Wearable Thermoelectric Devices Based on Au-Decorated Two-Dimensional MoS₂

Area of Science:

• Materials Science
• Nanotechnology
• Condensed Matter Physics

Background:

• Two-dimensional (2D) materials offer unique electronic properties for advanced flexible thermoelectric applications.
• Transition-metal dichalcogenides (TMDs) are promising candidates for thermoelectric devices, but their performance needs enhancement.
• Flexible thermoelectric generators (TEGs) are crucial for harvesting waste heat, particularly from the human body.

Purpose of the Study:

• To develop a feasible method for improving the thermoelectric performance of 2D molybdenum disulfide (MoS2).
• To investigate the effects of decorating MoS2 with gold (Au) nanoparticles on its thermoelectric properties.
• To explore the potential of Au-decorated MoS2 flexible films for applications in wearable energy harvesting.

Main Methods:

• In situ growth of Au nanoparticles on 2D MoS2 nanosheets.
• Fabrication of Au-decorated MoS2-assembled heterojunction systems.
• Characterization of the electronic transport properties and thermoelectric performance of the composite films.
• Analysis of the doping and band bending effects at the Au-MoS2 interface.

Main Results:

• Simultaneous enhancement of the Seebeck coefficient and electrical conductivity in Au-decorated MoS2.
• Observation of a decoupled phenomenon in the thermoelectric transport properties.
• Attribution of performance enhancement to p-type doping of MoS2 and energy filtering effects at the interface.
• Achieved a high power factor of 166.3 μW m⁻² K⁻² at room temperature.

Conclusions:

• Au nanoparticle decoration is an effective strategy to boost the thermoelectric performance of 2D MoS2.
• The Au-MoS2 heterojunction exhibits promising properties for flexible thermoelectric applications.
• These findings pave the way for efficient wearable devices for harvesting low-grade heat, such as human body heat.