High-Performance Hydrogen Gas Sensor Based on Pd-Doped MoS2/Si Heterojunction

High-performance hydrogen gas sensors have gained considerable interest for their crucial function in reducing H2 explosion risk. Although MoS2 has good potential for chemical sensing, its application in hydrogen detection at room temperature is limited by slow response and incomplete recovery. In this work, Pd-doped MoS2 thin films are deposited on a Si substrate, forming Pd-doped MoS2/Si heterojunctions via magnetron co-sputtering. The incorporation of Pd nanoparticles significantly enhances the catalytic activity for hydrogen adsorption and facilitates more efficient electron transfer. Owing to its distinct structural characteristics and sharp interface properties, the fabricated Pd-doped MoS2/Si heterojunction device exhibits excellent H2 sensing performance under room temperature conditions. The gas sensor device achieves an impressive sensing response of ~6.4 × 103% under 10,000 ppm H2 concentration, representing a 110% improvement compared to pristine MoS2. Furthermore, the fabricated heterojunction device demonstrates rapid response and recovery times (24.6/12.2 s), excellent repeatability, strong humidity resistance, and a ppb-level detection limit. These results demonstrate the promising application prospects of Pd-doped MoS2/Si heterojunctions in the development of advanced gas sensing devices.