In this paper we present results of intrinsic/non doped zinc oxide deposited at room temperature by rf magnetron sputtering able to be used as a semiconductor material on electronic devices, like for example ozone gas sensors and ultra-violet detectors. The produced films are polycrystalline with a c-axis preferential orientation parallel to the substrate. The films present a resistivity that varies from 4.0×10−2 Ωcm to 1.0×109 Ωcm depending on the deposition conditions used in this study (rf power density and oxygen partial pressure) without changing the optical properties (an average transmittance of 85 % and an optical band gap energy ≈3.44 eV). When exposed to UV light the sensor response exceeds more than 5 orders of magnitude recovering to the initial state in the presence of ozone. The sensitivity of the films is improved when the oxygen partial pressure increases and the rf power density decreases which are directly related to the structural properties of the films.