Abstract:
An OLED display device includes a substrate; pixel regions defined by gate and data lines, each pixel region including red, green, first blue and second blue sub-pixels; a TFT in each pixel region; a first electrode connected to the thin film transistor; an insulating layer exposing the first electrode; hole injecting and hole transporting layers stacked on the first electrode; red, green and blue emitting layer on the hole transporting layer, the red and green emitting layers respectively being in the red and green sub-pixels, and the blue emitting layer being in the first and second blue sub-pixels; electron transporting and electron injecting layers stacked on the red, green and blue emitting layers; and a second electrode on the insulating layer and the electron injecting layer, wherein the first electrode in the second blue sub-pixel has a multi-layered structure of the first electrode layer and at least one metal layer.

Description:
The present application claims the priority benefit of Korean Patent Application Nos. 10-2012-0155239 and 10-2013-0085411, filed in Republic of Korea on Dec. 27, 2012 and Jul. 19, 2013, respectively, all of which are herein incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an organic light emitting diode (OLED) display device, and more particularly, to an OLED display device including four color emitting layers and method of fabricating the OLED display device. 
     2. Related Art 
     An OLED display device of new flat panel display devices is a self-emitting type. Since the OLED display device does not require a backlight, which is required for a liquid crystal display device, the OLED device has a thin profile and light weight. 
     Particularly, various colors, e.g., red, green, blue, cyan, light-blue, and so on, can be displayed using an organic material. The red and green phosphorescent materials having excellent efficiency and lifetime are used, while the deep-blue fluorescent material having similar color property and lifetime as the red and green phosphorescent materials are used. However, the deep-blue fluorescent material has low efficiency such that there is a disadvantage in power consumption. 
       FIG. 1  is a graph of simulation data for showing power consumption in an OLED display device using a red phosphorescent material PH_R, a green fluorescent material FL_G, a green phosphorescent material PH_G, a blue phosphorescent material PH_B1 and a blue fluorescent material FL_B2. 
       FIG. 1  shows power consumption of the OLED display device, which uses the red phosphorescent material PH_R, the green phosphorescent material PH_G and the blue phosphorescent material PH_B1, is decreased by about 45% in comparison to the OLED, which uses the red phosphorescent material PH_R, the green phosphorescent material PH_G and the blue fluorescent material FL_B2. 
       FIG. 2  is a schematic plane view of the sub-pixel arrangement in the related art OLED device. 
     In  FIG. 2 , one pixel  100   a  includes red, green and blue sub-pixels R, G and B. On the other hand, another pixel  100   b  includes the red sub-pixel R, the green sub-pixel G, a light-blue sub-pixel B1 of a phosphorescent material and a deep-blue sub-pixel B2 of the fluorescent material to prevent a problem of power consumption increase resulted from the fluorescent material. 
     In addition, to display images, the light-blue material is used above 70%, and the deep-blue material is used below 30%. The light-blue image is displayed using the phosphorescent material, while the deep-blue is displayed using the fluorescent material. Accordingly, the four emitting materials and four deposition processes are required to fabricate the OLED display device having the pixel  100   b.    
     Referring to  FIG. 3 , which is a schematic cross-sectional view of the related art OLED display device including red, green, first blue and second blue sub-pixels, a fabricating process of the OLED display device is explained. 
     As shown in  FIG. 3 , the OLED display device includes an organic emitting cell. The organic emitting cell includes a first electrode  106  connected to a thin film transistor (TFT) T, which is formed on a substrate  101 , a hole injecting layer  107 , a hole transporting layer  108 , an emitting layer  109 , an electron transporting layer  110 , an electron injecting layer  111 , and a second electrode  112 . The hole injecting layer  107 , the hole transporting layer  108 , the emitting layer  109 , the electron transporting layer  110 , the electron injecting layer  111 , and the second electrode  112  are stacked on the first electrode  106 . 
     Particularly, after forming the TFT T on the substrate  101 , the first electrode  106 , the hole injecting layer  107  and the hole transporting layer  108  are formed. Next, the red emitting layer  109 R, the green emitting layer  109 G, the light-blue emitting layer  109 B 1  and the deep-blue emitting layer  109 B 2  are formed in the red sub-pixel R, the green sub-pixel G, the first blue sub-pixel B1 and the second blue sub-pixel B2. To form the four-colored pixel structure, a step of forming the light-blue emitting layer  109 B 1  or the deep-blue emitting layer  109 B 2  is further required. 
     Namely, since the OLED display device having the four-colored pixel structure includes the red, green, first blue and second blue sub-pixels R, G, B1 and B2, production costs and fabricating steps are increased in comparison to the OLED display device having the three-colored pixel structure. In addition, since the fluorescent material is used for displaying the deep-blue, there are still disadvantages in power consumption. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to an OLED display device and a method of fabricating the same that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
     Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. These and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. 
     In accordance with the present invention, as embodied and broadly described herein, OLED display device includes a substrate; pixel regions defined by gate lines and data lines formed on the substrate, each pixel region including red, green, first blue and second blue sub-pixels; a thin film transistor in each pixel region; a first electrode electrically connected to a drain electrode of the thin film transistor; an insulating layer exposing the first electrode; a hole injecting layer and a hole transporting layer sequentially stacked on the first electrode; red, green and blue emitting layer on the hole transporting layer, the red and green emitting layers respectively being in the red and green sub-pixels, and the blue emitting layer being in the first and second blue sub-pixels; an electron transporting layer and an electron injecting layer sequentially stacked on the red, green and blue emitting layers; and a second electrode on the insulating layer and the electron injecting layer, wherein the first electrode in the second blue sub-pixel has a multi-layered structure of the first electrode layer and at least one metal layer. 
     Preferably, the first blue sub-pixel may display a light-blue color, and the second blue sub-pixel may display a deep-blue color. 
     Preferably, the multi-layered structure may be a double-layered structure of the first electrode layer and a first metal layer under the first electrode layer, and the first metal layer includes Ag or Ag alloy, and wherein the first electrode layer includes ITO or IZO or other transparent conductive materials. 
     Preferably, the multi-layered structure may be a triple-layered structure of the first electrode layer, a first metal layer on the first electrode layer and a second metal layer on the first metal layer, and each of the first electrode layer and the second metal layer includes ITO or IZO or other transparent conductive materials, and wherein the first metal layer includes Ag or Ag alloy. 
     Preferably, the first electrode layer may have a thickness more than 0 angstrom and less than about 300 angstroms, and the first metal layer may have a thickness of about 100 to 200 angstroms. 
     Preferably, the first electrode layer may have a thickness more than 0 angstrom and less than about 300 angstroms, and the first metal layer may have a thickness of about 100 to 200 angstroms, and wherein the second metal layer has a thickness more than 0 angstrom and less than about 100 angstroms. 
     Preferably, the blue emitting layer in the first and second blue sub-pixels, may include the same blue phosphorescent organic material. 
     Preferably, the second electrode may include Al. 
     A substrate for an organic light emitting diode display device, comprising: a substrate; a plurality of pixel regions defined by a plurality of gate lines and a plurality of data lines formed on the substrate, each pixel region including red, green, first blue and second blue sub-pixels; a thin film transistor in each pixel region; a first electrode electrically connected to a drain electrode of the thin film transistor; an insulating layer exposing the first electrode; a hole injecting layer and a hole transporting layer sequentially stacked on the first electrode; red, green and blue emitting layer on the hole transporting layer, the red emitting layer being in the red sub-pixel, the green emitting layer being in the green sub-pixel, and the blue emitting layer being in the first and second blue sub-pixels; an electron transporting layer and an electron injecting layer sequentially stacked on the red, green and blue emitting layers; and a second electrode on the insulating layer and the electron injecting layer, wherein the first electrode in the second blue sub-pixel has a multi-layered structure of the first electrode layer and at least one metal layer. 
     Preferably, the multi-layered structure may be a double-layered structure of the first electrode layer and a first metal layer under the first electrode layer, or a triple-layered structure of the first electrode layer, a first metal layer on the first electrode layer and a second metal layer on the first metal layer. 
     Preferably, the blue emitting layer in the first and second blue sub-pixels may include the same blue phosphorescent organic material. 
     In the another aspect, a method of fabricating an organic light emitting diode display device includes forming a plurality of gate lines and a plurality of data lines to define a plurality of pixel regions, each pixel region including red, green, first blue and second blue sub-pixels; forming a thin film transistor in each pixel region, wherein the first electrode in the second blue sub-pixel has a multi-layered structure of the first electrode layer and at least one metal layer; forming a first electrode electrically connected to a drain electrode of the thin film transistor; forming an insulating layer exposing the first electrode; sequentially forming a hole injecting layer and a hole transporting layer stacked on the first electrode; forming red, green and blue emitting layer on the hole transporting layer, the red emitting layer being in the red sub-pixel, the green emitting layer being in the green sub-pixel, and the blue emitting layer being in the first and second blue sub-pixels; sequentially forming an electron transporting layer and an electron injecting layer sequentially stacked on the red, green and blue emitting layers; and forming a second electrode on the insulating layer and the electron injecting layer. 
     Preferably, the first blue sub-pixel may display a light-blue color, and the second blue sub-pixel may display a deep-blue color. 
     Preferably, the multi-layered structure may be a double-layered structure of the first electrode layer and a first metal layer under the first electrode layer, and the first metal layer may include Ag or Ag alloy, and wherein the first electrode layer may include ITO or IZO or other transparent conductive materials. 
     Preferably, the multi-layered structure may be a triple-layered structure of the first electrode layer, a first metal layer on the first electrode layer and a second metal layer on the first metal layer, and each of the first electrode layer and the second metal layer includes ITO or IZO or other transparent conductive materials, and wherein the first metal layer includes Ag or Ag alloy. 
     Preferably, the first electrode layer may have a thickness more than 0 angstrom and less than about 300 angstroms, and the first metal layer may have a thickness of about 100 to 200 angstroms. 
     Preferably, the first electrode layer may have a thickness more than 0 angstrom and less than about 300 angstroms, and the first metal layer may have a thickness of about 100 to 200 angstroms, and wherein the second metal layer may have a thickness more than 0 angstrom and less than about 100 angstroms. 
     Preferably, the blue emitting layer in the first and second blue sub-pixels may include the same blue phosphorescent organic material. 
     Preferably, the second electrode may include Al. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. 
         FIG. 1  shows power consumption according to materials of an emitting material for the OLED display device. 
         FIG. 2  is a schematic plane view of the sub-pixel arrangement in the related art OLED device. 
         FIG. 3  is a schematic cross-sectional view of the related art OLED display device including red, green, first blue and second blue sub-pixels. 
         FIG. 4  is a schematic cross-sectional view of an OLED display device according to an exemplary embodiment of the present invention. 
         FIGS. 5A to 5J  are cross-sectional views showing fabricating processes of an OLED display device according to an exemplary embodiment of the present invention. 
         FIG. 6  is a schematic cross-sectional view of an OLED display device according to another exemplary embodiment of the present invention. 
         FIG. 7  is a color-coordinate of first and second blue colors in an OLED display device according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. 
       FIG. 4  is a schematic cross-sectional view of an OLED display device according to an exemplary embodiment of the present invention. 
     As shown in  FIG. 4 , a gate electrode  202  is formed on a substrate  201 . For example, the gate electrode  202  may have a double-layered structure of molybdenum (Mo) and aluminum alloy (AlNd). 
     On the gate electrode  202 , a gate insulating layer  203  is formed to cover the substrate  201 . 
     On the gate insulating layer  203 , an oxide semiconductor layer  204  is formed to correspond to a region where the gate electrode  202  is formed. For example, the oxide semiconductor layer  204  may be formed of an oxide semiconductor material such as indium-gallium-zinc-oxide (IGZO) or indium-tin-zinc-oxide (ITZO). The oxide semiconductor layer  204  may have a width larger than the gate electrode  202 . On the oxide semiconductor layer  204 , an etch-stopper  205  is formed to prevent damages on the oxide semiconductor layer  204  resulting from an etching process of a metallic material for source and drain electrodes. For example, the etch-stopper  205  may have substantially the same width as the gate electrode  202 . The source and drain electrodes  206   a  and  206   b  are formed on the oxide semiconductor layer  204 . The source and drain electrodes  206   a  and  206   b  are spaced apart from each other with the etch-stopper  205  therebetween. 
     The gate electrode  202 , the gate insulating layer  203 , the semiconductor layer  204 , the etch-stopper  205 , the source electrode  206   a  and the drain electrode  206   b  constitute a driving thin film transistor in each sub-pixel region. Although not shown, a plurality of gate lines and a plurality of data lines are formed on the substrate  201 . The gate lines and the data lines cross each other to define the pixel regions. Each pixel region includes red, green, light-blue and deep-blue sub-pixels R, G, B1 and B2. In addition, a switching thin film transistor, which is connected to the gate line, the data line and the driving thin film transistor, is formed on the substrate and in each sub-pixel regions R, G, B1 and B2. 
     A first insulating layer  207  is formed on the substrate  201 , where the source and drain electrodes  206   a  and  206   b  are formed, and a contact hole exposing the drain electrode  206   b  is formed through the first insulating layer  207 . In a deep-blue sub-pixel B2, a first metal layer  220  is formed. The first metal layer  220  may be formed of Ag or Ag alloy. 
     Next, a first electrode layer  208  is formed on the first insulating layer  207  and the first metal layer  220 . The first electrode layer  208  is electrically connected to the drain electrode  206   b  through the contact hole. The first electrode layer  208  may be formed of a transparent conductive material such as ITO or IZO or other transparent materials. 
     As a result, the first electrode layer  208  and the first metal layer  220  are formed in the deep-blue sub-pixel B2, and the first electrode layer  208  without the first metal layer  220  is formed in the red, green and light-blue sub-pixels R, G and B1. In other words, a first electrode in the deep-blue sub-pixel B2 has a double-layered structure of the first metal layer  220  and the first electrode layer  208 , while a first electrode in the red, green and light-blue sub-pixel R, G and B1 has a single-layered structure of the first electrode layer  208 . 
     After forming the first metal layer  220  and the first electrode layer  208 , a second insulating layer  209  defining each of the sub-pixels R, G, B1 and B2 is formed, and a hole injecting layer  210  and a hole transporting layer  211  are sequentially formed on the first electrode layer  208  in each of the sub-pixels R, G, B1 and B2. 
     A red phosphorescent emitting layer  212 R is formed on the hole transporting layer  211  in the red sub-pixel R, and a green phosphorescent emitting layer  212 G is formed on the hole transporting layer  211  in the green sub-pixel G. In addition, a blue phosphorescent emitting layer  212 B is formed on the hole transporting layer  211  in the light-blue sub-pixel B1 and the deep-blue sub-pixel B2. 
     For example, the red phosphorescent emitting layer  212 R may include a host material such as carbazole biphenyl (CBP) or 1,3-bis(carbazol-9-yl) (mCP) and a dopant such as (bis(1-phenylisoquinoline)acetylacetonate iridium) (PIQIr(acac)), bis(1-henylquinoline)acetylacetonate iridium) (PQIr(acac)), (tris(1-phenylquinoline)iridium) (PQIr), or (octaethylporphyrin platinum) (PtOEP). 
     The green phosphorescent emitting layer  212 G may include a host material such as CBP or mCP and a dopant such as fac-tris(2-phenylpyridine)iridium (Ir(ppy) 3 ). 
     The blue phosphorescent emitting layer  212 B may include a host material such as CBP or mCP and a dopant such as FIrpic ([bis(4,6-di-fluorophenyl)-pyridinato-N,C2′] 2 iridium). 
     However, the materials for the red, green and blue phosphorescent emitting layers  212 R,  212 G and  212 B are not limited thereto. 
     On the red, green and blue phosphorescent emitting layers  212 R,  212 G and  212 B, an electron transporting layer  213  and an electron injecting layer  214  are sequentially formed, and a second electrode layer  215  is formed to cover the electron injecting layer  214  and the second insulating layer  209 . For example, the second electrode layer  215  may include aluminum (Al). 
       FIG. 6  is a schematic cross-sectional view of an OLED display device according to another exemplary embodiment of the present invention. 
     As shown in  FIG. 6 , a gate electrode  302  is formed on a substrate  301 . For example, the gate electrode  302  may have a double-layered structure of molybdenum (Mo) and aluminum alloy (AlNd). 
     On the gate electrode  302 , a gate insulating layer  303  is formed to cover the substrate  301 . 
     On the gate insulating layer  303 , an oxide semiconductor layer  304  is formed to correspond to a region where the gate electrode  302  is formed. For example, the oxide semiconductor layer  304  may be formed of an oxide semiconductor material such as indium-gallium-zinc-oxide (IGZO) or indium-tin-zinc-oxide (ITZO). The oxide semiconductor layer  304  may have a width larger than the gate electrode  302 . On the oxide semiconductor layer  304 , an etch-stopper  305  is formed to prevent damages on the oxide semiconductor layer  304  resulting from an etching process of a metallic material for source and drain electrodes. For example, the etch-stopper  305  may have substantially the same width as the gate electrode  302 . The source and drain electrodes  306   a  and  306   b  are formed on the oxide semiconductor layer  304 . The source and drain electrodes  306   a  and  306   b  are spaced apart from each other with the etch-stopper  305  therebetween. 
     A first insulating layer  307  is formed on the substrate  301 , where the source and drain electrodes  306   a  and  306   b  are formed, and a contact hole  308   h  exposing the drain electrode  306   b  is formed through the first insulating layer  307 . A first electrode layer  308  is deposited on the first insulating layer  307 . The first electrode layer  308  is electrically connected to the drain electrode  306   b  through the contact hole. The first electrode layer  308  may be formed of a transparent conductive material such as ITO or IZO. 
     On the first electrode layer  308 , a first metal layer  320  is deposited. The first metal layer  320  may be formed of Ag or Ag alloy. 
     Sequentially, a second metal layer  330  is deposited on the first metal layer  320 . the second metal layer  330  may be formed of ITO or other transparent materials. 
     Next, by performing a half-tone mask process, the first electrode layer  308 , the first metal layer  320  and the second metal layer  330  are formed in the deep-blue sub-pixel B2, and the first electrode  308  without the first and second metal layers  320  and  330  is formed in the red, green and blue sub-pixels R, G and B1. In other words, a first electrode in the deep-blue sub-pixel B2 has a triple-layered structure of the first electrode layer  308 , the first metal layer  220  and the second metal layer  330 , while a first electrode in the red, green and light-blue sub-pixel R, G and B1 has a single-layered structure of the first electrode layer  308 . 
     After forming the first and second metal layers  320  and  330  and the first electrode layer  308 , a second insulating layer  309  defining each of the sub-pixels R, G, B1 and B2, and a hole injecting layer  310  and a hole transporting layer  311  are sequentially formed on the second metal layer  330  in the deep-blue sub-pixel B2 and the first electrode layer  308  in each of the red, green and light-blue sub-pixels R, G and B1. 
     A red phosphorescent emitting layer  312 R is formed on the hole transporting layer  311  in the red sub-pixel R, and a green phosphorescent emitting layer  312 G is formed on the hole transporting layer  311  in the green sub-pixel G. In addition, a blue phosphorescent emitting layer  312 B is formed on the hole transporting layer  311  in the light-blue sub-pixel B1 and the deep-blue sub-pixel B2. 
     For example, the red phosphorescent emitting layer  312 R may include a host material such as carbazole biphenyl (CBP) or 1,3-bis(carbazol-9-yl) (mCP) and a dopant such as (bis(1-phenylisoquinoline)acetylacetonate iridium) (PIQIr(acac)), bis(1-henylquinoline)acetylacetonate iridium) (PQIr(acac)), (tris(1-phenylquinoline)iridium) (PQIr), or (octaethylporphyrin platinum) (PtOEP). 
     The green phosphorescent emitting layer  312 G may include a host material such as CBP or mCP and a dopant such as fac-tris(2-phenylpyridine)iridium (Ir(ppy) 3 ). 
     The blue phosphorescent emitting layer  312 B may include a host material such as CBP or mCP and a dopant such as FIrpic, (4,6-F2 ppy) 2 Irpic, or L2BD111. 
     However, the materials for the red, green and blue phosphorescent emitting layers  312 R,  312 G and  312 B are not limited thereto. 
     On the red, green and blue phosphorescent emitting layers  312 R,  312 G and  312 B, an electron transporting layer  313  and an electron injecting layer  314  are sequentially formed, and a second electrode layer  315  is formed to cover the electron injecting layer  314  and the second insulating layer  209 . For example, the second electrode layer  315  may include aluminum (Al). 
     Hereinafter, referring to  FIGS. 5A to 5J , which are cross-sectional views showing fabricating processes of an OLED display device according to an exemplary embodiment of the present invention, a method of fabricating an OLED display device shown in  FIG. 4  will be illustrated. 
     After depositing a metal layer for the gate electrode  202  on the substrate  201  as shown in  FIG. 5A , the gate electrode  202  is formed by a mask process as shown in  FIG. 5B . The gate electrode  202  has a double-layered structure of Mo and AlNd. After sequentially depositing Mo and AlNd layers, the AlNd and Mo layers are sequentially etched to form the gate electrode  202 . 
     Next, as shown in  FIG. 5C , the gate insulating layer  203  is formed on the substrate  201 , where the gate electrode  202  is formed, and the oxide semiconductor material layer is formed on the gate insulating layer  203 . 
     As shown in  FIG. 5D , the oxide semiconductor layer is patterned by a mask process to form the oxide semiconductor layer  204  over the gate electrode  202 . The oxide semiconductor layer  204  overlaps the gate electrode  202 . The oxide semiconductor layer  204  may be formed of IGZO, ITZO or indium-aluminum-zinc-oxide (IAZO). 
     Next, as shown in  FIG. 5E , the etch-stopper  205  is formed on the oxide semiconductor layer  204 , and the source electrode  206   a  and the drain electrode  206   b , which are spaced apart from each other with the etch-stopper  205  therebetween, are formed. The damages on the oxide semiconductor layer  204  resulting from an etching process for the source and drain electrodes  206   a  and  206   b  is prevented due to the etch-stopper  205 . 
     Next, as shown in  FIG. 5F , after forming the source and drain electrodes  206   a  and  206   b , the first insulating layer  207  is formed over the substrate  201 . The first insulating layer  209  is patterned to form the contact hole for contacting the drain electrode  206   b  and the first electrode layer  208 . 
     Next, the first metal layer  220  is formed on the first insulating layer  209  and in the deep-blue sub-pixel B2. The first metal layer  220  is formed of Ag or Ag alloy and has a thickness of about 100 to 200 angstroms. 
     Next, as shown in  FIG. 5G , the first electrode layer  208  is formed on the first insulating layer  209  and the first metal layer  220 . For example, the first electrode layer  208  is formed of ITO or IZO or other transparent conductive materials and has a thickness more than 0 angstrom and less than about 300 angstroms. If the first metal layer  220  is too thick, the color of the deep blue light could be changed when passing through the first metal layer  220 , because the present invention is bottom-emission type organic light emitting diode display device. 
     Next, as shown in  FIG. 5H , by etching the first electrode layer  208 , a double-layered structure of the first metal layer  220  and the first electrode layer  208  is formed in the deep-blue sub-pixel B2, and a single-layered structure of the first electrode layer  208  is formed in each of the red, green and light-blue sub-pixels R, G and B1. 
     Next, as shown in  FIG. 5I , the second insulating layer  209  is formed to define the sub-pixels R, G, B1 and B2. 
     Next, as shown in  FIG. 5J , the hole injecting layer  210 , the hole transporting layer  211 , the red, green and blue phosphorescent emitting layers  212 R,  212 G and  212 B, the electron transporting layer  213 , the electron injecting layer  214  and the second electrode  215  are formed. The red phosphorescent emitting layer  212 R is formed in the red sub-pixel R, and the green phosphorescent emitting layer  212 G is formed in the green sub-pixel G. The blue phosphorescent emitting layer  212 B is formed in the light-blue sub-pixel B1 and the deep-blue sub-pixel B2. The second electrode layer  215  includes Al. 
     In the OLED shown in  FIG. 6 , the processes for fabricating the gate electrode to the first insulating layer are substantially same as the above-illustrated processes. 
     After forming the first insulating layer  307 , the first electrode layer  308 , the first metal layer  320  and the second metal layer  330  are sequentially deposited. 
     For example, the first electrode layer  308  includes ITO and has a thickness less than about 300 angstroms. If the first metal layer  320  is too thick, the color of the deep blue light could be changed when passing through the first metal layer  320 , because the present invention is bottom-emission type organic light emitting diode display device. So the first metal layer  320  is desirable to include Ag or Ag alloy and to have a thickness of about 100 to 200 angstroms. The second metal layer  330  includes ITO and has a thickness more than 0 angstrom and less than about 100 But the present invention is not limited thereto. 
     Next, by etching the first electrode layer  308 , the first metal layer  320  and the second metal layer  330  using a half-tone mask process, a triple-layered structure of the first electrode layer  308 , the first metal layer  320  and the second metal layer  330  are formed in the deep-blue sub-pixel B2, and a single-layered structure of the first electrode  308  is formed in the red, green and blue sub-pixels R, G and B1. 
     Next, the hole injecting layer  310 , the hole transporting layer  311 , the red, green and blue phosphorescent emitting layers  312 R,  312 G and  312 B, the electron transporting layer  313 , the electron injecting layer  314  and the second electrode  315  are formed. The red phosphorescent emitting layer  312 R is formed in the red sub-pixel R, and the green phosphorescent emitting layer  312 G is formed in the green sub-pixel G. The blue phosphorescent emitting layer  312 B is formed in the light-blue sub-pixel B1 and the deep-blue sub-pixel B2. The second electrode layer  315  includes Al. 
     The phosphorescent organic material has excellent efficiency and lifetime. When the same blue phosphorescent organic material is deposited in the light-blue region and the deep-blue region, the light-blue color of an inherent property of the phosphorescent organic material is displayed in the light-blue region. However, in the deep-blue region, a deep-blue color is displayed due to a micro-cavity effect induced between the first metal layer  220 , 320  on or under the first electrode layer  208 , 308  and the second electrode  215 , 315 . 
     Deep blue light can be displayed by the micro-cavity effect that a specific wavelength of the light gets amplified by constructive reinforcement with reflecting repeatedly between the fi-rst metal layer  220 , 320  on or under the first electrode layer  208 , 308  and the second electrode  215 , 315  respectively. The specific wavelength can be decided by the distance between the first metal layer  220 , 320  and the second electrode  215 , 315 . 
       FIG. 7  is a color-coordinate of first and second blue colors in an OLED display device according to an exemplary embodiment of the present invention. The first blue color of the light-blue color is marked as “Gamut1”, and the second blue color of the deep-blue color is marked as “Gamut2”. With the same light-blue phosphorescent organic material used in the light-blue region and the deep-blue region, the color-coordinate of the light displayed in the light-blue region and the deep-blue region is different. 
     Table 1 shows the color-coordinate in  FIG. 7 . 
     
       
         
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 
                           
                 
                 x 
                 y 
               
               
                   
                   
               
             
             
               
                   
                 Gamut_B1 
                 0.1597 
                 0.1899 
               
               
                   
                 Gamut_B2 
                 0.1477 
                 0.0624 
               
               
                   
                   
               
             
          
         
       
     
     In the CIE color-coordinate index, as CIE(y) is higher, the light-blue is displayed. Accordingly, “Gamut1” is the light-blue color, and “Gamut2” is the deep-blue color. 
     In the OLED display device and the method of fabricating the OLED display device of present invention, since the light-blue color and the deep-blue color are displayed using the same blue phosphorescent organic material by forming a metal layer of Ag or Ag alloy in the deep-blue sub-pixel, one step of depositing an organic material is omitted and power consumption is reduced. In addition, the OLED display device having an increased lifetime with the four-pixels can be provided. 
     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. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.