Enhancement of the ionic response of field effect transducers using porous silicon

Oxidised porous silicon samples prepared from highly and weakly doped p-type silicon substrates, have been functionalised with calix[4]arene (CA) molecules. They have been used for sodium detection as electrolyte/insulator/silicon (EIS) structures. An over Nernstian behaviour was observed and correlated with physical parameters of porous silicon samples (porosity, resistivity). A generalised Nernstian equation was proposed in order to describe this property. CA functionalised EIS structures based on porous silicon present higher lifetime compared to flat structures.