The Growth And Properties Of The Ultralong Tin Oxide Nanowires

SnO₂is a kind of semiconductor oxide materials, Which has the extensiveapplication in the fields of electronics, optics, sensors etc. In recent years, with thedevelopment of nanometer materials, SnO₂nanomaterials show potential developmentprospects in the field of above. At present, The growth of the ultralong Tin Oxidenanowires is reported rarely, and has the repetitive problems, that Can hinder theapplications of the SnO₂one-dimensional nanomaterials in the fields of electronic andoptical electronics.In this paper, the author is using a vapour transportation method. The ultralongtin oxide （SnO₂） nanowires were grown on the substrate using vapour transportationmethod and the vapor-liquid-soild mechanism in the temperature of900℃. In thisprocess, the carrier gas are chosen to be the mixture of N2and O2, that N2acts asprotection gas and O2as the reaction gas. The morphology and structure of theproducts were characterized by scanning electron microscopy, transmission electronmicroscopy, X-ray diffraction etc. It indicted that the length of the SnO₂nanowirescould be over200m, and some were even up to several millmetres, and the widthscan be300nm to several micrometres, and the thicknesses were50nm to200nm. Atthe same time, According to the results of scanning electron microscopy, the goldparticles at the top of the nanowire can judge that the ultralong SnO₂nanowiresgrowth mechanism is the VLS mechanism. The results of Transmission electronmicroscope showed that nanowire growth direction was [101]. the results of X-raydiffraction （XRD） showed that the obtained nanowires was tetragonal rutile structure.The results of I-V characteristic curve showed that The resistivity of intrinsic SnO₂nanowires was high, so when SnO₂nanowires are used as electrode, they are usuallyreduced the resistivity by doping. The results of transmission test showed that theluminousness of SnO₂nanowires was the best in the infrared region，which can evenreach95%. In addition, This paper studied the effect of oxygen concentration,pressure and catalyst on the growth of SnO₂nanowires by using control variablemethod, a series of gradient tests. The results indicated that oxygen concentration hadlittle effect on the growth within a certain range. With the increase of the pressure,nanowires gradually widened. There is the catalyst or not, that not only affects the growth mechanism of SnO₂nanowires,but also the morphology and structure. Usingcatalyst showed that the growth mechanism of nanowires was the VLS mechanism,and that reduced the experimental requirements, at the same time,it could be alsomore easy to grow the ultralong SnO₂nanowires.