Palladium – Doped ZnO Thin Film Hydrogen Gas Sensor

Palladium – doped ZnO thin film was deposited by chemical spray pyrolysis on glass substrate to be a fast hydrogen gas sensor. The prepared ZnO films were doped by dipping in palladium chloride PdCl2 dissolved in ethanol C2H5OH. The optical properties and the surface morphology of the prepared films were studied. The sensitivity and response time behaviors of the ZnO – based gas sensor to hydrogen gas were investigated. The film sensitivity dependence on the temperature and test gas concentration were tested and the optimum operation temperature was determined at around 280 oC. The response time of 2-3 s of the doped ZnO film was highly improved compared to the slow response of few minutes of the traditional ZnO hydrogen gas sensors.