15 and the second electrode 14 can be further improved, and entry of moisture and oxygen can be prevented.

  Next, a configuration example of the printer head of the present invention will be described. FIG. 6 shows an organic EL panel 40 according to the present invention, and FIG. 7 shows an exposure apparatus according to the present invention. As shown in FIG. 6, in the organic EL panel 40, the organic EL elements 1 of the present invention are arranged in a line on an element substrate 41, and this organic EL panel 40 becomes the printer head of the present invention. In the organic EL panel 40, the number of organic EL elements to be arranged can be changed according to the purpose, and can be two lines or more instead of one line as shown in FIG. In that case, it can be divided into a main exposure light source and a sub-exposure light source. When the main exposure light source deteriorates and the light amount decreases, the sub-exposure light source can supplement the light amount and is effective.

The organic EL panel 40 includes a drive element 42 that drives the organic EL element 1, and a control circuit 43 that controls the drive element 42. Therefore, the drive element 42 is controlled by the control circuit 43, and energization to the organic EL element 1 is controlled by the drive element 42.
There is no restriction | limiting in particular as the drive element 42, Switching elements, such as a thin film transistor and a thin film diode, can be used.
In addition, since the organic EL element 1 in the present invention is a top emission type, the element substrate 41 is not particularly limited, and either a transparent substrate or an opaque substrate can be used.

  Although FIG. 7 shows a schematic diagram when one organic EL panel 40 is a printer head, there may be one organic EL panel 40 or a plurality of organic EL panels 40. In addition, since the organic EL element of the present invention is expected to improve reliability, the printer head of the present invention can also improve reliability and provide a stable light source.

Next, a configuration example of the exposure apparatus 50 of the present invention will be described with reference to FIG.
The exposure apparatus 50 of the present invention includes a light source in which the organic EL panel 40 shown in FIG. 6 serves as a printer head, and includes an optical imaging system 53 that forms an image of light emitted from the printer head. There is no restriction | limiting in particular as the optical image formation system 53, A well-known thing can be used, For example, a well-known lens element can be used. Further, in the exposure apparatus 50 of the present invention, the number of printer heads is not limited, and one may be used alone, or two or more may be used.

  The light emitted from the printer head is imaged by the optical imaging system 53 and is applied to, for example, the photoreceptor 70 of the image forming apparatus. The exposure device 50 causes the organic EL element to emit light for each pixel (dot) with a light emission pattern corresponding to an image to be formed, and exposes the photoconductor 70. As a result, a charging pattern corresponding to the image to be formed is formed on the charged photoconductor 70, and a toner image is formed on the photoconductor 70 by supplying toner, and is transferred and fixed to transfer paper. Since the organic EL element 1 of the present invention is expected to improve reliability, the exposure apparatus 50 can also improve the reliability and stably expose the photoconductor and the like.

  Next, a configuration example of the image forming apparatus 60 of the present invention will be described with reference to FIG. The schematic diagram of FIG. 8 shows an example of a full-color image forming apparatus in which the photoreceptors 70 are arranged in parallel. That is, a configuration example of a four-drum type digital color printer including four photosensitive members 71K, 71Y, 71M, and 71C for forming toner images of four different colors (black, yellow, magenta, and cyan) is shown. Has been.

  The image forming apparatus 60 includes photoconductors 70K, 70Y, 70M, and 70C that are image carriers for black (K), yellow (Y), magenta (M), and cyan (C). . As each photoconductor for each color, an OPC photoconductor is usually used. Around each of the photoreceptors 70K, 70Y, 70M, and 70C, a charging device 61, an exposure device 50 of the present invention, a developing device 63 (63K, 63Y, 63M, and 63C) for each color of black, magenta, yellow, and cyan, Primary transfer bias rollers 71K, 71Y, 71M, and 71C as a primary transfer unit, a cleaning device (not shown), a charge removal device 64, and the like are disposed.

  The photoreceptor 70, the charging device 61, the exposure device 50, the developing device 63, and the charge removal device 64 are accommodated in the image forming units 74K, 74Y, 74M, and 74C and are unitized, and can be replaced because they are detachable. It is. In this case, it is not necessary that all of the photoconductor 70, the charging device 61, the exposure device 50, the developing device 63, and the charge removal device 64 be unitized, and can be changed according to the purpose.

  The intermediate transfer belt 72, which is a belt component, is driven by a driving roller 65, and is interposed between the photoreceptors 70K, 70Y, 70M, and 70C and the primary transfer bias rollers 71K, 71Y, 71M, and 71C. Then, the toner images of the respective colors formed on the respective photoreceptors are sequentially superimposed and transferred.

  On the other hand, the transfer paper P is fed from the paper feed unit 69 and then carried by the transfer conveyance belt 66 which is a belt component through the registration roller 73. When the intermediate transfer belt 72 and the transfer conveyance belt 66 come into contact with each other, the toner image transferred onto the intermediate transfer belt 72 is subjected to secondary transfer (collective transfer) by a secondary transfer bias roller 67 as secondary transfer means. ) As a result, a color image is formed on the transfer paper P. The transfer paper P on which the color image is formed is conveyed to the fixing device 68 by the transfer conveying belt 66, and after the image transferred by the fixing device 68 is fixed, it is discharged out of the printer main body.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited by these Examples, unless the summary is exceeded.

Example 1
A first electrode 11 was formed on a substrate 10 made of Si that had been subjected to ultrasonic cleaning and UV ozone treatment, by sputtering to form a 150 nm Ag film through a shadow mask. Next, ITO was deposited to a thickness of 15 nm through a shadow mask by sputtering, and an ITO layer 12 was formed. Next, a bank 16 was formed by photolithography so that 1 mm □ was opened (bank material: DL-1000 (manufactured by Toray)). Further, UV ozone treatment was performed, the ITO surface was washed, transported to a glove box, and annealed at 120 ° C. for 5 minutes.

Next, α-NPD is deposited in a thickness of 50 nm (2 Å / s), Alq3 is 50 nm (2 Å / s), and LiF is 0.5 nm (0.05 Å / s) through a shadow mask by vacuum deposition. Then, an organic compound layer 13 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

Next, MgAg (20: 1) 15 nm (4 Å / s: 0.2 Å / s) is applied to the first electrode 11 (Ag layer), ITO layer 12, and organic compound layer through a shadow mask by vacuum deposition. The film was formed so as to completely cover the bank 16 and the second electrode 14 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

  Simultaneously with the formation of the second electrode 14, MgAg 15 nm as an adhesion layer 18 was formed outside the second electrode 14 so as not to be electrically connected to the second electrode 14 through a shadow mask.

  Next, SiN 2000 nm was deposited by CVD method so as to cover the second electrode 14 (MgAg) and the adhesion layer 18 through a shadow mask (30 Å / s), and the sealing layer 15 was formed.

  In the obtained organic EL element, the second electrode 14 as shown in FIGS. 1 and 2 covers the first electrode 11 and the like, the sealing layer 15 covers the second electrode 14, and The adhesion layer 18 was configured to be discontinuously formed outside the second electrode 14 and on the bonding surface with the sealing layer 15.

When a current characteristic of 100 mA / cm ² was applied and the luminance characteristics after continuous lighting for 1000 hours were measured, the luminance was reduced by 18% compared to the initial value, and the barrier property by the sealing layer 15 using SiN was greatly improved.

(Example 2)
A 150 nm Ag film was formed on a Si substrate that had been subjected to ultrasonic cleaning and UV ozone treatment by a sputtering method through a shadow mask to form the first electrode 11. Next, ITO was deposited to a thickness of 15 nm through a shadow mask by sputtering, and an ITO layer 12 was formed. Next, a bank 16 was formed by photolithography so that 1024 dots having a diameter of about 21 μm were arranged in a line shape (bank material: DL-1000 (manufactured by Toray)). Further, UV ozone treatment was performed, the ITO surface was washed, transported to a glove box, and annealed at 120 ° C. for 5 minutes.

Next, α-NPD is deposited in a thickness of 50 nm (2 Å / s), Alq3 is 50 nm (2 Å / s), and LiF is 0.5 nm (0.05 Å / s) through a shadow mask by vacuum deposition. Then, an organic compound layer 13 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

Next, MgAg (20: 1) 15 nm (4 Å / s: 0.2 Å / s) is applied to the first electrode 11 (Ag layer), ITO layer 12, and organic compound layer through a shadow mask by vacuum deposition. The film was formed so as to completely cover the bank 16 and the second electrode 14 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

  Simultaneously with the formation of the second electrode 14, MgAg 15 nm as an adhesion layer 18 was formed outside the second electrode 14 so as not to be electrically connected to the second electrode 14 through a shadow mask.

  Next, by CVD, SiN of 2000 nm is formed through the shadow mask so as to cover the second electrode 14 (MgAg) and the adhesion layer 18 (30 Å / s), the sealing layer 15 is formed, and the organic EL Element 1 was produced.

  Next, the organic EL elements 1 produced on the transparent substrate were arranged in a line to form the drive elements 42 and the control circuit 43, and the organic EL panel 40 was produced. The organic EL panel 40 produced in the head case of the printer head and the lens element (optical imaging system 53) for imaging light from the organic EL panel 40 were attached, and an exposure apparatus 50 as shown in FIG. 7 was produced. Observation of the light collected from the lens after applying current to the exposure device 50 confirmed the emission of dots arranged in a line.

(Comparative Example 1)
A first electrode 11 was formed on a substrate 10 made of Si that had been subjected to ultrasonic cleaning and UV ozone treatment, by sputtering to form a 150 nm Ag film through a shadow mask. Next, ITO was deposited to a thickness of 15 nm through a shadow mask by sputtering, and an ITO layer 12 was formed. Next, a bank 16 was formed by photolithography so that 1 mm □ was opened (bank material: DL-1000 (manufactured by Toray) was used). Further, UV ozone treatment was performed, the ITO surface was washed, transported to a glove box, and annealed at 120 ° C. for 5 minutes.

Next, α-NPD is deposited in a thickness of 50 nm (2 Å / s), Alq3 is 50 nm (2 Å / s), and LiF is 0.5 nm (0.05 Å / s) through a shadow mask by vacuum deposition. Then, an organic compound layer 13 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

Next, MgAg (20: 1) 15 nm (4 Å / s: 0.2 Å / s) was formed by vacuum evaporation through a shadow mask to form the second electrode 14 (back pressure: 3 × 10 ⁻⁵ Pa).

  Next, a SiN film having a thickness of 2000 nm (30 ＣＶＤ / s) was formed by a CVD method through a shadow mask to form the sealing layer 15.

  The obtained organic EL element had a configuration in which the second electrode 14 as shown in FIG. 3 did not cover the first electrode 11 or the like.

When a current characteristic of 100 mA / cm ² was applied and the luminance characteristics after 1000 hours of continuous lighting were measured, the luminance was reduced by 52% compared to the initial value.

(Reference Example 1)
A first electrode 11 was formed on a substrate 10 made of Si that had been subjected to ultrasonic cleaning and UV ozone treatment, by sputtering to form a 150 nm Ag film through a shadow mask. Next, ITO was deposited to a thickness of 15 nm through a shadow mask by sputtering, and an ITO layer 12 was formed. Next, a bank 16 was formed by photolithography so that 1 mm □ was opened (bank material: DL-1000 (manufactured by Toray)). Further, UV ozone treatment was performed, the ITO surface was washed, transported to a glove box, and annealed at 120 ° C. for 5 minutes.

Next, α-NPD is deposited in a thickness of 50 nm (2 Å / s), Alq3 is 50 nm (2 Å / s), and LiF is 0.5 nm (0.05 Å / s) through a shadow mask by vacuum deposition. Then, an organic compound layer 13 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

Next, MgAg (20: 1) 15 nm (4 Å / s: 0.2 Å / s) is applied to the first electrode 11 (Ag layer), ITO layer 12, and organic compound layer through a shadow mask by vacuum deposition. The film was formed so as to completely cover the bank 16 and the second electrode 14 was formed (back pressure: 3 × 10 ⁻⁵ Pa).

  Next, SiN 2000 nm was formed by CVD to cover the second electrode 14 (MgAg) through a shadow mask (30 Å / s), and the sealing layer 15 was formed.

  The obtained organic EL element has a configuration in which the second electrode 14 as shown in FIGS. 4 and 5 covers the first electrode 11 and the like, and the sealing layer 15 covers the second electrode 14. there were.

When a current characteristic of 100 mA / cm ² was applied and luminance characteristics after continuous lighting for 1000 hours were measured, the luminance was reduced by 24% compared to the initial value.

DESCRIPTION OF SYMBOLS 1 Organic EL element 10 Substrate 11 First electrode 12 ITO layer 13 Organic compound layer 14 Second electrode 15 Sealing layer 16 Bank 17 Light emitting area 18 Adhesion layer 40 Organic EL panel 41 Element substrate 42 Drive element 43 Control circuit 50 Exposure Device 53 Optical imaging system 60 Image forming device 61 Charging device 63, 63K, 63Y, 63M, 63C Developing device 64 Static eliminating device 65 Drive roller 66 Transfer conveyance belt 67 Secondary transfer bias roller 68 Fixing device 69 Paper feed unit 70, 70K , 70Y, 70M, 70C Photoconductor 71, 71K, 71Y, 71M, 71C Primary transfer bias roller 72 Intermediate transfer belt 73 Registration roller 74, 74K, 74Y, 74M, 74C Image forming unit P Transfer paper

Japanese Patent No. 4552390 JP 2012-151060 A

Claims (8)

A first electrode, an ITO (indium tin oxide) layer, an organic compound layer including a light emitting layer, a second electrode, an adhesion layer, and a sealing layer are formed on the substrate, and light emission from the light emitting layer is separated by a bank. A top emission type organic EL element,
The second electrode covers the first electrode, the ITO layer, the organic compound layer and the bank;
The sealing layer covers the second electrode;
The organic EL element, wherein the adhesion layer is formed discontinuously on the outer surface of the second electrode and on the bonding surface with the sealing layer.   2. The organic EL element according to claim 1, wherein the material of the adhesion layer is the same as the material of the second electrode.   The organic EL element according to claim 2, wherein the adhesion layer and the second electrode are made of at least a metal thin film.   The organic EL device according to claim 3, wherein the metal thin film is made of at least a magnesium alloy.   The organic EL device according to claim 4, wherein the magnesium alloy contains at least silver. A printer head comprising the organic EL elements according to any one of claims 1 to 5 arranged in a line. An exposure apparatus comprising the printer head according to claim 6. An image forming apparatus comprising the exposure apparatus according to claim 7.