Crystallographically-oriented nanoassembly by ZnS tricrystals and subsequent three-dimensional epitaxy

Abstract

Chemistry gives us the ability to manipulate atoms and molecules into nanometer and micrometer scale building blocks, while the science of crystallography is concerned with the spatial arrangement of atoms, ions, and molecules and thus the morphology and structures of materials. Complex three-dimensional ZnS nanostructures have been fabricated via step-by-step crystallographically-controlled chemical processes. Tricrystals of ZnS whiskers were prepared via a controlled thermal evaporation process, and then the tricrystals were thermally treated in an atmosphere formed by evaporating B-N-O precursors into N2/NH3 to afford BN-coated arrays of nanobranches. The ZnS nanobranches grew epitaxially on the ternary facets and extended in three [0001] directions forming ordered nanostructures. Meanwhile, the protecting insulating sheath of BN formed on the ZnS nanostructures confined the growth of the nanospines and enhanced their stability. The method may be extended to fabricate other semiconductor nanomaterials with novel structures.