| Summary: | 碩士 === 國立中興大學 === 材料工程學系所 === 95 === Abstract
In this study, hydrothermal technique was used to synthesize large-area SnO2 and In-doped SnO2 nanostructures at low temperatures.The aqueous solution consisting of SnCl4•5H2O and (NH2)2CO in presence of NaOH could form nanoblades of SnO2 on the glass substrates with a SnO2 buffer layer at 900C for 24 hours. An intense blue luminescence centered at 443.4 nm with a full width at half-maximum of 74 nm was observed in the as-grown SnO2 nanoblades. We would have seen a decrease of blue luminescence after oxygen annealing since the oxygen vacancies had been removed by chemisorbstion procedure. On the other hand, the oxygen vacancies density will increase due to desorption of surface oxygen, leading to a increase blue luminescence. From the ESR signals of the SnO2 nanoblades before and after annealing, the g value was calculated to be 2.00178, representing the paramagnetic defects in SnO2 nanoblades are single ionized oxygen vacancies, which are believed to be responsible for the intense blue luminescence. In addition to SnO2 nanoblades, In-doped SnO2 nanoblades were also synthesized on a glass substrate covered with a SnO2 buffer layer in an aqueous solution consisting of (SnCl4•5H2O+ InCl3•4H2O) and (NH2)2CO in presence of NaOH at 900C. The typical widths of the In-doped SnO2 nanoblades were about 100 nm and the lengths were about 6-10μm. From the SAED patterns, the crystalline structure of In-doped SnO2 nanoblades was confirmed to be a single crystalline rutile SnO2 structure and grows along the (100) direction. The EDS analysis attached to TEM was performed to examine the components of individual of the In-doped SnO2 nanoblades, showing the concentration of In was estimated to be around 4 at%.
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