ROOM TEMPERATURE AND ELEVATED TEMPERATURE CHARACTERIZATION OF NANOCRYSTALLINE SnO2 SURFACES BY SCANNING TUNNELING MICROSCOPY AND SPECTROSCOPY
| Autor: | G.T. Owen, M. K. Kennedy, G. Martinelli, Thierry G.G. Maffeis, Frank Einar Kruis, S. P. Wilks, C. Malagù |
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| Rok vydání: | 2004 |
| Předmět: |
Materials science
Band gap business.industry Nanoparticle Bioengineering Nanotechnology Condensed Matter Physics Nanocrystalline material Computer Science Applications law.invention Semiconductor law Density of states Optoelectronics General Materials Science Electrical and Electronic Engineering Scanning tunneling microscope business Spectroscopy Biotechnology Surface states |
| Zdroj: | International Journal of Nanoscience. :519-524 |
| ISSN: | 1793-5350 0219-581X |
| DOI: | 10.1142/s0219581x04002322 |
| Popis: | Semiconductor gas sensors based on nanocrystalline SnO 2 offer many advantages over current technologies for detecting reducing gases, such as low cost, long lifetime, and high selectivity and sensitivity. However, the local surface properties on the nanoscale of SnO 2 nanocrystals are not fully understood, which impedes the exploitation of the full potential of SnO 2 for gas sensing applications. In this paper, we present a scanning tunneling microscopy and spectroscopy (STM/STS) study of nanocrystalline SnO 2 at room temperature, and under standard sensing conditions at 120°C. STS data indicate that the electronic surface properties change with nanoparticle size, temperature and exposure to gas. The surface density of states in the band gap is shown to increase with temperature while CO exposures induce a large drop in the density of band gap states as the CO molecules react with chemisorbed oxygen species. |
| Databáze: | OpenAIRE |
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