GRAIN-BOUNDARY-LIMITED TRANSPORT IN SEMICONDUCTING SNO2 THIN-FILMS - MODEL AND EXPERIMENTS

We present a model that describes grain-boundary-limited conduction in polycrystalline semiconductors, for thermally assisted ballistic as w ell as diffusive transport, both for degenerate and nondegenerate dopi ng. In addition to bulk parameters (the carrier effective mass and mea n free path) the model contains grain boundary parameters (barrier hei ght and width) and a coefficient of current nonuniformity. Temperature -dependent conductivity and Hall measurements on polycrystalline SnO2 thin films with different Sb concentrations are consistently interpret ed. (C) 1998 American Institute of Physics. [S0021-8979(98)01302-4].