Electrical and gas sensing properties of por-Si/SnO$_x$ nanocomposite layers

The electrical characteristics and chemical reactant sensitivity of layers of heterogeneous nanocomposites based on porous silicon and nonstoichiometric tin oxide por-Si/SnO$_x$, fabricated by the magnetron sputtering of tin with subsequent oxidation, are studied. It is shown that, in the nanocomposite layers, a system of distributed heterojunctions (Si/SnO$_x$ nanocrystals) forms, which determine the electrical characteristics of such structures. The sensitivity of test sensor structures based on por-Si/SnO$_x$ nanocomposites to NO$_2$ is determined. A mechanism for the effect of the adsorption of NO$_2$ molecules on the current-voltage characteristics of the por-Si(p)/SnO$_x$(n) heterojunctions is suggested.