Porous Silicon organic and pollutant gas sensor

摘要

Porous silicon (PS) with different morphologies was prepared by electrochemical anodization of n, p or p~+ silicon wafers. Both DC volt amperometric technique and impedance spectroscopy were employed for electrical characterisation of the device in presence of gas mixtures. The sensitivity to organic vapours (such as ethanol and methanol in the range 200-2000 ppm) and NO_2 (in the range 1-15 ppm) changes according to the doping and the preparation conditions. P~+-type PS behaves as p-type semiconductor, while p and n-type PS behave as n-type semiconductor.