Pd-Pt Alloy-Based Hydrogen Sensors Based on Patterned Sapphire Substrate for Wide-Range Hydrogen Detection

In this paper, we present a hydrogen sensor on patterned sapphire substrate (PSS). The sensor not only outperforms pure palladium (Pd) hydrogen sensors in terms of sensitivity, but also enables a wide range of hydrogen detection, successfully extending the measurement range to 100% hydrogen concentration. The improved performance can be attributed to the annealing treatment and the alloying of Pd-platinum (Pt), as well as to the high surface area provided by the PSS substrate. The results show that the optimum annealing temperature was 400°C, and the optimum Pt/Pd metal ratio was 1:3. An increase in test temperature reduced the device sensitivity, but effectively alleviated sensitivity saturation at high hydrogen concentrations. Additionally, at room temperature, reducing the metal thickness within a certain range improved sensor sensitivity at high hydrogen concentrations. Our work represents a promising method for the design of H 2 sensors with enhanced performance at high H 2 concentrations. Graphical Abstract