Tuning the electrical and room-temperature gas sensing properties of transparent ZnO thin films through Mo doping

Pure as well as Mo-doped ZnO thin films were deposited on glass substrate using the chemical spray pyrolysis method. Doping with Mo was performed to tune the electrical and gas-sensing properties of ZnO at room temperature. The structure and purity of the films were confirmed from XRD analysis. Mo doping helped to change the morphology of ZnO from sphere to flakes. The electrical properties were modified by varying the carrier concentration, mobility and resistivity of films. Following doping, a change in the baseline current was seen. The films' gas sensing capabilities at room temperature towards various VOCs were investigated. The pure ZnO films could detect ammonia. The change in electrical properties and morphology reflected in sensing of acetaldehyde, benzene and ethanol for the doped film.