JP2009301841A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel (PDP) in which demonstration of superior image display performance and driving by low electric power is achieved stably by improving secondary electron emitting characteristics and charge retaining characteristics by improving a surface layer, and moreover, demonstration of high quality image display performance is expected at high resolution at high-speed driving by preventing occurrence of discharge delay in driving in addition to respective effects. <P>SOLUTION: On a face on a discharge space side of a dielectric layer 7, as a surface layer (protection film) 8 of a film thickness of about 1 μm, a crystalline film in which MgO is the main component and to which Ce of the concentration of 5 mol% or more and 20 mol% or less is added is formed. By this, in a forbidden band in the protection film 8, an electron level caused by Ce is formed at a fixed depth, and improvement of the secondary electron-emitting characteristics and the charge retention characteristics are realized. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plasma display panel using radiation by gas discharge, and more particularly to a technique for improving the characteristics of a surface layer (protective film).

  A plasma display panel (hereinafter referred to as “PDP”) is a flat display device using radiation from gas discharge. High-speed display and large size are easy, and it is widely put into practical use in fields such as video display devices and public information display devices. There are two types of PDPs: DC type (DC type) and AC type (AC type). Surface discharge type AC type PDPs have a particularly high technical potential in terms of life characteristics and increase in size, and are commercialized.

  FIG. 10 is a schematic diagram of a discharge cell structure which is a discharge unit of a general AC type PDP. A PDP 1x shown in FIG. 10 is formed by bonding a front panel 2 and a back panel 9 together. The front panel 2 that is the first substrate has a plurality of pairs of display electrodes 6 each including the scanning electrodes 5 and the sustain electrodes 4 on one side of the front panel glass 3 so as to cover the display electrode pairs 6. The dielectric layer 7 and the protective film 8 are sequentially laminated. The scan electrode 5 and the sustain electrode 4 are configured by laminating transparent electrodes 51 and 41 and bus lines 52 and 42, respectively.

The dielectric layer 7 is formed of a low melting point glass having a glass softening point in the range of about 550 ° C. to 600 ° C., and has a current limiting function peculiar to the AC type PDP.
The protective film 8 protects the dielectric layer 7 and the display electrode pair 6 from ion collision of plasma discharge, and efficiently emits secondary electrons and lowers the discharge start voltage. Usually, the protective film 8 is formed by a vacuum vapor deposition method or a printing method using magnesium oxide (MgO) having excellent secondary electron emission characteristics, sputtering resistance, and visible light transmittance. The same structure as the protective film 8 may be provided as a surface layer exclusively for the purpose of securing secondary electron emission characteristics.

  On the other hand, the back panel 9 as the second substrate has a plurality of data (address) electrodes 11 for writing image data on the back panel glass 10 so as to intersect the display electrode pair 6 of the front panel 2 in the orthogonal direction. It is attached. A dielectric layer 12 made of low-melting glass is disposed on the back panel glass 10 so as to cover the data electrodes 11. On the boundary of the dielectric layer 12 with adjacent discharge cells (not shown), a plurality of striped ribs 13 having a predetermined height made of low melting glass define a discharge space 15. The pattern parts 1231 and 1232 are formed by combining them in a grid pattern. A phosphor layer 14 (phosphor layers 14R, 14G, and 14B) is formed on the surface of the dielectric layer 12 and the side surfaces of the partition walls 13 by applying and firing phosphor inks of R, G, and B colors.

The front panel 2 and the back panel 9 are arranged so that the display electrode pair 6 and the data electrode 11 are orthogonal to each other with the discharge space 15 therebetween, and are sealed around each of them. At this time, the discharge space 15 sealed inside is filled with a rare gas such as Xe—Ne or Xe—He as a discharge gas at a pressure of about several tens of kPa. The PDP 1x is configured as described above.
In order to display an image using the PDP, a gradation expression method (for example, an intra-field time division display method) in which one field of video is divided into a plurality of subfields (SF) is used.

  By the way, recent electric appliances are desired to be driven with low power, and there is a similar demand for PDP. In a PDP that performs high-definition image display, the number of discharge cells is increased and the number of discharge cells is increased. Therefore, the operating voltage must be increased in order to increase the reliability of the write discharge. The operating voltage of the PDP depends on the secondary electron emission coefficient (γ) of the protective film. γ is a value determined by the material and discharge gas, and it is known that γ increases as the work function of the material decreases. An increase in the operating voltage becomes an obstacle to low power driving.

Therefore, Patent Document 1 discloses a technique for forming a protective film having an amorphous structure in which cerium oxide (CeO ₂ ) is added to MgO in a range of 0.1 mol% to 20 mol%. According to this, a protective film is composed of amorphous MgO with CeO _{2 as} an additive, and the protective film surface is prevented from reacting with the impurity gas and being altered (carbonized), thereby increasing the operating voltage. It is intended to suppress.

Patent Document 2 also discloses a technology for forming a protective film having an amorphous structure in which CeO ₂ is added to MgO in a range of 0.1 mol% to 20 mol%. It is described that this configuration reduces the discharge start voltage or the discharge sustain voltage.
Further, Patent Document 3 discloses a protective film in which CeO ₂ is added to MgO in a weight ratio range of 0.011 to 0.5, which describes that the operating voltage is reduced.
JP 2000-164143 A JP 11-339665 A JP 2003-1773738 A

However, in any of the above-described conventional techniques, it is difficult to say that the PDP has actually achieved low power driving sufficiently.
Further, since the protective film is colored when Ce is added, another problem that the visible light transmittance of the front panel is deteriorated can be caused by increasing the Ce concentration in the film. For this reason, the problem of reducing the operating voltage and the problem of preventing a decrease in luminance are in a trade-off relationship, and it is necessary to solve both problems together.

  Furthermore, the PDP has a problem of “discharge delay”. In the display field such as PDP, the definition of video sources is increasing, and the number of scanning electrodes (scanning lines) is increasing in order to display a high-definition image. For example, a full-spec high-definition TV has more than twice the number of scanning lines as compared to an NTSC TV. In order to display an image with a high-definition PDP, it is necessary to drive a one-field sequence at a high speed within 1/60 [s]. For this purpose, there is a method of narrowing the width of the pulse applied to the data electrode in the writing period in the subfield.

  However, when the PDP is driven, there is a problem of a time lag called “discharge delay” from the rise of the voltage pulse to the actual occurrence of discharge in the discharge cell. If the pulse width is shortened for high-speed driving, the influence of “discharge delay” increases, and the probability that discharge can be completed within the width of each pulse decreases. As a result, unlit cells (lighting failure) occur on the screen, and image display performance is impaired. In particular, in a PDP having an amorphous structure protective film as in Patent Document 1, since initial electrons that suppress discharge delay are difficult to emit, image quality deterioration can be a relatively large problem.

As described above, in the current PDP, there are some problems that are difficult to achieve at the same time.
The present invention has been made in view of the above-mentioned problems. As a first object, the surface layer is improved to improve the secondary electron emission characteristics and the charge retention characteristics, thereby improving the image display performance. To provide a plasma display panel that can stably achieve its performance and low power drive.

  As a second object, in addition to the above-described effects, there is provided a PDP capable of preventing the occurrence of a discharge delay during driving and expecting high-quality image display performance even with a high-definition PDP driven at high speed.

  In order to achieve the above object, according to the present invention, a first substrate on which a plurality of display electrodes are arranged is sealed in a state facing a second substrate through a discharge space filled with a discharge gas. In the plasma display panel, a surface layer containing magnesium oxide and cerium having a concentration of 5 mol% or more and 20 mol% or less is disposed on the surface of the first substrate facing the discharge space.

Here, the cerium concentration in the surface layer is preferably 10 mol% or more and 15 mol% or less.
Further, magnesium oxide fine particles can be further disposed on the discharge space side of the surface layer.
The magnesium oxide fine particles can be produced by a gas phase oxidation method. Alternatively, it can be produced by firing a magnesium oxide precursor.

  In the PDP of the present invention having the above-described configuration, Ce that is adjusted to a predetermined concentration that does not excessively reduce the visible light transmittance is included in the surface layer mainly composed of MgO. The resulting electronic level is formed. Therefore, when this PDP is driven, the energy that can be used for excitation acquired in the process of so-called Auger neutralization can be increased by using the electrons trapped in the electron level caused by Ce. By utilizing this increased energy, the secondary electron emission characteristics of the surface layer are greatly improved. Therefore, it is possible to realize a PDP that can start discharge with a high response at a relatively low discharge start voltage, prevent discharge delay, and exhibit excellent image display performance with low power drive.

Further, the electron level caused by Ce is formed at a certain depth from the vacuum level (that is, a depth that is not too shallow in terms of energy). Therefore, it is possible to suppress occurrence of “charge loss” due to excessive loss of charge from the protective film during driving, so that appropriate charge retention characteristics can be exhibited, and good secondary electron emission can be expected over time. It has become.
In addition, in such a surface layer, if a group of fine particles made of magnesium oxide fine particles produced by a vapor phase oxidation method or a precursor firing method is further provided on the surface, the secondary electron emission characteristics can be further improved. In addition to suppressing the discharge delay, the initial electron emission characteristics at the start of discharge are improved. As a result, even a PDP driven at a high speed with a high-definition cell with a small discharge space can generate a discharge with high responsiveness, so that an excellent image display performance is exhibited by utilizing abundant electrons in the discharge space, and a discharge delay is reduced. The problem and the problem of temperature dependence of the discharge delay can be improved. In addition, stable PDP driving can be performed in an environment with a wide range of driving temperatures.

Embodiments and examples of the present invention will be described below, but the present invention is naturally not limited to these forms, and may be appropriately modified and implemented without departing from the technical scope of the present invention. be able to.
<Embodiment 1>
(PDP configuration example)
FIG. 1 is a schematic cross-sectional view along the xz plane of the PDP 1 according to Embodiment 1 of the present invention. The PDP 1 is generally the same as the conventional configuration (FIG. 10) except for the configuration around the protective film 8.

  Here, the PDP 1 is an AC type of the 42-inch class NTSC specification example, but the present invention may naturally be applied to other specification examples such as XGA and SXGA. As a high-definition PDP having a resolution higher than HD (High Definition), for example, the following standard can be exemplified. When the panel sizes are 37, 42, and 50 inches, they can be set to 1024 × 720 (number of pixels), 1024 × 768 (number of pixels), and 1366 × 768 (number of pixels) in the same order. In addition, a panel having a higher resolution than that of the HD panel can be included. A panel having a resolution of HD or higher can include a full HD panel having 1920 × 1080 (number of pixels).

As shown in FIG. 1, the configuration of the PDP 1 is roughly divided into a first substrate (front panel 2) and a second substrate (back panel 9) that are disposed with their main surfaces facing each other.
A front panel glass 3 serving as a substrate of the front panel 2 has a pair of display electrodes 6 (scanning electrodes 5 and sustaining electrodes 4) disposed on one main surface thereof with a predetermined discharge gap (75 μm). It is formed over multiple pairs. Each display electrode pair 6 includes strip-shaped transparent electrodes 51 and 41 (thickness 0.1 μm, width 150 μm) made of a transparent conductive material such as indium tin oxide (ITO), zinc oxide (ZnO), and tin oxide (SnO ₂ ). ), Bus lines 52, 42 (such as Ag thick film (thickness 2 μm to 10 μm), Al thin film (thickness 0.1 μm to 1 μm), Cr / Cu / Cr laminated thin film (thickness 0.1 μm to 1 μm), etc. 7 μm thick and 95 μm wide) are laminated. The sheet resistance of the transparent electrodes 51 and 41 is lowered by the bus lines 52 and 42.

Here, the “thick film” refers to a film formed by various thick film methods formed by applying a paste containing a conductive material or the like and then baking it. The “thin film” refers to a film formed by various thin film methods using a vacuum process, including a sputtering method, an ion plating method, an electron beam evaporation method, and the like.
The front panel glass 3 provided with the display electrode pair 6 has a low melting point glass mainly composed of lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ), or phosphorus oxide (PO ₄ ) over the entire main surface. A dielectric layer 7 having a thickness of 35 μm is formed by a screen printing method or the like.

The dielectric layer 7 has a current limiting function peculiar to the AC type PDP, and is an element that realizes a longer life than the DC type PDP.
A protective film 8 having a thickness of about 1 μm is formed on the surface of the dielectric layer 7. The protective film 8 is disposed for the purpose of protecting the dielectric layer 7 from ion bombardment during discharge and reducing the discharge start voltage, and is made of a material excellent in sputtering resistance and secondary electron emission coefficient γ. The material is required to have better optical transparency and electrical insulation.

  The protective film 8 is a main characteristic part of the present invention, and Ce is added in a concentration range of 5 mol% or more and 20 mol% or less with respect to MgO as a main component, and as a whole, at least a microcrystalline structure or a crystalline structure of MgO. It is a crystalline film holding either one. Ce is added to form an electron level in the forbidden band of the protective film 8 as will be described later. The Ce concentration is more preferably 10 mol% or more and 15 mol% or less. By adding such a Ce element, the protective film 8 exhibits excellent secondary electron emission characteristics and charge retention characteristics, and enables stable low power driving by reducing the operating voltage (mainly the discharge start voltage and the discharge sustain voltage). It has become.

  If the Ce concentration is a low concentration of less than 5 mol%, the secondary electron emission characteristics and the charge retention characteristics of the protective film 8 are insufficient, which is not preferable. Further, when the Ce concentration is higher than 20 mol%, the crystallinity of the protective film 8 is lowered, and unnecessary coloration is increased to affect the visible light transmittance. Therefore, the above-described concentration range of 5 mol% or more and 20 mol% or less is important as the Ce concentration for achieving both good low power driving and visible light transmittance.

 As for the structure of the protective film 8, since a peak can be confirmed at a position equivalent to that of pure MgO in thin film X-ray analysis measurement using a CuKα ray as a radiation source, at least the same NaCl structure as that of MgO is retained. I can confirm. Since Ce atoms have a considerably different atomic radius from Mg atoms, if the Ce concentration in the protective film 8 is high (the amount of Ce added is too large), the MgO-based NaCl structure will be destroyed. The crystal structure (NaCl structure) of the protective film 8 is maintained by appropriately adjusting. In other words, it can be said that the protective film 8 of the present invention is not composed only of an amorphous structure.

  A back panel glass 10 serving as a substrate of the back panel 9 has an Ag thick film (thickness 2 μm to 10 μm), an Al thin film (thickness 0.1 μm to 1 μm) or a Cr / Cu / Cr laminated thin film ( The data electrodes 11 each having a thickness of 0.1 μm to 1 μm, etc., are arranged in parallel in stripes at a constant interval (360 μm) in the y direction with the width of 100 μm as the longitudinal direction. A dielectric layer 12 having a thickness of 30 μm is disposed over the entire surface of the back panel glass 9 so as to enclose each data electrode 11.

On the dielectric layer 12, a grid-like partition wall 13 (height: about 110 μm, width: 40 μm) is further arranged in accordance with the gap between adjacent data electrodes 11, and discharge cells are divided to prevent erroneous discharge. It plays a role in preventing the occurrence of optical crosstalk.
A phosphor layer 14 corresponding to each of red (R), green (G), and blue (B) for color display is provided on the side surface of two adjacent barrier ribs 13 and the surface of the dielectric layer 12 therebetween. Is formed. The dielectric layer 12 is not essential, and the data electrode 11 may be directly enclosed by the phosphor layer 14.

The front panel 2 and the back panel 9 are disposed to face each other so that the longitudinal directions of the data electrode 11 and the display electrode pair 6 are orthogonal to each other, and the outer peripheral edges of both the panels 2 and 9 are sealed with glass frit. A discharge gas composed of an inert gas component containing He, Xe, Ne or the like is sealed between the panels 2 and 9 at a predetermined pressure.
A space between the barrier ribs 13 is a discharge space 15. A region where a pair of adjacent display electrode pairs 6 and one data electrode 11 intersect with each other across the discharge space 15 is a discharge cell (“subpixel”) for image display. To say). The discharge cell pitch is 675 μm in the x direction and 300 μm in the y direction. One discharge pixel (675 μm × 900 μm) is composed of three discharge cells corresponding to adjacent RGB colors.

As shown in FIG. 2, scan electrode driver 111, sustain electrode driver 112, and data electrode driver 113 are connected to scan electrode 5, sustain electrode 4 and data electrode 11 as drive circuits, respectively, as shown in FIG.
(PDP drive example)
In the PDP 1 having the above-described configuration, an AC voltage of several tens to several hundreds kHz is applied to the gap between the display electrode pairs 6 by a known drive circuit (not shown) including the drivers 111 to 113 when driven. As a result, a discharge is generated in an arbitrary discharge cell, and ultraviolet rays (dotted line and arrow in FIG. 1) mainly including a resonance line mainly composed of 147 nm wavelength by excited Xe atoms and a molecular line mainly composed of wavelength 172 nm by excited Xe molecules are emitted from the phosphor layer. 14 is irradiated. The phosphor layer 14 is excited to emit visible light. The visible light passes through the front panel 2 and is emitted to the front surface.

  As an example of this driving method, an in-field time division gradation display method is adopted. In this method, a field to be displayed is divided into a plurality of subfields (SF), and each subfield is further divided into a plurality of periods. One subfield further includes (1) an initialization period in which all discharge cells are initialized, and (2) each discharge cell is addressed, and a display state corresponding to input data is selected and input to each discharge cell. The writing period is divided into four periods: (3) a sustain period for causing the discharge cells in the display state to emit light, and (4) an erase period for erasing wall charges formed by the sustain discharge.

In each subfield, after resetting the wall charge of the entire screen with the initialization pulse in the initialization period, a write discharge is performed in which the wall charge is accumulated only in the discharge cells to be lit in the write period, and the subsequent discharge sustain period In this case, an alternating voltage (sustain voltage) is applied to all the discharge cells all at once to maintain the discharge for a certain period of time, thereby displaying light.
Here, FIG. 3 shows an example of a driving waveform in the mth subfield in the field. As shown in FIG. 3, an initialization period, an address period, a discharge sustain period, and an erase period are allocated to each subfield.

  The initialization period is a period in which the wall charges on the entire screen are erased (initialization discharge) in order to prevent the influence of lighting of the discharge cells before that (influence of the accumulated wall charges). In the drive waveform example shown in FIG. 3, a higher voltage (initialization pulse) than the data electrode 11 and the sustain electrode 4 is applied to the scan electrode 5 to discharge the gas in the discharge cell. Since the charge generated thereby is accumulated on the wall of the discharge cell so as to cancel the potential difference among the data electrode 11, the scan electrode 5, and the sustain electrode 4, a negative charge is applied to the surface of the protective film 8 near the scan electrode 5. Accumulated as electric charge. Positive charges are accumulated as wall charges on the surface of the phosphor layer 14 near the data electrode 11 and the surface of the protective film 8 near the sustain electrode 4. Due to this wall charge, a predetermined wall potential is generated between scan electrode 5 and data electrode 11 and between scan electrode 5 and sustain electrode 4.

  The writing period is a period in which addressing (setting of lighting / non-lighting) of the discharge cell selected based on the image signal divided into subfields is performed. In this period, when the discharge cell is turned on, a voltage (scanning pulse) lower than that of the data electrode 11 and the sustain electrode 4 is applied to the scanning electrode 5. That is, a voltage is applied to scan electrode 5 -data electrode 11 in the same direction as the wall potential, and a data pulse is applied between scan electrode 5 and sustain electrode 4 in the same direction as the wall potential, thereby writing discharge (writing Discharge)). As a result, negative charges are accumulated on the surface of the phosphor layer 14 and the surface of the protective film 8 near the sustain electrode 4, and positive charges are accumulated on the surface of the protective film 8 near the scan electrode 5 as wall charges. Thus, a predetermined wall potential is generated between the sustain electrode 4 and the scan electrode 5.

  The discharge maintaining period is a period in which the lighting state set by the write discharge is expanded and the discharge is maintained in order to ensure the luminance corresponding to the gradation. Here, in the discharge cell in which the wall charges are present, a voltage pulse (for example, a rectangular wave voltage of about 200 V) for sustain discharge is applied to each of the pair of scan electrodes 5 and sustain electrodes 4 in different phases. As a result, a pulse discharge is generated every time the voltage polarity changes in the discharge cell in which the display state is written.

  By this sustain discharge, a resonance line of 147 nm is emitted from excited Xe atoms in the discharge space, and a molecular beam mainly composed of 173 nm is emitted from excited Xe molecules. The surface of the phosphor layer 14 is irradiated with the resonance line / molecular beam, and display light is emitted by visible light emission. Then, multi-color / multi-gradation display is performed by a combination of sub-field units for each color of RGB. In a non-discharge cell in which no wall charges are written in the protective film 8, no sustain discharge occurs and the display state is black.

In the erasing period, a gradual erasing pulse is applied to the scanning electrode 5 to erase wall charges.
(Reduction of discharge voltage)
The reason why the PDP 1 of the first embodiment having the above configuration can be driven at a lower voltage than the conventional one will be described.

The discharge voltage of the PDP is determined by the degree to which electrons are emitted from the surface layer (electron emission characteristics). As the electron emission from the surface layer, a process in which neon or xenon, which is a discharge gas, is excited at the time of driving and receives secondary energy from the Auger effect is dominant.
FIG. 4 is a schematic diagram showing an electron level of a surface layer (protective film 8) in the PDP of Embodiment 1 and a protective film in the conventional PDP. As shown in the figure, electrons in the vicinity of the valence band are largely involved in the electron emission of the surface layer.

  When neon having a relatively high ionization energy is used as the discharge gas, when neon is excited during driving, electrons fall into the ground state. The energy (21.6 eV) at this time is received by the Auger effect by electrons in the valence band of magnesium oxide as the surface layer. The amount of energy exchanged in this process (21.6 eV) is sufficient for electrons in the valence band to be emitted as secondary electrons.

  However, when xenon having a relatively low ionization energy is used as the discharge gas, when xenon electrons are excited during driving and fall into the ground state, the amount of energy received by the Auger effect by electrons in the valence band (12 .1 eV) is not sufficient for electron emission. For this reason, the probability of discharging becomes very low. As a result, the operating voltage increases significantly when the concentration of xenon in the discharge gas increases. This is a serious problem when a large amount of xenon is used as the discharge gas.

  Here, in the present invention, as one solution for suppressing an increase in discharge voltage, as shown in FIG. 4, an electron level capable of satisfactorily receiving the effect of the Auger effect is disposed in the forbidden band of magnesium oxide. . This electron level is formed by introducing Ce at a concentration of 5 to 20 mol% into the protective film 8 as described above. As a result, the energy used for excitation acquired in the process of neutralization of Auger increases, so the probability of secondary electron emission increases, and as a result, abundant secondary electrons can be used in the discharge space 15. it can. For this reason, in the PDP 1, the operating voltage is reduced and a discharge of a favorable scale is formed, so that a PDP having excellent image display performance can be driven with low power.

  In addition, such an electron level caused by Ce is formed in the protective film 8 at a certain depth from the vacuum level (for example, a position shallower by about 4 eV than the valence band of magnesium oxide). Accordingly, occurrence of “charge loss” due to excessive loss of charge from the protective film 8 in a short time during driving is suppressed. In the protective film of the present invention, stable charge retention characteristics can be exhibited in this way, and excellent secondary electron emission characteristics can also be expected over a long period of time in a PDP.

Next, in FIG. 5, the surface layer (protective film 8) made of 100% magnesium oxide and the surface layer of the present invention in which 10 mol% of Ce is contained in magnesium oxide are each measured in the vicinity of the valence band measured by XPS. The secondary electron spectrum of is shown. The valence band of magnesium oxide is oxygen 2p orbital (O _2p ), and O _2p corresponds to a broad peak in the range of 3 to 9 eV in the spectrum of FIG. It can be confirmed that this peak is detected in both samples.

However, it can be seen that the surface layer (protective film 8) of the present invention containing 10 mol% of Ce further has a peak in the vicinity of 1 eV. This peak corresponds to the Ce 4f orbit (Ce _4f ) and indicates that a new electron level exists in the forbidden band of the surface layer. Ce is a tetravalent atom, but due to the presence of this 4f orbit, the valence is expected to be trivalent when contained in magnesium oxide. This 4f orbit is considered to form an electron level in the forbidden band in the energy band of the surface layer.

In other words, in other words, by confirming the peak due to the 4f orbit in the secondary electron spectrum, the presence of the electron level in the forbidden band corresponding to the peak can be indirectly confirmed. In the present invention, by using such a relatively shallow electron level, the above-described effects are exhibited.
<Embodiment 2>
The second embodiment of the present invention will be described focusing on the differences from the first embodiment. FIG. 6 is a cross-sectional view showing the configuration of the PDP 1a according to the second embodiment.

  The basic structure of the PDP 1a is the same as that of the PDP 1, but is characterized in that MgO fine particles 16 having high initial electron emission characteristics are dispersed and arranged on the surface of the protective film 8 facing the discharge space 15. The dispersion density of the MgO fine particles 16 can be set so that the protective film 8 cannot be seen directly when the surface layer in the discharge cell 20 is viewed in plan from the Z direction, but is not limited thereto. For example, it may be provided partially or only at a position corresponding to the display electrode pair 6. In the PDP 1a, a surface layer is formed by a combination of the protective film 8 and the MgO fine particles 16.

For the sake of explanation, FIG. 6 schematically shows the MgO fine particles 16 disposed on the protective film 8 larger than the actual size. The MgO fine particles 16 may be produced by either a gas phase method or a precursor firing method. However, it has been experimentally known that MgO fine particles 16 with particularly good performance can be obtained by the precursor baking method described later.
According to the PDP 1a having such a configuration, the characteristics of the protective film 8 and the MgO fine particles 16 that are functionally separated from each other are synergistically exhibited in the surface layer.

That is, in the same manner as PDP 1 at the time of driving, the protective film 8 to which Ce is added at a concentration of 5 mol% or more and 20 mol% or less improves the secondary electron emission characteristics, reduces the operating voltage, and realizes low power driving. The Further, due to the improvement of the charge retention characteristics, the secondary electron emission characteristics described above are stably maintained over time during driving.
On the other hand, in the PDP 1a, the initial electron emission characteristics are further improved by arranging the MgO fine particles 16. As a result, the discharge response is dramatically improved, and a PDP in which the discharge delay and the problems related to the temperature dependence of the discharge delay are reduced can be realized. This effect is particularly effective in obtaining excellent image display performance in a PDP having a high-definition cell and driven at a high speed by a short pulse.

Further, by arranging the MgO fine particles 16, it is possible to prevent impurities from directly attaching to the surface of the protective film 8 from the discharge space 15, and further improvement of the life characteristics of the PDP can be expected.
(About MgO fine particles 16)
The MgO fine particles 16 provided in the PDP 1a are confirmed to have an effect of mainly suppressing the “discharge delay” in the write discharge and an effect of improving the temperature dependency of the “discharge delay” by the experiment conducted by the present inventor. Has been. Therefore, in the second embodiment, the MgO fine particles 16 are arranged on the surface of the protective film 8 as an initial electron emission portion at the time of driving by utilizing the property of superior initial electron emission characteristics compared to the protective film 8. It is.

  The “discharge delay” is considered to be mainly caused by a shortage of the amount of initial electrons that are triggered from the surface of the protective film 8 being discharged into the discharge space 15 at the start of discharge. Therefore, in order to effectively contribute to the initial electron emission properties with respect to the discharge space 15, MgO fine particles 16 having an extremely large initial electron emission amount than the protective film 8 are dispersedly arranged on the surface of the protective film 8. As a result, a large amount of initial electrons required in the address period are emitted from the MgO fine particles 16, thereby eliminating the discharge delay. By obtaining such initial electron emission characteristics, the PDP 1a can be driven at high speed with good discharge response even in the case of high definition.

Further, the configuration in which such MgO fine particles 16 are disposed on the surface of the protective film 8 mainly has an effect of improving the temperature dependency of the “discharge delay” in addition to the effect of suppressing the “discharge delay” in the write discharge. I know I can get it.
As described above, in the PDP 1a, the protective film 8 having the effects of low power driving, secondary electron emission characteristics, charge retention characteristics, and the like, and the MgO fine particles 16 having the effect of suppressing the discharge delay and its temperature dependence are combined. By configuring the surface layer, the PDP 1 as a whole can be driven at a high voltage with a low voltage even when it has a high-definition discharge cell, and a high-quality image display performance with suppressed generation of unlit cells can be expected. .

  Further, the MgO fine particles 16 are provided on the surface of the protective film 8 so as to have a certain protective effect on the protective film 8. That is, the protective film 8 has a high secondary electron emission coefficient and enables low power driving of the PDP, but has a relatively high adsorptivity for impurities such as water, carbon dioxide, and hydrocarbons. When the adsorption of impurities occurs, the initial discharge characteristics such as secondary electron emission characteristics are impaired. Therefore, if such a protective film 8 is covered with the MgO fine particles 16, it is possible to prevent impurities from adhering to the surface of the protective film 8 from the discharge space 15 in the covered region. Thereby, it can be expected to improve the life characteristics of the PDP 1a.

<Manufacturing method of PDP>
Next, a method for manufacturing PDP 1 and 1a in each of the above embodiments will be illustrated. The difference between PDP 1 and 1a is only the configuration of protective films 8 and 8a, and the other manufacturing steps are common.
(Production of back panel)
On the surface of a back panel glass made of soda-lime glass having a thickness of about 2.6 mm, a conductor material mainly composed of Ag is applied in a stripe pattern at a predetermined interval by a screen printing method. 5 μm) data electrodes are formed. As an electrode material of the data electrode 11, materials such as metals such as Ag, Al, Ni, Pt, Cr, Cu, and Pd, conductive ceramics such as carbides and nitrides of various metals, combinations thereof, or combinations thereof are used. A laminated electrode formed by laminating can also be used as necessary.

Here, in order to set the PDP 1 to be manufactured to the 40-inch class NTSC standard or VGA standard, the interval between two adjacent data electrodes is set to about 0.4 mm or less.
Subsequently, a glass paste made of lead-based or non-lead-based low-melting-point glass or SiO ₂ material is applied over the entire surface of the back panel glass on which the data electrodes are formed to a thickness of about 20 to 30 μm, and is fired. Form.

Next, partition walls 13 are formed in a predetermined pattern on the surface of the dielectric layer 12. Applying a low melting point glass material paste and using sandblasting or photolithography, a plurality of arrays of discharge cells are separated into rows and columns so as to partition the border with adjacent discharge cells (not shown). It forms with a pattern (refer FIG. 10).
Once the barrier ribs 13 are formed, the red (R) phosphor and the green (G) phosphor normally used in the AC type PDP are formed on the wall surfaces of the barrier ribs 13 and the surface of the dielectric layer 12 exposed between the barrier ribs 13. The fluorescent ink containing any one of the blue (B) phosphors is applied. This is dried and fired to form phosphor layers 14 respectively.

Examples of applicable chemical compositions of RGB color fluorescence are as follows.
Red phosphor; (Y, Gd) BO ₃ : Eu
Green phosphor; Zn ₂ SiO ₄ : Mn
Blue phosphor; BaMgAl ₁₀ O ₁₇ : Eu
As the form of each phosphor material, a powder having an average particle size of 2.0 μm is suitable. This is put in a server at a ratio of 50% by mass, 1.0% by mass of ethyl cellulose and 49% by mass of a solvent (α-terpineol) are added, and stirred and mixed in a sand mill to obtain 15 × 10 ⁻³ Pa · s. A phosphor ink is prepared. And this is sprayed and applied between the partition walls 13 from a nozzle having a diameter of 60 μm by a pump. At this time, the panel is moved in the longitudinal direction of the partition wall 20, and the phosphor ink is applied in a stripe shape. Thereafter, the phosphor layer 14 is formed by baking at 500 ° C. for 10 minutes.

Thus, the back panel 9 is completed.
In the above method example, the front panel glass 3 and the back panel glass 10 are made of soda lime glass. However, this is given as an example of the material and may be made of other materials.
(Preparation of front panel 2)
The display electrode pair 6 is produced on the surface of a front panel glass made of soda-lime glass having a thickness of about 2.6 mm. Here, an example in which the display electrode pair 6 is formed by a printing method is shown, but other than this, it can be formed by a die coating method, a blade coating method, or the like.

First, a transparent electrode material such as ITO, SnO ₂ , or ZnO is applied on the front panel glass in a predetermined pattern such as a stripe with a final thickness of about 100 nm and dried. Thereby, the transparent electrodes 41 and 51 are produced.
On the other hand, a photosensitive paste obtained by mixing a photosensitive resin (photodegradable resin) with Ag powder and an organic vehicle is prepared, and this is applied to the transparent electrodes 41 and 51 so as to be formed. Cover with a mask having a pattern. And it exposes from the said mask, a baking process is carried out at the baking temperature of about 590-600 degreeC through a development process. As a result, bus lines 42 and 52 having a final thickness of several μm are formed on the transparent electrodes 41 and 51. According to this photomask method, the bus lines 42 and 52 can be thinned to a line width of about 30 μm as compared with the screen printing method in which the line width of 100 μm is conventionally limited. As a metal material of the bus lines 42 and 52, in addition to Ag, Pt, Au, Al, Ni, Cr, tin oxide, indium oxide, or the like can be used. In addition to the above method, the bus lines 42 and 52 can also be formed by performing an etching process after forming an electrode material by vapor deposition or sputtering.

Next, an organic binder composed of lead-based or non-lead-based low-melting glass having a softening point of 550 ° C. to 600 ° C., SiO ₂ material powder, butyl carbitol acetate, or the like was mixed from above the formed display electrode pair 6. Apply paste. Then, baking is performed at about 550 ° C. to 650 ° C. to form the dielectric layer 7 having a final thickness of several μm to several tens of μm.
(Formation of surface layer)
The surface layer of PDP 1 or PDP 1a according to the first or second embodiment is formed by any one of the following steps.

First, the case where the protective film 8 is formed by the electron beam evaporation method will be described.
Prepare pellets for evaporation source. As a method for producing the beret, first, magnesium carbonate (MgCO ₃ ) powder, which is a starting material of magnesium oxide, and cerium oxide (CeO ₂ ) powder, which is an oxide of a rare earth metal element, are clarified at a predetermined ratio (to be clarified later). ), And the mixed powder is put into a mold and press-molded. Then, this is put into an alumina crucible and sintered in the atmosphere at a temperature of about 1400 ° C. for about 30 minutes to obtain a sintered body (pellet).

  The sintered body or pellet is placed in a deposition crucible of an electron beam deposition apparatus, and a protective film 8 containing Ce at a concentration of 5 mol% or more and 20 mol% or less in magnesium oxide is formed on the surface of the dielectric layer 7 using this as a deposition source. Form a film. The Ce concentration is adjusted by adjusting the mixing ratio of magnesium carbonate and cerium oxide at the stage of obtaining the mixed powder to be put into the alumina crucible. Thereby, the surface layer of PDP1 is completed.

As a method for forming the protective film, not only an electron beam evaporation method but also a known method such as a sputtering method or an ion plating method can be similarly applied.
Next, when manufacturing the PDP 1a, the MgO fine particles 16 are prepared. MgO fine particles can be produced by any one of the following vapor phase synthesis method or precursor firing method.
[Gas phase synthesis method]
A magnesium metal material (purity 99.9%) is heated in an atmosphere filled with an inert gas. While maintaining this heating state, a small amount of oxygen is introduced into the atmosphere, and magnesium is directly oxidized to produce MgO fine particles 16.

[Precursor firing method]
Next, the MgO precursor exemplified is uniformly fired at a high temperature (for example, 700 ° C. or higher), and this is gradually cooled to obtain MgO fine particles. Examples of the MgO precursor include magnesium alkoxide (Mg (OR) ₂ ), magnesium acetylacetone (Mg (acac) ₂ ), magnesium hydroxide (Mg (OH) ₂ ), magnesium carbonate, magnesium chloride (MgCl ₂ ), and magnesium sulfate. It is possible to select one or more of (MgSO ₄ ), magnesium nitrate (Mg (NO ₃ ) ₂ ), and magnesium oxalate (MgC ₂ O ₄ ) (two or more may be used in combination). it can. Depending on the selected compound, it may usually take the form of a hydrate, but such a hydrate may be used.

  The magnesium compound used as the MgO precursor is adjusted so that the purity of MgO obtained after firing is 99.95% or more, and the optimum value is 99.98% or more. This is because, when a certain amount or more of impurity elements such as various alkali metals, B, Si, Fe, and Al are mixed in the magnesium compound, undesired interparticle adhesion and sintering are caused during heat treatment, and highly crystalline MgO fine particles are formed. This is because it is difficult to obtain. For this reason, the precursor is adjusted in advance by removing the impurity element.

The MgO fine particles 16 obtained by any of the above methods are dispersed in a solvent. Then, the dispersion liquid is dispersed and dispersed on the surface of the protective film 8 based on a spray method, a screen printing method, or an electrostatic coating method. Thereafter, the solvent is removed through a drying / firing process, and the fine particles are fixed on the surface of the protective film 8.
The surface layer of PDP 1a is formed through the above steps.

(PDP completion)
The produced front panel 2 and back panel 9 are bonded together using sealing glass. Thereafter, the inside of the discharge space 15 is evacuated to a high vacuum (1.0 × 10 ⁻⁴ Pa), and a Ne—Xe or He—Ne—Xe system is used at a predetermined pressure (here, 66.5 kPa to 101 kPa). System, Ne—Xe—Ar, etc. discharge gas is enclosed.

The PDP 1 or 1a is completed through the above steps.
(Performance confirmation experiment)
Subsequently, in order to confirm the performance of the present invention, the following PDPs of Samples 1 to 17 having different configurations of only the surface layer were prepared.
Among these, samples 5 to 11 (Examples 1 to 7) correspond to the configuration of the PDP 1 of the first embodiment. Samples 16 and 17 (Examples 8 and 9) correspond to the configuration of the PDP 1a of the second embodiment.

Sample 1 (Comparative Example 1) has a surface layer (not including Ce) made of magnesium oxide formed by EB vapor deposition as the most basic conventional PDP configuration.
Sample 2 (Comparative Example 2) to Sample 4 (Comparative Example 4) are surface layers in which the ratio of the number of atoms represented by Ce / (Mg + Ce) is 0.01%, 0.1%, and 1%, respectively, in the same order. It was supposed to have.

In Sample 5 (Example 1) to Sample 11 (Example 7), the ratio of the number of atoms represented by Ce / (Mg + Ce) is 5%, 7%, 9%, 10%, 13% in the same order, respectively. The surface layer was 15% or 20%.
Sample 12 (Comparative Example 5) to Sample 14 (Comparative Example 7) have surface layers in which the ratio of the number of atoms represented by Ce / (Mg + Ce) is 30%, 50%, and 100% in the same order. It was.

Sample 15 (Comparative Example 8) had a protective film made only of magnesium oxide formed by EB vapor deposition and a surface layer on which MgO fine particles prepared by a precursor firing method were dispersedly arranged.
Sample 16 (Example 8) has a protective film in which the ratio of the number of atoms represented by Ce / (Mg + Ce) is 10%, and a surface layer on which MgO fine particles prepared by a vapor phase method are dispersedly arranged. It was supposed to have.

Sample 17 (Example 9) is a protective layer in which the ratio of the number of atoms represented by Ce / (Mg + Ce) is 10%, and a surface layer on which MgO fine particles prepared by the precursor firing method are dispersedly arranged. It was supposed to have.
The structure of the surface layer of each sample 1-17 and the experimental data obtained using these are summarized in Table 1.

［実験１］
（放電維持電圧の測定）
上記した各サンプルの作動電圧の特性を調べるために、放電ガスとしてＸｅ分圧が１５％のＸｅ−Ｎｅ混合ガスを用いた場合における放電維持電圧の測定を行った。

[Experiment 1]
(Measurement of sustaining voltage)
In order to examine the characteristics of the operating voltage of each sample described above, the discharge sustaining voltage was measured when a Xe-Ne mixed gas having a Xe partial pressure of 15% was used as the discharge gas.

FIG. 7 is a plot of the behavior of the sustaining voltage versus the Ce concentration in the film measured under the above conditions.
As shown in FIG. 7 and Table 1, when the Ce concentration is a low concentration of about 1% mol or less, the discharge sustaining voltage is about 170 V (Samples 1 to 4, Comparative Examples 1 to 4). It can be seen that when the Ce concentration is set to 5 mol% or more, the discharge sustaining voltage is lowered to 160 V or less and the low power driving is promoted (Samples 5 to 11 and Examples 1 to 7). This is presumably because by adding Ce, an electron level caused by Ce4f was formed in the forbidden band in the energy band of the protective film, and as a result, the secondary electron emission characteristics were improved. In the results shown in Table 1, when the Ce concentration is 10 mol% (Example 4 of Sample 8), the discharge sustain voltage is 138 V, indicating the lowest discharge sustain voltage in the Examples.

However, regarding samples 12 to 14 (Comparative Examples 5 to 7) having a Ce concentration of 30 mol% or more, a voltage increase was confirmed in another experiment. Thus, it can be seen that there is not much effect even if the concentration of Ce included in the protective film is too large, and there is an appropriate concentration range.
(Measurement of discharge delay)
Next, for samples 15 to 17 (Comparative Example 8 and Examples 8 and 9) having a surface layer in which MgO fine particles are disposed on the protective film, using the same discharge gas as described above, the discharge delay in the write discharge Was evaluated. As an evaluation method, a pulse corresponding to the initialization pulse in the drive waveform example shown in FIG. 3 was applied to an arbitrary cell in the PDP of each sample 1 to 17, and then a data pulse and a scan pulse were applied. The statistical delay that sometimes occurs was measured.

  As a result, in Samples 15 to 17 (Comparative Example 8, Examples 8 and 9) in which MgO fine particles are arranged, it is found that the discharge delay is more effectively reduced as compared with Sample 1 and the like. It was. Among these, assuming that the discharge delay time of the PDP (sample 1) having only the MgO protective film not containing Ce is 1, the MgO fine particles produced by the vapor phase method are disposed on the surface layer having the Ce concentration of 10 mol%. In Sample 16 (Example 8), the discharge delay time was 0.21. Further, in Sample 17 (Example 9) in which MgO fine particles produced by the precursor firing method were disposed on the same surface layer, the discharge delay time was 0.09.

As described above, the effect of preventing discharge delay in the PDP is further enhanced by arranging the MgO fine particles, but the effect is obtained by using the MgO fine particles produced by the precursor firing method rather than the MgO fine particles produced by the vapor phase method. Is bigger. Therefore, it can be said that the precursor firing method is a method for producing MgO fine particles suitable for the present invention.
As shown in the experimental data of Samples 16 and 17 (Examples 8 and 9), low power drive can be realized by forming a surface layer by dispersing MgO particles on the surface of the protective film having a predetermined Ce concentration. In addition, it was found that a PDP with a small discharge delay can be obtained.
[Experiment 2]
(Evaluation of surface stability)
In general, if the surface layer contains a large amount of carbonate, the secondary electron emission characteristic inherent to the surface layer cannot be obtained, resulting in an increase in operating voltage. In order to avoid this, an aging process is required in which the PDP before shipment is discharged for a certain period of time to remove contaminants on the surface layer. Considering the productivity of the PDP, it is desirable that the aging process is completed in a short time. Therefore, it is preferable to suppress the carbonate material in the surface layer as much as possible before the aging process. Assuming that the predetermined aging time is currently 1, when the carbonate is present at 15% or more on the surface, the time becomes 1 or more. Therefore, also in the surface layer of the present invention, the proportion of the surface carbonate is 15% or less. It is desirable to suppress.

  Therefore, in Experiment 2, the stability of the surface of the protective film was examined for each sample when the protective film made of MgO contained an impurity carbonate. As the method, the amount of carbonation contained on the surface of the protective film was measured based on X-ray photoelectron spectroscopy (XPS). The protective film of each sample was exposed to the atmosphere for a certain period after film formation, placed on a measurement plate, and placed in an XPS measurement chamber. Since it is expected that the carbonation reaction on the surface of the film always proceeds during exposure to the atmosphere, the exposure time required for the above setting was set to 5 minutes in order to make the processing conditions between samples uniform.

  As the XPS measurement apparatus, “QUANTERA” manufactured by ULBAC-PHI was used. The X-ray source was Al-Kα and a monochromator was used. An experimental sample as an insulator was neutralized by a neutralizing gun and an ion gun. The measurement was performed by accumulating 30 energy regions corresponding to Mg2p, Ce3d, C1s, and O1s, and the composition ratio of each element on the film surface was obtained from the peak area and sensitivity coefficient of the obtained spectrum. The C1s spectral peak is separated into a spectral peak detected at around 290 eV and a spectral peak of C and CH detected at around 285 eV to obtain respective ratios, and the ratio is calculated from the product of the composition ratio of C and the ratio of CO therein The amount of CO on the film surface was determined. The stability of the film surface, that is, the degree of carbonation was compared with the amount of CO determined by XPS.

FIG. 8 shows a graph obtained by performing XPS measurement based on the above conditions and plotting the ratio of the carbonate occupying the surface. From the position of the curve shown in FIG. 8, it can be said that the Ce concentration is preferably about 15 mol% or less in order to suppress the amount of carbonate in the surface layer to 15% or less.
From this result, it can be seen that the upper limit of the concentration of Ce contained in the surface layer is preferably 15 mol% or less in order to perform the aging process in a short time while minimizing the contamination of the surface layer with impurities.

[Experiment 3]
(Measurement of transmittance)
Next, the change in the transmittance of the protective film of each sample by adding Ce was examined. For each protective film, the atmospheric exposure time was set to 5 minutes as in Experiment 2 described above as a pretreatment for measurement.
For the transmittance measuring device, “UV2400” manufactured by Shimadzu Corporation was used. The light source was a halogen lamp and a deuterium lamp, and the slit width was 2 nm. The measurement sample was a film formed on a quartz substrate, and normalized by setting the transmittance of the quartz glass of the substrate to 100%.

Table 1 and FIG. 9 show the transmittance values of wavelengths near 380 nm that affect the chromaticity of each sample measured based on the above conditions.
From the results shown in Table 1 and FIG. 9, when the Ce / (Mg + Ce) ratio is in the range of 5% or less, the transmittance of the protective film is at least 93% or more, and any sample is close to 100% in consideration of measurement errors. I keep the value. However, when the Ce / (Mg + Ce) ratio increases from 5% to 20%, the transmittance decreases remarkably due to the increase in Ce concentration. Further, when the Ce / (Mg + Ce) ratio reaches 20% or more, the transmittance falls to about 50%, and thereafter remains at a substantially constant value.

Since light near 380 nm affects blue chromaticity, it is not preferable in terms of image display performance to reduce the transmittance of light having a wavelength near this wavelength. In order to display a good image without impairing the chromaticity, the transmittance needs to be about 50%, preferably 60% or more.
Therefore, considering the problem of chromaticity change and the result of transmittance measurement in Experiment 3, the Ce concentration of the protective film of the present invention is preferably such that the Ce / (Mg + Ce) ratio is 20% or less. It can be said that the Ce / (Mg + Ce) ratio is more preferably 15% or less.

From the above results, the Ce concentration in the protective film in the PDP of the present invention is preferably 5 mol% or more and 20 mol% or less, more preferably 10 mol% or more and 15 mol% or less, which is desirable for realizing low power driving. .
Moreover, if a surface layer is formed by dispersing predetermined MgO fine particles on the surface of the protective film, in addition to realizing low power drive, the problem of discharge delay and temperature dependence of discharge delay is suppressed, and high image quality is achieved. PDP can be driven.

  The PDP of the present invention can be applied to, for example, a gas discharge panel that displays a high-definition moving image by low-voltage driving. In addition, it can be used for information display devices in transportation facilities and public facilities, or television devices or computer displays in homes and workplaces.

It is typical sectional drawing which shows the structure of PDP which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows the relationship between each electrode and a driver. It is a figure which shows the drive waveform example of PDP. FIG. 6 is a schematic diagram showing each electron level of the surface layer of the PDP according to the first embodiment and a protective film of the conventional PDP, and the state of secondary electron emission in the Auger process. It is a graph which shows the spectrum of the valence band vicinity in XPS measurement. It is typical sectional drawing which shows the structure of PDP which concerns on Embodiment 2 of this invention. It is a graph which shows Ce density | concentration dependence of a discharge maintenance voltage. It is a graph which shows Ce density | concentration dependence of the ratio of the carbonate to the surface calculated | required by XPS measurement. It is a graph which shows the Ce density | concentration dependence of the transmittance | permeability in the light whose wavelength is 380 nm. It is a set figure which shows the discharge cell structure of the conventional general PDP.

Explanation of symbols

1, 1x PDP
2 Front panel 3 Front panel glass 4 Sustain electrode 5 Scan electrode 6 Display electrode pair 7, 12 Dielectric layer 8, 8a Surface layer (high γ film)
9 Back panel
10 Back panel glass 11 Data (address) electrode 13 Bulkhead 14, 14R, 14G, 14B Phosphor layer 15 Discharge space 16 MgO fine particles

Claims (5)

The first substrate on which a plurality of display electrodes are disposed is a plasma display panel sealed in a state facing the second substrate through a discharge space filled with a discharge gas,
A surface layer including magnesium oxide and cerium having a concentration of 5 mol% or more and 20 mol% or less is disposed on a surface of the first substrate facing the discharge space. The plasma display panel according to claim 1, wherein the cerium concentration in the surface layer is 10 mol% or more and 15 mol% or less. The plasma display panel according to claim 1, further comprising magnesium oxide fine particles disposed on the discharge space side of the surface layer. The plasma display panel according to claim 3, wherein the magnesium oxide fine particles are produced by a gas phase oxidation method. The plasma display panel according to claim 3, wherein the magnesium oxide fine particles are produced by firing a magnesium oxide precursor.

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