Metal-catalysed, bridging nanowires as vapour sensors and concept for their use in a sensor system

Metal-catalysed silicon nanowires were grown between silicon electrodes and exposed to vapours containing HCl or NH 3 at reduced pressure. Charge from adsorbed vapour modulated the conductance of the nanowires by changing the number of mobile carriers. Exposing the nanowires to HCl vapour increased the conductance while exposure to NH 3 vapour decreased the conductance. The observed results suggest the use of an array of nanowire sensors integrated with silicon electronics. Preliminary area estimates indicate that integrated amplification and signal processing is feasible for an array of 1000 sensors.