• Journal of the Korean Electrochemical Society
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• v.14 no.4
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• pp.196-200
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• 2011

The formation of niobium oxide microcones on niobium substrates was investigated in NaF to the HF electrolytes. This condition builds on the uniqueness of the microstructures niobium oxide. The dimensions and integrity of the bulk microstructures were found to be strongly dependent on potential, temperature, electrolyte composition, and anodization time. The anodic oxide was initially amorphous at all temperatures, but crystalline oxide nucleated during anodization. From XRD patterns of the anodized specimens, the microcones consisted of crystalline $Nb_2O_5$. We demonstrated niobium oxide microcone structures with nanorods. The anodized niobium oxide microcone texture revealed nanorod bundles. The surface of $Nb_2O_5$ microcones is very regular and has a nano-scale. The surface morphologies of the nanorods were examined using FE-SEM. EDS analyses show that the anodically prepared niobium oxide consists of $Nb_2O_5$. The aim of this study is to find the condition of forming the favorable nanorods by anodization method.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.4
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• pp.29-32
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• 2009

Dense and periodic arrays of nano-sized holes were patterned in oxide thin film on GaAs substrate. To obtain the nano-size patterns, self-assembling diblock copolymer was used to produce thin film of uniformly distributed parallel cylinders of polymethylmethacrylate (PMMA) in polystyrene (PS) matrix. The PMMA cylinders were removed with UV expose and acetic acid rinse to produce PS nanotemplate. By reactive ion etching, pattern of the PS template was transferred to under laid silicon oxide layer. Transferred patterns were reached to the GaAs substrate by controlling the dry etching time. We confirmed the achievement of etching through the removing oxide layer and observation of GaAs substrate surface. Optimized etching time was 90 to 100 sec. Pore sizes of the nanopattern in the silicon oxide layer were 20~22 nm.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.670-682
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• 2018

Engineered nanomaterials (ENMs) can be released to humans and the environment through the generation of waste containing engineered nanomaterials (WCNMs) and the use and disposal of nano-products. Nanoparticles can also be introduced intentionally or unintentionally into waste streams. This study examined WCNMs in domestic industries, and target nanomaterials, such as silicon dioxide, titanium oxide, zinc oxide, nano silver, and carbon nanotubes (CNTs), were selected. We tested 48 samples, such as dust, sludge, ash, and by-products from manufacturing facilities and waste treatment facilities. We analyzed leaching and content concentrations for heavy metals and hazardous constituents of the waste. Chemical compositions were also measured by XRD and XRF, and the unique properties of nano-waste were identified by using a particle size distribution analyzer and TEM. The dust and sludge generated from manufacturing facilities and the use of nanomaterials showed higher concentrations of metals such as lead, arsenic, chromium, barium, and zinc. Oiled cloths from facilities using nano silver revealed high concentrations of copper, and the leaching concentrations of copper and lead in fly ash were higher than those in bottom ash. In XRF measurements at the facilities, we detected compounds such as silicon dioxide, sulfur trioxide, calcium oxide, titanium dioxide, and zinc oxide. We found several chemicals such as calcium oxide and silicon dioxide in the bottom ash of waste incinerators.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3722-3726
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• 2013

Covalent functionalization of a $Zn_{12}O_{12}$ nano-cage with $CO_2$ molecule in terms of energetic, geometry, and electronic properties was investigated by density functional theory method. For chemisorption configurations, the adsorption energy of $CO_2$ on the $Zn_{12}O_{12}$ nano-cage for the first $CO_2$ was calculated -1.25 eV with a charge transfer of 1.00|e| from the nano-cage to the $CO_2$ molecule. The results show that $CO_2$ molecule was significantly detected by pristine $Zn_{12}O_{12}$ nano-cage, therefore the nano-cage can be used as $CO_2$ storage. Also, more efficient binding could not be achieved by increasing the $CO_2$ concentration. For Physisorption configurations, HOMO-LUMO gap of the configurations has not changed, while slight changes have been observed in the chemisorption configurations.

• Korean Journal of Materials Research
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• v.32 no.4
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• pp.193-199
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• 2022

In this study, lenses are fabricated using various nanomaterials as additives to a silicone polymer made with an optimum mixing ratio and short polymerization time. In addition, PVP is added at a ratio of 1 % to investigate the physical properties according to the degree of dispersion, and the compatibility with hydrophobic silicone and the possibility of application as a functional lens material are confirmed. The main materials are SIU as a silicone monomer, DMA, a hydrophilic copolymer, EGDMA as a crosslinking agent, and 2H2M as a photoinitiator. Holmium (III) oxide, Europium (III) oxide, aluminum oxide, and PVP are used. When Holmium (III) oxide and Europium (III) oxide are added based on the Ref sample, the characteristics of the lens tend to be similar overall, and the aluminum oxide shows a tendency slightly different from the previous two oxides. This material can be used as a silicone lens material with various nano oxides and polyvinylpyrrolidone (PVP) acting as a dispersant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3853-3858
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• 2010

This paper shows electrical analysis of the silicon solar cell according to the various ARC thickness using Medici program. we built a mesh structure of the solar cell that use ARC consisting of ITO(Indium-Tin-Oxide) transparent electrode, for the Medici modeling. About various oxide layer thickness of the ARC for 30 nm, 60 nm, 90 nm, changes of the I-V curve, Isc, Voc, transmittance and external collection efficiency performed according to wavelength of Incident ray. Simulation results show maximum power 22 mW/$cm^2$, fill factor 0.83 in condition of 60 nm ITO thickness.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.63-63
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• 2003

The nanotopography of silicon wafers has emerged as an important factor in the STI process since it affects the post-CMP thickness deviation (OTD) of dielectric films. Ceria slurry with surfactant is widely applied to STI-CMP as it offers high oxide-to-nitride removal selectivity. Aiming to control the nanotopography impact through ceria slurry characteristics, we examhed the effect of surfactant concentration and abrasive size on the nanotopography impact. The ceria slurries for this study were produced with cerium carbonate as the starting material. Four kinds of slurry with different size of abrasives were prepared through a mechanical treatment The averaged abrasive size for each slurry varied from 70 nm to 290 nm. An anionic organic surfactant was added with the concentration from 0 to 0.8 wt %. We prepared commercial 8 inch silicon wafers. Oxide Shu were deposited using the plasma-enhanced tetra-ethyl-ortho-silicate (PETEOS) method, The films on wafers were polished on a Strasbaugh 6EC. Film thickness before and after CMP was measured with a spectroscopic ellipsometer, ES4G (SOPRA). The nanotopogrphy height of the wafer was measured with an optical interferometer, NanoMapper (ADE Phase Shift)

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.74-79
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• 2016

The lanthanum oxide nano-rods were grown on the surface of 3 mol% Yttria Partially Stabilized Zirconia ceramic composite which containing Lanthanum-Strontium Manganate, $La_xSr_yMn_zO_3$ for the purpose of endorsing the antistatic property. The diameter and the aspect ratio of the nano-rods were greatly changed according to the growing condition. With the optical microscope observation, the nano-rods shining brightly. It was confirmed that the major components of nano-rods is La, and Sr, Mn, Si are minor components by SEM and TEM analyses.

• Korean Journal of Materials Research
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• v.12 no.2
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• pp.121-128
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• 2002

Anodic alumina layer can be used as templates for preparation of nano-structured materials, because porous oxide layer on aluminum shows a uniform pore size and a high pore density. In order to find out possibility for template material to prepare nano wire, the effects of the anodic applied potential, anodic time and the temperature of electrolyte on pore diameter of anodic alumina layer were studied using SEM and AFM. The pore diameter of anodic alumina layer increased with applied anodic potential and electrolytic temperature. Especially, the pore diameter of anodic oxide layers formed in chromic acid can be well replicated by widening process in $H_3$$PO_4$solution.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.60-60
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• 2010

1-D nanostructured materials have much more attention because of their outstanding properties and wide applicability in device fabrication. Bismuth oxide($Bi_2O_3$) is an important p-type semiconductor with main crystallographic polymorphs denoted by $\alpha-$, $\beta-$, $\gamma-$, and $\delta-Bi_2O_3$[1]. Due to its unique optical and electrical properties, $Bi_2O_3$ has been extensively investigated for various applications in gas sensors, photovoltaic cells, fuel cells, supercapacitors[2-4]. In this study, $Bi_2O_3$ NWs were grown by two step annealing process: in the first step, after annealing at $270^{\circ}C$ for 10h in a vaccum($3{\times}10^{-6}$ torr), we can obtain the bismuth nanowires. In the second step, after annealing at $300^{\circ}C$ for 2h in $O_2$ ambient, we successfully fabicated $Bi_2O_3$nanowires.