Potential 2D thermoelectric material ATeI (A = Sb and Bi) monolayers from a first-principles study

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) materials are crucial for advanced nanoscale electronic, optoelectronic, and thermoelectric devices.
• Theoretical predictions and experimental confirmations highlight the potential of various 2D materials.
• Understanding thermoelectric properties is key to developing efficient energy conversion technologies.

Purpose of the Study:

• To systematically investigate the thermoelectric properties of ATeI (A = Sb and Bi) monolayers.
• To analyze the influence of spin-orbit coupling (SOC) on electronic transport coefficients.
• To evaluate the potential of these materials for thermoelectric applications.

Main Methods:

• Semiclassical Boltzmann transport theory was employed for systematic investigation.
• Electronic transport coefficients were analyzed, considering the effect of spin-orbit coupling.
• Lattice thermal conductivity and thermoelectric figure of merit (ZT) were calculated.

Main Results:

• Spin-orbit coupling significantly affects p-type doping electronic transport but negatively impacts n-type doping.
• ATeI monolayers exhibit low room-temperature sheet thermal conductance (14.2 [Formula: see text] for SbTeI, 12.6 [Formula: see text] for BiTeI).
• Peak thermoelectric figure of merit (ZT) values reach 1.11 for SbTeI and 0.87 for BiTeI at room temperature, with p-type doping showing superior performance.

Conclusions:

• The low thermal conductivity of ATeI monolayers is attributed to small group velocities, short phonon lifetimes, and strong phonon anharmonicity.
• High-frequency optical branches significantly contribute to thermal conductivity, differing from conventional understanding.
• ATeI monolayers demonstrate potential as 2D thermoelectric materials, warranting further experimental synthesis and investigation.