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Chemical Synthesis, Characterization and Gas-Sensing Properties of Thin Films in the In2O3-SnO2 System

Published online by Cambridge University Press:  01 February 2011

Mauro Epifani
Affiliation:
CNR, Istituto per la Microelettronica ed i Microsistemi, Sezione di Lecce, via Arnesano, 73100 Lecce, Italy
Raül Díaz
Affiliation:
Universitat de Barcelona, Departament d'Electrònica, C. Martí i Franqués 1, 08028 Barcelona, Spain
Antonella Taurino
Affiliation:
CNR, Istituto per la Microelettronica ed i Microsistemi, Sezione di Lecce, via Arnesano, 73100 Lecce, Italy
Luca Francioso
Affiliation:
CNR, Istituto per la Microelettronica ed i Microsistemi, Sezione di Lecce, via Arnesano, 73100 Lecce, Italy
Pietro Siciliano
Affiliation:
CNR, Istituto per la Microelettronica ed i Microsistemi, Sezione di Lecce, via Arnesano, 73100 Lecce, Italy
Joan R. Morante
Affiliation:
Universitat de Barcelona, Departament d'Electrònica, C. Martí i Franqués 1, 08028 Barcelona, Spain
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Abstract

Thin films in the SnO2-In2O3 system, with relative concentrations of the two oxides ranging from 2% to 98% (molar percentage of the oxide), were deposited by sol-gel and solution processes. The films for the physical characterizations were deposited onto oxidized silicon substrates, while the films for the gas-sensing tests were deposited onto alumina. The starting solutions were characterized by FTIR spectroscopy, while the films on silicon, heated at various temperatures, were characterized by X-ray diffraction and SEM observations. The interaction between the two systems is particularly evident in the case of the system described by a 50% In2O3-50% SnO2 nominal composition. The crystallization on In2O3 during the film heat-treatment hinders the crystallization of SnO2, thus Sn is dispersed as an n-dopant in the In2O3 lattice, indeed showing a current signal, in the gas-sensing test, two orders of magnitude higher than the pure film. The response of the mixed-oxide based device to NO2 is better than pure In2O3. On the other hand, the response (relative resistance change) of pure SnO2 to low (from 0.1 to 1 ppm) NO2 concentrations ranges from 150 to 300, a result that can be correlated with the nanostructure of the film, which, from SEM and XRD results, seems constituted by very small grains.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1. Kohl, D., J. Phys. D: Appl. Phys. 34, R125–R149 (2001).Google Scholar
2. Swint, A. L., Bohn, P. W., Langmuir 20, 4076, (2004).Google Scholar
3. Salehi, A., Gholizadeh, M., Sens. Act. B 89, 173 (2003).Google Scholar
4. Lee, S. M., Lee, Y. S., Shim, C. H., Choi, N. J., Joo, B. S., Song, K. D., Huh, J. S., Lee, D. D., Sens. Act. B 93, 31 (2003).Google Scholar
5. Epifani, M., Capone, S., Rella, R., Siciliano, P., Vasanelli, L., Faglia, G., Nelli, P. and Sberveglieri, G., J. Sol-Gel. Sci. Techn. 26, 741 (2003).Google Scholar
6. Savaniu, C., Arnautu, A., Cobianu, C., Craciun, G., Flueraru, C., Zaharescu, M., Parlog, C., Paszti, F., Van den Berg, A., Thin Solid Films 349, 29, (1999).Google Scholar
7. Nakamoto, K., Infrared and Raman Spectra of Inorganic and Coordination Compounds. Part B: Applications in Coordination, Organometallic and Bioinorganic Chemistry, 5th ed. (Wiley, New York, 1997), pp. 9195.Google Scholar