银纳米线在Si(5512)表面上自组装(英文)

由于银不会在硅表面与硅形成任何硅化物,银线成为在具有排状结构的Si(5512)表面自组装纳米线的候选材料。本研究试用不同的银覆盖度和退火温度制作高纵横比的银纳米线。当覆盖度为0.1单原子层,先后两次退火温度分别为500℃和600～700℃,经缓慢冷却过程,非常规则的银链优先吸附在Si(5512)面的四聚体上,从而形成高纵横比的银纳米线。这一自组装的两步退火过程可理解为:低温退火使吸附的银原子与Si表面结合;高温退火提供银原子扩散到Si表面四聚体位置的能量。

Ag nanowires self-assembling on Si (5 5 12) surfaces

As Ag can not form any silicide on Si surfaces, Ag wire is a candidate for self-assembled nanowire on row-like Si (5 5 12) -2×1 surfaces. In the present study, various Ag cov-erages and post-annealing temperatures had been tested to fabricate Ag nanowires with high as-pect ratio. When Ag coverage was 0.1 ML and the post-annealing temperature was around 500 ℃,the additional subsequent annealing at 600-700 ℃ and slow-cooling process, the well-ordered Agchains preferentially adsorbed on the tetramer sites, resulting in Ag nanowires with relatively highaspect ratio. It can be understood that, in the double step annealing process, the lower tempera-ture annealing is required for cohesion of adsorbed Ag atoms and the higher temperature anneal-ing is for providing Ag atoms to the tetramer sites.