Controlling the size, structure and orientation of semiconductor nanocrystals using metastable phase recrystallization

摘要: Materials engineering at the nanometre scale should provide smaller technological devices than are currently available1,2. In particular, research on semiconductor nanostructures with size-dependent optical and electronic properties is motivated by potential applications which include quantum-dot lasers high-speed nonlinear switches3,4. Here we describe an approach for controlling size, orientation lattice structure of nanocrystals embedded in a transparent matrix. We form nanocrystalline precipitates implanting ions into single-crystal alumina substrate applying thermal annealing5,6,7. Control over microstructure achieved using amorphization recrystallization. essence, manipulated ion beams to induce changes impurity solubility, crystal symmetry cation bonding, exert profound influence precipitates—a concept familiar metallurgy8. This can be extended exercise control virtually any type precipitate (such as metals, insulators or magnetic clusters) well epitaxial thin films.