ZnO is a wide band gap semiconductor (3.37 eV) with higher excitation banding energy of 60 meV. ZnO one-dimensional materials have stimulated much attention due to the promising potentials in extensive applications

ranging form surface acoustic wave filters

optoelectronic devices

and light-emitting diodes. Many techniques have been used to grow ZnO nanowires

such as pulsed laser deposition

metal-organic chemical vapor deposition and template against anodic alumina membrane. Among the various techniques VLS (vapor-liquid-solid) method is favored for the simplicity and high quality products. This method often uses some of catalysts such as Au

Cu

Sn or other additives assist are often used in this method to control the growth process. There were reports about the syntheses of 1D ZnO nanowires arrays via a VLS process. However there is still the difficult problems about the controllable growth of the ZnOnanowires. We obtained ZnOnanowires through VLS method and researched controllability and growth mechanism of ZnO nanowires. ZnO powders were used as source material and the experiment was performed in a horizontal tube furnace. ZnO powders were spread in an alumina boat and place at the center of the furnace tube with temperature of 1350℃. Si(100) substrate covered with Ag catalysts was put down stream with the temperature of 400~800℃ for 30 min. Ar gas (40 sccm: standard cubic centimeter mass) was used as the carrier gas. The prepared nanowires were investigated by X-ray diffraction. The morphology and size distribution of the nanowires were characterized using SEM. Clearly the ZnO nanowires grown at substrate temperature ringing 600~700℃ are highly crystallized and exhibit a typical wurtzite structure. SEM showed that temperature of substrate has important influence on diameter and length of the ZnO nanowires. It was controllable that we can realize the ZnO nanowires growth through the catalyst and temperature. We have not seen that catalyst particle is on the top of ZnO nanowires

it is different from traditional VLS mechanism. The growth mechanism of ZnO nanowires was proposed.