Equipe 30 : Capteurs et Nano-Capteurs
Projet de l'équipe :
1- Maitrise and development of gas sensors
The detection of toxic gas species, harmful, vital, corrosive or explosive into the atmosphere, an important area of research for industry, the environment and safety of public places. In order to remedy these requirements, it is particularly interested in the realization and mastery of gas sensors: reliable, sensitive, rapid and less expensive.
Today, semiconductor materials are widely used for developing and development of innovative gas sensors due to their excellent properties. In addition, the semiconductor metal oxides, emerging from the main types of gas sensors.
For this purpose, from metal oxides that have given promising results in this domain, we are interested in the zinc oxide "ZnO" and the oxide of tin "SnO2" who are of the family of II-VI semiconductors and n-type transparent conductive oxides "TCO". They are characterized by a large bandgap of about 3.3eV to 4.2eV and 3.6 respectively for ZnO and SnO2. ZnO crystallizes in the hexagonal type Wurtzite, tandisque the SnO2 is tetragonal lattice structure of rutile. This is justified by the compromise between the optical and electrical properties of ZnO and SnO2, their very high thermal and chemical stability, their non-toxicity and their abundance in nature and their low cost. Moreover, they exhibit a transmittance of about 90% in the visible spectrum.
These oxides, deposited as thin films can be characterized by many techniques, such as spectroscopy optical transmission UV-visible to optical characterization, the technique of two points for the electric characteristics, X-ray diffraction for structural characterization and SEM scanning electron microscopy to check the morphology of the deposit.
In order to assess the applicability of these films of oxides as gas sensors, tests of adsorption and desorption of gas will be carried out at different temperatures followed by the variation of an electrical parameter.