Surface rotational phonon and its role in the reconstruction of cleavage surfaces of tetrahedrally coordinated compound semiconductors.

Abstract

Total-energy calculations reveal that the coupling between the surface dangling-bond charge and a surface rotational phonon mode may be regarded as the driving force for the reconstruction of the cleavage faces of both zinc-blende and wurtzite-structure compound semiconductors. In the incompressible-bond limit this coupling results in an ${\mathrm{sp}}^{2}$ planar bonding configuration for the top-layer cations at the (110) surfaces of zinc-blende structure materials as well as the (101\ifmmode\bar\else\textasciimacron\fi{}0) and (112\ifmmode\bar\else\textasciimacron\fi{}0) surfaces of wurtzite-structure materials, independent of the details of their electronic structure. The frequencies of the surface rotational phonon mode are calculated for the wurtzite (101\ifmmode\bar\else\textasciimacron\fi{}0) surfaces of ZnO, ZnS, ZnSe, CdS, and CdSe.