Effect of Position of Substrate in Morphology of ZnO Nanowires Grown via VLS Mechanism

ZnO is an n-type semiconductor which considered in electronics, photonics and optoelectronics because of its wide direct band gap (3.37 eV) and its large exciton binding energy (63 meV). Recently ZnO nanowires are considered because of their higher charge carrier concentration and also increase in their exciton binding energy. Application potential of these nanowires has been led to increase of importance of their fabrication methods [1]. Today’s VLS (Vapor/Liquid/Solid) method due to its numerous advantages, such as simplicity and its low-cost, has been known as most expanding method to fabricate ZnO nanowires. In this work, we have studied effect of location of substrate in the growth tube as one of more important parameters in the final morphology of nanowires