Jong-seo Choi

36.2: Distinguished Paper: New Polycrystalline MgO for a Thermally Stable and Fast Delay Time in AC PDP

We have extensively studied polycrystalline MgO sources for achieving a thermally stable and fast delay time in AC PDP. The key idea was to improve MgO film properties by doping p-type, equivalent, and n-type elements to the MgO matrix. Their behaviors in a gas discharge were tested. Most of them showed severe discharge jitters. By doping Ca, Al, Si, and a particular n-type element, the discharge instability was greatly reduced, so that the elements were studied in more details. We found that doping of the last element was highly effective in lowering the delay time, improving the thermal stability, and lowering the firing voltage. We proved that the improvement is largely due to the electron emission enhanced by defects in MgO band gap and lattice distortion which is induced by dopants.

32.1: Correlation between Wall Charge of a MgO Film and Discharge Delay Time

We prepared MgO films using e-beam deposition and polycrystalline MgO pellets and oxygen flow rates of 50 sccm and 100 sccm. These films were examined in gas discharge tests at different temperatures. The dependence of the discharge delay time on film temperature was smaller for the film grown at 100 sccm O2 flow compared to the film grown at 50 sccm. Their wall charges were also measured. This revealed that MgO films grown at 100 sccm had more wall charges. The analysis showed a difference in surface roughness. MgO films with a larger surface roughness had more wall charge.

Ion-induced electron emission from different crystalline phases of ZrO2

A detailed study of ZrO2 as a candidate material for a protective layer of plasma display panels has been performed. The ion-induced electron emission coefficient γ and the firing voltage were measured for cubic, tetragonal, and monoclinic ZrO2 films. Different crystalline phases of ZrO2 showed a very small difference in the coefficient γ and the firing voltage. Compared to MgO, the coefficient γ was smaller and, as a result, the firing voltage was higher for ZrO2.