Investigation of thermoelectric hydrogen sensor based on SiGe film

A novel hydrogen sensor with the working principle of thermoelectric effect was prepared. It was composed of a rf-sputtered SiGe film, and a rf-sputtered Pt catalyst film atop the half-surface area of the SiGe film. The molar ratio of Si and Ge component in the SiGe film is 4:1, and the alumina substrate was utilized for the preparation of the stacked-film structure. Due to the amorphous structure of the as-deposited SiGe film, an annealing process for the crystallization of SiGe film was conducted. The annealing effect on the phase structure of SiGe film and hydrogen sensing properties of the sensing device was investigated. In addition, some factors essential to the sensing properties, such as the operating temperature of the sensing device and the preparing condition of Pt catalyst as well as the detectable concentration range of hydrogen gas were all examined in detail.