Browsing by Author "Tsai, Hung-Yin"

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Low cost fabrication of the large-area anti-reflection films from polymer by nanoimprint/hot-embossing technology
(2008-05-21)
Ting, Chia-Jen
;
Huang, Meng-Chi
;
Tsai, Hung-Yin
;
Chou, Chang-Pin
;
Fu, Chien-Chung
In this paper, we present a low cost approach to produce large-area polymer sheets with sub-wavelength nanostructures. The fabricated polymer films would have great potentials to attach to optical or solar-cell-related consumer products when anti-reflection/anti-glaring is mandatory. We employed a special electron cyclotron resonance (ECR) plasma process to fabricate the SWSs with large area directly on silicon substrates. Homogeneously distributed nanotips on the full 4 inch silicon substrate were fabricated by using gas mixtures of silane, methane, argon and hydrogen. An Ni-Co metal mold with a hardness of 550 HV was produced through the replication of the Si mold by electroplating. Afterwards, the molding process was applied to manufacture the nanostructures in PMMA plates in large volume. The nanostructures in PMMA plates with aspect ratios of 4 and diameters of 150 nm were fabricated. The fabricated PMMA sheets could generate the gradient of the refractive indices, absorb the light and greatly reduce the reflectivity. Compared with the PMMA without SWSs, the reflectivity of PMMA with SWSs decreased dramatically from 4.25% to 0.5% at the wavelength of light from 400 to 800 nm.
Silicon Rice-Straw Array Emitters and Their Superior Electron Field Emission
(2010-11-01)
Wu, Hung-Chi
;
Tsai, Hung-Yin
;
Chiu, Hsin-Tien
;
Lee, Chi-Young
;
應用化學系
Free standing and vertically aligned silicon rice-straw like array emitters were fabricated by modified electroless metal deposition (EMD), using HFH(2)C(2) as an erching solution to reduce the emitter density and to make the emitter end of the formed silicon rice-straw arrays shaper than those formed by conventional EMD. These silicon rice-straw array emitters can be turned on at E(0) = 4.7 V/mu m, yielding an EFE (electron field emission) current density of f(c) = 139 mu A/cm(2) in an applied field of 12.8 V/mu m. According to a simple simulation, the excellent EFE performance of the silicon rice-straw array emitters originates in not only the favorable distribution of emitter arrays, but also the shape of the emitter apexes. The modified-EMD method is easily scaled up without expensive equipment, so silicon rice-straw array emitters are a promising alternative to silicon-based field emitters.