Hydrothermal Synthesis, Characterization and Optical Property of Single Crystal ZnO Nanorods Prabhakar Rai, Suraj Kumar Tripathy, Nam-Hee Park, Yeon-Tae Yu * Division of Advanced Materials Engineering and Research Centre for Advanced Materials Development, College of Engineering, Chonbuk National University, Jeonju 561-756, South Korea * Corresponding author: Y. T. Yu (E-Mail: yeontae@chonbuk.ac.kr, Tel: +82-63-270-2288, Fax: +82-63- 270-2305) Abstract: ZnO nanorods of 100±10 nm in diameter and 900±100 nm in length were synthesized by cetyl trimethylammonium bromide (CTAB) assisted hydrothermal technique from a single molecular precursor. The influence of pH on morphology and PL property of ZnO nanorods were investigated. The phase and structural analysis were carried out by X-ray diffraction. Morphology of the nanorods was investigated by electron microscopy techniques. Optical properties were investigated by photoluminescence spectroscopy. As prepared ZnO nanorods have been single crystalline without defect and shown intense room temperature photoluminescence peak in the ultraviolet region. Keywords: Electron microscopy, hydrothermal, luminescence, ZnO nanorods PACS: 68.37.Hk, 81.16.Be, 78.55.Qr, 61.46.Km INTRODUCTION ZnO, a wide band-gap (E g 3.37 eV) II-VI semiconductor material possesses interesting optical, dielectric and catalytic properties that make it suitable for various industrial applications such as pigments [1], dye-sensitized solar cells [2], photocatalysts [3] and sensors [4]. However, ZnO-based materials have immense prospects for high temperature optoelectronic applications due to its high exciton-binding energy (60 meV) and high optical gain (320 cm -1 ) at room temperature. Recently, intensive research has been focused on fabricating one-dimensional (1D) ZnO nanostructures such as nanotubes, nanowires (rods), and nanobelts (rings) due to their shape induced novel properties and potential applications [5–7].The large surface area of the nanorods make them attractive for gas and chemical sensing, and ability to control their nucleation sites makes them candidates for micro lasers and memory arrays. Since a long time ago various physical and chemical synthetic techniques have been investigated to explore the material quality of ZnO of diverse morphology for fabrication of devices such as blue lasers and ultraviolet light emitting diodes [8]. Hydrothermal synthesis has emerged as a simple route for the processing of transition metal oxides [9]. Hydrothermal growth of ZnO crystals with variable, yet controllable, morphologies has been reported widely [10,11]. The growth habit of ZnO is determined mainly by the internal structure of the crystal, but is also sensitive to a number of external conditions such as pH, the zinc source (and its counterion), the presence (or not) of any complexing agent, the nucleation conditions (including effects due to the presence of a substrate), the extent of super-saturation, etc. Vernadou and co-workers have investigated the pH effect on the morphology of the ZnO CPU 47, Transport and Optical Properties ofNanomaterials—ICTOPON - 2009, edited by M. R. Singh and R. H. Lipson © 2009 American Institute of Physics 978-0-7354-0684-l/09/$25.00 152 Downloaded 18 Sep 2009 to 203.254.159.101. Redistribution subject to AIP license or copyright; see http://proceedings.aip.org/proceedings/cpcr.jsp