E-MRS Spring Meeting, 31 May - 04 June 2021, pp.45
Hydrogen (H2) gas sensing properties of ultrathin platinum (Pt) and Pt - nickel (Ni) alloy films deposited on a glass substrate by co-sputter technique are investigated depending on alloy composition, temperature, and H2 concentration. The structural properties of ultrathin Pt and Pt-Ni alloy films are characterized by XRD, SEM, and EDS techniques. The amount of Ni atom in the alloy thin films is increased from 0 % up to 60 % and the H2 sensing properties of the alloy film sensors are examined in the concentration range of 25 ppm - 1000 ppm H2 at the temperature range from room temperature to 200 C. In order to measure four-point resistance measurements, four Au pad electrodes are contacted on the top of ultrathin Pt and Pt-Ni alloy films for H2 gas sensing measurements by using a thermal evaporator. The results revealed that the H2 sensing mechanism of the same thickness pure Pt and Pt-Ni alloy films could be explained with surface scattering phenomenon, and the ultrathin Pt79-Ni21 alloy film exhibited the best sensing performance to H2 at all measured temperature range. The limit of detection for ultrathin Pt and Pt-Ni alloy films is calculated as lower than 1 ppm and the response times of the films are decreased with rising H2 concentration and temperature.