扫描隧道显微镜功能化针尖对分子能级的选择成像

Selective analysis of molecular states by functionalized scanning tunneling microscope tips

摘要: 文章提出了一种通过修饰STM针尖使其功能化，调节扫描隧道显微镜(STM)的扫描偏压范围，实现对分子能级的选择性成像的方法.二萘嵌苯分子在Ag(110)表面上自组织形成的有序单层膜主要是通过分子的π电子态成像，而被二萘嵌苯分子修饰的STM针尖的能级失配于基底上吸附的分子的能级，从而只对分子的部分能级成像.这个结果为有机界面电子输运测量提供了一种更好的能级选择方法.

Abstract: Selective analysis of molecular states in scanning tunneling microscopy (STM) has so far been achieved in a few cases by tuning the bias range of the STM in high resolution measurements. Perylene adsorbed on Ag(110) is imaged mainly through the π-states of the molecule. By functionalizing the STM tip with a perylene molecule a mismatch is created between the energy levels of the STM tip and the molecule adsorbates, so that only the metal states of the underlying silver surface are imaged. This method opens a route for better energy selectivity in electron transport measurements through organic interfaces.