Browsing by Author "Van-Truong Dai"

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High-quality planar light emitting diode formed by induced two-dimensional electron and hole gases
(2014-02-24)
Van-Truong Dai
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Lin, Sheng-Di
;
Lin, Shih-Wei
;
Lee, Yi-Shan
;
Zhang, Yin-Jie
A high-quality planar two-dimensional p-i-n light emitting diode in an entirely undoped GaAs/AlGaAs quantum well has been fabricated by using conventional lithography process. With twin gate design, two-dimensional electron and hold gases can be placed closely on demand. The electroluminescence of the device exhibit high stability and clear transition peaks so it is promising for applications on electrically-driven single photon sources. (C) 2014 Optical Society of America
Lateral Two-Dimensional p-i-n Diode in a Completely Undoped GaAs/AlGaAs Quantum Well
(2013-01-01)
Van-Truong Dai
;
Lin, Sheng-Di
;
Lin, Shih-Wei
;
Wu, Jau-Yang
;
Li, Liang-Chen
A lateral two-dimensional p-i-n junction in an entirely undoped GaAs/AlGaAs quantum well has been fabricated. The optical and electrical characteristics of the junction are reported. The threshold voltage of the junction and the electroluminescence spectrum of the quantum well confirm the formation of the lateral two-dimensional junction. (C) 2013 The Japan Society of Applied Physics
Structural and nanoindentation studies of epitaxial titanium oxynitride (001) films grown on MgO(001) substrate
(2014-07-25)
Do, Hien
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Van-Truong Dai
;
Tian, Jr-Sheng
;
Yen, Tzu-Chun
;
Chang, Li
We investigate the effect of chemical composition and residual stress on the mechanical properties of high-quality epitaxial TiNxOy films deposited on MgO(001) substrates by using nanoindentation. The lattice parameters and residual strain/stress of TiNxOy films decrease as oxygen concentration increases. Hardness and Young\'s modulus determined by nanoindentation are about 17-26 GPa and 355-430 GPa, respectively, which vary with chemical composition and residual stress. (C) 2014 Elsevier B.V. All rights reserved.
Structure and property of epitaxial titanium oxynitride grown on MgO(001) substrate by pulsed laser deposition
(2013-01-15)
Do, Hien
;
Wu, Yue-Han
;
Van-Truong Dai
;
Peng, Chun-Yen
;
Yen, Tzu-Chun
High-quality epitaxial TiNxOy, films with different oxygen content were deposited on MgO(001) substrates by pulsed laser deposition method. The chemical composition of the deposited films was determined by X-ray photoelectron spectroscopy. X-ray diffraction results showed that the TiNxOy films are heteroepitaxially grown on MgO with good crystallinity and their lattice parameters decrease with increased oxygen concentration. Transmission electron microscopy analyses showed that TiNxOy films contain a low density of dislocations. Atomic force microscopy revealed very smooth surfaces of TiNxOy films with roughness of 026-0.29 nm. The resistivity of TiNxOy, films determined by Hall measurement was about 28-33 mu Omega cm. Nanoindentation measurements showed the film hardness and Young's modulus of about 23-26 GPa and 400-430 GPa, respectively. (C) 2012 Elsevier B.V. All rights reserved.