Capacitive humidity sensing properties of freestanding bendable porous SiO2/Si thin films
Soobin Park, Jinmyeong Seo, Jung‐Joon Park, Inseong Hwang, Han‐Seung Lee, Hyunsung Jung, Bongyoung Yoo
Abstract
Abstract The fabrication of freestanding bendable films without polymer substrates is demonstrated as a capacitive humidity-sensing material. The bendable and porous SiO 2 /Si films are simply prepared by electrochemical-assisted stripping, metal-assisted chemical etching, followed by oxidation procedures. The capacitive humidity-sensing properties of the fabricated porous SiO 2 /Si film are characterized as a function of the relative humidity and frequency. The remarkable sensing performance is demonstrated in the wide RH range from 13.8 to 79.0%. The sensing behavior of the porous SiO 2 /Si film is studied by electrochemical impedance spectroscopy analysis. Additionally, the reliability of the porous SiO 2 /Si sensing material is confirmed by cyclic and long-term sensing tests.