JP2002198169A - Organic el panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To readily provide an organic EL panel and at a lower cost that will have only few cases of adverse effects, such as deterioration of emission response and dispersion of luminous intensity of the organic EL panel, or the failure of light-emission of the whole panel due to sodium ions. SOLUTION: This is an organic EL pane l10 that has at least one or more organic layers, interposed between a positive electrode 13 and a negative electrode 18 on a translucent substrate 11. An undercoat layer 12, that prevents the sodium ions contained in the substrate 11 from entering into the above organic layer, is provided between the substrate 11 and the positive electrode 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic EL (electroluminescence) panel in which a laminate in which an organic layer having at least one light-emitting layer is sandwiched between an anode and a cathode is disposed on a light-transmitting substrate. About.

[0002]

2. Description of the Related Art Organic EL having a light emitting layer composed of an organic substance
The panel has attracted attention as one that realizes DC low-voltage driving. For example, Japanese Patent Publication No. 6-32307 discloses
As shown in FIG. 2, a substrate 1 made of translucent glass and indium tin oxide (ITO) formed on the upper surface of the substrate 1
, A hole injection layer 3, a light emitting layer 4, and an aluminum (AL)
And a power supply 6 connected between the anode 2 and the cathode 5 are disclosed. In the organic EL panel having such a configuration, holes generated at the anode 2 are transmitted to the interface between the hole injection layer 3 and the light emitting layer 4, where they combine with the electrons transmitted from the cathode 5 to generate visible light. Emit.

Further, in order to promote hole injection, an organic EL panel having a structure in which a hole transport layer is interposed between the hole injection layer 3 and the light emitting layer 4 or the hole injection layer 3 and the hole Organic E composed of a hole injection / transport layer integrated with a hole transport layer
An L panel is also known, and similarly to the above-described configuration, holes generated at the anode 2 are transferred to the interface between the hole injection layer 3 and the light emitting layer 4, where they are combined with electrons transferred from the cathode 5. Emit visible light.

[0004]

In such a configuration,
The substrate 1 made of translucent glass contains sodium ions. After the formation of the film, the sodium ions penetrate into the organic layers (the hole injection layer 3 and the light emitting layer 4) via the anode 2. Since the sodium ion has a very mobile property, if it is present in the organic layer, the anode 2
When a power supply 6 is connected between the anode and the cathode 5 and a current flows, a current flows preferentially to the sodium ions, thereby preventing a sufficient current from flowing to the organic layer. As a result, organic E
The light emission response of the L panel is deteriorated, the brightness of the light emission varies, or the whole panel stops emitting light.

[0005] Further, if a light-transmitting glass containing a small amount of the sodium ions is used as a substrate to reduce the adverse effects of the sodium ions, the adverse effects of the sodium ions can be reduced, but the cost increases. .

In view of such problems, the present invention more easily and inexpensively reduces the luminous response of an organic EL panel due to sodium ions, causes variations in luminous brightness, and has an adverse effect such that the entire panel does not emit light. An object is to provide a small number of organic EL panels.

[0007]

In order to solve the above-mentioned problems, the present invention provides, as described in claim 1, at least one or more organic layers sandwiched between an anode and a cathode on a light-transmitting substrate. An organic EL panel having a layer, comprising an undercoat layer between the substrate and the anode for preventing sodium ions contained in the substrate from entering the organic layer.

According to a second aspect of the present invention, there is provided an organic EL panel having at least one or more organic layers sandwiched between an anode and a cathode on a light-transmitting substrate, wherein the substrate and the anode are connected to each other. And an undercoat layer having a dense molecular structure for preventing sodium ions contained in the substrate from entering the organic layer, and having an insulating light-transmitting property.

[0009] In particular, in the first or second aspect, as set forth in the third aspect, the undercoat layer is made of silicon dioxide.

With this configuration, it is possible to more easily and inexpensively prevent sodium ions contained in the substrate from invading the organic layer, and it is possible to prevent deterioration of light emission response of the organic EL panel due to sodium ions and variation in light emission luminance. Outbreak,
Alternatively, it is possible to reduce an adverse effect such as that the entire panel stops emitting light.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on embodiments shown in the accompanying drawings.

FIG. 1 shows an organic EL according to an embodiment of the present invention.
It is a schematic cross section of a panel. The organic EL panel 10 includes a substrate 11 made of translucent glass, an undercoat layer 12 described below formed on the upper surface of the substrate 11, and a film formed of a translucent ITO film formed on the upper surface of the undercoat layer 12. An anode 13 having a thickness of 100 nm, and copper phthalocyanine (CuPc), which is a porphyrin-based organic substance and has a function of taking in holes from the anode 13, which is sequentially formed on the anode 13.
And a 4,4′-bis [N- (1-naphthyl) -N-phenyl- which is an amine-based organic substance having a function of sending the holes to a light-emitting layer described below. Amino] biphenyl (NPD) film thickness 70
hole transport layer 15, a light-emitting layer 16 made of 4,4'-bis (2,2'-diphenylvinyl) -biphenyl (DPVBi) having a thickness of 25 nm, and an alkylate having a function of sending electrons to the light-emitting layer 16. A 20 nm-thick electron transport layer 17 made of organic triquinolinolate aluminum (Alg3) and a film made of aluminum lithium (Al: Li) and having an electron injection effect so that the electron transport layer 17 can easily take in the electrons. And a cathode 18 having a thickness of 100 nm.
Connect.

The anode 13 is formed on the upper surface of the undercoat layer 12 by a sputtering method or the like, and forms an organic layer (a hole injection layer 14, a hole transport layer 15, a light emitting layer 16, an electron transport layer 1).
7), each of the cathodes 18 is laminated by vapor deposition.

The undercoat layer 12 is made of silicon dioxide (SiO 2) having a thickness of 20 nm, and is formed between the substrate 11 made of translucent glass and the anode 13 by a sputtering method or the like. Since SiO 2 has a very dense molecular structure, sodium ions contained in the substrate 11
3 and the organic layer is prevented from entering. Also,
Since the undercoat layer 12 has a light transmitting property, it does not prevent the light emitting display of the organic layer from being visually recognized.

According to such a configuration, the substrate 11 and the anode 13
The undercoat layer 12 is formed between the
Since it is possible to prevent the sodium ions contained in 1 from entering the organic layer, it is not necessary to use a translucent glass containing a small amount of the sodium ions, which is costly, as a substrate. Further, since the undercoat layer 12 can be formed by a sputtering method or the like in the same manner as the anode 13, it can be formed without providing any special forming means. Therefore, the adverse effects of the sodium ions can be reduced more easily and inexpensively.

In the embodiment of the present invention, the undercoat layer 12 is made of SiO 2. However, the undercoat layer 12 has a molecular structure that is so dense that it does not transmit sodium ions contained on the substrate 11 made of light-transmitting glass. Any material may be used as long as it has an insulating and transmissive property, and the material forming the undercoat layer 12 is not limited to SiO2.

Although the light emitting layer 16 has a single-layer structure,
A multilayer structure including a plurality of light emitting layers having a complementary color relationship with each other may be used.

The hole injection layer 14 and the hole transport layer 15 constitute a hole supply layer, and the electron transport layer 17 constitutes an electron supply layer. Is possible.

Further, the electron supply layer is formed as an electron transport layer 17.
And an electron injection layer located between the electron transport layer 17 and the cathode 18 and having a function of taking in electrons from the cathode 18. In this case, the electron transport layer 17 has Alg
3. Lithium fluoride (LiF) can be used for the electron injection layer. In this case, since the cathode 18 does not need to have an electron injection effect, Al can be used. Each of these layers can be formed by vapor deposition as described above.

[0020]

According to such a structure, a dense molecular structure is formed between a substrate made of a light-transmitting glass and an anode made of a translucent ITO film, and is made of a material having an insulating light-transmitting property. By forming the undercoat layer, it is possible to more easily and inexpensively prevent sodium ions contained in the substrate from invading the organic layer. Alternatively, it is possible to reduce an adverse effect such as that the entire panel stops emitting light.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of an organic EL panel according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view illustrating a configuration of a conventional technique.

[Explanation of symbols]

 Reference Signs List 10 organic EL panel 11 substrate 12 undercoat layer 13 anode 14 hole injection layer (hole supply layer) 15 hole transport layer (hole supply layer) 16 light emitting layer 17 electron transport layer 18 cathode 19 power supply

Claims (3)

[Claims] 1. An organic EL panel having at least one or more organic layers sandwiched between an anode and a cathode on a light-transmitting substrate, wherein sodium contained in the substrate is interposed between the substrate and the anode. An organic E layer comprising an undercoat layer for preventing ions from entering the organic layer.
L panel. 2. An organic EL panel having at least one organic layer sandwiched between an anode and a cathode on a light-transmitting substrate, wherein sodium contained in the substrate is interposed between the substrate and the anode. An organic EL panel comprising an undercoat layer having a dense molecular structure for preventing ions from entering the organic layer and having an insulating and transmissive property. 3. The method according to claim 1, wherein the undercoat layer is made of silicon dioxide.
The organic EL panel according to 1.