Percolation model of a nanocrystalline gas sensitive layer

A model for the nanocrystalline layer of a semiconducting gas sensor is dev eloped that takes into account the possibility of having ultrasmall compens ated grains that are insulating, The probability that an ultrasmall grain i s insulating depends on the diameter D and the number of next neighbors (th e coordination number k). The occurrence of insulating grains leads to spec ific percolation type effects on the conductivity of the layer, by which it s sensitivity can be improved. (C) 2001 Elsevier Science B.V. All rights re served.