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By varying the radio frequency-bias power in an inductively coupled CF 4 plasma, we have modified the nanoscale morphology and chemical bond structure of polyethylene terephthalate (PET) surface. Specifically, the ion impingement increased the surface roughness and created CFn (n= 2, 3) functional groups on the PET surface, making it hydrophobic. Also observed was a significant increase in the hydrophobicity of the plasma-modified surfaces over the course of several days following the treatment (a hydrophobic recovery). X-ray photoelectron spectroscopy analysis revealed that this spontaneous transformation to a more hydrophobic surface is accompanied by a decrease in the fluoride ion content. The change of plasma density and electron temperature with increasing bias power were discussed. In addition, the change of the ion energy distribution with increasing bias power was investigated.

In this article, the effects of the magnetic field on the through-silicon-via (TSV) etching characteristics in an inductively-coupled plasma (ICP) were investigated and the results were compared with those in an unmagnetized ICP. The densities of the radicals in the SF6/O2 plasma were measured by using actinometry, and the ion energy distribution and flux of the Ar plasma were determined by using an ion energy analyzer in order to understand the differences in etching behaviors. The silicon etching rate in the M-ICP was three times faster than that in the unmagnetized ICP under the same RF power and gas conditions. However, the etch anisotropy in the M-ICP was rather poor compared to that in the ICP. In order to observe differences in the etching characteristics, we varied the SF6/O2 gas mixing ratio and the pressure. Lowering pressure at the optimal ratio for the SF6/O2 gas mixture influenced the ratio of F radicals to O radicals and the mean free path of ions. Consequently, a high etching rate with good anisotropy in TSV etching could be achieved in a M-ICP.

We have studied the characteristics of the application of a high-gamma cathode material to a plasma display panel (PDP) for the improvement of the secondary electron emission property and consequent luminous efficacy. It had been found that the PDP with the MgCaO cathode layer and the SiO2 diffusion barrier, which can block the impurity diffusion from the underlying dielectric layer, is stable during the normal fabrication process and showed improved luminous efficacy at a lower sustain voltage compared with those of the conventional PDP with MgO.

In this paper, we present finite element method simulations of top-emitting organic light-emitting diodes for designing optimized red, green, and blue full-color device structures. The OLED structures in the simulation are used to evaluate the device parameters, such as the outcoupling efficiency, electroluminescence spectra, and angular emission characteristics on organic layers with varying thickness and different cathodes. The numerical study also extracts these parameters for nano-structured devices. By observing the agreement between the simulated and measured data precisely, our simulations show capability of predicting the fabricated device results. (C) 2016 Optical Society of America

The address discharge characteristics of the plasma display with a MgO single cathode layer and the one with a MgO-SrO double cathode layer were investigated. In particular, the conventional waveform with a positive-going ramp and the proposed waveform with a negative-going ramp were applied in order to demonstrate that the polarity of the scan electrode during the reset period affects the dynamic voltage margin and the address discharge time lag. It was confirmed that the total address discharge time lag of the plasma display with the MgO-SrO double cathode layer decreased by about 550 ns by applying the proposed waveform with the negative-going ramp.

In this paper, the address discharge characteristics of high-Xe PDPs with high-gamma cathode materials were investigated. It will be shown that the address discharge characteristics such as the dynamic voltage margin and the address discharge time lag of high-Xe PDP with MgO-SrO double cathode layer and one with MgCaO single cathode layer can be improved by inducing stable, continuous weak discharges during the reset period with a newly designed waveform. The deposition of pure MgO powder on high gamma cathode material has also proved to be effective in reducing the address discharge time lag of high-Xe PDP.

The discharge condition of Plasma Display Panel (PDP) changes as the operating time increases. Imaginary part of permittivity of dielectric material which is related to the dielectric loss has been often neglected because of the relatively small values compare to that of the real part. However we have found that some aspect of the long term behavior of PDP is closely related to the dielectric losses. We have studied and compared the thermal characteristics variation and temporal image sticking phenomenon of PDP with two different kinds of dielectrics and correlated with the dielectric losses.

To obtain highly efficient and stable discharges in mercury-free flat fluorescent lamps (MFFLs), the effects of the main electrode configuration on the electro-optical characteristics such as the operating voltage margin, luminance, and luminous efficacy are investigated. The spatiotemporal characteristic of the infrared emission from discharges in different electrode configurations (conventional coplanar, counter, and combination discharges) is also studied with an intensified charge-coupled device camera to see the differences with the electrode configuration variation. The MFFL having the combination electrode configuration with Ne-30% Xe gas mixture and a total pressure of 13.3 kPa showed high luminance from 3102 to 22 067 cd/m2 and high luminous efficacy from 49 to 93.5 lm/W for the warm white daylight with a color coordinate of (0.36, 0.36).

In this paper, the effect of oxygen and nitrogen gas addition to the Ne-Xe mixture discharge gas on the various kinds of image retention was investigated in 42-inch AC Plasma Display Panels. The image retentions were dramatically relieved with a small amount of molecular gas addition. It was observed that the temporal variation of the reset threshold voltage induced by discharge heat-run can be suppressed by adding a small amount of molecular gases to the discharge gas. Both residual gas and cathodoluminescence analyzes showed that the added molecular gases could be incorporated in MgO surface during the discharge. With the investigation on the feasibility, we suggest that a small amount of nitrogen gas addition is suitable for the relief of image retentions which can be adapted in industry.

In this paper, we observe the lifetime characteristics of a single-sustainer-driven ac plasma display panel (PDP) based on the variation of luminance which is one of the important points to be considered for a practical application. It was found that the application of bipolar sustain pulse waveforms for the sustain discharge deteriorated the long-term lifetime characteristics in single-sustainer driving compared to conventional monopolar pulse driving. This phenomenon was investigated through 3-D discharge cell simulation. In the sustain operation using the bipolar sustain pulses, it was found that more amount of ion energy was transferred to the surface of the phosphor layer. Moreover, the temporal variation of the luminance in the PDP is assumed to be related to the phosphor deterioration resulting from the ion bombardment or the redeposition of the sputtered Mg particles from the protecting layer. In order to decrease the deterioration of the phosphor layer, we modified the address electrode potential to be floated during the sustain discharge. The calculated ion energy to the phosphor surface decreased with the modified waveforms in the discharge cell simulation. Furthermore, the same effect was observed in the conventional monopolar pulse driving, which led the improvement of lifetime characteristics. The effect of the modified waveforms was also verified through experiments in the test panel.

We propose a new high-speed reset waveform which uses a negatively biased voltage to the common electrode and an alternating ramp voltage to the scan electrode during the reset period and an erase address scheme. It showed a less than 800-ns time lag, a wide address margin over 40 V, and improved jitter characteristics among different color cells in a plasma display panel with a 50-in full-high-definition resolution. Its fast discharge characteristics were attributed to the formation of a higher wall voltage near the middle of the gap during the reset period and the consequent bigger electric field during the scan period which was confirmed by the 3-D emission observation and cell-voltage-domain analysis.

A new drive method designed for the adaptive local dimming lighting of a multistructured 32-in diagonal-sized mercury-free flat fluorescent lamp (MFFL) which consists of a matrix array of 10 × 16 60-mm diagonal-sized unit cells is proposed. The adoption of the dual auxiliary electrode and the bipolar-pulse drive scheme resulted in a wide stable operating voltage margin at low driving voltages. The cell turn-on or turn-off selectivity can be obtained through the change of the connection state of the dual electrode. Using the proposed MFFL with the dual auxiliary electrode as a data electrode and the subfield method, a new drive scheme for a 2-b adaptive local dimming control of 10 × 16 lamp array with one inverter system is proposed and demonstrated.

A highly efficient mercury-free fluorescent lamp (MFFL) was developed for an alternative to fluorescent lamps containing mercury. The lamp has a simple structure with two main electrodes running parallel to each other and an auxiliary electrode. In order to improve the luminance and luminous efficacy of MFFLs further, we optimized the thickness of rear and front phosphors on the inner surfaces of the lamp, and then adopted an uneven distribution profile for the rear phosphor to increase the surface area of the phosphor. The MFFL with the optimized phosphor profile showed a wide luminance range from 3315 to 17133 cd/m2 with the corresponding luminous efficacy from 75.2 to 42.5 lm/W with the color coordinate around (0.32, 0.32) for daylight.

We propose a new plasma display panel cell structure, called the dual ignition discharge electrodes (DIDE) structure, with a long electrode gap to realize high luminous efficacy. The proposed DIDE structure has a long electrode gap (200 ?m ~ 400 ?m) but can nevertheless be driven at relatively low voltage because of auxiliary electrodes that are formed on the front panel. The discharge characteristic of the DIDE structure is much different from the characteristic of the conventional structure, and it was analyzed through infrared emission images that are taken by an intensified charge-coupled device camera and discharge current waveforms. These studies explain the unique discharge characteristics of the DIDE structure, which originate in the ignition discharge that is generated by its own electrode structure and driving waveform. The proposed long electrode gap and low voltage effect of the DIDE structure resulted in a very high luminous efficacy of 7.5 lm/W in a monochrome green test with Ne-Xe (12%) mixture at 400 torr.

In this paper, the long-term stability of the discharge characteristics in a plasma display panel is investigated with the small addition of nitrogen to the conventional Ne-Xe gas mixture. It is found that the characteristics of temporal variation in discharge voltages and full black brightness are enhanced with nitrogen gas addition, which could result in the reduction of mis-writing probability and the enhancement of image quality. In the study of the temporal variation of discharge voltages via a Vt close curve, it is observed that nitrogen addition suppresses the changes in discharge voltages. Regarding discharge voltage variation, the change in elements on the surface of the phosphor layer and the temporal modification of the protecting layer are investigated with overfrequency discharge aging using secondary-ion mass spectrometry and a scanning electron microscope, respectively. A small change in elements on the surface of the phosphor layer is observed in the panel, with nitrogen being added to the gas mixture. The reduced ion energy with the addition of nitrogen gas is suggested as a potential reason to induce the different variation of MgO transfer characteristics and discharge voltage.

We investigated the discharge characteristics of conventional and single-sustainer driving for various pulses applied in an ac plasma display panel (PDP) through experimental observation and three-dimensional numerical simulations. In the single-sustainer driving method, bipolar pulses with both positiveand negative-going pulses are applied to one of the sustain electrodes while the other electrodes are maintained at ground. In single-sustainer driving with bipolar pulses, the luminance shows a higher value in comparison with that of conventional driving and the luminous e cacy tends to increase with increasing sustain voltage in accordance with the tendency of the relative IR (infrared) e cacy by positive-going pulse application. We performed a discharge analysis by using the spatiotemporal distribution of IR emission observed by using an image-intensi ed chargecoupled device (ICCD) camera and the density pro le of excited Xe species through a numerical simulation of a PDP plasma discharge.

We propose a new address-while-display (AWD) driving method for a plasma display panel to obtain a high contrast ratio and a wide operation margin, which is composed of a short ramp reset (SRR) period, a short erase period, a sustain period, and an address period as the basic units. The SRR pulse and the short pulse erase period make it possible to obtain a wide operating voltage margin and minimize the background luminance by redistributing the wall charges in a short initialization time between the address and the scan electrode. As a result, a high darkroom contrast ratio of 10 000 :1 could be achieved with a wide operating voltage margin of 40 V for a stable address.

We investigated the discharge characteristics of a Kr gas mixture in an ac plasma display panel through two-dimensional numerical simulations. In a Ne-Kr gas mixture, the VUV output and the e cacy increase with higher Kr content due to an increase in the VUV source. In order to analyze the e ect of Kr content on the luminous characteristics for various gas mixtures, we compared the results for Ne-Kr, Ne-Kr-Xe and Ne-Xe mixtures. As the Kr content was decreased and the Xe content increased, the VUV generation e cacy increased because the lower energy level of the Xe excited state caused the generation of excited species to be more e ective than that of Kr gas.

In order to enhance the display characteristics of plasma display panel (PDP), it is essential to have a thorough understanding of the discharge characteristics. In this paper, we performed the discharge analysis of PDP plasma through the numerical simulation using the newly developed energy fluid (EF) model by incorporating the electron's energy conservation equation with the aim of understanding the discharge dynamics. There is a clear difference in the spatiotemporal distribution of electron temperature and Xe excited species obtained with the EF model compared with those of the previous simulation model which used the local field approximation (LFA). In particular, the experimentally observed striation phenomenon in the anode region could be seen, which could not be otherwise observed in the LFA model. Based on the difference in having the striation phenomena in the simulation results using two different models, we explained the striation phenomena occurring as a result of the ionization wave instability associated with the electron streaming in the anode region of the PDP cell.

Through two-dimensional numerical simulations, we analyzed the effects of new cell structure for the luminous efficacy improvement in an ac plasma display panel. In the new structure with 5 electrodes, two auxiliary electrodes are arranged between X and Y electrodes with long gap. Through the application of adequate auxiliary pulse on the address electrode, the luminous efficacy in the new cell structure showed the improvement of 52[%] in comparison with that of conventional cell structure with short gap between X and Y electrodes. Consequently, as the short gap discharge between auxiliary electrodes decreases and the long gap discharge between X and Y electrodes increases, the result of VUV generation efficacy shows higher improvement. The reliability of simulation result could he confirmed by the experimental result in the test panel.

A long gap structure alternating current plasma display panel (ac PDP) with ignition electrodes is suggested, and its luminous characteristics are investigated. The operation voltages of the long gap structure PDP can be reduced with the help of ignition electrodes. Luminance and luminous efficacy are improved compared with those of an ac PDP with electrodes having the conventional short discharge gap. The luminance and luminous efficacy of the suggested structure can be further improved by applying address auxiliary pulses synchronized with the sustain pulses. The detailed current waveform analysis suggests that the application of address auxiliary pulse changes the discharge current ratio between the long gap electrodes to the ignition electrodes. By increasing the address auxiliary pulse voltage to a certain extent, the luminous efficacy increased along with the discharge current ratio. It has been also observed that when the width of the long gap discharge electrode is increased, the dynamic voltage margin increased accordingly.

This paper investigates the effect of applying auxiliary short pulses to an address electrode with varying Xe contents on the improvement of luminous efficacy. The luminous efficacy increases with the application of auxiliary pulse; however, as the Xe content increases in the Ne-Xe mixture discharge gas, the efficacy improvement effect by auxiliary address pulse discharge decreases. The surface discharge was hardly affected by the face ignition discharge between the address and sustain electrodes, and thus, the high-driving-voltage problem still remains when the high-Xe-content gas is used to get the high luminous efficacy. To decrease the sustain voltages of the high-Xe-content gas, we adopted locally thin dielectric layer structure near the electrode gap. The panel with the suggested grooved dielectric layer structure showed decreased driving voltage margin and improved luminous efficacy even for high-Xe-content gases. We obtained 5 lm/W and 3700 cd/m2 at 220-V, 50-kHz continuous sustaining condition from a monochrome green test panel with the Ne-Xe (16%) mixture, which was about two-and-a-half times improved luminous efficacy as compared to that of the reference structure with Ne-Xe (4%). Full driving feasibility was also checked by applying the auxiliary address pulses to the grooved structure panel. The misaddressing could occur when the auxiliary pulses are applied continuously to the address electrodes in the sustain period, which decreased the driving voltage margin. However, this demerit can be compensated by lowering the driving voltage margin with the adoption of the grooved structure. Also, the address discharge delay decreased by about 48% in the panel with the grooved structure.

We have investigated the effect of cell resolution change on the luminous efficacy of AC PDP with the 3-dimensional computer simulation and experiment. The luminous efficacy decreased and the minimum sustain voltage increased as the resolution increased from VGA to full HD resolution, due to increased particle loss. A simple increase of the Xe content to realize the high luminous efficacy resulted in a much enhanced luminous efficacy decremental ratio as the cell resolution increases, because of the increased plasma loss and decreased electron heating efficacy. The increase of the sustain electrode gap from the commonly used value of 60μm to 140μm in the 50″ full HD cell with Ne-Xe [20%] gas resulted in the luminous efficacy value comparable to that of the XGA cell with 60μm gap which indicates that a large electrode gap with a high Xe content gas is an effective way of realizing high luminous efficacies. However the excessive increase of driving voltage and the discharge time lag with the large electrode gap and high Xe content gas should be compromised in order to be used in the commercial product and increase the luminous efficacy further. A new cell structure with an auxiliary electrode (DIDE: Dual Ignition Discharge Electrode), optimized thickness of dielectric and phosphor layer, driving waveform, is demonstrated to show a luminous efficacy of 5.8 lm / W (Green, 25 kHz) with the address minimum voltage as low as 50V as an example of high luminous efficacy cell with low driving voltage.

We investigated the effect of sustain electrode gap variation with various Xe content gas in a coplanar-type ac plasma display panel through 2-D numerical simulation to understand the inherent high-luminous-efficacy mechanism. For the low-Xe content gas condition of 5%, the optimal sustain electrode gap was found to be about 200 mum, because of the steep decrease of electric power delivered to electrons with the increase of electrode gap longer than 200 mum. On the other hand, with the high-Xe content gas of 20%, the efficacy continuously increased as the electrode gap increased beyond 200 mum . We have found that the high luminous efficacy under the condition of long electrode gap and high-Xe content gas is due to the high-electron-heating efficacy in the cathode sheath region

The luminous efficiency characteristics of a new alternating current plasma display panel (ac PDP) structure with the segmented electrodes in delta color arrayed subpixels with enclosed barrier ribs (SDE) are investigated. The SDE structure which has a 4:3 horizontal to vertical cell dimension ratio showed higher luminance and luminous efficiency increment characteristics as the Xe partial pressure increased compared to those of the conventional stripe type with 1:3 ratio for a given resolution. The luminance and luminous efficiency increases with the electrode width, which provides a means to change the color temperature for the full color panel without using other method such as the subpixel size change. The driving feasibility of SDE structure panel with various electrode widths is confirmed by demonstrating the existence of sufficient driving voltage margin

We investigated the effect of Xe content variation on the luminous efficiency of two different subpixel types, i.e., segmented electrode in delta color arrayed, enclosed subpixel (SDE) and conventional stripe barrier type, in an alternating current plasma display panel through three-dimensional (3-D) numerical simulations. The simulation result agreed well with the experimental result where the SDE structure showed to have higher luminous efficiency improvement with increasing Xe content than the conventional structure did. The conventional cell type was found to have higher vacuum ultraviolet (VUV) generation efficiency at low Xe content as compared with SDE structure, but as the Xe content increased, the SDE type showed a higher improvement in efficiency due to the lower plasma loss to the enclosing surfaces. Using the ray-optics code in conjunction with the 3-D plasma simulation, the transport efficiency of visible light from phosphor through the front plate in the SDE structure, which has a higher aperture ratio, was higher than that of the conventional structure with much increased improvement with the increase of Xe content

In this paper, we describe the experimental approaches to understand the microdischarge physics of an alternating current plasma display panel (ac PDP) cell. We discuss the experimental techniques to explore the major parameters to understand the operation of ac PDP such as the vacuum ultra violet (VUV) emission and wall charge variation. Regarding the discharge dynamics, the detailed VUV emission characteristics were measured and explained by the gas reaction modeling and the microdischarge characteristics during the ramp reset period were compared with the simulation result. The wall voltage and wall charge distribution were measured by laser induced fluorescence (LIF) and electro-optic modulation method. The slight increase of the wall voltage by Xe addition to pure He discharge gas was observed by LIF. And the existence of self-erasing discharge results in the drastic decrease of wall charge near discharge gap.

In this paper, we describe the experimental techniques and numerical modeling approaches to understand the alternating current plasma display panel (ac PDP) discharge physics. Conventional ac PDP uses microscale dielectric barrier discharge, and the spatio-temporal visualization of discharge not only helps to understand the discharge dynamics, but also validates the models adopted in the computer simulation study of PDP cell. The experimental observations using optical spectroscopy and imaging method turned out to be very helpful especially for the understanding of discharge dynamics including gas reactions and wall charge formation. The numerical simulation shows good agreement with experimental observations which allows us to use the computer simulation to extract more useful information with more confidence. Some parametric study, such as the effects of the variations of cell pitches, address electrode width, barrier rib height, and geometrical structure, etc., on the luminous characteristics of PDP had been carried out and could now well be explained.