Experiment and Theory for the Thickness Effect of Nano Metal Oxide Gas Sensing Thin Film <Ⅲ> The Thickness Effect and Mesoscopic Theory of Conductance Activity Energy

摘要

The Characteristics of Conductance activity energy of SnO2 thin film varies with film thickness l and grain size ro are given by experiment results. The cross-section current formula of porous materials and the conductance formula of gas sensing thin film with adsorbed oxygen negative ion are given. The mesoscopic theory of nano-thin film conductance activity energy was proposed, and using the corrected Fermi statistic formula for the concentration of adsorbed negative ion, the theoretical curve of Eact varies with grain size ro yield; from which, the related problems are discussed.