KR20080032787A - Organic light emitting diode display - Google Patents

Abstract

An organic light emitting diode display is provided to obtain desired white light by selectively emitting blue light from the white light radiated from a light emitting layer to improve blue color purity. An organic light emitting diode display includes a red pixel, a green pixel, a blue pixel(B), and a white pixel(W). Each of the pixels has a first electrode, a second electrode, and a light emitting member. The second electrode is opposite to the first electrode. The light emitting member is arranged between the first and second electrodes. The white pixel has semi-transparent members(192) on a top or a bottom of the first electrode to form a microcavity with the second electrode.

Description

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

1 is an equivalent circuit diagram of an organic light emitting diode display according to an exemplary embodiment of the present invention.

2 is a schematic diagram illustrating an arrangement of a plurality of pixels in an organic light emitting diode display according to an exemplary embodiment of the present invention.

3 is a layout view illustrating two neighboring pixels in the OLED display of FIG. 2.

4 and 5 are cross-sectional views of the organic light emitting diode display of FIG. 3 taken along lines IV-IV'-IV "-IV" 'and V-V.

6 is a schematic diagram illustrating an example of a shape of a translucent member formed in the white pixel W;

7 to 11 are cross-sectional views sequentially illustrating a method of manufacturing an organic light emitting diode display according to an exemplary embodiment of the present invention.

12, 14, 16, 19, and 22 are layout views sequentially illustrating a method of manufacturing an OLED display according to an exemplary embodiment.

FIG. 13 is a cross-sectional view of the organic light emitting diode display of FIG. 12 taken along the line XIII-XIII′-XIII ″.

FIG. 15 is a cross-sectional view of the organic light emitting diode display of FIG. 14 taken along the line XV-XV′-XV ″. FIG.

17 and 18 are cross-sectional views of the organic light emitting diode display of FIG. 16 taken along lines XVII-XVII'-XVII "-XVII" 'and XVIII-XVIII.

20 and 21 are cross-sectional views of the organic light emitting diode display of FIG. 19 taken along the lines XX-XX'-XX "-XX" 'and XXI-XXI.

23 and 24 are cross-sectional views of the organic light emitting diode display of FIG. 22 taken along lines XXIII-XXIII'-XXIII "-XXIII" 'and XXIV-XXIV.

25 is a layout view of an organic light emitting diode display according to another exemplary embodiment.

FIG. 26 is a cross-sectional view of the organic light emitting diode display of FIG. 25 taken along the line XXVI-XXVI.

<Description of Drawing>

110: insulating substrate 121: gate line

124a: switching control electrode 124b: drive control electrode

129: end of gate line

140: gate insulating film 154a: switching semiconductor

154b: driving semiconductors 163a, 163b, 165a, and 165b: ohmic contacts

171: data line 172: driving voltage line

173a: switching input electrode 173b: drive input electrode

175a: switching output electrode 175b: driving output electrode

179: end of data line 81, 82: contact auxiliary member

85: connecting member

181, 182, 184, 185a, 185b: contact hole

191: pixel electrode 192, 193: translucent member

270: common electrode 361: insulating weir

365: opening 370: light emitting layer

Qs: switching thin film transistor Qd: driving thin film transistor

LD: organic light emitting diamond Vss: common voltage

Cst: retaining capacitor

The present invention relates to an organic light emitting display device.

Recently, there is a demand for weight reduction and thinning of a monitor or a television, and according to such a demand, a cathode ray tube (CRT) has been replaced by a liquid crystal display (LCD).

However, the liquid crystal display device requires not only a separate backlight as a light emitting device, but also has many problems in response speed and viewing angle.

Recently, as a display device capable of overcoming such a problem, an organic light emitting diode display (OLED display) has attracted attention.

The organic light emitting diode display includes two electrodes and a light emitting layer interposed therebetween, and electrons injected from one electrode and holes injected from another electrode are combined in the light emitting layer to form excitons. The excitons emit light while releasing energy.

The OLED display is self-luminous and does not require a separate light source, which is advantageous in terms of power consumption, and also has excellent response speed, viewing angle, and contrast ratio.

The organic light emitting diode display may include a plurality of pixels, such as a red pixel, a blue pixel, and a green pixel, and may combine these pixels to display full color.

However, the organic light emitting diode display has different luminous efficiency depending on the light emitting material. In this case, a material having low luminous efficiency among red, green, and blue cannot produce a color having a desired color coordinate, and white luminous efficiency is lowered due to a lower luminous efficiency even in the case of white light emission of a combination of red, green, and blue. .

Accordingly, an object of the present invention is to solve this problem, and to improve color characteristics of the organic light emitting diode display.

An organic light emitting diode display according to an exemplary embodiment of the present invention includes a red pixel, a green pixel, a blue pixel, and a white pixel, each pixel including a first electrode, a second electrode facing the first electrode, and the first electrode. And a light emitting member positioned between the electrode and the second electrode, wherein the white pixel is formed under or over the first electrode and forms a first translucent member forming microcavity with the second electrode. Include.

The first translucent member may include at least one selected from silver (Ag) or aluminum (Al).

The light emitting member may include a plurality of light emitting layers emitting light having different wavelengths, and the light having different wavelengths may be combined to emit white light.

The white light emission may be yellowish white.

The first translucent member may be formed only in a part of a region through which the white light passes.

The red pixel, the green pixel, and the blue pixel may further include a color filter formed under the first electrode.

Pixels having the lowest luminous efficiency among the red pixel, the green pixel, and the blue pixel may further include a second translucent member formed below or above the first electrode and forming a fine resonance with the second electrode. have.

The pixel having the lowest luminous efficiency may be a blue pixel.

The second translucent member may include at least one selected from silver (Ag) or aluminum (Al).

The second translucent member may be formed in all regions through which the white light passes.

The red pixel and the green pixel may further include a color filter formed under the first electrode.

The display device may further include a driving thin film transistor connected to the first electrode and including a polycrystalline semiconductor, and a switching thin film transistor connected to the driving thin film transistor and including an amorphous semiconductor.

The driving thin film transistor further includes a driving input electrode formed on the polycrystalline semiconductor, a driving output electrode facing the driving input electrode on the polycrystalline semiconductor, and a driving control electrode formed on the driving input electrode and the driving output electrode. It may include.

The switching thin film transistor includes a switching control electrode formed under the amorphous semiconductor, a switching input electrode formed on the amorphous semiconductor, and a switching output facing the switching input electrode on the amorphous semiconductor and connected to the driving control electrode. It may further include an electrode.

In another exemplary embodiment, an organic light emitting diode display includes a plurality of pixels, wherein each pixel includes a switching thin film transistor, a driving thin film transistor connected to the switching thin film transistor, and the driving thin film transistor. And a first electrode connected to the first electrode, a light emitting member formed on the first electrode, and emitting white light, and a second electrode formed on the light emitting member, wherein the plurality of pixels pass through the white light. A first pixel group in which a translucent member for forming fine resonance with the first electrode or the second electrode is formed in a region, and a second pixel group in which a color filter is formed in a region through which the white light passes. .

The white light may be yellowish white.

The first pixel group may include white pixels.

The translucent member may be formed in part of a region through which the white light passes.

The first pixel group may include a blue pixel.

The second pixel group may include at least one of a red pixel and a green pixel.

 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the other part being "right over" but also another part in the middle. On the contrary, when a part is "just above" another part, there is no other part in the middle.

First, an organic light emitting diode display according to an exemplary embodiment of the present invention will be described in detail with reference to FIG. 1.

1 is an equivalent circuit diagram of an organic light emitting diode display according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the organic light emitting diode display according to the present exemplary embodiment 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 a substantially matrix form. ).

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

The switching thin film transistor Qs has a control terminal, an input terminal, and an output terminal, and the control terminal is connected to the gate line 121, and the input terminal is a data line ( The output terminal is connected to the driving thin film transistor Qd. The switching thin film transistor Qs transmits a data signal applied to the data line 171 to the driving thin film transistor Qd in response to a scan 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, and the output terminal is organic. It is connected to the light emitting diode LD. The driving thin film transistor Qd flows an output current I _LD whose magnitude varies depending on 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 a data signal applied to the control terminal of the driving thin film transistor Qd and maintains it 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 displays an image by emitting light having a different intensity depending on the output current I _LD of the driving thin film transistor Qd.

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. In addition, the connection relationship between the thin film transistors Qs and Qd, the capacitor Cst, and the organic light emitting diode LD may be changed.

 Next, the detailed structure of the organic light emitting diode display illustrated in FIG. 1 will be described in detail with reference to FIGS. 2 to 5.

2 is a schematic diagram illustrating an arrangement of a plurality of pixels in an organic light emitting diode display according to an exemplary embodiment of the present invention, and FIG. 3 is a layout view illustrating two neighboring pixels in the organic light emitting diode display of FIG. 2. 5 is a cross-sectional view of the organic light emitting diode display of FIG. 3 taken along a line IV-IV'-IV "-IV" 'and a line VV.

First, referring to FIG. 2, an organic light emitting diode display according to an exemplary embodiment includes a red pixel R displaying red, a green pixel G displaying green, a blue pixel B displaying blue, and the like. White pixels W which do not display colors are alternately arranged. For example, 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 may be variously modified.

As described above, the luminance may be improved by further including the white pixel W in addition to the red pixel R, the green pixel G, and the blue pixel B.

Next, a detailed structure of the organic light emitting diode display will be described in detail with reference to FIGS. 3 to 5.

In FIG. 3, only the white pixels W and the blue pixels B shown by dotted lines in the OLED display of FIG. 2 are illustrated. Except for the organic light emitting diode, the two pixels have the same structure as the gate line 121, the data line 171, the driving voltage line 172, the switching thin film transistor Qs and the driving thin film transistor Qd. The same components therefore bear the same reference numerals.

A plurality of driving semiconductors 154b and a plurality of linear semiconductor members 151 are formed on an insulating substrate 110 made of transparent glass or plastic.

The driving semiconductor 154b is island-shaped, and the linear semiconductor member 151 mainly extends in the horizontal direction. The driving semiconductor 154b and the linear semiconductor member 151 may be made of a crystalline semiconductor material such as microcrystalline silicon or polycrystalline silicon.

A plurality of gate lines 121, a plurality of driving input electrodes 173b, and a plurality of driving output electrodes 175b are formed on the driving semiconductor 154b and the linear semiconductor member 151. It is.

The gate line 121 transmits a gate signal and mainly extends in a horizontal direction. Each gate line 121 includes an end portion 129 having a large area for connecting the switching control electrode 124a extending upward to another layer or an external driving circuit. When a gate driving circuit (not shown) generating a gate signal is integrated on the substrate 110, the gate line 121 may extend to be directly connected to the gate driving circuit.

The gate line 121 has a plane shape substantially the same as that of the linear semiconductor member 151.

The driving input electrode 173b and the driving output electrode 175b each have an island shape and are separated from the gate line 121. The driving input electrode 173b and the driving output electrode 175b face each other over the driving semiconductor 154b.

The gate line 121, the driving input electrode 173b, and the driving output electrode 175b include aluminum-based metals such as aluminum (Al) and aluminum alloys, silver-based metals such as silver (Ag) and silver alloys, and copper (Cu) and copper. It may be made of copper-based metals such as alloys, molybdenum-based metals such as molybdenum (Mo) or molybdenum alloys, chromium (Cr), tantalum (Ta) and titanium (Ti). However, they may have a multilayer structure including two conductive films (not shown) having different physical properties.

The gate line 121, the driving input electrode 173b, and the driving output electrode 175b are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30 ° to about 80 °.

A plurality of pairs of ohmic contacts 163b and 165b are formed between the driving semiconductor 154b and the driving input electrode 173b and between the driving semiconductor 154b and the driving output electrode 175b, respectively. In addition, a linear semiconductor member 161 is doped with an impurity between the gate line 121 and the linear semiconductor member 151.

The ohmic contacts 163b and 165b and the linear semiconductor member 161 doped with impurities are crystalline with dopants such as fine crystalline silicon or polycrystalline silicon doped with a high concentration of n-type impurities such as phosphorus (P). It can be made of a semiconductor material.

A gate insulating layer 140 made of silicon oxide (SiO ₂ ) or silicon nitride (SiN _x ) is formed on the gate line 121, the driving input electrode 173b, and the driving output electrode 175b. The gate insulating layer 140 may be a single layer or a plurality of layers including a first layer made of silicon oxide and a second layer made of silicon nitride.

A plurality of switching semiconductors 154a made of hydrogenated amorphous silicon are formed on the gate insulating layer 140. The switching semiconductor 154a has an island shape and overlaps the switching control electrode 124a.

A plurality of data lines 171, a plurality of driving voltage lines 172, and a plurality of electrode members 176 are formed on the switching semiconductor 154a and the gate insulating layer 140.

The data line 171 transmits a data signal and mainly extends in the vertical direction to cross the gate line 121. Each data line 171 has a wide end portion 179 for connection with a plurality of switching input electrodes 173a extending toward the switching control electrode 124a and another layer or an external driving circuit. Include. When a data driving circuit (not shown) generating a data signal is integrated on the substrate 110, the data line 171 may be extended to be directly connected to the data driving circuit.

The driving voltage line 172 transfers a driving voltage and mainly extends in a vertical direction to cross the gate line 121 and is substantially parallel to the data line 171. Each driving voltage line 172 includes a protrusion 177.

The electrode member 176 is an island and is separated from the data line 171 and the driving voltage line 172. The electrode member 176 overlaps the portion facing the switching input electrode 173a (hereinafter referred to as a 'switching output electrode') 175a and the driving semiconductor 154b (hereinafter referred to as a 'drive control electrode') ( 124b). The switching input electrode 173a and the switching output electrode 175a face each other over the switching semiconductor 154a.

The data line 171, the driving voltage line 172, and the electrode member 176 may be made of the same material as the gate line 121 described above.

Side surfaces of the data line 171, the driving voltage line 172, and the electrode member 176 are inclined with respect to the surface of the substrate 110, and the inclination angle is preferably about 30 ° to about 80 °.

A plurality of pairs of ohmic contacts 163a and 165a are formed between the switching semiconductor 154a and the switching input electrode 173a and between the switching semiconductor 154a and the switching output electrode 175a, respectively. The ohmic contacts 163a and 165a have an island shape and may be made of n + hydrogenated amorphous silicon in which impurities such as phosphorus (P) are heavily doped.

The color filter is formed on the data line 171, the driving voltage line 172, and the electrode member 176. 3 to 5 show only the white pixel W and the blue pixel B, the blue filter 230B is shown only in the blue pixel B. However, the red pixel R, the green pixel G, A red filter (not shown), a green filter (not shown), and a blue filter 230B are formed in the blue pixel B, respectively. The white pixel W may not include a color filter or may include a transparent white filter (not shown).

The color filter 230B is not formed at the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 to be connected to an external circuit, and the edge of the color filter 230B is a data line. 171 and the gate line 121 may overlap. As described above, the edges of the color filters 230B are overlapped to block light leaking between the pixels.

An interlayer insulating film (not shown) may be formed under the color filter 230B. The interlayer insulating film can prevent the pigment of the color filter from flowing into the semiconductor.

A passivation layer 180 is formed on the color filter 230B, the data line 171, the driving voltage line 172, and the electrode member 176.

The passivation layer 180 is formed with a plurality of contact holes 185a and 182 exposing the protrusion 177 of the driving voltage line 172 and the end portion 179 of the data line 171, and the passivation layer 180. ) And the gate insulating layer 140, a plurality of contact holes 181, 184, and 185b exposing the end portion 129 of the gate line 121, the driving input electrode 173b, and the driving output electrode 175b are formed. .

A plurality of pixel electrodes 191, a plurality of connection members 85, and a plurality of contact assistants 81 and 82 are formed on the passivation layer 180.

The pixel electrode 191 is connected to the driving output electrode 175b through the contact hole 185b.

The connecting member 85 is connected to the protrusion 177 of the driving voltage line 172 and the driving input electrode 173b through the contact holes 184 and 185a, respectively, and partially overlaps with the driving control electrode 124b. (storage capacitor) (Cst).

The contact auxiliary members 81 and 82 are connected to the end portion 129 of the gate line 121 and the end portion 179 of the data line 171 through the contact holes 181 and 182, respectively. The contact auxiliary members 81 and 82 compensate for and protect the adhesion between the end portions 129 and 179 of the gate line 121 and the data line 171 and the external device.

The pixel electrode 191, the connection member 85, and the contact assistants 81 and 82 may be made of a transparent conductor such as ITO or IZO.

A plurality of semi-transparent members 192 are formed on the pixel electrode 191 of the white pixel W. The translucent member 192 is not particularly limited as long as it is a material having a property of transmitting a portion of light and reflecting a portion of light, and includes about 10 opaque, low-absorbance conductors such as aluminum (Al) or silver (Ag). It can be made translucent by forming into a thin thickness of -100 kPa.

In the present exemplary embodiment, only the translucent member 192 is positioned on the pixel electrode 191, but it may be located below the pixel electrode 191.

Except the white pixel W, the red pixel R, the green pixel G, and the blue pixel B do not include the translucent member 192.

The translucent member 192 is formed only in a portion of the region through which the light from the light emitting layer passes, and the pixel electrode 191 is exposed in the remaining region.

3 to 5 exemplarily illustrate the lattice translucent member 192, but the present invention is not limited thereto and may be formed in the shape of, for example, FIG. 6.

6 is a schematic diagram illustrating an example of the shape of the translucent member 192 formed in the white pixel W. As shown in FIG.

In FIG. 6, (a) shows a shape in which the translucent member 192 is formed along the edge of the pixel electrode 191, and (b) shows that the translucent member 192 is formed only at one corner of the pixel electrode 191. Shape (c) shows that the translucent member 192 is formed at the center of the pixel electrode 191. In any case, only a portion of a region through which light from the light emitting layer passes is formed, and the pixel electrode 191 is exposed in the remaining region. At this time, light passing through the pixel electrode 191 passes through the front surface of the substrate, a part of the light passing through the translucent member 192 passes through the front surface of the substrate and a part of the light is reflected.

An insulating bank 361 is formed on the pixel electrode 191, the translucent member 192, the connection member 85, and the contact auxiliary members 81 and 82. The weir 361 defines an opening 365 by surrounding the edge of the pixel electrode 191. Weir 361 may be made of an organic insulator such as acrylic resin, polyimide resin, or an inorganic insulator such as silicon oxide (SiO ₂ ) or titanium oxide (TiO ₂ ). It may be, and may be two or more layers. Weir 361 may also be made of a photosensitive material containing black pigment, in which case weir 361 acts as a light shielding member and the forming process is simple.

An organic light emitting member is formed on the bank 361 and the pixel electrode 191.

The organic light emitting member may include an auxiliary layer (not shown) for improving the light emitting efficiency of the light emitting layer in addition to the light emitting layer 370 that emits light.

The light emitting layer 370 may emit white light. Subsequently, a material that uniquely emits light such as red, green, and blue may be stacked to form a plurality of sub light emitting layers (not shown), and the color may be combined to emit white light. In this case, the sub light emitting layer is not limited to being formed vertically, but may be formed horizontally. If the combination is capable of emitting white light, the sub light emitting layer is not limited to red, green and blue, and may be formed in various color combinations.

The light emitting layer 370 may be made of, for example, a high molecular material or a low molecular material, and the high molecular material may include a polyfluorene derivative, a (poly) paraphenylenevinylene derivative, and a polyphenylene. Derivatives, polyvinylcarbazole, polythiophene derivatives, and the like, and the like, and low molecular weight substances such as 9,10-diphenylanthracene (anthracene), tetraphenylbutadiene Butadiene, such as (tetraphenylbutadiene), tetracene (tetracene), distyrylarylene derivatives, benzazole derivatives and carbazole derivatives (carbazole) may be included. Or the above-mentioned high molecular material or low molecular material as a host material, for example, xanthene, perylene, coumarin, rhodamine, rubrene, dish Aminomethylenepyran compound, thiopyran compound, (thia) pyrilium compound, periflanthene derivative, indenoperylene derivative, carbostyryl Dopant such as a compound, nile red, and quinacridone may be used to increase luminous efficiency.

The auxiliary layer includes an electron transport layer (not shown) and a hole transport layer (not shown) for balancing electrons and holes, and an electron injection layer for enhancing the injection of electrons and holes ( electron injecting layer (not shown) and hole injecting layer (hole injecting layer) (not shown) and the like, and may include one or two or more layers selected from them. The hole transport layer and the hole injection layer are made of a material having a HOMO level between the work function of the pixel electrode 191 and the highest occupied molecular orbital (HOMO) level of the light emitting layer, and the electron transport layer and the electron injection layer are formed of the common electrode 270. It is made of a material having a LUMO level between the work function and the lower unoccupied molecular orbital (LUMO) level of the light emitting layer. For example, the hole transport layer or the hole injection layer may include diamines, MTDATA ([4,4 ', 4 "-tris (3-methylphenyl) phenylamino] triphenylamine), TPD (N, N'-diphenyl-N, N'-di ( 3-methylphenyl) -1,1'-biphenyl-4,4'-diamine), 1,1-bis (4-di-p-tolylaminophenyl) cyclohexane (1,1-bis (4-di-p -tolylaminophenyl) cyclohexane), N, N, N ', N'-tetra (2-naphthyl) -4,4-diamino-p-terphenyl (N, N, N', N'-tetra (2- naphthyl) -4,4-diamino-p-terphenyl), 4,4 ', 4-tris [(3-methylphenyl) phenylamino] triphenylamine (4,4', 4-tris [(3-methylphenyl) phenylamino ] triphenylamine, polypyrrole, polyaniline, a mixture of polyethylenedioxythiophene and polystyrenesulfonic acid (poly- (3,4-ethylenedioxythiophene: polystyrenesulfonate, PEDOT: PSS)) can be used.

The common electrode 270 is formed on the organic light emitting member 370. The common electrode 270 may be made of a metal having a low work function and high reflectivity, such as aluminum or aluminum alloy, gold (Au), platinum (Pt), nickel (Ni), copper (Cu), tungsten (W). ) Or alloys thereof. The common electrode 270 is formed on the entire surface of the substrate, and pairs with the pixel electrode 191 to send a current to the organic light emitting member 370.

Hereinafter, the white pixel W will be described.

The common electrode 270 generates a microcavity effect together with the translucent member 192. The fine resonance effect is to amplify the light of a specific wavelength by repeatedly reflecting the reflective layer and the translucent layer where the light is separated by a predetermined distance. The common electrode 270 serves as a reflective layer and the translucent member 192 serves as a translucent layer.

The common electrode 270 forms a microcavity that greatly modifies the light emission characteristics of the light emitted from the light emitting layer 370, and light emission near the wavelength corresponding to the resonance wavelength of the micro resonance is enhanced through the translucent member 192, and the other Light of the wavelength is suppressed. In this case, the enhancement and suppression of light of a specific wavelength may be determined according to the distance between the common electrode 270 and the translucent member 192. Therefore, light of a specific wavelength may be enhanced and suppressed by controlling the thickness of the light emitting layer 370 and the auxiliary layer (not shown).

In the present embodiment, blue light may be selectively emitted from white light emitted from the light emitting layer 370 to improve blue purity. Accordingly, the desired white light can be obtained by overcoming the limitation of the light emission efficiency according to the light emitting material.

At this time, as described above, only a part of the pixel electrode 191 is covered with the translucent member 192, and a part of the pixel electrode 191 is exposed. Therefore, the portion where the translucent member 192 is formed may emit blue light due to the fine resonance effect, and the portion where the translucent member 192 is not formed, that is, the portion where the pixel electrode 191 is exposed, is left as it is. White light passes through In this case, since the white light emitted through the pixel electrode 191 does not include the blue light partially reflected by the translucent member 192, the white light of the white light is yellowish white in which blue light is partially reduced. Finally, the light emitted to the outside of the substrate may be a combination of blue light and yellow-based white light to give a complete white.

In the absence of the above-described fine resonance effect, when the same current is applied to the light emitting layer, the sub light emitting layer having high luminous efficiency, that is, the red sub light emitting layer and / or the green sub light emitting layer and the low light emitting efficiency, i.e., the blue sub light emitting layer, have different colors. Since it has a color with characteristics, it is difficult to combine them completely to emit white light. In this embodiment, the desired white light can be obtained by overcoming the limitation of the luminous efficiency according to the light emitting material.

In the organic light emitting diode display, the switching control electrode 124a connected to the gate line 121, the switching input electrode 173a connected to the data line 171, and the switching output electrode 175a are connected to the switching semiconductor 154a. And a switching TFT Qs, and a channel of the switching TFT Qs is a switching semiconductor 154a between the switching input electrode 173a and the switching output electrode 175a. Is formed. The driving control electrode 124b connected to the switching output electrode 175a, the driving input electrode 173b connected to the driving voltage line 172, and the driving output electrode 175b connected to the pixel electrode 191 are driven. A driving TFT Qd is formed together with the semiconductor 154b, and a channel of the driving TFT Qd is formed in the driving semiconductor 154b between the driving input electrode 173b and the driving output electrode 175b. do.

The pixel electrode 191, the organic light emitting member 370, and the common electrode 270 form an organic light emitting diode LD, and the pixel electrode 191 is an anode and the common electrode 270 is a cathode. Alternatively, the pixel electrode 191 becomes a cathode and the common electrode 270 becomes an anode.

As described above, the switching semiconductor 154a is made of an amorphous semiconductor, and the driving semiconductor 154b is made of a crystalline semiconductor. That is, the channel of the switching thin film transistor Qs is formed in the amorphous semiconductor, and the channel of the driving thin film transistor Qd is formed in the crystalline semiconductor.

As described above, in the present invention, the channels of the switching thin film transistor Qs and the driving thin film transistor Qd are formed in semiconductors having different crystal states, thereby satisfying the characteristics required for each thin film transistor.

By forming the channel of the driving thin film transistor Qd in the microcrystalline or polycrystalline semiconductor, it may have high carrier mobility and stability, thereby increasing the amount of current flowing through the light emitting device, thereby increasing luminance. have. In addition, by forming the channel of the driving thin film transistor Qd in the microcrystalline or polycrystalline semiconductor, image sticking is prevented by preventing the Vth shift caused by the continuous application of positive voltage during driving. ) And shortened lifespan.

On the other hand, since the switching thin film transistor Qs plays a role of controlling the data voltage, on / off characteristics are important, and in particular, it is important to reduce the off current. However, since the microcrystalline or polycrystalline semiconductor has a large off current, the data voltage passing through the switching thin film transistor Qs may decrease and cross talk may occur. Accordingly, in the present invention, the switching thin film transistor Qs is formed of an amorphous semiconductor having a small off current, thereby preventing a decrease in data voltage and reducing cross talk.

Although only one switching thin film transistor Qs and one driving thin film transistor Qd are shown in the present embodiment, at least one thin film transistor and a plurality of wirings for driving the thin film transistor are further included. It is possible to prevent or compensate the deterioration of the LD and the driving transistor Qd to prevent the life of the organic light emitting diode display from being shortened.

In the present embodiment, a case in which the light emitted from the light emitting layer is a bottom emission structure that transmits toward the substrate 110 is described. However, a top emission structure in which light emitted from the light emitting layer is transmitted toward the common electrode 170 is also possible. In this case, the pixel electrode 191 may be made of an opaque conductor such as aluminum or an aluminum alloy, gold (Au), platinum (Pt), nickel (Ni), copper (Cu), tungsten (W), or an alloy thereof. The common electrode may be made of a transparent conductor. In addition, in the upper light emitting structure, the color filter 230B is positioned above the light emitting layer.

Next, a method of manufacturing the OLED display illustrated in FIGS. 2 to 5 will be described in detail with reference to FIGS. 7 to 23.

7 to 11 are cross-sectional views sequentially illustrating a method of manufacturing an organic light emitting diode display according to an exemplary embodiment of the present invention, and FIGS. 12, 14, 16, 19, and 22 are diagrams illustrating exemplary embodiments of the present invention. FIG. 13 is a cross-sectional view illustrating a method of manufacturing an organic light emitting diode display, and FIG. 13 is a cross-sectional view of the organic light emitting diode display of FIG. 12 taken along the line XIII-XIII′-XIII ″, and FIG. 15 is an organic light emitting diode display of FIG. 14. Is a cross-sectional view taken along the line XV-XV'-XV ", and FIGS. 17 and 18 show the organic light emitting diode display of FIG. 16 along the line XVII-XVII'-XVII" -XVII "'and XVIII-XVIII 20 and 21 are cross-sectional views of the organic light emitting diode display of FIG. 19 taken along lines XX-XX'-XX "-XX" 'and XXI-XXI, and FIGS. 23 and 24. 22 is a cross-sectional view of the organic light emitting diode display of FIG. 22 taken along lines XXIII-XXIII'-XXIII "-XXIII" 'and XXIV-XXIV. 25 is a layout view of an OLED display according to another embodiment of the invention, Figure 26 is a cross-sectional view cut along the line XXVI-XXVI of the OLED display of Fig.

First, as shown in FIGS. 7 and 8, the amorphous silicon layer 150a and the amorphous silicon layer 160a doped with impurities are sequentially stacked on the insulating substrate 110.

Subsequently, the amorphous silicon layer 150a and the doped amorphous silicon layer 160a are crystallized to form the polycrystalline silicon layer 150b and the doped polycrystalline silicon layer 160b. Crystallization may be performed by solid phase crystallization (SPC), rapid thermal annealing (RTA), liquid phase recrystallization (LPR), or excimer laser annealing (ELA). Among them, a solid phase crystallization method is preferred.

Subsequently, a conductive layer 120 such as aluminum is stacked on the polycrystalline silicon layer 160b doped with impurities, and a photosensitive film 40 is coated thereon.

Subsequently, a mask 10 having a light transmitting region 10a, a light blocking region 10b, and a semi-transmissive region 10c is disposed on the photosensitive film 40. The semi-transmissive region 10c includes a slit pattern, a lattice pattern, or a thin film having a medium transmittance or a medium thickness. When using the slit pattern, it is preferable that the width of the slits and the interval between the slits are smaller than the resolution of the exposure machine used for the photographic process.

Next, as shown in FIG. 9, the photosensitive film 40 is exposed and developed to form the first photosensitive pattern 40a and the second photosensitive pattern 40b thinner than the first photosensitive pattern 40a.

For convenience of description, the portion where the gate line 121, the driving input electrode 173b, and the driving output electrode 175b are to be formed is called an electrode portion A, and the portion where the channel is to be formed on the driving semiconductor 154b is a channel. The region except for the electrode portion A and the channel portion B is called the remaining portion C.

The first photosensitive pattern 40a positioned at the electrode portion A is formed thicker than the second photosensitive pattern 40b positioned at the channel portion B, and all of the photosensitive film of the remaining portion C is removed. At this time, the ratio of the thickness of the first photosensitive pattern 40a to the thickness of the second photosensitive pattern 40b may vary depending on the process conditions in the etching process, which will be described later. It is preferable to set it as 1/2 or less of the thickness of the 1st photosensitive pattern 40a.

Next, as illustrated in FIG. 10, the conductive layer 120 exposed to the remaining portion C is wet-etched using the first photosensitive pattern 40a and the second photosensitive pattern 40b. The gate line 121 and the conductive member 174b including the switching control electrode 124a and the end portion 129 are formed.

Next, the dry etching of the polycrystalline silicon layer 150b exposed to the remaining portion C and the doped polycrystalline silicon layer 160b using the gate line 121 and the conductive member 174b as a mask is performed. The linear semiconductor member 151, the driving semiconductor 154b, the linear semiconductor member 161 doped with impurities, and the ohmic contact layer 164b are formed. In this case, the linear semiconductor member 151 and the linear semiconductor member 161 doped with impurities are formed in substantially the same planar shape as the gate line 121, and the driving semiconductor 154b and the ohmic contact layer 164b are formed. It is formed in substantially the same planar shape as the conductive member 174b.

Next, as shown in FIG. 11, the second photosensitive pattern 40b existing in the channel portion B is removed using an etch back process such as ashing. At this time, since the first photosensitive pattern 40a is also removed by the thickness of the second photosensitive pattern 40b, the thickness becomes thin.

Subsequently, the conductive member 174b is separated into the driving input electrode 173b and the driving output electrode 175b by patterning using the first photosensitive pattern 40a and between the driving input electrode 173b and the driving output electrode 175b. The ohmic contact 164b is exposed on the channel portion of the.

Next, as shown in FIGS. 12 and 13, the first photosensitive pattern 40a is removed, and the ohmic contact layer 164b is dry-etched using the driving input electrode 173b and the driving output electrode 175b as a mask. As a result, a pair of ohmic contacts 163b and 165b are formed.

Next, as shown in FIGS. 14 and 15, an amorphous silicon doped with a gate insulating layer 140, an intrinsic amorphous silicon layer, and impurities on the gate line 121, the driving input electrode 173b, and the driving output electrode 175b. After the layers are sequentially stacked, the switching semiconductor 154a and the ohmic contact layer 164a are formed by photo etching the intrinsic amorphous silicon layer and the doped amorphous silicon layer.

Next, as shown in FIGS. 16 to 18, the conductive layer is stacked and photo-etched on the gate insulating layer 140 and the ohmic contact layer 164a to include the switching input electrode 173a and the end portion 179. The line 171, the driving voltage line 172, and the electrode member 176 are formed. The electrode member 176 includes a switching output electrode 175a and a drive control electrode 124b.

Subsequently, the ohmic contact layer 164a is etched using the switching input electrode 173a and the switching output electrode 175a as a mask to form a pair of ohmic contacts 163a and 165a, and a part of the switching semiconductor 154a. Expose

Next, as shown in FIGS. 19 to 21, the color filter 230B is disposed on the data line 171, the driving voltage line 172, the electrode member 176, the exposed switching semiconductor 154a, and the gate insulating layer 140. To form. The color filter 230B forms a red filter in the red pixel R, a green filter in the green pixel G, and a blue filter in the blue pixel B according to the pixel arrangement of FIG. 2, and separately in the white pixel W. The color filter may not be formed or a transparent insulating film may be formed.

Next, the passivation layer 180 is laminated on the color filter 230B. Subsequently, the passivation layer 180 and the gate insulating layer 140 are etched to form a plurality of contact holes 181, 182, 184, 185a and 185b.

Next, as shown in FIGS. 22 to 24, the ITO or IZO is deposited on the passivation layer 180, and then etched to photograph the plurality of pixel electrodes 191, the connection member 85, and the plurality of contact assistants 81. 82).

Subsequently, a translucent member 192 is formed on the pixel electrode 191 of the white pixel W.

3 and 4, a photosensitive organic layer is formed on the pixel electrode 191, the translucent member 192, the connection member 85, the plurality of contact auxiliary members 81 and 82, and the passivation layer 180. After coating, it is exposed and developed to form an insulating weir 361 having a plurality of openings 365.

Subsequently, a plurality of auxiliary layers (not shown) and the light emitting layer 370 are sequentially formed. The auxiliary layer and the light emitting member 370 may be formed by a deposition method or an inkjet printing method.

Finally, the common electrode 270 is formed on the insulating weir 361 and the light emitting layer 370.

Hereinafter, an organic light emitting diode display according to another exemplary embodiment will be described with reference to FIGS. 25 and 26.

FIG. 25 is a layout view of an organic light emitting diode display according to another exemplary embodiment. FIG. 26 is a cross-sectional view of the organic light emitting diode display of FIG. 25 taken along a line XXVI-XXVI.

The organic light emitting diode display according to the present exemplary embodiment is almost the same as the above-described embodiment except for the color filter and the organic light emitting diode.

That is, the plurality of driving semiconductors 154b and the plurality of linear semiconductor members 151 made of crystalline semiconductor materials such as microcrystalline silicon or polycrystalline silicon are formed on the insulating substrate 110.

A plurality of gate lines 121, a plurality of driving input electrodes 173b, and a plurality of driving output electrodes 175b are formed on the driving semiconductor 154b and the linear semiconductor member 151.

A plurality of pairs of ohmic contacts 163b and 165b are formed between the driving semiconductor 154b and the driving input electrode 173b and between the driving semiconductor 154b and the driving output electrode 175b, respectively. In addition, a linear semiconductor member 161 is doped with an impurity between the gate line 121 and the linear semiconductor member 151.

A gate insulating layer 140 is formed on the gate line 121, the driving input electrode 173b, and the driving output electrode 175b, and a plurality of switching semiconductors 154a made of hydrogenated amorphous silicon are formed on the gate insulating layer 140. It is.

The data line 171 including the switching input electrode 173a, the driving voltage line 172 including the protrusion 177, the switching output electrode 175a, and the driving control electrode are disposed on the switching semiconductor 154a and the gate insulating layer 140. An electrode member 176 including 124b is formed.

A plurality of pairs of ohmic contacts 163a and 165a are formed between the switching semiconductor 154a and the switching input electrode 173a and between the switching semiconductor 154a and the switching output electrode 175a, respectively.

The color filter is formed on the data line 171, the driving voltage line 172, and the electrode member 176. At this time, unlike the above-described embodiment, the color filter is formed only in the red pixel R and the green pixel G. The white pixel W does not include a color filter or includes a transparent white filter (not shown) and the blue pixel B does not include a color filter.

A passivation layer 180 having a plurality of contact holes 181, 192, 184, 185a, and 185b is formed on the data line 171, the driving voltage line 172, and the electrode member 176.

A plurality of pixel electrodes 191, a plurality of connection members 85, and a plurality of contact assistants 81 and 82 are formed on the passivation layer 180.

Translucent members 192 and 193 are formed on the pixel electrodes 191 of the white pixel W and the blue pixel B, respectively. At this time, the translucent member 192 of the white pixel W is formed only in a part of the region through which the light from the light emitting layer passes, as in the above-described embodiment, and the pixel electrode 191 is partially exposed. On the other hand, the translucent member 193 of the blue pixel B is formed in the entire region through which the light from the light emitting layer passes.

In the present exemplary embodiment, only the translucent members 192 and 193 are formed on the pixel electrode 191, but it may be located below the pixel electrode 191.

Except the white pixel W and the blue pixel B, the red pixel R and the green pixel G do not include the translucent members 192 and 193.

An insulating weir 361 is formed on the pixel electrode 191, the translucent members 192 and 193, the connection member 85, and the contact auxiliary members 81 and 82. Weir 361 defines opening 365.

A plurality of sub light emitting layers (not shown) are sequentially stacked on the bank 361 and the pixel electrode 191 to emit white light, and a common electrode 270 is formed thereon.

In the present embodiment, the white pixel W is the same as the above-described embodiment. That is, in the portion where the translucent member 192 is formed, the light emitted from the light emitting layer 370 may generate a fine resonance effect between the common electrode 270 and the translucent member 192 to emit blue light, and the translucent member 192 In a portion where) is not formed, yellow-based white light emitted through the pixel electrode 191 may be emitted as it is, and these may be combined to emit completely white light.

On the other hand, in the present embodiment, unlike the above-described embodiment, the blue pixel B also does not include a color filter. In the blue pixel B, light emitted from the emission layer 370 may generate a fine resonance effect between the common electrode 270 and the translucent member 193 to emit blue light. In this case, since the translucent member 193 of the blue pixel B is formed on the entire surface through which light passes, only the blue light may be emitted. Therefore, blue light having high color purity can be emitted without a separate color filter.

In the above-described embodiment, it was assumed that the luminous efficiency of the blue light emitting material is the lowest among the red, green, and blue light emitting materials, but the same applies to the red pixel or the green pixel when the efficiency of the red or green light emitting material is lower. can do. In addition, in the case of generating white light by combining other colors besides red, green, and blue, the same may be applied in consideration of luminous efficiency.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the invention.

It is possible to overcome the limitations of the luminous efficiency according to the luminescent material and to obtain light exhibiting desired color characteristics.

Claims (20)

In an organic light emitting display device including a red pixel, a green pixel, a blue pixel, and a white pixel, Each pixel is First electrode, A second electrode facing the first electrode, and A light emitting member positioned between the first electrode and the second electrode Including, The white pixel A first translucent member is formed below or above the first electrode and forms a microcavity with the second electrode. OLED display. In claim 1, The first translucent member includes at least one selected from silver (Ag) or aluminum (Al). In claim 1, The light emitting member It includes a plurality of sub light emitting layer for emitting light of different wavelengths, The light of different wavelengths combine to emit white light OLED display. In claim 3, The white light emitting display has a yellowish white color. In claim 3, The first translucent member is formed in only a part of a region through which the white light passes. In claim 3, The red pixel, the green pixel and the blue pixel The organic light emitting display device further comprises a color filter formed under the first electrode. In claim 3, Among the red pixels, the green pixels, and the blue pixels, the pixel having the lowest luminous efficiency is A second translucent member formed on the lower or upper portion of the first electrode and forming a fine resonance with the second electrode An organic light emitting display device further comprising. In claim 7, The pixel having the lowest luminous efficiency is a blue pixel. In claim 7, The second translucent member includes at least one selected from silver (Ag) and aluminum (Al). In claim 7, And the second translucent member is formed in all regions through which the white light passes. In claim 7, The red pixel and the green pixel further include a color filter formed under the first electrode. In claim 1, A driving thin film transistor connected to the first electrode and including a polycrystalline semiconductor, and A switching thin film transistor connected to the driving thin film transistor and including an amorphous semiconductor. An organic light emitting display device further comprising. In claim 12, The driving thin film transistor is A driving input electrode formed on the polycrystalline semiconductor, A drive output electrode facing said drive input electrode on said polycrystalline semiconductor, and A drive control electrode formed on the drive input electrode and the drive output electrode; An organic light emitting display device further comprising. In claim 13, The switching thin film transistor A switching control electrode formed under the amorphous semiconductor, A switching input electrode formed on the amorphous semiconductor, and A switching output electrode facing the switching input electrode on the amorphous semiconductor and connected to the driving control electrode An organic light emitting display device further comprising. In an organic light emitting diode display including a plurality of pixels, Each pixel is Switching thin film transistor, A driving thin film transistor connected to the switching thin film transistor, A first electrode connected to the driving thin film transistor, A light emitting member formed on the first electrode and emitting white light; and A second electrode formed on the light emitting member Including; The plurality of pixels A first pixel group in which a translucent member for forming a fine resonance with the first electrode or the second electrode is formed in a region where the white light passes; and A second pixel group in which a color filter is formed in a region through which the white light passes; An organic light emitting display device comprising a. The method of claim 15, The white light has a yellowish white color. The method of claim 16, The first pixel group includes white pixels. The method of claim 17, The translucent member is formed in a part of the region through which the white light passes. The method of claim 17, The first pixel group includes blue pixels. The method of claim 16, The second pixel group includes at least one of a red pixel and a green pixel.

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