2 resultados para La Chapelle, Armand Boisbeleau de, 1676-1746,
em Chinese Academy of Sciences Institutional Repositories Grid Portal
Resumo:
A complete Raman study of GaP nanowires is presented. By comparison with the Raman spectra of GaP bulk material, microcrystals and nanoparticles, we give evidence that the Raman spectrum is affected by the one-dimensional shape of the nanowires. The Raman spectrum is sensitive to the polarization of the laser light. A specific shape of the overtones located between 600 and 800 cm(-1) is actually a signature of the nanowires. Some phonon confinement and thermal behavior is also observed for nanowires.
Resumo:
报道了用纳米碳管模板法制备的GaP纳米棒的拉曼光谱特征,观测到声子限制效应引起的GaP纳米棒TO和LO模的红移,红移量一般在2-10cm^-1之间,与所测到的纳米棒的尺寸有关,在偏振特性研究中,发现GaP纳米棒的偏振特性不能用单根纳米棒的选择定则来解释,而与测量光斑内多根纳米棒的无序取向有关,无序程度越高,偏振特性的方向性越弱,当激发光功率增加时,GaP纳米棒的TO和LO模的频率显著减少,表明纳米棒中的激光加热效应比体材料中强很多,而且GaP纳米棒的拉曼散射强度随激发光功率的增加先饱和,然后减小,表明在强激发功率下GaP纳米棒中的缺陷会迅速增加。