Spirkoska D, Abstreiter G, Fontcuberta I Morral A
Walter Schottky Institut, Technische Universität München, Am Coulombwall 3, D-85748 Garching, Germany.
Nanotechnology. 2008 Oct 29;19(43):435704. doi: 10.1088/0957-4484/19/43/435704. Epub 2008 Sep 22.
Gallium arsenide nanowires were synthesized by gallium-assisted molecular beam epitaxy. By varying the growth time, nanowires with diameters ranging from 30 to 160 nm were obtained. Raman spectra of the nanowire ensembles were measured. The small linewidth of the optical phonon modes agree with an excellent crystalline quality. A surface phonon mode was also revealed, as a shoulder at lower frequencies of the longitudinal optical mode. In agreement with the theory, the surface mode shifts to lower wavenumbers when the diameter of the nanowires is decreased or the environment dielectric constant increased.
通过镓辅助分子束外延法合成了砷化镓纳米线。通过改变生长时间，获得了直径范围为30至160纳米的纳米线。测量了纳米线集合体的拉曼光谱。光学声子模式的小线宽与优异的晶体质量相符。还揭示了一种表面声子模式，作为纵向光学模式较低频率处的一个肩峰。与理论一致，当纳米线直径减小或环境介电常数增加时，表面模式向更低波数移动。
