KR200257242Y1 - The organic electro-luminescence device - Google Patents

Abstract

The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device (OLED) including a configuration for preventing the polymer organic layer, which is a light emitting layer, from being exposed to ultraviolet rays.

In detail, in the top emission type organic light emitting device emitting light to the top of the switching device, the sealant used to attach the protective film used to pack the organic light emitting device may be cured or In addition, when a plurality of organic films or inorganic films are stacked and used as a protective film, ultraviolet rays (UV) used to cure them include a self-ray blocking means for protecting the lower polymer organic light emitting layer.

In this way, the organic film can be prevented from being deteriorated by ultraviolet rays, thereby extending the life of the organic light emitting device.

Description

The organic electro-luminescence device

The present invention relates to an organic electroluminescent device, and more particularly, to an organic electroluminescent device having a structure that blocks ultraviolet rays from being absorbed into the interior.

In general, organic light emitting diodes inject electrons and holes into the light emitting layer from the electron injection electrodes and the hole injection electrodes, respectively, to inject the injected electrons. ) Is a device that emits light when an exciton, which is a combination of holes and holes, drops from the excited state to the 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, a configuration and operation of a general active matrix organic light emitting diode will be described with reference to FIG. 1.

1 is a cross-sectional view schematically showing a part of a general organic EL device. (An active matrix organic EL device including a p-type thin film transistor as a switching device will be described.)

Unlike the passive matrix type organic light emitting device, the active matrix type organic light emitting device configures a thin film transistor in each of a plurality of pixel regions, thereby driving each pixel 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 an active layer 18, a gate electrode 12, a source electrode 14, and a drain electrode 16, and the source electrode 14 and the drain electrode 16. The active layer 15 is formed in between.

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 device through the above 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, the hole 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.

The above-described configuration has been described with an example in which the switching element is a p-type thin film transistor.

Hereinafter, a configuration of an active matrix organic light emitting diode using a top emission thin film transistor will be described with reference to FIG. 2.

Unlike the p-type thin film transistor, the n-type thin film transistor has a structure in which the main carrier injected from the thin film transistor T into the polymer organic film 32 is electron, and the drain electrode 36 of the thin film transistor T is formed. The first electrode 30 in contact with) becomes a cathode electrode.

2 is a cross-sectional view illustrating a cross section of an organic light emitting diode having a top emission method according to a first embodiment of the present invention.

As illustrated, a thin film transistor T including a gate electrode 32, a source electrode 34, a drain electrode 36, and an active layer 38 is configured as a switching element for driving a plurality of pixels P. do.

In this case, an ohmic contact layer 39 is formed between the source electrode 34, the drain electrode 36, and the active layer 38.

When the thin film transistor T is driven, a main carrier flowing through an active channel (active layer exposed between the source electrode and the drain electrode) of the thin film transistor T is formed of electrons. do.

Thus, the pixel is formed with a first electrode 40 which is a cathode electrode in contact with the drain electrode 36 of the thin film transistor.

As the first electrode 40, one selected from a group of conductive metals having a low work function such as aluminum (Al), calcium (Ca), and magnesium (Mg) is deposited and patterned to form the pixel P. ) To form independently.

Next, a polymer material is deposited on the first electrode 40 to form an electron transport layer (ETL) 42a, and subsequently light is emitted by an applied electric field on the electron transport layer 42a. The polymer organic light emitting layer 42c and the hole transport layer (HTL) 42b are formed on the organic light emitting layer 42c.

On the upper portion of the hole transport layer 42b, one of a transparent conductive metal group having a high work function, such as indium tin oxide (ITO) and indium zinc oxide (IZO), is selected and formed to form an anode electrode ( A second electrode 46 which is an anode is formed.

In this case, the second electrode 46 is formed on the entire surface of the substrate.

Subsequently, a transparent inorganic insulating material is deposited on the second electrode 46 or an organic insulating material is deposited to form the protective layer 48.

Next, a protective film or protective plate 52 made of a transparent polymer material is formed on the protective layer 48 by an adhesive 50.

The reason why the protective layer 48 and the protective film or the protective plate 52 are formed on the second electrode 46 will be described below.

Since the lifespan of the organic light emitting device is greatly reduced by external oxygen or moisture, a packing is required to block the organic light emitting device. In this case, in the case of the top emission organic light emitting device, an inorganic film or an organic film is coated on the upper portion of the second electrode 40 as the transparent electrode as the protective layer 48 to block moisture and oxygen. And a protective film or protective plate 52 as described above to maintain mechanical strength.

Finally, a method of curing the sealant 50 by irradiating the sealant 50 with ultraviolet (UV) light is performed to increase the adhesive force of the protective film or the protective plate 52.

In addition to the above-described configuration, a structure in which an organic film and an inorganic film are laminated in place of the protective film or the protective plate 52 may be used, which will be described below with reference to FIG. 3.

As illustrated, an n-type thin film transistor T including an active layer 38, a gate electrode 32, a source electrode 34, and a drain electrode 36, and a drain electrode of the thin film transistor T ( A first electrode 40, which is a cathode electrode contacting 36, is independently formed for each pixel P. A first electrode 40, which is a cathode electrode, is disposed on the first electrode 40 with a polymer organic layer 42 interposed therebetween. Two electrodes 46 are configured.

In this case, the polymer organic layer 42 includes an electron transport layer 42a formed on the first electrode 40, a light emitting layer 42c formed on the electron transport layer 42a, and an upper portion of the light emitting layer. It consists of the hole transport layer 42b.

A feature of the second conventional example is that the transparent organic films 50a, 50c and 50e and the inorganic films 50b and 50d are stacked on the second electrode 46 as the passivation film 54.

In this case, silicon nitride (SiN _x ) and silicon oxide (SiO ₂ ) are used as the inorganic film, and a polymer film polymerized by irradiating light after forming a monomer is formed as an organic film. Or ultraviolet (UV) curable resins may be used.

With the above structure, the organic EL device of the top emission method according to the conventional example can be manufactured.

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

In particular, in the case of the organic light emitting device manufactured in the configuration as shown in FIGS. 2 and 3, when the protective film is cured using the process of curing the adhesive or the UV curable resin, ultraviolet rays pass through the lower transparent layer. It is irradiated to the polymer organic film containing a light emitting layer.

In this case, in the case of some polymers, when the ultraviolet rays are irradiated, deterioration occurs while causing a substitution reaction to a double bond site in the molecular structure, thereby reducing the electroluminescent properties of the organic material and shortening the lifespan.

Therefore, the present invention has been devised for the purpose of solving the above problems, and proposes an organic EL device having a new configuration in which the organic polymer film is not exposed to ultraviolet rays.

1 is a cross-sectional view schematically showing a general active matrix organic electroluminescent device,

2 is a cross-sectional view schematically showing an active matrix organic light emitting device according to a first example of the related art,

3 is a cross-sectional view schematically showing an active matrix organic light emitting device according to a second example of the related art.

4 is a cross-sectional view schematically showing an active matrix organic light emitting diode according to a first embodiment of the present invention,

5 is a schematic cross-sectional view 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

103: active layer 104: source electrode

106: drain electrode 110: first electrode

112: multilayer organic film 114: second electrode

116: UV blocking film 118: protective layer

120: sealant 122: protective film

An organic light emitting display device according to a first aspect of the present invention for achieving the above object includes 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 first electrode in contact with the drain electrode and independently configured for each pixel; A second electrode formed on the first electrode; An organic film disposed between the first electrode and the second electrode and emitting light by an electric field generated between the first electrode and the second electrode; An ultraviolet blocking film formed on the second electrode; A protective film formed on the UV blocking film; It includes.

The first electrode and the second electrode may be formed of one selected from aluminum (Al), calcium (Ca) and magnesium (Mg), or one selected from indium tin oxide (ITO) and indium zinc oxide (IZO). .

The UV blocking film is formed of one selected from a group of polymer materials that absorb ultraviolet light and allow visible light to pass therethrough.

An organic light emitting display device according to a second aspect of the present invention includes 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 first electrode in contact with the drain electrode and configured independently for each pixel; A second electrode formed on the entire surface of the substrate above the first electrode; An organic film disposed between the first electrode and the second electrode and emitting light by an electric field generated between the first electrode and the second electrode; an ultraviolet blocking film formed on the second electrode; A protective film is formed by alternately stacking an organic film and an inorganic film on the UV blocking film.

First Embodiment

A first embodiment according to the present invention is a means for protecting the light emitting layer from the ultraviolet light to be irradiated, characterized in that further configured to block the ultraviolet light on the upper portion of the light emitting layer.

The UV blocking means transmits visible light while blocking (absorbing) ultraviolet light.

4 is a schematic cross-sectional view showing an active organic light emitting diode according to a first embodiment of the present invention.

As illustrated, a thin film transistor array unit A is formed on a transparent plastic substrate or a glass substrate 100.

In general, the thin film transistor array unit A 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. do.

The switching element and the driving element use a thin film transistor T composed of a gate electrode 102, a source electrode and a drain electrode 104, 106, and an active layer 103.

The thin film transistor T is an n + type thin film transistor in which a plurality of carriers are electrons.

The light emitting part B including the first electrode 110, the organic layer 112, and the second electrode 114 is formed on the substrate 100 having the thin film transistor T.

The organic layer 112 includes an electron injection layer 112a, an organic emission layer 112c, and a hole injection layer 112b, and the electrons are formed on the first electrode 110 of the multilayer organic layer 112. An injection layer 112a is formed, an emission layer 112b is formed on the electron injection layer 112a, and a hole injection layer 112c is formed on the emission layer 112b.

The first electrode 110 is an electron injection electrode for injecting electrons into the electron injection layer 112a and is connected to the drain electrode 106 to receive a signal current.

The second electrode 114 is a hole injection electrode (anode) for injecting a hole into the hole injection layer 112b, is connected to a common wiring (not shown) formed separately on the substrate is formed.

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 formed of one selected from the group of conductive metals having a low work function including aluminum (Al), calcium (Ca), and magnesium (Mo). The electrode 114 is generally formed of a transparent conductive metal having a high work function such as indium-tin-oxide and indium-zinc-oxide.

An ultraviolet blocking film 116 is formed on the second electrode.

An example of the UV blocking layer 116 may be formed by depositing a transparent polymer material that blocks ultraviolet rays. In this case, the UV blocking film 116 may be formed by stacking a polymer film in multiple layers as necessary.

The protective layer 118 is formed by depositing an organic insulating material or an inorganic insulating material on the UV blocking film.

The passivation layer or passivation plate 122 is formed on the passivation layer 118 through the sealant 120.

The organic light emitting device according to the first embodiment of the present invention can be manufactured with the configuration as described above.

In the above-described configuration of the first embodiment, the protective film or the protective plate may be composed of a single layer or formed by alternately stacking a plurality of organic films or inorganic films, which will be described in detail with reference to the second embodiment.

Second Embodiment

According to a second embodiment of the present invention, a protective film for protecting a polymer organic film in a top emission type organic light emitting device has a structure in which a multilayer organic film and an inorganic film are laminated. It is characterized by further comprising a UV blocking means on the top.

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

As shown in the drawing, after the thin film transistor array unit A is described, the light emitting unit B including the first electrode 212, the organic layer 210, and the second electrode 214 is formed. .

An ultraviolet blocking film 216 is formed on the second electrode 214.

In this case, the UV blocking layer 216 may be formed anywhere on the second electrode 214.

As described above, the UV blocking layer 216 may be formed by depositing a transparent polymer material that absorbs ultraviolet light and passes visible light.

The protective layer 218 is formed by depositing an organic insulating material or an inorganic insulating material on the UV blocking film.

The passivation layer 220 is formed by alternately stacking the transparent organic layers 220a, 220c and 220d and the inorganic layers 220b and 220e on the passivation layer.

Through the first embodiment and the second embodiment as described above it is possible to manufacture a UV blocking organic EL device according to the present invention.

When the organic electroluminescent device is configured according to the above-described constitution of the present invention, since the organic film, which is the light emitter, can be prevented from being exposed to ultraviolet rays, the life of the organic film can be extended.

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

Claims (6)

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 first electrode in contact with the drain electrode and independently configured for each pixel; A second electrode formed on the first electrode; An organic film disposed between the first electrode and the second electrode and emitting light by an electric field generated between the first electrode and the second electrode; An ultraviolet blocking film formed on the second electrode; A protective film formed on the UV blocking film; Active matrix organic light emitting device comprising a. The method of claim 1, The first electrode and the second electrode is one selected from aluminum (Al), calcium (Ca), magnesium (Mg), or formed of one selected from indium tin oxide (ITO) and indium zinc oxide (IZO). Active matrix organic light emitting device. The method of claim 1, The UV blocking film is an active matrix type organic light emitting device that is selected from the group of polymer materials that absorb ultraviolet light and allow visible light to pass therethrough. 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 first electrode in contact with the drain electrode and configured independently for each pixel; A second electrode formed on the entire surface of the substrate above the first electrode; An organic film disposed between the first electrode and the second electrode and emitting light by an electric field generated between the first electrode and the second electrode; An ultraviolet blocking film formed on the second electrode; A protective film formed by alternately stacking an organic film and an inorganic film on the UV blocking film. Active matrix organic electroluminescent device comprising a. The method of claim 4, wherein The first electrode and the second electrode is one selected from aluminum (Al), calcium (Ca), magnesium (Mg), or formed of one selected from indium tin oxide (ITO) and indium zinc oxide (IZO). Active matrix organic light emitting device. The method of claim 4, wherein The UV blocking film is an active matrix type organic light emitting device that is selected from the group of polymer materials that absorb ultraviolet light and allow visible light to pass therethrough.