Mg-Zr-O protective layers for alternating current plasma display panels were deposited by e-beam evaporation. The effect of the ZrO2 addition on both the discharge properties (firing voltage Vf, minimum sustaining voltage Vs, and memory coefficient (MC)) and the microstructure of deposited Mg-Zr-O films were investigated. The results show that the film microstructure changes and the electron emission enhancement due to the ZrO2 addition are the main reasons for the improvements of the discharge properties of Mg-Zr-O films. A small amount of Zr solution in MgO under its solid solubility can effectively increase the outer-shell valence electron emission yield so as to decrease Vf and Vs compared with using a pure MgO protective layer. The ZrO2/(MgO+ZrO2) ratio has a great effect on the film surface conditions. Proper surface morphologies make a good contribution to obtain large MC in accordance with lower firing voltage.

e-radius emitter is studied with particle-in-cell simulations to extend the classical one-dimensional (1D) Child–Langmuir law to two-dimensions. It is found that the 2D space-charge-limited current density in units of the classical 1D value follows a monotonically decreasing function of the dimensionless ratio of emitter radius (R) to gap separation (D), and the function can be extended to relativistic regime without significant modification. It is also verified that Lau's analytical prediction of the 2D Child-Langmuir law is in better agreement with the simulation results in comparison with Rokhlenko's.

A new method is developed to measure the wall charge waveforms in coplanar alternating current plasma display panel (AC PDP). In the method, two groups of display electrodes are selected from a coplanar AC PDP and two capacitors are respectively connected with these two groups of display electrodes in series, and a measuring circuit and a reference circuit are thus constructed. With the help of special processing, discharge takes place in the cells included in the measuring circuit under a normal drive voltage but no discharge takes place in the cells included in the reference circuit under a normal drive voltage. The wall charge waveforms are obtained from the voltage difference between the two capacitors. Using the method, the wall charge waveforms are measured during resetting period, addressing period and sustaining period for the 304.8mm (12-inch) test PDP panel. The result shows that the wall voltage is about 96V during the sustaining period.