Ab initio Studies of Indium Clustering on the Ge(111)-5x5 Surface

Abstract

This thesis reports an \textit{ab initio} study of the Ge(111)-5$\times$5 reconstruction, which forms on top of a Si(111)-7$\times$7 substrate. Detailed descriptions of the structural and electronic properties of this surface, obtained from density-functional calculations, are presented and analyzed. A study of In clusters on this surface is performed, and compared with recent experimental work on this system. The effect of surface strain as well as the issue of the Si-Ge interface is addressed. Also, a preliminary investigation of some dynamical aspects of an In atom on the 5$\times$5 surface is presented.