Preparation and characterization of highly oriented ZnO single crystal submicrorod arrays

Highly oriented ZnO submicrorod arrays have been prepared on SnO₂ conducting glass substrates which were modified with densely packed ZnO crystal nucleus. The growth procedure of ZnO submicrorod arrays consists of two steps: (1) modification of SnO₂ conducting glass substrates with dispersed ZnO crystal nucleus by immersing the substrates into concentrated solution, and (2) hydrothermal growth of ZnO submicrorods in aqueous solution. Scanning electron microscope (SEM), selected area electron diffraction(SAED) and X-ray diffraction (XRD) have been employed to investigate the ZnO submicrorod arrays. SEM images indicate that ZnO hexagonal submicrorod arrays grow nearly perpendicularly to the substrates. The diameter and the length of ZnO submicrorod are about 400-500 nm and 2 μm for 2 h growth time, respectively. Result of SAED reveals that the ZnO submicrorod arrays are single-crystalline hexagonal rods. XRD shows that the ZnO submicrorods are wurtzite. The significantly higher intensity obtained from the (002) diffraction peak indicates that the submicrorods are preferentially oriented in the c-axis direction (grown along the [001] crystallographic face direction).