KR100782937B1 - The organic electro-luminescence device - Google Patents

Abstract

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device for preventing the organic film from being exposed to ultraviolet rays.

In detail, an ultraviolet blocking means is provided in a passive matrix type or an active matrix type organic electroluminescent device so that the organic layer is not exposed to ultraviolet rays.

In this way, it is possible to prevent the organic film from being deteriorated by ultraviolet rays, thereby extending the life of the organic light emitting display device.

Description

The organic electro-luminescence device             

1 is a cross-sectional view schematically showing a part of an organic light emitting display device,

2 is a view showing the molecular structure of an organic material,

3 is a cross-sectional view showing a part of an active matrix organic light emitting display device according to a first embodiment of the present invention;

4 is a cross-sectional view showing the configuration of a polymer film.

5 is a cross-sectional view showing a part of a passive matrix organic light emitting display device according to a first embodiment of the present invention;

6 is a cross-sectional view showing a part of an active matrix organic light emitting display device according to a second embodiment of the present invention.

<Brief description of the main parts of the drawing>

100 substrate 102 gate electrode

104: source electrode 106: drain electrode

108: active layer 110: organic film

112: first electrode 114: second electrode (cathode)                 

A: TFT array portion B: light emitting portion

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to organic electroluminescent devices, and more particularly, to organic electroluminescent devices having a structure that blocks ultraviolet rays from being absorbed into the interior.

In general, an organic light emitting diode is an electron injected by injecting electrons and holes into the light emitting layer from an electron injection electrode and a hole injection electrode, respectively. Is an element that emits light when an exciton combined with a hole falls from an excited state to a ground state.

As a result, unlike the conventional thin liquid crystal display device, since a separate light source is not required, the device can reduce the volume and weight of the device and can simplify the process.

Hereinafter, the configuration and operation of the organic light emitting display device will be described with reference to FIG. 1.

1 is a cross-sectional view schematically showing a part of a general organic light emitting display device. (The active matrix organic light emitting display device will be described as an example.)

Unlike the passive matrix type organic light emitting device, the active matrix type organic light emitting device forms a thin film transistor in each pixel area so that each pixel can be driven independently.

Therefore, as shown in the drawing, a thin film transistor T which is a driving element is formed for each pixel region P defined on the substrate 10.

The thin film transistor T includes a gate electrode 12, a source electrode 14, and a drain electrode 16, and an active layer 18 is formed between the source electrode 14 and the drain electrode 16. .

The pixel region P is formed of a first electrode 20 which contacts the drain electrode 16 and injects holes into the organic layer, and a multilayer or single layer formed on the first electrode 20. An organic film 22 and a second electrode 24 for injecting electrons are formed on the organic film 22.

When the organic layer is formed of a multilayer, an electron transporting layer (ETL) and a hole transporting layer are formed.

Hereinafter, the operation of the organic light emitting display device through the above-described configuration will be described schematically.

(The case where the said organic film is a multilayer structure as mentioned above is demonstrated to an example.)

When an electric field is formed between the first electrode 20 and the second electrode 24, holes and the second injected into the hole transport layer 22a of the organic layer 22 through the first electrode 20. Electrons injected into the electron transport layer 22b through the electrode 24 meet at the light emitting layer 22c, where electrons and holes are combined in the light emitting layer 22c to generate excitons having high energy. The excitons fall to low energy and emit their own light.                         

Through the operation as described above, the organic electroluminescent device can implement an image.

In the organic light emitting device having the above-described configuration, the characteristics of the organic film are very important, and a product defect may occur due to deterioration or chemical modification of the organic film.

In particular, as shown in FIG. 2, the molecular structure 30 constituting the organic layer 22 is deteriorated due to a substitution reaction to a double bond site 34 or the like when exposed to ultraviolet rays (UV), thereby causing electroluminescence characteristics of the organic material. This decreases the problem.

For the purpose of solving such a problem, the present invention proposes an organic electroluminescent device in which the organic film is not exposed to ultraviolet rays.

According to a first aspect of the present invention, there is provided a passive matrix type organic light emitting display device comprising: a transparent insulating substrate on which a plurality of pixels are defined; A first electrode formed in one direction and spaced apart from each other by a predetermined distance on an upper portion of the transparent insulating substrate; A second electrode formed in one direction while crossing the first electrode and spaced apart from each other by a predetermined distance on an upper portion of the first electrode; An organic layer disposed between the first electrode and the second electrode, the organic layer emitting light by combining holes injected from the first electrode and electrons injected from the second electrode; It is configured on the back of the substrate, and includes a UV blocking means for transmitting visible light and blocking ultraviolet light.

The first electrode is formed of one selected from indium tin oxide (ITO) and indium zinc oxide (IZO).

The second electrode is formed of one of aluminum (Al), calcium (Ca), and magnesium (Mg).

The UV blocking means is a polymer film or a liquid polymer of a spray type.

An active matrix type organic light emitting display device according to a first aspect of the present invention comprises: a substrate in which a plurality of pixels are defined; A driving element composed of a gate electrode active layer source electrode and a drain electrode for each pixel; A plurality of first electrodes in contact with the drain electrode and independently formed in each of the pixels and injecting holes; A second electrode formed on the front surface of the substrate above the first electrode and injecting electrons; An organic layer disposed between the first electrode and the second electrode, the organic layer emitting light by combining holes injected from the first electrode and electrons injected from the second electrode; It is configured on the back of the substrate, and includes a UV blocking means for transmitting visible light and blocking ultraviolet light.

According to a second aspect of the present invention, an active matrix organic light emitting display device includes: a substrate on which a plurality of pixels are defined; A driving element composed of a gate electrode active layer source electrode and a drain electrode for each pixel; Ultraviolet blocking means which is configured on the front surface of the substrate including the driving element, and which transmits visible light and blocks ultraviolet rays; A plurality of first electrodes in contact with the drain electrode and independently formed in each of the pixels and injecting holes; A second electrode formed on the entire surface of the substrate above the organic layer and injecting electrons; An organic layer is disposed between the first electrode and the second electrode and emits a predetermined light while the holes injected from the first electrode and the electrons injected from the second electrode are coupled to each other.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

First Embodiment

A first feature of the present invention is characterized in that the UV blocking means is provided on the substrate backside of the active organic light emitting display device having the TFT array and the organic light emitting body.

The UV blocking means transmits visible light while blocking UV light.

3 is a cross-sectional view schematically showing a part of an active organic light emitting display device according to a first embodiment of the present invention.

As shown, a thin film transistor (T) array is formed on a transparent plastic substrate or a glass substrate 100.

In general, the thin film transistor T array includes a plurality of pixels P, a switching element in the pixel P, and a driving element T for driving the pixel P according to a signal of the switching element. .                     

The switching element and the driving element use a thin film transistor T formed of a gate electrode 102, a source electrode, a drain electrode 104, 106, and an active layer 108.

In the above-described configuration, the pixel region P includes an organic layer 110 composed of a single layer or a multi layer, and the first electrode 112 with the organic layer 110 therebetween. And the second electrode 114.

The first electrode 112 is a hole injection electrode (anode) for injecting a hole (hole) in the organic layer 110, is connected to the drain electrode 106 receives a signal current .

The second electrode 114 is an electron injection electrode for injecting electrons into the organic layer 110, and is connected to a common wiring (not shown) separately formed on a substrate.

The switching element (not shown) is configured to be connected to a gate wiring (not shown) and a data wiring (not shown) configured in one direction on the substrate 100.

In the above-described configuration, the first electrode 112 is generally formed of a transparent conductive metal such as indium-tin-oxide and indium-zinc-oxide, and the The second electrode 114 is formed of aluminum (Al) having a low work function.

As described above, UV blocking means for blocking 90% or more of ultraviolet light but transmitting 90% or more of visible light is attached to the rear surface of the substrate 100 on which both the thin film transistor array part A and the light emitting part B are formed.                     

As an example of the UV blocking means, the polymer film 116 may be attached. The polymer film 116 is a colorless transparent material, as shown in FIG. 4, and the two thin polymer films 116a and 116b are acrylic. The adhesive 116c is made of a transparent material such as resin, and then bonded to the back surface of the substrate 100 after fabricating the polymer film 116 having a certain thickness.

This configuration is a structure corresponding to the case where the thickness of the polymer film is very fine, and depending on the conditions, one sheet of the polymer film may be used.

In this case, the material forming the polymer film 116 may use polyethylene terephthalate.

As another method for forming the UV blocking means on the substrate 100, as described above, a spray type sunscreen that is made in a liquid form and sprayed on the substrate 100 may be sprayed onto the substrate 100 even if the film is not in the form of a film. Can also be used.

At this time, the liquid polymer is benzophenone-1 (benzophenone-1: 2,4-Dihydroxy Benzophenone) and benzophenone-3 (benzophenone-3: Oxybenzone 2-Hydroxy-4-Methoxy Benzophenone) and benzophenone-12 (benzophenone- 12: 2-Hydroxy-4-Octoxy Benzophenone) may be prepared by dissolving a high molecular material in a solvent such as benzene.

The characteristics of the present invention as described above can be applied to the passive matrix type organic electroluminescent device as well as the active matrix type organic electroluminescent device.                     

5 is a schematic cross-sectional view of a passive matrix organic light emitting display device according to the present invention.

Although not illustrated in plan view, in general, the planar configuration of the passive matrix organic light emitting display device may include a plurality of first electrodes 102 and one first electrode 102 arranged in one direction spaced apart from each other on the substrate 100. The organic layer 106 which is configured on the upper side and emits light with a predetermined light when the electric field is applied, and the organic layer 106 which is formed on the organic layer, intersects perpendicularly to the first electrode 102 to define the pixel P. The second electrode 108 is formed to be spaced apart at a predetermined interval in one direction.

As shown in the drawing, a pixel P is defined on a substrate, and the first electrode 102 transparent to the substrate 100 in which each pixel P is defined, and each pixel on the first electrode 102 ( Between P), partition walls 104 formed of an insulating material and having a predetermined height H are formed.

An organic layer 106 is deposited on the pixel P and the partition 104, and a second electrode 108 is formed on the organic layer 106.

As described above, the first electrode 102 is a hole injection electrode for injecting holes into the organic layer 106, and the second electrode 108 is an electron in the organic layer 106. ) To function as an electron injection electrode.

In the process of forming the second electrode 108, the partition 104 changes the characteristics of the organic layer 106 by chemicals during the developing process and the chemical etching process. Used to prevent doing so.                     

In other words, it is configured for the purpose of independently forming the second electrode 108 without using a general photo-lithography process.

Therefore, when the barrier rib 104 is formed, and then the organic layer 106 is deposited, the organic membrane 106 is not deposited on the side surface of the barrier rib 104 and the top of the barrier rib is planarly formed. The result formed only on the first electrode 102 of each pixel can be obtained.

In this case, the organic layer 106 may be formed of a multilayer including a hole transport layer, a light emitting layer, and an electron transport layer, and conversely, may be formed of a single layer composed of only a light emitting layer.

In the case of depositing the second electrode 108, the deposition direction may be controlled. As a representative method, the deposition direction is inclined at a predetermined inclination (for such a process, a position of a target for depositing a metal is selected). Control or tilting the substrate), the second electrode 108 is deposited on and on one side of the partition wall 104 and on the organic layer 106 of each pixel.

As described above, the ultraviolet blocking means 110 is further formed on the rear surface of the passive matrix organic electroluminescent device, which is roughly composed of the first electrode 102, the second electrode 108, and the organic film 106.

As described above, the UV blocking means may use a polymer film, it may be formed of a liquid polymer of the spray type.

The spray type liquid polymer material utilizes a property of being hardened after being sprayed onto a substrate.

Hereinafter, another embodiment of the present invention is proposed.

Second Embodiment

A feature of the second embodiment of the present invention is a structure in which the ultraviolet blocking means is inserted between the light emitting layer and the thin film transistor array of the active matrix organic EL device.

6 is a schematic cross-sectional view of an organic light emitting display device according to a second exemplary embodiment of the present invention.

As shown, after forming the thin film transistor array unit A described above, the light emitting unit B including the first electrode 212, the organic layer 210, and the second electrode 214 is formed. In the entire process, the ultraviolet blocking means 216 is formed.

That is, the ultraviolet blocking means 216 is formed before forming the first electrode in contact with the drain electrode 206 of the thin film transistor T.

As described above, the UV blocking means 216 may be a transparent material, and visible light may be transmitted while UV light may be blocked.

It is possible to configure the organic electroluminescent device according to the present invention through the configuration as described above.

Therefore, when the organic electroluminescent device is constructed according to the above-described configuration of the present invention, the organic film, which is the light emitter, can be prevented from being exposed to ultraviolet rays, thereby extending the life of the organic film.

Therefore, there is an effect that can improve the quality of the product.

Claims (16)

delete delete delete delete delete delete delete delete delete delete A substrate in which a plurality of pixels are defined; A driving element composed of a gate electrode, an active layer, a source electrode and a drain electrode for each pixel; UV blocking means configured to correspond to the front surface of the substrate including the driving element, and transmit visible light and block ultraviolet rays; A plurality of first electrodes formed on the ultraviolet shielding means and configured to be in contact with the drain electrode for each pixel; An organic layer formed on the first electrode to correspond to the entire surface of the substrate; A second electrode configured to correspond to the entire surface of the substrate on the organic layer; Active matrix organic electroluminescent device comprising a. The method of claim 11, The first electrode is an active matrix organic light emitting diode formed of one selected from indium tin oxide (ITO) and indium zinc oxide (IZO). The method of claim 11, The second electrode is an active matrix organic light emitting diode formed of one of aluminum (Al), calcium (Ca) and magnesium (Mg). delete The method of claim 11, The UV blocking means is an active matrix organic light emitting device, characterized in that the liquid polymer material. The method of claim 15, The liquid polymer material is an active matrix organic light emitting diode, characterized in that selected from benzopanone-1, benzopanone-3, benzopanone-12.

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