KR20030013700A - The organic electroluminescence device - Google Patents

Abstract

PURPOSE: An organic electro-luminescence device is provided to display full colors of high luminance by using a color changed medium. CONSTITUTION: A plurality of pixels(Rp,Gp,Bp) are defined on the first substrate(200). Switching devices and driving devices are formed at each pixel(Rp,Gp,Bp). The switching devices and the driving devices are TFTs(T). The TFT(T) has an active layer(202) formed with a polysilicon layer. The first electrode(216) is formed on the pixel(P) of the TFT(T). An organic layer is formed on the first electrode(216). The organic layer is formed with a hole transporting layer, an electron transporting layer, and an electro-luminescence layer. The second electrode(220) is formed on the organic layer. A plurality of color changed media(304,306) are formed on the second substrate(300). A black matrix(302) is formed between each pixel(Rp,Gp,Bp). A plurality of color filter layers(308,310,312) are formed on the color changed media(304,306) and the second substrate(300).

Description

The organic electroluminescence device

The present invention relates to an organic light emitting device, in particular, a light emitting layer for emitting blue light when an electric field is applied, and a color conversion medium for absorbing light emitted from the light emitting layer to emit green light and red light (color changed medium: CCM), respectively. The present invention relates to an active matrix type organic electroluminescence device that displays full color.

In general, organic light emitting diodes emit light by themselves and thus do not require a separate light source.

That is, the organic light emitting device is a light emitting device using electro-luminescence that generates light when an electric field is applied to the light emitter for a predetermined time or more.

As a method for realizing the color display of the aforementioned organic electroluminescent device, three methods have been mainly proposed.

The first method is a method of forming a light emitting layer emitting red, green, and blue light by using different light emitting materials on each pixel displaying red, green, and blue colors. The light emitting layer realizes white light emission and divides it into three primary colors using a color filter.

Lastly, the third method is a method of expressing color by converting light from a blue light emitting layer into three primary colors in a color change medium.

A third of the foregoing methods has been proposed in US Pat. No. " USP 5294870. "

Hereinafter, with reference to FIG. 1, the structure of the passive matrix type color organic electroluminescent element which comprises the color conversion layer limited to the previously filed "USP 5294870", and its manufacturing method are demonstrated.

1 is a plan view schematically showing a passive organic light emitting display device according to the related art.

As shown in the drawing, a transparent substrate that transmits light and a planarization film 101 having electrical insulating properties are formed on the substrate.

On the top of the planarization film 101, a plurality of first electrodes, each referred to as R1, R2, R3, R4, and R5, are spaced apart from each other and configured in one direction (horizontal direction).

An organic light emitting body 8 is formed on the first electrodes R1, R2, and R5, and most of the first electrodes are in contact with the organic light emitting body 8.

In addition, the organic light emitting body 8 is formed to overlap the second electrode portions C1, C2, C3 .. C6, which are spaced apart from each other in the longitudinal direction.

The second electrode part is spaced apart from each other and formed in the vertical direction, and divided into three sub electrodes a, b, and c spaced apart in parallel in the horizontal direction.

The horizontal first electrodes R1, R2, and R5 and the vertical sub electrodes a, b and c cross each other to define the pixel area P. FIG.

Referring to the pixel C6 in which the second electrode is omitted, the pixel C6 is divided into sub-pixels G _P , R _P , and B _P.

At this time, although not shown in detail, the vertical electrodes belonging to the plurality of pixel parts (the sub-electrodes a, b, and c of the second electrode parts C1, C2, C3 .. C6) are equally divided.

For example, the subpixels Gp, R _P and B _P of each vertical electrode include the sub electrodes a, b and c of the second electrode portions C1, C2, C3 .. C6, respectively.

In this case, each of the sub pixels Gp, R _P , and B _P emits red, green, and blue light, respectively.

Hereinafter, a method of manufacturing an organic light emitting display device according to the related art will be described with reference to FIG. 2.

2 and 3 are cross-sectional views taken along the line II-II and III-III of FIG. 1.

As shown, on the transparent insulating substrate 2, a color conversion layer G (herein referred to as "a fluorescent medium") emitting green and a color conversion layer R emitting red are formed.

The color conversion layers G and R are formed to correspond to the subpixels G _P and R _P , respectively.

In this case, each of the color conversion layers G and R may be selected from various materials capable of withstanding the general patterning technique, that is, photo-lithography that does not deteriorate the characteristics of each color conversion layer.

In order to planarize the surface of the substrate 2 on which the color conversion layers G and R are formed, and to separate the adjacent sub-pixels G _P and R _P , a transparent insulating material is used. The planarization film 4 is formed.

The planarization layer 4 does not require a separate pattern, and may be formed using spin-coating or sol-gel.

Next, a first electrode R1 is formed on the planarization film 4.

The planarization film 4 is intended to protect the patterned color conversion layers G and R below it, and can withstand the same during a pattern process such as photolithography.

The first electrode R1 is electrically conductive, and should be able to pass light, and preferably transparent.

In particular, the material for forming the first electrode R1 may be indium-tin-oxide (ITO), which may be formed as an electrode through general photolithography patterning. .

In the above-described configuration, the planarization film 4 and the first electrode R1 should have chemically stable properties for any photolithography process performed on the surface of the configuration in a continuous manufacturing step.

Next, the partition wall 6 is formed on the substrate 2 on which the first electrode R1 is formed.

The partition wall 6 is located at the boundary between the pixels arranged in the vertical direction and can be formed using a general pattern technique.

(In other words, if a plurality of pixels arranged in the vertical direction are referred to as "pixel portions P", barrier ribs are formed at the boundary between the pixel portions.)

The partition wall 6 may be formed by coating a photoresist on a substrate by a method such as spin coating and then patterning the photoresist.

In addition to the photoresist, a material such as silicon oxide (SiO ₂ ), silicon nitride (SiN _X ), and aluminum oxide (Al ₂ O ₃ ) may be used.

The organic light emitting body 8 is deposited on the entire surface of the substrate 2 on which the partition wall 6 is formed.

In this case, as shown in FIG. 1, when the entire substrate is considered, the organic electroluminescent body 8 is not formed on the left side and the lower side A of the deposition surface for depositing the organic electroluminescent body. Therefore, a part of the electrode extended to this area becomes a means for receiving electricity from the outside.

In order to prevent the organic electroluminescent body 8 from depositing, the side region A may use a stripe-type tape as a mask or collide with the organic electroluminescent body after depositing the entire surface of the substrate 2. Can be removed mechanically (dry etching by ion collision).

Next, a process of forming the second electrode (a, b, c), in order to obtain a sufficient efficiency of the organic light emitting device, the second electrode (a, b, c) is in contact with the organic light emitting body 8, Metals having a low work function are required.

On the deposition surface, in order to obtain the deposition pattern of the second electrodes (a, b, c) spaced apart from each other in the longitudinal direction, it must be located in relation to the source (metal target) to be deposited.

That is, when one side of the barrier rib is located at a distance close to the source, while the deposition of metal is performed on one side G of the barrier rib 6 close to the organic light emitting body 8, the other side of the barrier rib 8 This results in no metal being deposited in the portion H of the organic electroluminescent body 8 adjacent thereto.

Thus, a portion of the organic light emitting body not deposited with the metal provides a space between the second electrodes (a, b, c) close to each other in the longitudinal direction.

In the process as described above, a conventional organic light emitting display device can be manufactured.

In the structure of the organic light emitting device manufactured through the above process, in order to obtain a desirable image pattern, each sub-electrode (a, b, c) of the second electrode portion (C1, C2, ... C6 of Figure 1) Should be an electrically independent address while the first electrodes R1, R2 ... R5 are electrically biased.

If, for example, only green light emission is desired in one vertical electrode including the second electrodes C2, C3, and C4, the second electrode may be kept in the vertical electrode to maintain light emission while the second electrode is not electrically biased. Any second electrode element is biased.

In this manner, light emission is performed at the pixel for which light emission is desired.

When the organic light emitting body 8 is selected, it emits light in the blue region of the spectrum. In blue light emission, the light of the subpixel B _P emitted by the organic light emitting body 8 passes through the first electrode R1, the planarization film 4, and the substrate 2 to be emitted by the observer into blue light. Is observed.

Thus, the blue light emitting organic electroluminescent body is used as a blue light emitting subpixel.

At the same time, the blue light emitted from the blue subpixel passes through the first electrode and the flat layer, but in the subpixels G _p and R _p , phosphors G and R are inserted to absorb the blue light emitted by the organic light emitting emitter. .

The blue light emission stimulates fluorescent light emission in green or red color.

This method has the advantage of obtaining very good red and green light.

As described above, conventionally, as described above, the organic light emitting diode is manufactured by operating in a passive matrix shape.

Since the passive matrix method sequentially drives the scan lines over time to drive each pixel, in order to indicate the required average brightness, the instantaneous brightness must be equal to the average brightness multiplied by the number of lines.

Therefore, the more lines there are, the higher voltage and more current must be applied instantaneously, which accelerates the deterioration of the device and increases the power consumption, which is not suitable for the large-area display device of high luminance.

Accordingly, the present invention has been made for the purpose of solving the above-described problem, and an organic light emitting device that can express full color of high brightness using a color changed medium (CCM) schematically. We propose a method and its structure for fabricating an active matrix.

1 is a plan view showing a part of a conventional passive matrix organic EL device according to the related art,

2 is a cross-sectional view taken along II-II and III-III of FIG. 1,

3 is an equivalent circuit diagram of a single pixel of an active matrix organic light emitting display device,

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

5A to 5C are cross-sectional views illustrating a process sequence of forming the thin film transistor array unit and the light emitting unit of FIG. 4;

6A through 6C are cross-sectional views illustrating a process sequence for forming the color conversion unit of FIG. 4.

7 is a cross-sectional view showing an active matrix organic light emitting display device as another example of the first embodiment of the present invention;

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

9A to 9C are cross-sectional views illustrating a process sequence for forming the organic light emitting display device of FIG. 8;

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

11A through 11D are cross-sectional views illustrating a process sequence for manufacturing the organic light emitting display device of FIG. 10.

<Brief description of the main parts of the drawing>

200: first substrate 212: drain electrode

216: first electrode 218: organic film

220: second electrode 300: second substrate

302: black matrix 304: green color conversion layer

306: red color conversion layer 308: red color filter

310: green color filter 312: blue color filter

According to a first aspect of the present invention, an active matrix organic light emitting display device includes: a transparent first substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode which is a hole injection electrode configured in the pixel while being in contact with the drain electrode of the driving element; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light while combining holes injected from the first electrode with electrons injected from the second electrode when an electric field is applied; A transparent second substrate formed in contact with the first substrate and having a plurality of pixels defined therein; A red color filter, a green color filter, and a blue color filter respectively configured in the pixels on the second substrate; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter and absorbing blue light emitted from the light emitting layer to emit red light and green light; It includes a protective film formed on the front surface of the substrate configured with the color conversion layer.

A hole transporting layer is formed between the light emitting layer and the first electrode, and an electron transporting layer is further formed between the light emitting layer and the second electrode.

The color conversion layer is formed of an organic material that emits light by absorbed light.

A blocking film is formed between the green color filter, the red color filter, and the blue color filter.

An active matrix organic light emitting display device according to a second aspect of the present invention comprises: a transparent first substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode which is a hole injection electrode configured in the pixel while being in contact with the drain electrode of the driving element; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light when the holes injected from the first electrode and the electrons injected from the second electrode are coupled when an electric field is applied; A second substrate configured to be spaced apart from the first substrate by a predetermined distance; A red color filter, a green color filter, and a blue color filter positioned between the first substrate and the second substrate and configured in an upper region of the second substrate corresponding to the plurality of pixels defined in the first substrate; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter and absorbing blue light emitted from the light emitting layer to emit red light and green light; And a passivation layer formed on the entire surface of the substrate including the color conversion layer and configured to contact the second substrate.

An organic light emitting display device according to a third aspect of the present invention includes a transparent substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first passivation layer formed on an entire surface of the substrate including the driving device; A red color filter, a green color filter, and a blue color filter formed corresponding to each pixel on the first passivation layer; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter, and emitting red light and green light when absorbing blue light; A second passivation layer formed on the color conversion layer; A first electrode corresponding to each pixel on the second passivation layer, the first electrode being a hole injection electrode in contact with the drain electrode; A second electrode formed on the first electrode and serving as an electron injection electrode; The light emitting layer is disposed between the first electrode and the second electrode, and emits blue light while combining holes injected from the first electrode and electrons injected from the second electrode when an electric field is applied.

An organic light emitting display device according to a fourth aspect of the present invention comprises: a substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode in contact with the drain electrode of the driving element, the first electrode being a hole injection electrode configured in the pixel; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light while combining holes injected from the first electrode with electrons injected from the second electrode when an electric field is applied; A first passivation layer formed on the light emitting layer; A blue color filter, a green color filter, and a red color filter formed on the passivation layer and formed to correspond to the pixels; A green color converting layer and a red color converting layer disposed on the green color filter and the red color filter and emitting green light and red light when absorbing the blue light emitted from the light emitting layer; And a second passivation layer formed on an entire surface of the substrate on which the color conversion layer is formed.

The first electrode uses an opaque conductive metal having a high work function.

The second electrode is formed of a thin aluminum layer that transmits light and a transparent conductive metal layer.

In the above-described configuration, the present invention provides a color conversion layer (CCM) with a color filter on a sub-pixel representing red, green, and blue. The organic electroluminescent device thus constructed is characterized in that it is configured in an active matrix type.

First, before describing an embodiment according to the present invention, a configuration of an organic light emitting device operating in an active matrix shape will be described.

Since the method of manufacturing the thin film transistor array is different for each company, the configuration of the array substrate will be described with an equivalent circuit.

In general, an active matrix liquid crystal display device includes a switching element, a driving element, and a storage capacitor for each of a plurality of pixels defined on a substrate, and each of the switching element or the driving element is one or more thin films according to characteristics of an operation. It can be composed of a combination of transistors.

For convenience of description, FIG. 3 shows an equivalent circuit in which the switching element and the driving element are formed of one thin film transistor, for example.

3 is an equivalent circuit diagram of one pixel of a general active matrix type organic light emitting display device.

As shown, a plurality of gate wirings 102 formed in one direction on the substrate 100 by being spaced apart from each other by a predetermined distance, and a plurality of data wirings arranged in one direction on the substrate 100 and spaced apart from each other by a predetermined distance ( 104 is configured to intersect.

A region defined by the intersection of the two wires is called a pixel.

In this case, the single pixel includes a switching element T1, a driving element T2, and a storage unit S. The switching element T1 and the driving element T2 include a gate electrode, an active layer, a source electrode, and a drain. A thin film transistor including an electrode is used.

In the above configuration, the gate electrode of the switching element T1 is connected to the gate wiring 102 and the source electrode is electrically connected to the data wiring 104.

The drain electrode of the switching element T1 is electrically connected to the gate electrode of the driving element T2.

The pixel includes a first electrode (anode) in contact with the drain electrode of the driving element, a second electrode (cathode) formed on the first electrode and an organic film, which is a light-emitting body, a light emitting unit (D) which is a PN contact diode. The first electrode is a hole injection electrode and electrically connected to the drain electrode of the driving element T2.

The driving device is operated by the signal of the switching device T1, and a signal current flows through the first electrode of the light emitting unit D due to the operation of the driving device.

In this configuration, the switching element T1 and the driving element T2 are connected to the storage unit S, and are compensated by the storage unit S when a signal loss occurs.

That is, the voltage applied to the pixel is charged in the storage unit S, and the power is applied until the next frame signal is applied, thereby continuing to drive for one screen regardless of the number of scan lines. .

Therefore, in the active matrix system, since the same luminance is displayed even when a low current is applied, low power consumption, high definition, and large size can be obtained. .

Hereinafter, a configuration of a liquid crystal display array substrate and a method of manufacturing the same will be described.

First Embodiment

A feature of the first embodiment of the present invention is characterized in that the color conversion layer (CCM) is formed on a separate substrate.

4 is a cross-sectional view showing a part of an organic light emitting display device according to a first embodiment of the present invention. 3 is a cross-sectional view of the driving device and a light emitting portion connected to the driving device.

The first feature of the present invention is to configure the color conversion unit E including the color conversion layers 304 and 306 and the color filters 308, 310 and 312 on a separate substrate 300, and the thin film transistor array unit F and the light emitting unit ( The substrate 200 having the D) and the substrate 300 having the color conversion unit E are configured together to produce an active matrix type organic light emitting display device displaying full color.

The first substrate defines a plurality of pixels R _P , G _P , and B _P respectively displaying red, green, and blue colors, and thin film transistors for each of the pixels R _P , G _P , and B _P. A switching element (not shown) that is a transistor and a driving element T are configured.

The thin film transistor TFT adopts a coplanar structure in which the active layer 202 is formed of a polysilicon layer.

A first electrode 216 is formed on the pixel P including the thin film transistor T to contact the drain electrode 212 of the thin film transistor T.

In this case, the first electrode 216 is configured independently for each pixel R _P , G _P , and B _P.

An organic film 218 having a multilayer structure is formed on the first electrode 216, and a second electrode 220 is formed on the multilayer organic film.

In this case, the organic layer 218 may include a hole transporting layer (HTL) 218a in contact with the first electrode 216, and an electron transporting layer EL in contact with the second electrode 220 ( 218c) and an electroluminescent organic film (hereinafter referred to as "light emitting layer") 218b which emits blue light between the hole hydrogen layer 218a and the electron transport layer 218b.

When the organic film is formed as described above, the quantum efficiency (photon out per charge injected) can be increased, and the driving voltage can be lowered through the two-stage injection process through the transport layer without the carriers being directly injected. There is an advantage.

In addition, electrons and holes injected into the light emitting layer 218b may be blocked by the opposite transport layer when the electrons and holes move to the opposite electrode through the light emitting layer, thereby controlling recombination. This can improve the luminous efficiency.

In the above-described configuration, the first electrode (anode) 216 is a electrode for hole injection using a transparent metal oxide having a high work function and the emitted light can come out of the device, the most widely used Indium-tin-oxide (hereinafter, referred to as "ITO") is used as the hole injection electrode.

On the other hand, in the above-described configuration, the second electrode (cathod) 220, which is an electrode for injecting electrons into the electron transport layer 218c, is a metal having a small work function of calcium (Ca), magnesium (Mg), and aluminum (Al). The reason why the electrode having a low work function is used as an electron injection electrode is mainly used because a high electron density can be obtained in electron injection by lowering a barrier between the electrode and the organic electroluminescent layer.

This can increase the luminous efficiency of the device.

Therefore, while calcium (Ca) has the lowest work function, it shows high efficiency while aluminum (Al) has a relatively high work function while having low efficiency.

However, calcium (Ca) is mainly used because it has a problem of being easily oxidized by oxygen or moisture in the air and aluminum (Al) is useful as a material that is stable in the air.

A second substrate 300 on which a color conversion material is patterned is formed on a rear surface of the first substrate 200 including the light emitter 218, and an upper portion of the first substrate 200 is formed on the second substrate 300. The color conversion layers 304 and 306 are formed in regions corresponding to the pixels G _P and R _P displaying green and red among the plurality of pixels R _P , G _P , and B _P.

The color conversion layers 304 and 306 may include a red color conversion layer formed of a red light emission color conversion material and a green light emission color conversion material that absorb light emitted from the light emitting elements constituting the organic layer 218 to emit red light and green light. 306 and the green color conversion layer 304.

Further, by between each pixel (R _P, G _P, B _P) has a black matrix 302, a color clear without the light-emitting light mixed with each other in the pixel regions (R _P, G _P, B _P) To make it appear.

In the above-described configuration, when an electric field is formed between the first electrode 216 and the second electrode 220, a hole injected into the hole transport layer 218a through the first electrode 216 and the Electrons injected into the electron transporting layer through the second electrode are met at the blue light emitting layer 218b, where electrons and holes are combined in the light emitting layer 218b to have high energy. exciton), and the exciton falls to low energy to generate blue light.

The blue light passes through the blue color filter 312 through the first electrode 216, which is a transparent electrode, and the second substrate 300, which is in contact with the rear surface of the first substrate 200. 304 and the red color conversion layer 306 is absorbed.

Stimulated by the absorbed blue light, green and red light are emitted from each of the color conversion layers 304 and 306, and clear green light and red light are emitted to the outside while passing through the green color filter 310 and the red color filter 308. do.

At this time, the blue light passing through the blue color filter 312 is emitted to the outside with high color purity.

A method of manufacturing the organic electroluminescent device according to the first embodiment of the present invention which operates as described above will be briefly described through the process cross-sectional views of FIGS. 5A to 5C.

First, as shown in FIG. 5A, a process of forming a thin film transistor T on a substrate 200 is performed.

The thin film transistor T includes an active layer 202 formed of polysilicon, and source and drain electrodes 210 and 212 and a gate electrode 206. The process of forming the active layer 202 of the above-described configuration is first performed.

The active layer 202 deposits amorphous silicon (a-Si: H) on the substrate 200, crystallizes it by a predetermined method, and then patterns it. The patterned active layer 202 is defined as a first active region 202a serving as an active channel and a second active region 202b in direct contact with the source electrode 204 and the drain electrode 206.

Next, a gate insulating layer as a first insulating layer is deposited by depositing one selected from the group of inorganic insulating materials including silicon oxide (SiO ₂ ) and silicon nitride (SiN _x ) on the entire surface of the substrate 200 on which the active layer 202 is formed. 204 is formed.

Next, a conductive metal is deposited on the gate insulating layer 204 and then patterned to form a gate electrode 206 on the first active region 202a.

Next, an insulating material is deposited on the entire surface of the substrate 200 on which the gate electrode 202 is formed to form an interlayer insulating film 208, which is a second insulating film, and then patterned to form a portion of the second active region 202b. Expose

Next, a process of doping a dopant into the second active region 202b is performed.

When the dopant is doped with a Group 3 element such as B ₂ H ₆ , the dopant is operated as a P-type semiconductor, and when the Group 5 element such as PH ₃ is doped.

Next, molybdenum (Mo), chromium (Cr), tungsten (W), titanium (Ti), aluminum (Al) and alloys thereof (AlNd), etc., on the entire surface of the substrate 200 on which the second insulating film 208 is formed. The conductive metal is deposited and patterned to form a source electrode 210 and a drain electrode 212 in contact with the second active region 202b on both sides of which the portion is exposed.

Next, as shown in FIG. 5B, benzocyclobutene (BCB) and acrylic resin (resin) and the like are placed on the entire surface of the substrate 200 on which the source electrode 210 and the drain electrode 212 are formed. A protective film 214 is formed by applying a selected one of the group of transparent organic insulating materials to be included and patterning the third insulating film to expose a portion of the drain electrode 212.

Next, a metal having a high work function, such as indium-tin-oxide, is deposited and patterned on the entire surface of the substrate 200 on which the passivation layer 214 is formed. The first electrode 216 is formed at R _P , G _P , and B _P.

Next, as illustrated in FIG. 5C, an organic layer in which the hole transport layer 218a, the light emitting layer 218b, and the electron transport layer 218c are sequentially stacked on the entire surface of the substrate 200 on which the first electrode 216 is formed ( 218).

Next, a conductive metal having a low work function such as aluminum (Al), calcium (Ca), and magnesium (Mg) is deposited on the entire surface of the substrate 200 on which the organic layer 218 including the plurality of layers is formed. The pattern is formed to form the second electrode 220.

In this process, the thin film transistor array F and the light emitting part D emitting blue light by the electric field can be formed on the first substrate.

6A to 6C are cross-sectional views illustrating a process of forming a color conversion unit in which a color conversion layer is formed on a separate substrate.

First, as illustrated in FIG. 6A, a plurality of sub pixels R _P , G _P , and B _P are defined on a transparent insulating substrate 300 such as plastic or glass, and then the substrate 300 is formed. After depositing the blocking material on the entire surface, a patterned black matrix (blocking film) 302 is formed to remain only at the boundaries of the sub-pixels R _P , G _P , and B _P.

Next, when the blue light is absorbed, the color conversion organic material that emits red light and green light, respectively, is processed in the same process as that of a general negative type photoresist, that is, spin coating and extrusion ( After the coating is applied by an extrusion method or the like, the red color conversion layers and the green color conversion layers 304 and 306 are formed.

The pixel B _P , which is still blue, is a shape in which the lower substrate 300 is exposed between the black matrices 302.

Next, as shown in 6b, one color resin of red, green, and blue is selected on the entire surface of the substrate 300 on which the black matrix 302 and the color conversion layers 304 and 306 are formed ( In the present invention, the process proceeds in the order of red, green, and blue, for example). After the deposition, the pattern is formed to form a red color filter 308 on the red color conversion layer 306.

Next, a green color filter 310 is formed on the green color conversion layer 304 through the same process as above.

Subsequently, a blue color filter 312 is formed in a portion corresponding to the pixel B _P displaying blue.

Next, as shown in FIG. 6C, benzocyclobutene (BCB), acryl, or polyimide resin, etc., are formed on the entire surface of the substrate 300 on which the color filters 308, 310, and 312 are formed. A transparent organic insulating material is applied to form a planarization film 312 for planarizing the surface of the substrate on which the color filters are formed.

The color conversion unit E may be configured by the above-described process.

The color conversion layers 304 and 306 and the color filters 308, 310, and 312 may be configured in the region corresponding to the black matrix 302 and the pixels R _P and G _P as shown in FIG. 7. The red color filter 308 and the green color filter 310 are configured.

Next, a red color conversion layer 306 and a green color conversion layer 304 are formed on the red color filter 308 and the green color filter 310, respectively.

The above-described configuration is configured such that the first substrate 200 is in contact with the planarization layer 312 formed on the second substrate 300.

Hereinafter, a second embodiment according to the present invention will be described.

Second Embodiment

According to a second embodiment of the present invention, a color conversion layer is formed between the thin film transistor array unit and the light emitting unit.

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

As shown, the second embodiment is characterized in that the organic light emitting diode comprises a thin film transistor array portion F, a light emitting portion D, and a color conversion portion E on a substrate 400. (D) is interposed between the thin film transistor array portion (F) and the color conversion portion (E).

That is, a substrate including a thin film transistor T including an active layer 402, a gate electrode 404, a source electrode 406, and a drain electrode 408 for each pixel R _P , G _P , and B _P ( A red color filter 410, a green color filter 412, and a blue color filter 414 are formed on the upper portion of the 400.

The red color conversion layer 416 and the green color conversion layer 418, which are organic light emitting layers, are respectively formed on the red color filter 410 and the green color filter 412.

The planarization film 420, which is an insulating film for planarizing the surface, is formed on the entire surface of the substrate 400 including the color conversion layers 416 and 418.

A first electrode 422 is formed on the planarization layer 420 to be in electrical contact with the drain electrode 408 of the thin film transistor T.

The multilayer organic film 424 including the hole transporting layer 424a, the light emitting layer 424b, and the electron transporting layer 424c is formed on the first electrode 422.

The second electrode 426 is formed on the organic layer 424.

A method of manufacturing the organic light emitting device configured as described above will now be described with reference to FIGS. 9A to 9C.

9A to 9C are cross-sectional views sequentially illustrating a manufacturing process of an active matrix organic light emitting diode according to a second exemplary embodiment of the present invention.

(The manufacturing process of the thin film transistor is the same as in the first embodiment, so it is omitted.)

As shown in FIG. 9A, on the substrate 400 on which a plurality of pixels R _P , G _P , and B _P displaying red, green, and blue colors are defined, the same process as described in the first embodiment is performed. After forming a protective film 409 by applying a transparent organic insulating material such as benzocyclobutene (BCB), acrylic or polyimide resin on top of the formed thin film transistor (T), A portion of the drain electrode 408 constituting the transistor T is exposed.

Next, formed in each of said each pixel (R _P, G _P, B _P) red, green, and blue color filters (410 412 414) wherein each of the pixel (R _P, G _P, B _P) on.

Subsequently, among the pixels R _P , G _P , and B _P configured with the color filters 410, 412, 414, when the blue light is absorbed on the upper part of the green color filter 412 and the upper part of the red color filter 410, the green light red light respectively. The green color conversion layer 418 and the red color conversion layer 416, which are organic films that emit light, are formed.

The planarization layer 420, which is a transparent organic insulating material, is formed on the entire surface of the substrate 400 on which the color filters 410, 412, 414 and the color conversion layers 416, 418 are formed.

Next, a first electrode 422, which is an electrode for injecting holes into the pixels R _P , G _P , and B _P on the planarization layer 420, is formed.

The first electrode 422 is independently formed for each pixel R _P , G _P , and B _P and is formed of a metal having a high work function.

In general, the first electrode 422 is formed of transparent indium-tin-oxide so as to pass the emitted light.

Next, an organic layer 424 formed of multiple layers is formed on the entire surface of the substrate 400 on the first electrode 422.

The multilayer organic film 424 includes a hole transport layer 424a, a light emitting layer 424b that emits blue light by an electric field, and an electron transport layer 424c.

In this case, the hole transport layer 424a is configured to be in contact with the first electrode 422, and the electron injection layer is in contact with the second electrode 426 formed in a subsequent process.

Next, one of aluminum (Al), magnesium (Mg), and calcium (Ca), which is a metal having a low work function, is formed on the organic layer 424, or lithium flowline / aluminum ( The second electrode 426 is formed of a double metal layer composed of LiF / Al).

As described above, an active matrix organic light emitting display device according to a second embodiment of the present invention can be manufactured.

The above-described configuration is an exciton in which holes and electrons injected into the organic film from the first electrode 422 and the second electrode 426 through the hole transport layer 424a and the electron transport layer 424c are combined. Is excited from a high energy level to a low energy level and emits blue light, and the emitted blue light is primarily absorbed by the green color conversion layer 418 and the red color conversion layer 416 and at the same time the blue color filter 414. Will pass).

The green color conversion layer 418 absorbed by the blue light emits green light, and the red color conversion layer 416 absorbed by the blue light emits red light.

Each of the emitted light passes through the green color filter 412 and the red color filter 410 to emit green light and red light having high color purity.

Hereinafter, a third embodiment of the present invention will be described.

-Third Example-

A third embodiment of the present invention is characterized by configuring a color filter and a color conversion layer on the organic electroluminescent layer.

10 is a cross-sectional view of an active matrix organic light emitting display device according to a third embodiment of the present invention.

As illustrated, the first electrode 512, the hole transport layer 514a, the light emitting layer 514b, and the electron transport layer 514c are disposed on the array portion F that constitutes the thin film transistor T and the array wiring (not shown). A light emitting portion D composed of a multi-layer organic film 514 and a second electrode 516, and is formed on the light emitting portion D corresponding to each pixel R _P , G _P , B _P. The color conversion unit E including the color filters 522, 524, 526 and the color conversion layers 528, 530 is formed.

Hereinafter, a method of manufacturing an organic light emitting device having the above-described configuration will be described with reference to the process cross sections of FIGS. 11A to 11D.

11A to 11D are cross-sectional views sequentially illustrating a manufacturing process of an active matrix organic light emitting display device according to a third exemplary embodiment of the present invention.

First, as illustrated in FIG. 11A, each pixel region R _P and G is disposed on a transparent insulating substrate 500 such as plastic or glass in which a plurality of pixel regions R _P , G _P and B _P are defined. _The thin film transistor T including the active layer 502, the gate electrode 504, the source electrode, and the drain electrodes 506 and 508 is formed for each of _P and B _P.

Next, a transparent organic insulating material, such as benzocyclobutene (BCB), acryl, or polyimide resin, is deposited on the thin film transistor T, and then patterned. A protective film 510 exposing a portion of the electrode 508 is formed.

Next, as illustrated in FIG. 11B, a conductive metal having a high work function is deposited on the passivation layer 510 to which the drain electrode 508 is exposed, and then patterned to form the exposed drain electrode ( The first electrode 512, which is configured independently of each pixel R _P , G _P and B _P , is formed at the same time as the 508.

The first electrode is formed by depositing an opaque conductive metal having a high work function.

Next, the organic layer 514 including the hole transport layer 514a, the light emitting layer 514b, and the electron transport layer 514c is formed on the entire surface of the substrate 500 on which the first electrode 512 is formed. do.

The method of forming the organic layer 514 may be formed in the form of deposition or coating according to the molecular structure of the organic layer 514.

Next, a second electrode 516 is formed on the entire surface of the substrate 500 on which the organic layer 514 is formed.

Since the second electrode should be represented transparently, after depositing a thin aluminum (Al) 516a having a low work function (having a thickness of about 50 GPa), the transparent electrode layer 516b is disposed on the aluminum layer 516a. This is a form formed again.

The reason for thinly depositing the aluminum layer 516a is that the second electrode 516 must be transparently represented.

The transparent electrode layer 516b is further formed for the purpose of protecting the aluminum layer because it is deposited too thin.

Next, as shown in FIG. 11C, one selected from the group of inorganic insulating materials including silicon nitride (SiN _X ) and silicon oxide (SiO ₂ ) on the entire surface of the substrate 500 on which the second electrode 516 is formed. Deposited to form a first passivation film 518.

Subsequently, a second passivation layer 520 is formed to planarize the surface by applying the transparent organic insulating material as described above.

Next, a black matrix 521 is formed on the boundary of the pixels R _P , G _P , and B _P on the second passivation layer 520 and then exposed between the black matrices. Blue, green, and red color filters 522, 524, and 526 are formed in the pixels R _P , G _P , and B _P , respectively.

Next, as illustrated in FIG. 11D, a green color conversion layer 530 is formed on the green color filter 524 to absorb blue light emitted from the emission layer of the organic layer and emit green light. The red color conversion layer 528 is formed on the filter 522.

Thus, the color conversion unit E composed of the color filter and the color conversion layer is configured.

Next, a third passivation layer 532 is formed on the color conversion part to protect the color conversion part.

The third passivation layer 532 is formed using the transparent organic insulating material as described above.

By the methods as described above, an active matrix organic light emitting device expressing full color according to the present invention can be manufactured.

When the active matrix organic light emitting diode according to the present invention is manufactured by the method as described above, there is an effect that a large area display device can be manufactured.

In addition, since the color filter and the color conversion layer are used at the same time, the color reproducibility is excellent and there is an effect of producing a display device of clear image quality.

Claims (29)

A transparent first substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode which is a hole injection electrode configured in the pixel while being in contact with the drain electrode of the driving element; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light while combining holes injected from the first electrode with electrons injected from the second electrode when an electric field is applied; A transparent second substrate formed in contact with the first substrate and having a plurality of pixels defined therein; A red color filter, a green color filter, and a blue color filter respectively configured in the pixels on the second substrate; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter and absorbing blue light emitted from the light emitting layer to emit red light and green light; An active matrix type color organic light emitting device comprising a protective film formed on the front surface of the substrate having the color conversion layer. The method of claim 1, And a hole transporting layer between the light emitting layer and the first electrode, and an electron transporting layer between the light emitting layer and the second electrode. The method of claim 2, And the hole transporting layer and the electron transporting layer are organic layers. The method of claim 1, The first electrode is an indium-tin-oxide (active matrix organic light emitting device). The method of claim 1, And the second electrode is one selected from the group of conductive materials having a small work function including calcium, aluminum and magnesium. The method of claim 1, The color conversion layer is an active matrix organic light emitting device formed of an organic material emitting light by absorbed light. The method of claim 1, An active matrix organic light emitting display device comprising a blocking film for blocking light between the green color filter, the red color filter, and the blue color filter. A transparent first substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode which is a hole injection electrode configured in the pixel while being in contact with the drain electrode of the driving element; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light when the holes injected from the first electrode and the electrons injected from the second electrode are coupled when an electric field is applied; A second substrate configured to be spaced apart from the first substrate by a predetermined distance; A red color filter, a green color filter, and a blue color filter positioned between the first substrate and the second substrate and configured in an upper region of the second substrate corresponding to the plurality of pixels defined in the first substrate; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter and absorbing blue light emitted from the light emitting layer to emit red light and green light; And a protective film formed on the front surface of the substrate having the color conversion layer formed thereon and contacting the second substrate. The method of claim 8, And a hole transporting layer between the light emitting layer and the first electrode, and an electron transporting layer between the light emitting layer and the second electrode. The method of claim 8, And the hole transporting layer and the electron transporting layer are organic layers. The method of claim 8, The first electrode is an active matrix organic electroluminescent device formed by depositing an opaque conductive metal having a high work function. The method of claim 8, And the second electrode is formed of one selected from the group of conductive materials having a small work function including calcium, aluminum, and magnesium. The method of claim 8, The color conversion layer is an active matrix organic light emitting device formed of an organic material that emits light by absorbed light. The method of claim 8, An active matrix organic light emitting display device comprising a blocking film for blocking light between the green color filter, the red color filter, and the blue color filter. A transparent substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first passivation layer formed on an entire surface of the substrate including the driving device; A red color filter, a green color filter, and a blue color filter formed corresponding to each pixel on the first passivation layer; A red color conversion layer and a green color conversion layer formed on the red color filter and the green color filter, and emitting red light and green light when absorbing blue light; A second passivation layer formed on the color conversion layer; A first electrode corresponding to each pixel on the second passivation layer, the first electrode being a hole injection electrode in contact with the drain electrode; A second electrode formed on the first electrode and serving as an electron injection electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting an blue light when the electric field is applied and the hole injected from the first electrode and the electron injected from the second electrode are combined; Active matrix organic electroluminescent device comprising a. The method of claim 15, And a hole transporting layer between the light emitting layer and the first electrode, and an electron transporting layer between the light emitting layer and the second electrode. The method of claim 15, And the hole transporting layer and the electron transporting layer are organic layers. The method of claim 15, The first electrode is an indium-tin-oxide (active matrix organic light emitting device). The method of claim 15, And the second electrode is formed of one selected from the group of conductive materials having a small work function including calcium, aluminum, and magnesium. The method of claim 15, The color conversion layer is an active matrix organic light emitting device formed of an organic material that emits light by absorbed light. A substrate defining a plurality of pixels; A driving element formed on the substrate and including a gate electrode, an active layer, a source electrode and a drain electrode; A first electrode in contact with the drain electrode of the driving element, the first electrode being a hole injection electrode configured in the pixel; A second electrode which is an electron injection electrode formed on the first electrode; A light emitting layer positioned between the first electrode and the second electrode and emitting blue light while combining holes injected from the first electrode with electrons injected from the second electrode when an electric field is applied; A first passivation layer formed on the light emitting layer; A blue color filter, a green color filter, and a red color filter formed on the passivation layer and formed to correspond to the pixels; A green color conversion layer and a red color conversion layer disposed on the green color filter and the red color filter and emitting green light and red light when absorbing the blue light emitted from the light emitting layer; The second protective film formed on the entire surface of the substrate on which the color conversion layer is formed Active matrix organic light emitting device comprising a. The method of claim 21, And a hole transporting layer between the light emitting layer and the first electrode, and an electron transporting layer between the light emitting layer and the second electrode. The method of claim 21, And the hole transporting layer and the electron transporting layer are organic layers. The method of claim 21, The first electrode is an active matrix organic light emitting device comprising an opaque conductive metal having a high work function. The method of claim 21, The second electrode is an active matrix organic light emitting device comprising a thin aluminum layer and a transparent conductive metal layer for transmitting light. The method of claim 25, The aluminum layer has an active matrix type organic light emitting device having a value of about 45 Hz to 55 Hz. The method of claim 21, The color conversion layer is an active matrix organic light emitting device formed of an organic material that emits light by absorbed light. The method of claim 21, An active matrix organic light emitting display device comprising a blocking film for blocking light between the green color filter, the red color filter, and the blue color filter. The method of claim 21, The first passivation layer is an active matrix organic light emitting display device, in which an organic insulating layer and an inorganic insulating layer are stacked.