Gas Discharge Characteristics of PDP Cell using
3-dimensional Simulation

Dr. Heui Seob Jeong, Post-doctoral Fellow, Display and Optical Devices Division

I have worked at NHK STRL as a post-doctoral fellow since completing my Ph.D. at Seoul National University, Korea, in October 1998. My research specialty has been development and analysis using numerical simulators, and VUV emission measurement of PDP cells. There are few diagnostic tools available since the discharge volume is so small (<0.05mm3), so numerical analysis and direct measurement of emission profiles from a PDP cell are very useful methods for investigating the gas discharge characteristics of PDP cells. Recently, I have been involved in research and development concerning a 3-dimensional simulator of a PDP cell and the analysis of PDP emission.

Higher luminous efficiency can be obtained through better design of the cell and electrode structure, gas mixtures, phosphor, and driving circuit, which in turn requires better understanding of the fundamental discharge physics of the PDP plasma. Most analysis of the discharge characteristics of a PDP cell for increasing efficiency and luminance has been done through one- or two-dimensional analysis, with assumptions made concerning the address electrode and barrier ribs. There have been few attempts to analyze discharge characteristics through 3-dimensional simulation.
Heui Seob Jeong, a post-doctoral fellow at the STRL, has developed a 3-dimensional simulator that solves the continuity equation for charged particles, the electron energy equation, the diffusion equation for excited neutral particles, and Poisson's equation.
The 3-dimensional simulator made possible the following findings, and is expected to play a conspicuous role in improving the PDP :

Discharges are significantly affected by the width of the address electrode, and drift/diffusion losses are caused by the barrier ribs.

To increase luminous efficiency, there is leeway to optimize the width of the address electrode through annihilation by barrier ribs.

The simulator can indicate the optimum value for the address electrode width.

A schematic diagram of an AC PDP cell and typical 3-dimensional contour plots of electron density are shown in the figures. With the help of 3-dimensional analysis of PDP cells, we can understand profound fundamental discharge characteristics and thus increase luminance and luminous efficiency.