A Palladium-Deposited Molybdenum Disulfide-Based Hydrogen Sensor at Room Temperature

Recently, hydrogen (H2) energy has attracted attention among eco-friendly energy sources because H2 energy is eco-friendly, energy-efficient, and abundant in nature. However, when the concentration of H2 in the atmosphere is more than 4%, H2 has a risk of explosion. H2 is a colorless, tasteless, and odorless gas that is difficult to detect with human senses. Therefore, developing an optimized hydrogen sensor is essential. Palladium (Pd) has good reactivity to hydrogen. Molybdenum disulfide (MoS2) has high carrier mobility, sensitive reactivity to toxic gases, and high surface-area-to-volume ratio. Therefore, we proposed hydrogen sensors that use Pd and MoS2. The main fabrication processes include MoS2 deposition through CVD and Pd deposition through DC sputtering. In this study, we utilized Pd and MoS2 to enable sensing at room temperature. By optimizing the Pd to a nanoparticle structure with an expansive surface area of 4 nm, we achieved a fast response time of 4-5 s and an enhanced yield through a simplified structure. Hydrogen sensors inherently exhibit sensitivity to various environmental factors. To address these challenges, technologies such as machine learning can be incorporated. Emphasizing low-power consumption and various application compatibilities becomes pivotal to promoting commercialization across diverse industries.