Browsing by Author "Ke, Wen-Chen"

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Structural and optical properties of In-rich InGaN nanodots grown by metallo-organic chemical vapor deposition
(2007-10-10)
Tsai, Wen-Che
;
Lin, Hsuan
;
Ke, Wen-Chen
;
Chang, Wen-Hao
;
Chou, Wu-Ching
The surface morphologies, alloy compositions and emission properties of In- rich InxGa1-xN nanodots ( x >= 0.87) grown by metallo-organic chemical vapor deposition at various growth temperatures (550-750 degrees C) were investigated. We found that the nucleation of InGaN dots was dominated by the surface migration of In adatoms. A higher Ga content can be achieved at lower growth temperatures due to the relatively lower migration ability of Ga adatoms. At higher growth temperatures, the InGaN dots tend to decompose into In- rich islands and a thin Ga-rich layer. These In- rich islands exhibit photoluminescence emission in the near-infrared range. Another visible emission band was also observed for samples grown at higher temperatures. The formation of a thin Ga-rich layer is likely to be responsible for the visible emission.
Structural and optical properties of indium-rich InGaN islands
(2008)
Tsai, Wen-Che
;
Lin, Hsuan
;
Ke, Wen-Chen
;
Chang, Wen-Hao
;
Chou, Wu-Ching
Indium-rich InxGa1-xN islands (x >= 0.87) grown by metalor-ganic chemical vapor deposition at growth temperatures ranging from 550-750 degrees C were investigated. With the increasing growth temperature, the InGaN dot size increases while the dot density decreases due to the enhanced surface migration of In/Ga adatoms at elevated temperatures. In addition, the compositiom of InGaN-islands was also found to be varied with the growth temperature. At lower growth temperatures, a higher Ga content can be achieved due to the relatively lower migration ability of Ga adatoms. At higher growth temperatures, the deposited InGaN material tend to decompose into In-rich islands and a thin Ga-rich layer, Photoluminescence investigations show that these In-rich islands exhibit a near-infrared emission band . For samples grown at higher temperatures a visible emission band was also observed. The visible emission band may arise from defect hands introduced during the formation of Ga-rich InGaN layer. (c) 2008 WILEY-VCH Veriag GmbH & Co. KGaA, Weinheim.