Browsing by Author "Ku, Y.-P."

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Terahertz emission from vertically aligned InN nanorod arrays
(2007-09-24)
Ahn, H.
;
Ku, Y.-P.
;
Wang, Y.-C.
;
Chuang, C.-H.
;
Gwo, S.
Terahertz emission from indium nitride (InN) nanorods and InN film grown by molecular-beam epitaxy on Si(111) substrates has been investigated. Terahertz emission from InN nanorods is at least three times more intense than that from InN film and depends strongly on the size distribution of the nanorods. Surface electron accumulation at the InN nanorods effectively screens out the photo-Dember field in the accumulation layer formed under the surface. The nanorods with considerably large diameter than the thickness of accumulation layer are found to be dominant in the emission of terahertz radiation from InN nanorod arrays. (c) 2007 American Institute of Physics.
Terahertz spectroscopic study of vertically aligned InN nanorods
(2007-10-15)
Ahn, H.
;
Ku, Y.-P.
;
Wang, Y.-C.
;
Chuang, C.-H.
;
Gwo, S.
Terahertz time-domain spectroscopy has been used to investigate terahertz conductivity and dielectric response of indium nitride (InN) nanorod array and epitaxial film. The complex terahertz conductivity of InN film is well fitted by the Drude model, while the negative imaginary conductivity of the InN nanorods can be described by using the Drude-Smith model. The electron mobility of the InN film is 1217 +/- 58 cm(2)/V s, while that of the InN nanorods is 80 +/- 5 cm(2)/V s. The reduced mobility of carriers for the latter can be attributed to the restricted carrier transport within the nanorods. (C) 2007 American Institute of Physics.