Ge(001) as a template for long-range assembly of π-stacked coronene rows.
Ge(001) as a template for long-range assembly of π-stacked coronene rows.
复制标题
Ge(001) 作为 π 堆叠晕苯列长程组装的模板。
作者：
J. Martínez;A. Mascaraque;Y. Dedkov;K. Horn
通过扫描隧道显微镜（STM）研究了晕苯分子（C（24）H（12））在Ge（001）表面上的吸附。在室温沉积时，晕苯分子以直立的几何形状吸附，形成成排图案的致密层，覆盖一个单层或更少，这是迄今为止研究的唯一一个纯芳烃在非钝化半导体表面上形成有序单层的例子。在半单层时，分子行由 π 堆叠分子的长链组成，分子平面之间的距离为 8 Å。将系统冷却到 Ge(001) 转变温度 (~220 K) 以下后，这种构型得以维持，但分子层也经历了从垂直于 Ge 二聚体行到平行于 Ge 二聚体行的转变。我们根据分子和基质之间的弱结合来解释我们的观察结果，这有助于形成大的有序分子域，揭示Ge(001)作为这种和其他芳香烃生长的理想模板。
The adsorption of coronene molecules (C(24)H(12)) on the Ge(001) surface has been studied by means of scanning tunnelling microscopy (STM). Upon room temperature deposition, the coronene molecules adsorb in an upright geometry forming compact layers patterned in rows for coverages of one monolayer and less, being the only example investigated so far in which a pure aromatic hydrocarbon forms a well-ordered monolayer on a non-passivated semiconductor surface. At half monolayer, the molecular rows consist of long chains of π-stacked molecules and the distance between molecular planes is 8 Å. This configuration is maintained upon cooling the system below the transition temperature of Ge(001) (~220 K), but the molecular layer experiences also a transition from rows perpendicular to rows parallel to the Ge dimer rows. We interpret our observations in terms of a weak bonging between molecules and substrate, which facilitates the formation of large ordered domains of molecules, revealing Ge(001) as an ideal template for the growth of this and other aromatic hydrocarbons.