Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where S.S. Yang is active.

Publication


Featured researches published by S.S. Yang.


Journal of Physics D | 2005

Particle and fluid simulations of low-temperature plasma discharges: benchmarks and kinetic effects

H C Kim; Felipe Iza; S.S. Yang; M. Radmilovíc-Radjenovíc; J. K. Lee

Fluid, particle-in-cell and hybrid models are the numerical simulation techniques commonly used for simulating low-temperature plasma discharges. Despite the complexity of plasma systems and the challenges in describing and modelling them, well-organized simulation methods can provide physical information often difficult to obtain from experiments. Simulation results can also be used to identify research guidelines, find optimum operating conditions or propose novel designs for performance improvements. In this paper, we present an overview of the principles, strengths and limitations of the three simulation models, including a brief history and the recent status of their development. The three modelling techniques are benchmarked by comparing simulation results in different plasma systems (plasma display panels, capacitively coupled plasmas and inductively coupled plasmas) with experimentally measured data. In addition, different aspects of the electron and ion kinetics in these systems are discussed based upon simulation results.


Journal of Applied Physics | 2002

Three-dimensional fluid simulation of a plasma display panel cell

Hyeong-Do Kim; Min Sup Hur; S.S. Yang; Seungjun Shin; J K Lee

In order to understand the discharge characteristics in an alternating current plasma display panel (ac PDP) and optimize it further, a three-dimensional fluid code (FL3P) has been developed. Using this simulator, various three-dimensional features of discharges are investigated in the sustain mode of PDP. First, the striations of wall charge are observed at both the anode and cathode side. Second, the local efficiency is obtained as a function of position. It is mainly divided into the anode region and the cathode region and highest near the anode center. Finally, the effects of various three-dimensional parameters are studied. As one of the examples showing the effect of electrode shaping, the discharge characteristics of a T-shaped electrode cell are compared with those of a conventional cell. The phosphor on barrier ribs contributes to over 44% of the total luminance, but barrier ribs themselves do not play an important role in the overall discharge efficiency. Address electrode width is not always pr...


Physics of Plasmas | 2002

Two-dimensional self-consistent radiation transport model for plasma display panels

Hae June Lee; Hyun-Chul Kim; S.S. Yang; Jae Koo Lee

A two-dimensional radiation transport model is coupled with a fluid simulation to incorporate the resonance radiation trapping effect in a plasma display panel cell. Compared with the conventional trapping factor approach, this model has an advantage in describing the spatial evolution of the radiative excited-state density. Compared with a Monte Carlo model, it also takes advantage of its fast computation to couple the radiation transport self-consistently with the time-dependent fluid model. The effect of the spatial evolution of the resonant excited state on the light emission is investigated for the variations of system sizes and the gas mixture ratio, and the results are compared with those of the conventional trapping factor approach. The discrepancy between the two methods increases as the gap size between the dielectrics increases, but does not change significantly for the variation of the gas mixture ratio.


Journal of Physics D | 2006

Secondary electron emission coefficients in plasma display panels as determined by particle and fluid simulations

S.S. Yang; Seung Min Lee; Felipe Iza; Jae Koo Lee

The secondary electron emission coefficient (γse) of ions and excited species in a plasma display panel (PDP) was studied by means of 2-dimensional fluid and 1-dimensional particle-in-cell Monte Carlo collision simulations. Relations between the driving voltage and the luminous efficiency observed in experiments are reproduced at low and high Xe concentrations. Agreement between experiments and simulations, however, requires careful selection of the γse of ions and excited species. The trend of the efficiency as a function of the driving voltage is particularly sensitive to the γse of Xe excited species. For the conditions typically encountered in PDP cells (pd = 1–10 Torr cm), the dependence of the γse on the energy of impinging ions can be neglected in discharges of pure gases. This is a consequence of multiple charge exchange collisions in the cathode region. In Xe–Ne mixtures, however, the ion energy distribution function on the cathode depends on the mixture ratio. Typically more energetic ions can reach the cathode in gas mixtures and the γse is enhanced.


IEEE Transactions on Plasma Science | 2003

Application of two-dimensional numerical simulation for luminous efficiency improvement in plasma display panel cell

S.S. Yang; Hyun-Chul Kim; Sang Woo Ko; Jae Koo Lee

To improve the low luminous efficiency of a coplanar-type ac plasma display panel cell, two kinds of new cell designs have been proposed using two-dimensional numerical simulation. To generate more excited xenon atoms in the anode and the cathode regions, we use additional one or two small electrodes in conventional geometry. An auxiliary electrode between two sustain electrodes induces the positive column discharge by the particular driving voltage pulse waveform. Moreover, two bus electrodes embedded in the dielectric layer play an important role in creating excited xenon species. The use of these additional electrodes results in 80%-90% increment of the luminous efficiency in comparison with the conventional model.


Journal of Applied Physics | 2005

The mechanism of striation formation in plasma display panels

Felipe Iza; S.S. Yang; Hyoungkyun Kim; Jae Koo Lee

Despite the high pressure employed in plasma display panels, the energy balance of low-energy electrons is found to be dominated by inelastic collisions, and the resulting nonlocal electron kinetics plays a key role in the striation formation. Surface charge accumulation on the anode dielectric, however, is also needed for striations to form. It is the combined effect of surface charges and nonlocal electron kinetics that results in the striation formation in plasma display panel cells. Two-dimensional fluid simulations, which assume local electron kinetics, and two-dimensional particle-in-cell Monte Carlo collision simulations with a bare conducting anode show that striations do not form if either the nonlocal electron kinetics or the surface charge accumulation is not considered.


Journal of Applied Physics | 2003

Three-dimensional self-consistent radiation transport model for the fluid simulation of plasma display panel cell

Hyoungkyun Kim; S.S. Yang; J. K. Lee

In plasma display panels (PDPs), the resonance radiation trapping is one of the important processes. In order to incorporate this effect in a PDP cell, a three-dimensional radiation transport model is self-consistently coupled with a fluid simulation. This model is compared with the conventional trapping factor method in gas mixtures of neon and xenon. It shows the differences in the time evolutions of spatial profile and the total number of resonant excited states, especially in the afterglow. The generation rates of UV light are also compared for the two methods. The visible photon flux reaching the output window from the phosphor layers as well as the total UV photon flux arriving at the phosphor layer from the plasma region are calculated for resonant and nonresonant excited species. From these calculations, the time-averaged spatial profiles of the UV flux on the phosphor layers and the visible photon flux through the output window are obtained. Finally, the diagram of the energy efficiency and the c...


IEEE Transactions on Plasma Science | 2002

Three-dimensional fluid simulation of an AC-PDP cell

Hyun-Chul Kim; S.S. Yang; Jae Koo Lee

Using a three-dimensional fluid model, we present top-views of AC-PDP cells with three different electrode shapes-a conventional electrode cell, a T-shaped electrode cell, and an asymmetric electrode cell. Figures include the contours of consumed power and photon generation power that are time averaged over the half period and space averaged over the direction that is not shown.


SID Symposium Digest of Technical Papers | 2001

P‐57: Striation Phenomenon of Plasma Display Panel (PDP) Cell and Its Application to Efficiency Improvement

C. H. Shon; J. K. Lee; Hyoungkyun Kim; Sheikh Dastgeer; S.S. Yang; Seungjun Shin

The first observation of striation in plasma display panel (PDP) cell by kinetic and fluid simulations is presented. The striation phenomenon in the kinetic simulation is clearer than that in fluid simulation. The striation is due to the self-consistent interaction of plasma, dielectric wall, and applied voltages. Simulation results indicate that the phenomenon occurs due to the non-uniform accumulation of surface charges on the sustain electrodes, which consequently deform the local potential profile. The surface and space charges locally create multiple-tier potential distribution near anode region that makes plasma bunches. The discharge in this region is governed by ionization process, but the cathode discharge depends on the secondary-electron emission process on the dielectric surface. Based on these discharge characteristics, 80 % efficiency increase of PDP cell is obtained due to triggered striation by the modification of front dielectric material and MgO protective-layer.


international conference on plasma science | 2003

Comparison of the simulation results with measured excited Xe species density in plasma display panel cell

S.S. Yang; Hyoungkyun Kim; Seongyun Ko; J. K. Lee

Summary form only given, as follows. We have compared the 2D and 3D simulation results of alternating current plasma display panel (AC-PDP) cell with experimentally measured excited Xe species characteristics PDPs use the UV radiation emitted from plasma discharge and visible light.

Collaboration


Dive into the S.S. Yang's collaboration.

Top Co-Authors

Avatar

J. K. Lee

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Hyoungkyun Kim

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Jae Koo Lee

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Hyun-Chul Kim

Pennsylvania State University

View shared research outputs
Top Co-Authors

Avatar

Felipe Iza

Loughborough University

View shared research outputs
Top Co-Authors

Avatar

Seungjun Shin

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Seongyun Ko

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Hyeong-Do Kim

Pohang University of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Min Sup Hur

Ulsan National Institute of Science and Technology

View shared research outputs
Top Co-Authors

Avatar

Sang Woo Ko

Pohang University of Science and Technology

View shared research outputs
Researchain Logo
Decentralizing Knowledge