Transient Response in Aqueous Solution of an Anions Porous Silicon Based Sensor

Abstract

A porous silicon based sensor has been developed to detect anions in a salt solution by the application of DC pulses on a Semiconductor/Electrolyte system. The sensor performance can be explained invoking a model where charge accumulation in the semiconductor surface states directly affects their geometric capacitances. By varying anions concentrations in salt solution, the results show a fairly constant value of substrate resistance, whereas variations in those geometric capacitances depend on the anion concentration. The constancy of substrate resistance and variability of geometric capacitance constitute key points for the development of an anion solution sensor.