Preparation Of SnO₂Nanostructures With SnO₂Powder And Study On Luminescence Properties

Nano science and technology has been recognized as one of the most importantscience and technology in the21st century. The semiconductor materials will havesurface effect, small size effect, quantum size effect,and macroscopic quantum tunneleffect when its size reaches nanometer order of magnitude.And the special qualities ledthe semiconductor nanomaterials show the peculiar physical and chemical properties. Sothey were widely used in pressure sensitive resistance, quantum components, conductivematerials and some other aspects. As a kind of wide band gap n-type semiconductormaterials, tin oxide have important research value. In this paper,we have synthesizeddifferent morphology of tin oxide nanostructures by chemical vapor deposition (CVD)with SnO2powder as raw materia. The morphology and size of SnO2nanostructureswere changed by different conditions, such as temperature, annealing time. Themorphology, structure and luminescence properties of samples were characterized byscanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-raydiffraction (XRD), X-ray energy spectrum analysis (EDS) and optical luminescence (PL)technique. And the growth mechanism was also discussed. The details of this article are summarizedbriefly as follows：(1) With a mixture of SnO2powder and graphite powder as the source material, SnO2nanoparticles were prepared on the single-crystal Si substrate splashed with Au by CVDat900℃under a flow of high-purity N2as carrier gas. The diameter of SnO2nanoparticles is around300-800nm. The surface topography of samples were observedby SEM and the XRD of the samples to the structure characterization indicated that thepreparation of SnO2particles is quartet rutile structure. The luminescencecharacteristics of samples were analyzed by PL technology at room temperature, and thePhotoluminescence peaks appeared at399nm,450nm,550nm and613nm,whichshowed good luminescence properties, expecting to be used in the application ofelectronic devices. And then the formation mechanism of SnO2particles was discussed. (2) With a mixture of SnO2powder and graphite powder as the source material, rutilestructure SnO2nanowires were prepared on the single-crystal Si substrate splashed withAu by CVD at1000℃under a flow of high-purity N2as carrier gas. The growth processof SnO2nano-wires was recreated by controlling the annealing time. The growthmechanism conforms to the VLS mechanism. The luminescence characteristics ofsamples were analyzed by PL technology at room temperature, and thePhotoluminescence peaks appeared at358nm、372nm、399nm、451nm、468nm、515nm、550nm、572nm、613nm. And a new pesk appeared at672nm.(3) With a mixture of SnO2powder and Sn powder as source and graphite powder asthe reducing agent, rutile structure SnO2nanowires have been successfully synthesizedby CVD at1000℃annealing for90min. The preparation of SnO2nanowires is verystraight and up to dozens of micrometers. And small circular particles was at the top ofthe nanowires which indicated that its growth follows the VLS growth mechanism. Witha mixture of SnO2powder and Sn powder as source and graphite powder as the reducingagent, the bead of SnO2nanorods have benen prepared by CVD at1050℃annealingfor90min. The nanorods were single-crystalline structure. Only four elements(C, Si, O,Sn) were measured from the sample by EDS corresponding to the result of XRD. ThePhotoluminescence peaks of one dimensional nanostructure appeared at370nm,470nm,570nm and610nm.