KR101458906B1 - Organic light emitting diode display and method for manufacturing the same - Google Patents

Abstract

The present invention provides an OLED display device including a first pixel, a second pixel, and a third pixel that display different colors, wherein each pixel includes a first electrode, a second electrode facing the first electrode, And a light emitting layer disposed between the first electrode and the second electrode, wherein the first electrode of the first and second pixels comprises a first conductive oxide layer, and at least one of a lower portion and an upper portion of the first conductive oxide layer Wherein the first electrode of the third pixel includes a second conductive oxide layer different from the first conductive oxide layer, and a second conductive oxide layer that is different from the first conductive oxide layer, And a semi-transparent conductive layer formed on at least one of a lower portion and an upper portion of the organic light emitting display and forming a fine resonance with the second electrode, and a method of manufacturing the same.

Fine resonance, green pixel, pixel electrode, etch ratio

Description

TECHNICAL FIELD [0001] The present invention relates to an organic light emitting diode (OLED) display device,

The present invention relates to an organic light emitting display and a method of manufacturing the same.

2. Description of the Related Art In recent years, a cathode ray tube (CRT) has been replaced by a liquid crystal display (LCD) in accordance with such a demand.

However, a liquid crystal display device requires not only a backlight but also a response speed and a viewing angle.

Recently, organic light emitting diode (OLED) displays have been attracting attention as display devices capable of overcoming these limitations.

The organic light emitting display includes two electrodes and a light emitting layer disposed therebetween. Electrons injected from one electrode and holes injected from the other electrode are combined in the light emitting layer to form an exciton And the exciton emits light while emitting energy.

Since the organic light emitting display device is of a self-emission type and does not require a separate light source, it is advantageous not only in terms of power consumption but also in response speed, viewing angle, and contrast ratio.

On the other hand, the organic light emitting display includes a plurality of pixels such as a red pixel, a blue pixel, and a green pixel, and these pixels can be combined to represent a full color.

At this time, the red pixel, the blue pixel, and the green pixel can express a color by including a red luminescent layer, a blue luminescent layer, and a green luminescent layer, respectively. Such a light emitting layer can be deposited for each pixel by using a fine shadow mask. However, there is a limitation in depositing the light emitting layer for each pixel using the fine shadow mask while the display device is becoming large.

Accordingly, a red light emitting layer, a blue light emitting layer, and a green light emitting layer are sequentially stacked on the entire display device using an open mask to emit white light, and a color filter is placed at a position where the emitted light passes, , Green, and blue.

However, due to the color reproducibility limit of the color filter itself, the light passing through the color filter has to exhibit the same or lower color reproducibility. In this case, it is difficult to achieve high color reproducibility required by the National Television Systems Committee (NTSC).

Therefore, a problem to be solved by the present invention is to achieve high color reproducibility in a white light emitting organic light emitting display.

According to an embodiment of the present invention, an OLED display includes a first pixel, a second pixel, and a third pixel that display different colors, and each pixel includes a first electrode, a second electrode facing the first electrode, And a light emitting layer disposed between the first electrode and the second electrode, wherein the first electrode of the first and second pixels includes a first conductive oxide layer, and a lower portion of the first conductive oxide layer, Wherein the first electrode of the third pixel is a second conductive oxide layer different from the first conductive oxide layer, and the second conductive oxide layer is a second conductive oxide layer that is different from the first conductive oxide layer. And a semi-transparent conductive layer formed on at least one of a lower portion and an upper portion of the second conductive oxide layer and forming a fine resonance with the second electrode.

The first pixel may be a red pixel, the second pixel may be a blue pixel, and the third pixel may be a green pixel.

The light emitting layer includes a plurality of sub-emission layers that emit light of different wavelengths, and light of different wavelengths may be combined to emit white light.

The first pixel, the second pixel, and the third pixel may each further include a color filter formed under the first electrode.

Wherein the first electrode of the first and second pixels includes the semitransparent conductive layer and the first conductive oxide layer formed on the semitransparent conductive layer, and the first electrode of the third pixel includes the semi- And the second conductive oxide layer formed on the semitransparent conductive layer, wherein the second conductive oxide layer has an etch rate different from that of the first conductive oxide layer and may be thicker than the first conductive oxide layer.

One of the first conductive oxide layer and the second conductive oxide layer may comprise crystalline ITO and the other may comprise ITO formed from IZO or an amorphous state.

Wherein the white pixel further comprises a first electrode, a second electrode facing the first electrode, and a second electrode disposed between the first electrode and the second electrode, And the first electrode of the white pixel may include the first conductive oxide layer and the second conductive oxide layer.

The sum of the thicknesses of the first conductive oxide layer and the second conductive oxide layer may be 500 to 1500 ANGSTROM.

The thickness of the semitransparent conductive layer may be 100 to 400 Å.

The first conductive oxide layer may include a lower first conductive oxide layer positioned below the opaque conductive layer and an upper first conductive oxide layer disposed on the opaque conductive layer.

Wherein the first electrode of the first and second pixels is formed of the lower first conductive oxide layer, the semi-transparent conductive layer formed on the lower first conductive oxide layer, and the upper portion of the upper conductive oxide layer, 1 conductive oxide layer, and the first electrode of the third pixel includes the lower first conductive oxide layer, the semitransparent conductive layer formed on the lower first conductive oxide layer, the upper portion of the semi- A first conductive oxide layer, and the second conductive oxide layer formed on the upper first conductive oxide layer.

The lower first conductive oxide layer and the upper first conductive oxide layer may include ITO, and the second conductive oxide layer may be formed of IZO or amorphous ITO.

Wherein the white pixel further comprises a first electrode, a second electrode facing the first electrode, and a second electrode disposed between the first electrode and the second electrode, And the first electrode of the white pixel may include the lower first conductive oxide layer.

The thickness of the lower first conductive oxide layer may be 500 to 1500 ANGSTROM.

A method of manufacturing an organic light emitting display according to an embodiment of the present invention includes forming a first electrode on a red pixel, a blue pixel, and a green pixel, forming a light emitting layer on the first electrode, Wherein the forming of the first electrode comprises forming an opaque conductive layer on each of the red, blue and green pixels, forming a first electrode on at least some of the red, blue and green pixels, Forming a conductive oxide layer on the first conductive oxide layer, and forming a second conductive oxide layer having a different etching ratio from the first conductive oxide layer on the green pixel.

Wherein the forming of the first electrode comprises forming an opaque conductive layer on each of the red, blue and green pixels, forming a first conductive oxide layer on each opaque conductive layer of the red and blue pixels, And forming a second conductive oxide layer on the opaque conductive layer of the pixel, wherein the thickness of the second conductive oxide layer may be different from that of the first conductive oxide layer.

Wherein the organic light emitting display device further comprises a white pixel that does not display color, the forming of the first electrode of the white pixel comprises: forming the first conductive oxide layer; forming a second conductive oxide layer on the first conductive oxide layer; And forming a second conductive oxide layer.

The forming of the first electrode may include laminating an opaque conductive layer on the entire surface of the substrate, applying and patterning a first photosensitive film on the opaque conductive layer to form a first photosensitive pattern on the red, Forming an opaque conductive layer on each of the red, blue and green pixels by photo-etching the opaque conductive layer using the first photosensitive pattern, laminating a first conductive oxide layer on the entire surface of the substrate including the opaque conductive layer Forming a second photosensitive pattern on the red, blue, and white pixels, respectively, by applying and patterning a second photosensitive film on the first conductive oxide layer, forming the first conductive oxide layer by photolithography using the second photosensitive pattern, Forming a first conductive oxide layer on each of the red, blue, and white pixels, forming a first conductive oxide layer on the substrate including the first conductive oxide layer, Forming a third photosensitive pattern on the green and white pixels, respectively, by applying and patterning a third photosensitive film on the second conductive oxide layer, and forming a third photosensitive pattern using the third photosensitive pattern, And photo-etching the second conductive oxide layer to form a second conductive oxide layer on the green and white pixels, respectively.

One of the first conductive oxide layer and the second conductive oxide layer may include crystalline ITO and the other may include IZO or amorphous ITO.

The forming of the first conductive oxide layer may include forming a lower first conductive oxide layer below the opaque conductive layer and forming an upper first conductive oxide layer on the opaque conductive layer .

The forming of the first electrode may include forming a lower first conductive oxide layer on the red, blue, and green pixels, respectively, forming an opaque conductive layer on the lower first conductive oxide layer of the red, Forming an upper first conductive oxide layer on each of the opaque conductive layers of the red, blue, and green pixels, and forming a second conductive oxide layer on the upper first conductive oxide layer of the green pixel, . ≪ / RTI >

The organic light emitting diode display may further include a white pixel that does not display color, and the step of forming the first electrode of the white pixel may be formed together in the step of forming the lower first conductive oxide layer.

The forming of the first electrode may include laminating a lower first conductive oxide layer on the entire surface of the substrate, applying a first photoresist over the lower first conductive oxide layer and patterning the first lower conductive oxide layer to form red, Forming a lower first conductive oxide layer on the red, blue, green, and white pixels, respectively, by photoetching the lower first conductive oxide layer using the first photosensitive pattern; Forming an upper opaque conductive layer and an upper first conductive oxide layer on the entire surface of the substrate including the lower first conductive oxide layer; applying a second photoresist over the upper first conductive oxide layer and patterning the resultant to form red Forming an upper first conductive oxide layer and an opacity degree using the second photosensitive pattern, Forming an upper first conductive oxide layer and an opaque conductive layer on the red, blue, and green pixels, respectively, by photolithographically etching all of the layers; laminating a second conductive oxide layer on the entire surface of the substrate including the opaque conductive layer; Forming a third photosensitive pattern on the green pixel by applying a third photosensitive film on the first conductive oxide layer and patterning the third photosensitive film on the second conductive oxide layer; 2 < / RTI > conductive oxide layer.

The step of forming the light emitting layer includes sequentially laminating a first sub-emissive layer emitting red light, a second sub-emissive layer emitting blue light, and a third sub-emissive layer emitting green light all over the red, blue and green pixels . ≪ / RTI >

The method may further include forming a color filter before forming the first electrode.

By providing a fine resonance structure in the red, green, and blue pixels, light in a narrow wavelength range can be enhanced and light in other wavelength ranges can be suppressed to improve color purity and color reproducibility. Further, by setting the fine resonance length uniquely in the green pixel, the color purity and color reproducibility of the green region can be enhanced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

[Example 1]

An organic light emitting display according to an embodiment of the present invention will now be described in detail with reference to FIG.

1 is an equivalent circuit diagram of an OLED display according to an embodiment of the present invention.

1, the OLED display includes a plurality of signal lines 121, 171, and 172 and a plurality of pixels PX connected to the plurality of signal lines 121, 171, and 172 and arranged in the form of a matrix. do.

The signal line includes a plurality of gate lines 121 for transmitting gate signals (or scanning signals), a plurality of data lines 171 for transmitting data signals, and a plurality of driving voltage lines 172 for transmitting driving voltages. The gate lines 121 extend substantially in the row direction, are substantially parallel to each other, and the data lines 171 and the driving voltage lines 172 extend in a substantially column direction and are substantially parallel to each other.

Each pixel PX includes a switching thin film transistor Qs, a driving thin film transistor Qd, a storage capacitor Cst, and an organic light emitting diode (LD).

The switching thin film transistor Qs has a control terminal, an input terminal and an output terminal. The control terminal is connected to the gate line 121, the input terminal is connected to the data line 171, And is connected to the transistor Qd. The switching thin film transistor Qs transfers a data signal applied to the data line 171 to the driving thin film transistor Qd in response to a scanning signal applied to the gate line 121. [

The driving thin film transistor Qd also has a control terminal, an input terminal and an output terminal. The control terminal is connected to the switching thin film transistor Qs, the input terminal is connected to the driving voltage line 172, It is connected to a light emitting diode (LD). The driving thin film transistor Qd passes an output current I _LD whose magnitude varies according to the voltage applied between the control terminal and the output terminal.

The capacitor Cst is connected between the control terminal and the input terminal of the driving thin film transistor Qd. The capacitor Cst charges the data signal applied to the control terminal of the driving thin film transistor Qd and maintains the data signal even after the switching thin film transistor Qs is turned off.

The organic light emitting diode LD has an anode connected to the output terminal of the driving thin film transistor Qd and a cathode connected to the common voltage Vss. The organic light emitting diode LD emits light with different intensity according to the output current I _LD of the driving thin film transistor Qd to display an image.

The switching thin film transistor Qs and the driving thin film transistor Qd are n-channel field effect transistors (FETs). However, at least one of the switching thin film transistor Qs and the driving thin film transistor Qd may be a p-channel field effect transistor. Also, the connection relationship between the thin film transistors Qs and Qd, the capacitor Cst, and the organic light emitting diode LD can be changed.

The organic light emitting display shown in FIG. 1 will now be described with reference to FIG.

2 is a plan view schematically showing the arrangement of a plurality of pixels in an organic light emitting display according to an embodiment of the present invention.

2, a red pixel R for displaying red, a green pixel G for displaying green, a blue pixel B for displaying blue, and a blue pixel B for displaying blue are arranged in the OLED display according to an embodiment of the present invention. And white pixels W that do not display white are alternately arranged. The red pixel R, the green pixel G and the blue pixel B are basic pixels for expressing full color, and the brightness can be increased by further including the white pixel W.

Four pixels including a red pixel R, a green pixel G, a blue pixel B, and a white pixel W may be repeated in rows and / or columns in a group. However, the arrangement of the pixels can be variously modified.

The red pixel R, the blue pixel B, and the green pixel G include a microcavity structure, and the white pixel W does not include a fine resonance structure.

The detailed structure of the organic light emitting display shown in FIG. 2 will be described with reference to FIG.

3 is a cross-sectional view illustrating a structure of an OLED display according to an exemplary embodiment of the present invention.

A plurality of thin film transistor arrays are arranged on the insulating substrate 110. The thin film transistor array includes a switching thin film transistor Qs and a driving thin film transistor Qd arranged for each pixel, and they are electrically connected.

A lower insulating film 112 is formed on the thin film transistor array. A plurality of contact holes (not shown) are formed in the lower insulating film 112 to expose a part of the switching thin film transistor Qs and the driving thin film transistor Qd.

A red filter 230R for the red pixel R, a green filter 230G for the green pixel G and a blue filter 230B for the blue pixel B are formed on the lower insulating film 112, W may be formed with no color filter or with a transparent white filter (not shown). The color filters 230R, 230G, and 230B may be arranged in a color filter on array (CoA) manner.

An upper insulating layer 180 is formed on the color filters 230R, 230G, and 230B and the lower insulating layer 112. [ A plurality of contact holes (not shown) are formed in the upper insulating film 180.

On the upper insulating film 180, pixel electrodes 191R, 191G, 191B, and 191W are formed. The pixel electrodes 191R, 191G, 191B, and 191W are electrically connected to the driving thin film transistor Qd through a contact hole (not shown) and may serve as an anode.

The pixel electrodes 191R, 191G, 191B, and 191W of the respective pixels have different lamination structures.

The pixel electrode 191R of the red pixel R is a double film including the semitransparent conductive layer 192R and the first transparent conductive layer 193R and the pixel electrode 191B of the blue pixel B is also a double- 192B and a first transparent conductive layer 193B.

The pixel electrode 191G of the green pixel G is a double film including a semitransparent conductive layer 192G and a second transparent conductive layer 193G.

The pixel electrode 191W of the white pixel W is a double film including a first transparent conductive layer 192W and a second transparent conductive layer 193W.

The translucent conductive layers 192R, 192B and 192G formed on the red pixel R, the blue pixel B and the green pixel W are made of a material having a property of transmitting a part of light and reflecting a part of light For example, silver (Ag), aluminum (Al), gold (Au), nickel (Ni), magnesium (Mg), and alloys thereof may be formed to a thickness of about 100 to 400 Å. The semitransparent conductive layers 192R, 192B and 192G form a fine resonance structure with the common electrode 270, which will be described later.

The first transparent conductive layers 193R, 193B and 192W and the second transparent conductive layers 193G and 193W may be made of a transparent conductive oxide such as ITO, IZO and ZnO, 192W and the second transparent conductive layers 193G and 193W must have different etch ratios. For example, when the first transparent conductive layers 193R, 193B, and 192W are made of crystalline ITO, the second transparent conductive layers 193G and 193W may be formed of IZO or ZnO or ITO in an amorphous state. The thicknesses of the first transparent conductive layers 193R, 193B and 192W and the second transparent conductive layers 193G and 193W may be about 100 to 500 ANGSTROM and about 400 to 1000 ANGSTROM respectively and the second transparent conductive layers 193G and 193W And is thicker than the first transparent conductive layers 193R and 193B.

A plurality of insulating members 361 for defining each pixel are formed on the pixel electrodes 191R, 191B, 191G and 191W. On the insulating members 361 and the pixel electrodes 191R, 191B, 191G and 191W An organic light emitting member is formed.

The organic light emitting member may include an organic light emitting layer 370 for emitting light and a sub layer (not shown) for improving the light emitting efficiency of the organic light emitting layer 370.

The organic light emitting layer 370 may include a plurality of sub-light emitting layers (not shown) by sequentially laminating a material that uniquely emits light such as red, green, and blue, and emit white light by combining these colors. At this time, the sub-emission layer may be formed not only vertically but also horizontally, and it may be formed of a combination of various colors instead of red, green and blue as long as it can emit white light.

The sub-layer may be at least one selected from an electron transporting layer, a hole transporting layer, an electron injecting layer, and a hole injecting layer.

A common electrode 270 is formed on the organic light emitting member. The common electrode 270 can be made of a metal having high reflectance and serves as a cathode. The common electrode 270 is formed on the entire surface of the substrate and paired with the pixel electrodes 191R, 191B, 191G, and 191W serving as an anode to flow current to the organic light emitting layer 370. [

 As described above, in the embodiment of the present invention, the semitransparent conductive layers 192R, 192B, and 192G are included in the red pixel R, the blue pixel B, and the green pixel W, .

A fine resonance structure is a structure in which light is repeatedly reflected between a reflective layer and a semi-transparent layer that are separated by an optical length, thereby amplifying light of a specific wavelength by constructive interference. Here, the common electrode 270 serves as a reflective layer and the semitransparent conductive layers 192R, 192B and 192G serve as a translucent layer.

The common electrode 270 greatly improves the luminescence characteristics emitted from the organic light emitting layer 370 and light in the vicinity of the wavelength corresponding to the resonance wavelength of the fine resonance among the modified light is transmitted through the translucent conductive layers 192R, 192B and 192G And light of other wavelengths is suppressed.

Since the optical path length is a distance between the common electrode 270 and the semitransparent conductive layers 192R, 192B, and 192G, the optical path length of each pixel is determined by the light emitting layer 370 And the thickness of the pixel electrodes 191R, 191G, and 191B. Since the light emitting layer 370 is formed on the entire surface of the substrate under the same deposition condition, the semitransparent conductive layers 192R, 192B and 192G are also formed on the red pixel R, the green pixel G and the blue pixel B ) Under the same deposition condition and the same photolithography condition, it can be assumed that the thickness is constant for each pixel. Therefore, the optical path length can be adjusted to the thicknesses of the first transparent conductive layers 193R, 193B and the second transparent conductive layer 193G of the pixel electrodes 191R, 191G, 191B.

The red pixel R and the blue pixel B have first transparent conductive layers 193R and 193B of about 100 to 500 ANGSTROM on the semitransparent conductive layers 192R and 192B, Since the second transparent conductive layer 193G is thicker than the first transparent conductive layers 193R and 193B with the second transparent conductive layer 193G on the conductive layer 192G of about 400 to 1000 angstroms, The optical path length can be made larger.

This will be described with reference to FIG. 22 and FIG.

FIG. 22 is a graph showing the emission spectrum of the organic light emitting display according to an embodiment of the present invention, and FIG. 23 is a color coordinate showing the color reproducibility of the organic light emitting display according to an embodiment of the present invention.

Referring to FIG. 22, the white light emitted from the light emitting layer 370 has peaks at about 460 nm (blue region), about 530 nm (green region), and about 610 nm (red region) The emission spectrum is shown. Among these, the spectrum of the green region spans a wide wavelength range and overlaps with the spectrum of the long wavelength side of the blue region, and its boundary is unclear. The emission spectrum of the green region is also remarkably low.

When the white light passes through the color filter CF, the green emission spectrum is transmitted through the emission spectrum of the long wavelength side of blue, and the color purity of green is greatly lowered (see 'Green (CF)'). In addition, it can be seen that the color purity of the blue light emission spectrum (Blue (CF)) passing through the blue filter and the red emission spectrum (Red (CF)) passing through the red filter are lower than that of the white light (White). This is because, when the color purity is 100% in each wavelength region of white light, the color filter has a lower color purity, so that the light passing through the color filter has a color reproducibility equal to or lower than that of the color filter .

In this embodiment, a fine resonance structure is provided for the red pixel R, the blue pixel B and the green pixel G so as to have a high color reproducibility beyond the limit of the color filter itself, It is possible to amplify light in a green wavelength range, especially in a weak peak of the white light emission spectrum, by uniquely setting the fine resonance length of the white light emission spectrum uniquely different from that of the red pixel R and the blue pixel B.

Referring to FIG. 22, a red region (μCavity Red), a green region (μCavity Red), and a green region (μCavity) are formed in a structure including a fine resonance structure in each of a red pixel R, a blue pixel B, and a green pixel G according to an embodiment of the present invention. Green) and blue (μCavity Blue), respectively, in a narrow wavelength range. Having a peak in such a narrow wavelength range means that the color purity and color reproducibility have been improved, and the higher light emission intensity means that the light efficiency is improved.

In particular, the green emission spectrum in the narrow wavelength range is set to a unique fine resonance length corresponding to the green wavelength region unlike the red region and the blue region, so that the light in the narrow wavelength region of about 520 to 550 nm is strengthened and the light in the other wavelength region is suppressed . Since the green emission spectrum does not overlap with the longer wavelength side of the blue emission spectrum, the color purity and color reproducibility of green can be improved.

23, when the NTSC region is assumed to have a color reproducibility of 100%, a structure in which fine resonance is formed in the red pixel R, the green pixel G and the blue pixel B has a high color reproducibility of about 108.5% . It can be seen that the color reproducibility is remarkably improved as compared with the case where the structure including only the white light emission (Normal White) and the color filter (CF) has the color reproducibility of about 72% without forming the fine resonance.

On the other hand, the first transparent conductive layer 192W and the second transparent conductive layer 193W are sequentially stacked on the white pixel W, so that light emitted from the light emitting layer can pass through without any fine resonance structure.

A method of manufacturing the OLED display of FIG. 3 will now be described with reference to FIGS. 4 to 13. FIG.

FIGS. 4 to 13 are cross-sectional views sequentially illustrating a method of manufacturing the organic light emitting diode display of FIG. 3 according to an embodiment of the present invention.

Referring to FIG. 4, a plurality of switching thin film transistors Qs and a plurality of driving thin film transistors Qd are formed on an insulating substrate 110. Here, the switching thin film transistor Qs and the driving thin film transistor Qd include a step of laminating and patterning the conductive layer, the insulating layer and the semiconductor layer.

Referring to FIG. 5, a lower insulating film 112 is laminated on the switching thin film transistor Qs and the driving thin film transistor Qd and patterned to form a plurality of contact holes (not shown).

Subsequently, a plurality of color filters 230R, 230G, and 230B are formed on the lower insulating film 112. [

6, an upper insulating layer 180 is formed on the lower insulating layer 112 and the color filters 230R, 230G, and 230B and patterned to form a plurality of contact holes (not shown).

Referring to FIG. 7, a lower conductive layer 190p is formed on the upper insulating layer 180. Referring to FIG. The lower conductive layer 190p may be formed of Ag, Al, Au, Ni, Mg, or an alloy thereof to a thickness of about 100 to 400 Å .

A first photosensitive pattern 40a is formed on the red pixel R, the green pixel G and the blue pixel B by applying and patterning a first photosensitive film (not shown) on the lower conductive layer 190p .

Next, referring to FIGS. 7 and 8, the red, green and blue pixels R, G and B are formed by photolithography the lower conductive layer 190p using the first photosensitive pattern 40a, Conductive layers 192R, 192G, and 192B are formed.

Next, referring to FIG. 9, an intermediate conductive layer 190q is stacked on the semi-transparent conductive layers 192R, 192G, and 192B and the upper insulating layer 180. FIG. The intermediate conductive layer 190q is formed by depositing ITO at about 200 to 400 degrees.

Next, a second photoresist pattern (not shown) is applied on the intermediate conductive layer 190q and patterned to form a second photoresist pattern 50a on the red pixel R, the blue pixel B, and the white pixel W.

Next, referring to FIGS. 9 and 10, the intermediate conductive layer 190q is photo-etched by using the second photosensitive pattern 50a to form red, green, and blue pixels R, 1 transparent conductive layers 193R, 193B, and 192W are formed.

The semitransparent conductive layer 192R of the red pixel R and the first transparent conductive layer 193R form the pixel electrode 191R of the red pixel R and the semitransparent conductive layer 192B of the blue pixel B and the semi- The first transparent conductive layer 193B forms the pixel electrode 191B of the blue pixel B.

11, the upper conductive layer 190r is laminated on the first transparent conductive layers 193R, 193B, and 192W, the semi-transparent conductive layer 192G, and the upper insulating layer 180. Next, The upper conductive layer 190r may be formed by depositing ITO at a relatively low temperature of about 20 to 150 degrees to form amorphous ITO, or by depositing IZO. The upper conductive layer 190r is formed thicker than the intermediate conductive layer 190q.

A third photoresist pattern 60a is formed on the green pixel G and the white pixel W by applying and patterning a third photoresist layer (not shown) on the upper conductive layer 190r.

Next, referring to FIGS. 11 and 12, a second transparent conductive layer 193G is formed on the green pixel G and the white pixel W by photoetching the upper conductive layer 190r using the third photosensitive pattern 60a, , 193W).

At this time, the upper conductive layer 190r is made of ITO or IZO in an amorphous state and the first transparent conductive layers 193R and 193B are made of ITO in a crystalline state, so that the etch ratios thereof are different. Therefore, in the step of etching the upper conductive layer 190r, the first transparent conductive layers 193R and 193B located below the upper conductive layer 190r are not affected.

The semitransparent conductive layer 191G and the second transparent conductive layer 193G of the green pixel G constitute the pixel electrode 191G of the green pixel G and the first transparent conductive layer 192W of the white pixel W, And the second transparent conductive layer 193W constitute the pixel electrode 191W of the white pixel W. [

Next, referring to FIG. 13, an insulating film is coated on the pixel electrodes 191R, 191G, 191B, and 191W and the upper insulating film 180 and patterned to form a plurality of insulating members 191R, 191G, 191B, and 191W positioned between the pixel electrodes 191R, (361).

Next, a light emitting layer 370 is formed by sequentially laminating a red light emitting layer (not shown), a blue light emitting layer (not shown) and a green light emitting layer (not shown) on the entire surface of the substrate.

Next, a common electrode 270 is formed on the light emitting layer 370.

Thus, in order to form the transparent conductive layer as a pixel electrode in each pixel and to form the transparent conductive layer of the green pixel and the transparent conductive layer of the red and blue pixels differently, the first transparent conductive layer and the second transparent conductive layer And the first transparent conductive layers 193R and 193B and the second transparent conductive layer 193G are made of materials having different etching ratios, thereby simplifying the process without additional processes and masks.

[Example 2]

Hereinafter, another embodiment of the present invention will be described in detail with reference to FIG. 14 with reference to FIG. 1 and FIG.

FIG. 14 is a cross-sectional view illustrating a structure of an organic light emitting display according to another embodiment of the present invention. Referring to FIG.

The same explanations as those of the above embodiments are omitted and the same constituent elements are given the same reference numerals.

A plurality of thin film transistor arrays including the switching thin film transistor Qs and the driving thin film transistor Qd arranged for each pixel are arranged on an insulating substrate 110. [

A red filter 230R is formed on the red pixel, a green filter 230G is formed on the green pixel, and a blue filter 230B is formed on the blue pixel on the lower insulating layer 112 And the white pixel W may have no color filter formed thereon or a transparent white filter (not shown) may be formed. An upper insulating layer 180 is formed on the color filters 230R, 230G, and 230B and the lower insulating layer 112. [

On the upper insulating film 180, pixel electrodes 191R, 191G, 191B, and 191W are formed.

In this embodiment, the pixel electrodes 191R, 191G, 191B, and 191W have different lamination structures from pixel to pixel. However, the laminated structure is different from the above-described embodiment.

The pixel electrode 191R of the red pixel R is a triple film including a lower first transparent conductive layer 194R, a semi-transparent conductive layer 195R, and an upper first transparent conductive layer 196R.

The pixel electrode 191B of the blue pixel B is also a triple film including the lower first transparent conductive layer 194B, the semi-transparent conductive layer 195B and the upper first transparent conductive layer 196B.

The pixel electrode 191G of the green pixel G includes the lower first transparent conductive layer 194G, the semi-transparent conductive layer 195G, the upper first transparent conductive layer 196G, and the second transparent conductive layer 197G It is the midgut.

The pixel electrode 191W of the white pixel W is a single film including a transparent conductive layer.

The semi-transparent conductive layers 195R, 195B, and 195G formed on the red pixel R, the blue pixel B, and the green pixel W form a fine resonance structure with the common electrode 270. [

The lower first transparent conductive layers 194R, 194B and 194G, the upper first transparent conductive layers 196R, 196B and 196G formed in the red pixel R, the blue pixel B and the white pixel W, The pixel electrode 191W of the pixel W may be a conductive oxide such as ITO, IZO, and ZnO, and may have a thickness of about 500 to 1500 ANGSTROM.

The second transparent conductive layer 197G formed on the green pixel G may be a conductive oxide such as ITO, IZO, or ZnO, but the first transparent conductive layer 194R, the first transparent conductive layer 194G, The layers 196R, 196B, and 196G and the pixel electrode 191W of the white pixel W must have different etching ratios. When the pixel electrode 191W of the lower first transparent conductive layer 194R, 194B, 194G, the upper first transparent conductive layer 196R, 196B, 196G and the white pixel W is crystalline ITO, (193G, 193W) may be formed from IZO or ZnO or amorphous ITO. The thickness of the second transparent conductive layer 197G may be about 200 to 500 ANGSTROM.

A plurality of insulating members 361 are formed on the pixel electrodes 191R, 191B, 191G and 191W and an organic light emitting layer 370 is formed on the plurality of insulating members 361 and the pixel electrodes 191R, 191B, 191G and 191W Emitting element is formed. A common electrode 270 is formed on the organic light emitting member.

 This embodiment also includes the semitransparent conductive layers 195R, 195B, and 195G in the red pixel R, the blue pixel B, and the green pixel G, respectively, as in the above- Thereby forming a resonant structure.

The green pixel G may include the lower first transparent conductive layer 194G and the upper first transparent conductive layer 196G in the same manner as the red pixel R and the blue pixel B, The second transparent conductive layer 197G may be further different from the red pixel R and the blue pixel B so that the optical path length can be set differently.

A method of manufacturing the OLED display of FIG. 14 will now be described with reference to FIGS. 15 to 21. FIG.

15 to 21 are sectional views sequentially showing a method of manufacturing the organic light emitting diode display of FIG. 14 according to another embodiment of the present invention.

15, a plurality of switching thin film transistors Qs and a plurality of driving thin film transistors Qd are formed on an insulating substrate 110, and a lower insulating film 112, a plurality of Color filters 230R, 230G, and 230B, and an upper insulating film 180 are sequentially formed.

Then, a lower conductive layer 190s is stacked on the upper insulating layer 180. Next, The lower conductive layer 190s is formed by depositing ITO at about 200 to 400 degrees. The lower conductive layer 190s is formed to a thickness of about 500 to 1500 ANGSTROM.

A first photosensitive pattern (not shown) is applied on the lower conductive layer 190s and patterned to form a first photosensitive pattern (not shown) on the red pixel R, the green pixel G, the blue pixel B and the white pixel W 70a.

Next, referring to FIGS. 15 and 16, the lower conductive layer 190s is etched by using the first photosensitive pattern 70a to form the red (R), green (G) and blue The first transparent conductive layers 194R, 194G, and 194B and the pixel electrode 191W of the white pixel W are formed.

17, an intermediate conductive layer 190t and an upper conductive layer 190u are sequentially stacked on the lower first transparent conductive layers 194R, 194G, and 194B, the pixel electrode 191W, and the upper insulating layer 180 . The intermediate conductive layer 190t may be formed to have a thickness of about 100 to 400 angstroms such as silver (Ag), aluminum (Al), gold (Au), nickel (Ni), magnesium (Mg) And the upper conductive layer 190u may be formed by depositing ITO at about 200 to 400 degrees.

A second photosensitive pattern 80a is formed on the red pixel R, the blue pixel B and the green pixel G by applying and patterning a second photoresist layer (not shown) on the upper conductive layer 190u.

Next, referring to FIGS. 17 and 18, the red photoresist R, the blue photoresist B, and the black photoresist B are formed by successively photo-etching the upper conductive layer 190u and the intermediate conductive layer 190t using the second photosensitive pattern 80a. The semi-transparent conductive layers 195R, 195B, and 195G and the first upper transparent conductive layers 196R, 196B, and 196G are formed in the green pixel G, respectively.

The lower first transparent conductive layer 194R, the semi-transparent conductive layer 195R and the upper first transparent conductive layer 196R of the red pixel R constitute the pixel electrode 191R of the red pixel R, The lower first transparent conductive layer 194B, the semi-transparent conductive layer 195B and the upper first transparent conductive layer 196B of the blue pixel B constitute the pixel electrode 191B of the blue pixel B. [

19, the uppermost conductive layer 190v is stacked on the upper first transparent conductive layers 196R, 196B, and 196G, the pixel electrode 191W of the white pixel W, and the upper insulating layer 180. Referring to FIG. The uppermost conductive layer 190v may be formed by depositing ITO at a relatively low temperature of about 20 to 150 degrees to form amorphous ITO, or by depositing IZO.

Next, a third photoresist pattern (not shown) is coated on the uppermost conductive layer 190v and patterned to form a third photoresist pattern 90a on the green pixel G.

19 and 20, a second transparent conductive layer 197G is formed on the green pixel G by photoetching the upper conductive layer 190r using the third photosensitive pattern 90a.

The lower first transparent conductive layer 194G, the semi-transparent conductive layer 195G, the upper first transparent conductive layer 196G and the second transparent conductive layer 197G of the green pixel G are electrically connected to the pixel electrode (191G).

Next, referring to FIG. 21, an insulating film is applied and patterned on the pixel electrodes 191R, 191G, 191B, and 191W and the upper insulating film 180 to form a plurality of insulating members 191R, 191G, 191B, and 191W positioned between the pixel electrodes 191R, (361).

Next, a light emitting layer 370 is formed by sequentially laminating a red light emitting layer (not shown), a blue light emitting layer (not shown) and a green light emitting layer (not shown) on the entire surface of the substrate.

Next, a common electrode 270 is formed on the light emitting layer 370.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

1 is an equivalent circuit diagram of an OLED display according to an embodiment of the present invention,

2 is a plan view schematically showing the arrangement of a plurality of pixels in an organic light emitting display according to an embodiment of the present invention,

3 is a cross-sectional view illustrating a structure of an OLED display device according to an exemplary embodiment of the present invention,

FIGS. 4 to 13 are cross-sectional views sequentially illustrating a method of manufacturing the OLED display of FIG. 3 according to an embodiment of the present invention,

14 is a cross-sectional view illustrating a structure of an OLED display device according to another embodiment of the present invention,

15 to 21 are sectional views sequentially showing a method of manufacturing the organic light emitting diode display of FIG. 14 according to an embodiment of the present invention,

 22 is a graph showing an emission spectrum of an organic light emitting display according to an embodiment of the present invention,

23 is a color coordinate showing the color reproducibility of the OLED display according to an embodiment of the present invention.

Claims (27)

In an OLED display device including a first pixel, a second pixel, and a third pixel that display different colors, Each of the pixels The first electrode, A second electrode facing the first electrode, and A light emitting layer disposed between the first electrode and the second electrode, / RTI > The first electrode of the first and second pixels A first conductive oxide layer, and A semi-transparent conductive layer formed on at least one of a lower portion and an upper portion of the first conductive oxide layer and forming a fine resonance with the second electrode, / RTI > The first electrode of the third pixel A second conductive oxide layer different from the first conductive oxide layer, and A semi-transparent conductive layer formed on at least one of a lower portion and an upper portion of the second conductive oxide layer and forming a fine resonance with the second electrode, / RTI > Wherein the second conductive oxide layer is made of a material having an etching rate different from that of the first conductive oxide layer and is formed thicker than the first conductive oxide layer Organic light emitting display. The method of claim 1, Wherein the first pixel is a red pixel, the second pixel is a blue pixel, and the third pixel is a green pixel. 3. The method of claim 2, The light- And a plurality of sub-emission layers for emitting light of different wavelengths, The lights of different wavelengths are combined to emit white light Organic light emitting display. 4. The method of claim 3, Wherein the first pixel, the second pixel, and the third pixel each further include a color filter formed under the first electrode. 5. The method of claim 4, The first electrode of the first and second pixels The semitransparent conductive layer, and Wherein the first conductive oxide layer formed on the translucent conductive layer / RTI > The first electrode of the third pixel The semitransparent conductive layer, and The second conductive oxide layer formed on the translucent conductive layer, / RTI > Organic light emitting display. The method of claim 5, Wherein one of the first conductive oxide layer and the second conductive oxide layer includes crystalline ITO and the other includes ITO formed from IZO or an amorphous state. The method of claim 6, Further comprising a white pixel which does not display a color, The white pixel The first electrode, A second electrode facing the first electrode, and A light emitting layer disposed between the first electrode and the second electrode, / RTI > Wherein the first electrode of the white pixel includes the first conductive oxide layer and the second conductive oxide layer. 8. The method of claim 7, Wherein a sum of thicknesses of the first conductive oxide layer and the second conductive oxide layer is 500 to 1500 ANGSTROM. 9. The method of claim 8, Wherein the semitransparent conductive layer has a thickness of 100 to 400 ANGSTROM. 5. The method of claim 4, The first conductive oxide layer A lower first conductive oxide layer located below the semi-transparent conductive layer, and An upper first conductive oxide layer positioned above the semi- And an organic light emitting diode. 11. The method of claim 10, The first electrode of the first and second pixels The lower first conductive oxide layer, The semi-transparent conductive layer formed on the lower first conductive oxide layer, and The upper first conductive oxide layer < RTI ID = 0.0 > / RTI > The first electrode of the third pixel The lower first conductive oxide layer, The semi-transparent conductive layer formed on the lower first conductive oxide layer, An upper first conductive oxide layer formed on the semi-transparent conductive layer, and The second conductive oxide layer formed on the upper first conductive oxide layer, And an organic light emitting diode. 12. The method of claim 11, Wherein the lower first conductive oxide layer and the upper first conductive oxide layer comprise ITO and the second conductive oxide layer is formed from IZO or amorphous ITO. The method of claim 12, Further comprising a white pixel which does not display a color, The white pixel The first electrode, A second electrode facing the first electrode, and A light emitting layer disposed between the first electrode and the second electrode, / RTI > Wherein the first electrode of the white pixel includes the lower first conductive oxide layer. The method of claim 13, Wherein the thickness of the lower first conductive oxide layer is 500 to 1500 ANGSTROM. A method of manufacturing an organic light emitting display device including a red pixel, a blue pixel, and a green pixel, Forming a first electrode, Forming a light emitting layer on the first electrode, and Forming a second electrode on the light emitting layer Lt; / RTI > The step of forming the first electrode Forming a semitransparent conductive layer on each of the red, blue and green pixels, Forming a first conductive oxide layer on at least some of the red, blue, and green pixels, and Forming a second conductive oxide layer on the green pixel Lt; / RTI > Wherein the second conductive oxide layer is made of a material having a different etch ratio from the first conductive oxide layer and is thicker than the first conductive oxide layer. 16. The method of claim 15, The step of forming the first electrode Forming a semitransparent conductive layer on each of the red, blue and green pixels, Forming a first conductive oxide layer on each of the semitransparent conductive layers of the red and blue pixels, and Forming a second conductive oxide layer on the semitransparent conductive layer of the green pixel / RTI > A method of manufacturing an organic light emitting display device. 17. The method of claim 16, Further comprising a white pixel which does not display a color, Wherein forming the first electrode of the white pixel comprises: Forming the first conductive oxide layer, and A step of forming the second conductive oxide layer on the first conductive oxide layer Wherein the organic light emitting display device further comprises: The method of claim 17, The step of forming the first electrode Laminating a semitransparent conductive layer on the entire surface of the substrate, Applying and patterning a first photoresist over the semitransparent conductive layer to form a first photoresist pattern on the red, blue, and green pixels, respectively; Forming a semitransparent conductive layer on the red, blue, and green pixels, respectively, by photo-etching the semitransparent conductive layer using the first photosensitive pattern; Laminating a first conductive oxide layer on the entire surface of the substrate including the semi-transparent conductive layer, Forming a second photosensitive pattern on the red, blue, and white pixels, respectively, by applying and patterning a second photosensitive film on the first conductive oxide layer; Forming a first conductive oxide layer on the red, blue, and white pixels, respectively, by photoetching the first conductive oxide layer using the second photosensitive pattern; Stacking a second conductive oxide layer on the entire surface of the substrate including the first conductive oxide layer, Forming a third photosensitive pattern on the green and white pixels, respectively, by applying and patterning a third photosensitive film on the second conductive oxide layer; and Forming a second conductive oxide layer on the green and white pixels by photo-etching the second conductive oxide layer using the third photosensitive pattern, Wherein the organic light emitting display device further comprises: The method of claim 18, Wherein one of the first conductive oxide layer and the second conductive oxide layer includes crystalline ITO and the other includes IZO or amorphous ITO. 16. The method of claim 15, The step of forming the first conductive oxide layer Forming a lower first conductive oxide layer below the semi-transparent conductive layer, and Forming an upper first conductive oxide layer on the semi-transparent conductive layer Wherein the organic light emitting display device further comprises: 20. The method of claim 20, The step of forming the first electrode Forming a lower first conductive oxide layer on the red, blue, and green pixels, respectively; Forming a semitransparent conductive layer on the lower first conductive oxide layer of each of the red, blue and green pixels, Forming an upper first conductive oxide layer on each of the semitransparent conductive layers of the red, blue, and green pixels, and Forming a second conductive oxide layer on the upper first conductive oxide layer of the green pixel Wherein the organic light emitting display device further comprises: 22. The method of claim 21, Further comprising a white pixel which does not display a color, Wherein forming the first electrode of the white pixel comprises: And forming the lower first conductive oxide layer together A method of manufacturing an organic light emitting display device. The method of claim 22, The step of forming the first electrode Stacking a lower first conductive oxide layer on the entire surface of the substrate, Forming a first photosensitive pattern on the red, blue, green, and white pixels, respectively, by applying and patterning a first photosensitive film on the lower first conductive oxide layer, Forming a lower first conductive oxide layer on the red, blue, green, and white pixels, respectively, by photoetching the lower first conductive oxide layer using the first photosensitive pattern; Laminating a semi-transparent conductive layer and an upper first conductive oxide layer on the entire surface of the substrate including the lower first conductive oxide layer, Applying and patterning a second photoresist over the upper first conductive oxide layer to form a second photoresist pattern on the red, green, and blue pixels, respectively; Forming an upper first conductive oxide layer and a semitransparent conductive layer on the red, blue, and green pixels, respectively, by sequentially photo-etching the upper first conductive oxide layer and the semitransparent conductive layer using the second photosensitive pattern, Laminating a second conductive oxide layer on the entire surface of the substrate including the semi-transparent conductive layer, Applying and patterning a third photosensitive film on the second conductive oxide layer to form a third photosensitive pattern on the green pixel, Forming a second conductive oxide layer on the green pixel by photo-etching the second conductive oxide layer using the third photosensitive pattern; Wherein the organic light emitting display device further comprises: 16. The method of claim 15, The step of forming the light emitting layer Luminescent layer for emitting blue light, and a third sub-emissive layer for emitting green light are sequentially stacked over the red, blue and green pixels, ≪ / RTI > 25. The method of claim 24, Further comprising forming a color filter before forming the first electrode. The method according to claim 1, Wherein a distance between the semitransparent conductive layer of the first and second pixels and the second electrode is closer to a distance between the semitransparent conductive layer and the second electrode of the third pixel, Organic light emitting display. 16. The method of claim 15, Wherein a distance between the semitransparent conductive layer and the second electrode of the red and blue pixels is less than a distance between the semitransparent conductive layer and the second electrode of the green pixel, A method of manufacturing an organic light emitting display device.

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