Synthesis And Physical Properties Of SnO₂ One-dimensional Composite Nanomaterials

SnO₂ one-dimensional nanostuctures have attracted considerable attention for their extinguished physical properties and promising applications in optoelectronic devices,gas sensors,transparent electrode, solar cell,and etc.In order to modulate and optimize the optical and electrical properties of SnO₂ one-dimensional nanostructures,synthesis and characterization of SnO₂ one-dimensional composite nanostructures based on metal-doping has become a hot subject in nanoscience and nanotechnology.In this thesis,by adjusting experimental parameters,such as pressure,distribution of temperature,evaporating velocity of source material,the oxygen density in the carrier gas,one-dimensional SnO₂ nanostructures(including nanowires,nanorods,nanobelts and nano -needles) with controllable diameters were successfully prepared by chemical vapor deposition method.Experimental results also indicate that the morphologies of SnO₂ nanostructures depend strongly on the density and gradient of Sn and O₂ near the growth point.Mo-doped SnO₂(MTO) nanowires were synthesized via an in situ doping chemical vapor deposition method.Raman scattering spectra indicate that the lattice symmetry of MTO nanowires lowers with Mo doping,which implies that Mo ions do enter into the lattice of SnO₂ nanowire.Ultraviolet-visible diffuse reflectance spectra show that the band gap of MTO nanowires decreases with the increase of Mo concentration.The photoluminescence emission of SnO₂ nanowires around 580 nm at room temperature can also be controlled accurately by Mo-doping,which is extremely sensitive to Mo ions and will disappear under the atomic ratio of 0.46%.On the basis of controllable synthesis of SnO₂ one-dimensional nanostructures,n-type and p-type semiconducting SnO₂ nanowires have been successfully synthesized by In-doping and Sb-doping.And then SnO₂ one-dimensional superlattice nanostructures have been successfully fabricated by In-doping and Sb-doping alternately during their growth.Characterization of their nanostructures and properties of which is ongoing.