Abstract
The electronic transport properties of the Si(111)--Sn surface formed on the low-doped Si substrates are studied using two-probe conductivity measurements and tunneling spectroscopy. We demonstrate that the ground state corresponds to a Mott-Hubbard insulator with a band gap of , which vanishes quickly upon the temperature increase at . The energy gap at the Fermi level observed in tunneling spectroscopy measurements at higher temperatures could be described in terms of the dynamic Coulomb blockade approximation. The temperature dependence of the surface conductivity above 45 K corresponds to the Efros-Shklovskii hopping conduction law. The obtained localization length of the electron is .
- Received 15 December 2016
- Revised 31 March 2017
DOI:https://doi.org/10.1103/PhysRevB.95.195151
©2017 American Physical Society