ZnO multipods, submicron wires, and spherical structures and their unique field emission behavior.
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.
Ramgir
Niranjan S
NS
Physical and Materials Chemistry Division, National Chemical Laboratory, Pune 411008, India.
Late
Dattatray J
DJ
Bhise
Ashok B
AB
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Mahendra A
MA
Mulla
Imtiaz S
IS
Joag
Dilip S
DS
Vijayamohanan
K
K