Remotely Controlling the Charge State of Oxygen Adatoms on a Rutile TiO2 (110) Surface Using Atomic Force Microscopy

摘要

Remotely controlling the charge state plays a key role in an oxidized rutile TiO2 (110) surface, which determines the nanoscale properties of photooxidation reactions. However, the remote charging mechanism of the oxygen adatoms has not been investigated. Here, we demonstrate that the remote injection/removal of electrons into/from oxygen adatoms can reversibly switch the charge state. Moreover, we found that the injection of an electron into O-ad(-) (oxygen adatom with one negative charge) forms a clear circular distribution of O-ad(2-) (oxygen adatom with two negative charges). This observation can be explained by the radial propagation of electrons to Q(ad)(-) via an electric field. By creating individual defects with the atomic force microscopy (AFM) tip, the additional oxygen vacancy can also induce the remote charging. Our results will pave the way for controlling the charge state at the spatial distance on the semiconductor surface.