title: ZnO multipods, submicron wires, and spherical structures and their unique field emission behavior.
abstract: A simple method of vapor deposition for the shape selective synthesis of ZnO structures, namely, multipods, submicron wires, and spheres, has been successfully demonstrated. A plausible growth mechanism based on the studies of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) is proposed. Our studies suggest that the growth of a multipod structure is governed by the screw dislocation propagation while the vapor-liquid-solid (VLS) mechanism is responsible for the formation of submicron wires and spheres. Moreover, the flow rate of the carrier gas plays a crucial role in governing the morphology. Further, these structures exhibit an enhanced field emission behavior. The nonlinearity in the Fowler-Nordheim (F-N) plot, a characteristic feature of electron emission from semiconductors, is explained by considering the contributions from both the conduction and the valence bands of ZnO.
authors.affiliation: Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008, India.
authors.forename: Niranjan S
authors.initials: NS
authors.lastname: Ramgir
authors.forename: Dattatray J
authors.initials: DJ
authors.lastname: Late
authors.forename: Ashok B
authors.initials: AB
authors.lastname: Bhise
authors.forename: Mahendra A
authors.initials: MA
authors.lastname: More
authors.forename: Imtiaz S
authors.initials: IS
authors.lastname: Mulla
authors.forename: Dilip S
authors.initials: DS
authors.lastname: Joag
authors.forename: K
authors.initials: K
authors.lastname: Vijayamohanan