Silicon nanowire based sensorics of acids and bases

This work is devoted to obtaining new data on adsorption properties of silicon in nanowire (NW) geometry for application in sensors. It has been experimentally shown that silicon without modification can be used for selective detection of ammonia and hydrochloric acid. Quantum chemistry modeling has shown that during the adsorption of NH3, HCl, and H2O molecules, the electron density redistributes between the adsorbate and the silicon surface, leading to changes in electrical conductivity of the silicon sample. A model linking the change in the conductivity of the silicon sample with the time it was exposing to analyte vapor has been developed. The effective sticking coefficient for water adsorption on the silicon NW surface was estimated from experimental results and quantum chemical calculations.