Ultralow Thermal Conductivity of Monolayer SnTe2

This paper investigates the thermal properties of monolayer tin telluride (SnTe2), a 2D metallic material. The research is significant because it identifies the microscopic origins of its ultralow lattice thermal conductivity, making it promising for thermoelectric applications. The study uses first-principles calculations to analyze the material's stability, electronic structure, and phonon dispersion. The findings highlight the role of heavy Te atoms, weak Sn-Te bonding, and flat acoustic branches in suppressing phonon-mediated heat transport. The paper also explores the material's optical properties, suggesting potential for optoelectronic applications.