Controlled Synthesis, Structural Evolution, and Photoluminescence Properties of Nanoscale One-Dimensional Hierarchical ZnO/ZnS Heterostructures

One-dimensional (1-D) hierarchical heterostructures have attracted much attention due to potential applications in nanoscale building blocks for future optoelectronics devices and systems. In the present article, ZnO/ZnS heterostructures have been synthesized by a controlled vapor deposition method in which all precursors are mixed together in the reaction chamber. The temperature, as well as the flow rate of the inert carrier Ar gas, plays an important role in defining the morphology of the heterostructures. The morphology and structure of as grown heterostructures have been characterized by field emission scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The microscopic results reveal that the products consist of heterostructures with a verity of morphology. The structural analysis shows that the brushlike heterostructures are composed of side-by-side and up and down interfaces between two materials. In addition, the photoluminescence spectra of the heterostructures exhibit a strong blue-shift similar to 63 nm and an increase intensity of green emission which give them potential for optoelectronics devices. Furthermore, a brief growth mechanism has also been proposed.