Well-oriented pyrazine lines and arrays on Si(001) formed by thermal activation of substrate
Well-oriented pyrazine lines and arrays on Si(001) formed by thermal activation of substrate
复制标题
通过衬底热激活在 Si(001) 上形成良好取向的吡嗪线和阵列
DOI：
10.1021/jp300101t
复制
发表时间：
2012
影响因子：
3.7
通讯作者：
Masaru Shimomura
中科院分区：
文献类型：
--
作者：
Takuma Omiya;Hirokazu Yokohara;Masaru Shimomura
用扫描隧道显微镜（STM）研究了高温下在裸Si（001）表面形成的自组装分子结构。在加热的Si（001）衬底上，观察到吡嗪（C4 H4 N2）吸附物通过沿着Si二聚体键方向自组装而成的线性排列.在升高的衬底温度（160 -170 °C）下的分子的一维有序度比在室温下的分子的一维有序度提高。在较高剂量下，STM也观察到有序的（2 × 2）分子阵列。我们发现，分子往往吸附在台阶边缘和缺陷网站。利用这种在台阶边缘的选择性吸附，成功地在相邻的Si衬底上以规则的间距制备了吡嗪线。吡嗪吸附质在台阶边缘的局部结构与平台上的相同。表面上分子的有序性与吸附物可以通过高温衬底上具有N-Si键的亚稳结构迁移而不分解的事实密切相关。
Self-assembled molecular structures formed on a bare Si(001) surface at high temperature have been studied by scanning tunneling microscopy (STM). Linearly arranged pyrazine (C4H4N2) adsorbates were observed that had grown by self-assembly along the Si dimer bond direction on the heated Si(001) substrate. The degree of one-dimensional ordering of the molecules at elevated substrate temperatures (∼60–170 °C) was improved over that at room temperature. In cases of higher pyrazine dosage, well-ordered (2 × 2) molecular arrays were also observed by STM. We found that the molecules tend to adsorb on step edges and defect sites. Utilizing this selective adsorption near the step edge, pyrazine lines were successfully fabricated at regular spacing on the vicinal Si substrate. The local structure of the pyrazine adsorbate on the step edge is the same as that on the terrace. The ordering of molecules on the surface is closely related to the fact that the adsorbate can migrate without decomposition through metastable structures with a N–Si bond on the high-temperature substrate.