http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : William Thomas Nichols (검색결과 6 건)
- 무료
- 기관 내 무료
- 유료
-
김성웅,박시현,권선영,William Thomas Nichols,박원일 한국물리학회 2015 Current Applied Physics Vol.15 No.6
The nanostructures found in nature sometimes have elaborate, three-dimensional structures that consist of soft and flexible constituents, and which exhibit diverse mechanical and optical functions. Here, we introduce a facile, low-cost and scalable nanofabrication approach based on a hot embossing process that can replicate sub-micron to nanoscale features on elastomeric substrates.We have further developed this technique to achieve polymer/metal heterostructure nanopillar arrays via conformal coating of Au films on polymeric templates. Each nanopillar displays a smooth surface and a constant diameter along the vertical direction. Raman spectroscopy studies revealed that the metallic nanostructures decorated with methylene blue exhibited a dominant Raman peak at 1624 cm-1 that was enhanced more than 3000 times and seven times relative to bare planar Si and Au-coated planar polystyrene substrates, respectively. These results indicate that our nanopillar array can be exploited as a flexible, large area platform for surface-enhanced Raman spectroscopy.
-
Fabrication of Noble-metal Nanoparticle-doped SiO2-B2O3-P2O5 Waveguide Films
Hunhyeong Lee,강민경,William Thomas Nichols,신동욱 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.9
In this article, we report the fabrication and the characterization of Pt/SiO2-B2O3-P2O5 and Au/SiO2-B2O3-P2O5 composite thin films suitable for planar lightwave circuits (PLCs). The host material was prepared by using flame hydrolysis deposition (FHD). Platinum was doped from colloidal solutions with concentrations of 500, 1000, and 2000 ppm. Gold was doped by sputtering with various deposition times. The samples displayed absorption peaks originating from the surface plasmon resonance (SPR) of the dopant metal particles. With increasing dopant particle size, the absorption peak shifted toward longer wavelength, and the full width at half maximum (FWHM) of the absorption band broadened. The Maxwell-Garnett theory was used to explain the size dependence of the plasmon peaks. The dopant metal particles were found to order as a monolayer within the silica matrix, opening the possibility for surface-plasmon-resonance-based waveguiding in optical devices.
-
Growth of Single Crystal GaAs Nanowires by a Surface Diffusion-Mediated Solid-Liquid-Solid Process
이정민,Fan Xia,William Thomas Nichols,최창환,박원일 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.5
A facile route to synthesize GaAs nanowires by simply heating Au-coated GaAs substrates to 700 °C under vacuum (~10−3Torr) was developed in this study. Detailed structural analyses showed that ultrathin single crystal GaAs nanowires with an average diameter of ~15 nm were grown outward from the Au metal droplets remaining on the surface of the GaAs substrate. On the other hand, the substrate surface region contacting the metal layer became porous, and the depth of the porous layer increased with increasing processing time. Based on these results, it was concluded that the nanowires were grown by a solidliquid-solid process involving the surface diffusion of adatoms from the underlying solid substrates to the Au liquid droplets.
-
Self-assembled Diatom Substrates with Plasmonic Functionality
Sun Yong Kwon,박세현,William Thomas Nichols 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.8
Marine diatoms have an exquisitely complex exoskeleton that is promising for engineered surfacessuch as sensors and catalysts. For such applications, creating uniform arrays of diatom frustulesacross centimeter scales will be necessary. Here, we present a simple, low-cost floating interfacetechnique to self-assemble the diatom frustules. We show that well-prepared diatoms form floatinghexagonal close-packed arrays at the air-water interface that can be transferred directly to a substrate. We functionalize the assembled diatom surfaces with gold and characterize the plasmonicfunctionality by using surface enhanced Raman scattering (SERS). Thin gold films conform to thecomplex, hierarchical diatom structure and produce a SERS enhancement factor of 2 × 104. Smallgold nanoparticles attached to the diatom’s surface produce a higher enhancement of 7 × 104 dueto stronger localization of the surface plasmons. Taken together, the large-scale assembly and plasmonicfunctionalization represent a promising platform to control the energy and the material flowsat a complex surface for applications such as sensors and plasmonic enhanced catalysts.
-
Site-Specific Synthesis of ZnO Nanocrystalline Networks via a Hydrothermal Method
이재석,Ji-yeob Kim,Hyang Gi Jin,Seungmok Song,최창환,William Thomas Nichols,박원일 대한금속·재료학회 2012 METALS AND MATERIALS International Vol.18 No.5
ZnO nanocrystalline networks (NCNWs) consisting of percolating nanocrystals with irregular shape and size were synthesized using Al seed layers in a hydrothermal process. Various thicknesses of Al films were used to assess the effects of film thickness on the formation of ZnO NCNWs; the coverage and size of the ZnO nanocrystals increased with an increasing Al film thickness. In addition, by exploiting the seed layer-dependent crystal growth behaviors, two distinctly different ZnO nanostructures, nanorods on ZnO seed and NCNWs on Al seed, could be selectively achieved on the same substrate under the same growth conditions. Spectrally- and spatially-resolved investigations of these two ZnO nanostructures were performed using cathodoluminescence, which provided a significant opportunity to study the effect of the nanostructures on the luminescent characteristics. The ZnO NCNWs have an extremely high surface to volume ratio and sufficient inter-space, which enabled the conversion of the surface property from hydrophilic to superhydrophobic.
-
MoO3 thin film synthesis by chemical vapor transport of volatile MoO3(OH)2
오승탁,김영도,Young Jung Lee,Chang Won Park,Dae-Gun Kim,William Thomas Nichols 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.1
Molybdenum oxide thin films with good adhesion and crystallinity were homogeneously deposited by the chemical vapor transport of MoO3(OH)2 and subsequent dehydration to the Mo oxide phase during hydrogen-reduction. This new deposition technique would be an effective deposition method for MoO3 thin films due to the simple, low-cost, large area deposition and eco-friendly process. The surface morphology dramatically changed by thermal annealing at different temperatures and a uniform ~1 μm thickness was obtained. The effect of the annealing temperature is discussed.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
