JP2009158249A - Organic el element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic EL element capable of suppressing sufficiently deterioration of a light-emitting part due to water. <P>SOLUTION: The organic EL element 1 is provided with a substrate 2, a light-emitting part 3 including an organic luminous layer 12, and a sealing film 4. The sealing film 4 suppresses deterioration of the light-emitting part 3 due to water, oxygen or the like. The sealing film 4 is composed of an ionic crystal layer consisting of an ionic crystal containing Li. In this case, LiB<SB>x</SB>N<SB>y</SB>and LiB<SB>x</SB>O<SB>y</SB>or the like can be applied for the ionic crystal containing Li. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an organic EL (electroluminescence) element provided with a sealing film.

  2. Description of the Related Art Conventionally, an organic EL element including a light emitting part including an organic light emitting layer and a sealing film for sealing the light emitting part is known.

Patent Document 1 discloses an organic EL element including a substrate, a light emitting unit including an anode, an organic light emitting layer, and a cathode sequentially stacked on the substrate, and a sealing film for sealing them. Yes. The sealing film is made of an inorganic material such as SiO _{2 and} a covalent bond crystal.

In this organic EL element, by forming the sealing film, water can be prevented from entering the light emitting part including the organic light emitting layer.
JP-A-7-142168

  However, in the organic EL element of Patent Document 1, since the sealing film is composed of an inorganic substance of a covalently bonded crystal in which one unit is difficult to break, the water blocking property is not sufficient. For this reason, there exists a subject that a light emission part deteriorates with water.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide an organic EL element capable of suppressing deterioration of a light emitting part due to water.

  In order to achieve the above object, the invention described in claim 1 includes a light emitting portion including an organic light emitting layer and a first ion crystal layer composed of three or more elements, and covers the light emitting portion. An organic EL element comprising a stop film.

  According to a second aspect of the present invention, in the first ionic crystal layer, at least any two or more elements selected from B (boron), O (oxygen), and N (nitrogen) and Li (lithium) are used. It is an organic EL element of Claim 1 characterized by the above-mentioned.

  According to a third aspect of the present invention, the sealing film is a second ionic crystal layer different from the first ionic crystal layer, and has a second ionic crystal layer composed of three or more elements. It is an organic EL element of any one of Claim 1 or Claim 2 characterized by the above-mentioned.

  The invention according to claim 4 is characterized in that the second ionic crystal layer contains at least any two elements selected from B, O or N and Li. This is an organic EL element.

  In addition, in the invention described in claim 5, the sealing film has an inorganic layer made of an inorganic substance of a covalent bond crystal. The organic EL according to any one of claims 1-4. It is an element.

  The invention according to claim 6 is the organic EL element according to any one of claims 1 to 5, wherein the sealing film has an organic layer made of an organic material. .

  According to the present invention, the light emitting portion is covered with the sealing film having the first ion crystal layer made of the ion crystal that is easily broken. Thereby, each element contained in the first ionic crystal layer can be regarded as one unit. Thereby, since 1 unit becomes small, the clearance gap in a 1st ion crystal layer can be reduced, and more water can be interrupted | blocked. As a result, it is possible to suppress a decrease in the light emitting part due to water.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of an organic EL element according to the first embodiment.

  As shown in FIG. 1, the organic EL element 1 according to the first embodiment includes a substrate 2, a light emitting unit 3, and a sealing film 4.

The substrate 2 is made of SiO ₂ that can transmit light. The thickness of the substrate 2 is not particularly limited, but is preferably 100 μm or less when it is desired to suppress the diffusion of light from the light emitting unit 3. In addition, you may comprise the board | substrate 2 with the resin-made flexible substrate which can deform | transform.

  The light emitting unit 3 is formed on one surface (hereinafter referred to as a surface) 2 a of the substrate 2. The light emitting unit 3 includes an anode electrode 11, an organic light emitting layer 12, and a cathode electrode 13.

  The anode electrode 11 is for injecting holes into the organic light emitting layer 12. The anode electrode 11 is made of ITO (indium tin oxide) having a thickness of about 100 nm capable of transmitting light. The anode electrode 11 is formed on the surface 2 a of the substrate 2.

The organic light emitting layer 12 is for emitting white light. The organic light emitting layer 12 is formed on the anode electrode 11 in an electrically connected state. In the organic light emitting layer 12, a hole transport layer and an electron transport layer are sequentially stacked from the anode electrode 11. For the hole transport layer, an NPD (diphenylnaphthyldiamine) film having a thickness of about 50 nm can be employed. As the electron transport layer, a quinolinol aluminum complex (Alq ₃ ) film having a thickness of about 50 nm mixed with a dye can be employed. Further, copper phthalocyanine (CuPc) may be laminated between the anode electrode 11 and the organic light emitting layer 12 in order to promote hole injection from the anode electrode 11.

  The cathode electrode 13 is for injecting electrons into the organic light emitting layer 12. The cathode electrode 13 is made of an Mg / Ag alloy or an Al film having a thickness of about 100 nm. The cathode electrode 13 is formed on the organic light emitting layer 12. Thereby, the organic light emitting layer 12 is sandwiched between the anode electrode 11 and the cathode electrode 13.

The sealing film 4 is for suppressing the light emitting unit 3 from being deteriorated by water, oxygen, or the like. The sealing film 4 is formed so as to cover a part of the light emitting unit 3. Specifically, the sealing film 4 is formed so as to cover a part of the anode electrode 11, the side surface of the organic light emitting layer 12, and the cathode electrode 13. The sealing film 4 is made of an ion crystal layer made of an ion crystal containing Li. Here, the ionic crystal containing _Li, can be applied _{LiB x N y, LiB x O} y, the LiB _x N y _{O z} and the like.

  Next, the operation of the organic EL element 1 described above will be described.

  First, a voltage is applied between the anode electrode 11 and the cathode electrode 13. Thereby, holes are injected from the anode electrode 11 into the organic light emitting layer 12, and electrons are injected from the cathode electrode 13 into the organic light emitting layer 12. The injected holes and electrons recombine in the organic light emitting layer 12 to emit light. Thereafter, the light passes through the anode electrode 11 and the substrate 2 and is irradiated to the outside.

  Next, the manufacturing method of the organic EL element 1 mentioned above is demonstrated. 2-5 is sectional drawing of the organic EL element of 1st Embodiment in each manufacturing process.

  First, as shown in FIG. 2, a patterned anode electrode 11 is formed on the surface 2 a of the substrate 2 by a photolithography technique, a lift-off method, or the like.

  Next, as shown in FIG. 3, the organic light emitting layer 12 is formed in a desired region on the anode electrode 11 by vapor deposition using the metal mask 15 in which the opening 15a is formed.

  Next, as shown in FIG. 4, the cathode electrode 13 is formed on the organic light emitting layer 12 by vapor deposition using the metal mask 16 in which the opening 16a is formed.

  Next, as shown in FIG. 5, a resist film 17 is formed by photolithography. Thereafter, the sealing film 4 made of an ion crystal is formed so as to cover the light emitting portion 3 by a sputtering method capable of introducing a reactive gas, and then the resist film 17 is removed. Thereby, the organic EL element 1 shown in FIG. 1 is completed.

As described above, the organic EL device 1 according to the first embodiment includes the sealing film 4 made of an ionic crystal (for example, LiB _x N _y ) that is easily broken. Here, the SiO ₂ of the covalent bond crystal used in the conventional sealing film becomes a plurality of SiO _{2 in} which one unit is huge. On the other hand, in the sealing film 4 made of ionic crystals, one unit of crystal can be regarded as each element (Li, B, N). Thereby, since one unit becomes small, the sealing film 4 can reduce the gap | interval in a film | membrane compared with the sealing film which consists of a covalent bond crystal | crystallization. As a result, the sealing film 4 can block more water, so that deterioration of the light emitting unit 3 can be suppressed. Furthermore, since the barrier property is improved even for oxygen gas having a molecular size larger than that of water molecules, oxidation of the light emitting portion 3 can be suppressed.

  Further, in the organic EL element 1, the sealing film 4 is composed of a three-element crystal. As a result, the gap in the sealing film 4 can be reduced and the barrier property against water can be improved as compared with the two-element crystal.

  Moreover, even when a flexible substrate is employed as the substrate 2 of the organic EL element 1, it is possible to suppress the loss of flexibility of the flexible substrate.

(Second Embodiment)
Next, an organic EL element according to the second embodiment in which the organic EL element of the first embodiment is partially changed will be described. FIG. 6 is a cross-sectional view of an organic EL element according to the second embodiment. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 6, the sealing film 4A of the organic EL element 1A according to the second embodiment has a stacked structure in which a first sealing layer 21 and a second sealing layer 22 are sequentially stacked.

  Hereinafter, a combination of the first sealing layer 21 and the second sealing layer 22 will be described.

<Combination of two different ionic crystal layers>
The first sealing layer 21 is composed of a first ion crystal layer composed of a first ion crystal, and the second sealing layer 22 is composed of a second ion crystal layer composed of a second ion crystal different from the first ion crystal. May be. Here, as the different ion crystals, for example, any two of LiB _x N _y , LiB _x O _{y and} LiB _x N _y O _z can be adopted. In the case where the sealing film 4A is composed of two types of inorganic layers as described above, it can be formed in sequence using two different types of targets.

<Combination of ionic crystal layer and inorganic layer>
The first sealing layer 21 may be composed of an ionic crystal layer made of an ionic crystal, and the second sealing layer 22 may be made of an inorganic layer made of an inorganic substance of a covalent bond crystal. Here, SiN, SiON, etc. are employable as a covalent bond crystal which comprises an inorganic layer.

<Combination of ionic crystal layer and organic layer>
The first sealing layer 21 may be composed of an ion crystal layer made of an ionic crystal, and the second sealing layer 22 may be made of an organic layer made of an organic material. Here, CF _x or the like can be adopted as an organic material constituting the organic layer. By adopting the organic layer in this manner, the organic layer becomes a buffer film in the sealing film 4A, and cracks and the like can be suppressed. As a method for forming the organic layer, a CVD method, an ion plating method, or the like can be applied.

  As mentioned above, although this invention was demonstrated in detail using embodiment, this invention is not limited to embodiment described in this specification. The scope of the present invention is determined by the description of the claims and the scope equivalent to the description of the claims. Hereinafter, modified embodiments in which the above-described embodiment is partially modified will be described.

  For example, the material, shape, numerical value, and the like of each component of the organic EL element described above can be appropriately changed.

  Although the sealing film of the organic EL element described above has been described by taking a single layer or a two-layer structure as an example, it may be configured in a laminated structure of three or more layers.

It is sectional drawing of the organic EL element by 1st Embodiment. It is sectional drawing of the organic EL element of 1st Embodiment in each manufacturing process. It is sectional drawing of the organic EL element of 1st Embodiment in each manufacturing process. It is sectional drawing of the organic EL element of 1st Embodiment in each manufacturing process. It is sectional drawing of the organic EL element of 1st Embodiment in each manufacturing process. It is sectional drawing of the organic EL element by 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1A Organic EL element 2 Board | substrate 2a Surface 3 Light emission part 4, 4A Sealing film 11 Anode electrode 12 Organic light emitting layer 13 Cathode electrode 15, 16 Metal mask 15a, 16a Opening part 21 1st sealing layer 22 2nd sealing layer

Claims (6)

A light emitting part including an organic light emitting layer;
An organic EL element comprising: a first ion crystal layer composed of three or more elements; and a sealing film that covers the light emitting portion.   The first ion crystal layer includes at least any two or more elements selected from B (boron), O (oxygen), and N (nitrogen) and Li (lithium). The organic EL element of description.   The said sealing film is a 2nd ion crystal layer different from a 1st ion crystal layer, Comprising: The 2nd ion crystal layer comprised by the element more than 3 elements is characterized by the above-mentioned. 3. The organic EL device according to any one of 2 above.   4. The organic EL element according to claim 3, wherein the second ionic crystal layer contains at least any two elements selected from B, O, and N and Li. 5.   5. The organic EL element according to claim 1, wherein the sealing film has an inorganic layer made of an inorganic substance of a covalent bond crystal.   The organic EL element according to claim 1, wherein the sealing film has an organic layer made of an organic material.

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