Seed-catalyzed heteroepitaxial growth and nonlinear optical properties of zinc selenide nanowires

Seed-catalyzed, heteroepitaxial growth of high aspect-ratio, uniform ZnSe nanowires is reported, in which Ag2Se nanoparticles serve as heterogeneous seeds and as epitaxial substrates. Due to the difference in solubility product constants (Ksp: Ag2Se ≪ ZnSe), Ag2Se is precipitated before ZnSe and in situ seeds and catalyzes the nanowire growth in a one-pot solution synthesis. The lattice match between metastable tetragonal Ag2Se{212} and cubic ZnSe{220} planes facilitates the heteroepitaxial growth of ZnSe nanowires. Conversion of small, uniform Ag particles, which are produced from the reduction of Ag+ ions by reductants/surfactants such as polyvinyl pyrrolidone (PVP) and oleylamine (OA), into Ag2Se with small size and high uniformity is shown to be an effective strategy to control the diameter size and distribution of ZnSe nanowires. The third-order nonlinear optical behavior of the as-prepared nanowires has been evaluated by Z-scan measurements.