A general combustion approach to multipod ZnO and its characterization

By a general approach of combustion oxidation at high temperature, multipod ZnO was synthesized without any catalysts or additives. The morphology and optical properties of the multipod ZnO were studied in detail. The growth mechanism was discussed preliminarily. An ultraviolet (UV) emission peak at 374 nm and a broad green emission peak centered at 502 nm are observed in photoluminescence spectrum of the multipod ZnO. The multipod structure exhibits significant enhancement of UV emission intensity and green light emission intensity compared with the tetrapod structure, which are attributed to less structural defects and increased surface area respectively. Furthermore, compared with nano-particle and micro-particle ZnO, UV emission peak of multipod ZnO appears a slight blue shift. Due to slim tips of the legs, quantum size effect cause a slight blue shift of UV emission peak. We believe that these optical properties of the multipod structure have extensive applications in nanoscale optical devices.