Abstract:
Provided is a plasma display panel (PDP) comprising electron emission members including electron emission amplification layers corresponding to pairs of sustain electrodes so as to reduce a driving voltage for performing a discharge and increase luminescence efficiency.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION  
       [0001]     This application claims the benefit of Korean Patent Application No. 10-2005-0096231, filed on Oct. 12, 2005 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present embodiments relate to a plasma display panel (PDP), and more particularly, to a PDP comprising an accelerated electron emitter between sustain electrodes to effectively emit electrons in a discharge space so as to provide high brightness and high luminescence efficiency.  
         [0004]     2. Description of the Related Art  
         [0005]     Plasma display panels (PDPs) display images using visible light emitted through a process of exciting a phosphor material with ultraviolet rays generated from a discharge of a discharge gas between electrodes when a direct voltage or an alternating voltage is applied to the electrodes.  
         [0006]     PDPs are classified into DC type panels and AC type panels according to discharge types. Also, PDPs are classified into facing discharge type panels and surface discharge type panels according to the arrangement of electrodes.  
         [0007]     However, conventional PDPs generate ultraviolet rays by ionizing the discharge gas and allowing excited xenon (Xe*) to stabilize by performing a plasma discharge. Therefore, conventional PDPs have a high driving voltage and low luminescence efficiency since a large amount of energy is necessary to ionize the discharge gas.  
       SUMMARY OF THE INVENTION  
       [0008]     According to one aspect of the present embodiments, there is provided a PDP comprising: first and second substrates separated by a predetermined distance and facing each other to form a discharge space therebetween; a plurality of barrier ribs interposed between the first and second substrates and partitioning the discharge space into discharge cells; a plurality of pairs of sustain electrodes; address electrodes crossing the plurality of pairs of sustain electrodes; electron emission members comprising electron emission amplification layers to amplify the emission of electrons in the discharge cells being formed, and corresponding to the plurality of pairs of sustain electrodes; phosphor layers formed in the discharge cells; and a discharge gas in the discharge cells.  
         [0009]     The plurality of pairs of sustain electrodes may be parallel to one another and disposed in the barrier ribs.  
         [0010]     The electron emission members may have the same width as the sustain electrodes, and the sustain electrodes may comprise bus electrodes, and the electron emission members may have the same width as the bus electrodes.  
         [0011]     Another embodiment refers to a PDP comprising a first substrate and a second substrate spaced apart from each other with a discharge space therebetween; a plurality of barrier ribs interposed between the first and second substrates and partitioning the discharge space into a plurality of discharge cells; first discharge electrodes disposed on the first substrate; second discharge electrodes disposed on the second substrate and crossing the first electrodes; electron emission members comprising electron emission amplification layers to amplify the emission of electrons in discharge cells being formed corresponding to one of the first and second discharge electrodes; phosphor layers arranged in the discharge cells; and a discharge gas in the discharge cells.  
         [0012]     The electron emission amplification layers may have any of the following characteristics: be oxidized porous silicon (OPS) layers, have a metal-insulator-metal (MIM) structure, be formed of a boron nitride bamboo shoot (BNBS), be formed of carbon nanotubes (CNTs), and further comprise emission electrodes disposed on the electron emission amplification layers.  
         [0013]     The phosphor layers may include a quantum dot (QD).  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]     The above and other features and advantages of the present embodiments will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:  
         [0015]      FIG. 1  is an exploded perspective view of a plasma display panel (PDP) according to an embodiment;  
         [0016]      FIG. 2  is a cross-sectional view of the PDP of  FIG. 1  taken along line II-II in  FIG. 1 ;  
         [0017]      FIG. 3  is a cross-sectional view of a PDP according to another embodiment;  
         [0018]      FIG. 4  is a cross-sectional view of a PDP according to another embodiment;  
         [0019]      FIG. 5  is a cross-sectional view of a PDP according to another embodiment;  
         [0020]      FIG. 6A  is a cross-sectional view of a PDP on which a test to determine luminous efficiency according to beam current density was performed;  
         [0021]      FIG. 6B  is a graph of the results of the test performed on the PDP illustrated in  FIG. 6A ;  
         [0022]      FIGS. 7A through 7G  illustrate various arrangements of electron emission members used for simulations for determining luminescence efficiency when an electronic beam having a current density of 1 mA/cm 2  is continuously emitted from the electron emission members;  
         [0023]      FIG. 7H  is a graph of the results of the simulation performed with the arrangements illustrated in  FIGS. 7A through 7G ;  
         [0024]      FIG. 8A  illustrates an arrangement of electron emission members used for simulation for determining luminous efficiency, the electrons being emitted from the electron emission member which is of negative voltage above the predetermined voltage;  
         [0025]      FIG. 8B  is a graph of the results of the test performed on the PDP illustrated in  FIG. 8A ;  
         [0026]      FIG. 9  is a graph of luminescence efficiency according to discharge firing voltage when an electron beam having a current density of 100 mA/cm 2  and emitted from the electron emission member to which more than 3V/μm of an electric field is applied in the alternating current type PDP illustrated in  FIG. 8A  is used and when no electron beam is used;  
         [0027]      FIG. 10  is a cross-sectional view of a PDP according to another embodiment;  
         [0028]      FIG. 11  is a cross-sectional view of a PDP according to another embodiment;  
         [0029]      FIG. 12  is a cross-sectional view of a PDP according to another embodiment;  
         [0030]      FIG. 13  is a cross-sectional view of a PDP according to another embodiment;  
         [0031]      FIG. 14  is a cross-sectional view of a PDP according to another embodiment;  
         [0032]      FIG. 15  is a cross-sectional view of a PDP according to another embodiment;  
         [0033]      FIG. 16  is a cross-sectional view of a PDP according to another embodiment; and  
         [0034]      FIG. 17  is a cross-sectional view of a PDP according to another embodiment. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     The present embodiments will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments are shown.  
         [0036]      FIG. 1  is an exploded perspective view of a plasma display panel (PDP) according to an embodiment.  FIG. 2  is a cross-sectional view of the PDP of  FIG. 1  taken along line II-II in  FIG. 1 . Referring to  FIGS. 1 and 2 , the PDP comprises a first substrate  110 , a second substrate  120 , barrier ribs  113 , X and Y sustain electrodes  121  and  122  (see  FIG. 6A ), a first dielectric layer  112 , address electrodes  111 , a second dielectric layer  123 , phosphor layers  115 , a protective layer  124 , and electron emission members  125 .  
         [0037]     The first substrate  110  and the second substrate  120  are separated by a predetermined distance and face each other to form a discharge space. The second substrate  120  is formed of a transparent material such as glass to transmit visible light. However, the present embodiments are not limited thereto. For example, the first substrate  110  can be formed of a transparent material, or both the first substrate  110  and the second substrate  120  can be formed of a transparent material. Also, the first substrate  110  and the second substrate  120  can be formed of a translucent material and comprise a color filter. Therefore, the present embodiments can be applied to a backlit PDP or a reflective PDP in which visible light generated by projecting vacuum ultraviolet (VUV) rays from an excited discharge gas onto the phosphor layers  115  is reflected as well.  
         [0038]     The barrier ribs  113  partitions the discharge space between the first substrate  110  and the second substrate  120  into discharge cells as basic units of an image, and prevents cross talk between discharge cells. The barrier ribs  113  can have rectangular cross-sections, but the present embodiments are not limited thereto. For example, the barrier ribs  113  can have cross-sections in the shape of ovals, circles, or polygons such as hexagons, octagons, etc.  
         [0039]     The X and Y sustain electrodes  121  and  122  are parallel to one another on the bottom surface of the second substrate  120 . The X electrodes  121  each include a transparent electrode  121  a and a bus electrode  121  b, and the Y electrodes  122  each include a transparent electrode  122   a  and a bus electrode  122   b . The transparent electrodes  121   a  and  122   a  are formed of a transparent material such as indium tin oxide (ITO) to transmit visible light. However, ITO has high electrical resistance and causes a large voltage drop, and thus cannot itself apply a constant driving voltage to all discharge cells. Therefore, to supplement the transparent electrodes  121   a  and  122   a , the bus electrodes  121   b  and  122   b  that have narrower widths and greater electrical conductivity than the transparent electrodes  121   a  and  122   a  are disposed on the transparent electrodes  121   a  and  122   a  and electrically connected to the transparent electrodes  121   a  and  122   a , but the present embodiments are not limited thereto. In an embodiment, the PDP includes transparent electrodes not formed of ITO and excludes bus electrodes.  
         [0040]     In the backlit PDP, the X and Y electrodes  121  and  122  are not transparent electrodes, and are formed of an opaque and electrically conductive material such as Cu, Al, or the like, however, there is no particular restriction to an electrode material in this case.  
         [0041]     The first dielectric layer  112  covers the address electrodes  111  and is formed of a material having high resistance since it is used to insulate the address electrodes  111 . The first dielectric layer  112  does not need to transmit visible light, and thus, does not need to be formed of a material having high light transmittance, whereas the second dielectric layer  123  transmits visible light. The second dielectric layer  123  covers the X and Y electrodes  121  and  122  disposed on the second substrate  120 , and insulates the X and Y electrodes  121  and  122 . Thus, the second dielectric layer  123  is formed of a material having high resistance and high light transmittance. The protective layer  124  covers the second dielectric layer  123  and discharges secondary electrons to facilitate the discharge.  
         [0042]     The protective layer  124  is formed of magnesium oxide (MgO). The protective layer  124  covers the surface of the electron emission members  125  and the second dielectric layer  123  but the present embodiments are not limited thereto. In detail, the protective layer  124  can be disposed on a dielectric layer on which the electron emission members  125  are not formed, or on the electron emission members  125 .  
         [0043]     The phosphor layers  115  cover inner walls of discharge cells  114  partitioned by the barrier ribs  113  and the first dielectric layer  112 , and provide photoluminescence (PL) by emitting visible light when electrons excited by absorbed VUV rays generated by the discharge are stabilized. The phosphor layers  115  include red, green, blue phosphor layers such that the PDP can display a color image. A combination of three adjacent discharge cells including the red, green, and blue phosphor layers constitute a unit pixel. The phosphor layers  115  can be formed of at least one of a PL phosphor layer that generates visible light when atoms receive energy in a region of ultraviolet rays and are stabilized, a cathodoluminescence (CL) phosphor layer, and a quantum dot (QD). The CL phosphor layer or the QD can be arranged in the discharge cells  114  when an electron beam is directly radiated from the electron emission members  125 , and the PL phosphor layer can be arranged in the discharge cells  114  when an electronic beam is not directly radiated from the electron emission members  125 .  
         [0044]     In particular, there is no interference between atoms in the QD when the QD receives energy from the outside. Therefore, since the discharge gas can be excited using low energy, the PDP of the present embodiments can have increased luminescence efficiency, perform a printing process, and be large-sized.  
         [0045]     Each of the electron emission members  125  comprises a base electrode  125   a  disposed on the bottom surface of the second dielectric layer  123  and an electron emission amplification layer  125   b  that is formed on the bottom surface of the base electrode  125   a  and has the same width as the base electrode  125   a . The base electrodes  125   a  correspond to the X and Y electrodes  121  and  122 , are formed on the bottom surface of the second dielectric layer  123 , and can have the same width as the X and Y electrodes  121  and  122 . For example, referring to  FIG. 2 , the base electrodes  125   a  correspond to the transparent electrodes  121   a  and  122   a , and can be formed on the bottom surface of the second dielectric layer  123  with the same width as the transparent electrodes  121   a  and  122   a . If the electron emission amplification layers  125   b  and  126   b  are formed on the bus electrodes  121   b  and  122   b , then the base electrodes are not required since the bus electrodes  121   b  and  122   b  serve as cathode electrodes. As will be described later, the structure of the electron emission members  125  is useful for transmitting visible light in the reflective PDP.  
         [0046]     The base electrodes  125   a  serve as cathode electrodes and provide electrons to the electron emission amplification layers  125   b . The base electrodes  124   a  can be formed of one of ITO, Al, Ag, etc. Referring to  FIGS. 2 through 5 , the base electrodes  125   a  of the reflective PDP may be formed of a transparent material to transmit visible light.  
         [0047]     The electron emission amplification layers  125   b  accelerate or amplify the electrons from the base electrodes  125   a . The electron emission amplification layers  125   b  may be oxidized porous silicon (OPS) layers. OPS layers can be oxidized porous polysilicon (OPPS) layers or oxidized porous amorphous silicon (OPAS) layers. A method of forming an OPS layer includes applying a proper current density to a silicon layer and anodizing the silicon layer using a solution mixing hydrogen fluoride (HF) and ethanol to change the silicon layer into a porous layer. The anodized silicon layer is electrochemically oxidized and is changed into the OPS layer having a predetermined thickness.  
         [0048]     The electron emission amplification layers  125   b  can have a metal-insulator-metal (MIM) structure. The MIM structure includes a thin insulating layer. The thickness of the insulating layer is relevant to increase electron emission efficiency of the electron emission members  125  having the MIM structure. The insulating layer can be formed of, for example, one of A 1   2 O 3 , Si 3 N 4 , SiO 2 , etc., and must be thin enough to allow tunneling. However, the insulating layers must be sufficiently thick not to break when voltages are applied to ends of the base electrodes  125   a  and emission electrodes.  
         [0049]     The electron emission amplification layers  125   b  can be formed of a boron nitride bamboo shoot (BNBS). The BNBS has transparent properties over a wavelength range of from about 380 to about 780 nm, which is a visible light range, and good electron emission characteristics since it has negative electronic affinity. The BNBS formed in the sustain electrodes has very sharp ends, and thus it produces a strong electric field, thereby maintaining a sustain discharge at a low voltage.  
         [0050]     The electron emission amplification layers  125   b  can be formed of carbon nanotubes (CNTs). However, the present embodiments are not limited thereto. The electron emission amplification layers  125   b  can be formed of a material that amplifies electron emission and generates an electron beam. The electron emission amplification layers  125   b  can be also formed of a material such as MgO for reducing the discharge voltage.  
         [0051]      FIGS. 3 through 5  are respective cross-sectional views of PDPs according to other embodiments. Referring to  FIGS. 3 through 5 , the electron emission members  125  can further comprise discharge electrodes  125   c  disposed on the electron emission amplification layers  125   b . The emission electrodes  125  can be formed of ITO or fine wire mesh. The discharge electrodes  125   c  can be thin enough to allow tunneling. However, the discharge electrodes  125   c  should be thin, but thick enough not to break due to deterioration due to collisions with electrons. The emission electrodes  125   c  can be formed of Au/Pt/Ir, Pt/Ti, tungsten silicide, etc. A direct current is supplied between the base electrodes  125   a  and the discharge electrodes  125   c  such that a voltage of the discharge electrodes  125   c  is greater than that of the base electrodes  125   a . The electron emission members  125  can control a voltage applied to the electron emission amplification layers  125   b  to control the energy of emitted electrons.  
         [0052]     A discharge gas of a general PDP can be a mixture containing one or more of Ne gas, He gas, and Ar gas mixed with Xe gas. However, the electron beam emitted from the electron emission member  125  of the current embodiment excites a gas that in turn generates ultraviolet rays. That is, various gases including N 2 , deuterium, carbon dioxide, hydrogen gas, carbon monoxide, Kr, etc. and air at atmospheric pressure can be used instead of gases including Xe. Therefore, the PDPs according to some embodiments can use discharge gases used by general PDPs as well as other gases.  
         [0053]     The function and operation of the PDPs will now be described. First, the PDPs perform an initial reset operation to produce wall charges in each of the discharge cells  114 . When an operating voltage is applied between the X and Y electrodes  121  and  122  in a selected discharge cell, the discharge between the X and Y electrodes  121  and  122  is performed. When the discharge is performed, discharge gas particles of the discharge cells  114  and charges collide, thereby generating plasma. The phosphor layers  115 , which cover the sidewalls and bottom surface of the barrier ribs  113 , absorb VUV rays emitted when discharge gas atoms excited in the plasma are stabilized. The absorbed VUV rays excite electrons in the phosphor layers  115 , and the excited electrons are stabilized, thereby emitting visible light. The emitted visible light from the discharge cells  114  transmit through the second substrate  120 , thereby forming an image.  
         [0054]     When an alternating current voltage (for example, ranging between 0 V and 200 V) is applied to the X electrodes  121  and the Y electrodes  122 , an electric field is formed between a portion of a dielectric layer corresponding to the X electrodes  121  and a portion of the dielectric layer corresponding to the Y electrodes  122  in the discharge cells  114 , such that electrons flow from the base electrodes  125   a  on the Y electrodes  122  to the electron emission amplification layers  125   b  and are accelerated or amplified to emit the electron beam into the discharge cells  114 . If the voltage applied between the X and Y electrodes  121  and  122  is reversed, the electrons are accelerated or amplified through the electron emission member  125  on the X electrodes  121  to emit the electron beam into the discharge cells  114 . The emitted electron beam excites the gas and the exited gas is stabilized to emit ultraviolet rays. The ultraviolet rays excite the phosphor layers  115  to emit visible light.  
         [0055]     With regard to the PDP illustrated in  FIG. 3 , if a predetermined voltage is applied between the base electrodes  125   a  and the emission electrodes  125   c , an electric field is formed between the base electrodes  125   a  and the emission electrodes  125   c , and electrons flow from the base electrodes  125   a  and are emitted as electron beams into the discharge cells  114  through the discharge electrodes  125   c . The energy of the electron beams may be greater than the energy necessary to excite the discharge gas and less than the energy necessary to ionize the gas.  
         [0056]     That is, in addition to the VUV rays generated when discharge gas atoms ionized by the plasma discharge are stabilized, the electron beams that are accelerated and emitted through the electron emission amplification layers  125  further excite the discharge gas, resulting in the generation of additional VUV rays. Also, the electron beams that are accelerated through the emission amplification layers  125  such as the OPS layers in the discharge cells to augment the discharge, thereby realizing high brightness and high luminescence efficiency. Although the PDPs illustrated in  FIGS. 1 through 5  are alternating current type PDPs including the dielectric layers  112  and  123 , the present embodiments are not limited thereto. That is, the present embodiments can be applied to a direct current type PDP in which the X and Y electrodes  121  and  122  cross each other and in which discharge is performed directly between the X and Y electrodes  121  and  122 . In this case, the electron emission members  125  are formed on the surfaces of the X and Y electrodes  121  and  122 . The X and Y electrodes  121  and  122  serve as the base electrodes  125   a , and thus the base electrodes  125   a  are not required.  
         [0057]      FIG. 6A  is a cross-sectional view of a PDP on which a test to determine luminous efficiency according to beam current density was performed, and  FIG. 6B  is a graph of the results of the test. Referring to  FIG. 6A , the electron emission members  125  are formed on the second dielectric layer  123  covering the X and Y electrodes  121  and  122 , and have the same width as the X and Y electrodes  121  and  122 . Unlike an alternating current type PDP that alternately emits the electronic beam according to pulse signals, the electronic beam is continually emitted through the electron emission members  125 . Referring to FIG.  6 B, the graph shows that the luminescence efficiency increases as the current density of the electron beam emitted into the discharge cells  114  is increased.  
         [0058]      FIGS. 7A through 7G  illustrate various arrangements of electron emission members used for simulations for determining luminescence efficiency when an electronic beam having a current density of 1 mA/cm 2  is continuously emitted from the electron emission members.  FIG. 7H  is a graph illustrating the results of the simulations.  
         [0059]     Referring to  FIG. 7C , the electron emission members  125  have the same width as the bus electrodes  121   b  and  122   b , and are formed on the bus electrodes  121   b  and  122   b  (structure SI). Referring to  FIG. 7D , the electron emission members  125  have the same width as the transparent electrodes  121   a  and  122   a , and are formed on the second dielectric layer  123  (structure S 2 ). Referring to  FIG. 7E , the electron emission members  125  are formed between the transparent electrodes  121   a  and  122   a  on the second dielectric layer  123  (structure S 3 ). Referring to  FIG. 7F , the electron emission members  125  are formed on the surface of the second dielectric layer  123  on which the transparent electrodes  121  a and  122   a  are not formed (structure S 4 ). Referring to  FIG. 7G , the electron emission members  125  are formed between the bus electrodes  121   b  and  122   b  and the X and Y electrodes  121  and  122  on the second dielectric layer  123  (structure S 5 ).  
         [0060]     Referring to  FIG. 7H , the graph shows that the luminescence efficiencies in the structures S 1  and S 2  illustrated in  FIGS. 7C and 7D  are respectively 15% and 55% greater than the luminescence efficiency of a standard structure. However, since the electron emission members  125  block visible light in a backlit PDP, the electron emission members  125  having the structure S 1  is advantageous. Therefore, the electron emission members  125  may have the same width as the bus electrodes  121   a  and  122   a  and be formed on the bus electrodes  121   a  and  122   a , or have the same width as the transparent electrodes  121   a  and  122   a  and correspond to the transparent electrodes  121   a  and  122   a.    
         [0061]      FIG. 8A  illustrates an arrangement of electron emission members used for simulation for determining luminous efficiency, wherein the electrons being emitted from the electron emission member is of negative voltage above the predetermined voltage.  FIG. 8B  is a graph of the results of the test performed on the PDP illustrated in  FIG. 8A . Referring to  FIG. 8A , the electron emission members  125  have the same width as the X and Y electrodes  121  and  122 , and are formed on the second dielectric layer  123  covering the X and Y electrodes  121  and  122  to correspond to the X and Y electrodes  121  and  122 . In the simulation, alternate negative pulse signals are applied to the electron emission member and the electron beam is supposed to be emitted from the electron emission member  125  having a negative voltage of an electric field of more than 3 V/μm. Referring to  FIG. 8B , the graph shows that the luminescence efficiency of the discharge cells  114  increases as the current density of the electron beam increases. This result is the same as the result of the simulation described above with reference to  FIGS. 6A and 6B  in which the electron beam is emitted from both electron emission members  125 . The luminescence efficiency of the discharge cells  114  is increased by the electron emission member  125 .  
         [0062]      FIG. 9  is a graph of luminescence efficiency according to discharge firing voltage when an electron beam having a current density of 100 mA/cm 2  and emitted from the electron emission member to which more than 3V/μm of an electric field is applied in the alternating current type PDP illustrated in  FIG. 8A  is used and when no electron beam is used. Referring to  FIG. 9 , the graph shows that in a standard case using a standard structure, a driving voltage of 180 V is required to initiate a discharge, whereas, when e-beam produced by the electron emission member  125  is used, a driving voltage of 150 V is required to initiate discharge. Thus the driving voltage is reduced by about 30 V. Also, when the driving voltage is 200 V, the luminescence efficiency was increased by 55%.  
         [0063]      FIGS. 10 through 17  are cross-sectional views of PDPs according to embodiments. Like reference numerals in  FIGS. 10 through 17  denote like elements, and thus their description will not be repeated. The differences between the PDP illustrated in  FIGS. 1 and 2  and the PDPs illustrated in  FIGS. 10 through 17  will now be described.  
         [0064]     Referring to  FIG. 10 , the PDP comprises a first substrate  210 , a second substrate  220 , barrier ribs  213 , two pairs of sustain electrodes  221  and  222 , a first dielectric layer  212 , an address electrode  211 , a second dielectric layer  22 , a phosphor layer  215 , a protective layer  224 , and electron emission members  225  and  226 . The barrier ribs  213  are interposed between the first substrate  210  and the second substrate  220 , and are formed of a dielectric substance. The two pairs of sustain electrodes  221  and  222  are disposed in the barrier ribs  213 . The dielectric substance prevents the barrier ribs  213  from being damaged by the collision of charged particles on the sustain electrodes  221  and  222 , and allow wall charges to accumulate thereon by inducing the charge particles. The dielectric substance may be one of PbO, B 2 O 3 , SiO 2 , etc.  
         [0065]     The sustain electrodes  221  and  222  disposed in the barrier ribs  213  surround the discharge cell  214  and cross the address electrode  211 . Since the sustain electrodes  221  and  22  are disposed in the barrier ribs  213 , common electrodes  221  and scan electrodes  222  constituting the sustain electrodes  221  and  222  are not transparent, and can be formed of a material including a conductive metal such as, for example, Ag, Al, Cu, etc. In  FIGS. 10 and 11 , the sustain electrodes  221  and  222  have a rectangular cross-section, but the present embodiments are not limited thereto. That is, the sustain electrodes  221  and  222  can have a variety of cross-sections as long as they can surround the discharge cell  214 . Each of the PDPs in  FIGS. 10 and 11  performs the sustain discharge throughout the entire discharge cell  214 , and thus a discharge area is relatively increased, the PDP can operate at a low voltage, and luminescence efficiency is increased. Since the barrier ribs  213  provide the function of the second dielectric layer  123  in the above described embodiments covering the sustain electrodes  221  and  222 , the PDPs shown in  FIGS. 10 and 11  do not require second dielectric layer.  
         [0066]     The electron emission members  225  and  226  respectively comprise base electrodes  225   a  and  226   a  that are disposed on the barrier ribs  213  and correspond to the sustain electrodes  221  and  222 , and electron emission amplification layers  225   b  and  226   b  that are formed on the base electrodes  225   a  and  226   a  and have the same width as the base electrodes  225   a  and  226   a . The base electrodes  225   a  and  226   a  serve as cathode electrodes providing electrons to the electron emission amplification layers  225   b  and  226   b . The base electrodes  225   a  and  226   a  do not need to be formed of a transparent conductive material since they are not disposed on the first substrate  210  or the second substrate  220 . As in the PDP illustrated in  FIGS. 1 and 2 , the electron emission amplification layers  225   b  and  226   b  can be formed of a material that amplifies emitted electrons and generates an electron beam such as an OPS, an MIM, a BNBS, a CNT, etc.  
         [0067]     Referring to  FIG. 11 , the electron emission members  225  and  226  can further respectively comprise emission electrodes  225   c  and  226   c  disposed in the electron emission amplification layers  225   b  and  226   b . The emission electrodes  225   c  and  226   c  can be formed of ITO or fine wire mesh. The sidewalls of the barrier ribs  213  and the electron emission members  225  and  226  can be covered by the protective layer  224 . The protective layer  224  is formed of MgO, which prevents the barrier ribs  213  formed of a dielectric substance and the sustain electrodes  221  and  222  from being damaged due to sputtering of plasma particles, emits secondary electrons, and reduces a driving voltage. In the PDPs of  FIGS. 10 and 11 , the phosphor layer  215  is coated on the inner walls of the discharge cells  214  and the first dielectric layer  212 , but the present embodiments are not limited thereto. That is, the phosphor layer  215  can be coated in the etched second substrate  220 , and can have a variety of other structures. As with the PDP illustrated in  FIGS. 1 and 2 , the phosphor layer  215  can be at least one of a PL phosphor layer, a CL phosphor layer, and a QD.  
         [0068]     The function and operation of the PDPs illustrated in  FIGS. 10 and 11  will now be described. An electron beam is emitted throughout the entire discharge cell  214  by the electron emission members  225  and  226 , and thus high luminescence efficiency is obtained at a low voltage. The remaining functions and operations of the PDPs illustrated in  FIGS. 10 and 11  are similar to those of the PDP illustrated in  FIGS. 1 and 2 .  
         [0069]     The PDPs illustrated in  FIGS. 10 and 11  are reflective PDPs in which visible light generated by the discharge are excited the phosphor layer  215 , reflected, and transmitted through the second substrate  220 , but the present embodiments are not limited thereto. The principles of the PDPs illustrated in  FIGS. 10 and 11  can also be applied to backlit PDPs. In this case, the address electrode  211  may be formed of a transparent conductive material to transmit visible light.  
         [0070]     The PDPs illustrated in  FIG. 12  are alternating current (AC) type 3D facing discharge PDPs. The PDP of  FIG. 12  comprises a first substrate  310 , a second substrate  320 , barrier ribs  313 , two pairs of sustain electrodes  321  and  322 , a first dielectric layer  312 , an address electrode  311 , a phosphor layer  315 , a protective layer  324 , and electron emission members  325  and  326 .  
         [0071]     The two pairs of sustain electrodes  321  and  322  are discharge electrodes in the form of strips and disposed in the barrier ribs  313 , include common electrodes  321  and scan electrodes  322  that are spaced apart from each other, and cross the address electrode  311 . The electron emission members  325  and  326  respectively comprise base electrodes  325   a  and  326   a  that are disposed on the barrier ribs  313  and correspond to the common electrodes  321  and the scan electrodes  322 , and electron emission amplification layers  325   b  and  326   b  that are formed on the base electrodes  325   a  and  326   a  and have the same width as the base electrodes  325   a  and  326   a . The base electrodes  325   a  and  326   a  serve as cathode electrodes providing electrons to the electron emission amplification layers  325   b  and  326   b . The base electrodes  325   a  and  326   a  do not need to be formed of a transparent conductive material since they are not disposed on the first substrate  310  and the second substrate  320 . As with the PDP illustrated in  FIGS. 1 and 2 , the electron emission amplification layers  325   b  and  326   b  can be formed of a material that amplifies emitted electrons and generates an electron beam such as an OPS, an MIM, a BNBS, a CNT, etc.  
         [0072]     In the embodiment illustrated in  FIG. 13 , the electron emission members  325  and  326  respectively further comprise emission electrodes  325   c  and  326   c  disposed on the electron emission amplification layers  325   b  and  326   b . The emission electrodes  325   c  and  326   c  can be formed of ITO or fine wire mesh. The protective layer  324  can cover the sidewalls of the barrier ribs  313  and the electron emission members  325  and  326 .  
         [0073]     The function and operation of the PDPs illustrated in  FIGS. 12 and 13  will now be described. After an initial reset operation is performed, and wall charges are formed in the discharge cells  314 , a discharge is initiated between the sustain electrodes  321  and  322  in the discharge cell  314 . The common electrodes  321  and the scan electrodes  322 , which facilitate the sustain discharge, are disposed in the barrier ribs  313 , and thus the sustain discharge is a facing discharge that is not performed on a surface. When an AC voltage is applied between the common electrodes  321  and the scan electrodes  322 , an electric field in the discharge cell  314  between the common electrodes  321  and the scan electrodes  322  regularly reverses direction.  
         [0074]     Therefore, electrons flow from the base electrode  325   a  adjacent to the common electrodes  321  to the electron emission amplification layer  325   b  and are accelerated or amplified to form the electron beam in the discharge cell  314 . When the voltage between the sustain electrodes  321  and  322  is reversed, the electrons are accelerated or amplified by the electron emission members  325  adjacent to the scan electrodes  322  to emit the electron beam into the discharge cell  314 . The emitted electron beam excites a gas and the exited gas stabilizes to emit ultraviolet rays. The ultraviolet rays excite the phosphor layers  315  to emit visible light.  
         [0075]     The facing discharge PDP has sufficient space between the sustain electrodes  321  and  322 , which facilitate the sustain discharge, and thus has high luminescence efficiency. However, the driving voltage for initiating the discharge is increased due to the wide space between the sustain electrodes  321  and  322 . Since the electron beam is emitted through the electron emission members  325  and  326 , the driving voltage for initiating the discharge is reduced and luminescence efficiency is increased. Other functions and operations of the PDPs illustrated in  FIGS. 12 and 13  are identical to those of the embodiments illustrated in  FIG. 1, 2 ,  10 , and  11 .  
         [0076]     The PDPs of  FIGS. 14 and 15  are AC 2D facing discharge PDPs. The PDP of  FIG. 14  comprises a first substrate  410 , a second substrate  420 , barrier ribs (not shown), a first discharge electrode  411 , a second discharge electrode  421 , a first dielectric layer  412 , a second dielectric layer  423 , a phosphor layer (not shown), a protective layer  424 , and electron emission members  425  and  426 .  
         [0077]     The first discharge electrode  411  is disposed on the upper surface of the first substrate  410 . The second discharge electrode  421  is disposed on the bottom surface of the second substrate  420  and crosses the first discharge electrode  411 . The first discharge electrode  411  and the second discharge electrode  421  serve as a scan electrode and an address electrode, respectively, or vice versa. The first discharge electrode  411  and the second discharge electrode  421  form strips, but the present embodiments are not limited thereto. That is, the first discharge electrode  411  and the second discharge electrode  421  can form various patterns, including a zigzag.  
         [0078]     The electron emission members  425  and  426  respectively comprise base electrodes  425   a  and  426   a  that are disposed on the second discharge electrode  421  and the second dielectric layer  412  and correspond to the second discharge electrode  421  and the first discharge electrode  411 , and electron emission amplification layers  425   b  and  426   b  that are formed on the base electrodes  425   a  and  426   a  and have the same width as the base electrodes  425   a  and  426   a . The base electrodes  425   a  and  426   a  serve as cathode electrodes providing electrons to the electron emission amplification layers  425   b  and  426   b . The base electrodes  425   a  and  426   a  may be formed of a transparent conductive material to transmit visible light. As with the PDP illustrated in  FIGS. 1 and 2 , the electron emission amplification layers  425   b  and  426   b  can be formed of a material that amplifies emitted electrons and generates an electron beam such as an OPS, an MIM, a BNBS, a CNT, etc.  
         [0079]     In the PDP illustrated in  FIG. 15 , the electron emission members  425  and  426  respectively further comprise emission electrodes  425   c  and  426   c  disposed on the electron emission amplification layers  425   b  and  426   b . The emission electrodes  425   c  and  426   c  can be formed of ITO or fine wire mesh. The phosphor layer (not shown) can be formed in a variety of locations including on the barrier ribs of the discharge cell  414 . As in the PDP illustrated in  FIGS. 1 and 2 , the phosphor layer (not shown) can be at least one of a PL phosphor layer, a CL phosphor layer, and a QD.  
         [0080]     The function and operation of the PDPs illustrated in  FIGS. 14 and 15  will now be described. After an initial reset operation is performed, and wall charges are formed in the discharge cell  414 , a predetermined AC voltage is applied between the first and second discharge electrodes  411  and  421 , an electric field in the discharge cell  314  between the first discharge electrode  411  to the second discharge electrode  421  periodically changes direction.  
         [0081]     Therefore, electrons flow from the base electrode  426   a  on the first discharge electrode  411  (but only electron emitter  425  is above the first discharge electrode  411 ) to the electron emission amplification layers  425   b  and  426   b  and are accelerated or amplified to produce the electron beam in the discharge cell  414 . When the voltage between the first and second discharge electrodes  411  and  421  is reversed, electrons are accelerated or amplified by the electron emission member  425  on the second discharge electrode  421  (but only electron emitter  425  is above the second discharge electrode  421 ) to form the electron beam in the discharge cell  414 . Since the electron beam is emitted through the electron emission members  425  and  426 , the driving voltage required to initiate the discharge is reduced and luminescence efficiency is increased. Other functions and operations of the PDPs illustrated in  FIGS. 14 and 15  are the same as those of the PDPs illustrated in  FIGS. 1, 2 ,  10 ,  11 ,  12 , and  13 .  
         [0082]     The PDPs illustrated in  FIGS. 16 and 17  are direct current (DC) 2D facing discharge PDPs. The PDP of  FIG. 16  comprises a first substrate  510 , a second substrate  520 , a first discharge electrode  511 , a second discharge electrode  521 , a phosphor layer (not shown), and an electron emission member  526 .  
         [0083]     The first discharge electrode  511  is disposed on the upper surface of the first substrate  510 . The second discharge electrode  521  is disposed on the bottom surface of the second substrate  520  and crosses the first discharge electrode  511 . The first discharge electrode  511  and the second discharge electrode  521  are formed in strips, but the present embodiments are not limited thereto. That is, the first discharge electrode  511  and the second discharge electrode  521  can also have various patterns including a zigzag.  
         [0084]     The electron emission member  526   b  comprises an electron emission amplification layer  526   b  that is formed on the first discharge electrode  511  and has the same width as the first discharge electrode  511 . The first discharge electrode  511  contacts the electron emission member  526 , is a base electrode  526   a  of the electron emission member  526 , and serves as a cathode electrode. Therefore, a base electrode is not required. The electron emission amplification layer  526   b  is formed on the first discharge electrode  511  but the present embodiments are not limited thereto. For example, the electron emission amplification layer  526   b  can be formed on the second discharge electrode  521 . In this case, the second discharge electrode  521  serves as the cathode electrode.  
         [0085]     As in the PDP illustrated in  FIGS. 1 and 2 , the electron emission amplification layer  526   b  can be formed of a material that amplifies emitted electrons and generates an electronic beam, such as an OPS, an MIM, a BNBS, a CNT, etc. As illustrated in  FIG. 17 , the electron emission member  526   b  can further comprise a emission electrode  525   c  disposed on the electron emission amplification layer  526   b . The emission electrode  525   c  can be formed of ITO or fine wire mesh. The phosphor layer (not shown) can be formed in a variety of locations in a discharge cell. As in the PDP illustrated in  FIGS. 1 and 2 , the phosphor layer (not shown) can be at least one of a PL phosphor layer, a CL phosphor layer, and a QD.  
         [0086]     The function and operation of the PDPs illustrated in  FIGS. 16 and 17  will now be described. An addressing operation of selecting a discharge cell  514  for discharge is performed using a simple scan method, a self-scan™ method, a pulse memory drive method, etc. Thereafter, a discharge voltage is applied between the first electrode  511  and the second electrode  512  from an external power source, and electrons are emitted from the first electrode  511  serving as the cathode electrode and transmitted through the electron emission amplification layer  526   b . Thus, an electron beam is accelerated or amplified and is emitted into the discharge cell  514 . The emitted electrons are absorbed by the second discharge electrode  521 , serving as an anode electrode.  
         [0087]     In this regard, the discharge is performed directly between the first discharge electrode  511  and the second discharge electrode  512 , causing the flow of a discharge current. To control the discharge operation, the discharge current must be properly controlled. In the PDP illustrated in  FIG. 17 , a proper ratio of thickness of the first discharge electrode  511  to the thickness of the second discharge electrode  512  is selected, a doping process is controlled according to the selected ratio of thicknesses, and a predetermined DC voltage is applied to control the discharge current.  
         [0088]     Since the electron beam is emitted through the electron emission members  526 , a driving voltage for initiating the discharge is reduced and luminescence efficiency is increased. The DC 2D opposed discharge PDPs illustrated in  FIGS. 16 and 17  comprise the electron emission member  526  to control the discharge current. Therefore, the DC 2D facing discharge PDPs do not comprises a resistor for controlling the discharge current (unclear), thereby reducing manufacturing time and costs. Although not shown in the drawings, an electron emission member for improving the electron emission characteristics can be applied to a flat lamp used as a backlight for LCDs.  
         [0089]     The flat lamp comprises upper and lower panels. The upper and lower panels face each other and form a discharge space therebetween. A plurality of spacers are interposed between the upper and bottom panels and partition the discharge space into a plurality of discharge cells. The discharge cells are filled with a discharge gas containing Ne, Xe, a mixture of He and Xe, a mixture of Ne, Ar and Xe or a mixture of He, Ne and Xe. Phosphor layers are formed on inner walls of the discharge cells. The bottom panel comprises a bottom substrate, and at least one discharge electrode disposed on the bottom substrate. The upper panel comprises an upper substrate, and at least one discharge electrode disposed on the upper substrate. The flat lamp further comprises a base electrode that is disposed on one of the upper and bottom panels and corresponds to the discharge electrode, and an electron emission member including an electron emission amplification layer formed on the base electrode. The electron emission member can further comprise an emission electrode on the electron emission amplification layer. The emission electrode can be formed of ITO or fine wire mesh. The electron emission amplification layer can be formed of a material that amplifies emitted electrons and generates an electronic beam such as an OPS, an MIM, a BNBS, a CNT, etc. A phosphor layer can be formed in any location of the discharge cell. As in the PDP illustrated in  FIGS. 1 and 2 , the phosphor layer can be formed of at least one of a PL phosphor layer, a CL phosphor layer, and a QD.  
         [0090]     In connection with the function and operation of the flat lamp, when a predetermined voltage is applied to the discharge electrode, electrons are amplified or accelerated in the electron emission amplification layer, and are emitted into the discharge cell, thereby increasing brightness and luminescence efficiency of the flat lamp.  
         [0091]     The present embodiments provide a plasma display panel (PDP) with improved electronic emission characteristics due to the inclusion of an electronic emission member such as an oxidized porous silicon layer that reduces an operating voltage and increases luminescence efficiency.  
         [0092]     While the present embodiments have been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present embodiments as defined by the following claims.