X射线光电子能谱法研究硅纳米线的能带结构

制备了氧辅助热分解法，以一氧化硅为原料，以氩气为载气，维持管内压强为1000Pa，在高温炉中于1250℃下反应5 h后得到硅纳米线。硅纳米线经5%氢氟酸水溶液处理5 min后，与1×10-3 mol·L-1的氯化金溶液中反应5 min，在硅纳米线的表面上修饰了金纳米粒子，用X射线粉末衍射表征了产物的结构，同时观察到单质硅和金的XRD图谱；用电子扫描和透射显微镜观察了产物的形貌，表明氧辅助方法可制得大量均匀的硅纳米线，修饰在硅纳米线上的金纳米点形状整齐，尺寸均匀，平均直径约8 nm；并用X射线光电子能谱分析了修饰过程中能带结构的变化。结果表明，金纳米粒子表面带负电，它在施主能级和受主能级上都有电子存在；由于氧杂质的存在，硅纳米线的费米能级移向价带顶。

The Study on Energy Band Structure of Silicon Nanowires with XPS

Silicon nanowires were obtained via oxide-assisted method, which was operated in a high temperature furnace at 1250 degrees C under 1000 Pa for 5 h using Ar as carrier gas. The silicon nanowires were etched with 5% HF aqueous solution for 5 min, and reacted with 1 X 10(-3) mol X L(-1) AuCL3 solution, and Au-modified silicon nanowires were obtained. The crystal structure of the products was characterized with XRD, and both of the patterns of Si and Au were observed. The morphology checked with SEM and TEM indicated large scale uniform silicon nanowires and Au particles on the surface of silicon nanowires. The average diameter of Au nanoparticls was 8 nm. The energy band structures obtained with XPS showed that gold nanoparticles are in negative charge and exist both at donor and acceptor levels. The Fermi level moved towards the top of valence band due to oxygen.