Ozone senosr using ZnO based film bulk acoustic resonator

This abstract describes room temperature ozone sensing using a ZnO based film bulk acoustic resonator (FBAR). The resonant frequency of the FBAR decreased upon ozone exposure due to the density increase of the ZnO film. Ozone can be adsorbed on the ZnO surface by capturing free electrons from the film, which increases the film density. The minimum detectable concentration is 21 ppb (parts per billion) with a response time of 12 s. An analytical model was developed to predict the relationship between resonant frequency and ozone concentration. In agreement with the experiment, a hyperbolic function was obtained.