Phase transition of the Si(111)-4x1-In surface reconstruction investigated by electron transport measurements

摘要

We measure the electron conductivity of the surface states and the subsurfacespace charge layer originating from the Si(111)-4x1-In reconstruction as afunction of temperature. The conductivity of the surface states drops sharplyaround 130 K with decreasing temperature, revealing a metal-insulator phasetransition of the surface reconstruction. In contrast, the influence of thephase transition on the conductivity of the space charge layer is limited totemperatures above 60 K. This means that the surface Fermi level remainsstrongly pinned despite the phase transition, indicating the presence of freecarriers in the surface states down to rather low temperatures.