• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.401-401
• /
• 2016

Although vertically aligned one-dimensional (1D) structure has been considered as efficient forms for photoelectrode, development of efficient 1D nanostructured photocathode are still required. In this sense, we recently demonstrated a simple fabrication route for CuInS2 (CIS) nanorod arrays from aqueous solution by template-assisted growth-and-transfer method and their feasibility as a photoelectrode for water splitting. In this study, we further evaluated the photoelectrochemical properties surface-modified CIS nanorod arrays. Surface modification with CdS and ZnS was performed by successive ion layer adsorption and reaction (SILAR) method, which is well known as suitable technique for conformal coating throughout nanoporous structure. With surface modification of CdS and ZnS, both photoelectrochemical performance and stability of CuInS2 nanorod arrays were improved by shifting of the flat-band potential, which was analyzed both onset potential and Mott-schottky plot.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.380.1-380.1
• /
• 2016

In this study, we report a novel antioxidant ZnO nanoparticle that is newly designed and prepared by simple surface modification process. Antioxidative functionality is provided by the immobilization of antioxidant of 3,4,5-trihydroxybenzoic acid (galic acid, GA) onto the surface of ZnO nanoparticles. Microstructure and physical properties of the ZnO@GA nanoparticles were investigated by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR) and steady state spectroscopic methods. The antioxidative activity of ZnO@GA was also evaluated using ABTS (3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay. Notably, ZnO@GA showed strong antioxidative activity in spite of the conjugation process of GA on the ZnO surface. These results provide that GA-coating onto ZnO nanoparticles may offer an intriguing potential for biomedical devices as well as nanomaterials.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2002.02a
• /
• pp.149-152
• /
• 2002

SrZrO3 resistive oxide barriers on Ag sheathed Bi2223 tapes prepared by the sol-gel and dip coating method were evaluated with an aid of Taguchi method and orthogonal arrays to elucidate the effects of experimental parameters, such as ratio of starting solution, amount of additives, and heat treatment temperature and time on the properties of the thin films. Six experimental parameters were selected and then Ll8(21x37) orthogonal arrays were constructed. Finally, SEM and XRD results were related to signal to noise (S/N) ratio to evaluate the optimized experimental condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2009.06a
• /
• pp.328-329
• /
• 2009

This paper presents the effect of organic Ag complex sintering temperature on the MEH-PPV photoluminescence (PL) properties. MEH-PPV and organic Ag complex was coated on the glass substrate by spin coating method. The coated Ag complex was sintered in an air atmosphere. The sintering temperature was varied from 100 to $200^{\circ}C$ and sintering time was 5 min. The Ag film sintered at temperature higher than $120^{\circ}C$ shows very low sheet resistance less than $0.5\;{\Omega}{/\square}$. The coated MEH-PPV measure photoluminescence (PL) intensity at 580 nm. The PL peak was shifted to the higher wavelength with increasing the sintering temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.05a
• /
• pp.39-42
• /
• 1995

In this study, PLZT thin films prepared by Sol-Gel method were deposited on ITO glass by spin coating and cryatallized at 750$^{\circ}C$ for 5 min by RTA in oreder to investigate their electrical and optical properties. Although thin film experieneced narrowing their hysteresis loops with increasing La content, E$\sub$c/ and P.sub r/ were higher for thin film than for bulk materials. $\varepsilon$$\sub$r/ and optical transmittance increased with increasing La content.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1995.05a
• /
• pp.187-191
• /
• 1995

Thin film of the (Pb$\_$1-x/La.sub x/)(Zr$\_$0.25/Ti/Sub 0.48/) O$_3$(x=0~13[at%]) were prepared by Sol - Gel method. Multi-layer PLZT thin films were fabricated by spin-coating on Pt/Ti/SiO$_2$/Si substrate. The crystallinity and microstructure of the films were investigated with the sintering condition. At the sintering temperature of of 600[$^{\circ}C$], the perovskite phase was dominat. PLZT(11/52/48)thin films sintered at 600[$^{\circ}C$], 1[hr] had good dielectric constant (1236), dielectric loss (2.2[%]), remanent polarization (1.38[${\mu}$C/$\textrm{cm}^2$] and coercive field(16.86[ kV/cm]) respectively.

• Journal of Welding and Joining
• /
• v.5 no.2
• /
• pp.27-34
• /
• 1987

The characteristics of arc sprayed layer were studied with hardness test and microstructural observation. The erosion resistance of arc sprayed layer was also evaluated using a method of steel ball blasting test which was proposed in this study as a test method for measuring the erosion properties in the impact wear condition. By an impact of the molten droplets on the redeposited substrate, lamella structure was formed which contains laminated oxide layers, fissures, and porosities. As a result of mechanical tests, it was shown that the sprayed specimen showed higher hardness than the substrate, but it resulted in higher erosion rate than the substrate. The poor erosion property obtained with a sprayed coating was considered to be attributable to easy flaking off the the layers laminated with brittle oxide layers.

• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.605-608
• /
• 1998

In this paper, we have investigated the pyroelectric characteristics of the $20\mu\textrm{m}-thick$ $LiTaO_3$ single crystal with black coating by using the nondestructive dynamic method. The $LiTaO_3shows$ the maximum pyroelectric coefficient (${\gamma}$) of $1.56$\times$10-8C/\textrm{cm}^2K$ at 40Hz and the responsivity (Rv) is 488V/W at 2Hz. The noise equivalent power (NEP) is obtained as 3.95$\times$10-10W/√Hz at 40Hz. The detectivity (D*) is obtained divided by the sample area and estimated to be 5.6$\times$108cm√Hz/W at 40Hz. These results, shows that the $LiTaO_3$ single crystals are the best candidates to pyroelectric IR sensors.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.134-135
• /
• 2002

Sm$^{2＋}$가 도핑된 불화물 결정은 실온에서 영구적 스펙트럼 홀 생성이 나타나며, 이러한 실온에서의 영구적 스펙트럼 홀 생성은 새로운 광 메모리의 개발에 매우 중요하므로 많은 관심을 받고 있다. 본 연구에서는 Sm$^{2＋}$가 도핑된 10Al$_2$O$_3$.90SiO$_2$ 박막을 제조하여 SEM 및 발광 스펙트럼(Photo-Luminescence; PL)을 측정함으로서 제조된 박막의 구조적, 광학적 특성을 조사하였다. (중략)

• Journal of Surface Science and Engineering
• /
• v.28 no.5
• /
• pp.267-275
• /
• 1995

Electron beam can provide convenient way to heat the substrate during Hollow Cathode Discharge (HCD) ion plating of Ti(C, N)films. Densification of columnar structrue is enhanced by longer duration of electron beam heating(EBH). While strong(111) texture is identified always to be formed, the amount of (200) oriented grains which coherently interfaced with carbide particles of the substrate increased with heating(EBH). In turns, these crystallogaphical change lead to the increase of micro hardness and adhesion of coating. Adhesion of Ti(C, N) films increased more dramatically in case of ASP30 substrate of which carbide particles dispersed more finely than M42. Therefore, it could be concluded that both the density of film and interfacial structure can affect the adhesion property. Overheating of substrate could be resulted in low adhesion resistance due to high residual stress developed in the film.