The thermal and thermoelectric transport properties of SiSb, GeSb and SnSb monolayers

Abstract

We investigated the electronic structure and the electrical and thermal transport properties of SiSb, GeSb and SnSb monolayers by first-principles methods. All three are indirect bandgap semiconductors. Transport calculations show that they have large n-type Seebeck coefficients and thermoelectric power factors at optimal doping levels, especially in SiSb. The intrinsic lattice thermal conductivity was explored and SiSb monolayer in particular was found to have a very low thermal conductivity (4.75 W m⁻¹ K⁻¹ at 300 K). This combined with the electrical properties suggest a high ZT value, perhaps as much as ZT = 2. Importantly, the nature of the material suggests it is a model system for understanding the effects of dimensional reduction on thermoelectric properties.