KR102113609B1 - Organic light emitting display and manufactucring method of the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device capable of improving light emission efficiency and color viewing angle, and a method for manufacturing the same, wherein the method of manufacturing an organic light emitting display device according to the present invention includes red, green, blue and white sub pixel areas on a substrate. Forming a first electrode of the; Forming a white organic common layer on the first electrode; And forming a second electrode on the white organic common layer, wherein a thickness of a first electrode in two sub-pixels among the red, green, blue, and white sub-pixels is first in the remaining two sub-pixels. It is formed of a transparent conductive layer having a multilayer structure thicker than an electrode, and at least two layers except for the bottom layer of the first electrode formed of the multi-layer structure are formed to cover both sides of the bottom layer.

Description

Organic light-emitting display device and its manufacturing method {ORGANIC LIGHT EMITTING DISPLAY AND MANUFACTUCRING METHOD OF THE SAME}

The present invention relates to an organic light emitting display device and a method for manufacturing the same, and more particularly, to an organic light emitting display device capable of improving luminous efficiency and color viewing angle, and a method for manufacturing the same.

A video display device that embodies various information as a screen is a key technology in the information and communication era, and is developing toward a thinner, lighter, more portable, and high-performance device. Accordingly, an organic electroluminescent display device for controlling an emission amount of an organic emission layer to display an image as a flat panel display device capable of reducing weight and volume, which is a disadvantage of a cathode ray tube (CRT), has been spotlighted.

In an organic light emitting device (OLED), pixels composed of sub-pixels of three colors (R, G, B) are basically arranged in a matrix form to display an image. However, in WOLED, which is one of the organic light emitting display devices, R, G, and B color filters are formed on a white organic light emitting cell to realize color. However, since the white organic light emitting cell implements white by using a light emitting layer that emits different colors, there is a problem in that viewing angles and efficiency characteristics are deteriorated due to different emission characteristics for each wavelength.

The present invention has been devised to solve the above problems, and to provide an organic light emitting display device capable of improving light emission efficiency and color viewing angle, and a method for manufacturing the same.

In order to achieve the above object, a method of manufacturing an organic light emitting display device according to the present invention includes forming a first electrode in a red, green, blue and white sub-pixel region on a substrate; Forming a white organic common layer on the first electrode; And forming a second electrode on the white organic common layer, wherein a thickness of a first electrode in two sub-pixels among the red, green, blue, and white sub-pixels is first in the remaining two sub-pixels. It is formed of a transparent conductive layer having a multilayer structure thicker than an electrode, and at least two layers except for the bottom layer of the first electrode formed of the multi-layer structure are formed to cover both sides of the bottom layer.

The thickness of the first electrodes of the red and blue sub-pixels is about 300 to 500 mm thick than the thickness of the first electrodes of the green and white sub-pixels.

The thickness of the first electrode of each of the red and blue sub-pixels is the same, and the thickness of the first electrode of each of the green and white sub-pixels is the same.

The first electrode of each of the red and blue sub-pixels is formed to a thickness of 1100 to 1500 Å, and the first electrode of each of the green and white sub-pixels is formed to a thickness of 600 to 1200 Å.

The forming of the first electrode may include forming first electrodes made of first to third transparent conductive layers in each of the red and blue sub-pixels, and forming the first to third transparent pixels in the green and white sub-pixels, respectively. And forming a first electrode made of at least one of the conductive layers.

The forming of the first electrode may include forming a first transparent conductive layer in each of the red, green, blue, and white sub-pixels through a photolithography process and an etching process; Forming a second transparent conductive layer covering one side of the first transparent conductive layer through a photolithography process and an etching process in each of the red, green, blue, and white sub-pixels; And forming a third transparent conductive layer covering the other side of the first and second transparent conductive layers through a photolithography process and an etching process in each of the red and blue sub-pixels.

To achieve the above technical problem, a substrate having red, green, blue and white sub-pixel regions; A first electrode formed on the substrate; A second electrode facing the first electrode; A white organic common layer formed between the first and second electrodes; The thickness of the first electrode in two sub-pixels among the red, green, blue, and white sub-pixels is formed of a transparent conductive layer having a multilayer structure thicker than the first electrode in the other two sub-pixels, and At least two layers except for the lowermost layer of one electrode are formed to cover both sides of the lowermost layer.

The red and blue sub-pixels having the same thickness of the first electrode are arranged adjacently, and the green and white sub-pixels are arranged adjacently.

The white organic common layer includes at least two light emitting units formed between the first and second electrodes; And at least one charge generating layer formed between the at least two light emitting units.

The white organic common layer is formed on the first electrode, and includes a first light emitting unit having a first light emitting layer that implements blue; A first charge generating layer formed on the first light emitting unit; It is formed on the first charge generating layer, it characterized in that it comprises a second light emitting unit having a second light emitting layer to implement a yellow-green.

The white organic common layer includes a second charge generating layer formed on the second light emitting unit; It is formed on the second charge generating layer, it characterized in that it further comprises a third light emitting unit having a third light emitting layer that implements blue.

The white organic common layer includes a second charge generating layer formed on the second light emitting unit; It is formed on the second charge generating layer, it characterized in that it further comprises a third light emitting unit having a third light emitting layer that implements red and a fourth light emitting layer that implements blue.

In the organic light emitting display device of the present invention and a method of manufacturing the same, the thicknesses of the first electrodes of the red and blue sub-pixels are thicker than the thicknesses of the first electrodes of the green and white sub-pixels. Accordingly, the organic light emitting display device and the manufacturing method according to the present invention can improve viewing angle and efficiency.

1 is a plan view showing an organic electroluminescent display panel according to a first exemplary embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating the organic electroluminescent display panel shown in FIG. 1.
3 is a cross-sectional view illustrating in detail the organic common layer illustrated in FIG. 2.
4A and 4B are cross-sectional views illustrating another embodiment of the first electrode illustrated in FIG. 2.
5 is a diagram illustrating another example of arrangement of red, green, blue, and white sub-pixels shown in FIG. 1.
6A to 6C are views showing the emission spectra of Comparative Examples 1 and 2 and Example 1.
7A to 7F are cross-sectional views illustrating a method of manufacturing the organic light emitting display device illustrated in FIG. 2.
8A to 8C are cross-sectional views for describing in detail a method of manufacturing the first electrode illustrated in FIG. 7D.
9 is a cross-sectional view illustrating an organic electroluminescent display device according to a second exemplary embodiment of the present invention.
10A to 10C are views showing the emission spectra of Comparative Examples 3 and 4 and Example 2.
11 is a cross-sectional view illustrating an organic electroluminescent display device according to a third embodiment of the present invention.
12A to 12C are views showing emission spectra of Comparative Examples 5 and 6 and Example 3.

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

1 is an equivalent circuit diagram of R, G, and B sub-pixel regions according to the present invention, and FIG. 2 is a cross-sectional view of an organic electroluminescent display panel according to the R, G, and B sub-pixel regions shown in FIG. 1.

1 and 2, an organic electroluminescent display panel according to an exemplary embodiment of the present invention includes a plurality of sub-pixel regions formed at intersections of a gate line GL, a data line DL, and a power line PL. .

The plurality of sub-pixel areas are composed of a red (R) sub-pixel area, a green (G) sub-pixel area, a blue (B) sub-pixel area, and a white (W) sub-pixel area, and the red (R), green (G), The blue (B) and white (W) sub-pixel areas are arranged in a matrix form to display an image.

Each of the red (R), green (G), blue (B), and white (W) sub-pixel regions includes a cell driver 200 and an organic light-emitting cell connected to the cell driver 200.

The cell driver 200 includes a switch thin film transistor TS connected to a gate line GL and a data line DL, a switch thin film transistor TS and a power line PL, and a first electrode of the organic electroluminescent device ( The driving thin film transistor TD connected between 122 and a storage capacitor C connected between the power line PL and the drain electrode 110 of the switch thin film transistor TS are provided.

The gate electrode of the switch thin film transistor TS is connected to the gate line GL, the source electrode is connected to the data line DL, and the drain electrode is connected to the gate electrode and the storage capacitor C of the driving thin film transistor TD. . The source electrode of the driving thin film transistor TD is connected to the power supply line PL, and the drain electrode 110 is connected to the first electrode 122. The storage capacitor C is connected between the power supply line PL and the gate electrode of the driving thin film transistor TD.

When the scan pulse is supplied to the gate line GL, the switch thin film transistor TS is turned on to supply the data signal supplied to the data line DL to the storage capacitor C and the gate electrode of the driving thin film transistor TD. do. The driving thin film transistor TD controls the current I supplied from the power supply line PL to the organic electroluminescent device in response to the data signal supplied to the gate electrode to adjust the amount of light emitted from the organic electroluminescent device. In addition, even if the switch thin film transistor TS is turned off, the driving thin film transistor TD is supplied by a voltage charged in the storage capacitor C until the data signal of the next frame is supplied, thereby inducing the current. The electroluminescent element keeps luminescence.

The driving thin film transistor TD is connected to the gate line GL as shown in FIG. 2, the gate electrode 102 formed on the substrate 100, and the gate insulating film 112 formed on the gate electrode 102. The oxide semiconductor layer 114 formed to overlap the gate electrode 102 with the gate insulating film 112 interposed therebetween, and an oxide to protect the oxide semiconductor layer 114 from damage and to protect the oxide semiconductor layer 114 from being affected by oxygen. It includes an etch stopper 106 formed on the semiconductor layer 114, a source electrode 108 connected to the data line DL, and a drain electrode 110 formed facing the source electrode 108. In addition, an organic passivation layer 118 of an organic insulating material is formed on the driving thin film transistor TD to planarize the substrate 100 on which the driving thin film transistor is formed. Alternatively, the protective film on the driving thin film transistor TD may be formed of two layers, an inorganic protective film formed of an inorganic insulating material and an organic protective film formed of an organic insulating material. The oxide semiconductor layer 114 is formed of an oxide containing at least one metal selected from Zn, Cd, Ga, In, Sn, Hf, and Zr. The thin film transistor including the oxide semiconductor layer 114 has advantages of higher charge mobility and lower leakage current characteristics than the thin film transistor including the silicon semiconductor layer. In addition, the thin film transistor including the silicon semiconductor layer is formed through a high-temperature process, and since a crystallization process must be performed, the larger the area, the less uniformity during the crystallization process, which is disadvantageous for large area. On the other hand, the thin film transistor including the oxide semiconductor layer 114 is capable of a low temperature process, and is advantageous in large area.

In the color filter, a red (R) color filter 124R is formed on the passivation layer 118 in the red (R) sub-pixel region to emit red (R), and on the passivation layer 118 in the green (G) sub-pixel region. A green (G) color filter 124G is formed to emit green (G), and a blue (B) color filter 124B is formed on the passivation layer 118 of the blue (B) sub-pixel region to form blue (B). ), And a color filter is not formed on the passivation layer 118 in the white (W) sub-pixel region, and white (W) is emitted.

The light emitting cell includes a first electrode 122 connected to the drain electrode 110 of the driving thin film transistor TD, a bank insulating layer 130 having a bank hole 132 exposing the first electrode 122, and An organic common layer 134 and a second electrode 136 formed on the organic common layer 134 are provided on one electrode 122.

The organic common layer 134 includes first and second light emitting units 134a and 134b formed with the charge generating layer CGL and the charge generating layer CGL interposed therebetween. Each of the first and second light emitting units 134a and 134b includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), and an electron transport layer (ETL). In particular, the light emitting layer 134a of the first light emitting unit 134a includes a blue fluorescent dopant and a host to emit blue light, and the light emitting layer of the second light emitting unit 134b contains a yellow-green phosphorescent dopant and a host, which is yellow- Emits green light. Accordingly, the blue light of the first light emitting unit 134a and the yellow-green light of the second light emitting unit 134b are mixed, so that the organic common layer 134 may implement white light. In addition, the organic common layer 134 may implement white light using other fluorescent dopants and phosphorescent dopants.

The first electrode 122 is an anode, and is formed to have different thicknesses for each of the red (R), green (G), blue (B), and white (W) sub-pixels. That is, the first electrodes 122G and 122W of the green (G) and white (W) sub-pixels that determine the viewing angle are formed with a first thickness, and the red (R) and blue (B) sub-pixels that determine the luminous efficiency. The first electrode (122R, 122B) is formed to a second thickness of about 300 ~ 500Å thicker than the first thickness. For example, the first electrodes 122G and 122W of the green (G) and white (W) sub-pixels are formed of 600 to 1200 ,, and the first electrodes 122R of the red (R) and blue (B) sub-pixels are formed. 122B) is formed to a thickness of 1100 ~ 1500Å.

The first electrode 122 is formed of a single-layer or multi-layer transparent conductive material using ITO (Indum Tin Oxide; ITO), IZO (Indum Zinc Oxide; IZO), and IGZO. When ITO and IZO are stacked to form the first electrode 122, when the thickness of ITO is thicker than that of IZO, the intensity of yellow-green light decreases, so it is preferable to form the thickness of IZO thicker than ITO. In particular, as shown in Table 1, the embodiment having a first electrode formed of 1200 to 1300 되어 in which ITO and IZO are stacked (ITO / IZO or IZO / ITO) has a yellow-green light efficiency while maximizing the efficiency of blue light, thus reducing the efficiency of blue light. The color viewing angle is improved than the comparative example having the first electrode formed of.

Conditions of the first electrode Color viewing angle Comparative Example (ITO 500Å) 0.053 Example (Lamination of ITO and IZO (1200Å)) 0.010 Example (Lamination of ITO and IZO (1300Å)) 0.015

Likewise, when ITO and IZO are mixed to form one layer of the first electrode 122, it is preferable to make the content of IZO more than the content of ITO.

The first electrodes 122R and 122B of the red (R) and blue (B) sub-pixels are formed by stacking the first to third transparent conductive layers 122a, 122b, and 122c, and green (G) and white. (W) The first electrodes 122G and 122W of the sub-pixel are formed of at least one of the first to third transparent conductive layers 122a, 122b, and 122c. In FIG. 2, the case where the first electrodes 122G and 122W of the green (G) and white (W) sub-pixels are formed by stacking the first and second transparent conductive layers 122a and 122b will be described as an example.

The first to third transparent conductive layers 122a, 122b, and 122c of the first electrodes 122R, 122B of the red (R) and blue (B) sub-pixels are as shown in FIGS. 2, 4A, or 4B. Stacked.

The second transparent conductive layer 122b illustrated in FIG. 2 is formed to cover one side of the first transparent conductive layer 122a, and the third transparent conductive layer 122c includes first and second transparent conductive layers 122a, It is formed to cover the other side of 122b).

The second transparent conductive layer 122b illustrated in FIG. 4A is formed to cover one side of the first transparent conductive layer 122a, and the third transparent conductive layer 122c is formed of the second transparent conductive layers 122a and 122b. It is formed to cover one side.

The second transparent conductive layer 122b illustrated in FIG. 4B is formed to cover both sides of the first transparent conductive layer 122a, and the third transparent conductive layer 122c is formed of the second transparent conductive layers 122a and 122b. It is formed to cover one side. In this case, the first electrodes 122G and 122W of the green (G) and white (W) sub-pixels may be formed by stacking the first and third transparent conductive layers 122a and 122c.

In addition, the first electrodes 122R and 122B of the red (R) and blue (B) sub-pixels can be changed to other forms.

As described above, the first electrode 122 is formed by forming a multi-layered transparent conductive layer constituting the first electrode 122 of the red (R), green (G), blue (B), and white (W) sub-pixels in a stepped structure. The step coverage of the overcoat layer 126 formed to cover both sides of is improved.

In addition, the fine resonance length of the red (R) and blue (B) sub-pixels is formed to be longer than the fine resonance length of the green (G) and white (W) sub-pixels by the thickness difference of the first electrode 122. Accordingly, the intensity of white light emitted through the first electrodes 122R and 122B of the red (R) sub-pixel region and the blue (B) sub-pixel region is enhanced, thereby improving luminous efficiency. Particularly, in the red (R) and blue (B) sub-pixels, the total thickness from the lower surface of the first electrodes 122R and 122B to the upper surface of the organic common layer 134 satisfies the resonance condition of Equation 1 below. Is formed.

In Equation 1, λ _y is the peak wavelength of yellow-green light, d ^a is the thickness of the first electrode 122, d ^w is the total thickness of the organic common layer 134, n ^w is the organic common layer 134 ), N ^a represents the refractive index of the first electrode 122. Here, the sum of the thicknesses of the first electrodes 122R and 122B of the red (R) and blue (B) sub-pixels and the thickness of the organic common layer 134 is preferably about 2500 to 5000 mm 2. In order to satisfy the condition of the above sum, as the thickness of the first electrodes 122R and 122B increases, the thickness of the organic common layer 134 must decrease, and the thickness change ratio is 1: 1 or more. When the thickness of the first electrode is formed at a maximum of 1500 Å, the thickness of the organic common layer 134 can be reduced to reduce the material cost, and the distance between the first and second electrodes 122 and 136 is close to reduce the driving voltage Can be.

The second electrode 136 is formed of a reflective metal material such as aluminum (Al) as a cathode. As illustrated in FIG. 2, the present invention may emit back light, but may emit back light, front light, or double light depending on the material of the first and second electrodes 122 and 136.

 In the organic light emitting cell, when a voltage is applied between the first electrode 122 and the second electrode 136, holes are injected from the first electrode 122 and electrons are injected from the second electrode 136. As it is recombined in the light emitting layer, excitons are generated due to this, and light is emitted to the bottom as the excitons fall to the ground state.

On the other hand, in FIG. 2 of the present invention, the red (R), green (G), blue (B), and white (W) sub-pixels are arranged in the order, but the sub-pixels having the same thickness of the first electrode 122 are adjacent to each other. Can be arranged. That is, as shown in FIG. 5, red (R), blue (B), green (G), and white (W) sub-pixels are arranged in this order.

6A to 6C are diagrams showing emission spectra according to the thickness of the first electrode of the comparative example and the embodiment. 6A to 6C, a photoluminescence peak (PL peak) is a peak of light emitted from each light-emitting layer, and an emission peak (EM peak) is an organic common layer between the first and second electrodes. The peak of light that varies depending on the thickness of each layer and optical properties, and the emission peak (Electro-Luminescence Peak; EL peak) represents the product of PL peak and EM peak.

6A to 6C and Table 2, Comparative Example 1 is an organic light emitting display device in which the first electrodes of the red, green, blue, and white sub-pixel regions are formed to a first thickness, and Comparative Example 2 is red and green. , An organic light emitting display device in which the first electrodes in the blue and white sub-pixel regions are formed to a second thickness that is thicker than the first thickness. In Example 1, the first electrodes in the red and blue sub-pixel regions are formed to a second thickness. , An organic light emitting display device in which first electrodes of green and white sub-pixel regions are formed to a first thickness. The organic light emitting diode display of Comparative Example 1 and Comparative Example 2 and Example 1 includes a first light emitting unit 134a generating blue light and a second light emitting unit 134b generating yellow-green light as shown in FIG. 3. Is made of

Luminescence peak efficiency (Cd / A) Color viewing angle
(△ u'v ') Panel efficiency
(cd / A) R G B W Comparative Example 1 6.0 18.8 2.2 63.6 0.016 23.9 Comparative Example 2 5.0 14.3 2.6 55.3 0.057 27.5 Example 6.0 18.8 2.6 63.6 0.016 27.0

Each of the half-width of the EM peak wavelength of the yellow-green light of Comparative Example 1 shown in FIG. 6A and the half-width of the EM peak wavelength of blue light, respectively, are EM of the yellow-green light of Comparative Example 2 shown in FIG. 6B. The half-width of the peak wavelength and the half-width of the EM peak wavelength of blue light are formed to be wider. Accordingly, it can be seen that Comparative Example 2 in which the first electrode was formed in a second thickness has lower color viewing angle characteristics than Comparative Example 1 in which the first electrode was formed in a first thickness, as shown in Table 2.

In addition, the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 1 shown in FIG. 6A is lower than the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 2 shown in FIG. 6B. Accordingly, it can be seen that Comparative Example 1 in which the first electrode was formed in a first thickness, panel efficiency characteristics were lower than Comparative Example 2 in which the first electrode was formed in a second thickness, as shown in Table 2. In particular, as shown in Table 1, the efficiency of the red and blue and sub-pixels of Comparative Example 1 in which the first electrode is formed to a first thickness is the efficiency of the red and blue sub-pixels of Comparative Example 2 in which the first electrode is formed to a second thickness. It can be seen that it has decreased more.

On the other hand, in the case of Example 1, as shown in FIG. 6C, white light emitted from the green and white sub-pixel regions having the first electrodes 122G and 122W of the first thickness and the first electrode of the second thickness ( The phases of the emission peak wavelengths of the white light emitted from the red and blue sub-pixel regions having 122R and 122B are similar. Accordingly, in Example 1, as shown in Table 2, panel efficiency is improved than Comparative Examples 1 and 2, and color viewing angle characteristics equivalent to those of Comparative Example 1 can be obtained.

7A to 7F are cross-sectional views illustrating a method of manufacturing an organic electroluminescent display panel according to an exemplary embodiment of the present invention shown in FIG. 2.

Referring to FIG. 7A, a driving thin film transistor including a gate electrode 106, a gate insulating layer 112, a semiconductor pattern 115, a source electrode 108, and a drain electrode 110 is formed on the substrate 100. .

Specifically, a gate metal layer is formed on the substrate 100 through a deposition method such as a sputtering method. The gate metal layer is used as a metal material such as Mo, Ti, Cu, AlNd, Al, Cr, Mo alloy, Cu alloy, Al alloy, and Mo-Ti alloy. Next, the gate electrode 102 is formed by patterning the gate metal layer by a photolithography process and an etching process.

Then, the gate insulating layer 112 is formed by forming an inorganic insulating material such as silicon oxide (SiOx) or silicon nitride (SiNx) on the substrate 100 on which the gate electrode 102 is formed. Then, the oxide semiconductor layer 114 and the etch stopper layer 116 are sequentially formed on the substrate 100 on which the gate insulating layer 112 is formed through a photolithography process and an etching process.

Thereafter, a data metal layer is formed on the substrate 100 on which the semiconductor pattern is formed through a deposition method such as a sputtering method. Here, as the data metal layer, titanium (Ti), tungsten (W), aluminum (Al) -based metal, molybdenum (Mo), copper (Cu), or the like is used. Subsequently, the source electrode 108 and the drain electrode 110 are formed by patterning the data metal layer through a photolithography process and an etching process.

Referring to FIG. 7B, an organic passivation layer 118 is formed on the substrate 100 on which the source and drain electrodes 108 and 110 are formed, and each of the R, G, and B color filters 124R, 124G, and 124B is a corresponding sub-pixel region. It is formed on each.

Specifically, the organic protective layer 118 is formed by forming an organic insulating material such as an acrylic resin on the substrate 100 on which the source and drain electrodes 108 and 110 are formed. Subsequently, after applying a red color resist colored with red (R), a red color filter 124R is formed on the organic passivation layer 118 in the R sub-pixel region by a photolithography process and an etching process. Thereafter, after the green (G) colored green color resist is applied, a green color filter 124G is formed on the organic passivation layer 118 in the G sub-pixel region by a photolithography process and an etching process. Then, after the blue (B) colored blue color resist is applied, a blue color filter 124B is formed on the organic passivation layer 118 in the B sub-pixel region by a photolithography process and an etching process. Accordingly, R, G, and B color filters 124R, 124G, and 124B are formed in each of the R, G, and B sub-pixel regions.

Referring to FIG. 7C, an overcoat layer 126 having a pixel contact hole 120 is formed on a substrate 100 on which R, G, and B color filters 124R, 124G, and 124B are formed.

Specifically, an overcoat layer 126 is formed because a photosensitive organic film such as an acrylic resin is formed on the substrate 100 on which the R, G and B color filters 124R, 124G, and 124B are formed. Subsequently, the pixel contact hole 120 is formed by patterning the organic passivation layer 118 and the overcoat layer 126 by a photolithography process and an etching process. The pixel contact hole 120 exposes the drain electrode 110 of the driving thin film transistor in the corresponding sub-pixel region.

Referring to FIG. 7D, first electrodes 122R and 122G on red (R), green (G), blue (B), and white (W) sub-pixel regions on the substrate 100 on which the pixel contact hole 120 is formed , 122B, 122W) are formed.

Specifically, a first such as ITO (Indum Tin Oxide; ITO), IZO (Indum Zinc Oxide; IZO) through a deposition method such as sputtering on the substrate 100 on which the pixel contact hole 120 is formed A transparent conductive material is formed. Subsequently, as shown in FIG. 8A, the first transparent conductive material is etched using the first photoresist pattern 140a formed through the exposure and development process using the first photomask as a mask to red (R), green ( G), the first transparent conductive layer 122a is formed on the blue (B) and white (W) sub-pixel regions.

Then, on the substrate 100 on which the first transparent conductive layer 122a is formed, such as ITO (Indum Tin Oxide; ITO), IZO (Indum Zinc Oxide; IZO), etc., are deposited through a deposition method such as a sputtering method. A second transparent conductive material is formed. At this time, the second transparent conductive material is formed of the same or different material from the first transparent conductive material. Subsequently, as shown in FIG. 8B, the second transparent conductive material is etched using the second photoresist pattern 140b formed through the exposure and development process using a photomask as a mask to red (R), green (G). , A second transparent conductive layer 122b is formed on the blue (B) and white (W) sub-pixel regions. Accordingly, first electrodes 122G and 122W formed of the first and second transparent conductive layers 122a and 122b are formed on the green and white sub-pixel regions. Meanwhile, when misalignment occurs within the error range when the photomask is aligned on the second transparent conductive material or the photomask is shifted to one side, the second transparent conductive layer 122b is the first transparent as shown in FIG. 8B. It is formed to cover one side of the conductive layer 122a.

Then, on the substrate 100 on which the second transparent conductive layer 122b is formed, such as ITO (Indum Tin Oxide; ITO), IZO (Indum Zinc Oxide; IZO), etc., are deposited through a deposition method such as a sputtering method. A third transparent conductive material is formed. At this time, the third transparent conductive material is formed of the same or different material from at least one of the first and second transparent conductive materials. Subsequently, as shown in FIG. 8C, red (R) and blue (B) are etched by etching the third transparent conductive material using the third photoresist pattern 140c formed through the exposure and development process using a photomask as a mask. The third transparent conductive layer 122b is formed on the sub pixel area. Accordingly, first electrodes 122R and 122B formed of the first to third transparent conductive layers 122a, 122b, and 122c are formed on the red (R) and blue (B) sub-pixel regions. As described above, it is possible to shorten the etching time by dividing and etching the first electrode 122 having a thickness of up to 1500 으로 at least twice as in the present invention, so as to increase the efficiency of the process.

Referring to FIG. 7E, a bank insulating layer 130 having a bank hole 132 is formed on the substrate 100 on which the first electrode 122 is formed.

Specifically, the bank insulating layer 130 formed of an organic insulating material such as photo acrylic is coated on the substrate 100 on which the first electrode 122 is formed. Subsequently, the bank insulating layer 130 is patterned by a photolithography process and an etching process, thereby forming the bank insulating layer 130 having the bank holes 132 exposing the first electrode 122.

Referring to FIG. 7F, an organic common layer 134 is formed on the substrate 100 on which the bank insulating layer 130 is formed, and a second electrode 136 is formed on the organic common layer 134.

Specifically, the organic common layer 134 having the stacked structure of FIG. 3 is formed on the first electrode 122. Then, aluminum (Al) and silver (Ag) are deposited on the organic common layer 134 to form the second electrode 136.

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

The organic light emitting display device illustrated in FIG. 9 has the same components except for having three light emitting units in contrast to the organic light emitting display device illustrated in FIG. 1. Accordingly, detailed description of the same components will be omitted.

The organic common layer 134 illustrated in FIG. 9 includes first to third light emitting units 134a, 134b, and 134c formed between the first and second electrodes 122 and 136, and first and second light emitting units 134a. , 134b), and a second charge generation layer CGL2 formed between the second and third light emitting units 134b and 134c.

Each of the first to third light emitting units 134a, 134b, and 134c includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), and an electron transport layer (ETL). In particular, the first light emitting layer EML1 of the first light emitting unit 134a includes a blue fluorescent dopant and a host to emit blue light, and the second light emitting layer EML2 of the second light emitting unit 134b is a yellow-green phosphorescent dopant. And a host are included to emit yellow-green light, and the third emission layer EML3 of the third emission unit 134c includes a blue fluorescent dopant and a host to emit blue light. Accordingly, the blue light of the first light emitting unit 134a, the yellow-green light of the second light emitting unit 134b, and the blue light of the third light emitting unit 134c are mixed, so that the organic common layer 134 is implemented with white light. Can be. In addition, the organic common layer 134 may implement white light using other fluorescent dopants and phosphorescent dopants.

10A to 10C are diagrams showing emission spectra according to thicknesses of Comparative Examples 3 and 4 and the first electrode of Example 2;

10A to 10C and Table 3, Comparative Example 3 is an organic light emitting display device in which the first electrodes of the red, green, blue, and white sub-pixel regions are formed with a first thickness, and Comparative Example 4 is red, green, and blue. And an organic light emitting display device in which the first electrode of the white sub-pixel area is formed to a second thickness thicker than the first thickness, and the second embodiment forms the first electrodes of the red and blue sub-pixel areas to a second thickness, and green. And a first electrode of a white sub-pixel region having a first thickness, and in Comparative Examples 3 and 4 and Example 2, the light-emitting cells of each sub-pixel region are shown in FIG. 9. The first to third light emitting layers EML1, EML2, and EML3 are provided.

Luminescence peak efficiency (Cd / A) Color viewing angle
(△ u'v ') Panel efficiency
(cd / A) R G B W Comparative Example 3 5.4 32.5 3.3 90.7 0.020 32.5 Comparative Example 4 6.0 26.9 3.9 81.3 0.043 27.4 Example 2 6.0 32.5 3.9 90.7 0.020 32.5

The half-width of the EM peak wavelength of the yellow-green light of Comparative Example 3 shown in FIG. 10A, and the half-width of the EM peak wavelength of the blue light, respectively, are the half-width of the EM peak wavelength of the yellow-green light of Comparative Example 4 shown in FIG. It is formed wider than each half width of the EM peak wavelength. Accordingly, it can be seen that Comparative Example 4 in which the first electrode was formed to a second thickness had lower color viewing angle characteristics than Comparative Example 3 in which the first electrode was formed in the first thickness, as shown in Table 3.

In addition, the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 3 shown in FIG. 10A is lower than the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 4 shown in FIG. 10B. Accordingly, it can be seen that Comparative Example 3 in which the first electrode was formed to a first thickness has lower panel efficiency characteristics than Comparative Example 4 in which the first electrode was formed to a second thickness as shown in Table 3. In particular, as shown in Table 3, the efficiency of the red and blue and sub-pixels of Comparative Example 3 in which the first electrode is formed to the first thickness is the efficiency of the red and blue sub-pixels of Comparative Example 4 in which the first electrode is formed to the second thickness. It can be seen that it decreased more.

On the other hand, in the case of Example 2, as shown in FIG. 10C, white light emitted from the green and white sub-pixel regions having the first electrodes 122G and 122W having the first thickness and the first electrode having the second thickness ( The phases of the emission peak wavelengths of the white light emitted from the red and blue sub-pixel regions having 122R and 122B are similar. Accordingly, Example 2 can obtain panel efficiency characteristics equivalent to Comparative Example 4 higher than Comparative Example 3 as shown in Table 3, and color viewing angle characteristics equivalent to Comparative Example 3 higher than Comparative Example 4. Particularly, Example 2 further includes a third light emitting unit that generates blue light as compared to Example 1, so that the EL peak intensity of blue light is increased compared to Example 1, thereby improving the efficiency of blue light.

As described above, in the organic light emitting diode display according to the second embodiment of the present invention, blue light having a wavelength range of 450 to 480 nm and yellow-green light having a wavelength range of 540 to 570 nm are emitted as shown in FIG. 10C. -It can emit light with peaks.

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

The organic light emitting display device illustrated in FIG. 11 has the same components except for having three light emitting units in contrast to the organic light emitting display device illustrated in FIG. 1. Accordingly, detailed description of the same components will be omitted.

The organic common layer 134 illustrated in FIG. 11 includes first to third light emitting units 134a, 134b, and 134c formed between the first and second electrodes 122 and 136, and first and second light emitting units 134a. , 134b), and a second charge generation layer CGL2 formed between the second and third light emitting units 134b and 134c.

Each of the first to third light emitting units 134a, 134b, and 134c includes a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), and an electron transport layer (ETL). In particular, the first light emitting layer EML1 of the first light emitting unit 134a includes a blue fluorescent dopant and a host to emit blue light, and the second light emitting layer EML2 of the second light emitting unit 134b is a yellow-green phosphorescent dopant. And a host to emit yellow-green light, and the third emission layer EML3 of the third emission unit 134c includes a red phosphorescent or fluorescent dopant and a host to emit red light, and the fourth emission layer EML4 is blue Fluorescent or phosphorescent dopants and hosts are included to emit blue light. Accordingly, the blue light of the first light emitting unit 134a, the yellow-green light of the second light emitting unit 134b, and the red light-blue light of the third light emitting unit 134c are mixed, so that the organic common layer 134 has white light. Can be implemented. In addition, the organic common layer 134 may implement white light using other fluorescent dopants and phosphorescent dopants. As described above, since the organic light emitting diode display according to the third exemplary embodiment of the present invention includes a fourth light emitting layer EML4 for generating red light, color gamut is improved.

12A to 12C are views showing emission spectra according to thicknesses of the first electrodes of Comparative Examples 5 and 6 and Example 3. FIG.

12A to 12C and Table 4, Comparative Example 5 is an organic light emitting display device in which the first electrodes of the red, green, blue, and white sub-pixel regions are formed to a first thickness, and Comparative Example 6 is red, green, and blue. And an organic light emitting display device in which the first electrode of the white sub-pixel region is formed to a second thickness that is thicker than the first thickness. In Example 3, the first electrodes of the red and blue sub-pixel regions are formed to a second thickness, and green. And an organic light emitting display device in which the first electrode of the white sub-pixel region is formed to have a first thickness. In Comparative Examples 5 and 6, and Example 3, the light emitting cells of each sub-pixel region are The first to fourth light emitting layers EML1, EML2, EML3, and EML4 are provided.

Luminescence peak efficiency (Cd / A) Color viewing angle
(△ u'v ') Panel efficiency
(cd / A) R G B W Comparative Example 5 7.9 30.8 2.8 88 0.020 31.9 Comparative Example 6 8.6 25.4 3.3 79.3 0.042 33.2 Example 3 8.6 30.8 3.3 88 0.020 33.2

The half-width of the EM peak wavelength of the yellow-green light of Comparative Example 5 shown in FIG. 12A and the half-width of the EM peak wavelength of the blue light, respectively, are the full-width of the EM peak wavelength of the yellow-green light of Comparative Example 2 shown in FIG. 12B. at Half Maximum) and the half width of the EM peak wavelength of the blue light is formed wider. Accordingly, it can be seen that Comparative Example 6 in which the first electrode was formed in a second thickness has lower color viewing angle characteristics than Comparative Example 5 in which the first electrode was formed in a first thickness, as shown in Table 4.

In addition, the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 5 shown in FIG. 12A is lower than the intensity of the EM peak of each of the blue light and yellow-green light of Comparative Example 6 shown in FIG. 12B. Accordingly, it can be seen that Comparative Example 5 in which the first electrode was formed to a first thickness has lower panel efficiency characteristics than Comparative Example 6 in which the first electrode was formed to a second thickness as shown in Table 4. In particular, as shown in Table 4, the efficiency of the red and blue and sub-pixels of Comparative Example 5 in which the first electrode is formed to the first thickness is the efficiency of the red and blue sub-pixels of Comparative Example 6 in which the first electrode is formed to the second thickness. It can be seen that it decreased more.

On the other hand, in the case of Example 3, as shown in FIG. 12C, the white light emitted from the green and white sub-pixel regions having the first electrodes 122G and 122W of the first thickness and the first electrode of the second thickness ( The phases of the emission peak wavelengths of the white light emitted from the red and blue sub-pixel regions having 122R and 122B are similar. Accordingly, Example 3 can obtain panel efficiency characteristics equivalent to Comparative Example 6 higher than Comparative Example 5 as shown in Table 4, and obtain color viewing angle characteristics equivalent to Comparative Example 5 higher than Comparative Example 6.

As described above, the organic light emitting diode display according to the third embodiment of the present invention includes blue light having a wavelength range of 450 to 480 nm, yellow-green light having a wavelength range of 540 to 570 nm, and 620 to as illustrated in FIG. 12C. Since red light having a wavelength range of 640 nm is emitted, light having 3-peak can be emitted.

On the other hand, the organic light emitting display device according to the present invention has been exemplified as having up to three light emitting units, but may also include three or more light emitting units.

The above description is merely illustrative of the present invention, and various modifications may be made without departing from the technical spirit of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be interpreted by the following claims, and all technologies within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

100: substrate 102: gate electrode
108: source electrode 110: drain electrode
112: gate insulating film 114: active layer
116: buffer film 118: organic protective film
120: pixel contact hole
122R, 122G, 122B, 122W: First electrode
124R, 124G, 124B: red, green, blue color filters
126: overcoat layer 130: bank insulating film
132: bank hole 134: organic common layer
136: second electrode

Claims (22)

Forming first electrodes of red, green, blue, and white sub-pixel regions on the substrate;
Forming a white organic common layer on the first electrode;
And forming a second electrode on the white organic common layer,
The thickness of the first electrode in two sub-pixels among the red, green, blue, and white sub-pixels is formed of a transparent conductive layer having a multilayer structure thicker than the first electrode in the other two sub-pixels,
At least two layers except for the bottom layer of the first electrode formed of the multi-layer structure are formed to cover both sides of the bottom layer,
A method of manufacturing an organic light emitting display device having the same thickness as the first electrode of each of the green and white sub-pixels. According to claim 1,
The thickness of the first electrode of the red and blue sub-pixels is 300 to 500Å thicker than the thickness of the first electrode of the green and white sub-pixels. According to claim 2,
A method of manufacturing an organic light emitting diode display having the same thickness as the first electrode of each of the red and blue sub-pixels. The method of claim 3,
The first electrode of each of the red and blue sub-pixels is formed to a thickness of 1100 ~ 1500Å,
The first electrode of each of the green and white sub-pixels is a method of manufacturing an organic light emitting display device formed to a thickness of 600 ~ 1200Å. According to claim 2,
The step of forming the first electrode
A first electrode made of a first to third transparent conductive layer is formed on each of the red and blue sub-pixels, and a first made of at least one of the first to third transparent conductive layers on each of the green and white sub-pixels. A method of manufacturing an organic light emitting display device comprising forming an electrode. The method of claim 5,
The step of forming the first electrode
Forming a first transparent conductive layer on each of the red, green, blue, and white sub-pixels through a photolithography process and an etching process;
Forming a second transparent conductive layer covering one side of the first transparent conductive layer through a photolithography process and an etching process in each of the red, green, blue, and white sub-pixels;
And forming a third transparent conductive layer covering the other side of the first and second transparent conductive layers through a photolithography process and an etching process in each of the red and blue sub-pixels. According to claim 1,
The step of forming the white organic common layer is
Forming at least two light emitting units between the first and second electrodes;
And forming at least one charge generating layer between the at least two light emitting units. The method of claim 7,
The step of forming the white organic common layer is
Forming a first light emitting unit having a first light emitting layer that implements blue on the first electrode;
Forming a first charge generating layer on the first light emitting unit;
And forming a second light emitting unit having a second light emitting layer that implements a yellow-green color on the charge generating layer. The method of claim 8,
The step of forming the white organic common layer is
Forming a second charge generating layer on the second light emitting unit;
And forming a third light emitting unit having a third light emitting layer that implements blue on the second charge generating layer. The method of claim 8,
The step of forming the white organic common layer is
Forming a second charge generating layer on the second light emitting unit;
And forming a third light emitting unit having a third light emitting layer that implements red and a fourth light emitting layer that implements blue on the second charge generating layer. A substrate having red, green, blue and white sub-pixel regions;
A first electrode formed on the substrate;
A second electrode facing the first electrode;
A white organic common layer formed between the first and second electrodes;
The thickness of the first electrode in two sub-pixels among the red, green, blue, and white sub-pixels is formed of a transparent conductive layer having a multi-layer structure thicker than the first electrode in the other two sub-pixels,
At least two layers except for the bottom layer of the first electrode formed of the multi-layer structure are formed to cover both sides of the bottom layer,
An organic light emitting display device having the same thickness as the first electrode of each of the green and white sub-pixels. The method of claim 11,
The thickness of the first electrode of the red and blue sub-pixels is 300 to 500Å thicker than the thickness of the first electrode of the green and white sub-pixels. The method of claim 11,
An organic light emitting diode display having the same thickness as the first electrode of each of the red and blue sub-pixels. The method of claim 13,
The first electrode of each of the red and blue sub-pixels is formed to a thickness of 1100 ~ 1500Å,
The first electrode of each of the green and white sub-pixels is formed to a thickness of 600 ~ 1200Å. The method of claim 14,
An organic light emitting display device in which red and blue sub-pixels having the same thickness of the first electrode are adjacently arranged, and green and white sub-pixels are adjacently arranged. The method of claim 12,
The first electrode of each of the red and blue sub-pixels
A first transparent conductive layer formed on the substrate;
A second transparent conductive layer formed to cover one side of the first transparent conductive layer;
It is made of a third transparent conductive layer formed to cover the other side of the first and second transparent conductive layers,
The first electrode of each of the green and white sub-pixels
An organic light emitting display device formed of at least one of the first to third transparent conductive layers. The method of claim 11,
The common white organic layer
At least two light emitting units formed between the first and second electrodes;
And at least one charge generating layer formed between the at least two light emitting units. The method of claim 17,
The common white organic layer
A first light emitting unit formed on the first electrode and having a first light emitting layer that implements blue;
A first charge generating layer formed on the first light emitting unit;
An organic light emitting display device formed on the first charge generating layer and having a second light emitting unit having a second light emitting layer that implements yellow-green. The method of claim 18,
The common white organic layer
A second charge generating layer formed on the second light emitting unit;
An organic light emitting display device formed on the second charge generating layer and further comprising a third light emitting unit having a third light emitting layer that implements blue. The method of claim 18,
The common white organic layer
A second charge generating layer formed on the second light emitting unit;
An organic light emitting display device formed on the second charge generating layer, and further comprising a third light emitting unit having a third light emitting layer that implements red and a fourth light emitting layer that implements blue. The method of claim 11,
The first electrode includes an ITO layer made of ITO and an IZO layer made of IZO,
The IZO layer has a thickness greater than that of the ITO layer. The method of claim 11,
The first electrode is formed by mixing ITO and IZO,
The content of the IZO is more than the content of the ITO organic light emitting display device.

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