Highly sensitive detection of VOC using impact ionization induced by photoelectron

Abstract

We have developed a highly sensitive volatile organic compounds (VOCs) sensor using impact ionization induced by photoelectron. A novel mechanism of VOC detection, the screening effect of VOC cations, was proposed and experimentally verified for the first time. The fabricated sensor could detect various concentrations of toluene ranging from 500 down to 10 ppm under long wavelength of UV light (254 nm) illumination. In addition, reliable and repeatable sensing characteristics were obtained at the exposure to ethylene with high ionization energy.