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Abstract

Hetero–epitaxial growth along three–dimensional interface from materials with intrinsic large lattice is key challenge to date. In this work, we reported for the first time on a controlled synthesis of vertically aligned ZnO/ZnS core/shell nanorod array composed of single crystalline wurtzite (WZ) structured ZnS that conformally grows on ZnO rods along the three–dimensional interface through a facile two–step thermal evaporation method. Structural characterization reveals a crystallographic epitaxial relationship between the WZ structured ZnO core and ZnS shell, which is (01-10)ZnO//(01-10)ZnS and [0001]ZnO//[0001]ZnS. Excitingly, array of single crystalline hollow ZnS nanotubes with WZ structure is also innovatively obtained by simply etching away the inner ZnO cores. On the basis of systematic structural analyses, a rational growth mechanism for the formation of hetero–epitaxial core/shell nanorods is proposed. Optical properties are also investigated via cathodoluminescence and photoluminescence measurements. Remarkably, the as-synthesized ZnO/ZnS core/shell heterostructures exhibit a greatly reduced ultraviolet emission and dramatically enhanced green emission comparing to the pure ZnO nanorods. The present single crystalline heterostructures and hollow nanotubes arrays are envisaged to be highly promising for the novel optoelectronic nanoscale devices, such as UV–A photodetectors, lasers, solar cells, and nanogenerators.