Epitaxial (101) SnO2 thin films, with thicknesses ranging from 6 to 100nm, were deposited onto (10•2) α-Al2O3 substrates by fs-pulse laser ablation. Due to the lattice and thermal expansion mismatch with the substrate, the SnO2 film exhibited interfacial misfit dislocations, antiphase boundaries and partial dislocations. The antiphase boundaries lay along the (¯101) planes, with a displacement of ½[101]. The densities of antiphase boundaries and partial dislocations vary with film thickness, whereas the average spacing of misfit dislocations remained constant. Hall effect measurements showed that both electron concentration and mobility decrease with a reduction in the film thickness, which was attributed to the scattering of electrons by crystal defects and interfaces and the effect of a native space charge region at the near-surface region of the films. The response of the films to reducing gases was found to depend upon the electron concentration of the film and the relative fraction, with respect to film thickness, of material that was depleted of electrons.

Effect of Crystal Defects on the Electrical Properties in Epitaxial Tin Dioxide Thin Films. J.E.Dominguez, L.Fu, X.Q.Pan: Applied Physics Letters, 2002, 81[27], 5168-70