KR100796610B1 - Organic light emitting display device and fabrication method thereof - Google Patents

Abstract

An organic light emitting display device and a method for fabricating the same are provided to ensure a high color reproducibility by directly patterning a color with a poor light emitting efficiency and realizing the other colors by a color filter. An organic light emitting display device includes a substrate(200), a first electrode(230), an organic film layer(250), and a second electrode(260). The substrate includes first, second, third, and fourth pixel regions(a-c). The first electrode is placed on the substrate. The organic film layer is placed on the first electrode and has a first light emitting layer(251), a second light emitting layer(252), and a third light emitting layer(253). The second light emitting layer is placed on the first light emitting layer in the second, third, and fourth pixel regions. The third light emitting layer is placed on the second light emitting layer. The second electrode is placed on the organic film layer. The fourth pixel region is a white pixel region.

Description

Organic light emitting device and method of manufacturing the same {Organic Light Emitting Display Device and Fabrication Method

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

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

3 is a cross-sectional view of an organic light emitting display device according to another embodiment of the present invention.

Figure 4 is a graph showing the spectrum of the organic light emitting display device according to an embodiment of the present invention.

<Brief Description of Drawings>

100, 200, 300: substrate 110, 210, 310: color filter layer

120,220,320: overcoat layer 130,230,330: first electrode

140,240,340: pixel definition layer 150,250,350: organic layer

151,251,351: first light emitting layer 152,252,352: second light emitting layer

153,253,353: third emission layer 160,260,360: second electrode

370: transparent shield

The present invention relates to an organic light emitting display device and a method of manufacturing the same, which are easy to implement and have improved luminous efficiency. An electroluminescent device and a method of manufacturing the same.

In general, an organic light emitting display device includes a substrate, an anode located on the substrate, an emission layer (EML) located on the anode, and a cathode located on the emission layer. In the organic light emitting device, a voltage is applied between the anode and the cathode, holes and electrons are injected into the light emitting layer, holes and electrons injected into the light emitting layer are recombined in the light emitting layer to generate excitons. These excitons emit light as they transition from the excited state to the ground state.

In order to promote full colorization of the organic light emitting device, there is a method of forming a light emitting layer corresponding to each of R, G, and B. However, the organic light emitting diode has a different light emitting efficiency (Cd / A) for each of the R, G, and B light emitting layers. Due to this, the luminance of each light emitting layer is different, and in general, the luminance of the light emitting layer is approximately proportional to the current value. Therefore, when the same current is applied, some colors have low luminance and some have high luminance, and thus it is difficult to obtain a proper color balance or white balance. For example, since the luminous efficiency of the green light emitting layer is 3 to 6 times higher than that of the red light emitting layer and the blue light emitting layer, more current must be applied to the red and blue light emitting layers to achieve white balance.

In order to solve this problem, a light emitting layer emitting light of a single color, that is, white light is formed, and a color filter layer for extracting light corresponding to a predetermined color from the light emitting layer or light emitted from the light emitting layer is converted into light of a predetermined color. There is a method of forming a color conversion layer.

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

Referring to FIG. 1, a substrate 100 including blue (a), green (b), and red (c) pixel regions is provided, and the pixel regions a, b, and c on the substrate 100 are provided. The color filter layers 110 are formed to be spaced apart from each other.

An overcoat layer 120 is formed over the entire surface of the substrate including the color filter layers 110. First electrodes 130 are formed on the overcoat layer 120 in a region corresponding to the color filter layers 110. A thin film transistor may be further included between the first electrode 130 and the substrate 100.

An opening (not shown) is formed by forming and patterning a pixel definition layer 140 on the first electrodes 130. The organic layer 150 may be formed by sequentially forming a blue light emitting layer as the first light emitting layer 151, a green light emitting layer as the second light emitting layer 152, and a red light emitting layer as the third light emitting layer 153 on the first electrodes 130. Complete

The second electrode 160 is formed on the organic layer 150 to complete the organic light emitting diode.

As described above, the conventional organic light emitting device uses a color filter layer to extract light corresponding to red, green, and blue to white light using an organic film layer in which a blue light emitting layer, a green light emitting layer, and a red light emitting layer are sequentially stacked. However, the color reproducibility of the organic light emitting device is affected by the intensity of each wavelength of the white light emitted from the light emitting layer, and the white light of the conventional organic light emitting device is not uniform in intensity of the three light of red, green, and blue. Therefore, a problem arises in that color reproducibility of an organic light emitting display device using red, green, and blue color filter layers is not good.

Accordingly, an object of the present invention is to provide an organic light emitting display device and a method of manufacturing the same, which are to solve the above problems and to improve luminous efficiency and easy implementation.

In order to achieve the above object, a substrate comprising a first, second and third pixel region; A first electrode on the substrate; An organic layer disposed on the first electrode and including a first light emitting layer, a second light emitting layer on the first light emitting layer of the second and third pixel regions, and a third light emitting layer on the second light emitting layer; It provides an organic electroluminescent device comprising a second electrode positioned on the organic film layer.

The present invention also provides a substrate including first, second and third pixel regions, a first electrode is formed on the substrate, and a first light emitting layer, the second and third are formed on the first electrode. Forming an organic layer by sequentially forming a second emission layer on the first emission layer and a third emission layer on the second emission layer in the pixel region, and forming an organic electrode layer on the organic emission layer Provided is a method for manufacturing a device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. In the figures, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout the specification.

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

Referring to FIG. 2, a substrate 200 including a first pixel area a, a second pixel area b, and a third pixel area c is provided. The substrate 200 is preferably a transparent substrate through which light can pass.

The first pixel area (a) is one selected from a blue pixel area, a green pixel area, and a red pixel area, and the second pixel area (b) is selected from among a blue pixel area, a green pixel area, and a red pixel area. Any one not selected as the pixel area (a), and the third pixel area (c) is the first pixel area (a) and the second pixel area (b) among the blue pixel area, the green pixel area, and the red pixel area. It is either not selected.

In addition, the substrate 200 may further include a fourth pixel area that is a white pixel area.

The color filter layer 210 is formed on the substrate 200 of the second and third pixel regions b and c to be spaced apart from each other. The color filter layer 210 may be selected from among the red color filter layer, the green color filter layer, and the blue color filter layer as the first emission color implemented in the first pixel region a.

Subsequently, an overcoat layer 220 is formed over the entire surface of the substrate including the color filter layer 210. The overcoat layer 220 serves to protect the color filter layer 210 from physical impact as a transparent film, and serves to alleviate the step caused by the color filter layer 210.

The first electrode 230 is formed for each pixel area on the overcoat layer 220. In the case of the first electrode 230 of the second and third pixel areas b and c, the first electrode 230 is formed in a region corresponding to the color filter layer 210 on the overcoating layer 220. It is preferable to use ITO or IZO having a high work function as the first electrode 230. A thin film transistor may be further included between the first electrode 230 and the substrate 200.

The pixel defining layer 240 is formed and patterned on the first electrode 230 to form an opening (not shown) exposing the first electrode 230. The pixel definition layer 230 may be formed of an organic layer such as polyimide, polyamide, acrylic resin, benzocyclobutene, or an inorganic layer such as spin on glass.

Subsequently, a first emission layer 251 is formed on the first electrode 230, and a second emission layer 252 is formed on the first emission layer 251 of the second and third pixel areas b and c. Form. The third emission layer 253 is formed on the second emission layer 252 to complete the organic layer 230.

Since the second light emitting layer 252 and the third light emitting layer 253 are not formed on the first light emitting layer 251 in the first pixel area a, the first light emitting layer 233 may have a first structure. Emissive color is directly implemented. On the other hand, the color filter layer 210 is formed in the second and third pixel areas b and c among the regions in which the first light emitting layer 251, the second light emitting layer 252, and the third light emitting layer 253 are sequentially stacked. ) Can be implemented in colors other than the first emission color.

The first light emitting layer 251 is any one selected from among the blue light emitting layer, the green light emitting layer, and the red light emitting layer, and the second light emitting layer 252 is not selected as the first light emitting layer 251 among the blue light emitting layer, the green light emitting layer, and the red light emitting layer. The third light emitting layer 253 is not selected as the first light emitting layer 251 and the second light emitting layer 252 among the blue light emitting layer, the green light emitting layer, and the red light emitting layer.

It is preferable that the thicknesses of the first light emitting layer 251, the second light emitting layer 252, and the third light emitting layer 253 be 30 to 300 μs, respectively. The reason for this is that it is difficult to maintain a balance when the balance is less than 30 Hz or exceeds 300 Hz, thereby causing a problem in implementing white light.

The first light emitting layer 251 is a blue light emitting layer, the second light emitting layer 252 is a green light emitting layer, and the third light emitting layer 253 is most preferably a red light emitting layer. Because the order of the organic light emitting layer is stacked, the mobility of the host material itself and the bandgap energy of the bandgap energy dopant material itself affect the recombination region. This is because the laminated structure of. In addition, when the blue light emitting layer, the green light emitting layer and the red light emitting layer is a laminated structure, the thickness of the blue light emitting layer is 30 ~ 200Å, the thickness of the green light emitting layer is 50 ~ 300Å and the thickness of the red light emitting layer is most preferably 100 ~ 300Å.

The reason why the first light emitting layer 251 is formed in only one pixel area is to protect light having a particularly poor luminous efficiency among the organic light emitting layers emitting single light, that is, white light. This is because direct patterning can improve light efficiency.

In addition, the organic layer 250 may further include a single layer or multiple layers selected from a hole injection layer, a hole transport layer, an electron transport layer and an electron injection layer.

Subsequently, a second electrode 260 that is a reflective electrode is formed on the organic layer 250 to complete an organic light emitting display device according to an embodiment of the present invention.

3 is a cross-sectional view showing another embodiment according to the present invention.

Referring to FIG. 3, a substrate 300 including first, second, and third pixel regions a, b, and c is provided. The substrate 300 may be formed of glass, plastic, stainless steel, or the like.

The first pixel area (a) is any one selected from among a blue pixel area, a red pixel area, and a green pixel area, and the second pixel area (b) is selected from among a blue pixel area, a red pixel area, and a green pixel area. The third pixel area (c) is not selected as the one pixel area (a), and the third pixel area (c) includes the first pixel area (a) and the second pixel area (a blue pixel area, a red pixel area, and a green pixel area). c) is not selected.

In addition, the substrate 300 may further include a fourth pixel area that is a white pixel area.

Subsequently, a first electrode 330 including a reflective film is formed on the substrate 300. A thin film transistor, a capacitor, or the like may be further included between the substrate 300 and the first electrode 330. The first electrode 330 may have a double structure or a triple structure in which a reflective film including ITO or IZO having a high work function and silver or aluminum is stacked.

An opening (not shown) is formed by forming and patterning a pixel definition layer 340 on the first electrode 330. The pixel definition layer 340 may be an organic layer made of polyimide, polyamide, acrylic resin, benzocyclobutene, or the like, or an inorganic layer made of spin-on glass.

Subsequently, a first emission layer 351 is formed on the first electrode 330. A second light emitting layer 352 is formed on the first light emitting layer 351 of the second and third pixel regions b and c, and a third light emitting layer 353 is formed on the second light emitting layer 352. The organic film layer 350 is completed.

The first light emitting layer 351 is any one selected from a blue light emitting layer, a red light emitting layer, and a green light emitting layer, and the second light emitting layer 352 is selected as the first light emitting layer 351 from a blue light emitting layer, a red light emitting layer, and a green light emitting layer. The third light emitting layer 353 is not selected as the first light emitting layer 351 and the second light emitting layer 352 among the blue light emitting layer, the red light emitting layer, and the green light emitting layer.

Here, the thickness of the first light emitting layer 351, the second light emitting layer 352 and the third light emitting layer 353 is characterized in that 30 ~ 300 30. In addition, it is most preferable that the first light emitting layer 351 is a blue light emitting layer, the second light emitting layer 352 is a green light emitting layer, and the third light emitting layer 353 is a red light emitting layer. When the organic layer 350 is a laminated structure of a blue light emitting layer, a green light emitting layer and a red light emitting layer, the thickness of the blue light emitting layer is 30 to 200Å, the thickness of the green light emitting layer is 50 to 300Å and the thickness of the red light emitting layer is 100 to 300Å. Most preferred.

The description of the organic layer 350 is omitted in the description of FIG. 2.

Subsequently, a second electrode 360 is formed on the organic layer 350. The second electrode 360 is a transflective electrode, and may be formed of aluminum silver (Al-Ag) or magnesium silver (MgAg).

Subsequently, a transparent protective film 370 is formed on the second electrode 360 in the second and third pixel regions b and c. The transparent protective film 370 may be formed of an inorganic film, an organic film, or an organic-inorganic composite film. Preferably the inorganic film is one selected from the group consisting of ITO, IZO, SiO ₂ , SiNx, Y ₂ O 3 and Al ₂ O ₃ , the organic film is parylene or HDPE, the organic-inorganic composite film is It is a composite film of Al ₂ O ₃ and organic polymer.

The color filter layer 310 is formed in a region corresponding to the first electrode 330 on the transparent protective film 370. The color filter layer 310 includes two of the blue color filter layer, the red color filter layer, and the green color filter layer except for the first emission color implemented in the first pixel region a.

An overcoat layer 320 is formed on the color filter layer 310. The overcoat layer 320 serves to protect the color filter layer 310 from physical damage.

Thus, an organic light emitting display device according to another embodiment of the present invention is completed.

Example 1

Idemit's IDE406 was formed in a patterned test cell as a hole injection layer to a thickness of 750 Å, and Idemit's IDE320 was formed to a thickness of 150 Å as the hole transport layer on the hole injection layer. On the hole transport layer, a blue light emitting layer containing BW215 of Idemitsu Co., Ltd. as a host material and 3 wt% of BD512 of Idemitsu Co., Ltd. as a dopant material was formed to a thickness of 60 Hz. Subsequently, a green light-emitting layer containing 6 wt% of Idemitsu Co., Ltd. BH215 as a host material and 6 wt% of Idemitsu Co., Ltd. as a dopant material was formed in a portion of the blue light-emitting layer to a thickness of 100 kW. Subsequently, a red light emitting layer material containing 150 wt% of BH215 of Idemitsu Corp. as a host material and 9 wt% of P1 of Idemitsu Corp. as a dopant material was formed on the green light emitting layer. Subsequently, Alq3, which is an electron transporting layer, was formed on the red light emitting layer to a thickness of 250 GPa, and LiF, which was an electron injection layer, was formed on the electron transporting layer. Subsequently, Al 2000 μs was formed on the electron injection layer using a cathode and sealed to complete a test cell.

3 is a graph measuring wavelength and intensity when a current of 11.6 Cd / A is applied to Example 1. FIG. The x-axis represents the wavelength and the unit is nm. The y-axis represents intensity, which is relative intensity. In addition, the white color coordinate for Example 1, that is, CIExy is (0.35, 0.39).

Referring to FIG. 3, a peak of about 0.75 intensity is located between wavelengths 440 to 460 nm, and a peak of about 0.85 intensity is positioned between wavelengths of 500 to 520 nm. Moreover, the peak of intensity about 0.80 is located between wavelength 580-600 nm. As such, it can be seen that three peaks are implemented at relatively uniform intensities in each of the wavelength regions of blue, green, and red.

The organic electroluminescent device according to an embodiment of the present invention is implemented by employing a color filter directly to the color of poor luminous efficiency and the remaining color by employing a color filter on the white light, it is excellent in color reproducibility and the luminous efficiency is increased.

While the invention has been shown and described with reference to certain preferred embodiments, the invention is not so limited, and the invention is not limited to the scope and spirit of the invention as defined by the following claims. It will be readily apparent to one of ordinary skill in the art that various modifications and variations can be made.

The organic electroluminescent device of the present invention directly implements a pattern of poor luminous efficiency and implements the remaining colors by employing a color filter on white light, thereby improving color reproduction and increasing luminous efficiency.

Claims (10)

A substrate including first, second, third and fourth pixel regions; A first electrode on the substrate; A second light emitting layer on the first electrode, a second light emitting layer on the first light emitting layer of the second, third and fourth pixel regions, and a third light emitting layer on the second light emitting layer; Organic film layer; A second electrode positioned on the organic layer; And the fourth pixel area is a white pixel area. delete The method of claim 1 The first light emitting layer is any one selected from among red, green and blue light emitting layers, and the second light emitting layer is any one selected from among the red, green and blue light emitting layers, and the third light emitting layer is red and green. And a blue light emitting layer which is not selected as the first light emitting layer and the second light emitting layer. The method of claim 1, Wherein the first light emitting layer is a blue light emitting layer, the second light emitting layer is a green light emitting layer, and the third light emitting layer is a red light emitting layer. The method of claim 1, The thickness of each of the first, second and third light emitting layer is 30 ~ 300Å organic light emitting device, characterized in that. The method of claim 1, The organic light emitting diode further comprises a color filter layer in the second and third pixel areas. delete delete Providing a substrate including first, second, third and fourth pixel regions, Forming a first electrode on the substrate, An organic layer is formed by sequentially forming a first light emitting layer on the first electrode, a second light emitting layer on the first light emitting layer of the second, third and fourth pixel regions, and a third light emitting layer on the second light emitting layer. and, And forming a second electrode on the organic layer, wherein the fourth pixel area is a white pixel area. delete

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