Nanostructured tin oxide based materials elaborated through sol-gel process
Résumé
Tin oxide is a well-known wide band gap semiconductor that is used in particular in gas
sensor [1] and in optoelectronic devices [2]. One of the results of the previous works [3] was
to show that the optical properties are directly related to the size of the SnO2 nanocrystals.
Sol-gel route is a cheaper process allowing to elaborate nanostructured bulk materials and thin
films. One of the key parameter of the control of the mean size of the elaborated nanocrystals
is the initial homogeneity of the gel. We have recently elaborated through such sol-gel process
both tin oxide thin films [4] and bulk materials made of nanosized SnO2 crystals embedded in
silica matrix [5]. Our approach is mainly based on the used of tin alkoxide allowing to control
carefully the formation of the sol and the gelation process. Tin alkoxide are very sensitive to
the water and moreover there are often not soluble in their parent alcohol. We have overcome
those drawbacks using mixed toluene-isopropanol solvent [6].
Those elaboration strategies and the characteristics of the resulting products will be reviewed
during the talk. A particular attention will be paid on the ability of the sol-gel process to give
various types of nanostructured materials.
References:
[1] S. Capone, M. Epifani, F. Quaranta, P. Siciliano, L. Vasanelli, Thin Solid Films, 391 (2001) 314.
[2] N. Chiodini, A. Paleari, D. DiMarco, G. Spinolo, Appl. Phys. Lett. 81 (2002) 1702.
[3] N. Chiodini, A. Paleari, G. Spinolo, Phys. Rev. Lett. 90 (2003) 055507.
[4] W.Hamd, Y.C. Wu, A. Boulle, E. Thune, R. Guinebretière, Thin Solid Films 518 (2009) 1.
[5] Y.C. Wu, W.Hamd, E. Thune, A. Boulle, C. Rochas, R. Guinebretière, J. non Cryst. Sol. 355 (2009) 951.
[6] W.Hamd, A. Boulle, E. Thune, R. Guinebretière, in press in J. Sol-Gel Sci. Technol.