Abstract:
Described is a plasma switched organic electroluminescent display, which includes an electroluminescent part including a cathode layer, an electroluminescent layer on the cathode layer, and an anode layer on the electroluminescent layer, a first power supply unit connected electrically to the anode layer and disconnected electrically to the cathode layer so as to supply the electroluminescent layer with a first power, a plasma generating part generating a plasma wherein the plasma becomes contacted with the cathode layer, and a second power supply unit generating the plasma by supplying the plasma generating part with a second power, wherein the cathode layer is connected electrically to the first power supply unit through the plasma, thereby enabling to emit light by organic electroluminescent as well as drive the display by a low driving voltage using a plasma discharge as a switch.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an organic electroluminescent display, and more particularly, to a plasma switched organic electroluminescent display driven by plasma switches. 
     2. Background of the Related Art 
     As information telecommunication technologies have been greatly developed, a variety of demands for electronic display devices are highly increased to keep up with the developing information society. And, so do the demands for various displays. In order to satisfy the demands of the information society, for electronic display devices are required characteristics such as high-resolution, large-size, low-cost, high-performance, slim-dimension, and small-size and the like, for which new flat panel displays(FPD) are developed as substitutions for the conventional cathode ray tube(CRT). 
     The FPDs include LCD(liquid crystal display), ELD(electroluminescent display), PDP(plasma display panel), FED(field emission display), VFD(vacuum fluorescence display), and LED(light emitting display), and the like. 
     Compared to the non-emissive device such as LCD, ELD attracts attention as FPD having a response speed faster than that of the non-emissive display, excellent brightness by self-luminescence, easy fabrication thanks to a simple structure, and light weight/slim design. Thus, ELD is widely applied to various fields such as LCD backlight, mobile terminal, car navigation system(CNS), notebook computer, wall TV, and the like. 
     Such an ELD is divided into two categories, i.e. organic electroluminescent display (hereinafter abbreviated OELD) and inorganic electroluminescent display (hereinafter abbreviated IELD) in accordance with materials used for luminescent layers respectively. 
     IELD, which emits light using the collisions of electrons accelerated by an high electric field, is classified into AC thin film ELD, AC thick film ELD, DC thin film ELD, and the like in accordance with thickness of the thin films and driving systems. 
     And, OELD, which emits light by a current flow, is classified into low-molecular OELD and high-molecular OELD. 
     FIG. 1 illustrates a cross-sectional view of a basic construction of OELD using a high molecular electroluminescent material according to a related art. 
     Referring to FIG. 1, stacked on a transparent substrate  11  such as a glass substrate in order are a transparent anode layer  12  formed of ITO(indium tin oxide) or IZO(indium zinc oxide), a hole transport layer  13 , an electroluminescent layer  14 , and a cathode layer  15  formed of a metal. 
     A material for the electroluminescent layer  14  is a conductive high molecule as a kind of conjugated polymers disclosed on U.S. Pat. No. 5,399,502, and U.S. Pat. No. 5,807,627 such as poly(p-phenylenevinylene), i.e. PPV, poly(thiophene), poly(2,5-dialkoxyphenylene-vinylene, i.e. PDMeOPV or the like. 
     FIG. 2 illustrates a cross-sectional view of a basic construction of OELD using a low molecular electroluminescent material for fluorescence according to a related art. 
     Referring to FIG. 2, stacked on a transparent substrate  21  such as a glass substrate in order are a transparent anode layer  22  formed of ITO(indium tin oxide) or IZO(indium zinc oxide), a hole injection layer  23 , a hole transport layer  24 , an electroluminescent layer  25 , an electron transport layer  26 , and a cathode layer  27  formed of metal. The hole injection layer  23 , hole transport layer  24 , and electron transport layer  26  play an auxiliary role in increasing a luminescent efficiency of OELD. In this case, the electroluminescent layer  25  is formed of aluminum tris(8-hydroxyquinoline), i.e. Alq3, perylene, or the like, which are disclosed on U.S. Pat. No. 4,769,292 and U.S. Pat. No. 5,294,870. 
     FIG. 3 illustrates a cross-sectional view of a basic construction of OELD using a low molecular electroluminescent material for phosphorescence according to a related art. 
     Referring to FIG. 3, stacked on a transparent substrate  31  such as a glass substrate in order are a transparent anode layer  32  formed of ITO(indium tin oxide) or IZO(indium zinc oxide), a hole injection layer  33 , a hole transport layer  34 , an electroluminescent layer  35 , a hole blocking layer  36 , an electron transport layer  37 , and a cathode layer  38  formed of metal. 
     The hole injection layer  33 , hole transport layer  34 , hole blocking layer  36 , and electron transport layer  37  play an auxiliary role in increasing a luminescent efficiency of OELD. In this case, the electroluminescent layer  35  is formed of one of phosphorescent emitting materials disclosed on U.S. Pat. No. 6,090,149 such as platinum 2,3,7,8,12,12,17,18-octaethyl-21H,23H-porphine, i.e. PtOEP, iridium complex of Ir(PPY)3, and the like. And, the hole blocking layer  36  is formed of bathocuproine, i.e. BCP, cabazole biphenyl, i.e. CBP, N,N′-diphenyl-N,N′-bis-alpha-napthylbenzidine, i.e. NPD. 
     OELD is divided into active and passive types in accordance with the driving systems. The passive type OELD is driven by a current driving system so that an efficiency of power consumption and a device reliability are decreased as a panel size increases. To settle such problems in case that a diagonal diameter of a panel is longer than 10 inches, the active type OELD using polysilicon thin film transistors(poly-Si TFT) as driving devices is widely used. 
     Yet, when the polysilicon TFT is used as the driving device, the current technology fails to secure a uniformity of the polysilicon TFT, and a device reliability to drive OELD. And, the current technology also requires at least two TFTs for driving the OELD, thereby failing to secure a sufficient yield as well as realize a large-sized screen. And, the current technology also needs a complicated fabricating process, a high-vacuum process requiring an ultra vacuum environment and an expensive equipment for fine photolithography, and a high cleanness less than class 100, whereby a high cost of production is inevitable. 
     Meanwhile, at the stage of commercial use is a plasma display panel (hereinafter abbreviated PDP) using a memory function of plasma. Specifically, PDP is more suitable for a wide screen exceeding a size over 42 inches than OELD or Poly-Si TFT display. 
     FIG. 4 illustrates a schematic bird&#39;s-eye view of disassembled upper and lower plates of PDP for pixel areas according to a related art, in which shown is an example of a general AC type 3-electrodes surface discharge PDP disclosed on U.S. Pat. No. 5,420,602, U.S. Pat. No. 5,661,500, and U.S. Pat. No. 5,674,553. And, the pixel areas of the 3-electrodes surface discharge PDP are shown in the drawing. 
     And, FIG. 5 schematically illustrates cross-sectional views of the assembled upper and lower plates of PDP shown in FIG. 4 along bisecting lines A-A′ and B-B′, respectively, in which the cross-sectional views of the upper and lower plates are combined each other in case that the upper plate is rotated clockwise at 90° for the convenience of understanding. 
     Referring to FIG.  4  and FIG. 5, the pixel areas are provided by a front substrate  41  like a transparent plate such as a glass on an image display surface and a rear substrate  42  placed in parallel with the front substrate  41 . 
     On the front substrate  41  formed are a plurality of transparent sustain electrodes  47  constructing pairs of electrodes X and Y on a surface confronting the rear substrate  42  with uniform intervals therebetween, a plurality of auxiliary sustain electrodes  48  formed on the sustain electrodes  47  respectively so as to reduce resistances of the sustain electrodes  26  respectively, a transparent dielectric layer  49  controlling a discharge current formed on a display (active) area including the auxiliary sustain and sustain electrodes  47  and  48 , and a protecting layer  50  on the transparent dielectric layer  49  so as to protect the transparent dielectric layer  49  from plasma etch using of a material such as MgO or the like having a high secondary electron discharge coefficient to help to generate plasma with ease. 
     Meanwhile, on the rear substrate  42  formed are a plurality of stripe type barrier ribs  43  defining a plurality of discharge spaces so as to cross the sustain electrodes  47  at right angles respectively, a plurality of address electrodes  44  between the barrier ribs  43  so as to cross the sustain electrodes  47  at right angles respectively, a white back dielectric layer  45  covering the entire pixel areas including the address electrodes  44  so as to protect the address electrodes  44  as well as reflect lights emitted from a fluorescent (phosphor) layer  46 , and a fluorescent layer  46  on the white back dielectric layer  45  and both inner walls of the respective barrier ribs  43  inside the respective discharge spaces so as to radiate visible rays on plasma discharge. Specifically, in order to increase the contrast ratio when the barrier ribs  43  are formed, lower barrier ribs  43 A are firstly formed and then black upper barrier ribs  43 B are formed on the lower barrier ribs  43 A. 
     Hg or one of noble gases such as He, Ne, Ar, Xe, Kr, Rn, and the like is used for plasma discharge. And, a mixed gas such as Ne—Xe, Ne—Xe—Ar, or the like is injected into the plasma discharge spaces at a pressure below atmosphere. 
     Explained in the following is an image display process of a random cell in the above-constructed surface discharge AC type PDP(hereinafter abbreviated AC-PDP) according to a related art. 
     The image display process mainly includes a total white and erase period carrying out a whole surface discharge and a whole surface erase, an address period bringing about a discharge selectively in accordance with display data, and a sustain period carrying out a sustain discharge on a lighted cell during the address period. 
     The total white and erase period includes an erase step of discharging a whole surface of the pixel area and removing generated wall charges so as to initialize the whole surface of PDP uniformly and constantly. 
     In order to discharge the whole surface of the pixel area, an initializing voltage of 150V˜300V is applied between the X and Y electrodes constructing the pair of the sustain electrodes (line). 
     In the discharge space where a ‘discharge’ is generated, wall charges and charged particles exist. The total white and erase period is completed by applying an erase voltage enough not to generate the discharge to the X and Y electrodes so as to remove the wall charges and charged particles. The erase voltage, using the same potential of the initializing voltage, may be applied thereto for a short period of time so as not to generate the discharge. 
     The address period is carried out by applying a positive address pulse to the address electrode in order and by applying a negative scan pulse synchronized with the address pulse to the Y electrode in accordance with the display data selectively. 
     The scan pulse is applied to the pixel area having the display data only but fails to be applied to the pixel area having no display data. As a result, the discharge is generated from the cell to which the address and scan pulses are applied simultaneously. Hence, wall charges are accumulated in the lighted cell. 
     And, the sustain period generates a plurality of the number of times of ‘sustain discharges’ from the cell where the wall charges are accumulated by applying sustain discharge pulses to the X and Y electrodes alternately. In this case, a brightness of the corresponding cell is controlled by the number of times (frequency). The sustain discharge pulse should include a discharge voltage and a discharge period so that the discharge occurs in the cell selected during the address period, and vice versa. 
     However, the 3-electrodes surface discharge PDP excites the inorganic fluorescent material by vacuum UV rays generated from the plasma discharge and uses light irradiated from the inorganic fluorescent material. 
     Unfortunately, the 3-electrodes surface discharge PDP according to the related art has a decay time amounting to several ˜tens ms, thereby showing a residual image when presenting moving pictures. 
     Moreover, the 3-electrodes surface discharge PDP according to the related art has a low efficiency below 3 lm/W as well as a high driving voltage over 180V, whereby a cost of driving IC is too expensive. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention is directed to a plasma switched organic electroluminescent display that substantially obviates one or more of the problems due to limitations and disadvantages of the related art. 
     An object of the present invention is to provide a plasma switched organic electroluminescent display (PSOELD) enabling to emit light by organic electroluminescence having a decay time below several˜tens ns as well as drive the display by a low driving voltage below 160V using a plasma discharge as a switch. 
     Another object of the present invention is to provide a plasma switched organic electroluminescent display (PSOELD) enabling to be fabricated by a simple and easy process using both a general PDP fabricating process and an OELD fabrication process. 
     Another object of the present invention is to provide a plasma switched organic electroluminescent display (PSOELD) enabling to reduce a cost of production by lowering a driving voltage to use a cheaper driving IC as well as provide a large-sized active type PSOELD with ease. 
     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. The objectives 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. 
     To achieve these and other advantages, and in accordance with the purpose of the present invention as embodied and broadly described, a plasma switched organic electroluminescent display according to the present invention includes an electroluminescent part including a cathode layer, an electroluminescent layer on the cathode layer, and an anode layer on the electroluminescent layer, a first power supply unit connected electrically to the anode layer and disconnected electrically to the cathode layer so as to supply the electroluminescent layer with a first power, a plasma generating part generating a plasma wherein the plasma becomes contacted with the cathode layer, and a second power supply unit generating the plasma by supplying the plasma generating part with a second power, wherein the cathode layer is connected electrically to the first power supply unit through the plasma. 
     Preferably, the plasma switched electroluminescent display further includes an address electrode installed between the plasma generating part and the first power supply unit so as to connect the cathode layer electrically to the first power supply unit through the plasma. 
     Preferably, the first power is applied to the cathode layer by the plasma via the address electrode, and the cathode layer is a floating electrode. 
     Preferably, the electroluminescent layer is selected from the group consisting of high molecular organic electroluminescent material, low molecular electroluminescent material using fluorescence, and low molecular electroluminescent material using phosphorescence. 
     In another aspect of the present invention, a plasma switched organic electroluminescent display includes upper and lower plates. The lower plate includes a first substrate, a plurality of sustain electrodes arranged on the first substrate in parallel with each other so as to construct a plurality of sustain electrode pairs wherein each of the sustain electrode pairs comprises a pair of the sustain electrodes adjacent to each other, a dielectric layer on the first substrate including the sustain electrodes, and a plurality of barrier ribs formed on the dielectric layer to define a plurality of pixel areas constructing a plurality of rows and columns so that each of the sustain electrode pairs is placed in the corresponding row or column. The upper plate includes a second substrate, a plurality of address electrodes arranged on the second substrate so as to leave a predetermined interval each other wherein the address electrodes cross the sustain electrodes at right angles, a plurality of anode layers arranged on the second substrate so as to be placed next to the address electrodes in the pixel areas, a plurality of inner insulating/separating layers formed on the second substrate, each of the inner insulating/separating layers having an address electrode opening exposing the corresponding address electrode and an anode opening exposing the corresponding anode, a plurality of electroluminescent layers formed on the inner insulating/separating layers in the pixel areas, each of the electroluminescent layers contacted with the corresponding anode layer exposed through the anode opening, and a plurality of cathode layers formed on the electroluminescent layers. 
     Preferably, the plasma switched organic electroluminescent display further includes a protecting layer formed of MgO on the dielectric layer. 
     Preferably, the anode layers are selected from the group consisting of ITO (indium tin oxide) and IZO (indium zinc oxide). 
     Preferably, each of the anode openings extends to edges of a top of the corresponding anode layer so as to increase an aperture ratio of the display. 
     Preferably, the electroluminescent layers are formed by a means selected from the group consisting of screen print, ink-jet print, dry film laminate, and vacuum evaporation using a shadow mask. 
     Preferably, the plasma switched organic electroluminescent display further includes a plurality of hole injection layers and a plurality of hole transport layers stacked in order between the anode layers and the electroluminescent layers, a plurality of hole blocking layers formed on the electroluminescent layers, and a plurality of electron transport layers formed on the hole blocking layers. 
     In a further aspect of the;present invention, a plasma switched organic electroluminescent display includes upper and lower plates. The lower plate includes a first substrate, a plurality of sustain electrodes arranged on the first substrate in parallel with each other so as to construct a plurality of sustain electrode pairs wherein each of the sustain electrode pairs comprises a pair of the sustain electrodes adjacent to each other, a dielectric layer on the first substrate including the sustain electrodes, a plurality of barrier ribs formed on the dielectric layer to define a plurality of pixel areas constructing a plurality of rows and columns so that each of the sustain electrode pairs is placed in the corresponding row or column, a protecting layer covering the dielectric layer exposed between the barrier ribs, and a plurality of exposed electrodes running in parallel with each other on portions of the protecting layer corresponding to middle parts of the sustain electrode pairs. The upper plate includes a second substrate, a plurality of address electrodes arranged on the second substrate so as to leave a predetermined interval each other wherein the address electrodes cross the sustain electrodes at right angles, a plurality of anode layers arranged on the second substrate so as to be placed next to the address electrodes in the pixel areas, a plurality of inner insulating/separating layers formed on the second substrate, each of the inner insulating/separating layers having an anode opening exposing the corresponding anode layer, a plurality of electroluminescent layers formed on the inner insulating/separating layers in the pixel areas, each of the electroluminescent layers contacted with the corresponding anode layer exposed through the anode opening, and a plurality of cathode layers formed on the electroluminescent layers. 
     Preferably, each of the-anode openings extends to edges of a top of the corresponding anode layer so as to increase an aperture ratio of the display. 
     Preferably, the electroluminescent layers are formed by a means selected from the group consisting of screen print, ink-jet print, dry film laminate, and vacuum evaporation using a shadow mask. 
     Preferably, the plasma switched organic electroluminescent display further includes a plurality of hole injection layers and a plurality of hole transport layers stacked in order between the anode layers and the electroluminescent layers, a plurality of hole blocking layers formed on the electroluminescent layers, and a plurality of electron transport layers formed on the hole blocking layers. 
     In another further aspect of the present invention, a plasma switched organic electroluminescent display includes upper and lower plates. The lower plate includes a first substrate, a plurality of sustain electrodes arranged on the first substrate in parallel with each other so as to construct a plurality of sustain electrode pairs wherein each of the sustain electrode pairs comprises a pair of the sustain electrodes adjacent to each other, a dielectric layer on the first substrate including the sustain electrodes, and a plurality of barrier ribs formed on the dielectric layer to define a plurality of pixel areas constructing a plurality of rows and columns so that each of the sustain electrode pairs is placed in the corresponding row or column. The upper plate includes a second substrate, a plurality of address electrodes arranged on the second substrate so as to leave a predetermined interval each other wherein the address electrodes cross the sustain electrodes at right angles, a plurality of exposed electrodes in parallel with each other on the second substrate between the address electrodes, a plurality of anode layers arranged on the second substrate so as to be placed between the address electrodes and the exposed electrodes in the pixel areas, a plurality of inner insulating/separating layers formed on the second substrate including the address electrodes and the anode layers except the exposed electrodes, each of the inner insulating/separating layers having an anode opening exposing the corresponding anode layer, a plurality of electroluminescent layers formed on the inner insulating/separating layers in the pixel areas, each of the electroluminescent layers contacted with the corresponding anode layer exposed through the anode opening, and a plurality of cathode layers formed on the electroluminescent layers. 
     Preferably, each of the anode openings extends to edges of a top of the corresponding anode layer so as to increase an aperture ratio of the display. 
     Preferably, the electroluminescent layers are formed by a means selected from the group consisting of screen print, ink-jet print, dry film laminate, and vacuum evaporation using a shadow mask. 
     Preferably, the plasma switched organic electroluminescent display further includes a plurality of hole transport layers inserted between the anode layers and the electroluminescent layers. 
     More preferably, the plasma switched organic electroluminescent display further includes a plurality of hole injection layers inserted between the anode layers and the hole transport layers. 
     Preferably, the plasma switched organic electroluminescent display further includes a plurality of electron transport layers inserted between the electroluminescent layers and the cathode layers. 
     More preferably, the plasma switched organic electroluminescent display further includes a plurality of hole blocking layers inserted between the electroluminescent layers and the electron transport layers. 
     Preferably, the plasma switched organic electroluminescent display further includes a protecting layer formed of MgO on the dielectric layer. 
     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. 
     In the drawings: 
     FIG. 1 illustrates a cross-sectional view of a basic construction of OELD using-a high molecular electroluminescent material according to a related art; 
     FIG. 2 illustrates a cross-sectional view of a basic construction of OELD using a low molecular electroluminescent material for fluorescence according to a related art; 
     FIG. 3 illustrates a cross-sectional view of a basic construction of OELD using a low molecular electroluminescent material for phosphorescence according to a related art; 
     FIG. 4 illustrates a schematic bird&#39;s-eye view of disassembled upper and lower plates of PDP according to a related art; 
     FIG. 5 illustrates schematically cross-sectional views of the upper and lower plates of PDP shown in FIG. 4 along bisecting lines A-A′ and B-B′, respectively; 
     FIG. 6 illustrates a schematic bird&#39;s-eye view of PSOELD according to a first embodiment of the present invention; 
     FIG. 7 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 6 along bisecting lines A-A′ and B-B′, respectively; 
     FIG. 8A illustrates a cross-sectional diagram for explaining a plasma generated from a plasma discharge space in PSOELD according to the present invention; 
     FIG. 8B illustrates a cross-sectional diagram for explaining a plasma failing to occur in a plasma discharge space in PSOELD according to the present invention; 
     FIG. 9 illustrates a schematic bird&#39;s-eye view of PSOELD according to a second embodiment of the present invention; 
     FIG. 10 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 9 along bisecting lines A-A′ and B-B′, respectively; 
     FIG. 11 illustrates a schematic bird&#39;s-eye view of PSOELD according to a third embodiment of the present invention; and 
     FIG. 12 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 11 along bisecting lines A-A′ and B-B′, respectively. 
    
    
     DETAILED DESCRIPTION OF THE 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. Where possible, the same reference numerals will be used to illustrate like elements throughout the specification. And, detailed component materials and techniques of the embodiments of the present invention include all those used for the related art. 
     First Embodiment 
     A plasma switched organic electroluminescent display(hereinafter abbreviated PSOELD) and a fabricating method thereof according to a first embodiment of the present invention are described as follows. 
     FIG. 6 illustrates a schematic bird&#39;s-eye view of PSOELD according to a first embodiment of the present invention, and FIG. 7 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 6 along bisecting lines A-A′ and B-B′, respectively. And, FIG. 7 schematically illustrates cross-sectional views of the assembled upper and lower plates of PSOELD shown in FIG. 6, in which the cross-sectional views of upper and lower plates are combined each other in case that the upper plate is rotated clockwise at 90° for the convenience of understanding. 
     Referring to FIG.  6  and FIG. 7, PSOELD according to the first embodiment of the present invention includes an upper plate  110  and a lower plate  120 . 
     The lower plate  120  includes a rear substrate  52 , sustain electrodes  54 , a dielectric layer  55 , barrier ribs  53 , and protecting layers  56 . And, the upper plate  110  includes a front substrate  51 , address electrodes  57 , anode layers  58 , inner insulating/separating layers  59 , anode contact holes  60 , address electrode contact holes  61 , electroluminescent layers  62 , and cathode layers  63 . 
     On the rear substrate  52  confronting to the front substrate  51 , a plurality of the sustain electrodes  54  are formed in parallel with each other like stripes by photolithography. In this case, every two X and Y of the sustain electrodes  54  construct a plurality of sustain electrode pairs. The sustain electrode X leaves an interval with the other sustain electrode Y as long as several tens˜several hundreds μm, and the sustain electrodes  54  are several hundreds μm wide. 
     The dielectric layer  55  restricting a discharge current is formed on the rear substrate  52  several˜several tens μm thick by screen print so as to cover the exposed surfaces of the sustain electrodes  54 . 
     A plurality of the barrier ribs  53  are formed several hundreds μm tall on the dielectric layer  55  by repeating screen print about ten times so as to interrupt spaces to prevent a plasma discharge from diffusing into other cells. In this case, the barrier ribs  53  are formed to provide a lattice structure including a plurality of lattices so that a pair of the sustain electrodes  54  constructing the sustain electrode pair is placed in specific ones of the corresponding discharge spaces in the same row or column of the lattice structure. 
     And, a plurality of the protecting layers  56  are formed on the exposed surface of the dielectric layer  55  between the barrier ribs  53  by vacuum evaporation using MgO or the like having a high secondary electron discharge coefficient to protect the dielectric layer  55  from plasma etch as well as make a plasma occur with ease. 
     Meanwhile, as mentioned in the foregoing description, the upper plate  110  includes a front substrate  51 , address electrodes  57 , anode layers  58 , inner insulating/separating layers  59 , anode contact holes  60 , address electrode contact holes  61 , electroluminescent layers  62 , and cathode layers  63 . 
     On the front substrate  51  confronting the lower plate  120 , a plurality of the address electrodes  57  are formed in parallel with each other like stripes crossing the sustain electrodes  54  of the lower plate  120  by patterning a conductive metal by photolithography. 
     A plurality of anode layers  58  like stripes in parallel wish each other are formed on the front substrate  51  between the address electrodes  57 , using a transparent conductive material such as ITO (indium tin oxide), IZO (indium zinc oxide), or the like. 
     In order to increase a contrast ratio by cutting off light from a plasma discharge, a plurality of the inner insulating/separating layers  59  formed of a black material are formed on the front substrate  51  including the address electrodes  57  and anode layers  58 . 
     In the inner insulating/separating layers  59  corresponding to the discharge spaces of the lower plate  120 , a plurality of the through-hole type anode contact holes  60  and address electrode contact holes  61  exposing portions of the anode layers  58  and address electrodes  57  are formed. 
     In this case, each of the anode contact holes  60  is formed to have a maximum exposed central area of the anode layer  58  corresponding to the pixel area defined by the corresponding barrier ribs  53 , thereby enabling to prevent the anode layer  58  from being electrically connected to the cathode layer  63  right over the anode layer  58 . 
     Besides, each of the address electrode contact holes  61  is formed next to the corresponding anode contact hole  60  so as to expose a portion of the corresponding address electrode  57  in the discharge space defined by the corresponding barrier ribs  53 . And, each size of the address electrode contact holes  61  is smaller than that of the anode contact holes  60 . 
     Furthermore, the inner insulating/separating layers  59 , anode contact holes  60 , and address electrode contact holes  61  are formed by photolithography. And, the anode contact holes  60  and address electrode contact holes  61  are formed in the discharge spaces defined by the barrier ribs  53 . 
     A plurality of the electroluminescent layers  62  are formed on the inner insulating/separating layers  59  including the anode contact holes  60 . In this case, each of the electroluminescent layers  62  is formed rectangular enough to cover the corresponding anode contact hole  60 . 
     And, a plurality of the cathode layers  63  formed of a conductive metal such as Al or the like are formed on the electroluminescent layers  62 , by vacuum evaporation. 
     In this case, the electroluminescent layers  62  are selected from the group consisting of high molecular organic electroluminescent material, low molecular electroluminescent material using fluorescence, low molecular electroluminescent material using phosphorescence, and the like. 
     The upper and lower plates  110  and  120  are aligned so that each of the anode contact holes  60  and address electrode contact holes  61  are placed between the corresponding barrier ribs  53  as well as confront the corresponding sustain electrode pair X and Y. A mixed gas of Ne—Xe or Ne—Xe—Ar is injected into the respective discharge spaces between the barrier ribs  53  at a pressure below atmosphere, thereby enabling to generate plasma. For instance, the mixed gas of Ne(96%)—Xe(4%) is injected at 500 torr to generate plasma. 
     When the electroluminescent layers  62  are formed of the high molecular organic electroluminescent material by ink-jet or screen print, hole transport layers are further formed on the anode layers  58  so that the electroluminescent layers  62  are preferably placed on the hole transport layers. 
     When the electroluminescent layers  62  are formed of the low molecular organic electroluminescent material using fluorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  58  and the electroluminescent layers  62 , and electron transport layers are further inserted between the electroluminescent layers  62  and the cathode layers  63 . 
     And, When the electroluminescent layers  62  are formed of the low molecular organic electroluminescent material using phosphorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  58  and the electroluminescent layers  62 , and both hole blocking layers and electron transport layers are further inserted between the electroluminescent layers  62  and the cathode layers  63 . 
     FIG. 8A illustrates a cross-sectional diagram for explaining a plasma generated from a plasma discharge space in PSOELD according to the present invention, and FIG. 8B illustrates a cross-sectional diagram for explaining a plasma failing to occur in a plasma discharge space in PSOELD according to the present invention. In FIG.  8 A and FIG. 8B using the same numerals in FIG.  6  and FIG. 7, the cross-sectional views of upper and lower plates are combined each other in case that the upper plate is rotated clockwise at 90° for the convenience of understanding. 
     Referring to FIG.  8 A and FIG. 8B, the organic electroluminescent layer  62  is inserted between the anode and cathode layers  58  and  63 . And, the plasma discharge space  64 , from which plasma is generated, is defined by the cathode layer  63 , address electrode  57 , protecting layer  56 , and barrier ribs  53  surrounding the protecting layer  56 . 
     Through the total white and erase period and the address period applied generally to a 3-electrodes surface discharge structure for operating PSOELD, when a sustain voltage is applied to a first power source V 1  while wall charges are formed on the protecting layer  56  in the cell selected by the address period, plasma PLASMA, as shown in FIG. 8A, is generated in the plasma discharge space  64  so that the cathode layer  63  is electrically connected (turned on) to the address electrode  57  through the generated plasma PLASMA. Hence, the organic electroluminescent layer  62  emits light by a second power source V 2 . 
     Yet, another cell unselected by the address period fails to form wall charges on the protecting layer  56 , thereby being unable to generate the plasma in the plasma discharge space  64  despite applying the sustain voltage to the first power source V 1 . Thus, the cathode layer  63  and the address electrode  57  maintains turned off, whereby the organic electroluminescent layer  62  fails to emit light. 
     Therefore, the plasma occurrence in the plasma discharge space  64  functions as a switch determining whether the organic electroluminescent layer  62  emits light or not. 
     Second Embodiment 
     FIG. 9 illustrates a schematic bird&#39;s-eye view of PSOELD according to a second embodiment of the present invention, and FIG. 10 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 9 along bisecting lines A-A′ and B-B′, respectively. And, FIG. 10 schematically illustrates cross-sectional views of the assembled upper and lower plates of PSOELD shown in FIG. 9, in which the cross-sectional views of upper and lower plates are combined each other in case that the upper plate is rotated clockwise at 90° for the convenience of understanding. 
     Referring to FIG.  9  and FIG. 10, PSOELD according to the second embodiment of the present invention includes an upper plate  130  and a lower plate  140 . 
     The lower plate  140  includes a rear substrate  72 , sustain electrodes  74 , a dielectric layer  75 , barrier ribs  73 , protecting layers  76 , and exposed electrodes  85 . And, the upper plate  130  includes a front substrate  71 , address electrodes  77 , anode layers  78 , inner insulating/separating layers  79 , anode contact holes  80 , electroluminescent layers  82 , and cathode layers  83 . 
     On the rear substrate  72  confronting to the front substrate  71 , a plurality of the sustain electrodes  74  are formed in parallel with each other like stripes by photolithography. In this case, every two X and Y of the sustain electrodes  74  construct a plurality of sustain electrode pairs. The sustain electrode X leaves an interval with the other sustain electrode Y as long as several tens˜several hundreds μm, and each of the sustain electrodes  54  is several hundreds μm wide. 
     The dielectric layer  75  restricting a discharge current is formed on the rear substrate  72  several˜several tens μm thick by screen print so as to cover the exposed surfaces of the sustain electrodes  74 . 
     A plurality of the barrier ribs  73  are formed several hundreds μm tall on the dielectric layer  75  by repeating screen print about ten times so as to interrupt spaces to prevent a plasma discharge from diffusing into other cells. In this case, the barrier ribs  73  are formed to provide a lattice structure including a plurality of lattices so that a pair of the sustain electrodes  74  constructing the sustain electrode pair is placed in specific ones of the corresponding discharge spaces in the same row or column of the lattice structure. 
     A plurality of the protecting layers  76  are formed on the exposed surface of the dielectric layer  75  between the barrier ribs  73  by vacuum evaporation using MgO or the like having a high secondary electron discharge coefficient to protect the dielectric layer  75  from plasma etch as well as make a plasma occur with ease. 
     And, a plurality of the exposed electrodes  85  are formed on the protecting layers  76  overlapped with the middle parts between the two sustain electrodes  74  constructing the sustain electrode pair X and Y in the discharge spaces. In this case, the exposed electrodes  85  are formed by vacuum evaporation using a shadow mask so as to be arranged on the protecting layers like stripes in parallel with the sustain electrodes  74 . 
     Meanwhile, as mentioned in the foregoing description, the upper plate  130  includes the front substrate  71 , address electrodes  77 , anode layers  78 , inner insulating/separating layers  79 , anode contact holes  80 , electroluminescent layers  82 , and cathode layers  83 . 
     On the front substrate  71  confronting the lower plate  140 , a plurality of the address electrodes  77  are formed in parallel with each other like stripes crossing the sustain electrodes  74  of the lower plate  140  at right angles by patterning a conductive metal by photolithography. 
     A plurality of anode layers  78  like stripes in parallel with the address electrodes  77  are formed on the front substrate  71  between the address electrodes  77 , using a transparent conductive material such as ITO(indium tin oxide), IZO(indium zinc oxide), or the like. 
     In order to increase a contrast ratio by cutting off light from a plasma discharge, a plurality of the inner insulating/separating layers  79  formed of a black material are formed on the front substrate  51  including the address electrodes  77  and anode layers  78 . 
     In the inner insulating/separating layers  79  corresponding to the discharge spaces of the lower plate  140 , a plurality of the through-hole type anode contact holes  80  exposing portions of the anode layers  78  are formed. 
     In this case, each of the anode contact holes  80  is formed to have a maximum exposed central area of the anode layer  78  corresponding to the pixel area defined by the corresponding barrier ribs  73 , thereby enabling to prevent the anode layer  78  from being electrically connected(shorted) to the cathode layer  83  over the anode layer  78 . 
     Besides, the inner insulating/separating layers  79  and anode contact holes  80  are formed by photolithography. And, the anode contact holes  80  are formed in the discharge spaces defined by the barrier ribs  73 . 
     A plurality of the electroluminescent layers  82  are formed on the inner insulating/separating layers  79  including the anode contact holes  80 . In this case, each of the electroluminescent layers  82  is formed rectangular enough to cover the corresponding anode contact hole  80 . 
     And, a plurality of the cathode layers  83  formed of a conductive metal such as Al or the like are formed on the electroluminescent layers  82 , by vacuum evaporation. 
     In this case, the electroluminescent layers  82  are selected from the group consisting of high molecular organic electroluminescent material, low molecular electroluminescent material using fluorescence, low molecular electroluminescent material using phosphorescence, and the like. 
     The upper and lower plates  130  and  140  are aligned so that each of the anode contact holes  80  is placed between the corresponding barrier ribs  73  as well as confronts the corresponding sustain electrode pair X and Y. A mixed gas of Ne—Xe or Ne—Xe—Ar is injected into the respective discharge spaces between the barrier ribs  73  at a pressure below atmosphere, thereby enabling to generate plasma. For instance, the mixed gas of Ne(96)—Xe(4%) is injected at 500 torr to generate plasma. 
     When the electroluminescent layers  82  are formed of the high molecular organic electroluminescent material by ink-jet or screen print, hole transport layers are further formed on the anode layers  78  so that the electroluminescent layers  82  are preferably placed on the hole transport layers. 
     When the electroluminescent layers  82  are formed of the low molecular organic electroluminescent material using fluorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  78  and the electroluminescent layers  82 , and electron transport layers are further inserted between the electroluminescent layers  82  and the cathode layers  83 . 
     And, When the electroluminescent layers  82  are formed of the low molecular organic electroluminescent material using phosphorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  78  and the electroluminescent layers  82 , and both hole blocking layers and electron transport layers are further inserted between the electroluminescent layers  82  and the cathode layers  83 . 
     Third Embodiment 
     FIG. 11 illustrates a schematic bird&#39;s-eye view of PSOELD according to a third embodiment of the present invention, and FIG. 12 illustrates schematically cross-sectional views of upper and lower plates of PSOELD shown in FIG. 11 along bisecting lines A-A′ and B-B′, respectively. And, FIG. 12 schematically illustrates cross-sectional views of the assembled upper and lower plates of PSOELD shown in FIG. 11, in which the cross-sectional views of upper and lower plates are combined each other in case that the upper plate is rotated clockwise at 90° for the convenience of understanding. 
     Referring to FIG.  11  and FIG. 12, PSOELD according to the third embodiment of the present invention includes an upper plate  150  and a lower plate  160 . 
     The lower plate  160  includes a rear substrate  92 , sustain electrodes  94 , a dielectric layer  95 , barrier ribs  93 , and protecting layers  96 . And, the upper plate  150  includes a front substrate  91 , address electrodes  97 , anode layers  98 , inner insulating/separating layers  99 , anode contact holes  100 , electroluminescent layers  102 , cathode layers  103 , and exposed electrodes  105 . 
     On the rear substrate  92  confronting to the front substrate  91 , a plurality of the sustain electrodes  94  are formed in parallel with each other like stripes by photolithography. In this case, every two X and Y of the sustain electrodes  94  construct a plurality of sustain electrode pairs. The sustain electrode X leaves an interval with the other sustain electrode Y as long as several tens˜several hundreds μm, and the sustain electrodes  94  are several hundreds μm wide. 
     The dielectric layer  95  restricting a discharge current is formed on the rear substrate  92  several˜several tens μm thick by screen print so as to cover the exposed surfaces of the sustain electrodes  94 . 
     A plurality of the barrier ribs  93  are formed several hundreds μm tall on the dielectric layer  95  by repeating screen print about ten times so as to interrupt spaces to prevent a plasma discharge from diffusing into other cells. In this case, the barrier ribs  93  are formed to provide a lattice structure including a plurality of lattices so that a pair of the sustain electrodes  94  constructing the sustain electrode pair is placed in specific ones of the corresponding discharge spaces in the same row or column of the lattice structure. 
     And, a plurality of the protecting layers  96  are formed on the exposed surface of the dielectric layer  95  between the barrier ribs  93  by vacuum evaporation using MgO or the like having a high secondary electron discharge coefficient to protect the dielectric layer  95  from plasma etch as well as make a plasma occur with ease. 
     Meanwhile, as mentioned in the foregoing description, the upper plate  150  includes the front substrate  91 , address electrodes  97 , anode layers  98 , inner insulating/separating layers  99 , anode contact holes  100 , electroluminescent layers  102 , cathode layers  103 , and exposed electrodes  105 . 
     On the front substrate  91  confronting the lower plate  160 , a plurality of the address electrodes  97  and exposed electrodes  105  are formed alternately in parallel with each other like stripes crossing the sustain electrodes  94  of the lower plate  160  at right angles by patterning a conductive metal by photolithography. 
     A plurality of anode layers  98  like stripes between and in parallel with the address electrodes  97  and the exposed electrodes  105  are formed on the front substrate  91 , using a transparent conductive material such as ITO (indium tin oxide), IZO (indium zinc oxide), or the like. 
     In order to increase a contrast ratio by cutting off light from a plasma discharge, a plurality of the inner insulating/separating layers  99  formed of a black material are formed on the front substrate  91  including the address electrodes  77  and anode layers  78  so as to expose the exposed electrodes  105 . 
     In the inner insulating/separating layers  99  corresponding to the discharge spaces of the lower plate  160 , a plurality of the through-hole type anode contact holes  100  exposing portions of the anode layers  98  are formed. 
     In this case, each of the anode contact holes  100  is formed to have a maximum exposed central area of the anode layer  98  corresponding to the pixel area defined by the corresponding barrier ribs  93 , thereby enabling to prevent the anode layer  98  from being electrically connected(shorted) to the corresponding cathode layer  103  over the anode layer  98 . 
     Besides, the inner insulating/separating layers  99  and anode contact holes  100  are formed by photolithography. And, the anode contact holes  100  are formed in the discharge spaces defined by the barrier ribs  93 . 
     A plurality of the electroluminescent layers  102  are formed on the inner insulating/separating layers  99  including the anode contact holes  100 . In this case, each of the electroluminescent layers  102  is formed rectangular enough to cover the corresponding anode contact hole  100 . 
     And, a plurality of the cathode layers  103  formed of a conductive metal such as Al or the like are formed on the electroluminescent layers  102 , by vacuum evaporation. 
     In this case, the electroluminescent layers  102  are selected from the group consisting of high molecular organic electroluminescent material, low molecular electroluminescent material using fluorescence, low molecular electroluminescent material using phosphorescence, and the like. 
     The upper and lower plates  150  and  160  are aligned so that each of the anode contact holes  100  is placed between the corresponding barrier ribs  93  as well as confronts the corresponding sustain electrode pair X and Y. A mixed gas of Ne—Xe or Ne—Xe—Ar is injected into the respective discharge spaces between the barrier ribs  93  at a pressure below atmosphere, thereby enabling to generate plasma. For instance, the mixed gas of Ne(96%)—Xe(4%) is injected at 500 torr to generate plasma. 
     When the electroluminescent layers  102  are formed of the high molecular organic electroluminescent material by ink-jet or screen print, hole transport layers are further formed on the anode layers  98  so that the electroluminescent layers  102  are preferably placed on the hole transport layers. 
     When the electroluminescent layers  102  are formed of the low molecular organic electroluminescent material using fluorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  98  and the electroluminescent layers  102 , and electron transport layers are further inserted between the electroluminescent layers  102  and the cathode layers  103 . 
     And, When the electroluminescent layers  102  are formed of the low molecular organic electroluminescent material using phosphorescence by vacuum evaporation, both hole injection layers and hole transport layers are further inserted between the anode layers  98  and the electroluminescent layers  102 , and both hole blocking layers and electron transport layers are further inserted between the electroluminescent layers  102  and the cathode layers  103 . 
     As mentioned in the above description, the PSOELD according to the present invention enables to be driven by a driving voltage lower than that of the PDP according to the related art by using a plasma switch as a driving device playing a role as a switch only instead of a purpose for irradiating massive vacuum UV rays from the generation of plasma. 
     And, the present invention enables to fabricate a high efficient display free from a residual color effect by emitting light through an organic electroluminescence. 
     Moreover, compared to the display using TFT as a driving device, the present invention enables to be fabricated by a simple fabricating process. 
     Furthermore, the present invention enables to provide a large-sized display with ease. 
     The foregoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.