High thermoelectric properties of disordered layered Ge1-xSnxTe semiconductors

Abstract

For layered GeTe based materials, a typical strategy to reduce the thermal conductivity of the lattice is to introduce disorder and increase the lattice anharmonicity of the material, while enhancing the mass/stress field fluctuations of the sample. Due to the Sn doping, the GeTe-based material forms a disordered structure, and the resulting strong phonon scattering leads to a sharp decrease in the lattice thermal conductivity over the entire temperature range. In addition, Sn doping was able to enhance the effective mass of the material, significantly increasing the seebeck coefficient of GeTe, ZT 1.49 at 730 K. Finally, the thermoelectric properties of the GeTe-based materials synthesized by Sn doping are significantly improved.