• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.17-20
• /
• 2000

This study is about a retrograde triple well employed in the Cell tr. of next DRAM and flash memory. Triple well structure is formed deep n-well under the light p-well using MeV ion implantation. MeV P implanted deep n-well was observed to show greatly improved characteristics of electrical isolation and soft error. Junction leakage current, however, showed a critical behavior as a function of implantation and annealing conditions. {311} defects were observed to be responsible for the leakage current. {311} defects were generated near the R$\_$p/ (Projected range) region and grown upward to the surface during annealing. This is study on the defect behavior in device region as a function of implantation and annealing conditions.

• Journal of the Korean Vacuum Society
• /
• v.18 no.4
• /
• pp.254-258
• /
• 2009

We herein report on polymer phosphorescent light-emitting devices doped with iridium complex. The emitting layer of poly(N-vinylcabazole) and tris(2-phenylpyridine)iridium was fabricated by low speed dip-coating of 10, $20{\mu}m$/s. The devices showed stable current increasing leakage current at turn-on voltage. Compared to conventional spin-coating based organic light-emitting devices, the driving voltage by dip-coating observed lower values of 5.8 and 6.7 V at the luminance of 100 Cd/$cm^2$.

• Korean Journal of Materials Research
• /
• v.24 no.9
• /
• pp.502-507
• /
• 2014

Recently, improvement in the conversion efficiency of silicon-based solar cells has been achieved by decreasing emitter doping concentration, because the lightly doped emitter can effectively prevent the recombination of electrons and holes generated by solar light irradiation. This type of emitter is very thin due to the low doping concentration, thus conductive materials (i.e., silver) used for front electrodes can easily penetrate the emitter during a firing process because of their large diffusivity in silicon. This results in junction leakage currents which might reduce cell efficiencies. In this study, $Al_2O_3$-coated Ag powders were synthesized by an ultrasonic spray pyrolysis method and applied to the conductive materials of the front electrode to control the junction leakage current. The $Al_2O_3$ shell obstructs the Ag diffusion into the emitter during the firing process. The powder is spherical with a core-shell structure and the thickness of the $Al_2O_3$ shell is tens of nanometers. Solar cells were fabricated using pure Ag powders or the $Al_2O_3$-coated Ag powder as front electrode materials, and the conversion efficiency and junction leakage current were compared to investigate the role of the $Al_2O_3$ shell during the firing processes.

• Restorative Dentistry and Endodontics
• /
• v.27 no.1
• /
• pp.24-33
• /
• 2002

Leakage studies have been performed frequently, since a fluid-tight seal provided by various dental fill-ing materials has been considered clinically important. The leakage of the various root-end filling materials has been widely investigated mostly dye penetration method. These dye studies cannot offer any information about the quality of the seal of a test material over a long period of time The purpose of this study was to evaluate the microleakage of root end cavities in blood contamination filed amalgam, intermediate restorative material(IRM), light cured glass ionomer cement(GI) and mineral trioxide aggregate(MTA) by means of a modified fluid transport model. Fifty standard human root sections, each 5mm high and with a central pulp lumen of 3mm in diameter, were and filled with our commonly used or potential root end fill ing materials after they were contaminated with blood. At 24h. 72h, 1, 2, 4, 8, and 12 weeks after filling, leakage along these filling materials was determined under a low pressure of 10KPa(0.1atm) using a fluid transport model. The results were as follows : 1 MTA group showed a tendency of decreasing percent of gross leakage (20m1/day) in process of time, whereas the other materials showed a tendency of increasing in the process time. 2. At the all time interval, GI group leaked significantly less than amalgam group and IRM group (p＜0.05). 3. At the 4 weeks, the percentage of gross leakage in MTA group decreased to 0% thereafter, the low per-centage of gross leakage was maintained in MTA group until the end of the experiment, whereas the percentage in IRM group increased to 100% 4. At the 12 weeks, percentage of gross leakage was significantly low in MTA group(0%), comparison with GI group(40%), amalgam group(90%) and IRM group(100%), but there was no significant difference between latter two materials.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.13 no.3
• /
• pp.140-147
• /
• 2011

We studied the influence of livestock waste leachate on oxidative damage and antioxidative responses in poplar clones in August which increase the demand of antioxidants because of high temperature and high light during this period. We measured ion leakage, antioxidant enzyme activities (APX, GR), and carotenoid contents. Oxidative damage and antioxidative responses by treated livestock waste leachate in poplar clones showed various results. We divided poplar clones into three groups using the criteria based on ion leakage which represent cell damage induced oxidative stress. Eco 28, 62-10, Bonghwa1 and Dorskamp belonged to the first group in which the cell damaged level was lower than that of the control. The results suggest that this group augmented for demand of antioxidative in summer because high concentration of nitrogen induced by treatment of live stock wastes acted as environmental stress. Consequently, they failed to keep up the homeostasis of reactive oxygen species. The second group in which the cell damaged level was similar to that of the control was Suwon, 72-30 and 72-31 clones. Finally, 97-18 clone belonged to the third group in which the cell damaged level was lower than that of the control group. In this case, nitrogen treated by livestock waste leakage decreased oxidative stress. 97-18 clone was the clones with the least damage in summer oxidative stresses treated by livestock waste leakage. These results suggest that the high concentration nitrogen due to the livestock waste leakage can act differently upon the clones. We speculate that the added oxidation damage in the summer (growing season) may have an effect on the total fresh weight and also influence the purification ability for livestock waste leakage. However, further studies are needed for the confirmation.

• Proceedings of the IEEK Conference
• /
• 2005.11a
• /
• pp.853-856
• /
• 2005

we proposed the optimized conditions of the uniaxial and biaxial compensation films to suppress the light leakage to improve viewing angle characteristics. Compared with conventional OCB mode, the maximum transmittance is increased about 30% and the minimum transmittance is slightly decreased. From here results, we can about OCB mode with wide viewing angle and high contrast ratio.

• Proceedings of the Optical Society of Korea Conference
• /
• 2001.02a
• /
• pp.127-134
• /
• 2001

With the increasing demands for hand-held devices with lightweight and low-power-consumption displays, the role of reflective liquid crystal displays (LCDs) is becoming more and more important. Especially, the single polarizer mode is considered as a suitable structure for reflective LCDs because it can provide high brightness. However, the single-polarizer LCDs have demerit in that the contrast is lower than double-polarizer LCDs because of the light leakage in thedark state. (omitted)

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.940-943
• /
• 2007

The objective of the research presented in this paper is to design a highly efficient LCD-TV backlight unit (BLU) which minimizes lamp count without light leakage from the BLU. A new optical plate helps to successfully distribute spatial luminance in a 46inch LCD-BLU consisting of only 20 CCFLs.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.1182-1184
• /
• 2004

We have studied contrast ratio of a homogeneously aligned nematic liquid crystal (LC) display as a function of the angle between the polarizer axis and LC director. The results show that a cell configuration in which a polarizer axis facing a light source coincides with a short LC axis has a better process margin in terms of high contrast ratio than that of the cell coinciding with a long LC axis.

• Restorative Dentistry and Endodontics
• /
• v.13 no.1
• /
• pp.139-150
• /
• 1988

The purpose of this study was to evaluate the marginal adaptation of Class V resin restorations by the filling techniques. The cavities were filled with Heliosit$^{(R)}$ light curing composite resin system in accordance with the following three filling techniques - bulk-pack placement technique, apical to occlusal layering placement technique, and buccolingual layering placement technique. And the interface between the restoration and the tooth structure was observed with scanning electron microscope. The following results were obtained. 1. Marginal adaptation of enamel showed excellent irrespective of the filling techniques. 2. Marginal leakage of dentin was observed irrespective of the filling techniques. 3. No difference of marginal adaptation according to the filling techniques was observed in light curing composite resin.