KR101450905B1 - Organic light emitting diodde desplay device and fabricating method therof - Google Patents

Abstract

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

The organic light emitting diode display element includes a first reflective electrode; A buffer layer formed on the first reflective electrode; A second reflective electrode formed on the buffer layer in the G light emitting cell; A transparent anode electrode formed on the buffer layer in the R and B light emitting cells and formed on the second reflective electrode in the G light emitting cell; A white organic light emitting diode element formed on the anode electrode in the R, G and B light emitting cells; And a transflective cathode electrode formed on the white organic light emitting diode device in the R, G, and B light emitting cells.

Description

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

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

2. Description of the Related Art Recently, various flat panel display devices capable of reducing weight and volume, which are disadvantages of cathode ray tubes (CRTs), have been developed. Such a flat panel display device includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP) And a light emitting device (Electroluminescence Device).

An electroluminescent device is divided into an inorganic electroluminescent device and an organic light emitting diode device depending on the material of the light emitting layer, and is self-luminous device that emits itself, has a high response speed, and has advantages of high luminous efficiency, brightness and viewing angle.

An active matrix type organic light emitting diode (AMOLED) display device uses an organic thin film transistor (hereinafter referred to as "TFT") to control a current flowing in an organic light emitting diode . Such an organic light emitting diode display device displays an image in the form of top emission, bottom emission, double-side emission or the like depending on the structure of the organic light emitting diode device.

An organic light emitting diode display element having a top emission structure as shown in FIG. 1 has an expensive fine metal mask (FMM) in order to realize light emitting cells of red (R), green (G) and blue An emission layer (EML) and a common layer are separately deposited for each of the R, G, and B light emitting cells, thereby realizing different optical thicknesses between the anode and the cathode for each RGB light emitting cell. Here, the common layer includes an electron injection layer (EIL), an electron transport layer (ETL), a hole transport layer (HTL), and a hole injection layer (HIL) . In FIG. 1, the anode electrode is formed of Mg-Ag and the cathode electrode is a double layered structure of ITO (indium tin oxide: ITO) and Ag. The organic light emitting diode display device of FIG. 1 can achieve a color image because a micro-cavity can be obtained by varying the optical thickness between the anode and the cathode for each RGB light emitting cell. However, in order to realize the organic light emitting diode display device as shown in FIG. 1, in order to make the thickness of one of the light emitting layer and the common layer different in the RGB light emitting cells, the process water and the process cost are increased.

An organic light emitting diode display element having a bottom emission structure as shown in FIG. 2 combines a white organic light emitting diode (hereinafter, referred to as a white OLED) and a color filter to realize a color image. However, the organic light emitting diode display device as shown in FIG. 2 has broad emission characteristics of RGB light emission spectrum, so that the color reproduction of the display image is not high and the luminous efficiency is low even though it passes through the color filter. In order to increase the color reproduction rate in the organic light emitting diode display device as shown in FIG. 2, the transmittance should be lowered.

An organic light emitting diode display element having a top emission structure as shown in FIG. 3 was proposed by Sony Corporation, and an RGB color filter is formed on a top plate and a white OLED is formed on a bottom plate. In this organic light emitting diode display device, ITO or IZO (Indium Zinc Oxide) is formed as a transparent conductor on an anode electrode serving as a reflective electrode in order to realize a microcavit effect, and the thickness of the transparent conductor is different for each RGB light emitting cell . However, since the organic light emitting diode display device as shown in FIG. 3 has to form three times transparent conductive materials having different thicknesses for each RGB light emitting cell and repeatedly perform a photolithography process and an etching process, the number of processes and the process cost are high . In order to form the ITO as shown in FIG. 3, when the ITO thickness is 100 Å in the B light emitting cell, ITO thickness is 500 Å in the G light emitting cell, and ITO thickness is 1000 Å in the R light emitting cell, After the ITO is deposited on the R light emitting cell, a photolithography process and an etching process are performed using a first photomask that transmits light only in the R light emitting cell. After ITO is deposited again to a thickness of 400 ANGSTROM, After a photolithography process and an etching process using a second photomask to be transmitted are performed, ITO is deposited to a thickness of 100 Å, and then a photolithography process using a third photomask that transmits light in all the R, G, and B light emitting cells The lithography process and the etching process are performed. As another method for forming ITO as shown in FIG. 3, ITO And then a photolithography process and an etching process using a photomask that transmits light in all of the R, G, and B light emitting cells are performed. Then, in the G and R light emitting cells, The G and R light emitting cells are masked by forming a photoresist (PR), and dry etching is performed on ITO in a B light emitting cell to a desired thickness, that is, 100 ANGSTROM, and ITO is changed to PR After masking, ITO is dry-etched to a desired thickness, i.e., 500 ANGSTROM, in the G light emitting cell. Since the above methods require a large number of photomasks and a large number of processes, the advantages of white OLEDs without a fine metal mask (FMM) are eliminated because of the increase in process cost in actual production.

Accordingly, it is an object of the present invention to provide an organic light emitting diode display device capable of reducing the number of process steps and process cost, increasing the luminance of R, G, B and optimizing the color coordinates, And a manufacturing method thereof.

According to an aspect of the present invention, there is provided an organic light emitting diode display device comprising: a first reflective electrode; A buffer layer formed on the first reflective electrode; A second reflective electrode formed on the buffer layer in the G light emitting cell; A transparent anode electrode formed on the buffer layer in the R and B light emitting cells and formed on the second reflective electrode in the G light emitting cell; A white organic light emitting diode element formed on the anode electrode in the R, G, and B light emitting cells; And a transflective cathode electrode formed on the white organic light emitting diode device in the R, G, and B light emitting cells.

A method of fabricating an organic light emitting diode display device according to an embodiment of the present invention includes: forming a buffer layer on a first reflective electrode; Forming a second reflective electrode on the buffer layer in the G light emitting cell; Forming a transparent anode electrode on the buffer layer in the R and B light emitting cells and forming the transparent anode electrode on the second reflective electrode in the G light emitting cell; Forming a white organic light emitting diode device on the anode electrode in the R, G, and B light emitting cells; And forming a transflective cathode electrode on the white organic light emitting diode device in the R, G, and B light emitting cells.

The organic light emitting diode display device and the method of manufacturing the same according to embodiments of the present invention can reduce the number of process steps and process cost by manufacturing the same structure of the R and B light emitting cells, G and B can be increased and the color coordinates can be optimized.

Hereinafter, preferred embodiments of the present invention will be described with reference to FIGS. 4 to 11. FIG.

Referring to FIG. 4, an organic light emitting diode display device according to an embodiment of the present invention applies a white OLED having the same structure to both R, G, and B light emitting cells.

를 만족한다. 여기서, n은 양의 정수이며, λ는 빛의 파장이다. 광학적 두께와 빛의 파장에 관한 상관관계는 1994 American Institute of Physics에 개시된 "Microcavity effects in organic semiconductors by A. Dodabalapur, L.J. Rothberg, T.M. Miller, and E.W. Kwock" 등에서 공지된 바 있다. The R and B light emitting cells are formed by the same (first, second, third, fourth, fifth, sixth and seventh) light emitting cells including a transparent OLED, a transparent anode electrode ANO and a transflective cathode electrode CAT Cell structure. In the R and B light emitting cells, the optical thickness (d2) between the transflective cathode electrode (CAT) and the first reflective electrode REFL1 simultaneously emits the wavelength of red light and the wavelength of blue light Conditions of Micro Cavity that can be

. Here, n is a positive integer, and? Is a wavelength of light. The correlation between the optical thickness and the wavelength of light has been disclosed in "Microcavity effects in organic semiconductors by A. Dodabalapur, LJ Rothberg, TM Miller, and EW Kwock", 1994, American Institute of Physics.

를 만족한다. 여기서, n은 양의 정수이며, λ는 빛의 파장이다. G 발광셀에서 마이크로 캐비티 효과를 만족하는 반사 체들 간의 광학적 두께(d1)는 R 및 B 발광셀들에서 마이크로 캐비티 효과를 만족하는 반사체들 간의 광학적 두께(d2)보다 작다. The G light emitting cell has a structure different from that of the R and B light emitting cells, including a transflective cathode electrode CAT and a second reflective electrode REFL2 separated by d1 with white OLED and transparent anode electrode ANO interposed therebetween. In the G light emitting cell, the optical thickness d1 between the transflective cathode electrode CAT and the second reflective electrode REFL2 corresponds to the microcavity condition capable of emitting the wavelength of the green light

. Here, n is a positive integer, and? Is a wavelength of light. The optical thickness d1 between the reflectors satisfying the micro-cavity effect in the G light-emitting cells is smaller than the optical thickness d2 between the reflectors satisfying the micro-cavity effect in the R and B light-emitting cells.

FIG. 5 is a graph showing an experimental result of the organic light emitting diode device as shown in FIG. In this experiment, a white OLED (WOLED) was formed to a thickness of approximately 2000 ANGSTROM and a transparent anode electrode (ANO) was formed to a thickness of approximately 500 ANGSTROM. The buffer layer (BUF) was formed of ITO having a thickness of approximately 650 ANGSTROM.

In this experiment, the optical thickness d2 between the transflective cathode electrode CAT and the first reflective electrode REFL1 in the R and B light emitting cells was approximately 3150 Å. Due to the optical thickness d2 between the reflectors, the R and B light emitting cells satisfy the micro-cavity condition of emitting red light and blue light, and simultaneously emit red light and blue light as shown in the upper left graph of FIG.

In this experiment, the optical thickness d1 between the transflective cathode electrode CAT and the second reflective electrode REFL2 in the G light emitting cell was approximately 2500 ANGSTROM. Due to the optical thickness d1 between the reflectors, the G light emitting cell satisfies the micro-cavity condition for emitting green light and emits green light as shown in the upper right graph of FIG.

In the present invention, the optical thicknesses d1 and d2 between the reflectors satisfying the micro-cavity condition in each light emitting cell are not limited to the above-described experiment because there are several values depending on the desired wavelength. The optical thickness d1 between the reflectors emitting green light in the G light emitting cell can be optimized by adjusting the thickness of the hole injection layer (HIL) in the white OLED (WOLED). Here, the hole injection layer (HIL) is not a hole injection layer (HIL) existing in the G light emitting cell but a hole injection layer formed as a common layer in the R, G and B light emitting cells. Therefore, the thickness of the optimized hole injection layer (HIL) optimized for satisfying the micro-cavity condition emitting green light is the same in the R, G, and B light emitting cells. The optical thickness d2 between the reflectors simultaneously emitting red and blue light in the R and B light emitting cells can be optimized by adjusting the thickness of the buffer layer BUF.

For the color implementation, the organic light emitting diode display device according to the embodiment of the present invention forms a red color filter which transmits only the wavelength of red light to the R light emitting cell region on the top plate, transmits only the wavelength of blue light to the B light emitting cell region A blue color filter is formed. The G light emitting cell does not necessarily have to form a color filter because the optical thickness between the reflectors satisfies the micro-cavity condition that emits green light and emits only green light, but it may be formed to increase the color purity.

One pixel in the organic light emitting diode display device according to the embodiment of the present invention can be implemented as shown in FIGS.

Referring to FIG. 6, the pixel structure according to the first embodiment of the present invention includes a color coordinate optimizing cell W, an R light emitting cell, a G light emitting cell, and a B light emitting cell.

The color coordinate optimizing cell W includes a buffer layer BUF formed between the first reflective electrode REFL1 and the transflective cathode electrode CAT, a second reflective electrode REFL2, a transparent anode electrode ANO, and a white OLED ). In the color coordinate optimizing cell W, the second reflective electrode REFL2 is patterned to form a plurality of openings. The optical thickness between the transflective cathode electrode CAT and the second reflective electrode REFL2 is equal to the optical thickness d1 between the reflectors satisfying the microcavity conditions capable of emitting green light in the G light emitting cells. The optical thickness between the transflective cathode electrode CAT and the first reflective electrode REFL1 at the position of the aperture formed by the patterning of the second reflective electrode REFL2 is set so that the red light and the blue light Is equal to the optical thickness d2 between the reflectors satisfying the micro-cavity condition capable of emitting simultaneously. Therefore, the color coordinates of R, G, and B can be optimized by adjusting the width D of the aperture of the second reflective electrode REFL1 in the color coordinate optimizer cell W. [

The R and B light emitting cells have the same cell structure. The R and B light emitting cells include a buffer layer BUF, a transparent anode electrode ANO, and a white OLED (WOLED) formed between the first reflective electrode REFL1 and the transflective cathode electrode CAT. In the R and B light emitting cells, there is no reflector between the transparent anode electrode ANO and the white OLED (WOLED). The optical thickness d2 between the transflective cathode electrode CAT and the second reflective electrode REFL2 in the R and B light emitting cells satisfies the microcavity condition capable of simultaneously emitting the red light and the blue light.

The G light emitting cells are different from the R and B light emitting cells in the cell structure, in particular, the reflectors facing each other with the white OLED (WOLED) interposed therebetween. The G light emitting cell includes a buffer layer BUF, a second reflective electrode REFL2, a transparent anode electrode ANO and a white OLED (WOLED) formed between the first reflective electrode REFL1 and the transflective cathode electrode CAT do. In the G light emitting cell, the first reflective electrode REFL1 may be removed as shown in FIG. 10 because it is independent of the micro-cavity condition that emits green light. The optical thickness d1 between the transflective cathode electrode CAT and the second reflective electrode REFL2 in the G light emitting cell satisfies the microcavity condition capable of emitting green light.

The optical thickness d1 between the color coordinate optimizing cell W and the opposed reflectors CAT and REFL2 in the G light emitting cell with the white OLED WOLED and the transparent anode electrode ANO interposed therebetween, (HIL). ≪ / RTI > The optical thickness between the reflectors CAT and REFL1 opposed to each other across the white OLED WOLED, the transparent anode electrode ANO and the buffer layer BUF in the color coordinate optimizing cell W, the R light emitting cell and the B light emitting cells is (d2) can be optimized by adjusting the thickness of the buffer layer (BUF).

No color filter is formed in the color coordinate optimizing cell W.

6, the white OLED (WOLED) in the color coordinate optimizing cell W, the R light emitting cell, the G light emitting cell and the B light emitting cell are the same.

7 shows a pixel structure according to a second embodiment of the present invention.

Referring to FIG. 7, the pixel structure according to the second embodiment of the present invention includes an R light emitting cell, a G light emitting cell, and a B light emitting cell. The pixel according to the second embodiment of the present invention does not include the color coordinate optimizing cell W in comparison with the first embodiment of Fig. Since the R, G, and B light emitting cells have the same structure as those of the first embodiment, a detailed description thereof will be omitted.

6, the optical thickness d1 between the white OLED (WOLED) and the opposed reflectors (CAT and REFL2) with the transparent anode electrode ANO interposed therebetween, Can be optimized by adjusting the thickness of the hole injection layer (HIL) as described above. The optical thickness d2 between the reflectors CAT and REFL1 facing each other with the white OLED (WOLED), the transparent anode electrode ANO and the buffer layer BUF in between the R and B light emitting cells, Can be optimized.

8 shows a pixel structure according to the third embodiment of the present invention.

Referring to FIG. 8, the pixel structure according to the third embodiment of the present invention includes a color coordinate optimizing cell W, an R light emitting cell, a G light emitting cell, and a B light emitting cell. In the pixel according to the third embodiment of the present invention, the color coordinate optimizing cell W, the R light emitting cell and the B light emitting cell are substantially the same as the first embodiment of Fig. 6, It is implemented in a different structure from the example. Therefore, the detailed description of the color coordinate optimizing cell W, the R light emitting cell, and the B light emitting cell will be omitted.

The G light emitting cell has a cell structure different from that of the R and B light emitting cells. The G light emitting cell includes a transparent anode electrode ANO and a white OLED (WOLED) formed between the first reflective electrode REFL1 and the transflective cathode electrode CAT. Unlike the color coordinate optimizing cell W, the R light emitting cell, and the B light emitting cell, the G light emitting cell is removed from the buffer layer BUF. Due to the removal of the buffer layer BUF, the optical thickness d1 between the first reflective electrode REF1 and the transflective cathode electrode CAT in the G light emitting cell has an optical thickness d1 that satisfies the microcavity conditions capable of emitting green light Lt; / RTI >

In this embodiment, the optical thickness d1 between the color coordinate optimizing cell W and the reflectors CAT and REFL2 opposed to each other with the white OLED WOLED and the transparent anode electrode ANO in the G light- Can be optimized by adjusting the thickness of the hole injection layer (HIL). The optical thickness (between the reflectors CAT and REFL1) opposed to each other with the white OLED (WOLED), the transparent anode electrode ANO and the buffer layer BUF in between the color coordinate optimizing cell W, R light emitting cell and B light emitting cells d2 can be optimized by adjusting the thickness of the buffer layer BUF.

8, the white OLED (WOLED) in the color coordinate optimizing cell W, the R light emitting cell, the G light emitting cell and the B light emitting cell are the same.

9 shows a pixel structure according to a fourth embodiment of the present invention.

Referring to FIG. 9, the pixel structure according to the fourth embodiment of the present invention includes an R light emitting cell, a G light emitting cell, and a B light emitting cell. The pixel according to the fourth embodiment of the present invention does not include the color coordinate optimizing cell W in comparison with the third embodiment of Fig. Since the R, G, and B light emitting cells have the same structure as those of the third embodiment in FIG. 8, a detailed description thereof will be omitted.

In the fourth embodiment, as in the third embodiment, the optical thickness d1 between the reflectors CAT and REFL1 opposed to each other with the white OLED WOLED and the transparent anode electrode ANO sandwiched between the G light- Can be optimized by adjusting the thickness of the hole injection layer (HIL). (D2) between the reflectors (CAT and REFL1) facing each other with the white OLED (WOLED), the transparent anode electrode (ANO) and the buffer layer BUF sandwiched between the R and B light emitting cells, It can be optimized by thickness control.

10 is a cross-sectional view showing a TFT & OLED array of a pixel structure as shown in FIG. 7 in detail.

10, the present invention is a method of depositing a metal or alloy of aluminum (Al), aluminum neodymium (AlNd), and molybdenum (Mo) on a glass substrate (GLS) by a sputtering process A photolithograph process and an etching process are performed to form a gate metal pattern including a gate electrode of the TFT, a gate line connected to the gate electrode, and a gate pad connected to the end of the gate line. Next, the present invention deposits silicon oxide (SiO ₂ ) or silicon nitride (SiN x) by a chemical vapor deposition (CVD) process to form a gate insulating film (GI) on the glass substrate (GLS) to cover the gate metal pattern.

The present invention forms an active pattern (ACT) of a TFT by depositing amorphous silicon on a gate insulating film (GI) by a CVD process and then patterning it by a photolithography process and an etching process. Then, the present invention is an active pattern (ACT) cover to the CVD process, a silicon oxide (SiO ₂₎ or silicon nitride (SiNx) deposited by the first buffer (BUF1) a gate insulating film (GI) and an active pattern (ACT) a The first buffer layer BUF1 is etched through the photolithography process and the etching process to form contact holes for exposing the active pattern ACT at the positions of the source electrode S and the drain electrode D of the TFT .

In the present invention, a source / drain metal made of a metal selected from molybdenum (Mo), aluminum neodymium (AlNd), chromium (Cr), copper (Cu), etc. or a laminate or alloy thereof is formed on a gate insulating film The source electrode S and the drain electrode D of the TFT connected to the active pattern ACT, the data lines orthogonal to the gate lines, and the ends of the data lines, respectively, after patterning by the photolithography process and the etching process, A source / drain metal pattern including a data pad connected to the first buffer layer BUF1 is formed on the first buffer layer BUF1. Each of the source electrode S and the drain electrode D of the TFT is connected to the active layer ACT through contact holes formed in the first buffer layer BUF1. Then, an organic insulating material such as an acryl based organic compound, a benzo-cyclo-butene (BCB) or a perfluorocyclobutane (PFCB) is coated on the first buffer layer BUF1 so as to cover the source / drain metal pattern Alternatively, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiN x) may be deposited on the passivation layer PAS to expose the source electrode S of the TFT through a photolithography process and an etching process Contact holes are formed in the passivation layer (PAS).

In the present invention, after aluminum (Al), silver (Ag), or an alloy thereof is deposited on a passivation layer (PAS) by a sputtering method, the metal is patterned through a photolithography process and an etching process, The electrode REFL1 is formed, or the first reflective electrode REFL1 is formed only in the R light emitting cell and the B light emitting cell as shown in the drawing. The first reflective electrode REFL1 is connected to the source electrode of the TFT through the contact hole passing through the passivation layer PAS. Then, the present invention is deposited over the first reflective electrode in a silicon oxide by a sputtering method so as to cover the (REFL1) (SiO ₂₎ or of silicon nitride (SiNx) a first reflective electrode (REFL1) and the passivation layer (PAS) After forming the second buffer layer BUF2, a contact hole exposing the source electrode S of the TFT in the G light-emitting cell through a photolithography process and an etching process, and a second contact hole exposing the first reflective electrode REFL1 in the R and B light- Are formed in the second buffer layer BUF2.

In the present invention, aluminum (Al), silver (Ag), or an alloy thereof is formed on a second buffer layer (BUF2) by a sputtering method and then the metal is partially removed through a photolithography process and an etching process, The second reflective electrode REFL2 is formed on the second buffer layer BUF2. Next, a transparent body such as ITO is deposited on the second buffer layer 2 and the second reflective electrode REFL2 by a sputtering method, and the transparent conductor is patterned through a photolithography process and an etching process, A transparent anode electrode ANO is formed. In the G light emitting cell, the transparent anode electrode ANO overlaps with the second reflective electrode REFL2 and is connected to the source electrode S of the TFT via the contact hole passing through the second buffer layer BUF2 and the second reflective electrode REFL2. As shown in Fig. In the R and B light emitting cells, the transparent anode electrode AND is connected to the first reflective electrode REFL1 through the contact holes passing through the second buffer layer BUF2, and is connected to the first reflective electrode REFL1 via the first reflective electrode REFL1. And is electrically connected to the source electrode S.

In the present invention, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited by a CVD process, and the inorganic insulating material is patterned through a photolithography process and an etching process to form R, And a bank pattern BANK buried in the contact holes passing through the second buffer layer BUF2 is formed on the second buffer layer BUF2 and the transparent anode electrode AND. Next, the present invention is a method of continuously depositing a hole injecting layer material, a hole transporting layer material, a white luminescent layer material, an electron transporting layer material, and an electron injecting layer material by a thermal evaporation process, (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL). Next, the present invention is a method of forming a semi-transmissive cathode electrode (CAT) by depositing aluminum (Al), silver (Ag) or an alloy thereof on a thin electron injection layer (EIL) EIL). The transflective cathode electrode (CAT) reflects approximately 50% of the light incident from the white OLED and transmits the remaining 50% of the light.

6, the color coordinate optimizing cell W includes the first reflective electrode REFL1 formed in the same shape as the R and G light emitting cells, and the second reflective electrode REFL1 formed between the second buffer layer BUF2 and the transparent anode electrode ANO And a second reflective electrode REFL2. The second reflective electrode REFL2 formed in the color coordinate optimizing cell W has aperture holes as shown in FIG.

When the second reflective electrode REFL2 is patterned, apertures are formed through the second reflective electrode REFL2 in the color coordinate optimizer cell W. The color coordinate optimizing cell W is substantially the same as the structure of the R and B light emitting cells in other structures other than the aperture hole penetrating the second reflective electrode REFL2.

When the TFT & OLED array substrate is thus completed, the present invention uses a TFT & OLED array substrate and a color filter array substrate on which a color filter is formed, as a sealant.

11 is a cross-sectional view showing a TFT < ' > OLED array of a pixel structure as shown in Fig. 9 in detail. In this embodiment, the steps from the gate metal patterning process to the passivation process are substantially the same as those in the embodiment of FIG. 10 described above, and thus detailed description thereof will be omitted.

Referring to FIG. 11, the present invention is a method of forming a gate metal pattern, a gate insulating film (GI), an active pattern (ACT), a source / drain metal pattern, and a passivation layer (PAS) sequentially, ), Silver (Ag) or an alloy thereof is deposited on the passivation layer (PAS), and then the metal is patterned through a photolithography process and an etching process to form a first reflective electrode REFL1 in all the light emitting cells. The first reflective electrode REFL1 is connected to the source electrode of the TFT through the contact hole passing through the passivation layer PAS. Then, the present invention is deposited over the first reflective electrode in a silicon oxide by a sputtering method so as to cover the (REFL1) (SiO ₂₎ or of silicon nitride (SiNx) a first reflective electrode (REFL1) and the passivation layer (PAS) After the second buffer layer BUF2 is formed, the thickness of the second buffer layer BUF2 in the G light emitting cell is reduced or the second buffer layer BUF2 is completely removed through the photolithography process and the etching process, The contact holes exposing the first reflective electrode REFL1 are formed in the second buffer layer BUF2. Therefore, the thickness of the second buffer layer BUF2 formed in the G light emitting cell becomes lower than the thickness of the second buffer layer BUF2 formed in the R and B light emitting cells.

In the present invention, aluminum (Al), silver (Ag), or an alloy thereof is formed on a second buffer layer (BUF2) by a sputtering method and then the metal is partially removed through a photolithography process and an etching process, The second reflective electrode REFL2 is formed on the second buffer layer BUF2 or the passivation layer PAS having a low thickness. And the second reflective electrode REFL2 is connected to the source electrode S of the TFT through the contact hole. Next, a transparent body such as ITO is deposited on the second buffer layer 2 and the second reflective electrode REFL2 by a sputtering method, and the transparent conductor is patterned through a photolithography process and an etching process, A transparent anode electrode ANO is formed. In the G light emitting cell, the transparent anode electrode ANO overlaps with the second reflective electrode REFL2 and is electrically connected to the source electrode S of the TFT via the contact hole and the second reflective electrode REFL2. In the R and B light emitting cells, the transparent anode electrode AND is connected to the first reflective electrode REFL1 through the contact holes, and electrically connected to the source electrode S of the TFT via the first reflective electrode REFL1 do.

In the present invention, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited by a CVD process, and the inorganic insulating material is patterned through a photolithography process and an etching process to form R, And a bank pattern BANK buried in the contact holes passing through the second buffer layer BUF2 is formed on the second buffer layer BUF2 and the transparent anode electrode AND. Next, the present invention is a method of continuously depositing a hole injecting layer material, a hole transporting layer material, a white luminescent layer material, an electron transporting layer material, and an electron injecting layer material by a thermal evaporation process, (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL). The structure and thickness of the white OLED thus formed are the same in all light emitting cells. Next, the present invention is a method of forming a semi-transmissive cathode electrode (CAT) by depositing aluminum (Al), silver (Ag) or an alloy thereof on a thin electron injection layer (EIL) EIL).

The color coordinate optimizing cell W shown in FIG. 8 includes a first reflective electrode REFL1 formed in the same shape as the R and G light emitting cells, and also includes a second buffer layer BUF2 and a transparent anode electrode ANO And a second reflective electrode REFL2. The second reflective electrode REFL2 formed in the color coordinate optimizing cell W has aperture holes as shown in FIG.

When the TFT & OLED array substrate is thus completed, the present invention uses a TFT & OLED array substrate and a color filter array substrate on which a color filter is formed, as a sealant.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

FIGS. 1 to 3 are sectional views showing the structure of organic light emitting diode display devices of the related art.

4 is a cross-sectional view schematically illustrating a structure of a light emitting cell of an organic light emitting diode display device according to an embodiment of the present invention.

5 is a graph showing an experimental result of the organic light emitting diode display device shown in FIG.

6 is a cross-sectional view illustrating a pixel structure of an organic light emitting diode display device according to a first embodiment of the present invention.

7 is a cross-sectional view illustrating a pixel structure of an organic light emitting diode display device according to a second embodiment of the present invention.

8 is a sectional view showing a pixel structure of an organic light emitting diode display device according to a third embodiment of the present invention.

9 is a cross-sectional view illustrating a pixel structure of an organic light emitting diode display device according to a fourth embodiment of the present invention.

10 is a cross-sectional view showing a TFT & OLED array of a pixel structure as shown in FIG. 7 in detail.

11 is a cross-sectional view showing a TFT < ' > OLED array of a pixel structure as shown in Fig. 9 in detail.

Description of the Related Art

WOLED: White OLED CAT: Transflective cathode electrode

ANO: transparent anode electrode BUF, BUF1, BUF2: buffer layer

REFL, REFL1, REF2: reflection electrode

Claims (12)

A first reflective electrode; A buffer layer formed on the first reflective electrode; A second reflective electrode formed on the buffer layer in the G light emitting cell; A transparent anode electrode formed on the buffer layer in the R and B light emitting cells and formed on the second reflective electrode in the G light emitting cell; A white organic light emitting diode element formed on the anode electrode in the R, G and B light emitting cells; And And a transflective cathode electrode formed on the white organic light emitting diode device in the R, G, and B light emitting cells. The method according to claim 1, The R and B light emitting cells have the same structure, Wherein an optical thickness between the first reflective electrode and the transflective cathode in the R and B light emitting cells is spaced by an optical thickness that satisfies a cavity condition simultaneously emitting red light and blue light. device. The method according to claim 1, The G light emitting cell has a different structure from the R and B light emitting cells, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the G light emitting cell is separated by an optical thickness that satisfies a cavity condition for emitting green light, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the G light emitting cell is smaller than the optical thickness between the first reflective electrode and the transflective cathode in the R and B light emitting cells. Light emitting diode display element. The method according to claim 1, Wherein the first reflective electrode comprises: Wherein the organic light emitting diode display device is formed on the R, G, and B light emitting cells or only on the R and B light emitting cells. The method according to claim 1, Further comprising a color coordinate optimizing cell for adjusting a color coordinate of the organic light emitting diode display element, The color coordinate optimizing cell includes a first reflective electrode, a buffer layer formed on the first reflective electrode, a second reflective electrode formed on the buffer layer, a transparent anode electrode formed on the buffer layer and having a plurality of openings therein, A white organic light emitting diode element formed on the anode electrode, and a transflective cathode electrode formed on the white organic light emitting diode element, The optical thickness between the first reflective electrode and the transflective cathode opposite to each other in the aperture coordinate position in the color coordinate optimization cell is spaced apart by an optical thickness satisfying a cavity condition simultaneously emitting red light and blue light, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the optimized cell is spaced by an optical thickness that satisfies a cavity condition for emitting green light. The method according to claim 1, Wherein the thickness of the buffer layer formed in the R and B light emitting cells is greater than the thickness of the buffer layer formed in the G light emitting cells. Forming a buffer layer on the first reflective electrode; Forming a second reflective electrode on the buffer layer in the G light emitting cell; Forming a transparent anode electrode on the buffer layer in the R and B light emitting cells and forming the transparent anode electrode on the second reflective electrode in the G light emitting cell; Forming white organic light emitting diode devices on the anode electrodes in the R, G, and B light emitting cells; And And forming a red, green and blue light emitting cells on the white organic light emitting diode device. 8. The method of claim 7, The R and B light emitting cells have the same structure, Wherein an optical thickness between the first reflective electrode and the transflective cathode in the R and B light emitting cells is spaced by an optical thickness that satisfies a cavity condition simultaneously emitting red light and blue light. / RTI > 8. The method of claim 7, The G light emitting cell has a different structure from the R and B light emitting cells, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the G light emitting cell is separated by an optical thickness that satisfies a cavity condition for emitting green light, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the G light emitting cell is smaller than the optical thickness between the first reflective electrode and the transflective cathode in the R and B light emitting cells. A method of manufacturing a light emitting diode display element. 8. The method of claim 7, Wherein the first reflective electrode comprises: Wherein the light emitting cells are formed on the R, G, and B light emitting cells or only on the R and B light emitting cells. 8. The method of claim 7, Further comprising forming a color coordinate optimizing cell for adjusting a color coordinate of the organic light emitting diode display element, Wherein forming the color coordinate optimization cell comprises: Forming a buffer layer on the first reflective electrode; Forming a second reflective electrode on the buffer layer; Forming a transparent anode electrode having a plurality of apertures on the buffer layer; Forming the white organic light emitting diode device on the anode electrode; And forming a transflective cathode electrode on the white organic light emitting diode device, The optical thickness between the first reflective electrode and the transflective cathode opposite to each other in the aperture coordinate position in the color coordinate optimization cell is spaced apart by an optical thickness satisfying a cavity condition simultaneously emitting red light and blue light, Wherein the optical thickness between the second reflective electrode and the transflective cathode in the optimized cell is spaced by an optical thickness that satisfies a cavity condition for emitting green light. 8. The method of claim 7, Wherein the thickness of the buffer layer formed in the R and B light emitting cells is greater than the thickness of the buffer layer formed in the G light emitting cells.

Images