Low level NO gas sensing properties of Cu doped ZnO thin films prepared by SILAR method

We report the successful synthesis and characterization of Zn1−xCuxO (x = 0.05, 0.10, 0.15, 0.20) thin films prepared by a simple and facile Successive Ionic Layer Adsorption and Reaction (SILAR) method. The nitrogen monoxide (NO) gas sensing properties of the Zn1−xCuxO sensors were studied systematically. The sensors were proved to have acceptable responses towards 20 ppb NO gas. Zn0.90Cu0.10O exhibited improved sensing performance at operating temperature of 55 °C compared to other samples. To improve sensor selectivity, a molecular zeolite filter was coated on the Zn0.90Cu0.10O sensor. The gas sensing results showed that the selectivity of intergrown zeolite filter coated Zn0.90Cu0.10O sensor enhanced significantly compared to uncoated sensors.