Novel fabrication of various size ZnO nanorods using hydrothermal method

ZnO nanorods are grown on ZnO seed layers by hydrothermal synthesis of mixture solution of zinc nitrate hexahydrate and hexamethylenetetramine. The seed layers have different sizes defined by lift-off photolithography and have different thicknesses sputter-deposited of ZnO target. Average length of the nanorods grown in a fixed time is longer for thinner seed layers than thicker ones when thickness of the seed layers is less than 400 nm. SEM images show that growth of the nanorods seems to start from the edge of the seed layer when thickness of the seed layers is less than 110 nm. It is also observed that as the width of the seed layers becomes smaller, the length and diameter of nanorods becomes larger, and it might be due to the surface energy difference between narrow and wide seed layers. XRD observation shows strong (0 0 0 2) orientation of ZnO by the hypothermal growth. (C) 2009 Elsevier B.V. All rights reserved.