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

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Molybdenum disulfide (MoS₂) shows promise for chemical sensing but faces limitations in hydrogen detection at room temperature, including slow response and recovery.
• Reducing hydrogen (H₂) explosion risk necessitates the development of high-performance hydrogen gas sensors.

Purpose of the Study:

• To enhance the room-temperature hydrogen sensing performance of MoS₂ by incorporating palladium (Pd) nanoparticles.
• To fabricate and characterize Pd-doped MoS₂/Si heterojunctions for advanced gas sensing applications.

Main Methods:

• Fabrication of Pd-doped MoS₂ thin films on Si substrates using magnetron co-sputtering to form Pd-doped MoS₂/Si heterojunctions.
• Evaluation of the gas sensor device's H₂ sensing performance, including response, recovery time, repeatability, humidity resistance, and detection limit.

Main Results:

• The Pd-doped MoS₂/Si heterojunction exhibited a significantly enhanced sensing response of ~6.4 × 10³% to 10,000 ppm H₂, a 110% improvement over pristine MoS₂.
• The device demonstrated rapid response and recovery times (24.6/12.2 s), a ppb-level detection limit, excellent repeatability, and strong humidity resistance.
• Pd incorporation improved catalytic activity for H₂ adsorption and facilitated efficient electron transfer.

Conclusions:

• Pd-doped MoS₂/Si heterojunctions offer a promising platform for developing advanced, high-performance room-temperature hydrogen gas sensors.
• The enhanced sensing capabilities address limitations of pristine MoS₂, paving the way for improved safety in hydrogen handling.
• The developed heterojunctions show significant potential for practical applications in gas sensing technology.