Structural properties of porous silicon/SnO2:F heterostructures

In this work we present structural studies made on SnO₂ deposited on macroporous silicon structures. The porous silicon substrates were prepared by anodization of p-type silicon wafers. The SnO₂ doped layers were synthesized by the sol-gel method from SnCl₄·5H₂O-ethanolic precursor, where the effect of fluorine doping level on structural properties was investigated. The fundamental structural parameters of tin oxide such as the lattice parameter and the crystallite size were studied in correlation with the dopant concentration. In addition, the effect of fluorine incorporation into the structure of tin oxide was analyzed on the basis of theoretical calculations that take into account the structural factor. The results obtained indicate that incorporation of fluorine occurs only at substitutional sites for SnO₂ deposited on porous silicon.