• Korean Journal of Materials Research
• /
• v.17 no.7
• /
• pp.376-381
• /
• 2007

Fluorine-doped tin oxide (FTO) thin film was coated on aluminosilicate glass at $450^{\circ}C$ by spray pyrolysis method. In the range of 0-2.7 molar ratio of F/Sn, the variations of electrical conductivity and visible light transmission were investigated. At the F/Sn ratio of 1.765, the film showed the lowest electrical resistivity value of $3.0{\times}10^{-4}{\Omega}\;cm$, the highest carrier concentration of $2.404{\times}10^{21}/cm^3$, and about $8\;cm^2/V{\cdot}sec$ of electronic mobility. The FTO film showed a preferred orientation of (200) plane parallel to the substrate. X-ray photoelectron spectroscopy analysis results indicated that the contents of $Sn^{4+}-O$ bonding are the highest at 1.765 of F/Sn molar ratio.

• Journal of the Korean institute of surface engineering
• /
• v.56 no.3
• /
• pp.169-179
• /
• 2023

This work studies dielectric breakdown behavior of AAO (anodic aluminum oxide) films formed on pure aluminum at a constant current density in 5 ~ 20 vol.% sulfuric acid (SA) and 2 ~ 8 wt.% oxalic acid (OA) solutions. It was observed that dielectric breakdown voltage of AAO film with the same thickness increased with increasing concentration of both SA and OA solutions up to 15 vol.% and 6 wt.%, respectively, above which it decreased slightly. The dielectric breakdown resistance of the OA films appeared to be superior to that of SA films. After dielectric breakdown test, cracks and a hole were observed. The crack length increased with increasing SA film thickness but it did not increase with increasing OA film thickness. To explain the reason why shorter cracks formed on the OA films than the SA films after dielectric breakdown test, the generation of tensile stresses at the oxide/metal interface was discussed in relation to porosity of AAO films obtained from cross-sectional morphologies.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2009.10a
• /
• pp.247-247
• /
• 2009

본 연구에서는 indium-tin oxide (ITO) 나노 입자 용액을 이용하여 간단한 공정을 통해 ITO 나노 패턴을 직접적으로 제작하는 기술에 대한 연구를 진행하였다. 이를 이용하여 300nm급 ITO 나노 dot 패턴을 제작하는데 성공하였으며 이를 glass 표면에 구현하는데 성공하였다.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.4 no.2
• /
• pp.94-99
• /
• 2004

silicided 50-nm-gate-length n-type Schottky barrier metal-oxide-semiconductor field-effect-transistors (SB-MOSFETs) with 5 nm gate oxide thickness are manufactured. The saturation current is $120{\mu}A/{\mu}m$ and on/off-current ratio is higher than $10^5$ with low leakage current less than $10{\mu}A/{\mu}m$. Novel phenomena of this device are discussed. The increase of tunneling current with the increase of drain voltage is explained using drain induced Schottky barrier thickness thinning effect. The abnormal increase of drain current with the decrease of gate voltage is explained by hole carrier injection from drain into channel. The mechanism of threshold voltage increase in SB-MOSFETs is discussed. Based on the extracted model parameters, the performance of 10-nm-gate-length SB-MOSFETs is predicted. The results show that the subthreshold swing value can be lower than 60 mV/decade.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2005.12a
• /
• pp.123-123
• /
• 2005

• Journal of the Korean Electrochemical Society
• /
• v.5 no.2
• /
• pp.43-46
• /
• 2002

Commercial titanium rod was anodized in three types of electrolytes such as 0.06 mol/L $\beta-glycerophosphate+0.3mol/L$ calcium acetate, 0.06mol/L $\beta-glycerophosphate+0.3mol/L$ sodium acetate and 0.06 mol/L $\beta-glycerophosphate+5mol/L$ calcium phosphate. The titanium oxide layer $(TiO_2)$ was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD) and electron spectroscopy chemical analysis (ESCA). Numerous micropores were observed on the titanium oxide layer by SEM. The diameter of micropores increased with the increase of electrolytic voltage. The titanium oxide layer was composed of anatase structure. The phosphorous element was detected at 130 eV binding energy, but calcium was not found in the oxide layer because of lower contents. After anodizing the oxide layer was etched in the 30g/L NaOH solution at $80^{\circ}C$ for 1hr. The surroundings of micropores were much more smoothed and rounded than before alkaline etching.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.482-484
• /
• 2008

Anodic aluminum oxide (AAO) which prepared with two-step anodizing method (with dissimilar solutions) was used as a template to fabricate highly ordered, free standing metal nano-rods. AAO nano-template technique can realize self-organized hexagonal pore structure with nanometer dimension size, it's easy to control pore diameter, length and density by varying anodizing conditions. Ni and Ni/Fe/Cu multi-metal layer nanorods were electrochemically deposited into AAO nano-template by AC voltage in simple sulfate solutions.. The properties of samples are tested by X-ray diffraction (XRD), field emission microscopy (FE-SEM).

• Korean Journal of Metals and Materials
• /
• v.48 no.9
• /
• pp.831-841
• /
• 2010

Indium tin oxide (ITO) nanopowders were synthesized by coprecipitation and the sol-gel method to prepare a stable dispersion of ITO nano-colloid for antistatic coating of a display panel. The colloidal dispersions were prepared by attrition process with a vibratory milling apparatus using a suitable dispersant in organic solvent. The ITO coating solution was spin-coated on a glass panel followed by the deposition of partially hydrolyzed alkyl silicate as an over-coat layer. The double-layered coating films were characterized by measuring the sheet resistance and reflectance spectrum for antistatic and antireflective properties.

• Advances in nano research
• /
• v.6 no.4
• /
• pp.357-375
• /
• 2018

Two dimensional (2D) atomic layered nanomaterials exhibit some of the most striking phenomena in modern materials research and hold promise for a wide range of applications including energy and biomedical technologies. Graphene has received much attention for having extremely high surface area to mass ratio and excellent electric conductivity. Graphene has also been shown to maximize the activity of surface-assembled metal nanoparticle catalysts due to its unique characteristics of enhancing mass transport of reactants to catalysts. This paper specifically investigates the strategy of pre-formed nanoparticle self-assembly used for the formation of various metal nanoparticles supported on graphene families such as graphene, graphene oxide, and reduced graphene oxide and aims at understanding the interactions between ligand-capped metal nanoparticles and 2D nanomaterials. By varying the functional groups on the ligands between alkyl, aromatic, amine, and alcohol groups, different interactions such as van der Waals, ${\pi}-{\pi}$ stacking, dipole-dipole, and hydrogen bonding are formed as the 2D hybrids produced.

• Journal of Powder Materials
• /
• v.23 no.3
• /
• pp.240-246
• /
• 2016

In order to improve the high-temperature oxidation stability, sintered 434L stainless steel is studied, focusing on the effect of the addition of metallic oxides to form stable oxide films on the inner particle surface. The green compacts of Fecralloy powder or amorphous silica are added on STS434L and oxidized at $950^{\circ}C$ up to 210 h. The weight change ratio of 434L with amorphous silica is higher than that of 434L mixed with Fecralloy, and the weight increase follows a parabolic law, which implies that the oxide film grows according to oxide diffusion through the densely formed oxide film. In the case of 434L mixed with Fecralloy, the elements in the matrix diffuse through the grain boundaries and form $Al_2O_3$ and Fe-Cr oxides. Stable high temperature corrosion resistance and electrical resistivity are obtained for STS434L mixed with Fecralloy.