Phonon-driven electron scattering and magnetothermoelectric effect in two-dimensional tin selenide

Area of Science:

• Condensed matter physics
• Materials science
• Solid-state physics

Background:

• Bulk tin selenide (SnSe) exhibits excellent thermoelectric properties due to strong phonon-phonon interactions.
• Understanding electron-phonon coupling (EPC) is crucial for optimizing thermoelectric materials.

Purpose of the Study:

• To investigate the influence of electron-phonon coupling (EPC) on the transport properties of two-dimensional (2D) SnSe sheets.
• To explore the magnetothermoelectric effects in 2D SnSe.

Main Methods:

• Theoretical investigation of electron-phonon coupling in 2D SnSe.
• Analysis of transport properties, including scattering rates and magnetothermoelectric effects.
• Comparison with experimental data.

Main Results:

• Electron-phonon coupling (EPC) is identified as a critical factor in scattering rates, particularly when the constant relaxation time approximation is insufficient.
• The EPC strength in 2D SnSe is significantly larger compared to pristine graphene.
• The scattering rate shows a strong dependence on temperature and carrier density near the band edge.
• Remarkable magnetoelectrical and magnetothermal resistivity exceeding 200% were observed at low temperatures.

Conclusions:

• Electron-phonon coupling is essential for understanding the transport phenomena in 2D SnSe.
• The significant magnetothermoelectric effects suggest promising potential for 2D SnSe in device applications.
• The findings align well with existing experimental observations, validating the theoretical approach.