ANION-TERMINATED ZINCBLENDE CDS(100) SURFACE

Using the local-orbital density-functional molecular-dynamics method, we have studied the surface structure of the strain-stabilized zinc-bl ende monolayer anion-terrainated CdS(100) surface. By analogy with the GaAs(100) surface, we have considered four structural models and foun d that the structure with a (2 x 4) unit cell, in which there are a tw o-dimer unit and a two-shifted-dimer unit, is the most favorable. Thes e results can be understood in terms of physical properties associated with ionicity.