Reactive sputtering refined Pd-decorated VO2 thin films for hydrogen sensing

The safe use of hydrogen in commercial and industrial settings relies on highly sensitive and fast-response hydrogen sensors to effectively detect leaks. In this study, Pd/VO2 films were prepared by magnetron sputtering technology, and the effects of magnetron sputtering process parameters (including substrate temperature, oxygen partial pressure, sputtering power, pressure, and sputtering time) on the crystallinity and surface texture (morphology and roughness) of the films were systematically studied, and the internal relationship between them was revealed. In order to further explore the relationship between the surface texture and the hydrogen-sensitive property of the material, the response to 1% H2 of Pd/VO2 films with different surface textures was investigated. It is found that the film with a more prominent surface texture prepared by extending the sputtering time based on the flattest film exhibits an improved sensing response of 796%, a response time of 197 s, and a recovery time of 185 s. This result shows that the enhancement of surface texture can improve the hydrogen response performance of the material. This study provides the experimental basis and theoretical guidance for improving the gas-sensitive properties by systematically regulating the surface texture of materials through the magnetron sputtering process and lays a solid foundation for the design and preparation of high-performance hydrogen sensors.