Growth mechanism and surface atomic structure of AgInSe₂

The growth of (112)A-oriented AgInSe₂ on GaAs (111)A and its surface reconstruction were studied by scanning tunneling microscopy, atomic force microscopy, and other techniques. Films were grown by a sputtering and evaporation method. Topographic STM images reveal that the film grew by atomic incorporation into surface steps resulting from screw dislocations on the surface. The screw dislocation density was ∼10¹⁰ cm². Atomically resolved images also show that the surface atomic arrangement appears to be similar to that of the bulk, with a spacing of 0.35–0.41 nm. There is no observable reconstruction, which is unexpected for a polar semiconductor surface.