排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Hyuncheol Kim Hyeong-Ho Park Hyeongtag Jeon Ho Jung Chang Youngchul Chang Hyung-Ho Park 《Ceramics International》2009
Direct-patterning of ZnO hybrid films containing MWNT was realized without using photoresist and dry etching. Photosensitive 2-nitrobenzaldehyde was introduced into the solution precursors as a stabilizer and contributed to form a cross-linked network structure during photochemical reaction. According to the incorporation of multi-walled nanotube (MWNT) into ZnO films, the transmittance of ZnO hybrid film containing MWNT did not change but the sheet resistance was improved due to the enhancement of charge mobility due to π-bonding nature of MWNT. These results suggested a possibility that a micro-patterned system can be fabricated relatively easily and without high-cost processes, for example, by conventional etching procedure. 相似文献
2.
Chae-Seon Hong Hyeong-Ho Park Hyung-Ho Park Ho Jung Chang 《Journal of Electroceramics》2009,22(4):353-356
Low-temperature crystallized ZnO thin film was achieved by sol–gel process using zinc acetate dihydrate and 2-methoxyethanol
as starting precursor and solvent, respectively. Ag nanoparticles were prepared with uniform size at 4.4 nm by spontaneous
reduction method of Ag 2-ethylhexanoate in dimethyl sulfoxide (DMSO). The optical and electrical properties of ZnO thin films
containing various contents of Ag-nanoparticles were monitored. Light scattering and charge emission and scattering behaviors
of Ag nanoparticles in ZnO film were found. The incorporation of Ag nanoparticles into Al-doped ZnO film was also investigated.
The optical transmittance was not degraded but the increase of electrical sheet resistance was found. The effect of Al-dopant
on the transmittance and electrical sheet resistance of ZnO film was found too great to distinguish the positive effect of
the incorporation of Ag nanoparticles into Al-doped ZnO thin films. 相似文献
3.
Jin HH Lee CH Kim DH Kim TW Hwang KH Lee JK Park HC Yoon SY 《Journal of nanoscience and nanotechnology》2011,11(8):7438-7441
The apatite was formed on the titanium plates with NaOH and heat treatments by biomimetic process. The influence of titanium surface microstructure on the apatite formation onto titanium substrate in SBF solution was investigated. After biomimetic process, nano-sized apatite layers were found on the Ti plates with NaOH and heat treatments. However, the morphologies of formed apatite on substrate had different shapes such as coated, load-like, and linked. The morphology of apatite formed by biomimetic process would be affected by alkaline treatment, and substrate morphology and phase. 相似文献
4.
Amorphous silicon thin films were formed by chemical vapor deposition of reactive particle beam assisted inductively coupled plasma type with various reflector bias voltages. During the deposition, the substrate was heated at 150 °C. The effects of reflector bias voltage on the physical and chemical properties of the films were systematically studied. X-ray diffraction and Raman spectroscopy results showed that the deposited films were amorphous and the films under higher reflector voltage had higher internal energy to be easily crystallized. The chemical state of amorphous silicon films was revealed as metallic bonding of Si atoms by using X-ray photoelectron spectroscopy. An increase in reflector voltage induced an increase of surface morphology of films and optical bandgap and a decrease of photoconductivity. 相似文献
5.
Hyeong-Ho Park Hong-Sub Lee Hyung-Ho Park Xin Zhang Ross H. Hill 《Journal of Electroceramics》2010,24(3):214-218
Direct-patterned lead zirconate titanate (PZT) films prepared from an electron beam sensitive stock solution were investigated
for advanced stage applications in sub 50-nm patterned systems. The required electron beam dose for the direct-patterning
of PZT precursor films was 4.5 mC/cm2. The PZT precursor films with pattern size of 500 × 500 μm2 were exposed to an electron beam for 2 h and annealed at 400°C for 30 min under an O2 ambient. After exposure and annealing, values of the remnant polarization and coercive field were 7.0 μC/cm2 and 97 kV/cm at 10 V, respectively. These results suggest a possible application of PZT films in micro- or nano-electromechanical
systems. 相似文献
6.
Hyeong-Ho ParkXin Zhang Soon-Won LeeDong-Joo Jeong Sang-Moo LeeKi-don Kim Dae-Geun ChoiJun-Hyuk Choi Jihye LeeEung-Sug Lee Ho Kwan KangHyung-Ho Park Ross H. HillJun-Ho Jeong 《Microelectronic Engineering》2011,88(6):923-928
A direct ultraviolet (UV)-assisted nanoimprinting procedure using photosensitive titanium di-n-butoxide bis(2-ethylhexanoate) is employed in this study for the nanopatterning of anatase titanium dioxide (TiO2) structure. Upon annealing at 400 °C for 1 h, the lateral shrinkage and thickness shrinkage of the TiO2 nanostructure were 39.6% and 52.5%, respectively, which indicated an anisotropic volume loss. During UV irradiation and annealing treatment, the refractive index of UV-irradiated TiO2 film is gradually increased by improvement in the packing density and crystallinity of the film. According to increasing UV exposure time and annealing temperature, the optical band gap (Eg) of UV-irradiated TiO2 film is red-shifted from 3.73 to 3.33 eV due to the formation of lattice defects, vacancies and voids during the photochemical reaction and due to the effect of quantum confinement during annealing treatment. These results suggest that the refractive index and optical Eg of TiO2 nanostructure could be controlled by tuning the UV exposure time and annealing treatment conditions. Nanopatterns of TiO2 fabricated by direct UV-assisted nanoimprint lithography are potential candidates for use in protective coatings for optical mirrors and filters, high-reflectivity mirrors, broadband interference filters and active electro-optical devices where ordered surface nanostructures could be necessary. 相似文献
7.
Park SJ Sohee-Jeong Park HH Lee SW Jeon S Lee JH Choi DG Jeong JH Choi JH 《Journal of nanoscience and nanotechnology》2011,11(1):422-426
Recently, various research strategies have been employed to improve light extraction efficiency in organic LEDs, including the recent development of localized surface plasmon resonance (LSPR), as well as the more widely-known application of a photonic crystal layer. Here, we report on the development of a process method for forming a two-dimensional nanosilver patterned array to achieve LSPR-coupled light-emission efficiency enhancement. The process scheme involves the spin-coating of nanosilver colloidal ink onto a glass substrate, followed by optimized thermal annealing to create an array of isolated nanosilver islands. The resulting Ag islands are in the size range 50 approximately 80 nm, which is larger than the diameter of the Ag nanoparticles in the colloidal suspension. Then, silicon oxide is thermally sputtered to provide a spacer layer to prevent luminescence quenching of the red-emitting nanocrystal quantum dot (NQD) layer, which is deposited in a subsequent spin-coating process. When the NQD layer is excited, the energy of the photoelectron is confined to the surfaces of the nanosilver islands in the near-field. In this study, the localized surface plasmon resonance peaks were at a wavelength of 625 nm, and out-coupling efficiency was enhanced more than sixfold. 相似文献
8.
Jin Yong Kim Hyeong-Ho Park A. Sivasankar Reddy Ho Jung Chang Hyeongtag Jeon Youngchul Chang Hyung-Ho Park 《Ceramics International》2008,34(4):1055-1058
In this paper, the effect of different sizes of Ag-nanoparticles dispersed in ZnO matrix using sol–gel method has been focused. Low-temperature crystallized ZnO thin films was achieved by sol–gel process, using zinc acetate dihydrate and 2-methoxyethanol as starting precursor and solvent, respectively. Various sizes of Ag-nanoparticles could be prepared by the spontaneous reduction method with changing the preparation temperatures and mole concentrations of Ag 2-ethylhexanoate in dimethyl sulfoxide solvent. The crystallographic structure of the Ag–ZnO hybrid film was analyzed by X-ray diffraction. Ag-nanoparticle size and optical property of Ag–ZnO hybrid films were measured by UV–vis spectrophotometer. 相似文献
9.
Masanori Hara Hyeong-Ho Lee Takashi Egashira Kazutami Oyama 《Electrical Engineering in Japan》1991,111(3):37-46
The influence of a metallic particle attached to a supporting insulator is remarkable in decreasing the dielectric strength in an SF6 insulated apparatus. To solve this problem, a series of studies has been conducted on a method of improving the particle-initiated breakdown performance. In this paper, dc breakdown voltage characteristics and the breakdown mechanism are investigated under metallic-particle contaminated conditions in SF6 gas by varying the particle condition and the surface shape of the acrylic plate with a rod-plane electrode. The main results show that a rib increases the breakdown voltage by a corona stabilization effect and the elongation of discharge path, but a groove decreases its effect drastically at lower gas pressures. The breakdown voltage at pressures higher than 4 atm may be estimated on the basis of the discharge-maintaining field and the discharge length which depend on the gas pressure and the surface shape. 相似文献
10.
Tae-Wan Kim Young Min Park Dong-Hyun Kim Hyeong-Ho Jin Keun-Koo Shin Jin Sup Jung Hong-Chae Park Seog-Young Yoon 《Ceramics International》2012,38(3):1965-1974
The co-precipitation technique has been applied to synthesize biphasic calcium phosphate (BCP). After annealing at 900 °C for 24 h, hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) were obtained as a single phase at 1.67 and 1.5 Ca/P ratios, respectively. Between these two extremes, a whole range of BCP preparations could be synthesized by using this technique with an accurate control of starting reactants. The biological performance of BCP granulates with a specific content of 62% HAp and 38% β-TCP was investigated. After immersion in Hanks’ balanced salt solution (HBSS) for 1 week, a precipitation started to be formed with individual small granules on the specimen surface. An MTT assay indicated that BCP granulates have no cytotoxic effects on MG-63 cells, and that they have good biocompatibility. An implantation experiment in mouse skulls revealed that BCP granulate provides a strong positive effect on bone formation in vivo in mice. 相似文献