Electrical humidity response of sol-gel processed LiCl-doped SiO2 thin films

In this report SiO₂ thin films were prepared by a sol-gel processing as sensitive humidity elements. Sol was prepared using tetraethylorthosilicate as a starting precursor. LiCl was added into the sol as a dopant to modify the humidity sensitivity of the films. The films were prepared by dipping the glass substrates in the sol. The humidity-sensitive electrical properties of the thin films were studied using dc measurements in the working relative humidity range from 35 to 90%. It was found that an addition of 20% LiCl significantly improved the relative humidity response up to 3 times compared to undoped film.