The evolution of the local electronic structure of the $\mathrm{Si}\left(111\right)\text{−}(7\times 7)$ surface containing adatom vacancies is resolved by energy-dependent scanning tunneling microscopy. The $dI∕dV$ images show clear and rich features that are bias dependent and can be sorted into several patterns. The probed $dI∕dV$ patterns reflect the different hybridized electronic features arising from the adatom vacancies. A typical electronic state associated with the single adatom vacancy in the surface is experimentally found to be at about $0.55\mathrm{eV}$ below the Fermi energy level, which is essentially attributed to the two upward backbone atoms around the adatom vacancy. We also find that adatom vacancies can induce the images of some rest atoms to be invisible in the $dI∕dV$ maps.

• Received 2 August 2006

DOI:https://doi.org/10.1103/PhysRevB.75.085329