PNNL

Abstract

A gallium focused ion beam has been used to create discrete pits on the surface of a SrTiO3 (100) surface with the idea that these pits will serve as the nucleation sites for subsequent Cu2O quantum dot growth. Immediately after pit formation and following wet chemical etching and thermal annealing of the surface, the concentration of gallium within these pits has been analyzed using a high-resolution Auger system,. Using atomic force microscopy, the geometry of the pits has also been determined following etching and annealing. Growth of Cu2O quantum dots on the patterned surfaces has been performed. Growth of Cu2O quantum dots within the pits is the primary mode of dot formation. In several samples, dot growth within pits appears to occur by a two-step process with pits filling prior to initiation of a second, distinct phase of quantum dot growth above the plane of the original SrTiO3 surface.