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| Author(s): |
Mateus Gallucci Masteghin
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Araraquara. 2018-06-28. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Química. Araraquara |
| Defense date: | 2018-06-06 |
| Advisor: | Marcelo Ornaghi Orlandi |
| Abstract | |
In the following work, it was carried out a study in order to understand the transport mechanisms and the gas-solid interactions that occur on the surface of SnO, Sn3O4, and SnO2 nanostructures, made-up over different devices. As the main goal of a better understanding regarding involved interaction phenomena, it was chosen to study the nanostructures individually (single-element devices) and as multiple structures (carpet mode devices), in which the former allows to discard extrinsic interferences, such as potential Schottky-type barriers as a result of the semiconductor/semiconductor contact, and in the most of the cases when dealing with single-element devices, without the possible metal/semiconductor non-ohmic contact. Thus, the materials were synthesized by the carbothermal reduction method and characterized by XRD, Raman Spectroscopy, UV-Vis light measurements, and SEM-FEG. The materials were investigated as gas sensors, using oxidizing and reducing gases (such as NO2 and CO) in low concentration levels (ppm), and with working temperatures ranging from 100 °C to 300 °C. These working temperatures were reached using the conventional heating and the self-heating methods, the latter being advantageous for not requiring an external source to the heating, resulting in low dissipated power and allowing higher mobility when seeking for in-situ leakage detections. The highlighted contributions from this work are the Sn3O4 nanobelts and SnO micro-disks characterization as single-element gas sensor devices and the study of different diameters of the same material (nanobelts with same oxidation state), that allowed to calculate the depletion layer length (Debye length) for each stoichiometry; besides the use of the self-heating method in the gas sensor study of SnO and Sn3O4. In the end, the author wishes that all the study performed allows the development of gas sensor devices with high sensitivity, selectivity, fast response and recovery times, and the miniaturization capability. (AU) | |
| FAPESP's process: | 15/21033-0 - Comparison of the gas sensor response of devices with single and multiple tin oxide nanobelts |
| Grantee: | Mateus Gallucci Masteghin |
| Support Opportunities: | Scholarships in Brazil - Master |