Tunneling and thermionic contributions to conductivity in nanostructured SnO2.

C. MALAGÚ; C.M. ALDAO; M.C. CAROTTA; M.S. CASTRO; M.A. PONCE; G. MARTINELLI

Polonia

Workshop; 6th International Workshop-Zakopane, Anta³ówka Conference Centre –; 2008

Anta³ówka Conference Centre

Abstract A deep analysis of conductance in nanostructured SnO2 thick films has been performed. A model for field-assisted-thermionic barrier crossing is being proposed to explain the film conductivity. The model has been applied to explain the behavior of resistance in vacuum of two sets of nanostructured thick-films with grains having two well distinct characteristic radii (R=25nm and R=125nm). In the first case the grain radius is shorter than the depletion region width, a limit at which overlapping of barriers takes place, and in the second case it is longer. The behavior of resistance in the presence of dry air has been explained through the mechanism of barrier modulation through gas chemisorption.