Some investigation results of the instability of humidity sensors based on alumina and porous silicon materials

Alumina and porous silicon were prepared by the anodization method for humidity sensor fabrication. The humidity sensors, based on these materials, have the humidity sensitive range of 20% to 95% RH. The first experimental results showed that the conductivity and the instability of the sensors may depend on the porous structure and conductive mechanism of porous materials during reaction with water vapor. Raman Spectroscopy and thermal annealing were used to study the porous films.