ZnO nanorod growth by chemical bath method

Abstract

Controlled growth of ZnO nanorods on various substrates is of great interest in photonic and electronic device applications. Among the various growth techniques developed, wet chemical processes hold great promise as a low cost, low temperature deposition technique. In this study we report properties of ZnO nanorods grown on indium tin oxide coated glass substrates by heating an equimolar solution of zinc (II) nitrate and hexamethylenetetramine solution. The morphology of ZnO nanorods exhibited both open and closed hexagonal shapes under various deposition conditions above 90°C. At 95°C, growth of equimolar ratio of zinc (II) nitrate and hexamethylenetetramine after 4h examined by scanning electron microscope exhibited mainly open hexagonal structures. The same equimolar ratio at 95°C grown at 9h and longer duration of chemical bath exhibited closed hexagonal structure. The ratio of the open area of nanorods to the closed surface decreases dramatically as the deposition time is increased from 4h to 26h. Peak shape analysis of ZnO nanorods under X-ray diffraction spectrum suggests average crystallite size domains of 200 nanometers. Surface morphology measured using Atomic Force Microscope (AFM) indicates that the 26h sample is slightly rougher than the 4h grown ZnO sample.