• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.19-22
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• 2020

The thermal evaporation source is used to prepare thin films by physical vapor deposition. Materials of metals, organic materials, were tested and explained for thermal evaporation experiments. The developed effusion cell performance depends on the type of deposition material, the size of the crucible, the performance of the reflector, etc. and the proper conditions were found by producing, comparing and analyzing several sets of effusion cell to quantitatively evaluate the performance of the cell. The effusion cell for thermal evaporation source is used to prepare thin films of Ag, Cu, Mg.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.371-371
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• 2007

In this study, liquid crystal (LC) aligning capabilities for vertical alignment on the $CeO_x$ thin film by thermal evaporation method were investigated. Also, the control of pretilt angles and thermal stabilities of the NLC treated on $CeO_x$ thin film were investgated. The uniform LC alignment on the $CeO_x$ thin film surfaces and good thermal stabilities with thermal evaporation can be achieved. It is considerated that the LC alignment on the $CeO_x$ thin film by thermal evaporation is attributed to elastic interaction between LC molecules and micro-grooves at the $CeO_x$ thin film surface created by evaporation. In addition, it can be achieved the good electro-optical (EO) properties of the VA-LCD on $CeO_x$ thin film layer with oblique thermal evaporation.

• Journal of ILASS-Korea
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• v.26 no.1
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• pp.1-8
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• 2021

Droplet evaporation has been known as a common phenomenon in daily life, and it has been widely used for many applications. In particular, the influence of the different heated substrates on evaporation flux and flow characteristics is essential in understanding heat and mass transfer of evaporating droplets. This study aims to simulate the droplet evaporation process by considering variation of thermal property depending on the substrates and the surface temperature. The commercial program of ANSYS Fluent (V.17.2) is used for simulating the conjugated heat transfer in the solid-liquid-vapor domains. Moreover, we adopt the diffusion-limited model to predict the evaporation flux on the different heated substrates. It is found that the evaporation rate significantly changes with the increase in substrate temperature. The evaporation rate substantially varies with different substrates because of variation of thermal property. Also, the droplet evaporates more rapidly as the surface temperature increases owing to an increase in saturation vapor pressure as well as the free convection effect caused by the density gradient.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.25-25
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• 2009

Zinc Oxide (ZnO) nanorod were grown on Si wafer by a thermal evaporation method at various temperatures. And their structure and optical properties were measured using Photoluminescence(PL), Scanning electron microscopy(SEM), and X-ray diffraction(XRD) analysis.

• Journal of the Korean Ceramic Society
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• v.32 no.3
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• pp.349-358
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• 1995

The ceramic composite membrane was synthesized by thermal oxidation after evaporation of Al on the support prepared by slip casting process. Oxidation was performed at $700^{\circ}C$ and 80$0^{\circ}C$ under dry oxygen atmosphere. It was considered as optimum oxidation condition that the membrane showed a knudsen behaviro. A further oxidation resulted in an increase of gas permeability because top layer became densified. Then, a multi-layered composite membrane was synthesized through a sol-gel method, evaporation and thermal oxidation of Al coating processes. While the membrane was thermally stable up to 80$0^{\circ}C$, gas permeability was rapidly decreased even at a slight amount of deposition of Al.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.4
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• pp.294-297
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• 2013

ZnO crystals with octahedral shape were synthesized by thermal evaporation technique. $ZnF_2$ powder was used as the source material. The thermal evaporation and oxidation of $ZnF_2$ powder was carried out for 1 hr at $1,000^{\circ}C$ in air under atmospheric pressure. SEM images showed that the ZnO crystals produced by oxidizing $ZnF_2$ vapor possessed a characteristic octahedral shape. XRD spectrum revealed that the ZnO octahedron had hexagonal wurtzite structure. In the room temperature photoluminescence spectrum, a strong green emission peak at around 510 nm was observed.

• Journal of the Korean Ceramic Society
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• v.47 no.2
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• pp.142-145
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• 2010

We made a film of a few ${\mu}m$ thickness by evaporating $As_2S_3$ piece to perpendicularly cut optical fiber by thermal evaporation process. Linear refractive index(n) and linear absorption coefficient(k) of amorphous $As_2S_3$ are 2.525 and $1.727{\times}10^{-3}$, respectively. A surface roughness did not exceed 2 nm and a transmission spectrum showed that the sample of thermal evaporation was homogeneous.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.8
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• pp.766-769
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• 2008

Zinc oxide (ZnO) nanowires were prepared on Si substrates by a thermal evaporation method at different temperatures and $O_2$ pressure. Microstructural analysis of the obtained ZnO nanowires was performed by using transmission electron microscopy(TEM) and scanning electron microscopy(SEM). Phase analysis was done using X-ray diffraction(XRD). As the deposition temperature and oxygen pressure were increased, the diameter and length of ZnO nanowires had a tendency to increase. Based on TEM and XRD analyses, the nanowires are single crystalline in nature and consist of a single phase. According to the measurements, the ZnO nanowires grown at 1100$^{\circ}C$, Ar 50 sccm, $O_2$ 10 sccm have good properties.

• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.69-78
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• 1999

We present the results of one-dimensional numerical simulations of SNR evolution in the in­homogeneous medium considering the effects of the evaporation of the cloud and the thermal conduction. We have included the effects of changing evaporation rate as a function of cloud size and the ambient temperature so that the clouds could be evaporated completely before they reach the center of the SNR. The heat conduction markedly changes the density distribution in the remnant interior. To explain the observed morphologies of the centrally peaked X-ray SNRs(for example W44), the maximal thermal conduction is required. However, this is unlikely due to the magnetic field and the turbulent motion. The effects of the evaporation of the cloud and the thermal conduction described here may explain the class of remnants observed to have centrally peaked X-ray emmision.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.11
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• pp.873-877
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• 2012

The effect of oxygen pressure in the synthesis of ZnO nanostructures through thermal evaporation of Zn powder was investigated. The thermal evaporation process was carried out in oxygen ambient for 1 hr at $1,000^{\circ}C$ under different pressures. The oxygen pressure was changed in range of 0.5 ~ 900 Torr. Any nanostructure was not formed on the specimens prepared at oxygen pressures lower than 10 Torr. When oxygen pressure was 100 Torr, ZnO nanowires were observed. With increasing the oxygen pressure to 500 Torr, the morphology of ZnO nanostructures changed from wire to tetrapod. For all the samples, room temperature photoluminescence spectra show a strong green emission peak at around 550 nm.