KR100645717B1 - Organic light emitting display device - Google Patents

Abstract

An organic light emitting display device is provided to improve the brightness of a displayed image by freely displaying images on one of both surfaces of the organic light emitting display device. An organic light emitting display device(220) includes at least one transparent TFT(Thin Film Transistor)(213) and a light emitting portion(210) on one surface of a transparent substrate(200). A buffer layer(201) is formed on the transparent substrate. A semiconductor layer(202), which includes an LDD(Lightly Doped Drain) layer between an active channel layer(202a) and an ohmic contact layer(202b), is formed on one portion of the buffer layer. A gate insulation film(203) and a gate electrode(204) are patterned on the semiconductor layer. An interlayer dielectric(205) is formed on the gate electrode, such that the ohmic contact layer is exposed. Source and drain electrodes(206a,206b) are formed on a portion of the interlayer dielectric such that the source and drain electrodes are contacted with the ohmic contact layer.

Description

Organic light emitting display device {ORGANIC LIGHT EMITTING DISPLAY DEVICE}

1 is a schematic cross-sectional view of a conventional organic light emitting display device;

2 is a schematic cross-sectional view showing an embodiment of an organic light emitting display device according to the present invention;

♣ Explanation of symbols for the main parts of the drawing ♣

100, 200: substrate

113,213: Transparent Thin Film Transistor

214: Encapsulant

215: first transparent electrode

216: second transparent electrode

217 liquid crystal

219 polarizing member

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device capable of maximizing the effect of double-sided light emission of an organic light emitting display device using a transparent thin film transistor.

In recent years, with the advent of the highly information society, the demand for a personal computer, a car navigation system, a portable information terminal, an information communication device, or a combination thereof is increasing. These products require characteristics such as good visibility, wide visual characteristics, and ability to display moving images with high-speed response, and the organic light emitting display device has been attracting attention as a next-generation display in the future.

In general, a thin film transistor is a switching that operates each pixel in a display device such as an organic light emitting display device (OLED) or a liquid crystal display device (LCD). It is widely used as an element. Accordingly, much attention has been paid to the manufacture of thin film transistors, and organic light emitting display devices using more efficient thin film transistors have been devised.

Hereinafter, a conventional organic light emitting display device will be described in detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a conventional organic light emitting display device.

Referring to FIG. 1, a conventional organic light emitting diode display 120 includes a substrate 100, a buffer layer 101 formed on the substrate 100, and an active layer 102a formed on one region of the buffer layer 101. ) And a semiconductor layer 102 formed of an ohmic contact layer 102b and a gate insulating layer 103 formed on the semiconductor layer 102. The gate electrode 104 formed on one region of the gate insulating layer 103 and the interlayer insulating layer 105 are formed on the gate electrode 104. The source and drain electrodes 106a and 106b formed on one region of the interlayer insulating layer 105 are formed to be connected to the one region where the ohmic contact layer 102b is exposed, and the source and drain electrodes 106a, The planarization layer 107 is formed on 106b). The first electrode layer 108 formed on one region of the planarization layer 107 is formed to be connected to one region where the source and drain electrodes 106a and 106b are exposed, and the first electrode layer 108 and the planarization layer are formed. A pixel definition layer 109 is formed on the layer 107 and has an opening (not shown) that exposes at least one region of the first electrode layer 108. The emission layer 110 is formed on the opening, and the second electrode layer 111 is formed on the emission layer 110 and the pixel defining layer 109. A moisture absorbent 113 is formed on the second electrode layer 111, and an encapsulation member 114 is formed on the moisture absorbent 113 to seal the moisture absorbent 113 formed on the second electrode layer 111. In the end region of the encapsulation member 114, an adhesive (not shown) is configured.

Here, the gate electrode 104 including the semiconductor layer 102 and the source and drain electrodes 106a and 106b are formed of an opaque material. In particular, the semiconductor layer 102 may be formed of amorphous silicon or polycrystalline silicon. (poly silicon) or the like. However, since these materials are not transparent, when the opaque thin film transistor 113 is used as the switching element of the organic light emitting diode display, there is a limit in widening the channel width due to the characteristics of the opaque semiconductor layer 102. Therefore, a large current cannot flow through the channel and a high voltage must be applied to the thin film transistor 113. As a result, the light emitting device of the conventional organic light emitting diode display is deteriorated and power consumption is increased.

In addition, there is a problem that the user can not selectively emit both sides of the light or the front light according to the desired time or the brightness of the surroundings.

Accordingly, an aspect of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide an organic light emitting display device for maximizing the effect of double-sided light emission of an organic light emitting display device using a transparent thin film transistor. .

Another object of the present invention is to provide an organic light emitting display device which can improve the width of a channel by a transparent semiconductor layer by using a transparent thin film transistor.

In order to achieve the above object, the organic light emitting diode display according to the present invention includes a light emitting unit including at least one organic light emitting element formed on one surface of the transparent substrate and at least one transparent thin film transistor for driving the organic light emitting element. An organic light emitting display unit including a driving unit; An encapsulation portion formed on one surface of the organic light emitting display portion to encapsulate the organic light emitting display portion and including a polarization encapsulant having a polarization function; And a light control unit formed on the other surface of the organic light emitting display unit and configured to transmit and block light emitted from the organic light emitting display unit.

Here, the encapsulation portion is formed to enclose a hygroscopic material and the hygroscopic material configured to absorb moisture therein.

The light control unit may include: a first transparent electrode and a second transparent electrode formed at predetermined intervals from each other; A liquid crystal layer formed between the first transparent electrode and the second transparent electrode and driven by voltage application of the first transparent electrode and the second transparent electrode; A transparent plate configured on the second transparent electrode; And a polarization member formed on the transparent plate to provide a polarization function, wherein the encapsulation portion includes a polarization encapsulation material having a polarization function.

The control unit may further include a control unit applying a voltage to the first transparent electrode or the second transparent electrode, and the control unit may be automatically controlled by manual or photosensitive.

The transparent thin film transistor of the organic light emitting display unit may include a transparent semiconductor layer formed on the transparent substrate and an electrode formed on the transparent semiconductor layer.

In this case, the transparent semiconductor layer, a buffer layer formed on the transparent substrate; And an active channel layer and an ohmic contact layer formed on one region of the buffer layer. , TlSnO, InGaZnO, CuAlO, SrCuO, LaCuOS, GaN, InGaN, AlGaN, InGaAlN, SiC and diamond, and is formed of at least one material selected from the group consisting of.

In addition, the transparent electrode is at least one selected from the group consisting of a material that is simultaneously provided with conductivity and transparency, that is, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO) and a translucent metal It is formed of a substance.

Hereinafter, an organic light emitting diode display according to an exemplary embodiment will be described in detail with reference to the accompanying drawings.

2 is a schematic cross-sectional view illustrating an embodiment of an organic light emitting diode display according to the present invention.

In the present invention, in order to simplify the description, the concept of "transparent" shall include the concept of "transparent or translucent".

2 is a schematic cross-sectional view illustrating a first embodiment of an organic light emitting diode display according to the present invention.

As shown in FIG. 2, in the organic light emitting diode display 220 according to the present invention, at least one transparent thin film transistor 213 and the light emitting unit 210 are formed on one surface of the transparent substrate 200.

The structure of the transparent thin film transistor 213 formed on one surface of the transparent substrate 200 will be briefly described. A buffer layer 201 is formed on the transparent substrate 200, and an active channel layer is formed on one region of the buffer layer 201. A semiconductor layer 202 including an LDD layer (not shown) is formed between the 202a and the ohmic contact layer 202b. The gate insulating layer 203 and the gate electrode 204 are patterned on the semiconductor layer 202 and sequentially formed. A source and a second interlayer insulating layer 205 formed on the gate electrode 204 to contact the interlayer insulating layer 205 formed to expose the ohmic contact layer 202b of the semiconductor layer 202 and the exposed ohmic contact layer 202b. Drain electrodes 206a and 206b are formed on one region of the interlayer insulating layer 205.

In addition, a planarization layer 207 is formed on the transparent thin film transistor 213, and one region of the planarization layer 207 is etched on the planarization layer 207 of the source and drain electrodes 206a and 206b. One of the source and drain electrodes 206a and 206b and the first electrode layer 208 are electrically connected through the via hole 212 formed to expose one of them. The first electrode layer 208 is formed in one region of the planarization layer 207, and the pixel definition layer 209 having an opening at least partially exposing the first electrode layer 208 on the planarization layer 207. Is formed. The emission layer 210 is formed on the opening of the pixel definition layer 209, and the second electrode layer 211 is formed on the pixel definition layer 209 and the emission layer 210.

The transparent substrate 200 is preferably formed of glass, plastic or sapphire having transparency.

The semiconductor layer 202, the gate electrode 204, the source and drain electrodes 206a and 206b of the transparent thin film transistor 213 are formed of a transparent or semitransparent material.

The semiconductor layer 202 is formed of a broadband semiconductor material having a band gap of 3.0 eV or more, and is formed of a material having transparency. For example, at least one material selected from Zno, ZnSnO, CdSnO, GaSnO, GaSnO, TlSnO, InGaZnO, CuAlO, SrCuO, LaCuOS oxide series, GaN, InGaN, AlGaN, InGaAlN nitride series, or carbide-based SiC and diamond Is formed.

In addition, the gate electrode 204 and the source and drain electrodes 206a and 206b are indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and a translucent metal, which have good conductivity and transparency. Etc., but is not limited thereto.

The gate insulating layer 203 and the interlayer insulating layer 205 are formed of an oxide film, a nitride film, a transparent insulating material, or the like, but are not limited thereto.

An encapsulant 214 is formed on the second electrode layer 211 to encapsulate the encapsulant 214. A hygroscopic material 213 is provided between the second electrode layer 211 and the encapsulant 214 to absorb moisture therein. It is composed.

Preferably, the encapsulant 214 is composed of a polarizing encapsulant 214 having a polarizing function. The polarization encapsulant 214 has a polarization function and an encapsulation function to improve illuminance of light emitted. The polarization encapsulant 214 is formed in the same manner as a conventional encapsulant is formed.

Since the polarizing encapsulant 214 is formed in the same manner as a conventional encapsulating member, an adhesive is used to seal the end thereof, but the description thereof is omitted.

On the other surface of the substrate 200, a first transparent electrode 215 and a second transparent electrode 216 are formed at a predetermined interval from each other, and between the first transparent electrode 215 and the second transparent electrode 216. The liquid crystal layer 217 is provided.

The liquid crystal layer 217 is driven by a voltage application between the first transparent electrode 215 and the second transparent electrode by a controller (not shown), and is formed of a conventional liquid crystal material.

The driving of the liquid crystal layer 217 by the control unit is either blocking light by applying current between the first transparent electrode 215 and the second transparent electrode, or blocking light by transmitting light and applying a current ratio, or transmitting light. Either way is possible.

More precisely, the transparent plate 218 is provided on the other surface of the second transparent electrode 216 on which the liquid crystal layer 217 is formed on one surface of the second transparent electrode 216 to transmit light. Be sure to

The transparent plate 218 is preferably formed of glass, plastic or sapphire having transparency.

The polarizing member 219 is provided on the other surface of the transparent plate 218 having the second transparent electrode 216 formed on one surface thereof. The polarizing member 219 has a polarizing function to improve illuminance of light emitted.

Although the technical spirit of the present invention has been described in detail according to the above-described preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, according to the present invention, an organic light emitting display device using a transparent thin film transistor maintains a transparent state in a normal state, and one side becomes opaque according to a desired time point or a set time point that the user wants to freely display on both sides or a single side. It is possible to express and improve image illumination.

In addition, according to the present invention, the channel width is improved by the transparent semiconductor layer of the organic light emitting diode display using the transparent thin film transistor, so that the organic light emitting diode display can be driven with a large current and power consumption can be reduced as the current is improved. have.

Claims (12)

An organic light emitting display unit including a light emitting unit including at least one organic light emitting element formed on one surface of a transparent substrate and a driving unit including at least one transparent thin film transistor for driving the organic light emitting element; The transparent thin film transistor may include: an organic light emitting display unit including a transparent semiconductor layer formed on the transparent substrate and a transparent electrode formed on the transparent semiconductor layer and made of a material having both conductivity and transparency; An encapsulation portion formed on one surface of the organic light emitting display portion to encapsulate the organic light emitting display portion and including a polarization encapsulant having a polarization function; And A light control unit formed on the other surface of the organic light emitting display unit and configured to transmit and block light emitted from the organic light emitting display unit; An organic light emitting display device comprising a. The method of claim 1, The encapsulation unit includes an absorbent material configured to absorb moisture therein and an encapsulation material formed to encapsulate the absorbent material. The method of claim 1, The light control unit, A first transparent electrode and a second transparent electrode formed at predetermined intervals from each other; A liquid crystal layer formed between the first transparent electrode and the second transparent electrode and driven by voltage application of the first transparent electrode and the second transparent electrode; A transparent plate configured on the second transparent electrode; And A polarizing member formed on the transparent plate to provide a polarizing function; An organic light emitting display device comprising a. The method of claim 3, And a controller configured to apply a voltage to the first transparent electrode or the second transparent electrode. The method of claim 4, wherein The controller is manually driven. The method of claim 4, wherein The control unit is an organic light emitting display device which is automatically controlled by photosensitization. delete The method of claim 1, The transparent semiconductor layer, A buffer layer formed on the transparent substrate; And An active channel layer and an ohmic contact layer formed on one region of the buffer layer; An organic light emitting display device comprising a. The method of claim 8, And the transparent semiconductor layer is formed of a broadband semiconductor material having a band gap of 3.0 eV or more. The method of claim 9, The broadband semiconductor material is formed of at least one material selected from the group consisting of Zno, ZnSnO, CdSnO, GaSnO, GaSnO, TlSnO, InGaZnO, CuAlO, SrCuO, LaCuOS, GaN, InGaN, AlGaN, InGaAlN, SiC, and diamond. Organic light emitting display device. delete The method of claim 1, The conductive and transparent material may be formed of at least one material selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and a translucent metal. .

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