Browsing by Author "Wu, Meng-Hsun"

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Graphene films grown at low substrate temperature and the growth model by using MBE technique
(2013-09-01)
Lin, Meng-Yu
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Guo, Wei-Ching
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Wu, Meng-Hsun
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Wang, Pro-Yao
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Lee, Si-Chen
By depositing atomic C atoms on the grained Cu foil by using molecular beam epitaxy technique (MBE), high-quality graphene is obtained at low substrate temperature 300 degrees C. A model of initial graphene flake formation as crystal seeds and following lateral graphene growth is established to explain the growth mechanisms. After atomic C atom deposition, no significant difference is observed before and after MBE growth. The results suggest that the deposition of atomic C atoms will not improve the crystalline quality of pre-formed C films. The low substrate temperature required would be advantageous for the practical application of graphene. (c) 2013 Elsevier B.V. All rights reserved.
Low-temperature grown graphene films by using molecular beam epitaxy
(2012-11-26)
Lin, Meng-Yu
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Guo, Wei-Ching
;
Wu, Meng-Hsun
;
Wang, Pro-Yao
;
Liu, Te-Huan
Complete graphene film is prepared by depositing carbon atoms directly on Cu foils in a molecular beam epitaxy chamber at 300 degrees C. The Raman spectrum of the film has indicated that high-quality few-layer graphene is obtained. With back-gated transistor architecture, the characteristic current modulation of graphene transistors is observed. Following the similar growth procedure, graphitization is observed at room temperature, which is consistent with the molecular dynamics simulations of graphene growth. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4768948]
The influence of background As on GaSb/GaAs quantum dots and its application in infrared photodetectors
(2012)
Lin, Wei-Hsun
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Tseng, Chi-Che
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Wu, Shung-Yi
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Wu, Meng-Hsun
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Lin, Shih-Yen
In this paper, GaSb nanostructures prepared under different Sb/background As ratios are investigated. With decreasing Sb/background As ratios, the morphologies of GaSb nanostructure changing from quantum dots (QDs) to quantum rings (QRs) are observed. The higher optical recombination probabilities of GaSb QRs are attributed to enhanced electron-hole wave function overlapping and more surrounding electrons around the GaSb QR core shell. With well-control Sb/background As ratios, the high-temperature operation GaSb quantum-dot infrared photodetector (QDIP) with simple stacked structure has been demonstrated. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim