Low temperature phases of Pb/Si(111) and related surfaces

We present an extensive first-principles study of the structural and electronic properties of the Pb/Si(111) surface. We start from the low coverages cases, and we examine all the possible structural and electronic instabilities that may drive the system towards low temperature phase transitions. We then move to the higher coverage case and study the energetics of some possible surface reconstructions and analyze in details the structural and bonding properties of the surface. Finally, we also investigate coadsorbtion of (Pb, Sn) on the Si(111) and identify the most stable reconstruction through a comparison with available experimental data. For all the structures considered we analyze in detail the electronic and bonding properties, adding more insights to the complex scenario of the physics of groups IV adsorbates on group IV(111) surfaces. (C) 2007 Elsevier B.V. All rights reserved.