关键词: 氧化锌纳米带, 晶体生长, 固-气机理, 纳米结构, 光致发光

Abstract: Uniform ZnO nanobelts and toothed-nanobelts were synthesized respectively through pure zinc powder evaporation without catalyst at temperature of 600 ℃. In each processing, the total gas flow rate of argon and oxygen was 200～300 cm³•min^－1, and the fraction of oxygen was 1％～5％ according to changes of the conditions. The experiments indicated that the key of the preparation method is to control the flow rates and partial pressures of argon, oxygen, and zinc vapor. The flow rates and partial pressures influenced the size of nanostructures, and more sensitively determined the belts with or without teeth. 　　Scanning electron microscopy (SEM) observations showed that the fabricated ZnO nanobelts had several types in morphology. The high-resolution transmission electron microscopy (HRTEM) images and selected area electron diffraction (SAED) patterns revealed that the ZnO nanobelts were single crystalline. HRTEM images and SAED patterns also suggested that the teeth of the toothed-nanobelts grew along the [0001] or [2110] direction, i. e., the teeth of such belts may grow in “c” or “a” direction, the backbones of the belts may grow in “a” or “c” direction accordingly. X-ray diffraction (XRD) investigations on the structures showed that all the deposited nanobelts on the silicon substrate were pure ZnO with hexagonal wurtzite structure. Investigations through HRTEM and XRD indicated that the growth of ZnO nanobelts was controlled by vapor-solid (VS) mechanism. 　　Photoluminescence(PL) spectrum of ZnO toothed-nanobelts at room temperature was measured and showed a UV emission at ～390 nm and a broad green emission with 4 subordinate peaks at 455～495 nm.

Key words: ZnO nanobelts, Crystal growth, Vapor-solid mechanism, Nanostructures, Photoluminescence