Browsing by Author "Chao, YC"

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Growth and characterization of chemical-vapor-deposited zinc oxide nanorods
(2006-03-01)
Wu, CL
;
Chang, L
;
Chen, HG
;
Lin, CW
;
Chang, TF
ZnO nanorods were grown on Si substrates by metal-organic chemical vapor deposition (CVD). The ZnO nanorods were characterized by scanning electron microscopy, transmission electron microscopy (TEM), and X-ray diffraction. It was found that highly oriented ZnO single-crystalline nanorods were formed only on the substrate coated with a gold film. Without the gold, ZnO was deposited as a continuous film. No Au was observed on top of the ZnO nanorods, implying that the Au plays no role as catalytic metal in vapor-liquid-solid mechanism for formation of ZnO nanorods. In CVD, oriented ZnO nanorods along the c-axis were grown as a result of < 111 > textured Au. High-resolution TEM shows that the gold layer and ZnO are in orientation relationship of Au 111 planes//ZnO (0002) basal planes. (c) 2005 Elsevier B.V. All rights reserved.
Polymer hot-carrier transistor
(2005-12-19)
Chao, YC
;
Yang, SL
;
Meng, HF
;
Horng, SF
;
物理研究所
Metal-base hot-carrier transistor with conjugated polymer emitter and collector is demonstrated. The device is fabricated by multiple spin coating with the metal base sandwiched between two polymers. A thin insulating layer of LiF is inserted between the emitter and base to enhance the hot carrier kinetic energy and reduce mutual dissolution. Using poly(9-vinylcarbazole) as the emitter, Al as the base, and poly(3-hexylthiophene) as the collector, common-emitter current gain of 25 is obtained with operation voltage as low as 5 V.
Polymer space-charge-limited transistor
(2006-05-29)
Chao, YC
;
Meng, HF
;
Horng, SF
;
物理研究所
;
電子工程學系及電子研究所
A metal grid is sandwiched between poly(3-hexylthiophene) to form a solid-state version of vacuum tube triode, where the vertical space-charge-limited current is modulated by the grid potential. The Al grid contains random submicron openings formed by a nonlithographic method. The multilayer polymer structure is made by spin coating. The operating voltage of the polymer space-charge-limited transistor is 3 V, and the current gain of 506 is obtained. The characteristics of the transistor can be tuned by the diameters and the density of the openings on the grid. Similar to the vacuum tube triode, the current follows a power law voltage dependence.