• Korean Journal of Materials Research
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• v.29 no.5
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• pp.322-327
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• 2019

Hole carrier selective MoOx film is obtained by atomic layer deposition(ALD) using molybdenum hexacarbonyl[$Mo(CO)_6$] as precursor and ozone($O_3$) oxidant. The growth rate is about 0.036 nm/cycle at 200 g/Nm of ozone concentration and the thickness of interfacial oxide is about 2 nm. The measured band gap and work function of the MoOx film grown by ALD are 3.25 eV and 8 eV, respectively. X-ray photoelectron spectroscopy(XPS) result shows that the $Mo^{6+}$ state is dominant in the MoOx thin film. In the case of ALD-MoOx grown on Si wafer, the ozone concentration does not affect the passivation performance in the as-deposited state. But, the implied open-circuit voltage increases from $576^{\circ}C$ to $620^{\circ}C$ at 250 g/Nm after post-deposition annealing at $350^{\circ}C$ in a forming gas ambient. Instead of using a p-type amorphous silicon layer, high work function MoOx films as hole selective contact are applied for heterojunction silicon solar cells and the best efficiency yet recorded (21 %) is obtained.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.08a
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• pp.44-47
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• 2003

In this paper, the electric field distribution in dielectric tube with one layer and spherical dielectric($ZrO_2$) in water was simulated. The reactor was made up of the spherical dielectric that is diameter : 3.0[mm], $ZrO_2(\varepsilon_r:10)$ and one glass plate of thickness(2[mm]), $\varepsilon_r$(10) as electrode. The discharge gap was 8[mm]. To get more strong electric field, the dielectric constant should be higher comparatively. Using the spherical dielectric for water discharge in dielectric tube, the location of equipotential line was shifting from the interior to the exterior. At real water discharge experimental, ozone was measured higher dissolved ozone in water at condition of water rate(l[l/min]) and injector than condition of non-injector or 2~3[l/min].

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.7
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• pp.58-64
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• 2006

Recently deep interests have been paid on the effective generation of ozone, which has been widely used for water treatment, deodorization, color removal, and chemical processing of exhausted smoke. The silent discharge reaction has been proposed as the most effective one in the many ozone generation methods, because the silent discharge can be generated under the conditions of lower applied voltage and power consumption, compared other ones. In this paper, in order to improve the ozone generation and ozone generation efficiency, the conventional silent discharge chamber with $Al_2O_3$ dielectric layer and tubular ferroelectric bed discharge reactor packed with $Al_2O_3$ pellets were made, and the silent discharge of the reactors were studied experimentally. The ozone generation characteristics are also discussed based on the discharge characteristics, especially on the wall charge accumulation properties and power consumption. The results show that the electric charges of discharge tube with bead are around 2.5 times as large as those without bead. In the discharge chamber packed with dielectric beads, the ozone concentration and the energy yield characteristics were also improved, compared with those in the conventional silent discharge reactor.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.6
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• pp.631-639
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• 2007

We examined diurnal and seasonal variations of ozone ($O_3$) concentrations and its relation to meteorological parameters observed at the Ieodo Ocean Research Station ($32.07^{\circ}N$, $125.10^{\circ}E$, 36 m above sea level) during June 2003 and May 2005. Over the 2-year period, the mean ozone concentration was $49.5{\pm}15.5\;ppbv$. Ozone concentrations show great variability with a monthly mean up to 68.2 ppbv in May 2005 and seasonal variations with being highest in spring and fall, and lowest in summer. However, the amplitude of diurnal variation was less than ${\sim}4\;ppbv$ with a maximum at $3{\sim}4\;p.m.$ and minimum at $7{\sim}8\;a.m.$ HYSPLIT backward air trajectory indicated that the air masses with higher ozone came from the north or northwest and those with lower ozone arrived mainly via southerly or southeasterly. Ozone distributions at Ieodo Ocean Research Station were observed to be significantly impacted by long-range transport and regional scale air circulation.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.497-506
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• 2002

A Photochemical-Trajectory model was used to understand the production of ozone in the atmospheric boundary layer. This model was composed of the trajectory and the photochemical models. To calculate trajectories of air parcels, winds were obtained from the three-dimensional nonhydrostatic mesoscale model (PSU/NCAR MM5V2), and the results were interpolated into constant height surfaces. Numerical integration in the trajectory model was performed by the Runge-Kutta method. The photochemical model consisted of chemical reactions and photodissociation processes. Chemical equations were integrated by the semi-implicit Bulirsch-Stoer method. We performed our experiments from 21 July to 23 July 1994 during the summer time for Seoul area. During the time of maximum ozone concentration in Seoul, four trajectories of air parcels which traveled from Inchon to Seoul were selected. Ozone concentrations estimated by two models are compared with observed one in Seoul area and the photochemical-trajectory model is better fitted than pure photochemical model. During the selected period, high ozone concentrations in Seoul area were more influenced by transferred pollutants from Inchon than emitted pollutants in Seoul.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1071-1074
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• 2002

This paper presents Bi thin films have been fabricated by atomic layer-by-layer deposition and co-deposition at an IBS method. The growth rates of the films was set in the region from 0.17 to 0.27 nm/min. MgO(100) was used as a substrate. In order to appreciate stable existing region of Bi 2212 phase with temperature and ozone pressure, the substrate temperature was varied between 655 and $820^{\circ}C$ and the highly condensed ozone gas pressure$(PO_3)$ in vacuum chamber was varied between $2.0{\times}10^{-6}$ and $2.3{\times}10^{-5}Torr$. Bi 2212 phase appeared in the temperature range of 750 and $795^{\circ}C$: and single phase of Bi 2201 existed in the lower region than $785^{\circ}C$. Whereas, $PO_3$ dependance on structural formation was scarcely observed regardless of the pressure variation. And high quality of c-axis oriented Bi 2212 thin film with $T_c$(onset) of about 90 K and $T_c$(zero) of about 45 K is obtained. Only a small amount of CuO in some films was observed as impurity, and no impurity phase such as $CaCuO_2$ was observed in all of the obtained films.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.320.1-320.1
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• 2013

We have investigated the effect of surface passivation for crystalline silicon solar cell using ozone-based atomic layer deposited (ALD) $Al_2O_3$. We examined passivation properties such as uniformity, carrier lifetime, thickness, negative fixed charge density at AlOx/Si interface, and reflectance. The influences of process temperature and heat treatment were investigated using microwave photoconductance decay (PCD). Ozone-based ALD $Al_2O_3$ film shows the best carrier lifetime at lower deposition temperature than $H_2O$-based ALD.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1336-1343
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• 2007

The HVAC takes the most important role in the Electric Multiple Unit for maintaining the healthy and comfortable indoor environment, however we also should consider the outdoor environment in terms of "environment's friendly" because the refrigerant used for the HVAC system is strongly related with the issues of "the Protection of environment" such as "the Global Warming" and "The Ozone layer Depletion". Therefore we survey (1)the potentially harmful impact on human health and the environment through modification of the ozone layer and the Green house effect, and (2)the international and the domestic environment's policies and (3)the potential alternative refrigerants usable for the EMU HVAC in terms of "the environment friendly properties", "the performance" and (4) "the applicabilities of the refrigerant for the EMU HVAC".

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2008.04a
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• pp.148-150
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• 2008

Halon gas agent has been widely used as the extinguishing agent for B class and C class fires because of its excellent extinguishing power. But Halon was found to contribute to the ozone layer destruction, eventually Halon designated as one of ozone-layer-destroying materials in the Montreal Protocol in 1987, In this study, in the context of such researches, we measured the characteristics of flame concentrations of inert gaseous agents by Cup-burner method.

• Journal of the Korean Society of Safety
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• v.23 no.6
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• pp.95-99
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• 2008

Halon was known as a cause of the ozone layer destruction. In 1987, it was designated as one of the ozone-layer-destroying materials in the Montreal Protocol. Therefore substitutes of Halon agent has been developed including inert gas extinguish system, which is one of the most widely used fire extinguishing system. This study intended to increase the efficiency of inert gas extinguishing agent by using inert gas additives. As IG-541 shows high extinguishing power, the experiment was performed to measure the effects of gaseous additives to it. Cup-burner fire extinguishing apparatus was used with n-Heptane fuel. Among many of pure inert gaseous agents, Helium showed the most excellent extinguishing power. When Helium was added to IG-541, fire extinguishing power was increased and the concentration of oxygen in chimney also risen. By adding Helium to IG-541, the effectiveness of inert gas fire extinguishing system is able to be increased.