The factors which dominate the luminance and luminous efficiency of the color PDPs were discussed on the basis of the plasma physics, following the brief introduction of circumstance for the research and development on plasma displays(PDPs), in particular, color PDPs such as the color surface-discharge PDPs. The latest innovative results of the research and development on the color PDPs were describded in relation to the improvement of their performance.
In order to improve light emission efficinecy of plasma display panel(PDP), the applicability of Thomson scattering to the measurements of electron temperature and density of the PDP discharges was investigated. Two following main difficulties for the application were assessed. (i)Although the Tohmson signal might be small due to the small size of the discharge, it was found that the signal could be detected by optimizing the system and using the photon-counting method. (ii)The stray laser light from discharge electrodes was detected to be very strong at the laser wavelength. However, the Thomson scattered light which has a broadening of several nanometers could be separated from it spectrally by using a triple-grating polychromator.
Experimental results of opticla emission and laser induced fluorescence measurements of plasma and sputtered atoms in the reactive sputter-deposition process of indium tin oxide films which have been used as transparent conductive electrodes in PDP, are presented. In addition, preliminary experimental reuslts of spatio-temporally resolved optical emission measuremet, which has been done recently using 3 inch AC-PDP test cell, are presented.
A blue-emitting phosphor, a material for PDP phospers, is largely subjected to be degraded on the way to execution, compared to the other phosphors. This difference of degradation is considered to be caused by the bombardment of the charged species in plasma state given a rise by the discharge for the PDP emission as well as of non-charged ones in the vacuum ultraviolet regime. Thus, the degradation of each color is studied by an bombardment of Ar particle using FAB instrument. Moreover, the recovery is also studied by annealing each phosper degrated after FAB bomberdment.
The BAM(BaMgAl_<10>O_<17> : Eu^<2+>solid solution with the barium-poor aluminate(Ba_<0.75>Al_<11>O_<17.25>)developed in the present work show the strong resistant property to the thermal degradation, such as luminous efficiency and the color coordinate compared to the conventional BAM. From adopting the BAM solid solution system for color PDPs, it is confirmed that the maintenance rate for the luminous degradation and the alteration of the color coordinate y value after heat treatment is improved to be about 1.3 times of those of the conventional BAM, respectively.
In order to improve luminous efficiency, we proposed a positive column PDP with a bending discharge path. The fabricated 3-inch panel achieved 1.4 times higher luminous efficiency than that of the coventional positive column PDP, and 21m/W(white). Employment of a new cathode structure with an AC-cathode achieves a low firing voltage even in a long discharge path. We found an aging method for this cathode to lower the firing voltage, and reproduced TV pictures by a line scan drive scheme. We expect to achieve nearly 41m/W through improvement of the fabrication process and drive scheme.
Preparation of MgO thin films using reactive magnetron sputtering of Mg target in argon/oxygen mixture is fascinating with respct to decreased process cost and improved film quality, irrespective of its small deposition rate. Fabrication and control of MgO films by this process was studied experimentally and theoretically. First, the experimental results of mode transition observed in sputter-deposition property associated with the discharge property are reported. Next, a reactive sputtering model considering the particle balance of oxygen as well as the change in secondary electron emission coefficient on the target is shown. Based on them, quantitative and systematic modeling of reactive sputtering of Mg target is discussed.
Color ac-PDPs applies photoluminescnet phenomena from phosphors by the irradiation of ultraviolet rays caused by the gas discharge. MgO has been used as the protecting material for monochrome and color ac-PDPs, because it has the best property as the protecting material for ac-PDPs. MgO, however, has the drawback that MgO absorbs the utltraviolet rays completely. In order to improve the luminous efficiency of color PDPs, the present work measered the ion-induced secondary electron emission yield to evaluated whether a new protecting material, MgAl_2O_4, absorbs the ultraviolet rays or not.