Porous silicon as a potentiometric transducer for ion detection: effect ofthe porosity on the sensor response

This paper shows the possibility to use the oxidized porous silicon (PS) as a transducer material for ion sensor application. It aims to study the ove r Nernstian behavior of the porous material towards the concentration of so dium ions in contact. We have studied the dependence of the PS sensitivity on the porosity of the samples, which are prepared from a lightly doped sil icon substrate, Then, we have presented a model to explain the mechanism of the ionic species adsorption at the electrolyte/SiO2 interface, and to int erpret the observed large sensitivity against the different concentrations of the cations. The reproducibility of the sensor response and its lifetime were satisfactory for a frequent use. (C) 2001 Elsevier Science B.V. All r ights reserved.