• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1245-1248
• /
• 2007

We propose new approaches to thin film transistor fabrication that use carbon nanotubes and semiconductor nanowires as active elements. These nanomaterials which are essentially studied in the context of the post CMOS era will certainly impact the active matrix display industry in the near future.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2005.04a
• /
• pp.59-59
• /
• 2005

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.402.2-402.2
• /
• 2016

In photoelectrochemical (PEC) water splitting, Cu2ZnSnS4 (CZTS) compound has attracted intense attention as a photocathode due to not only large optical absorption coefficient, but also earth-abundance of constituent elements and suitable band alignment. With rapid development of nanotechnology, one-dimensional nanostructures of CZTS have been investigated as a potential form to achieve high efficiency because the nanostructures are expected to be capable of capturing more light and enhancing charge separation and transport. Here, we report a well-controlled fabrication route for vertically-aligned CZTS nanorod arrays on anodic aluminium oxide (AAO) template via simple sol-gel process followed by deposition of ZnS or CdS buffer layers on the CZTS nanorod to enhance charge separation. The structure, morphology, composition, optical absorption, and PEC properties of the resulting CZTS nanorod samples were characterized using X-ray diffraction, Raman spectroscopy, transmission electron microscopy, energy dispersive X-ray spectrometry, scanning electron microscopy, and UV-vis spectroscopy.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2004.04b
• /
• pp.50.2-50.2
• /
• 2004

• Nuclear Engineering and Technology
• /
• v.55 no.6
• /
• pp.2139-2146
• /
• 2023

During reactor operation, the divertor must withstand unprecedented simultaneous high heat fluxes and high-energy neutron irradiation. The extremely severe service environment of the divertor imposes a huge challenge to the bonding quality of divertor joints, i.e., the joints must withstand thermal, mechanical and neutron loads, as well as cyclic mode of operation. In this paper, potassium-doped tungsten (KW) is selected as the plasma facing material (PFM), oxygen-free copper (OFC) as the interlayer, oxide dispersion strengthened copper (ODS-Cu) alloy as the heat sink material, and reduced activation ferritic/martensitic (RAFM) steel as the structural material. In this study, a vacuum brazing technology is proposed and optimized to bond Cu and ODS-Cu alloy with the silver-free brazing material CuSnTi. The most appropriate brazing parameters are a brazing temperature of 940 ℃ and a holding time of 15 min. High-quality bonding interfaces have been successfully obtained by vacuum brazing technology, and the average shear strength of the as-obtained KW/Cu and ODS-Cu alloy joints is ~268 MPa. And a fabrication route for manufacturing the flat-type divertor target based on brazing technology is set. For evaluating the reliability of the fabrication technologies under the reactor relevant condition, the high heat flux test at 20 MW/m² for the as-manufactured flat-type KW/Cu/ODS-Cu/RAFM mockup is carried out by using the Electron-beam Material testing Scenario (EMS-60) with water cooling. This paper reports the improved vacuum brazing technology to connect Cu to ODS-Cu alloy and summarizes the production route, high heat flux (HHF) test, the pre and post non-destructive examination, and the surface results of the flat-type KW/Cu/ODS-Cu/RAFM mockup after the HHF test. The test results demonstrate that the mockup manufactured according to the fabrication route still have structural and interfacial integrity under cyclic high heat loads.

• Journal of Institute of Convergence Technology
• /
• v.1 no.1
• /
• pp.48-51
• /
• 2011

Transdermal drug delivery device is a method of drug delivery through the skin. Skin has a very large area, so it is attractive route to drug delivery. When drug delivery through the skin, microneedle has a advantage that painless, constant drug deliver and penetration efficient; nevertheless the cost is expensive because fabrication process need a particular equipment and not suitable in mass production. This study shows microneedle fabrication process using convergence of general MEMS process and dicing process that can make 3-D sharp microneedle tip and this fabrication process suitable for mass production.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2003.10a
• /
• pp.116.1-116
• /
• 2003

• Proceedings of the Korean Magnestics Society Conference
• /
• 2013.12a
• /
• pp.89-89
• /
• 2013

Rare earth (RE) - transition metal based high energy density magnets are of immense significance in various engineering applications. $Nd_2Fe_{14}B$ magnets possess the highest energy product and are widely used in whole industries. Simultaneously, composite alloys that are cheap, cost effective and strong commercially available have drawn great attention, because rare-earth metals are costly, less abundant and strategic shortage. We designed rare-earth free alloys and fabrication process and developed novel route to prepare $Nd_2Fe_{14}B$ powders by wet process employing spray drying and reduction-diffusion (R-D) without the use of high purity metals as raw material. MnAl-base permanent magnetic powders are potentially important material for rare-earth free magnets. We have prepared the nano-sized MnAl powders by plasma arc discharge and micron-sized MnAl powders by gas atomization. They showed good magnetic property, compared with that from conventional processes. $Nd_2Fe_{14}B$ powders with high coercivity of more than 10 kOe were successfully synthesized by adjusting R-D step, followed by precise washing system. It is considered that this process can be applied for the recycling of RE-elements extracted from ewaste including motors.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.9
• /
• pp.1457-1462
• /
• 2007

A simple and facile sonochemical route was described for the fabrication of diameter-controlled ZnO nanorod arrays on Si wafers. The diameter of ZnO nanorods was controlled by the concentration of zinc cations and hydroxyl anions in aqueous precursor solution. At high concentration of the precursor solution, thick ZnO nanorod arrays were formed. On the contrary, thin ZnO nanorod arrays were formed at low concentration of the precursor solution. The average diameter of ZnO nanorods varies from 40 to 200 nm. ZnO nanorod arrays with sharp tip were also fabricated by the step-by-step decrease in precursor solution concentration. The crystal structure and optical characteristics of ZnO nanorods were investigated by transmission electron microscopy, X-ray diffraction, and photoluminescence spectroscopy. Growth mechanism of ZnO nanorod arrays was also proposed.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.27.2-27.2
• /
• 2010

In recent years, there is a strong requirement of low cost, stable microelectro mechanical systems (MEMS) for resonators, microswitches and sensors. Most of these devices consist of freely suspended microcantilevers, which are usually made by the etching of some sacrificial materials. Herein, we have attempted to use Si nanowires, inherited from the parent Si wafer, as a sacrificial material due to its porosity, low cost and ease of fabrication. Prior to the fabrication of the Si nanowires silver nanoparticles were continuously formed on the surface of Si wafer. Vertically aligned Si nanowires were fabricated from the parent Si wafers by aqueous chemical route at $50^{\circ}C$. Afterwards, the morphological and structural characteristics of the Si nanowires were investigated. The morphology of nanowires was strongly modulated by the resistivity of the parent wafer. The 3-step etching of nanowires in diluted KOH solution was carried out at room temperature in order to control the fast etching. A layer of $Si_3N_4$ (300 nm) was used for the selective fabrication of nanowires. Finally, a freely suspended bridge of zinc oxide (ZnO) was fabricated after the removal of nanowires from the parent wafer. At present, we believe that this technique may provide a platform for the inexpensive fabrication of futuristic MEMS.