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.
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。