Abstract
The electronic structure of the Si(110)-() surface was studied by scanning tunneling microscopy at room temperature (RT) and at 78 K. A combination of point tunneling spectroscopy measurements and local density of states mappings reveal details of the electronic structure of the () reconstruction both in empty and occupied states. Point tunneling spectra show a small band gap indicating that Si(110)-() is a semiconductor. The pentagon, which is the main building block in the Si(110)-() surface, consists of at least four electronic states. The pentagon in empty states is created by the superposition of two states with different origins: a four-lobed pattern similar to that observed in filled states; and another state that causes splitting of one of the lobes. The 78 K data show that the band responsible for the four-lobed shape in filled states (located at 0.2 eV) splits further. We present a very simple structure, calculated by density functional theory, which partially explains the experimental data.
- Received 13 March 2011
DOI:https://doi.org/10.1103/PhysRevB.84.115317
©2011 American Physical Society